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Sample records for infected knee prostheses

  1. [Infected knee prostheses. Part 2: chronic late infections].

    Science.gov (United States)

    Herrmann, P; Thoele, P; Heppert, V

    2013-06-01

    Treatment of late and chronic infections, which require the replacement of all the infected implant material. All infections lasting more than 4 weeks that have been proven to be bacterial and/or obvious signs of infection. Unsuitable for anesthesia, high acute infection with sepsis and risk for bacteremia with danger to life, large soft tissue damage where plastic surgery coverage is not possible. Arthrotomy, synovectomy, removal of all foreign bodies including all residue of polymethylmethacrylate (PMMA), jet lavage, spacer, drainage, wound closure or temporary closure using vacuum sealing. Bed rest with a leg brace and drainage until daily drainage volume is exchange of the spacer. In the literature, the success rate for both the one-stage or the two-stage procedure is about 80-95%. In our very nonhomogeneous collective the overall rate of success is about 81%.

  2. Heat generated by knee prostheses.

    Science.gov (United States)

    Pritchett, James W

    2006-01-01

    Temperature sensors were placed in 50 knees in 25 patients who had one or both joints replaced. Temperature recordings were made before walking, after walking, and after cycling. The heat generated in healthy, arthritic, and replaced knees was measured. The knee replacements were done using eight different prostheses. A rotating hinge knee prosthesis generated a temperature increase of 7 degrees C in 20 minutes and 9 degrees C in 40 minutes. An unconstrained ceramic femoral prosthesis articulating with a polyethylene tibial prosthesis generated a temperature increase of 4 degrees C compared with a healthy resting knee. The other designs using a cobalt-chrome alloy and high-density polyethylene had temperature increases of 5 degrees-7 degrees C with exercise. Frictional heat generated in a prosthetic knee is not immediately dissipated and may result in wear, creep, and other degenerative processes in the high-density polyethylene. Extended periods of elevated temperature in joints may inhibit cell growth and perhaps contribute to adverse performance via bone resorption or component loosening. Prosthetic knees generate more heat with activity than healthy or arthritic knees. More-constrained knee prostheses generate more heat than less-constrained prostheses. A knee with a ceramic femoral component generates less heat than a knee with the same design using a cobalt-chromium alloy.

  3. Articulating spacers used in two-stage revision of infected hip and knee prostheses abrade with time.

    Science.gov (United States)

    Fink, Bernd; Rechtenbach, Annett; Büchner, Hubert; Vogt, Sebastian; Hahn, Michael

    2011-04-01

    Articulating spacers used in two-stage revision surgery of infected prostheses have the potential to abrade and subsequently induce third-body wear of the new prosthesis. We asked whether particulate material abraded from spacers could be detected in the synovial membrane 6 weeks after implantation when the spacers were removed for the second stage of the revision. Sixteen hip spacers (cemented prosthesis stem articulating with a cement cup) and four knee spacers (customized mobile cement spacers) were explanted 6 weeks after implantation and the synovial membranes were removed at the same time. The membranes were examined by xray fluorescence spectroscopy, xray diffraction for the presence of abraded particles originating from the spacer material, and analyzed in a semiquantitative manner by inductively coupled plasma mass spectrometry. Histologic analyses also were performed. We found zirconium dioxide in substantial amounts in all samples, and in the specimens of the hip synovial lining, we detected particles that originated from the metal heads of the spacers. Histologically, zirconium oxide particles were seen in the synovial membrane of every spacer and bone cement particles in one knee and two hip spacers. The observations suggest cement spacers do abrade within 6 weeks. Given the presence of abrasion debris, we recommend total synovectomy and extensive lavage during the second-stage reimplantation surgery to minimize the number of abraded particles and any retained bacteria.

  4. Radionuclide arthrogram to evaluate knee prostheses loosening

    International Nuclear Information System (INIS)

    Ahn, U.

    2009-01-01

    Full text:This case is about a 78 year old lady who had 3TKRs on her left knee. The 2nd revision surgery was performed due to infection. After 6 weeks long procedure, that patient was discharged with satisfactory movement without sign of infection. 15 months after the surgery, the orthopaedic surgeon found that some pressure wave effects and pain with walking. There was no sign of infection clinically. Once X-ray could not confirm any micro-loosening, the surgeon wanted to investigate with radionuclide arthrogram for this difficult case. 40 MBq in 2mls of Calcium phytate colloid (from RADPHARM Australia) was injected into the knee joint space. 30 minutes static views revealed the tracer started to travel below the tibial component. 4 hours statics views clearly indicate the tibial component loosening also there was leakage of tracer through anterior tibial osteotomy screws into the level of ankle subcutaneously. Cobalt57 flood images provided the anatomical localisation. While the surgeon was planning new component for the 3rd revision surgery, the patient's pain disappeared with time. No more revision was considered with satisfactory level of movement. This was the first and only case of radio arthogram to our department, although we perform many bone scans with same reason. On published articles, overall sensitivity and specificity are variable from 85% to 100%. When we take look at other clinical experience, there are a number of reasons in the high accuracy and reliability of radionuclide arthrogram especially for knee prosthesis loosening. Therefore I want to emphasise the benefit of radionuclide arthrogram for both patient and surgeon as a reliable diagnosis with minimum discomfort.

  5. Indium-111 chloride imaging in the detection of infected prostheses

    International Nuclear Information System (INIS)

    Sayle, B.A.; Fawcett, H.D.; Wilkey, D.J.; Cierny, G. III; Mader, J.T.

    1985-01-01

    Thirty-three patients with painful joint prostheses and a suspicion of infection were imaged with [ 111 In]chloride. A final diagnosis was established by culture in 19. Of these, 12 were categorized as true positives and three as true negatives. There were two false-positive studies, occurring in patients with knee prostheses. In both, the culture was obtained by aspiration. The sensitivity was 86%, specificity 60%, and accuracy 79%. Seventeen of the proven cases had bone imaging prior to [ 111 In]chloride imaging. All 17 static images were positive and were not helpful in differentiating loosening from infection. Using increased uptake on the blood-pool image as a criteria for infection, the sensitivity was 89%, but the specificity was 0. Adding flow studies made little difference in interpreting the blood-pool images. This study shows that [ 111 In]chloride imaging is more accurate in evaluating infection in prosthesis than bone imaging

  6. Does knee awareness differ between different knee arthroplasty prostheses?

    DEFF Research Database (Denmark)

    Thomsen, Morten G; Latifi, Roshan; Kallemose, Thomas

    2016-01-01

    BACKGROUND: Low knee awareness after Total Knee Arthroplasty (TKA) has become the ultimate goal in trying to achieve a natural feeling knee that meet patient expectations. To accommodate this manufacturers of TKAs have developed new prosthetic designs that potentially could give patients a more...... natural feeling knee during activities. The purpose af this study was to compare the Forgotten Joint Score (FJS) and Oxford Knee Score (OKS) of patients treated with a previous generation standard Cruciate Retaining (CR) TKA to the scores obtained by patients treated with a newer generation CR TKA...

  7. Radiological follow-up of uncemented knee prostheses. Preliminary study

    International Nuclear Information System (INIS)

    Martin Hervas, C.; Gomez Barrena, E.; Marquez Moreno, I.; Calle Yuste, F.; Ordonez Parra, J.M.

    1993-01-01

    The preliminary results of a prospective study of 40 uncemented total knee prostheses (TKP) are presented following a radiological protocol with fluoroscopic control and follow-up of over 2 years. The prosthesis-bone interface and the components alignment were assessed. Several radiological signs were studied to assess this interface with respect to the fixing of the component, but they showed little clinical correlation. Statistical significance (p<0.05, chisquare) was found only in the observation of sclerosis in areas of support for the tibital tray as a reaction of the bone. This radiological follow-up is of interest to determine the evolution of the interface and position of the implant to prevent complications (especially loosening) in patients, particularly those under 60 years old, who represent the group that can most benefit from prosthetic systems with uncemented anchorage because of their life expectation and level of activity. Author

  8. International comparative evaluation of knee replacement with fixed or mobile-bearing posterior-stabilized prostheses.

    Science.gov (United States)

    Graves, Stephen; Sedrakyan, Art; Baste, Valborg; Gioe, Terence J; Namba, Robert; Martínez Cruz, Olga; Stea, Susanna; Paxton, Elizabeth; Banerjee, Samprit; Isaacs, Abby J; Robertsson, Otto

    2014-12-17

    Posterior-stabilized total knee prostheses were introduced to address instability secondary to loss of posterior cruciate ligament function, and they have either fixed or mobile bearings. Mobile bearings were developed to improve the function and longevity of total knee prostheses. In this study, the International Consortium of Orthopaedic Registries used a distributed health data network to study a large cohort of posterior-stabilized prostheses to determine if the outcome of a posterior-stabilized total knee prosthesis differs depending on whether it has a fixed or mobile-bearing design. Aggregated registry data were collected with a distributed health data network that was developed by the International Consortium of Orthopaedic Registries to reduce barriers to participation (e.g., security, proprietary, legal, and privacy issues) that have the potential to occur with the alternate centralized data warehouse approach. A distributed health data network is a decentralized model that allows secure storage and analysis of data from different registries. Each registry provided data on mobile and fixed-bearing posterior-stabilized prostheses implanted between 2001 and 2010. Only prostheses associated with primary total knee arthroplasties performed for the treatment of osteoarthritis were included. Prostheses with all types of fixation were included except for those with the rarely used reverse hybrid (cementless tibial and cemented femoral components) fixation. The use of patellar resurfacing was reported. The outcome of interest was time to first revision (for any reason). Multivariate meta-analysis was performed with linear mixed models with survival probability as the unit of analysis. This study includes 137,616 posterior-stabilized knee prostheses; 62% were in female patients, and 17.6% had a mobile bearing. The results of the fixed-effects model indicate that in the first year the mobile-bearing posterior-stabilized prostheses had a significantly higher hazard

  9. Wear Distribution Detection of Knee Joint Prostheses by Means of 3D Optical Scanners

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    Saverio Affatato

    2017-03-01

    Full Text Available The objective of this study was to examine total knee polyethylene inserts from in vitro simulation to evaluate and display—using a 3D optical scanner—wear patterns and wear rates of inserts exposed to wear by means of simulators. Various sets of tibial inserts have been reconstructed by using optical scanners. With this in mind, the wear behavior of fixed and mobile bearing polyethylene knee configurations was investigated using a knee wear joint simulator. After the completion of the wear test, the polyethylene menisci were analyzed by an innovative 3D optical scanners in order to evaluate the 3D wear distribution on the prosthesis surface. This study implemented a new procedure for evaluating polyethylene bearings of joint prostheses obtained after in vitro wear tests and the proposed new approach allowed quantification of the contact zone on the geometry of total knee prostheses. The results of the present study showed that mobile TKPs (total knee prosthesis have lower wear resistance with respect to fixed TKPs.

  10. Malassezia species infection of the synovium after total knee arthroplasty surgery

    Directory of Open Access Journals (Sweden)

    Leylabadlo, Hamed Ebrahimzadeh

    2016-09-01

    Full Text Available Infection is a serious complication after implantation of total knee-prostheses. However, fungal infection is rarely found in periprosthetic joints, and in most reports, the infecting organism is a species. This is a case report of infection after left knee total arthroplasty caused by species. The patient is still undergoing antifungal therapy with voriconazole and is still being followed-up. To the authors’ knowledge, the present case is the first report of species in a patient after total knee arthroplasty.

  11. {sup 99m}Tc-HMPAO-labelled leucocyte scintigraphy in the diagnosis of infection after total knee replacement arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dong Rib [College of Medicine, Kunkuk Univ., Seoul (Korea, Republic of); Kim, Jae Seung; Ryu, Jin Sook; Moon, Dae Hyuk; Bin, Seong Il; Cho, Woo Shin; Lee, Hee Kyung [College of Medicine, Ulsan Univ., Seoul (Korea, Republic of)

    1999-08-01

    This study was performed to evaluate the usefulness of {sup 99m}Tc-HMPAO-labelled leucocyte scintigraphy for diagnosing prosthetic infection after total knee replacement arthroplasty without the aid of following bone marrow scintigraphy. The study subjects were 25 prostheses of 17 patients (one man and 16 women, mean age: 65 years) who had total knee replacement arthroplasty. After injection of {sup 99m}Tc-HMPAO-labelled leucocyte, the whole body planar and knee SPECT images were obtained in all patients. The subjects were classified into three groups according to clinical suspicion of prosthetic infection: Group A (n=11) with high suspicion of infection; Group B (n=6) with equivocal suspicion of infection, and Group C (n=8) with asymptomatic contralateral prostheses. Final diagnosis of infection was based on surgical, histological and bacteriological data and clinical follow-up. Infection was confirmed in 13 prostheses (11 in Group A and 2 in Group B). All prostheses in Group A were true positive. There were two true positive, one false positive and three true negative in Group B, and six true negatives and two false positive in Group C. Overall sensitivity, specificity, and accuracy for diagnosis of the infected knee prosthesis were 100%, 75% and 88%, respectively. {sup 99m}Tc-HMPAO-labelled leucocyte scintigraphy is a sensitive method for the diagnosis of infected knee prosthesis. However, false positive uptakes even in asymptomatic prosthesis suggest that bone marrow scintigraphy may be needed to achieve improved specificity.

  12. 99mTc-HMPAO-labelled leucocyte scintigraphy in the diagnosis of infection after total knee replacement arthroplasty

    International Nuclear Information System (INIS)

    Park, Dong Rib; Kim, Jae Seung; Ryu, Jin Sook; Moon, Dae Hyuk; Bin, Seong Il; Cho, Woo Shin; Lee, Hee Kyung

    1999-01-01

    This study was performed to evaluate the usefulness of 99m Tc-HMPAO-labelled leucocyte scintigraphy for diagnosing prosthetic infection after total knee replacement arthroplasty without the aid of following bone marrow scintigraphy. The study subjects were 25 prostheses of 17 patients (one man and 16 women, mean age: 65 years) who had total knee replacement arthroplasty. After injection of 99m Tc-HMPAO-labelled leucocyte, the whole body planar and knee SPECT images were obtained in all patients. The subjects were classified into three groups according to clinical suspicion of prosthetic infection: Group A (n=11) with high suspicion of infection; Group B (n=6) with equivocal suspicion of infection, and Group C (n=8) with asymptomatic contralateral prostheses. Final diagnosis of infection was based on surgical, histological and bacteriological data and clinical follow-up. Infection was confirmed in 13 prostheses (11 in Group A and 2 in Group B). All prostheses in Group A were true positive. There were two true positive, one false positive and three true negative in Group B, and six true negatives and two false positive in Group C. Overall sensitivity, specificity, and accuracy for diagnosis of the infected knee prosthesis were 100%, 75% and 88%, respectively. 99m Tc-HMPAO-labelled leucocyte scintigraphy is a sensitive method for the diagnosis of infected knee prosthesis. However, false positive uptakes even in asymptomatic prosthesis suggest that bone marrow scintigraphy may be needed to achieve improved specificity

  13. Phaeohyphomycosis infection in the knee

    Directory of Open Access Journals (Sweden)

    David Sadigursky

    2016-04-01

    Full Text Available Phaeohyphomycosis is caused by cutaneous fungi and rarely affects large joints. This is a case report on phaeohyphomycosis in the left knee of an elderly individual without immunosuppression. It was accompanied by pain and swelling the anterior knee. The case was first suspected to be suprapatellar bursitis, and was treated with nonsteroidal anti-inflammatory drugs, without remission of symptoms. Surgical treatment was performed, with resection of the suprapatellar bursa and anterior region of the quadriceps tendon. The material was sent for anatomopathological examination and culturing. The pathological examination showed phaeohyphomycosis. The treatment instituted consisted of itraconazole, 200 mg/day for six weeks, and complete remission of symptoms was achieved. The physical examination remained normal after one year of follow-up. This is the first published case of phaeohyphomycosis infection in the suprapatellar region of the knee. Although almost all the cases reported have been associated with immunosuppressed patients, this was an exception. It is important to suspect phaeohyphomycosis in cases of knee infection, in the area of the suprapatellar bursa, when the symptoms do not resolve after clinical treatment.

  14. Clinical outcome after treatment of infected primary total knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Henrik; Jensen, Tim Toftgaard

    2002-01-01

    Twenty-six consecutive cases of infected primary total knee arthroplasties were treated at our institution from 1989 through 2000. Eleven patients had debridement and irrigation performed within 2 months of index arthroplasty or hematogenous spread; only one infection was eradicated. Twenty......-five patients had their prostheses removed; 17 had two-stage revision arthroplasty, following which infection was eradicated in 15; one had a permanent spacer, 7 had arthrodesis (following failed revision arthroplasty in one) and 2 had a femur amputation (following failed revision arthroplasty in one) at follow......-up of mean 24 months. Infections were cured equally well with revision arthroplasty and arthrodesis. Among the 15 patients who ended up with revision arthroplasty, 11 had a better range of motion compared to the index arthroplasty, but 8 had daily pain. We present our treatment protocol, which eradicated 15...

  15. Obturator or "lateral" bypass in the management of infected vascular prostheses at the groin

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    Davidović Lazar B.

    2002-01-01

    Full Text Available The infection of the previously implanted vascular graft at the groin, is associated with great mortality and morbidity rate [1]. The authors present a retrospective study in which they analyzed management of infected vascular prostheses at the groin, using obturator bypass in 26 cases, and "lateral" bypass in 15 cases. The indications for obturator bypass reconstructions included: 20 infections of aorto-femoral grafts, two infected pse udoaneurysms in the groin after RTA of the superficial femoral artery, and 4 infections of iliac-femoral grafts. The indications for lateral bypass reconstructions were: infections after aorto-femoral reconstructions - 8 cases; infection after femora-popliteal reconstructions - 4 cases; infection after iliac-femoral reconstruction - 2 patients, and one infected pseudoaneurysm in the groin after RTA of the superficial femoral artery. In 3 subjects obturator bypass was performed using extraperitoneal approach while in other 23 patients transperitoneal approach was done by donor's artery. The obturator bypass was performed using a PTFE graft in 3 cases and Dacron graft in 23. The donor's artery used for obturator bypass was a noninfected proximal part of aortofemoral graft in 20 cases, and iliac artery in 6 patients. The superfical femoral artery was recipient artery for obturator bypass in 3 cases, deep femoral artery in one case, and above the knee popliteal artery in 22 cases (Figure 1. In two patients transperitoenal approach to donors artery for "lateral" bypass has been used, and in 13 cases extraperitoneal. The proximal noninfected part of aorto femoral graft was used as a donor's artery for lateral bypass in 8 patients, while common iliac artery in 7 subjects. In 5 cases recon structions were performed using PTFE grafts, in 3 using autologous saphenous vein grafts, and in 7 using Dacron grafts. The recipient artery for "lateral" bypass was deep femoral in 8 cases, superficial femoral in three patients and

  16. Radionuclide arthrogram with SPECT/CT for the evaluation of mechanical loosening of hip and knee prostheses

    International Nuclear Information System (INIS)

    Chew, C.G.; Lewis, P.; Middleton, F.; Wijngaard, R. van den; Deshaies, A.

    2010-01-01

    The Objective of this study was to evaluate the value of single photon emission computed tomography (SPECT)/CT in radionuclide arthrogram (RNA) for the assessment of mechanical loosening of hip and knee prostheses. A retrospective audit of 117 RNA SPECT/CTs evaluated by a single reader- 40 hips, (1 hemiarthroplasty) and 77 knees (12 unicompartmental). The detection of any radiotracer within the bone/prosthetic interface was deemed positive for loosening. The operative assessment of 29 hip and 44 knee prosthetic joints was known and used as the gold standard. A subsequent blinded reassessment of the planar images was performed and compared with the SPECT/CT results for 26 of the 29 hip and 42 of the 44 knee prostheses. The respective SPECT/CT versus planar results were as follows: hips- acetabular cup: sensitivity: 73 versus 0%; specificity: 71 versus 100%; positive predictive value: 62% versus indeterminate; negative predictive value: 80% versus 72% (p=0.0044). Hips- femoral component: sensitivity: 78 versus 63%; specificity: 90 versus 94%; positive predictive value: 78 versus 83%; negative predictive value: 90 versus 85% (p=0.2482). Knees- femoral component: sensitivity: 75 versus 17%; specificity 63 versus 97%; positive predictive value: 43 versus 67%; negative predictive value: 87 versus 74% (p=0.0001). Knees- tibial component: sensitivity: 86 versus 63%; specificity: 86 versus 76%; positive predictive value: 55 versus 38%; negative predictive value: 97 versus 90% (p=0.6831). For evaluation of mechanical loosening of the hip prosthesis SPECT/CT was significantly better than planar scanning for the acetabular cup, but not for the femoral stem. For evaluation of the knee prosthesis, a significant improvement was noted using SPECT/CT for the femoral component, and although superior results were also noted for the tibial component, statistical significance was not reached. Taking into account the limitations of this retrospective audit, the value of using RNA SPECT

  17. Rapidly growing non-tuberculous mycobacteria infection of prosthetic knee joints: A report of two cases.

    Science.gov (United States)

    Kim, Manyoung; Ha, Chul-Won; Jang, Jae Won; Park, Yong-Beom

    2017-08-01

    Non-tuberculous mycobacteria (NTM) cause prosthetic knee joint infections in rare cases. Infections with rapidly growing non-tuberculous mycobacteria (RGNTM) are difficult to treat due to their aggressive clinical behavior and resistance to antibiotics. Infections of a prosthetic knee joint by RGNTM have rarely been reported. A standard of treatment has not yet been established because of the rarity of the condition. In previous reports, diagnoses of RGNTM infections in prosthetic knee joints took a long time to reach because the condition was not suspected, due to its rarity. In addition, it is difficult to identify RGNTM in the lab because special identification tests are needed. In previous reports, after treatment for RGNTM prosthetic infections, knee prostheses could not be re-implanted in all cases but one, resulting in arthrodesis or resection arthroplasty; this was most likely due to the aggressiveness of these organisms. In the present report, two cases of prosthetic knee joint infection caused by RGNTM (Mycobacterium abscessus) are described that were successfully treated, and in which prosthetic joints were finally reimplanted in two-stage revision surgery. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. [PVD-silicoating before cementation of zirconia-based knee prostheses effects better cement adhesion and lower aseptic loosening rates].

    Science.gov (United States)

    Marx, R; Faramarzi, R; Oberbach, T; Begand, S; Grätz, N; Wirtz, D C

    2012-02-01

    CoCrMo alloys are contraindicated for allergy patients. For these patients, cemented or uncemented prostheses made of titanium alloy are indicated. Uncemented prostheses, however, have low primary retention, particularly the tibial components of knee joint prostheses because of the lack of a positive locking. Therefore, for knee replacement cemented CoCrMo prostheses may be suitable also for allergy sufferers if these are masked by ZrN or TiNbN layers. Alternatively the CoCrMo alloy may be replaced by high-strength oxide ceramics. For adhesion of bone cement to the ceramic surface, however, only inefficient mechanical retention spots are exposed as compared with a metal surface. Undercuts generated by corundum blasting, although highly efficient on a CoCrMo surface, are not such efficient centres on a ceramic surface due to its brittleness. Therefore, the mechanical component of retention is significantly reduced. When specific adhesion between bone cement and surface does not exist due to physical and chemical forces, the hydrolytic stability will be insufficient. Micromotions are promoted and early aseptic loosening is predictable. Silicoating of the ceramic surface will allow specific adhesion and can result in better hydrolytic stability of bonding. In order to evaluate the effectiveness of silicoating the bond strengths of blasted (mean size of corundum grains 50 µm) and silicate layered alumina-toughened zirconia (ATZ) surfaces were compared with "as fired" surfaces by utilising TiAlV probes (diameter 6 mm) for traction-adhesive strength testing. Samples machined out of CoCrMo alloy were utilised for reference. After preparing the samples for traction-adhesive strength testing (sequence: substrate, silicate and silane, protective lacquer [PolyMA], bone cement, TiAlV probe) they were aged up to 360 days at 37 °C in Ringer's solution. The bond strengths observed for all ageing intervals were well above 20 MPa and much higher and more hydrolytically

  19. Revision of infected knee arthroplasties in Denmark

    DEFF Research Database (Denmark)

    Lindberg-Larsen, Martin; Jørgensen, Christoffer C; Bagger, Jens

    2016-01-01

    Background and purpose - The surgical treatment of periprosthetic knee infection is generally either a partial revision procedure (open debridement and exchange of the tibial insert) or a 2-stage exchange arthroplasty procedure. We describe the failure rates of these procedures on a nationwide...... basis. Patients and methods - 105 partial revisions (100 patients) and 215 potential 2-stage revision procedures (205 patients) performed due to infection from July 1, 2011 to June 30, 2013 were identified from the Danish Knee Arthroplasty Register (DKR). Failure was defined as surgically related death...

  20. Radiological follow-up of uncemented knee prostheses. Preliminary study. Seguimiento radiologico de protesis de rodilla no cementadas. Estudio preliminar

    Energy Technology Data Exchange (ETDEWEB)

    Martin Hervas, C.; Gomez Barrena, E.; Marquez Moreno, I.; Calle Yuste, F.; Ordoez Parra, J.M.

    1993-10-01

    The preliminary results of a prospective study of 40 uncemented total knee prostheses (TKP) are presented following a radiological protocol with fluoroscopic control and follow-up of over 2 years. The prosthesis-bone interface and the components alignment were assessed. Several radiological signs were studied to assess this interface with respect to the fixing of the component, but they showed little clinical correlation. Statistical significance (p<0.05, chisquare) was found only in the observation of sclerosis in areas of support for the tibital tray as a reaction of the bone. This radiological follow-up is of interest to determine the evolution of the interface and position of the implant to prevent complications (especially loosening) in patients, particularly those under 60 years old, who represent the group that can most benefit from prosthetic systems with uncemented anchorage because of their life expectation and level of activity. Author

  1. The role of synovial fluid analysis in the detection of periprosthetic hip and knee infections: a systematic review and meta-analysis.

    Science.gov (United States)

    De Fine, Marcello; Giavaresi, Gianluca; Fini, Milena; Illuminati, Andrea; Terrando, Silvio; Pignatti, Giovanni

    2018-05-01

    This study tried to ascertain (1) the accuracy of synovial fluid white blood cell count and polymorphonucleate percentage in the diagnosis of periprosthetic hip and knee infections, (2) which test yielded superior test performance, and (3) the influence on diagnostic accuracy of study characteristics such as patient number, study design, study level, anatomic site, and threshold value. A systematic search was conducted including papers assessing more effective cutoffs for synovial fluid tests, having comparative design, evaluating an exclusive cohort of hip or knee prostheses, including a clear definition of infected cases, and reporting sufficient data for the calculation of true-positive, false-positive, false-negative, and true-negative. A total of 375 articles were collected and, given the inclusion criteria, ten manuscripts were included. These studies assessed 1155 hip prostheses (276 infected cases) and 1235 knee prostheses (401 infected cases). The specificity of synovial fluid white blood cell count was significantly increased by using the threshold value ≥ 3000 cell/μL (p = 0.006); the sensitivity of polymorphonucleate percentage was significantly higher in detecting knee infections (p = 0.034). Both tests had a high specificity and sensitivity in detecting periprosthetic joint infections, and no clear superiority of one over the other existed. Furthermore, cutoff and anatomic site significantly influenced synovial fluid white blood cell count and polymorphonucleate percentage, respectively. Synovial fluid analysis is adequate in differentiating patients with periprosthetic hip and knee infections. Our data confirms international guidelines suggesting the use of 3000 cell/μL as cutoff threshold for synovial fluid white blood cell count. Since an anatomic site effect has been demonstrated, the goal of future studies will be to identify different cutoffs for hip and knee prostheses.

  2. Isolated Lactobacillus chronic prosthetic knee infection.

    Science.gov (United States)

    Bennett, David M; Shekhel, Tatyana; Radelet, Matt; Miller, Michael D

    2014-01-01

    Lactobacillus is a gram-positive rod bacteria found primarily in the gastrointestinal and female genital tracts. Prosthetic infections in implants are being increasingly reported. The authors present a case of a 58-year-old patient with Lactobacillus septic prosthetic knee joint infection. To the authors’ knowledge, this is the first reported case of chronic prosthetic knee infection with isolated Lactobacillus species. Lactobacillus has been most commonly implicated with bacteremia and endocarditis and rarely with pneumonia, meningitis, and endovascular infection, and a vast majority of the cases are reported in immunocompromised patients. In the current case, diabetes mellitus, hepatitis, malnutrition, anemia, and liver failure were comorbid conditions, placing the patient at increased risk of infection. The findings suggest that further case series are necessary to establish the significance of Lactobacillus as an etiologic agent in chronic low-virulence, and potentially vancomycin-resistant, prosthetic joint infection. The need also exists for further research aimed at the risk of prosthetic joint infection with oral intake of certain probiotic foods and supplements. The goal of this case report is to bring to light the potential of this organism to be a cause of subtle chronic prosthetic joint infection.

  3. Shock absorption of below-knee prostheses : A comparison between the SACH and the Multiflex foot

    NARCIS (Netherlands)

    van Leeuwen, J. L.; Speth, L. A W M; Daanen, H. A M

    1990-01-01

    Shock waves were measured during walking on a treadmill on the metal tube of a below-knee KBM prosthesis, provided either with a SACH foot or with a Multiflex foot. Accelerations were measured in the axial direction and the dorso-ventral direction, about 160 mm proximal to the sole of the shoe. The

  4. Multicriteria Decision Analysis in Improving Quality of Design in Femoral Component of Knee Prostheses: Influence of Interface Geometry and Material

    Directory of Open Access Journals (Sweden)

    Ali Jahan

    2015-01-01

    Full Text Available Knee prostheses as medical products require careful application of quality and design tool to ensure the best performance. Therefore, quality function deployment (QFD was proposed as a quality tool to systematically integrate consumer’s expectation to perceived needs by medical and design team and to explicitly address the translation of customer needs into engineering characteristics. In this study, full factorial design of experiment (DOE method was accompanied by finite element analysis (FEA to evaluate the effect of inner contours of femoral component on mechanical stability of the implant and biomechanical stresses within the implant components and adjacent bone areas with preservation of the outer contours for standard Co-Cr alloy and a promising functionally graded material (FGM. The ANOVA revealed that the inner shape of femoral component influenced the performance measures in which the angle between the distal and anterior cuts and the angle between the distal and posterior cuts were greatly influential. In the final ranking of alternatives, using multicriteria decision analysis (MCDA, the designs with FGM was ranked first over the Co-Cr femoral component, but the original design with Co-Cr material was not the best choice femoral component, among the top ranked design with the same material.

  5. A biodegradable gentamicin-hydroxyapatite-coating for infection prophylaxis in cementless hip prostheses

    Directory of Open Access Journals (Sweden)

    D Neut

    2015-01-01

    Full Text Available A degradable, poly (lactic-co-glycolic acid (PLGA, gentamicin-loaded prophylactic coating for hydroxyapatite (HA-coated cementless hip prostheses is developed with similar antibacterial efficacy as offered by gentamicin-loaded cements for fixing traditional, cemented prostheses in bone. We describe the development pathway, from in vitro investigation of antibiotic release and antibacterial properties of this PLGA-gentamicin-HA-coating in different in vitro models to an evaluation of its efficacy in preventing implant-related infection in rabbits. Bone in-growth in the absence and presence of the coating was investigated in a canine model. The PLGA-gentamicin-HA-coating showed high-burst release, with antibacterial efficacy in agar-assays completely disappearing after 4 days, minimising risk of inducing antibiotic resistance. Gentamicin-sensitive and gentamicin-resistant staphylococci were killed by the antibiotic-loaded coating, in a simulated prosthesis-related interfacial gap. PLGA-gentamicin-HA-coatings prevented growth of bioluminescent staphylococci around a miniature-stem mounted in bacterially contaminated agar, as observed using bio-optical imaging. PLGA-gentamicin-HA-coated pins inserted in bacterially contaminated medullary canals in rabbits caused a statistically significant reduction in infection rates compared to HA-coated pins without gentamicin. Bone ingrowth to PLGA-gentamicin-HA-coated pins, in condylar defects of Beagle dogs was not impaired by the presence of the degradable, gentamicin-loaded coating. In conclusion, the PLGA-gentamicin-HA-coating constitutes an effective strategy for infection prophylaxis in cementless prostheses.

  6. The use of interlocking prostheses for both temporary and definitive management of infected periprosthetic femoral fractures.

    Science.gov (United States)

    Konan, Sujith; Rayan, Faizal; Manketelow, Andrew R J; Haddad, Fares S

    2011-12-01

    Infected periprosthetic fractures around total hip arthroplasties are an extremely challenging problem. We describe our experience of managing infected periprosthetic femoral fractures using interlocking long-stem femoral prostheses either as temporary functional spacers or as definitive implants. The Cannulock (Orthodesign, Christchurch, United Kingdom) uncoated stem was used in 12 cases, and the Kent hip prosthesis (Biomet Merck, Bridgend, United Kingdom), in 5 cases. Satisfactory outcome was noted in all cases, and in 11 cases, revision to a definitive stem has been undertaken after successful control of infection and fracture union. The use of interlocking stems offers a relatively appealing solution for a complex problem and avoids the complications that would be associated with resection of the entire femur or the use of large quantities of bone cement. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Knee arthrodesis – ultima ratio for the treatment of the infected knee

    Directory of Open Access Journals (Sweden)

    Tiemann, Andreas H. H.

    2013-04-01

    Full Text Available The irretrievable destruction of the knee due to trauma, tumor or infection is the indication for knee arthrodesis. The main reason for knee arthrodesis in terms of infection ist the infected total knee arthroplasty. Central problem is the definition of the term “irretrievable”. It is based on the subjective opinion of the attending physician and depends on his expert knowledge of this specific entity. The preservation of a functioning extremity is the main goal.This article shows the typical indications and contraindications for knee arthrodesis following septic knee diseases. In addition it gives insight into the biomechanical and technical considerations to be kept in mind. Finally the postoperative care and outcome of different techniques are analysed.

  8. Differential bacterial load on components of total knee prosthesis in patients with prosthetic joint infection.

    Science.gov (United States)

    Holinka, Johannes; Pilz, Magdalena; Hirschl, Alexander M; Graninger, Wolfgang; Windhager, Reinhard; Presterl, Elisabeth

    2012-10-01

    The purpose of our study was to evaluate and quantify the bacterial adherence on different components of total knee prosthesis with the sonication culture method. Explanted components of all patients with presumptive prosthetic or implant infection were treated by sonication separately in sterile containers to dislodge the adherent bacteria from the surfaces and cultured. The bacterial load of the different knee components (femur, tibia, PE-inlay and patella) was evaluated by counting of colony-forming units (CFU) dislodged from the components surfaces using the sonication culture method. Overall, 27 patients had positive sonication cultures of explanted total knee prostheses. Microorganisms were detected from 88 of 100 explanted components. Twenty femoral components were culture positive and 7 negative, 23 tibial components as well as 23 polyethylene (PE) platforms had positive microorganism detection from the surface. Staphylococcus epidermidis adhered to the highest number of components whereas Staphylococcus aureus yielded the highest load of CFU in the sonication cultures. Although not significant, PE-inlays and tibial components were most often affected. The highest CFU count was detected in polyethylene components. The sonication culture method is a reliable method to detect bacteria from the components. Additionally, the results demonstrate that bacterial adherence is not affecting a single component of knee prosthesis only. Thus, in septic revision surgery partial prosthetic exchange or exchange of single polyethylene components alone may be not sufficient.

  9. [Periprosthetic knee infection. One-stage exchange].

    Science.gov (United States)

    Friesecke, C; Wodtke, J

    2006-09-01

    Systematic diagnostics and successful therapy of periprosthetic infection of the knee can only be achieved under optimal conditions. History, clinical examination and an elevated CRP level are the basis for suspicion of infection. Diagnosis is confirmed by identification of the pathogen through aspiration of the joint under sterile conditions. The microbiological examination is done in a laboratory, which is specialised in foreign body infections. Identification of the causing pathogens and their resistance pattern are essential to determine the topical and systemic course of antibiotics. When these conditions are fulfilled, the one-stage exchange procedure offers great advantages in comparison with procedures performed in two or more stages for all those involved--patients, surgeons and health care systems--while providing the same chance of a successful elimination of the infection, with an even better functional outcome. Currently, the treatment costs are not adequately reimbursed. In the future, prompt treatment of these especially unfortunate patients will only be possible, if the tremendous resources consumed by these patients are fully covered.

  10. TREATMENT OF INFECTION AFTER TOTAL KNEE ARTHROPLASTY.

    Science.gov (United States)

    Cury, Ricardo de Paula Leite; Cinagawa, Eduardo Hitoshi Tsuge; Camargo, Osmar Pedro Arbix; Honda, Emerson Kiyoshi; Klautau, Giselle Burlamaqui; Salles, Mauro José Costa

    2015-01-01

    To identify and compare the rate of success of therapeutic modalities applied in surgeries for the treatment of infections associated with total knee arthroplasty (TKA), and to evaluate the functional outcome and pain in different therapeutic modalities by means of quality of life scores. We evaluated all patients who developed periprosthetic infection after TKA for primary or secondary osteoarthritis, in the period from January 1(st), 2008 to December 31(st), 2010. In the study period, 29 patients with TKA had infection, and 12 of these underwent debridement and retention of the prosthesis (D+R), seven received two-stage and six one-stage exchange arthroplasties, and four patients were treated with suppressive antibiotic therapy because they could not undergo another surgical procedure. The D+R, one-stage revision and two-stage revision success rates were 75%, 83.3%, and 100%, respectively. The best results of quality of life (QoL) and function occur in patients undergoing D+R. In contrast, the worst QoL and functional results were obtained in patients treated with two-stage revision arthroplasty. Level of Evidence II, Prognostic Studies - Investigating the Effect of a Patient Characteristic on the Outcome of Disease.

  11. Dual-energy CT and ceramic or titanium prostheses material reduce CT artifacts and provide superior image quality of total knee arthroplasty.

    Science.gov (United States)

    Kasparek, Maximilian F; Töpker, Michael; Lazar, Mathias; Weber, Michael; Kasparek, Michael; Mang, Thomas; Apfaltrer, Paul; Kubista, Bernd; Windhager, Reinhard; Ringl, Helmut

    2018-06-07

    To evaluate the influence of different scan parameters for single-energy CT and dual-energy CT, as well as the impact of different material used in a TKA prosthesis on image quality and the extent of metal artifacts. Eight pairs of TKA prostheses from different vendors were examined in a phantom set-up. Each pair consisted of a conventional CoCr prosthesis and the corresponding anti-allergic prosthesis (full titanium, ceramic, or ceramic-coated) from the same vendor. Nine different (seven dual-energy CT and two single-energy CT) scan protocols with different characteristics were used to determine the most suitable CT protocol for TKA imaging. Quantitative image analysis included assessment of blooming artifacts (metal implants appear thicker on CT than they are, given as virtual growth in mm in this paper) and streak artifacts (thick dark lines around metal). Qualitative image analysis was used to investigate the bone-prosthesis interface. The full titanium prosthesis and full ceramic knee showed significantly fewer blooming artifacts compared to the standard CoCr prosthesis (mean virtual growth 0.6-2.2 mm compared to 2.9-4.6 mm, p energy CT protocols showed less blooming (range 3.3-3.8 mm) compared to single-energy protocols (4.6-5.5 mm). The full titanium and full ceramic prostheses showed significantly fewer streak artifacts (mean standard deviation 77-86 Hounsfield unit (HU)) compared to the standard CoCr prosthesis (277-334 HU, p energy CT protocols had fewer metal streak artifacts (215-296 HU compared to single-energy CT protocols (392-497 HU)). Full titanium and ceramic prostheses were ranked superior with regard to the image quality at the bone/prosthesis interface compared to a standard CoCr prosthesis, and all dual-energy CT protocols were ranked better than single-energy protocols. Dual-energy CT and ceramic or titanium prostheses reduce CT artifacts and provide superior image quality of total knee arthroplasty at the bone/prosthesis interface

  12. Assessment of suspected infection of hip or knee endoprosthesis by nuclear medicine techniques

    International Nuclear Information System (INIS)

    Schmidt, M.; Dietlein, M.; Schicha, H.; Delank, K.S.

    2007-01-01

    . Concerning knee prostheses such a differentiation with the help of 18 F-FDG pattern recognition has not been successful so far. Therefore, in knee endoprosthesis labelled antibodies or labelled fragments of antibodies may be regarded as the method of choice for most nuclear medicine physicians. It may be regarded as somehow disappointing that a basically attractive approach with 99m Tc-ciprofloxacine has not fulfilled the expectations of excellent discrimination between prosthetic loosening and septic inflammation. No single diagnostic procedure in nuclear medicine is able to detect bacterial infection in a direct manner. Therefore, it is important to know the limitations of the diagnostic methods in nuclear medicine. (orig.)

  13. Long-term clinical outcomes and survivorship of press-fit condylar sigma fixed-bearing and mobile-bearing total knee prostheses in the same patients.

    Science.gov (United States)

    Kim, Young-Hoo; Park, Jang-Won; Kim, Jun-Shik; Kulkarni, Sourabh S; Kim, Yoon-Hong

    2014-10-01

    We are aware of no study that has compared press-fit condylar Sigma fixed-bearing and mobile-bearing total knee prostheses in the same patients after more than ten years of follow-up. The purpose of the current study was to compare these two implants with respect to the functional and radiographic results, prevalence of osteolysis, and overall revision rates at a mean of 12.1 years of follow-up. The study consisted of a consecutive series of 444 patients (mean age [and standard deviation], 66.5 ± 7.4 years) who underwent simultaneous bilateral total knee arthroplasty, with one side treated immediately after the other. All of the patients received a press-fit condylar Sigma mobile-bearing prosthesis on one side and a press-fit condylar Sigma fixed-bearing prosthesis on the contralateral side. The minimum duration of follow-up was ten years (mean, 12.1 years; range, ten to thirteen years). At the time of each follow-up visit, the patients were assessed clinically and radiographically. Postoperative total knee scores (95 and 94 points), Western Ontario and McMaster Universities Osteoarthritis Index (19 and 18 points), University of California, Los Angeles activity score (both prostheses, 5 points), range of motion (129° ± 6.3° and 127° ± 6.8°), and radiographic findings did not differ significantly between the press-fit condylar Sigma mobile and fixed-bearing designs at the final follow-up. The prevalence of aseptic loosening (1.4% and 1.8%) did not differ significantly between the mobile and fixed-bearing implant designs. No knee in either group had osteolysis. The estimated survival rate with revision as the end point was 98.2% (95% confidence interval, 91% to 99%) and 97.5% (95% confidence interval, 91% to 99%) at 12.1 years for the mobile and fixed-bearing implant groups, respectively. The results of the present long-term clinical study suggest that excellent clinical and radiographic results were achieved with both the press-fit condylar Sigma mobile and

  14. Post-Cam Design and Contact Stress on Tibial Posts in Posterior-Stabilized Total Knee Prostheses: Comparison Between a Rounded and a Squared Design.

    Science.gov (United States)

    Watanabe, Toshifumi; Koga, Hideyuki; Horie, Masafumi; Katagiri, Hiroki; Sekiya, Ichiro; Muneta, Takeshi

    2017-12-01

    The post-cam mechanism in posterior stabilized (PS) prostheses plays an important role in total knee arthroplasty (TKA). The purpose of this study is to clarify the difference of the contact stress on the tibial post between a rounded post-cam design and a squared design during deep knee flexion and at hyperextension using the three-dimensional (3D) finite element models. We created 2 types of 3D, finite element models of PS prostheses (types A and B), whose surfaces were identical except for the post-cam geometries: type A has a rounded post-cam design, while type B has a squared design. Both types have a similar curved-shape intercondylar notch of the femoral component. Stress distributions, peak contact stresses, and contact areas on the tibial posts at 90°, 120°, and 150° flexion with/without 10° tibial internal rotation and at 10° hyperextension were compared between the 2 models. Type B demonstrated more concentrated stress distribution compared to type A. The peak contact stresses were similar in both groups during neutral flexion; however, the stresses were much higher in type B during flexion with 10° rotation and at hyperextension. The higher peak contact stresses corresponded to the smaller contact areas in the tibial post. A rounded post-cam design demonstrated less stress concentration during flexion with rotation and at hyperextension compared with a squared design. The results would be useful for development of implant designs and prediction of the contact stress on the tibial post in PS total knee arthroplasty. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. A biodegradable gentamicin-hydroxyapatite-coating for infection prophylaxis in cementless hip prostheses

    NARCIS (Netherlands)

    Neut, D.; Dijkstra, R. J. B.; Thompson, J. I.; Kavanagh, C.; van der Mei, H. C.; Busscher, H. J.

    2015-01-01

    A degradable, poly (lactic-co-glycolic acid) (PLGA), gentamicin-loaded prophylactic coating for hydroxyapatite (HA)-coated cementless hip prostheses is developed with similar antibacterial efficacy as offered by gentamicin-loaded cements for fixing traditional, cemented prostheses in bone. We

  16. Infected primary knee arthroplasty: Risk factors for surgical treatment failure

    Directory of Open Access Journals (Sweden)

    Joao Gabriel Duarte Paes Pradella

    2013-09-01

    Full Text Available OBJECTIVE: To present epidemiological data and risk factors associated with surgical out-comes favorable or unfavorable for the treatment of infection in infected total knee arthroplasty. METHODS: We reviewed medical records of 48 patients who underwent treatment of primary total knee arthroplasty for infection between January 1994 and December 2008, in the Orthopedics and Traumatology Department of the Santa Casa de Misericórdia de São Paulo. The variables associated with favorable outcome of surgical treatment (debridement and retention or exchange arthroplasty in two days or unfavorable (arthrodesis or death infection. RESULTS: A total of 39 cases of infection after primary total knee arthroplasty, 22 progressed to 17 for a favorable outcome and unfavorable outcome. Early infections (OR: 14.0, 95% CI 1.5-133.2, p = 0.016 and diabetes (OR: 11.3, 95% CI 1.4-89.3, p = 0.032 were associated with arthrodesis joint and death respectively. CONCLUSION: Patients with early infection had a higher risk of developing surgical procedure with unfavorable outcome (arthrodesis and diabetics had higher odds of death after infection of primary knee arthroplasties.

  17. TREATMENT OF DEEP PERIPROSTHETIC INFECTION OF KNEE JOINT

    Directory of Open Access Journals (Sweden)

    Ivantsov V. A.

    2018-03-01

    Full Text Available In connection with the increase in arthroplasty of joints, the problem of infectious complications becomes topical. The aim of the study was to increase the effectiveness of purulent complications treatment after total knee arthroplasty. Material and methods. Treatment of patients with deep periprosthetic infection of the knee joint dealt with surgical debridement with the preservation of endoprosthesis, its removal and placement of a cement spacer or with the removal of endoprosthesis and arthrodesis of the knee joint. Surgical debridement was related to the radical excision of necrotic tissues and the remains of the synovial membrane. To prepare the cement spacer bone cement "CEMFIX" or "GENTAFIX" impregnated with antibiotic was used. For arthrodesis of the knee joint, Medbiotech core apparatus (the Republic of Belarus superimposed on the limb in the frontal and sagittal planes was applied. Results. The use of a differentiated and individual approach to the treatment of deep periprosthetic infection of the knee joint enabled to obtain positive results in 85.6% of cases. Conclusions. The two-stage method of treatment of deep periprosthetic infection of the knee joint is preferred, as compared to a one-stage method, which enables to obtain better results.

  18. [Multicentre study of infection incidence in knee prosthesis].

    Science.gov (United States)

    Jaén, F; Sanz-Gallardo, M I; Arrazola, M P; García de Codes, A; de Juanes, A; Resines, C

    2012-01-01

    To determine the incidence of surgical site infection in knee prosthesis surgical procedure for a follow-up period of one year in twelve hospitals in Madrid region. A prospective study was carried out from January to December 2009 using a national surveillance system called Indicadores Clínicos de Mejora Continua de Calidad. Primary and revision knee joint replacements in patients operated on in the previous year were included. Criteria used to define surgical site infection and patient risk index categories were those established by the Centers for Disease Control and Prevention and National Nosocomial Infections Surveillance. The incidence rates were worked out crude and adjusted by hazard ratio. 2,088 knee prosthesis procedures were analyzed. The overall incidence of surgical site infection was 2.1%. Sixty-five percent of the infections were organ/space. Sixty percent of the infections were identified in the early postoperative period. Of all surgical site infections, 41.9% were microbiologically confirmed. Antibiotic prophylaxis was implemented correctly in 63.3% of the cases. The most important cause of inappropriate prophylaxis was an unsuitable duration in 85.7% of the cases. The presurgical preparation was carried out correctly in 50.3% of surgical operations. The incidence of knee arthroplasty infection was twice as high as in the National Healthcare Safety Network and similar to national rates. In this study, the incidence of infection was within the range of infection rates in other published European studies. Surveillance and control strategies of health care for associated infections allow us to assess trends and the impact of preventive measures. Copyright © 2011 SECOT. Published by Elsevier Espana. All rights reserved.

  19. Mycobacterium smegmatis infection of a prosthetic total knee arthroplasty.

    Science.gov (United States)

    Saffo, Zaid; Ognjan, Anthony

    2016-01-01

    The most common organisms causing prosthetic knee joint infections are staphylococci. However, arthroplasty infections with atypical microbial pathogens, such as Mycobacteria can occur. Due to the rarity of mycobacterial prosthetic joint infections, diagnosis, treatment, and management of these atypical infections represent a clinical challenge. A 71-year old female post-operative day 40 after a left total knee arthroplasty was hospitalized secondary to left knee pain and suspected arthroplasty infection. She had failed outpatient oral antimicrobial treatment for superficial stitch abscess; and outpatient IV/Oral antimicrobials for a clinical postoperative septic bursitis. Ultimately, resection arthroplasty with operative tissue acid fast bacterial cultures demonstrated growth of the Mycobacterium smegmatis group. Post-operatively, she completed a combination course of oral doxycycline and levofloxacin and successfully completed a replacement arthroplasty with clinical and microbial resolution of the infection. To our knowledge, literature review demonstrates three case of knee arthroplasty infection caused by the Mycobacterium smegmatis group. Correspondingly, optimal surgical procedures and antimicrobial management including antimicrobial selection, treatment duration are not well defined. Presently, the best treatment options consists of two step surgical management including prosthesis hardware removal followed by extended antimicrobial therapy, followed by consideration for re-implantation arthroplasty. Our case illustrates importance of considering atypical mycobacterial infections in post-operative arthroplasty infections not responding to traditional surgical manipulations and antimicrobials. For an arthroplasty infection involving the atypical Mycobacterium smegmatis group, two step arthroplasty revision, including arthroplasty resection, with a combination of oral doxycycline and levofloxacin can lead to successful infection resolution, allowing for a

  20. Importance of SPECT/CT for knee and hip joint prostheses; Stellenwert der SPECT/CT bei Knie- und Hueftgelenkprothesen

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, K.; Steurer-Dober, I.; Huellner, M.W.; Veit-Haibach, P.; Allgayer, B. [Luzerner Kantonsspital (Switzerland). Institut fuer Nuklearmedizin und Roentgendiagnostik

    2012-07-15

    Complications, such as loosening or infections are common problems after hip or knee arthroplasty. If conventional X-rays are equivocal bone scintigraphy is the classical second-line imaging modality. Single photon emission computed tomography/computed tomography (SPECT/CT) offers metabolic and morphologic information in one imaging step and is becoming increasingly more available in larger hospitals. The SPECT/CT procedure is a promising method and is increasingly being used in daily routine to evaluate joint arthroplasty. The additional benefit compared with classical conventional bone scintigraphy has to be evaluated in further prospective studies. In our hospital SPECT/CT regularly gives important additional information regarding prosthetic joint complications. SPECT/CT is increasingly being used as the second step imaging standard modality if conventional X-rays are equivocal. (orig.) [German] Komplikationen wie Lockerung und Infekt stellen ein haeufiges Problem nach Hueft- und Kniegelenkprothesen dar. Wenn die konventionelle Roentgenaufnahme nicht zum Ziel fuehrt, ist die klassische konventionelle Skelettszintigraphie die am haeufigsten verwendete ''Second-line''-Bildgebung. Die ''single photon emission computed tomography''/CT (SPECT/CT) bietet metabolische und morphologische Informationen bzgl. Prothesenkomplikationen in einem Untersuchungsgang und ist zunehmend in groesseren Kliniken verfuegbar. Die SPECT/CT ist eine viel versprechende Methode und wird im klinischen Alltag bei der Evaluation von Gelenkprothesen zunehmend eingesetzt. Es sind noch mehr prospektive Studien noetig, um die Leistungsfaehigkeit und den Zusatznutzen gegenueber der klassischen Szintigraphie zu evaluieren. In unserer Klinik wird die Knochenszintigraphie bei der Abklaerung von Prothesenkomplikationen zumeist mit einer SPECT/CT kombiniert und liefert regelmaessig wichtige Zusatzinformationen. Die SPECT/CT entwickelt sich zunehmend zum Standard

  1. Incidence of Early Post Operative Infection after Primary Total Knee ...

    African Journals Online (AJOL)

    Incidence of Early Post Operative Infection after. Primary Total Knee Arthroplasty at an East African. Centre. Kigera JWM1, Kimpiatu P2. 1. School of Medicine, University of Nairobi. 2. PCEA Kikuyu Hospital. Correspondence to: Dr James Kigera, P.O Box 30197 – 00100 Nairobi. Email: jameskigera@yahoo.co.uk. Abstract.

  2. Unicompartmental knee prostheses: in vitro wear assessment of the menisci tibial insert after two different fixation methods

    International Nuclear Information System (INIS)

    Affatato, S; Spinelli, M; Zavalloni, M; Viceconti, M; Carmignato, S; Lopomo, N; Marcacci, M

    2008-01-01

    Knee osteoarthritis is a complex clinical scenario where many biological and mechanical factors influence the severity of articular degenerative changes. Minimally invasive knee prosthetic surgery, with only a compartment replacement (unicompartmental knee replacement), might be a good compromise between osteotomy and total knee prosthesis. The focus of this study was to develop and validate a protocol to assess the fixation method of the femoral components in mechanical simulation, for pre-clinical validation; the wear behaviour of two different fixation frames was quantified and compared. In particular, two different wear tests were conducted using the same knee simulator, the same load profiles and the same kinematics; two different fixation methods were applied to the femoral sleds (synthetic femur and metal block). Surface characterization on both articulating bearings was performed by a roughness measuring machine and coordinate measuring machine. The wear produced by the tibial inserts using the synthetic femur was considerably higher than the wear registered by the metal-block holder. Roughness measurements on femoral sleds showed a limited number of scratches with high R t values for the metal-block set-up; the damaged surface broadened in the case of femoral condyles and tibial inserts mounted on composite bone, but lower R t and linear penetration values were measured. The two holding frames showed different wear activities as a consequence of dissimilar dynamic performance. Further observations should be made in vivo to prove the actual importance of synthetic bone simulations and specific material behaviour

  3. Unicompartmental knee prostheses: in vitro wear assessment of the menisci tibial insert after two different fixation methods

    Energy Technology Data Exchange (ETDEWEB)

    Affatato, S; Spinelli, M; Zavalloni, M; Viceconti, M [Laboratorio di Tecnologia Medica, Istituti Ortopedici Rizzoli, Via di Barbiano, 1/10, 40136 Bologna (Italy); Carmignato, S [Laboratorio di Metrologia Geometrica e Industriale, Universita degli Studi di Padova, Padova (Italy); Lopomo, N; Marcacci, M [Laboratorio di Biomeccanica, Istituti Ortopedici Rizzoli, Bologna (Italy)], E-mail: affatato@tecno.ior.it

    2008-10-07

    Knee osteoarthritis is a complex clinical scenario where many biological and mechanical factors influence the severity of articular degenerative changes. Minimally invasive knee prosthetic surgery, with only a compartment replacement (unicompartmental knee replacement), might be a good compromise between osteotomy and total knee prosthesis. The focus of this study was to develop and validate a protocol to assess the fixation method of the femoral components in mechanical simulation, for pre-clinical validation; the wear behaviour of two different fixation frames was quantified and compared. In particular, two different wear tests were conducted using the same knee simulator, the same load profiles and the same kinematics; two different fixation methods were applied to the femoral sleds (synthetic femur and metal block). Surface characterization on both articulating bearings was performed by a roughness measuring machine and coordinate measuring machine. The wear produced by the tibial inserts using the synthetic femur was considerably higher than the wear registered by the metal-block holder. Roughness measurements on femoral sleds showed a limited number of scratches with high R{sub t} values for the metal-block set-up; the damaged surface broadened in the case of femoral condyles and tibial inserts mounted on composite bone, but lower R{sub t} and linear penetration values were measured. The two holding frames showed different wear activities as a consequence of dissimilar dynamic performance. Further observations should be made in vivo to prove the actual importance of synthetic bone simulations and specific material behaviour.

  4. The robustness and accuracy of in vivo linear wear measurements for knee prostheses based on model-based RSA.

    Science.gov (United States)

    van Ijsseldijk, E A; Valstar, E R; Stoel, B C; Nelissen, R G H H; Reiber, J H C; Kaptein, B L

    2011-10-13

    Accurate in vivo measurements methods of wear in total knee arthroplasty are required for a timely detection of excessive wear and to assess new implant designs. Component separation measurements based on model-based Roentgen stereophotogrammetric analysis (RSA), in which 3-dimensional reconstruction methods are used, have shown promising results, yet the robustness of these measurements is unknown. In this study, the accuracy and robustness of this measurement for clinical usage was assessed. The validation experiments were conducted in an RSA setup with a phantom setup of a knee in a vertical orientation. 72 RSA images were created using different variables for knee orientations, two prosthesis types (fixed-bearing Duracon knee and fixed-bearing Triathlon knee) and accuracies of the reconstruction models. The measurement error was determined for absolute and relative measurements and the effect of knee positioning and true seperation distance was determined. The measurement method overestimated the separation distance with 0.1mm on average. The precision of the method was 0.10mm (2*SD) for the Duracon prosthesis and 0.20mm for the Triathlon prosthesis. A slight difference in error was found between the measurements with 0° and 10° anterior tilt. (difference=0.08mm, p=0.04). The accuracy of 0.1mm and precision of 0.2mm can be achieved for linear wear measurements based on model-based RSA, which is more than adequate for clinical applications. The measurement is robust in clinical settings. Although anterior tilt seems to influence the measurement, the size of this influence is low and clinically irrelevant. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Plesiomonas shigelloides Periprosthetic Knee Infection After Consumption of Raw Oysters.

    Science.gov (United States)

    Hustedt, Joshua W; Ahmed, Sarim

    Periprosthetic infections are a leading cause of morbidity after total joint arthroplasty. Common pathogens include Staphylococcus aureus, streptococcus, enterococcus, Escherichia coli, and Pseudomonas aeruginosa. However, there are many cases in which rare bacteria are isolated. This case report describes a periprosthetic knee infection caused by Plesiomonas shigelloides. In the United States, P shigelloides and 2 other Vibrionaceae family members, Vibrio vulnificus and Vibrio parahaemolyticus, are most often contracted from eating raw oysters and shellfish. P shigelloides usually causes a self-limiting watery diarrhea, but in immunosuppressed people it can cause septicemia. In this case report, a chemically and biologically immunosuppressed man consumed raw oysters and developed P shigelloides septicemia and acute periprosthetic knee infection that required surgical intervention.

  6. Rotationplasty with vascular reconstruction for prosthetic knee joint infection.

    Science.gov (United States)

    Fujiki, Masahide; Miyamoto, Shimpei; Nakatani, Fumihiko; Kawai, Akira; Sakuraba, Minoru

    2015-01-01

    Rotationplasty is used most often as a function-preserving salvage procedure after resection of sarcomas of the lower extremity; however, it is also used after infection of prosthetic knee joints. Conventional vascular management during rotationplasty is to preserve and coil major vessels, but recently, transection and reanastomosis of the major vessels has been widely performed. However, there has been little discussion regarding the optimal vascular management of rotationplasty after infection of prosthetic knee joints because rotationplasty is rarely performed for this indication. We reviewed four patients who had undergone resection of osteosarcomas of the femur, placement of a prosthetic knee joint, and rotationplasty with vascular reconstruction from 2010 to 2013. The mean interval between prosthetic joint replacement and rotationplasty was 10.4 years and the mean interval between the diagnosis of prosthesis infection and rotationplasty was 7.9 years. Rotationplasty was successful in all patients; however, in one patient, arterial thrombosis developed and necessitated urgent surgical removal and arterial reconstruction. All patients were able to walk independently with a prosthetic limb after rehabilitation. Although there is no consensus regarding the most appropriate method of vascular management during rotationplasty for revision of infected prosthetic joints, vascular transection and reanastomosis is a useful option.

  7. Salvage of infected total knee arthroplasty with Ilizarov external fixator

    Directory of Open Access Journals (Sweden)

    Venkata Gurava Reddy

    2011-01-01

    Full Text Available Background: Knee arthrodesis may be the only option of treatment in cases of chronic infected total knee arthroplasty (TKA with concomitant irreparable extensor mechanism disruption, extensive bone loss or severe systemic morbidities. Circular external fixation offers possible progressive adjustment to stimulate the bony fusion and to make corrections in alignment. We evaluated the results of knee arthrodesis with one or two stage circular external fixator for infected TKA. Materials and Methods: 16 cases of femoro-tibial fusion were retrospectively evaluated. Male-to-female ratio was 10:6. Mean age of the patients was 62.2 years. Cierney-Mader classification was used for anatomical and physiological evaluation while the bone stock deficiency was classified into mild, moderate and severe. Surgical technique involved either single or two stage arthrodesis using circular external fixator. Results: Union was achieved in 15 patients (93.75%. The mean duration for union (frame application time in these patients was 28.33 weeks (range 22 to 36 weeks. Analysis showed that in the group with frame application time of less than 28 weeks, the incidence of mild to moderate bone deficiency was 83.33%, while in the frame application time more than 28 weeks group the incidence was 20% (P-value 0.034. Similarly the incidence of Cierney-Mader 4B (Bl, Bs, Bls was found to be 33.33% in the group of frame application time of less than 28 weeks, while it was 90% in the group with frame application time more than 28 weeks (P-value 0.035. Conclusion: Circular external fixator is a safe and reliable method to achieve knee arthrodesis in cases of deep infection following TKA. Severe bone stock deficiency and Cierney- Mader type B host are likely risk factors for prolonged frame application time. We recommend a two-stage procedure especially when there is compromised host or severe bone loss.

  8. Results of infected total knee arthroplasty treated with arthroscopic debridement and continuous antibiotic irrigation system

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    Che-Wei Liu

    2013-01-01

    Conclusion: Arthroscopic debridement combined with continuous antibiotic irrigation and suction is an effective treatment for patients with acute presentation of late infected total knee arthroplasty.

  9. Validation of a model-based measurement of the minimum insert thickness of knee prostheses: a retrieval study.

    Science.gov (United States)

    van IJsseldijk, E A; Harman, M K; Luetzner, J; Valstar, E R; Stoel, B C; Nelissen, R G H H; Kaptein, B L

    2014-10-01

    Wear of polyethylene inserts plays an important role in failure of total knee replacement and can be monitored in vivo by measuring the minimum joint space width in anteroposterior radiographs. The objective of this retrospective cross-sectional study was to compare the accuracy and precision of a new model-based method with the conventional method by analysing the difference between the minimum joint space width measurements and the actual thickness of retrieved polyethylene tibial inserts. Before revision, the minimum joint space width values and their locations on the insert were measured in 15 fully weight-bearing radiographs. These measurements were compared with the actual minimum thickness values and locations of the retrieved tibial inserts after revision. The mean error in the model-based minimum joint space width measurement was significantly smaller than the conventional method for medial condyles (0.50 vs 0.94 mm, p model-based measurements was less than 10 mm in the medial direction in 12 cases and less in the lateral direction in 13 cases. The model-based minimum joint space width measurement method is more accurate than the conventional measurement with the same precision. Cite this article: Bone Joint Res 2014;3:289-96. ©2014 The British Editorial Society of Bone & Joint Surgery.

  10. Evaluation of a Prototype Hybrid Vacuum Pump to Provide Vacuum-Assisted Suspension for Above-Knee Prostheses.

    Science.gov (United States)

    Major, Matthew J; Caldwell, Ryan; Fatone, Stefania

    2015-12-01

    Vacuum-assisted suspension (VAS) of prosthetic sockets utilizes a pump to evacuate air from between the prosthetic liner and socket, and are available as mechanical or electric systems. This technical note describes a hybrid pump that benefits from the advantages of mechanical and electric systems, and evaluates a prototype as proof-of-concept. Cyclical bench testing of the hybrid pump mechanical system was performed using a materials testing system to assess the relationship between compression cycles and vacuum pressure. Phase 1 in vivo testing of the hybrid pump was performed by an able-bodied individual using prosthesis simulator boots walking on a treadmill, and phase 2 involved an above-knee prosthesis user walking with the hybrid pump and a commercial electric pump for comparison. Bench testing of 300 compression cycles produced a maximum vacuum of 24 in-Hg. In vivo testing demonstrated that the hybrid pump continued to pull vacuum during walking, and as opposed to the commercial electric pump, did not require reactivation of the electric system during phase 2 testing. The novelty of the hybrid pump is that while the electric system provides rapid, initial vacuum suspension, the mechanical system provides continuous air evacuation while walking to maintain suspension without reactivation of the electric system, thereby allowing battery power to be reserved for monitoring vacuum levels.

  11. Experimental substantiation of a method of early diagnosis of infectivity of vascular prostheses with the help of 99mTc-leukocytes

    International Nuclear Information System (INIS)

    Zatevakhin, I.I.; Malov, G.A.; Govorunov, G.V.; Dobronravov, D.S.; Makhmudov, S.Ya.; Komrakov, V.E.

    1988-01-01

    Experiments on 9 dogs were staged for a study of a method of early diagnosis of infectivity of vascular prostheses of the abdominal aorta with the help of 99m Tc-labeled leukocytes. A sterile synthetic vascular prosthesis was used for prosthetics of the abdominal aorta in the 1st control group of animals, a prosthesis, previously infected with St. aureus, was used in the 2nd group, a sterile prosthesis with its subsequent infecting by i.v. injection of St. aureus was used in the 3rd group. The tolre of antibiotic therapy in infectivity of vascular prostheses was studied on the animals of the 3rd group. A radionuclide study with autologous 99m Tc-labeled leukocytes was conducted using the Deina-2 camera (Picker). Visualization of the prostheses was unobserved in the 1st control group; in the 2nd group the accumulation of 99m Tc-leucocytes in the zone of the prosthesis and its vizualization on the 4th-5th min. were noted; in the 3rd group the prothesis was visualized on the 10th-15th min. After antibiotic therapy in the 3rd group visualization of the prothesis was undetectable. The proposed method permitted visualization of a zone of infection in the early postoperative period, observation of the time course of infection development, and assessment of the efficacy of antibiotic therapy

  12. A Facile Technique to Make Articulating Spacers for Infected Total Knee Arthroplasty

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    Yu-Ping Su

    2009-03-01

    Conclusion: Treating infected total knee arthroplasty with these self-made articulating spacers eradicates infection effectively, improves the life quality before reimplantation and provides good final results without significant complications.

  13. Microbiological diagnosis in revision of infected knee arthroplasties in Denmark

    DEFF Research Database (Denmark)

    Lindberg-Larsen, Martin; Pitter, Frederik Taylor; Voldstedlund, Marianne

    2017-01-01

    . METHODS: One hundred and two partial revisions (open debridement and exchange of tibial insert) and 213 two-stage procedures performed due to infection in 275 patients from 1 July 2011 to 30 June 2013 were included and analysed by linkage to data from a nationwide registry on microbiological test results....... RESULTS: 78 (24.8%) revisions were culture negative, 192 (60.9%) showed monomicrobial growth and 43 (14.3%) polymicrobial growth. Staphylococcus aureus was the most frequent isolate in mono-culture in 70 (22.2%) revisions and in polymicrobial culture in 15 revisions with a total frequency of 27.0%. Only...... one case (1.4%) of methicillin-resistance was registered. Coagulase-negative staphylococci (CoNS) were frequent, sole pathogen in 65 revisions and in polymicrobial cultures in 28 revisions with a total frequency of 29.5%. A pre-operative knee aspiration was performed in 50% and preoperative blood...

  14. Infection after total knee replacement: diagnosis and treatment

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    Lucio Honorio de Carvalho Junior

    2013-09-01

    Full Text Available Infection after total knee replacement (IATJ is a rare complication. It is associated with increased morbidity and mortality increasing the final costs. Gram positive coccus and Staphylococcus coagulase-negative and Staphylococcus aureus are the most common isolated germs (>50% of the cases. Conditions related to the patient, to the surgical procedure and even to the post op have been identified as risk factors to IATJ. Many complementary methods together with clinical symptoms are useful to a proper diagnosis. Treatment for IATJ must be individualized but generally is a combination of systemic antibiotic therapy and surgical treatment. Prosthesis exchange in one or two stages is the first choice procedure. Debridement with prosthesis retention is an option in acute cases with stable implants and antibiotic sensible germs.

  15. Lactobacillus as a rare cause of an infected total knee replacement: a case report

    Science.gov (United States)

    2009-01-01

    Introduction We report a rare case of an infected revision total knee replacement as a result of a Lactobacillus species infection. Lactobacillus infections have been associated with prolonged broad-spectrum antibiotic use. This can have implications in revision surgery, especially when patients have been on previous long-term suppressive antibiotic therapy. Case presentation An 81-year-old British man with a previous history of complex revision knee arthroplasty for infection presented with a hot, swollen knee joint. He had previously been on long-term suppressive antibiotic therapy. Aspiration of the knee joint yielded a culture of Lactobacillus species. Conclusion In patients undergoing revision joint arthroplasty, especially for previous infection, the presence of common and uncommon bacterial species must be excluded and eradicated before further surgical intervention. PMID:19830207

  16. The Clinical usefulness of 99mTc HMPAO Leukocyte/99mTc phytate bone marrow scintigraphy for diagnosis of prosthetic knee infection: A preliminary study

    International Nuclear Information System (INIS)

    Jung, Kyung Pyo; Park, Ji Sun; Lee, Ah Young; Choi, Su Jung; Lee, Seok Mo; Bae, Sang Kyun

    2012-01-01

    The preferred radionuclide imaging procedure for diagnosing prosthetic joint infection is combined radiolabeled leukocyte/ 99mT c sulfur colloid bone marrow scintigraphy, which has an accuracy of over 90%. Unfortunately, sulfur colloid is no longer available in South Korea. in this study, we evaluated the usefulness of 99mT c phytate, a substitute for 99mT c sulfur colloid, when combined with radiolabeled leukocyte scintigraphy in suspected prosthetic knee infections. Eleven patients (nine women, two men; mean age 72±6 years) with painful knee prostheses and a suspicion of infection underwent both 99mT c phytate bone marrow scintigraphy (BMS). The combined images were interpreted as positive for infection when radioactivity in the LS at the sits of clinical interest clearly exceeded that of the BMS (discordant); they were interpreted as negative when the increased activity in the LS was consistent with an increased activity in the BMS(concordant). The final diagnosis was made with microbiological or intraoperative findings and a clinical follow up of at least 12 months. Five of eleven patients were diagnosed as having an infected prosthesis. The overall sensitivity, specificity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of the combined LS/BMS were 100%, 83%, 83%, 100% and 91%, respectively. We find that combined 99mT c HMPAO LS/ 99mT c phytate BMS shows comparable diagnostic performance to other studies utilizing sulfur colloid. Combined 99mT c HMPAO LS/ 99mT c phytate BMS is therefore expected to be an acceptable alternative to combined radiolabeled LS/ 99ms ulfur colloid BMS for diagnosing prosthetic knee infections

  17. Assessment of suspected infection of hip or knee endoprosthesis by nuclear medicine techniques; Nuklearmedizinische Abklaerung bei vermuteter Infektion einer Hueft- oder Knie-TEP

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, M.; Dietlein, M.; Schicha, H. [Koeln Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Delank, K.S. [Koeln Univ. (Germany). Klinik und Poliklinik fuer Orthopaedie

    2007-06-15

    infection. Concerning knee prostheses such a differentiation with the help of {sup 18}F-FDG pattern recognition has not been successful so far. Therefore, in knee endoprosthesis labelled antibodies or labelled fragments of antibodies may be regarded as the method of choice for most nuclear medicine physicians. It may be regarded as somehow disappointing that a basically attractive approach with {sup 99m}Tc-ciprofloxacine has not fulfilled the expectations of excellent discrimination between prosthetic loosening and septic inflammation. No single diagnostic procedure in nuclear medicine is able to detect bacterial infection in a direct manner. Therefore, it is important to know the limitations of the diagnostic methods in nuclear medicine. (orig.)

