Differences Regarding Branded HA in Italy, Part 2: Data from Clinical Studies on Knee, Hip, Shoulder, Ankle, Temporomandibular Joint, Vertebral Facets, and Carpometacarpal Joint

Science.gov (United States)

Migliore, A.; Bizzi, E.; De Lucia, O.; Delle Sedie, A.; Tropea, S.; Bentivegna, M.; Mahmoud, A.; Foti, C.

2016-01-01

OBJECTIVES The aim of the current study is to collect scientific data on all branded hyaluronic acid (HA) products in Italy that are in use for intra-articular (IA) injection in osteoarthritis (OA) compared with that reported in the leaflet. METHODS An extensive literature research was performed for all articles reporting data on the IA use of HA in OA. Selected studies were taken into consideration only if they are related to products based on HAs that are currently marketed in Italy with the specific joint indication for IA use in patients affected by OA. RESULTS Sixty-two HA products are marketed in Italy: 30 products are indicated for the knee but only 8 were proved with some efficacy; 9 products were effective for the hip but only 6 had hip indication; 7 products proved to be effective for the shoulder but only 3 had the indication; 5 products proved effective for the ankle but only one had the indication; 6 products were effective for the temporomandibular joint but only 2 had the indication; only 2 proved effective for vertebral facet joints but only 1 had the indication; and 5 products proved effective for the carpometacarpal joint but only 2 had the indication. CONCLUSIONS There are only a few products with some evidences, while the majority of products remain without proof. Clinicians and regulators should request postmarketing studies from pharmaceuticals to corroborate with that reported in the leaflet and to gather more data, allowing the clinicians to choose the adequate product for the patient. PMID:27279754

The thumb carpometacarpal joint: curvature morphology of the articulating surfaces, mathematical description and mechanical functioning.

Science.gov (United States)

Dathe, Henning; Dumont, Clemens; Perplies, Rainer; Fanghänel, Jochen; Kubein-Meesenburg, Dietmar; Nägerl, Hans; Wachowski, Martin M

2016-01-01

The purpose is to present a mathematical model of the function of the thumb carpometacarpal joint (TCMCJ) based on measurements of human joints. In the TCMCJ both articulating surfaces are saddle-shaped. The aim was to geometrically survey the shapes of the articulating surfaces using precise replicas of 28 TCMCJs. None of these 56 articulating surfaces did mathematically extend the differential geometrical neighbourhood around the main saddle point so that each surface could be characterised by three main parameters: the two extreme radii of curvature in the main saddle point and the angle between the saddles' asymptotics (straight lines). The articulating surfaces, when contacting at the respective main saddle points, are incongruent. Hence, the TCMCJ has functionally five kinematical degrees of freedom (DOF); two DOF belong to flexion/extension, two to ab-/adduction. These four DOF are controlled by the muscular apparatus. The fifth DOF, axial rotation, cannot be adjusted but stabilized by the muscular apparatus so that physiologically under compressive load axial rotation does not exceed an angle of approximately ±3°. The TCMCJ can be stimulated by the muscular apparatus to circumduct. The mechanisms are traced back to the curvature incongruity of the saddle surfaces. Hence we mathematically proved that none of the individual saddle surfaces can be described by a quadratic saddle surface as is often assumed in literature. We derived an algebraic formula with which the articulating surfaces in the TCMCJ can be quantitatively described. This formula can be used to shape the articulating surfaces in physiologically equivalent TCMCJ-prostheses.

Sacroiliac joint stability: Finite element analysis of implant number, orientation, and superior implant length.

Science.gov (United States)

Lindsey, Derek P; Kiapour, Ali; Yerby, Scott A; Goel, Vijay K

2018-03-18

To analyze how various implants placement variables affect sacroiliac (SI) joint range of motion. An experimentally validated finite element model of the lumbar spine and pelvis was used to simulate a fusion of the SI joint using various placement configurations of triangular implants (iFuse Implant System ® ). Placement configurations were varied by changing implant orientation, superior implant length, and number of implants. The range of motion of the SI joint was calculated using a constant moment of 10 N-m with a follower load of 400 N. The changes in motion were compared between the treatment groups to assess how the different variables affected the overall motion of the SI joint. Transarticular placement of 3 implants with superior implants that end in the middle of the sacrum resulted in the greatest reduction in range of motion (flexion/extension = 73%, lateral bending = 42%, axial rotation = 72%). The range of motions of the SI joints were reduced with use of transarticular orientation (9%-18%) when compared with an inline orientation. The use of a superior implant that ended mid-sacrum resulted in median reductions of (8%-14%) when compared with a superior implant that ended in the middle of the ala. Reducing the number of implants, resulted in increased SI joint range of motions for the 1 and 2 implant models of 29%-133% and 2%-39%, respectively, when compared with the 3 implant model. Using a validated finite element model we demonstrated that placement of 3 implants across the SI joint using a transarticular orientation with superior implant reaching the sacral midline resulted in the most stable construct. Additional clinical studies may be required to confirm these results.

Physicochemical and microscopic characterization of implant-abutment joints.

Science.gov (United States)

Lopes, Patricia A; Carreiro, Adriana F P; Nascimento, Rubens M; Vahey, Brendan R; Henriques, Bruno; Souza, Júlio C M

2018-01-01

The purpose of this study was to investigate Morse taper implant-abutment joints by chemical, mechanical, and microscopic analysis. Surfaces of 10 Morse taper implants and the correlated abutments were inspected by field emission gun-scanning electron microscopy (FEG-SEM) before connection. The implant-abutment connections were tightened at 32 Ncm. For microgap evaluation by FEG-SEM, the systems were embedded in epoxy resin and cross-sectioned at a perpendicular plane of the implant-abutment joint. Furthermore, nanoindentation tests and chemical analysis were performed at the implant-abutment joints. Results were statistically analyzed via one-way analysis of variance, with a significance level of P abutment surfaces. The minimum and maximum size of microgaps ranged from 0.5 μm up to 5.6 μm. Furthermore, defects were detected throughout the implant-abutment joint that can, ultimately, affect the microgap size after connection. Nanoindentation tests revealed a higher hardness (4.2 ± 0.4 GPa) for abutment composed of Ti6Al4V alloy when compared to implant composed of commercially pure Grade 4 titanium (3.2 ± 0.4 GPa). Surface defects produced during the machining of both implants and abutments can increase the size of microgaps and promote a misfit of implant-abutment joints. In addition, the mismatch in mechanical properties between abutment and implant can promote the wear of surfaces, affecting the size of microgaps and consequently the performance of the joints during mastication.

Avascular necrosis of the trapezoid bone following carpometacarpal arthroplasty.

Science.gov (United States)

Kane, Patrick; Waryasz, Greg; Katarincic, Julie

2014-03-03

A 58-year-old female developed avascular necrosis of her trapezoid approximately 3 months after undergoing carpometacarpal arthroplasty. The patient was treated conservatively with immobilization and had complete resolution of her clinical symptoms during her year of follow-up. Additionally, radiographic examination showed complete restoration of the height of her trapezoid approximately 1 year after the index procedure. Avascular necrosis of the trapezoid is extremely rare with very few cases described in the literature. This is the first description of avascular necrosis following carpometacarpal arthroplasty.

Prosthesis of the wrist-joint

Energy Technology Data Exchange (ETDEWEB)

Feldmeier, C.

1983-02-25

Function of the hand-joint and the well-being of patients can be severely affected by arthrosis of the wrist-joint. Therapeutically, arthrodesis usually results in a painfree status of stiffness. A painless and well functioning joint can be achieved by alloplastic joint replacement or resurfacing. The possibilities and clinical results in cases of arthrosis of the carpo-metacarpal joint of the thumb, pseudarthrosis of the scaphoid, aseptic necrosis of the Lunate and severe arthrosis of the radio-carpal joint are demonstrated.

Prosthesis of the wrist-joint

International Nuclear Information System (INIS)

Feldmeier, C.

1983-01-01

Function of the hand-joint and the well-being of patients can be severely affected by arthrosis of the wrist-joint. Therapeutically, arthrodesis usually results in a painfree status of stiffness. A painless and well functioning joint can be achieved by alloplastic joint replacement or resurfacing. The possibilities and clinical results in cases of arthrosis of the carpo-metacarpal joint of the thumb, pseudarthrosis of the scaphoid, aseptic necrosis of the Lunate and severe arthrosis of the radio-carpal joint are demonstrated. (orig.) [de

The field size matters: low dose external beam radiotherapy for thumb carpometacarpal osteoarthritis : Importance of field size.

Science.gov (United States)

Kaltenborn, Alexander; Bulling, Elke; Nitsche, Mirko; Carl, Ulrich Martin; Hermann, Robert Michael

2016-08-01

The purpose of this work was to evaluate the efficacy of low-dose radiotherapy (RT) for thumb carpometacarpal osteoarthritis (rhizarthrosis). The responses of 84 patients (n = 101 joints) were analyzed 3 months after therapy (n = 65) and at 12 months (n = 27). Patients were treated with 6 fractions of 1 Gy, two times a week, with a linear accelerator. At the end of therapy, about 70 % of patients reported a response (partial remission or complete remission), 3 months later about 60 %, and 1 year after treatment 70 %. In univariate regression analysis, higher patient age and field size greater than 6 × 4 cm were associated with response to treatment, while initial increase of pain under treatment was predictive for treatment failure. Duration of RT series (more than 18 days), gender, time of symptoms before RT, stress pain or rest pain, or prior ortheses use, injections, or surgery of the joint were not associated with treatment efficacy. In multivariate regression analysis, only field size and initial pain increase were highly correlated with treatment outcome. In conclusion, RT represents a useful treatment option for patients suffering from carpometacarpal osteoarthritis. In contrast to other benign indications, a larger field size (>6 × 4 cm) seems to be more effective than smaller fields and should be evaluated in further prospective studies.

Surgeons' Perspectives on Premium Implants in Total Joint Arthroplasty.

Science.gov (United States)

Wasterlain, Amy S; Bello, Ricardo J; Vigdorchik, Jonathan; Schwarzkopf, Ran; Long, William J

2017-09-01

Declining total joint arthroplasty reimbursement and rising implant prices have led many hospitals to restrict access to newer, more expensive total joint arthroplasty implants. The authors sought to understand arthroplasty surgeons' perspectives on implants regarding innovation, product launch, costs, and cost-containment strategies including surgeon gain-sharing and patient cost-sharing. Members of the International Congress for Joint Reconstruction were surveyed regarding attitudes about implant technology and costs. Descriptive and univariate analyses were performed. A total of 126 surgeons responded from all 5 regions of the United States. Although 76.9% believed new products advance technology in orthopedics, most (66.7%) supported informing patients that new implants lack long-term clinical data and restricting new implants to a small number of investigators prior to widespread market launch. The survey revealed that 66.7% would forgo gain-sharing incentives in exchange for more freedom to choose implants. Further, 76.9% believed that patients should be allowed to pay incremental costs for "premium" implants. Surgeons who believed that premium products advance orthopedic technology were more willing to forgo gain-sharing (P=.040). Surgeons with higher surgical volume (P=.007), those who believed implant companies should be allowed to charge more for new technology (Pnew implants with patients. Many surgeons support alternative payment models permitting surgeons and patients to retain implant selection autonomy. Most respondents prioritized patient beneficence and surgeon autonomy above personal financial gain. [Orthopedics. 2017; 40(5):e825-e830.]. Copyright 2017, SLACK Incorporated.

Do "premium" joint implants add value?: analysis of high cost joint implants in a community registry.

Science.gov (United States)

Gioe, Terence J; Sharma, Amit; Tatman, Penny; Mehle, Susan

2011-01-01

Numerous joint implant options of varying cost are available to the surgeon, but it is unclear whether more costly implants add value in terms of function or longevity. We evaluated registry survival of higher-cost "premium" knee and hip components compared to lower-priced standard components. Premium TKA components were defined as mobile-bearing designs, high-flexion designs, oxidized-zirconium designs, those including moderately crosslinked polyethylene inserts, or some combination. Premium THAs included ceramic-on-ceramic, metal-on-metal, and ceramic-on-highly crosslinked polyethylene designs. We compared 3462 standard TKAs to 2806 premium TKAs and 868 standard THAs to 1311 premium THAs using standard statistical methods. The cost of the premium implants was on average approximately $1000 higher than the standard implants. There was no difference in the cumulative revision rate at 7-8 years between premium and standard TKAs or THAs. In this time frame, premium implants did not demonstrate better survival than standard implants. Revision indications for TKA did not differ, and infection and instability remained contributors. Longer followup is necessary to demonstrate whether premium implants add value in younger patient groups. Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Locomotor adaptations reflected in the wrist joints of early tertiary primates (adapiformes).

Science.gov (United States)

Hamrick, M W

1996-08-01

The positional behaviors inferred for early Tertiary adapiform primates have been the subject of considerable debate. Adapiform wrist morphology is analyzed here within the context of extant morphoclines in carpal joint shape in order to reconstruct adapiform positional behavior. Extant vertical clingers, slow climbers, and arboreal quadrupeds differ significantly from one another in length of the m flexor carpi ulnaris lever arm, shape of the midcarpal joint articular surface, and size and divergence of the pollical carpometacarpal articulation. These morphological differences are functionally related to differential requirements for wrist flexion, midcarpal mobility and stability, and pollical grasping, respectively. Adapis, Notharctus, and Smilodectes share with living arboreal quadrupeds a tall pisiform body, a mediolaterally flat midcarpal joint surface, and a relatively unexpanded thumb joint. Functionally, these features are related to flexing the wrist from extended positions during palmigrade, quadrupedal locomotion, increasing midcarpal joint stability during quadrupedal, weight-bearing postures, and grasping arboreal supports of predominantly horizontal and oblique orientation. The Messel adapiform (genus indet.) shares certain features of the midcarpal and pollical carpometacarpal articulations with extant vertical clingers, suggesting that this taxon used vertical substrates more frequently than other adapiforms.

[Staple fixation for the treatment of hamate metacarpal joint injury].

Science.gov (United States)

Tang, Yang-Hua; Zeng, Lin-Ru; Huang, Zhong-Ming; Yue, Zhen-Shuang; Xin, Da-Wei; Xu, Can-Da

2014-03-01

To investigate the effcacy of the staple fixation for the treatment of hamate metacarpal joint injury. From May 2009 to November 2012,16 patients with hamate metacarpal joint injury were treated with staple fixation including 10 males and 6 females with an average age of 33.6 years old ranging from 21 to 57 years. Among them, 11 cases were on the fourth or fifth metacarpal base dislocation without fractures, 5 cases were the fourth or fifth metacarpal base dislocation with avulsion fractures of the back of hamatum. Regular X-ray review was used to observe the fracture healing, joint replacement and position of staple fixation. The function of carpometacarpal joint and metacarpophalangeal joint were evaluated according to ASIA (TAM) system evaluation method. All incision were healed well with no infection. All patients were followed up from 16 to 24 months with an average of (10.0 +/- 2.7) months. No dislocation recurred, the position of internal fixator was good,no broken nail and screw withdrawal were occurred. Five patients with avulsion fracture of the back of hamatum achieved bone healing. The function of carpometacarpal joint and metacarpophalangeal was excellent in 10 cases,good in 5 cases, moderate in 1 case. The application of the staple for the treatment of hamatometacarpal joint injury has the advantages of simple operation, small trauma, reliable fixation, early postoperative function exercise and other advantages, which is the ideal operation mode for hamatometacarpal joint injury.

A personalized 3D-printed prosthetic joint replacement for the human temporomandibular joint: From implant design to implantation.

Science.gov (United States)

Ackland, David C; Robinson, Dale; Redhead, Michael; Lee, Peter Vee Sin; Moskaljuk, Adrian; Dimitroulis, George

2017-05-01

Personalized prosthetic joint replacements have important applications in cases of complex bone and joint conditions where the shape and size of off-the-shelf components may not be adequate. The objective of this study was to design, test and fabricate a personalized 3D-printed prosthesis for a patient requiring total joint replacement surgery of the temporomandibular joint (TMJ). The new 'Melbourne' prosthetic TMJ design featured a condylar component sized specifically to the patient and fixation screw positions that avoid potential intra-operative damage to the mandibular nerve. The Melbourne prosthetic TMJ was developed for a 58-year-old female recipient with end-stage osteoarthritis of the TMJ. The load response of the prosthesis during chewing and a maximum-force bite was quantified using a personalized musculoskeletal model of the patient's masticatory system developed using medical images. The simulations were then repeated after implantation of the Biomet Microfixation prosthetic TMJ, an established stock device. The maximum condylar stresses, screw stress and mandibular stress at the screw-bone interface were lower in the Melbourne prosthetic TMJ (259.6MPa, 312.9MPa and 198.4MPa, respectively) than those in the Biomet Microfixation device (284.0MPa, 416.0MPa and 262.2MPa, respectively) during the maximum-force bite, with similar trends also observed during the chewing bite. After trialing surgical placement and evaluating prosthetic TMJ stability using cadaveric specimens, the prosthesis was fabricated using 3D printing, sterilized, and implanted into the female recipient. Six months post-operatively, the prosthesis recipient had a normal jaw opening distance (40.0 mm), with no complications identified. The new design features and immediate load response of the Melbourne prosthetic TMJ suggests that it may provide improved clinical and biomechanical joint function compared to a commonly used stock device, and reduce risk of intra-operative nerve damage

An instrumented implant for in vivo measurement of contact forces and contact moments in the shoulder joint.

Science.gov (United States)

Westerhoff, P; Graichen, F; Bender, A; Rohlmann, A; Bergmann, G

2009-03-01

To improve implant design, fixation and preclinical testing, implant manufacturers depend on realistic data of loads acting on the shoulder joint. Furthermore, these data can help to optimize physiotherapeutic treatment and to advise patients in their everyday living conditions. Calculated shoulder joint loads vary extremely among different authors [Anglin C, Wyss UP, Pichora DR. Glenohumeral contact forces. Proc Inst Mech Eng [H] 2000;214:637-44]. Additionally the moments acting in the joint caused by friction or incongruent articular surfaces, for example, are not implemented in most models. An instrumented shoulder joint implant was developed to measure the contact forces and the contact moments acting in the glenohumeral joint. This article provides a detailed description of the implant, containing a nine-channel telemetry unit, six load sensors and an inductive power supply, all hermetically sealed inside the implant. The instrumented implant is based on a clinically proven BIOMET Biomodular shoulder replacement and was calibrated before implantation by using complex mathematical calculation routines in order to achieve an average measuring precision of approximately 2%.

Removal Torque and Biofilm Accumulation at Two Dental Implant-Abutment Joints After Fatigue.

Science.gov (United States)

Pereira, Jorge; Morsch, Carolina S; Henriques, Bruno; Nascimento, Rubens M; Benfatti, Cesar Am; Silva, Filipe S; López-López, José; Souza, Júlio Cm

2016-01-01

The aim of this study was to evaluate the removal torque and in vitro biofilm penetration at Morse taper and hexagonal implant-abutment joints after fatigue tests. Sixty dental implants were divided into two groups: (1) Morse taper and (2) external hexagon implant-abutment systems. Fatigue tests on the implant-abutment assemblies were performed at a normal force (FN) of 50 N at 1.2 Hz for 500,000 cycles in growth medium containing human saliva for 72 hours. Removal torque mean values (n = 10) were measured after fatigue tests. Abutments were then immersed in 1% protease solution in order to detach the biofilms for optical density and colony-forming unit (CFU/cm²) analyses. Groups of implant-abutment assemblies (n = 8) were cross-sectioned at 90 degrees relative to the plane of the implant-abutment joints for the microgap measurement by field-emission guns scanning electron microscopy. Mean values of removal torque on abutments were significantly lower for both Morse taper (22.1 ± 0.5 μm) and external hexagon (21.1 ± 0.7 μm) abutments after fatigue tests than those recorded without fatigue tests (respectively, 24 ± 0.5 μm and 24.8 ± 0.6 μm) in biofilm medium for 72 hours (P = .04). Mean values of microgap size for the Morse taper joints were statistically signicantly lower without fatigue tests (1.7 ± 0.4 μm) than those recorded after fatigue tests (3.2 ± 0.8 μm). Also, mean values of microgap size for external hexagon joints free of fatigue were statistically signicantly lower (1.5 ± 0.4 μm) than those recorded after fatigue tests (8.1 ± 1.7 μm) (P abutments (Abs630nm at 0.06 and 2.9 × 10⁴ CFU/cm²) than that on external hexagon abutments (Abs630nm at 0.08 and 4.5 × 10⁴ CFU/cm²) (P = .01). The mean values of removal torque, microgap size, and biofilm density recorded at Morse taper joints were lower in comparison to those recorded at external hexagon implant-abutment joints after fatigue tests in a simulated oral environment for 72 hours.

Influence of abutment materials on the implant-abutment joint stability in internal conical connection type implant systems

OpenAIRE

Jo, Jae-Young; Yang, Dong-Seok; Huh, Jung-Bo; Heo, Jae-Chan; Yun, Mi-Jung; Jeong, Chang-Mo

2014-01-01

PURPOSE This study evaluated the influence of abutment materials on the stability of the implant-abutment joint in internal conical connection type implant systems. MATERIALS AND METHODS Internal conical connection type implants, cement-retained abutments, and tungsten carbide-coated abutment screws were used. The abutments were fabricated with commercially pure grade 3 titanium (group T3), commercially pure grade 4 titanium (group T4), or Ti-6Al-4V (group TA) (n=5, each). In order to assess ...

Carpometacarpal subchondral cysts due to repetitive movements in shoemaker: a case report.

Science.gov (United States)

Tonini, Stefano; Candura, Stefano M; Lanfranco, Andrea; Mennoia, N Valerio

2011-12-01

Subchondral carpometacarpal cysts are classic and almost pathognomonic lesions found in workers using vibrating instruments over prolonged periods of time. We present the case of a 53-year-old woman who worked for 30 years sewing shoe uppers, a task which required grasping firmly a pear-shaped handle awl and pushing it through the leather upper and the sole of the shoe, with combined flexion and supination movement of the wrist. After approximately 20 years of working, the patient noted gradual onset of paresthesias in the dominant (right) hand, with increasing difficulty in grasping the awl. Subsequent diagnosis of carpal tunnel syndrome was confirmed by electrophysiologic testing and its surgical release was performed. Nevertheless, hand pain, paresthesias and weakness persisted. Ultrasound of the snuffbox tendons excluded DeQuervain tenosynovitis. Radiographic imaging of the symptomatic hand showed carpometacarpal subchondral cystic formations. In addition to demonstrating the usefulness of radiographic imaging in patients with persistent hand pain post-carpal release, this case is important in illustrating that repetitive movements with high pressure over the palmar carpal area may cause bone cysts, even if the subjects do not use vibrating tools.

Effect of radial head implant shape on joint contact area and location during static loading.

Science.gov (United States)

Shannon, Hannah L; Deluce, Simon R; Lalone, Emily A; Willing, Ryan; King, Graham J W; Johnson, James A

2015-04-01

To examine the effect of implant shape on radiocapitellar joint contact area and location in vitro. We used 8 fresh-frozen cadaveric upper extremities. An elbow loading simulator examined joint contact in pronation, neutral rotation, and supination with the elbow at 90° flexion. Muscle tendons were attached to pneumatic actuators to allow for computer-controlled loading to achieve the desired forearm rotation. We performed testing with the native radial head, an axisymmetric implant, a reverse-engineered patient-specific implant, and a population-based quasi-anatomic implant. Implants were inserted using computer navigation. Contact area and location were quantified using a casting technique. We found no significant difference between contact locations for the native radial head and the 3 implants. All of the implants had a contact area lower than the native radial head; however, only the axisymmetric implant was significantly different. There was no significant difference in contact area between implant shapes. The similar contact areas and locations of the 3 implant designs suggest that the shape of the implant may not be important with respect to radiocapitellar joint contact mechanics when placed optimally using computer navigation. Further work is needed to explore the sensitivity of radial head implant malpositioning on articular contact. The lower contact area of the radial head implants relative to the native radial head is similar to previous benchtop studies and is likely the result of the greater stiffness of the implant. Radial head implant shape does not appear to have a pronounced influence on articular contact, and both axisymmetric and anatomic metal designs result in elevated cartilage stress relative to the intact state. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

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

Biofabrication of implants for articular joint repair : Cartilage regeneration in reinforced gelatin-based hydrogels

NARCIS (Netherlands)

Visser, J.

2015-01-01

Implants were biofabricated for the repair of chondral and osteochondral articular joint defects. The implants were based on gelatin methacrylamide (GelMA) hydrogels combined with printed fibers from polycaprolactone (PCL) for mechanical reinforcement. In Part I of the thesis, biological

Influence of the implant-abutment connection design and diameter on the screw joint stability

Science.gov (United States)

Shin, Hyon-Mo; Huh, Jung-Bo; Yun, Mi-Jeong; Jeon, Young-Chan; Chang, Brian Myung

2014-01-01

PURPOSE This study was conducted to evaluate the influence of the implant-abutment connection design and diameter on the screw joint stability. MATERIALS AND METHODS Regular and wide-diameter implant systems with three different joint connection designs: an external butt joint, a one-stage internal cone, and a two-stage internal cone were divided into seven groups (n=5, in each group). The initial removal torque values of the abutment screw were measured with a digital torque gauge. The postload removal torque values were measured after 100,000 cycles of a 150 N and a 10 Hz cyclic load had been applied. Subsequently, the rates of the initial and postload removal torque losses were calculated to evaluate the effect of the joint connection design and diameter on the screw joint stability. Each group was compared using Kruskal-Wallis test and Mann-Whitney U test as post-hoc test (α=0.05). RESULTS The postload removal torque value was high in the following order with regard to magnitude: two-stage internal cone, one-stage internal cone, and external butt joint systems. In the regular-diameter group, the external butt joint and one-stage internal cone systems showed lower postload removal torque loss rates than the two-stage internal cone system. In the wide-diameter group, the external butt joint system showed a lower loss rate than the one-stage internal cone and two-stage internal cone systems. In the two-stage internal cone system, the wide-diameter group showed a significantly lower loss rate than the regular-diameter group (P<.05). CONCLUSION The results of this study showed that the external butt joint was more advantageous than the internal cone in terms of the postload removal torque loss. For the difference in the implant diameter, a wide diameter was more advantageous in terms of the torque loss rate. PMID:24843398

Influence of the implant-abutment connection design and diameter on the screw joint stability.

Science.gov (United States)

Shin, Hyon-Mo; Huh, Jung-Bo; Yun, Mi-Jeong; Jeon, Young-Chan; Chang, Brian Myung; Jeong, Chang-Mo

2014-04-01

This study was conducted to evaluate the influence of the implant-abutment connection design and diameter on the screw joint stability. Regular and wide-diameter implant systems with three different joint connection designs: an external butt joint, a one-stage internal cone, and a two-stage internal cone were divided into seven groups (n=5, in each group). The initial removal torque values of the abutment screw were measured with a digital torque gauge. The postload removal torque values were measured after 100,000 cycles of a 150 N and a 10 Hz cyclic load had been applied. Subsequently, the rates of the initial and postload removal torque losses were calculated to evaluate the effect of the joint connection design and diameter on the screw joint stability. Each group was compared using Kruskal-Wallis test and Mann-Whitney U test as post-hoc test (α=0.05). THE POSTLOAD REMOVAL TORQUE VALUE WAS HIGH IN THE FOLLOWING ORDER WITH REGARD TO MAGNITUDE: two-stage internal cone, one-stage internal cone, and external butt joint systems. In the regular-diameter group, the external butt joint and one-stage internal cone systems showed lower postload removal torque loss rates than the two-stage internal cone system. In the wide-diameter group, the external butt joint system showed a lower loss rate than the one-stage internal cone and two-stage internal cone systems. In the two-stage internal cone system, the wide-diameter group showed a significantly lower loss rate than the regular-diameter group (P<.05). The results of this study showed that the external butt joint was more advantageous than the internal cone in terms of the postload removal torque loss. For the difference in the implant diameter, a wide diameter was more advantageous in terms of the torque loss rate.

Biomechanical Analysis of Implanted Clavicle Hook Plates With Different Implant Depths and Materials in the Acromioclavicular Joint: A Finite Element Analysis Study.

Science.gov (United States)

Lee, Cheng-Hung; Shih, Cheng-Min; Huang, Kui-Chou; Chen, Kun-Hui; Hung, Li-Kun; Su, Kuo-Chih

2016-11-01

Clinical implantation of clavicle hook plates is often used as a treatment for acromioclavicular joint dislocation. However, it is not uncommon to find patients that have developed acromion osteolysis or had peri-implant fracture after hook plate fixation. With the aim of preventing complications or fixation failure caused by implantation of inappropriate clavicle hook plates, the present study investigated the biomechanics of clavicle hook plates made of different materials and with different hook depths in treating acromioclavicular joint dislocation, using finite element analysis (FEA). This study established four parts using computer models: the clavicle, acromion, clavicle hook plate, and screws, and these established models were used for FEA. Moreover, implantations of clavicle hook plates made of different materials (stainless steel and titanium alloy) and with different depths (12, 15, and 18 mm) in patients with acromioclavicular joint dislocation were simulated in the biomechanical analysis. The results indicate that deeper implantation of the clavicle hook plate reduces stress on the clavicle, and also reduces the force applied to the acromion by the clavicle hook plate. Even though a clavicle hook plate made of titanium alloy (a material with a lower Young's modulus) reduces the force applied to the acromion by the clavicle hook plate, slightly higher stress on the clavicle may occur. The results obtained in this study provide a better reference for orthopedic surgeons in choosing different clavicle hook plates for surgery. Copyright © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

The KineSpring® Knee Implant System: an implantable joint-unloading prosthesis for treatment of medial knee osteoarthritis

Directory of Open Access Journals (Sweden)

Clifford AG

2013-05-01

Full Text Available Anton G Clifford,1 Stefan M Gabriel,1 Mary O’Connell,1 David Lowe,1 Larry E Miller,2,3 Jon E Block31Moximed, Inc, Hayward, CA, USA; 2Miller Scientific Consulting, Inc, Arden, NC, USA; 3The Jon Block Group, San Francisco, CA, USAAbstract: Symptomatic medial compartment knee osteoarthritis (OA is the leading cause of musculoskeletal pain and disability in adults. Therapies intended to unload the medial knee compartment have yielded unsatisfactory results due to low patient compliance with conservative treatments and high complication rates with surgical options. There is no widely available joint-unloading treatment for medial knee OA that offers clinically important symptom alleviation, low complication risk, and high patient acceptance. The KineSpring® Knee Implant System (Moximed, Inc, Hayward, CA, USA is a first-of-its-kind, implantable, extra-articular, extra-capsular prosthesis intended to alleviate knee OA-related symptoms by reducing medial knee compartment loading while overcoming the limitations of traditional joint-unloading therapies. Preclinical and clinical studies have demonstrated excellent prosthesis durability, substantial reductions in medial compartment and total joint loads, and clinically important improvements in OA-related pain and function. The purpose of this report is to describe the KineSpring System, including implant characteristics, principles of operation, indications for use, patient selection criteria, surgical technique, postoperative care, preclinical testing, and clinical experience. The KineSpring System has potential to bridge the gap between ineffective conservative treatments and irreversible surgical interventions for medial compartment knee OA.Keywords: KineSpring, knee, medial, osteoarthritis, prosthesis

Subluxation of the Carpus in Thirteen Horses

OpenAIRE

Bailey, J.V.; Barber, S.M.; Fretz, P.B.; Jacobs, K.A.

1984-01-01

The records of 13 horses of various breeds with subluxation of the radiocarpal, intercarpal or carpometacarpal joint, or combinations of these were reviewed. Subluxation was most common at the carpometacarpal joint (n = 10) and concomitant fractures of individual carpal bones or metacarpus II and IV were seen (n = 12).

Characteristic complications after autologous chondrocyte implantation for cartilage defects of the knee joint

DEFF Research Database (Denmark)

Niemeyer, Philipp; Pestka, Jan M; Kreuz, Peter C

2008-01-01

BACKGROUND: Although autologous chondrocyte implantation (ACI) is a well-established therapy for the treatment of isolated cartilage defects of the knee joint, little is known about typical complications and their treatment after ACI. HYPOTHESIS: Unsatisfactory outcome after ACI is associated...

Triangular Titanium Implants for Minimally Invasive Sacroiliac Joint Fusion: 2-Year Follow-Up from a Prospective Multicenter Trial.

Science.gov (United States)

Duhon, Bradley S; Bitan, Fabien; Lockstadt, Harry; Kovalsky, Don; Cher, Daniel; Hillen, Travis

2016-01-01

Sacroiliac joint (SIJ) dysfunction is an underdiagnosed condition. Several published cohorts have reported favorable mid-term outcomes after SIJ fusion using titanium implants placed across the SIJ. Herein we report long-term (24-month) results from a prospective multicenter clinical trial. One hundred and seventy-two subjects at 26 US sites with SI joint dysfunction were enrolled and underwent minimally invasive SI joint fusion with triangular titanium implants. Subjects underwent structured assessments preoperatively and at 1, 3, 6, 12, 18 and 24 months postoperatively, including SIJ pain ratings (0-100 visual analog scale), Oswestry Disability Index (ODI), Short Form-36 (SF-36), EuroQOL-5D (EQ-5D), and patient satisfaction. Adverse events were collected throughout follow-up. All participating patients underwent a high-resolution pelvic CT scan at 1 year. Mean subject age was 50.9 years and 69.8% were women. SIJ pain was present for an average of 5.1 years prior to surgical treatment. SIJ pain decreased from 79.8 at baseline to 30.4 at 12 months and remained low at 26.0 at 24 months (pdysfunction, minimally invasive SI joint fusion using triangular titanium implants showed marked improvements in pain, disability and quality of life at 2 years. Imaging showed that bone apposition to implants was common but radiographic evidence of intraarticular fusion within the joint may take more than 1 year in many patients. This prospective multicenter clinical trial was approved by local or regional IRBs at each center prior to first patient enrollment. Informed consent with IRB-approved study-specific consent forms was obtained from all patients prior to participation.

[Partial replacement of the knee joint with patient-specific instruments and implants (ConforMIS iUni, iDuo)].

Science.gov (United States)

Beckmann, J; Steinert, A; Zilkens, C; Zeh, A; Schnurr, C; Schmitt-Sody, M; Gebauer, M

2016-04-01

Knee arthroplasty is a successful standard procedure in orthopedic surgery; however, approximately 20 % of patients are dissatisfied with the clinical results as they suffer pain and can no longer achieve the presurgery level of activity. According to the literature the reasons are inexact fitting of the prosthesis or too few anatomically formed implants resulting in less physiological kinematics of the knee joint. Reducing the number of dissatisfied patients and the corresponding number of revisions is an important goal considering the increasing need for artificial joints. In this context, patient-specific knee implants are an obvious alternative to conventional implants. For the first time implants are now matched to the individual bone and not vice versa to achieve the best possible individual situation and geometry and more structures (e.g. ligaments and bone) are preserved or only those structures are replaced which were actually destroyed by arthrosis. According to the authors view, this represents an optimal and pioneering addition to conventional implants. Patient-specific implants and the instruments needed for correct alignment and fitting can be manufactured by virtual 3D reconstruction and 3D printing based on computed tomography (CT) scans. The portfolio covers medial as well as lateral unicondylar implants, medial as well as lateral bicompartmental implants (femorotibial and patellofemoral compartments) and cruciate ligament-preserving as well as cruciate ligament-substituting total knee replacements; however, it must be explicitly emphasized that the literature is sparse and no long-term data are available.

[Resection of a carpal bone row in a Pustertaler Sprinze cow with chronic purulent arthritis of the carpal joint and osteomyelitis].

Science.gov (United States)

Kofler, J; Peterbauer, C

2014-01-01

This case report describes the clinical and radiographic findings and the surgical treatment of a serofibrinous arthritis of the antebrachiocarpal joint and of a chronic purulent arthritis of the intercarpal and carpometacarpal joints with osteomyelitis of the distal carpal bones and subchondral osteomyelitis of the proximal metacarpal bones in a cow of the breed "Pustertaler Sprinze". The therapy comprised an arthrotomy of both joint spaces and the resection of the distal row of the carpal bones. The right forelimb had been immobilised for 70 days by a full limb cast. After this period, radiographs revealed an ob- vious ankylosis of the carpal joint, and the cow showed only a slight lameness. Six years postoperatively this cow was still in the herd and had produced six calves.

Influence of abutment materials on the implant-abutment joint stability in internal conical connection type implant systems.

Science.gov (United States)

Jo, Jae-Young; Yang, Dong-Seok; Huh, Jung-Bo; Heo, Jae-Chan; Yun, Mi-Jung; Jeong, Chang-Mo

2014-12-01

This study evaluated the influence of abutment materials on the stability of the implant-abutment joint in internal conical connection type implant systems. Internal conical connection type implants, cement-retained abutments, and tungsten carbide-coated abutment screws were used. The abutments were fabricated with commercially pure grade 3 titanium (group T3), commercially pure grade 4 titanium (group T4), or Ti-6Al-4V (group TA) (n=5, each). In order to assess the amount of settlement after abutment fixation, a 30-Ncm tightening torque was applied, then the change in length before and after tightening the abutment screw was measured, and the preload exerted was recorded. The compressive bending strength was measured under the ISO14801 conditions. In order to determine whether there were significant changes in settlement, preload, and compressive bending strength before and after abutment fixation depending on abutment materials, one-way ANOVA and Tukey's HSD post-hoc test was performed. Group TA exhibited the smallest mean change in the combined length of the implant and abutment before and after fixation, and no difference was observed between groups T3 and T4 (P>.05). Group TA exhibited the highest preload and compressive bending strength values, followed by T4, then T3 (Pabutment material can influence the stability of the interface in internal conical connection type implant systems. The strength of the abutment material was inversely correlated with settlement, and positively correlated with compressive bending strength. Preload was inversely proportional to the frictional coefficient of the abutment material.

Triangular Titanium Implants for Minimally Invasive Sacroiliac Joint Fusion: A Prospective Study.

Science.gov (United States)

Duhon, Bradley S; Cher, Daniel J; Wine, Kathryn D; Kovalsky, Don A; Lockstadt, Harry

2016-05-01

Study Design Prospective multicenter single-arm interventional clinical trial. Objective To determine the degree of improvement in sacroiliac (SI) joint pain, disability related to SI joint pain, and quality of life in patients with SI joint dysfunction who undergo minimally invasive SI joint fusion using triangular-shaped titanium implants. Methods Subjects (n = 172) underwent minimally invasive SI joint fusion between August 2012 and January 2014 and completed structured assessments preoperatively and at 1, 3, 6, and 12 months postoperatively, including a 100-mm SI joint and back pain visual analog scale (VAS), Oswestry Disability Index (ODI), Short Form-36 (SF-36), and EuroQOL-5D. Patient satisfaction with surgery was assessed at 6 and 12 months. Results Mean SI joint pain improved from 79.8 at baseline to 30.0 and 30.4 at 6 and 12 months, respectively (mean improvements of 49.9 and 49.1 points, p < 0.0001 each). Mean ODI improved from 55.2 at baseline to 32.5 and 31.4 at 6 and 12 months (improvements of 22.7 and 23.9 points, p < 0.0001 each). SF-36 physical component summary improved from 31.7 at baseline to 40.2 and 40.3 at 6 and 12 months (p < 0.0001). At 6 and 12 months, 93 and 87% of subjects, respectively, were somewhat or very satisfied and 92 and 91%, respectively, would have the procedure again. Conclusions Minimally invasive SI joint fusion resulted in improvement of pain, disability, and quality of life in patients with SI joint dysfunction due to degenerative sacroiliitis and SI joint disruption.

Educational Quality of YouTube Videos in Thumb Exercises for Carpometacarpal Osteoarthritis: A Search on Current Practice.

Science.gov (United States)

Villafañe, Jorge Hugo; Cantero-Tellez, Raquel; Valdes, Kristin; Usuelli, Federico Giuseppe; Berjano, Pedro

2017-09-01

Conservative treatments are commonly performed therapeutic interventions for the management of carpometacarpal (CMC) joint osteoarthritis (OA). Physical and occupational therapies are starting to use video-based online content as both a patient teaching tool and a source for treatment techniques. YouTube is a popular video-sharing website that can be accessed easily. The purpose of this study was to analyze the quality of content and potential sources of bias in videos available on YouTube pertaining to thumb exercises for CMC OA. The YouTube video database was systematically searched using the search term thumb osteoarthritis and exercises from its inception to March 10, 2017. Authors independently selected videos, conducted quality assessment, and extracted results. A total of 832 videos were found using the keywords. Of these, 10 videos clearly demonstrated therapeutic exercise for the management of CMC OA. In addition, the top-ranked video found by performing a search of "views" was a video with more than 121 863 views uploaded in 2015 that lasted 12.33 minutes and scored only 2 points on the Global Score for Educational Value rating scale. Most of the videos viewed that described conservative interventions for CMC OA management have a low level of evidence to support their use. Although patients and novice hand therapists are using YouTube and other online resources, videos that are produced by expert hand therapists are scarce.

Joint immobilization inhibits spontaneous hyaline cartilage regeneration induced by a novel double-network gel implantation.

Science.gov (United States)

Arakaki, Kazunobu; Kitamura, Nobuto; Kurokawa, Takayuki; Onodera, Shin; Kanaya, Fuminori; Gong, Jian-Ping; Yasuda, Kazunori

2011-02-01

We have recently discovered that spontaneous hyaline cartilage regeneration can be induced in an osteochondral defect in the rabbit, when we implant a novel double-network (DN) gel plug at the bottom of the defect. To clarify whether joint immobilization inhibits the spontaneous hyaline cartilage regeneration, we conducted this study with 20 rabbits. At 4 or 12 weeks after surgery, the defect in the mobile knees was filled with a sufficient volume of the hyaline cartilage tissue rich in proteoglycan and type-2 collagen, while no cartilage tissues were observed in the defect in the immobilized knees. Type-2 collagen, Aggrecan, and SOX9 mRNAs were expressed only in the mobile knees at each period. This study demonstrated that joint immobilization significantly inhibits the spontaneous hyaline cartilage regeneration induced by the DN gel implantation. This fact suggested that the mechanical environment is one of the significant factors to induce this phenomenon.

Bioabsorbable Suture Anchor Migration to the Acromioclavicular Joint: How Far Can These Implants Go?

Directory of Open Access Journals (Sweden)

Giovanna Medina

2014-01-01

Full Text Available Few complications regarding the use of bioabsorbable suture anchors in the shoulder have been reported. What motivated this case report was the unusual location of the anchor, found in the acromioclavicular joint which, to our knowledge, has never been reported so far. A 53-year old male with previous rotator cuff (RC repair using bioabsorbable suture anchors presented with pain and weakness after 2 years of surgery. A suspicion of retear of the RC led to request of a magnetic resonance image, in which the implant was found located in the acromioclavicular joint. The complications reported with the use of metallic implants around the shoulder led to the development of bioabsorbable anchors. Advantages are their absorption over time, minimizing the risk of migration or interference with revision surgery, less artifacts with magnetic resonance imaging, and tendon-to-bone repair strength similar to metallic anchors. Since the use of bioabsorbable suture anchors is increasing, it is important to know the possible complications associated with these devices.

Acromioclavicular joint reconstruction using the LockDown synthetic implant: a study with cadavers.

Science.gov (United States)

Taranu, R; Rushton, P R P; Serrano-Pedraza, I; Holder, L; Wallace, W A; Candal-Couto, J J

2015-12-01

Dislocation of the acromioclavicular joint is a relatively common injury and a number of surgical interventions have been described for its treatment. Recently, a synthetic ligament device has become available and been successfully used, however, like other non-native solutions, a compromise must be reached when choosing non-anatomical locations for their placement. This cadaveric study aimed to assess the effect of different clavicular anchorage points for the Lockdown device on the reduction of acromioclavicular joint dislocations, and suggest an optimal location. We also assessed whether further stability is provided using a coracoacromial ligament transfer (a modified Neviaser technique). The acromioclavicular joint was exposed on seven fresh-frozen cadaveric shoulders. The joint was reconstructed using the Lockdown implant using four different clavicular anchorage points and reduction was measured. The coracoacromial ligament was then transferred to the lateral end of the clavicle, and the joint re-assessed. If the Lockdown ligament was secured at the level of the conoid tubercle, the acromioclavicular joint could be reduced anatomically in all cases. If placed medial or 2 cm lateral, the joint was irreducible. If the Lockdown was placed 1 cm lateral to the conoid tubercle, the joint could be reduced with difficulty in four cases. Correct placement of the Lockdown device is crucial to allow anatomical joint reduction. Even when the Lockdown was placed over the conoid tubercle, anterior clavicle displacement remained but this could be controlled using a coracoacromial ligament transfer. ©2015 The British Editorial Society of Bone & Joint Surgery.

Patient risk taking and spending habits correlate with willingness to pay for novel total joint arthroplasty implants

Directory of Open Access Journals (Sweden)

Ran Schwarzkopf, MD, MSc

2015-03-01

Full Text Available In this study, we compare patients' risk-taking and spending behaviors to their willingness to pay (WTP for novel implants in a joint arthroplasty. 210 patients were surveyed regarding risk-taking and spending behavior, and WTP for novel implants with either increased-longevity, increased-longevity with higher risk of complications, or decreased risk of complications compared to a standard implant. Patients with increased recreational risk-taking behavior were more WTP for increased-longevity. Patients who “rarely“ take health-risks were more WTP for decreased risk of complications. Patients with higher combined risk scores were more WTP for all novel implants. Patients who paid more than $50,000 for their current car were more WTP for decreased complications. This study shows that patients' risk taking and spending behavior influences their WTP for novel implants.

Cancer risk among patients with finger and hand joint and temporo-mandibular joint prostheses in Denmark.

Science.gov (United States)

Fryzek, J P; Mellemkjaer, L; McLaughlin, J K; Blot, W J; Olsen, J H

1999-05-31

The use of artificial joint implants has risen greatly over the past years. However, few investigations of the cancer risk associated with implants have been performed. We investigated cancer risk in patients with finger and hand joint and temporo-mandibular (TMJ) joint implants. A nationwide cohort in Denmark of patients with finger and hand joint prostheses (n = 858) or TMJ implants (n = 389) was followed from January 1, 1977, to December 31, 1995, to evaluate any potential cancer risks subsequent to receiving these implants. Standardized incidence ratios (SIRs) for all cancers were 1.0 (95% CI = 0.8-1.2) for the finger and hand joint cohort and 1.1 (95% CI = 0.8-1.7) for the TMJ cohort. A significant risk for non-Hodgkin's lymphoma was found in the finger and hand joint cohort (SIR = 3.8, 95% CI = 1.5-7.8). When the finger and hand joint cohort was stratified by diagnosis of rheumatoid arthritis, the excess risk was seen only in the group with rheumatoid arthritis. This is consistent with past studies, which have found an association between rheumatoid arthritis and non-Hodgkin's lymphoma. Our results provide evidence that the cancer risk for patients with finger and hand joint prostheses and TMJ implants is similar to that for the general population.

Osteoarthritis of the first carpometacarpal joint: a study of radiology and clinical epidemiology:

DEFF Research Database (Denmark)

Sonne-Holm, Stig; Jacobsen, J

2006-01-01

Epidemiological studies show an increased prevalence of osteoarthritis of the knee and hand with increased body mass index [BMI]. Osteoarthritis of the hip joint is not related to BMI. The connection between obesity and osteoarthritis cannot exclusively be explained by genetic factors or by the a...

Is early osteoarthritis associated with differences in joint congruence?

Science.gov (United States)

Conconi, Michele; Halilaj, Eni; Parenti Castelli, Vincenzo; Crisco, Joseph J

2014-12-18

Previous studies suggest that osteoarthritis (OA) is related to abnormal or excessive articular contact stress. The peak pressure resulting from an applied load is determined by many factors, among which is shape and relative position and orientation of the articulating surfaces or, referring to a more common nomenclature, joint congruence. It has been hypothesized that anatomical differences may be among the causes of OA. Individuals with less congruent joints would likely develop higher peak pressure and thus would be more exposed to the risk of OA onset. The aim of this work was to determine if the congruence of the first carpometacarpal (CMC) joint differs with the early onset of OA or with sex, as the female population has a higher incidence of OA. 59 without and 38 with early OA were CT-scanned with their dominant or arthritic hand in a neutral configuration. The proposed measure of joint congruence is both shape and size dependent. The correlation of joint congruence with pathology and sex was analyzed both before and after normalization for joint size. We found a significant correlation between joint congruence and sex due to the sex-related differences in size. The observed correlation disappeared after normalization. Although joint congruence increased with size, it did not correlate significantly with the onset of early OA. Differences in joint congruence in this population may not be a primary cause of OA onset or predisposition, at least for the CMC joint. Copyright © 2014 Elsevier Ltd. All rights reserved.

Posteromedial impingement (POMI) of the ankle: MR imaging features

International Nuclear Information System (INIS)

Koulouris, G.; Connell, D.

2002-01-01

Full text: The purpose of this study is to describe the normal MR Imaging appearance of the supporting ligaments of the first carpometacarpal joint in asymptomatic volunteers and the ligamentous injury in patients following dislocation. Three healthy volunteers underwent MR Imaging of the first carpometacarpal joint in order to describe the normal ligaments and optimise the scanning technique for assessment of this joint. Six patients underwent MR Imaging after injury to the ligament. All patients were injured after a fall in which the thumb was subluxed during hyperextension.The Anterior Oblique Ligament (AOL) was evaluated for abnormal morphology and signal intensity, including the site of the injury and the degree of tearing. Joint alignment was assessed for instability. The four ligaments felt to contribute to the stability of the first joint were reliably identified. The normal ligament is a continuous band of low signal running from one bone attachment to another. With injury, there is disruption of the ligament, hyperintensity and perforated stripping. The AOL was shown to be consistently injured after dislocation close to the metacarpal side. MR Imaging allows accurate evaluation of injuries of the AOL of the first carpometacarpal joint and identifies patients who would benefit from surgical reconstruction. Copyright (2002) Blackwell Science Pty Ltd

Nanostructured diamond film deposition on curved surfaces of metallic temporomandibular joint implant

Energy Technology Data Exchange (ETDEWEB)

Fries, Marc D; Vohra, Yogesh K [Department of Physics, University of Alabama at Birmingham (UAB), Birmingham, AL (United States)

2002-10-21

Microwave plasma chemical vapour deposition of nanostructured diamond films was carried out on curved surfaces of Ti-6Al-4V alloy machined to simulate the shape of a temporomandibular joint (TMJ) dental implant. Raman spectroscopy shows that the deposited films are uniform in chemical composition along the radius of curvature of the TMJ condyle. Thin film x-ray diffraction reveals an interfacial carbide layer and nanocrystalline diamond grains in this coating. Nanoindentation hardness measurements show an ultra-hard coating with a hardness value of 60{+-}5 GPa averaged over three samples. (rapid communication)

Biomechanical analysis of clavicle hook plate implantation with different hook angles in the acromioclavicular joint.

Science.gov (United States)

Hung, Li-Kun; Su, Kuo-Chih; Lu, Wen-Hsien; Lee, Cheng-Hung

2017-08-01

A clavicle hook plate is a simple and effective method for treating acromioclavicular dislocation and distal clavicle fractures. However, subacromial osteolysis and peri-implant fractures are complicated for surgeons to manage. This study uses finite element analysis (FEA) to investigate the post-implantation biomechanics of clavicle hook plates with different hook angles. This FEA study constructed a model with a clavicle, acromion, clavicle hook plate, and screws to simulate the implantation of clavicle hook plates at different hook angles (90°, 95°, 100°, 105°, and 110°) for treating acromioclavicular joint dislocations. This study investigated the biomechanics of the acromion, clavicle, hook plate, and screws. A smaller hook angle increases the stress on the middle third of the clavicle. A larger hook angle increases the force exerted by the clavicle hook plate on the acromion. The screw at the most medial position on the plate generated the highest stress. The highest stress on the implanted clavicle hook plate was on the turning corner of the hook. A clavicle hook plate with different hook angles may induce different biomechanical behaviors in the clavicle and acromion. Orthopedic surgeons must select a suitable clavicle hook plate based on the anatomical structure of each patient.

[Clinical Trial to Test the iFuse Implant System® in Patients with Sacroiliac Joint Syndrome: One Year Results].

Science.gov (United States)

Bornemann, R; Pflugmacher, R; Webler, M; Koch, E M W; Dengler, J; Wirtz, D C; Frey, S P

2016-12-01

Background: This study reports one year post-operative monitoring of the efficacy and safety of iFuse Implant System® in patients with sacroiliac joint syndrome. Material and Methods: After 6 months of inadequate conservative treatment, patients with properly proven ISG syndrome were selected for surgery. The iFuse implants had a triangular profile and coating of porous titanium plasma spray and were used in the minimally invasive procedures. The procedure was performed under general anaesthesia and fluoroscopic control. In each case, three implants were placed. Results: 24 patients (22 f; 92 %; 54.9 ± 14 years) participated in the study. The operations were performed in 11 patients (46 %) on the left and in 13 patients (54 %) on the right. The mean operative time was 42.4 minutes (95 % CI: 35.6-49.3). The reduction in pain intensity on the VAS scale was 58 ± 11 mm (68 ± 7 %). The Oswestry score showed a median decrease of 44 percentage points (57 %). After 12 months, 15 patients (63 %) reported that they were taking no more painkillers. Conclusion: The minimally invasive treatment of patients with sacroiliac joint syndrome using the iFuse Implant System leads to significant analgesic effects over the period of one year; it also contributes significantly to improving the functioning of the patient. Georg Thieme Verlag KG Stuttgart · New York.

Sacroiliac Joint Fusion Using Triangular Titanium Implants vs. Non-Surgical Management: Six-Month Outcomes from a Prospective Randomized Controlled Trial.

Science.gov (United States)

Whang, Peter; Cher, Daniel; Polly, David; Frank, Clay; Lockstadt, Harry; Glaser, John; Limoni, Robert; Sembrano, Jonathan

2015-01-01

Sacroiliac (SI) joint pain is a prevalent, underdiagnosed cause of lower back pain. SI joint fusion can relieve pain and improve quality of life in patients who have failed nonoperative care. To date, no study has concurrently compared surgical and non-surgical treatments for chronic SI joint dysfunction. We conducted a prospective randomized controlled trial of 148 subjects with SI joint dysfunction due to degenerative sacroiliitis or sacroiliac joint disruptions who were assigned to either minimally invasive SI joint fusion with triangular titanium implants (N=102) or non-surgical management (NSM, n=46). SI joint pain scores, Oswestry Disability Index (ODI), Short-Form 36 (SF-36) and EuroQol-5D (EQ-5D) were collected at baseline and at 1, 3 and 6 months after treatment commencement. Six-month success rates, defined as the proportion of treated subjects with a 20-mm improvement in SI joint pain in the absence of severe device-related or neurologic SI joint-related adverse events or surgical revision, were compared using Bayesian methods. Subjects (mean age 51, 70% women) were highly debilitated at baseline (mean SI joint VAS pain score 82, mean ODI score 62). Six-month follow-up was obtained in 97.3%. By 6 months, success rates were 81.4% in the surgical group vs. 23.9% in the NSM group (difference of 56.6%, 95% posterior credible interval 41.4-70.0%, posterior probability of superiority >0.999). Clinically important (≥15 point) ODI improvement at 6 months occurred in 75% of surgery subjects vs. 27.3% of NSM subjects. At six months, quality of life improved more in the surgery group and satisfaction rates were high. The mean number of adverse events in the first six months was slightly higher in the surgical group compared to the non-surgical group (1.3 vs. 1.0 events per subject, p=0.1857). Six-month follow-up from this level 1 study showed that minimally invasive SI joint fusion using triangular titanium implants was more effective than non-surgical management

The Not-So-Good Prognosis of Streptococcal Periprosthetic Joint Infection Managed by Implant Retention : The Results of a Large Multicenter Study

NARCIS (Netherlands)

Lora-Tamayo, Jaime; Senneville, Éric; Ribera, Alba; Bernard, Louis; Dupon, Michel; Zeller, Valérie; Li, Ho Kwong; Arvieux, Cédric; Clauss, Martin; Uçkay, Ilker; Vigante, Dace; Ferry, Tristan; Iribarren, José Antonio; Peel, Trisha N; Sendi, Parham; Miksic, Nina Gorišek; Rodríguez-Pardo, Dolors; Del Toro, María Dolores; Fernández-Sampedro, Marta; Dapunt, Ulrike; Huotari, Kaisa; Davis, Joshua S; Palomino, Julián; Neut, Danielle; Clark, Benjamin M; Gottlieb, Thomas; Trebše, Rihard; Soriano, Alex; Bahamonde, Alberto; Guío, Laura; Rico, Alicia; Salles, Mauro J C; Pais, M José G; Benito, Natividad; Riera, Melchor; Gómez, Lucía; Aboltins, Craig A; Esteban, Jaime; Horcajada, Juan Pablo; O'Connell, Karina; Ferrari, Matteo; Skaliczki, Gábor; Juan, Rafael San; Cobo, Javier; Sánchez-Somolinos, Mar; Ramos, Antonio; Giannitsioti, Efthymia; Jover-Sáenz, Alfredo; Baraia-Etxaburu, Josu Mirena; Barbero, José María

2017-01-01

Background.: Streptococci are not an infrequent cause of periprosthetic joint infection (PJI). Management by debridement, antibiotics, and implant retention (DAIR) is thought to produce a good prognosis, but little is known about the real likelihood of success. Methods.: A retrospective,

Precision of fit between implant impression coping and implant replica pairs for three implant systems.

Science.gov (United States)

Nicoll, Roxanna J; Sun, Albert; Haney, Stephan; Turkyilmaz, Ilser

2013-01-01

The fabrication of an accurately fitting implant-supported fixed prosthesis requires multiple steps, the first of which is assembling the impression coping on the implant. An imprecise fit of the impression coping on the implant will cause errors that will be magnified in subsequent steps of prosthesis fabrication. The purpose of this study was to characterize the 3-dimensional (3D) precision of fit between impression coping and implant replica pairs for 3 implant systems. The selected implant systems represent the 3 main joint types used in implant dentistry: external hexagonal, internal trilobe, and internal conical. Ten impression copings and 10 implant replicas from each of the 3 systems, B (Brånemark System), R (NobelReplace Select), and A (NobelActive) were paired. A standardized aluminum test body was luted to each impression coping, and the corresponding implant replica was embedded in a stone base. A coordinate measuring machine was used to quantify the maximum range of displacement in a vertical direction as a function of the tightening force applied to the guide pin. Maximum angular displacement in a horizontal plane was measured as a function of manual clockwise or counterclockwise rotation. Vertical and rotational positioning was analyzed by using 1-way analysis of variance (ANOVA). The Fisher protected least significant difference (PLSD) multiple comparisons test of the means was applied when the F-test in the ANOVA was significant (α=.05). The mean and standard deviation for change in the vertical positioning of impression copings was 4.3 ±2.1 μm for implant system B, 2.8 ±4.2 μm for implant system R, and 20.6 ±8.8 μm for implant system A. The mean and standard deviation for rotational positioning was 3.21 ±0.98 degrees for system B, 2.58 ±1.03 degrees for system R, and 5.30 ±0.79 degrees for system A. The P-value for vertical positioning between groups A and B and between groups A and R was <.001. No significant differences were found for

Effect of lubricant on the reliability of dental implant abutment screw joint: An in vitro laboratory and three-dimension finite element analysis.