  18. Primary Candida guilliermondii Infection of the Knee in a Patient without Predisposing Factors

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    Gun Woo Lee

    2012-01-01

    Full Text Available Isolated primary candidal infection of joint is extremely rare, with only a few reported cases. It occurs as a result of accidental implantations of fungus during traumatic procedures, such as surgery, and is usually reported in patients with predisposing factors such as immunosuppression, malignancy, and drug abuse. If left untreated, irreversible deformity and pain with severe osteoarticular destruction occur. Thus, early diagnosis and treatment are important. This paper presents a case of 72-year-old man with primary C. guilliermondii infection of knee joint without predisposing factors and previous traumatic procedures, who was misdiagnosed with advanced degenerative osteoarthritis. Our case is the second case of primary C. guilliermondii arthritis of knee to be reported in the English-language literature and the first to be successfully treated with total knee arthroplasty following IV amphotericin B and oral fluconazole. Primary candidal infection of joint is generally asymptomatic or involves only mild pain and swelling in the affected knee. Thus, although the majority of knee joint infections are of a pyogenic or tuberculous origin, if a patient complains of mild pain and swelling in the knee and has mild signs of infection, the possibility of fungal infection should be considered.

  19. Advance pre-operative chlorhexidine reduces the incidence of surgical site infections in knee arthroplasty.

    Science.gov (United States)

    Zywiel, Michael G; Daley, Jacqueline A; Delanois, Ronald E; Naziri, Qais; Johnson, Aaron J; Mont, Michael A

    2011-07-01

    Surgical site infections following elective knee arthroplasties occur most commonly as a result of colonisation by the patient's native skin flora. The purpose of this study was to evaluate the incidence of deep surgical site infections in knee arthroplasty patients who used an advance cutaneous disinfection protocol and who were compared to patients who had peri-operative preparation only. All adult reconstruction surgeons at a single institution were approached to voluntarily provide patients with chlorhexidine gluconate-impregnated cloths and a printed sheet instructing their use the night before and morning of surgery. Records for all knee arthroplasties performed between January 2007 and December 2008 were reviewed to determine the incidence of deep incisional and periprosthetic surgical site infections. Overall, the advance pre-operative protocol was used in 136 of 912 total knee arthroplasties (15%). A lower incidence of surgical site infection was found in patients who used the advance cutaneous preparation protocol as compared to patients who used the in-hospital protocol alone. These findings were maintained when patients were stratified by surgical infection risk category. No surgical site infections occurred in the 136 patients who completed the protocol as compared to 21 infections in 711 procedures (3.0%) performed in patients who did not. Patient-directed skin disinfection using chlorhexidine gluconate-impregnated cloths the evening before, and the morning of, elective knee arthroplasty appeared to effectively reduce the incidence of surgical site infection when compared to patients who underwent in-hospital skin preparation only.

  20. Diagnostics of 'non-acute' vascular prosthesis infection using {sup 18}F-FDG PET/CT: our experience with 96 prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Spacek, M. [First Faculty of Medicine and General Teaching Hospital, Second Clinical Department of Cardiovascular Surgery, Prague (Czech Republic); Na Homolce Hospital, Department of Vascular Surgery, Prague (Czech Republic); Belohlavek, O.; Votrubova, J. [PET Centre, Na Homolce Hospital, Department of Nuclear Medicine, Prague (Czech Republic); Sebesta, P.; Stadler, P. [Na Homolce Hospital, Department of Vascular Surgery, Prague (Czech Republic)

    2009-05-15

    Vascular prosthesis infection (VPI) is a life-threatening complication that occurs in 0.5-5% of prostheses. Low-grade infections in non-acute patients are a diagnostic challenge requiring a new method with good diagnostic accuracy. The aim of this work was to define the accuracy of {sup 18}F-FDG PET/CT in these settings and to identify essential parameters of the evaluation. PET/CT was performed prospectively in 76 consecutive patients with a total of 96 vascular prosthetic grafts in which infection was suspected. PET/CT scans were analysed in terms of the presence and intensity of focal and diffuse FDG uptake, the presence of an anastomotic pseudoaneurysm, the presence of an irregular boundary of infiltration, a combination of these, and the uptake ratio between the graft and blood background. The gold standard was based on operative/histopathological finding or a clinical follow up of >6 months. Among the various assessed parameters only focal FDG uptake and an irregular graft boundary were significant predictors of VPI. Focal intense FDG uptake together with an irregular boundary of the lesion on CT scan predicted VPI with 97% probability, while smooth lesion boundaries and no focal FDG uptake predicted a probability of VPI of less than 5%. Even in lesions with nondiagnostic inhomogeneous focal FDG uptake (18/96) an irregular boundary effectively helped in decision-making with a probability of 28% (smooth) or 77% (irregular) for VPI. PET/CT gave reliable results with an accuracy >95% in 75% of prostheses. PET/CT can identify those prostheses (25% of prosthesis) for which its diagnostic accuracy is diminished to 70-75%. In our series PET/CT was an excellent diagnostic modality for suspected VPI. (orig.)

  1. Trichosporon Asahii Infection after Total Knee Arthroplasty: A Case Report and Review of the Literature

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    Qiang Zuo

    2015-01-01

    Full Text Available Reports of fungal infection after total knee arthroplasty are extremely rare. In most reports, the infecting organism is a Candida species. The present report describes a case involving a 73-year-old immunocompetent woman who underwent total knee arthroplasty and presented one month later with signs of prosthetic infection. She underwent joint debridement and the fluid was sent for culture and sensitivity testing. The culture showed growth of Trichosporon asahii. The patient was administered intravenous and intra-articular injections of amphotericin B, followed by antifungal treatment with voriconazole for one year. At 26 months of follow-up, there was no evidence of infection and the patient was ambulating with a walker. To the authors’ knowledge, the present case is the first report of T asahii infection following knee replacement. Early detection, prompt institution of the appropriate antibiotics and regular follow-up are recommended.

  2. Good results in postoperative and hematogenous deep infections of 89 stable total hip and knee replacements with retention of prosthesis and local antibiotics.

    Science.gov (United States)

    Geurts, Jan A P; Janssen, Daniël M C; Kessels, Alfons G H; Walenkamp, Geert H I M

    2013-12-01

    Deep postoperative and hematogenous prosthesis infections may be treated with retention of the prosthesis, if the prosthesis is stable. How long the infection may be present to preclude a good result is unclear. We retrospectively studied 89 deep-infected stable prostheses from 69 total hip replacements and 20 total knee replacements. There were 83 early or delayed postoperative infections and 6 hematogenous. In the postoperative infections, treatment had started 12 days to 2 years after implantation. In the hematogenous infections, symptoms had been present for 6 to 9 days. The patients had been treated with debridement, prosthesis retention, systemic antibiotics, and local antibiotics: gentamicin-PMMA beads or gentamicin collagen fleeces. The minimum follow-up time was 1.5 years. We investigated how the result of the treatment had been influenced by the length of the period the infection was present, and by other variables such as host characteristics, infection stage, and type of bacteria. In postoperative infections, the risk of failure increased with a longer postoperative interval: from 0.2 (95% CI: 0.1-0.3) if the treatment had started ≥ 4 weeks postoperatively to 0.5 (CI: 0.2-0.8) if it had started at ≥ 8 weeks. The relative risk for success was 0.6 (CI: 0.3-0.95) if the treatment had started ≥ 8 weeks. In the hematogenous group, 5 of 6 infections had been treated successfully. A longer delay before the start of the treatment caused an increased failure rate, but this must be weighed against the advantage of keeping the prosthesis. We consider a failure rate of < 50% to be acceptable, and we therefore advocate keeping the prosthesis for up to 8 weeks postoperatively, and in hematogenous infections with a short duration of symptoms.

  3. Primary Total Knee Replacement: Is Suction a Portal of Infection?

    Science.gov (United States)

    Budnar, Vijaya M; Amirfeyz, Rouin; Ng, Michael; Bannister, Gordon C; Blom, Ashley W

    2009-01-01

    INTRODUCTION Pulsed lavage during a total knee replacement usually leaves a pool of fluid on the surgical drapes. It is common practice to suck away this fluid using the same suction device used intra-operatively. This could be a cause of direct wound contamination. We hypothesised that bacteria contaminate fluid that collects around the foot in total knee replacement surgery and that suction equipment could be a portal of contamination. We also hypothesised that bacterial count in the fluid is lower if chlorhexidine, rather than saline, is used in the pulsed lavage. PATIENTS AND METHODS Forty patients undergoing primary total knee replacement were divided into two groups. The first group had pulsed lavage with normal saline and the second with 0.05% chlorhexidine. RESULTS At the end of the operation, 20 ml of fluid, pooled on the surgical drapes was aspirated and cultured for bacterial growth. None of the fluid samples showed bacterial growth. CONCLUSIONS Suction device used peri-operatively during knee replacement is unlikely to be a cause of wound contamination. Pulsed lavage with normal saline is as effective as lavage with chlorhexidine. PMID:19335972

  4. Correction of tibial malunion in a patient with ipsilateral total knee and ankle prostheses using external ring fixation and the ilizarov method

    Directory of Open Access Journals (Sweden)

    Alexander M Smith

    2017-01-01

    Full Text Available Total ankle replacement (TAR aims at reestablishing a functional and painless ankle joint while maintaining motion and preventing adjacent joint arthritis. TAR can be complicated by comorbidities such as ipsilateral knee arthritis and deformity with subsequent arthroplasty and/or other lower extremity malalignment issues. We present a case of a 67-year-old female with severe right ankle pain and a history of ipsilateral subtalar and calcaneocuboid fusion, bilateral total knee arthroplasty, and a malunion of a conservatively treated ipsilateral segmental tibial fracture. Following TAR, there was recurrent lateral hindfoot pain due to subtle malalignment from the tibial malunion which resulted in persistent hindfoot valgus. This caused symptomatic subfibular impingement in addition to limb length discrepancy. To address that, a circular external fixator was applied to realign the ankle and lengthen the tibia, eliminating pain and avoiding complications with either implant.

  5. First Case Report of a Late Onset Knee Periprosthetic Joint Infection Caused by Lactococcus garvieae

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    V.-I. Neagoe

    2016-01-01

    Full Text Available Lactococcus garvieae is known as a Gram-positive, catalase-negative, and facultatively anaerobic fish pathogen. The association between Lactococcus spp. and human infectious diseases is described as being mainly associated with lumbar osteomyelitis, hepatic abscess, and infective endocarditis. In the literature of orthopedic post-prosthetic infections, L. garvieae was associated with a case of hip prosthetic infection in a fishmonger woman. We present the case of a 79-year-old male patient with multiple comorbidities, who is admitted to our center with a 5-day history of pain, swelling, and motility disorder of the right knee by the presence of a bicondylar knee replacement surgery, which was performed due to gonarthrosis 17 years ago. The radiographies of the right knee revealed no signs of displacement or loosening of the prothesis. After multiple radical debridements including VAC therapy and targeted antibiotic therapy we have managed to defeat the infection without exchange arthroplasty. Although we could not demonstrate the source of infection, we can only presume that in our case the source of infection was represented by the ingestion of possibly contaminated food. The patient had a habit of eating Nile perch fish (Lates niloticus every 4 weeks. We illustrated once more the possibility of a late onset L. garvieae related orthopedic periprosthetic joint infection by multiple comorbidities.

  6. Short Operative Duration and Surgical Site Infection Risk in Hip and Knee Arthroplasty Procedures.

    Science.gov (United States)

    Dicks, Kristen V; Baker, Arthur W; Durkin, Michael J; Anderson, Deverick J; Moehring, Rebekah W; Chen, Luke F; Sexton, Daniel J; Weber, David J; Lewis, Sarah S

    2015-12-01

    To determine the association (1) between shorter operative duration and surgical site infection (SSI) and (2) between surgeon median operative duration and SSI risk among first-time hip and knee arthroplasties. Retrospective cohort study A total of 43 community hospitals located in the southeastern United States. Adults who developed SSIs according to National Healthcare Safety Network criteria within 365 days of first-time knee or hip arthroplasties performed between January 1, 2008 and December 31, 2012. Log-binomial regression models estimated the association (1) between operative duration and SSI outcome and (2) between surgeon median operative duration and SSI outcome. Hip and knee arthroplasties were evaluated in separate models. Each model was adjusted for American Society of Anesthesiology score and patient age. A total of 25,531 hip arthroplasties and 42,187 knee arthroplasties were included in the study. The risk of SSI in knee arthroplasties with an operative duration shorter than the 25th percentile was 0.40 times the risk of SSI in knee arthroplasties with an operative duration between the 25th and 75th percentile (risk ratio [RR], 0.40; 95% confidence interval [CI], 0.38-0.56; Poperative duration did not demonstrate significant association with SSI for hip arthroplasties (RR, 1.04; 95% CI, 0.79-1.37; P=.36). Knee arthroplasty surgeons with shorter median operative durations had a lower risk of SSI than surgeons with typical median operative durations (RR, 0.52; 95% CI, 0.43-0.64; Poperative durations were not associated with a higher SSI risk for knee or hip arthroplasty procedures in our analysis.

  7. Late Streptococcus bovis infection of total knee replacement complicated by infective endocarditis and associated with colonic ulcers

    Science.gov (United States)

    Nagy, Mathias Thomas; Hla, Sann Minn; Keys, Graham Watson

    2013-01-01

    Streptococcus bovis is rare cause of late infections after total knee replacement (TKR). This report presents a case of confirmed late septic arthritis following TKR caused by S bovis that was further complicated with infective endocarditis resulting in aortic valve insufficiency in an immunecompetent patient. As an association between S bovis and gastrointestinal malignancies is suggested, a workup for such malignancies was performed that revealed non-malignant ulcers in patient's ascending colon. The patient is currently recovering from his aortic valve replacement surgery and is scheduled to have annual colonoscopies. His knee joint has improved; however, he developed constant pain because of underlying chronic infection in the affected joint and has difficulties mobilising. Therefore, a revision TKR is considered but postponed until he fully recovers from his heart valve surgery. PMID:23744853

  8. Antibiotic-impregnated articulating cement spacer for infected total knee arthroplasty

    Directory of Open Access Journals (Sweden)

    Parag Garg

    2011-01-01

    Full Text Available Background : Standard treatment of chronic infected total knee arthroplasty (TKA is a two-stage revision, the first step being placement of an antibiotic-impregnated cement spacer. Here we describe the results of a new technique (modification of the Goldstien′s technique for intraoperative manufacture of a customized articulating spacer at minimal cost and with relatively good conformity and longevity. Materials and Methods : Thirty-six infected knees underwent this procedure from June 2002 to May 2007. The technique consists of using the freshened femur and tibia interface as molds wrapped in a tin foil for manufacturing the two components of the spacer with antibiotic-impregnated methyl methycrylate cement. We used the spacer and the femoral component of the trial set of a TKA system to mold them to perfect articulation. We also reinforced the spacer with a K-wire scaffold to prevent fracture of the cement mantle in the last 21 cases. Results : All 36 knees showed excellent results in terms of infection control, mobility, and stability. There was significant improvement in the WOMAC and Knee Society Scores (20 and 39 points respectively. There were two fractures of the spacers in the initial 15 cases that did not have K-wire scaffolding but none in the last 21 that had reinforcement. Conclusion : This technique provides a more conforming spacer, with good range of motion and stability. The reinforcement helps in preventing the fracture of the cement mantle and is cost effective.

  9. The infection of Mycoplasma hominis after total knee replacement: Case report and literature review

    Directory of Open Access Journals (Sweden)

    Hong-Jiu Qiu

    2017-08-01

    Full Text Available The Mycoplasma hominis infection is a rare postoperative complication after joint replacement. Based on our knowledge, there were only two cases reported by Korea all over the world currently. A case of postoperative Mycoplasma hominis infection after total knee replacement in our hospital was reported in this article. It was confirmed through mass spectrometer and Mycoplasma cultivation and treated by the first stage debridement, polyethylene insert replacement, and then drainage and irrigation combined with sensitive antibiotics after the operation. We observed that the C reactive protein (CRP level correlates with the development of disease, while the erythrocyte sedimentation rate (ESR remains at a high level, indicating the relevance between the Mycoplasma hominis infection caused by knee joint replacement and CRP. This study aims to report the case and review relevant literature.

  10. The Clinical usefulness of {sup 99mT}c HMPAO Leukocyte/{sup 99mT}c phytate bone marrow scintigraphy for diagnosis of prosthetic knee infection: A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kyung Pyo; Park, Ji Sun; Lee, Ah Young; Choi, Su Jung; Lee, Seok Mo; Bae, Sang Kyun [Inje Univ., Pusan Paik Hospital, Pusan (Korea, Republic of)

    2012-12-15

    The preferred radionuclide imaging procedure for diagnosing prosthetic joint infection is combined radiolabeled leukocyte/{sup 99mT}c sulfur colloid bone marrow scintigraphy, which has an accuracy of over 90%. Unfortunately, sulfur colloid is no longer available in South Korea. in this study, we evaluated the usefulness of {sup 99mT}c phytate, a substitute for {sup 99mT}c sulfur colloid, when combined with radiolabeled leukocyte scintigraphy in suspected prosthetic knee infections. Eleven patients (nine women, two men; mean age 72{+-}6 years) with painful knee prostheses and a suspicion of infection underwent both {sup 99mT}c phytate bone marrow scintigraphy (BMS). The combined images were interpreted as positive for infection when radioactivity in the LS at the sits of clinical interest clearly exceeded that of the BMS (discordant); they were interpreted as negative when the increased activity in the LS was consistent with an increased activity in the BMS(concordant). The final diagnosis was made with microbiological or intraoperative findings and a clinical follow up of at least 12 months. Five of eleven patients were diagnosed as having an infected prosthesis. The overall sensitivity, specificity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of the combined LS/BMS were 100%, 83%, 83%, 100% and 91%, respectively. We find that combined {sup 99mT}c HMPAO LS/{sup 99mT}c phytate BMS shows comparable diagnostic performance to other studies utilizing sulfur colloid. Combined {sup 99mT}c HMPAO LS/{sup 99mT}c phytate BMS is therefore expected to be an acceptable alternative to combined radiolabeled LS/{sup 99ms}ulfur colloid BMS for diagnosing prosthetic knee infections.

  11. The outcome of infected total knee arthroplasty: culture-positive versus culture-negative.

    Science.gov (United States)

    Kim, Young-Hoo; Park, Jang-Won; Kim, Jun-Shik; Kim, Dong-Jin

    2015-10-01

    We studied the outcome in culture-positive and culture-negative infected total knee arthroplasty (TKA). We retrospectively reviewed 140 patients with culture-positive and 102 patients with culture-negative infected TKAs. We determined the infection control rate and clinical outcome after repeated debridement, and repeated 2-stage TKA in the culture-positive and culture-negative groups. The mean follow-up was 9.3 years (range 5-14 years) in the culture-positive group and 10.6 years (5-22) in the culture-negative group. The overall infection control rate was 56 % in both groups after the first treatment. The overall infection control rate was 90 % in the culture-positive group and 95 % in the culture-negative group. A functional knee was obtained in 90 % in the culture-positive group and 95 % in the culture-negative group. The data suggest that treatment according to the types of infection in both culture-positive and culture-negative groups after TKA controlled infection and maintained functional TKA with a firm level of fixation for most patients. Repeated debridement and repeated two-stage exchange TKA further improved infection control rates after the initial treatment and increased the likelihood of maintaining a functional TKA.

  12. [Tuberculous prosthetic knee joint infection: a case report and literature review].

    Science.gov (United States)

    Lara-Oya, A; Liébana-Martos, M C; Rodríguez-Granger, J; Sampedro-Martínez, A; Aliaga-Martínez, L; Gutierrez-Fernández, J; Navarro-Marí, J M

    2016-08-01

    Prosthetic late infection occurs in the second month after surgery in the context of haematogenous spread from another source. Prosthetic mycobacterial infection is a rare complication whose clinical management is not standardized. Patient of 77 years with no personal history except for diabetes and a prosthetic replacement of right knee with osteoarthritis three years ago. Patient goes to hospital emergency box for 6 months pain in the right knee with mechanical inflammatory signs but no fever associated. After their return within 5 days and clinical worsening is reporting growth of Mycobacterium tuberculosis in knee aspirate and antitubercular treatment is established for 9 months. Nuclear magnetic resonance imaging studies also confirmed the diagnosis of tuberculosis spondylitis in the clinical context of the patients. After surgery, M. tuberculosis was again isolated from intraoperative samples and therefore the patient received another batch of treatment for 9 months. After a year of monitoring, the development was acceptable but few months later, the patient died for cardiovascular causes. In the literature review, 15 publications with a total of 17 clinical cases of prosthetic infection by M. tuberculosis were found from 1980 to 2014. Prosthetic tuberculous arthritis, although it is a rare presentation, it should be noted, especially in patients with predisposing conditions with a history of tuberculosis infection.

  13. Predicting 3D pose in partially overlapped X-ray images of knee prostheses using model-based Roentgen stereophotogrammetric analysis (RSA).

    Science.gov (United States)

    Hsu, Chi-Pin; Lin, Shang-Chih; Shih, Kao-Shang; Huang, Chang-Hung; Lee, Chian-Her

    2014-12-01

    After total knee replacement, the model-based Roentgen stereophotogrammetric analysis (RSA) technique has been used to monitor the status of prosthetic wear, misalignment, and even failure. However, the overlap of the prosthetic outlines inevitably increases errors in the estimation of prosthetic poses due to the limited amount of available outlines. In the literature, quite a few studies have investigated the problems induced by the overlapped outlines, and manual adjustment is still the mainstream. This study proposes two methods to automate the image processing of overlapped outlines prior to the pose registration of prosthetic models. The outline-separated method defines the intersected points and segments the overlapped outlines. The feature-recognized method uses the point and line features of the remaining outlines to initiate registration. Overlap percentage is defined as the ratio of overlapped to non-overlapped outlines. The simulated images with five overlapping percentages are used to evaluate the robustness and accuracy of the proposed methods. Compared with non-overlapped images, overlapped images reduce the number of outlines available for model-based RSA calculation. The maximum and root mean square errors for a prosthetic outline are 0.35 and 0.04 mm, respectively. The mean translation and rotation errors are 0.11 mm and 0.18°, respectively. The errors of the model-based RSA results are increased when the overlap percentage is beyond about 9%. In conclusion, both outline-separated and feature-recognized methods can be seamlessly integrated to automate the calculation of rough registration. This can significantly increase the clinical practicability of the model-based RSA technique.

  14. Antibiotic prophylaxis adequacy in knee arthroplasty and surgical wound infection: Prospective cohort study.

    Science.gov (United States)

    Del-Moral-Luque, J A; Checa-García, A; López-Hualda, Á; Villar-Del-Campo, M C; Martínez-Martín, J; Moreno-Coronas, F J; Montejo-Sancho, J; Rodríguez-Caravaca, G

    Antibiotic prophylaxis is the most suitable tool for preventing surgical wound infection. This study evaluated adequacy of antibiotic prophylaxis in surgery for knee arthroplasty and its effect on surgical site infection. Prospective cohort study. We assessed the degree of adequacy of antibiotic prophylaxis, the causes of non-adequacy, and the effect of non-adequacy on surgical site infection. Incidence of surgical site infection was studied after a maximum incubation period of a year. To assess the effect of prophylaxis non-adequacy on surgical site infection we used the relative risk adjusted with the aid of a logistic regression model. The study covered a total of 1749 patients. Antibiotic prophylaxis was indicated in all patients and administered in 99.8% of cases, with an overall protocol adequacy of 77.6%. The principal cause of non-compliance was the duration of prescription of the antibiotics (46.5%). Cumulative incidence of surgical site infection was 1.43%. No relationship was found between prophylaxis adequacy and surgical infection (RR=1.15; 95% CI: .31-2.99) (P>.05). Surveillance and infection control programs enable risk factors of infection and improvement measures to be assessed. Monitoring infection rates enables us to reduce their incidence. Adequacy of antibiotic prophylaxis was high but could be improved. We did not find a relationship between prophylaxis adequacy and surgical site infection rate. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Preoperative diagnostic for periprosthetic joint infection prior to total knee revision arthroplasty

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    Leif Claassen

    2014-08-01

    Full Text Available Periprosthetic joint infection (PJI after total knee arthroplasty remains a challenging problem. The aim of this study was to evaluate the accuracy of diagnostic knee aspiration and serum inflammatory markers in diagnostic of a PJI after total knee arthroplasty. Within 2011 and 2012, 46 patients received a one- or two-stage revision arthroplasty of the knee joint. These patients received a total number of 77 operations. A preoperative aspiration was performed in each case. We analyzed the microbiological and histological examinations of the samples from the aspiration and from the revision operation and additionally estimated serum inflammatory markers. The diagnostic aspiration had a specificity of 0.87, a sensitivity of 0.39, a positive predictive value of 0.67 and a negative predictive value of 0.68. For C-reactive protein the specificity was 0.61 and the sensitivity was 0.48, the serum white blood cell count had a specificity of 0.98 and a sensitivity of 0.23. Our data queries whether diagnostic joint aspiration or serum inflammatory markers are sufficient to verify or exclude a PJI.

  16. Custom-made hinged spacers in revision knee surgery for patients with infection, bone loss and instability.

    Science.gov (United States)

    Macmull, S; Bartlett, W; Miles, J; Blunn, G W; Pollock, R C; Carrington, R W J; Skinner, J A; Cannon, S R; Briggs, T W R

    2010-12-01

    Polymethyl methacrylate spacers are commonly used during staged revision knee arthroplasty for infection. In cases with extensive bone loss and ligament instability, such spacers may not preserve limb length, joint stability and motion. We report a retrospective case series of 19 consecutive patients using a custom-made cobalt chrome hinged spacer with antibiotic-loaded cement. The "SMILES spacer" was used at first-stage revision knee arthroplasty for chronic infection associated with a significant bone loss due to failed revision total knee replacement in 11 patients (58%), tumour endoprosthesis in four patients (21%), primary knee replacement in two patients (11%) and infected metalwork following fracture or osteotomy in a further two patients (11%). Mean follow-up was 38 months (range 24-70). In 12 (63%) patients, infection was eradicated, three patients (16%) had persistent infection and four (21%) developed further infection after initially successful second-stage surgery. Above knee amputation for persistent infection was performed in two patients. In this particularly difficult to treat population, the SMILES spacer two-stage technique has demonstrated encouraging results and presents an attractive alternative to arthrodesis or amputation. Copyright © 2009 Elsevier B.V. All rights reserved.

  17. Ertapenem Articulating Spacer for the Treatment of Polymicrobial Total Knee Arthroplasty Infection

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    Dragan Radoicic

    2016-01-01

    Full Text Available Introduction. Periprosthetic joint infections (PJIs are the primary cause of early failure of the total knee arthroplasty (TKA. Polymicrobial TKA infections are often associated with a higher risk of treatment failure. The aim of the study was to assess the efficacy of ertapenem loaded spacers in the treatment of polymicrobial PJI. Methods. There were 18 patients enrolled; nine patients with polymicrobial PJI treated with ertapenem loaded articulating spacers were compared to the group of 9 patients treated with vancomycin or ceftazidime loaded spacers. Results. Successful reimplantation with revision implants was possible in 66.67%. Ertapenem spacers were used in 6 cases in primary two-stage procedure and in 3 cases in secondary spacer exchange. Successful infection eradication was achieved in all cases; final reimplantation with revision knee arthroplasty implants was possible in 6 cases. Conclusion. Ertapenem can be successfully used as antimicrobial addition to the cement spacers in two-stage revision treatment of polymicrobial PJIs. However, this type of spacer may also be useful in the treatment of infections caused by monomicrobial extended spectrum beta-lactamases producing gram-negative bacilli. Further clinical studies are required to evaluate the efficacy and safety of ertapenem spacers in the treatment of polymicrobial and monomicrobial PJIs.

  18. Outcome of prosthesis exchange for infected knee arthroplasty: the effect of treatment approach.

    Science.gov (United States)

    Jämsen, Esa; Stogiannidis, Ioannis; Malmivaara, Antti; Pajamäki, Jorma; Puolakka, Timo; Konttinen, Yrjö T

    2009-02-01

    Two-stage revision remains the gold standard in the treatment of infected knee arthroplasty. Lately, good long-term results of direct exchange arthroplasty have been reported. The purpose of this literature review is to compare the clinical outcome achieved with one-stage revision and two-stage revision with different types of spacers. A thorough systematic review of literature was undertaken to idenepsy reports on the treatment alternatives. Papers written in English or including an English abstract, published from 1980 through 2005, and reporting either the success rate in eradication of infection or the clinical status achieved were reviewed. 31 original articles describing the results of 154 one-stage exchange arthoplasties and of 926 two-stage exchange arthoplasties were included. The depth of detail in the description of materials and methods varied markedly, making it impossible to perform a meta-analysis. Instead, a descriptive review of the results is presented. With a follow-up of 12-122 months, the overall success rate in eradication of infection was 73-100% after one-stage revisions and 82-100% after two-stage revisions. Reinfection rates were the lowest in series where articulating cement spacers were used, though the follow-up was relatively short. Studies using articulating spacers reported the highest average postoperative ranges of motion. Otherwise, no correlations were observed between the clinical outcome and the length of follow-up, the type of revision, or the type of spacer. The clinical outcome (knee scores and range of motion) of the one-stage revisions was no different from that of the two-stage revisions. Two-stage exchange is an effective treatment. Mobile spacers may further improve the range of motion. More experience in one-stage revision is required in order to define its role in the management of infected knee arthroplasties.

  19. Success rates for initial eradication of peri-prosthetic knee infection treated with a two-stage procedure.

    Science.gov (United States)

    Kaminski, Andrzej; Citak, Mustafa; Schildhauer, Thomas Armin; Fehmer, Tobias

    2014-01-01

    In Germany, rates of primary total knee arthroplasty procedures and exchange arthroplasty procedures continue to rise. Late-onset peri-prosthetic infection constitutes a serious complication whose management may be dependent upon the spectrum of micro-organisms involved. The aim of this study was to provide a retrospective analysis of the effectiveness of initial eradication measures performed as part of a two-stage procedure. Between 2002 and 2008, a total of 328 patients who had received a first-time diagnosis of chronic peri-prosthetic knee infection following total knee arthroplasty (TKA) subsequently underwent surgery at our clinic. The surgical approach consisted of a two-stage procedure, with the initial procedure consisting of the removal of the prosthesis and radical debridement, followed by insertion of an antibiotic-loaded static spacer. The effectiveness of the procedure was assessed after six weeks, with each patient undergoing a number of clinical and laboratory-based tests, including knee joint aspiration. Staphylococcus aureus strains were responsible for 68% (n=223) of the total number of cases of peri-prosthetic knee infection. 19% of cases (n=62) showed evidence of gram-negative bacteria, while MRSA accounted for 15% (n=49) of cases. Six weeks after completion of the above-named treatment regimen, eradication of infection was considered successful in 289 patients (88.1%). Eradication was unsuccessful in 22% of MRSA infections (n=11) and 7% of MSSA infections (n=23). The treatment regimen outlined in this report is capable of achieving satisfactory results in the management of late-onset peri-prosthetic knee infection, with one exception: patients with infections caused by MRSA showed high failure rates.

  20. Salmonella typhimurium infection in total knee arthroplasty: A case report with review of literature

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    Sujeesh Sebastian

    2017-01-01

    Full Text Available Salmonella enterica serotype Typhimurium is a rare cause of prosthetic joint infection (PJI. The recognized predisposing risk factors for Salmonella septic arthritis include diabetes mellitus, renal failure, human immunodeficiency virus infection and chronic corticosteroid use. We describe a case of PJI of the knee in a 74-year-old lady who was on antitubercular treatment. The patient presented with discharging sinus and raised inflammatory markers. She was successfully treated by the removal of prosthesis and debridement followed by ciprofloxacin therapy for 6 weeks. This case report highlights the potential virulence of Salmonella in immunocompromised patient with a joint prosthesis. Continuous monitoring and close collaboration of microbiologists and orthopedicians helped obtain the resolution of infection in our patient.

  1. Peri-Prosthetic Knee Infection Management: Spacers Loaded with Two or Three Antibiotic Agents.

    Science.gov (United States)

    Ortola, David Joaquin; Fenga, Domenico; Marcellino, Sandra; Rosi, Massimiliano; Centofanti, Francesco; Rosa, Michele Attilio

    2017-07-01

    The purpose of this work was to compare pre-made antibiotic-loaded spacers with two commercially available antibiotic agents and custom-made cements with three antibiotic agents added. We evaluated: (a) the validity of our procedures, (b) the control of the rate of infection in the long term, (c) complications, and (d) quality of life and patient satisfaction. A retrospective cohort study was performed on 112 consecutively treated patients between January 2010 and December 2013; 56 patients were treated with a pre-formed cement spacer (clindamycin + gentamicin), and 56 patients were treated with a spacer loaded with three antibiotic agents (clindamycin + gentamicin + vancomycin). Demographic data were collected: Classification of infection according to criteria of Cierny-Mader; microbiologic results; number of previous operations; and years of disease. Infection control or relapse after at least 18 months of follow-up was evaluated. Complications were recorded. Every patient completed the SF-36 test and Oxford Knee Score. With a follow-up of 32.87 months (standard deviation 12.04), at the end of treatment, amputation occurred in three of 112 patients because of recurrence of infection, and one patient died from other causes not related to the infection. The study population presented a rate of recurrence of infection of 2.70%. Our results suggest that a two stage re-implant with three antibiotic agents added to the spacer should be considered to avoid rescue procedures, especially in patients with multi-resistant micro-organism infections.

  2. [Endo-exo prostheses : Osseointegrated percutaneously channeled implants for rehabilitation after limb amputation].

    Science.gov (United States)

    Aschoff, H-H; Juhnke, D-L

    2016-05-01

    In 1999 the first endo-exo femoral prosthesis (EEFP) was implanted in Germany in a patient who had suffered a traumatic above-knee amputation. This procedure involves a skeletally anchored exoprosthetic device that is inserted into the residual femur. The distal part of the implant protrudes transcutaneously and allows attachment to a prosthetic limb which provides direct force transmission to the external prosthetic components. The technique originated from dental implantology and helps to avoid possible problems resulting from treatment of amputated limbs using socket prostheses. In the meantime, durability times of over 10 years have now helped to invalidate the initially well-founded reservations held against the procedure. What advantages can be achieved by osseointegrated and percutaneously channeled prostheses and which problems had to be overcome for treatment. Critical evaluation of data from patients operated on in Lübeck, Germany from January 2003 to December 2014. With osseointegrated and percutaneously channeled prostheses permanent durability times can be achieved. Infection-associated soft tissue problems at the site of skin protrusion (stoma) can be successfully prevented. The creation of this so-called stoma means acceptance of a possible bacterial portal of entry into the body. Patient satisfaction has so far been high, postoperative rehabilitation is simplified and the technique could possibly lower the costs of medical treatment. Endo-exo prostheses have proved to be successful for more than 15 years. A critical appraisal of the indications as well as a close cooperation between the surgeon, orthopedic technician and the associated rehabilitation facilities with the patient are the basis for the long-term success of this relatively new treatment approach.

  3. Combined bone scintigraphy with 99mTc-MDP and 99mTc-ciprofloxacin in differentiation of hip and knee prosthesis aseptic loosening and infection: A preliminary study

    Directory of Open Access Journals (Sweden)

    Pucar Dragan

    2017-01-01

    Full Text Available Background/Aim. Although the number of new primary implantation of hip and knee prostheses every year increases, the rate of failed arthroplasty is nearly the same. The main question is whether it is an aseptic instability or instability caused by infection. The aim of this preliminary study was an attempt with combined 99mTc-ciprofloxacin and 99mTc-methylene diphosphonate (MDP bone scintigraphy to improve diagnostic accuracy in the differentiation of hip and knee prosthesis aseptic loosening and periprosthetic joint infection. Methods. Inclusion criteria of patients for this study were based on suspected periprosthetic joint infection: painful prosthetic joint, restricted joint movements and increased value of erythrocyte sedimentation rate or levels of C-reactive protein. We examined 20 patients with implanted 14 hip and 6 knee prosthesis. All patients also underwent plain radiography of suspected joint. In all patients, three-phase 99mTc-MDP bone scintigraphy was performed. Three to five days after the bone scan, we performed scintigraphy using 99mTc-ciprofloxacin with the calculation of accumulation index. Periprosthetic joint infection was confirmed on the basis of microbiological findings. Results. Periprosthetic joint infection was confirmed in fourteen of twenty observed joints, in five of them the aseptic loosening was present and in one patient’s symptoms were not related to the prosthesis (poor biomechanics of prosthetic joints caused by weaknesses of muscle. Estimated sensitivity/specificity for 99mTc-MDP bone scintigraphy alone were 100/17%; for 99mTc-ciprofloxacin scintigraphy were 85,7/100%. Sensitivity and specificity were 92,3% and 83,3%, respectively for results obtained with combined assessment by both methods. Our study confirmed the high negative predictive value of 99mTc-MDP bone scan. The negative result of bone scan virtually excludes the possibility of periprosthetic infection. On the other hand, positive findings of

  4. Risk factors for deep infection after total knee arthroplasty: a meta-analysis.

    Science.gov (United States)

    Chen, Jie; Cui, Yunying; Li, Xin; Miao, Xiangwan; Wen, Zhanpeng; Xue, Yan; Tian, Jing

    2013-05-01

    Estimated the risk factors for postoperative infection after total knee arthroplasty (TKA) to prevent its occurrence. The meta-analysis collected twelve cohorts or case-control studies which included 548 infected persons in 57,223 general cases. Review Manager 5.0 was operated to assess the heterogeneity and to give an overall estimate of the association of factors with postoperative infection after TKA. The main factors distinctly associated with infection after TKA were BMI (BMI >30: OR = 2.53, 95 % CI 1.25, 5.13; BMI >40: OR = 4.00, 95 % CI 1.23, 12.98), diabetes mellitus (OR = 3.72, 95 % CI 2.30, 6.01), hypertension (OR = 2.53, 95 % CI 1.07, 5.99), steroid therapy (OR = 2.04, 95 % CI 1.11, 3.74), and rheumatoid arthritis (OR = 1.83; 95 % CI 1.42, 2.36). It had no sufficient evidences to reveal that gender could lead to infection after TKA. Osteoarthritis appeared to have a moderately protective effect. Statistical analysis revealed no correlation between urinary tract infection, fixation method, ASA, bilateral operation, age, transfusion, antibiotics, bone graft, and infection. There were positive evidences for some certain factors which could be targeted for prevention of the onset of infection, but more studies are needed to define the association of some other controversial factors in infection, like osteoarthritis, gender and so on. The quality of studies also needs to be improved.

  5. 75% success rate after open debridement, exchange of tibial insert, and antibiotics in knee prosthetic joint infections.

    Science.gov (United States)

    Holmberg, Anna; Thórhallsdóttir, Valdís Gudrún; Robertsson, Otto; W-Dahl, Annette; Stefánsdóttir, Anna

    2015-01-01

    Prosthetic joint infection (PJI) is a leading cause of early revision after total knee arthroplasty (TKA). Open debridement with exchange of tibial insert allows treatment of infection with retention of fixed components. We investigated the success rate of this procedure in the treatment of knee PJIs in a nationwide material, and determined whether the results were affected by microbiology, antibiotic treatment, or timing of debridement. 145 primary TKAs revised for the first time, due to infection, with debridement and exchange of the tibial insert were identified in the Swedish Knee Arthroplasty Register (SKAR). Staphylococcus aureus was the most common pathogen (37%) followed by coagulase-negative staphylococci (CNS) (23%). Failure was defined as death before the end of antibiotic treatment, revision of major components due to infection, life-long antibiotic treatment, or chronic infection. The overall healing rate was 75%. The type of infecting pathogen did not statistically significantly affect outcome. Staphylococcal infections treated without a combination of antibiotics including rifampin had a higher failure rate than those treated with rifampin (RR = 4, 95% CI: 2-10). In the 16 cases with more than 3 weeks of symptoms before treatment, the healing rate was 62%, as compared to 77% in the other cases (p = 0.2). The few patients with a revision model of prosthesis at primary operation had a high failure rate (5 of 8). Good results can be achieved by open debridement with exchange of tibial insert. It is important to use an antibiotic combination including rifampin in staphylococcal infections.

  6. Tibial rotation kinematics subsequent to knee arthroplasty

    Science.gov (United States)

    Collins, Duane J.; Khatib, Yasser H.; Parker, David A.; Jenkin, Deanne E.; Molnar, Robert B.

    2015-01-01

    Background The use of computer assisted joint replacement has facilitated precise intraoperative measurement of knee kinematics. The changes in “screw home mechanism” (SHM) resulting from Total Knee Arthroplasty (TKA) with different prostheses and constraints has not yet been accurately described. Methods A pilot study was first completed. Intraoperative kinematic data was collected two groups of 15 patients receiving different prostheses. Results On average, patients lost 5.3° of ER (SD = 6.1°). There was no significant difference between the prostheses or different prosthetic constraints. Conclusions There significant loss of SHM after TKA. Further research is required to understand its impact on patient function. PMID:25829754

  7. Predictors of revision, prosthetic joint infection and mortality following total hip or total knee arthroplasty in patients with rheumatoid arthritis

    DEFF Research Database (Denmark)

    Cordtz, Rene Lindholm; Zobbe, Kristian; Højgaard, Pil

    2018-01-01

    OBJECTIVES: To investigate predictors of 10-year risk of revision and 1-year risk of prosthetic joint infection (PJI) and death following total hip/total knee arthroplasty (THA/TKA) in (1) patients with rheumatoid arthritis (RA) compared with patients with osteoarthritis (OA); and (2) patients...

  8. FDG-PET for diagnosing prosthetic joint infection: systematic review and metaanalysis

    International Nuclear Information System (INIS)

    Kwee, Thomas C.; Kwee, Robert M.; Alavi, Abass

    2008-01-01

    The aim of this study was to systematically review and metaanalyze published data on the diagnostic performance of 18 F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) in detecting prosthetic hip or knee joint infection. A systematic search for relevant studies was performed of the PubMed/MEDLINE and Embase databases. Two reviewers independently assessed the methodological quality of each study. A metaanalysis of the reported sensitivity and specificity of each study was performed. Subgroup analyses were performed if results of individual studies were heterogeneous. The inclusion criteria were met by 11 studies; there was a total sample size of 635 prostheses. Overall, the studies had good methodological quality. Pooled sensitivity and specificity of FDG-PET for the detection of prosthetic hip or knee joint infection were 82.1% (95%CI = 68.0-90.8%) and 86.6% (95%CI = 79.7-91.4%), respectively. Heterogeneity among the results of individual studies was present (I 2 = 68.8%). Diagnostic performance was influenced by type of joint prostheses (hip prostheses vs. knee prostheses) and type of reconstruction method used (filtered back vs. iterative) (p = 0.0164 and p = 0.0235, respectively). In this metaanalysis, overall diagnostic performance of FDG-PET was moderate to high. Caution is warranted, however, because results of individual studies were heterogeneous and could not be fully explored. Future studies should further explore potential causes of heterogeneity and validate the use of FDG-PET for diagnosing prosthetic joint infection. (orig.)

  9. Patella tendon injuries secondary to cement spacers used at first-stage revision of infected total knee replacement

    Directory of Open Access Journals (Sweden)

    Wasim S Khan

    2015-04-01

    Full Text Available We describe a series of three patients who sustained patella tendon injuries in infected TKAs following the use of a static cement spacer at first-stage knee revision. The patella tendon injuries resulted in significant compromise to wound healing and knee stability requiring multiple surgeries. The mid-term function was poor with an Oxford score at 24 months ranging from 12-20. Based on our experience, we advise caution in the use of static cement spacer blocks. If they are to be used, we recommend that they should be keyed in the bone to prevent patella tendon injuries.

  10. Negative pressure wound therapy for the treatment of infected wounds with exposed knee joint after patellar fracture.

    Science.gov (United States)

    Lee, Sang Yang; Niikura, Takahiro; Miwa, Masahiko; Sakai, Yoshitada; Oe, Keisuke; Fukazawa, Takahiro; Kawakami, Yohei; Kurosaka, Masahiro

    2011-06-14

    Treatment of soft tissue defects with exposed bones and joints, resulting from trauma, infection, and surgical complications, represents a major challenge. The introduction of negative pressure wound therapy has changed many wound management practices. Negative pressure wound therapy has recently been used in the orthopedic field for management of traumatic or open wounds with exposed bone, nerve, tendon, and orthopedic implants. This article describes a case of a patient with a large soft tissue defect and exposed knee joint, in which negative pressure wound therapy markedly improved wound healing. A 50-year-old man presented with an ulceration of his left knee with exposed joint, caused by severe wound infections after open reduction and internal fixation of a patellar fracture. After 20 days of negative pressure wound therapy, a granulated wound bed covered the exposed bones and joint.To our knowledge, this is the first report of negative pressure wound therapy used in a patient with a large soft tissue defect with exposed knee joint. Despite the chronic wound secondary to infection, healing was achieved through the use of the negative pressure wound therapy, thus promoting granulation tissue formation and closing the joint. We suggest negative pressure wound therapy as an alternative option for patients with lower limb wounds containing exposed bones and joints when free flap transfer is contraindicated. Our result added to the growing evidence that negative pressure wound therapy is a useful adjunctive treatment for open wounds around the knee joint. Copyright 2011, SLACK Incorporated.

  11. The Impact of use of Double Set-up on Infection Rates in Revision Total Knee Replacement and Limb Salvage Procedures

    Directory of Open Access Journals (Sweden)

    Jennifer Waterman

    2015-03-01

    Full Text Available A retrospective analysis was performed to determine the impact of utilizing a double set-up procedure on reducing infection rates revision total knee and limb salvage procedures in patients with known joint infection.  Eighteen cases fit selection criteria.  The recurrence rate of infection was 5.5% which is less than reported recent literature review.   This suggests the use of a double set-up in combination with other infection reducing protocols may help further reduce recurrent infection.  Keywords: double set-up, infection, revision total knee arthroplasty, limb-salvage

  12. Does Preoperative Antimicrobial Prophylaxis Influence the Diagnostic Potential of Periprosthetic Tissues in Hip or Knee Infections?

    Science.gov (United States)

    Bedenčič, Klemen; Kavčič, Martina; Faganeli, Nataša; Mihalič, Rene; Mavčič, Blaž; Dolenc, Jožica; Bajc, Zlatka; Trebše, Rihard

    2016-01-01

    Undiagnosed low-grade prosthetic joint infections (PJI) are recognized as an important reason for early failure of presumably aseptic revisions. Preoperatively administered antimicrobial prophylaxis reduces the incidence of PJI but it may reduce the sensitivity of microbiologic periprosthetic tissue cultures and consequently increase the incidence of undiagnosed septic prosthetic joint failures, which can lead to catastrophic serial revisions. We wished to determine whether administration of preoperative antibiotics decreases the likelihood of diagnosing PJI in patients undergoing revision hip or knee arthroplasty in whom infection is suspected. We prospectively enrolled and evaluated 40 patients (29 with THAs and 11 with TKAs) who met the following inclusion criteria: older than 18 years, with suspected PJI of unknown cause, undergoing surgical revision. After arthrotomy, three tissue samples were obtained for microbiologic analysis and diagnosis, and antimicrobial prophylaxis (cefazolin 2 g intravenously) then was administered. Later during the procedure, but before débridement and irrigation, the second set of three tissue samples was obtained from the same surgical area and was cultured. Tissue concentration of prophylactic antibiotic was verified with the second set of samples. A positive culture result was defined as one or more positive cultures (growth on agar at or before 14 days). We then compared the yield on the microbiologic cultures obtained before administration of antibiotics with the yield on the cultures obtained after antibiotics were administered. An a priori analysis was performed; with the numbers available, we had 98% power to detect a difference in diagnostic sensitivity of 33%. With the numbers available, we found no difference in the likelihood that an infection would be diagnosed between the samples obtained before and after administration of antimicrobial prophylaxis (odds ratio [OR] for positive microbial culture = 0.99; 95% CI, 0

  13. The Current State of Screening and Decolonization for the Prevention of Staphylococcus aureus Surgical Site Infection After Total Hip and Knee Arthroplasty.

    Science.gov (United States)

    Weiser, Mitchell C; Moucha, Calin S

    2015-09-02

    The most common pathogens in surgical site infections after total hip and knee arthroplasty are methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), and coagulase-negative staphylococci. Patients colonized with MSSA or MRSA have an increased risk for a staphylococcal infection at the site of a total hip or knee arthroplasty. Most colonized individuals who develop a staphylococcal infection at the site of a total hip or total knee arthroplasty have molecularly identical S. aureus isolates in their nares and wounds. Screening and nasal decolonization of S. aureus can potentially reduce the rates of staphylococcal surgical site infection after total hip and total knee arthroplasty. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

  14. 99m-Tc-ubiquicidin scintigraphy in diagnosis of knee prosthesis infection and comparison with F-18 fluorodeoxy-glucose positron emission tomography/computed tomography

    International Nuclear Information System (INIS)

    Kamaleshwaran, Koramadai Karuppusamy; Rajkumar, N; Mohanan, Vyshak; Kalarikal, Radhakrishnan; Shinto, Ajit Sugunan

    2005-01-01

    Total knee arthroplasty has witnessed a significant increase in recent years. Despite the advantages of this surgical procedure, it has some complications, the most serious of which is prosthetic infection. The discrimination of bacterial infections from sterile inflammatory processes is of great importance in the management of periprosthetic infection (PPI). Ubiquicidin (UBI) is a synthetic antimicrobial peptide fragment reported to be highly infection-specific. Tc99m-UBI has recently been reported to be a promising radiotracer for infection imaging. We report a case of left knee PPI diagnosed using 99mTc-UBI scintigraphy and compared with F-18 fluorodeoxy-glucose positron emission tomography

  15. The Effect on Long-Term Survivorship of Surgeon Preference for Posterior-Stabilized or Minimally Stabilized Total Knee Replacement: An Analysis of 63,416 Prostheses from the Australian Orthopaedic Association National Joint Replacement Registry.

    Science.gov (United States)

    Vertullo, Christopher J; Lewis, Peter L; Lorimer, Michelle; Graves, Stephen E

    2017-07-05

    Controversy still exists as to the optimum management of the posterior cruciate ligament (PCL) in total knee arthroplasty. Surgeons can choose to kinematically substitute the PCL with a posterior-stabilized total knee replacement or alternatively to utilize a cruciate-retaining, also known as minimally stabilized, total knee replacement. Proponents of posterior-stabilized total knee replacement propose that the reported lower survivorship in registries when directly compared with minimally stabilized total knee replacement is due to confounders such as selection bias because of the preferential usage of posterior-stabilized total knee replacement in more complex or severe cases. In this study, we aimed to eliminate these possible confounders by performing an instrumental variable analysis based on surgeon preference to choose either posterior-stabilized or minimally stabilized total knee replacement, rather than the actual prosthesis received. Cumulative percent revision, hazard ratio (HR), and revision diagnosis data were obtained from the Australian Orthopaedic Association National Joint Replacement Registry from September 1, 1999, to December 31, 2014, for 2 cohorts of patients, those treated by high-volume surgeons who preferred minimally stabilized replacements and those treated by high-volume surgeons who preferred posterior-stabilized replacements. All patients had a diagnosis of osteoarthritis and underwent fixed-bearing total knee replacement with patellar resurfacing. At 13 years, the cumulative percent revision was 5.0% (95% confidence interval [CI], 4.0% to 6.2%) for the surgeons who preferred the minimally stabilized replacements compared with 6.0% (95% CI, 4.2% to 8.5%) for the surgeons who preferred the posterior-stabilized replacements. The revision risk for the surgeons who preferred posterior-stabilized replacements was significantly higher for all causes (HR = 1.45 [95% CI, 1.30 to 1.63]; p total knee replacement compared with the patients of

  16. Limitations of Gram staining for the diagnosis of infections following total hip or knee arthroplasty.

    Science.gov (United States)

    Ouyang, Zhengxiao; Zhai, Zanjing; Qin, A N; Li, Haowei; Liu, Xuqiang; Qu, Xinhua; Dai, Kerong

    2015-05-01

    The diagnosis of prosthetic joint infection (PJI) following total joint arthroplasty is difficult for clinicians to make decisions due to the similar symptoms presented by aseptic loosening and infection. Gram staining (GS) is a widely used test but its value remains controversial due to conflicting results in the diagnosis of PJI. The aim of the present study was therefore to evaluate the value of GS in the diagnosis of PJI. Searches using MEDLINE, EMBASE and OVID databases were conducted for data published between January 1990 and December 2013. Meta-analysis was used to pool the sensitivity, specificity, diagnostic odd ratios (DORs), area under the receiver-operating characteristic curve (AUC), positive-likelihood ratios (PLRs), negative-likelihood ratios (NLRs) and post-test probability. The heterogeneity and publication bias were assessed, and subgroup and meta-regression analyses were conducted. A total of 18 studies, including a total of 4,647 patients, were selected for analysis. The pooled sensitivity and specificity values for the diagnosis of PJI were 0.19 and 1.00, respectively. The AUC, PLR and NLR were 0.89, 41.6 and 0.82, respectively. Subgroup analyses indicated that the sensitivity/specificity for total hip arthroplasty was 0.14/0.99, whereas that for total knee arthroplasty was 0.14/1.00. Synovial fluid best reflected accurate GS-based diagnoses, with the highest DOR of 242, whereas tissue had the highest AUC of 0.96 (95% CI, 0.94-0.97). GS had a poor clinically acceptable diagnostic value for detecting PJI. These data do not support the routine use of GS, without additional proof of infection, for diagnosing PJI; instead, GS could be used as an adjuvant tool to support the results of other investigations.

  17. Topical Tranexamic Acid Use in Knee Periprosthetic Joint Infection Is Safe and Effective.

    Science.gov (United States)

    Waddell, Bradford S; Zahoor, Talal; Meyer, Mark; Ochsner, Lock; Chimento, George

    2016-07-01

    Tranexamic acid (TXA) has been shown to decrease hemoglobin loss and reduce the need for transfusions in primary hip and knee arthroplasty. Our study evaluated the safety and efficacy of topical TXA in revision TKA for periprosthetic joint infection (PJI). We performed a retrospective review of patients who underwent removal of hardware with antibiotic spacer placement (stage 1) and/or revision TKA (stage 2) for PJI at our institution between September 2007 and July 2013. During that time, 49 patients underwent stage-1 procedures (20 knees with TXA, 29 without TXA) and 47 patients underwent stage-2 revisions (28 with TXA, 19 without TXA). We evaluated hemoglobin loss, need for transfusion, reinfection rate, length of stay (LOS), complications, and mortality with and without the use of TXA in these patients. All data sets were analyzed with a two-sample t-test. Average follow-up was 3.15 years (range, 1-7 years). TXA use led to a significantly lower percentage drop in the postoperative lowest hemoglobin compared with the preoperative hemoglobin in stage-1 surgeries (19.8 vs. 30.05%, p = 0.0004) and stage-2 revisions (24.5 vs 32.01%, p = 0.01). In both groups, TXA use was associated with a significant reduction in transfusion rates (stage-1, 25 vs 51.7%, p = 0.04; stage-2, 25 vs. 52.6%, p = 0.05). There was a nonstatistical decreased LOS in both groups in which TXA was used (stage 1, 5.15 vs. 6.72 days, p = 0.055; stage 2, 5.21 vs. 6.84 days, p = 0.09). There was no difference in the reinfection rate (4 vs. 4, p = 0.56) or mortality rate between groups (0 vs. 2 non-TXA group). A single upper extremity deep vein thrombosis occurred in a stage-1 patient who received TXA, and no pulmonary embolism occurred. We show that topical TXA is safe and effective for use in both stages of revision TKA for PJI. Previous studies have shown TXA to aggravate a staphylococcal infection in mice; however, topical TXA doesn't appear to negatively effect on the

  18. Intraoperative Corticosteroid Injection at the Time of Knee Arthroscopy Is Associated With Increased Postoperative Infection Rates in a Large Medicare Population.

    Science.gov (United States)

    Cancienne, Jourdan M; Gwathmey, F Winston; Werner, Brian C

    2016-01-01

    To employ a national database of Medicare patients to evaluate the association of ipsilateral intra-articular knee corticosteroid injections at the time of knee arthroscopy with the incidence of postoperative infection. A national Medicare insurance database was queried for patients who underwent ipsilateral intra-articular corticosteroid injection of the knee at the time of knee arthroscopy from 2005 to 2012. Patients who underwent arthroscopically assisted open procedures, those who underwent more complex arthroscopic procedures, and those for whom laterality were not coded were excluded. This study group was compared to a control cohort of patients without intraoperative steroid injections that was matched to the study group for age, gender, obesity, diabetes mellitus, and smoking status. Infection rates within 3 and 6 months postoperatively were assessed using International Classification of Diseases, 9th Revision, and Current Procedural Terminology codes. The incidence of postoperative infection rates after knee arthroscopy was significantly higher at 3 months (0.66%; odds ratio [OR], 2.6; P arthroscopy (n = 2,866) compared with matched controls without intraoperative injections (n = 170,350) at 3 months (0.25%) and 6 months (0.54%). The present study demonstrates a significant increase in postoperative infection in Medicare patients who underwent ipsilateral intra-articular knee corticosteroid injections at the time of knee arthroscopy compared with a matched control group without intraoperative injection. Therapeutic Level III, retrospective comparative study. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  19. Protective prostheses during radiation therapy

    International Nuclear Information System (INIS)

    Poole, T.S.; Flaxman, N.A.

    1986-01-01

    Current applications and complications in the use of radiotherapy for the treatment of oral malignancy are reviewed. Prostheses are used for decreasing radiation to vital structures not involved with the lesion but located in the field of radiation. With a program of oral hygiene and proper dental care, protective prostheses can help decrease greatly the morbidity seen with existing radiotherapy regimens

  20. Nuclear medicine and prostheses

    International Nuclear Information System (INIS)

    Bordenave, L.; Baquey, Ch.

    2004-01-01

    Whatever the bio-material, prosthesis or medical device concerned, from design to experimental then clinical validation, nuclear medicine (NM) techniques offer a unique opportunity in all indications, (in vitro diagnosis, in vivo diagnosis and therapy) to investigate, assess and predict the behaviour of the device, qualitatively and quantitatively. All research fields involving prostheses and their constitutive biomaterials may take advantage of NM. In order to review published works, one can analyze provided data according to two strategies: an upright one related to medical and surgical specialties that integrate NM and a more horizontal one, that is to describe what kind of contribution is brought by such investigations. The latter approach was preferred in our review. We discuss and illustrate benefits of NM in the following indications: as an in vitro tool, as an in vivo tool for the diagnosis i) of device integration in recipient, ii) of functional outcome after use or implantation, iii) and predictive assessment of undesirable side effects, iv) of occurrence of complications associated to the device implantation, v) of a new therapy efficiency; finally as in vivo tool of therapy. Tissue engineering and regenerative medicine domains with stem cell potential as well as that of medical device associated with vigilance are new fields in basic research and clinical assessment that seem increasingly promising for the nuclear physician and to which NM could and would contribute from molecule to integrated system in order to improve knowledge and achievement of prostheses. (author)

  1. The value of indium 111 leukocyte scanning in the evaluation of painful or infected total knee arthroplasties

    International Nuclear Information System (INIS)

    Rand, J.A.; Brown, M.L.

    1990-01-01

    Evaluation of painful total knee arthroplasties (TKAs) for infection can be difficult. Indium 111 ( 111 In) leukocyte bone scanning provides a minimally invasive technique for evaluation of possible infection. Thirty-eight patients with a painful TKA who had surgical exploration after 111 In leukocyte scanning were reviewed. The scan had an accuracy of 84%, a sensitivity of 83%, and a specificity of 85%. The 111 In leukocyte scans must be interpreted in conjunction with the clinical evaluation of the patient because they are less accurate for study of TKAs than of total hip arthroplasties

  2. Knee arthrodesis with lengthening: experience of using Ilizarov techniques to salvage large asymmetric defects following infected peri-articular fractures.

    Science.gov (United States)

    Barwick, Thomas W; Montgomery, Richard J

    2013-08-01

    We present four patients with large bone defects due to infected internal fixation of knee condylar fractures. All were treated by debridement of bone and soft tissue and stabilisation with flap closure if required, followed by bone transport arthrodesis of the knee with simultaneous lengthening. Four patients (three male and one female), mean age 46.5 years (37-57 years), with posttraumatic osteomyelitis at the knee (three proximal tibia and one distal femur) were treated by debridement of infected tissue and removal of internal fixation. Substantial condylar bone defects resulted on the affected side of the knee joint (6-10 cm) with loss of the extensor mechanism in all tibial cases. Two patients required muscle flaps after debridement. All patients received intravenous antibiotics for at least 6 weeks. Bone transport with a circular frame was used to achieve an arthrodesis whilst simultaneously restoring a functional limb length. In three cases a 'peg in socket' docking technique was fashioned to assist stability and subsequent consolidation of the arthrodesis. Arthrodesis of the knee, free of recurrent infection, was successfully achieved in all cases. None has since required further surgery. Debridement to union took an average of 25 months (19-31 months). The median number of interventions undertaken was 9 (8-12). Two patients developed deep vein thrombosis (DVT), one complicated by PE, which delayed treatment. Two required surgical correction of pre-existent equinus contracture using frames. The median limb length discrepancy (LLD) at the end of treatment was 3 cm (3-4 cm). None has required subsequent amputation. Bone loss and infection both reduce the success rate of any arthrodesis. However, by optimising the host environment with eradication of infection by radical debridement, soft-tissue flaps when necessary and bone transport techniques to close the defect, one can achieve arthrodesis and salvage a useful limb. The residual LLD can result from not

  3. The 2018 Definition of Periprosthetic Hip and Knee Infection: An Evidence-Based and Validated Criteria.

    Science.gov (United States)

    Parvizi, Javad; Tan, Timothy L; Goswami, Karan; Higuera, Carlos; Della Valle, Craig; Chen, Antonia F; Shohat, Noam

    2018-05-01

    synovial fluid white blood cell count (>3000 cells/μL), alpha-defensin (signal-to-cutoff ratio >1), leukocyte esterase (++), polymorphonuclear percentage (>80%), and synovial CRP (>6.9 mg/L) received 3, 3, 3, 2, and 1 points, respectively. Patients with an aggregate score of greater than or equal to 6 were considered infected, while a score between 2 and 5 required the inclusion of intraoperative findings for confirming or refuting the diagnosis. Intraoperative findings of positive histology, purulence, and single positive culture were assigned 3, 3, and 2 points, respectively. Combined with the preoperative score, a total of greater than or equal to 6 was considered infected, a score between 4 and 5 was inconclusive, and a score of 3 or less was not infected. The new criteria demonstrated a higher sensitivity of 97.7% compared to the MSIS (79.3%) and International Consensus Meeting definition (86.9%), with a similar specificity of 99.5%. This study offers an evidence-based definition for diagnosing hip and knee PJI, which has shown excellent performance on formal external validation. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Clinical results of Hi-tech Knee II total knee arthroplasty in patients with rheumatoid athritis: 5- to 12-year follow-up

    Directory of Open Access Journals (Sweden)

    Yamanaka Hajime

    2012-02-01

    Full Text Available Abstract Background Total knee arthroplasty (TKA is a common form of treatment to relieve pain and improve function in cases of rheumatoid arthritis (RA. Good clinical outcomes have been reported with a variety of TKA prostheses. The cementless Hi-Tech Knee II cruciate-retaining (CR-type prosthesis, which has 6 fins at the anterior of the femoral component, posterior cruciate ligament (PCL retention, flat-on-flat surface component geometry, all-polyethylene patella, strong initial fixation by the center screw of the tibial base plate, 10 layers of titanium alloy fiber mesh, and direct compression molded ultra high molecular weight polyethylene (UHMWPE, is appropriate for TKA in the Japanese knee. The present study was performed to evaluate the clinical results of primary TKA in RA using the cementless Hi-Tech Knee II CR-type prosthesis. Materials and methods We performed 32 consecutive primary TKAs using cementless Hi-Tech Knee II CR-type prosthesis in 31 RA patients. The average follow-up period was 8 years 3 months. Clinical evaluations were performed according to the American Knee Society (KS system, knee score, function score, radiographic evaluation, and complications. Results The mean postoperative maximum flexion angle was 115.6°, and the KS knee score and function score improved to 88 and 70 after surgery, respectively. Complications, such as infection, occurred in 1 patient and revision surgery was performed. There were no cases of loosening in this cohort, and prosthesis survival rate was 96.9% at 12 years postoperatively. Conclusion These results suggest that TKA using the cementless Hi-Tech Knee II CR-type prosthesis is a very effective form of treatment in RA patients at 5 to 12 years postoperatively. Further long-term follow-up studies are required to determine the ultimate utility of this type of prosthesis.

  5. Total replace in the knee with deformity in the valgus

    International Nuclear Information System (INIS)

    Lara Cortassio, Gilberto; Pineros Ramirez, Daniel Francisco

    2006-01-01

    The total knee arthroplasty with valgus deformity is a technically demanding surgery. The bone deformities and the soft tissues make difficult to balance the soft tissues, the mechanic axis restoration and the prostheses placement. We present the results of a retrospective study, observational, descriptive type series of cases of 40 patients (42 prostheses), operated on with valgus deformity of more than 10 grades, using the I. White side technique to balance the soft tissue, with and average following up of 4.5 years. Based on the knee society scale (KSS) we found satisfactory results in more than 92% of the cases (39 prostheses). The complications were: total lost of the knee extension in 2 patients and i femoropatellar misalignment. We recommend practicing a sequential liberation of the lateral soft tissue to obtain a good clinical result and prostheses longevity

  6. Application of individually performed acrylic cement spacers containing 5% of antibiotic in two-stage revision of hip and knee prosthesis due to infection.

    Science.gov (United States)

    Babiak, Ireneusz

    2012-07-03

    Deep infection of a joint endoprosthesis constitutes a threat to the stability of the implant and joint function. It requires a comprehensive and interdisciplinary approach, involving the joint revision and removal of the bacterial biofilm from all tissues, the endoprosthesis must be often removed and bone stock infection treated. The paper presents the author's experience with the use of acrylic cement spacers, custom-made during the surgery and containing low dose of an antibiotic supplemented with 5% of a selected, targeted antibiotic for the infection of hip and knee endoprostheses. 33 two-stage revisions of knee and hip joints with the use of a spacer were performed. They involved 24 knee joints and 9 hip joints. The infections were mostly caused by staphylococci MRSA (18) and MSSA (8), and in some cases Enterococci (4), Salmonella (1), Pseudomonas (1) and Acinetobacter (1). The infection was successfully treated in 31 out of 33 cases (93.93%), including 8 patients with the hip infection and 23 patients with the knee infection. The endoprosthesis was reimplanted in 30 cases: for 7 hips and 23 knees, in 3 remaining cases the endoprosthesis was not reimplanted. Mechanical complications due to the spacer occurred in 4 cases: 3 dislocations and 1 fracture (hip spacer). The patients with hip spacers were ambulatory with a partial weight bearing of the operated extremity and those with knee spacers were also ambulatory with a partial weight bearing, but the extremity was initially protected by an orthosis. The spacer enables to maintain a limb function, and making it by hand allows the addition of the specific bacteria targeted antibiotic thus increasing the likelihood of the effective antibacterial treatment.

  7. Perioperative blood saving measures in total hip and knee arthroplasty

    NARCIS (Netherlands)

    Horstmann, W.G.

    2011-01-01

    This dissertation explores and discusses different aspects of blood loss and blood-saving measures in total hip and knee arthroplasty. Background: Worldwide, approximately 1 million total hip and 1 million total knee prostheses are implanted each year. Total hip arthroplasty and total

  8. [Medial unicompartmental knee prosthesis for patients with unicompartmental gonarthrosis

    NARCIS (Netherlands)

    Kort, N.P.; Deutman, R.; Raay, J.J. van; Horn, J.R. van

    2004-01-01

    The function and survival time of unicompartmental knee prostheses for patients with severe gonarthrosis have been improved the past few years by developments in their design, the instrumentarium and the surgical technique. A medial unicompartmental knee prosthesis may be indicated in patients with

  9. The knee

    International Nuclear Information System (INIS)

    Rand, J.A.; Berquist, T.H.

    1985-01-01

    Evaluation of infection is difficult on the basis of radiographs. A clinical history suggestive of infection, such as excessive prolonged pain, drainage, fever, or a postoperative hematoma, is helpful in assessment. Radiographs may reveal periosteal new bone formation in long-standing cases of infection. Aspiration of the knee may or may not be helpful. Differential Tc-99m and gallium bone scans may be a useful adjunct in difficult cases. The gallium scan should show increased uptake relative to the Tc-99m scan to be considered positive. Bone scanning is not a useful criterion by itself for assessment of loosening

  10. Knee effusion after total knee replacement.

    OpenAIRE

    Cameron, H. U.

    1993-01-01

    The various causes of effusions in artificial knees can be divided into four groups: implant related, technique related, interface problems, and infection. Diagnosis can be made from the patient's history and a clinical examination. Treatment is usually surgical revision.