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Wu, Tingting; Fan, Hongyi; Ma, Ruiyang; Chen, Hongyu; Li, Zhi; Yu, Haiyang

2017-06-01

Biomechanical factors play a key role in the success of dental implants. Fracture and loosening of abutment screws are major issues. This study investigated the effect of lubricants on the stability of dental implant-abutment connection. As lubricants, graphite and vaseline were coated on the abutment screw surface, respectively, and a blank without lubricant served as the control. The total friction coefficient (μ tot ), clamping force, fatigue behavior and detorque of the joint combined with dynamic cyclic loading were measured under different lubricating conditions. Further, a three-dimensional finite element analysis was used to investigate stress distribution, in conjunction with experimental images. The results showed that the lubricant reduced μ tot , which in turn led to an increase in clamping force. Decrease in loading increased the fatigue life of the screw. However, use of lubricant at high load reduced the fatigue life. Ductile fracture at the first thread of the screw was the chief failure mode, which was due to maximum von Mises stress. Higher stress levels occurred in the lubricant groups. Lubricated screws resulted in lower detorque which made the joint easier to loosen. In conclusion, the lubricant cannot effectively improve the reliability of dental implant-abutment connection. Keeping the interfaces of implant-screw uncontaminated and strengthening the surface of the screw may be recommend for clinical operation and future design. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of prosthesis design and implantation technique on implant stresses after cementless revision THR

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Duda Georg N

2011-05-01

Full Text Available Abstract Background Femoral offset influences the forces at the hip and the implant stresses after revision THR. For extended bone defects, these forces may cause considerable bending moments within the implant, possibly leading to implant failure. This study investigates the influences of femoral anteversion and offset on stresses in the Wagner SL revision stem implant under varying extents of bone defect conditions. Methods Wagner SL revision stems with standard (34 mm and increased offset (44 mm were virtually implanted in a model femur with bone defects of variable extent (Paprosky I to IIIb. Variations in surgical technique were simulated by implanting the stems each at 4° or 14° of anteversion. Muscle and joint contact forces were applied to the reconstruction and implant stresses were determined using finite element analyses. Results Whilst increasing the implant's offset by 10 mm led to increased implant stresses (16.7% in peak tensile stresses, altering anteversion played a lesser role (5%. Generally, larger stresses were observed with reduced bone support: implant stresses increased by as much as 59% for a type IIIb defect. With increased offset, the maximum tensile stress was 225 MPa. Conclusion Although increased stresses were observed within the stem with larger offset and increased anteversion, these findings indicate that restoration of offset, key to restoring joint function, is unlikely to result in excessive implant stresses under routine activities if appropriate fixation can be achieved.

Post-operative X-ray morphology: Joints

International Nuclear Information System (INIS)

Vogel, H.

1987-01-01

The description of X-ray findings after operations with the object of implanting protheses in joints makes up most of the contents of this book. The reconstruction of joints after trauma is only marginally dealt with. Among the various indications for implanting protheses, the replacement of joints destroyed by wear and trauma is the most important. Also considered were X-ray examinations after hallux-valgus operations and plastic surgery on hands and feet, as well as X-ray findings following operations on the lumbar part of the vertebral column (disc surgery). (orig./MG) [de

Joint unloading implant modifies subchondral bone trabecular structure in medial knee osteoarthritis: 2-year outcomes of a pilot study using fractal signature analysis

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Miller LE

2015-01-01

Full Text Available Larry E Miller,1,2 Miki Sode,3 Thomas Fuerst,3 Jon E Block2 1Miller Scientific Consulting, Inc., Asheville, NC, USA; 2The Jon Block Group, San Francisco, CA, USA; 3Bioclinica, Newark, CA, USA Background: Knee osteoarthritis (OA is largely attributable to chronic excessive and aberrant joint loading. The purpose of this pilot study was to quantify radiographic changes in subchondral bone after treatment with a minimally invasive joint unloading implant (KineSpring® Knee Implant System.Methods: Nine patients with unilateral medial knee OA resistant to nonsurgical therapy were treated with the KineSpring System and followed for 2 years. Main outcomes included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC pain, function, and stiffness subscores and independent core laboratory determinations of joint space width and fractal signature of the tibial cortex.Results: WOMAC scores, on average, improved by 92% for pain, 91% for function, and 79% for stiffness over the 2-year follow-up period. Joint space width in the medial compartment of the treated knee significantly increased from 0.9 mm at baseline to 3.1 mm at 2 years; joint space width in the medial compartment of the untreated knee was unchanged. Fractal signatures of the vertically oriented trabeculae in the medial compartment decreased by 2.8% in the treated knee and increased by 2.1% in the untreated knee over 2 years. No statistically significant fractal signature changes were observed in the horizontally oriented trabeculae in the medial compartment or in the horizontal or vertical trabeculae of the lateral compartment in the treated knee.Conclusion: Preliminary evidence suggests that the KineSpring System may modify knee OA disease progression by increasing joint space width and improving subchondral bone trabecular integrity, thereby reducing pain and improving joint function. Keywords: disease modification, KineSpring, joint space, pain, trabecular

Hand osteoarthritis: Differential diagnosis with inflammatory joint diseases and treatment policy

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Yu. A. Olyunin

2015-01-01

Full Text Available Osteoarthritis (OA usually affects certain joint groups selectively and the hand joints (HJ are one of its classical locations. Hand OA is widespread in the population. In their practice rheumatologists encounter HJ injury in OA in 38% of cases. It is conventional to identify three main types of hand OA. These are 1 interphalangeal OA that may or may not be accompanied by nodulation; 2 first carpometacarpal OA; and 3 erosive OA. At the same time, the rate of clinical forms ranges from 2.0 to 6.2%; it is 4.7 to 20.4% in the elderly. Nonsteroidal antiinflammatory drugs (NSAIDs are most commonly used to relieve pain that is the main manifestation of the disease. The risk for NSAID-related adverse gastrointestinal (GI events is substantially reduced by the drugs that exert their effects mainly on cyclooxygenase 2. These include nimesulide in particular. Undesirable GI effects may be also considerably minimized by using NSAIDs that have both their gastroprotective and antiinflammatory activities. By suppressing pain and inflammatory changes, the recently designed NSAID amtolmetin guacil simultaneously exerts a protective effect on the GI mucosa, by elevating its nitric oxide levels.

Does aquatic exercise reduce hip and knee joint loading? In vivo load measurements with instrumented implants.

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Ines Kutzner

Full Text Available Aquatic exercises are widely used for rehabilitation or preventive therapies in order to enable mobilization and muscle strengthening while minimizing joint loading of the lower limb. The load reducing effect of water due to buoyancy is a main advantage compared to exercises on land. However, also drag forces have to be considered that act opposite to the relative motion of the body segments and require higher muscle activity. Due to these opposing effects on joint loading, the load-reducing effect during aquatic exercises remains unknown. The aim of this study was to quantify the joint loads during various aquatic exercises and to determine the load reducing effect of water. Instrumented knee and hip implants with telemetric data transfer were used to measure the resultant joint contact forces in 12 elderly subjects (6x hip, 6x knee in vivo. Different dynamic, weight-bearing and non-weight-bearing activities were performed by the subjects on land and in chest-high water. Non-weight-bearing hip and knee flexion/extension was performed at different velocities and with additional Aquafins. Joint forces during aquatic exercises ranged between 32 and 396% body weight (BW. Highest forces occurred during dynamic activities, followed by weight-bearing and slow non-weight-bearing activities. Compared to the same activities on land, joint forces were reduced by 36-55% in water with absolute reductions being greater than 100%BW during weight-bearing and dynamic activities. During non-weight-bearing activities, high movement velocities and additional Aquafins increased the joint forces by up to 59% and resulted in joint forces of up to 301%BW. This study confirms the load reducing effect of water during weight-bearing and dynamic exercises. Nevertheless, high drag forces result in increased joint contact forces and indicate greater muscle activity. By the choice of activity, movement velocity and additional resistive devices joint forces can be modulated

Neural network based automated algorithm to identify joint locations on hand/wrist radiographs for arthritis assessment

International Nuclear Information System (INIS)

Duryea, J.; Zaim, S.; Wolfe, F.

2002-01-01

Arthritis is a significant and costly healthcare problem that requires objective and quantifiable methods to evaluate its progression. Here we describe software that can automatically determine the locations of seven joints in the proximal hand and wrist that demonstrate arthritic changes. These are the five carpometacarpal (CMC1, CMC2, CMC3, CMC4, CMC5), radiocarpal (RC), and the scaphocapitate (SC) joints. The algorithm was based on an artificial neural network (ANN) that was trained using independent sets of digitized hand radiographs and manually identified joint locations. The algorithm used landmarks determined automatically by software developed in our previous work as starting points. Other than requiring user input of the location of nonanatomical structures and the orientation of the hand on the film, the procedure was fully automated. The software was tested on two datasets: 50 digitized hand radiographs from patients participating in a large clinical study, and 60 from subjects participating in arthritis research studies and who had mild to moderate rheumatoid arthritis (RA). It was evaluated by a comparison to joint locations determined by a trained radiologist using manual tracing. The success rate for determining the CMC, RC, and SC joints was 87%-99%, for normal hands and 81%-99% for RA hands. This is a first step in performing an automated computer-aided assessment of wrist joints for arthritis progression. The software provides landmarks that will be used by subsequent image processing routines to analyze each joint individually for structural changes such as erosions and joint space narrowing

Utility of Intraoperative Neuromonitoring during Minimally Invasive Fusion of the Sacroiliac Joint.

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Woods, Michael; Birkholz, Denise; MacBarb, Regina; Capobianco, Robyn; Woods, Adam

2014-01-01

Study Design. Retrospective case series. Objective. To document the clinical utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion for patients diagnosed with sacroiliac joint dysfunction (as a direct result of sacroiliac joint disruptions or degenerative sacroiliitis) and determine stimulated electromyography thresholds reflective of favorable implant position. Summary of Background Data. Intraoperative neuromonitoring is a well-accepted adjunct to minimally invasive pedicle screw placement. The utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion using a series of triangular, titanium porous plasma coated implants has not been evaluated. Methods. A medical chart review of consecutive patients treated with minimally invasive surgical sacroiliac joint fusion was undertaken at a single center. Baseline patient demographics and medical history, intraoperative electromyography thresholds, and perioperative adverse events were collected after obtaining IRB approval. Results. 111 implants were placed in 37 patients. Sensitivity of EMG was 80% and specificity was 97%. Intraoperative neuromonitoring potentially avoided neurologic sequelae as a result of improper positioning in 7% of implants. Conclusions. The results of this study suggest that intraoperative neuromonitoring may be a useful adjunct to minimally invasive surgical sacroiliac joint fusion in avoiding nerve injury during implant placement.

Utility of Intraoperative Neuromonitoring during Minimally Invasive Fusion of the Sacroiliac Joint

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Michael Woods

2014-01-01

Full Text Available Study Design. Retrospective case series. Objective. To document the clinical utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion for patients diagnosed with sacroiliac joint dysfunction (as a direct result of sacroiliac joint disruptions or degenerative sacroiliitis and determine stimulated electromyography thresholds reflective of favorable implant position. Summary of Background Data. Intraoperative neuromonitoring is a well-accepted adjunct to minimally invasive pedicle screw placement. The utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion using a series of triangular, titanium porous plasma coated implants has not been evaluated. Methods. A medical chart review of consecutive patients treated with minimally invasive surgical sacroiliac joint fusion was undertaken at a single center. Baseline patient demographics and medical history, intraoperative electromyography thresholds, and perioperative adverse events were collected after obtaining IRB approval. Results. 111 implants were placed in 37 patients. Sensitivity of EMG was 80% and specificity was 97%. Intraoperative neuromonitoring potentially avoided neurologic sequelae as a result of improper positioning in 7% of implants. Conclusions. The results of this study suggest that intraoperative neuromonitoring may be a useful adjunct to minimally invasive surgical sacroiliac joint fusion in avoiding nerve injury during implant placement.

Natural polyphenols enhance stability of crosslinked UHMWPE for joint implants.

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Shen, Jie; Gao, Guorong; Liu, Xincai; Fu, Jun

2015-03-01

Radiation-crosslinked UHMWPE has been used for joint implants since the 1990s. Postirradiation remelting enhances oxidative stability, but with some loss in strength and toughness. Vitamin E-stabilized crosslinked UHMWPE has shown improved strength and stability as compared with irradiated and remelted UHMWPE. With more active phenolic hydroxyl groups, natural polyphenols are widely used in the food and pharmaceutical industries as potent stabilizers and could be useful for oxidative stability in crosslinked UHMWPE. We asked whether UHMWPE blended with polyphenols would (1) show higher oxidation resistance after radiation crosslinking; (2) preserve the mechanical properties of UHMWPE after accelerated aging; and (3) alter the wear resistance of radiation-crosslinked UHMWPE. The polyphenols, gallic acid and dodecyl gallate, were blended with medical-grade UHMWPE followed by consolidation and electron beam irradiation at 100 kGy. Radiation-crosslinked virgin and vitamin E-blended UHMWPEs were used as reference materials. The UHMWPEs were aged at 120 °C in air with oxidation levels analyzed by infrared spectroscopy. Tensile (n = 5 per group) and impact (n = 3 per group) properties before and after aging as per ASTM F2003 were evaluated. The wear rates were examined by pin-on-disc testing (n = 3 per group). The data were reported as mean ± SDs. Statistical analysis was performed by using Student's t-test for a two-tailed distribution with unequal variance for tensile and impact data obtained with n ≥ 3. A significant difference is defined with p Accelerated aging of these polyphenol-blended UHMWPEs resulted in ultimate tensile strength of 50.4 ± 1.4 MPa and impact strength of 53 ± 5 kJ/m(2) for 100 kGy-irradiated UHMWPE with 0.05 wt% dodecyl gallate, for example, in comparison to 51.2 ± 0.7 MPa (p = 0.75) and 58 ± 5 kJ/m(2) (p = 0.29) before aging. The pin-on-disc wear rates of 100 kGy-irradiated UHMWPE with 0.05 wt% dodecyl gallate and 0.05 wt% gallic acid

Design and clinical outcome of a novel 3D-printed prosthetic joint replacement for the human temporomandibular joint.

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Ackland, David; Robinson, Dale; Lee, Peter Vee Sin; Dimitroulis, George

2018-05-11

Stock prosthetic temporomandibular joint replacements come in limited sizes, and do not always encompass the joint anatomy that presents clinically. The aims of this study were twofold. Firstly, to design a personalized prosthetic total joint replacement for the treatment of a patient's end-stage temporomandibular joint osteoarthritis, to implant the prosthesis into the patient, and assess clinical outcome 12-months post-operatively; and secondly, to evaluate the influence of changes in prosthetic condyle geometry on implant load response during mastication. A 48-year-old female patient with Grade-5 osteoarthritis to the left temporomandibular joint was recruited, and a prosthesis developed to match the native temporomandibular joint anatomy. The prosthesis was 3D printed, sterilized and implanted into the patient, and pain and function measured 12-months post-operatively. The prosthesis load response during a chewing-bite and maximum-force bite was evaluated using a personalized multi-body musculoskeletal model. Simulations were performed after perturbing condyle thickness, neck length and head sphericity. Increases in prosthetic condyle neck length malaligned the mandible and perturbed temporomandibular joint force. Changes in condylar component thickness greatly influenced fixation screw stress response, while a more eccentric condylar head increased prosthetic joint-contact loading. Post-operatively, the prosthetic temporomandibular joint surgery reduced patient pain from 7/10 to 1/10 on a visual analog scale, and increased intercisal opening distance from 22 mm to 38 mm. This study demonstrates effectiveness of a personalized prosthesis that may ultimately be adapted to treat a wide-range of end-stage temporomandibular joint conditions, and highlights sensitivity of prosthesis load response to changes in condylar geometry. Copyright © 2018 Elsevier Ltd. All rights reserved.

Physicochemical and microscopic characterization of implant–abutment joints

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Lopes, Patricia A.; Carreiro, Adriana F. P.; Nascimento, Rubens M.; Vahey, Brendan R.; Henriques, Bruno; Souza, Júlio C. M.

2018-01-01

Objective: The purpose of this study was to investigate Morse taper implant–abutment joints by chemical, mechanical, and microscopic analysis. Materials and Methods: Surfaces of 10 Morse taper implants and the correlated abutments were inspected by field emission gun-scanning electron microscopy (FEG-SEM) before connection. The implant–abutment connections were tightened at 32 Ncm. For microgap evaluation by FEG-SEM, the systems were embedded in epoxy resin and cross-sectioned at a perpendicular plane of the implant–abutment joint. Furthermore, nanoindentation tests and chemical analysis were performed at the implant–abutment joints. Statistics: Results were statistically analyzed via one-way analysis of variance, with a significance level of P abutment surfaces. The minimum and maximum size of microgaps ranged from 0.5 μm up to 5.6 μm. Furthermore, defects were detected throughout the implant–abutment joint that can, ultimately, affect the microgap size after connection. Nanoindentation tests revealed a higher hardness (4.2 ± 0.4 GPa) for abutment composed of Ti6Al4V alloy when compared to implant composed of commercially pure Grade 4 titanium (3.2 ± 0.4 GPa). Conclusions: Surface defects produced during the machining of both implants and abutments can increase the size of microgaps and promote a misfit of implant–abutment joints. In addition, the mismatch in mechanical properties between abutment and implant can promote the wear of surfaces, affecting the size of microgaps and consequently the performance of the joints during mastication. PMID:29657532

Granulomatous pseudotumors in total joint replacement

International Nuclear Information System (INIS)

Griffiths, H.J.; Burke, J.; Bonfiglio, T.A.

1987-01-01

Fourteen patients (15 joints) developed a foreign body reaction to methylmethacrylate, polyethylene, or metal adjacent to a total joint implant, a condition we would like to term granulomatous pseudotumors. There were eight male and six female patients. Their average age was 61 years. The hip was involved in 14 joints (femoral component 11 times, acetabulum 7, and greater trochanter once). One patient presented with granulomatous pseudotumors of the knee. The principal findings included increasing pain and radiographic evidence of loosening occurring on average 2.7 years following the implant. This was followed by a characteristic and gradually developing radiographic pattern of discrete rounded lucencies. These developed into large ovoid lytic areas, destroying both methylmethacrylate and bone. Histologically, the appearances were characterized by histiocytic infiltration and the presence of multiple foreign body giant cells. Foreign material was identified in 9 of 11 cases. The pathogenesis is unknown but appears related to micromovement or loosening of the implant. (orig.)

Intrinsic constraint of unlinked total elbow replacements--the ulnotrochlear joint.

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Kamineni, S; O'Driscoll, S W; Urban, M; Garg, A; Berglund, L J; Morrey, B F; An, K N

2005-09-01

Many unlinked total elbow replacement designs with radically differing articular geometries exist, suggesting that there is no consensus regarding an optimal design. A feature inherent to the articular design is the intrinsic constraint afforded to the joint by the implant. Our aim was to compare the intrinsic constraints of unlinked implants with that of the normal ulnotrochlear joint. We tested twelve cadaveric ulnotrochlear joints with a custom-made multiple-axis materials testing machine. With compressive loads ranging from 10 to 100 N, the joints were moved in either valgus or varus directions at 90 degrees of flexion. The ulnotrochlear components from a single example of five medium-sized unlinked elbow replacements (Ewald, Kudo, Pritchard ERS, Sorbie-Questor, and Souter-Strathclyde) were also tested. The recorded measurements included the torques and forces, angular displacement, and axial displacement of the humerus relative to the ulna. In general, the peak torque and the constraint ratio significantly increased with increasing compressive load for the implants as well as for the normal elbow. In valgus displacement, the Souter-Strathclyde implant had the highest and the Sorbie-Questor had the smallest peak torque and the Souter-Strathclyde had the highest and the Ewald had the smallest constraint ratio. In varus displacement, the Kudo had the highest and the Ewald had the smallest peak torque and constraint ratio. The constraint ratio is a characteristic that is useful for describing elbow joint behavior and for comparing the behavior of implants with that of the human elbow. Of the unlinked implants tested, the Souter-Strathclyde and Kudo prostheses most closely approximated the behavior of the human elbow joint. Implants that resemble the human elbow in appearance do not replicate normal behavior consistently, whereas other implants that do not resemble the human elbow closely do not deviate markedly from human behavior. Thus, much basic information

Outcome Assessment after Aptis Distal Radioulnar Joint (DRUJ Implant Arthroplasty

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Amir Reza Kachooei

2014-09-01

Full Text Available Background:  Conventional treatments after complicated injuries of the distal radioulnar joint (DRUJ such as Darrach and Kapandji-Sauvé procedures have many drawbacks, which may eventually lead to a painful unstable distal ulna.  The development of DRUJ prosthesis has significantly evolved over the past years. In this study, we assessed the outcome results of patients after DRUJ implant arthroplasty using the Aptis (Scheker prosthesis. Methods: We identified 13 patients with 14 prosthesis during the past 10 years. Patients underwent DRUJ arthroplasty due to persistent symptoms of instability, chronic pain, and stiffness. Records and follow-up visits were reviewed to find the final post-operative symptoms, pain, range of motion, and grip strength with a mean follow-up of 12 months (range: 2-25 months. Also, patients were contacted prospectively by phone in order to  minister the disabilities of the armshoulder and hand (DASH, patient rated wrist evaluation (PRWE, and visual analogue scale (VAS, and to interview regarding satisfaction and progress in daily activities. Eleven patients out of 13 could be reached with a median followup time of 60 months (range: 2 to 102 months.  Results: No patient required removal of the prosthesis. Only two patients underwent secondary surgeries in which both required debridement of the screw tip over the radius. The median DASH score, PRWE score, VAS, and satisfaction were 1.3, 2.5, 0, and 10, respectively. The mean range of flexion, extension, supination, and pronation was 62, 54, 51, and 64, respectively. Conclusions: Distal radioulnar joint injuries are disabling and patients usually undergo one or more salvage surgeries prior to receiving an arthroplasty. The Scheker prosthesis has shown satisfactory results with 100% survival rate in all reports. The constrained design of this prosthesis gives enough stability to prevent painful subluxation.

Effects of the implant design on peri-implant bone stress and abutment micromovement: three-dimensional finite element analysis of original computer-aided design models.

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Yamanishi, Yasufumi; Yamaguchi, Satoshi; Imazato, Satoshi; Nakano, Tamaki; Yatani, Hirofumi

2014-09-01

Occlusal overloading causes peri-implant bone resorption. Previous studies examined stress distribution in alveolar bone around commercial implants using three-dimensional (3D) finite element analysis. However, the commercial implants contained some different designs. The purpose of this study is to reveal the effect of the target design on peri-implant bone stress and abutment micromovement. Six 3D implant models were created for different implant-abutment joints: 1) internal joint model (IM); 2) external joint model (EM); 3) straight abutment (SA) shape; 4) tapered abutment (TA) shapes; 5) platform switching (PS) in the IM; and 6) modified TA neck design (reverse conical neck [RN]). A static load of 100 N was applied to the basal ridge surface of the abutment at a 45-degree oblique angle to the long axis of the implant. Both stress distribution in peri-implant bone and abutment micromovement in the SA and TA models were analyzed. Compressive stress concentrated on labial cortical bone and tensile stress on the palatal side in the EM and on the labial side in the IM. There was no difference in maximum principal stress distribution for SA and TA models. Tensile stress concentration was not apparent on labial cortical bone in the PS model (versus IM). Maximum principal stress concentrated more on peri-implant bone in the RN than in the TA model. The TA model exhibited less abutment micromovement than the SA model. This study reveals the effects of the design of specific components on peri-implant bone stress and abutment displacement after implant-supported single restoration in the anterior maxilla.

Randomized Controlled Trial of Minimally Invasive Sacroiliac Joint Fusion Using Triangular Titanium Implants vs Nonsurgical Management for Sacroiliac Joint Dysfunction: 12-Month Outcomes

Science.gov (United States)

Polly, David W.; Wine, Kathryn D.; Whang, Peter G.; Frank, Clay J.; Harvey, Charles F.; Lockstadt, Harry; Glaser, John A.; Limoni, Robert P.; Sembrano, Jonathan N.

2015-01-01

BACKGROUND: Sacroiliac joint (SIJ) dysfunction is a prevalent cause of chronic, unremitting lower back pain. OBJECTIVE: To concurrently compare outcomes after surgical and nonsurgical treatment for chronic SIJ dysfunction. METHODS: A total of 148 subjects with SIJ dysfunction were randomly assigned to minimally invasive SIJ fusion with triangular titanium implants (n = 102) or nonsurgical management (n = 46). Pain, disability, and quality-of-life scores were collected at baseline and at 1, 3, 6, and 12 months. Success rates were compared using Bayesian methods. Crossover from nonsurgical to surgical care was allowed after the 6-month study visit was complete. RESULTS: Six-month success rates were higher in the surgical group (81.4% vs 26.1%; posterior probability of superiority > 0.9999). Clinically important (≥ 15 point) Oswestry Disability Index improvement at 6 months occurred in 73.3% of the SIJ fusion group vs 13.6% of the nonsurgical management group (P Sacroiliac Fusion Treatment MCS, mental component summary NSM, nonsurgical management ODI, Oswestry Disability Index PCS, physical component summary RFA, radiofrequency ablation SF-36, Short Form-36 SIJ, sacroiliac joint TTO, time trade-off VAS, visual analog scale PMID:26291338

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

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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.

Histological fate of abdominal dermis-fat grafts implanted in the temporomandibular joint of the rabbit following condylectomy.

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Dimitroulis, G; Slavin, J; Morrison, W

2011-02-01

The histological fate of abdominal dermis-fat grafts implanted into the temporomandibular joint (TMJ) following condylectomy was studied. 21 rabbits underwent left TMJ discectomies and condylectomies; 6 were controls (Group A; no graft used); 15 (Group B) had autogenous abdominal grafts transplanted into the left TMJ. Animals were killed after 4, 12 and 20 weeks. Specimens of the TMJ were histologically and histomorphometrically evaluated. At 4 weeks, fat necrosis was clear in all specimens. The dermis component survived and formed cysts with no necrosis. By 12 weeks, viable fat deposits appeared with no evidence of necrotic fat. At 20 weeks, large amounts of viable fat were present in Group B specimens. Group A had no fat, although the missing condyles regenerated. In the presence of viable fat, Group B showed little condyle regeneration 20 weeks after condylectomy. Non-vascularised fat grafts do not survive transplantation, but stimulate neoadipogenesis. The fate of the dermis component of the graft is independent of the fat component. Fat in the joint space disrupts the regeneration of a new condylar head. Neoadipogensis inhibits growth of new bone and cartilage. This has clinical implications for TMJ ankylosis management and preventing heterotopic bone formation around prosthetic joints. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Treatment of first metatarsophalangeal joint arthritis using hemiarthroplasty with a synthetic cartilage implant or arthrodesis: A comparison of operative and recovery time.

Science.gov (United States)

Glazebrook, Mark; Younger, Alastair S E; Daniels, Timothy R; Singh, Dishan; Blundell, Chris; de Vries, Gwyneth; Le, Ian L D; Nielsen, Dominic; Pedersen, M Elizabeth; Sakellariou, Anthony; Solan, Matthew; Wansbrough, Guy; Baumhauer, Judith F

2017-05-29

First metatarsophalangeal joint (MTPJ1) hemiarthroplasty using a novel synthetic cartilage implant was as effective and safe as MTPJ1 arthrodesis in a randomized clinical trial. We retrospectively evaluated operative time and recovery period for implant hemiarthroplasty (n=152) and MTPJ1 arthrodesis (n=50). Perioperative data were assessed for operative and anaesthesia times. Recovery and return to function were prospectively assessed with the Foot and Ankle Ability Measure (FAAM) Sports and Activities of Daily Living (ADL) subscales and SF-36 Physical Functioning (PF) subscore. Mean operative time for hemiarthroplasty was 35±12.3min and 58±21.5min for arthrodesis (pSport, FAAM ADL, and SF-36 PF subscores versus arthrodesis patients. MTPJ1 hemiarthroplasty with a synthetic cartilage implant took less operative time and resulted in faster recovery than arthrodesis. III, Retrospective case control study. Copyright © 2017 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Partial trapeziectomy and interposition of fascia lata allograft in the operative treatment of thumb base osteoarthritis

NARCIS (Netherlands)

Spaans, Anne J.; Weijns, Marieke E.; Braakenburg, Assa; Van Minnen, Leo Paul; Mink Van Der Molen, Aebele B.

2016-01-01

Aim: The purpose of this retrospective cohort study was to evaluate the results of fascia lata allograft interposition after partial trapeziectomy in patients with symptomatic first carpometacarpal joint osteoarthritis. Methods and results: Twenty-one patients (22 thumbs) with Eaton-Glickel stage II

Hyaluronic acid for the treatment of osteoarthritis in all joints except the knee: what is the current evidence?