  11. Microbial biofilms on silicone facial prostheses

    NARCIS (Netherlands)

    Ariani, Nina

    2015-01-01

    Facial disfigurements can result from oncologic surgery, trauma and congenital deformities. These disfigurements can be rehabilitated with facial prostheses. Facial prostheses are usually made of silicones. A problem of facial prostheses is that microorganisms can colonize their surface. It is hard

  12. Radionuclide bone scintigraphy in the detection of significant complications after total knee joint replacement

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.L.; Wastie, M.L.; Forster, I

    2001-03-01

    AIM: Post-arthroplasty knee pain is common and clinically it can be difficult to identify those patients with complications requiring active treatment. The aim of this study was to determine the usefulness of{sup 99}Tc{sup m}-MDP bone scintigraphy. METHOD: A retrospective study of all patients having a{sup 99}Tc{sup m}-MDP bone scintigram for a painful knee arthroplasty between 1993 and 1999 was performed. Bone scintigrams were classified as normal or abnormal by a single observer. The results of these investigations were correlated with clinical outcome. RESULTS: Seventy-five patients with painful knee arthroplasties were referred for investigation. A total of 80 bone scintigrams were performed. The average patient age was 66.2 years (42 female and 33 male). The mean time period between surgery and onset of knee pain was 3 years. A final clinical diagnosis based on arthroscopy, open surgery, and extended clinical follow-up was available for all patients. Forty-three (53.8%) of the scintigrams were normal and 37 (46.3%) abnormal. Two patients with a normal bone scintigram has loose prostheses. Thirteen patients with an abnormal study had normal prostheses on follow-up and these tended to be patients scanned less than a year after surgery. The sensitivity, specificity, positive predictive value and negative predictive value of an unequivocally normal or abnormal bone scintigram was 92.3, 75.9, 64.9 and 95.0%, respectively. The pattern of isotope uptake in the abnormal studies was not specific enough to reliably differentiate aseptic from septic loosening. CONCLUSION: Radionuclide bone scintigraphy is useful in the assessment of the painful knee arthroplasty. A negative bone scintigram is reassuring and makes loosening or infection unlikely. Smith, S.L. et al. (2001)

  13. Radionuclide bone scintigraphy in the detection of significant complications after total knee joint replacement

    International Nuclear Information System (INIS)

    Smith, S.L.; Wastie, M.L.; Forster, I.

    2001-01-01

    AIM: Post-arthroplasty knee pain is common and clinically it can be difficult to identify those patients with complications requiring active treatment. The aim of this study was to determine the usefulness of 99 Tc m -MDP bone scintigraphy. METHOD: A retrospective study of all patients having a 99 Tc m -MDP bone scintigram for a painful knee arthroplasty between 1993 and 1999 was performed. Bone scintigrams were classified as normal or abnormal by a single observer. The results of these investigations were correlated with clinical outcome. RESULTS: Seventy-five patients with painful knee arthroplasties were referred for investigation. A total of 80 bone scintigrams were performed. The average patient age was 66.2 years (42 female and 33 male). The mean time period between surgery and onset of knee pain was 3 years. A final clinical diagnosis based on arthroscopy, open surgery, and extended clinical follow-up was available for all patients. Forty-three (53.8%) of the scintigrams were normal and 37 (46.3%) abnormal. Two patients with a normal bone scintigram has loose prostheses. Thirteen patients with an abnormal study had normal prostheses on follow-up and these tended to be patients scanned less than a year after surgery. The sensitivity, specificity, positive predictive value and negative predictive value of an unequivocally normal or abnormal bone scintigram was 92.3, 75.9, 64.9 and 95.0%, respectively. The pattern of isotope uptake in the abnormal studies was not specific enough to reliably differentiate aseptic from septic loosening. CONCLUSION: Radionuclide bone scintigraphy is useful in the assessment of the painful knee arthroplasty. A negative bone scintigram is reassuring and makes loosening or infection unlikely. Smith, S.L. et al. (2001)

  14. Clinical Outcomes in Men and Women following Total Knee Arthroplasty with a High-Flex Knee: No Clinical Effect of Gender

    OpenAIRE

    Nassif, Jeffrey M.; Pietrzak, William S.

    2015-01-01

    While it is generally recognized that anatomical differences exist between the male and female knee, the literature generally refutes the clinical need for gender-specific total knee prostheses. It has been found that standard, unisex knees perform as well, or better, in women than men. Recently, high-flex knees have become available that mechanically accommodate increased flexion yet no studies have directly compared the outcomes of these devices in men and women to see if gender-based dif...

  15. Imaging of knee arthroplasty

    International Nuclear Information System (INIS)

    Miller, Theodore T.

    2005-01-01

    Knee replacement surgery, either with unicompartmental or total systems, is common. The purpose of this manuscript is to review the appearance of normal knee arthroplasty and the appearances of complications such as infection, polyethylene wear, aseptic loosening and particle-induced osteolysis, patellofemoral abnormalities, axial instability, and periprosthetic and component fracture. Knowledge of the potential complications and their imaging appearances will help the radiologist in the diagnostic evaluation of the patient with a painful knee arthroplasty

  16. Imaging of knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Theodore T. [Department of Radiology, North Shore University Hospital, 825 Northern Blvd., Great Neck, NY 11021 (United States)]. E-mail: TMiller@NSHS.edu

    2005-05-01

    Knee replacement surgery, either with unicompartmental or total systems, is common. The purpose of this manuscript is to review the appearance of normal knee arthroplasty and the appearances of complications such as infection, polyethylene wear, aseptic loosening and particle-induced osteolysis, patellofemoral abnormalities, axial instability, and periprosthetic and component fracture. Knowledge of the potential complications and their imaging appearances will help the radiologist in the diagnostic evaluation of the patient with a painful knee arthroplasty.

  17. Two-stage revision of septic knee prosthesis with articulating knee spacers yields better infection eradication rate than one-stage or two-stage revision with static spacers.

    Science.gov (United States)

    Romanò, C L; Gala, L; Logoluso, N; Romanò, D; Drago, L

    2012-12-01

    The best method for treating chronic periprosthetic knee infection remains controversial. Randomized, comparative studies on treatment modalities are lacking. This systematic review of the literature compares the infection eradication rate after two-stage versus one-stage revision and static versus articulating spacers in two-stage procedures. We reviewed full-text papers and those with an abstract in English published from 1966 through 2011 that reported the success rate of infection eradication after one-stage or two-stage revision with two different types of spacers. In all, 6 original articles reporting the results after one-stage knee exchange arthoplasty (n = 204) and 38 papers reporting on two-stage revision (n = 1,421) were reviewed. The average success rate in the eradication of infection was 89.8% after a two-stage revision and 81.9% after a one-stage procedure at a mean follow-up of 44.7 and 40.7 months, respectively. The average infection eradication rate after a two-stage procedure was slightly, although significantly, higher when an articulating spacer rather than a static spacer was used (91.2 versus 87%). The methodological limitations of this study and the heterogeneous material in the studies reviewed notwithstanding, this systematic review shows that, on average, a two-stage procedure is associated with a higher rate of eradication of infection than one-stage revision for septic knee prosthesis and that articulating spacers are associated with a lower recurrence of infection than static spacers at a comparable mean duration of follow-up. IV.

  18. Knee Injuries

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Knee Injuries KidsHealth / For Teens / Knee Injuries What's in ... can do to protect them. What's in a Knee? The knee is a joint , actually the largest ...

  19. Knee Replacement

    Science.gov (United States)

    Knee replacement is surgery for people with severe knee damage. Knee replacement can relieve pain and allow you to ... Your doctor may recommend it if you have knee pain and medicine and other treatments are not ...

  20. The improvement of polyethylene prostheses through radiation crosslinking

    International Nuclear Information System (INIS)

    Du Plessis, T.A.; Grobbelaar, C.J.; Marais, F.

    1977-01-01

    During the past decade, remarkable progress has been made in the utilization of high-density polyethylene (HDPE) as a material for the manufacture of prostheses used in orthopaedic operations. This polymer contributes largely to the success of total hip replacement. In the case of total knee replacement it was considered imperative that a more hard-wearing polymer should be developed if at all possible, because not only are the cold-flow characteristics of ordinary high-density polyethylene at high pressures a limiting factor, but particle formation from friction can furthermore lead to physiological side-effects which adversely affect the efficacy of joints made from this material, especially so in the case of knee-joints. Bearing in mind the excellent improvements to be obtained through the radiation crosslinking of polyethylene film, the radiation crosslinking of high-density polyethylene prostheses seemed to be a logical avenue to investigate. Experimental details are presented. Gamma radiation was used. Impact strength and tensile strength measurements were made on specimens irradiated over a dose range of 0 to 80 Mrad. The results are discussed. (U.K.)

  1. COMPARISON OF CULTURE OF SYNOVIAL FLUID, PERIPROSTHETIC TISSUE AND PROSTHESIS SONICATE FOR THE DIAGNOSIS OF KNEE PROSTHESIS INFECTION

    Directory of Open Access Journals (Sweden)

    Andrej Trampuž

    2003-03-01

    Full Text Available Background. Synovial fluid and periprosthetic tissue specimens are the standard specimens cultured for the diagnosis of prosthetic joint infection (PJI. We hypothesize that ultrasonication of the explanted prosthesis may improve diagnosis of PJI by dislodging biofilm bacteria from the prosthesis surface and improve the sensitivity and specificity of diagnosis of PJI.Methods. Included were patients undergoing knee prosthesis exchange for septic or biomechanical failure and have not received antimicrobial therapy in the last 2 weeks prior specimen collection. Cultures of synovial fluid and periprosthetic tissue specimens were performed per the usual clinical practice. Additionally, explanted joint components were sonicated for 5 minutes at frequency 40 kHz in sterile Ringer’s solution; aliquots of 0.5 ml sonicate were plated onto five aerobic and five anaerobic blood agar plates, and incubated at 37 °C and examined for the next seven days. The number and identity of each colony morphology was recorded.Results. 35 patients undergoing knee replacement have been studied (24 for aseptic biomechanical failure and 11 for suspected PJI. In patients with PJI, coagulase-negative staphylococci (7 cases, Corynebacterium spp. (2 cases, Staphylococcus aureus (1 case, and viridans group streptococcus (1 case were recovered. Culture sensitivity and specificity were for synovial fluid 88% and 100%, for periprosthetic tissue 83% and 81%, and for explant sonicate 91% and 100%, respectively. In sonicate cultures higher numbers of microorganisms than in periprosthetic tissue cultures were consistently detected.Conclusions. Using synovial fluid, periprosthetic tissue, and explant sonicate cultures, 12%, 17% and 9% of PJI were missed, respectively. Explant sonicate cultures were the most sensitive with respect to the diagnosis of PJI, indicating that explant ultrasonication may improve bacterial recovery. In sonicate cultures, infecting organisms were detected in

  2. FDG-PET for diagnosing prosthetic joint infection: systematic review and metaanalysis

    Energy Technology Data Exchange (ETDEWEB)

    Kwee, Thomas C. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Kwee, Robert M. [University Medical Center Maastricht, Department of Radiology, Maastricht (Netherlands); Alavi, Abass [Hospital of the University of Pennsylvania, Division of Nuclear Medicine, Philadelphia, PA (United States)

    2008-11-15

    The aim of this study was to systematically review and metaanalyze published data on the diagnostic performance of {sup 18}F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) in detecting prosthetic hip or knee joint infection. A systematic search for relevant studies was performed of the PubMed/MEDLINE and Embase databases. Two reviewers independently assessed the methodological quality of each study. A metaanalysis of the reported sensitivity and specificity of each study was performed. Subgroup analyses were performed if results of individual studies were heterogeneous. The inclusion criteria were met by 11 studies; there was a total sample size of 635 prostheses. Overall, the studies had good methodological quality. Pooled sensitivity and specificity of FDG-PET for the detection of prosthetic hip or knee joint infection were 82.1% (95%CI = 68.0-90.8%) and 86.6% (95%CI = 79.7-91.4%), respectively. Heterogeneity among the results of individual studies was present (I {sup 2} = 68.8%). Diagnostic performance was influenced by type of joint prostheses (hip prostheses vs. knee prostheses) and type of reconstruction method used (filtered back vs. iterative) (p = 0.0164 and p = 0.0235, respectively). In this metaanalysis, overall diagnostic performance of FDG-PET was moderate to high. Caution is warranted, however, because results of individual studies were heterogeneous and could not be fully explored. Future studies should further explore potential causes of heterogeneity and validate the use of FDG-PET for diagnosing prosthetic joint infection. (orig.)

  3. Actinobaculum schaalii, a new cause of knee prosthetic joint infection in elderly.

    Science.gov (United States)

    Jacquier, H; Benmansour, H; Zadegan, F; Hannouche, D; Micaelo, M; Mongiat-Artus, P; Salomon, E; Cambau, E; Berçot, B

    2016-08-01

    Actinobaculum schaalii is an emerging pathogen particularly involved in urinary tract infection of elderly people and/or patient with urological risk factors of urinary tract infection. This microorganism is a difficult-to-diagnose pathogen and is rarely involved in systemic or deep infections. Here, we report the first case of prosthetic joint infection due to A. schaalii in an 84-year-old man with a benign prostatic hyperplasia associated with chronic retention of urine. This case underlines the importance to optimize the diagnosis of emerging uropathogens as A. schaalii, to prevent systemic infections, particularly in patients with orthopaedic implants.

  4. Total knee arthroplasty

    DEFF Research Database (Denmark)

    Schrøder, Henrik M.; Petersen, Michael M.

    2016-01-01

    Total knee arthroplasty (TKA) is a successful treatment of the osteoarthritic knee, which has increased dramatically over the last 30 years. The indication is a painful osteoarthritic knee with relevant radiographic findings and failure of conservative measures like painkillers and exercise...... surgeon seems to positively influence the rate of surgical complications and implant survival. The painful TKA knee should be thoroughly evaluated, but not revised except if a relevant indication can be established. The most frequent indications for revision are: aseptic loosening, instability, infection...

  5. Cementless Hydroxyapatite Coated Hip Prostheses

    Science.gov (United States)

    Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Ibarz, Elena; Gabarre, Sergio; Más, Yolanda

    2015-01-01

    More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality. PMID:25802848

  6. Cementless Hydroxyapatite Coated Hip Prostheses

    Directory of Open Access Journals (Sweden)

    Antonio Herrera

    2015-01-01

    Full Text Available More than twenty years ago, hydroxyapatite (HA, calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality.

  7. Antibiotic cements in articular prostheses: current orthopaedic concepts.

    Science.gov (United States)

    Langlais, F; Belot, N; Ropars, M; Thomazeau, H; Lambotte, J C; Cathelineau, G

    2006-08-01

    The possibilities and limits of antibiotic cements (ACs) have been assessed by many researchers. ACs are now approved by many drug agencies, including the US Food and Drug Administration (approval in 2003), with widespread use in prophylaxis and curative treatments. Laboratory experiments have achieved satisfactory antibiotic delivery without impairing the mechanical properties of ACs. Implantation in large animals (e.g. sheep) showed an antibiotic concentration in the bone cortex four times the minimal inhibitory concentration (MIC) 6 months after implantation. Human pharmacokinetics during total hip replacement (THR) show antibiotic concentrations 20 times the MIC in drainage fluids. No toxic concentrations have been detected in blood or urine, and no allergies, toxic effects, mechanical failures or selection of resistant microorganisms have been observed. Antibioprophylaxis has been assessed in prospective studies in over 1600 cases. In data from the Scandinavian arthroplasty registers, with an exhaustive follow-up of more than 240000 THRs, infection rate was reduced by ca. 50% (0.9% compared with 1.9%). In prostheses with severe infection, use of AC increases the infection control rate from 86% to 93% when using two-stage prosthetic exchanges. In moderate infection, a similar infection control rate (86%) was achieved either by two-stage exchange without local antibiotic or by one-stage exchange with AC; however, one-stage exchange achieved better functional results at lower cost and with reduced pain and hospital stay. Therefore, AC prophylaxis is widely used in countries with prostheses registers (Northern Europe), and use of ACs as treatment for infected prostheses is often considered as the gold standard in the EU and North America. However, AC is only an adjuvant treatment, and excision of infected and devascularized tissues as well as systemic antibiotic treatment managed by a multidisciplinary team remain the main factors of infection control.

  8. Two-stage exchange knee arthroplasty: does resistance of the infecting organism influence the outcome?

    Science.gov (United States)

    Kurd, Mark F; Ghanem, Elie; Steinbrecher, Jill; Parvizi, Javad

    2010-08-01

    Periprosthetic joint infection after TKA is a challenging complication. Two-stage exchange arthroplasty is the accepted standard of care, but reported failure rates are increasing. It has been suggested this is due to the increased prevalence of methicillin-resistant infections. We asked the following questions: (1) What is the reinfection rate after two-stage exchange arthroplasty? (2) Which risk factors predict failure? (3) Which variables are associated with acquiring a resistant organism periprosthetic joint infection? This was a case-control study of 102 patients with infected TKA who underwent a two-stage exchange arthroplasty. Ninety-six patients were followed for a minimum of 2 years (mean, 34.5 months; range, 24-90.1 months). Cases were defined as failures of two-stage exchange arthroplasty. Two-stage exchange arthroplasty was successful in controlling the infection in 70 patients (73%). Patients who failed two-stage exchange arthroplasty were 3.37 times more likely to have been originally infected with a methicillin-resistant organism. Older age, higher body mass index, and history of thyroid disease were predisposing factors to infection with a methicillin-resistant organism. Innovative interventions are needed to improve the effectiveness of two-stage exchange arthroplasty for TKA infection with a methicillin-resistant organism as current treatment protocols may not be adequate for control of these virulent pathogens. Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

  9. Neisseria meningitidis Infecting a Prosthetic Knee Joint: A New Case of an Unusual Disease

    Directory of Open Access Journals (Sweden)

    Berta Becerril Carral

    2017-01-01

    Full Text Available Primary meningococcal meningitis is an infrequent but known disease. However, the infection of a prosthetic joint with Neisseria meningitidis is rare. We hereby describe the second case of an arthroplasty infected with Neisseria meningitidis that responded favourably to prosthesis retention with surgical debridement, in combination with antibiotics treatment.

  10. Perioperative Allogeneic Red Blood-Cell Transfusion Associated with Surgical Site Infection After Total Hip and Knee Arthroplasty.

    Science.gov (United States)

    Everhart, Joshua S; Sojka, John H; Mayerson, Joel L; Glassman, Andrew H; Scharschmidt, Thomas J

    2018-02-21

    Perioperative allogeneic red blood-cell transfusion is a suspected risk factor for surgical site infection (SSI) after total joint arthroplasty (TJA), but the interrelationships among SSI risk, transfusion dose, preoperative anemia, and the presence of coagulopathies have not been well described. Data on SSI within 1 year after surgery as well as on transfusion with blood products within 30 days after surgery were obtained for 6,788 patients who had undergone primary or revision total hip or knee arthroplasty from 2000 to 2011 in a single hospital system. Multivariate logistic regression modeling was used to determine the independent association between allogeneic red blood-cell transfusion and SSI. There was a dose-dependent association between allogeneic red blood-cell transfusion and SSI, with the infection rate increasing as the transfusion dose increased from 1 unit (odds ratio [OR] = 1.97; 95% confidence interval [CI] = 1.38, 2.79; p 3 units (OR = 7.40; CI = 4.91, 11.03; p conservation strategies. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

  11. A method for performance comparison of polycentric knees and its application to the design of a knee for developing countries.

    Science.gov (United States)

    Anand, T S; Sujatha, S

    2017-08-01

    Polycentric knees for transfemoral prostheses have a variety of geometries, but a survey of literature shows that there are few ways of comparing their performance. Our objective was to present a method for performance comparison of polycentric knee geometries and design a new geometry. In this work, we define parameters to compare various commercially available prosthetic knees in terms of their stability, toe clearance, maximum flexion, and so on and optimize the parameters to obtain a new knee design. We use the defined parameters and optimization to design a new knee geometry that provides the greater stability and toe clearance necessary to navigate uneven terrain which is typically encountered in developing countries. Several commercial knees were compared based on the defined parameters to determine their suitability for uneven terrain. A new knee was designed based on optimization of these parameters. Preliminary user testing indicates that the new knee is very stable and easy to use. The methodology can be used for better knee selection and design of more customized knee geometries. Clinical relevance The method provides a tool to aid in the selection and design of polycentric knees for transfemoral prostheses.

  12. [Posturographic study of total prostheses in the leg. Apropos of 88 patients examined].

    Science.gov (United States)

    Lord, G; Gentaz, R; Gagey, P M; Baron, J B

    1976-01-01

    By suppressing certain articular sensory receptors, the reconstructive surgery of joints using total prostheses modifies tonic postural activity and, by this means, alters the regulation of balance in the subjects of operation. This doubtless explains certain discrepancies between the apparently excellent results in respect of joint movement and muscle strength and poor utilisation of the joint in every day life (instability, use of sticks or failure to use the joint in walking). Drawing on the experience and basic work of specialists in posture, the authors have undertaken a study of tonic postural activity in patients who had received a total prosthesis in the lower limb, both from the clinical aspect and by graphic measurement using an electronic apparatus, the statokinesiometer. Fourteen normal subjects were tested to calibrate the apparatus and 8 patients suffering from established osteoarthritis of the hip were studied as controls. Analysis of tonic postural activity was made in 66 patients who had received total prostheses in the lower limb. The results showed significant disturbance in balance in ankle prostheses, minimal disturbance in knee prostheses and not significant disturbance in hip prostheses. Certain therapeutic implications are derived from this study.

  13. Rapid Molecular Microbiologic Diagnosis of Prosthetic Joint Infection

    Science.gov (United States)

    Cazanave, Charles; Greenwood-Quaintance, Kerryl E.; Hanssen, Arlen D.; Karau, Melissa J.; Schmidt, Suzannah M.; Gomez Urena, Eric O.; Mandrekar, Jayawant N.; Osmon, Douglas R.; Lough, Lindsay E.; Pritt, Bobbi S.; Steckelberg, James M.

    2013-01-01

    We previously showed that culture of samples obtained by prosthesis vortexing and sonication was more sensitive than tissue culture for prosthetic joint infection (PJI) diagnosis. Despite improved sensitivity, culture-negative cases remained; furthermore, culture has a long turnaround time. We designed a genus-/group-specific rapid PCR assay panel targeting PJI bacteria and applied it to samples obtained by vortexing and sonicating explanted hip and knee prostheses, and we compared the results to those with sonicate fluid and periprosthetic tissue culture obtained at revision or resection arthroplasty. We studied 434 subjects with knee (n = 272) or hip (n = 162) prostheses; using a standardized definition, 144 had PJI. Sensitivities of tissue culture, of sonicate fluid culture, and of PCR were 70.1, 72.9, and 77.1%, respectively. Specificities were 97.9, 98.3, and 97.9%, respectively. Sonicate fluid PCR was more sensitive than tissue culture (P = 0.04). PCR of prosthesis sonication samples is more sensitive than tissue culture for the microbiologic diagnosis of prosthetic hip and knee infection and provides same-day PJI diagnosis with definition of microbiology. The high assay specificity suggests that typical PJI bacteria may not cause aseptic implant failure. PMID:23658273

  14. Synovial fluid white cell count and histopathological examination of periprosthetic tissue samples (frozen and permanent sections in the diagnosis of prosthetic knee infection

    Directory of Open Access Journals (Sweden)

    Obada B.

    2017-02-01

    Full Text Available The aim of the study was to determine prospectively the importance of synovial fluid white cell count and intraoperative frozen and permanent sections analysis (number of polymorphonuclear leukocytes per high-power field in the diagnosis of septic total knee arthroplasty. There were studied prospectively 72 patients who needed a revision total knee arthroplasty between 2013-2015. 30 patients were diagnosed with prosthetic joint infection due to high rates of ESR (93% and CRP (90% and preoperative positive culture from aspirated synovial fluid and 42 patients were considered to have aseptic failure according to negative preoperative culture from joint aspirate. For all the patients was analysed synovial fluid white cell count and histopathological aspect of intraoperative frozen and permanent sections of periprosthetic tissue. The results showed a median value of 13800 of sinovial white cells count for infected knee and 92 for noninfected knee. 90% of the patients with joint infection had more than 5 polymorphonuclear leukocytes per high power field on intraoperative frozen sections and 83% on permanent sections. None of the patients from aseptic group had more than 5 polymorphonuclear leukocytes per field on permanent sections. The erythrocyte sedimentation rate and C-reactive protein level can be supplemented with cultures of aspirated joint fluid and fluid white cell count to confirm the diagnosis of periprosthetic infection. When the preoperative diagnosis remain unclear, the histological examination of frozen or permanent sections of periprosthetic tissue with at least 5 polymorphonuclear leukocytes per high power field, is predictive for the presence of infection.

  15. One-stage versus two-stage exchange arthroplasty for infected total knee arthroplasty: a systematic review.

    Science.gov (United States)

    Nagra, Navraj S; Hamilton, Thomas W; Ganatra, Sameer; Murray, David W; Pandit, Hemant

    2016-10-01

    Infection complicating total knee arthroplasty (TKA) has serious implications. Traditionally the debate on whether one- or two-stage exchange arthroplasty is the optimum management of infected TKA has favoured two-stage procedures; however, a paradigm shift in opinion is emerging. This study aimed to establish whether current evidence supports one-stage revision for managing infected TKA based on reinfection rates and functional outcomes post-surgery. MEDLINE/PubMed and CENTRAL databases were reviewed for studies that compared one- and two-stage exchange arthroplasty TKA in more than ten patients with a minimum 2-year follow-up. From an initial sample of 796, five cohort studies with a total of 231 patients (46 single-stage/185 two-stage; median patient age 66 years, range 61-71 years) met inclusion criteria. Overall, there were no significant differences in risk of reinfection following one- or two-stage exchange arthroplasty (OR -0.06, 95 % confidence interval -0.13, 0.01). Subgroup analysis revealed that in studies published since 2000, one-stage procedures have a significantly lower reinfection rate. One study investigated functional outcomes and reported that one-stage surgery was associated with superior functional outcomes. Scarcity of data, inconsistent study designs, surgical technique and antibiotic regime disparities limit recommendations that can be made. Recent studies suggest one-stage exchange arthroplasty may provide superior outcomes, including lower reinfection rates and superior function, in select patients. Clinically, for some patients, one-stage exchange arthroplasty may represent optimum treatment; however, patient selection criteria and key components of surgical and post-operative anti-microbial management remain to be defined. III.

  16. Development of friction and wear full-scale testing for TKR prostheses with reliable low cost apparatus

    Science.gov (United States)

    Suwandi, Agri; Soemardi, Tresna P.; Kiswanto, Gandjar; Kusumaningsih, Widjajalaksmi; I. Gusti Agung I. G., W.

    2018-02-01

    Prostheses products must undergo simulation and physical testing, before clinical testing. Finite element method is a preliminary simulation for in vivo test. The method visualizes the magnitude of the compressive force and the critical location of the Total Knee Replacement (TKR) prostheses design. In vitro testing is classified as physical testing for prostheses product. The test is conducted to evaluate the potential failure of the product and the characteristics of the prostheses TKR material. Friction and wear testing are part of the in vivo test. Motion of knee joints, which results in the phenomena of extension and deflection in the femoral and tibia insert, is represented by friction and wear testing. Friction and wear tests aim to obtain an approximate lifetime in normal and extreme load patterns as characterized by the shape of the friction surface area. The lifetime estimation requires friction and wear full-scale testing equipments for TKR prostheses products. These are necessary in obtaining initial data on potential product failures and characterizing of the material based on the ASTM F2724-08 standards. Based on the testing result and statistical analysis data, the average wear rate value per year is 2.19 × 10-3 mg/MC, with a 10 % safety limit of volume and 14,400 cycles times, for 15 hours moving nonstop then the prediction of wear life of the component tibia insert is ± 10 years.

  17. Knee arthroscopy

    Science.gov (United States)

    ... debridement; Meniscus repair; Lateral release; Knee surgery; Meniscus - arthroscopy; Collateral ligament - arthroscopy ... pain relief (anesthesia) may be used for knee arthroscopy surgery: Local anesthesia. Your knee may be numbed ...

  18. Magnetic resonance imaging of breast prostheses

    African Journals Online (AJOL)

    G5

    and the commonest cause of replacement of the prosthesis. Older prostheses contained silicone gel. Rupture of these prostheses, although asymptomatic in most patients, has been associated with collagen vascular disorders and chronic fatigue syndrome. However more current data disputes any of these associations.

  19. Reporting surgical site infections following total hip and knee arthroplasty: impact of limiting surveillance to the operative hospital.

    Science.gov (United States)

    Yokoe, Deborah S; Avery, Taliser R; Platt, Richard; Huang, Susan S

    2013-11-01

    Public reporting of surgical site infections (SSIs) by hospitals is largely limited to infections detected during surgical hospitalizations or readmissions to the same facility. SSI rates may be underestimated if patients with SSIs are readmitted to other hospitals. We assessed the impact of readmissions to other facilities on hospitals' SSI rates following primary total hip arthroplasty (THA) or total knee arthroplasty (TKA). This was a retrospective cohort study of all patients who underwent primary THA or TKA at California hospitals between 1 January 2006 and 31 December 2009. SSIs were identified using ICD-9-CM diagnosis codes predictive of SSI assigned at any California hospital within 365 days of surgery using a statewide repository of hospital data that allowed tracking of patients between facilities. We used statewide data to estimate the fraction of each hospital's THA and TKA SSIs identified at the operative hospital versus other hospitals. A total of 91 121 THA and 121 640 TKA procedures were identified. Based on diagnosis codes, SSIs developed following 2214 (2.3%) THAs and 2465 (2.0%) TKAs. Seventeen percent of SSIs would have been missed by operative hospital surveillance alone. The proportion of hospitals' SSIs detected at nonoperative hospitals ranged from 0% to 100%. Including SSIs detected at nonoperative hospitals resulted in better relative ranking for 61% of THA hospitals and 61% of TKA hospitals. Limiting SSI surveillance to the operative hospital caused varying degrees of SSI underestimation and substantially impacted hospitals' relative rankings, suggesting that alternative methods for comprehensive postdischarge surveillance are needed for accurate benchmarking.

  20. Comparison of patellofemoral outcomes after TKA using two prostheses with different patellofemoral design features.

    Science.gov (United States)

    Bae, Dae Kyung; Baek, Jong Hun; Yoon, Kyung Tack; Son, Hyuck Sung; Song, Sang Jun

    2017-12-01

    The purpose of the present study was to compare the clinical and radiographic results after TKA using two prostheses with different sagittal patellofemoral design features, including outcomes related to compatibility of the patellofemoral joint. The clinical and radiographic results of 81 patients (100 knees) who underwent TKA using the specific prosthesis (group A) were compared with those in a control group who underwent TKA using the other prosthesis (group B). The presence of anterior knee joint pain, patellar crepitation, and patellar clunk syndrome was also checked. The function score and maximum flexion angle at the last follow-up were slightly better in group A than those in group B (92.0 ± 2.3 vs. 90.6 ± 4.2) (133.6° ± 8.4° vs. 129.6° ± 11.4°). Anterior knee pain was observed in 6 knees and patellar crepitation in four knees in group A. In group B, these symptoms were observed in 22 knees and 18 knees, respectively. There was no patellar clunk syndrome in either group. The alignment was corrected with satisfactory positioning of components. The patellar height remained unchanged after TKA in the two groups. The differences between preoperative and postoperative patellar tilt angle and patellar translation were small. When comparing the clinical and radiographic results after TKA using two prostheses with different sagittal patellofemoral design features, TKA using the specific prosthesis provided satisfactory results with less clinical symptoms related to the patellofemoral kinematics with TKA using the other prosthesis. III.

  1. The unsuspected prosthetic joint infection : incidence and consequences of positive intra-operative cultures in presumed aseptic knee and hip revisions.

    Science.gov (United States)

    Jacobs, A M E; Bénard, M; Meis, J F; van Hellemondt, G; Goosen, J H M

    2017-11-01

    Positive cultures are not uncommon in cases of revision total knee and hip arthroplasty (TKA and THA) for presumed aseptic causes. The purpose of this study was to assess the incidence of positive intra-operative cultures in presumed aseptic revision of TKA and THA, and to determine whether the presence of intra-operative positive cultures results in inferior survival in such cases. A retrospective cohort study was assembled with 679 patients undergoing revision knee (340 cases) or hip arthroplasty (339 cases) for presumed aseptic causes. For all patients three or more separate intra-operative cultures were obtained. Patients were diagnosed with a previously unsuspected prosthetic joint infection (PJI) if two or more cultures were positive with the same organism. Records were reviewed for demographic details, pre-operative laboratory results and culture results. The primary outcome measure was infection-free implant survival at two years. The incidence of unsuspected PJI was 27 out of 340 (7.9%) in TKA and 41 out of 339 (12.1%) in THA. Following revision TKA, the rate of infection-free implant survival in patients with an unsuspected PJI was 88% (95% confidence intervals (CI) 60 to 97) at two years compared with 98% (95% CI 94 to 99) in patients without PJI (p = 0.001). After THA, the rate of survival was similar in those with unsuspected PJI (92% (95% CI 73 to 98) at two years) and those without (94% (95% CI 89 to 97), p = 0.31). Following revision of TKA and THA for aseptic diagnoses, around 10% of cases were found to have positive cultures. In the knee, such cases had inferior infection-free survival at two years compared with those with negative cultures; there was no difference between the groups following THA. Cite this article: Bone Joint J 2017;99-B:1482-9. ©2017 The British Editorial Society of Bone & Joint Surgery.

  2. Arthroscopic surgery for degenerative knee

    DEFF Research Database (Denmark)

    Thorlund, J B; Juhl, C B; Roos, E M

    2015-01-01

    OBJECTIVE: To determine benefits and harms of arthroscopic knee surgery involving partial meniscectomy, debridement, or both for middle aged or older patients with knee pain and degenerative knee disease. DESIGN: Systematic review and meta-analysis. MAIN OUTCOME MEASURES: Pain and physical function....... RESULTS: The search identified nine trials assessing the benefits of knee arthroscopic surgery in middle aged and older patients with knee pain and degenerative knee disease. The main analysis, combining the primary endpoints of the individual trials from three to 24 months postoperatively, showed a small...... included symptomatic deep venous thrombosis (4.13 (95% confidence interval 1.78 to 9.60) events per 1000 procedures), pulmonary embolism, infection, and death. CONCLUSIONS: The small inconsequential benefit seen from interventions that include arthroscopy for the degenerative knee is limited in time...

  3. Testicular prostheses in children: Is earlier better?

    Science.gov (United States)

    Peycelon, M; Rossignol, G; Muller, C O; Carricaburu, E; Philippe-Chomette, P; Paye-Jaouen, A; El Ghoneimi, A

    2016-08-01

    The absence of a testis occurs for various reasons in children, but testicular prosthesis implantation in children is uncommon. The optimal time for prosthesis placement is still unclear, and its complication rate has been poorly studied in children. The aim of this study was to determine the risk factors of complications in cases of testicular prosthesis implantation in children. A monocentric, retrospective review was performed of children implanted with a testicular prosthesis between 2008 and 2014. All implantations were performed through an inguinal incision with a standardized procedure. Children were divided into two groups depending on the interval after orchiectomy: (A) early implantation (delay between surgeries prosthesis implantation at the mean age of 14.7 years (range 9-18) (A, 14.3; B, 14.6) with a mean delay of 36.1 months (A, 1.3; B, 80.3). Indications were mainly spermatic cord torsion (27%), bilateral anorchia (27%), and testicular atrophy after cryptorchidism surgery (19.2%). Complications (10.5%) included two cases of extrusion, one infection and one migration. Patient 1 had a history of acute lymphoblastic leukemia with testicle relapse 2 years after induction therapy. High-dose chemotherapy, total body irradiation and bilateral orchiectomies were performed, and bilateral prostheses were implanted 12 years after the end of chemotherapy. Complications happened 85 days after surgery. Patient 2 was followed-up for a proximal hypospadias. The tunica vaginalis flap, which was used during a redo urethroplasty, lead to testicular atrophy. Thirteen years after the last penile surgery, a testicular prosthesis was placed through an inguinal incision, and extrusion occurred 203 days after surgery. Bacterial cultures of the prostheses were sterile and histological review showed no sign of granuloma or graft rejection. The complication rate was significantly higher if the delay between the two surgeries exceeded 1 year (P = 0.01). Indications of

  4. Sensitivity and specificity of simultaneously acquired (dual channel) radiogallium and Tc-99m-HDP in painful hip and knee prosthetic joints

    International Nuclear Information System (INIS)

    Skarzynski, J.J.; Sziklas, J.J.; Rosenberg, R.J.; Rich, D.A.; Spencer, R.P.

    1985-01-01

    Differentiation of prosthetic loosening from infection, by use of sequential bone and radiogallium imaging, has been discussed in the literature. The authors investigated simultaneous (2 channel) imaging of Ga-67 and Tc-99m-HDP in multiviews, in order to assess the parameter of Tc-99m-Ga-67 incongruity. Acquisition of data was carried out 2 days after 5 mCi of Ga-67 citrate IV and 2 hours after 8 mCi of Tc-99m-HDP. Dual data channels were used to insure perfect superimposition of the images and to reduce total imaging time. Normalized bone images were taken, then subtracted from those of Ga-67, by means of progressive weighting factors. A total of 68 studies were carried out on 43 patients. Exams involved both knee and hip prostheses, in population with 63% of the patients over age 60 years. Time from placement of the prosthesis to the dual radionuclide exam was within 2 years in 48% and within 5 years in 78%. Sensitivity was 0.88 and specificity 0.89. Using information on the follow-up dual channel studies, 40/43 cases were correctly identified (93%). Dual channel radionuclide imaging offers a readily available and accurate means of differentiating infection from loosening of hip or knee prostheses

  5. A silver ion-doped calcium phosphate-based ceramic nanopowder-coated prosthesis increased infection resistance.

    Science.gov (United States)

    Kose, Nusret; Otuzbir, Ali; Pekşen, Ceren; Kiremitçi, Abdurrahman; Doğan, Aydin

    2013-08-01

    Despite progress in surgical techniques, 1% to 2% of joint arthroplasties become complicated by infection. Coating implant surfaces with antimicrobial agents have been attempted to prevent initial bacterial adhesion to implants with varying success rates. We developed a silver ion-containing calcium phosphate-based ceramic nanopowder coating to provide antibacterial activity for orthopaedic implants. We asked whether titanium prostheses coated with this nanopowder would show resistance to bacterial colonization as compared with uncoated prostheses. We inserted titanium implants (uncoated [n = 9], hydroxyapatite-coated [n = 9], silver-coated [n = 9]) simulating knee prostheses into 27 rabbits' knees. Before implantation, 5 × 10(2) colony-forming units of Staphylococcus aureus were inoculated into the femoral canal. Radiology, microbiology, and histology findings were quantified at Week 6 to define the infection, microbiologically by increased rate of implant colonization/positive cultures, histologically by leukocyte infiltration, necrosis, foreign-body granuloma, and devitalized bone, and radiographically by periosteal reaction, osteolysis, or sequestrum formation. Swab samples taken from medullary canals and implants revealed a lower proportion of positive culture in silver-coated implants (one of nine) than in uncoated (eight of nine) or hydroxyapatite-coated (five of nine) implants. Silver-coated implants also had a lower rate of colonization. No cellular inflammation or foreign-body granuloma was observed around the silver-coated prostheses. Silver ion-doped ceramic nanopowder coating of titanium implants led to an increase in resistance to bacterial colonization compared to uncoated implants. Silver-coated orthopaedic implants may be useful for resistance to local infection but will require in vivo confirmation.

  6. Runner's Knee

    Science.gov (United States)

    ... require a lot of knee bending, such as biking, jumping, or skiing. Runner's knee happens when the ... is out of alignment, activities like running or biking can wear down the cartilage of the kneecap ( ...

  7. Evaluation of white cell count and differential in synovial fluid for diagnosing infections after total hip or knee arthroplasty.

    Directory of Open Access Journals (Sweden)

    Xinhua Qu

    Full Text Available BACKGROUND: The accuracy of synovial fluid (SF white cell count (WCC and polymorphonuclear (PMN cell evaluation for predicting prosthetic joint infection (PJI at the total hip arthroplasty (THA or total knee arthroplasty (TKA site is unknown. Therefore, we performed a meta-analysis to summarize the diagnostic validity of SF-WCC and SF-PMN for diagnosing PJI. METHODS: The MEDLINE, EMBASE, and OVID databases were searched for studies that had evaluated the diagnostic validity of SF-WCC and SF-PMN between January 1990 and May 2013. Meta-analysis methods were used to pool sensitivity, specificity, diagnostic odd ratios (DORs, the area under the receiver-operating characteristic curve (AUC, positive likelihood ratios (PLR, negative likelihood ratios (NLR, and post-test probability. We also conducted heterogeneity, publication bias, subgroup, and meta-regression analyses. RESULTS: Fifteen articles (15 SF-WCC and 14 SF-PMN that included a total of 2787 patients fulfilled the inclusion criteria and were considered for analysis. The pooled sensitivity and specificity for PJI detection was 0.88 (95% confidence intervals [CI], 0.81-0.93 and 0.93 (95% CI, 0.88-0.96 for SF-WCC and 0.90 (95% CI, 0.84-0.93 and 0.88 (95% CI, 0.83-0.92 for SF-PMN, respectively. The AUC was 0.96 for SF-WCC and 0.95 for SF-PMN. PLR and NLR were 13.3 and 0.13 for SF-WCC, and 7.6 and 0.12 for SF-PMN, respectively. There was no evidence of publication bias. Low-clinical-scenario (pre-test probability, 20% post-test probabilities were 3% for both negative SF-WCC and SF-PMN results. The subgroup analyses indicated that the sensitivity/specificity of THA were 0.73/0.96 for SF-WCC and 0.85/0.83 for SF-PMN, whereas those of TKA were 0.90/0.91 for SF-WCC and 0.90/0.88 for SF-PMN. We also found that collection of SF-WCC preoperatively had a higher sensitivity than that obtained intraoperatively (0.91 vs. 0.77. CONCLUSIONS: SF-WCC and SF-PMN have an adequate and clinically acceptable

  8. The efficacy of {sup 99m}Tc-ciprofloxacin (infecton) imaging in suspected prosthetic infection following total knee replacement arthroplasty (pilot study)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Ho; Choi, Tae Hyun; Kim, Nam Bum [Gachon Medical School, Incheon (Korea, Republic of)

    2002-07-01

    The aims of this study were 1) to increase the labelling efficiency of {sup 99m}Tc-ciprofloxacin (infecton) and 2) to determine the value of infecton imaging in demonstrating infection following total knee replacement arthroplasty (TKRA). Five patients (4 female, 1 male: mean age 52.8{+-}13.5 years, both TKRA in 3 pt) with suspected prosthetic infective conditions were included. In order to increase labelling efficiency, infection was labelled with stannous tartrate instead of previousely used formamidine sulfinic acid (FSA). Immediate perfusion, 5min blood pool, 1hr, 4hr and 24hr delayed images were perfomed. All images were blindly interpreted by two independent observers with visual findings being classified according to a four-grade scale(0.1.2.3). Images graded 0 and 1, and also those regions which showed faintly increase or unchanged uptake grade on late images as compared with early images, were classified as negative; grades 2 and 3 were classified as positive. The diagnosis was confirmed by intraoperative microbiological / histological findings or by the presence of gross purulence. Labelling efficiency increased up to over 98% with formation of radiocolloid less than 1%. All of four pt with prosthetic infection showed positive infecton images but one pt with sterile loosening of prosthesis showed negative infection images. The easy availability as well as new labelling technique make infecton imaging the better option for the detection of prosthetic orthopedic infection.

  9. The efficacy of 99mTc-ciprofloxacin (infecton) imaging in suspected prosthetic infection following total knee replacement arthroplasty (pilot study)

    International Nuclear Information System (INIS)

    Kim, Jong Ho; Choi, Tae Hyun; Kim, Nam Bum

    2002-01-01

    The aims of this study were 1) to increase the labelling efficiency of 99m Tc-ciprofloxacin (infecton) and 2) to determine the value of infecton imaging in demonstrating infection following total knee replacement arthroplasty (TKRA). Five patients (4 female, 1 male: mean age 52.8±13.5 years, both TKRA in 3 pt) with suspected prosthetic infective conditions were included. In order to increase labelling efficiency, infection was labelled with stannous tartrate instead of previousely used formamidine sulfinic acid (FSA). Immediate perfusion, 5min blood pool, 1hr, 4hr and 24hr delayed images were perfomed. All images were blindly interpreted by two independent observers with visual findings being classified according to a four-grade scale(0.1.2.3). Images graded 0 and 1, and also those regions which showed faintly increase or unchanged uptake grade on late images as compared with early images, were classified as negative; grades 2 and 3 were classified as positive. The diagnosis was confirmed by intraoperative microbiological / histological findings or by the presence of gross purulence. Labelling efficiency increased up to over 98% with formation of radiocolloid less than 1%. All of four pt with prosthetic infection showed positive infecton images but one pt with sterile loosening of prosthesis showed negative infection images. The easy availability as well as new labelling technique make infecton imaging the better option for the detection of prosthetic orthopedic infection

  10. Anterior knee pain

    Science.gov (United States)

    Patellofemoral syndrome; Chondromalacia patella; Runner's knee; Patellar tendinitis; Jumper's knee ... kneecap (patella) sits over the front of your knee joint. As you bend or straighten your knee, ...

  11. Analysis of the unicompartmental knee arthroplasty results

    Directory of Open Access Journals (Sweden)

    S. A. Firsov

    2015-01-01

    Full Text Available In 2012-2014 total 67 unicompartmental arthroplasty surgeries with use of Oxford knee meniscal bearing were performed. The surgeries were performed by a single surgeon. Minimally invasive approach was used. All patients were evaluated clinically, radiographically and with Oxford Knee score scale, Knee Society score scale and functional scale. Obtained data was processed with nonparametric Mann-Whitney-Wilcoxon test. Results were processed using the statistical analysis application package SPSS, version 10.07. Analysis of of mid-term results showed that the average for Oxford Knee score increased from 16.4 (95% CI 9-23 to 41.3 (95% CI 29-47. Average for Knee Society score scale increased from 42.7 (95% CI 31-55 to 88.6 (95% CI 73-100. No occurrence of early postoperative complications have been reported. Statistically significant improvements of knee function in patients after unicompartmental arthroplasty have been observed. Unicompartmental arthroplasty currently can be considered as an advanced treatment option for medial knee joint pathology. Meniscal bearing cemented prostheses such as Oxford III are preferable.

  12. [Knee disarticulation and through-knee amputation].

    Science.gov (United States)

    Baumgartner, R

    2011-10-01

    A knee disarticulation or a through-knee stump is superior compared to a transfemoral stump. The thigh muscles are all preserved, and the muscle balance remains undisturbed. The range of motion of the hip joint is not limited. The bulbous shape of the stump allows full weight bearing at the stump end and can easily be fitted with a prosthesis. An amputee with a bilateral knee disarticulation is able to walk "barefoot". A more distal amputation level, e.g., an ultra-short transtibial amputation, is not possible. Important alternative to transfemoral amputations. Possible for any etiology except for Buerger-Winiwarter's disease. New indications are infected and loosened total knee replacements. Preservation of the knee joint is possible. Knee disarticulation is a very atraumatic procedure, compared to transfemoral amputations. Neither bones nor muscles have to be severed, just skin, ligaments, vessels, and nerves. Even the meniscal cartilages may be left in place to act as axial shock absorbers. The cartilage of the femur is not resected, but only bevelled in case of osteoarthritis. There are no tendon attachments or myoplastic procedures necessary. The patella remains in place and is held in position only by the retinacula. Skin closure must be performed without the slightest tension, and if possible not in the weight-bearing area. Transcondylar amputations across the femoral condyles only are indicated when there are not sufficient soft tissues for wound closure of a knee disarticulation. Alternatives as the techniques of Gritti, Klaes, and Eigler, the shortening of the femur and the Sauerbruch's rotation plasty [14] are presented and discussed. The risk of decubital ulcers is rather high. Correct bandaging of the stump is, therefore, particularly important. Prosthetic fitting is possible 3-6 weeks after surgery. The type of prosthesis depends on the amputee's activity level. The superior performance of amputees with knee disarticulations in sports prove the

  13. Survival, complications and functional outcomes of cemented megaprostheses for high-grade osteosarcoma around the knee.

    Science.gov (United States)

    Zhang, Chunlin; Hu, Jianping; Zhu, Kunpeng; Cai, Tao; Ma, Xiaolong

    2018-04-01

    study, a total of 51 complications occurred in 45 patients, and at the end of follow-up, 59 patients had prostheses in situ. The estimated overall five-year and eight-year implant survival rates were 77.7% (95% CI: 67.9-87.5%) and 54.5% (95% CI: 31.4-77.6%), respectively, when patients who died with their original prostheses were censored. In total, 21 (21/108, 19.4%) implants failed, five due to infections (5/21), eight due to aseptic loosening (8/21), four due to local recurrence (4/21), three due to structural failure (3/21) and one due to soft tissue failure (1/21). The average Musculoskeletal Tumor Society Score (MSTS) at the most recent follow-up was 22.9 (9-30) points on a 30-point scale, which indicated an excellent or good functional outcome. Analysis of the results based on implant site revealed a slight difference of the estimated five-year prosthesis survival between implants located in the distal femur and those located in the proximal tibia [86.1% (95% CI: 75.5-97%) versus 66.9% (95% CI: 49.8-83.9%); P = 0.09]. However, the functional outcomes and complication rates of prostheses located in the distal femur were both better than those located in the proximal tibia. With effective management strategies for complications, cemented endoprosthetic reconstruction of the proximal tibia and distal femur using an extensor mechanism reconstruction technique provides a reliable method of reconstruction following tumour resection around the knee. Level of Evidence Level IV, therapeutic study.

  14. Evaluation of osseous integration of PVD-silver-coated hip prostheses in a canine model.

    Science.gov (United States)

    Hauschild, Gregor; Hardes, Jendrik; Gosheger, Georg; Stoeppeler, Sandra; Ahrens, Helmut; Blaske, Franziska; Wehe, Christoph; Karst, Uwe; Höll, Steffen

    2015-01-01

    Infection associated with biomaterials used for orthopedic prostheses remains a serious complication in orthopedics, especially tumor surgery. Silver-coating of orthopedic (mega)prostheses proved its efficiency in reducing infections but has been limited to surface areas exposed to soft tissues due to concerns of silver inhibiting osseous integration of cementless stems. To close this gap in the bactericidal capacity of silver-coated orthopedic prostheses extension of the silver-coating on surface areas intended for osseous integration seems to be inevitable. Our study reports about a PVD- (physical-vapor-deposition-) silver-coated cementless stem in a canine model for the first time and showed osseous integration of a silver-coated titanium surface in vivo. Radiological, histological, and biomechanical analysis revealed a stable osseous integration of four of nine stems implanted. Silver trace elemental concentrations in serum did not exceed 1.82 parts per billion (ppb) and can be considered as nontoxic. Changes in liver and kidney functions associated with the silver-coating could be excluded by blood chemistry analysis. This was in accordance with very limited metal displacement from coated surfaces observed by laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) 12 months after implantation. In conclusion our results represent a step towards complete bactericidal silver-coating of orthopedic prostheses.

  15. Design and Control of a New Biomimetic Transfemoral Knee Prosthesis Using an Echo-Control Scheme

    Directory of Open Access Journals (Sweden)

    Mario G. Bernal-Torres

    2018-01-01

    Full Text Available Passive knee prostheses require a significant amount of additional metabolic energy to carry out a gait cycle, therefore affecting the natural human walk performance. Current active knee prostheses are still limited because they do not reply with accuracy of the natural human knee movement, and the time response is relatively large. This paper presents the design and control of a new biomimetic-controlled transfemoral knee prosthesis based on a polycentric-type mechanism. The aim was to develop a knee prosthesis able to provide additional power and to mimic with accuracy of the natural human knee movement using a stable control strategy. The design of the knee mechanism was obtained from the body-guidance kinematics synthesis based on real human walking patterns obtained from computer vision and 3D reconstruction. A biomechanical evaluation of the synthesized prosthesis was then carried out. For the activation and control of the prosthesis, an echo-control strategy was proposed and developed. In this echo-control strategy, the sound side leg is sensed and synchronized with the activation of the knee prosthesis. An experimental prototype was built and evaluated in a test rig. The results revealed that the prosthetic knee is able to mimic the biomechanics of the human knee.

  16. Partial knee replacement

    Science.gov (United States)

    ... good range of motion in your knee. The ligaments in your knee are stable. However, most people with knee arthritis have a surgery called a total knee arthroplasty (TKA). Knee replacement is most often done in people age 60 ...

  17. Jumper's Knee (Patellar Tendonitis)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Jumper's Knee KidsHealth / For Teens / Jumper's Knee What's in this ... continued damage to the knee. How Does the Knee Work? To understand how jumper's knee happens, it ...

  18. Clinical Outcomes in Men and Women following Total Knee Arthroplasty with a High-Flex Knee: No Clinical Effect of Gender.

    Science.gov (United States)

    Nassif, Jeffrey M; Pietrzak, William S

    2015-01-01

    While it is generally recognized that anatomical differences exist between the male and female knee, the literature generally refutes the clinical need for gender-specific total knee prostheses. It has been found that standard, unisex knees perform as well, or better, in women than men. Recently, high-flex knees have become available that mechanically accommodate increased flexion yet no studies have directly compared the outcomes of these devices in men and women to see if gender-based differences exist. We retrospectively compared the performance of the high-flex Vanguard knee (Biomet, Warsaw, IN) in 716 male and 1,069 female knees. Kaplan-Meier survivorship was 98.5% at 5.6-5.7 years for both genders. After 2 years, mean improvements in Knee Society Knee and Function scores for men and women (50.9 versus 46.3; 26.5 versus 23.1) and corresponding SF-12 Mental and Physical scores (0.2 versus 2.2; 13.7 versus 12.2) were similar with differences not clinically relevant. Postoperative motion gains as a function of preoperative motion level were virtually identical in men and women. This further confirms the suitability of unisex total knee prostheses for both men and women.

  19. Clinical Outcomes in Men and Women following Total Knee Arthroplasty with a High-Flex Knee: No Clinical Effect of Gender

    Directory of Open Access Journals (Sweden)

    Jeffrey M. Nassif

    2015-01-01

    Full Text Available While it is generally recognized that anatomical differences exist between the male and female knee, the literature generally refutes the clinical need for gender-specific total knee prostheses. It has been found that standard, unisex knees perform as well, or better, in women than men. Recently, high-flex knees have become available that mechanically accommodate increased flexion yet no studies have directly compared the outcomes of these devices in men and women to see if gender-based differences exist. We retrospectively compared the performance of the high-flex Vanguard knee (Biomet, Warsaw, IN in 716 male and 1,069 female knees. Kaplan-Meier survivorship was 98.5% at 5.6–5.7 years for both genders. After 2 years, mean improvements in Knee Society Knee and Function scores for men and women (50.9 versus 46.3; 26.5 versus 23.1 and corresponding SF-12 Mental and Physical scores (0.2 versus 2.2; 13.7 versus 12.2 were similar with differences not clinically relevant. Postoperative motion gains as a function of preoperative motion level were virtually identical in men and women. This further confirms the suitability of unisex total knee prostheses for both men and women.

  20. Successful total knee arthroplasty in the presence of sporotrichal arthritis.

    NARCIS (Netherlands)

    Koeter, S.; Jackson, R.W.

    2006-01-01

    Articular sporotrichosis, a chronic granulomatous fungal infection, is a rare entity but when present may lead to significant joint destruction. Severe knee arthrosis due to sporotrichal arthritis has traditionally been treated with arthrodesis. Total knee arthroplasty in the presence of

  1. Knee Replacement

    Science.gov (United States)

    ... days. Medications prescribed by your doctor should help control pain. During the hospital stay, you'll be encouraged to move your ... exercise your new knee. After you leave the hospital, you'll continue physical ... mobility and a better quality of life. And most knee replacements can be ...

  2. Migration and clinical outcome of mobile-bearing versus fixed-bearing single-radius total knee arthroplasty.

    Science.gov (United States)

    Van Hamersveld, Koen T; Marang-Van De Mheen, Perla J; Van Der Heide, Huub J L; Van Der Linden-Van Der Zwaag, Henrica M J; Valstar, Edward R; Nelissen, Rob G H H

    2018-04-01

    Background and purpose - Mobile-bearing total knee prostheses (TKPs) were developed in the 1970s in an attempt to increase function and improve implant longevity. However, modern fixed-bearing designs like the single-radius TKP may provide similar advantages. We compared tibial component migration measured with radiostereometric analysis (RSA) and clinical outcome of otherwise similarly designed cemented fixed-bearing and mobile-bearing single-radius TKPs. Patients and methods - RSA measurements and clinical scores were assessed in 46 randomized patients at baseline, 6 months, 1 year, and annually thereafter up to 6 years postoperatively. A linear mixed-effects model was used to analyze the repeated measurements. Results - Both groups showed comparable migration (p = 0.3), with a mean migration at 6-year follow-up of 0.90 mm (95% CI 0.49-1.41) for the fixed-bearing group compared with 1.22 mm (95% CI 0.75-1.80) for the mobile-bearing group. Clinical outcomes were similar between groups. 1 fixed-bearing knee was revised for aseptic loosening after 6 years and 2 knees (1 in each group) were revised for late infection. 2 knees (1 in each group) were suspected for loosening due to excessive migration. Another mobile-bearing knee was revised after an insert dislocation due to failure of the locking mechanism 6 weeks postoperatively, after which study inclusion was preliminary terminated. Interpretation - Fixed-bearing and mobile-bearing single-radius TKPs showed similar migration. The latter may, however, expose patients to more complex surgical techniques and risks such as insert dislocations inherent to this rotating-platform design.

  3. Rolamento posterior do fêmur na artroplastia total do joelho: comparação entre as próteses com preservação e com sacrifício do ligamento cruzado posterior Femoral roll back in total knee arthroplasty: comparison between prostheses that preserve and sacrifice the posterior cruciate ligament

    Directory of Open Access Journals (Sweden)

    Lúcio Honório de Carvalho Júnior

    2011-01-01

    Full Text Available OBJETIVO: Comparar a posteriorização do ponto de contato entre o componente femoral e o polietileno tibial à medida em que o joelho é fletido em dois tipos de artroplastia total do joelho, uma com sacrifício e outra com preservação do ligamento cruzado posterior (LCP. MÉTODOS: Foram analisados, sob fluoroscopia, 36 joelhos de 32 pacientes submetidos a artroplastia total do joelho. Analisando as imagens em perfil, foi medido o ponto de contato do fêmur com o polietileno tibial com o joelho em extensão completa e em 90 graus de flexão, mensurando-se o percentual de "rolamento" posterior do fêmur nas artroplastias em que o ligamento cruzado posterior (LCP foi sacrificado e naquelas nas quais esse foi preservado. RESULTADOS: O percentual médio de posteriorização do fêmur foi de 13,24% nos casos em que o LCP foi sacrificado e de 5,75% nos casos em que esse foi preservado. A diferença entre essas medidas foi estatisticamente significativa, com p = 0,026615. CONCLUSÃO: Na artroplastia total do joelho, sacrificar o LCP aumenta a translação posterior do ponto de contato entre o fêmur e a tíbia à medida em que o joelho é flexionado até 90 graus.OBJECTIVE: To compare the rollback of the contact point between the femoral component and the tibial polyethylene as the knee is flexed, in two types of total knee arthroplasty: one that sacrifices and the other that preserves the posterior cruciate ligament (PCL. METHODS: Under fluoroscopy, 36 knees from 32 patients who underwent total knee arthroplasty were evaluated. Using lateral images, the contact points between the femur and the tibial polyethylene with the knee in complete extension and at 90° of flexion were measured, thereby measuring the percentage rollback of the femur in arthroplasties in which the PCL was sacrificed and in those in which it was preserved. RESULTS: The mean percentage rollback of the femur was 13.24% in the cases in which the PCL was sacrificed and 5.75% in

  4. Gamma Ray Sterilization of Starr-Edwards Heart Valve Prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, J. R. P.; Alladine, M. F. [London Chest Hospital, London (United Kingdom)

    1967-09-15

    Starr-Edwards valves have normally been sterilized by exposure to ethylene oxide or by autoclaving. Patients having a prosthetic valve replacement are known to have a higher incidence of endocarditis in comparison with patients in which no prosthesis has been used. Ethylene oxide will only sterilize the surface of the valve and autoclaving has caused distortion of the polytetrafluorethylene ring. Work has been done on the effect of gamma radiation on the components of these valve prostheses and is given in detail. The bacteriological efficiency, at a total absorbed dose of 2. 5 Mrad, has been established. Thirty valves treated by this method have now been inserted and twelve patients have been examined post-operatively for a period of one to two years. All valves are working normally and there has been no evidence of blood-borne infection or malfunction of the valve. (author)

  5. Late rupture of the posterior cruciate ligament after total knee replacement.

    OpenAIRE

    Montgomery, R. L.; Goodman, S. B.; Csongradi, J.

    1993-01-01

    To our knowledge there have been no reports of late rupture of the posterior cruciate ligament (PCL) as a cause of instability in PCL-retaining total knee prostheses. In our experience of 150 total knee replacements using PCL-retaining prosthesis, three cases (2.0%) of late rupture of the posterior cruciate ligament have occurred, each leading to chronic instability, disabling pain, and revision arthroplasty. In each case rupture of the posterior cruciate ligament was confirmed at the time of...

  6. Gait Parameters and Functional Outcomes After Total Knee Arthroplasty Using Persona Knee System With Cruciate Retaining and Ultracongruent Knee Inserts.

    Science.gov (United States)

    Rajgopal, Ashok; Aggarwal, Kalpana; Khurana, Anshika; Rao, Arun; Vasdev, Attique; Pandit, Hemant

    2017-01-01

    Total knee arthroplasty is a well-established treatment for managing end-stage symptomatic knee osteoarthritis. Currently, different designs of prostheses are available with majority ensuring similar clinical outcomes. Altered surface geometry is introduced to strive toward gaining superior outcomes. We aimed to investigate any differences in functional outcomes between 2 different polyethylene designs namely the Persona CR (cruciate retaining) and Persona UC (ultracongruent) tibial inserts (Zimmer-Biomet, Warsaw, IN). This prospective single blind, single-surgeon randomized controlled trial reports on 105 patients, (66 female and 39 male), who underwent simultaneous bilateral total knee arthroplasty using the Persona knee system (Zimmer-Biomet) UC inserts in one side and CR inserts in the contralateral side. By a blind assessor, at regular time intervals patients were assessed in terms of function and gait. The functional knee scoring scales used were the Western Ontario and McMaster Universities Osteoarthritis Index and Modified Knee Society Score. The gait parameters evaluated were foot pressure and step length. During the study period, no patient was lost to follow-up or underwent revision surgery for any cause. Western Ontario and McMaster Universities Osteoarthritis Index scores, Modified Knee Society Score, and knee range of motion of all 105 patients assessed preoperatively and postoperatively at 6 months, 1 year, and 2 years showed statistically better results (P < .05) for UC inserts. Gait analysis measuring foot pressures and step length, however, did not show any statistically significant differences at 2-year follow-up. Ultracongruent tibial inserts show significantly better functional outcomes as compared to CR inserts during a 2-year follow-up period. However, in this study these findings were not shown to be attributed to differences in gait parameters. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Cemented versus Uncemented Oxford Unicompartmental Knee Arthroplasty: Is There a Difference?

    Directory of Open Access Journals (Sweden)

    Burak Akan

    2013-01-01

    Full Text Available Purpose. The use of uncemented unicompartmental knee prostheses has recently increased. However, few studies on the outcomes of uncemented unicompartmental knee prostheses have been performed. The purpose of this study was to compare the outcomes of cemented and uncemented Oxford unicompartmental knee arthroplasty. Materials and Methods. This retrospective observational study evaluated the clinical and radiological outcomes of 263 medial Oxford unicompartmental prostheses (141 cemented, 122 uncemented implanted in 235 patients. The mean follow-up was 42 months in the cemented group and 30 months in the uncemented group. Results. At the last follow-up, there were no significant differences in the clinical results or survival rates between the two groups. However, the operation time in the uncemented unicompartmental knee arthroplasty group was shorter than that in the cemented unicompartmental knee arthroplasty group. In addition, the cost of uncemented arthroplasty was greater. Conclusion. Despite the successful midterm results in the uncemented unicompartmental knee arthroplasty group, a longer follow-up period is required to determine the best fixation mode.

  8. Biomechanical Considerations in the Design of High-Flexion Total Knee Replacements

    Directory of Open Access Journals (Sweden)

    Cheng-Kung Cheng

    2014-01-01

    Full Text Available Typically, joint arthroplasty is performed to relieve pain and improve functionality in a diseased or damaged joint. Total knee arthroplasty (TKA involves replacing the entire knee joint, both femoral and tibial surfaces, with anatomically shaped artificial components in the hope of regaining normal joint function and permitting a full range of knee flexion. In spite of the design of the prosthesis itself, the degree of flexion attainable following TKA depends on a variety of factors, such as the joint’s preoperative condition/flexion, muscle strength, and surgical technique. High-flexion knee prostheses have been developed to accommodate movements that require greater flexion than typically achievable with conventional TKA; such high flexion is especially prevalent in Asian cultures. Recently, computational techniques have been widely used for evaluating the functionality of knee prostheses and for improving biomechanical performance. To offer a better understanding of the development and evaluation techniques currently available, this paper aims to review some of the latest trends in the simulation of high-flexion knee prostheses.

  9. Immunoscintigraphy with antigranulocyte monoclonal antibodies for the diagnosis of septic loosening of hip prostheses

    International Nuclear Information System (INIS)

    Boubaker, A.; Bischof Delaloye, A.; Blanc, C.H.; Dutoit, M.; Leyvraz, P.F.; Delaloye, B.

    1995-01-01

    To determine the value of immunoscintigraphy (IS) with antigranulocyte monoclonal antibodies (Mab) in the diagnosis of subacute or chronic infection of hip prostheses, we prospectively studied 57 patients (23 women and 34 men; age 29-92 years, mean 72.7 years) sent to our institution in the past 6 years for clinical suspicion of septic loosening of a hip prosthesis. Nineteen patients had bilateral prostheses and one of them was studied twice. A total of 78 prostheses were examined. All patients had three-phase bone scans followed by IS with technetium-99m antigranulocyte Mab BW 250/183. Intervals between bone scans and IS varied from 2 days to 4 weeks. Final diagnosis was assessed by culture in 48 cases (articular puncture or intraoperative sampling) and by clinical follow-up of at least 8 months in 30 cases. Twelve prostheses were considered septic and 66 non-septic. The overall sensitivity and specificity were 92% and 64% respectively for bone scans, 67% and 75% for IS and 67% and 84% for both modalities together. In three cases, IS was doubtful and the final clinical diagnosis was negative for infection. False-positive results were observed in the presence of massive loosening of the prosthesis or in association with metaplastic peri-articular bone formation. In three of the four false-negative results, infection was proven only after enrichment of the culture, and the bacterium was Staphylococcus epidermidis. In 12/33 (36%) positive bone scans IS allowed the diagnosis of infection to be excluded. Overall accuracy of both modalities together was 81% and the negative predictive value was 93%, which compares favourably with the results reported for other non-invasive methods. (orig.)

  10. COMPARISON OF GAIT USING A MULTIFLEX FOOT VERSUS A QUANTUM FOOT IN KNEE DISARTICULATION AMPUTEES

    NARCIS (Netherlands)

    BOONSTRA, AM; FIDLER, [No Value; SPITS, GMA; HOF, AL; Tuil, P.

    The subjective responses and gait patterns of unilateral knee disarticulation amputees wearing prostheses fitted first with the Multiflex foot and then with the Quantum foot were studied. Nine amputees were included in the trial. A questionnaire asked the amputees about their preference for one of

  11. Knee pain

    Science.gov (United States)

    ... Fracture of the kneecap or other bones. Iliotibial band syndrome . Injury to the thick band that runs from your hip to the outside ... of your knee pain. When to Contact a Medical Professional Call your provider if: You cannot bear ...

  12. Knee Injuries and Disorders

    Science.gov (United States)

    Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty ...

  13. Multi-Disciplinary Antimicrobial Strategies for Improving Orthopaedic Implants to Prevent Prosthetic Joint Infections in Hip and Knee

    Science.gov (United States)

    Getzlaf, Matthew A.; Lewallen, Eric A.; Kremers, Hilal M.; Jones, Dakota L.; Bonin, Carolina A.; Dudakovic, Amel; Thaler, Roman; Cohen, Robert C.; Lewallen, David G.; van Wijnen, Andre J.

    2016-01-01

    Like any foreign object, orthopaedic implants are susceptible to infection when introduced into the human body. Without additional preventative measures, the absolute number of annual prosthetic joint infections will continue to rise, and may exceed the capacity of health care systems in the near future. Bacteria are difficult to eradicate from synovial joints due to their exceptionally diverse taxonomy, complex mechanistic attachment capabilities, and tendency to evolve antibiotic resistance. When a primary orthopaedic implant fails from prosthetic joint infection, surgeons are generally challenged by limited options for intervention. In this review, we highlight the etiology and taxonomic groupings of bacteria known to cause prosthetic joint infections, and examine their key mechanisms of attachment. We propose that antimicrobial strategies should focus on the most harmful bacteria taxa within the context of occurrence, taxonomic diversity, adhesion mechanisms, and implant design. Patient-specific identification of organisms that cause prosthetic joint infections will permit assessment of their biological vulnerabilities. The latter can be targeted using a range of antimicrobial techniques that exploit different colonization mechanisms including implant surface attachment, biofilm formation, and/or hematogenous recruitment. We anticipate that customized strategies for each patient, joint, and prosthetic component will be most effective at reducing prosthetic joint infections, including those caused by antibiotic-resistant and polymicrobial bacteria. PMID:26449208

  14. Evaluation of Osseous Integration of PVD-Silver-Coated Hip Prostheses in a Canine Model

    Directory of Open Access Journals (Sweden)

    Gregor Hauschild

    2015-01-01

    Full Text Available Infection associated with biomaterials used for orthopedic prostheses remains a serious complication in orthopedics, especially tumor surgery. Silver-coating of orthopedic (megaprostheses proved its efficiency in reducing infections but has been limited to surface areas exposed to soft tissues due to concerns of silver inhibiting osseous integration of cementless stems. To close this gap in the bactericidal capacity of silver-coated orthopedic prostheses extension of the silver-coating on surface areas intended for osseous integration seems to be inevitable. Our study reports about a PVD- (physical-vapor-deposition- silver-coated cementless stem in a canine model for the first time and showed osseous integration of a silver-coated titanium surface in vivo. Radiological, histological, and biomechanical analysis revealed a stable osseous integration of four of nine stems implanted. Silver trace elemental concentrations in serum did not exceed 1.82 parts per billion (ppb and can be considered as nontoxic. Changes in liver and kidney functions associated with the silver-coating could be excluded by blood chemistry analysis. This was in accordance with very limited metal displacement from coated surfaces observed by laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS 12 months after implantation. In conclusion our results represent a step towards complete bactericidal silver-coating of orthopedic prostheses.

  15. SPONGE ROBOTIC HAND DESIGN FOR PROSTHESES

    OpenAIRE

    Mine Seçkin

    2016-01-01

    In this study robotic hands and fingers’ materials are investigated from past to present and a sponge robotic hand is designed for biomedical applications. Emergence and necessity of soft robotic technology are explained and description of soft robot is made. Because of the importance of hand in a person’s body, researchers have dealt with robotic hand prostheses for many centuries and developed many hand types. To mimic the best for the human limbs, softness of the hand is one of the importa...

  16. Stimulation and recording electrodes for neural prostheses

    CERN Document Server

    Pour Aryan, Naser; Rothermel, Albrecht

    2015-01-01

    This book provides readers with basic principles of the electrochemistry of the electrodes used in modern, implantable neural prostheses. The authors discuss the boundaries and conditions in which the electrodes continue to function properly for long time spans, which are required when designing neural stimulator devices for long-term in vivo applications. Two kinds of electrode materials, titanium nitride and iridium are discussed extensively, both qualitatively and quantitatively. The influence of the counter electrode on the safety margins and electrode lifetime in a two electrode system is explained. Electrode modeling is handled in a final chapter.

  17. [The method and result analyses of pathogenic bacteria culture on chronic periprosthetic joint infection after total knee arthroplasty and total hip arthroplasty].

    Science.gov (United States)

    Ji, Baochao; Xu, Enjie; Cao, Li; Yang, Desheng; Xu, Boyong; Guo, Wentao; Aili, Rehei

    2015-02-01

    To analyze the results of pathogenic bacteria culture on chronic periprosthetic joint infection after total knee arthroplasty (TKA) and total hip arthroplasty (THA). The medical data of 23 patients with chronic periprosthetic joint infection after TKA or THA from September 2010 to March 2014 were reviewed. Fifteen cases of TKA and 8 cases of THA were included in this study. There were 12 male and 11 female patients with the mean age of 62 years (range from 32 to 79 years), and among them 9 patients with sinus. All patients discontinued antibiotic therapy for a minimum of 2 weeks before arthrocentesis, taking pathogenic bacteria culture and antimicrobial susceptibility test by using synovial fluid taken preoperatively and intraoperatively of revision. Common pathogenic bacteria culture and pathological biopsy were taken on tissues intraoperatively of revision. Culture-negative specimens were prolonged the period of incubation for 2 weeks. The overall culture-positive rate of all 23 patients for 1 week before revision was 30.4% (7/23), and the positive rate of culture-negative samples which prolonged for 2 weeks was 39.1% (9/23). The overall culture-positive rate of patients for 1 week intraoperatively of revision was 60.9% (14/23), and the positive rate of culture-negative samples which prolonged for 2 weeks was 82.6% (19/23). The incubation results of 7 cases (30.4%) preoperatively conformed to that of intraoperation. The culture-positive rate of pathogenic bacteria culture can be increased evidently by discontinuing antimicrobial therapy for a minimum of 2 weeks prior to the definite diagnosis.

  18. MECHANICAL HEART-VALVE PROSTHESES - SOUND LEVEL AND RELATED COMPLAINTS

    NARCIS (Netherlands)

    LAURENS, RRP; WIT, HP; EBELS, T

    In a randomised study, we investigated the sound production of mechanical heart valve prostheses and the complaints related to this sound. The CarboMedics, Bjork-Shiley monostrut and StJude Medical prostheses were compared. A-weighted levels of the pulse-like sound produced by the prosthesis were

  19. Oral cavity anaerobic pathogens in biofilm formation on voice prostheses

    NARCIS (Netherlands)

    Bertl, Kristina; Zijnge, Vincent; Zatorska, Beata; Leonhard, Matthias; Schneider-Stickler, Berit; Harmsen, Hermie J. M.

    BACKGROUND: A polymerase chain reaction (PCR)-based method has been used to identify oral anaerobic pathogens in biofilms on voice prostheses. The purpose of the present study was to determine the location of those pathogens inside the biofilms. METHODS: Biofilms of 15 voice prostheses were sampled

  20. Lactobacilli : Important in biofilm formation on voice prostheses

    NARCIS (Netherlands)

    Buijssen, Kevin J. D. A.; Harmsen, Hermie J. M.; van der Mei, Henny C.; Busscher, Henk J.; van der Laan, Bernard F. A. M.

    OBJECTIVE: We sought to identify bacterial strains responsible for biofilm formation on silicone rubber voice prostheses. STUDY DESIGN: We conducted an analysis of the bacterial population in biofilms on used silicone rubber voice prostheses by using new microbiological methods. METHODS: Two

  1. 3D-printed upper limb prostheses : a review

    NARCIS (Netherlands)

    ten Kate, J; Smit, G.; Breedveld, P.

    2017-01-01

    Goal: This paper aims to provide an overview with quantitative information of existing 3D-printed upper limb prostheses. We will identify the benefits and drawbacks of 3D-printed devices to enable improvement of current devices based on the demands of prostheses users. Methods: A review was

  2. Confirming Sterility of an Autoclaved Infected Femoral Component for Use in an Articulated Antibiotic Knee Spacer: A Pilot Study.

    Science.gov (United States)

    Lyons, Steven T; Wright, Coy A; Krute, Christina N; Rivera, Frances E; Carroll, Ronan K; Shaw, Lindsey N

    2016-01-01

    Antibiotic spacer designs have proven effective at eradicating infection during a two-stage revision arthroplasty. Temporary reuse of the steam-sterilized femoral component and a new all poly tibia component has been described as an effective articulating antibiotic spacer, but sterility concerns persist. Six explanted cobalt chrome femurs from patients with grossly infected TKA's and six stock femurs inoculated with different bacterial species were confirmed to be bacteria-free after autoclaving under a standard gravity-displacement cycle. The effect of steam sterilization on cobalt chrome fragments contaminated with MRSA biofilm was analyzed microscopically to quantify remaining biofilm. The autoclave significantly reduced the biofilm burden on the cobalt chrome fragments. This study confirmed sterility of the femur after a standard gravity-displacement cycle (132°C, 27 PSIG, 10 minutes). Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Risk factors for periprosthetic joint infection following primary total hip or knee arthroplasty: a meta-analysis.

    Science.gov (United States)

    Kong, Lingde; Cao, Junming; Zhang, Yingze; Ding, Wenyuan; Shen, Yong

    2017-06-01

    To identify risk factors for periprosthetic joint infection following primary total joint arthroplasty, a systematic search was performed in Pubmed, Embase and Cochrane library databases. Pooled odds ratios (ORs) or standardised mean differences (SMDs) with 95% confidence intervals (CIs) were calculated. Patient characteristics, surgical-related factors and comorbidities, as potential risk factors, were investigated. The main factors associated with infection after total joint arthroplasty (TJA) were male gender (OR, 1·48; 95% CI, 1.19-1.85), age (SMD, -0·10; 95% CI, -0.17--0.03), obesity (OR, 1·54; 95% CI, 1·25-1·90), alcohol abuse (OR, 1·88; 95% CI, 1·32-2·68), American Society of Anesthesiologists (ASA) scale > 2 (OR, 2·06; 95% CI, 1·77-2·39), operative time (SMD, 0·49; 95% CI, 0·19-0·78), drain usage (OR, 0·36; 95% CI, 0·18-0·74), diabetes mellitus (OR, 1·58; 95% CI, 1·37-1·81), urinary tract infection (OR, 1·53; 95% CI, 1.09-2.16) and rheumatoid arthritis (OR, 1·57; 95% CI, 1·30-1·88). Among these risk factors, ASA score > 2 was a high risk factor, and drain usage was a protective factor. There was positive evidence for some factors that could be used to prevent the onset of infection after TJA. © 2016 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  4. Excellent AUC for joint fluid cytology in the detection/exclusion of hip and knee prosthetic joint infection.

    Science.gov (United States)

    Gallo, Jiri; Juranova, Jarmila; Svoboda, Michal; Zapletalova, Jana

    2017-09-01

    The aim of this study was to evaluate the characteristics of synovial fluid (SF) white cell count (SWCC) and neutrophil/lymphocyte percentage in the diagnosis of prosthetic joint infection (PJI) for particular threshold values. This was a prospective study of 391 patients in whom SF specimens were collected before total joint replacement revisions. SF was aspirated before joint capsule incision. The PJI diagnosis was based only on non-SF data. Receiver operating characteristic plots were constructed for the SWCC and differential counts of leukocytes in aspirated fluid. Logistic binomic regression was used to distinguish infected and non-infected cases in the combined data. PJI was diagnosed in 78 patients, and aseptic revision in 313 patients. The areas (AUC) under the curve for the SWCC, the neutrophil and lymphocyte percentages were 0.974, 0.962, and 0.951, respectively. The optimal cut-off for PJI was 3,450 cells/μL, 74.6% neutrophils, and 14.6% lymphocytes. Positive likelihood ratios for the SWCC, neutrophil and lymphocyte percentages were 19.0, 10.4, and 9.5, respectively. Negative likelihood ratios for the SWCC, neutrophil and lymphocyte percentages were 0.06, 0.076, and 0.092, respectively. Based on AUC, the present study identified cut-off values for the SWCC and differential leukocyte count for the diagnosis of PJI. The likelihood ratio for positive/negative SWCCs can significantly change the pre-test probability of PJI.

  5. Closed Incision Negative Pressure Therapy Versus Standard of Care Surgical Dressing in Revision Total Knee Arthroplasty

    Science.gov (United States)

    2018-06-07

    Surgical Wound; Revision Total Knee Arthroplasty; Wounds and Injuries; Joint Disease; Musculoskeletal Disease; Prosthesis-Related Infections; Infection; Postoperative Complications; Pathologic Processes

  6. A computer-based biomechanical analysis of the three-dimensional motion of cementless hip prostheses.

    Science.gov (United States)

    Gilbert, J L; Bloomfeld, R S; Lautenschlager, E P; Wixson, R L

    1992-04-01

    A computer-based mathematical technique was developed to measure and completely describe the migration and micromotion of a femoral hip prosthesis relative to the femur. This technique utilized the mechanics of rigid-body motion analysis and apparatus of seven linear displacement transducers to measure and describe the complete three-dimensional motion of the prosthesis during cyclic loading. Computer acquisition of the data and custom analysis software allowed one to calculate the magnitude and direction of the motion of any point of interest on the prostheses from information about the motion of two points on the device. The data were also used to replay the tests using a computer animation technique, which allowed a magnified view of the three-dimensional motion of the prosthesis. This paper describes the mathematical development of the rigid-body motion analysis, the experimental method and apparatus for data collection, the technique used to animate the motion, the sources of error and the effect of the assumptions (rigid bodies) on the results. Selected results of individual test runs of uncemented and cemented prostheses are presented to demonstrate the efficacy of the method. The combined effect of the vibration and electrical noise resulted in a resolution of the system of about 3-5 microns motion for each transducer. Deformation effects appear to contribute about 3-15 microns to the measurement error. This measurement and analysis technique is a very sensitive and powerful means of assessing the effects of different design parameters on the migration and micromotion of total joint prostheses and can be applied to any other case (knee, dental implant) where three-dimensional relative motion between two bodies is important.

  7. Laser vibrometer measurements and middle ear prostheses

    Science.gov (United States)

    Flock, Stephen T.; Dornhoffer, John; Ferguson, Scott

    1997-05-01

    One of us has developed an improved partial ossicular replacement prosthesis that is easier to implant and, based on pilot clinical measurements, results in better high-frequency hearing as compared to patients receiving one of the alternative prostheses. It is hypothesized that the primary reason for this is because of the relatively light weight (about 25 mg) and low compliance of the prosthesis, which could conceivably result in better high frequency vibrational characteristics. The purpose of our initial work was to develop an instrument suitable for objectively testing the vibrational characteristics of prostheses. We have developed a laser based device suitable for measuring the vibrational characteristics of the oval window or other structures of the middle ear. We have tested this device using a piezoelectric transducer excited at audio frequencies, as well as on the oval window in human temporal bones harvested from cadavers. The results illustrate that it is possible to non-invasively monitor the vibrational characteristics of anatomic structures with a very inexpensive photonic device.

  8. Radiological and scintigraphic evaluation of hip prostheses

    International Nuclear Information System (INIS)

    Bessler, W.; Schaub, W.

    1979-01-01

    The radiological findings following the introduction of hip prostheses are often equivocal. Additional bone scintigrams often provide important information for the evaluation of the prostheses. 1. An unstable hip prosthesis is characterised by abnormal uptake in bone, due to static and mechanical stress. 2. A positive scintigram does not necessarily indicate instability of the prosthesis. Increased uptake may also be due to inflammatory bone changes, healing, bone replacement, abnormal local stresses or soft tissue calcification. 3. In evaluating the scintigram one must take account not only of the intensity of isotope uptake, but also its distribution and exact localisation. 4. It is essential to compare the scintigram with the radiograph. Radiological features of possible instability become diagnostic if they correspond with appropriate increased radioactivity. If the latter is absent, the of instability remains doubtful. 5. In some cases early loosening of the stem of the prosthesis can be diagnosed while the radiograph is still negative. Increased radioactivity in the acetabulum is frequently seen in the presence of a stable acetabular prosthesis and must be interpreted with caution as a sign of loosening of the prosthesis. (orig.) [de

  9. The effect of posterior tibial slope on knee flexion in posterior-stabilized total knee arthroplasty.

    Science.gov (United States)

    Shi, Xiaojun; Shen, Bin; Kang, Pengde; Yang, Jing; Zhou, Zongke; Pei, Fuxing

    2013-12-01

    To evaluate and quantify the effect of the tibial slope on the postoperative maximal knee flexion and stability in the posterior-stabilized total knee arthroplasty (TKA). Fifty-six patients (65 knees) who had undergone TKA with the posterior-stabilized prostheses were divided into the following 3 groups according to the measured tibial slopes: Group 1: ≤4°, Group 2: 4°-7° and Group 3: >7°. The preoperative range of the motion, the change in the posterior condylar offset, the elevation of the joint line, the postoperative tibiofemoral angle and the preoperative and postoperative Hospital for Special Surgery (HSS) scores were recorded. The tibial anteroposterior translation was measured using the Kneelax 3 Arthrometer at both the 30° and the 90° flexion angles. The mean values of the postoperative maximal knee flexion were 101° (SD 5), 106° (SD 5) and 113° (SD 9) in Groups 1, 2 and 3, respectively. A significant difference was found in the postoperative maximal flexion between the 3 groups (P slope resulted in a 1.8° flexion increment (r = 1.8, R (2) = 0.463, P slope can significantly increase the postoperative maximal knee flexion. The tibial slope with an appropriate flexion and extension gap balance during the operation does not affect the joint stability.

  10. Pathogenic characteristics of Candida albicans isolated from oral cavities of denture wearers and cancer patients wearing oral prostheses.

    Science.gov (United States)

    Mothibe, J V; Patel, M

    2017-09-01

    Candida albicans cause opportunistic infections including oral candidiasis in immunocompromised patients. It has an ability to cause infection due to its virulence factors. This study investigated the pathogenic characteristics of C. albicans isolated from the oral cavities of healthy subjects and two vulnerable groups, denture wearers and cancer patients wearing oral prostheses. Oral rinse samples were collected and cultured for the quantitative and qualitative analysis of Candida. Twenty strains of C. albicans isolated from the healthy individuals and denture wearers and, 14 strains isolated from the cancer patients were selected and their pathogenic characteristics were measured. The results of the study groups were compared using a Scheffe test for pairwise comparison and a chi square test. Denture wearer and cancer patients with prostheses carried significantly higher number (p production were significantly higher in the strains from denture wearers. In addition, high number of isolates from the denture wearers produced phospholipase and proteinase (85% and 80% respectively) compared to the strains from normal subjects (25% and 60% respectively). Only the germ tube formation and adherence ability were significantly higher in the strains from the cancer patients with prostheses (p = 0.05 and p oral cavity and prostheses is important in the prevention of colonization of Candida and the development of oral candidiasis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Total Knee Replacement: 12 Years Retrospective Review and Experience

    Directory of Open Access Journals (Sweden)

    Ahmad Hafiz Z

    2011-03-01

    Full Text Available This retrospective study was undertaken to evaluate the outcome of primary total knee arthroplasty (TKA performed from January 1986 to December 1997 at this institution. Case review included Knee Society scores and functional knee score. The records of 94 patients (128 knees were available for analysis with the sample comprised of 76 females (80.9% and 18 males (19.1% and a mean age was 61.4 years. TKA was performed for osteoarthritis (OA in 96 knees (75% and rheumatoid arthritis (RA in 32 knees (25%. Cemented TKAs were performed in all patients. The mean knee score improved from 38.8 preoperatively to 90.9 postoperatively. The mean functional score improved from 19.1 preoperatively to 62.5 postoperatively. Both scores showed significant improvement when comparing preoperative to post operative results (p< 0.005. Arthroplasty was designated failures if the prostheses used had been removed. Survivorship at 12 years was 89.5%.

  12. The Use of Prostheses in Pelvic Reconstructive Surgery: Joy or Toy?

    Directory of Open Access Journals (Sweden)

    Ming-Ping Wu

    2008-06-01

    Full Text Available The high recurrence rate of pelvic organ prolapse (POP of up to 30% after pelvic reconstructive surgery makes a more refined surgery imperative, as well as the need for either biological or synthetic prostheses as adjuvant treatment. Patients with recurrence risks may benefit from the adjuvant treatment: (1 to substitute for the lack of supportive tissue; (2 to reinforce inadequate tissue; (3 to induce new supportive tissue; and (4 to consolidate and complement the insufficient surgical techniques. However, some debatable issues in use of the prosthetics remain. The use of prosthetics enables the simultaneous repair of all vaginal defects of POP and concomitant anti-incontinence surgery to be faster, easier and more precise. Nevertheless, great care should be devoted to the actual and theoretical short- and long-term risks, many of which have not been fully elucidated. Despite the lack of various ideal characteristics, the type I monofilament, macroporous polypropylene, has been suggested to have the lowest incidence of infection and erosion among the nonabsorbable prostheses. There is good evidence to support the use of nonabsorbable synthetic mesh for abdominal sacrocolpopexy, while the use of prostheses for repairing isolated anterior and posterior compartment defects remains controversial. There have been no long-term studies with sufficient patient numbers to prove whether synthetic or biological prostheses are superior during vaginal surgery. Tension-free vaginal mesh techniques with procedural kits are being adopted increasingly, despite the paucity of data. Although short-term follow-up studies have shown tension-free vaginal mesh to be a safe and effective technique to correct POP, anatomic and functional results of long-term follow-up studies, however, have not yet confirmed the effectiveness and safety. Mesh erosion remains a concern, with variable rates according to different materials and approaches. Newly developed prostheses offer

  13. Clinical Outcome of Medial Pivot Compared With Press-Fit Condylar Sigma Cruciate-Retaining Mobile-Bearing Total Knee Arthroplasty.

    Science.gov (United States)

    Kim, Young-Hoo; Park, Jang-Won; Kim, Jun-Shik

    2017-10-01

    The purpose of this study was to compare the long-term clinical results, radiographic results, range of knee motion, patient satisfaction, and the survival rate of Medial-Pivot posterior cruciate-substituting, knee prosthesis and a press-fit condylar (PFC) Sigma cruciate-retaining mobile-bearing knee prosthesis in the same patients. One hundred eighty-two patients received Medial-Pivot knee prosthesis in one knee and a PFC Sigma knee prosthesis in the contralateral knee. The minimum duration of follow-up was 11 years (range, 11-12.6 years). The knees with a Medial-Pivot knee prosthesis had significantly worse results than those with a PFC Sigma knee prosthesis at the final follow-up with regard to the mean postoperative Knee Society knee scores (90 compared with 95 points), Western Ontario and McMaster Universities Osteoarthritis Index score (25 compared with 18 points), and range of knee motion (117° compared with 128°). Patients were more satisfied with PFC Sigma knee prosthesis (93%) than with Medial-Pivot knee prosthesis (75%). Complication rates were significantly higher in the Medial-Pivot knee group (26%) than those in the PFC Sigma knee group (6.5%). Radiographic results and survival rates (99% compared with 99.5%) were similar between the 2 groups. Although the long-term fixation and survival rate of both Medial-Pivot and PFC Sigma prostheses were similar, we observed a worse knee score, worse range of knee motion, and patient satisfaction was less in the Medial-Pivot knee group than in the PFC Sigma knee group. Furthermore, complication rate was also higher in the Medial-Pivot knee group than the other group. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Crossover study of amputee stair ascent and descent biomechanics using Genium and C-Leg prostheses with comparison to non-amputee control.

    Science.gov (United States)

    Lura, Derek J; Wernke, Matthew W; Carey, Stephanie L; Kahle, Jason T; Miro, Rebecca M; Highsmith, M Jason

    2017-10-01

    This study was a randomized crossover of stair ambulation of Transfemoral Amputees (TFAs) using the Genium and C-Leg prosthetic knees. TFAs typically have difficulty ascending and descending stairs, limiting community mobility. The objective of this study was to determine the relative efficacy of the Genium and C-Leg prostheses for stair ascent and descent, and their absolute efficacy relative to non-amputees. Twenty TFAs, and five non-amputees participated in the study. TFAs were randomized to begin the study with the Genium or C-Leg prosthesis. Informed consent was obtained from all participants prior to data collection and the study was listed on clinicaltrials.gov (#NCT01473662). After fitting, accommodation, and training, participants were asked to demonstrate their preferred gait pattern for stair ascent and descent and a step-over-step pattern if able. TFAs then switched prosthetic legs and repeated fitting, accommodation, training, and testing. An eight camera Vicon optical motion analysis system, and two AMTI force plates were used to track and analyze the participants' gait patterns, knee flexion angles, knee moment normalized by body weight, and swing time. For stair descent, no significant differences were found between prostheses. For stair ascent, Genium use resulted in: increased ability to use a step-over-step gait pattern (p=0.03), increased prosthetic side peak knee flexion (pstair ascent relative to the C-Leg, by enabling gait patterns that more closely resembled non-amputees. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. [Surgical silicone prostheses in the treatment of biliary tract cancers: long prostheses or short prostheses? Results apropos of 500 cases].

    Science.gov (United States)

    Kron, B

    1992-10-01

    The interest of surgical prostheses in the palliative treatment of biliary tract cancer is well established, on the basis of their good tolerance, the more than 15 year follow up experience and the number of patients operated upon. After exeresis, they allow re-establishment of continuity, either by use of a prosthesis in Y when the right and let ducts can be dissected, or by using two prostheses, a multiperforated long prosthesis reimplanted in the duodenum and a short prosthesis reimplanted in the common bile duct without attaining the sphincter of Oddi. Of the 1000 cases treated, 500 were the object of a statistical analysis, 46 being operated upon by the author, in 60% of cases for biliary tract cancer, either primary or as an extension from the gallbladder. One-third of the patients had advanced lesions and a short survival of less than 3 months. Two-thirds a median survival of 9 months. In 10%, a radical exeresis was performed with survival of more than one year without recurrence of jaundice. Failure of treatment with persistence of jaundice was due to advanced disease for which surgery is unsatisfactory. Essential complications were premature bile leaks (5%) without serious consequences if sufficient drainage was maintained, since it stopped spontaneously, and angiocholitis (6%), the result of territory exclusion or reflux. Recurrence of jaundice was related to extension of the neoplasm to the secondary bile ducts, and to hepatic metastases. Obstruction of the prosthesis before two months was rare (6%) and was preceded by angiocholitis. In the absence of recurrence of the cancer the prosthesis can be replaced surgically without difficulty.

  16. AQUACEL® Ag Surgical Dressing Reduces Surgical Site Infection and Improves Patient Satisfaction in Minimally Invasive Total Knee Arthroplasty: A Prospective, Randomized, Controlled Study

    Directory of Open Access Journals (Sweden)

    Feng-Chih Kuo

    2017-01-01

    Full Text Available The use of modern surgical dressings to prevent wound complications and surgical site infection (SSI after minimally invasive total knee arthroplasty (MIS-TKA is lacking. In a prospective, randomized, controlled study, 240 patients were randomized to receive either AQUACEL Ag Surgical dressing (study group or a standard dressing (control group after MIS-TKA. The primary outcome was wound complication (SSI and blister. The secondary outcomes were wear time and number of dressing changes in the hospital and patient satisfaction (pain, comfort, and ease of use. In the intention-to-treat analysis, there was a significant reduction in the incidence of superficial SSI (0.8%, 95% CI∶ 0.00–2.48 in the study group compared to 8.3% (95% CI∶ 3.32–13.3 in the control group (p=0.01. There were no differences in blister and deep/organ-space SSIs between the two groups. Multivariate analysis revealed that AQUACEL Ag Surgical dressing was an independent risk factor for reduction of SSI (odds ratio: 0.07, 95% CI: 0.01–0.58, p=0.01. The study group had longer wear time (5.2±0.7 versus 1.7±0.4 days, p<0.0001 and lower number of dressing changes (1.0±0.2 versus 3.6±1.3 times, p<0.0001. Increased patient satisfaction (p<0.0001 was also noted in the study group. AQUACEL Ag Surgical dressing is an ideal dressing to provide wound care efficacy, patient satisfaction, reduction of SSI, and cost-effectiveness following MIS-TKA.

  17. CKS knee prosthesis: biomechanics and clinical results in 42 cases.

    Science.gov (United States)

    Martucci, E; Verni, E; Del Prete, G; Stulberg, S D

    1996-01-01

    From 1991 to 1993 a total of 42 CKS prostheses were implanted for the following reasons: osteoarthrosis (34 cases), rheumatoid arthritis (7 cases) tibial necrosis (1 case). At follow-up obtained after 17 to 41 months the results were: excellent or good: 41; the only poor result was probably related to excessive tension of the posterior cruciate ligament. 94% of the patients reported complete regression of pain, 85% was capable of going up and down stairs without support. Mean joint flexion was 105 degrees. Radiologically the anatomical axis of the knee had a mean valgus of anatomical axis of the knee had a mean valgus of 6 degrees. The prosthetic components were always cemented. The posterior cruciate ligament was removed in 7 knees, so that the prosthesis with "posterior stability" was used. The patella was never prosthetized. One patient complained of peri-patellar pain two months after surgery which then regressed completely.

  18. Knee arthroscopy - discharge

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000199.htm Knee arthroscopy - discharge To use the sharing features on this ... surgery to treat problems in your knee (knee arthroscopy). You may have been checked for: Torn meniscus. ...

  19. Knee microfracture surgery

    Science.gov (United States)

    Cartilage regeneration - knee ... Three types of anesthesia may be used for knee arthroscopy surgery: Medicine to relax you, and shots of painkillers to numb the knee Spinal (regional) anesthesia General anesthesia (you will be ...

  20. Preventing Knee Injuries

    Science.gov (United States)

    ... Our Newsletter Donate Blog Skip breadcrumb navigation Preventing Knee Injuries Knee injuries in children and adolescent athletes ... this PDF Share this page: WHAT ARE COMMON KNEE INJURIES? Pain Syndromes One of the most common ...

  1. Tribology of total hip arthroplasty prostheses

    Science.gov (United States)

    Rieker, Claude B.

    2016-01-01

    Articulating components should minimise the generation of wear particles in order to optimize long-term survival of the prosthesis. A good understanding of tribological properties helps the orthopaedic surgeon to choose the most suitable bearing for each individual patient. Conventional and highly cross-linked polyethylene articulating either with metal or ceramic, ceramic-on-ceramic and metal-on-metal are the most commonly used bearing combinations. All combinations of bearing surface have their advantages and disadvantages. An appraisal of the individual patient’s objectives should be part of the assessment of the best bearing surface. Cite this article: Rieker CB. Tribology of total hip arthroplasty prostheses: what an orthopaedic surgeon should know. EFORT Open Rev 2016;1:52-57. DOI: 10.1302/2058-5241.1.000004. PMID:28461928

  2. Computer-aided dental prostheses construction using reverse engineering.

    Science.gov (United States)

    Solaberrieta, E; Minguez, R; Barrenetxea, L; Sierra, E; Etxaniz, O

    2014-01-01

    The implementation of computer-aided design/computer-aided manufacturing (CAD/CAM) systems with virtual articulators, which take into account the kinematics, constitutes a breakthrough in the construction of customised dental prostheses. This paper presents a multidisciplinary protocol involving CAM techniques to produce dental prostheses. This protocol includes a step-by-step procedure using innovative reverse engineering technologies to transform completely virtual design processes into customised prostheses. A special emphasis is placed on a novel method that permits a virtual location of the models. The complete workflow includes the optical scanning of the patient, the use of reverse engineering software and, if necessary, the use of rapid prototyping to produce CAD temporary prostheses.

  3. Candida albicans in patients with oronasal communication and obturator prostheses

    OpenAIRE

    MATTOS, Beatriz Silva Câmara; SOUSA, Andréa Alves de; MAGALHÃES, Marina Helena C. G. de; ANDRÉ, Marcia; BRITO E DIAS, Reinaldo

    2009-01-01

    Patients using obturator prostheses often present denture-induced stomatitis. In order to detect the presence of oral Candida albicans in patients with oronasal communications and to evaluate the effectiveness of a topical antifungal treatment, cytological smears obtained from the buccal and palatal mucosa of 10 adult patients, and from the nasal acrylic surface of their obturator prostheses were examined. A therapeutic protocol comprising the use of oral nystatin (Mycostatin®) and prosthesis...

  4. Characterizing the Mechanical Properties of Running-Specific Prostheses

    Science.gov (United States)

    Beck, Owen N.; Taboga, Paolo; Grabowski, Alena M.

    2016-01-01

    The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (prunning 3 m/s and 6 m/s (10°-25°) compared to neutral (0°) (pRunning-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness. PMID:27973573

  5. Failure of aseptic revision total knee arthroplasties.

    Science.gov (United States)

    Leta, Tesfaye H; Lygre, Stein Håkon L; Skredderstuen, Arne; Hallan, Geir; Furnes, Ove

    2015-02-01

    In Norway, the proportion of revision knee arthroplasties increased from 6.9% in 1994 to 8.5% in 2011. However, there is limited information on the epidemiology and causes of subsequent failure of revision knee arthroplasty. We therefore studied survival rate and determined the modes of failure of aseptic revision total knee arthroplasties. This study was based on 1,016 aseptic revision total knee arthroplasties reported to the Norwegian Arthroplasty Register between 1994 and 2011. Revisions done for infections were not included. Kaplan-Meier and Cox regression analyses were used to assess the survival rate and the relative risk of re-revision with all causes of re-revision as endpoint. 145 knees failed after revision total knee arthroplasty. Deep infection was the most frequent cause of re-revision (28%), followed by instability (26%), loose tibial component (17%), and pain (10%). The cumulative survival rate for revision total knee arthroplasties was 85% at 5 years, 78% at 10 years, and 71% at 15 years. Revision total knee arthroplasties with exchange of the femoral or tibial component exclusively had a higher risk of re-revision (RR = 1.7) than those with exchange of the whole prosthesis. The risk of re-revision was higher for men (RR = 2.0) and for patients aged less than 60 years (RR = 1.6). In terms of implant survival, revision of the whole implant was better than revision of 1 component only. Young age and male sex were risk factors for re-revision. Deep infection was the most frequent cause of failure of revision of aseptic total knee arthroplasties.

  6. Knee pain (image)

    Science.gov (United States)

    The location of knee pain can help identify the problem. Pain on the front of the knee can be due to bursitis, arthritis, or ... synovial fluid) that forms behind the knee. Overall knee pain can be due to bursitis, arthritis, tears in ...

  7. Prosthetic joint infection caused by Pasteurella multocida: a case series and review of literature.

    Science.gov (United States)

    Honnorat, Estelle; Seng, Piseth; Savini, Hélène; Pinelli, Pierre-Olivier; Simon, Fabrice; Stein, Andreas

    2016-08-20

    Pasteurella multocida is a well-recognized zoonotic agent following dog or cat bites or scratches. Nevertheless, prosthetic joint infection caused by P. multocida are rarely reported. We report here a series of six cases of prosthetic joint infection caused by P. multocida managed at a referral centre for the treatment of bone and joint infection in southern France. We also reviewed the 26 cases reported in literature. The mean age of our cases was 74 years [±8.2, range 63-85]. In majority of our cases (5 cases) were associated with knee prostheses and one case with a hip prosthesis. Most of cases occurred after cat or dog scratches or licks or contact. Diagnoses of prosthetic joint infection caused by P. multocida were made by positive cultures of surgical biopsies or needle aspiration. Mean time delay between prosthetic joint implantation and infection onset was 7.6 years (±5.12 years, range 2-17). Local inflammation, which occurred in all six cases, was the most frequent clinical symptom, followed by pain in five cases, fever and swollen joints in four cases, and a fistula with purulent discharge inside the wound in two cases. The mean time of antibiotic therapy was 8 months. Surgical treatment with prosthesis removal was performed in three cases. Six of our cases were in remission without apparent relapse at 3 years after end of treatment. Prosthetic joint infections caused by P. multocida usually occur after animal scratches or bites, but can occasionally occur after a short animal lick. These infections are usually resulting from a contiguous infection and localized in the knee. An early antibiotic therapy after surgical debridement could avoid prosthetic withdrawal, notably in elderly patients. Patients with prosthetic joints should be warned that animals are potential sources of serious infection and urgent medical advice should be sought if they are bitten or scratched.

  8. Platelet thrombosis in cardiac-valve prostheses

    International Nuclear Information System (INIS)

    Dewanjee, M.K.

    1989-01-01

    The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both mechanical and tissue valves in our one-day study in the dog model was similar (< 1% if injected In-111 platelets = 5 billion platelets). As the fibrous ingrowth covered the sewing ring, the thrombus formation decreased significantly. Only a small amount of thrombus was found on the leaflets at one month in both the dog and calf models. 38 refs., 9 figs., 5 tabs

  9. Platelet thrombosis in cardiac-valve prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Dewanjee, M.K.

    1989-01-01

    The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both mechanical and tissue valves in our one-day study in the dog model was similar (< 1% if injected In-111 platelets = 5 billion platelets). As the fibrous ingrowth covered the sewing ring, the thrombus formation decreased significantly. Only a small amount of thrombus was found on the leaflets at one month in both the dog and calf models. 38 refs., 9 figs., 5 tabs.

  10. The Great Mimic Again? A Case of Tuberculosis Knee

    Directory of Open Access Journals (Sweden)

    Teo SH

    2011-11-01

    Full Text Available Tuberculosis (TB, once a disease confined to undeveloped or developing nations is currently in resurgence due to pandemic human immunodeficiency virus infection and immigration from endemic areas. TB is also known as the ‘great mimicker’. Extra-pulmonary tuberculosis affecting the knee is rare in all forms of TB (0.1-0.3%. Here, we report a case of isolated highly erosive TB knee in a previously fit Burmese migrant worker. He presented with after a history of fall into a drain. The patient also reported pain and swelling over his left knee for the previous three years. He had been treated for a bacterial infection of the knee in another hospital but defaulted due to financial constraints. Arthrotomy of the knee was performed including washout. Diagnosis of TB of the knee was made based on the synovial fluid and tissue culture. Treatment with anti- tuberculosis drugs was then initiated.

  11. Postoperative imaging of knee, hip and shoulder arthroplasty; Postoperative Bildgebung nach Gelenkersatz. Knie, Huefte, Schulter

    Energy Technology Data Exchange (ETDEWEB)

    Saupe, Nadja; Zanetti, Marco [Klinik Hirslanden, Zuerich (Switzerland). Zentrum fuer Muskuloskelettale Radiologie; Romero, Jose [Endoclinic Zuerich (Switzerland). Knie-Chirurgische Kompetenz-Praxis; Hersche, Otmar [Klinik Hirslanden, Zuerich (Switzerland). Endoclinic

    2017-12-15

    Numerous joint prostheses are used in orthopedic practice. This article reviews the current status of knee, hip and shoulder replacement and the expected radiographic appearances. Different types and techniques of replacement, various designs of hardware, the imaging appearance of complications of replacement and of revisions will be discussed. This article will also acknowledge some of the basic principles to reduce metal-induced susceptibility artifacts originate in MR images. Common ways to reduce or modify artifacts will be presented too.

  12. Migration and clinical outcome of mobile-bearing versus fixed-bearing single-radius total knee arthroplasty : A randomized controlled trial

    NARCIS (Netherlands)

    Van Hamersveld, Koen T.; Marang-Van De Mheen, Perla J.; Van Der Heide, Huub J.L.; Van Der Linden-Van Der Zwaag, Henrica M.J.; Valstar, E.R.; Nelissen, R.G.H.H.

    2018-01-01

    Background and purpose — Mobile-bearing total knee prostheses (TKPs) were developed in the 1970s in an attempt to increase function and improve implant longevity. However, modern fixed-bearing designs like the single-radius TKP may provide similar advantages. We compared tibial component

  13. Development of an above-knee prosthesis equipped with a microcomputer-controlled knee joint: first test results.

    Science.gov (United States)

    Aeyels, B; Peeraer, L; Vander Sloten, J; Van der Perre, G

    1992-05-01

    The shortcomings of conventional above-knee prostheses are due to their lack of adaptive control. Implementation of a microcomputer controlling the knee joint in a passive way has been suggested to enhance the patient's gait comfort, safety and cosmesis. This approach was used in the design of a new prosthetic system for the above-knee amputee, and tested on one patient. The knee joint of a conventional, modular prosthesis was replaced by a knee joint mechanism, equipped with a controllable brake on the knee joint axis. Sensors and a microcomputer were added, keeping the system self-contained. The modularity of the design permits the use of an alternative, external, PC-based control unit, emulating the self-contained one, and offering extended data monitoring and storage facilities. For both units an operating environment was written, including sensor/actuator interfacing and the implementation of a real-time interrupt, executing the control algorithm. A double finite state approach was used in the design of the control algorithm. On a higher level, the mode identification algorithm reveals the patient's intent. Within a specific mode (lower level), the relevant mode control algorithm looks for the current phase within the gait cycle. Within a particular phase, a specific simple control action with the brake replaces normal knee muscle activity. Tests were carried out with one prosthetic patient using a basic control algorithm for level walking, allowing controlled knee flexion during stance phase. The technical feasibility of such a concept is illustrated by the test results, even though only flexion during early stance phase was controlled during the trials.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. The use of MRI in the investigation of lateral meniscal tear post medial unicompartmental knee replacement

    Directory of Open Access Journals (Sweden)

    Sanil H. Ajwani, MBChB, BSc (Hons, MRCS

    2015-06-01

    Full Text Available The evaluation of lateral knee pain in patients with a medial unicompartmental knee replacement (UKR is complex. The native lateral compartment structures are prone to the same injuries as patients with normal knees. Historical reports of lateral meniscal injury post medial UKR have argued MRI evaluation is obsolete due to artefact caused by the prosthesis. We report a case of lateral meniscal injury in a patient two years after successful medial UKR. We identified the offending pathology via utilization of MRI scanners adopting metal artefact reduction sequences (MARS. The MARS MRI protocol helps clinicians accurately and non-invasively evaluate soft tissue structures in knees with metal prostheses. It also allows surgeons to accurately counsel patients and provides a higher degree of certainty in treating the pathology.

  15. [Periprosthetic knee fractures].

    Science.gov (United States)

    Mittlmeier, T; Beck, M; Bosch, U; Wichelhaus, A

    2016-01-01

    The cumulative incidence of periprosthetic fractures around the knee is increasing further because of an extended indication for knee replacement, previous revision arthroplasty, rising life expectancy and comorbidities. The relevance of local parameters such as malalignment, osseous defects, neighbouring implants, aseptic loosening and low-grade infections may sometimes be hidden behind the manifestation of a traumatic fracture. A differentiated diagnostic approach before the treatment of a periprosthetic fracture is of paramount importance, while the physician in-charge should also have particular expertise in fracture treatment and in advanced techniques of revision endoprosthetics. The following work gives an overview of this topic. Valid classifications are available for categorising periprosthetic fractures of the femur, the tibia and the patella respectively, which are helpful for the selection of treatment. With the wide-ranging modern treatment portfolio bearing in mind the substantial rate of complications and the heterogeneous functional outcome, the adequate analysis of fracture aetiology and the corresponding transformation into an individualised treatment concept offer the chance of an acceptable functional restoration of the patient at early full weight-bearing and prolonged implant survival. The management of complications is crucial to the final outcome.

  16. Description of the rates, trends and surgical burden associated with revision for prosthetic joint infection following primary and revision knee replacements in England and Wales: an analysis of the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man.

    Science.gov (United States)

    Lenguerrand, Erik; Whitehouse, Michael R; Beswick, Andrew D; Toms, Andrew D; Porter, Martyn L; Blom, Ashley W

    2017-07-10

    To describe the prevalence rates of revision surgery for the treatment of prosthetic joint infection (PJI) for patients undergoing knee replacement, their time trends, the cumulative incidence function of revision for PJI and estimate the burden of PJI at health service level. We analysed revision knee replacements performed due to a diagnosis of PJI and the linked index procedures recorded in the National Joint Registry from 2003 to 2014 for England and Wales. The cohort analysed consisted of 679 010 index primary knee replacements, 33 920 index revision knee replacements and 8247 revision total knee replacements performed due to a diagnosis of PJI. The prevalence rates, their time trends investigated by time from index surgery to revision for PJI, cumulative incidence functions and the burden of PJI (total procedures) were calculated. Overall linear trends were investigated with log-linear regression. The incidence of revision total knee replacement due to PJI at 2 years was 3.2/1000 following primary and 14.4/1000 following revision knee replacement, respectively. The prevalence of revision due to PJI in the 3 months following primary knee replacement has risen by 2.5-fold (95% CI 1.2 to 5.3) from 2005 to 2013 and 7.5-fold (95% CI 1.0 to 56.1) following revision knee replacement. Over 1000 procedures per year are performed as a consequence of knee PJI, an increase of 2.8 from 2005 to 2013. Overall, 75% of revisions were two-stage with an increase in use of single-stage from 7.9% in 2005 to 18.8% in 2014. Although the risk of revision due to PJI following knee replacement is low, it is rising, and coupled with the established and further predicted increased incidence of both primary and revision knee replacements, this represents an increasing and substantial treatment burden for orthopaedic service delivery in England and Wales. This has implications for future service design and the funding of individual and specialist centres. © Article author

  17. Reflections on the present and future of upper limb prostheses.

    Science.gov (United States)

    Farina, Dario; Amsüss, Sebastian

    2016-01-01

    Despite progress in research and media attention on active upper limb prostheses, presently the most common commercial upper limb prosthetic devices are not fundamentally different from solutions offered almost one century ago. Limited information transfer for both control and sensory-motor integration and challenges in socket technology have been major obstacles. By analysing the present state-of-the-art and academic achievements, we provide our opinion on the future of upper limb prostheses. We believe that surgical procedures for muscle reinnervation and osseointegration will become increasingly clinically relevant; muscle electrical signals will remain the main clinical means for prosthetic control; and chronic electrode implants, first in muscles (control), then in nerves (sensory feedback), will become viable clinical solutions. After decades of suspended clinically relevant progress, it is foreseeable that a new generation of upper limb prostheses will enter the market in the near future based on such advances, thereby offering substantial clinical benefit for patients.

  18. Above-knee prosthesis design based on fatigue life using finite element method and design of experiment.

    Science.gov (United States)

    Phanphet, Suwattanarwong; Dechjarern, Surangsee; Jomjanyong, Sermkiat

    2017-05-01

    The main objective of this work is to improve the standard of the existing design of knee prosthesis developed by Thailand's Prostheses Foundation of Her Royal Highness The Princess Mother. The experimental structural tests, based on the ISO 10328, of the existing design showed that a few components failed due to fatigue under normal cyclic loading below the required number of cycles. The finite element (FE) simulations of structural tests on the knee prosthesis were carried out. Fatigue life predictions of knee component materials were modeled based on the Morrow's approach. The fatigue life prediction based on the FE model result was validated with the corresponding structural test and the results agreed well. The new designs of the failed components were studied using the design of experimental approach and finite element analysis of the ISO 10328 structural test of knee prostheses under two separated loading cases. Under ultimate loading, knee prosthesis peak von Mises stress must be less than the yield strength of knee component's material and the total knee deflection must be lower than 2.5mm. The fatigue life prediction of all knee components must be higher than 3,000,000 cycles under normal cyclic loading. The design parameters are the thickness of joint bars, the diameter of lower connector and the thickness of absorber-stopper. The optimized knee prosthesis design meeting all the requirements was recommended. Experimental ISO 10328 structural test of the fabricated knee prosthesis based on the optimized design confirmed the finite element prediction. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  19. Tratamento das infecções pós artroplastia total de joelho: resultados com 2 anos de seguimento Treatment of infections following total knee arthroplasty: 2-year follow-up outcomes

    Directory of Open Access Journals (Sweden)

    Caio Oliveira D'Elia

    2007-01-01

    Full Text Available INTRODUÇÃO: A (ATJ Artroplastia Total do Joelho é cirurgia de grande porte e sujeita a complicações pós operatórias, sendo a infecção uma das piores e mais temidas. No Instituto de Ortopedia e Traumatologia da Faculdade de Medicina da Universidade de São Paulo, a incidência de infecção nas ATJ tem se mantido ao redor de 3% nos últimos 3 anos. O objetivo desse estudo é analisar e padronizar o protocolo de tratamento das infecções pós artroplastia total de joelho. MATERIAIS AND MÉTODOS: Dentre os anos de 2003 e 2004, vinte e nove pacientes com o diagnóstico de infecção pós artroplastia total de joelho primária foram submetidos a o protocolo de tratamento, sendo o período médio de seguimento 20 meses. Dentre os casos nove eram de infecção superficial, três de infecção profunda aguda, e dezoito de infecção profunda crônica. A classificação é baseada em critérios clínicos locais e no tempo de apresentação dos sintomas. RESULTADOS: Foram tratados oito pacientes com quadro de infecção superficial e três pacientes com infecção profunda aguda, com índice de cura de 100%, sem nenhuma recidiva. Foram tratados dezoito casos de infecção profunda crônica, com cura sem recidiva no período de seguimento em 14 pacientes. CONCLUSÃO: Consideramos nossos resultados e nosso protocolo de tratamento adequados e compatíveis com a literatura.OBJECTIVE: The objective of this study is to analyze and standardize the treatment protocol of infections following total knee arthroplasty proposed by the Knee Group and the Infectology Group of IOT-HC-FMUSP. MATERIALS AND METHODS: Between 2003 and 2004, twenty-nine patients (19 women and 10 men, mean age: 67 years diagnosed with infection after total primary knee arthroplasty were hospitalized at IOT-HC FMUSP (Institute of Orthopedics and Traumatology of Hospital das Clínicas, Medical College, University of Sao Paulo, SP, Brazil and subjected to a treatment protocol. The mean

  20. REDUCED THROMBOGENICITY OF VASCULAR PROSTHESES BY COATING WITH ADP-ASE

    NARCIS (Netherlands)

    VANDERLEI, B; ROBINSON, PH; BAKKER, WW; Bartels, H.

    1992-01-01

    In this pilot study ADP-ase coated polyurethane (PL) vascular prostheses and noncoated (control) PU vascular prostheses (all vascular prostheses: ID 1.5 mm, length 1,5 cm) were implanted into the carotid artery of the rabbit to test wheter ADP-ase might function as an adequate anti-thrombogenic

  1. Imaging patellar complications after knee arthroplasty

    International Nuclear Information System (INIS)

    Melloni, Pietro; Valls, Rafael; Veintemillas, Maite

    2008-01-01

    The purpose of this study is to describe complications affecting the patella in patients with total or partial knee arthroplasty. We respectively analysed plain-film radiographs, as well as ultrasound images when acquired, in a consecutive series of 1272 patients. The mean interval from knee replacement to patellar complications was 5 years and 7 months (range, 5 months to 14 years). The complications described include fracture, instability, dislocation or luxation, necrosis of the patella, infection of the patella, erosion of the patella, patellar impingement on the prosthesis and patellar or quadricipital tendon tear. We discuss the pathological imaging findings in the patella and their differential diagnosis after knee arthroplasty. Patellar complications after knee arthroplasty are uncommon but often potentially serious

  2. Imaging patellar complications after knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Melloni, Pietro [Unitat de Imatge d' Alta Tecnologia, Centre Diagnostic, Corporacio Parc Tauli, Universitat Autonoma de Barcelona, Sabadell (Barcelona) (Spain)], E-mail: pmelloni@cspt.es; Valls, Rafael; Veintemillas, Maite [Unitat de Imatge d' Alta Tecnologia, Centre Diagnostic, Corporacio Parc Tauli, Universitat Autonoma de Barcelona, Sabadell (Barcelona) (Spain)

    2008-03-15

    The purpose of this study is to describe complications affecting the patella in patients with total or partial knee arthroplasty. We respectively analysed plain-film radiographs, as well as ultrasound images when acquired, in a consecutive series of 1272 patients. The mean interval from knee replacement to patellar complications was 5 years and 7 months (range, 5 months to 14 years). The complications described include fracture, instability, dislocation or luxation, necrosis of the patella, infection of the patella, erosion of the patella, patellar impingement on the prosthesis and patellar or quadricipital tendon tear. We discuss the pathological imaging findings in the patella and their differential diagnosis after knee arthroplasty. Patellar complications after knee arthroplasty are uncommon but often potentially serious.

  3. Partial knee replacement - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  4. Knee braces - unloading

    Science.gov (United States)

    ... most people talk about the arthritis in their knees, they are referring to a type of arthritis ... is caused by wear and tear inside your knee joints. Cartilage, the firm, rubbery tissue that cushions ...

  5. Loss of knee-extension strength is related to knee swelling after total knee arthroplasty

    DEFF Research Database (Denmark)

    Holm, Bente; Kristensen, Morten T; Bencke, Jesper

    2010-01-01

    To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA).......To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA)....

  6. Periprosthetic fracture-dislocation in a loosened total knee replacement treated by knee arthrodesis

    International Nuclear Information System (INIS)

    Lozano Moreno, Francisco Jose

    2004-01-01

    We present a patient who was operated four years before performing a total knee replacement. She fell down resulting a periprosthetic femoral fracture and a prosthetic dislocation. After evaluating different treatments, we decided to do prosthetic removal and a knee arthrodesis using an intramedullar nail. The femoral fracture was fixed with wire cerclages. Knee arthrodesis is a procedure uses as a last option for the treatment of infected or loosed arthroplasties. In our case it was difficult to consider any other reconstructive procedure due to the association of fracture, dislocation and loosening. The evolution has been satisfactory with good functional result and without pain

  7. 500 penile prostheses implanted by a surgeon in Italy in the last 30 years

    Directory of Open Access Journals (Sweden)

    Diego Pozza

    2015-09-01

    Full Text Available Objectives: The aim of our study was to report our experience with patients affected by Erectile Dysfunction (ED and undergoing penile prosthetic implantation (PPI in a single center by a single surgeon. Material and Methods: We retrospectively evaluated the clinical outcome of 500 patients (mean age: 51.5 years, range: 20-86 years affected by ED and referred to our private andrological center from January 1984 to December 2013 who underwent penile prosthesis implantation, including the reported level of patient satisfaction. Results: 182 silicone, 180 malleable, 18 monocomponent hydraulic and 120 multicomponents hydraulic prostheses were implanted by the same experienced surgeon. All patients were hospitalized for the procedure. All patients were evaluated immediately, 1 month (496 patients and, for the great majority, every year after implantation. One hundred twenty five patients were lost to follow-up. Twenty two patients underwent revision surgery for complications in the postoperative period. The most serious postoperative complications were mechanical problems (45 patients, 9.0% and infection (15 patients, 3%. Forty two (8.4% prostheses were explanted. Overall, 80% (400/500 of patients were able to have sexual intercourse and were fully satisfied with the results. Conclusions: In our experience prosthetic surgery should be considered a good solution for men affected by ED and not responsive to other therapeutic solutions. Prosthetic surgery can be performed not only in large public hospitals but also in smaller private facilities.

  8. Arthroplasty knee registry of Catalonia: What scientific evidence supports the implantation of our prosthesis?

    Science.gov (United States)

    Samaniego Alonso, R; Gaviria Parada, E; Pons Cabrafiga, M; Espallargues Carreras, M; Martinez Cruz, O

    2018-02-28

    In our environment, it is increasingly necessary to perform an activity based on scientific evidence and the field of prosthetic surgery should be governed by the same principles. The national arthroplasty registries allow us to obtain a large amount of data in order to evaluate this technique. The aim of our study is to analyse the scientific evidence that supports the primary total knee arthroplasties implanted in Catalonian public hospitals, based on the Arthoplasty Registry of Catalonia (RACat) MATERIAL AND METHODS: A review of the literature was carried out on knee prostheses (cruciate retaining, posterior stabilized, constricted and rotational) recorded in RACat between the period 2005-2013 in the following databases: Orthopedic Data Evaluation Panel, PubMed, TripDatabase and Google Scholar. The prostheses implanted in fewer than 10 units (1,358 prostheses corresponding to 62 models) were excluded. 41,947 prostheses (96.86%) were analysed out of 43,305 implanted, corresponding to 74 different models. In 13 models (n = 4,715) (11.24%) no clinical evidence to support their use was found. In the remaining 36 models (n = 13,609) (32.45%), level iv studies were the most predominant evidence. There was a significant number of implanted prostheses (11.24%) for which no clinical evidence was found. The number of models should be noted, 36 out of 110, with fewer than 10 units implanted. The use of arthroplasty registries has proved an extremely useful tool that allows us to analyse and draw conclusions in order to improve the efficiency of this surgical technique. Copyright © 2018 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Knee Arthrodesis After Failure of Knee Arthroplasty

    DEFF Research Database (Denmark)

    Gottfriedsen, Tinne B; Morville Schrøder, Henrik; Odgaard, Anders

    2016-01-01

    BACKGROUND: Arthrodesis is considered a salvage procedure after failure of a knee arthroplasty. Data on the use of this procedure are limited. The purpose of this study was to identify the incidence, causes, surgical techniques, and outcomes of arthrodesis after failed knee arthroplasty...... in a nationwide population. METHODS: Data were extracted from the Danish Civil Registration System, the Danish National Patient Register, and the Danish Knee Arthroplasty Register. A total of 92,785 primary knee arthroplasties performed in Denmark from 1997 to 2013 were identified by linking the data using....... Differences in cumulative incidence were compared with the Gray test. RESULTS: A total of 164 of the 165 arthrodeses were performed for causes related to failed knee arthroplasty. The 15-year cumulative incidence of arthrodesis was 0.26% (95% confidence interval, 0.21% to 0.31%). The 5-year cumulative...

  10. Microbial colonization of silicone voice prostheses used in laryngectomized patients

    NARCIS (Netherlands)

    Eerenstein, S. E.; Grolman, W.; Schouwenburg, P. F.

    1999-01-01

    The aim of this study was to identify the microbial colonization of dysfunctioning voice prostheses in laryngectomized patients and determine the influence of patient radiation therapy on prosthesis life span. In a 40-month period, 257 outpatient voice prosthesis replacements were carried out in a

  11. Critiquing the Computer-Aided Design of Dental Prostheses.

    Science.gov (United States)

    Fitzpatrick, F. J.; And Others

    This paper describes RaPiD, a computer-aided assistant for the design of dental prostheses called removable partial dentures. The user manipulates icons directly to indicate the desired design solution to a given clinical situation. A developing design is represented as a logic database of components in a design; expert rules are applied as…

  12. Magnetic resonance imaging of breast prostheses | Corr | SA ...

    African Journals Online (AJOL)

    Breast MR imaging is the most accurate imaging investigation to detect breast prosthesis rupture. Rupture is common in older prostheses (> 10 years post implantation) and is often asymptomatic. The radiological signs of rupture are due to collapse of the elastomer shell which is eneveloped by silicone gel and when the ...

  13. Study of effects of radiation on silicone prostheses

    International Nuclear Information System (INIS)

    Shedbalkar, A.R.; Devata, A.; Padanilam, T.

    1980-01-01

    Radiation effects on silicone gel and dose distribution of radiation through mammary prostheses were studied. Silicone gel behaves like tissue. Half value thickness for silicone gel and water are almost the same. Linear absorption coefficient for silicone gel and water are comparable

  14. Evaluation of pneumatic cylinder actuators for hand prostheses

    NARCIS (Netherlands)

    Peerdeman, B.; Smit, Gerwin; Stramigioli, Stefano; Plettenburg, Dick; Misra, Sarthak

    2012-01-01

    DC motors are currently the preferred actuation method for externally powered hand prostheses. However, they are often heavy and large, which limits the number of actuators that can be integrated into the prosthesis. Alternative actuation methods are being researched, but have not yet found wide

  15. Novel strategies to improve the patency of vascular prostheses

    NARCIS (Netherlands)

    Heyligers, J.M.M.

    2006-01-01

    Two novel strategies to improve the patency of vascular prostheses are described in this thesis. To improve the outcome of synthetic vascular bypass surgery, cell seeding is a promising concept that has extensively been investigated and is still evolving. To improve the short term effects due to

  16. [The costs for different voice prostheses depending on the lifetime].

    Science.gov (United States)

    Schuldt, T; Ovari, A; Dommerich, S

    2013-06-01

    Voice prostheses are available in different types of architecture und from different producers. Especially the ones with antifungal properties are characterized by a high pricing. The aim of this paper is to check, whether these prices are reflected by the prosthesis life time.A Benchmarking with usage of mean lifetime and prosthesis costs. Comparing Provox 1, Provox 2, Provox Vega, Provox ActiValve, ESKA-Herrmann, Blom Singer Classic, Phonax, Blom Singer Advantage.The voice prosthesis Provox 1 offers the best price-lifetime-ratio (1.0). It's 6.7-times higher than the one of the Provox ActiValve (0.15). In addition, the classic prostheses Provox 2 (0.53), Blom Singer Classic (0.54) and ESKA-Herrmann (0.72) offer a good ratio compared to Provox 1, too.The mean lifetime of the voice prostheses do not reflect the pricing. The Provox 1 offers the best ratio and should be used as a reference in pricing the prostheses. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Cobalt release and complications resulting from the use of dental prostheses

    DEFF Research Database (Denmark)

    Al-Imam, Hiba; Benetti, Ana R.; Özhayat, Esben B.

    2016-01-01

    of the functional prostheses released cobalt, whereas this was observed in 24 of 32 non-functional prostheses. None of the patients had contact allergy to cobalt. Of the 66 patients, 11 showed signs of inflammation of the oral mucosa, 2 had oral candidiasis, 16 had ill-fitting prostheses, and all had insufficient...... oral hygiene. CONCLUSIONS: Dental prostheses released cobalt during the fabrication stages, but not 1-5 years after insertion. No allergic reactions were observed. Signs of inflammation were related to candidiasis, insufficient oral hygiene, and ill-fitting prostheses....

  18. Fracture analysis of randomized implant-supported fixed dental prostheses

    Science.gov (United States)

    Esquivel-Upshaw, Josephine F.; Mehler, Alex; Clark, Arthur E.; Neal, Dan; Anusavice, Kenneth J.

    2014-01-01

    Objective Fractures of posterior fixed dental all-ceramic prostheses can be caused by one or more factors including prosthesis design, flaw distribution, direction and magnitude of occlusal loading, and nature of supporting infrastructure (tooth root/implant), and presence of adjacent teeth. This clinical study of implant-supported, all-ceramic fixed dental prostheses, determined the effects of (1) presence of a tooth distal to the most distal retainer; (2) prosthesis loading either along the non-load bearing or load bearing areas; (3) presence of excursive contacts or maximum intercuspation contacts in the prosthesis; and (4) magnitude of bite force on the occurrence of veneer ceramic fracture. Methods 89 implant-supported FDPs were randomized as either a three-unit posterior metal-ceramic (Au-Pd-Ag alloy and InLine POM, Ivoclar, Vivadent) FDP or a ceramic-ceramic (ZirCAD and ZirPress, Ivoclar, Vivadent) FDP. Two implants (Osseospeed, Dentsply) and custom abutments (Atlantis, Dentsply) supported these FDPs, which were cemented with resin cement (RelyX Universal Cement). Baseline photographs were made with markings of teeth from maximum intercuspation (MI) and excursive function. Patients were recalled at 6 months and 1 to 3 years. Fractures were observed, their locations recorded, and images compared with baseline photographs of occlusal contacts. Conclusion No significant relationship exists between the occurrence of fracture and: (1) the magnitude of bite force; (2) a tooth distal to the most distal retainer; and (3) contacts in load-bearing or non-load-bearing areas. However, there was a significantly higher likelihood of fracture in areas with MI contacts only. Clinical Significance This clinical study demonstrates that there is a need to evaluate occlusion differently with implant-supported prostheses than with natural tooth supported prostheses because of the absence of a periodontal ligament. Implant supported prostheses should have minimal occlusion and

  19. 3D-printed upper limb prostheses: a review.

    Science.gov (United States)

    Ten Kate, Jelle; Smit, Gerwin; Breedveld, Paul

    2017-04-01

    This paper aims to provide an overview with quantitative information of existing 3D-printed upper limb prostheses. We will identify the benefits and drawbacks of 3D-printed devices to enable improvement of current devices based on the demands of prostheses users. A review was performed using Scopus, Web of Science and websites related to 3D-printing. Quantitative information on the mechanical and kinematic specifications and 3D-printing technology used was extracted from the papers and websites. The overview (58 devices) provides the general specifications, the mechanical and kinematic specifications of the devices and information regarding the 3D-printing technology used for hands. The overview shows prostheses for all different upper limb amputation levels with different types of control and a maximum material cost of $500. A large range of various prostheses have been 3D-printed, of which the majority are used by children. Evidence with respect to the user acceptance, functionality and durability of the 3D-printed hands is lacking. Contrary to what is often claimed, 3D-printing is not necessarily cheap, e.g., injection moulding can be cheaper. Conversely, 3D-printing provides a promising possibility for individualization, e.g., personalized socket, colour, shape and size, without the need for adjusting the production machine. Implications for rehabilitation Upper limb deficiency is a condition in which a part of the upper limb is missing as a result of a congenital limb deficiency of as a result of an amputation. A prosthetic hand can restore some of the functions of a missing limb and help the user in performing activities of daily living. Using 3D-printing technology is one of the solutions to manufacture hand prostheses. This overview provides information about the general, mechanical and kinematic specifications of all the devices and it provides the information about the 3D-printing technology used to print the hands.

  20. Kinematics and early migration in single-radius mobile- and fixed-bearing total knee prostheses

    NARCIS (Netherlands)

    Wolterbeek, N.; Garling, E.H.; Mertens, B.J.; Nelissen, R.G.H.H.; Valstar, E.R.

    2012-01-01

    Background The mobile-bearing variant of a single-radius design is assumed to provide more freedom of motion compared to the fixed-bearing variant because the insert does not restrict the natural movements of the femoral component. This would reduce the contact stresses and wear which in turn may

  1. Helical axes of skeletal knee joint motion during running.

    Science.gov (United States)

    van den Bogert, A J; Reinschmidt, C; Lundberg, A

    2008-01-01

    The purpose of this study was to determine the changes in the axis of rotation of the knee that occur during the stance phase of running. Using intracortical pins, the three-dimensional skeletal kinematics of three subjects were measured during the stance phase of five running trials. The stance phase was divided into equal motion increments for which the position and orientation of the finite helical axes (FHA) were calculated relative to a tibial reference frame. Results were consistent within and between subjects. At the beginning of stance, the FHA was located at the midepicondylar point and during the flexion phase moved 20mm posteriorly and 10mm distally. At the time of peak flexion, the FHA shifted rapidly by about 10-20mm in proximal and posterior direction. The angle between the FHA and the tibial transverse plane increased gradually during flexion, to about 15 degrees of medial inclination, and then returned to zero at the start of the extension phase. These changes in position and orientation of FHA in the knee should be considered in analyses of muscle function during human movement, which require moment arms to be defined relative to a functional rotation axis. The finding that substantial changes in axis of rotation occurred independent of flexion angle suggests that musculoskeletal models must have more than one kinematic degree-of-freedom at the knee. The same applies to the design of knee prostheses, if the goal is to restore normal muscle function.

  2. [Surgical technique and clinical results of total knee arthroplasty in treating endstage gonarthrosis combined with valgus knee deformity].

    Science.gov (United States)

    Wang, Xingshan; Weng, Xisheng; Lin, Jin; Jin, Jin; Qian, Wenwei

    2012-05-01

    To investigate the surgical technique and the clinical results of total knee arthroplasty (TKA) in treating end-stage gonarthrosis combined with valgus knee deformity. Between November 1998 and October 2010, 64 patients (72 knees) with end-stage gonarthrosis combined with valgus knee deformity underwent TKA by a medial parapatellar approach. Of the 64 patients, 18 were male and 46 were female with an average age of 62.5 years (range, 23-82 years), including 44 cases (49 knees) of osteoarthritis, 17 cases (20 knees) of rheumatoid arthritis, 2 cases (2 knees) of haemophilic arthritis, and 1 case (1 knee) of post-traumatic arthritis. Bilateral knees were involved in 8 cases, and single knee in 56 cases. The flexion and extension range of motion (ROM) of the knee joint was (82.2 +/- 28.7) degrees; the femur-tibia angle (FTA) was (18.0 +/- 5.8) degrees; according to Knee Society Score (KSS) criterion, the preoperative clinical score was 31.2 +/- 10.1 and functional score was 37.3 +/- 9.0. According to Krackow's classification, there were 65 knees of type I and 7 knees of type II. By medial parapatellar approach, conventional osteotomy and Ranawat soft tissue release were performed in all cases. Prosthesis of preserved posterior cruciate ligament were used in 7 cases (7 knees), posterior stabilize prosthesis in 54 cases (60 knees), constrained prosthesis in 4 cases (5 knees). Incisions healed by first intention in all cases. Peroneal nerve palsy occurred in 1 patient with haemophilic arthritis, severe valgus deformity (FTA was 41 degrees), and flexion contracture (20 degrees), which was cured after 1 year of conservative treatment. Revison surgery was performed in 1 case of deep infection at 2 years after surgery. All the patients were followed up 4.9 years on average (range, 1-13 years). At last follow-up, the FTA was (7.0 +/- 2.5) degrees, showing significant difference when compared with preoperative value (t = 15.502, P = 0.000). The KSS clinical score was 83.0 +/- 6

  3. Traumatic knee extension deficit (the locked knee)

    DEFF Research Database (Denmark)

    Helmark, I C; Neergaard, K; Krogsgaard, M R

    2007-01-01

    In the present study we investigated the validity of magnetic resonance imaging (MRI) and arthroscopy in knees with acute, traumatic extension deficit (the "locked knee"), and evaluated whether arthroscopy of knees with no mechanical pathology could be avoided by MRI evaluation. The study consisted...... of 50 patients who had an acute, traumatic extension deficit of the knee. All patients were submitted to MRI prior to arthroscopy. Following MRI and surgery, standardized forms were filled out, attempting to objectify the findings. The orthopaedic surgeon was not aware of the MRI result prior to surgery....... Evaluating MRI, all grade-3 meniscal lesions were considered able to cause a mechanical block as well as acute partial or total anterior cruciate ligament (ACL)-ruptures. ACL-ruptures with an old appearance were not considered able to cause locking. Assuming that arthroscopy was the gold standard...

  4. Longitudinal research on the oral environment of elderly wearing fixed or removable prostheses.

    Science.gov (United States)

    Tanaka, Junko; Tanaka, Masahiro; Kawazoe, Takayoshi

    2009-04-01

    The purpose of this study was to investigate oral environmental risk factors involved in caries incidence in the elderly. We investigated the relationship between the oral environment factors of the elderly with both fixed prostheses and removable prostheses at baseline and at follow-up and examined time-course changes of each oral environmental factor by prosthesis type. The subject group consisted 11 elderly patients with fixed prostheses and 11 who wore removable prostheses. We examined oral environmental factors by saliva tests. Five oral environmental factors were examined: the stimulated salivary flow rate, buffering capacity, and the counts of mutans streptococci (SM), lactobacilli (LB), and Candida (CA). We compared these factors for subjects with fixed prostheses and those wearing removable prostheses at baseline and at follow-up. Furthermore, 3-year changes in the factors of each oral environment were compared and evaluated. Significant differences were observed between the two groups in the salivary microbial counts of SM and LB at baseline and at follow-up. The LB counts increased in the Denture group during the 3-year period and significant differences were noted. We found that fixed prostheses are less cariogenic, and removable prostheses cause an increase in the cariogenic bacterial count. Regarding time-course changes by the type of prosthesis, the LB count tended to increase in the subjects with removable prostheses. The risk of caries due to a fixed prosthesis may be lower than that of removable prostheses.

  5. Micromotion in knee arthroplasty. A roentgen stereophotogrammetric analysis of four different concepts of prosthetic fixation

    International Nuclear Information System (INIS)

    Ryd, L.

    1985-05-01

    In a prospective study, micromotion between tibial components and bone was analysed using roentgen stereophotogrammetric analysis (RSA), the potential of which was assessed. The patient material consisted of 96 arthrotic knees subjected to arthroplasty with six types of prosthese representing four different fixation concepts with and without bone cement. Provided stable conditions of the objects studied, RSA proved to have an accuracy (=resolution) of 0.3 degrees for rotation and 0.2 mm for translation (3 S.D.). This resolution was 10 times better than conventional radiography and sufficient for the study of micromotion. Micromotion, both gradual over time (migration) and instant, in response to applied forces (inducible displacement), was found for all tibial components studied. For conventional cemented prostheses the mean migration was 1-1.5 mm for the different groups. Most of the migration occurred during the first 6 months. Inducible displacement of 0.2-1.0 mm was found in most cases. Metal support did not improve the prosthetic fixation. For the non-cemented cases both migration and inducible displacement was significantly larger than in cemented cases. All prostheses proved to be bonded to the bone in a semi-rigid way permitting micromotion. The newer fixation concept did not prove superior to conventional cementing of all-polyethylene prostheses. The micromotion occurred wihtin the soft tissue layer constituing the radiolucent zone, which in some cases was of tensile origin. Other radiographic of clinical variables did not correlate with the micromotion. (Author)

  6. Arthroscopic surgery for degenerative knee

    DEFF Research Database (Denmark)

    Thorlund, Jonas Bloch; Juhl, C B; Roos, E M

    2015-01-01

    . DATA SOURCES: Systematic searches for benefits and harms were carried out in Medline, Embase, CINAHL, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) up to August 2014. Only studies published in 2000 or later were included for harms. ELIGIBILITY CRITERIA FOR SELECTING...... included symptomatic deep venous thrombosis (4.13 (95% confidence interval 1.78 to 9.60) events per 1000 procedures), pulmonary embolism, infection, and death. CONCLUSIONS: The small inconsequential benefit seen from interventions that include arthroscopy for the degenerative knee is limited in time...

  7. Jumper's Knee (Patellar Tendonitis) (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Jumper's Knee (Patellar Tendonitis) KidsHealth / For Parents / Jumper's Knee (Patellar ... prevent continued damage to the knee. How the Knee Works To understand how jumper's knee happens, it ...

  8. The pediatric knee.

    Science.gov (United States)

    Orth, Robert C

    2013-03-01

    Knee pain is a common problem in children and adolescents, and MRI of the knee is the most commonly performed pediatric cross-sectional musculoskeletal imaging exam. The purpose of this pictorial review is to highlight differences between adult and pediatric knee imaging with an emphasis on normal developmental variants, injury and disease patterns unique to children and adolescents, and differences in response and presentation to conditions affecting both adults and children.

  9. Manufacturing implant supported auricular prostheses by rapid prototyping techniques.

    Science.gov (United States)

    Karatas, Meltem Ozdemir; Cifter, Ebru Demet; Ozenen, Didem Ozdemir; Balik, Ali; Tuncer, Erman Bulent

    2011-08-01

    Maxillofacial prostheses are usually fabricated on the models obtained following the impression procedures. Disadvantages of conventional impression techniques used in production of facial prosthesis are deformation of soft tissues caused by impression material and disturbance of the patient due to. Additionally production of prosthesis by conventional methods takes longer time. Recently, rapid prototyping techniques have been developed for extraoral prosthesis in order to reduce these disadvantages of conventional methods. Rapid prototyping technique has the potential to simplify the procedure and decrease the laboratory work required. It eliminates the need for measurement impression procedures and preparation of wax model to be performed by prosthodontists themselves In the near future this technology will become a standard for fabricating maxillofacial prostheses.