Science.gov (United States)

Colen, Sascha; Haverkamp, Daniel; Mulier, Michiel; van den Bekerom, Michel P J

2012-04-01

The use of intra-articular hyaluronic acid (HA) is a well known treatment in patients with knee osteoarthritis (OA). In other joints, less evidence is available about the efficacy of treatment with intra-articular HA. HA is also used intra-articularly in the metatarsophalangeal-1 joint, the ankle, the hip, the sacroiliac joint, the facet joints, the carpometacarpal-1 joint, the shoulder and the temporo-mandibular joint. In this systematic review we include all prospective studies about the effects of intra-articular HA in the above-mentioned joints. Its use in the knee joint, however, will be discussed in a separate article in this journal. A systematic review was conducted using databases including MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Clinical Trial Register, and EMBASE. After performing a solid systematic review using a rigid methodology and trying to pool the outcomes of different studies, we noticed that, compared with baseline, there is statistical evidence for a positive effect of intra-articular HA. However, there is limited evidence HA is superior to placebo and no evidence that intra-articular HA is better than corticosteroids or other conservative therapies. Our recommendation for future research is that one should focus on adequately powered randomized trials comparing HA treatment with other types of intra-articular or conservative treatment. We think it is useless to further perform and publish (large) non-comparative prospective studies about the use of HA in the treatment of problems caused by OA. It is well perceived that HA exerts positive effects in the treatment of OA, but up to now there is no (strong) evidence available that HA is superior to other treatments of OA such as corticosteroids, physiotherapy or other conservative measures.

[Design and application of implantable medical device information management system].

Science.gov (United States)

Cao, Shaoping; Yin, Chunguang; Zhao, Zhenying

2013-03-01

Through the establishment of implantable medical device information management system, with the aid of the regional joint sharing of resources, we further enhance the implantable medical device traceability management level, strengthen quality management, control of medical risk.

Principles of human joint replacement design and clinical application

CERN Document Server

Buechel, Frederick F

2015-01-01

This book is written for the users and designers of joint replacements. In its second extended edition it conveys to the reader the knowledge accumulated by the authors during their forty year effort on the development of replacement devices for the lower limb for the purpose of aiding the reader in their design and evaluation of joint replacement devices. The early chapters describe the engineering, scientific and medical principles needed for replacement joint evaluation. One must understand the nature and performance of the materials involved and their characteristics in vivo, i.e. the response of the body to implant materials. It is also essential to understand the response of the implants to applied loading and motion, particularly in the hostile physiological environment. A chapter describes the design methodology now required for joint replacement in the USA and EU countries. The remaining chapters provide a history of joint replacement, an evaluation of earlier and current devices and sample case hist...

Multidisciplinary approach for in-deep assessment of joint prosthesis failure.

Science.gov (United States)

Tessarolo, F; Caola, I; Piccoli, F; Dorigotti, P; Demattè, E; Molinari, M; Malavolta, M; Barbareschi, M; Caciagli, P; Nollo, G

2009-01-01

In spite of advancement in biomaterials and biomechanics, in development of new osteo-integrative materials and coatings, and in macro- micro- component design, a non negligible fraction of the implanted prosthesis fails before the expected lifetime. A prospective observational clinical study has been conducted to define and apply a set of experimental techniques to in-deep assess the failure of joint prosthesis. Microbiological, histological and micro-structural techniques were implemented to specifically address phenomena occurring at the tissue-implant interface. Results obtained from 27 cases of prosthetic joint failure are discussed in terms of sensitivity and specificity. A procedural flow-chart is finally proposed for the assessment of joint prosthesis failure.

Assessment of Embedded Conjugated Polymer Sensor Arrays for Potential Load Transmission Measurement in Orthopaedic Implants

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Carolina Micolini

2017-11-01

Full Text Available Load transfer through orthopaedic joint implants is poorly understood. The longer-term outcomes of these implants are just starting to be studied, making it imperative to monitor contact loads across the entire joint implant interface to elucidate the force transmission and distribution mechanisms exhibited by these implants in service. This study proposes and demonstrates the design, implementation, and characterization of a 3D-printed smart polymer sensor array using conductive polyaniline (PANI structures embedded within a polymeric parent phase. The piezoresistive characteristics of PANI were investigated to characterize the sensing behaviour inherent to these embedded pressure sensor arrays, including the experimental determination of the stable response of PANI to continuous loading, stability throughout the course of loading and unloading cycles, and finally sensor repeatability and linearity in response to incremental loading cycles. This specially developed multi-material additive manufacturing process for PANI is shown be an attractive approach for the fabrication of implant components having embedded smart-polymer sensors, which could ultimately be employed for the measurement and analysis of joint loads in orthopaedic implants for in vitro testing.

Implant-Abutment Contact Surfaces and Microgap Measurements of Different Implant Connections Under 3-Dimensional X-Ray Microtomography.

Science.gov (United States)

Scarano, Antonio; Valbonetti, Luca; Degidi, Marco; Pecci, Raffaella; Piattelli, Adriano; de Oliveira, P S; Perrotti, Vittoria

2016-10-01

The presence of a microgap between implant and abutment could produce a bacterial reservoir which could interfere with the long-term health of the periimplant tissues. The aim of this article was to evaluate, by x-ray 3-dimensional microtomography, implant-abutment contact surfaces and microgaps at the implant-abutment interface in different types of implant-abutment connections. A total of 40 implants were used in this in vitro study. Ten implants presented a screw-retained internal hexagon abutment (group I), 10 had a Morse Cone taper internal connection (group II), 10 another type of Morse Cone taper internal connection (group III), and 10 had a screwed trilobed connection (group IV). In both types of Morse Cone internal connections, there was no detectable separation at the implant-abutment in the area of the conical connection, and there was an absolute congruity without any microgaps between abutment and implant. No line was visible separating the implant and the abutment. On the contrary, in the screwed abutment implants, numerous gaps and voids were present. The results of this study support the hypothesis that different types of implant-abutment joints are responsible for the observed differences in bacterial penetration.

The manufacture of generic replicas of implants for arthroplasty of the hip and knee: is it regulated and will it save money?

Science.gov (United States)

Atrey, A; Heylen, S; Gosling, O; Porteous, M J L; Haddad, F S

2016-07-01

Joint replacement of the hip and knee remain very satisfactory operations. They are, however, expensive. The actual manufacturing of the implant represents only 30% of the final cost, while sales and marketing represent 40%. Recently, the patents on many well established and successful implants have expired. Companies have started producing and distributing implants that purport to replicate existing implants with good long-term results. The aims of this paper are to assess the legality, the monitoring and cost saving implications of such generic implants. We also assess how this might affect the traditional orthopaedic implant companies. Cite this article: Bone Joint J 2016;98-B:892-900. ©2016 The British Editorial Society of Bone & Joint Surgery.

Association Between Patient Factors and Outcome of Synthetic Cartilage Implant Hemiarthroplasty vs First Metatarsophalangeal Joint Arthrodesis in Advanced Hallux Rigidus.

Science.gov (United States)

Goldberg, Andy; Singh, Dishan; Glazebrook, Mark; Blundell, Chris M; De Vries, Gwyneth; Le, Ian L D; Nielsen, Dominic; Pedersen, M Elizabeth; Sakellariou, Anthony; Solan, Matthew; Younger, Alastair S E; Daniels, Timothy R; Baumhauer, Judith F

2017-11-01

We evaluated data from a clinical trial of first metatarsophalangeal joint (MTPJ1) implant hemiarthroplasty and arthrodesis to determine the association between patient factors and clinical outcomes. Patients ≥18 years with hallux rigidus grade 2, 3, or 4 were treated with synthetic cartilage implant MTPJ1 hemiarthroplasty or arthrodesis. Pain visual analog scale (VAS), Foot and Ankle Ability Measure (FAAM) sports and activities of daily living (ADL) scores, and Short Form-36 Physical Function (SF-36 PF) subscore were obtained preoperatively, and at 2, 6, 12, 24, 52, and 104 weeks postoperatively. Final outcome data, great toe active dorsiflexion motion, secondary procedures, radiographs, and safety parameters were evaluated for 129 implant hemiarthroplasties and 47 arthrodeses. The composite primary endpoint criteria for clinical success included VAS pain reduction ≥30%, maintenance/improvement in function, no radiographic complications, and no secondary surgical intervention at 24 months. Predictor variables included hallux rigidus grade; gender; age; body mass index (BMI); symptom duration; prior MTPJ1 surgery; preoperative hallux valgus angle, range of motion (ROM), and pain. Two-sided Fisher exact test was used ( P .05) when stratified by hallux rigidus grade, gender, age, BMI, symptom duration, prior MTPJ1 surgery status, and preoperative VAS pain, hallux valgus, and ROM. Synthetic cartilage implant hemiarthroplasty was appropriate for patients with grade 2, 3, or 4 hallux rigidus. Its results in those with associated mild hallux valgus (≤20 degrees) or substantial preoperative stiffness were equivalent to MTPJ1 fusion, irrespective of gender, age, BMI, hallux rigidus grade, preoperative pain or symptom duration. Level II, randomized clinical trial.

Bioactive Coatings for Orthopaedic Implants—Recent Trends in Development of Implant Coatings

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Bill G. X. Zhang

2014-07-01

Full Text Available Joint replacement is a major orthopaedic procedure used to treat joint osteoarthritis. Aseptic loosening and infection are the two most significant causes of prosthetic implant failure. The ideal implant should be able to promote osteointegration, deter bacterial adhesion and minimize prosthetic infection. Recent developments in material science and cell biology have seen the development of new orthopaedic implant coatings to address these issues. Coatings consisting of bioceramics, extracellular matrix proteins, biological peptides or growth factors impart bioactivity and biocompatibility to the metallic surface of conventional orthopaedic prosthesis that promote bone ingrowth and differentiation of stem cells into osteoblasts leading to enhanced osteointegration of the implant. Furthermore, coatings such as silver, nitric oxide, antibiotics, antiseptics and antimicrobial peptides with anti-microbial properties have also been developed, which show promise in reducing bacterial adhesion and prosthetic infections. This review summarizes some of the recent developments in coatings for orthopaedic implants.

Wear mechanisms in ceramic hip implants.

Science.gov (United States)

Slonaker, Matthew; Goswami, Tarun

2004-01-01

The wear in hip implants is one of the main causes for premature hip replacements. The wear affects the potential life of the prosthesis and subsequent removals of in vivo implants. Therefore, the objective of this article is to review various joints that show lower wear rates and consequently higher life. Ceramics are used in hip implants and have been found to produce lower wear rates. This article discusses the advantages and disadvantages of ceramics compared to other implant materials. Different types of ceramics that are being used are reviewed in terms of the wear characteristics, debris released, and their size together with other biological factors. In general, the wear rates in ceramics were lower than that of metal-on-metal and metal-on-polyethylene combinations.

A new solution in cartilage repair surgery of joint lesions

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Patrascu JM¹,

2016-12-01

Full Text Available OBJECTIVES AND BACKGROUND The purpose of this study is to provide a simple, cost-effective, reproducible technology that is able to regenerate durable hyaline cartilage. Traumas and sports along with different diseases such as obesity or gradual degeneration over time of the joint surface determine cartilage defects resulting in pain and dysfunctionality. MATERIALS AND METHODS Since 2011 a number of 183 pacients were treated using Agili-C, out of which 40 pacients were operated in the IInd Clinic of Orthopaedics of the Timișoara Emergency County Hospital. The implant is a biphasic, porous, resorbable tissue regeneration scaffold used in the treatment of osteochondral defects. The surgical procedure is performed through minimal arthrotomy, with a good exposure of the cartilage defect. The implant is inserted so that the articular surface of the implant is parallel with the surrounding healthy cartilage. When in place, it facilitates vascularization thus allowing tissue formation to commence from the periphery towards the center of the defect. RESULTS Until now, results are promising, showing obvious improvements in pain and function in both degenerative and post-traumatic joint lesions in the knee, ankle and first MP joint. CONCLUSIONS Agili-C is a cell free, single stage, off the shelf implant that will hopefully meet market demands and become a reliable procedure in joint repair surgery in the future. Figure 1: Intra-operative aspect after the implant is in place. REFERENCES 1. Mehdi Kazemzadeh-Narbat et al. Biomaterials.2010. p.31. 2. Scaglione et al. Tissue engineering: Part A. 2009;15:1. FOOTNOTE Agili-C is a product of CartiHeal Company

Trapezium excision and suture suspensionplasty (TESS) for the treatment of thumb carpometacarpal arthritis.

Science.gov (United States)

Putnam, Matthew D; Meyer, Nicholas J; Baker, Daniel; Brehmer, Jess; Carlson, Brent D

2014-06-01

Basilar thumb arthritis, or first carpometacarpal arthritis, is a common condition affecting older women and some men. It is estimated that as many as one third of postmenopausal woman are affected. Surgical treatment of this condition includes options ranging from arthrodesis to prosthetic arthroplasty. Intermediate options include complete or partial trapezial excision with or without interposition of a cushioning/stabilizing material (auto source, allo source, synthetic source). A multitude of methods appear to offer similar end results, although some methods definitely involve more surgical work and perhaps greater patient risk. Through retrospective evaluation of a cohort of patients who underwent suture suspensionplasty, we determined the postoperative effect on strength, motion, patient satisfaction, complications, and radiographic maintenance of the scaphoid-metacarpal distance. This review shows the method to be clinically effective and, by comparison with a more traditional ligament reconstruction trapezial interposition arthroplasty, the method does not require use of autograft or allograft tendon and has fewer surgical steps. Forty-four patients were included in this retrospective study. The results showed that 91% of patients were satisfied with the procedure. Pinch and grip strength remained the same preoperatively and postoperatively. A Disabilities of the Arm, Shoulder, and Hand patient-reported outcome instrument (DASH) scores averaged 30 at final follow-up. Three patients developed a late complication requiring further surgical intervention. In summary, this technique appears to be technically reproducible, requires no additional tendon material, and achieves objectively and subjectively similar results to other reported procedures used to manage first CMC Arthritis.

Long-term prospective outcomes after minimally invasive trans-iliac sacroiliac joint fusion using triangular titanium implants.

Science.gov (United States)

Darr, Emily; Meyer, S Craig; Whang, Peter G; Kovalsky, Don; Frank, Clay; Lockstadt, Harry; Limoni, Robert; Redmond, Andy; Ploska, Philip; Oh, Michael Y; Cher, Daniel; Chowdhary, Abhineet

2018-01-01

Minimally invasive sacroiliac joint fusion (SIJF) has become an increasingly accepted surgical option for chronic sacroiliac (SI) joint dysfunction, a prevalent cause of unremitting low back/buttock pain. The objective of this study was to report clinical and functional outcomes of SIJF using triangular titanium implants (TTI) in the treatment of chronic SI joint dysfunction due to degenerative sacroiliitis or sacroiliac joint (SIJ) disruption at 3 years postoperatively. A total of 103 subjects with SIJ dysfunction at 12 centers were treated with TTI in two prospective clinical trials (NCT01640353 and NCT01681004) and enrolled in this long-term follow-up study (NCT02270203). Subjects were evaluated in study clinics at study start and again at 3, 4, and 5 years. Mean (SD) preoperative SIJ pain score was 81.5, and mean preoperative Oswestry Disability Index (ODI) was 56.3. At 3 years, mean pain SIJ pain score decreased to 26.2 (a 55-point improvement from baseline, p <0.0001). At 3 years, mean ODI was 28.2 (a 28-point improvement from baseline, p <0.0001). In all, 82% of subjects were very satisfied with the procedure at 3 years. EuroQol-5D (EQ-5D) time trade-off index improved by 0.30 points ( p <0.0001). No adverse events definitely related to the study device or procedure were reported; one subject underwent revision surgery at year 3.7. SIJ pain contralateral to the originally treated side occurred in 15 subjects of whom four underwent contralateral SIJF. The proportion of subjects who were employed outside the home full- or part-time at 3 years decreased somewhat from baseline ( p =0.1814), and the proportion of subjects who would have the procedure again was lower at 3 years compared to earlier time points. In long-term (3-year) follow-up, minimally invasive trans-iliac SIJF with TTI was associated with improved pain, disability, and quality of life with relatively high satisfaction rates. Level II. SIJF with TTI.

Minimally invasive arthrodesis for chronic sacroiliac joint dysfunction using the SImmetry SI Joint Fusion system.

Science.gov (United States)

Miller, Larry E; Block, Jon E

2014-01-01

Chronic sacroiliac (SI) joint-related low back pain (LBP) is a common, yet under-diagnosed and undertreated condition due to difficulties in accurate diagnosis and highly variable treatment practices. In patients with debilitating SI-related LBP for at least 6 months duration who have failed conservative management, arthrodesis is a viable option. The SImmetry(®) SI Joint Fusion System is a novel therapy for SI joint fusion, not just fixation, which utilizes a minimally invasive surgical approach, instrumented fixation for immediate stability, and joint preparation with bone grafting for a secure construct in the long term. The purpose of this report is to describe the minimally invasive SI Joint Fusion System, including patient selection criteria, implant characteristics, surgical technique, postoperative recovery, and biomechanical testing results. Advantages and limitations of this system will be discussed.

Value of tomosynthesis for lesion evaluation of small joints in osteoarthritic hands using the OARSI score.

Science.gov (United States)

Martini, K; Becker, A S; Guggenberger, R; Andreisek, G; Frauenfelder, T

2016-07-01

To determine the diagnostic performance of tomosynthesis in depicting osteoarthritic lesions in comparison to conventional radiographs, with use of computed tomography (CT) as standard-of-reference. Imaging of 12 cadaveric hands was performed with tomosynthesis in dorso-palmar (dp) projection, conventional radiographs (dp) and multi-detector CT. Distal interphalangeal joint (DIP)II, DIPIII, proximal interphalangeal joint (PIP)II, PIPIII, first carpometacarpal (CMC) and scaphotrapezotrapezoidal joint (STT) were graded by two independent readers using the Osteoarthritis Research Society International (OARSI) score. The mean score for each feature was calculated for all modalities. Additional wrists were evaluated for presence of calcium pyrophosphate disease (CPPD). CT served as reference-standard. Inter-reader agreement (ICC) was calculated. Comparing tomosynthesis and conventional radiographs to CT, the sensitivity for the presence of osteophytes was 95,7% vs 65,2%; for joint space narrowing 95,8% vs 52,1%; for subchondral sclerosis 61,5% vs 51,3%; for lateral deformity 83.3% vs 83,3%; and for subchondral cysts 45,8% vs 29,2%. Erosions were not present. While tomosynthesis showed no significant difference in OARSI score grading to CT (mean OARSI-score CT: 16.8, SD = 10.6; mean OARSI-score Tomosynthesis: 16.3, SD = 9.6; P = 0.84), conventional radiographs had significant lower mean OARSI scores (mean OARSI-score X-ray: 11.1, SD = 8.3; P = 0.04). Inter-reader agreement for OARSI scoring was excellent (ICC = 0.99). CPPD calcifications present in CT, were also visible with tomosynthesis, but not with conventional radiography. In conclusion, tomosynthesis depicts more osteoarthritic changes in the small joints of the hand than conventional radiography using the OARSI scoring system and CT as the standard of reference. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Principles of Human Joint Replacement Design and Clinical Application

CERN Document Server

Buechel, Frederick F

2012-01-01

Drs. Buechel, an orthopaedic surgeon, and Pappas, a professor of Mechanical Engineering, are the designers of several successful joint replacement systems. The most well-known of these is the pioneering LCS knee replacement. They have written this book for the users and designers of joint replacements. It is an attempt to convey to the reader the knowledge accumulated by the authors during their thirty five year effort on the development of replacement devices for the lower limb for the purpose of aiding the reader in their design and evaluation of joint replacement devices. The early chapters describe the engineering, scientific and medical principles needed for replacement joint evaluation. One must understand the nature and performance of the materials involved and their characteristics in vivo, i.e. the response of the body to implant materials. It is also essential to understand the response of the implants to applied loading and motion, particularly in the hostile physiological environment. A chapter de...

Tophaceous Gout simulating infected Ankle Implants

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Ioannis K

2016-11-01

Full Text Available Gout is a well known metabolic disorder characterized by the formation of urate crystals in joints resulting in recurrent attacks of acute inflammatory arthritis following which tophi can occur in joints or subcutaneous tissues. We report a rare localization of gouty tophi in a 52 years old male. The tophi had formed over the stainless steel implant used for the fixation of a lateral malleolus fracture 20 years ago.

High-tech hip implant for wireless temperature measurements in vivo.

Directory of Open Access Journals (Sweden)

Georg Bergmann

Full Text Available When walking long distances, hip prostheses heat up due to friction. The influence of articulating materials and lubricating properties of synovia on the final temperatures, as well as any potential biological consequences, are unknown. Such knowledge is essential for optimizing implant materials, identifying patients who are possibly at risk of implant loosening, and proving the concepts of current joint simulators. An instrumented hip implant with telemetric data transfer was developed to measure the implant temperatures in vivo. A clinical study with 100 patients is planned to measure the implant temperatures for different combinations of head and cup materials during walking. This study will answer the question of whether patients with synovia with poor lubricating properties may be at risk for thermally induced bone necrosis and subsequent implant failure. The study will also deliver the different friction properties of various implant materials and prove the significance of wear simulator tests. A clinically successful titanium hip endoprosthesis was modified to house the electronics inside its hollow neck. The electronics are powered by an external induction coil fixed around the joint. A temperature sensor inside the implant triggers a timer circuit, which produces an inductive pulse train with temperature-dependent intervals. This signal is detected by a giant magnetoresistive sensor fixed near the external energy coil. The implant temperature is measured with an accuracy of 0.1°C in a range between 20°C and 58°C and at a sampling rate of 2-10 Hz. This rate could be considerably increased for measuring other data, such as implant strain or vibration. The employed technique of transmitting data from inside of a closed titanium implant by low frequency magnetic pulses eliminates the need to use an electrical feedthrough and an antenna outside of the implant. It enables the design of mechanically safe and simple instrumented implants.

Hip implants - Paper VI - Ion concentrations

Energy Technology Data Exchange (ETDEWEB)

Sargeant, A. [Department of Biological Sciences, Ohio Northern University, Ada, OH 45810 (United States); Goswami, T. [Department of Mechanical Engineering, Ohio Northern University, Ada, OH 45810 (United States)]. E-mail: t-goswami@onu.edu

2007-07-01

Total hip-joint arthroplasty is performed in increasing numbers where it translates to about 0.16-0.2% of population per year in industrial countries. In most cases, an implant is a metallic component articulating with a metal, ceramic or poly-ethylene liner as seen in the case of hip, knee and spine. The metal implants release ions in vivo. Therefore, there is a need to study metallic implants and ions released as a result. Toxic concentrations of ions can lead to many adverse physiological effects, including cytotoxicity, genotoxicity, carcinogenicity, and metal sensitivity. There is a need to map ion concentrations establishing boundaries between normal and toxic levels; which however, does not exist. Reference levels of ion concentrations in body fluids and tissues determined by many studies are compiled, reviewed, and presented in this paper. The concentrations of ions released from different alloys, including cobalt, chromium, nickel, molybdenum titanium, aluminum, and vanadium, are presented in this paper. This paper reviews the literature pertaining to clinical data on metal ion concentrations in patients with metal joint prostheses, and laboratory data on the physiological effects of the metals.

Fixation of revision implants is improved by a surgical technique to crack the sclerotic bone rim.

Science.gov (United States)

Kold, Søren; Bechtold, Joan E; Mouzin, Olivier; Elmengaard, Brian; Chen, Xinqian; Søballe, Kjeld

2005-03-01

Revision joint replacement has poorer outcomes compared with primary joint replacement, and these poor outcomes have been associated with poorer fixation. We investigated a surgical technique done during the revision operation to improve access from the marrow space to the implant interface by locally cracking the sclerotic bone rim that forms during aseptic loosening. Sixteen implants were inserted bilaterally by distal femur articulation of the knee joint of eight dogs, using our controlled experimental model that replicates the revision setting (sclerotic bone rim, dense fibrous tissue, macrophages, elevated cytokines) by pistoning a loaded 6.0-mm implant 500 microm into the distal femur with particulate PE. At 8 weeks, one of two revision procedures was done. Both revision procedures included complete removal of the membrane, scraping, lavaging, and inserting a revision plasma-spray Ti implant. The crack revision procedure also used a splined tool to circumferentially locally perforate the sclerotic bone rim before insertion of an identical revision implant. Superior fixation was achieved with the cracking procedure in this experimental model. Revision implants inserted with the rim cracking procedure had a significantly higher pushout strength (fivefold median increase) and energy to failure (sixfold median increase), compared with the control revision procedure. Additional evaluation is needed of local perforation of sclerotic bone rim as a simple bone-sparing means to improve revision implant fixation and thereby increase revision implant longevity.

Does occupational therapy reduce the need for surgery in carpometacarpal osteoarthritis? Protocol for a randomized controlled trial.

Science.gov (United States)

Kjeken, Ingvild; Eide, Ruth Else Mehl; Klokkeide, Åse; Matre, Karin Hoegh; Olsen, Monika; Mowinckel, Petter; Andreassen, Øyvor; Darre, Siri; Nossum, Randi

2016-11-15

In the absence of disease-modifying interventions for hand osteoarthritis (OA), occupational therapy (OT) comprising patient education, hand exercises, assistive devices and orthoses are considered as core treatments, whereas surgery are recommended for those with severe carpometacarpal (CMC1) OA. However, even though CMC1 surgery may reduce pain and improve function, the risk of adverse effects is high, and randomized controlled trials comparing surgery with non-surgical interventions are warranted. This multicentre randomized controlled trial aims to address the following questions: Does OT in the period before surgical consultation reduce the need for surgery in CMC1-OA? What are patients' motivation and reasons for wanting CMC1-surgery? Are there differences between departments of rheumatology concerning the degree of CMC1-OA, pain and functional limitations in patients who are referred for surgical consultation for CMC1 surgery? Is the Measure of Activity Performance of the Hand a reliable measure in patients with CMC1-OA? Do patients with CMC1-OA with and without affection of the distal and proximal interphalangeal finger joints differ with regard to symptoms and function? Do the degree of CMC1-OA, symptoms and functional limitations significantly predict improvement after 2 years following OT or CMC1-surgery? Is OT more cost-effective than surgery in the management of CMC1-OA? All persons referred for surgical consultation due to their CMC1-OA at one of three Norwegian departments of rheumatology are invited to participate. Those who agree attend a clinical assessment and report their symptoms, function and motivation for surgery in validated outcome measures, before they are randomly selected to receive OT in the period before surgical consultation (estimated n = 180). The primary outcome will be the number of participants in each group who have received surgical treatment after 2 years. Secondary and tertiary outcomes are pain, function and

21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle...

Joint angle sensors for closed-loop control

Science.gov (United States)

Ko, Wen H.; Miao, Chih-Lei

In order to substitute braces that have built-in goniometers and to provide feedback signals for closed loop control of lower extremity Functional Neuromuscular System in paraplegics, a stretchable capacitive sensor was developed to accurately detect angular movement in joints. Promising clinical evaluations on the knee joints of a paraplegic and a volunteer were done. The evaluations show great promise for the possibility of implantation applications.

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...

Stereo-radiographic analysis of loosening processes of alloplastic hip joint replacement

International Nuclear Information System (INIS)

Probst, K.J.

1980-01-01

A computer-aided diagnostic system has been developed by which implant dislocation of an order of 0.2 mm can be detected in all three dimensions. The diagnostic system is based on a point-by-point evaluation of stereoradiographic pictures; precise localisation of the implant relative to its place of insertion is made possible by special mathematical operations which are discussed in detail in the methodical part of the book. The method has been tested in clinical practice in 351 cases (208 patients) in the period between September 1, 1977, and May 31, 1979. By taking functional pictures during adduction and abduction of the extremity carrying the endoprosthesis and then evaluating these pictures, the diagnostic system can detect dislocations of the endoprosthesis inside the bone at a given moment. Also, the fate of hip joints with endoprostheses can be followed in the framework of longitudinal research. The method described here may also help to solve other problems of clinical relevance. The only precondition for this is the imaging of the structures of interest in the X-ray picture. A program to analyze loosening processes of alloplastic knee joint implants is new being worked on which will be of great use to the increasing number of patients with alloplastic knee joint implants. (orig./MG) [de

Patellofemoral Joint Replacement and Nickel Allergy: An Unusual Presentation

Directory of Open Access Journals (Sweden)

Farhan Syed

2015-01-01

Full Text Available Metal allergy is an unusual complication of joint replacement that may cause aseptic loosening and necessitate joint revision surgery. We present the case of nickel allergy causing aseptic loosening following patellofemoral joint replacement (PFJR in a 54-year-old male. Joint revision surgery to a nickel-free total knee replacement was performed with good results. Our literature review shows that there is no evidence to guide the management of metal allergy in PFJR. The evidence from studies of total knee replacement is limited to retrospective case series and case reports and gives contradictory recommendations. The optimal management strategy for metal allergy in PFJR is not clear. We recommend allergy testing in patients with history of metal allergy and use of an allergen-free implant in those with positive tests. As there is no gold standard test to establish metal allergy, the choice of test should be guided by availability and recommendation from the local unit of dermatology and allergy testing. We recommend investigation for metal allergy in patients with implant loosening where other causes have been excluded.

Quantification of in vitro wear of a synthetic meniscus implant using gravimetric and micro-CT measurements.