  10. Polyrethene nasolacrimal prostheses. Assessment of the complications using computed tomography

    International Nuclear Information System (INIS)

    Pino, I. T.; Paul, L.; Duran, M. A.; Grande, C.

    1999-01-01

    To assess the outcome of treatment of epiphora secondary to nasolacrimal duct obstruction by placement of a polyurethane prosthesis. We placed 20 polyurethane prostheses (song's prostheses) in 19 patients with nasolacrimal duct obstruction who presented idiopathic grade III-IV epiphora. All the patients underwent CT with follow-up studies 10 days, one month and three months after prosthesis placement. Epiphora resolved completely in 13 cases and partially in four. In two cases, the prosthesis was poorly positioned; one of them was replaced and the other functions to date. There were three cases of obstruction. We observed limited epistaxis in 7 patients and headache in one. The treatment of epiphora by polyurethane prosthesis placement is a simple procedure that is well tolerated by patients and has a high success rate. (Author) 14 refs

  11. Manufacturing Implant Supported Auricular Prostheses by Rapid Prototyping Techniques

    OpenAIRE

    Karatas, Meltem Ozdemir; Cifter, Ebru Demet; Ozenen, Didem Ozdemir; Balik, Ali; Tuncer, Erman Bulent

    2011-01-01

    Maxillofacial prostheses are usually fabricated on the models obtained following the impression procedures. Disadvantages of conventional impression techniques used in production of facial prosthesis are deformation of soft tissues caused by impression material and disturbance of the patient due to. Additionally production of prosthesis by conventional methods takes longer time. Recently, rapid prototyping techniques have been developed for extraoral prosthesis in order to reduce these disadv...

  12. Workflow Optimization for Tuning Prostheses with High Input Channel

    Science.gov (United States)

    2017-10-01

    of Specific Aim 1 by driving a commercially available two DoF wrist and single DoF hand. The high -level control system will provide analog signals...AWARD NUMBER: W81XWH-16-1-0767 TITLE: Workflow Optimization for Tuning Prostheses with High Input Channel PRINCIPAL INVESTIGATOR: Daniel Merrill...Unlimited The views, opinions and/or findings contained in this report are those of the author(s) and should not be construed as an official Department

  13. Clinical Management of Implant Prostheses in Patients with Bruxism

    Science.gov (United States)

    Komiyama, Osamu; Lobbezoo, Frank; De Laat, Antoon; Iida, Takashi; Kitagawa, Tsuyoshi; Murakami, Hiroshi; Kato, Takao; Kawara, Misao

    2012-01-01

    There is general agreement that excessive stress to the bone-implant interface may result in implant overload and failure. Early failure of the implant due to excessive loading occurs shortly after uncovering the implant. Excess load on a final restoration after successful implant integration can result in physical failure of the implant structure. Many clinicians believe that overload of dental implants is a risk factor for vertical peri-implant bone loss and/or may be detrimental for the suprastructure in implant prostheses. It has been documented that occlusal parafunction, such as, bruxism (tooth grinding and clenching) affects the outcome of implant prostheses, but there is no evidence for a causal relation between the failures and overload of dental implants. In spite of this lack of evidence, often metal restorations are preferred instead of porcelain for patients in whom bruxism is presumed on the basis of tooth wear. The purpose of this paper is to discuss the importance of the occlusal scheme used in implant restorations for implant longevity and to suggest a clinical approach and occlusal materials for implant prostheses in order to prevent complications related to bruxism. PMID:22701484

  14. Magnetic resonance imaging in patients with heart valve prostheses

    International Nuclear Information System (INIS)

    Bachmann, R.; Juengehuelsing, M.; Schicha, H.; Deutsch, H.J.; Sechtem, U.; Hilger, H.H.

    1991-01-01

    Artifical valve prostheses are often regarded as a contraindication for magnetic resonance imaging (MRI), although preliminary in vitro studies suggested, that patients with these metallic implants might safely undergo MR examination. This study reports on the experience with a group of 89 patients with 100 heart valve prostheses who were examined by spin-echo MR and gradient-echo MR. MR examination was performed in all patients without complications. The spin-echo sequence showed advantages in the depiction of anatomical structures like paravalvular abcesses. Anatomical structures adjacent to the artificial valve were clearly visivle and the metal components of the valves showes no or only small artifacts. Artifacts were accentuated when using gradient-echo sequences. Gradient-echo sequences provided valuable information regarding the presence of valvular insufficiency. Physiological valvular regurgitation was easy to differentiate from pathological paravalvular or transvalvular regurgitation. These results demonstrate that patients with artificial valve prostheses can be imaged by MR without risk and that prosthesis-induced artifacts do no interfere with image interpretation. (orig.) [de

  15. Evaluation of the gait performance of above-knee amputees while walking with 3R20 and 3R15 knee joints

    Directory of Open Access Journals (Sweden)

    AliReza Taheri

    2012-01-01

    Full Text Available Background: The performance of the subjects with above-knee amputation is noticeably poorer than normal subjects. Various types of components have been designed to compensate their performance. Among various prosthetic components, the knee joint has great influence on the function. Two types of knee joints (3R15, 3R20 have been used broadly for above-knee prostheses. However, there is not enough research to highlight the influence of these joints on the gait performance of the subjects. Therefore, an aim of this research was to investigate the performance of the above-knee amputees while walking with 3R15 and 3R20 knee joints. Materials and Methods: 7 above-knee amputees were recruited in this research study. They were asked to walk with a comfortable speed to investigate the gait function of the subjects with 3 cameras 3D motion analysis system (Kinematrix system. The difference between the performances of the subjects with these joints was compared by use of paired t-test. Results: The results of this study showed that, the performances of the subjects with 3R20 were better than that with 3R15. The walking speed of the subjects with 3R20 was 66.7 m/min compared to 30.4 m/min (P-value = 0.045. Moreover; the symmetry of walking with 3R20 was more than that with 3R15, based on the spatio- temporal gait parameters values (P-value <0.05. Conclusion: The difference between the performances of the subjects with 3R20 and 3R15 knee joints was related to the walking speed, which improved while walking with 3R20 joint.

  16. Fabrication of biosynthetic vascular prostheses by 193-nm excimer laser radiation

    Science.gov (United States)

    Husinsky, Wolfgang; Csek, Ch.; Bartel, A.; Grabenwoeger, M.; Fitzal, F.; Wolner, Ernst

    1998-05-01

    This study was undertaken to investigate the feasibility of transmural capillary ingrowth into the inner surface of biosynthetic vascular prostheses (OmniflowTM) through perforations created by an excimer-laser, thus inducing an endothelial cell coverage. The biosynthetic vascular prostheses (10 cm length, 6 mm (phi) ) were perforated with an excimer laser ((phi) of the holes 50 - 100 micrometer, distance 4 mm) and implanted into the carotid arteries of 8 sheep. The laser tissue interaction process of 193 nm radiation ensures minimal thermal damage to the prostheses. They were compared to untreated OmniflowTM prostheses implanted at the contralateral side. Three months after implantation the prostheses were explanted and evaluated by gross morphology, histological examination and scanning electron microscopy. Scanning electron microscopy showed endothelial cells in the midgraft portion of all perforated prostheses, whereas collagen fibers, fibrin meshwork and activated platelets formed the inner layer in 6 out of 8 untreated OmniflowTM prostheses. It can be concluded, that spontaneous endothelialization of biosynthetic vascular prostheses can be achieved by transmural capillary ingrowth through perforations in the wall of the prostheses in an experimental sheep model.

  17. Musculoskeletal MR: knee

    International Nuclear Information System (INIS)

    Staebler, A.; Glaser, C.; Reiser, M.

    2000-01-01

    Magnetic resonance imaging is the most sensitive, specific, and accurate noninvasive method for diagnosing internal derangement of the knee. During the past 15 years knowledge of pathologic conditions of the knee had evolved significantly. Beyond the basic principles of imaging knee injuries great impact was made on the understanding of indirect or collateral findings, even in rare diseases. In this article the spectrum of disorders of the knee are reviewed and an overview of the current literature is given. This includes considerations about how to achieve a high-standard MR imaging study of the knee, and principles of imaging anterior cruciate ligament and meniscal tears. A focus is put on distinct diseases including intra-articular and intraosseous ganglion cysts, iliotibial band friction syndrome, transient osteoporosis, osteonecrosis, osteochondritis dissecans, and imaging of the articular cartilage. (orig.)

  18. Late dislocation of rotating platform in New Jersey Low-Contact Stress knee prosthesis.

    Science.gov (United States)

    Huang, Chun-Hsiung; Ma, Hon-Ming; Liau, Jiann-Jong; Ho, Fang-Yuan; Cheng, Cheng-Kung

    2002-12-01

    Five patients with late rotational dislocation of the rotating platform bearing in the New Jersey Low-Contact Stress total knee arthroplasty are reported. The prostheses had functioned well for 8 to 12 years before failure. Preoperative radiographs showed asymmetric femorotibial joint spaces. Entrapment of the dislocated bearing in three patients and spontaneous reduction of the dislocated bearing in another two patients were seen at revision. Femorotibial ligamentous instability was found after reduction. The retrieved polyethylene bearings showed advanced wear and cold flow deformities and the thickness was reduced. The revision arthroplasty was accomplished by replacement with a thicker bearing element. Progressive femorotibial ligament laxity and reduction of the thickness of polyethylene with wearing break down the originally well-balanced soft tissue tension of the knee. The rotational degree of the rotating platform bearing is unrestricted, which may result in late dislocation. Polyethylene wear is unavoidable in knee prostheses using metal contact with polyethylene even with a mobile-bearing design. Efforts to reduce polyethylene wear are mandatory.

  19. [CLINICAL APPLICATION OF OXFORD MOBILE-BEARING BIPOLAR PROSTHESIS UNICOMPARTMENTAL KNEE ARTHROPLASTY FOR SINGLE COMPARTMENTAL KNEE OSTEOARTHRITIS].

    Science.gov (United States)

    Wang, Shangzeng; Cheng, Shao; Wang, Yisheng

    2016-01-01

    To evaluate the effectiveness of Oxford mobile-bearing bipolar prosthesis unicompartmental knee arthroplasty (UKA) in the treatment of single compartmental knee osteoarthritis. Between June 2011 and July 2013, 22 cases of single compartmental knee osteoarthritis were treated by Oxford mobile-bearing bipolar prosthesis UKA. Of 22 cases, 8 were male and 14 were female with an average age of 65 years (range, 45-80 years); the left knee was involved in 12 cases, and the right knee in 10 cases, with a mean disease duration of 32.5 months (range, 8-90 months). The mean weight was 55.2 kg (range, 50-65 kg), and the mean body mass index was 20.8 kg/m2 (range, 17-25 kg/m2). Osteoarthritis involved in the single knee medial compartment in all patients. Knee society score (KSS) and range of motion (ROM) were measured to evaluate the knee joint function. Primary healing of incision was obtained in all patients, and there was no complication of infection, bedsore, or deep venous thrombosis. Postoperative follow-up was 2-4 years (mean, 3.2 years). The X-ray films showed good position of prosthesis, no prosthesis dislocation, or periprosthetic infection during follow-up. Knee ROM, KSS function score, and KSS clinical score were significantly improved at 1 week after operation and at last follow-up when compared with preoperative ones (P 0.05). Oxford mobile-bearing bipolar prosthesis UKA is an effective method to treat single compartmental knee osteoarthritis, with the advantages of less trauma, earlier rehabilitation exercise, near physiological state in joint function, and less risk of complications.

  20. Radiographic and scintigraphic evaluation of total knee arthroplasty

    International Nuclear Information System (INIS)

    Schneider, R.; Soudry, M.

    1986-01-01

    Various radiographic and scintigraphic methods are used to supplement clinical findings in the evaluation of total knee arthroplasty and its complications. Serial roentgenograms offer reliable information for diagnosing mechanical loosening. Wide and extensive radiolucency at the cement-bone interface and shift in position and alignment of prosthetic components can be seen in almost all cases by the time revision is necessary. Radiographic abnormalities are usually not present in acute infection, but are often present in chronic infection. Bone scanning has a high sensitivity for diagnosis of infection or loosening, but is nonspecific because increased uptake is often present around asymptomatic total knee arthroplasties with normal radiographs. Differential bone and Gallium scanning and scanning with Indium 111-labeled leukocytes have a greater specificity for diagnosis of infection than does bone or Gallium scanning alone. Routine radiographic and scintigraphic studies have shown a high incidence of deep vein thrombosis in the calf after total knee arthroplasty. Clinically significant pulmonary embolization is infrequent

  1. Malignant Fibrohisticytoma of the Knee in a Patient with HIV

    Directory of Open Access Journals (Sweden)

    Riccardo Gomes Gobbi

    2012-01-01

    Full Text Available This case report describes a patient presenting with anterior knee pain (extensor mechanism pain, a poorly studied complaint in the HIV population. The final diagnosis was malignant fibrohistiocytoma, a rare condition among knee pathologies, successfully treated with endoprosthesis after tumor resection. This article focuses on what the authors learned after treating this patient, particularly on the difficulty in making a correct diagnosis of this group of patients due to lack of adequate epidemiological characterization. By assuming that the pathology was related to long-term infection and treatment of HIV (knee hoffitis, the authors underestimated the gravity of the case, almost compromising the result of treatment.

  2. Infection,

    Science.gov (United States)

    1980-10-16

    characteristic in severe gram-negative sepsis. Hypertriglyceridemia results from an increase in hepatic synthesis in combination with diminished activity of...induced stress, and tissue repair (1). The magnitude and type of nutritional losses caused by an infection reflect both the severity and duration of an... several functional forms of nutrient loss must be anticipated. Functional losses are defined as the within-body losses of nutrients due to infection

  3. [In situ aortofemoral reconstructions in surgical treatment of infected aortofemoral grafts].

    Science.gov (United States)

    Badretdinov, I A; Pokrovsky, A V

    2015-01-01

    The article presents a review of literature sources covering possibilities of peiforming in situ aortofemoral reconstructions in surgical treatment of infected aortofemoral grafts. This methodology makes it possible to improve the outcomes of treatment for paraprosthetic infection at the expense of decreasing lethality and morbidity, increasing parameters of patency of grafts and lower limb salvage in the remote postoperative period. Mention should be made that in situ secondary aortofemoral reconstructions are fraught with danger of relapsing paraprosthetic infection, therefore many publications are dedicated to search for prostheses most resistant to infection. The article also presents the results of works devoted to the use of various types of prostheses for in situ secondary aortofemoral reconstructions: prostheses made of polytetrafluoroethylene (PTFE), synthetic grafts saturated with various antibacterial drugs and gelatine, cadaveric allografts, synthetic prostheses treated with silver ions, autovenous conduits based on the femoral and popliteal veins.

  4. Mobile-bearing total knee arthroplasty: a full traumatic rotation of 180°.

    Science.gov (United States)

    Sudanese, Alessandra; Castiello, Emanuela; Affatato, Saverio

    2013-06-25

    From February 2008 to September 2012 we implanted 204 mobile-bearing knee prostheses in 192 patients. All the prostheses were cemented (both femoral and tibial components), and the patella was not replaced. Only one early complication of the implants (1/204 = 0.004%) occurred after a traumatic event as a full 180° rotation of the mobile-bearing polyethylene insert. A 78-year-old woman presented with swelling and severe pain at her right knee. This traumatic event was the only case among our mobile-bearing insert patients. 
The failed polyethylene inserts were retrieved and studied using a scanning electron microscope (SEM, ZEISS EVO 50 EP, Cambridge, UK) operating at 20 kV. 
Scratching and pitting were found on the UHMWPE insert perpendicular to the machining tracks for the concave surface. SEM micrographs of the insert showed burnishing on the concave surfaces and longitudinal scratches were clearly detectable and well-marked on the analyzed surfaces. 
A traumatic, fully rotating, polyethylene insert is rare and our case is the first report describing a traumatic event with a complete 180 degree rotation mobile-bearing in a total knee prosthesis. 
In the literature few reports discuss clinical outcomes after total knee arthroplasty in patients with Parkinson's disease and they cite mixed results. However, some authors suggest that posterior-stabilized and cruciate-retaining TKA should work well while others prefer cruciate-retaining, condylar constrained kinetics, or hinged devices. Although we did not implant a posterior-stabilized mobile-bearing total knee prosthesis or a constrained prosthesis, we obtained good clinical and radiological results at the 2-year followup.

  5. Stress analysis in oral obturator prostheses, part II: photoelastic imaging

    Science.gov (United States)

    Pesqueira, Aldiéris Alves; Goiato, Marcelo Coelho; da Silva, Emily Vivianne Freitas; Haddad, Marcela Filié; Moreno, Amália; Zahoui, Abbas; dos Santos, Daniela Micheline

    2014-06-01

    In part I of the study, two attachment systems [O-ring; bar-clip (BC)] were used, and the system with three individualized O-rings provided the lowest stress on the implants and the support tissues. Therefore, the aim of this study was to assess the stress distribution, through the photoelastic method, on implant-retained palatal obturator prostheses associated with different attachment systems: BOC-splinted implants with a bar connected to two centrally placed O-rings, and BOD-splinted implants with a BC connected to two distally placed O-rings (cantilever). One photoelastic model of the maxilla with oral-sinus-nasal communication with three parallel implants was fabricated. Afterward, two implant-retained palatal obturator prostheses with the two attachment systems described above were constructed. Each assembly was positioned in a circular polariscope and a 100-N axial load was applied in three different regions with implants by using a universal testing machine. The results were obtained through photograph record analysis of stress. The BOD system exhibited the highest stress concentration, followed by the BOC system. The O-ring, centrally placed on the bar, allows higher mobility of the prostheses and homogeneously distributes the stress to the region of the alveolar ridge and implants. It can be concluded that the use of implants with O-rings, isolated or connected with a bar, to rehabilitate maxillectomized patients allows higher prosthesis mobility and homogeneously distributes the stress to the alveolar ridge region, which may result in greater chewing stress distribution to implants and bone tissue. The clinical implication of the augmented bone support loss after maxillectomy is the increase of stress in the attachment systems and, consequently, a higher tendency for displacement of the prosthesis.

  6. Monte Carlo dose calculations for phantoms with hip prostheses

    International Nuclear Information System (INIS)

    Bazalova, M; Verhaegen, F; Coolens, C; Childs, P; Cury, F; Beaulieu, L

    2008-01-01

    Computed tomography (CT) images of patients with hip prostheses are severely degraded by metal streaking artefacts. The low image quality makes organ contouring more difficult and can result in large dose calculation errors when Monte Carlo (MC) techniques are used. In this work, the extent of streaking artefacts produced by three common hip prosthesis materials (Ti-alloy, stainless steel, and Co-Cr-Mo alloy) was studied. The prostheses were tested in a hypothetical prostate treatment with five 18 MV photon beams. The dose distributions for unilateral and bilateral prosthesis phantoms were calculated with the EGSnrc/DOSXYZnrc MC code. This was done in three phantom geometries: in the exact geometry, in the original CT geometry, and in an artefact-corrected geometry. The artefact-corrected geometry was created using a modified filtered back-projection correction technique. It was found that unilateral prosthesis phantoms do not show large dose calculation errors, as long as the beams miss the artefact-affected volume. This is possible to achieve in the case of unilateral prosthesis phantoms (except for the Co-Cr-Mo prosthesis which gives a 3% error) but not in the case of bilateral prosthesis phantoms. The largest dose discrepancies were obtained for the bilateral Co-Cr-Mo hip prosthesis phantom, up to 11% in some voxels within the prostate. The artefact correction algorithm worked well for all phantoms and resulted in dose calculation errors below 2%. In conclusion, a MC treatment plan should include an artefact correction algorithm when treating patients with hip prostheses

  7. Heart valve prostheses: who protects our patients, and from what?

    Science.gov (United States)

    Beall, A C

    1977-01-01

    Phenomenal advances in the development of cardiac valve prostheses have taken place in less than two decades. However, the currently prevailing atmosphere of consumer protectionism in existence 20 years ago probably would have made such developments impossible. Recent passage of the Medical Device Amendments of 1976 (P.L. 94-295) will not only make future development extremely difficult, but also may force the field of cardiac valve replacement back into the era of the 1950s. Regulations implementing this legislation may be even more disastrous. It is time for someone to protect patients from their so-called protectors.

  8. Provisional prostheses during ridge augmentation and implant dentistry.

    Science.gov (United States)

    Livada, Rania; Hottel, Timothy L; Shiloah, Jacob

    2013-01-01

    Recent advancements in ridge augmentation and bone regeneration have expanded the pool of patients that could benefit from dental implants. However, providing the patient with a temporary prosthesis during the wound healing phase without impairing the process is a challenging task. This article summarizes available information pertaining to provisional prostheses, both tooth-supported and soft tissue-supported, that may meet the patient needs. The advantages and disadvantages of each class of prosthesis, along with indications and contraindications, were taken into consideration to aid the restorative dentist in choosing the optimal provisional for their patients.

  9. [124I]FIAU: Human dosimetry and infection imaging in patients with suspected prosthetic joint infection

    International Nuclear Information System (INIS)

    Zhang, Xiaoyan M.; Zhang, Halle H.; McLeroth, Patrick; Berkowitz, Richard D.; Mont, Michael A.; Stabin, Michael G.; Siegel, Barry A.; Alavi, Abass; Barnett, T. Marc; Gelb, Jeffrey; Petit, Chantal; Spaltro, John; Cho, Steve Y.; Pomper, Martin G.; Conklin, James J.; Bettegowda, Chetan; Saha, Saurabh

    2016-01-01

    Introduction: Fialuridine (FIAU) is a nucleoside analog that is a substrate for bacterial thymidine kinase (TK). Once phosphorylated by TK, [ 124 I]FIAU becomes trapped within bacteria and can be detected with positron emission tomography/computed tomography (PET/CT). [ 124 I]FIAU PET/CT has been shown to detect bacteria in patients with musculoskeletal bacterial infections. Accurate diagnosis of prosthetic joint infections (PJIs) has proven challenging because of the lack of a well-validated reference. In the current study, we assessed biodistribution and dosimetry of [ 124 I]FIAU, and investigated whether [ 124 I]FIAU PET/CT can diagnose PJIs with acceptable accuracy. Methods: To assess biodistribution and dosimetry, six subjects with suspected hip or knee PJI and six healthy subjects underwent serial PET/CT after being dosed with 74 MBq (2 mCi) [ 124 I]FIAU intravenously (IV). Estimated radiation doses were calculated with the OLINDA/EXM software. To determine accuracy of [ 124 I]FIAU, 22 subjects with suspected hip or knee PJI were scanned at 2–6 and 24–30 h post IV injection of 185 MBq (5 mCi) [ 124 I]FIAU. Images were interpreted by a single reader blinded to clinical information. Representative cases were reviewed by 3 additional readers. The utility of [ 124 I]FIAU to detect PJIs was assessed based on the correlation of the patient's infection status with imaging results as determined by an independent adjudication board (IAB). Results: The kidney, liver, spleen, and urinary bladder received the highest radiation doses of [ 124 I]FIAU. The effective dose was 0.16 to 0.20 mSv/MBq and doses to most organs ranged from 0.11 to 0.76 mGy/MBq. PET image quality obtained from PJI patients was confounded by metal artifacts from the prostheses and pronounced FIAU uptake in muscle. Consequently, a correlation with infection status and imaging results could not be established. Conclusions: [ 124 I]FIAU was well-tolerated in healthy volunteers and subjects with

  10. [(124)I]FIAU: Human dosimetry and infection imaging in patients with suspected prosthetic joint infection.

    Science.gov (United States)

    Zhang, Xiaoyan M; Zhang, Halle H; McLeroth, Patrick; Berkowitz, Richard D; Mont, Michael A; Stabin, Michael G; Siegel, Barry A; Alavi, Abass; Barnett, T Marc; Gelb, Jeffrey; Petit, Chantal; Spaltro, John; Cho, Steve Y; Pomper, Martin G; Conklin, James J; Bettegowda, Chetan; Saha, Saurabh

    2016-05-01

    Fialuridine (FIAU) is a nucleoside analog that is a substrate for bacterial thymidine kinase (TK). Once phosphorylated by TK, [(124)I]FIAU becomes trapped within bacteria and can be detected with positron emission tomography/computed tomography (PET/CT). [(124)I]FIAU PET/CT has been shown to detect bacteria in patients with musculoskeletal bacterial infections. Accurate diagnosis of prosthetic joint infections (PJIs) has proven challenging because of the lack of a well-validated reference. In the current study, we assessed biodistribution and dosimetry of [(124)I]FIAU, and investigated whether [(124)I]FIAU PET/CT can diagnose PJIs with acceptable accuracy. To assess biodistribution and dosimetry, six subjects with suspected hip or knee PJI and six healthy subjects underwent serial PET/CT after being dosed with 74MBq (2mCi) [(124)I]FIAU intravenously (IV). Estimated radiation doses were calculated with the OLINDA/EXM software. To determine accuracy of [(124)I]FIAU, 22 subjects with suspected hip or knee PJI were scanned at 2-6 and 24-30h post IV injection of 185MBq (5mCi) [(124)I]FIAU. Images were interpreted by a single reader blinded to clinical information. Representative cases were reviewed by 3 additional readers. The utility of [(124)I]FIAU to detect PJIs was assessed based on the correlation of the patient's infection status with imaging results as determined by an independent adjudication board (IAB). The kidney, liver, spleen, and urinary bladder received the highest radiation doses of [(124)I]FIAU. The effective dose was 0.16 to 0.20mSv/MBq and doses to most organs ranged from 0.11 to 0.76mGy/MBq. PET image quality obtained from PJI patients was confounded by metal artifacts from the prostheses and pronounced FIAU uptake in muscle. Consequently, a correlation with infection status and imaging results could not be established. [(124)I]FIAU was well-tolerated in healthy volunteers and subjects with suspected PJI, and had acceptable dosimetry. However, the

  11. Purely transvaginal/perineal management of complications from commercial prolapse kits using a new prostheses/grafts complication classification system.

    Science.gov (United States)

    Firoozi, Farzeen; Ingber, Michael S; Moore, Courtenay K; Vasavada, Sandip P; Rackley, Raymond R; Goldman, Howard B

    2012-05-01

    Commercial prolapse mesh kits are increasingly used in the management of pelvic organ prolapse. We present our experience with the transvaginal/perineal management of synthetic mesh related complications from prolapse kits. In addition, we used the new ICS/IUGA (International Continence Society/International Urogynecological Association) prostheses/grafts complication classification system to report on our contemporary series. A retrospective chart review of all patients who underwent surgical removal of transvaginal mesh for mesh related complications after prolapse kit use from November 2006 to April 2010 at 1 institution was performed. We report our contemporary series of mesh complications using the new ICS/IUGA prostheses/grafts complication classification system. Postoperative pain, degree of improvement and presence of continued symptoms were reported by patients at last followup. A total of 23 patients underwent transvaginal removal of mesh during the study period. Mean patient age was 61 years. Median period of latency to mesh related complication was 10 months (range 1 to 27). Indications for mesh removal included vaginal/pelvic pain (39%), dyspareunia (39%), vaginal mesh extrusion/exposure (26%), urinary incontinence (35%), recurrent pelvic organ prolapse (22%), bladder mesh perforation with recurrent urinary tract infection (22%), rectal mesh perforation (4%), ureteral perforation injury (4%), retained foreign body (surgical sponge) in the bladder (4%) and vesicovaginal fistula (9%), with most patients citing more than 1 reason. Although technically difficult in some cases, purely transvaginal mesh excision appears to be safe with resolution of almost all presenting symptoms. Although slightly cumbersome, the new ICS/IUGA prostheses/graft complication classification system can be used to report and more accurately characterize mesh complications. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc

  12. Recovering a "Disfigured"¹ Face: Cosmesis in the Everyday Use of Facial Prostheses

    NARCIS (Netherlands)

    Yaron, Gili; Widdershoven, G.A.M.; Slatman, Jenny

    2017-01-01

    Prosthetic devices that replace an absent body part are generally considered to be either cosmetic or functional. Functional prostheses aim to restore (some degree of) lost physical functioning. Cosmetic prostheses attempt to restore a “normal” appearance to bodies that lack (one or more) limbs by

  13. A need for a more user-centered design in body powered prostheses

    NARCIS (Netherlands)

    Hichert, M.; Plettenburg, D.H.; Vardy, A.N.; Will, Wendy; Scheme, Erik

    2014-01-01

    Users of body powered prostheses (BPP) complain about too high operating forces, leading to pain and/or fatigue during or after prosthetic operation. In the worst case nerve and vessel damage can occur [1, 2], leading to nonuse of prostheses. Smit et al. investigated cable forces and displacements

  14. Articulation prostheses made of polymers which are improved by ionizing radiations

    International Nuclear Information System (INIS)

    Gaussens, G.; Nicaise, M.; Tran, K.O.

    1981-10-01

    Articulation prostheses for the human body are generally made of the couple very high molecular weight polyethylene-special steels. Polyethylene properties are modified by ionizing radiations: creep resistance is improved and friction coefficient is decreased. Modifications are controlled by the choice of radiation dose and dose rate. Wear tests have been made on hip prostheses [fr

  15. Air-flow resistances of silicone rubber voice prostheses after formation of bacterial and fungal biofilms

    NARCIS (Netherlands)

    Elving, GJ; van der Mei, HC; Busscher, HJ; van Weissenbruch, R; Albers, FWJ

    Laryngectomized patients use silicone rubber voice prostheses to rehabilitate their voice. However, biofilm formation limits the lifetime of voice prostheses by causing leakage or an increased air-flow resistance and the prosthesis has to be replaced. To determine which bacterial or yeast strains,

  16. Dual jaw treatment of edentulism using implant-supported monolithic zirconia fixed prostheses.

    Science.gov (United States)

    Altarawneh, Sandra; Limmer, Bryan; Reside, Glenn J; Cooper, Lyndon

    2015-01-01

    This case report describes restoration of the edentulous maxilla and mandible with implant supported fixed prostheses using monolithic zirconia, where the incisal edges and occluding surfaces were made of monolithic zirconia. Edentulism is a debilitating condition that can be treated with either a removable or fixed dental prosthesis. The most common type of implant-supported fixed prosthesis is the metal acrylic (hybrid), with ceramo-metal prostheses being used less commonly in complete edentulism. However, both of these prostheses designs are associated with reported complications of screw loosening or fracture and chipping of acrylic resin and porcelain. Monolithic zirconia implant-supported fixed prostheses have the potential for reduction of such complications. In this case, the CAD/CAM concept was utilized in fabrication of maxillary and mandibular screw-retained implant-supported fixed prostheses using monolithic zirconia. Proper treatment planning and execution coupled with utilizing advanced technologies contributes to highly esthetic results. However, long-term studies are required to guarantee a satisfactory long-term outcome of this modality of treatment. This case report describes the clinical and technical procedures involved in fabrication of maxillary and mandibular implant-supported fixed prostheses using monolithic zirconia as a treatment of edentulism, and proposes the possible advantages associated with using monolithic zirconia in eliminating dissimilar interfaces in such prostheses that are accountable for the most commonly occurring technical complication for these prostheses being chipping and fracture of the veneering material. © 2015 Wiley Periodicals, Inc.

  17. Movement characteristics of upper extremity prostheses during basic goal-directed tasks

    NARCIS (Netherlands)

    Bouwsema, Hanneke; van der Sluis, Corry K.; Bongers, Raoul M.

    Background: After an upper limb amputation a prosthesis is often used to restore the functionality. However, the frequency of prostheses use is generally low. Movement kinematics of prostheses use might suggest origins of this low use. The aim of this study was to reveal movement patterns of

  18. High cable forces deteriorate pinch force control in voluntary-closing body-powered prostheses

    NARCIS (Netherlands)

    Hichert, M.; Abbink, D.A.; Kyberd, P.J.; Plettenburg, D.H.

    2017-01-01

    Background It is generally asserted that reliable and intuitive control of upper-limb prostheses requires adequate feedback of prosthetic finger positions and pinch forces applied to objects. Bodypowered prostheses (BPPs) provide the user with direct proprioceptive feedback. Currently available

  19. Individual Leg and Joint Work during Sloped Walking for People with a Transtibial Amputation Using Passive and Powered Prostheses

    Directory of Open Access Journals (Sweden)

    Jana R. Jeffers

    2017-12-01

    Full Text Available People with a transtibial amputation using passive-elastic prostheses exhibit reduced prosthetic ankle power and push-off work compared to non-amputees and compensate by increasing their affected leg (AL hip joint work and unaffected leg (UL ankle, knee, and hip joint and leg work during level-ground walking. Use of a powered ankle–foot prosthesis normalizes step-to-step transition work during level-ground walking over a range of speeds for people with a transtibial amputation, but the effects on joint work during level-ground, uphill, and downhill walking have not been assessed. We investigated how use of passive-elastic and powered ankle–foot prostheses affect leg joint biomechanics during level-ground and sloped walking. 10 people with a unilateral transtibial amputation walked at 1.25 m/s on a dual-belt force-measuring treadmill at 0°, ±3°, ±6°, and ±9° using their own passive-elastic and a powered prosthesis (BiOM T2, BionX Medical Technologies, Inc., Bedford, MA, USA while we measured kinematic and kinetic data. We calculated AL and UL prosthetic, ankle, knee, hip, and individual leg positive, negative, and net work. Use of a powered compared to passive-elastic ankle–foot prosthesis resulted in greater AL prosthetic and individual leg net work on uphill and downhill slopes. Over a stride, AL prosthetic positive work was 23–30% greater (p < 0.05 during walking on uphill slopes of +6°, and +9°, prosthetic net work was up to 10 times greater (more positive (p ≤ 0.005 on all uphill and downhill slopes and individual leg net work was 146 and 82% more positive (p < 0.05 at uphill slopes of +6° and +9°, respectively, with use of the powered compared to passive-elastic prosthesis. Greater prosthetic positive and net work through use of a powered ankle–foot prosthesis during uphill and downhill walking improves mechanical work symmetry between the legs, which could decrease metabolic cost and improve functional

  20. FDG and FDG-labelled leucocyte PET/CT in the imaging of prosthetic joint infection

    Energy Technology Data Exchange (ETDEWEB)

    Aksoy, Sabire Yilmaz; Asa, Sertac; Ozhan, Meftune; Sager, M.S.; Halac, Metin; Kabasakal, Levent; Soenmezoglu, Kerim; Kanmaz, Bedii [University of Istanbul, Department of Nuclear Medicine, Cerrahpasa Medical Faculty, Aksaray, Istanbul (Turkey); Ocak, Meltem [University of Istanbul, Department of Pharmaceutical Technology, Faculty of Pharmacy, Istanbul (Turkey); Erkan, Melih Engin [Duzce University School of Medicine, Department of Nuclear Medicine, Duzce (Turkey)

    2014-03-15

    The demand for arthroplasty is rapidly growing as a result of the ageing of the population. Although complications such as heterotrophic ossification, fracture and dislocation are relatively rare, differentiating aseptic loosening, the most common complication of arthroplasty from infection, is a major challenge for clinicians. Radionuclide imaging is currently the imaging modality of choice since it is not affected by orthopaedic hardware. Whereas FDG PET/CT imaging has been widely used in periprosthetic infection, it cannot discriminate aseptic from septic inflammation. In this study we aimed to evaluate the role of FDG PET/CT and FDG-labelled leucocyte PET/CT in the diagnosis of periprosthetic infection. Of 54 patients with painful joint arthroplasty who were imaged by FDG PET/CT for diagnosis of periprosthetic infection examined, 46 (36 women, 10 men; mean age 61.04 ± 12.2 years, range 32 - 89 years) with 54 painful joint prostheses (19 hip, 35 knee) with grade 2 (above liver uptake) FDG accumulation on FDG PET/CT were included in the study and these 46 patients also underwent FDG-labelled leucocyte PET/CT. Final diagnoses were made by histopathological-microbiological culture or clinical follow-up. The final diagnosis showed infection in 15 (28 %) and aseptic loosening in 39 (72 %) of the 54 prostheses. FDG PET/CT was found to have a positive predictive value of 28 % (15/54). Since patients with no FDG uptake on FDG PET/CT were excluded from the study, the sensitivity, specificity, negative predictive value and accuracy could not be calculated. The sensitivity, specificity, and positive and negative predictive values of FDG-labelled leucocyte PET/CT were 93.3 % (14/15), 97.4 % (38/39), 93.3 % and 97.4 %, respectively. Since FDG is not specific to infection, the specificity of FDG PET/CT was very low. FDG-labelled leucocyte PET/CT with its high specificity may be a useful method and better than labelled leucocyte scintigraphy in periprosthetic infection

  1. Knee joint replacement

    Science.gov (United States)

    ... to make everyday tasks easier. Practice using a cane, walker , crutches , or a wheelchair correctly. On the ... ask your doctor Knee joint replacement - discharge Preventing falls Preventing falls - what to ask your doctor Surgical ...

  2. Editorial Commentary: Intra-articular Corticosteroid Injection at the Time of Knee Arthroscopy Is Not Recommended.

    Science.gov (United States)

    Hunt, Timothy J

    2016-01-01

    In a population of Medicare patients undergoing knee arthroscopy, a significant increase in the incidence of postoperative infection at 3 and 6 months was found in patients who received an intra-articular corticosteroid injection at the time of knee arthroscopy compared with a matched control group that did not receive an injection. Intra-articular corticosteroid injection at the time of knee arthroscopy is not recommended. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  3. Oral Implant-Prostheses: New Teeth for a Brighter Brain.

    Directory of Open Access Journals (Sweden)

    Vincenzo De Cicco

    Full Text Available Several studies have demonstrated that chewing can be regarded as a preventive measure for cognitive impairment, whereas masticatory deficiency, associated with soft-diet feeding, is a risk factor for the development of dementia. At present the link between orofacial sensorimotor activity and cognitive functions is unknown. In subjects with unilateral molar loss we have shown asymmetries in both pupil size and masticatory muscles electromyographic (EMG activity during clenching: the molar less side was characterized by a lower EMG activity and a smaller pupil. Since implant-prostheses, greatly reduced both the asymmetry in EMG activity and in pupil's size, trigeminal unbalance, leading to unbalance in the activity of the Locus Coeruleus (LC, may be responsible for the pupil's asymmetry. According to the findings obtained in animal models, we propose that the different activity of the right and left LC may induce an asymmetry in brain activity, thus leading to cognitive impairment. According to this hypothesis, prostheses improved the performance in a complex sensorimotor task and increased the mydriasis associated with haptic tasks. In conclusion, the present study indicates that the implant-prosthesis therapy, which reduces the unbalance of trigeminal proprioceptive afferents and the asymmetry in pupil's size, may improve arousal, boosting performance in a complex sensorimotor task.

  4. Toward Balance Recovery With Leg Prostheses Using Neuromuscular Model Control

    Science.gov (United States)

    Geyer, Hartmut

    2016-01-01

    Objective Lower limb amputees are at high risk of falling as current prosthetic legs provide only limited functionality for recovering balance after unexpected disturbances. For instance, the most established control method used on powered leg prostheses tracks local joint impedance functions without taking the global function of the leg in balance recovery into account. Here we explore an alternative control policy for powered transfemoral prostheses that considers the global leg function and is based on a neuromuscular model of human locomotion. Methods We adapt this model to describe and simulate an amputee walking with a powered prosthesis using the proposed control, and evaluate the gait robustness when confronted with rough ground and swing leg disturbances. We then implement and partially evaluate the resulting controller on a leg prosthesis prototype worn by a non-amputee user. Results In simulation, the proposed prosthesis control leads to gaits that are more robust than those obtained by the impedance control method. The initial hardware experiments with the prosthesis prototype show that the proposed control reproduces normal walking patterns qualitatively and effectively responds to disturbances in early and late swing. However, the response to mid-swing disturbances neither replicates human responses nor averts falls. Conclusions The neuromuscular model control is a promising alternative to existing prosthesis controls, although further research will need to improve on the initial implementation and determine how well these results transfer to amputee gait. Significance This work provides a potential avenue for future development of control policies that help improve amputee balance recovery. PMID:26315935

  5. Edentulous patients' knowledge of dental hygiene and care of prostheses.

    Science.gov (United States)

    de Castellucci Barbosa, Luciano; Ferreira, Manoela Rejane Maia; de Carvalho Calabrich, Carolina Freire; Viana, Aline Cavalcanti; de Lemos, Maria Catarina Lavigne; Lauria, Roberta Andrade

    2008-06-01

    The aim of this study was to analyse denture users' oral care habits with regard to the use of their prostheses. Rehabilitative treatment is only successful when patients are motivated and aware of correct prosthesis use and hygiene. Questionnaires were distributed to 150 complete denture users at the Federal University of Bahia School of Dentistry, the Esmeralda Natividade Health Center, the Bahian Science Development Foundation and a Salvador nursing home. The questionnaire included information on gender, age, length of prosthesis use, cleaning methods and materials, etc. The data were analysed using EpiInfo version 6 software. The chi-squared test was used for statistical analysis, with a significance level of 5%. Questionnaire results showed that 78% of the subjects, with an average age of 67.3 years, had used the same complete denture for over 5 years. 64% slept with their prostheses and 44% removed them from the mouth only for cleaning. None of the patients interviewed knew anything about brushes designed specifically for complete dentures. 37.3% had a restricted diet and 44% believed that a complete denture would last for more than 10 years. Within the limitations of this study, it was concluded that the edentulous patients surveyed had limited awareness of prosthetic hygiene and long-term oral care despite extended periods of denture use.

  6. CT of the knee

    International Nuclear Information System (INIS)

    Ghelman, B.

    1987-01-01

    CT can be combined with arthrography of the knee to study the following abnormalities: meniscal tears and cysts, synovial plicae, chondromalacia patellae, and osteochondritis dissecans. The CT-arthrogram images present abnormalities in a manner that resembles the ''in situ'' surgical findings, allowing management decisions to be made with greater confidence. The CT techniques for imaging the knee after arthrography are discussed, as is the use of plain CT

  7. Dashboard (in the) knee.

    Science.gov (United States)

    Patel, M S; Qureshi, A A; Green, T P

    2015-03-01

    We present the case of a 19-year-old individual presenting to an orthopaedic outpatient clinic several months following a dashboard knee injury during a road traffic accident with intermittent mechanical symptoms. Despite unremarkable examination findings and normal magnetic resonance imaging, the patient was identified subsequently as having an intra-articular plastic foreign body consistent with a piece of dashboard on arthroscopic knee assessment, the retrieval of which resulted in a complete resolution of symptoms.

  8. Prevalent knee pain and sport

    DEFF Research Database (Denmark)

    Hahn, Thomas; Foldspang, Anders

    1998-01-01

    STUDY OBJECTIVE: To estimate the prevalence of knee pain in active athletes and to investigate potential associations to type, amount and duration of sports participation. MEASUREMENTS: 339 athletes gave information about occupation, sports activity and different features of knee pain, based...... on a self-filled questionnaire. MAIN RESULTS: The prevalence of knee pain within the preceding 12 months, constant or recurrent knee pain, absence from sport and absence from work due to knee pain, was 54%, 34%, 19% and 4%, respectively. Knee pain was positively associated with years of jogging...... and with weekly hours of participation in competitive gymnastics but negatively with weekly hours of tennis. Constant or recurrent knee pain was positively associated with years of swimming. Absence from sport due to knee pain was positively associated with weekly hours of soccer participation. CONCLUSIONS: Knee...

  9. Taking care of your new knee joint

    Science.gov (United States)

    Knee arthroplasty - precautions; Knee replacement - precautions ... After you have knee replacement surgery , you will need to be careful about how you move your knee, especially for the first few ...

  10. Arthroscopic-assisted Arthrodesis of the Knee Joint With the Ilizarov Technique: A Case Report and Literature Review.

    Science.gov (United States)

    Waszczykowski, Michal; Niedzielski, Kryspin; Radek, Maciej; Fabis, Jaroslaw

    2016-01-01

    Arthrodesis of the knee joint is a mainly a salvage surgical procedure performed in cases of infected total knee arthroplasty, tumor, failed knee arthroplasty or posttraumatic complication.The authors report the case of 18-year-old male with posttraumatic complication of left knee because of motorbike accident 1 year before. He was treated immediately after the injury in the local Department of Orthopaedics and Traumatology. The examination in the day of admission to our department revealed deformation of the left knee, massive scar tissue adhesions to the proximal tibial bone and multidirectional instability of the knee. The plain radiographs showed complete lack of lateral compartment of the knee joint and patella. The patient complained of severe instability and pain of the knee and a consecutive loss of supporting function of his left limb. The authors decided to perform an arthroscopic-assisted fusion of the knee with Ilizarov external fixator because of massive scar tissue in the knee region and the prior knee infection.In the final follow-up after 54 months a complete bone fusion, good functional and clinical outcome were obtained.This case provides a significant contribution to the development and application of low-invasive techniques in large and extensive surgical procedures in orthopedics and traumatology. Moreover, in this case fixation of knee joint was crucial for providing good conditions for the regeneration of damaged peroneal nerve.

  11. Metal hypersensitivity after knee arthroplasty: fact or fiction?

    Science.gov (United States)

    Innocenti, Massimo; Vieri, Berti; Melani, Tommaso; Paoli, Tommaso; Carulli, Christian

    2017-06-07

    Hypersensitivity to metals in the general population has an incidence of about 15%, and in rising also for the higher number of joint replacements in the last decades. Total Knee Arthroplasty (TKA) represents the most performed orthopaedic procedure during last years, and it seems to be particularly associated with sensitization after surgery. On the other hand, there is a rising amount of patients with painful but well implanted and functioning TKAs: in certain cases, after the exclusion of the most frequent causes of failure, a condition of hypersensitivity may be found, and a revision with anallergic implants is mandatory. The present study is a review of the potential problems related to hypersensitivity in TKA, its possible diagnostic procedures, and the surgical options to date available. Medical history, patch testing, and other specific laboratory assays are useful to assess a status of metals hypersensitivity before surgery in subjects undergoing a knee replacement, or even after TKA in patients complaining pain in otherwise well implanted and aligned prostheses. However, few groups worlwide deal with such condition, and all proposed diagnostic protocols may be considered still today conjectural. On the other hand, these represent the most updated knowledge of this condition, and may be useful for both the patient and the orthopaedic surgeon. Once assessed a possible or ascertained allergy to metals, several options are available for primary andr revision knee surgery, in order to avoid the risk of hypersensitivity. A review of the recent publications on this topic and an overview of the related aspects has been made to understand a condition to date considered negligible. Hypersensitivity to metals has not to be nowadays considered a "fiction", but rather a possible preoperative risk or a postoperative cause of failure of TKA. Crucial is the information of patients and the medical history, associated in suspect cases to laboratory testings. Today in the

  12. Comparison of Customized Cutting Block and Conventional Cutting Instrument in Total Knee Arthroplasty: A Randomized Controlled Trial.

    Science.gov (United States)

    Tammachote, Nattapol; Panichkul, Phonthakorn; Kanitnate, Supakit

    2018-03-01

    Customized cutting block (CCB) was designed to ensure the accurate alignment of knee prostheses during total knee arthroplasty. Given the paucity of CCB efficacy data, we compare CCB with conventional cutting guide using a randomized controlled trial. One hundred eight osteoarthritic knee patients underwent total knee arthroplasty by one experienced surgeon were randomized to receive CCB (n = 54) or conventional cutting instrument (CCI) surgery (n = 54). The primary outcomes were limb alignment, prostheses position, and operative time. The secondary outcomes were hemodynamic alteration after surgery, functional outcomes (modified Western Ontario and McMaster University Osteoarthritis Index) and range of motion at 2 years after surgery. Mean hip-knee-ankle angle in the CCB group was 179.4° ± 1.8° vs 179.1° ± 2.4° in the CCI group, Δ = 0 (95% confidence interval [CI] -0.6 to 1.1, P = .55). Mean operative time was faster in the CCB arm: 93 ± 12 vs 104 ± 12 minutes, Δ = 11 (95% CI -16.7 to -7.2, P < .0001). There were no differences in hemodynamic parameters, mean blood loss (446 [CCB] vs 514 mL [CCI], Δ = -68 [95% CI -138 to 31 mL, P = .21]), postoperative hemoglobin changes, incidence of hypotension (systolic <90 mm Hg), oliguria, and rates of blood transfusion. Functional outcomes and range of motion were also similar. There was no improvement in alignment, hemodynamic changes, blood loss, and knee functional outcomes. CCB reduced surgical time by 11 minutes in our population. CCB cost-effectiveness should be further investigated. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Clinical practice guidelines for rest orthosis, knee sleeves, and unloading knee braces in knee osteoarthritis.

    Science.gov (United States)

    Beaudreuil, Johann; Bendaya, Samy; Faucher, Marc; Coudeyre, Emmanuel; Ribinik, Patricia; Revel, Michel; Rannou, François

    2009-12-01

    To develop clinical practice guidelines concerning the use of bracing--rest orthosis, knee sleeves and unloading knee braces--for knee osteoarthritis. The French Physical Medicine and Rehabilitation Society (SOFMER) methodology, associating a systematic literature review, collection of everyday clinical practice, and external review by multidisciplinary expert panel, was used. Few high-level studies of bracing for knee osteoarthritis were found. No evidence exists for the effectiveness of rest orthosis. Evidence for knee sleeves suggests that they decrease pain in knee osteoarthritis, and their use is associated with subjective improvement. These actions do not appear to depend on a local thermal effect. The effectiveness of knee sleeves for disability is not demonstrated for knee osteoarthritis. Short- and mid-term follow-up indicates that valgus knee bracing decreases pain and disability in medial knee osteoarthritis, appears to be more effective than knee sleeves, and improves quality of life, knee proprioception, quadriceps strength, and gait symmetry, and decreases compressive loads in the medial femoro-tibial compartment. However, results of response to valgus knee bracing remain inconsistent; discomfort and side effects can result. Thrombophlebitis of the lower limbs has been reported with the braces. Braces, whatever kind, are infrequently prescribed in clinical practice for osteoarthritis of the lower limbs. Modest evidence exists for the effectiveness of bracing--rest orthosis, knee sleeves and unloading knee braces--for knee osteoarthritis, with only low level recommendations for its use. Braces are prescribed infrequently in French clinical practice for osteoarthritis of the knee. Randomized clinical trials concerning bracing in knee osteoarthritis are still necessary.

  14. Gram-negative prosthetic joint infection: outcome of a debridement, antibiotics and implant retention approach. A large multicentre study.

    Science.gov (United States)

    Rodríguez-Pardo, D; Pigrau, C; Lora-Tamayo, J; Soriano, A; del Toro, M D; Cobo, J; Palomino, J; Euba, G; Riera, M; Sánchez-Somolinos, M; Benito, N; Fernández-Sampedro, M; Sorli, L; Guio, L; Iribarren, J A; Baraia-Etxaburu, J M; Ramos, A; Bahamonde, A; Flores-Sánchez, X; Corona, P S; Ariza, J

    2014-11-01

    We aim to evaluate the epidemiology and outcome of gram-negative prosthetic joint infection (GN-PJI) treated with debridement, antibiotics and implant retention (DAIR), identify factors predictive of failure, and determine the impact of ciprofloxacin use on prognosis. We performed a retrospective, multicentre, observational study of GN-PJI diagnosed from 2003 through to 2010 in 16 Spanish hospitals. We define failure as persistence or reappearance of the inflammatory joint signs during follow-up, leading to unplanned surgery or repeat debridement>30 days from the index surgery related death, or suppressive antimicrobial therapy. Parameters predicting failure were analysed with a Cox regression model. A total of 242 patients (33% men; median age 76 years, interquartile range (IQR) 68-81) with 242 episodes of GN-PJI were studied. The implants included 150 (62%) hip, 85 (35%) knee, five (2%) shoulder and two (1%) elbow prostheses. There were 189 (78%) acute infections. Causative microorganisms were Enterobacteriaceae in 78%, Pseudomonas spp. in 20%, and other gram-negative bacilli in 2%. Overall, 19% of isolates were ciprofloxacin resistant. DAIR was used in 174 (72%) cases, with an overall success rate of 68%, which increased to 79% after a median of 25 months' follow-up in ciprofloxacin-susceptible GN-PJIs treated with ciprofloxacin. Ciprofloxacin treatment exhibited an independent protective effect (adjusted hazard ratio (aHR) 0.23; 95% CI, 0.13-0.40; pInfection © 2014 European Society of Clinical Microbiology and Infectious Diseases.

  15. Implant-level prostheses in the edentulous maxilla: a comparison with conventional abutment-level prostheses after 5 years of use.

    Science.gov (United States)

    Hjalmarsson, Lars; Smedberg, Jan-Ivan; Pettersson, Mattias; Jemt, Torsten

    2011-01-01

    Long-term comparisons of frameworks at the implant or abutment level are not available, and knowledge of the clinical function of cobalt-chromium (Co-Cr) alloy frameworks is limited. Primarily, the aim of this study was to compare the 5-year clinical performance of frameworks with or without abutment connections to implants. Secondly, the outcomes of prostheses made from Co-Cr alloy with porcelain veneers to those made of commercially pure titanium (CP Ti) with acrylic veneers were compared. The test groups comprised patients treated with screw-retained fixed prostheses made at the implant level according to the Cresco method in either dental porcelain-veneered Co-Cr alloy (n = 15) or acrylic-veneered CP Ti (n = 25). A control group of 40 randomly selected patients were provided with prostheses made at the standard abutment level in CP Ti with acrylic veneers. For all patients, clinical and radiologic 5-year data were retrospectively collected and evaluated. Five-year implant cumulative survival rates (CSRs) were 98.6% and 97.6% for test and control groups, respectively (P > .05). No major differences in bone level were demonstrated between the groups after 5 years (P > .05). Significantly more complications occurred in the test groups compared to the control group (P level prostheses made of porcelain-veneered Co-Cr or acrylic-veneered CP Ti seem comparable to acrylic-veneered titanium prostheses made at the standard abutment level regarding implant CSR and bone levels. However, more complications were registered in implant-level prostheses compared to the standard abutment-level prostheses.

  16. Knee arthrography today

    International Nuclear Information System (INIS)

    Otto, H.; Kallenberger, R.

    1987-01-01

    The role of knee arthrography today is demonstrated and technical problems are discussed. Among a lot of variants the position of the patient and the choice of contrast media play a great part concerning the result of the examination. Mild complications occur in 0.25% of the examinations, severe and live threatening complications are extremely rare. Diagnosis of meniscal lesions is most important for knee arthrography; arthroscopy and arthrography are complementary examinations and not mutually exclusive, they achieve combined an accuracy of 97-98%. In the same way arthrography is able to evaluate the condropathy of the femoro-tibial joint, whereas accuracy of arthroscopy in the diagnosis of patellar chondropathy is much higher. There is a great reliability of arthrography regarding the evaluation of lesions of the capsule, but accuracy in lesions of the cruciate ligaments is low. Arthrography is very suitable for evaluation of Baker-cysts, since indications for almost occuring internal derangement of the knee are even available. Knee arthrography is a complex and safe procedure with very less discomfort for the patient; it has a central position in the evaluation of lesions of the knee. (orig.) [de

  17. Epidemiology of jumper's knee.

    Science.gov (United States)

    Ferretti, A

    1986-01-01

    Jumper's knee is a typical functional overload injury because it affects those athletes who submit their knee extensor mechanisms to intense and repeated stress, e.g. volleyball and basketball players, high and long jumpers. According to the classification of Perugia and colleagues, it is an insertional tendinopathy affecting, in order of frequency, the insertion of the patellar tendon into the patella (65% of cases), attachment of the quadriceps tendon to the patella (25%) and the attachment of the patellar tendon to the tibial tuberosity (10%). The frequent occurrence of this injury in athletes led to the study of factors that may contribute to its onset and aggravation. These factors are divided into extrinsic (i.e. kind of sport practised and training methods used) and intrinsic (i.e. connected with the somatic and morphological characteristics of the athletes). On the basis of our experience and after a review of the literature it appears, contrary to what has been repeatedly claimed in the past, the extrinsic factors are more important than the intrinsic in the aetiology of jumper's knee. The effect of traumatic incidents and use of elastic kneecap guards should also be considered negligible. The intrinsic causes of jumper's knee, can be sought in the mechanical properties of tendons (resistance, elasticity and extensibility) rather than in morphological or biomechanical abnormalities of the knee extensor mechanism.

  18. Cortical visual prostheses: from microstimulation to functional percept

    Science.gov (United States)

    Najarpour Foroushani, Armin; Pack, Christopher C.; Sawan, Mohamad

    2018-04-01

    Cortical visual prostheses are intended to restore vision by targeted electrical stimulation of the visual cortex. The perception of spots of light, called phosphenes, resulting from microstimulation of the visual pathway, suggests the possibility of creating meaningful percept made of phosphenes. However, to date electrical stimulation of V1 has still not resulted in perception of phosphenated images that goes beyond punctate spots of light. In this review, we summarize the clinical and experimental progress that has been made in generating phosphenes and modulating their associated perceptual characteristics in human and macaque primary visual cortex (V1). We focus specifically on the effects of different microstimulation parameters on perception and we analyse key challenges facing the generation of meaningful artificial percepts. Finally, we propose solutions to these challenges based on the application of supervised learning of population codes for spatial stimulation of visual cortex.

  19. MR imaging of 22 Charnley-Mueller total hip prostheses

    International Nuclear Information System (INIS)

    Lemmens, J.A.M.; Ruijs, J.H.J.

    1986-01-01

    To find out whether MR imaging is contraindicated in patients with metallic implants or can be a routine diagnostic procedure, MR investigations in 18 patients with 22 Charnley-Mueller total hip prostheses were performed on a 0.5 T Gyroscan S 5, Philips. No adverse reactions during or post MR investigation were encountered. The imaging of the soft tissue was superior to CT and showed less distortion. The diagnosis of loosening, by detection of demarcation lines at the interfaces was at its best in the distal part of the femoral stem prosthesis and was poor in the acetabular component and in the upper part of the stem prosthesis due to artifacts. (orig.) [de

  20. Myoelectric signal processing for control of powered limb prostheses.

    Science.gov (United States)

    Parker, P; Englehart, K; Hudgins, B

    2006-12-01

    Progress in myoelectric control technology has over the years been incremental, due in part to the alternating focus of the R&D between control methodology and device hardware. The technology has over the past 50 years or so moved from single muscle control of a single prosthesis function to muscle group activity control of multifunction prostheses. Central to these changes have been developments in the means of extracting information from the myoelectric signal. This paper gives an overview of the myoelectric signal processing challenge, a brief look at the challenge from an historical perspective, the state-of-the-art in myoelectric signal processing for prosthesis control, and an indication of where this field is heading. The paper demonstrates that considerable progress has been made in providing clients with useful and reliable myoelectric communication channels, and that exciting work and developments are on the horizon.

  1. Electric stimulation with sinusoids and white noise for neural prostheses

    Directory of Open Access Journals (Sweden)

    Daniel K Freeman

    2010-02-01

    Full Text Available We are investigating the use of novel stimulus waveforms in neural prostheses to determine whether they can provide more precise control over the temporal and spatial pattern of elicited activity as compared to conventional pulsatile stimulation. To study this, we measured the response of retinal ganglion cells to both sinusoidal and white noise waveforms. The use of cell-attached and whole cell patch clamp recordings allowed the responses to be observed without significant obstruction from the stimulus artifact. Electric stimulation with sinusoids elicited robust responses. White noise analysis was used to derive the linear kernel for the ganglion cell’s spiking response as well as for the underlying excitatory currents. These results suggest that in response to electric stimulation, presynaptic retinal neurons exhibit bandpass filtering characteristics with peak response that occur 25ms after onset. The experimental approach demonstrated here may be useful for studying the temporal response properties of other neurons in the CNS.

  2. [Significance of various implantate localizations of Sparks prostheses, experimental studies in rats].

    Science.gov (United States)

    Brieler, H S; Parwaresch, R; Thiede, A

    1976-01-01

    Our investigations show that Sparks prostheses after subcutaneous implantation are suitable for vascular grafting. At the end of the organization period the connective tissue becomes strong, and after the third and fourth weeks collagenous and elastic fibers can be seen. Ten weeks after s.c. implantation, collagenous fibers predominate. After this the Sparks prostheses can be used as a vascular graft. Intraperitoneal implantation, however, shows a histologically different picture with characteristic findings: only fat cells can be observed, a strong granulation tissue with elastic and collagenous fibers is not present. After intraperitoneal implantation Sparks prostheses are therefore unsuitable for vascular grafts.

  3. Bicruciate-retaining Total Knee Replacement Provides Satisfactory Function and Implant Survivorship at 23 Years.

    Science.gov (United States)

    Pritchett, James W

    2015-07-01

    One of the goals of a TKA is to approximate the function of a normal knee. Preserving the natural ligaments might provide a method of restoring close to normal function. Sacrifice of the ACL is common and practical during a TKA. However, this ligament is functional in more than 60% of patients undergoing a TKA and kinematic studies support the concept of bicruciate-retaining (that is, ACL-preserving) TKA; however, relatively few studies have evaluated patients treated with bicruciate-retaining TKA implants. I asked: (1) what is the long-term (minimum 20-year) survivorship, (2) what are the functional results, and (3) what are the reasons for revision of bicruciate-retaining knee arthroplasty prostheses? From January 1989 to September 1992, I performed 639 total knee replacements in 537 patients. Of these, 489 were performed in 390 patients using a bicruciate-retaining, minimally constrained device. During the period in question, this knee prosthesis was used for all patients observed intraoperatively to have an intact, functional ACL with between 15° varus and 15° valgus joint deformity. There were 234 women and 156 men with a mean age at surgery of 65 years (range, 42-84 years) and a primary diagnosis of osteoarthritis in 89%. The patella was resurfaced in all knees. The mean followup was 23 years (range, 20-24 years). At the time of this review, 199 (51%) patients had died and 31 (8%) patients were lost to followup, leaving 160 (41%) patients (214 knees) available for review. Component survivorship was determined by competing-risks analysis and Kaplan Meier survivorship analysis with revision for any reason as the primary endpoint. Patients were evaluated every 2 years to assess ROM, joint laxity, knee stability, and to determine American Knee Society scores. The Kaplan-Meier survivorship was 89% (95% CI, 82%-93%) at 23 years with revision for any reason as the endpoint. Competing-risks survivorship was 94% (95% CI, 91%%-96 %) at 23 years. At followup, the mean

  4. Auditory Neural Prostheses – A Window to the Future

    Directory of Open Access Journals (Sweden)

    Mohan Kameshwaran

    2015-06-01

    Full Text Available Hearing loss is one of the commonest congenital anomalies to affect children world-over. The incidence of congenital hearing loss is more pronounced in developing countries like the Indian sub-continent, especially with the problems of consanguinity. Hearing loss is a double tragedy, as it leads to not only deafness but also language deprivation. However, hearing loss is the only truly remediable handicap, due to remarkable advances in biomedical engineering and surgical techniques. Auditory neural prostheses help to augment or restore hearing by integration of an external circuitry with the peripheral hearing apparatus and the central circuitry of the brain. A cochlear implant (CI is a surgically implantable device that helps restore hearing in patients with severe-profound hearing loss, unresponsive to amplification by conventional hearing aids. CIs are electronic devices designed to detect mechanical sound energy and convert it into electrical signals that can be delivered to the coch­lear nerve, bypassing the damaged hair cells of the coch­lea. The only true prerequisite is an intact auditory nerve. The emphasis is on implantation as early as possible to maximize speech understanding and perception. Bilateral CI has significant benefits which include improved speech perception in noisy environments and improved sound localization. Presently, the indications for CI have widened and these expanded indications for implantation are related to age, additional handicaps, residual hearing, and special etiologies of deafness. Combined electric and acoustic stimulation (EAS / hybrid device is designed for individuals with binaural low-frequency hearing and severe-to-profound high-frequency hearing loss. Auditory brainstem implantation (ABI is a safe and effective means of hearing rehabilitation in patients with retrocochlear disorders, such as neurofibromatosis type 2 (NF2 or congenital cochlear nerve aplasia, wherein the cochlear nerve is damaged

  5. Bouncy knee in a semi-automatic knee lock prosthesis.

    Science.gov (United States)

    Fisher, L D; Lord, M

    1986-04-01

    The Bouncy Knee concept has previously proved of value when fitted to stabilised knee units of active amputees. The stance phase flex-extend action afforded by a Bouncy Knee increased the symmetry of gait and also gave better tolerance to slopes and uneven ground. A bouncy function has now been incorporated into a knee of the semi-automatic knee lock design in a pilot laboratory trial involving six patients. These less active patients did not show consistent changes in symmetry of gait, but demonstrated an improved ability to walk on slopes and increased their walking range. Subjective response was positive, as noted in the previous trials.

  6. Microscopical analysis of synovial fluid wear debris from failing CoCr hip prostheses

    Science.gov (United States)

    Ward, M. B.; Brown, A. P.; Cox, A.; Curry, A.; Denton, J.

    2010-07-01

    Metal on metal hip joint prostheses are now commonly implanted in patients with hip problems. Although hip replacements largely go ahead problem free, some complications can arise such as infection immediately after surgery and aseptic necrosis caused by vascular complications due to surgery. A recent observation that has been made at Manchester is that some Cobalt Chromium (CoCr) implants are causing chronic pain, with the source being as yet unidentified. This form of replacement failure is independent of surgeon or hospital and so some underlying body/implant interface process is thought to be the problem. When the synovial fluid from a failed joint is examined particles of metal (wear debris) can be found. Transmission Electron Microscopy (TEM) has been used to look at fixed and sectioned samples of the synovial fluid and this has identified fine (< 100 nm) metal and metal oxide particles within the fluid. TEM EDX and Electron Energy Loss Spectroscopy (EELS) have been employed to examine the composition of the particles, showing them to be chromium rich. This gives rise to concern that the failure mechanism may be associated with the debris.

  7. Enhancing the soft tissue seal around intraosseous transcutaneous amputation prostheses using silanized fibronectin titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Chimutengwende-Gordon, M; Pendegrass, C; Blunn, G, E-mail: mukai.cg@mac.com [Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, University College London, Brockley Hill, Stanmore, HA7 4LP (United Kingdom)

    2011-04-15

    The success of intraosseous transcutaneous amputation prostheses (ITAP) relies on achieving a tight seal between the soft tissues and the implant in order to avoid infection. Fibronectin (Fn) may be silanized onto titanium alloy (Ti-6Al-4V) in order to promote soft-tissue attachment. The silanization process includes passivation with sulphuric acid, which alters surface characteristics. This study aimed to improve in vitro fibroblast adhesion to silanized fibronectin (SiFn) titanium alloy by omitting the passivation stage. Additionally, the study assessed the effects of SiFn on in vivo dermal attachment, comparing the results with adsorbed Fn, hydroxyapatite (HA), Fn adsorbed onto HA (HAFn) and uncoated controls. Surface topography was assessed using scanning electron microscopy, profilometry and contact angle measurement. Anti-vinculin antibodies were used to immunolocalize fibroblast adhesion sites. A histological assessment of soft-tissue attachment and cell alignment relative to implants in an in vivo ovine model was performed. Passivation resulted in rougher, more hydrophobic, microcracked surfaces and was associated with poorer fibroblast adhesion than unpassivated controls. SiFn and HAFn surfaces resulted in more favourable cell alignment in vivo, implying that dermal attachment was enhanced. These results suggest that SiFn and HAFn surfaces could be useful in optimizing the soft tissue seal around ITAP.

  8. Total knee replacement with tibial tubercle osteotomy in rheumatoid patients with stiff knee.

    Science.gov (United States)

    Eid, Ahmed Salem; Nassar, Wael Ahmed Mohamed; Fayyad, Tamer Abdelmeguid Mohamed

    2016-11-01

    Total knee arthroplasty (TKA) is a well-proven modality that can provide pain relief and restore mobility for rheumatoid arthritis (RA) patients with advanced joint destruction. Patellar ligament avulsion, especially in presence of poor bone quality and knee stiffness, is one of the special considerations that must be addressed in this unique population of patients. This study aimed to determine the functional results in a series of rheumatoid patients with stiff knee and end-stage joint destruction who underwent tibial tubercle osteotomy during TKA. Twenty-three knees in 20 patients (16 women; four men) at a mean age of 54 years with end-stage arthritis and knee stiffness due to RA were operated upon for TKA using tibial tubercle osteotomy as a step during the operation. Patients were reviewed clinically and radiographically with a minimum follow-up of two years. Complications were noted. Hospital for Special Surgery (HSS) score was recorded pre-operatively and at six and 12 months postoperatively. Union occurred at the osteotomy site in 21 of 23 cases. One case had deep venous thrombosis (DVT). There was no infection or periprosthetic fracture, and at last follow-up, no patient required revision. HSS score improved from 46 (15-60) pre-operatively to 85 (71-96) post-operatively. Tibial tubercle osteotomy during TKA in patients with RA and stiff knee is technically demanding yet proved to be effective in improving post-operative range of movement and minimising the complication of patellar ligament avulsion.

  9. Visual pattern and serial quantitation of {sup 18}F-sodium fluoride PET/CT in asymptomatic patients after hip and knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Son, Hye Joo; Jeong, Young Jin; Yoon, Hyun Jin; Wang, Lih; Kim, Hyeon Jun; Kang, Do Young [Dong-A University Medical Center, Dong-A University College of Medicine, Busan (Korea, Republic of); Park, Jong Hwan [Institute of Convergence Bio-Health, Dong-A University, Busan (Korea, Republic of)

    2016-12-15

    We investigated the visual tracer distribution pattern and serial changes in uptake ratio in different anatomical zones during the natural postoperative course in order to establish a reference for evaluation of patients with complications. A total of 36 patients without symptoms after hip or knee arthroplasty were grouped according to the interval between surgery and the scan. The serial changes in SUVmean in each periprosthetic zone were quantified using the volume of interest isocontour method. Images were classified according to the uptake distribution pattern. The uptake ratios in the postoperative period groups were then compared using the Kruskal-Wallis test. The correlation between uptake ratio and postoperative period was then determined. Tracer distribution patterns in hip prostheses were classified into three types and the patterns in knee prostheses into five types. In hip prostheses, intense osteoblastic activity was observed during 3-6 months and then declined in most patients, but showed a slight increase over 15-25 months in 5-10 % of patients. The correlation coefficients varied among the zones. Significant differences in uptake ratios among the period groups was found for all zones, except zone 8. Porous coated areas showed higher uptake than uncoated areas only for the period the 3-6 months. In knee prostheses, uptake ratios showed a curvilinear pattern, increasing from 3-6 to 8-15 months and declining later. The uptake ratios were different among the period groups. Every zone showed a positive correlation from 3-6 to 8-15 months, and negative correlations from 8-15 to 22-25 months. This is the first {sup 18}F-sodium fluoride PET/CT study investigating the stability of implants and sets a reference for evaluation of patients with complications.