Science.gov (United States)

Elsner, Jonathan J; Shemesh, Maoz; Shefy-Peleg, Adaya; Gabet, Yankel; Zylberberg, Eyal; Linder-Ganz, Eran

2015-09-01

A synthetic meniscus implant was recently developed for the treatment of patients with mild to moderate osteoarthritis with knee pain associated with medial joint overload. The implant is distinctively different from most orthopedic implants in its pliable construction, and non-anchored design, which enables implantation through a mini-arthrotomy without disruption to the bone, cartilage, and ligaments. Due to these features, it is important to show that the material and design can withstand knee joint conditions. This study evaluated the long-term performance of this device by simulating loading for a total of 5 million gait cycles (Mc), corresponding to approximately five years of service in-vivo. All five implants remained in good condition and did not dislodge from the joint space during the simulation. Mild abrasion was detected by electron microscopy, but µ-CT scans of the implants confirmed that the damage was confined to the superficial surfaces. The average gravimetric wear rate was 14.5 mg/Mc, whereas volumetric changes in reconstructed µ-CT scans point to an average wear rate of 15.76 mm(3)/Mc (18.8 mg/Mc). Particles isolated from the lubricant had average diameter of 15 µm. The wear performance of this polycarbonate-urethane meniscus implant concept under ISO-14243 loading conditions is encouraging. Copyright © 2015 Elsevier Ltd. All rights reserved.

21 CFR 872.3940 - Total temporomandibular joint prosthesis.

Science.gov (United States)

2010-04-01

... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3940 Total temporomandibular joint... implanted in the human jaw to replace the mandibular condyle and augment the glenoid fossa to functionally...

Acinetobacter Prosthetic Joint Infection Treated with Debridement and High-Dose Tigecycline.

Science.gov (United States)

Vila, Andrea; Pagella, Hugo; Amadio, Claudio; Leiva, Alejandro

2016-12-01

Prosthesis retention is not recommended for multidrug-resistant Acinetobacter prosthetic joint infection due to its high failure rate. Nevertheless, replacing the prosthesis implies high morbidity and prolonged hospitalization. Although tigecycline is not approved for the treatment of prosthetic joint infection due to multidrug resistant Acinetobacter baumannii, its appropriate use may preclude prosthesis exchange. Since the area under the curve divided by the minimum inhibitory concentration is the best pharmacodynamic predictor of its efficacy, we used tigecycline at high dose, in order to optimize its efficacy and achieve implant retention in 3 patients who refused prosthesis exchange. All patients with prosthetic joint infections treated at our Institution are prospectively registered in a database. Three patients with early prosthetic joint infection of total hip arthroplasty due to multidrug resistant A. baumannii were treated with debridement, antibiotics and implant retention, using a high maintenance dose of tigecycline (100 mg every 12 hours). The cases were retrospectively reviewed. All patients signed informed consent for receiving off-label use of tigecycline. Tigecycline was well tolerated, allowing its administration at high maintenance dose for a median of 40 days (range 30-60). Two patients were then switched to minocycline at standard doses for a median of 3.3 months in order to complete treatment. Currently, none of the patients showed relapse. Increasing the dose of tigecycline could be considered as a means to better attain pharmacodynamic targets in patients with severe or difficult-to-treat infections. Tigecycline at high maintenance dose might be useful when retention of the implant is attempted for treatment for prosthetic joint infections due to multidrug resistant Acinetobacter. Although this approach might be promising, off-label use of tigecycline should be interpreted cautiously until prospective data are available. Tigecycline is

Randomized Controlled Trial of Minimally Invasive Sacroiliac Joint Fusion Using Triangular Titanium Implants vs Nonsurgical Management for Sacroiliac Joint Dysfunction: 12-Month Outcomes.

Science.gov (United States)

Polly, David W; Cher, Daniel J; Wine, Kathryn D; Whang, Peter G; Frank, Clay J; Harvey, Charles F; Lockstadt, Harry; Glaser, John A; Limoni, Robert P; Sembrano, Jonathan N

2015-11-01

Sacroiliac joint (SIJ) dysfunction is a prevalent cause of chronic, unremitting lower back pain. To concurrently compare outcomes after surgical and nonsurgical treatment for chronic SIJ dysfunction. A total of 148 subjects with SIJ dysfunction were randomly assigned to minimally invasive SIJ fusion with triangular titanium implants (n = 102) or nonsurgical management (n = 46). Pain, disability, and quality-of-life scores were collected at baseline and at 1, 3, 6, and 12 months. Success rates were compared using Bayesian methods. Crossover from nonsurgical to surgical care was allowed after the 6-month study visit was complete. Six-month success rates were higher in the surgical group (81.4% vs 26.1%; posterior probability of superiority > 0.9999). Clinically important (≥ 15 point) Oswestry Disability Index improvement at 6 months occurred in 73.3% of the SIJ fusion group vs 13.6% of the nonsurgical management group (P dysfunction caused by degenerative sacroiliitis or SIJ disruptions. Pain, disability, and quality of life also improved after crossover from nonsurgical to surgical treatment.

Peri-implant stress correlates with bone and cement morphology: Micro-FE modeling of implanted cadaveric glenoids.

Science.gov (United States)

Wee, Hwabok; Armstrong, April D; Flint, Wesley W; Kunselman, Allen R; Lewis, Gregory S

2015-11-01

Aseptic loosening of cemented joint replacements is a complex biological and mechanical process, and remains a clinical concern especially in patients with poor bone quality. Utilizing high resolution finite element analysis of a series of implanted cadaver glenoids, the objective of this study was to quantify relationships between construct morphology and resulting mechanical stresses in cement and trabeculae. Eight glenoid cadavers were implanted with a cemented central peg implant. Specimens were imaged by micro-CT, and subject-specific finite element models were developed. Bone volume fraction, glenoid width, implant-cortex distance, cement volume, cement-cortex contact, and cement-bone interface area were measured. Axial loading was applied to the implant of each model and stress distributions were characterized. Correlation analysis was completed across all specimens for pairs of morphological and mechanical variables. The amount of trabecular bone with high stress was strongly negatively correlated with both cement volume and contact between the cement and cortex (r = -0.85 and -0.84, p implant-cortex distance. Contact between the cement and underlying cortex may dramatically reduce trabecular bone stresses surrounding the cement, and this contact depends on bone shape, cement amount, and implant positioning. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

management of bilateral fracture femur with implant failure

African Journals Online (AJOL)

Keywords: Implant failure, nonunion, plating, intramedullary nailing, stress risers, stress shielding. CASE REPORT ... and the patient was thrust forwards, injuring both ... stress once weight bearing starts will be guided by .... J. Bone Joint Surg.

Vancomycin-Rifampin Combination Therapy Has Enhanced Efficacy against an Experimental Staphylococcus aureus Prosthetic Joint Infection

Science.gov (United States)

Niska, Jared A.; Shahbazian, Jonathan H.; Ramos, Romela Irene; Francis, Kevin P.; Bernthal, Nicholas M.

2013-01-01

Treatment of prosthetic joint infections often involves a two-stage exchange, with implant removal and antibiotic spacer placement followed by systemic antibiotic therapy and delayed reimplantation. However, if antibiotic therapy can be improved, one-stage exchange or implant retention may be more feasible, thereby decreasing morbidity and preserving function. In this study, a mouse model of prosthetic joint infection was used in which Staphylococcus aureus was inoculated into a knee joint containing a surgically placed metallic implant extending from the femur. This model was used to evaluate whether combination therapy of vancomycin plus rifampin has increased efficacy compared with vancomycin alone against these infections. On postoperative day 7, vancomycin with or without rifampin was administered for 6 weeks with implant retention. In vivo bioluminescence imaging, ex vivo CFU enumeration, X-ray imaging, and histologic analysis were carried out. We found that there was a marked therapeutic benefit when vancomycin was combined with rifampin compared with vancomycin alone. Taken together, our results suggest that the mouse model used could serve as a valuable in vivo preclinical model system to evaluate and compare efficacies of antibiotics and combinatory therapy for prosthetic joint infections before more extensive studies are carried out in human subjects. PMID:23917317

Missing upper incisors: a retrospective study of orthodontic space closure versus implant.

Science.gov (United States)

Jamilian, Abdolreza; Perillo, Letizia; Rosa, Marco

2015-02-25

The aim of this retrospective study was to compare the esthetic, periodontal, and functional outcomes of orthodontic space closure versus implant substitution in patients with missing maxillary incisors 5 years after completion of treatment. The study group consisted of ten patients treated with orthodontic space closure (six males, four females, mean age 19 ± 2.1 years at the completion of treatment) and ten patients treated with implant insertion (five males, five females, mean age 20 ± 1.4 years at the time of implant insertion). Tooth mobility, plaque index, probing depth, infraocclusion, open gingival embrasure (black triangle), and temporomandibular joint function were recorded at the 5.6 years follow-up. Self-perceived dental esthetic appearance was also evaluated through a visual analog scale (VAS) questionnaire. T-test was used to evaluate the data. All patients were equally satisfied with the appearance of their teeth 5.6 ± 0.4 years after the completion of treatment. No statistically significant differences were found in relation to the VAS scores of the subjects (P Orthodontic space closure and implant of missing maxillary incisors produced similar, well-accepted esthetic results. None of the treatments impaired temporomandibular joint function. Nevertheless, infraocclusion was evident in implant patients. Space closure patients also showed better periodontal health in comparison with implant patients.

Utility of Intraoperative Neuromonitoring during Minimally Invasive Fusion of the Sacroiliac Joint

OpenAIRE

Woods, Michael; Birkholz, Denise; MacBarb, Regina; Capobianco, Robyn; Woods, Adam

2014-01-01

Study Design. Retrospective case series. Objective. To document the clinical utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion for patients diagnosed with sacroiliac joint dysfunction (as a direct result of sacroiliac joint disruptions or degenerative sacroiliitis) and determine stimulated electromyography thresholds reflective of favorable implant position. Summary of Background Data. Intraoperative neuromonitoring is a well-accepted adjunct...

21 CFR 888.3360 - Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint femoral (hemi-hip) metallic cemented or... Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis is a device intended to be implanted...

Biomechanics of unilateral and bilateral sacroiliac joint stabilization: laboratory investigation.

Science.gov (United States)

Lindsey, Derek P; Parrish, Robin; Gundanna, Mukund; Leasure, Jeremi; Yerby, Scott A; Kondrashov, Dimitriy

2018-03-01

OBJECTIVE Bilateral symptoms have been reported in 8%-35% of patients with sacroiliac (SI) joint dysfunction. Stabilization of a single SI joint may significantly alter the stresses on the contralateral SI joint. If the contralateral SI joint stresses are significantly increased, degeneration may occur; alternatively, if the stresses are significantly reduced, bilateral stabilization may be unnecessary for patients with bilateral symptoms. The biomechanical effects of 1) unilateral stabilization on the contralateral SI joint and 2) bilateral stabilization on both SI joints are currently unknown. The objectives of this study were to characterize bilateral SI joint range of motion (ROM) and evaluate and compare the biomechanical effects of unilateral and bilateral implant placement for SI joint fusion. METHODS A lumbopelvic model (L5-pelvis) was used to test the ROM of both SI joints in 8 cadavers. A single-leg stance setup was used to load the lumbar spine and measure the ROM of each SI joint in flexion-extension, lateral bending, and axial rotation. Both joints were tested 1) while intact, 2) after unilateral stabilization, and 3) after bilateral stabilization. Stabilization consisted of lateral transiliac placement of 3 triangular titanium plasma-sprayed (TPS) implants. RESULTS Intact testing showed that during single-leg stance the contralateral SI joint had less ROM in flexion-extension (27%), lateral bending (32%), and axial rotation (69%) than the loaded joint. Unilateral stabilization resulted in significant reduction of flexion-extension ROM (46%) on the treated side; no significant ROM changes were observed for the nontreated side. Bilateral stabilization resulted in significant reduction of flexion-extension ROM of the primary (45%) and secondary (75%) SI joints. CONCLUSIONS This study demonstrated that during single-leg loading the ROMs for the stance (loaded) and swing (unloaded) SI joints are significantly different. Unilateral stabilization for SI

Adhesive bone bonding prospects for lithium disilicate ceramic implants

Science.gov (United States)

Vennila Thirugnanam, Sakthi Kumar

Temporomandibular Joint (TMJ) implants articulating mandible with temporal bone in humans have a very high failure rate. Metallic TMJ implants available in the medical market are not osseointegrated, but bond only by mechanical interlocking using screws which may fail, mandating a second surgery for removal. Stress concentration around fixture screws leads to aseptic loosening or fracture of the bone. It has been proposed that this problem can be overcome by using an all-ceramic TMJ implant bonded to bone with dental adhesives. Structural ceramics are promising materials with an excellent track record in the field of dentis.

Alendronate treatment in the revision setting, with and without controlled implant motion

DEFF Research Database (Denmark)

Søballe, Kjeld; Chen, Xinqian; Jensen, Thomas B

2007-01-01

Introduction Bisphosphonates have been proposed to delay or prevent loosening of joint replacement implants by reducing bone resorption. It is known, however, that implant motion prevents the bone anchorage necessary to maintain secure implant fixation. Methods We used our experimental implant...... conditions, even with alendronate. With alendronate and stabilized implants, increased bone was observed near the sclerotic shell of the revision cavity, but it was reduced with alendronate when the implant was unstable. Interpretation Our findings suggest that it may be difficult for alendronate...... administration alone to rescue implants that are already loose. In implants that have not progressed to loosening, alendronate may increase bone density at the border with the sclerotic shell, but the effect of this bone in delaying eventual loosening is not known. Udgivelsesdato: 2007-Dec...

Mecanobiología de la interfase hueso-implante dental Mechanobiology of bone-dental implant interphase

Directory of Open Access Journals (Sweden)

Juan Carlos Vanegas Acosta

2010-03-01

Full Text Available La osteointegración es la conexión estructural y funcional entre el hueso y un implante. Cuando un implante se inserta en el hueso, se crea la denominada interfase hueso-implante, una zona de unión entre la superficie del biomaterial del implante y el hueso circundante. La cicatrización de esta interfase depende de las condiciones biológicas del hueso, las características de diseño del implante y la distribución de cargas entre hueso e implante. En este artículo se hace una revisión del proceso de cicatrización de la interfase hueso-implante para el caso de un implante dental. El objetivo es describir la secuencia de eventos biológicos iniciados con la lesión causada por la inserción del implante y que concluyen con la formación de nuevo hueso en la interfase. Esta descripción incluye una novedosa clasificación de los fenómenos mecánicos que intervienen durante el proceso de cicatrización de los tejidos lesionados. Esta descripción mecanobiológica de la interfase hueso-implante dental se utiliza para determinar las características más relevantes a tener en cuenta en la formulación de un modelo matemático de la osteointegración de implantes dentales.The osteointegration is the structural and functional connection between bone and implant. When an implant is inserted in bone, it creates the so-called bone-implant interphase, a joint zone between implant biomaterial surface and the surrounding bone. The healing of this interphase depends on bone biological conditions, characteristic of implant design and the distribution of loads between bone and implant. The aim of present article is to review of healing process of bone-implant interphase for a dental implant and also to describe the sequence of biological events beginning with lesion caused by implant insertion and leading to the formation of a new bone in the interphase. This description includes a novel classification of mechanical phenomena present in the healing

Bone Response to Two Dental Implants with Different Sandblasted/Acid-Etched Implant Surfaces: A Histological and Histomorphometrical Study in Rabbits

Directory of Open Access Journals (Sweden)

Antonio Scarano

2017-01-01

Full Text Available Background. Scientific evidence in the field of implant dentistry of the past 20 years established that titanium rough surfaces have shown improved osseointegration rates. In a majority of dental implants, the surface microroughness was obtained by grit blasting and/or acid etching. The aim of the study was to evaluate in vivo two different highly hydrophilic surfaces at different experimental times. Methods. Calcium-modified (CA and SLActive surfaces were evaluated and a total of 18 implants for each type of surface were positioned into the rabbit articular femoral knee-joint in a split model experiment, and they were evaluated histologically and histomorphometrically at 15, 30, and 60 days of healing. Results. Bone-implant contact (BIC at the two-implant surfaces was significantly different in favor of the CA surface at 15 days (p=0.027, while SLActive displayed not significantly higher values at 30 (p=0.51 and 60 days (p=0.061. Conclusion. Both implant surfaces show an intimate interaction with newly formed bone.

Postoperative radiologic imaging of joint arthroplasty; Postoperative radiologische Beurteilung von Gelenkendoprothesen

Energy Technology Data Exchange (ETDEWEB)

Aldinger, P.R. [Abt. Orthopaedie I, Orthopaedische Universitaetsklinik Heidelberg (Germany); Ludwig, K. [Sektion Diagnostische Radiologie, Orthopaedische Universitaetsklinik Heidelberg (Germany)

2006-06-15

With increased life expectancy in industrialised countries, improvement of implant design and operative technique, arthroplasty has become a routine procedure. The hip and knee joints are treated by arthroplasty most frequently. Nowadays joint replacement can be performed in many other joints. Radiologic imaging is an important tool for evaluation of the operative results and for detection of early and late complications. In the following article we describe the relevance of different imaging modalities as well as their systematic application in patients with joint arthroplasty. (orig.)

Osteomyelitis of sternum and rib after breast prosthesis implantation: A rare or underestimated infection?

Directory of Open Access Journals (Sweden)

Piseth Seng

2015-01-01

Full Text Available Sternum and rib osteomyelitis complicated from breast implant infection is rare. We report a case of early sternum and rib osteomyelitis occurred during breast implant infection managed in an inter-regional referral center for bone/joint infections in the south of France.

Minimally invasive arthrodesis for chronic sacroiliac joint dysfunction using the SImmetry SI Joint Fusion system

Directory of Open Access Journals (Sweden)

Miller LE

2014-05-01

Full Text Available Larry E Miller,1,2 Jon E Block21Miller Scientific Consulting, Inc., Asheville, NC, USA; 2The Jon Block Group, San Francisco, CA, USA Abstract: Chronic sacroiliac (SI joint-related low back pain (LBP is a common, yet under-diagnosed and undertreated condition due to difficulties in accurate diagnosis and highly variable treatment practices. In patients with debilitating SI-related LBP for at least 6 months duration who have failed conservative management, arthrodesis is a viable option. The SImmetry® SI Joint Fusion System is a novel therapy for SI joint fusion, not just fixation, which utilizes a minimally invasive surgical approach, instrumented fixation for immediate stability, and joint preparation with bone grafting for a secure construct in the long term. The purpose of this report is to describe the minimally invasive SI Joint Fusion System, including patient selection criteria, implant characteristics, surgical technique, postoperative recovery, and biomechanical testing results. Advantages and limitations of this system will be discussed. Keywords: arthrodesis, fusion, minimally invasive, sacroiliac, SImmetry

Radiographic study of the hip joint to determine anthropometric parameters for Indian population

International Nuclear Information System (INIS)

Bagaria, Vaibhav; Deshpande, Shirish; Kuthe, Abhay; Rasalkar, Darshana D.; Paunipagar, Bhawan K.; Madhugiri, Tanushree Subhash

2012-01-01

Hip replacement surgeries are on the rise in India. However, for these surgeries, most of the implants used are imported and manufactured entirely to suit the geometrical considerations of the western population. Studies in the past have shown that there are anatomical variations in the hip joint for different ethnic backgrounds and geographical locations. There is paucity of anthropometric hip joint data related to Indian population and anthropometric variations in skeletal geometry between Asian and Western counterparts have not yet been thoroughly reviewed and considered for implant manufacturing. The purpose of this anthropometric study is to determine any anatomical variations in the normal hip joint among the Indian population and to statistically compare the mean values with the existing data on western population. 422 Hip radiographs of 211 individuals (141 males and 70 females) with normal and healthy hip joints were evaluated to obtain the horizontal offset, vertical offset and neck shaft angle. For males, mean neck shaft angle was 127.68° (SD = 3.94), horizontal offset was 34.60 mm (SD = 6.55) and vertical offset was 39.17 mm (SD = 5.86). For females, mean neck shaft angle was 125.92° (SD = 4.75), horizontal offset was 32.96 mm (SD = 7.04) and vertical offset was 36.38 mm (SD = 6.28). When these parameters were compared to the data available from western world, there were significant anatomical variations and it was evident that there is a need to evaluate existing implants in relation to this data and possibly design the implants suited and relevant to Indian population.

Silver-based antibacterial surfaces for bone implants

NARCIS (Netherlands)

Necula, B.S.

2013-01-01

Total hip arthroplasty (THA) is the most effective and safest method for treating severe degenerative, post-traumatic and other diseases of the joints. With an aging population that is increasingly active, the use of biomedical implants will continue to rise. It is estimated that more than 1,000,000

Cobalt Alloy Implant Debris Induces Inflammation and Bone Loss Primarily through Danger Signaling, Not TLR4 Activation: Implications for DAMP-ening Implant Related Inflammation

OpenAIRE

Samelko, Lauryn; Landgraeber, Stefan; McAllister, Kyron; Jacobs, Joshua; Hallab, Nadim James

2016-01-01

Cobalt alloy debris has been implicated as causative in the early failure of some designs of current total joint implants. The ability of implant debris to cause excessive inflammation via danger signaling (NLRP3 inflammasome) vs. pathogen associated pattern recognition receptors (e.g. Toll-like receptors; TLRs) remains controversial. Recently, specific non-conserved histidines on human TLR4 have been shown activated by cobalt and nickel ions in solution. However, whether this TLR activation ...

Detection of periprosthetic joint infections in presumed aseptic patients

DEFF Research Database (Denmark)

Xu, Yijuan; Lorenzen, Jan; Thomsen, Trine Rolighed

2016-01-01

Title: Detection of periprosthetic joint infections in presumed aseptic patients Yijuan Xu1, Jan Lorenzen1, Trine Rolighed Thomsen1,2, Kathrin Kluba3, Kathrin Chamaon3, Christoph Lohmann3 1. Danish Technological Institute, Aarhus, Denmark 2. Center for Microbial Communities, Department of Biotech......Title: Detection of periprosthetic joint infections in presumed aseptic patients Yijuan Xu1, Jan Lorenzen1, Trine Rolighed Thomsen1,2, Kathrin Kluba3, Kathrin Chamaon3, Christoph Lohmann3 1. Danish Technological Institute, Aarhus, Denmark 2. Center for Microbial Communities, Department...... of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Denmark 3. Department of Orthopaedics, Otto-von-Guericke University of Magdeburg, Germany Aim: ”The HypOrth project (New approaches in the development of Hypoallergenic implant material in Orthopaedics: Steps to personalised medicine......) aims to investigate adverse immune reactions to implant materials. For this project, it is of utmost importance to exclude patients with periprosthetic joint infections (PJIs). The aim of this study was to rule out PJIs in included patients using prolonged culture and next generation sequencing (NGS...

A new three-dimensional, print-on-demand temporomandibular prosthetic total joint replacement system: Preliminary outcomes.

Science.gov (United States)

Dimitroulis, George; Austin, Stephen; Sin Lee, Peter Vee; Ackland, David

2018-05-16

The aim of this study is to present the preliminary clinical data on the OMX Temporomandibular Joint (TMJ) Prosthetic total joint replacement system. A prospective, cohort, clinical study was undertaken of consecutive adult patients with Category 5 end-stage joint disease who were implanted with the OMX TMJ prosthesis between May 2015 and April 2017. A total of 50 devices were implanted in 38 patients, with 12 patients receiving bilateral prosthetic joints. There were 31 females and 7 males in this cohort, who ranged in age from 20 to 66 years, with a mean of 43.8 years (±14.0 years). Ten of the 50 prosthetic joints (20%) were fully customized, while the remaining were patient matched using virtual planning software. Based on a mean follow-up period of 15.3 months (range 12-24 months) following the TMJ total joint replacement, preliminary results suggest the OMX TMJ prosthesis has made a positive impact on clinical outcomes, with a mean 74.4% reduction in joint pain levels and significant improvements (p < 0.05) in jaw function as measured by the visual analogue scales for mouth opening (30.8%), diet (77.1%), and function (59.2%). No device failures were reported during the study period. This study suggests that the print-on-demand OMX TMJ prosthesis, designed for rapid delivery of both patient-matched and fully customize devices, represents a safe, reliable and versatile implantable joint replacement system for the treatment of category 5 end-stage TMJ disease. Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Radiographical survey of carpal joints with ulcerous lesions of articular cartilage in Japanese black cattle

International Nuclear Information System (INIS)

Taura, Y.; Nishimura, R.; Sasaki, N.; Takeuchi, A.; Usui, K.

1989-01-01

For the purpose of investigating a different feeding factor in the outbreak of ulcerous lesions of articular cartilage, a radiographical survey of carpal joints was carried out, using Japanese Black cattle at Yamanashi prefecture, and the following results were obtained. 1) The samples for this study were obtained from farms in which using different feeding systems were adopted, such as fattening in drylot (A) : 12 steers (7-32 months old, 221-643 kg body weight), rearing in pasture (B) : 10 steers (7-12 months old, 124-210 kg body weight) and fattening in drylot after rearing in pasture (C) : 5 steers (11-14 months old, 238-271 kg body weight). 2) The radiographic lesions of the carpometacarpal joint were classified into the following five grades, normal (0), slight (I, II), moderate (III) and severe (IV), using a high contrast radiogram. 3) In group A, the lesions were observed in all the metacarpal bone III and carpal bone II@@@III. In the former case, incidence of radiographic lesions was 100%, in which 67% were severe and the remaining 33% consisted of moderate (25%) and slight changes (8%), which was higher than the others. 4) In group B, the incidence of the radiographic lesions of metacarpal bone III was 90%, but in which all of those were of slight changes (I and II). 5) In group C, the incidence of radiographic lesions of the metacarpal bone III was 80%, in which 20% were severe and the remaining 60% were slight ones. 6) No lesions were observed in any lateral half of the joint (carpal bone IV and metacarpal bone IV). 7) Although only the 7 months old steers of group A had very severe radiographic changes, the 10-12 months old steers of the group B showed no clear changes

[Carbon fiber-reinforced plastics as implant materials].

Science.gov (United States)

Bader, R; Steinhauser, E; Rechl, H; Siebels, W; Mittelmeier, W; Gradinger, R

2003-01-01

Carbon fiber-reinforced plastics have been used clinically as an implant material for different applications for over 20 years.A review of technical basics of the composite materials (carbon fibers and matrix systems), fields of application,advantages (e.g., postoperative visualization without distortion in computed and magnetic resonance tomography), and disadvantages with use as an implant material is given. The question of the biocompatibility of carbon fiber-reinforced plastics is discussed on the basis of experimental and clinical studies. Selected implant systems made of carbon composite materials for treatments in orthopedic surgery such as joint replacement, tumor surgery, and spinal operations are presented and assessed. Present applications for carbon fiber reinforced plastics are seen in the field of spinal surgery, both as cages for interbody fusion and vertebral body replacement.

Contact mechanics of reverse engineered distal humeral hemiarthroplasty implants.

Science.gov (United States)

Willing, Ryan; King, Graham J W; Johnson, James A

2015-11-26

Erosion of articular cartilage is a concern following distal humeral hemiarthroplasty, because native cartilage surfaces are placed in contact with stiff metallic implant components, which causes decreases in contact area and increases in contact stresses. Recently, reverse engineered implants have been proposed which are intended to promote more natural contact mechanics by reproducing the native bone or cartilage shape. In this study, finite element modeling is used in order to calculate changes in cartilage contact areas and stresses following distal humeral hemiarthroplasty with commercially available and reverse engineered implant designs. At the ulna, decreases in contact area were -34±3% (p=0.002), -27±1% (pengineered and cartilage reverse engineered designs, respectively. Peak contact stresses increased by 461±57% (p=0.008), 387±127% (p=0.229) and 165±16% (p=0.003). At the radius, decreases in contact area were -21±3% (p=0.013), -13±2% (p0.999), 241±32% (p=0.010) and 61±10% (p=0.021). Between the three different implant designs, the cartilage reverse engineered design yielded the largest contact areas and lowest contact stresses, but was still unable to reproduce the contact mechanics of the native joint. These findings align with a growing body of evidence indicating that although reverse engineered hemiarthroplasty implants can provide small improvements in contact mechanics when compared with commercially available designs, further optimization of shape and material properties is required in order reproduce native joint contact mechanics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Functional angiography of arteries near the knee joint: Consequences for stent implantation. Funktionsangiographie der kniegelenknahen Arterien: Konsequenzen fuer die Stentimplantation

Energy Technology Data Exchange (ETDEWEB)

Zocholl, G; Zapf, S; Schild, H; Thelen, M [Mainz Univ. (Germany, F.R.). Inst. fuer Klinische Strahlenkunde

1990-12-01

Angiographic studies of the arteries adjoining the knee in 25 patients show extensive kinking and stenoses of the popliteal artery and less frequently of the distal femoral artery during flexion of the knee joint. This is due to the loss of elasticity with increasing age forcing the vessel into a tortuous course during shortening of the pathway of the popliteal artery with knee flexion. Independent of the principle of the different stents available they probably will not increase the contractility of the stented vessel in the longitudinal axis. It is to expect that after implantation of stents into the original artery kinking will occur predominantly in the original segments of the vessel and at the transitions to the stented segments leading to intimal damage by shear forces thus propagating local progress of atherosclerosis. (orig.).

A new condyle implant design concept for an alloplastic temporomandibular joint in bone resorption cases.

Science.gov (United States)

Ramos, António; Mesnard, Michel

2016-10-01

The purpose of this article is to present and evaluate an innovative intramedullary implant concept developed for total alloplastic reconstruction in bone resorption cases. The main goal of this innovative concept is to avoid the main problems experienced with temporomandibular (TMJ) devices on the market, associated with bone fixation and changes in kinematics. A three-dimensional finite element model was developed based on computed tomography (CT) scan images, before and after implantation of the innovative implant concept. To validate the numerical model, a clean cadaveric condyle was instrumented with four rosettes and loaded before and after implantation with the innovative concept TMJ implant. The experimental results validate the numerical models comparing the intact and implanted condyles, as they present good correlation. They show that the most critical region is around rosette #1, with an increase in strains in the proximal region of the condyle of 140%. The maximum principal strain and stress generated with the implant is less than 2200 με and 75 MPa in the posterior region of the cortical bone. Shortly after insertion of this press-fit implant, stress and strain results appear to be within the normal limits and show some similarities with the intact condyle. If these responses do not change over time, the screw fixation used at present could be avoided or replaced. This solution reduces bone resection and lessens surgical damage to the muscles. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Analyzer-based imaging technique in tomography of cartilage and metal implants: A study at the ESRF

International Nuclear Information System (INIS)

Coan, Paola; Mollenhauer, Juergen; Wagner, Andreas; Muehleman, Carol; Bravin, Alberto

2008-01-01

Monitoring the progression of osteoarthritis (OA) and the effects of therapy during clinical trials is still a challenge for present clinical imaging techniques since they present intrinsic limitations and can be sensitive only in case of advanced OA stages. In very severe cases, partial or complete joint replacement surgery is the only solution for reducing pain and restoring the joint functions. Poor imaging quality in practically all medical imaging technologies with respect to joint surfaces and to metal implant imaging calls for the development of new techniques that are sensitive to stages preceding the point of irreversible damage of the cartilage tissue. In this scenario, X-ray phase contrast modalities could play an important role since they can provide improved contrast compared to conventional absorption radiography, with a similar or even reduced tissue radiation dose. In this study, the analyzer-based imaging (ABI), a technique sensitive to the X-ray refraction and permitting a high scatter rejection, has been successfully applied in vitro on excised human synovial joints and sheep implants. Pathological and healthy joints as well as metal implants have been imaged in projection and computed tomography ABI mode at high resolution and clinically compatible doses (<10 mGy). Volume rendering and segmentation permitted visualization of the cartilage from volumetric CT-scans. The results demonstrate that ABI can provide an unequivocal non-invasive diagnosis of the state of disease of the joint and be considered a new tool in orthopaedic research

Remoção da cartilagem articular associada ou não a implante homógeno ou enxerto autógeno de osso esponjoso em cães submetidos à artrodese atlantoaxial Joint cartilage removal associated or not to homologous implant or autologous cancellous bone graft in dogs submitted to atlantoaxial arthrodesis

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Rafael Festugatto

2013-03-01

Full Text Available O objetivo deste estudo foi avaliar o grau de fusão articular e formação óssea na articulação atlantoaxial de cães submetidos à artrodese após a remoção da cartilagem articular associada ou não ao implante homógeno ou enxerto autógeno de osso esponjoso. Foram utilizados 12 cães, adultos, distribuídos aleatoriamente em três grupos iguais. Grupo I (GI: realizada apenas a remoção da cartilagem articular e imobilização articular com pinos e resina acrílica. Grupo II (GII: feita a remoção da cartilagem articular e imobilização da articulação, seguida da colocação e modelagem do implante ósseo esponjoso homógeno entre as superfícies articulares. Grupo III (GIII: foi realizado o mesmo procedimento do GII, mais o enxerto ósseo esponjoso autógeno no local determinado. Realizaram-se exames radiográficos em todos os animais aos 30, 60 e 90 dias de pós-operatório (PO. Aos 90 dias de PO foi feita a eutanásia para o emprego do teste de palpação manual, avaliação tomográfica e histopatológica. Para análise estatística da associação entre o grau de fusão articular, aplicou-se o Teste Qui-quadrado de independência. Os resultados dos testes foram avaliados pela significância exata e considerados significantes a 5% (PThe aim of this study was to evaluate the degree of joint fusion and bone formation in dogs undergoing atlantoaxial arthrodesis after removal of articular cartilage associated or not to implant homogenous or autogenous cancellous bone. Twelve dogs, weighing between 8 and 12kg were randomly divided into three groups. Group I (GI performed only the removal of joint cartilage and joint immobilization with acrylic resin and pins. Group II (GII: after removel of joint cartilage and articular immobilization was performed modeling and placement of homogenous cancellous bone at the given location. The volume of homograft placed in the joint was measured using a precision balance and all animals received the

Antimicrobial and Antifouling Polymeric Agents for Surface Functionalization of Medical Implants.

Science.gov (United States)

Zeng, Qiang; Zhu, Yiwen; Yu, Bingran; Sun, Yujie; Ding, Xiaokang; Xu, Chen; Wu, Yu-Wei; Tang, Zhihui; Xu, Fu-Jian

2018-05-09

Combating implant-associated infections is an urgent demand due to the increasing numbers in surgical operations such as joint replacements and dental implantations. Surface functionalization of implantable medical devices with polymeric antimicrobial and antifouling agents is an efficient strategy to prevent bacterial fouling and associated infections. In this work, antimicrobial and antifouling branched polymeric agents (GPEG and GEG) were synthesized via ring-opening reaction involving gentamicin and ethylene glycol species. Due to their rich primary amine groups, they can be readily coated on the polydopamine-modified implant (such as titanium) surfaces. The resultant surface coatings of Ti-GPEG and Ti-GEG produce excellent in vitro antibacterial efficacy toward both Staphylococcus aureus and Escherichia coli, while Ti-GPEG exhibit better antifouling ability. Moreover, the infection model with S. aureus shows that implanted Ti-GPEG possessed excellent antibacterial and antifouling ability in vivo. This study would provide a promising strategy for the surface functionalization of implantable medical devices to prevent implant-associated infections.

Biological Strategies for Improved Osseointegration and Osteoinduction of Porous Metal Orthopedic Implants

Science.gov (United States)

Riester, Scott M.; Bonin, Carolina A.; Kremers, Hilal Maradit; Dudakovic, Amel; Kakar, Sanjeev; Cohen, Robert C.; Westendorf, Jennifer J.

2015-01-01

The biological interface between an orthopedic implant and the surrounding host tissue may have a dramatic effect upon clinical outcome. Desired effects include bony ingrowth (osseointegration), stimulation of osteogenesis (osteoinduction), increased vascularization, and improved mechanical stability. Implant loosening, fibrous encapsulation, corrosion, infection, and inflammation, as well as physical mismatch may have deleterious clinical effects. This is particularly true of implants used in the reconstruction of load-bearing synovial joints such as the knee, hip, and the shoulder. The surfaces of orthopedic implants have evolved from solid-smooth to roughened-coarse and most recently, to porous in an effort to create a three-dimensional architecture for bone apposition and osseointegration. Total joint surgeries are increasingly performed in younger individuals with a longer life expectancy, and therefore, the postimplantation lifespan of devices must increase commensurately. This review discusses advancements in biomaterials science and cell-based therapies that may further improve orthopedic success rates. We focus on material and biological properties of orthopedic implants fabricated from porous metal and highlight some relevant developments in stem-cell research. We posit that the ideal primary and revision orthopedic load-bearing metal implants are highly porous and may be chemically modified to induce stem cell growth and osteogenic differentiation, while minimizing inflammation and infection. We conclude that integration of new biological, chemical, and mechanical methods is likely to yield more effective strategies to control and modify the implant–bone interface and thereby improve long-term clinical outcomes. PMID:25348836

The Pathology of Orthopedic Implant Failure Is Mediated by Innate Immune System Cytokines

OpenAIRE

Landgraeber, Stefan; Jäger, Marcus; Jacobs, Joshua J.; Hallab, Nadim James

2014-01-01

All of the over 1 million total joint replacements implanted in the US each year are expected to eventually fail after 15–25 years of use, due to slow progressive subtle inflammation at the bone implant interface. This inflammatory disease state is caused by implant debris acting, primarily, on innate immune cells, that is, macrophages. This slow progressive pathological bone loss or “aseptic loosening” is a potentially life-threatening condition due to the serious complications in older peop...

Management of pain secondary to temporomandibular joint syndrome with peripheral nerve stimulation.

Science.gov (United States)

Rodriguez-Lopez, Manuel J; Fernandez-Baena, Mariano; Aldaya-Valverde, Carlos

2015-01-01

Temporomandibular joint syndrome, or Costen syndrome, is a clinically diagnosed disorder whose most common symptoms include joint pain and clicking, difficulty opening the mouth, and temporomandibular joint discomfort. The temporomandibular joint (TMJ) is supplied by the auriculotemporal nerve, a collateral branch of the mandibular nerve (the V3 branch of the trigeminal nerve). The aim of this study is to assess the effectiveness and safety of permanent peripheral nerve stimulation to relieve TMJ pain. This case series is a prospective study. Pain Unit of a regional universitary hospital. The study included 6 female patients with temporomandibular pain lasting from 2 to 8 years that did not respond to intraarticular local anesthetic and corticoid injections. After a positive diagnostic block test, the patients were implanted with quadripolar or octapolar leads in the affected preauricular region for a 2-week stimulation test phase, after which the leads were connected to a permanent implanted pulse generator. Results of the visual analog scale, SF-12 Health Survey, Brief Pain Inventory, and drug intake were recorded at baseline and at 4, 12, and 24 weeks after the permanent implant. Five out of 6 patients experienced pain relief exceeding 80% (average 72%) and received a permanent implant. The SF-12 Health Survey results were very positive for all specific questions, especially items concerning the physical component. Patients reported returning to normal physical activity and rest at night. Four patients discontinued their analgesic medication and 1 patient reduced their gabapentin dose by 50%. Sample size; impossibility of placebo control. Patients affected with TMJ syndrome who do not respond to conservative treatments may find a solution in peripheral nerve stimulation, a simple technique with a relatively low level of complications.

COMPLEX OPTICAL CHARACTERIZATION OF MESH IMPLANTS AND ENCAPSULATION AREA

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VALERIY P. ZAKHAROV

2013-04-01

Full Text Available Complex investigation of mesh implants was performed involving laser confocal microscopy, backscattered probing and OCT imaging methods. The growth of endomysium and fat tissue with microcirculation vessels was observed in the mesh encapsulation region. Confocal microscopy analysis shows that such pathologies complications such as necrosis formation and microcavities were localized in the area near implant fibers with the size compatible with fiber diameter. And the number of such formations increase with the increase of the size, number and density of microdefects on the implant surface. Results of numerical simulations show that it is possible to control implant installation up to the depth to 4 mm with a help of backscattering probing. The applicability of OCT imaging for mesh implant control was demonstrated. Special two-stage OCT image noise-reduction algorithm, including empirical mode decomposition, was proposed for contrast increase and better abnormalities visualization by halving the signal-to-noise ratio. Joint usage of backscattered probing and OCT allows to accurately ascertain implant and surrounding tissue conditions, which reduces the risk of relapse probability.

Analysis of postmarket complaints database for the iFuse SI Joint Fusion System®: a minimally invasive treatment for degenerative sacroiliitis and sacroiliac joint disruption.

Science.gov (United States)

Miller, Larry E; Reckling, W Carlton; Block, Jon E

2013-01-01

The sacroiliac joint is a common but under-recognized source of low back and gluteal pain. Patients with degenerative sacroiliitis or sacroiliac joint disruption resistant to nonsurgical treatments may undergo open surgery with sacroiliac joint arthrodesis, although outcomes are mixed and risks are significant. Minimally invasive sacroiliac joint arthrodesis was developed to minimize the risk of iatrogenic injury and to improve patient outcomes compared with open surgery. Between April 2009 and January 2013, 5319 patients were treated with the iFuse SI Joint Fusion System® for conditions including sacroiliac joint disruption and degenerative sacroiliitis. A database was prospectively developed to record all complaints reported to the manufacturer in patients treated with the iFuse device. Complaints were collected through spontaneous reporting mechanisms in support of ongoing mandatory postmarket surveillance efforts. Complaints were reported in 204 (3.8%) patients treated with the iFuse system. Pain was the most commonly reported clinical complaint (n = 119, 2.2%), with nerve impingement (n = 48, 0.9%) and recurrent sacroiliac joint pain (n = 43, 0.8%) most frequently cited. All other clinical complaints were rare (≤0.2%). Ninety-six revision surgeries were performed in 94 (1.8%) patients at a median follow-up of four (range 0-30) months. Revisions were typically performed in the early postoperative period for treatment of a symptomatic malpositioned implant (n = 46, 0.9%) or to correct an improperly sized implant in an asymptomatic patient (n = 10, 0.2%). Revisions in the late postoperative period were performed to treat symptom recurrence (n = 34, 0.6%) or for continued pain of undetermined etiology (n = 6, 0.1%). Analysis of a postmarket product complaints database demonstrates an overall low risk of complaints with the iFuse SI Joint Fusion System in patients with degenerative sacroiliitis or sacroiliac joint disruption.

Long-Term Symptoms Onset and Heterotopic Bone Formation around a Total Temporomandibular Joint Prosthesis: a Case Report

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Luca Guarda-Nardini

2014-04-01

Full Text Available Background: The literature on total alloplastic temporomandibular joint (TMJ reconstructions is encouraging, and studies on total alloplastic TMJ replacements outcomes showed acceptable improvements in terms of both pain levels and jaw function. Nevertheless, some adverse events, such as heterotopic bone formation around the implanted prosthesis, may occur. In consideration of that, the present manuscript describes a case of heterotopic bone formation around a total temporomandibular joint prosthesis, which occurred several years after the implant. Methods: The present manuscript describes a case of heterotopic bone formation around a total TMJ prosthesis, which occurred several years after the implant in patients, who previously underwent multiple failed TMJ surgeries. Results: Ten years after the surgical TMJ replacement to solve an ankylotic bone block, the patient came to our attention again referring a progressive limitation in mouth opening. A computerized tomography showed evidence of marked heterotopic bone formation in the medial aspects of the joint, where a new-born ankylotic block occupied most part of the gap created by resecting the coronoid process at the time of the TMJ prosthesis insertion. Conclusions: Despite this adverse event has been sometimes described in the literature, this is the first case in which its occurrence happened several years after the temporomandibular joint replacement. It can be suggested that an accurate assessment of pre-operative risk factors for re-ankylosis (e.g., patients with multiple failed temporomandibular joint surgeries and within-intervention prevention (e.g., strategies to keep the bone interfaces around the implant separated should be better standardized and define in future studies.

Development and application of biomimetic electrospun nanofibers in total joint replacement

Science.gov (United States)

Song, Wei

Failure of osseointegration (direct anchorage of an implant by bone formation at the bone-implant surface) and implant infection (such as that caused by Staphylococcus aureus, S. aureus) are the two main causes of implant failure and loosening. There is a critical need for orthopedic implants that promote rapid osseointegration and prevent bacterial colonization, particularly when placed in bone compromised by disease or physiology of the patients. A better understanding of the key factors that influence cell fate decisions at the bone-implant interface is required. Our study is to develop a class of "bone-like" nanofibers (NFs) that promote osseointegration while preventing bacterial colonization and subsequent infections. This research goal is supported by our preliminary data on the preparation of coaxial electrospun NFs composed of polycaprolactone (PCL) and polyvinyl alcohol (PVA) polymers arranged in a core-sheath shape. The PCL/PVA NFs are biocompatible and biodegradable with appropriate fiber diameter, pore size and mechanical strength, leading to enhanced cell adhesion, proliferation and differentiation of osteoblast precursor cells. The objective is to develop functionalized "bone-like" PCL/PVA NFs matrix embedded with antibiotics (doxycycline (Doxy), bactericidal and anti-osteoclastic) on prosthesis surface. Through a rat tibia implantation model, the Doxy incorporated coaxial NFs has demonstrated excellent in promoting osseointegration and bacteria inhibitory efficacy. NFs coatings significantly enhanced the bonding between implant and bone remodeling within 8 weeks. The SA-induced osteomyelitis was prevented by the sustained release of Doxy from NFs. The capability of embedding numerous bio-components including proteins, growth factors, drugs, etc. enables NFs an effective solution to overcome the current challenged issue in Total joint replacement. In summary, we proposed PCL/PVA electrospun nanofibers as promising biomaterials that can be applied on

Effect of carbon ion implantation on the tribology of metal-on-metal bearings for artificial joints

Directory of Open Access Journals (Sweden)

Koseki H

2017-05-01

Full Text Available Hironobu Koseki,1 Masato Tomita,2 Akihiko Yonekura,2 Takashi Higuchi,1 Sinya Sunagawa,2 Koumei Baba,3,4 Makoto Osaki2 1Department of Locomotive Rehabilitation Science, Unit of Rehabilitation Sciences, 2Department of Orthopedic Surgery, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan; 3Industrial Technology Center of Nagasaki, Ikeda, Omura, Nagasaki, Japan; 4Affiliated Division, Nagasaki University School of Engineering, Bunkyo, Nagasaki, Japan Abstract: Metal-on-metal (MoM bearings have become popular due to a major advantage over metal-on-polymer bearings for total hip arthroplasty in that the larger femoral head and hydrodynamic lubrication of the former reduce the rate of wear. However, concerns remain regarding adverse reactions to metal debris including metallosis caused by metal wear generated at the taper-head interface and another modular junction. Our group has hypothesized that carbon ion implantation (CII may improve metal wear properties. The purpose of this study was to investigate the wear properties and friction coefficients of CII surfaces with an aim to ultimately apply these surfaces to MoM bearings in artificial joints. CII was applied to cobalt-chromium-molybdenum (Co-Cr-Mo alloy substrates by plasma source ion implantation. The substrates were characterized using scanning electron microscopy and a 3D measuring laser microscope. Sliding contact tests were performed with a simple geometry pin-on-plate wear tester at a load of 2.5 N, a calculated contact pressure of 38.5 MPa (max: 57.8 MPa, a reciprocating velocity of 30 mm/s, a stroke length of 60 mm, and a reciprocating cycle count of 172,800 cycles. The surfaces of the CII substrates were generally featureless with a smooth surface topography at the same level as untreated Co-Cr-Mo alloy. Compared to the untreated Co-Cr-Mo alloy, the CII-treated bearings had lower friction coefficients, higher resistance to catastrophic damage, and

Behaviour of tantalum- and ceramics implants in the organism

International Nuclear Information System (INIS)

Reich, M.

1987-01-01

Studies of human and animal tissues after the use of orthopaedic implants were carried out by means of instrumental neutron activation analysis (INAA), as well as studies on the corrosion behaviour of tantalum by means of tracer techniques. After the use of an Al 2 O 3 -ceramic-metal compound prosthesis of the hip joint samples from the joint capsule and the Fascia Lata of 9 patients were studied. The measured Al amounts in the capsule tissues were greater than the normal values by up to 3 orders of magnitude. The corrosion experiment with tantalum was carried out in Ringer's solution as a model of body fluids. Local and systemic changes because of tantalum implants in animal experiments showed massive local stress of the contact tissue as a result of corrosion. Along with this, increased values of Ta were found in the spleen and the liver. (orig./RB) [de

Long-term prospective outcomes after minimally invasive trans-iliac sacroiliac joint fusion using triangular titanium implants

Directory of Open Access Journals (Sweden)

Darr E

2018-04-01

Full Text Available Emily Darr,1 S Craig Meyer,2 Peter G Whang,3 Don Kovalsky,4 Clay Frank,5 Harry Lockstadt,6 Robert Limoni,7 Andy Redmond,8 Philip Ploska,9 Michael Y Oh,10 Daniel Cher,11 Abhineet Chowdhary12 1Orthopaedics and Physical Medicine, Medical University of South Carolina, Charleston, SC, USA; 2Columbia Orthopaedic Medical Group, Columbia, MO, USA; 3Department of Orthopedics, Yale University, New Haven, CT, USA; 4Orthopaedic Center of Southern Illinois, Mt. Vernon, IL, USA; 5Integrated Spine Care, Wauwatosa, WI, USA; 6Bluegrass Orthopedics, Lexington, KY, USA; 7Orthopedics & Sports Medicine, BayCare Clinic, Green Bay, WI, USA; 8Precision Spine Care, Tyler, TX, USA; 9OrthoSpine Solutions, Stockbridge, GA, USA; 10Allegheny General Hospital, Pittsburgh, PA, USA; 11SI-BONE, Inc., San Jose, CA, USA; 12Overlake Medical Center, Bellevue, WA, USA Background: Minimally invasive sacroiliac joint fusion (SIJF has become an increasingly accepted surgical option for chronic sacroiliac (SI joint dysfunction, a prevalent cause of unremitting low back/buttock pain. Objective: The objective of this study was to report clinical and functional outcomes of SIJF using triangular titanium implants (TTI in the treatment of chronic SI joint dysfunction due to degenerative sacroiliitis or sacroiliac joint (SIJ disruption at 3 years postoperatively. Methods: A total of 103 subjects with SIJ dysfunction at 12 centers were treated with TTI in two prospective clinical trials (NCT01640353 and NCT01681004 and enrolled in this long-term follow-up study (NCT02270203. Subjects were evaluated in study clinics at study start and again at 3, 4, and 5 years. Results: Mean (SD preoperative SIJ pain score was 81.5, and mean preoperative Oswestry Disability Index (ODI was 56.3. At 3 years, mean pain SIJ pain score decreased to 26.2 (a 55-point improvement from baseline, p<0.0001. At 3 years, mean ODI was 28.2 (a 28-point improvement from baseline, p<0.0001. In all, 82% of subjects were very

Development and fabrication of patient-specific knee implant using additive manufacturing techniques

Science.gov (United States)

Zammit, Robert; Rochman, Arif

2017-10-01

Total knee replacement is the most effective treatment to relief pain and restore normal function in a diseased knee joint. The aim of this research was to develop a patient-specific knee implant which can be fabricated using additive manufacturing techniques and has reduced wear rates using a highly wear resistant materials. The proposed design was chosen based on implant requirements, such as reduction in wear rates as well as strong fixation. The patient-specific knee implant improves on conventional knee implants by modifying the articulating surfaces and bone-implant interfaces. Moreover, tribological tests of different polymeric wear couples were carried out to determine the optimal materials to use for the articulating surfaces. Finite element analysis was utilized to evaluate the stresses sustained by the proposed design. Finally, the patient-specific knee implant was successfully built using additive manufacturing techniques.

Bone graft materials in fixation of orthopaedic implants in sheep

DEFF Research Database (Denmark)

Babiker, Hassan

2013-01-01

Bone graft is widely used within orthopaedic surgery especially in revision joint arthroplasty and spine fusion. The early implant fixation in the revision situation of loose joint prostheses is important for the long-term survival. Bone autograft has been considered as gold standard in many...... orthopaedic procedures, whereas allograft is the gold standard by replacement of extensive bone loss. However, the use of autograft is associated with donor site morbidity, especially chronic pain. In addition, the limited supply is a significant clinical challenge. Limitations in the use of allograft include...... the risk of bacterial contamination and disease transmission as well as non-union and poor bone quality. Other bone graft and substitutes have been considered as alternative in order to improve implant fixation. Hydroxyapatite and collagen type I composite (HA/Collagen) have the potential in mimicking...

The effects of hydroxyapatite coating and bone allograft on fixation of loaded experimental primary and revision implants

DEFF Research Database (Denmark)

Søballe, Kjeld; Mouzin, Olivier R G; Kidder, Louis A

2003-01-01

We used our established experimental model of revision joint replacement to examine the roles of hydroxyapatite coating and bone graft in improving the fixation of revision implants. The revision protocol uses the Søballe micromotion device in a preliminary 8-week period of implant instability...... a titanium alloy (Ti) or a hydroxyapatite (HA) 6.0 mm plasma-sprayed implant, in the presence or absence of allograft packed into the initial 0.75 mm peri-implant gap. The contralateral limb is subjected to primary surgery with the same implant configuration, and serves as control. 8 implants were included...

Long-term results of uncemented alumina acetabular implants.

Science.gov (United States)

Boehler, M; Knahr, K; Plenk, H; Walter, A; Salzer, M; Schreiber, V

1994-01-01

We report the clinical and tribological performance of 67 ceramic acetabular prostheses implanted between 1976 and 1979 without bone cement. They articulated with ceramic femoral heads mounted on mental femoral stems. After a mean elapsed period of 144 months, 59 sockets were radiographically stable but two showed early signs and six showed late signs of loosening. Four of the loose sockets have been revised. Histological analysis of the retrieved tissue showed a fibrous membrane around all the implants, with fibrocartilage in some. There was no bone ingrowth, and the fibrous membrane was up to 6 mm thick and infiltrated with lymphocytes, plasma cells, and macrophages. Intra- and extracellular birefringent wear particles were seen. Tribological analysis showed total wear rates in two retrieved alumina-on-alumina joints of 2.6 microns per year in a stable implant and 68 microns in a loose implant. Survival analysis showed a revision rate of 12.4% at 136 months.

Metallic and/or oxygen ion implantation into AlN ceramics as a method of preparation for its direct bonding with copper

International Nuclear Information System (INIS)

Barlak, M.; Borkowska, K.; Olesinska, W.; Kalinski, D.; Piekoszewski, J.; Werner, Z.; Jagielski, J.; Sartowska, B.

2006-01-01

Direct bonding (DB) process is recently getting an increasing interest as a method for producing high quality joints between aluminum nitride (AlN) ceramics and copper. The metallic ions were implanted using an MEVVA type TITAN implanter with unseparated beam. Oxygen ions were implanted using a semi-industrial ion implanter without mass separation equipped with a gaseous ion source. The substrate temperature did not exceed 200 o C. Ions were implanted at two acceleration voltages, i.e. 15 and 70 kV. The fluence range was between 1·E16 and 1·E18 cm -2 . After implantation, some of the samples were characterized by the Rutherford backscattering (RBS) method. In conclusion: (a) The investigations performed in the present work confirm an assumption that ion implantation is a very promising technique as a pretreatment of AlN ceramics for the formation of the joints with copper in direct bonding process. (b) It has been shown that titanium implantation gives the best results in comparison to other metals examined (Fe, Cr, Cu) but also in comparison to double Ti+O and O+Ti implantations

The Pathology of Orthopedic Implant Failure Is Mediated by Innate Immune System Cytokines

Directory of Open Access Journals (Sweden)

Stefan Landgraeber

2014-01-01

Full Text Available All of the over 1 million total joint replacements implanted in the US each year are expected to eventually fail after 15–25 years of use, due to slow progressive subtle inflammation at the bone implant interface. This inflammatory disease state is caused by implant debris acting, primarily, on innate immune cells, that is, macrophages. This slow progressive pathological bone loss or “aseptic loosening” is a potentially life-threatening condition due to the serious complications in older people (>75 yrs of total joint replacement revision surgery. In some people implant debris (particles and ions from metals can influence the adaptive immune system as well, giving rise to the concept of metal sensitivity. However, a consensus of studies agrees that the dominant form of this response is due to innate reactivity by macrophages to implant debris where both danger (DAMP and pathogen (PAMP signalling elicit cytokine-based inflammatory responses. This paper discusses implant debris induced release of the cytokines and chemokines due to activation of the innate (and the adaptive immune system and the subsequent formation of osteolysis. Different mechanisms of implant-debris reactivity related to the innate immune system are detailed, for example, danger signalling (e.g., IL-1β, IL-18, IL-33, etc., toll-like receptor activation (e.g., IL-6, TNF-α, etc., apoptosis (e.g., caspases 3–9, bone catabolism (e.g., TRAP5b, and hypoxia responses (Hif1-α. Cytokine-based clinical and basic science studies are in progress to provide diagnosis and therapeutic intervention strategies.

The Pathology of Orthopedic Implant Failure Is Mediated by Innate Immune System Cytokines

Science.gov (United States)

Landgraeber, Stefan; Jäger, Marcus; Jacobs, Joshua J.; Hallab, Nadim James

2014-01-01

All of the over 1 million total joint replacements implanted in the US each year are expected to eventually fail after 15–25 years of use, due to slow progressive subtle inflammation at the bone implant interface. This inflammatory disease state is caused by implant debris acting, primarily, on innate immune cells, that is, macrophages. This slow progressive pathological bone loss or “aseptic loosening” is a potentially life-threatening condition due to the serious complications in older people (>75 yrs) of total joint replacement revision surgery. In some people implant debris (particles and ions from metals) can influence the adaptive immune system as well, giving rise to the concept of metal sensitivity. However, a consensus of studies agrees that the dominant form of this response is due to innate reactivity by macrophages to implant debris where both danger (DAMP) and pathogen (PAMP) signalling elicit cytokine-based inflammatory responses. This paper discusses implant debris induced release of the cytokines and chemokines due to activation of the innate (and the adaptive) immune system and the subsequent formation of osteolysis. Different mechanisms of implant-debris reactivity related to the innate immune system are detailed, for example, danger signalling (e.g., IL-1β, IL-18, IL-33, etc.), toll-like receptor activation (e.g., IL-6, TNF-α, etc.), apoptosis (e.g., caspases 3–9), bone catabolism (e.g., TRAP5b), and hypoxia responses (Hif1-α). Cytokine-based clinical and basic science studies are in progress to provide diagnosis and therapeutic intervention strategies. PMID:24891761

Conductive polymer sensor arrays for smart orthopaedic implants

Science.gov (United States)

Micolini, Carolina; Holness, F. B.; Johnson, James A.; Price, Aaron D.