  10. Impact of Powered Knee-Ankle Prosthesis on Low Back Muscle Mechanics in Transfemoral Amputees: A Case Series

    Directory of Open Access Journals (Sweden)

    Chandrasekaran Jayaraman

    2018-03-01

    Full Text Available Regular use of prostheses is critical for individuals with lower limb amputations to achieve everyday mobility, maintain physical and physiological health, and achieve a better quality of life. Use of prostheses is influenced by numerous factors, with prosthetic design playing a critical role in facilitating mobility for an amputee. Thus, prostheses design can either promote biomechanically efficient or inefficient gait behavior. In addition to increased energy expenditure, inefficient gait behavior can expose prosthetic user to an increased risk of secondary musculoskeletal injuries and may eventually lead to rejection of the prosthesis. Consequently, researchers have utilized the technological advancements in various fields to improve prosthetic devices and customize them for user specific needs. One evolving technology is powered prosthetic components. Presently, an active area in lower limb prosthetic research is the design of novel controllers and components in order to enable the users of such powered devices to be able to reproduce gait biomechanics that are similar in behavior to a healthy limb. In this case series, we studied the impact of using a powered knee-ankle prostheses (PKA on two transfemoral amputees who currently use advanced microprocessor controlled knee prostheses (MPK. We utilized outcomes pertaining to kinematics, kinetics, metabolics, and functional activities of daily living to compare the efficacy between the MPK and PKA devices. Our results suggests that the PKA allows the participants to walk with gait kinematics similar to normal gait patterns observed in a healthy limb. Additionally, it was observed that use of the PKA reduced the level of asymmetry in terms of mechanical loading and muscle activation, specifically in the low back spinae regions and lower extremity muscles. Further, the PKA allowed the participants to achieve a greater range of cadence than their predicate MPK, thus allowing them to safely

  11. Anterior approach for knee arthrography

    International Nuclear Information System (INIS)

    Zurlo, J.V.; Towers, J.D.; Golla, S.

    2001-01-01

    Objective. To develop a new method of magnetic resonance arthrography (MRA) of the knee using an anterior approach analogous to the portals used for knee arthroscopy.Design. An anterior approach to the knee joint was devised mimicking anterior portals used for knee arthroscopy. Seven patients scheduled for routine knee MRA were placed in a decubitus position and under fluoroscopic guidance a needle was advanced from a position adjacent to the patellar tendon into the knee joint. After confirmation of the needle tip location, a dilute gadolinium solution was injected.Results and conclusion. All the arthrograms were technically successful. The anterior approach to knee MRA has greater technical ease than the traditional approach with little patient discomfort. (orig.)

  12. Natural History of Bone Response to Hydroxyapatite-Coated Hip Prostheses Implanted in Humans

    OpenAIRE

    Frayssinet, P.; Hardy, D.; Hanker, J. S.; Giammara, B. L.

    1995-01-01

    A series of 15 autopsied femurs containing hydroxyapatite- coated (HA-coated) prostheses was analysed histologically. Their implantation time ranged from 5 days up to 3 years. The coating thickness of some prostheses and the percentage of the coating in contact with bone at different levels were evaluated using an image analysis device. After the newly formed bone tissue had became mature, several bone morphotypes were identified at the coating contact. From the proximal to the distal part of...

  13. Knee osteoarthritis in traumatic knee symptoms in general practice: 6-year cohort study

    NARCIS (Netherlands)

    M. Kastelein (Marlous); P.A.J. Luijsterburg (Pim); I.M. Koster (Ingrid); J.A.N. Verhaar (Jan); D. Vroegindeweij (Dammis); S.M. Bierma-Zeinstra (Sita); E.H.G. Oei (Edwin)

    2016-01-01

    textabstractAim: To identify degenerative knee abnormalities using MRI and radiography 6 years after knee trauma, their relation with persistent knee symptoms and baseline prognostic factors. Methods: Adults (18–65 years) with incident traumatic knee symptoms visiting their

  14. Knees Lifted High

    Centers for Disease Control (CDC) Podcasts

    The Eagle Books are a series of four books that are brought to life by wise animal characters - Mr. Eagle, Miss Rabbit, and Coyote - who engage Rain That Dances and his young friends in the joy of physical activity, eating healthy foods, and learning from their elders about health and diabetes prevention. Knees Lifted High gives children fun ideas for active outdoor play.

  15. Knee injuries in football

    African Journals Online (AJOL)

    swimming and basketball.1 In 2001 it was reported to have injury rates of 1 000 times ... knee injury in football are the age of the player, a previous injury and the ligamentous .... football is possible, although the success rates may vary from ...

  16. Unicompartmental knee arthroplasty

    NARCIS (Netherlands)

    Kort, Nanne Pieter

    2007-01-01

    This thesis concerns technical aspects of unicompartmental knee arthroplasty. Recent years have witnessed a resurgence of interest in unicompartmental arthroplasty, particularly with the introduction of the minimally invasive technique. In the light of the excellent long-term results of the total

  17. Through Knee Amputation: Technique Modifications and Surgical Outcomes

    Directory of Open Access Journals (Sweden)

    Frank P Albino

    2014-09-01

    Full Text Available BackgroundKnee disarticulations (KD are most commonly employed following trauma or tumor resection but represent less than 2% of all lower extremity amputations performed in the United States annually. KDs provide enhanced proprioception, a long lever arm, preservation of adductor muscle insertion, decreased metabolic cost of ambulation, and an end weight-bearing stump. The role for KDs in the setting of arterial insufficiency or overwhelming infection is less clear. The purpose of this study is to describe technique modifications and report surgical outcomes following KDs at a high-volume Limb Salvage Center.MethodsA retrospective study of medical records for all patients who underwent a through-knee amputation performed by the senior author (C.E.A. between 2004 and 2012 was completed. Medical records were reviewed to collect demographic, operative, and postoperative information for each of the patients identified.ResultsBetween 2004 and 2012, 46 through-knee amputations for 41 patients were performed. The mean patient age was 68 and indications for surgery included infection (56%, arterial thrombosis (35%, and trauma (9%. Postoperative complications included superficial cellulitis (13%, soft tissue infection (4%, and flap ischemia (4% necessitating one case of surgical debridement (4% and four trans-femoral amputations (9%. 9 (22% patients went on to ambulate. Postoperative ambulation was greatest in the traumatic cohort and for patients less than 50 years of age, P<0.05. Alternatively, diabetes mellitus and infection reduced the likelihood of postoperative ambulation, P<0.01.ConclusionsKnee disarticulations are a safe and effective alternative to other lower extremity amputations when clinically feasible. For patient unlikely to ambulate, a through-knee amputation maximizes ease of transfers, promotes mobility by providing a counterbalance, and eliminates the potential for knee flexion contracture with subsequent skin breakdown.

  18. Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability.

    Science.gov (United States)

    Gustafson, Jonathan A; Gorman, Shannon; Fitzgerald, G Kelley; Farrokhi, Shawn

    2016-01-01

    Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (pknee flexion excursions (pknee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. In vitro method for assessing the biomechanics of the patellofemoral joint following total knee arthroplasty.

    Science.gov (United States)

    Coles, L G; Gheduzzi, S; Miles, A W

    2014-12-01

    The patellofemoral joint is a common site of pain and failure following total knee arthroplasty. A contributory factor may be adverse patellofemoral biomechanics. Cadaveric investigations are commonly used to assess the biomechanics of the joint, but are associated with high inter-specimen variability and often cannot be carried out at physiological levels of loading. This study aimed to evaluate the suitability of a novel knee simulator for investigating patellofemoral joint biomechanics. This simulator specifically facilitated the extended assessment of patellofemoral joint biomechanics under physiological levels of loading. The simulator allowed the knee to move in 6 degrees of freedom under quadriceps actuation and included a simulation of the action of the hamstrings. Prostheses were implanted on synthetic bones and key soft tissues were modelled with a synthetic analogue. In order to evaluate the physiological relevance and repeatability of the simulator, measurements were made of the quadriceps force and the force, contact area and pressure within the patellofemoral joint using load cells, pressure-sensitive film, and a flexible pressure sensor. The results were in agreement with those previously reported in the literature, confirming that the simulator is able to provide a realistic physiological loading situation. Under physiological loading, average standard deviations of force and area measurements were substantially lower and comparable to those reported in previous cadaveric studies, respectively. The simulator replicates the physiological environment and has been demonstrated to allow the initial investigation of factors affecting patellofemoral biomechanics following total knee arthroplasty. © IMechE 2014.

  20. Manufacturing conditioned roughness and wear of biomedical oxide ceramics for all-ceramic knee implants.

    Science.gov (United States)

    Turger, Anke; Köhler, Jens; Denkena, Berend; Correa, Tomas A; Becher, Christoph; Hurschler, Christof

    2013-08-29

    Ceramic materials are used in a growing proportion of hip joint prostheses due to their wear resistance and biocompatibility properties. However, ceramics have not been applied successfully in total knee joint endoprostheses to date. One reason for this is that with strict surface quality requirements, there are significant challenges with regard to machining. High-toughness bioceramics can only be machined by grinding and polishing processes. The aim of this study was to develop an automated process chain for the manufacturing of an all-ceramic knee implant. A five-axis machining process was developed for all-ceramic implant components. These components were used in an investigation of the influence of surface conformity on wear behavior under simplified knee joint motion. The implant components showed considerably reduced wear compared to conventional material combinations. Contact area resulting from a variety of component surface shapes, with a variety of levels of surface conformity, greatly influenced wear rate. It is possible to realize an all-ceramic knee endoprosthesis device, with a precise and affordable manufacturing process. The shape accuracy of the component surfaces, as specified by the design and achieved during the manufacturing process, has a substantial influence on the wear behavior of the prosthesis. This result, if corroborated by results with a greater sample size, is likely to influence the design parameters of such devices.

  1. [Morphological features of utilization intraperitoneal double-sided prostheses in inguinoplasty in dogs].

    Science.gov (United States)

    de Andrade, Luiz Carlos; Ceneviva, Reginaldo; Coutinho-Netto, Joaquim; Silva Júnior, Orlando de Castro e; dos Santos, José Sebastião; Sukeda, Daniel Hirochi

    2009-10-01

    To asses the morphological features of the behavior of a double-sided prostheses using inguinoplasty laparotomy in dogs with latex side turned to the visceras. Twenty dogs were divided into two groups of 10 and submitted into infraumbilical laparotomy with double-sided prostheses fixed in an inguinal area and in the other side area a control prostheses of polipropilene (PPL). Macroscopics itens were studied on the 14th and 28th day post-operatory, and they were related to obstruction and intestinal fistulas, encystation, fusion and especially sticker. The microscopic analysis covered the inflammatory process in its acute, chronic and restored phase Infectious process, obstruction or intestinal fistula did not happen. The prostheses presented good accommodation and incorporation. The stickers happened with more prevalent and intensity with the PPL (p0,05). The double-sided prostheses in its parietal side adds the advantages of the incorporation's potential to the noticed material with PPL to the biocompatibility from the latex in its visceral side. The little distance between the PPL disc and the edge of the double-sided prostheses (2 cm) allied to its sticking with just five staples is not enough to avoid gaps, through which the epíploon migrated towards to the inflammatory process provoked by PPL in the parietal side.

  2. Does Extracellular DNA Production Vary in Staphylococcal Biofilms Isolated From Infected Implants versus Controls?

    Science.gov (United States)

    Zatorska, Beata; Groger, Marion; Moser, Doris; Diab-Elschahawi, Magda; Lusignani, Luigi Segagni; Presterl, Elisabeth

    2017-08-01

    Prosthetic implant infections caused by Staphylococcus aureus and epidermidis are major challenges for early diagnosis and treatment owing to biofilm formation on the implant surface. Extracellular DNA (eDNA) is actively excreted from bacterial cells in biofilms, contributing to biofilm stability, and may offer promise in the detection or treatment of such infections. (1) Does DNA structure change during biofilm formation? (2) Are there time-dependent differences in eDNA production during biofilm formation? (3) Is there differential eDNA production between clinical and control Staphylococcal isolates? (4) Is eDNA production correlated to biofilm thickness? We investigated eDNA presence during biofilm formation in 60 clinical and 30 control isolates of S aureus and S epidermidis. The clinical isolates were isolated from patients with infections of orthopaedic prostheses and implants: 30 from infected hip prostheses and 30 from infected knee prostheses. The control isolates were taken from healthy volunteers who had not been exposed to antibiotics and a hospital environment during the previous 3 and 12 months, respectively. Control S epidermidis was isolated from the skin of the antecubital fossa, and control S aureus was isolated from the nares. For the biofilm experiments the following methods were used to detect eDNA: (1) fluorescent staining with 4',6-diamidino-2-phenylindole (DAPI), (2) eDNA extraction using a commercial kit, and (3) confocal laser scanning microscopy for 24-hour biofilm observation using propidium iodide and concanavalin-A staining; TOTO ® -1 and SYTO ® 60 staining were used for observation and quantification of eDNA after 6 and 24 hours of biofilm formation. Additionally antibiotic resistance was described. eDNA production as observed by confocal laser scanning microscopy was greater in clinical isolates than controls (clinical isolates mean ± SD: 1.84% ± 1.31%; control mean ± SD: 1.17% ± 1.37%; p biofilm formation. After 24 hours, the

  3. Clinical and Economic Burden of Revision Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Mohit Bhandari

    2012-01-01

    Full Text Available Surgery is indicated for symptomatic knee osteoarthritis (OA when conservative measures are unsuccessful. High tibial osteotomy (HTO, unicompartmental knee arthroplasty (UKA, and total knee arthroplasty (TKA are surgical options intended to relieve knee OA pain and dysfunction. The choice of surgical intervention is dependent on several factors such as disease location, patient age, comorbidities, and activity levels. Regardless of surgical treatment, complications such as infection, loosening or lysis, periprosthetic fracture, and postoperative pain are known risks and are indications for revision surgery. The clinical and economic implications for revision surgery are underappreciated. Over 55,000 revision surgeries were performed in 2010 in the US, with 48% of these revisions in patients under 65 years. Total costs associated with each revision TKA surgery have been estimated to be in excess of $49,000. The current annual economic burden of revision knee OA surgery is $2.7 billion for hospital charges alone. By 2030, assuming a 5-fold increase in the number of revision procedures, this economic burden will exceed $13 billion annually. It is appealing to envision a therapy that could delay or obviate the need for arthroplasty. From an actuarial standpoint, this would have the theoretical downstream effect of substantially reducing the number of revision procedures. Although no known therapies currently meet these criteria, such a breakthrough would have a tremendous impact in lessening the clinical and economic burden of knee OA revision surgery.

  4. Long-term follow-up study of bilateral above-the-knee amputees from the Vietnam War.

    Science.gov (United States)

    Dougherty, P J

    1999-10-01

    Because caring for patients who have combat-related amputations is a discontinuous practice, military surgeons must relearn treatment techniques during each conflict. The purpose of the present long-term study (average duration of follow-up, 27.5 years) was to document the status of patients who had sustained a bilateral above-the-knee amputation in Vietnam and had been managed by the only separate amputee service in the United States Army. A review of the records of 484 battle amputees identified thirty individuals (6 percent) who had a bilateral above-the-knee amputation. Twenty-six (87 percent) of the thirty patients had been injured by a land mine or a booby trap. Fifty-three (88 percent) of the sixty limbs were amputated because of trauma, and the other seven (12 percent) were amputated secondarily because of infection. Data regarding education, employment, marriage and family life, prosthetic use, and psychological care were collected by mail or telephone for twenty-three (85 percent) of the twenty-seven surviving patients. Respondents also completed the Short Form-36 (SF-36) Health Survey. At the time of the study, five (22 percent) of the twenty-three respondents used prostheses for walking; the devices were used for an average of 7.7 hours per day. Sixteen respondents (70 percent) were or had been employed outside of the home since the time of discharge. The physical functioning score on the SF-36 questionnaire was significantly lower for the study group than it was for a group of age and gender-matched controls (p < 0.001; Student two-tailed t test). With the numbers available, no significant differences could be detected between the groups with regard to physical role functioning (p = 0.377), bodily pain (p = 0.603), general health (p = 0.407), vitality (p = 0.949), social functioning (p = 0.460), emotional role functioning (p = 0.029), or mental health (p = 0.102). The patients in the present study have led relatively normal, productive lives within the

  5. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral (hemi-knee...

  6. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be implanted...

  7. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made of...

  8. Knee Motion Generation Method for Transfemoral Prosthesis Based on Kinematic Synergy and Inertial Motion.

    Science.gov (United States)

    Sano, Hiroshi; Wada, Takahiro

    2017-12-01

    Previous research has shown that the effective use of inertial motion (i.e., less or no torque input at the knee joint) plays an important role in achieving a smooth gait of transfemoral prostheses in the swing phase. In our previous research, a method for generating a timed knee trajectory close to able-bodied individuals, which leads to sufficient clearance between the foot and the floor and the knee extension, was proposed using the inertial motion. Limb motions are known to correlate with each other during walking. This phenomenon is called kinematic synergy. In this paper, we measure gaits in level walking of able-bodied individuals with a wide range of walking velocities. We show that this kinematic synergy also exists between the motions of the intact limbs and those of the knee as determined by the inertial motion technique. We then propose a new method for generating the motion of the knee joint using its inertial motion close to the able-bodied individuals in mid-swing based on its kinematic synergy, such that the method can adapt to the changes in the motion velocity. The numerical simulation results show that the proposed method achieves prosthetic walking similar to that of able-bodied individuals with a wide range of constant walking velocities and termination of walking from steady-state walking. Further investigations have found that a kinematic synergy also exists at the start of walking. Overall, our method successfully achieves knee motion generation from the initiation of walking through steady-state walking with different velocities until termination of walking.

  9. Detection of low-grade prosthetic joint infections using 99mTc-antigranulocyte SPECT/CT: initial clinical results

    International Nuclear Information System (INIS)

    Graute, Vera; Lehner, Sebastian; Haug, Alexander; Bartenstein, Peter; Hacker, Marcus; Feist, Markus; Mueller, Peter Ernst

    2010-01-01

    Low-grade joint infections are characterized by infiltration of granulocytes, which mediate aspects of inflammatory changes. We evaluated retrospectively the contribution of SPECT/CT as an addition to planar scintigraphy with 99m Tc-labelled antigranulocyte antibodies for diagnosing and localizing low-grade joint infections. Planar scintigraphy using 99m Tc-labelled antigranulocyte BW 250/183 antibodies was performed in 31 patients with suspected joint infections at 5 min, 5 h and 24 h after injection, with additional SPECT/CT performed 6 h after injection. With reference to gold standard clinical data, we assessed the diagnostic sensitivity of scintigraphy alone and in conjunction with SPECT/CT. Joint infections were diagnosed clinically in 9 of the 31 patients (1 hip and 8 knee prostheses). Planar scintigraphy revealed 6 true-positives, 13 true-negatives, 9 false-positives and 3 false-negative results, indicating sensitivity, specificity, positive and negative predictive values of, respectively, 0.66, 0.60, 0.4 and 0.81. With the addition of SPECT images, corresponding sensitivity, specificity, positive and negative predictive values increased to 0.89, 0.45, 0.40 and 0.91. Implementation of fused SPECT/CT led to a further increase to 0.89, 0.73, 0.57 and 0.94. Relative to planar scintigraphy, SPECT with and without CT substantially improved the utility of imaging with 99m Tc-labelled antigranulocyte antibodies for diagnosis and localization of suspected joint infections. Optimal accuracy was obtained through image fusion, which permitted anatomical allocation of foci of pathological tracer accumulation as well as providing information on the extent of the infection. This imaging method seems suited for selection of patients requiring surgical therapy. (orig.)

  10. Efficacy of a novel PCR- and microarray-based method in diagnosis of a prosthetic joint infection

    Science.gov (United States)

    2014-01-01

    Background and purpose Polymerase chain reaction (PCR) methods enable detection and species identification of many pathogens. We assessed the efficacy of a new PCR and microarray-based platform for detection of bacteria in prosthetic joint infections (PJIs). Methods This prospective study involved 61 suspected PJIs in hip and knee prostheses and 20 negative controls. 142 samples were analyzed by Prove-it Bone and Joint assay. The laboratory staff conducting the Prove-it analysis were not aware of the results of microbiological culture and clinical findings. The results of the analysis were compared with diagnosis of PJIs defined according to the Musculoskeletal Infection Society (MSIS) criteria and with the results of microbiological culture. Results 38 of 61 suspected PJIs met the definition of PJI according to the MSIS criteria. Of the 38 patients, the PCR detected bacteria in 31 whereas bacterial culture was positive in 28 patients. 15 of the PJI patients were undergoing antimicrobial treatment as the samples for analysis were obtained. When antimicrobial treatment had lasted 4 days or more, PCR detected bacteria in 6 of the 9 patients, but positive cultures were noted in only 2 of the 9 patients. All PCR results for the controls were negative. Of the 61 suspected PJIs, there were false-positive PCR results in 6 cases. Interpretation The Prove-it assay was helpful in PJI diagnostics during ongoing antimicrobial treatment. Without preceding treatment with antimicrobials, PCR and microarray-based assay did not appear to give any additional information over culture. PMID:24564748

  11. CURBSIDE CONSULTATION IN KNEE ARTHROPLASTY: 49 CLINICAL QUESTIONS

    Directory of Open Access Journals (Sweden)

    Craig J. Della Vale

    2008-12-01

    chapter there are revision questions including painful total knee arthroplasty, periprosthetic infection, exposure in revision knee arthroplasty, surgical technique, using stem, offset stems, massive bone loss, retaining patellar component, severe patellar bone loss, assessing joint line position, inserts, chronic extensor mechanism deficiency, spacers, knee fusion, positive culture. AUDIENCE Mainly orthopedic surgeons and residents who are interested in knee arthroplasty have been targeted but the current information related to total knee replacement surgery will also be welcomed by experienced clinicians practicing in knee arthroplasty. Also non-physician personnel may benefit the brief knowledge. ASSESSMENT The brief answers including current concepts and opinions of expert arthroplasty surgeons to carefully chosen questions related to the problems faced in the daily practice of knee artroplasty forming the sections are making almost comprehensive source knowledge for total knee replacement surgery. This reference of complicated cases and controversies in knee arthroplasty by Craig J. Della Vale, MD.and his collaborators will be one of the most practical source of current solutions in the management of knee arthroplasty . Providing straightforward, brief and useful advices, in the form of pearls and pitfalls for frequently encountered problems in total knee replacement surgery makes the text a user friendly, essential reference. The casual style of articles resembling the advices in a dialog of colleagues on a curbside consult makes the text easier to read and understand. Various image and diagrams enhances the knowledge in the text

  12. Patients Unicondylar Knee Replacement vs. Total Knee Replacement

    OpenAIRE

    Hedra Eskander

    2017-01-01

    The aim of this review article is to analyse the clinical effectiveness of total knee replacement (TKR) compared to unicondylar knee replacement (UKR) on patients. In terms of survival rates, revision rates and postoperative complications. The keywords used were: knee arthroplasty. Nearly three thousand articles were found on 25 August 2016. Of those, only twenty-five were selected and reviewed because they were strictly focused on the topic of this article. Compared with those who have TKR, ...

  13. Complete integration of technology for improved reproduction of auricular prostheses.

    Science.gov (United States)

    Watson, Jason; Hatamleh, Muhanad M

    2014-05-01

    The accurate reproduction of the form and surface details of missing body structures is an essential part of any successful prosthetic rehabilitation. It helps mask the prosthesis and gives confidence to the patient. This clinical report details the integration of multiple in-house digital technologies of laser scanning, rapid prototyping, and digital color scanning and formulating to improve the shape, texture, orientation, and color of auricular prostheses for 3 patients with missing unilateral ears. A structured light laser scanner was used to digitize the patient's nondefect ear. The digitized data were then manipulated in specialist software and mirrored to reflect the opposing side. A rapid prototyping machine was used to manufacture a 3-dimensional (3D) model of the soft tissue required. This 3D mirrored ear model allowed the accurate reproduction of missing soft tissue. A color spectrometer was used to accurately reproduce the skin tones digitally and physically. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  14. Implant-supported prostheses versus conventional permanent and removable dentures

    Directory of Open Access Journals (Sweden)

    Koszuta Agnieszka

    2014-06-01

    Full Text Available Social, economic and technological progress results in an increasing range of treatment and rehabilitation methods for patients with partial or complete edentulism. The role of the dentist is to inform the patient about the full range of available missing teeth treatment options leading to complete rehabilitation of the masticatory organ in agreement with the patient’s aesthetic and functional expectations. The aim of the paper was to identify the type of prostheses used by patients before opting for implantsupported teeth replacements, according to the patients’ age, sex, marital status, place of residence and education. The study covered 464 patients, women and men, aged 20-74, treated with dental implants. The patients answered questions in an anonymous questionnaire. The influence of the prosthetic replacement type according to age and marital status was highly statistically significant, whereas it was statistically significant according to sex, place of residence and education. The female respondents who previously used tissue-borne complete or partial dentures opted for implant treatment more frequently. The respondents younger than 40 and between 40-60 years of age who did not previously used any prosthetic replacements opted for implant treatment more frequently. The respondents who did not use any prosthetic replacements decided to undergo implant treatment most frequently, regardless of their marital status, education and place of residence. The patients opted for implant treatment to improve their quality of life, despite the high cost of such therapy.

  15. Wireless technologies for closed-loop retinal prostheses

    Science.gov (United States)

    Ng, David C.; Bai, Shun; Yang, Jiawei; Tran, Nhan; Skafidas, Efstratios

    2009-12-01

    In this paper, we discuss various technologies needed to develop retinal prostheses with wireless power and data telemetry operation. In addition to the need to communicate with the implanted device, supply of power to the retinal prosthesis is especially difficult. This is because, in the implanted state, the device is not fixed in position due to constant motion of the eye. Furthermore, a retinal prosthesis incorporating a high density electrode array of more than 1000 electrodes is expected to consume approximately 45 mW of power and require 300 kbps of image and stimulation data. The front end of the wireless power and data transmission, the antenna, needs to be small compared to the size of the eye. Also, the wireless module is expected to operate in the reactive near-field region due to small separation between the transmit and receive antennas compared to their size and corresponding operating wavelength. An inductive link is studied as a means to transfer power and for data telemetry between the implant and external unit. In this work, the use of integrated circuit and microfabrication technologies for implementing inductive links is discussed. A closed-loop approach is taken to improve performance and reach optimum operation condition. Design and simulation data are presented as the basis for development of viable wireless module prototypes.

  16. Hydrogel-Electrospun Fiber Mat Composite Coatings for Neural Prostheses

    Directory of Open Access Journals (Sweden)

    Ning eHan

    2011-03-01

    Full Text Available Achieving stable, long-term performance of implanted neural prosthetic devices has been challenging because of implantation related neuron loss and a foreign body response that results in encapsulating glial scar formation. To improve neuron-prosthesis integration and form chronic, stable interfaces, we investigated the potential of neurotrophin-eluting hydrogel-electrospun fiber mat (EFM composite coatings. In particular, poly(ethylene glycol-poly(ε-caprolactone (PEGPCL hydrogel- poly(ε-caprolactone (PCL EFM composites were applied as coatings for multielectrode arrays (MEAs. Coatings were stable and persisted on electrode surfaces for over 1 month under an agarose gel tissue phantom and over 9 months in a PBS immersion bath. To demonstrate drug release, a neurotrophin, nerve growth factor (NGF, was loaded in the PEGPCL hydrogel layer, and coating cytotoxicity and sustained NGF release were evaluated using a PC12 cell culture model. Quantitative MTT assays showed that these coatings had no significant toxicity toward PC12 cells, and neurite extension at day 7 and 14 confirmed sustained release of NGF at biologically significant concentrations for at least 2 weeks. Our results demonstrate that hydrogel-EFM composite materials can be applied to neural prostheses as a means to improve neuron-electrode proximity and enhance long-term device performance and function.

  17. [Communication prostheses and behavioral alignment in hospital leaflets].

    Science.gov (United States)

    Vasconcellos-Silva, Paulo Roberto; Rivera, Francisco Javier Uribe; Rozemberg, Brani

    2003-08-01

    Review was made of publications that describe experience with printed material distributed to the lay public in hospital institutions. From the 146 leaflets examined, those aimed at professionals or disabled people, thus leaving 75 papers that illustrate the present pattern for the rationality behind the production, use and evaluation of this type of resource. In a general manner, such leaflets invest in the power of "ideal printed information" to align behavior with the hospital's biomedical agenda. The underlying rationality that permeates them perceives the "perfect information package" as one that efficiently describes its technical content for the purpose of unidirectional persuasion, is up-to-date in relation to readability scales and embellished by graphic design, and emphasizes the priorities defined by the professionals. Such "communication prostheses" should be capable of electronic validation by means of software suitable for proportioning the "doses" to the subject matter. Information as a drug, cognitivism, the lack of research on message reception and the need for communicative action for the deconstruction of systems of closed thinking within the hospital environment have been discussed.

  18. Intraocular camera for retinal prostheses: Refractive and diffractive lens systems

    Science.gov (United States)

    Hauer, Michelle Christine

    The focus of this thesis is on the design and analysis of refractive, diffractive, and hybrid refractive/diffractive lens systems for a miniaturized camera that can be surgically implanted in the crystalline lens sac and is designed to work in conjunction with current and future generation retinal prostheses. The development of such an intraocular camera (IOC) would eliminate the need for an external head-mounted or eyeglass-mounted camera. Placing the camera inside the eye would allow subjects to use their natural eye movements for foveation (attention) instead of more cumbersome head tracking, would notably aid in personal navigation and mobility, and would also be significantly more psychologically appealing from the standpoint of personal appearances. The capability for accommodation with no moving parts or feedback control is incorporated by employing camera designs that exhibit nearly infinite depth of field. Such an ultracompact optical imaging system requires a unique combination of refractive and diffractive optical elements and relaxed system constraints derived from human psychophysics. This configuration necessitates an extremely compact, short focal-length lens system with an f-number close to unity. Initially, these constraints appear highly aggressive from an optical design perspective. However, after careful analysis of the unique imaging requirements of a camera intended to work in conjunction with the relatively low pixellation levels of a retinal microstimulator array, it becomes clear that such a design is not only feasible, but could possibly be implemented with a single lens system.

  19. Implant prostheses for convertibility, stress control, esthetics, and hygiene.

    Science.gov (United States)

    Garfield, R E

    1988-07-01

    A method of connecting "fixed partial denture" prostheses to osseointegrated implant fixtures has been described. The advantages of this system of restoration for partially and fully edentulous mouths are that it is more effective in addressing the problems of (1) stress-control on abutments, (2) a back-up system for abutment failures, (3) esthetics, and (4) control of bacterial plaques around abutments. To accomplish this procedure, the application of convertible periodontal prosthesis techniques with modifications to some existing implant systems is undertaken. The disadvantages of this method seem insignificant when one considers the complexities and risks involved with the present array of implant prosthesis alternatives. Some patients and dentists might consider the necessity of the prosthesis being detachable as one disadvantage. In reality, the prosthesis can be used as a fixed restoration until the patient has fully adapted to the new proprioception and appearance. A large percentage of patients feel uncomfortable with the word "removable" because it immediately creates a perception of unsightly metallic clasp display, palatal coverage, tongue interference, and negative body image. The use of the term "detachable" coupled with the doctor's offer to perform this task for the patient "whenever necessary" will usually relieve the patient's anxiety and allow the treatment to proceed. Once neuromuscular and esthetic adaptation have occurred and the patient has accepted the prosthesis, daily detaching and home-care hygiene by the patient will follow without incident. Esthetic improvement is obvious (Fig. 3).

  20. Aging of monolithic zirconia dental prostheses: Protocol for a 5-year prospective clinical study using ex vivo analyses

    OpenAIRE

    Koenig, Vinciane; Wulfman, Claudine P.; Derbanne, Mathieu A.; Dupont, Nathalie M.; Le Goff, Stéphane O.; Tang, Mie-Leng; Seidel, Laurence; Dewael, Thibaut Y.; Vanheusden, Alain J.; Mainjot, Amélie K.

    2016-01-01

    Background: Recent introduction of computer-aided design/computer-aided manufacturing (CAD/CAM) monolithic zirconia dental prostheses raises the issue of material low thermal degradation (LTD), a well-known problem with zirconia hip prostheses. This phenomenon could be accentuated by masticatory mechanical stress. Until now zirconia LTD process has only been studied in vitro. This work introduces an original protocol to evaluate LTD process of monolithic zirconia prostheses in the oral enviro...

  1. Total knee arthroplasty for severe valgus knee deformity.

    Science.gov (United States)

    Zhou, Xinhua; Wang, Min; Liu, Chao; Zhang, Liang; Zhou, Yixin

    2014-01-01

    Primary total knee arthroplasty (TKA) in severe valgus knees may prove challenging, and choice of implant depends on the severity of the valgus deformity and the extent of soft-tissue release. The purpose of this study was to review 8 to 11 years (mean, 10 years) follow-up results of primary TKA for varient-III valgus knee deformity with use of different type implants. Between January 2002 and January 2005, 20 women and 12 men, aged 47 to 63 (mean, 57.19 ± 6.08) years old, with varient-III valgus knees underwent primary TKA. Of the 32 patients, 37 knees had varient-III deformities. Pie crusting was carefully performed with small, multiple inside-out incisions, bone resection balanced the knee in lieu of soft tissue releases that were not used in the series. Cruciate-retaining knees (Gemini MKII, Link Company, Germany) were used in 13 knees, Genesis II (Simth & Nephew Company, USA) in 14 knees, and hinged knee (Endo-Model Company, Germany) in 10 knees. In five patients with bilateral variant-III TKAs, three patients underwent 1-stage bilateral procedures, and two underwent 2-stage procedures. All implants were cemented and the patella was not resurfaced. The Hospital for Special Surgery (HSS) knee score was assessed. Patients were followed up from 8 to 11 years. The mean HSS knee score were improved from 50.33 ± 11.60 to 90.06 ± 3.07 (P managed with rivaroxaban and thrombo-embolic deterrent stockings. There was no incidence of pulmonary embolism. Post-operative patient satisfaction was 80.7 ± 10.4 points in the groups. Prosthetic survival rate was 100% at mean 10 years postoperative. Not only hinged implants can be successfully used in variant-III valgus knees. As our results show, if proper ligament balancing techniques are used and proper ligament balance is attained, the knee may not require the use of a more constrained components. Our results also present alternative implant choices for severe knee deformities.

  2. Anterior Cruciate Ligament Reconstruction using Bone Patellar Tendon Bone autograft in ACL deficient Knee

    Directory of Open Access Journals (Sweden)

    Navin Kumar Karn

    2015-12-01

    Full Text Available Background & Objectives: Injury to Anterior Cruciate Ligament (ACL reconstruction has increased because of increased interest in sports. There are various grafts used for reconstruction of ACL, for example, Bone Patellar Tendon Bone, Hamstring etc. The study was conducted to evaluate the results of Bone Patellar Tendon Bone graft used for reconstruction of Anterior Cruciate Ligament.Materials & Methods: 40 patients with chronic ACL deficient knee presenting to Neuro Hospital from July 2011 to June 2013 were included in the study. The patients with intraarticular fracture of knee, severe OA knee, local active or suspected infection and systemic disease that might influence the study results were excluded from the study. Bone patellar tendon bone graft was harvested from ipsilateral knee in all the cases. The patient was followed till 2 year with specified programme of rehabilitation. The pain was assessed using VAS and the function of the knee was assessed using Modified WOMAC knee index.Results: The long term satisfactory results in terms of functional stability, symptom relief and return to preinjury level of activity was seen in 32 cases (80%. Two knees got infected out of which one required arthroscopic debridement. Mean visual analogue scale was 8 and modified WOMAC knee score was 3 at 2 year follow up.Conclusion: Bone patellar tendon bone graft is useful in high demand patients and cost effective option with high patient satisfaction rate for reconstruction of ACL.JCMS Nepal. 2015;11(3:12-15.

  3. Shifting bone marrow edema of the knee

    International Nuclear Information System (INIS)

    Moosikasuwan, Josh B.; Schultz, Elizabeth; Miller, Theodore T.; Math, Kevin

    2004-01-01

    The purpose of our study is to describe shifting bone marrow edema in the knee as the MR imaging feature of intra-articular regional migratory osteoporosis of the knee. Five men, aged 45-73 years, were referred by orthopedic surgeons for MR imaging evaluation of knee pain, which had been present for 2 weeks to 6 months. One patient had a prior history of blunt trauma. None had risk factors for osteonecrosis. Four patients had two MR examinations and the patient with prior blunt trauma had four. Plain radiographs were obtained in all patients. In all cases, a large area of marrow edema initially involved a femoral condyle, with migration of the bone marrow edema to the other femoral condyle, tibia, and/or patella occurring over a 2- to 4-month period. Adjacent soft tissue edema was present in all five patients, while none had a joint effusion. Radiographs of two patients showed generalized osteopenia. In the absence of acute trauma or clinical suspicion of infection, a large area of bone marrow edema without a zone of demarcation may represent intra-articular regional migratory osteoporosis. Demonstration of shifting bone marrow edema on follow-up examinations suggests this diagnosis. (orig.)

  4. [SECOT consensus on painful knee replacement].

    Science.gov (United States)

    Vaquero, J; Macule, F; Bello, S; Chana, F; Forriol, F

    2013-01-01

    The opinions of 21 experts in knee surgery were evaluated in this study, using a DELPHI questionnaire method in two successive rounds, on 64 controversial scenarios that covered both the diagnosis and possible treatment of painful knee replacements. The level of consensus was significantly unanimous in 42 items and of the design in 5, with no agreement in 17 of the questions presented. light of the published scientific evidence, the surgeons who took part showed to have a notable level of information on the most effective diagnostic tests, although, it should be pointed out that there was a lack of confidence in the possibility of ruling out an infection when the erythrocyte sedimentation rate and the C-reactive protein were within normal values, which have been demonstrated in the literature to have a high negative predictive value As regards the treatments to employ in the different situations, the responses of the expert panel were mainly in agreement with the data in the literature. The conclusions of this consensus may help other surgeons when they are faced with a painful knee prosthesis. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  5. An in vivo comparative study of the e-polytetrafluoroethylene vascular prostheses: Vitaflon and Gore-Tex.

    Science.gov (United States)

    Dobrova, N B; Gorodkov, A J; Sidorenko, E S; Schekhter, A B; Baquey, C

    1999-12-01

    A comparative study was performed in order to validate new Russian e-PTFE vascular prostheses Vitaflon (St. Petersburg, Russia). The Gore-Tex prostheses were chosen as a referential model. The prostheses were implanted in the venous and arterial positions in 13 dog experiments. After the implantation time was over a comprehensive histological and histochemical examination of excized specimens was performed. It was demonstrated that there is no difference in healing and functional properties between the two studied prostheses. Copyright 1999 Kluwer Academic Publishers

  6. Considerations for services from dental technicians in fabrication of fixed prostheses: A survey of commercial dental laboratories in Thessaloniki, Greece.

    Science.gov (United States)

    Hatzikyriakos, Andreas; Petridis, Haralampos P; Tsiggos, Nikolaos; Sakelariou, Sotirios

    2006-11-01

    Effective communication and cooperation between dentists and dental technicians are essential in providing quality services. There has been a lack of information regarding dentist-dental technician communications and current methods and materials used for the fabrication of fixed partial dentures (FPDs). This cross-sectional study identified the materials and techniques used for fabrication of FPDs, as well as the status of communication between dentists and dental technicians in Thessaloniki, Greece. A questionnaire was developed with 7 sections pertaining to procedures and materials used for the fabrication of fixed prostheses: general questions, infection control, impressions/interocclusal records, die technique/mounting, information from final casts, prostheses design/materials, and communication/shade selection. The questionnaire was anonymous and distributed by the Association of Dental Technicians of Thessaloniki to all member laboratories (228) in the wider province of Thessaloniki, Greece. Due to the absence of normal distribution of the results, frequencies and medians were reported. Ninety-six of 228 dental laboratories responded (42.1% response rate). Twenty-six percent of dental laboratories did not routinely disinfect incoming items. The dental technicians considered 30% of incoming final impressions and 20% of interocclusal registrations as inadequate. Half of the time (55%) final casts were mounted by technicians on simple hinge articulators. Only 20% of tooth preparations had adequate finish lines. The majority (70%) of fixed restorations were metal-ceramic. Fifty-seven percent of dental technicians considered the delivery time requested by dentists as insufficient. The information provided in this study indicates areas of weakness in communication between dentists and dental technicians, along with areas where both parties should use greater care during clinical and laboratory procedures.

  7. Muscle area of knee O.A

    International Nuclear Information System (INIS)

    Suzuki, Nobuharu; Onozawa, Toshihiro; Shibata, Minoru; Yamasita, Izumi; Kitsunai, Isamu; Asano, Akira

    1983-01-01

    The cross sectional area of the thigh muscles were studied by means of C.T. scan. Twelve normal knees, twelve primary knee O.A. knees, and six R.A. knees were examined. The cross sectional area of the Quadriceps femoris decreased significantly in the patient of the knee O.A. although flexors did not decrease. We discussed the etiology of the knee O.A. from this result. (author)

  8. The floating knee

    DEFF Research Database (Denmark)

    Muñoz Vives, Josep; Bel, Jean-Christophe; Capel Agundez, Arantxa

    2016-01-01

    In 1975, Blake and McBryde established the concept of 'floating knee' to describe ipsilateral fractures of the femur and tibia.1This combination is much more than a bone lesion; the mechanism is usually a high-energy trauma in a patient with multiple injuries and a myriad of other lesions...... fixation when both fractures (femoral and tibial) are extra-articular.Plates are the 'standard of care' in cases with articular fractures.A combination of implants are required by 40% of floating knees.Associated ligamentous and meniscal lesions are common, but may be irrelevant in the case of an intra......-articular fracture which gives the worst prognosis for this type of lesion. Cite this article: Muñoz Vives K, Bel J-C, Capel Agundez A, Chana Rodríguez F, Palomo Traver J, Schultz-Larsen M, Tosounidis, T. The floating knee.EFORT Open Rev2016;1:375-382. DOI: 10.1302/2058-5241.1.000042....

  9. Iodine-impregnated incision drape and bacterial recolonization in simulated total knee arthroplasty.

    Science.gov (United States)

    Milandt, Nikolaj; Nymark, Tine; Jørn Kolmos, Hans; Emmeluth, Claus; Overgaard, Søren

    2016-08-01

    Background and purpose - Iodine-impregnated incision drapes (IIIDs) are used to prevent surgical site infection (SSI). However, there is some evidence to suggest a potential increase in SSI risk as a result of IIID use, possibly from promotion of skin recolonization. A greater number of viable bacteria in the surgical field of an arthroplasty, and surgery in general, may increase the infection risk. We investigated whether IIID use increases bacterial recolonization compared to no drape use under conditions of simulated total knee arthroplasty (TKA). Methods - 20 patients scheduled for TKA were recruited. Each patient had 1 knee randomized for draping with IIID, while the contralateral knee was left bare. The patients thus served as their own control. The operating room conditions and perioperative procedures of a TKA were simulated. Cylinder samples were collected from the skin of each knee prior to disinfection, and again on 2 occasions after skin preparation-75 min apart. Quantities of bacteria were estimated using a spread plate technique under aerobic conditions. Results - We found similar quantities of bacteria on the intervention and control knees immediately after skin disinfection and after 75 min of simulated surgery. These quantities had not increased at the end of surgery when compared to baseline, so no recolonization was detected on the draped knees or on the bare knees. Interpretation - The use of IIIDs did not increase bacterial recolonization in simulated TKA. This study does not support the hypothesis that IIIDs promote bacterial recolonization and postoperative infection risk.

  10. A Study of Ossiculoplasty in Chronic Otitis Media using different types of Prostheses

    Directory of Open Access Journals (Sweden)

    Parthapratim Laha

    2013-12-01

    Full Text Available Abstract Introduction: A wide range of prostheses, autologus and synthetic are available for use these days. Ideally, the ossicular reconstruction prosthesis should be biocompatible, safe, easy to handle and capable of efficient sound transmission. Aim and objectives: To study operative ease and post-operative hearing results in patients undergoing ossiculoplasty with different types of prostheses. Materials and methods: A prospective randomized study of 25 patients with Chronic Otitis Media, undergoing ossiculoplasty was conducted at Command Hospital, Kolkata. Tragal cartilage was used in 05 patients, conchal cartilage in 05, refashioned incus in 05, hydroxyapatite in 05 and titanium prostheses in 05 patients. Subjects with mixed hearing loss, multiple co-morbidities and revision surgeries were excluded. Hearing assessment was done by pure tone audiometry pre-operatively and 04 and 12 weeks postoperatively. Results were analyzed statistically. Results: Using tragal or conchal cartilage took almost equal time as autologus incus. Using synthetic material saved time. Titanium prosthesis gives maximum surgical ease. Post-operative air-bone gap reduction within 20 dB was seen in all, irrespective of type of prostheses.  Conclusion: Surgical ease is considerably better with titanium prostheses; however hearing results are equally good in all.

  11. Esthetic, functional, and prosthetic outcomes with implant-retained finger prostheses.

    Science.gov (United States)

    Aydin, Cemal; Nemli, Secil Karakoca; Yilmaz, Handan

    2013-04-01

    Traumatic amputation of fingers results in a serious impairment of hand function and affects the psychological status of the patients. The implant-retained finger prostheses are an alternative treatment. The aim of this case report is to represent the use of osseointegrated implants for retention of finger prostheses in a patient with amputated thumb and index finger. Dental implants were placed in the residual bone of the fingers using two-stage surgery. Custom-made attachments were used to provide retention between implants and silicone prostheses. Prosthetic fingernails were made of composite resin material. After 6 months, implants were clinically successful, and the patient was satisfied with the appearance and the function of the prostheses. The complications of broken prosthetic nail and mild discoloration were observed. Reconstruction of amputated fingers with implant-retained prosthesis is a worthwhile treatment providing esthetic, functional, and psychological benefits, although some complications might be experienced. Clinical relevance Implant-retained finger prostheses are an acceptable treatment modality for patients with amputated fingers. Evaluating implant prognosis, functional results and prosthetic results of the patients are necessary to address the benefits and complications of the treatment.

  12. Fabrication of low cost soft tissue prostheses with the desktop 3D printer.

    Science.gov (United States)

    He, Yong; Xue, Guang-huai; Fu, Jian-zhong

    2014-11-27

    Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods.

  13. Dentistry investigations of teeth and dental prostheses using OCT

    Science.gov (United States)

    Sinescu, C.; Duma, V.-F.; Canjau, S.; Dobre, G.; Demian, D.; Cernat, R.; Negrutiu, M. L.; Todea, C.; Topala, F. I.; Hutiu, Gh.; Bradu, A.; Podoleanu, A. G.

    2016-04-01

    We present some of our recent investigations in Dental Medicine using Optical Coherence Tomography (OCT). Time Domain (TD), Spectral Domain (SD), and Swept Source (SS) OCT in-house developed systems are being used, for both ex vivo and in vivo investigations in the oral cavity. We study ex vivo the interface between the tooth and the dental sealant and demonstrate the limitations of the X-rays investigations that are now the gold standard for such procedures. Using OCT, defects in the interface that cannot be identified in radiographs can be determined both as position and magnitude. The drilling process of teeth can also be characterized in real time using OCT, to monitor the remaining dentin thickness (RDT) in order to avoid opening the pulp chamber. We demonstrate in this respect that an RDT of 0.5 mm is the minimum value to assure the integrity of the dentin wall between the drilled cavity and the pulp chamber; at an RDT of 0.3 mm or less a fracture is initiated, the dentin is punctured and endodontic treatment must follow. In vivo OCT investigations in the oral cavity were also performed (i.e., for metalloceramic prostheses and for ceramic inlay tooth interfaces), with the low cost, light weight and versatile handheld probes with 1D galvoscanners that we have developed and applied for a range of in-house developed OCT systems, in various clinical applications. They are briefly discussed, as well as some of our current and future work in the field, including for studies of soft tissue in the mouth.

  14. Simulating auditory and visual sensorineural prostheses: a comparative review

    Science.gov (United States)

    Hallum, L. E.; Dagnelie, G.; Suaning, G. J.; Lovell, N. H.

    2007-03-01

    Microelectronic vision prosthesis proposes to render luminous spots (so-called phosphenes) in the visual field of the otherwise blind subject by way of an implanted array of stimulating electrodes, and in doing so restore some spatial vision. There are now many research teams worldwide working towards a therapeutic device, analogous to the cochlear implant, for the profoundly blind. Despite the similarities between the cochlear implant and vision prostheses, there are few instances in the literature where the two approaches are compared and contrasted with a mind to informing the science and engineering of the latter. This is the focus of the present review; specifically, our interest is psychophysics and signal processing. Firstly, we examine the cochlear implant, and review a handful of psychophysical work: the acoustic simulation of cochlear implants and the method used. We focus on the use of normally hearing subjects (played coloured noise bands or sine waves) as a means of investigating cochlear-implant efficacy and speech processing algorithms. These results provide guidance to vision researchers, for they address the interpretation of simulation data, and flag key areas, such as 'artificial' perception in the presence of noise, that require experimental work in coming years. Secondly, we provide an up-to-date review of the body of analogous psychophysical work: the visual simulation, involving normal observers, of microelectronic vision prosthesis. These simulations allow predictions as to the likely clinical efficacy of the prosthesis; indeed, results to date suggest that a number on the order of 100 implanted electrodes will afford subjects mobility and recognition of faces (and other complex stimuli), while even fewer electrodes facilitate reading printed text and very simple visuomanual tasks. Further, the simulations allow investigations of image and signal processing strategies, plus they provide researchers in the field, and other interested persons

  15. Total hip and knee joint replacement: perioperative clinical aspects

    Directory of Open Access Journals (Sweden)

    Luciana Pereira Almeida de Piano

    2010-09-01

    Full Text Available Objective: To understand the profile of patients undergoing hip and knee replacement during two years, and to compare the data obtained with the literature. Methods: A total of 323 medical records were reviewed to analyze the perioperative data of patients submitted to hip and knee replacement. Results: Osteoarthritis was the main indication for both procedures and male patients were heavier than females (p < 0.05. Hypertension was the prevalent disease among patients. Blood loss was more frequent in knee surgery than in the hip. Conclusions: The profile of patients undergoing total arthroplasty improved substantially over the past decade due to shorter hospital stay, lower risk of thromboembolic events and no infection as compared to previous reports.

  16. Iodine-impregnated incision drape and bacterial recolonization in simulated total knee arthroplasty

    DEFF Research Database (Denmark)

    Milandt, Nikolaj; Nymark, Tine; Jørn Kolmos, Hans

    2016-01-01

    bacteria in the surgical field of an arthroplasty, and surgery in general, may increase the infection risk. We investigated whether IIID use increases bacterial recolonization compared to no drape use under conditions of simulated total knee arthroplasty (TKA). Methods - 20 patients scheduled for TKA were...... recruited. Each patient had 1 knee randomized for draping with IIID, while the contralateral knee was left bare. The patients thus served as their own control. The operating room conditions and perioperative procedures of a TKA were simulated. Cylinder samples were collected from the skin of each knee prior...... to disinfection, and again on 2 occasions after skin preparation-75 min apart. Quantities of bacteria were estimated using a spread plate technique under aerobic conditions. Results - We found similar quantities of bacteria on the intervention and control knees immediately after skin disinfection and after 75 min...

  17. Magnification bone scan of knees for knee pain evaluation

    International Nuclear Information System (INIS)

    Lee, Myoung Hoon; Park, Chan H.; Yoon, Seok Nam; Hwang, Kyung Hoon

    2001-01-01

    Knee pain is one of the common complaints of patients seen in our orthopedic clinic. Routine anterior and posterior views of whole body bone scan (WBBS) is often not sufficient in the evaluation of these patients. An ideal bone scan using pinhole collimator or single photon emission tomography (SPECT), however, is impractical and time consuming in busy nuclear medicine department with limited resources. Therefore, the aim of the study is to assess limited bone scan of knees with magnification (LNSKM) for knee pain evaluation. Technical aspect of LBSKM and diagnostic efficacy are discussed on this poster. Adult patients with knee pain were reffered for LBSKM from an orthopedic surgen specializing knees. Four hundred fifteen LBSKMs were performed since 1999. patients were given 740 MBq (20mCi) Tc-99m MDP intravenously and 3 hours later LBSKM was performed using a low energy high resolution parallel hole collimator and Siemens Orbitor camera. (Simens medical systems. Inc., Hoffman Estates, III., USA). Anterior view of the knees was taken for 5 min, without magnification and both lateral views of symptomatic knees were obtained with electronic magnification (1.25, upto 2.0) for 8 min each. Disease processes such as DJD, traumatic arthritis, P-F tendonitis, SONK, meniscus tear are detected and illustrated along with normal knee scan finding. We believe LBSKM may not be as good as SPECT or pinhole imaging of the knees in the evaluation of knee pain but superior to routine WBBS in the nuclear medicine department with limited resources of instrumentation and manpower

  18. Automatic locking orthotic knee device

    Science.gov (United States)

    Weddendorf, Bruce C. (Inventor)

    1993-01-01

    An articulated tang in clevis joint for incorporation in newly manufactured conventional strap-on orthotic knee devices or for replacing such joints in conventional strap-on orthotic knee devices is discussed. The instant tang in clevis joint allows the user the freedom to extend and bend the knee normally when no load (weight) is applied to the knee and to automatically lock the knee when the user transfers weight to the knee, thus preventing a damaged knee from bending uncontrollably when weight is applied to the knee. The tang in clevis joint of the present invention includes first and second clevis plates, a tang assembly and a spacer plate secured between the clevis plates. Each clevis plate includes a bevelled serrated upper section. A bevelled shoe is secured to the tank in close proximity to the bevelled serrated upper section of the clevis plates. A coiled spring mounted within an oblong bore of the tang normally urges the shoes secured to the tang out of engagement with the serrated upper section of each clevic plate to allow rotation of the tang relative to the clevis plate. When weight is applied to the joint, the load compresses the coiled spring, the serrations on each clevis plate dig into the bevelled shoes secured to the tang to prevent relative movement between the tang and clevis plates. A shoulder is provided on the tang and the spacer plate to prevent overextension of the joint.

  19. Recruitment of knee joint ligaments

    NARCIS (Netherlands)

    Blankevoort, L.; Huiskes, H.W.J.; Lange, de A.

    1991-01-01

    On the basis of earlier reported data on the in vitro kinematics of passive knee-joint motions of four knee specimens, the length changes of ligament fiber bundles were determined by using the points of insertion on the tibia and femur. The kinematic data and the insertions of the ligaments were

  20. Somatosensory abnormalities in knee OA.

    Science.gov (United States)

    Wylde, Vikki; Palmer, Shea; Learmonth, Ian D; Dieppe, Paul

    2012-03-01

    The aim of this study was to use quantitative sensory testing (QST) to explore the range and prevalence of somatosensory abnormalities demonstrated by patients with advanced knee OA. One hundred and seven knee OA patients and 50 age- and sex-matched healthy participants attended a 1-h QST session. Testing was performed on the medial side of the knee and the pain-free forearm. Light-touch thresholds were assessed using von Frey filaments, pressure pain thresholds using a digital pressure algometer, and thermal sensation and pain thresholds using a Thermotest MSA. Significant differences in median threshold values from knee OA patients and healthy participants were identified using Mann-Whitney U-tests. The z-score transformations were used to determine the prevalence of the different somatosensory abnormalities in knee OA patients. Testing identified 70% of knee OA patients as having at least one somatosensory abnormality. Comparison of median threshold values between knee OA patients and healthy participants revealed that patients had localized thermal and tactile hypoaesthesia and pressure hyperalgesia at the osteoarthritic knee. Tactile hypoaesthesia and pressure hyperalgesia were also present at the pain-free forearm. The most prevalent somatosensory abnormalities were tactile hypoaesthesia and pressure hyperalgesia, evident in between 20 and 34% of patients. This study found that OA patients demonstrate an array of somatosensory abnormalities, of which the most prevalent were tactile hypoaesthesia and pressure hyperalgesia. Further research is now needed to establish the clinical implications of these somatosensory abnormalities.

  1. Effect of knee joint icing on knee extension strength and knee pain early after total knee arthroplasty: a randomized cross-over study.

    Science.gov (United States)

    Holm, Bente; Husted, Henrik; Kehlet, Henrik; Bandholm, Thomas

    2012-08-01

    To investigate the acute effect of knee joint icing on knee extension strength and knee pain in patients shortly after total knee arthroplasty. A prospective, single-blinded, randomized, cross-over study. A fast-track orthopaedic arthroplasty unit at a university hospital. Twenty patients (mean age 66 years; 10 women) scheduled for primary unilateral total knee arthroplasty. The patients were treated on two days (day 7 and day 10) postoperatively. On one day they received 30 minutes of knee icing (active treatment) and on the other day they received 30 minutes of elbow icing (control treatment). The order of treatments was randomized. Maximal knee extension strength (primary outcome), knee pain at rest and knee pain during the maximal knee extensions were measured 2-5 minutes before and 2-5 minutes after both treatments by an assessor blinded for active or control treatment. The change in knee extension strength associated with knee icing was not significantly different from that of elbow icing (knee icing change (mean (1 SD)) -0.01 (0.07) Nm/kg, elbow icing change -0.02 (0.07) Nm/kg, P = 0.493). Likewise, the changes in knee pain at rest (P = 0.475), or knee pain during the knee extension strength measurements (P = 0.422) were not different between treatments. In contrast to observations in experimental knee effusion models and inflamed knee joints, knee joint icing for 30 minutes shortly after total knee arthroplasty had no acute effect on knee extension strength or knee pain.

  2. Use of digital impression systems with intraoral scanners for fabricating restorations and fixed dental prostheses.

    Science.gov (United States)

    Takeuchi, Yoshimasa; Koizumi, Hiroyasu; Furuchi, Mika; Sato, Yohei; Ohkubo, Chikahiro; Matsumura, Hideo

    2018-01-01

    Accurate impressions are essential in fabri-cating dental restorations and fixed dental prostheses. During the last decade, digital impression systems have improved substantially. This review discusses the accuracy of digital impression systems for fabrication of dental restorations and fixed dental prostheses. A literature search in PubMed was performed for the period from July 2010 through June 2017. The search keywords were Cerec, digital impression, direct digitalization, indirect digitalization, and intraoral scanner. Only relevant studies are summarized and discussed in this review. In general, the latest systems have considerably reduced the time required for impression making, and the accuracy and marginal fit of digital impression systems have recently improved. Restorations and fixed dental prostheses fabricated with currently available digital impression systems and intraoral scanners exhibit clinically acceptable ranges of marginal gap in both direct and indirect procedures.

  3. Progress in the clinical development and utilization of vision prostheses: an update

    Directory of Open Access Journals (Sweden)

    Brandli A

    2016-05-01

    Full Text Available Alice Brandli, Chi D Luu, Robyn H Guymer, Lauren N Ayton Centre for Eye Research Australia, Department of Surgery (Ophthalmology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia Abstract: Vision prostheses, or “bionic eyes”, are implantable medical bionic devices with the potential to restore rudimentary sight to people with profound vision loss or blindness. In the past two decades, this field has rapidly progressed, and there are now two commercially available retinal prostheses in the US and Europe, and a number of next-generation devices in development. This review provides an update on the development of these devices and a discussion on the future directions for the field. Keywords: vision prostheses, bionic eye, vision restoration, blindness, medical bionics, retinitis pigmentosa

  4. The floating knee: epidemiology, prognostic indicators & outcome following surgical management.

    Science.gov (United States)

    Rethnam, Ulfin; Yesupalan, Rajam S; Nair, Rajagopalan

    2007-11-26

    Floating Knee injuries are complex injuries. The type of fractures, soft tissue and associated injuries make this a challenging problem to manage. We present the outcome of these injuries after surgical management. 29 patients with floating knee injuries were managed over a 3 year period. This was a prospective study were both fractures of the floating knee injury were surgically fixed using different modalities. The associated injuries were managed appropriately. Assessment of the end result was done by the Karlstrom criteria after bony union. The mechanism of injury was road traffic accident in 27/29 patients. There were 38 associated injuries. 20/29 patients had intramedullary nailing for both fractures. The complications were knee stiffness, foot drop, delayed union of tibia and superficial infection. The bony union time ranged from 15 - 22.5 weeks for femur fractures and 17 - 28 weeks for the tibia. According to the Karlstrom criteria the end results were Excellent - 15, Good - 11, Acceptable - 1 and Poor - 3. The associated injuries and the type of fracture (open, intra-articular, comminution) are prognostic indicators in the Floating knee. Appropriate management of the associated injuries, intramedullary nailing of both the fractures and post operative rehabilitation are necessary for good final outcome.

  5. Detection of low-grade prosthetic joint infections using {sup 99m}Tc-antigranulocyte SPECT/CT: initial clinical results

    Energy Technology Data Exchange (ETDEWEB)

    Graute, Vera; Lehner, Sebastian; Haug, Alexander; Bartenstein, Peter; Hacker, Marcus [University of Munich, Department of Nuclear Medicine, Munich (Germany); Feist, Markus; Mueller, Peter Ernst [University of Munich, Department of Orthopedic Medicine, Munich (Germany)

    2010-09-15

    Low-grade joint infections are characterized by infiltration of granulocytes, which mediate aspects of inflammatory changes. We evaluated retrospectively the contribution of SPECT/CT as an addition to planar scintigraphy with {sup 99m}Tc-labelled antigranulocyte antibodies for diagnosing and localizing low-grade joint infections. Planar scintigraphy using {sup 99m}Tc-labelled antigranulocyte BW 250/183 antibodies was performed in 31 patients with suspected joint infections at 5 min, 5 h and 24 h after injection, with additional SPECT/CT performed 6 h after injection. With reference to gold standard clinical data, we assessed the diagnostic sensitivity of scintigraphy alone and in conjunction with SPECT/CT. Joint infections were diagnosed clinically in 9 of the 31 patients (1 hip and 8 knee prostheses). Planar scintigraphy revealed 6 true-positives, 13 true-negatives, 9 false-positives and 3 false-negative results, indicating sensitivity, specificity, positive and negative predictive values of, respectively, 0.66, 0.60, 0.4 and 0.81. With the addition of SPECT images, corresponding sensitivity, specificity, positive and negative predictive values increased to 0.89, 0.45, 0.40 and 0.91. Implementation of fused SPECT/CT led to a further increase to 0.89, 0.73, 0.57 and 0.94. Relative to planar scintigraphy, SPECT with and without CT substantially improved the utility of imaging with {sup 99m}Tc-labelled antigranulocyte antibodies for diagnosis and localization of suspected joint infections. Optimal accuracy was obtained through image fusion, which permitted anatomical allocation of foci of pathological tracer accumulation as well as providing information on the extent of the infection. This imaging method seems suited for selection of patients requiring surgical therapy. (orig.)

  6. Overuse Knee Injuries in Athletes

    Directory of Open Access Journals (Sweden)

    Miroslav Kezunović

    2013-03-01

    Full Text Available According to many statistics over 55% of all sports-related injuries are incurred in the knee joint (active sportsmen and recreationists. The statistics definitely differ, depending on type of sport and specific movements habitually performed in a particular sport. Therefore, in addition to acute knee injuries overuse syndromes are common in the knee area also due to specificities of patellofemoral joint just because specific diseases like „jumper's knee“ and „runner's knee“ are related to certain sport activities. Generally speaking, these syndromes occur due to poor orientation of the knee extensor mechanism, i.e. friction of iliotibial band and patellofemoral chondromalacia. It is believed that about 45% of all overuse syndromes in the knee area occur as a result of running.

  7. MR findings in knee osteoarthritis

    International Nuclear Information System (INIS)

    Guermazi, Ali; Taouli, Bachir; Genant, Harry K.; Zaim, Souhil; Miaux, Yves; Peterfy, Charles G.

    2003-01-01

    Knee osteoarthritis (OA) is a leading cause of disability. Recent advances in drug discovery techniques and improvements in understanding the pathophysiology of osteoarthritic disorders have resulted in an unprecedented number of new therapeutic agents. Of all imaging modalities, radiography has been the most widely used for the diagnosis and management of the progression of knee OA. Magnetic resonance imaging is a relatively recent technique and its applications to osteoarthritis have been limited. Compared with conventional radiography, MR imaging offers unparalleled discrimination among articular soft tissues by directly visualizing all components of the knee joint simultaneously and therefore allowing the knee joint to be evaluated as a whole organ. In this article we present the MR findings in knee OA including cartilage abnormalities, osteophytes, bone edema, subarticular cysts, bone attrition, meniscal tears, ligament abnormalities, synovial thickening, joint effusion, intra-articular loose bodies, and periarticular cysts. (orig.)

  8. Adhesion to silicone rubber of yeasts and bacteria isolated from voice prostheses : Influence of salivary conditioning films

    NARCIS (Netherlands)

    Busscher, HJ; GeertsemaDoornbusch, GI; vanderMei, HC

    Adhesion of yeasts and bacteria to silicone rubber is one of the first steps in the biodeterioration of silicone rubber voice prostheses. In this paper, adhesion of two streptococcal, staphylococcal, Candida albicans and Candida tropicalis strains, isolated from explanted voice prostheses was

  9. Anterior knee pain

    International Nuclear Information System (INIS)

    LLopis, Eva; Padron, Mario

    2007-01-01

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries

  10. Anterior knee pain

    Energy Technology Data Exchange (ETDEWEB)

    LLopis, Eva [Hospital de la Ribera, Alzira, Valencia (Spain) and Carretera de Corbera km 1, 46600 Alzira Valencia (Spain)]. E-mail: ellopis@hospital-ribera.com; Padron, Mario [Clinica Cemtro, Ventisquero de la Condesa no. 42, 28035 Madrid (Spain)]. E-mail: mario.padron@clinicacemtro.com

    2007-04-15

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries.

  11. What are estimated reimbursements for lower extremity prostheses capable of surgical and nonsurgical lengthening?

    Science.gov (United States)

    Henderson, Eric R; Pepper, Andrew M; Letson, G Douglas

    2012-04-01

    Growing prostheses accommodate skeletally immature patients with bone tumors undergoing limb-preserving surgery. Early devices required surgical procedures for lengthening; recent devices lengthen without surgery. Expenses for newer expandable devices that lengthen without surgery are more than for their predecessors but overall reimbursement amounts are not known. We sought to determine reimbursement amounts associated with lengthening of growing prostheses requiring surgical and nonsurgical lengthening. We retrospectively reviewed 17 patients with growing prostheses requiring surgical expansion and eight patients with prostheses capable of nonsurgical expansion. Insurance documents were reviewed to determine the reimbursement for implantation, lengthening, and complications. Growth data were obtained from the literature. Mean reimbursement amounts of surgical and nonsurgical lengthenings were $9950 and $272, respectively. Estimated reimbursements associated with implantation of a growing prosthesis varied depending on age, sex, and location. The largest difference was found for 4-year-old boys with distal femoral replacement where reimbursement for expansion to maturity for surgical and nonsurgical lengthening prostheses would be $379,000 and $208,000, respectively. For children requiring more than one surgical expansion, net reimbursements were lower when a noninvasive lengthening device was used. Annual per-prosthesis maintenance reimbursements to address complications for surgical and nonsurgical lengthening prostheses were $3386 and $1856, respectively. This study showed that reimbursements for lengthening of growing endoprostheses capable of nonsurgical expansion may be less expensive in younger patients, particularly male patients undergoing distal femur replacement, than endoprostheses requiring surgical lengthening. Longer outcomes studies are required to see if reimbursements for complications differ between devices. Level III, economic and decision

  12. New total ossicular replacement prostheses with a resilient joint: experimental data from human temporal bones.

    Science.gov (United States)

    Arechvo, Irina; Bornitz, Matthias; Lasurashvili, Nikoloz; Zahnert, Thomas; Beleites, Thomas

    2012-01-01

    New flexible total ossicular prostheses with an integrated microjoint can compensate for large static displacements in the reconstructed ossicular chain. When properly designed, they can mimic the function of the joints of the intact chain and ensure good vibration transfer in both straight and bent conditions. Prosthesis dislocations and extrusions are frequently observed after middle ear surgery. They are mainly related to the altered distance between the coupling points because of large static eardrum displacements. The new prostheses consist of 2 titanium shafts, which are incorporated into a silicone body. The sound transfer function and stapes footplate displacement at static loads were evaluated in human temporal bones after ossicular reconstruction using prostheses with 2 different silicones with different hardness values. The stiffness and bending characteristics of the prostheses were investigated with a quasi-static load. The sound transfer properties of the middle ears with the prostheses inserted under uncompressed conditions were comparable with those of ears with intact ossicular chains. The implant with the soft silicone had improved acoustic transfer characteristics over the implant with the hard silicone in a compressed state. In the quasi-static experiments, the minimum medial footplate displacement was found with the same implant. The bending characteristics depended on the silicone stiffness and correlated closely with the point and angle of the load incidence. The titanium prostheses with a resilient joint that were investigated in this study had good sound transfer characteristics under optimal conditions as well as in a compressed state. As a result of joint bending, the implants compensate for the small changes in length of the ossicular chain that occur under varying middle ear pressure. The implants require a stable support at the stapes footplate to function properly.

  13. Knees Lifted High

    Centers for Disease Control (CDC) Podcasts

    2008-08-04

    The Eagle Books are a series of four books that are brought to life by wise animal characters - Mr. Eagle, Miss Rabbit, and Coyote - who engage Rain That Dances and his young friends in the joy of physical activity, eating healthy foods, and learning from their elders about health and diabetes prevention. Knees Lifted High gives children fun ideas for active outdoor play.  Created: 8/4/2008 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 8/5/2008.

  14. Self-reported previous knee injury and low knee function increase knee injury risk in adolescent female football.

    Science.gov (United States)

    Clausen, M B; Tang, L; Zebis, M K; Krustrup, P; Hölmich, P; Wedderkopp, N; Andersen, L L; Christensen, K B; Møller, M; Thorborg, K

    2016-08-01

    Knee injuries are common in adolescent female football. Self-reported previous knee injury and low Knee injury and Osteoarthritis Outcome Score (KOOS) are proposed to predict future knee injuries, but evidence regarding this in adolescent female football is scarce. The aim of this study was to investigate self-reported previous knee injury and low KOOS subscale score as risk factors for future knee injuries in adolescent female football. A sample of 326 adolescent female football players, aged 15-18, without knee injury at baseline, were included. Data on self-reported previous knee injury and KOOS questionnaires were collected at baseline. Time-loss knee injuries and football exposures were reported weekly by answers to standardized text-message questions, followed by injury telephone interviews. A priori, self-reported previous knee injury and low KOOS subscale scores (female football. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Prostheses and orthoses in the collections of the Auschwitz-Birkenau State Museum.

    Science.gov (United States)

    Przeździak, Bogumił; Lutomirski, Adam; Kulczyk, Maria

    2011-01-01

    The authors described 424 orthopaedic appliances left by the prisoners of the Nazi Concentration Camp in Oświęcim. A collection of prostheses and orthoses, which is currently a part of the Auschwitz-Birkenau State Museum's exhibition, is extraordinary as it illustrates the fate of innocent, crippled people, who were incarcerated and murdered. Another point of value of the collection is its technical aspect, as it provides a clear picture of construction of prostheses and orthoses at the beginning of the 20th century.