2017-04-01

This study proposes and demonstrates the design, implementation, and characterization of a 3D-printed smartpolymer sensor array using conductive polyaniline (PANI) structures embedded in a polymeric substrate. The piezoresistive characteristics of PANI were studied to evaluate the efficacy of the manufacturing of an embedded pressure sensor. PANI's stability throughout loading and unloading cycles together with the response to incremental loading cycles was investigated. It is demonstrated that this specially developed multi-material additive manufacturing process for polyaniline is a good candidate for the manufacture of implant components with smart-polymer sensors embedded for the analysis of joint loads in orthopaedic implants.

Abductor pollicis longus tendon interposition for arthrosis of the first carpo-metacarpal joint. Long-term results.

Science.gov (United States)

Lied, Line; Bjørnstad, Kari; Woje, Ann K N; Finsen, Vilhjalmur

2016-02-01

We performed an interposition arthroplasty using the abductor pollicis longus tendon for arthrosis in the basal joint of the thumb that needed surgery from 1995 to 2010. In 2001 47 patients (55 thumbs) were reviewed after 3.5 (1-5) years. The pain relief was excellent in 32 thumbs, and 25 patients improved their ability to perform daily tasks. Mobility was well preserved. Key pinch and grip strengths averaged 78% and 89%, respectively, of those in unaffected hands. We have now re-examined all 33 available patients (36 thumbs) 11-14 years after surgery. Fourty one of the originally examined patients were still alive. Seven were too ill to attend a follow-up and one refused. The remainder were examined in a fashion as similar as possible to that at the original review. The patients' subjective estimations of pain during the last week and satisfaction with the cosmetic and general results were recorded on visual analogue scales. The patients' ability to perform various activities of daily living were recorded and they completed the Disability of the arm, shoulder and hand (DASH) questionnaire. The mobility of the wrist and abduction of the thumb of the operated hands were recorded with a goniometer. Grip and pinch strength were measured and new radiographs were obtained. Key pinch strength had increased significantly over the last 10 years. The mobility was still good, except for thumb abduction, which had decreased with time. The median DASH score had fallen from 28 to 20 between the two reviews. There was insignificant further median loss of distance between the scaphoid and the metacarpal since the earlier review. The good results of this procedure found soon after surgery are maintained long-term.

Metallic implants and exposure to radiofrequency radiation

International Nuclear Information System (INIS)

Joyner, K.H.; Fleming, A.H.F.; MacFarlane, I.P.; Hocking, B.

1988-01-01

There is increasing use of radiofrequency radiation (RFR) in industry for communications, welding, security, radio, medicine, navigation etc. It has been recognised for some years that RFR may interact with cardiac pacemakers and steps have been taken to prevent this interference. It is less well recognised that other metallic implants may also act as antennas in an RFR field and possibly cause adverse health effects by heating local tissues. There are a large and increasing number of implants having metal components which may be found in RFR workers. These implants include artificial joints, rods and plates used in orthopaedics, rings in heart valves, wires in sutures, bionic ears, subcutaneous infusion systems and (external) transdermal drug delivery patches 1 . The physician concerned with job placement of such persons requires information on the likelihood of an implant interacting with RFR so as to impair health. The following outlines the approach developed in Telecom Australia, beginning with the general principles and then presenting a specific example discussion of a specific example

A Preliminary Study to Enhance the Tribological Performance of CoCrMo Alloy by Fibre Laser Remelting for Articular Joint Implant Applications

Directory of Open Access Journals (Sweden)

Chi-Wai Chan

2018-03-01

Full Text Available CoCrMo alloy has long been used as a pairing femoral head material for articular joint implant applications because of its biocompatibility and reliable tribological performance. However, friction and wear issues are still present for CoCrMo (metal/CoCrMo (metal or CoCrMo (metal/ultrahigh molecular weight polyethylene (UHMWPE (plastic pairs in clinical observations. The particulate wear debris generated from the worn surfaces of CoCrMo or UHMWPE can pose a severe threat to human tissues, eventually resulting in the failure of implants and the need for revision surgeries. As a result, a further improvement in tribological properties of this alloy is still needed, and it is of great interest to both the implant manufacturers and clinical surgeons. In this study, the surface of CoCrMo alloy was laser-treated by a fibre laser system in an open-air condition (i.e., no gas chamber required. The CoCrMo surfaces before and after laser remelting were analysed and characterised by a range of mechanical tests (i.e., surface roughness measurement and Vickers micro-hardness test and microstructural analysis (i.e., XRD phase detection. The tribological properties were assessed by pin-on-disk tribometry and dynamic light scattering (DLS. Our results indicate that the laser-treated surfaces demonstrated a friction-reducing effect for all the tribopairs (i.e., CoCrMo against CoCrMo and CoCrMo against UHHMWPE and enhanced wear resistance for the CoCrMo/CoCrMo pair. Such beneficial effects are chiefly attributable to the presence of the laser-formed hard coating on the surface. Laser remelting possesses several competitive advantages of being a clean, non-contact, fast, highly accurate and automated process compared to other surface coating methods. The promising results of this study point to the possibility that laser remelting can be a practical and effective surface modification technique to further improve the tribological performance of Co

Settling of abutments into implants and changes in removal torque in five different implant-abutment connections. Part 1: Cyclic loading.

Science.gov (United States)

Kim, Ki-Seong; Han, Jung-Suk; Lim, Young-Jun

2014-01-01

The aim of this study was to evaluate and compare the settling of abutments into implants and the removal torque values (RTVs) before and after cyclic loading. Five different implant-abutment connections were tested: Ext = external butt joint + two-piece abutment; Int-H2 = internal hexagon + two-piece abutment; Int-H1 = internal hexagon + one-piece abutment; Int-O2 = internal octagon + two-piece abutment; and Int-O1 = internal octagon + one-piece abutment. Ten abutments from each group were secured to their corresponding implants (total n = 50). All samples were tested in a universal testing machine with a vertical load of 250 N for 100,000 cycles of 14 Hz. The amount of settling of the abutment into the implant was calculated from the change in the total length of the implant-abutment sample before and after loading, as measured with an electronic digital micrometer. The RTV after cyclic loading was compared to the initial RTV with a digital torque gauge. Statistical analysis was performed at a 5% significance level. A multiple-comparison test showed specific significant differences in settling values in each group after 250 N cyclic loading (Int-H1, Ext abutment type and related to the design characteristics of the implant-abutment connection.

Influence of Abutment Design on Clinical Status of Peri-Implant Tissues

OpenAIRE

Taiyeb-Ali, T. B.; Toh, C. G.; Siar, C. H.; Seiz, D.; Ong, S. T.

2017-01-01

Objective: To compare the clinical soft tissue responses around implant tooth-supported 3-unit bridges using tapered abutments with those using butt-joint abutments. Methods: In a split-mouth design study, 8 mm Ankylos (Dentsply Friadent, Germany) implants were placed in the second mandibular molar region of 8 adult Macaca fascicularis monkeys about I month after extraction of all mandibular molars. After 3 months of submerged healing, 3-unit metal bridges were constructed. Clinical data was ...

The effect of glenosphere diameter in reverse shoulder arthroplasty on muscle force, joint load, and range of motion.

Science.gov (United States)

Langohr, G Daniel G; Giles, Joshua W; Athwal, George S; Johnson, James A

2015-06-01

Little is known about the effects of glenosphere diameter on shoulder joint loads. The purpose of this biomechanical study was to investigate the effects of glenosphere diameter on joint load, load angle, and total deltoid force required for active abduction and range of motion in internal/external rotation and abduction. A custom, instrumented reverse shoulder arthroplasty implant system capable of measuring joint load and varying glenosphere diameter (38 and 42 mm) and glenoid offset (neutral and lateral) was implanted in 6 cadaveric shoulders to provide at least 80% power for all variables. A shoulder motion simulator was used to produce active glenohumeral and scapulothoracic motion. All implant configurations were tested with active and passive motion with joint kinematics, loads, and moments recorded. At neutral and lateralized glenosphere positions, increasing diameter significantly increased joint load (+12 ± 21 N and +6 ± 9 N; P  .8). Passive internal rotation was reduced with increased diameter at both neutral and lateralized glenosphere positions (-6° ± 6° and -12° ± 6°; P  .05). At neutral glenosphere position, increasing diameter increased the maximum angles of both adduction (+1° ± 1°; P = .03) and abduction (+8° ± 9°; P < .05). Lateralization also increased abduction range of motion compared with neutral (P < .01). Although increasing glenosphere diameter significantly increased joint load and deltoid force, the clinical impact of these changes is presently unclear. Internal rotation, however, was reduced, which contradicts previous bone modeling studies, which we postulate is due to increased posterior capsular tension as it is forced to wrap around a larger 42 mm implant assembly. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

“In vitro” Implantation Technique Based on 3D Printed Prosthetic Prototypes

Science.gov (United States)

Tarnita, D.; Boborelu, C.; Geonea, I.; Malciu, R.; Grigorie, L.; Tarnita, D. N.

2018-06-01

In this paper, Rapid Prototyping ZCorp 310 system, based on high-performance composite powder and on resin-high strength infiltration system and three-dimensional printing as a manufacturing method are used to obtain physical prototypes of orthopaedic implants and prototypes of complex functional prosthetic systems directly from the 3D CAD data. These prototypes are useful for in vitro experimental tests and measurements to optimize and obtain final physical prototypes. Using a new elbow prosthesis model prototype obtained by 3D printing, the surgical technique of implantation is established. Surgical implantation was performed on male corpse elbow joint.

Gold Bead Implantation in Acupoints for Coxofemoral Arthrosis in Dogs: Method Description and Adverse Effects

Directory of Open Access Journals (Sweden)

Lars Moe

2012-09-01

Full Text Available Gold bead implantation has been used for years as an alternative method to improve function in chronic joint disease both in humans and dogs. The aims of the present study were to describe the technique of implanting 24-karat gold beads around the hip joints of dogs with chronic hip dysplasia, and to record any side effects or complications of such treatment. A prospective placebo-controlled double-blinded clinical trial was performed. Eighty dogs were randomly allocated to treatment or placebo, with 38 in the gold implantation group and 42 in the placebo group, and followed intensely for six months. The implantation technique was simple to perform, using fluoroscopy and with the dogs under inhalation anesthesia for about 30 minutes. Adverse effects, measured as pain or discomfort, were seen for a period of up to four weeks in 15 of the dogs in the gold implantation group, compared to six dogs in the placebo group. During implantation, a technical difficulty occurred as 82% of the dogs showed leakage of blood and/or synovia from the needles. The dogs in the gold implantation group were radiographed 18 months later. Of the 30 dogs that were radiographed at both inclusion and 24 months, 80% (24 dogs showed a deterioration of the coxofemoral arthrosis, the other six had stable disease evaluated by radiography. Migration of gold beads was only observed in one dog.

Fatigue limits of titanium-bar joints made with the laser and the electric resistance welding techniques: microstructural characterization and hardness properties.

Science.gov (United States)

Degidi, Marco; Nardi, Diego; Morri, Alessandro; Sighinolfi, Gianluca; Tebbel, Florian; Marchetti, Claudio

2017-09-01

Fatigue behavior of the titanium bars is of utmost importance for the safe and reliable operation of dental implants and prosthetic constructions based on these implants. To date, however, only few data are available on the fatigue strength of dental prostheses made with electric resistance welding and laser welding techniques. This in-vitro study highlighted that although the joints made with the laser welding approach are credited of a superior tensile strength, joints made with electric resistance welding exhibited double the minimum fatigue strength with respect to the joints made with laser welding (120 vs 60 N).

The effect of ion implantation on the tribomechanical properties of carbon fibre reinforced polymers

International Nuclear Information System (INIS)

Mistica, R.; Sood, D.K.; Janardhana, M.N.

1993-01-01

Graphite fibre reinforced epoxy composite material (GFRP) is used extensively in the aerospace and other industries for structural application. The trend is to address the 20 to 30 year life endurance of this material in service. Mechanical joints in air crafts are exposed to dynamic loads during service and wear may be experienced by the composite material joint. Generally it has been shown that graphite fibre reinforced polymers have superior wear and friction properties as compared with the unfilled polymers. In the described experiment, ion implantation was used as a novel surface treatment. Wear and friction of a polymer composite material (GFRP) was studied and ion implantation was used in order to observe the effect on the tribomechanical properties of the material. It was found that ion implantation of C on GFRP sliding against Ti changes the tribological properties of the system, and in particular decreases the coefficient of friction and wear. 4 refs., 2 figs

The effect of ion implantation on the tribomechanical properties of carbon fibre reinforced polymers

Energy Technology Data Exchange (ETDEWEB)

Mistica, R.; Sood, D.K. [Royal Melbourne Inst. of Tech., VIC (Australia); Janardhana, M.N. [Deakin University, Geelong, VIC (Australia). School of Engineering and Technology

1993-12-31

Graphite fibre reinforced epoxy composite material (GFRP) is used extensively in the aerospace and other industries for structural application. The trend is to address the 20 to 30 year life endurance of this material in service. Mechanical joints in air crafts are exposed to dynamic loads during service and wear may be experienced by the composite material joint. Generally it has been shown that graphite fibre reinforced polymers have superior wear and friction properties as compared with the unfilled polymers. In the described experiment, ion implantation was used as a novel surface treatment. Wear and friction of a polymer composite material (GFRP) was studied and ion implantation was used in order to observe the effect on the tribomechanical properties of the material. It was found that ion implantation of C on GFRP sliding against Ti changes the tribological properties of the system, and in particular decreases the coefficient of friction and wear. 4 refs., 2 figs.

The effect of ion implantation on the tribomechanical properties of carbon fibre reinforced polymers

Energy Technology Data Exchange (ETDEWEB)

Mistica, R; Sood, D K [Royal Melbourne Inst. of Tech., VIC (Australia); Janardhana, M N [Deakin University, Geelong, VIC (Australia). School of Engineering and Technology

1994-12-31

Graphite fibre reinforced epoxy composite material (GFRP) is used extensively in the aerospace and other industries for structural application. The trend is to address the 20 to 30 year life endurance of this material in service. Mechanical joints in air crafts are exposed to dynamic loads during service and wear may be experienced by the composite material joint. Generally it has been shown that graphite fibre reinforced polymers have superior wear and friction properties as compared with the unfilled polymers. In the described experiment, ion implantation was used as a novel surface treatment. Wear and friction of a polymer composite material (GFRP) was studied and ion implantation was used in order to observe the effect on the tribomechanical properties of the material. It was found that ion implantation of C on GFRP sliding against Ti changes the tribological properties of the system, and in particular decreases the coefficient of friction and wear. 4 refs., 2 figs.

Sacroiliac Joint Fusion Minimally Affects Adjacent Lumbar Segment Motion: A Finite Element Study.

Science.gov (United States)

Lindsey, Derek P; Kiapour, Ali; Yerby, Scott A; Goel, Vijay K

2015-01-01

Adjacent segment disease is a recognized consequence of fusion in the spinal column. Fusion of the sacroiliac joint is an effective method of pain reduction. Although effective, the consequences of sacroiliac joint fusion and the potential for adjacent segment disease for the adjacent lumbar spinal levels is unknown. The objective of this study was to quantify the change in range of motion of the sacroiliac joint and the adjacent lumbar spinal motion segments due to sacroiliac joint fusion and compare these changes to previous literature to assess the potential for adjacent segment disease in the lumbar spine. An experimentally validated finite element model of the lumbar spine and pelvis was used to simulate a fusion of the sacroiliac joint using three laterally placed triangular implants (iFuse Implant System, SI-BONE, Inc., San Jose, CA). The range of motion of the sacroiliac joint and the adjacent lumbar spinal motion segments were calculated using a hybrid loading protocol and compared with the intact range of motion in flexion, extension, lateral bending, and axial rotation. The range of motions of the treated sacroiliac joints were reduced in flexion, extension, lateral bending, and axial rotation, by 56.6%, 59.5%, 27.8%, and 53.3%, respectively when compared with the intact condition. The stiffening of the sacroiliac joint resulted in increases at the adjacent lumbar motion segment (L5-S1) for flexion, extension, lateral bending, and axial rotation, of 3.0%, 3.7%, 1.1%, and 4.6%, respectively. Fusion of the sacroiliac joint resulted in substantial (> 50%) reductions in flexion, extension, and axial rotation of the sacroiliac joint with minimal (sacroiliac joint fusion, the long-term clinical results remain to be investigated.

In-vivo degradation mechanism of Ti-6Al-4V hip joints

DEFF Research Database (Denmark)

Lomholt, Trine Colding; Pantleon, Karen; Somers, Marcel A. J.

2011-01-01

In-vivo exposed Ti-6Al-4V implants were investigated to determine the degradation mechanism occurring during the articulating movements of the hip joint in the human body. Failed implants were compared to Ti-6Al-4V samples, which were tested in the laboratory for their tribocorrosion performance....... The results strongly indicate that degradation of Ti-6Al-4V has occurred with the same mechanism for both the implants and the laboratory tested samples and, hence, block-on-ring tribocorrosion testing was found to be a useful tool for mimicking the degradation occurring in the body.The degradation mechanism...

Effect of carbon ion implantation on the tribology of metal-on-metal bearings for artificial joints.

Science.gov (United States)

Koseki, Hironobu; Tomita, Masato; Yonekura, Akihiko; Higuchi, Takashi; Sunagawa, Sinya; Baba, Koumei; Osaki, Makoto

2017-01-01

Metal-on-metal (MoM) bearings have become popular due to a major advantage over metal-on-polymer bearings for total hip arthroplasty in that the larger femoral head and hydrodynamic lubrication of the former reduce the rate of wear. However, concerns remain regarding adverse reactions to metal debris including metallosis caused by metal wear generated at the taper-head interface and another modular junction. Our group has hypothesized that carbon ion implantation (CII) may improve metal wear properties. The purpose of this study was to investigate the wear properties and friction coefficients of CII surfaces with an aim to ultimately apply these surfaces to MoM bearings in artificial joints. CII was applied to cobalt-chromium-molybdenum (Co-Cr-Mo) alloy substrates by plasma source ion implantation. The substrates were characterized using scanning electron microscopy and a 3D measuring laser microscope. Sliding contact tests were performed with a simple geometry pin-on-plate wear tester at a load of 2.5 N, a calculated contact pressure of 38.5 MPa (max: 57.8 MPa), a reciprocating velocity of 30 mm/s, a stroke length of 60 mm, and a reciprocating cycle count of 172,800 cycles. The surfaces of the CII substrates were generally featureless with a smooth surface topography at the same level as untreated Co-Cr-Mo alloy. Compared to the untreated Co-Cr-Mo alloy, the CII-treated bearings had lower friction coefficients, higher resistance to catastrophic damage, and prevented the adhesion of wear debris. The results of this study suggest that the CII surface stabilizes the wear status due to the low friction coefficient and low infiltration of partner materials, and these properties also prevent the adhesion of wear debris and inhibit excessive wear. Carbon is considered to be biologically inert; therefore, CII is anticipated to be applicable to the bearing surfaces of MoM prostheses.

Augmented cartilage regeneration by implantation of cellular versus acellular implants after bone marrow stimulation: a systematic review and meta-analysis of animal studies

Directory of Open Access Journals (Sweden)

Michiel W. Pot

2017-10-01

Full Text Available Bone marrow stimulation may be applied to regenerate focal cartilage defects, but generally results in transient clinical improvement and formation of fibrocartilage rather than hyaline cartilage. Tissue engineering and regenerative medicine strive to develop new solutions to regenerate hyaline cartilage tissue. This systematic review and meta-analysis provides a comprehensive overview of current literature and assesses the efficacy of articular cartilage regeneration by implantation of cell-laden versus cell-free biomaterials in the knee and ankle joint in animals after bone marrow stimulation. PubMed and EMBASE (via OvidSP were systematically searched using tissue engineering, cartilage and animals search strategies. Included were primary studies in which cellular and acellular biomaterials were implanted after applying bone marrow stimulation in the knee or ankle joint in healthy animals. Study characteristics were tabulated and outcome data were collected for meta-analysis for studies applying semi-quantitative histology as outcome measure (117 studies. Cartilage regeneration was expressed on an absolute 0–100% scale and random effects meta-analyses were performed. Implantation of cellular biomaterials significantly improved cartilage regeneration by 18.6% compared to acellular biomaterials. No significant differences were found between biomaterials loaded with stem cells and those loaded with somatic cells. Culture conditions of cells did not affect cartilage regeneration. Cartilage formation was reduced with adipose-derived stem cells compared to other cell types, but still improved compared to acellular scaffolds. Assessment of the risk of bias was impaired due to incomplete reporting for most studies. Implantation of cellular biomaterials improves cartilage regeneration compared to acellular biomaterials.

Augmented cartilage regeneration by implantation of cellular versus acellular implants after bone marrow stimulation: a systematic review and meta-analysis of animal studies.

Science.gov (United States)

Pot, Michiel W; van Kuppevelt, Toin H; Gonzales, Veronica K; Buma, Pieter; IntHout, Joanna; de Vries, Rob B M; Daamen, Willeke F

2017-01-01

Bone marrow stimulation may be applied to regenerate focal cartilage defects, but generally results in transient clinical improvement and formation of fibrocartilage rather than hyaline cartilage. Tissue engineering and regenerative medicine strive to develop new solutions to regenerate hyaline cartilage tissue. This systematic review and meta-analysis provides a comprehensive overview of current literature and assesses the efficacy of articular cartilage regeneration by implantation of cell-laden versus cell-free biomaterials in the knee and ankle joint in animals after bone marrow stimulation. PubMed and EMBASE (via OvidSP) were systematically searched using tissue engineering, cartilage and animals search strategies. Included were primary studies in which cellular and acellular biomaterials were implanted after applying bone marrow stimulation in the knee or ankle joint in healthy animals. Study characteristics were tabulated and outcome data were collected for meta-analysis for studies applying semi-quantitative histology as outcome measure (117 studies). Cartilage regeneration was expressed on an absolute 0-100% scale and random effects meta-analyses were performed. Implantation of cellular biomaterials significantly improved cartilage regeneration by 18.6% compared to acellular biomaterials. No significant differences were found between biomaterials loaded with stem cells and those loaded with somatic cells. Culture conditions of cells did not affect cartilage regeneration. Cartilage formation was reduced with adipose-derived stem cells compared to other cell types, but still improved compared to acellular scaffolds. Assessment of the risk of bias was impaired due to incomplete reporting for most studies. Implantation of cellular biomaterials improves cartilage regeneration compared to acellular biomaterials.

Machine learning techniques for the optimization of joint replacements: Application to a short-stem hip implant.

Science.gov (United States)

Cilla, Myriam; Borgiani, Edoardo; Martínez, Javier; Duda, Georg N; Checa, Sara

2017-01-01

Today, different implant designs exist in the market; however, there is not a clear understanding of which are the best implant design parameters to achieve mechanical optimal conditions. Therefore, the aim of this project was to investigate if the geometry of a commercial short stem hip prosthesis can be further optimized to reduce stress shielding effects and achieve better short-stemmed implant performance. To reach this aim, the potential of machine learning techniques combined with parametric Finite Element analysis was used. The selected implant geometrical parameters were: total stem length (L), thickness in the lateral (R1) and medial (R2) and the distance between the implant neck and the central stem surface (D). The results show that the total stem length was not the only parameter playing a role in stress shielding. An optimized implant should aim for a decreased stem length and a reduced length of the surface in contact with the bone. The two radiuses that characterize the stem width at the distal cross-section in contact with the bone were less influential in the reduction of stress shielding compared with the other two parameters; but they also play a role where thinner stems present better results.

Patient and implant survival following joint replacement because of metastatic bone disease

DEFF Research Database (Denmark)

Sørensen, Michala S; Gregersen, Kristine G; Grum-Schwensen, Tomas

2013-01-01

Patients suffering from a pathological fracture or painful bony lesion because of metastatic bone disease often benefit from a total joint replacement. However, these are large operations in patients who are often weak. We examined the patient survival and complication rates after total joint...... replacement as the treatment for bone metastasis or hematological diseases of the extremities....

Theoretical optimum of implant positional index design.

Science.gov (United States)

Semper, W; Kraft, S; Krüger, T; Nelson, K

2009-08-01

Rotational freedom of the implant-abutment connection influences its screw joint stability; for optimization, influential factors need to be evaluated based on a previously developed closed formula. The underlying hypothesis is that the manufacturing tolerances, geometric pattern, and dimensions of the index do not influence positional stability. We used the dimensions of 5 commonly used implant systems with a clearance of 20 microm to calculate the extent of rotational freedom; a 3D simulation (SolidWorks) validated the analytical findings. Polygonal positional indices showed the highest degrees of rotational freedom. The polygonal profile displayed higher positional stability than the polygons, but less positional accuracy than the cam-groove connection. Features of a maximal rotation-safe positional index were determined. The analytical calculation of rotational freedom of implant positional indices is possible. Rotational freedom is dependent on the geometric design of the index and may be decreased by incorporating specific aspects into the positional index design.

Post-operative X-ray morphology: Joints. Handbook and atlas for clinical and practical use. Postoperative Roentgenmorphologie: Gelenke. Handbuch und Atlas fuer Klinik und Praxis

Energy Technology Data Exchange (ETDEWEB)

Vogel, H.

1987-01-01

The description of X-ray findings after operations with the object of implanting protheses in joints makes up most of the contents of this book. The reconstruction of joints after trauma is only marginally dealt with. Among the various indications for implanting protheses, the replacement of joints destroyed by wear and trauma is the most important. Also considered were X-ray examinations after hallux-valgus operations and plastic surgery on hands and feet, as well as X-ray findings following operations on the lumbar part of the vertebral column (disc surgery).

Physiological joint line total knee arthroplasty designs are especially sensitive to rotational placement - A finite element analysis.

Science.gov (United States)

Moewis, Philippe; Checa, Sara; Kutzner, Ines; Hommel, Hagen; Duda, Georg N

2018-01-01

Mechanical and kinematical aligning techniques are the usual positioning methods during total knee arthroplasty. However, alteration of the physiological joint line and unbalanced medio-lateral load distribution are considered disadvantages in the mechanical and kinematical techniques, respectively. The aim of this study was to analyse the influence of the joint line on the strain and stress distributions in an implanted knee and their sensitivity to rotational mal-alignment. Finite element calculations were conducted to analyse the stresses in the PE-Inlay and the mechanical strains at the bone side of the tibia component-tibia bone interface during normal positioning of the components and internal and external mal-rotation of the tibial component. Two designs were included, a horizontal and a physiological implant. The loading conditions are based on internal knee joint loads during walking. A medialization of the stresses on the PE-Inlay was observed in the physiological implant in a normal position, accompanied by higher stresses in the mal-rotated positions. Within the tibia component-tibia bone interface, similar strain distributions were observed in both implant geometries in the normal position. However, a medialization of the strains was observed in the physiological implant in both mal-rotated conditions with greater bone volume affected by higher strains. Although evident changes due to mal-rotation were observed, the stresses do not suggest a local plastic deformation of the PE-Inlay. The strains values within most of the tibia component-tibia bone interface were in the physiological strain zone and no significant bone changes would be expected. The physiological cut on the articular aspect showed no detrimental effect compared to the horizontal implant.

In Vivo Assessment of Phage and Linezolid Based Implant Coatings for Treatment of Methicillin Resistant S. aureus (MRSA Mediated Orthopaedic Device Related Infections.

Directory of Open Access Journals (Sweden)

Sandeep Kaur

Full Text Available Staphylococcus comprises up to two-thirds of all pathogens in orthopaedic implant infections with two species respectively Staphylococcus aureus and Staphylococcus epidermidis, being the predominate etiological agents isolated. Further, with the emergence of methicillin-resistant S. aureus (MRSA, treatment of S. aureus implant infections has become more difficult, thus representing a devastating complication. Use of local delivery system consisting of S.aureus specific phage along with linezolid (incorporated in biopolymer allowing gradual release of the two agents at the implant site represents a new, still unexplored treatment option (against orthopaedic implant infections that has been studied in an animal model of prosthetic joint infection. Naked wire, hydroxypropyl methylcellulose (HPMC coated wire and phage and /or linezolid coated K-wire were surgically implanted into the intra-medullary canal of mouse femur bone of respective groups followed by inoculation of S.aureus ATCC 43300(MRSA. Mice implanted with K-wire coated with both the agents i.e phage as well as linezolid (dual coated wires showed maximum reduction in bacterial adherence, associated inflammation of the joint as well as faster resumption of locomotion and motor function of the limb. Also, all the coating treatments showed no emergence of resistant mutants. Use of dual coated implants incorporating lytic phage (capable of self-multiplication as well as linezolid presents an attractive and aggressive early approach in preventing as well as treating implant associated infections caused by methicillin resistant S. aureus strains as assessed in a murine model of experimental joint infection.

Optimization of hip joint replacement location to decrease maximum von Mi ses Stress

International Nuclear Information System (INIS)

Pourjamali, H.; Najarian, S.; Katoozian, H. R.

2001-01-01

Hip replacement is used for inoperable femur head injuries and femur fractures where internal fixation can not be used. This operation is one of the most common orthopedic operations that many research have been done about it. Among these we can mention implant and cement materials and composites optimization and also implant shape optimization. This study was designed to optimize artificial hip joint position (placement) to decrease maximal von mi sees stress. First, a model of femur and implant were made and then a computer program was written with the ability to change the position of implant through an acceptable range in the femur. In each of these positions, the program simulated femur and implant according to finite element method and made, applied forces were weight and muscle traction. Our findings show that a small deviation of the implant from femur bone center causes a considerable decrease in von mi sees stress that consequently results in longer maintenance of the implant

An electrochemical investigation of TMJ implant metal alloys in an artificial joint fluid environment: the influence of pH variation.