  16. External breast prostheses. A survey of their use by women after mastectomy.

    Science.gov (United States)

    Tanner, R; Abraham, S F; Llewellyn-Jones, D

    1983-03-19

    Women who have had a mastectomy for breast cancer have to cope with two major problems: first, that they have cancer, and second, that they have lost their physical appearance. The provision of an appropriate prosthesis can reduce the sense of disfigurement. If women were to obtain the full psychological benefit of wearing a breast prosthesis, they need to be informed about the available breast forms, have an opportunity to choose between them, and to be satisfied with their choice. In this study of 49 women, only 44% had had the opportunity to choose a prosthesis, 28% were dissatisfied with their prostheses, and 17% were still using temporary prostheses.

  17. Early Experience with a Modern Generation Knee System: Average 2 Years’ Follow-up

    Directory of Open Access Journals (Sweden)

    Thomas Paszicsnyek

    2015-12-01

    Full Text Available Arthritis in the knee is a leading cause of pain and disability with total knee arthroplasty (TKA often the treatment of choice after failure of more conservative treatments. TKA has been demonstrated to be one of the most successful procedures performed.  However, despite the good long-term survivorship rates, patient satisfaction is still an issue post TKA with over 20% of patients exhibiting patient dissatisfaction most commonly due to anterior knee pain (over 18-28% patients and mediolateral or varus-valgus instability.  Recent studies have demonstrated that collateral ligament strains are altered post TKA which may lead to laxity and/or tightness of the ligaments resulting in patient discomfort, pain, stiffness and/or instability post TKA.  As a result, it may be beneficial to ensure ligamentous strains after TKA are similar or close to the native situation.  The purpose of this study was to evaluate the clinical and radiographic results of the Unity Knee™ Total Knee System (Corin Ltd, Cirencester, UK, a modern generation, single-radius total knee replacement (TKR and its accompanying instrumentation which is designed to help maintain proper ligament balance and restore the medial jointline.  A total of 89 knees (89 patients were implanted with the device in a single surgeon series.  All patients were assessed using the American Knee Society Score (AKSS, the Oxford Knee Score (OKS, and radiographs.  There was 1 revision due to infection and Kaplan-Meier survivorship was 98.9% at 2 years.  The mean AKSS knee score for the total cohort was 87.1 ± 7.98 and the mean Oxford Knee score was 45.89 + 3.69. Radiographic review found no signs of radiographic failure in any of the knees. This study demonstrates good survivorship, clinical, and radiographic results at 2 years for this TKR.

  18. Excellent Survival and Good Outcomes at 15 Years Using the Press-Fit Condylar Sigma Total Knee Arthroplasty.

    Science.gov (United States)

    Oliver, William M; Arthur, Calum H C; Wood, Alexander M; Clayton, Robert A E; Brenkel, Ivan J; Walmsley, Philip

    2018-03-27

    We report 15-year survival, clinical, and radiographic follow-up data for the Press-Fit Condylar Sigma total knee arthroplasty. Between October 1998 and October 1999, 235 consecutive TKAs were performed in 203 patients. Patients were reviewed at a specialist nurse-led clinic before surgery and at 5, 8-10, and 15 years postoperatively. Clinical outcomes, including Knee Society Score, were recorded prospectively at each clinic visit, and radiographs were obtained. Of our initial cohort, 99 patients (118 knees) were alive at 15 years, and 31 patients (34 knees) were lost to follow-up. Thirteen knees (5.5%) were revised; 5 (2.1%) for infection, 7 (3%) for instability, and 1 (0.4%) for aseptic loosening. Cumulative survival with the end point of revision for any reason was 92.3% at 15 years and with revision for aseptic failure as the end point was 94.4%. The mean Knee Society Score knee score was 77.4 (33-99) at 15 years, compared with 31.7 (2-62) preoperatively. Of 71 surviving knees for which X-rays were available, 12 (16.9%) had radiolucent lines and 1 (1.4%) demonstrated clear radiographic evidence of loosening. The Press-Fit Condylar Sigma total knee arthroplasty represents a durable, effective option for patients undergoing knee arthroplasty, with excellent survival and good clinical and radiographic outcomes at 15 years. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Investigating the primary stability of the transversal support tibial plateau concept to retain both cruciate ligaments during total knee arthroplasty.

    Science.gov (United States)

    Nowakowski, Andrej M; Stangel, Melanie; Grupp, Thomas M; Valderrabano, Victor

    2012-09-27

    The important roles of the anterior cruciate ligament regarding knee stability, physiologic kinematics, and proprioception are unquestioned. Thus, various efforts have been made to retain the ACL during total knee arthroplasty (TKA). Neither of the existing solutions to this problem, i.e. bicruciate retaining prostheses and implantation of two unicondylar prostheses, has been successful because of concept-specific problems as well as general difficulties with implant fixation. The new transversal support tibial plateau concept is a prosthesis of two individual joint surfaces reinforced beneath the articular line by joint surface supports and buttressed by a single transversal support. This configuration, which enables retention of both cruciate ligaments, should provide good bone fixation and ensure long-term alignment of the individual joint surfaces. In the current study, four prototypes based on this novel concept were developed and the resulting primary stability was analyzed using adapted load testing. The test set-up, with the model-loading of specially prepared Sawbones® and a sinusoidal oscillating load transmission with 25 000 cycles over 10 increasing load levels, achieved subsidence, which enabled comparison of the four different model variants regarding primary stability in view of bone anchoring. The model variant (TSmobile) that allowed transverse glide of the joint surface supports along the transversal support revealed the largest subsidence. A rigid attachment of the joint surface supports of the transversal support tibial plateau thus appears to offer increased primary stability regarding bone anchoring.

  20. Epidemiology of septic arthritis of the knee at Hospital das Clínicas, Universidade de São Paulo

    Directory of Open Access Journals (Sweden)

    Camilo Partezani Helito

    2014-01-01

    Conclusion: S. aureus is still the most common pathogen in acute knee infections in our environment. Gram staining, absence of fever and normal leukocyte count cannot be used to rule out septic arthritis.

  1. Oxidized zirconium versus cobalt-chromium against the native patella in total knee arthroplasty: Patellofemoral outcomes.

    Science.gov (United States)

    Matassi, Fabrizio; Paoli, Tommaso; Civinini, Roberto; Carulli, Christian; Innocenti, Massimo

    2017-10-01

    Oxidized zirconium (OxZr) has demonstrated excellent mechanical properties in vitro when used against articular cartilage; less coefficient of friction and less chondral damage have been found when compared with cobalt-chromium (CoCr) implants. However, controversy exists as to whether implants with a zirconium femoral component articulate safely with a native patella in total knee arthroplasty (TKA). To answer this question, the clinical and radiographic results were analysed from a group of patients who underwent a TKA with patella retention; the OxZr versus CoCr femoral components were compared. The present study prospectively evaluated 83 knees of 74 patients from 2009 to 2010. Each patient was evaluated clinically (visual analogue scale, Knee Society score, patellar score) and radiographically (long leg standing radiograph, anterior-posterior and latero-lateral projections, axial view of the patella) pre-operatively and postoperatively with a mean follow-up of 4.47years. The patellar tilt and shift, and progression of patellofemoral osteoarthritis were calculated with the axial view. There were no patient reported adverse reactions and none of the evaluated prostheses failed. Both the clinical and radiographic evaluations showed no statistically significant between-group differences. No adverse events were observed clinically or radiologically. These results justify pursuing the use of oxidized zirconium as an alternative bearing surface for a femoral component associated with patellar retention in TKA. Published by Elsevier B.V.

  2. Effect of knee joint icing on knee extension strength and knee pain early after total knee arthroplasty: a randomized cross-over study

    DEFF Research Database (Denmark)

    Holm, Bente; Husted, Henrik; Kehlet, Henrik

    2012-01-01

    Objective: To investigate the acute effect of knee joint icing on knee extension strength and knee pain in patients shortly after total knee arthroplasty.Design: A prospective, single-blinded, randomized, cross-over study.Setting: A fast-track orthopaedic arthroplasty unit at a university hospital.......Participants: Twenty patients (mean age 66 years; 10 women) scheduled for primary unilateral total knee arthroplasty.Interventions: The patients were treated on two days (day 7 and day 10) postoperatively. On one day they received 30 minutes of knee icing (active treatment) and on the other day they received 30...... minutes of elbow icing (control treatment). The order of treatments was randomized.Main outcome measures: Maximal knee extension strength (primary outcome), knee pain at rest and knee pain during the maximal knee extensions were measured 2-5 minutes before and 2-5 minutes after both treatments...

  3. Experimental knee pain reduces muscle strength

    DEFF Research Database (Denmark)

    Henriksen, Marius; Mortensen, Sara Rosager; Aaboe, Jens

    2011-01-01

    Pain is the principal symptom in knee pathologies and reduced muscle strength is a common observation among knee patients. However, the relationship between knee joint pain and muscle strength remains to be clarified. This study aimed at investigating the changes in knee muscle strength following...... experimental knee pain in healthy volunteers, and if these changes were associated with the pain intensities. In a crossover study, 18 healthy subjects were tested on 2 different days. Using an isokinetic dynamometer, maximal muscle strength in knee extension and flexion was measured at angular velocities 0....... Knee pain reduced the muscle strength by 5 to 15% compared to the control conditions (P knee extension and flexion at all angular velocities. The reduction in muscle strength was positively correlated to the pain intensity. Experimental knee pain significantly reduced knee extension...

  4. Postinfectious ankylosis of the knee after bacterial arthritis following routine anterior cruciate ligament (ACL) reconstruction

    OpenAIRE

    Mester, Bastian; Schoepp, Christian; Glombitza, Martin; Rixen, Dieter

    2016-01-01

    Aims and Objectives: Knee arthroscopy is a very common surgical procedure. It belongs to the most frequently performed procedures in orthopedics and traumatology and is considered to have a low complication rate. The risk of postoperative knee infection following ACL reconstrucion is estimated 1-2 %. Thereby the ACL reconstruction cannot always be preserved. Persistent defects after healing and postinfectios osteoarthritis are observed. We present the case of an adolescent patient suffering f...

  5. New Generation Lockable Knee Brace

    Science.gov (United States)

    2000-01-01

    A knee brace that uses Space Shuttle propulsion technology has moved a step closer to being available to help knee injury and stroke patients and may possibly benefit patients with birth defects, spinal cord injuries, and post-polio conditions. After years of hard work, inventors at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama, have turned over the final design and prototype to industry partners at Horton's Orthotic Lab in Little Rock, Arkansas for further clinical testing. The device, called the Selectively Lockable Knee Brace, may mean faster, less painful rehabilitation for patients by allowing the knee to move when weight is not on the heel. Devices currently on the market lock the knee in a rigid, straight-leg position, or allow continuous free motion. The knee brace is just one example of how space technology is being used to improve the lives of people on Earth. NASA's MSFC inventors Michael Shadoan and Neill Myers are space propulsion engineers who use the same mechanisms and materials to build systems for rockets that they used to design and develop the knee brace.

  6. Physiotherapy management of knee osteoarthritis.

    Science.gov (United States)

    Page, Carolyn J; Hinman, Rana S; Bennell, Kim L

    2011-05-01

    Knee osteoarthritis (OA) is a prevalent chronic joint disease causing pain and disability. Physiotherapy, which encompasses a number of modalities, is a non-invasive treatment option in the management of OA. This review summarizes the evidence for commonly used physiotherapy interventions. There is strong evidence to show short-term beneficial effects of exercise on pain and function, although the type of exercise does not seem to influence treatment outcome. Delivery modes, including individual, group or home exercise are all effective, although therapist contact may improve benefits. Attention to improving adherence to exercise is needed to maximize outcomes in the longer-term. Knee taping applied with the aim of realigning the patella and unloading soft tissues can reduce pain. There is also evidence to support the use of knee braces in people with knee OA. Biomechanical studies show that lateral wedge shoe insoles reduce knee load but clinical trials do not support symptomatic benefits. Recent studies suggest individual shoe characteristics also affect knee load and there is current interest in the effect of modified shoe designs. Manual therapy, while not to be used as a stand-alone treatment, may be beneficial. In summary, although the research is not equivocal, there is sufficient evidence to indicate that physiotherapy interventions can reduce pain and improve function in those with knee OA. © 2011 The Authors. International Journal of Rheumatic Diseases © 2011 Asia Pacific League of Associations for Rheumatology and Blackwell Publishing Asia Pty Ltd.

  7. Comparison of fixed-bearing and mobile-bearing total knee arthroplasty after high tibial osteotomy.

    Science.gov (United States)

    Hernigou, Philippe; Huys, Maxime; Pariat, Jacques; Roubineau, François; Flouzat Lachaniette, Charles Henri; Dubory, Arnaud

    2018-02-01

    There is no information comparing the results of fixed-bearing total knee replacement and mobile-bearing total knee replacement in the same patients previously treated by high tibial osteotomy. The purpose was therefore to compare fixed-bearing and mobile-bearing total knee replacements in patients treated with previous high tibial osteotomy. We compared the results of 57 patients with osteoarthritis who had received a fixed-bearing prosthesis after high tibial osteotomy with the results of 41 matched patients who had received a rotating platform after high tibial osteotomy. The match was made for length of follow-up period. The mean follow-up was 17 years (range, 15-20 years). The patients were assessed clinically and radiographically. The pre-operative knee scores had no statistically significant differences between the two groups. So was the case with the intra-operative releases, blood loss, thromboembolic complications and infection rates in either group. There was significant improvement in both groups of knees, and no significant difference was observed between the groups (i.e., fixed-bearing and mobile-bearing knees) for the mean Knee Society knee clinical score (95 and 92 points, respectively), or the Knee Society knee functional score (82 and 83 points, respectively) at the latest follow-up. However, the mean post-operative knee motion was higher for the fixed-bearing group (117° versus 110°). In the fixed-bearing group, one knee was revised because of periprosthetic fracture. In the rotating platform mobile-bearing group, one knee was revised because of aseptic loosening of the tibial component. The Kaplan-Meier survivorship for revision at ten years of follow-up was 95.2% for the fixed bearing prosthesis and 91.1% for the rotating platform mobile-bearing prosthesis. Although we did manage to detect significant differences mainly in clinical and radiographic results between the two groups, we found no superiority or inferiority of the mobile

  8. Mobile ankle and knee perturbator.

    Science.gov (United States)

    Andersen, Jacob Buus; Sinkjaer, Thomas

    2003-10-01

    A mobile ankle and knee perturbator has been developed. It consists of a functional joint with an integrated clutch. Four Bowden wires connect the joint to a powerful motor and a double pneumatic cylinder. When needed during any time of the gait cycle, it is possible to impose an ankle rotation by engaging the clutch and rotating the ankle or knee joint with a predefined displacement. The system is designed to investigate electrophysiological and biomechanical features of the human ankle or knee joint during gait.

  9. Evaluation and management of knee pain in young athletes: overuse injuries of the knee

    OpenAIRE

    Patel, Dilip R.; Villalobos, Ana

    2017-01-01

    Recurrent or chronic activity related knee pain is common in young athletes. Numerous intrinsic conditions affecting the knee can cause such pain. In addition, knee pain can be referred pain from low back, hip or pelvic pathology. The most common cause of knee pain in young athletes is patellofemoral pain syndrome, or more appropriately termed idiopathic anterior knee pain. Although, numerous anatomical and biomechanical factors have been postulated to contribute the knee pain in young athlet...

  10. Gait changes in patients with knee osteoarthritis are replicated by experimental knee pain

    DEFF Research Database (Denmark)

    Henriksen, Marius; Nielsen, Thomas Graven; Aaboe, Jens

    2010-01-01

    Medial knee osteoarthritis (OA) is characterized by pain and associated with abnormal knee moments during walking. The relationship between knee OA pain and gait changes remains to be clarified, and a better understanding of this link could advance the treatment and prevention of disease...... progression. This study investigated changes in knee moments during walking following experimental knee pain in healthy volunteers, and whether these changes replicated the joint moments observed in medial knee OA patients....

  11. [Loading and strength of single- and multi-unit fixed dental prostheses 2. Strength

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Meijers, C.C.A.J.; Vergoossen, E.L.; Creugers, N.H.J.

    2014-01-01

    The ultimate strength of a dental prosthesis is defined as the strongest loading force applied to the prosthesis until afracture failure occurs. Important key terms are strength, hardness, toughness and fatigue. Relatively prevalent complications of single- and multi-unit fixed dental prostheses are

  12. [Aftercare for durability and profitability of single-unit and multi-unit fixed dental prostheses

    NARCIS (Netherlands)

    Baat, C. de; Loveren, C. van; Maarel-Wierink, C.D. van der; Witter, D.J.; Creugers, N.H.J.

    2013-01-01

    An important aim ofa treatment with single-unit and multi-unit fixed dental prostheses is a durable and profitable treatment outcome. That requires aftercare, too. First, the frequency of routine oral examinations should be assessed, using an individual risk profile. The objectives of the routine

  13. Waterjet cutting of periprosthetic interface tissue in loosened hip prostheses: an in vitro feasibility study

    NARCIS (Netherlands)

    Kraaij, Gert; Tuijthof, Gabrielle J. M.; Dankelman, Jenny; Nelissen, Rob G. H. H.; Valstar, Edward R.

    2015-01-01

    Waterjet cutting technology is considered a promising technology to be used for minimally invasive removal of interface tissue surrounding aseptically loose hip prostheses. The goal of this study was to investigate the feasibility of waterjet cutting of interface tissue membrane. Waterjets with 0.2

  14. Restoring natural sensory feedback in real-time bidirectional hand prostheses

    DEFF Research Database (Denmark)

    Raspopovic, Stanisa; Capogrosso, Marco; Petrini, Francesco Maria

    2014-01-01

    Hand loss is a highly disabling event that markedly affects the quality of life. To achieve a close to natural replacement for the lost hand, the user should be provided with the rich sensations that we naturally perceive when grasping or manipulating an object. Ideal bidirectional hand prosthese...

  15. Clinical Fit of Partial Removable Dental Prostheses Based on Alginate or Polyvinyl Siloxane Impressions.

    NARCIS (Netherlands)

    Fokkinga, W.A.; Witter, D.J.; Bronkhorst, E.M.; Creugers, N.H.J.

    2017-01-01

    PURPOSE: The aim of this study was to analyze the clinical fit of metal-frame partial removable dental prostheses (PRDPs) based on custom trays used with alginate or polyvinyl siloxane impression material. MATERIALS AND METHODS: Fifth-year students of the Nijmegen Dental School made 25 correct

  16. [Technical aspects of treatments with single- and multi-unit fixed dental prostheses

    NARCIS (Netherlands)

    Wiersema, E.J.; Kreulen, C.M.; Latzke, P.; Witter, D.J.; Creugers, N.H.J.

    2014-01-01

    For the manufacture of single- and multi-unit fixed dental prostheses, effective communication between dentist and dental technician is required. Mutual insight concerning the (im)possibilities of available treatments and technical options is prerequisitefor this communication. The manufacture of

  17. The development of artificial organs and prostheses worldwide and in the Ottoman Empire.

    Science.gov (United States)

    Birdane, Leman; Cingi, Cemal; Elçioğlu, Ömür; Muluk, Nuray Bayar

    2016-08-01

    An artificial organ or prosthesis is a man-made device that is implanted or integrated into a human to replace a natural organ. There were many historical steps in the development of artificial organs and prostheses. New surgical techniques, the development of prosthetic materials and the creative ideas of engineers led to progress in this field. © The European Society of Cardiology 2014.

  18. HEALING OF MICROVENOUS PTFE PROSTHESES IMPLANTED INTO THE RAT FEMORAL VEIN

    NARCIS (Netherlands)

    VANDERLEI, B; DIJK, F; JONGEBLOED, WL; ROBINSON, PH; Bartels, H.

    44 PTFE prostheses (Gore-Tex(R); ID 1 mm) were implanted into rats' femoral veins by means of the sleeve anastomotic technique and were evaluated at regular intervals from 1 h up till 24 weeks after implantation by means of light and electron microscopy to study in detail their healing process. All

  19. [Loading and strength of single- and multi-unit fixed dental prostheses. 1. Retention and resistance

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Meijers, C.C.A.J.; Vergoossen, E.L.; Creugers, N.H.J.

    2014-01-01

    The degree to which single- and multi-unit fixed dental prostheses are able to withstand loading forces is dependent, among other things, on the quality of their retention and resistance. The quality of the retention and resistance of the configuration of an abutment tooth prepared for a metal and

  20. PATENCY AND HEALING OF MICROVASCULAR PROSTHESES - A REVIEW OF 10 YEARS OF EXPERIMENTAL WORK IN GRONINGEN

    NARCIS (Netherlands)

    VANDERLEI, B; ROBINSON, PH

    1993-01-01

    From 1982 onwards, in Groningen, The Netherlands, we have worked on the experimental evaluation and development of microvascular prostheses in rats and rabbits. In this review article a systematic overview of this experimental work is presented and the results are discussed with regard to the

  1. Screening of patients for first time prostheses after amputation of lower limbs

    Directory of Open Access Journals (Sweden)

    Vetra A.

    2016-01-01

    More than 25% of those who followed the recommended treatment and rehabilitation programme to prepare the amputation stump, reduced contracture and enhanced physical working abilities were declared to be appropriate for further prostheses. This indicates serious shortcomings in medical treatments during the early post-amputation period.

  2. Special features of total knee replacement in hemophilia.

    Science.gov (United States)

    Rodriguez-Merchan, Emerito Carlos

    2013-12-01

    Total knee replacement is an operation frequently needed by hemophilia patients, which greatly improves their quality of life. This operation, however, carries a higher risk of bleeding and infection for hemophiliacs than it does for osteoarthritis sufferers. It is advisable to implant prosthetic components using antibiotic-loaded cement. It is essential to maintain a level of 100% of the replacement clotting factor for 2 weeks. Hematological treatment must be established, depending on the patient's factor levels and other pharmacokinetic parameters such as recovery and half-life, optimal doses and treatment time. It is preferable to use general anesthesia due to the risk of spinal bleeding. The lifespan of total knee replacement in hemophilic patients is shorter than in patients with osteoarthritis because of the increased risk of infection.

  3. Post-cam mechanics and tibiofemoral kinematics: a dynamic in vitro analysis of eight posterior-stabilized total knee designs.

    Science.gov (United States)

    Arnout, N; Vanlommel, L; Vanlommel, J; Luyckx, J P; Labey, L; Innocenti, B; Victor, J; Bellemans, J

    2015-11-01

    Posterior cruciate ligament (PCL)-substituting total knee arthroplasty (TKA) designs were introduced to avoid paradoxical roll forward of the femur and to optimize knee kinematics. The aim of this in vitro study was to investigate post-cam function and contact mechanics and relate it to knee kinematics during squatting in eight contemporary posterior-stabilized TKA designs. All prostheses were fixed on custom-designed metal fixtures and mounted in a knee rig and five sequential-loaded squats were performed between 30° and 130° of flexion. Contact pressure and contact area were measured using pressure-sensitive Tekscan sensors on the posterior face of the post. Kinematics was recorded with reflective markers and infrared light-capturing cameras. The post-cam mechanisms analyzed in this study are very variable in terms of design features. This leads to large variations in terms of the flexion angle at which the post and cam engage maximal contact force, contact pressure and contact area. We found that more functional post-cam mechanisms, which engage at lower flexion angle and have a similar behavior as normal PCL function, generally show more normal rollback and tibial rotation at the expense of higher contact forces and pressures. All designs show high contact forces. A positive correlation was found between contact force and initial contact angle. Post-cam contact mechanics and kinematics were documented in a standardized setting. Post-cam contact mechanics are correlated with post-cam function. Outcomes of this study can help to develop more functional designs in future. Nevertheless, a compromise will always be made between functional requirements and risk of failure. We assume that more normal knee kinematics leads to more patient satisfaction because of better mobility. Understanding of the post-cam mechanism, and knowing how this system really works, is maybe the clue in further development of new total knee designs.

  4. Evaluation of taper joints with combined fatigue and crevice corrosion testing: Comparison to human explanted modular prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Reclaru, L., E-mail: lucien.reclaru@pxgroup.com [PX Group S.A., Dep R and D Corrosion and Biocompatibility Group, Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds (Switzerland); Brooks, R.A. [Orthopaedic Research, Addenbrooke' s Hospital, University of Cambridge, Box 180 Hills Road, CB2 0QQ Cambridge (United Kingdom); Zuberbühler, M. [Smith and Nephew Orthopaedics AG, Schachenalle 29, 5001 Aarau (Switzerland); Eschler, P.-Y.; Constantin, F. [PX Group S.A., Dep R and D Corrosion and Biocompatibility Group, Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds (Switzerland); Tomoaia, G. [University of Medicine and Pharmacy Iuliu Hateganu of Cluj-Napoca, Dept. of Orthopaedics and Traumatology, Cluj-Napoca (Romania)

    2014-01-01

    The requirement for revision surgery of total joint replacements is increasing and modular joint replacement implants have been developed to provide adjustable prosthetic revision systems with improved intra-operative flexibility. An electrochemical study of the corrosion resistance of the interface between the distal and proximal modules of a modular prosthesis was performed in combination with a cyclic fatigue test. The complexity resides in the existence of interfaces between the distal part, the proximal part, and the dynamometric screw. A new technique for evaluating the resistance to cyclic dynamic corrosion with crevice stimulation was used and the method is presented. In addition, two components of the proximal module of explanted Ti6Al4V and Ti6Al7Nb prostheses were investigated by optical and electron microscopy. Our results reveal that: The electrolyte penetrates into the interface between the distal and proximal modules during cyclic dynamic fatigue tests, the distal module undergoes cracking and corrosion was generated at the interface between the two models; The comparison of the explanted proximal parts with the similar prostheses evaluated following cyclic dynamic crevice corrosion testing showed that there were significant similarities indicating that this method is suitable for evaluating materials used in the fabrication of modular prostheses. - Highlights: • Electrochemical crevice corrosion testing combined with fatigue test conducted on Ti6Al7Nb and Ti6Al4V modular prostheses • Cations released from integral prostheses • Comparison of human explanted modular prostheses with the similar prostheses evaluated in cyclic dynamic crevice corrosion.

  5. Anterior Knee Pain (Chondromalacia Patellae).

    Science.gov (United States)

    Garrick, James G.

    1989-01-01

    This article presents a pragmatic approach to the definition, diagnosis, and management of anterior knee pain. Symptoms and treatment are described. Emphasis is on active involvement of the patient in the rehabilitation exercise program. (IAH)

  6. Unusual Cause of Knee Locking

    Directory of Open Access Journals (Sweden)

    Gazi Huri

    2013-01-01

    Full Text Available We report a case of partial intrasubstance tear of popliteus tendon as an unusual cause of pseudolocking of the knee. A 13-year-old semiprofessional soccer player applied to our clinic with a locked right knee in spite of the therapy applied (cold pack, NSAID, and immobilization in another institution 20 days after the injury. Significant extension loss was observed in his right knee with 30∘–90∘ ROM. Magnetic resonance imaging (MRI and arthroscopy confirmed the intrasubstance tear of popliteus tendon and synovitis. The ruptured part of the tendon was debrided, and the inflammatory tissue around the tendon, which may lead to pseudolocking, was gently removed with a shaver in order to regain the normal ROM. The patient was discharged with full ROM and weight bearing first day after the surgery. To our knowledge, this is the first case demonstrating intrasubstance tear of popliteus tendon causing pseudolocking of the knee.

  7. Bowlegs and Knock-Knees

    Science.gov (United States)

    ... Español Text Size Email Print Share Bowlegs and Knock-Knees Page Content Article Body Toddlers’ legs often ... about two years old, then they’ll look knock-kneed until they are about six years of ...

  8. Temperature variations in sintering ovens for metal ceramic dental prostheses: non-destructive assessment using OCT

    Science.gov (United States)

    Sinescu, C.; Bradu, A.; Duma, V.-F.; Topala, F. I.; Negrutiu, M. L.; Podoleanu, A. G.

    2018-02-01

    We present a recent investigation regarding the use of optical coherence tomography (OCT) in the monitoring of the calibration loss of sintering ovens for the manufacturing of metal ceramic dental prostheses. Differences in the temperatures of such ovens with regard to their specifications lead to stress and even cracks in the prostheses material, therefore to the failure of the dental treatment. Evaluation methods of the ovens calibration consist nowadays of firing supplemental samples; this is subjective, expensive, and time consuming. Using an in-house developed swept source (SS) OCT system, we have demonstrated that a quantitative assessment of the internal structure of the prostheses, therefore of the temperature settings of the ovens can be made. Using en-face OCT images acquired at similar depths inside the samples, the differences in reflectivity allow for the evaluation of the differences in granulation (i.e., in number and size of ceramic grains) of the prostheses material. Fifty samples, divided in five groups, each sintered at different temperatures (lower, higher, or equal to the prescribed one) have been analyzed. The consequences of the temperature variations with regard to the one prescribed were determined. Rules-of-thumb were extracted to monitor objectively, using only OCT images of currently manufactured samples, the settings of the oven. The method proposed allows for avoiding producing prostheses with defects. While such rules-of-thumb achieve a qualitative assessment, an insight in our on-going work on the quantitative assessment of such losses of calibration on dental ovens using OCT is also made.

  9. Objective clinical assessment of change in swallowing ability of maxillectomy patients when wearing obturator prostheses.

    Science.gov (United States)

    Matsuyama, Miwa; Tsukiyama, Yoshihiro; Koyano, Kiyoshi

    2005-01-01

    Evaluation of treatment outcome is important in maxillofacial rehabilitation. Although eating is one of the oral functions that most strongly influences patients' quality of life, only a few reports exist on the objective assessment of swallowing for maxillectomy patients. The purpose of this study was to identify changes in the swallowing ability of maxillectomy patients when wearing obturator prostheses through the use of an objective clinical assessment. The swallowing ability of 38 postmaxillectomy patients consecutively treated with obturator prostheses was objectively evaluated with the "water-drinking test" that was developed for the assessment of dysphagia patients after cerebrovascular disease. In this test, the subjects were instructed to drink 30 mL of water in one swallow. The profile was evaluated with the combination of the time required for drinking the water and the incidence of cough reflex. Statistical analysis was performed using the Wilcoxon signed-rank test, the paired t test, and the Chi-square test with StatView 5.0 for the Macintosh. Performance improved significantly when the patients wore prostheses (P = .0026, Wilcoxon signed-rank test). The mean drinking times without and with prostheses were 8.2 +/- 6.3 s and 5.0 +/- 3.5 s, respectively. Drinking time was shortened significantly when the prosthesis was worn (P = .0002, paired t test). The assessment of behavior and episodes revealed that the swallowing ability of the maxillectomy patients was significantly improved when a prosthesis was worn (P = .0002, Chi-square test). The swallowing ability of maxillectomy patients was quantitatively and qualitatively improved with obturator prostheses.

  10. Use of antibiotic-loaded cement in total knee arthroplasty.

    OpenAIRE

    Hinarejos Gómez, Pedro Angel; Guirro Castellnou, Pau; Puig Verdié, Luís; Torres Claramunt, Raúl; Leal Blanquet, Joan; Sánchez Soler, JF.; Monllau García, Juan Carlos

    2015-01-01

    Bone cement has the capacity to release antibiotic molecules if any antibiotic is included in it, and these elution properties are improved as cement porosity is increased. In vitro studies have shown high local antibiotic concentration for many hours or few days after its use. Antibiotic loaded bone cement (ALBC) is helpful when treating an infection in total knee arthroplasty (TKA) revision surgery. The purpose of this paper was to review the evidence for the routine use of ALBC in TKA in t...

  11. [Application of tibial mechanical axis locator in tibial extra-articular deformity in total knee arthroplasty].

    Science.gov (United States)

    Li, Guoliang; Han, Guangpu; Zhang, Jinxiu; Ma, Shiqiang; Guo, Donghui; Yuan, Fulu; Qi, Bingbing; Shen, Runbin

    2013-07-01

    To explore the application value of self-made tibial mechanical axis locator in tibial extra-articular deformity in total knee arthroplasty (TKA) for improving the lower extremity force line. Between January and August 2012, 13 cases (21 knees) of osteoarthritis with tibial extra-articular deformity were treated, including 5 males (8 knees) and 8 females (13 knees) with an average age of 66.5 years (range, 58-78 years). The disease duration was 2-5 years (mean, 3.5 years). The knee society score (KSS) was 45.5 +/- 15.5. Extra-articular deformities included 1 case of knee valgus (2 knees) and 12 cases of knee varus (19 knees). Preoperative full-length X-ray films of lower extremities showed 10-21 degrees valgus or varus deformity of tibial extra joint. Self-made tibial mechanical axis locator was used to determine and mark coronal tibial mechanical axis under X-ray before TKA, and then osteotomy was performed with extramedullary positioning device according to the mechanical axis marker.' All incisions healed by first intention, without related complications of infection and joint instability. All patients were followed up 5-12 months (mean, 8.3 months). The X-ray examination showed case of 2.9 degrees knee deviation angle at 3 days after operation, and the accurate rate was 95.2%. No loosening or instability of prosthesis occurred during follow-up. KSS score was 85.5 +/- 15.0 at last follow-up, showing significant difference when compared with preoperative score (t=12.82, P=0.00). The seft-made tibial mechanical axis locator can improve the accurate rate of the lower extremity force line in TKA for tibia extra-articular deformity.

  12. Value of knee joint arthrography

    International Nuclear Information System (INIS)

    Luzsa, Gyoergy; Kiss Toth, Peter

    1985-01-01

    On the basis of the literature and the analysis of 204 examinations, the method and clinical application of knee joint arthrography are reviewed. 50 out of the 54 operated cases were perfectly diagnosed. The double contrast knee joint arthrography can be applied to detect meniscus changes, popliteal cysts, synovial disorders and chondral defects. The effectiveness of arthrography and arthroscopy was compared and the introduction of the former in each county seat is suggested. (author)

  13. Does post-operative knee awareness differ between knees in bilateral simultaneous total knee arthroplasty? Predictors of high or low knee awareness

    DEFF Research Database (Denmark)

    Nielsen, Katrine Abildgaard; Thomsen, Morten Grove; Latifi, Roshan

    2016-01-01

    PURPOSE: To evaluate the difference in post-operative knee awareness between knees in patients undergoing bilateral simultaneous total knee arthroplasty (TKA) and to assess factors predicting high or low knee awareness. METHODS: This study was conducted on 99 bilateral simultaneous TKAs performed...... at our institution from 2008 to 2012. All patients received one set of questionnaires [Forgotten Joint Score (FJS) and Oxford Knee Score (OKS)] for each knee. Based on the FJS, the patients' knees were divided into two groups: "best" and "worst" knees. The median of the absolute difference in FJS and OKS...... within each patient was calculated. Multivariate linear regression was performed to identify factors affecting FJS. RESULTS: The difference between knees was 1 point (CI 0-5) for the FJS and 1 point (CI 0-2) for the OKS. The FJS for females increased (decreasing awareness) with increasing age. Males had...

  14. The Survival of Total Knee Arthroplasty: Current Data from Registries on Tribology: Review Article.

    Science.gov (United States)

    Civinini, Roberto; Carulli, Christian; Matassi, Fabrizio; Lepri, Andrea Cozzi; Sirleo, Luigi; Innocenti, Massimo

    2017-02-01

    Polyethylene (PE) wear is a major contributor to implant loosening following total knee arthroplasty (TKA), and advanced bearings in TKA are being investigated with hopes of reducing or eliminate wear-related loosening. Currently, information on knee tribology is available from national joint registries and may be the best tools to evaluate the efficacy and safety of design innovations in joint arthroplasty. We performed a review of national joint registries trying to answer the following questions: "Which is the main factor directly related to revisions rate in TKA?" and "Are there new bearing options better than conventional ones?" A review was performed of all published annual reports of National Joint Registers, as well as of the literature. The search was carried out using and comparing the National Joint Registers. Current data from registries for total knee arthroplasty indicates that age is the major factor affecting the outcome of primary total knee replacement. The 10-year cumulative revision rate for non-cross-linked PE was 5.8% and for XLPE it was 3.5%. The effect of cross-linked polyethylene was more evident in the younger patients. The survival of the oxidized zirconium (OxZr) femoral component appears better when compared to a similar age group of patients with conventional group of prostheses. Our review suggests that the revision rates are half for the OxZr components compared to conventional CoCr femoral components. Age is the most relevant single factor related to revision rate. Cross-linked PE has a statistical lower revision rate at 10 years compared to conventional PE and, in the OxZr group, the revision rate is 2 times lower than Co-Cr in the same group of age.

  15. Current antibiotic management of prosthetic joint infections in Italy: the 'Udine strategy'.

    Science.gov (United States)

    Bassetti, Matteo; Cadeo, Barbara; Villa, Giovanni; Sartor, Assunta; Cainero, Vanni; Causero, Araldo

    2014-09-01

    The rate of prosthetic joint infections followed and cured at our institution is constantly increasing, in line with epidemiological data from the recent literature. This is probably related to the greater number of knee and hip prostheses implanted every year. For intermediate and late infections, only the two-stage approach is applied, as this demonstrates the best outcome in our experience. Particular attention is paid to microbiological isolation of the pathogen: multiple samples of tissue are collected during the interventions, and kept in culture for a longer period of time than usual. Sonication of prosthetic devices is used to enhance the sensitivity and specificity of the microbiological cultures. Histological examination influences surgical choices either towards implantation of a new prosthesis or replacement of the spacer. An empirical antibiotic backbone of a glycopeptide/lipopeptide and rifampicin is chosen, due to the leading role of Gram-positive bacteria in this setting and the high incidence of methicillin resistance in our centre (>30%), followed by an antibiotic regimen containing linezolid. If specific risk factors are present, an anti-Gram-negative drug is added to the regimen. Duration of therapy depends upon the approach that is chosen, usually being 6 weeks when the prosthesis is removed. Despite at the moment being limited by its small sample size, data from our experience confirms that our empirical approach may represent a valid choice during the early phase of treatment, by keeping linezolid for a step-down therapy of shorter duration (4 weeks). © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  16. Methods of X-ray examination of condylar knee replacement

    International Nuclear Information System (INIS)

    Vavrik, P.

    1988-01-01

    A detailed description is presented of the methodology of X-ray examination of patients with a condylar knee replacement. Preoperative examination includes standard anterio-posterior and lateral projections, axial projection of the patella in 30 deg flexion of the knee, examination of the mechanical axis of the extremity on a 90 x 30 format and the radioscopic assessment of the centre of the hip joint, essential for the correct centering of the knee implant. Immediately after surgery the position of the implant is checked in two standard projections. Another X-ray check is made after six weeks, before partial loading of the joint is permitted. A complete X-ray examination is made prior to the full loading of the knee joint. The methods are also discussed of the X-ray evaluation of complications such as aseptic loosening of the components, infection, instability, fractures. The general solution od these problems is described. The necessity is underlined of the deliberate and qualified indication of X-ray examinations. The basic prerequisites are listed for reducing the present considerable radiation burden of these patients in the course of the many X-ray examinations. (author). 7 figs., 3 tab., 6 refs

  17. Impact of implant-supported prostheses on nutritional status and oral health perception in edentulous patients.

    Science.gov (United States)

    El Osta, Nada; El Osta, Lana; Moukaddem, Farah; Papazian, Tatiana; Saad, Robert; Hennequin, Martine; Rabbaa Khabbaz, Lydia

    2017-04-01

    Improvement of nutritional status and perception of oral health are supposed to be different with complete conventional denture or implant-supported fixed or removable prostheses. Since no study has been conducted in Lebanon, the aim of our study was to assess the nutritional status and oral heath related quality of life (OHRQoL) in totally edentulous patients after treatment with complete denture or implant supported-prostheses. This was an observational clinical prospective study. A convenient sample of Lebanese people aged 60 years or more was selected between September 2013 and July 2015 from the Departments of removable and fixed prosthesis at Saint-Joseph University of Beirut. The treatment options included complete denture, implant-supported complete denture and implant-supported fixed prostheses. Nutritional status and OHRQoL were assessed with the Mini-Nutritional Assessment Index (MNA) and the Geriatric Oral Health Assessment Index (GOHAI) respectively at Baseline (first visit before treatment), 2-3 weeks after treatment (t1), 3 months (t2) and 6 months (t3) after treatment. Fifty-one participants (mean age: 69.39 ± 7.164 years) were included. The results have shown an improvement over time in nutritional status and OHRQoL for all treatment groups. However, 2-3 weeks after treatment the number of participants at risk of malnutrition was higher with complete removable denture, intermediate with implant-supported complete denture and lower with implant-supported fixed prostheses (p-value = 0.049). Moreover, the mean GOHAI score was significantly lower over time with complete removable denture compared to implant-supported prostheses (p-value nutritional status for implant supported-prostheses compared to conventional removable dentures. Therefore, it is fundamental that dentists communicate with their patients about implant treatment to understand their expectations, to explain the outcomes and achieve the desired clinical result. Copyright © 2017

  18. Body mass index affects knee joint mechanics during gait differently with and without moderate knee osteoarthritis.

    Science.gov (United States)

    Harding, Graeme T; Hubley-Kozey, Cheryl L; Dunbar, Michael J; Stanish, William D; Astephen Wilson, Janie L

    2012-11-01

    Obesity is a highly cited risk factor for knee osteoarthritis (OA), but its role in knee OA pathogenesis and progression is not as clear. Excess weight may contribute to an increased mechanical burden and altered dynamic movement and loading patterns at the knee. The objective of this study was to examine the interacting role of moderate knee OA disease presence and obesity on knee joint mechanics during gait. Gait analysis was performed on 104 asymptomatic and 140 individuals with moderate knee OA. Each subject group was divided into three body mass categories based on body mass index (BMI): healthy weight (BMI30). Three-dimensional knee joint angles and net external knee joint moments were calculated and waveform principal component analysis (PCA) was applied to extract major patterns of variability from each. PC scores for major patterns were compared between groups using a two-factor ANOVA. Significant BMI main effects were found in the pattern of the knee adduction moment, the knee flexion moment, and the knee rotation moment during gait. Two interaction effects between moderate OA disease presence and BMI were also found that described different changes in the knee flexion moment and the knee flexion angle with increased BMI with and without knee OA. Our results suggest that increased BMI is associated with different changes in biomechanical patterns of the knee joint during gait depending on the presence of moderate knee OA. Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  19. Effect of treatment with fixed and removable dental prostheses. An oral health-related quality of life study

    DEFF Research Database (Denmark)

    Øzhayat, Esben Boeskov; Gotfredsen, Klaus

    2012-01-01

    The aim of the study was to evaluate patient-reported effects of treatment with fixed dental prostheses (FDP) and removable dental prostheses (RDP) and relate the change in Oral Health Related Quality of Life (OHRQoL) to the type of treatment and objective dental variables of aesthetics and masti......The aim of the study was to evaluate patient-reported effects of treatment with fixed dental prostheses (FDP) and removable dental prostheses (RDP) and relate the change in Oral Health Related Quality of Life (OHRQoL) to the type of treatment and objective dental variables of aesthetics...... were obtained. The participants completed the Oral Health Impact Profile 49 (OHIP-49) before and after treatment. A control group with no need for dental treatment also completed the OHIP-49. All participants had a significant improvement in OHRQoL. The improvement was higher for the RDP group than...

  20. Preliminary observations on influence of dairy products on biofilm removal from silicone rubber voice prostheses in vitro

    NARCIS (Netherlands)

    Busscher, HJ; Free, RH; Van Weissenbruch, R; Albers, FWJ; Van der Mei, HC

    We determined oropharyngeal biofilm removal from silicone rubber voice prostheses in an artificial throat after perfusion with different commercially available dairy products, including buttermilk, Lactobacillus casei Shirota fermented milk (Yakult, Yakult Netherlands BV, Almere, The Netherlands),

  1. Radiologic findings in cases involving complications arising from total knee arthroplasty

    International Nuclear Information System (INIS)

    Nam, Deok Ho; Ryu, Kyung Nam; Bae, Dae Kyung

    1999-01-01

    Total knee arthroplasty(TKA) has been used for the treatment of knee joint pain, deformity, and instability caused by osteoarthritis, rheumatoid arthritis, or tuberculous arthritis, and by virtue of good results and rapid development, the procedure has been increasingly employed. With the development of total knee prosthesis, complications have also increased, however, and due to complications occurring up to six years after surgery, fusion occurs in about 2% of all replaced knees. The most common complication of TKA is loosening, followed by infection. Others are thrombosis, subluxation, dislocation and fracture, and complications may be divided into four groups: biologic, technical, specific to type of components, and associated with certain diagnosis. Where these complications occur, a patient must undergo a second procedure, but the success rate is lower than for the initial procedure. Exact etiological evaluation important clinically and radiologically. We illustrate the etiologies and radiologic characteristics of TKA complications according to classification

  2. Radiologic findings in cases involving complications arising from total knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Deok Ho; Ryu, Kyung Nam; Bae, Dae Kyung [Kyunghee Univ. Hospital, Seoul (Korea, Republic of)

    1999-09-01

    Total knee arthroplasty(TKA) has been used for the treatment of knee joint pain, deformity, and instability caused by osteoarthritis, rheumatoid arthritis, or tuberculous arthritis, and by virtue of good results and rapid development, the procedure has been increasingly employed. With the development of total knee prosthesis, complications have also increased, however, and due to complications occurring up to six years after surgery, fusion occurs in about 2% of all replaced knees. The most common complication of TKA is loosening, followed by infection. Others are thrombosis, subluxation, dislocation and fracture, and complications may be divided into four groups: biologic, technical, specific to type of components, and associated with certain diagnosis. Where these complications occur, a patient must undergo a second procedure, but the success rate is lower than for the initial procedure. Exact etiological evaluation important clinically and radiologically. We illustrate the etiologies and radiologic characteristics of TKA complications according to classification.

  3. Active knee joint flexibility and sports activity

    DEFF Research Database (Denmark)

    Hahn, Thomas; Foldspang, Anders; Vestergaard, E

    1999-01-01

    was significantly higher in women than in men and significantly positively associated with weekly hours of swimming and weekly hours of competitive gymnastics. Active knee flexion was significantly positively associated with participation in basketball, and significantly negatively associated with age and weekly......The aim of the study was to estimate active knee flexion and active knee extension in athletes and to investigate the potential association of each to different types of sports activity. Active knee extension and active knee flexion was measured in 339 athletes. Active knee extension...... hours of soccer, European team handball and swimming. The results point to sport-specific adaptation of active knee flexion and active knee extension. Udgivelsesdato: 1999-Apr...

  4. Risks of hip and knee replacement

    Science.gov (United States)

    ... is normal to lose blood during and after hip or knee replacement surgery. Some people need a ... clot form are higher during and soon after hip or knee replacement surgery. Sitting or lying down ...

  5. Should silicone prostheses be considered for specimen banking? A pilot study into their use for human biomonitoring.

    Science.gov (United States)

    Allan, Ian J; Bæk, Kine; Kringstad, Alfhild; Roald, Helge E; Thomas, Kevin V

    2013-09-01

    Persistent organic pollutant (POP) biomonitoring in humans is challenging and generally carried out using blood, breast milk or adipose tissue, with concentrations normalised to the lipid content of the sample matrix. The goal of this cross-sectional pilot study was to evaluate the validity and feasibility of explanted silicone prostheses as a matrix for persistent organic pollutant biomonitoring in humans. We postulate that pollutant concentrations in silicone prostheses inserted in the body will equilibrate with that in the body over time and provide a measure of the overall body burden. This study included silicone prostheses from 22 female patients of the Colosseum clinic (Oslo, Norway) collected between September 2010 and April 2012. Absorption of chlorinated and brominated POPs into silicone prostheses during implantation was observed. Relative levels of the different contaminants measured in prostheses were in agreement with those from serum and breast milk analyses from the general Norwegian population. The comparison of serum and breast milk-based literature data with prosthesis concentrations transposed into lipid-normalised concentrations supports the validity of the prosthesis measurements. The median of relative percent differences between measurements with replicate silicone prostheses from 11 patients was below 30%. Observed increases in prosthesis concentrations with patients' age were found to be very similar to literature data from studies of the Norwegian population. Silicone prostheses therefore represent a promising matrix for the biomonitoring of nonpolar and non-ionic pollutants in humans. Sample accessibility and body burden representativeness of the silicone prostheses suggest that specimen banking should be initiated. © 2013.

  6. Arthroscopic treatment of patients with moderate arthrofibrosis after total knee replacement.

    Science.gov (United States)

    Jerosch, Joerg; Aldawoudy, Akram M

    2007-01-01

    The purpose of this study was to document the effect of arthroscopic management in patients with knee stiffness after total knee replacement. We present a case series study, in which 32 patients have been treated for moderate arthrofibrosis of the knee after total knee replacement, with the same regimen. We have excluded all cases of stiffness, because of infection, mechanical mal-alignment, loosening of the implants and other obvious reasons of stiffness of the knee, rather than pure arthrofibrosis. All patients first underwent a trial of conservative treatment before going for arthroscopic management. A pain catheter for femoral nerve block was inserted just before anesthesia for post-operative pain management. Arthroscopic arthrolysis of the intra-articular pathology was performed in a standardized technique with release of all fibrous bands in the suprapatellar pouch, reestablishing the medial and lateral gutter, release of the patella, resection of the remaining meniscal tissue or an anterior cyclops, if needed. Intensive physiotherapy and continuous passive motion were to start immediately post-operatively. All the patients were available for the follow up and they were evaluated using the knee society rating system. A total of 25 of the 32 procedures resulted in an improvement of the patients knee score. All the knees operated upon had intra-articular fibrous bands, hypertrophic synovitis and peri-patellar adhesions. A total of eight patients suffered from an anterior cyclops lesion and six patients showed pseudomenicus. In 19 cases a medial and lateral relapse of the patella was performed; only 5 patients got an isolated lateral release. The mean knee flexion was 119 degrees (100-130) at the end of arthroscopy and was 97 degrees (75-115) at the last follow up. The eight patients with extension lags decreased from 27 degrees (10 degrees-35 degrees) pre-operatively to 4 degrees (0-10) at time of follow up. The average knee society ratings increased from 70

  7. Knee Confidence as it Relates to Self-Reported and Objective Correlates of Knee Osteoarthritis

    DEFF Research Database (Denmark)

    Skou, Søren T; Rasmussen, Sten; Simonsen, Ole

    2015-01-01

    osteoarthritis (OA). Background Lack of knee confidence is a frequent symptom in patients with knee OA, but little is known of associations between knee confidence and other common correlates of knee OA. Methods Baseline data from 220 patients with knee OA were applied in ordinal regression analyses, with knee...... confidence, assessed using item Q3 of the Knee injury and Osteoarthritis Outcome Score, as the dependent variable and self-reported (pain on walking, general health, fear of movement, self-efficacy, function, and previous serious injury) and objective measures (muscle strength, 20-m walk time.......21; 95% CI: 1.09, 1.34), and general health (OR = 0.024; 95% CI: 0.002, 0.259) explained 19% of the variance in knee confidence (Pcommon finding in individuals with knee OA. Pain on walking was confirmed as a correlate of knee confidence, whereas...

  8. Slightly flexed knee position within a standard knee coil: MR delineation of the anterior cruciate ligament

    Energy Technology Data Exchange (ETDEWEB)

    Niitsu, M.; Itai, Y. [Department of Radiology, Institute of Clinical Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki 305 (Japan); Ikeda, K. [Department of Orthopedic Surgery, Institute of Clinical Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki 305 (Japan)

    1998-02-01

    The purpose of this study was to assess the value of positioning the knee slightly flexed within a standard MR knee coil in delineation of the anterior cruciate ligament (ACL). Within the confined space of a commercially available knee coil, knee could bend as much as 30 , average 17 of flexion. Sets of oblique sagittal MR images were obtained at both fully extended and slightly flexed positions. Twenty-two normal knees and 18 knees with ACL tears were examined and paired MR images were evaluated by two observers. Compared with knee extension, the MR images for knee flexion provided better clarity in 57 % of reviews of full length of the ACL and 53 % of the femoral attachment. In the extended position the anterior margin of the ligament was obscured due to partial averaging with the intercondylar roof. We recommend examining the knee in an achievable flexed position within the standard knee coil. (orig.) With 3 figs., 1 tab., 6 refs.

  9. Knee extensor muscle weakness is a risk factor for development of knee osteoarthritis

    DEFF Research Database (Denmark)

    Oiestad, B E; Juhl, C B; Eitzen, I

    2015-01-01

    The objective of this study was to perform a systematic review and meta-analysis on the association between knee extensor muscle weakness and the risk of developing knee osteoarthritis. A systematic review and meta-analysis was conducted with literature searches in Medline, SPORTDiscus, EMBASE......, CINAHL, and AMED. Eligible studies had to include participants with no radiographic or symptomatic knee osteoarthritis at baseline; have a follow-up time of a minimum of 2 years, and include a measure of knee extensor muscle strength. Hierarchies for extracting data on knee osteoarthritis and knee...... extensor muscle strength were defined prior to data extraction. Meta-analysis was applied on the basis of the odds ratios (ORs) of developing symptomatic knee osteoarthritis or radiographic knee osteoarthritis in subjects with knee extensor muscle weakness. ORs for knee osteoarthritis and 95% confidence...

  10. Slightly flexed knee position within a standard knee coil: MR delineation of the anterior cruciate ligament

    International Nuclear Information System (INIS)

    Niitsu, M.; Itai, Y.; Ikeda, K.

    1998-01-01

    The purpose of this study was to assess the value of positioning the knee slightly flexed within a standard MR knee coil in delineation of the anterior cruciate ligament (ACL). Within the confined space of a commercially available knee coil, knee could bend as much as 30 , average 17 of flexion. Sets of oblique sagittal MR images were obtained at both fully extended and slightly flexed positions. Twenty-two normal knees and 18 knees with ACL tears were examined and paired MR images were evaluated by two observers. Compared with knee extension, the MR images for knee flexion provided better clarity in 57 % of reviews of full length of the ACL and 53 % of the femoral attachment. In the extended position the anterior margin of the ligament was obscured due to partial averaging with the intercondylar roof. We recommend examining the knee in an achievable flexed position within the standard knee coil. (orig.)

  11. KNEE PROPRIOCEPTION FOLLOWING MENISCAL REPAIR

    Directory of Open Access Journals (Sweden)

    Brytsko A. A.

    2018-02-01

    Full Text Available Background. It is well known that meniscectomy leads to osteoarthritis of the knee and proprioception impairment. Objective. The aim of this study was to assess retrospectively the joint position sense after meniscal suture and partial medial meniscal resection and to estimate the patients’ satisfaction with knee function. Material and Methods. We evaluated the outcomes of 27 patients after meniscal repair and compared them to those of 24 patients after partial meniscal resection. We estimated the joint position sense at 30°, 45° and 60° of flexion using the Biodex system 4 Pro. All patients were assessed with the IKDC 2000 subjective knee score. Results. A statistically significant worsening in reproducing the injured joint position in comparison to the healthy limb in both groups was observed. These impairments were mostly expressed at 45° and 60° of knee flexion, and were worsening over time in the group of patients who had undergone medial meniscal resection. An average value by the IKDC 2000 scale after 24 months in the meniscorrhaphy group was 76.73 ± 11.17% and 68.93 ± 14.76% after partial medial meniscal resection. Сonclusion. The control over position of the knee is not impaired after meniscal repair. An overall satisfaction with joint function is higher in patients who undergo meniscal suture in comparison to the partial medial meniscal resection group.

  12. The Knee: Theory and Experiment

    International Nuclear Information System (INIS)

    Yodh, Gaurang B

    2006-01-01

    A review of current status of theoretical paradigm and results of direct and indirect experiments to study cosmic rays through the knee region are presented and discussed. There is general agreement that the knee is around a PeV and that it reflects a rigidity cutoff. The composition of cosmic rays in the knee region is mixed and changing with energy. The two direct experiments, JACEE and RUNJOB with measurements in the 100 TeV per particle to 1000 TeV per particle and with similar exposures do not agree. While JACEE indicates a increase in (lnA) from its low energy value of 1.5 to a value closer to 3 , the RUNJOB experiment sees no change in the composition albeit with large uncertainty. Of the indirect experiments, KASKADE, SPASEAMANDA, HEGRA-Airobic, CACTI, TUNKA and Tibet favor ''Heavy'' composition above the knee and beyond. The KASKADE energy range extends to 100 PeV where their analysis indicates iron dominance. KASKADE does not see a proton rigidity cutoff until about 3 PeV, while Tibet measures a steepening of the proton slope at a few hundred TeV. BLANCA and DICE favor little composition change or a change towards a proton dominated composition around 10 PeV. We need experiments with much better mass resolution in the energy range of the knee and a more quantitative understanding of the hadron production in the forward region at these energies to make definitive progress

  13. TOTAL KNEE REPLACEMENT IN PATIENTS WITH BELOW-KNEE AMPUTATION

    Science.gov (United States)

    Karam, Matthew D; Willey, Michael; Shurr, Donald G

    2010-01-01

    Total knee replacement (TKR) is reserved for patients with severe and disabling arthritis that is non-responsive to conservative measures. Based on existing data, total knee replacement is a safe and cost-effective treatment for alleviating pain and improving physical function in patients who do not respond to conservative therapy. Despite the large variation in health status of patients and types of prosthesis implanted, total knee replacement has proven to be a relatively low risk and successful operation. Each year in the United States surgeons perform approximately 300,000 TKR.1 Likewise, lower extremity amputation is commonly performed in the United States with an annual incidence of 110,000 per year.2 Nearly 70% of all lower extremity amputations are performed as the result of chronic vascular disease, followed by trauma (22%), congenital etiology and tumor (4% each).3 Approximately 50% of all lower extremity amputations are performed secondary to complications from Diabetes Mellitus. Norvell et al. demonstrated that patients who have previously undergone transtibial amputation and ambulate with a prosthesis are more likely to develop degenerative joint disease in the con-tralateral extremity than the ipsilateral extremity.4 Further, radiographic changes consistent with osteoporosis have been demonstrated in up to 88% of limbs that have undergone transtibial amputation.8 To our knowledge, there have been only three reported cases of total knee replacement in patients with ipsilateral transtibial amputation.5,7 The purpose of the present study is to review the existing data on total knee replacement in patients who have undergone transtibial amputation. Further we present a patient with a transtibial amputation who underwent contralateral total knee replacement. PMID:21045987

  14. The value of FDG-PET in patients with painful total knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Stumpe, Katrin D.M.; Schulthess, Gustav K. von; Strobel, Klaus [University Hospital, Department of Medical Radiology, Division of Nuclear Medicine, Zurich (Switzerland); Romero, Jose [Orthopaedic University Hospital Balgrist, Orthopaedic Surgery, Zurich (Switzerland); Center for Joint Diseases at Hirslanden Clinic, EndoClinic Zurich, Zurich (Switzerland); Ziegler, Oliver [Orthopaedic University Hospital Balgrist, Orthopaedic Surgery, Zurich (Switzerland); Ortho Zentrum Rosenheim, Rosenheim (Germany); Kamel, Ehab M. [University Hospital, Department of Medical Radiology, Division of Nuclear Medicine, Zurich (Switzerland); Centre Hospitalier Universitaire Vaudois (CHUV), Division of Nuclear Medicine, Lausanne (Switzerland); Hodler, Juerg [Orthopaedic University Hospital Balgrist, Department of Radiology, Zurich (Switzerland)

    2006-10-15

    The purpose of this study was to evaluate{sup 18}F-fluorodeoxyglucose (FDG) uptake in patients with painful total knee arthroplasty and to relate FDG uptake to the location of soft tissue pain. Twenty-eight patients with painful total knee arthroplasty had a clinical examination, standard radiographs, CT measurement of rotation of the femoral component and FDG-PET (18 PET/CT, 10 PET). The diagnosis of infection was based on microbiological examinations of surgical specimens (n=12) or clinical follow-up for at least 6 months (n=16),{sup 99m}Tc-labelled monoclonal antibody scintigraphy and joint aspiration. Twenty-seven of 28 patients presented with diffuse synovial FDG uptake. Additional focal extrasynovial FDG uptake was observed in 19 knees. Twenty-four of the 28 patients had a diagnosis of internal femoral malrotation. The remaining four patients showed no rotation (0 ) and 3 , 4 and 7 of external rotation, respectively. Three patients presented with the additional diagnosis of an infected total knee replacement. Pain was described as diffuse (n=10) or focal (n=18). In two knees a relationship between pain location and FDG uptake was observed. Of ten patients with a severe internal femoral component rotation (>6 ), seven had focal uptake, four in the femoral periosteum and three in the tibial periosteum. The difference between knees with severe malrotation and the remaining knees was not significant (p=1.000, Fisher's Exact Test). Diffuse synovial and focal extrasynovial FDG-PET uptake is commonly found in patients with malrotation of the femoral component and is not related to pain location. The information provided by FDG-PET does not contribute to the diagnosis and management of individual patients with persistent pain after total knee replacement. (orig.)

  15. The value of FDG-PET in patients with painful total knee arthroplasty

    International Nuclear Information System (INIS)

    Stumpe, Katrin D.M.; Schulthess, Gustav K. von; Strobel, Klaus; Romero, Jose; Ziegler, Oliver; Kamel, Ehab M.; Hodler, Juerg

    2006-01-01

    The purpose of this study was to evaluate 18 F-fluorodeoxyglucose (FDG) uptake in patients with painful total knee arthroplasty and to relate FDG uptake to the location of soft tissue pain. Twenty-eight patients with painful total knee arthroplasty had a clinical examination, standard radiographs, CT measurement of rotation of the femoral component and FDG-PET (18 PET/CT, 10 PET). The diagnosis of infection was based on microbiological examinations of surgical specimens (n=12) or clinical follow-up for at least 6 months (n=16), 99m Tc-labelled monoclonal antibody scintigraphy and joint aspiration. Twenty-seven of 28 patients presented with diffuse synovial FDG uptake. Additional focal extrasynovial FDG uptake was observed in 19 knees. Twenty-four of the 28 patients had a diagnosis of internal femoral malrotation. The remaining four patients showed no rotation (0 ) and 3 , 4 and 7 of external rotation, respectively. Three patients presented with the additional diagnosis of an infected total knee replacement. Pain was described as diffuse (n=10) or focal (n=18). In two knees a relationship between pain location and FDG uptake was observed. Of ten patients with a severe internal femoral component rotation (>6 ), seven had focal uptake, four in the femoral periosteum and three in the tibial periosteum. The difference between knees with severe malrotation and the remaining knees was not significant (p=1.000, Fisher's Exact Test). Diffuse synovial and focal extrasynovial FDG-PET uptake is commonly found in patients with malrotation of the femoral component and is not related to pain location. The information provided by FDG-PET does not contribute to the diagnosis and management of individual patients with persistent pain after total knee replacement. (orig.)

  16. Cross-pinning: the philosophy of retrievability applied practically to fixed, implant-supported prostheses.

    Science.gov (United States)

    Gervais, M J; Hatzipanagiotis, P; Wilson, P R

    2008-03-01

    Biologic and technical complications are widely reported in the dental literature and often compromise the functional and/or aesthetic features of fixed, implant-supported prostheses. Managing complications without damaging or destroying a restoration is an obvious advantage of implant-based dentistry where the option of prosthetic retrievability is almost always available. The technique of cross-pinning uses a transverse screw to secure a prosthesis to a milled implant abutment, allowing prosthetic retrievability irrespective of dental implant alignment. This study presents guidelines for cross-pinning implant-supported prostheses based on resistance form, screw mechanics and natural tooth contours. The technical aspects of cross-pinning are also discussed using examples from four implant systems.

  17. Mid- term results of stryker® scorpio plus mobile bearing total knee arthroplasty

    Directory of Open Access Journals (Sweden)

    Kobayashi Hideo

    2012-10-01

    Full Text Available Abstract Background The mobile bearing knee system was introduced to lessen contact stress on the articular bearing surface and reduce polyethylene wear. The purpose of the current study was to investigate the mid-term results of patients undergoing total knee arthroplasties (TKAs using Scorpio Plus Mobile Bearing Knee System (Stryker, Mahwah, NJ, and compare the outcomes between patients with osteoarthritis and osteonecrosis (OA·ON group and patients with rheumatoid arthritis (RA group. Methods Eight males and 58 females were followed up for a period of 4.4- 7.6 years from June 1, 2003 to December 31, 2005. There were 53 knees with osteoarthritis, 17 knees with rheumatoid arthritis, and 6 knees with osteonecrosis. Clinical and radiographic follow- up was done using The Japanese Orthopedic Association knee rating score (JOA score and Knee Society Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System. Results With regard to the JOA score, there was significant improvement in both groups. The postoperative range of motion was between 0.8°and 116.8° in OA·ON group, and between 0.0° and 113.7° in RA group. There were no significant differences with the radiographic evaluation between two groups. Spontaneous dislocation of a polyethylene insert occurred in one patient, and deep infection was occurred in one patient. Conclusion There was significant improvement with regard to the clinical and radiographic results of patients undergoing TKAs using the model. The risk of polyethylene insert dislocation related to the mobile bearing TKA is a cause for concern.

  18. Proprioception in knee osteoarthritis: a narrative review

    NARCIS (Netherlands)

    Knoop, J.; Steultjens, M.P.M.; van der Leeden, M.; van der Esch, M.; Thorstensson, C.A.; Roorda, L.D.; Lems, W.F.; Dekker, J.

    2011-01-01

    Objective: To give an overview of the literature on knee proprioception in knee osteoarthritis (OA) patients. Method: A literature search was performed and reviewed using the narrative approach. Results: (1) Three presumed functions of knee proprioception have been described in the literature:

  19. Mechanomyography-Based Wearable Monitor of Quasi-Isometric Muscle Fatigue for Motor Neural Prostheses.

    Science.gov (United States)

    Krueger, Eddy; Popović-Maneski, Lana; Nohama, Percy

    2018-02-01

    A motor neural prosthesis based on surface functional electrical stimulation (sFES) can restore functional movement (e.g., standing, walking) in patients with a spinal cord injury (SCI). sFES generates muscle contractions in antigravity muscles and allows balance-assisted standing. This induced standing has several benefits, such as improved cardiovascular function, decreased incidence of urinary infections, reduced joint contractures, and muscle atrophy. The duration of sFES assisted standing is limited due to the quick onset of muscle fatigue. Currently, there is no method available to reliably estimate real-time muscle fatigue during sFES. Simply monitoring the M-wave changes is not suitable due to the high signal disturbances that arise during multi-channel electrical stimulation. Mechanomyography (MMG) is immune to electrical stimulation artifacts and can be used to detect subtle vibrations on the surface of the skin related to activation of the underlying muscle's motor units (MU). The aim of this study was to develop a method for detecting muscle fatigue brought on by sFES. The method was tested in three different heads of the quadriceps muscle in SCI patients during electrically elicited quasi-isometric contraction. Six spinal cord-injured male volunteers, with no voluntary control of the quadriceps muscle participated in the study. Electrical bursts of voltage-controlled monophasic square pulses at frequencies of 1 kHz (50% duty cycle) at 50 Hz (15% duty cycle) were used to generate thigh muscle contractions that controlled the knee joint in the sagittal plane. The pulse amplitudes were set to position the knee joint at a 5° angle from the horizontal plane and when the knee angle dropped to 20° (e.g., the quadriceps were unable to hold the lower leg in the desired position), the test was terminated. Two data segments lasting 10 s each, at the beginning and end of each test, were analyzed. The muscle contraction was assessed by MMG sensors positioned on

  20. A fractographic study of clinically retrieved zirconia–ceramic and metal–ceramic fixed dental prostheses

    OpenAIRE

    Pang, Zhen; Chughtai, Asima; Sailer, Irena; Zhang, Yu

    2015-01-01

    A recent 3-year randomized controlled trial (RCT) of tooth supported three- to five-unit zirconia-ceramic and metal-ceramic posterior fixed dental prostheses (FDPs) revealed that veneer chipping and fracture in zirconia-ceramic systems occurred more frequently than those in metal-ceramic systems [1]. This study seeks to elucidate the underlying mechanisms responsible for the fracture phenomena observed in this RCT using a descriptive fractographic analysis

  1. Functional changes through the usage of 3D-printed transitional prostheses in children.

    Science.gov (United States)

    Zuniga, Jorge M; Peck, Jean L; Srivastava, Rakesh; Pierce, James E; Dudley, Drew R; Than, Nicholas A; Stergiou, Nicholas

    2017-11-08

    There is limited knowledge on the use of 3 D-printed transitional prostheses, as they relate to changes in function and strength. Therefore, the purpose of this study was to identify functional and strength changes after usage of 3 D-printed transitional prostheses for multiple weeks for children with upper-limb differences. Gross manual dexterity was assessed using the Box and Block Test and wrist strength was measured using a dynamometer. This testing was conducted before and after a period of 24 ± 2.61 weeks of using a 3 D-printed transitional prosthesis. The 11 children (five girls and six boys; 3-15 years of age) who participated in the study, were fitted with a 3 D-printed transitional partial hand (n = 9) or an arm (n = 2) prosthesis. Separate two-way repeated measures ANOVAs were performed to analyze function and strength data. There was a significant hand by time interaction for function, but not for strength. Conclusion and relevance to the study of disability and rehabilitation: The increase in manual gross dexterity suggests that the Cyborg Beast 2 3 D-printed prosthesis can be used as a transitional device to improve function in children with traumatic or congenital upper-limb differences. Implications for Rehabilitation Children's prosthetic needs are complex due to their small size, rapid growth, and psychosocial development. Advancements in computer-aided design and additive manufacturing offer the possibility of designing and printing transitional prostheses at a very low cost, but there is limited knowledge on the function of this type of devices. The use of 3D printed transitional prostheses may improve manual gross dexterity in children after several weeks of using it.

  2. Integration of the Residual Limb with Prostheses via Direct Skin-Bone-Peripheral Nerve Interface

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-16-1-0791 TITLE: Integration of the Residual Limb with Prostheses via Direct Skin- Bone-Peripheral Nerve Interface...ABOVE ADDRESS. 1. REPORT DATE October 2017 2. REPORT TYPE Annual 3. DATES COVERED 30 Sep 2016 - 29 Sep 2017 4. TITLE AND SUBTITLE Integration of the...translational study to develop Skin and Bone Integrated Pylon with Peripheral Neural Interface (SBIP-PNI) directly attached to the residuum and the

  3. Ranking of CT in persistent vertigo after implantation of stapes prostheses

    International Nuclear Information System (INIS)

    Koesling, S.; Woldag, K.; Meister, E.F.; Reschke, I.; Schulz, H.G.

    1995-01-01

    10 of 150 patients had persistent vertigo after implanation of stapes prostheses. These patients were evaluated by high resolution CT in the axial and coronal plane. Scans showed in all cases findings which related to the symptoms. The CT findings were proved intraoperatively in 9 cases. A new indirect sign of a perilymphatic fistula is described in form of an air bulla at the end of the prosthesis. Retympanotomy could be planned better with the help of HR-CT. (orig.) [de

  4. Human endothelium on vascular prostheses modified by extracellular matrix proteins in a flow experiment

    Czech Academy of Sciences Publication Activity Database

    Chlupáč, Jaroslav; Filová, Elena; Riedel, Tomáš; Brynda, Eduard; Remy-Zolghadri, M.; Bareille, R.; Fernandez, P.; Daculsi, R.; Bordenave, L.; Bačáková, Lucie

    2006-01-01

    Roč. 9, č. 58-60 (2006), s. 10-13 ISSN 1429-7248 R&D Projects: GA AV ČR(CZ) IAA5011301; GA AV ČR(CZ) IAA4050202; GA AV ČR(CZ) IAA400500507; GA AV ČR(CZ) 1QS500110564 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z40500505 Keywords : bioartificial vascular prostheses * laminin * fibrin Subject RIV: EI - Biotechnology ; Bionics

  5. Application of quality by design for 3D printed bone prostheses and scaffolds.

    Science.gov (United States)

    Martinez-Marquez, Daniel; Mirnajafizadeh, Ali; Carty, Christopher P; Stewart, Rodney A

    2018-01-01

    3D printing is an emergent manufacturing technology recently being applied in the medical field for the development of custom bone prostheses and scaffolds. However, successful industry transformation to this new design and manufacturing approach requires technology integration, concurrent multi-disciplinary collaboration, and a robust quality management framework. This latter change enabler is the focus of this study. While a number of comprehensive quality frameworks have been developed in recent decades to ensure that the manufacturing of medical devices produces reliable products, they are centred on the traditional context of standardised manufacturing techniques. The advent of 3D printing technologies and the prospects for mass customisation provides significant market opportunities, but also presents a serious challenge to regulatory bodies tasked with managing and assuring product quality and safety. Before 3D printing bone prostheses and scaffolds can gain traction, industry stakeholders, such as regulators, clients, medical practitioners, insurers, lawyers, and manufacturers, would all require a high degree of confidence that customised manufacturing can achieve the same quality outcomes as standardised manufacturing. A Quality by Design (QbD) approach to custom 3D printed prostheses can help to ensure that products are designed and manufactured correctly from the beginning without errors. This paper reports on the adaptation of the QbD approach for the development process of 3D printed custom bone prosthesis and scaffolds. This was achieved through the identification of the Critical Quality Attributes of such products, and an extensive review of different design and fabrication methods for 3D printed bone prostheses. Research outcomes include the development of a comprehensive design and fabrication process flow diagram, and categorised risks associated with the design and fabrication processes of such products. An extensive systematic literature review

  6. Progressive recovery of osseoperception as a function of the combination of implant-supported prostheses.

    Science.gov (United States)

    Batista, Mauro; Bonachela, Wellington; Soares, Janir

    2008-06-01

    The extraction of teeth involves the elimination of extremely sensitive periodontal mechanoreceptors, which play an important role in oral sensory perception. The aim of this study was to evaluate the recovery of interocclusal sensory perception for micro-thickness in individuals with different types of implant-supported prostheses. Wearers of complete dentures (CDs) comprised the negative control group (group A, n=17). The experimental group consisted of wearers of prostheses supported by osseointegrated implants (Group B, n=29), which was subsequently divided into 4 subgroups: B(1) (n=5)--implant supported overdentures (ISO) occluding with CD; B(2) (n=6)--implant-supported fixed prostheses (ISFP) occluding with CD; B(3) (n=8)--wearers of maxillary and mandibular ISFP, and B(4) (n=10)--ISFP occluding with natural dentition (ND). Individuals with ND represented the positive control group (Group C, n=24). Aluminum foils measuring 10 microm, 24 microm, 30 microm, 50 microm, 80 microm, and 104 microm thickness were placed within the premolar area, adding up to 120 tests for each individual. The mean tactile thresholds of groups A, B1, B2, B3, B4, and C were 92 microm, 27 microm, 27 microm, 14 microm, 10 microm, and 10 microm, respectively. [Correction added after publication online 18 April 2008: in the preceding sentence 92 microm, 27 microm, 14 microm, 10 microm and 10 microm, was corrected to 92 microm, 27 microm, 27 microm, 14 microm, 10 microm and 10 microm]. The Kruskal-Wallis test revealed significant difference among groups (P<0.05). The Dunn test revealed that group A was statistically different from groups C, B(3), and B(4), and that B(1) and B(2) were statistically different from group C. Progressive recovery of osseoperception as a function of the combination of implant-supported prostheses could be observed. Moreover, ISO and/or ISFP combinations may similarly maximize the recovery of osseoperception.

  7. Application of quality by design for 3D printed bone prostheses and scaffolds

    Science.gov (United States)

    Martinez-Marquez, Daniel; Mirnajafizadeh, Ali; Carty, Christopher P.

    2018-01-01

    3D printing is an emergent manufacturing technology recently being applied in the medical field for the development of custom bone prostheses and scaffolds. However, successful industry transformation to this new design and manufacturing approach requires technology integration, concurrent multi-disciplinary collaboration, and a robust quality management framework. This latter change enabler is the focus of this study. While a number of comprehensive quality frameworks have been developed in recent decades to ensure that the manufacturing of medical devices produces reliable products, they are centred on the traditional context of standardised manufacturing techniques. The advent of 3D printing technologies and the prospects for mass customisation provides significant market opportunities, but also presents a serious challenge to regulatory bodies tasked with managing and assuring product quality and safety. Before 3D printing bone prostheses and scaffolds can gain traction, industry stakeholders, such as regulators, clients, medical practitioners, insurers, lawyers, and manufacturers, would all require a high degree of confidence that customised manufacturing can achieve the same quality outcomes as standardised manufacturing. A Quality by Design (QbD) approach to custom 3D printed prostheses can help to ensure that products are designed and manufactured correctly from the beginning without errors. This paper reports on the adaptation of the QbD approach for the development process of 3D printed custom bone prosthesis and scaffolds. This was achieved through the identification of the Critical Quality Attributes of such products, and an extensive review of different design and fabrication methods for 3D printed bone prostheses. Research outcomes include the development of a comprehensive design and fabrication process flow diagram, and categorised risks associated with the design and fabrication processes of such products. An extensive systematic literature review

  8. Comparison of fixed implant-supported prostheses, removable implant-supported prostheses, and complete dentures: patient satisfaction and oral health-related quality of life.

    Science.gov (United States)

    Oh, Sung-Hee; Kim, Younhee; Park, Joo-Yeon; Jung, Yea Ji; Kim, Seong-Kyun; Park, Sun-Young

    2016-02-01

    The purpose of this study was to compare patient satisfaction and oral health-related quality of life (OHRQoL) among fully edentulous patients treated with either fixed implant-supported prostheses (FP), removable implant-supported prostheses (RP), or complete dentures (CD). Eighty-six patients - 29 FP, 27 RP, and 30 CD patients - participated in this study. The survey was conducted using face-to-face interviews with a questionnaire that included a patient satisfaction scale and Oral Health Impact Profile (OHIP-14). We measured patient satisfaction after prosthetic treatments and OHRQoL before and after the treatments. After prosthetic treatments, OHRQoL increased in all three groups (P patient satisfaction and OHRQoL, and both groups showed greater improvement compared with the CD group. Specifically, the OHRQoL dimensions of functional limitation, physical pain, psychological discomfort, and psychological disability in the FP group, and functional limitation in the RP group, improved greatly in comparison with the CD group (P patient satisfaction than the CD treatment. Reliable information of OHRQoL and patient satisfaction helps experts and patients choose the best prosthetic treatment option. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. EFFICIENCY OF PROSTHETIC TREATMENT WITH POST RESECTION PROSTHESES WITH SOLID SUBSTITUTE PART

    Directory of Open Access Journals (Sweden)

    Ivan Gerdzhikov

    2016-08-01

    Full Text Available Aim: The aim of this study is to track the effectiveness of prosthetic treatment with post resection dentures with solid substitute part and their role in the restoration of damaged functions. Materials and methods: The study included 14 patients (9 men and 5 women with different size and location of defects in the upper jaw treated in the period 2010-2016 with post resection prostheses with a solid substitute part. The impressions were taken with irreversible hydrocolloid impression material. The prostheses were completed by heat-curing acrylic with low quantity residual monomer. The effectiveness of prosthetics was evaluated by the method of Mihaylov for both oral-nasal examination of the pressure with the device "Oronasopneumotest." For objectifying and assess the occlusal-articulation ratios was held computerized occlusal analysis with the system T-SCAN 8. Results: The results showed successful obturation and sealing of defects in all patients. It was found satisfactory recovery of the speaking function and normalization of occlusal-articulation ratios. Conclusion: The prosthetic treatment with post resection prostheses with a solid substitute part allows successful recovery of the lost speech and chewing functions, helping to restore self esteem and social rehabilitation of patients.

  10. Visual prostheses: The enabling technology to give sight to the blind

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Maghami

    2014-01-01

    Full Text Available Millions of patients are either slowly losing their vision or are already blind due to retinal degenerative diseases such as retinitis pigmentosa (RP and age-related macular degeneration (AMD or because of accidents or injuries. Employment of artificial means to treat extreme vision impairment has come closer to reality during the past few decades. Currently, many research groups work towards effective solutions to restore a rudimentary sense of vision to the blind. Aside from the efforts being put on replacing damaged parts of the retina by engineered living tissues or microfabricated photoreceptor arrays, implantable electronic microsystems, referred to as visual prostheses, are also sought as promising solutions to restore vision. From a functional point of view, visual prostheses receive image information from the outside world and deliver them to the natural visual system, enabling the subject to receive a meaningful perception of the image. This paper provides an overview of technical design aspects and clinical test results of visual prostheses, highlights past and recent progress in realizing chronic high-resolution visual implants as well as some technical challenges confronted when trying to enhance the functional quality of such devices.

  11. Interest of Flow Diversion Prostheses in the Management of Unruptured Intracranial Aneurysms

    Directory of Open Access Journals (Sweden)

    Xavier Armoiry

    2012-01-01

    Full Text Available Flow diversion prostheses represent a new endovascular approach aimed at treating patients with large wide-neck aneurysms. Our objective is to present this new technology, to review the clinical studies on efficacy, and to emphasize its current limits. Flow diversion prostheses consist of a cylinder made of a large number of braided microfilaments providing a large metallic surface when deployed and inducing a blood flow diversion outside the aneurysm. Two different brands are currently available. Clinical data supporting their efficacy are currently limited to six non comparative cohort studies that included between 18 and 107 patients. Procedural implantation was shown to be feasible in more than 90% and safe with a thirty-day mortality between 2.8 and 5.5%. Complete occlusion rates at twelve months varied between 85.7 and 100%. Even though promising, the current status of flow diversion prostheses needs further evaluation with randomized, prospective, clinical trials with comparison to conventional strategies including endovascular coiling or surgical clipping.

  12. Biomedical Titanium alloy prostheses manufacturing by means of Superplastic and Incremental Forming processes

    Directory of Open Access Journals (Sweden)

    Piccininni Antonio

    2016-01-01

    Full Text Available The present work collects some results of the three-years Research Program “BioForming“, funded by the Italian Ministry of Education (MIUR and aimed to investigate the possibility of using flexible sheet forming processes, i.e. Super Plastic Forming (SPF and Single Point Incremental Forming (SPIF, for the manufacturing of patient-oriented titanium prostheses. The prosthetic implants used as case studies were from the skull; in particular, two different Ti alloys and geometries were considered: one to be produced in Ti-Gr23 by SPF and one to be produced in Ti-Gr2 by SPIF. Numerical simulations implementing material behaviours evaluated by characterization tests were conducted in order to design both the manufacturing processes. Subsequently, experimental tests were carried out implementing numerical results in terms of: (i gas pressure profile able to determine a constant (and optimal strain rate during the SPF process; (ii tool path able to avoid rupture during the SPIF process. Post forming characteristics of the prostheses in terms of thickness distributions were measured and compared to data from simulations for validation purposes. A good correlation between numerical and experimental thickness distributions has been obtained; in addition, the possibility of successfully adopting both the SPF and the SPIF processes for the manufacturing of prostheses has been demonstrated.

  13. Control Capabilities of Myoelectric Robotic Prostheses by Hand Amputees: A Scientific Research and Market Overview.

    Science.gov (United States)

    Atzori, Manfredo; Müller, Henning

    2015-01-01

    Hand amputation can dramatically affect the capabilities of a person. Cortical reorganization occurs in the brain, but the motor and somatosensorial cortex can interact with the remnant muscles of the missing hand even many years after the amputation, leading to the possibility to restore the capabilities of hand amputees through myoelectric prostheses. Myoelectric hand prostheses with many degrees of freedom are commercially available and recent advances in rehabilitation robotics suggest that their natural control can be performed in real life. The first commercial products exploiting pattern recognition to recognize the movements have recently been released, however the most common control systems are still usually unnatural and must be learned through long training. Dexterous and naturally controlled robotic prostheses can become reality in the everyday life of amputees but the path still requires many steps. This mini-review aims to improve the situation by giving an overview of the advancements in the commercial and scientific domains in order to outline the current and future chances in this field and to foster the integration between market and scientific research.

  14. Control Capabilities of Myoelectric Robotic Prostheses by Hand Amputees: A Scientific Research and Market Overview

    Directory of Open Access Journals (Sweden)

    Manfredo eAtzori

    2015-11-01

    Full Text Available Hand amputation can dramatically affect the capabilities of a person. Cortical reorganization occurs in the brain, but the motor and somatosensorial cortex can interact with the remnant muscles of the missing hand even many years after the amputation, leading to the possibility to restore the capabilities of hand amputees through myoelectric prostheses. Myoelectric hand prostheses with many degrees of freedom are commercially available and recent advances in rehabilitation robotics suggest that their natural control can be performed in real life. The first commercial products exploiting pattern recognition to recognize the movements have recently been released, however the most common control systems are still usually unnatural and must be learned through long training. Dexterous and naturally controlled robotic prostheses can become reality in the everyday life of amputees but the path still requires many steps. This mini-review aims to improve the situation by giving an overview of the advancements in the commercial and scientific domains in order to outline the current and future chances in this field and to foster the integration between market and scientific research.

  15. Neuromuscular coordination of masticatory muscles in subjects with two types of implant-supported prostheses.

    Science.gov (United States)

    Ferrario, Virgilio F; Tartaglia, Gianluca M; Maglione, Michele; Simion, Massimo; Sforza, Chiarella

    2004-04-01

    To compare the electromyographic (EMG) characteristics of masticatory muscles in patients with fixed implant-supported prostheses and implant overdentures. Nineteen subjects aged 45-79 years were examined. Fourteen were edentulous and had been successfully rehabilitated with (a) maxillary and mandibular implant-supported fixed prostheses (seven patients); (b) mandibular implant overdentures and maxillary complete dentures (seven patients). Five control subjects had natural dentition or single/partial (no more than two teeth) tooth or implant fixed dentures. Surface EMG of the masseter and temporal muscles was performed during unilateral gum chewing and during maximum teeth clenching. To reduce biological and instrumental noise, all values were standardized as percentage of a maximum clenching on cotton rolls. During clenching, temporal muscle symmetry was larger in control subjects and fixed implant-supported prosthesis patients than in overdenture patients (analysis of variance, P=0.005). No differences were found in masseter muscle symmetry or in muscular torque. Muscle activities (integrated areas of the EMG potentials over time) were significantly larger in control subjects than in implant-supported prosthesis patients (P=0.014). In both patient groups, a poor neuromuscular coordination during chewing, with altered muscular patterns, and a smaller left-right symmetry than in control subjects were found (P=0.05). No differences in masticatory frequency were found. Surface EMG analysis of clenching and chewing showed that fixed implant-supported prostheses and implant overdentures were functionally equivalent. Neuromuscular coordination during chewing was inferior to that found in subjects with natural dentition.

  16. Dental prostheses mimic the natural enamel behavior under functional loading: A review article

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    Ahmed A. Madfa

    2016-02-01

    Full Text Available Alumina- and zirconia-based ceramic dental restorations are designed to repair functionality as well as esthetics of the failed teeth. However, these materials exhibited several performance deficiencies such as fracture, poor esthetic properties of ceramic cores (particularly zirconia cores, and difficulty in accomplishing a strong ceramic–resin-based cement bond. Therefore, improving the mechanical properties of these ceramic materials is of great interest in a wide range of disciplines. Consequently, spatial gradients in surface composition and structure can improve the mechanical integrity of ceramic dental restorations. Thus, this article reviews the current status of the functionally graded dental prostheses inspired by the dentino-enamel junction (DEJ structures and the linear gradation in Young's modulus of the DEJ, as a new material design approach, to improve the performance compared to traditional dental prostheses. This is a remarkable example of nature's ability to engineer functionally graded dental prostheses. The current article opens a new avenue for recent researches aimed at the further development of new ceramic dental restorations for improving their clinical durability.

  17. Accelerated treatment protocols: full arch treatment with interim and definitive prostheses.

    Science.gov (United States)

    Drago, Carl

    2012-01-01

    With the advent of titanium, root form implants and osseointegration, dental treatment has undergone a metamorphosis in recent years. These new techniques enable dentists to provide anchorage for various kinds of prostheses that improve masticatory function, esthetics, and comfort for patients. Implant treatment protocols have been improved relative to implant macro- and micro-geometries, surgical and prosthetic components, and treatment times. Over the past 20 years, immediate occlusal function (also known as loading) has been established as a predictable treatment modality, provided certain specific criteria are met. In many cases, edentulous patients, crippled by the loss of their teeth, can undergo outpatient surgical and prosthetic procedures and return to a masticatory function that is near normal--sometimes after only one day of surgical and prosthetic treatment. This treatment option is also available for patients with advanced, generalized periodontal disease. Computer-assisted design/Computer-assisted manufacturing (CAD/CAM) has transformed how dental prostheses are made, offering improved accuracy, longevity, and biocompatibility; along with reduced labor costs and fewer complications than casting technologies. This article reviews the principles associated with immediate occlusal loading and illustrates one specific accelerated prosthodontic treatment protocol used to treat edentulous and partially edentulous patients with interim and definitive prostheses.

  18. High Cable Forces Deteriorate Pinch Force Control in Voluntary-Closing Body-Powered Prostheses.

    Directory of Open Access Journals (Sweden)

    Mona Hichert

    Full Text Available It is generally asserted that reliable and intuitive control of upper-limb prostheses requires adequate feedback of prosthetic finger positions and pinch forces applied to objects. Body-powered prostheses (BPPs provide the user with direct proprioceptive feedback. Currently available BPPs often require high cable operation forces, which complicates control of the forces at the terminal device. The aim of this study is to quantify the influence of high cable forces on object manipulation with voluntary-closing prostheses.Able-bodied male subjects were fitted with a bypass-prosthesis with low and high cable force settings for the prehensor. Subjects were requested to grasp and transfer a collapsible object as fast as they could without dropping or breaking it. The object had a low and a high breaking force setting.Subjects conducted significantly more successful manipulations with the low cable force setting, both for the low (33% more and high (50% object's breaking force. The time to complete the task was not different between settings during successful manipulation trials.High cable forces lead to reduced pinch force control during object manipulation. This implies that low cable operation forces should be a key design requirement for voluntary-closing BPPs.

  19. PIXE characterization of tissues surrounding metallic prostheses coated with biological glasses

    International Nuclear Information System (INIS)

    Barbotteau, Y.; Irigaray, J.L.; Moretto, Ph.

    2004-01-01

    Biological glasses can be used as coatings for metallic prostheses in order to prevent corrosion. According to their composition, these glasses have different properties. We studied, in vivo, two glasses referred to as BVA and BVH. They are used as coatings of Ti6Al4V metallic implant. BVA glass disappears after 3 months of implantation and is replaced by bone. Prostheses initially coated by this glass have a larger osseous contact perimeter compared to the uncoated prostheses. This ensures a better anchoring of the implant and limits the micro-motions which cause wear debris. BVH glass keeps a constant composition during implantation and it is used like a layer which isolates metal implant from biological environment. In order to characterize the bony environment surrounding implants, we have used PIXE and RBS methods. This paper shows results of the behavior of bony tissue under micro-beam, the quality tests of new bone which replaces the BVA glass coating and the evaluation of corrosion effects. Titanium release in bony tissues begins when the metal surface of the prosthesis is exposed to biological fluids. After a few months of implantation, the titanium contamination is stabilized and remains localized within the first tens of micrometers of surrounding bone

  20. MR imaging of the knee

    International Nuclear Information System (INIS)

    Mink, J.H.

    1987-01-01

    There is increasing evidence that MR imaging of the knee can accurately evaluate the menisci and the cruciate and collateral ligaments with an accuracy equal to that of conventional anthrography. MR imaging can, as a simple test, definitively assess a wide spectrum of the causes of knee pain, including osteonecrosis/osteochondritis dissecans, chondral and bony fractures, abnormal plicae, and chondromalacia. The presentation focuses on the optimal imaging parameters that will ensure accuracy and maximize patient throughput. The etiology and significance of meniscal signal is discussed, and the criteria for an MR imaging-based diagnosis of meniscal tears, cruciate and collateral ligament and extensor mechanism abnormalities, osteonecrosis, and stress fractures are presented

  1. Total knee arthroplasty in ochronosis

    Directory of Open Access Journals (Sweden)

    Vaibhav G. Patel, MBBS

    2015-09-01

    Full Text Available Alkaptonuria is disorder of tyrosine metabolism due to deficiency of homogentisic oxidase characterized by excretion of homogentisic acid in urine, deposition of oxidized homogensitate pigments in connective tissues and articular cartilages (ochronosis. The result is dark pigmentation and weakening of the tissues resulting in chronic inflammation and osteoarthritis. Management of alkaptonuric ochronic osteoarthritis is usually symptomatic and replacements have comparable outcomes to osteoarthritis in patients without ochronosis. I report a case of a patient with ochronosis of knee treated with total knee replacement and report operative pearls for surgery in this rare disorder.

  2. RELIABILITY AND RESPONSIVENESS OF THE DANISH MODIFIED INTERNATIONAL KNEE DOCUMENTATION COMMITTEE SUBJECTIVE KNEE FORM FOR CHILDREN WITH KNEE DISORDERS

    DEFF Research Database (Denmark)

    Jacobsen, Julie Sandell; Knudsen, Pernille; Fynbo, Charlotte

    2016-01-01

    Introduction The modified international Knee Documentation Committee Subjective Knee Form (Pedi-IKDC) is a widely used patient-reported tool applicable for children with knee disorders ranging on a scale from 0-100. We aimed to translate the Pedi-IKDC Subjective Knee Form into Danish......, and furthermore to assess its reliability and responsiveness. Material and Methods The Pedi-IKDC Subjective Knee Form was translated to Danish according to international guidelines. Reliability was assessed with Bland Altman plots, standard error of measurement (SEM), Minimal Detectable Change (MDC) and the Intra....... Reliability and responsiveness were assessed in 50 children (median 15 years) referred to hospital due to different knee disorders. Results The SEM was 4.2 points and the MDC was 11.5 points. The ICC was 0.91 (0.9-1.0). The change score of the Pedi-IKDC Subjective Knee form was correlated to the external...

  3. LEAK study : design of a nationwide randomised controlled trial to find the best way to treat wound leakage after primary hip and knee arthroplasty

    NARCIS (Netherlands)

    Löwik, Claudia A M; Wagenaar, Frank-Christiaan; van der Weegen, Walter; Poolman, Rudolf W; Nelissen, Rob G H H; Bulstra, Sjoerd K; Pronk, Yvette; Vermeulen, Karin M; Wouthuyzen-Bakker, Marjan; van den Akker-Scheek, Inge; Stevens, Martin; Jutte, Paul C

    2017-01-01

    INTRODUCTION: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are highly successful treatment modalities for advanced osteoarthritis. However, prolonged wound leakage after arthroplasty is linked to prosthetic joint infection (PJI), which is a potentially devastating complication. On

  4. Ten-year in vivo wear measurement of a fully congruent mobile bearing unicompartmental knee arthroplasty.

    Science.gov (United States)

    Price, A J; Short, A; Kellett, C; Beard, D; Gill, H; Pandit, H; Dodd, C A F; Murray, D W

    2005-11-01

    Polyethylene particulate wear debris continues to be implicated in the aetiology of aseptic loosening following knee arthroplasty. The Oxford unicompartmental knee arthroplasty employs a spherical femoral component and a fully congruous meniscal bearing to increase contact area and theoretically reduce the potential for polyethylene wear. This study measures the in vivo ten-year linear wear of the device, using a roentgenstereophotogrammetric technique. In this in vivo study, seven medial Oxford unicompartmental prostheses, which had been implanted ten years previously were studied. Stereo pairs of radiographs were acquired for each patient and the films were analysed using a roentgen stereophotogrammetric analysis calibration and a computer-aided design model silhouette-fitting technique. Penetration of the femoral component into the original volume of the bearing was our estimate of linear wear. In addition, eight control patients were examined less than three weeks post-insertion of an Oxford prosthesis, where no wear would be expected. The control group showed no measured wear and suggested a system accuracy of 0.1 mm. At ten years, the mean linear wear rate was 0.02 mm/year. The results from this in vivo study confirm that the device has low ten-year linear wear in clinical practice. This may offer the device a survival advantage in the long term.

  5. Anthropometric difference of the knee on MRI according to gender and age groups.

    Science.gov (United States)

    Han, Hyuksoo; Oh, Sohee; Chang, Chong Bum; Kang, Seung-Baik

    2016-03-01

    The purpose of this study was to analyze the anthropometric data from MRI images that were obtained from the non-arthritic knees in Asian adults, and to identify the existence of morphologic differences between age groups. This cross-sectional study included knee MR images of 535 patients (273 males, 262 females) taken for the evaluation of soft-tissue injuries, excluding cases with cartilage defect and malalignment. The age, gender, height, and BMI were also assessed. The patients were grouped into three different 20-year age groups (20-39, 40-59, and 60-79). The MRI analysis was performed on the anthropometric parameters of distal femur and posterior tibial slope. Age-related differences were found in femoral width, distance from the distal and posterior cartilage surface to the medial/lateral epicondyle, medial posterior condylar offset (PCO), and posterior condylar angle (PCA) (all P age groups was found in most parameters, but not in PCA, distance from the posterior cartilage surface to the medial epicondyle, or medial tibial slope. We found anthropometric differences among age groups exist in most of distal femoral parameters, but not in posterior tibial slope. The results of this study can be used by manufacturers to modify prostheses to be suitable for the future Asian elderly population.

  6. Biomechanical evaluation of tibial bone adaptation after revision total knee arthroplasty: A comparison of different implant systems.

    Directory of Open Access Journals (Sweden)

    María Paz Quilez

    Full Text Available The best methods to manage tibial bone defects following total knee arthroplasty remain under debate. Different fixation systems exist to help surgeons reconstruct knee osseous bone loss (such as tantalum cones, cement, modular metal augments, autografts, allografts and porous metaphyseal sleeves However, the effects of the various solutions on the long-term outcome remain unknown. In the present work, a bone remodeling mathematical model was used to predict bone remodeling after total knee arthroplasty (TKA revision. Five different types of prostheses were analyzed: one with a straight stem; two with offset stems, with and without supplements; and two with sleeves, with and without stems. Alterations in tibia bone density distribution and implant Von Mises stresses were quantified. In all cases, the bone density decreased in the proximal epiphysis and medullary channels, and an increase in bone density was predicted in the diaphysis and around stem tips. The highest bone resorption was predicted for the offset prosthesis without the supplement, and the highest bone formation was computed for the straight stem. The highest Von Mises stress was obtained for the straight tibial stem, and the lowest was observed for the stemless metaphyseal sleeves prosthesis. The computational model predicted different behaviors among the five systems. We were able to demonstrate the importance of choosing an adequate revision system and that in silico models may help surgeons choose patient-specific treatments.

  7. Long-term stress distribution patterns of the ankle joint in varus knee alignment assessed by computed tomography osteoabsorptiometry.

    Science.gov (United States)

    Onodera, Tomohiro; Majima, Tokifumi; Iwasaki, Norimasa; Kamishima, Tamotsu; Kasahara, Yasuhiko; Minami, Akio

    2012-09-01

    The stress distribution of an ankle under various physiological conditions is important for long-term survival of total ankle arthroplasty. The aim of this study was to measure subchondral bone density across the distal tibial joint surface in patients with malalignment/instability of the lower limb. We evaluated subchondral bone density across the distal tibial joint in patients with malalignment/instability of the knee by computed tomography (CT) osteoabsorptiometry from ten ankles as controls and from 27 ankles with varus deformity/instability of the knee. The quantitative analysis focused on the location of the high-density area at the articular surface, to determine the resultant long-term stress on the ankle joint. The area of maximum density of subchondral bone was located in the medial part in all subjects. The pattern of maximum density in the anterolateral area showed stepwise increases with the development of varus deformity/instability of the knee. Our results should prove helpful for designing new prostheses and determining clinical indications for total ankle arthroplasty.

  8. T2 black lesions on routine knee MRI: differential considerations

    International Nuclear Information System (INIS)

    Wadhwa, Vibhor; Cho, Gina; Moore, Daniel; Pezeshk, Parham; Coyner, Katherine; Chhabra, Avneesh

    2016-01-01

    The majority of abnormal findings or lesions on T2-weighted fast spin-echo (FSE) magnetic resonance imaging (MRI) are hyperintense due to increased perfusion or fluid content, such as infections, tumours or synovitis. Hypointense lesions on T2-weighted images (both fat-suppressed and non-fat-suppressed) are less common and can sometimes be overlooked. Such lesions have limited differential diagnostic possibilities, and include vacuum phenomenon, loose body, tenosynovial giant cell tumour, rheumatoid arthritis, haemochromatosis, gout, amyloid, chondrocalcinosis, hydroxyapetite deposition disease, lipoma arborescens, arthrofibrosis and iatrogenic lesions. These lesions often show characteristic appearances and predilections in the knee. In this article, the authors describe the MRI features of hypointense T2 lesions on routine knee MRI and outline a systematic diagnostic approach towards their evaluation. (orig.)

  9. Anterior Knee Pain in Children and Adolescents: Overview and Management.

    Science.gov (United States)

    Slotkin, Steven; Thome, Andrew; Ricketts, Cassandra; Georgiadis, Andrew; Cruz, Aristides I; Seeley, Mark

    2018-05-01

    Anterior knee pain (AKP) is a common presenting complaint for pediatricians and orthopaedic surgeons and is often seen in young athletes. AKP is multifactorial and has a broad differential diagnosis. The growth changes, biomechanics, and anatomy around the knee add to the complexity of diagnosis and treatment of AKP. Common causes of AKP include Osgood-Schlatter's disease, patellar tendinitis, and patellofemoral instability. In the diagnosis of AKP, it is important to rule out serious and morbid causes of pain, including infection and tumor. It is crucial to complete a detailed history and physical examination and obtain appropriate imaging studies. In general, the majority of patients will respond to nonoperative measures targeted to correct neuromuscular control and kinetic chain dysfunction. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  10. Association of knee confidence with pain, knee instability, muscle strength, and dynamic varus-valgus joint motion in knee osteoarthritis.

    Science.gov (United States)

    Skou, Søren T; Wrigley, Tim V; Metcalf, Ben R; Hinman, Rana S; Bennell, Kim L

    2014-05-01

    To investigate associations between self-reported knee confidence and pain, self-reported knee instability, muscle strength, and dynamic varus-valgus joint motion during walking. We performed a cross-sectional analysis of baseline data from 100 participants with symptomatic and radiographic medial tibiofemoral compartment osteoarthritis (OA) and varus malalignment recruited for a randomized controlled trial. The extent of knee confidence, assessed using a 5-point Likert scale item from the Knee Injury and Osteoarthritis Outcome Score, was set as the dependent variable in univariable and multivariable ordinal regression, with pain during walking, self-reported knee instability, quadriceps strength, and dynamic varus-valgus joint motion during walking as independent variables. One percent of the participants were not troubled with lack of knee confidence, 17% were mildly troubled, 50% were moderately troubled, 26% were severely troubled, and 6% were extremely troubled. Significant associations were found between worse knee confidence and higher pain intensity, worse self-reported knee instability, lower quadriceps strength, and greater dynamic varus-valgus joint motion. The multivariable model consisting of the same variables significantly accounted for 24% of the variance in knee confidence (P knee confidence is associated with higher pain, worse self-reported knee instability, lower quadriceps muscle strength, and greater dynamic varus-valgus joint motion during walking. Since previous research has shown that worse knee confidence is predictive of functional decline in knee OA, addressing lack of knee confidence by treating these modifiable impairments could represent a new therapeutic target. Copyright © 2014 by the American College of Rheumatology.

  11. Knee extension torque variability after exercise in ACL reconstructed knees.

    Science.gov (United States)

    Goetschius, John; Kuenze, Christopher M; Hart, Joseph M

    2015-08-01

    The purpose of this study was to compare knee extension torque variability in patients with ACL reconstructed knees before and after exercise. Thirty two patients with an ACL reconstructed knee (ACL-R group) and 32 healthy controls (control group) completed measures of maximal isometric knee extension torque (90° flexion) at baseline and following a 30-min exercise protocol (post-exercise). Exercise included 30-min of repeated cycles of inclined treadmill walking and hopping tasks. Dependent variables were the coefficient of variation (CV) and raw-change in CV (ΔCV): CV = (torque standard deviation/torque mean x 100), ΔCV = (post-exercise - baseline). There was a group-by-time interaction (p = 0.03) on CV. The ACL-R group demonstrated greater CV than the control group at baseline (ACL-R = 1.07 ± 0.55, control = 0.79 ± 0.42, p = 0.03) and post-exercise (ACL-R = 1.60 ± 0.91, control = 0.94 ± 0.41, p = 0.001). ΔCV was greater (p = 0.03) in the ACL-R group (0.52 ± 0.82) than control group (0.15 ± 0.46). CV significantly increased from baseline to post-exercise (p = 0.001) in the ACL-R group, while the control group did not (p = 0.06). The ACL-R group demonstrated greater knee extension torque variability than the control group. Exercise increased torque variability more in the ACL-R group than control group. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  12. [Overuse injury syndromes of the knee].

    Science.gov (United States)

    Pećina, M; Bojanić, I; Haspl, M

    2001-12-01

    Overuse injuries are frequent in the knee joint. The reason for this is that the knee joint is engaged in all sports activities. Furthermore, the joint area has numerous attachment points for muscles and tendons and numerous bursae. Another reason is that the specific joint between the patella and femur (patellofemoral joint) constitutes a part of the knee joint. Speaking in general terms, all overuse injuries in the knee joint can be divided in four groups according to the aspect: anterior aspect--patellofemoral pain syndrome, patellar tendinitis (jumper's knee), Osgood-Schlatter disease, Sinding Larson Johanson disease, stress fracture of the patella, fat pad syndrome; medial aspect--plica syndrome, semimembranosus tendinitis, pes anserinus tendinitis (bursitis), breaststroker's knee, medial retinaculitis; lateral aspect--Iliotibial band friction syndrome (runner's knee), Popliteal Tendinitis, Bicipital tendinitis; posterior aspect--fabellitis, medial gastrocnemius strain. There are numerous possible reasons for pain caused by overuse injuries around the knee joint, but two are the most frequent: patellar tendinitis (jumper's knee) and Iliotibial band friction syndrome (runner's knee). This paper gives a brief overview of overuse injuries of the knee joint including their definition, anatomy, aetiology, clinical symptoms and signs, and non-operative and surgical treatment.

  13. High infection control rate and function after routine one-stage exchange for chronically infected TKA.

    Science.gov (United States)

    Jenny, Jean-Yves; Barbe, Bruno; Gaudias, Jeannot; Boeri, Cyril; Argenson, Jean-Noël

    2013-01-01

    Many surgeons consider two-stage exchange the gold standard for treating chronic infection after TKA. One-stage exchange is an alternative for infection control and might provide better knee function, but the rates of infection control and levels of function are unclear. We asked whether a one-stage exchange protocol would lead to infection control rates and knee function similar to those after two-stage exchange. We followed all 47 patients with chronically infected TKAs treated with one-stage exchange between July 2004 and February 2007. We monitored for recurrence of infection and obtained Knee Society Scores. We followed patients a minimum of 3 years or until death or infection recurrence. Three of the 47 patients (6%) experienced a persistence or recurrence of the index infection with the same pathogen isolated. Three patients (6%) had control of the index infection but between 6 and 17 months experienced an infection with another pathogen. The 3-year survival rates were 87% for being free of any infection and 91% for being healed of the index infection. Twenty-five of the 45 patients (56%) had a Knee Society Score of more than 150 points. While routine one-stage exchange was not associated with a higher rate of infection recurrence failure, knee function was not improved compared to that of historical patients having two-stage exchange. One stage-exchange may be a reasonable alternative in chronically infected TKA as a more convenient approach for patients without the risks of two operations and hospitalizations and for reducing costs. The ideal one stage-exchange candidate should be identified in future studies.

  14. Composition of The Knee Index, a novel three-dimensional biomechanical index for knee joint load, in subjects with mild to moderate knee osteoarthritis

    DEFF Research Database (Denmark)

    Clausen, Brian; Andriacchi, Tom; Nielsen, Dennis Brandborg

    Background Knee joint load is an important factor associated with progression of knee osteoarthritis. To provide an overall understanding of knee joint loading, the Knee Index (KI) has been developed to include moments from all three planes (frontal, sagittal and transversal). However, before KI...... index of joint load for the knee, in patients with mild to moderate knee osteoarthritis. Methods The contribution of frontal, sagittal and transversal plane knee moments to KI was investigated in 24 subjects (13 women, age: 58 ± 7.6 years, BMI: 27.1 ± 3.0) with clinically diagnosed mild to moderate knee...... kinematics (i.e. the knee adduction moment), and secondarily the sagittal plane kinematics (i.e. the knee flexion moment). This holds promise for using KI in clinical trials since both frontal and sagittal knee joint moments have been suggested to be associated with the knee osteoarthritis disease...

  15. Knee motion variability in patients with knee osteoarthritis: the effect of self-reported instability

    Science.gov (United States)

    Gustafson, Jonathan A.; Robinson, Megan E.; Fitzgerald, G. Kelley; Tashman, Scott; Farrokhi, Shawn

    2015-01-01

    Background Knee osteoarthritis has been previously associated with a stereotypical knee-stiffening gait pattern and reduced knee joint motion variability due to increased antagonist muscle co-contractions and smaller utilized arc of motion during gait. However, episodic self-reported instability may be a sign of excessive motion variability for a large subgroup of patients with knee osteoarthritis. The objective of this work was to evaluate the differences in knee joint motion variability during gait in patients with knee osteoarthritis with and without self-reported instability compared to a control group of older adults with asymptomatic knees. Methods Forty-three subjects, 8 with knee osteoarthritis but no reports of instability (stable), 11 with knee osteoarthritis and self-reported instability (unstable), and 24 without knee osteoarthritis or instability (control) underwent Dynamic Stereo X-ray analysis during a decline gait task on a treadmill. Knee motion variability was assessed using parametric phase plots during the loading response phase of decline gait. Findings The stable group demonstrated decreased sagittal-plane motion variability compared to the control group (p=0.04), while the unstable group demonstrated increased sagittal-plane motion variability compared to the control (p=0.003) and stable groups (pknee motion variability in patients with knee osteoarthritis without self-reported instability supports previous research. However, presence of self-reported instability is associated with increased knee motion variability in patients with knee osteoarthritis and warrants further investigation. PMID:25796536

  16. Wireless link and microelectronics design for retinal prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wentai [Univ. of California, Santa Cruz, CA (United States)

    2012-02-29

    This project focuses on delivering power and data to the artificial retinal implant inside the eye and the implant microstimulator electronics which delivers the current pulses to stimulate the retinal layer to elicit visual perception. Since the use of invasive means such as tethering wires to transmit power and data results in discomfort to the patients which could eventually cause infection due to the abrasion caused by the wire and contact of the internals of the eye to the external environment, a completely wireless approach is used to transfer both power and data. Power is required inside the eye for the microelectronic implant which uses a dual voltage supply scheme (positive and negative) to deliver biphasic (anodic and cathodic) current pulses. Data in the form of digital bits from the data transmitter external to the eye, carries information about the amplitude, phase width, interphase delay, stimulation sequence for each implant electrode. The data receiver unit decodes the digital stream and the microstimulator unit generates the appropriate current stimuli. Since the external unit consisting of the power transmitter can experience coupling a variation with the power receiver due to the patient’s movements, a closed loop approach is used which varies the transmitted power dynamically to automatically compensate for such movements. This report presents the salient features of this research activities and results.

  17. The Identification of Influential Factors in Knee Osteoarthritis and Its Prevalence among Referals to Orthopedic Clinics in Tehran

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Ebrahim Mousavi

    2001-06-01

    observations such as joint atrophy, sub-cartilaginous bone sclerosis, cyst formation, osteophyte formation and biomechanical abnormality in the knee, all have significant effects on knee osteoarthritis. Factors including height, weight, knee trauma, knee infection record, using chairs, pharmaceutical treatment, health system type, doing exercises, and treatment non-pharmaceutical also have an impact on this condition.

  18. Investigation of the dosimetric accuracy of the isocenter shifting method in prostate cancer patients with and without hip prostheses

    International Nuclear Information System (INIS)

    Hwang, Andrew B.; Kinsey, Erica; Xia Ping

    2009-01-01

    Purpose: The use of image guided radiation therapy (IGRT) enables compensation for prostate movement by shifting the treatment isocenter to track the prostate on a daily basis. Although shifting the isocenter can alter the source to skin distances (SSDs) and the effective depth of the target volume, it is commonly assumed that these changes have a negligible dosimetric effect, and therefore, the number of monitor units delivered is usually not adjusted. However, it is unknown whether or not this assumption is valid for patient with hip prostheses, which frequently contain high density materials. Methods: The authors conducted a retrospective study to investigate dosimetric effect of the isocenter shifting method for prostate patients with and without hip prostheses. For each patient, copies of the prostate volume were shifted by up to 1.5 cm from the original position to simulate prostate movement in 0.5 cm increments. Subsequently, 12 plans were created for each patient by creating a copy of the original plan for each prostate position with the isocenter shifted to track the position of the shifted prostate. The dose to the prostate was then recalculated for each plan. For patients with hip prostheses, plans were created both with and without lateral beam angles entering through the prostheses. Results: Without isocenter shifting to compensate for prostate motion of 1.5 cm, the dose to the 95% of the prostate (D-95%) changed by an average of 30% and by up to 64%. This was reduced to less than 3% with the isocenter shifting method. It was found that for patients with hip prostheses, this technique worked best for treatment plans that avoided beam angles passing through the prostheses. Conclusions: The results demonstrated that the isocenter shifting method can accurately deliver dose to the prostate even in patients with hip prostheses.

  19. Dose attenuation effect of hip prostheses in a 9-MV photon beam. Commercial treatment planning system versus Monte Carlo calculations

    International Nuclear Information System (INIS)

    Mesbahi, A.; Nejad, F.S.

    2007-01-01

    The purpose of this study was to investigate the dosimetric effect of various hip prostheses on pelvis lateral fields treated by a 9-MV photon beam using Monte Carlo (MC) and effective path-length (EPL) methods. The head of the Neptun 10 pc linac was simulated using the MCNP4C MC code. The accuracy of the MC model was evaluated using measured dosimetric features including depth dose values and dose profiles in a water phantom. The Alfard treatment planning system (TPS) was used for EPL calculations. A virtual water phantom with dimensions of 30 x 30 x 30 cm 3 and a cube with dimensions of 4 x 4 x 4 cm 3 made of various metals centered in 12 cm depth was used for MC and EPL calculations. Various materials including titanium, Co-Cr-Mo, and steel alloys were used as hip prostheses. Our results showed significant attenuation in absorbed dose for points after and inside the prostheses. Attenuations of 32%, 54% and 55% were seen for titanium, Co-Cr-Mo, and steel alloys, respectively, at a distance of 5 cm from the prosthesis. Considerable dose increase (up to 18%) was found at the water-prosthesis interface due to back-scattered electrons using the MC method. The results of EPL calculations for the titanium implant were comparable to the MC calculations. This method, however, was not able to predict the interface effect or calculate accurately the absorbed dose in the presence of the Co-Cr-Mo and steel prostheses. The dose perturbation effect of hip prostheses is significant and cannot be predicted accurately by the EPL method for Co-Cr-Mo or steel prostheses. The use of MC-based TPS is recommended for treatments requiring fields passing through hip prostheses. (author)

  20. Osteonecrosis in HIV-infected patients

    International Nuclear Information System (INIS)

    Lama, E. de; Narvaez, J. A.; Roca, Y.; Pellicer, J. M.

    2001-01-01

    We present two cases of avascular osteonecrosis, one involving the knees and the other the hips, in patients with human immunodeficiency virus (HIV) infection who met the criteria for acquired immunodeficiency syndrome (AIDS). We review the literature concerning this rare complication of HIV infection, focussing especially on the clinical and radiological features and its possible etiopathogenesis. (Author) 30 refs

  1. Radiographic assessment of knee-ankle alignment after total knee arthroplasty for varus and valgus knee osteoarthritis.

    Science.gov (United States)

    Gao, Fuqiang; Ma, Jinhui; Sun, Wei; Guo, Wanshou; Li, Zirong; Wang, Weiguo

    2017-01-01

    There are unanswered questions about knee-ankle alignment after total knee arthroplasty (TKA) for varus and valgus osteoarthritis (OA) of the knee. The aim of this retrospective study was to assess knee-ankle alignment after TKA. The study consisted of 149 patients who had undergone TKA due to varus and valgus knee OA. The alignment and angles in the selected knees and ankles were measured on full-length standing anteroposterior radiographs, both pre-operatively and post-operatively. The paired t-test and Pearson's correlation tests were used for statistical analysis. The results showed that ankle alignment correlated with knee alignment both pre-operatively and postoperatively (Pknee was corrected (Pknee-ankle alignment on the non-operative side (P>0.05). These findings indicated that routine TKA could correct the varus or valgus deformity of a knee, and improve the tilt of the ankle. Ankle alignment correlated with knee alignment both pre-operatively and postoperatively. Both pre-operative knee and ankle malalignment can be simultaneously corrected following TKA. Level III. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Knee injury and obesity in patients undergoing total knee replacement: a retrospective study in 115 patients

    DEFF Research Database (Denmark)

    Jensen, Claus Hjorth; Rofail, S

    1999-01-01

    The prevalence of obesity and previous knee injury was assessed in a retrospective study of 115 patients under-going total knee replacement due to osteoarthritis. Obesity was considered a contributing factor in the development of osteoarthritis in 37% of the patients, and 33% of the patients had...... had an injury to the knee in question. Unilateral osteoarthritis was significantly more frequent than bilateral osteoarthritis among patients with a history of previous knee injury. The association of previous injury to the knee and unilateral osteoarthritis was stronger in men than women. Aggressive...... treatment of patients with knee injuries seems warranted....

  3. Ten- to 15-year results of the Oxford Phase III mobile unicompartmental knee arthroplasty: a prospective study from a non-designer group.

    Science.gov (United States)

    Lisowski, L A; Meijer, L I; Bekerom, M P J van den; Pilot, P; Lisowski, A E

    2016-10-01

    The interest in unicompartmental knee arthroplasty (UKA) for medial osteoarthritis has increased rapidly but the long-term follow-up of the Oxford UKAs has yet to be analysed in non-designer centres. We have examined our ten- to 15-year clinical and radiological follow-up data for the Oxford Phase III UKAs. Between January 1999 and January 2005 a total of 138 consecutive Oxford Phase III arthroplasties were performed by a single surgeon in 129 patients for medial compartment osteoarthritis (71 right and 67 left knees, mean age 72.0 years (47 to 91), mean body mass index 28.2 (20.7 to 52.2)). Both clinical data and radiographs were prospectively recorded and obtained at intervals. Of the 129 patients, 32 patients (32 knees) died, ten patients (12 knees) were not able to take part in the final clinical and radiological assessment due to physical and mental conditions, but via telephone interview it was confirmed that none of these ten patients (12 knees) had a revision of the knee arthroplasty. One patient (two knees) was lost to follow-up. The mean follow-up was 11.7 years (10 to 15). A total of 11 knees (8%) were revised. The survival at 15 years with revision for any reason as the endpoint was 90.6% (95% confidence interval (CI) 85.2 to 96.0) and revision related to the prosthesis was 99.3% (95% CI 97.9 to 100). The mean total Knee Society Score was 47 (0 to 80) pre-operatively and 81 (30 to 100) at latest follow-up. The mean Oxford Knee Score was 19 (12 to 40) pre-operatively and 42 (28 to 55) at final follow-up. Radiolucency beneath the tibial component occurred in 22 of 81 prostheses (27.2%) without evidence of loosening. This study supports the use of UKA in medial compartment osteoarthritis with excellent long-term functional and radiological outcomes with an excellent 15-year survival rate. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):41-7. ©2016 Lisowski et al.

  4. Adipose Derived Stromal Cell (ADSC) Injections for Pain Management of Osteoarthritis in the Human Knee Joint.

    Science.gov (United States)

    Fodor, Peter B; Paulseth, Stephen G

    2016-02-01

    This safety and feasibility study used autologous adipose-derived stromal vascular cells (the stromal vascular fraction [SVF] of adipose tissue), to treat 8 osteoarthritic knees in 6 patients of grade I to III (K-L scale) with initial pain of 4 or greater on a 10-point Visual Analog Scale (VAS). The primary objective of the study was evaluation of the safety of intra-articular injection of SVF. The secondary objective was to assess initial feasibility for reduction of pain in osteoarthritic knees. Adipose-derived SVF cells were obtained through enzymatic disaggregation of lipoaspirate, resuspension in 3 mL of Lactated Ringer's Solution, and injection directly into the intra-articular space of the knee, with a mean of 14.1 million viable, nucleated SVF cells per knee. Metrics included monitoring of adverse events and preoperative to postoperative changes in the Western Ontario and McMaster Universities Arthritis Index (WOMAC), the VAS pain scale, range of motion (ROM), timed up-and-go (TUG), and MRI. No infections, acute pain flares, or other adverse events were reported. At 3-months postoperative, there was a statistically significant improvement in WOMAC and VAS scores (P knee pain. Autologous SVF was shown to be safe and to present a new potential therapy for reduction of pain for osteoarthritis of the knee. LEVEL OF EVIDENCE 4: Therapeutic. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  5. An electromechanical swing-phase-controlled prosthetic knee joint for conversion of physiological energy to electrical energy: feasibility study.

    Science.gov (United States)

    Andrysek, Jan; Chau, Gilbert

    2007-12-01

    Microprocessor-controlled prostheses facilitate a more natural and efficient gait for individuals with above-knee amputations by continually adjusting the level of swing-phase damping. One caveat associated with these technologies is that the user must charge the onboard batteries on a daily basis. It is, therefore, the aim of this study to examine the feasibility of using an electromechanical system to provide prosthetic swing-phase damping and, concomitantly, the function of converting physiological energy that is normally dissipated during the swing phase, to electrical energy. Gait data from a single subject and data from a kinematic simulator were used to develop an empirical model. The findings in this study indicate that an electromagnetic system has appropriate characteristics for use in swing-phase control and also has the potential to recover energy under particular conditions.

  6. Immediate effect of Masai Barefoot Technology shoes on knee joint moments in women with knee osteoarthritis.

    Science.gov (United States)

    Tateuchi, Hiroshige; Taniguchi, Masashi; Takagi, Yui; Goto, Yusuke; Otsuka, Naoki; Koyama, Yumiko; Kobayashi, Masashi; Ichihashi, Noriaki

    2014-01-01

    Footwear modification can beneficially alter knee loading in patients with knee osteoarthritis. This study evaluated the effect of Masai Barefoot Technology shoes on reductions in external knee moments in patients with knee osteoarthritis. Three-dimensional motion analysis was used to examine the effect of Masai Barefoot Technology versus control shoes on the knee adduction and flexion moments in 17 women (mean age, 63.6 years) with radiographically confirmed knee osteoarthritis. The lateral and anterior trunk lean values, knee flexion and adduction angles, and ground reaction force were also evaluated. The influence of the original walking pattern on the changes in knee moments with Masai Barefoot Technology shoes was evaluated. The knee flexion moment in early stance was significantly reduced while walking with the Masai Barefoot Technology shoes (0.25±0.14Nm/kgm) as compared with walking with control shoes (0.30±0.19 Nm/kgm); whereas the knee adduction moment showed no changes. Masai Barefoot Technology shoes did not increase compensatory lateral and anterior trunk lean. The degree of knee flexion moment in the original walking pattern with control shoes was correlated directly with its reduction when wearing Masai Barefoot Technology shoes by multiple linear regression analysis (adjusted R2=0.44, Pknee flexion moment during walking without increasing the compensatory trunk lean and may therefore reduce external knee loading in women with knee osteoarthritis. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. A systematic review of endoprosthetic replacement for non-tumour indications around the knee joint.

    Science.gov (United States)

    Korim, Muhammad T; Esler, Colin N A; Reddy, Venuthurla R M; Ashford, Robert U

    2013-12-01

    Endoprosthetic replacement (EPR) for limb salvage is an established treatment modality for orthopaedic malignancies around the knee. Increasingly, they are being used for non-tumour indications such as fractures, bone loss associated with aseptic loosening, septic loosening and ligament insufficiencies. We reviewed the evolution and biomechanics of knee EPRs. MEDLINE was searched using the PubMed interface to identify relevant studies pertaining to the use of knee EPRs in non-tumour conditions. Failures, mortality and knee scores were the main outcome measures. Subgroup analysis in the non-tumour conditions was also performed. There were nine studies with an average follow-up of 3.3years (Range 1-5years) describing 241 EPRs used in non-tumour conditions. Re-operation for any reason occurred in 17% (41/241) of cases. The most common complication was infection (15%) followed by aseptic loosening (5%) and periprosthetic fractures (5%). The mortality rate averaged 22%. Infected knee arthroplasties were less likely to have a successful outcome when salvaged with an EPR with failure rates up to 33%. Endoprosthetic replacement is a limb salvage option when other surgical options are unfeasible, especially in low demand elderly patients with limited life expectancy. They have low rates of failure in the medium term. Level 1. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Customized versus Patient-Sized Cruciate-Retaining Total Knee Arthroplasty: An In Vivo Kinematics Study Using Mobile Fluoroscopy.

    Science.gov (United States)

    Zeller, Ian M; Sharma, Adrija; Kurtz, William B; Anderle, Mathew R; Komistek, Richard D

    2017-04-01

    Historically, knee arthroplasties have been designed using average patient anatomy. Recent advances in imaging and manufacturing have facilitated the development of customized prostheses designed to fit the unique shape of individual patients. The purpose of this study is to determine if improving implant design through customized total knee arthroplasty (TKA) improves kinematic function. Using state-of-the-art mobile fluoroscopy, tibiofemoral kinematics were analyzed for 24 subjects with a customized individually made (CIM), cruciate-retaining TKA, and 14 subjects having an asymmetric condylar cruciate-retaining TKA. Subjects performed a weight-bearing deep knee bend and a rise from a seated position. Each patient was evaluated for weight-bearing range of motion, femorotibial translation, femorotibial axial rotation, and condylar liftoff occurrence. Subjects having a CIM TKA experienced greater weight-bearing knee flexion compared with the traditional posterior cruciate-retaining (PCR) TKA design. During flexion, the CIM TKA subjects consistently exhibited more posterior femoral rollback than the traditional PCR TKA subjects. The CIM TKA was found to have statistically greater axial rotation compared with the traditional PCR TKA (P = .05). Of note, only the CIM TKA patients experienced femoral internal rotation at full extension, as exhibited in a normal knee. Compared with the traditional PCR TKA, the CIM TKAs demonstrated minimal occurrences of paradoxical sliding and reverse rotation during flexion and extension. The CIM TKA subjects showed minimal liftoff and hence better stability in earlyflexion to midflexion compared with the traditional PCR subjects. The CIM TKA demonstrated kinematics more similar to a normal knee. Therefore, using customized implant technology through CIM TKA designs affords benefits including more normal motion compared with a traditional PCR TKA. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Arthroscopic knee anatomy in young achondroplasia patients

    Science.gov (United States)

    del Pilar Duque Orozco, M.; Record, N. C.; Rogers, K. J; Bober, M. B.; Mackenzie, W. G.; Atanda, A.

    2017-01-01

    Abstract Purpose Achondroplasia is the most common form of skeletal dysplasia, affecting more than 250 000 individuals worldwide. In these patients, the developing knee undergoes multiple anatomical changes. The purpose of this study was to characterise the intra-articular knee anatomy in children with achondroplasia who underwent knee arthroscopy. Methods Records of achondroplasia patients who underwent knee arthroscopy between 2009 and 2014 were reviewed. Demographic data, operative reports, follow-up notes, MRI and arthroscopy images were reviewed. Bony, cartilaginous and ligamentous changes were noted. The trochlea sulcus angle was measured from intra-operative arthroscopic images. Results A total of 12 knee arthroscopies in nine patients were performed. The mean age at surgery was 16.9 years (12 to 22). In all patients, the indication for surgery was knee pain and/or mechanical symptoms that were refractory to non-operative treatment. Three anatomical variations involving the distal femur were found in all knees: a deep femoral trochlea; a high A-shaped intercondylar notch; and a vertically oriented anterior cruciate ligament. The average trochlea sulcus angle measured 123°. Pathology included: synovial plica (one knee); chondral lesions (three knees); discoid lateral meniscus (11 knees); and meniscal tears (six knees). All patients were pain-free and returned to normal activity at final follow-up. Conclusion Children with achondroplasia have characteristic distal femur anatomy noted during knee arthroscopy. These variations should be considered normal during knee arthroscopy in these patients. Arthroscopic findings confirmed previous MRI findings within this specific population with the addition of a deep trochlear groove which was not previously reported. PMID:28828058

  10. The role of knee joint moments and knee impairments on self-reported knee pain during gait in patients with knee osteoarthritis.

    Science.gov (United States)

    O'Connell, Megan; Farrokhi, Shawn; Fitzgerald, G Kelley

    2016-01-01

    The association between high mechanical knee joint loading during gait with onset and progression of knee osteoarthritis has been extensively studied. However, less attention has been given to risk factors related to increased pain during gait. The purpose of this study was to evaluate knee joint moments and clinical characteristics that may be associated with gait-related knee pain in patients with knee osteoarthritis. Sixty-seven participants with knee osteoarthritis were stratified into three groups of no pain (n=18), mild pain (n=27), or moderate/severe pain (n=22) based on their self-reported symptoms during gait. All participants underwent three-dimensional gait analysis. Quadriceps strength, knee extension range of motion, radiographic knee alignment and self-reported measures of global pain and function were also quantified. The moderate/severe pain group demonstrated worse global pain (Pknee flexion moments during the midstance phase of gait compared to the no pain group (P=0.02). Additionally, the moderate/severe pain group demonstrated greater varus knee malalignment (P=0.009), which was associated with higher weight acceptance peak knee adduction moments (P=0.003) and worse global pain (P=0.003) and physical function scores (P=0.006). Greater knee flexion moment is present during the midstance phase of gait in patients with knee osteoarthritis and moderate/severe pain during gait. Additionally, greater varus malalignment may be a sign of increased global knee joint dysfunction that can influence many activities of daily living beyond gait. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Radial Force: An Underestimated Parameter in Oversizing Transcatheter Aortic Valve Replacement Prostheses: In Vitro Analysis with Five Commercialized Valves.

    Science.gov (United States)

    Egron, Sandrine; Fujita, Buntaro; Gullón, Lucía; Désirée, Pott; Schmitz-Rode, Thomas; Ensminger, Stephan; Steinseifer, Ulrich

    2017-09-05

    The goal is to inform in depth on transcatheter aortic valve replacement (TAVR) prosthesis mechanical behavior, depending on frame type, design, and size, and how it crucially impacts the oversizing issue in clinical use, and ultimately the procedure outcome. Transcatheter aortic valve replacement is an established therapy for high-risk patients suffering from aortic stenosis, and the indication for TAVR is progressively expanding to intermediate-risk patients. Choosing the optimal oversizing degree is crucial to safely anchor the TAVR valve-which involves limiting the risks for embolism, aortic regurgitation, conductance disturbance, or annulus rupture-and to increase the valve prosthesis performance. The radial force (RF) profiles of five TAVR prostheses were measured in vitro: the CoreValve 23 and 26 (Medtronic, MN), the Acurate neo S (Symetis, Switzerland), and the SAPIEN XT 23 and 26 (Edwards Lifesciences, CA). Measurements were run with the RX Machine equipment (Machine Solutions Inc., AZ), which is used in ISO standard tests for intravascular stents. Test protocols were adapted for TAVR prostheses. With the prostheses RF profiles' results, mechanical behavior differences could be described and discussed in terms of oversizing strategy and clinical impact for all five valves. Besides, crossing the prostheses' RF profiles with their recommended size windows made the assessment of borderline size cases possible and helped analyze the risks when accurate measurement of patient aortic annulus proves difficult. The prostheses' RF profiles bring new support in clinical decision-making for valve type and size in patients.

  12. Reduction of metal artifacts from hip prostheses on CT images of the pelvis: value of iterative reconstructions.

    Science.gov (United States)

    Morsbach, Fabian; Bickelhaupt, Sebastian; Wanner, Guido A; Krauss, Andreas; Schmidt, Bernhard; Alkadhi, Hatem

    2013-07-01

    To assess the value of iterative frequency split-normalized (IFS) metal artifact reduction (MAR) for computed tomography (CT) of hip prostheses. This study had institutional review board and local ethics committee approval. First, a hip phantom with steel and titanium prostheses that had inlays of water, fat, and contrast media in the pelvis was used to optimize the IFS algorithm. Second, 41 consecutive patients with hip prostheses who were undergoing CT were included. Data sets were reconstructed with filtered back projection, the IFS algorithm, and a linear interpolation MAR algorithm. Two blinded, independent readers evaluated axial, coronal, and sagittal CT reformations for overall image quality, image quality of pelvic organs, and assessment of pelvic abnormalities. CT attenuation and image noise were measured. Statistical analysis included the Friedman test, Wilcoxon signed-rank test, and Levene test. Ex vivo experiments demonstrated an optimized IFS algorithm by using a threshold of 2200 HU with four iterations for both steel and titanium prostheses. Measurements of CT attenuation of the inlays were significantly (P algorithm for CT image reconstruction significantly reduces metal artifacts from hip prostheses, improves the reliability of CT number measurements, and improves the confidence for depicting pelvic abnormalities.

  13. Sport prostheses and prosthetic adaptations for the upper and lower limb amputees: an overview of peer reviewed literature.

    Science.gov (United States)

    Bragaru, Mihai; Dekker, Rienk; Geertzen, Jan H B

    2012-09-01

    Sport prostheses are used by both upper- and lower-limb amputees while participating in sports and other physical activities. Although the number of these devices has increased over the past decade, no overview of the peer reviewed literature describing them has been published previously. Such an overview will allow specialists to choose appropriate prostheses based on available scientific evidence rather than on personal experience or preference. To provide an overview of the sport prostheses as they are described by the papers published in peer reviewed literature. Literature review. Four electronic databases were searched using free text and Medical Subject Headings (MESH) terms. Papers were included if they concerned a prosthesis or a prosthetic adaptation used in sports. Papers were excluded if they did not originate from peer reviewed sources, if they concerned prostheses for body parts other than the upper or lower limbs, if they concerned amputations distal to the wrist or ankle, or if they were written in a language other than English. Twenty-four papers were included in this study. The vast majority contained descriptive data and consisted of expert opinions and technical notes. Data concerning the energy efficiency, technical characteristics and special mechanical properties of prostheses or prosthetic adaptations for sports, other than running, are scarce.

  14. Self-reported previous knee injury and low knee function increase knee injury risk in adolescent female football

    DEFF Research Database (Denmark)

    Clausen, Mikkel Bek; Tang, L; Zebis, M K

    2016-01-01

    with low KOOS subscale scores (Sport/Recreational (RR: 2.2) and Quality of Life (RR: 3.0) (P time-loss knee...... questionnaires were collected at baseline. Time-loss knee injuries and football exposures were reported weekly by answers to standardized text-message questions, followed by injury telephone interviews. A priori, self-reported previous knee injury and low KOOS subscale scores (... as independent variables in the risk factor analyses. The study showed that self-reported previous knee injury significantly increased the risk of time-loss knee injury [relative risk (RR): 3.65, 95% confidence (CI) 1.73-7.68; P time-loss knee injury was also significantly increased in players...

  15. Kinematic analysis of anterior cruciate ligament reconstruction in total knee arthroplasty

    OpenAIRE

    Liu, Hua-Wei; Ni, Ming; Zhang, Guo-Qiang; Li, Xiang; Chen, Hui; Zhang, Qiang; Chai, Wei; Zhou, Yong-Gang; Chen, Ji-Ying; Liu, Yu-Liang; Cheng, Cheng-Kung; Wang, Yan

    2016-01-01

    Background: This study aims to retain normal knee kinematics after knee replacement surgeries by reconstructing anterior cruciate ligament during total knee arthroplasty. Method: We use computational simulation tools to establish four dynamic knee models, including normal knee model, posterior cruciate ligament retaining knee model, posterior cruciate ligament substituting knee model, and anterior cruciate ligament reconstructing knee model. Our proposed method utilizes magnetic resonance ima...

  16. Medium term results of total knee arthroplasty as a primary treatment for knee fractures

    Directory of Open Access Journals (Sweden)

    Ebied Ayman

    2018-01-01

    Conclusion: Knee arthroplasty achieves highly successful outcome when performed as a primary treatment for comminuted intra and periarticular knee fractures in elderly patients. Survival of implants and functional range of movement at midterm are excellent.

  17. Effect of compression therapy on knee swelling and pain after total knee arthroplasty

    DEFF Research Database (Denmark)

    Munk, Stig; Jensen, Niels J. F.; Andersen, Ida Bøgh

    2013-01-01

    PURPOSE: Knee swelling after total knee arthroplasty may impair postoperative mobilisation and training, and as medical elastic compression stockings are well tolerated and effective to prevent oedema, haematoma and postoperative pain after venous surgery, we wanted to study whether this effect...... could be transferred to total knee arthroplasty surgery reducing postoperative swelling and pain and thereby facilitating mobilisation and improving patient-reported knee function. METHODS: In a randomised controlled study, 88 patients were randomised to use either a medical elastic compression stocking...... or no stocking from the first postoperative day and the following 4 weeks after total knee arthroplasty. Outcome measures were knee, calf and ankle swelling, knee flexion, pain and patient-reported knee function. RESULTS: Seventy per cent of the swelling had occurred before application of the stocking the day...

  18. Surface characterization of polymers used in fabrication of interim prostheses after treatment with photopolymerized glaze

    International Nuclear Information System (INIS)

    Santos, Daniela Micheline dos; Commar, Betina Chiarelo; Rocha Bonatto, Liliane da; Freitas da Silva, Emily Vivianne; Sônego, Mariana Vilela; Rangel, Elidiane Cipriano; Pesqueira, Aldieris Alves; Goiato, Marcelo Coelho

    2017-01-01

    The material used for interim prostheses fabrication must present excellent physical properties for greater longevity in the face of environmental conditions, which can occur in the oral cavity. The purpose of this study was to evaluate the effect of a photopolymerized glaze on the physical and mechanical properties of polymers used for the fabrication of interim prostheses, before and after thermocycling and immersion in staining solutions. One hundred samples of composite and acrylic resins were fabricated: Dencor chemically activated acrylic resin (CAAR) (n = 20) and heat-polymerized acrylic resin (HPAR) (n = 20), Charisma (n = 20), Structur (n = 20), and Protemp (n = 20). A mechanical polishing was performed on half of the samples, and a chemical polishing was performed on the remaining samples. Subsequently, all samples were submitted to thermocycling and immersion in coffee staining solution for 21 days. Analysis of color and microhardness, as well as atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive x-ray spectrometry (EDS) were performed. The data were submitted to repeated-measures analysis of variance (ANOVA), followed by the Tukey test (α = 0.05) and the Student t-test (α = 0.05). It was verified that the glaze decreased the chromatic alteration values, and increased the microhardness values of the samples, with the exception of the Charisma resin. The samples that did not receive chemical polishing had the greatest number of surface irregularities. This study concluded that the groups with glaze presented less color alteration. In addition, Charisma and Structur resins exhibited the greatest chromatic stability. As to the microhardness, the values were greater when the samples were treated with the glaze, with the exception of the Charisma group. - Highlights: • Polymers used in fabrication of interim prostheses were analyzed. • The influence of a chemical polishing on these polymers was analyzed.

  19. [Clinical characteristics of the Soviet low-profile heart valve prostheses EMIKS and LIKS].

    Science.gov (United States)

    Tsukerman, G I; Dobrova, N B; Faminskiĭ, D O; Pomortseva, L V; Gvakhariia, I N; Chigogidze, N A; Zaretskiĭ, Iu V

    1989-01-01

    The present work is devoted to the clinical assessment of the Soviet-made cardiac valve prostheses 'EMIKS' and 'LIKS'. From 1983 to May 1, 1988, 632 prostheses were implanted to 508 patients. A group of 348 patients were assessed: 139 after mitral (M) replacement, 130 after aortal (A) replacement, and 79 after mitral-aortal (M+A) replacement. Hospital mortality rate was: in M group--4.3 per cent, in A group--5.3 per cent, in M+A group--8.8 per cent. Survival rate on the fifth postoperative year was: in M group--89.5 +/- 9.2 per cent, in a group--90.0 +/- 4.2 per cent, in M+A group--91.0 +/- 6.2 per cent, the stability of the good results being 85.5 +/- 7.2, 79.5 +/- 6.2, and 75.0 +/- 9.1 per cent, respectively. At year 5 of the follow-up, patient numbers without thromboembolic complications amounted to 95.0 +/- 4.7 per cent in M group, 95.5 +/- 4.2 per cent in A group, and 85.0 +/- 9.1 in M+A group. 95.1 per cent patients belong to functional classes I and II. In mitral replacement, the mean 'EMIKS' gradient was 4.2 +/- 0.58 mm Hg, the 'LIKS' one--4.58 +/- 0.62 mm Hg. Intravascular hemolysis was not observed. The 'EMIKS' and 'LIKS' prostheses match the models produced in other countries. No significant differences between the two models were found.

  20. Whole-body angular momentum during stair walking using passive and powered lower-limb prostheses.

    Science.gov (United States)

    Pickle, Nathaniel T; Wilken, Jason M; Aldridge, Jennifer M; Neptune, Richard R; Silverman, Anne K

    2014-10-17

    Individuals with a unilateral transtibial amputation have a greater risk of falling compared to able-bodied individuals, and falling on stairs can lead to serious injuries. Individuals with transtibial amputations have lost ankle plantarflexor muscle function, which is critical for regulating whole-body angular momentum to maintain dynamic balance. Recently, powered prostheses have been designed to provide active ankle power generation with the goal of restoring biological ankle function. However, the effects of using a powered prosthesis on the regulation of whole-body angular momentum are unknown. The purpose of this study was to use angular momentum to evaluate dynamic balance in individuals with a transtibial amputation using powered and passive prostheses relative to able-bodied individuals during stair ascent and descent. Ground reaction forces, external moment arms, and joint powers were also investigated to interpret the angular momentum results. A key result was that individuals with an amputation had a larger range of sagittal-plane angular momentum during prosthetic limb stance compared to able-bodied individuals during stair ascent. There were no significant differences in the frontal, transverse, or sagittal-plane ranges of angular momentum or maximum magnitude of the angular momentum vector between the passive and powered prostheses during stair ascent or descent. These results indicate that individuals with an amputation have altered angular momentum trajectories during stair walking compared to able-bodied individuals, which may contribute to an increased fall risk. The results also suggest that a powered prosthesis provides no distinct advantage over a passive prosthesis in maintaining dynamic balance during stair walking. Copyright © 2014 Elsevier Ltd. All rights reserved.