Science.gov (United States)

Royhman, Dmitry; Radhakrishnan, Rashmi; Yuan, Judy Chia-Chun; Mathew, Mathew T; Mercuri, Louis G; Sukotjo, Cortino

2014-10-01

To investigate the corrosion behaviour of commonly used TMJ implants alloys (CoCrMo and Ti6Al4V) under simulated physiological conditions. Corrosion behaviour was evaluated using standard electrochemical corrosion techniques and galvanic corrosion techniques as per ASTM standards. Standard electrochemical tests (E(corr), I(corr), R(p) and C(f)) were conducted in bovine calf serum (BCS), as a function of alloys type and different pHs. Galvanic corrosion tests were conducted in BCS at a pH of 7.6. Alloy surfaces were characterized using white-light interferometry (WLI) and scanning electron microscopy (SEM). The potentiodynamic test results exhibited the enhanced passive layer growth and a better corrosion resistance of Ti6Al4V compared to CoCrMo. Electrochemical impedance spectroscopy measurements demonstrated the influence of protein as a function of pH on corrosion mechanisms/kinetics. Galvanic coupling was not a major contributor to corrosion. SEM and WLI images demonstrated a significantly higher in surface roughness in CoCrMo after corrosion. The results of this study suggest that Ti6Al4V shows superior corrosion behaviour to CoCrMo due to its strong passive layer, simulated joint fluid components can affect the electrochemical nature of the metal/electrolyte interface as a function of pH, and the galvanic effect of coupling CoCrMo and Ti6Al4V in a single joint is weak. Published by Elsevier Ltd.

Effect of Intraoperative Three-Dimensional Imaging During the Reduction and Fixation of Displaced Calcaneal Fractures on Articular Congruence and Implant Fixation

DEFF Research Database (Denmark)

Eckardt, Henrik; Lind, Marianne

2015-01-01

BACKGROUND: Operative treatment of displaced calcaneal fractures should restore joint congruence, but conventional fluoroscopy is unable to fully visualize the subtalar joint. We questioned whether intraoperative 3-dimensional (3D) imaging would aid in the reduction of calcaneal fractures......, resulting in improved articular congruence and implant positioning. METHOD: Sixty-two displaced calcaneal fractures were operated on using standard fluoroscopic views. When the surgeon had achieved a satisfactory reduction, an intraoperative 3D scan was conducted, malreductions or implant imperfections were...

Surface engineering by ion implantation

International Nuclear Information System (INIS)

Nielsen, Bjarne Roger

1995-01-01

Awidespread commercial applica tion iof particle accelerators is for ion implantation. Accelerator beams are used for ion implantation into metals, alloying a thin surface layer with foreign atoms to concentrations impossible to achieve by thermal processes, making for dramatic improvements in hardness and in resistance to wear and corrosion. Traditional hardening processes require high temperatures causing deformation; ion implantation on the other hand is a ''cold process'', treating the finished product. The ionimplanted layer is integrated in the substrate, avoiding the risk of cracking and delamination from normal coating processes. Surface properties may be ''engineered'' independently of those of the bulk material; the process does not use environmentally hazardous materials such as chromium in the surface coating. The typical implantation dose required for the optimum surface properties of metals is around 2 x 10 17 ion/cm 2 , a hundred times the typical doses for semiconductor processing. When surface areas of more than a few square centimetres have to be treated, the implanter must therefore be able to produce high beam currents (5 to 10 mA) to obtain an acceptable treatment time. Ion species used include nitrogen, boron, carbon, titanium, chromium and tantalum, and beam energies range from 50 to 200 keV. Since most components are three dimensional, it must be possible to rotate and tilt them in the beam, and control beam position over a large area. Examples of industrial applications are: - surface treatment of prostheses (hip and knee joints) to reduce wear of the moving parts, using biocompatible materials; - ion implantation into high speed ball bearings to protect against the aqueous corrosion in jet engines (important for service helicopters on oil rigs); - hardening of metal forming and cutting tools; - reduction of corrosive wear of plastic moulding tools, which are expensive to produce

Implant healing in experimental animal models of diabetes.

Science.gov (United States)

Le, Nga N; Rose, Michael B; Levinson, Howard; Klitzman, Bruce

2011-05-01

Diabetes mellitus is becoming increasingly prevalent worldwide. Additionally, there is an increasing number of patients receiving implantable devices such as glucose sensors and orthopedic implants. Thus, it is likely that the number of diabetic patients receiving these devices will also increase. Even though implantable medical devices are considered biocompatible by the Food and Drug Administration, the adverse tissue healing that occurs adjacent to these foreign objects is a leading cause of their failure. This foreign body response leads to fibrosis, encapsulation of the device, and a reduction or cessation of device performance. A second adverse event is microbial infection of implanted devices, which can lead to persistent local and systemic infections and also exacerbates the fibrotic response. Nearly half of all nosocomial infections are associated with the presence of an indwelling medical device. Events associated with both the foreign body response and implant infection can necessitate device removal and may lead to amputation, which is associated with significant morbidity and cost. Diabetes mellitus is generally indicated as a risk factor for the infection of a variety of implants such as prosthetic joints, pacemakers, implantable cardioverter defibrillators, penile implants, and urinary catheters. Implant infection rates in diabetic patients vary depending upon the implant and the microorganism, however, for example, diabetes was found to be a significant variable associated with a nearly 7.2% infection rate for implantable cardioverter defibrillators by the microorganism Candida albicans. While research has elucidated many of the altered mechanisms of diabetic cutaneous wound healing, the internal healing adjacent to indwelling medical devices in a diabetic model has rarely been studied. Understanding this healing process is crucial to facilitating improved device design. The purpose of this article is to summarize the physiologic factors that

Ulnar digits contribution to grip strength in patients with thumb carpometacarpal osteoarthritis is less than in normal controls.

Science.gov (United States)

Villafañe, Jorge H; Valdes, Kristin; Angulo-Diaz-Parreño, Santiago; Pillastrini, Paolo; Negrini, Stefano

2015-06-01

Grip testing is commonly used as an objective measure of strength in the hand and upper extremity and is frequently used clinically as a proxy measure of function. Increasing knowledge of hand biomechanics, muscle strength, and prehension patterns can provide us with a better understanding of the functional capabilities of the hand. The objectives of this study were to determine the contribution of ulnar digits to overall grip strength in individuals with thumb carpometacarpal (CMC) osteoarthritis (OA). Thirty-seven subjects participated in the study. This group consisted of 19 patients with CMC OA (aged 60-88 years) and 18 healthy subjects (60-88 years). Three hand configurations were used by the subjects during grip testing: use of the entire hand (index, middle, ring, and little fingers) (IMRL); use of the index, middle, and ring fingers (IMR); and use of only the index and middle fingers (IM). Grip strength findings for the two groups found that compared to their healthy counterparts, CMC OA patients had, on average, a strength deficiency of 45.6, 35.5, and 28.8 % in IMRL, IMR, and IM, respectively. The small finger contribution to grip is 14.3 % and the ring and small finger contribute 34 % in subjects with CMC OA. Grip strength decreases as the number of digits contributing decreased in both groups. The ulnar digits contribution to grip strength is greater than one third of total grip strength in subjects with CMC OA. Individuals with CMC OA demonstrate significantly decreased grip strength when compared to their healthy counterparts.

Intermittent Parathyroid Hormone Enhances Cancellous Osseointegration of a Novel Murine Tibial Implant

Science.gov (United States)

Yang, Xu; Ricciardi, Benjamin F.; Dvorzhinskiy, Aleksey; Brial, Caroline; Lane, Zachary; Bhimani, Samrath; Burket, Jayme C.; Hu, Bin; Sarkisian, Alexander M.; Ross, F. Patrick; van der Meulen, Marjolein C.H.; Bostrom, Mathias P.G.

2015-01-01

Background: Long-term fixation of uncemented joint implants requires early mechanical stability and implant osseointegration. To date, osseointegration has been unreliable and remains a major challenge in cementless total knee arthroplasty. We developed a murine model in which an intra-articular proximal tibial titanium implant with a roughened stem can be loaded through the knee joint. Using this model, we tested the hypothesis that intermittent injection of parathyroid hormone (iPTH) would increase proximal tibial cancellous osseointegration. Methods: Ten-week-old female C57BL/6 mice received a subcutaneous injection of PTH (40 μg/kg/day) or a vehicle (n = 45 per treatment group) five days per week for six weeks, at which time the baseline group was killed (n = 6 per treatment group) and an implant was inserted into the proximal part of the tibiae of the remaining mice. Injections were continued until the animals were killed at one week (n = 7 per treatment group), two weeks (n = 14 per treatment group), or four weeks (n = 17 per treatment group) after implantation. Outcomes included peri-implant bone morphology as analyzed with micro-computed tomography (microCT), osseointegration percentage and bone area fraction as shown with backscattered electron microscopy, cellular composition as demonstrated by immunohistochemical analysis, and pullout strength as measured with mechanical testing. Results: Preimplantation iPTH increased the epiphyseal bone volume fraction by 31.6%. When the data at post-implantation weeks 1, 2, and 4 were averaged for the iPTH-treated mice, the bone volume fraction was 74.5% higher in the peri-implant region and 168% higher distal to the implant compared with the bone volume fractions in the same regions in the vehicle-treated mice. Additionally, the trabecular number was 84.8% greater in the peri-implant region and 74.3% greater distal to the implant. Metaphyseal osseointegration and bone area fraction were 28.1% and 70.1% higher

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.

An inquiry into application of Gokyo (Aikido's Fifth Teaching) on human anatomy.

Science.gov (United States)

Olson, G D; Seitz, F C; Guldbrandsen, F

1996-06-01

In this anatomical analysis the authors examined Gokyo, Aikido's Fifth Teaching. Using their cadaver/anatomist-observer model, the authors observed that tissues manipulated by the technique were primarily on the dorsal side of the wrist, proximal to the second metacarpal. The source of the pain was thought to involve the manipulation of the wrist joints and associated carpometacarpal ligaments. Locations of the manipulated tissue and sources of pain associated with that tissue, and their limited practical application were discussed.

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.

Failure of total hip implants: metals and metal release in 52 cases

DEFF Research Database (Denmark)

Jakobsen, Stig Storgaard; Lidén, Carola; Søballe, Kjeld

2014-01-01

Background . The pathogenesis of total joint replacement failure is multifactorial. One hypothesis suggests that corrosion and wear of alloys result in metal ion release, which may then cause sensitization and even implant failure, owing to the acquired immune reactivity. Objectives . To assess c...

Residual gentamicin-release from antibiotic-loaded polymethylmethacrylate beads after 5 years of implantation

NARCIS (Netherlands)

Neut, D; van de Belt, H; van Horn, [No Value; van der Mei, HC; Busscher, HJ

In infected joint arthroplasty, high local levels of antibiotics are achieved through temporary implantation of non-biodegradable gentamicin-loaded polymethylmethacrylate beads. Despite their antibiotic release, these beads act as a biomaterial surface to which bacteria preferentially adhere, grow

MEMS-Based Power Generation Techniques for Implantable Biosensing Applications

Directory of Open Access Journals (Sweden)

Jonathan Lueke

2011-01-01

Full Text Available Implantable biosensing is attractive for both medical monitoring and diagnostic applications. It is possible to monitor phenomena such as physical loads on joints or implants, vital signs, or osseointegration in vivo and in real time. Microelectromechanical (MEMS-based generation techniques can allow for the autonomous operation of implantable biosensors by generating electrical power to replace or supplement existing battery-based power systems. By supplementing existing battery-based power systems for implantable biosensors, the operational lifetime of the sensor is increased. In addition, the potential for a greater amount of available power allows additional components to be added to the biosensing module, such as computational and wireless and components, improving functionality and performance of the biosensor. Photovoltaic, thermovoltaic, micro fuel cell, electrostatic, electromagnetic, and piezoelectric based generation schemes are evaluated in this paper for applicability for implantable biosensing. MEMS-based generation techniques that harvest ambient energy, such as vibration, are much better suited for implantable biosensing applications than fuel-based approaches, producing up to milliwatts of electrical power. High power density MEMS-based approaches, such as piezoelectric and electromagnetic schemes, allow for supplemental and replacement power schemes for biosensing applications to improve device capabilities and performance. In addition, this may allow for the biosensor to be further miniaturized, reducing the need for relatively large batteries with respect to device size. This would cause the implanted biosensor to be less invasive, increasing the quality of care received by the patient.

MEMS-based power generation techniques for implantable biosensing applications.

Science.gov (United States)

Lueke, Jonathan; Moussa, Walied A

2011-01-01

Implantable biosensing is attractive for both medical monitoring and diagnostic applications. It is possible to monitor phenomena such as physical loads on joints or implants, vital signs, or osseointegration in vivo and in real time. Microelectromechanical (MEMS)-based generation techniques can allow for the autonomous operation of implantable biosensors by generating electrical power to replace or supplement existing battery-based power systems. By supplementing existing battery-based power systems for implantable biosensors, the operational lifetime of the sensor is increased. In addition, the potential for a greater amount of available power allows additional components to be added to the biosensing module, such as computational and wireless and components, improving functionality and performance of the biosensor. Photovoltaic, thermovoltaic, micro fuel cell, electrostatic, electromagnetic, and piezoelectric based generation schemes are evaluated in this paper for applicability for implantable biosensing. MEMS-based generation techniques that harvest ambient energy, such as vibration, are much better suited for implantable biosensing applications than fuel-based approaches, producing up to milliwatts of electrical power. High power density MEMS-based approaches, such as piezoelectric and electromagnetic schemes, allow for supplemental and replacement power schemes for biosensing applications to improve device capabilities and performance. In addition, this may allow for the biosensor to be further miniaturized, reducing the need for relatively large batteries with respect to device size. This would cause the implanted biosensor to be less invasive, increasing the quality of care received by the patient.

Failure of Emperion modular femoral stem with implant analysis

Directory of Open Access Journals (Sweden)

Benjamin M. Stronach, MD, MS

2016-03-01

Full Text Available Modularity in total hip arthroplasty provides multiple benefits to the surgeon in restoring the appropriate alignment and position to a previously damaged hip joint. The vast majority of modern implants incorporate modularity into their design with some implants having multiple modular interfaces. There is the potential for failure at modular junctions because of fretting and crevice corrosion in combination with mechanical loading. This case report details the failure of an Emperion (Smith and Nephew, Memphis, TN femoral stem in a 67-year-old male patient 6 years after total hip replacement. Analysis of the implant revealed mechanically assisted crevice corrosion that likely accelerated fatigue crack initiation in the hip stem. The benefits of modularity come with the potential drawback of a combination of fretting and crevice corrosion at the modular junction, which may accelerate fatigue, crack initiation and ultimately reduce the hip longevity.

The Need for an Implant Identification Card at Airport Security Check.

Science.gov (United States)

Ali, Erden; Kosuge, Dennis; MacDowell, Andrew

2017-06-01

Joint replacement surgery is having an increasing demand as national healthcare systems confront an ever ageing population. Surgical complications associated with lower limb arthroplasty are well known but less investigation has been performed examining its effect on air travel, more specifically, unwanted and significant inconvenience caused to travelers going through airport security. In lower limb arthroplasty clinics, 50 patients who met our selection criteria were given questionnaires. Ten airport security officers from 4 international airports (London Stansted, London Gatwick, London Heathrow, and Amsterdam Schiphol International Airport) were also given a separate questionnaire. The opinion of the Civil Aviation Authority was also sought. All 50 patients (mean age, 70.4 years; range, 55 to 84 years) who were presenting in lower limb arthroplasty clinics and who met our selection criteria volunteered to enter the study. Twenty-eight of these patients were female (mean age, 69.1 years; range, 55 to 84 years) and 22 were male (mean age, 71.2 years; range, 58 to 81 years). Of the patients, 14% stated that their joint replacements did not set off the airport security alarm. Responses were received from 10 airport security officers as well. Six airport security officers were male and 4 were female. All of the airport officers were aware of some form of implant identification card with 90% stating that these were useful to them at airport security. Eight-four percent of the patients stated that an implant identification card outlining what joint replacement they possessed and when this had been done would be very useful. Sixteen percent of the patients did not think a card would be beneficial since all of them had set off the airport alarm system only once or less in their lifetime. It is the opinion of airport security officers and patients that joint replacement implant identification cards streamline airport security checks and decrease the need for more

Computed tomography of human joints and radioactive waste drums

International Nuclear Information System (INIS)

Martz, Harry E.; Roberson, G. Patrick; Hollerbach, Karin; Logan, Clinton M.; Ashby, Elaine; Bernardi, Richard

1999-01-01

X- and gamma-ray imaging techniques in nondestructive evaluation (NDE) and assay (NDA) have seen increasing use in an array of industrial, environmental, military, and medical applications. Much of this growth in recent years is attributed to the rapid development of computed tomography (CT) and the use of NDE throughout the life-cycle of a product. Two diverse examples of CT are discussed, 1.) Our computational approach to normal joint kinematics and prosthetic joint analysis offers an opportunity to evaluate and improve prosthetic human joint replacements before they are manufactured or surgically implanted. Computed tomography data from scanned joints are segmented, resulting in the identification of bone and other tissues of interest, with emphasis on the articular surfaces. 2.) We are developing NDE and NDA techniques to analyze closed waste drums accurately and quantitatively. Active and passive computed tomography (A and PCT) is a comprehensive and accurate gamma-ray NDA method that can identify all detectable radioisotopes present in a container and measure their radioactivity

The Effect of Ag and Ag+N Ion Implantation on Cell Attachment Properties

International Nuclear Information System (INIS)

Urkac, Emel Sokullu; Oztarhan, Ahmet; Gurhan, Ismet Deliloglu; Iz, Sultan Gulce; Tihminlioglu, Funda; Oks, Efim; Nikolaev, Alexey; Ila, Daryush

2009-01-01

Implanted biomedical prosthetic devices are intended to perform safely, reliably and effectively in the human body thus the materials used for orthopedic devices should have good biocompatibility. Ultra High Molecular Weight Poly Ethylene (UHMWPE) has been commonly used for total hip joint replacement because of its very good properties. In this work, UHMWPE samples were Ag and Ag+N ion implanted by using the Metal-Vapor Vacuum Arc (MEVVA) ion implantation technique. Samples were implanted with a fluency of 1017 ion/cm2 and extraction voltage of 30 kV. Rutherford Backscattering Spectrometry (RBS) was used for surface studies. RBS showed the presence of Ag and N on the surface. Cell attachment properties investigated with model cell lines (L929 mouse fibroblasts) to demonstrate that the effect of Ag and Ag+N ion implantation can favorably influence the surface of UHMWPE for biomedical applications. Scanning electron microscopy (SEM) was used to demonstrate the cell attachment on the surface. Study has shown that Ag+N ion implantation represents more effective cell attachment properties on the UHMWPE surfaces.

Strengthening of defected beam–column joints using CFRP

Directory of Open Access Journals (Sweden)

Mohamed H. Mahmoud

2014-01-01

Full Text Available This paper presents an experimental study for the structural performance of reinforced concrete (RC exterior beam–column joints rehabilitated using carbon-fiber-reinforced polymer (CFRP. The present experimental program consists of testing 10 half-scale specimens divided into three groups covering three possible defects in addition to an adequately detailed control specimen. The considered defects include the absence of the transverse reinforcement within the joint core, insufficient bond length for the beam main reinforcement and inadequate spliced implanted column on the joint. Three different strengthening schemes were used to rehabilitate the defected beam–column joints including externally bonded CFRP strips and sheets in addition to near surface mounted (NSM CFRP strips. The failure criteria including ultimate capacity, mode of failure, initial stiffness, ductility and the developed ultimate strain in the reinforcing steel and CFRP were considered and compared for each group for the control and the CFRP-strengthened specimens. The test results showed that the proposed CFRP strengthening configurations represented the best choice for strengthening the first two defects from the viewpoint of the studied failure criteria. On the other hand, the results of the third group showed that strengthening the joint using NSM strip technique enabled the specimen to outperform the structural performance of the control specimen while strengthening the joints using externally bonded CFRP strips and sheets failed to restore the strengthened joints capacity.

Strengthening of defected beam-column joints using CFRP.

Science.gov (United States)

Mahmoud, Mohamed H; Afefy, Hamdy M; Kassem, Nesreen M; Fawzy, Tarek M

2014-01-01

This paper presents an experimental study for the structural performance of reinforced concrete (RC) exterior beam-column joints rehabilitated using carbon-fiber-reinforced polymer (CFRP). The present experimental program consists of testing 10 half-scale specimens divided into three groups covering three possible defects in addition to an adequately detailed control specimen. The considered defects include the absence of the transverse reinforcement within the joint core, insufficient bond length for the beam main reinforcement and inadequate spliced implanted column on the joint. Three different strengthening schemes were used to rehabilitate the defected beam-column joints including externally bonded CFRP strips and sheets in addition to near surface mounted (NSM) CFRP strips. The failure criteria including ultimate capacity, mode of failure, initial stiffness, ductility and the developed ultimate strain in the reinforcing steel and CFRP were considered and compared for each group for the control and the CFRP-strengthened specimens. The test results showed that the proposed CFRP strengthening configurations represented the best choice for strengthening the first two defects from the viewpoint of the studied failure criteria. On the other hand, the results of the third group showed that strengthening the joint using NSM strip technique enabled the specimen to outperform the structural performance of the control specimen while strengthening the joints using externally bonded CFRP strips and sheets failed to restore the strengthened joints capacity.

Impact of Intentional Overload on Joint Stability of Internal Implant-Abutment Connection System with Different Diameter.

Science.gov (United States)

Lee, Ji-Hye; Lee, Won; Huh, Yoon-Hyuk; Park, Chan-Jin; Cho, Lee-Ra

2017-09-05

To evaluate the axial displacement of the implant-abutment assembly of different implant diameter after static and cyclic loading of overload condition. An internal conical connection system with three diameters (Ø 4.0, 4.5, and 5.0) applying identical abutment dimension and the same abutment screw was evaluated. Axial displacement of abutment and reverse torque loss of abutment screw were evaluated under static and cyclic loading conditions. Static loading test groups were subjected to vertical static loading of 250, 400, 500, 600, 700, and 800 N consecutively. Cyclic loading test groups were subjected to 500 N cyclic loading to evaluate the effect of excessive masticatory loading. After abutment screw tightening for 30 Ncm, axial displacement was measured upon 1, 3, 10, and 1,000,000 cyclic loadings of 500 N. Repeated-measure ANOVA and 2-way ANOVA were used for statistical analysis (α = 0.05). The increasing magnitude of vertical load and thinner wall thickness of implant increased axial displacement of abutment and reverse torque loss of abutment screw (p < 0.05). Implants in the Ø 5.0 diameter group demonstrated significantly low axial displacement, and reverse torque loss after static loading than Ø 4.0 and Ø 4.5 diameter groups (p < 0.05). In the cyclic loading test, all diameter groups of implant showed significant axial displacement after 1 cycle of loading of 500 N (p < 0.05). There was no significant axial displacement after 3, 10, or 1,000,000 cycles of loading (p = 0.603). Implants with Ø 5.0 diameter demonstrated significantly low axial displacement and reverse torque loss after the cyclic and static loading of overload condition. © 2017 by the American College of Prosthodontists.

BP/Mobil. Joint-venture directions for use

International Nuclear Information System (INIS)

Anon.

1997-01-01

This paper analyzes the economical reasons which have led BP and Mobil companies to join their forces in 1996. Thanks to their complementarity and to their European implantation, the two companies could win the first or second position in petroleum products marketing in 8 European countries. The cumulated petrol sales and the number of petrol stations of the BP/Mobil joint venture are the highest in Europe (800 petrol stations in France). (J.S.)

ISHKS joint registry: A preliminary report.

Science.gov (United States)

Pachore, Jawahir A; Vaidya, Shrinand V; Thakkar, Chandrasekhar J; Bhalodia, Haresh Kumar P; Wakankar, Hemant M

2013-09-01

Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are the most widely practiced surgical options for arthritis all over the world and its application is rising in India. Indian Society of Hip and Knee Surgeons (ISHKS) has established a joints registry and has been collecting data for last 6 years. All members of ISHKS are encouraged to actively participate in the registry. A simple two page knee and hip form can be downloaded from the website www.ishks.com. The information collected includes patient demographics, indication for surgery, implant details and in case of revision arthroplasty: the details of implants removed and the cause of failure of primary arthroplasty. These forms are mailed to the central registry office and the data is fed in computerized registry. Data collection started in October 2006. Joint registry is a very important initiative of ISHKS and till date, have data of 34,478 TKAs and 3604 THAs, contributed by 42 surgeons across India. Some important observations have emerged. Data of 34,478 TKAs was assessed: These included 8612 males (25%) and 25,866 females (75%). Average age was 64.4 years (Osteoarthritis range: 45 to 88 years; Rheumatoid arthritis range: 22 to 74 years). Average body mass index was 29.1 (Range: 18.1 to 42.9). The indication for TKA was osteoarthritis in 33,444 (97%) and rheumatoid arthritis in 759 (2.2%). Total of 3604 THA procedures were recorded. These included 2162 (60%) male patients and 1442 (40%) female patients. Average age was 52 years (Range 17 to 85 years) and average BMI was 25.8 (Range: 17.3 to 38.5). The indications for THA was AVN in 49%. The registry will become more meaningful in years to come. Active participation of all arthroplasty surgeons across India is vital for the success of the joints registry.

Metal-on-metal hip joint tribology.

Science.gov (United States)

Dowson, D; Jin, Z M

2006-02-01

The basic tribological features of metal-on-metal total hip replacements have been reviewed to facilitate an understanding of the engineering science underpinning the renaissance of these hard-on-hard joints. Metal-on-polymer hip replacements operate in the boundary lubrication regime, thus leading to the design guidance to reduce the femoral head diameter as much as is feasible to minimize frictional torque and volumetric wear. This explains why the gold-standard implant of this form from the past half-century had a diameter of only 22.225 mm (7/8 in). Metal-on-metal implants can operate in the mild mixed lubrication regime in which much of the applied load is supported by elastohydrodynamic films. Correct tribological design leads to remarkably low steady state wear rates. Promotion of the most effective elastohydrodynamic films calls for the largest possible head diameters and the smallest clearances that can reasonably be adopted, consistent with fine surface finishes, good sphericity and minimal structural elastic deformation of the cup on its foundations. This guidance, which is opposite in form to that developed for metal-on-polymer joints, is equally valid for solid (monolithic) metallic heads on metallic femoral stems and surface replacement femoral shells. Laboratory measurements of friction and wear in metal-on-metal joints have confirmed their potential to achieve a very mild form of mixed lubrication. The key lies in the generation of effective elastohydrodynamic lubricating films of adequate thickness compared with the composite roughness of the head and cup. The calculation of the film thickness is by no means easy, but the full procedure is outlined and the use of an empirical formula that displays good agreement with calculations based upon the full numerical solutions is explained. The representation of the lambda ratio, lambda, embracing both film thickness and composite roughness, is described.

Management of acute unstable acromioclavicular joint injuries.

Science.gov (United States)

Cisneros, Luis Natera; Reiriz, Juan Sarasquete

2016-12-01

Surgical management of acute unstable acromioclavicular joint injuries should be focused on realigning the torn ends of the ligaments to allow for healing potential. The most widely utilized treatment methods incorporate the use of metal hardware, which can alter the biomechanics of the acromioclavicular joint. This leads to a second surgical procedure for hardware removal once the ligaments have healed. Patients with unstable acromioclavicular joint injuries managed with arthroscopy-assisted procedures have shown good and excellent clinical outcomes, without the need for a second operation. These procedures incorporate a coracoclavicular suspension device aimed to function as an internal brace, narrowing the coracoclavicular space thus allowing for healing of the torn coracoclavicular ligaments. The lesser morbidity of a minimally invasive approach and the possibility to diagnose and treat concomitant intraarticular injuries; no obligatory implant removal, and the possibility of having a straight visualization of the inferior aspect of the base of the coracoid (convenient when placing coracoclavicular fixation systems) are the main advantages of the arthroscopic approach over classic open procedures. This article consists on a narrative review of the literature in regard to the management of acute acromioclavicular joint instability.

3D reconstruction of bony elements of the knee joint and finite element analysis of total knee prosthesis obtained from the reconstructed model.

Science.gov (United States)

Djoudi, Farid

2013-01-01

Two separate themes are presented in this paper. The first theme is to present a graphical modeling approach of human anatomical structures namely, the femur and the tibia. The second theme involves making a finite element analysis of stresses, displacements and deformations in prosthetic implants (the femoral implant and the polyethylene insert). The graphical modeling approach comes in two parts. The first is the segmentation of MRI scanned images, retrieved in DICOM format for edge detection. In the second part, 3D-CAD models are generated from the results of the segmentation stage. The finite element analysis is done by first extracting the prosthetic implants from the reconstructed 3D-CAD model, then do a finite element analysis of these implants under objectively determined conditions such as; forces, allowed displacements, the materials composing implant, and the coefficient of friction. The objective of this work is to implement an interface for exchanging data between 2D MRI images obtained from a medical diagnosis of a patient and the 3D-CAD model used in various applications, such as; the extraction of the implants, stress analysis at the knee joint and can serve as an aid to surgery, also predict the behavior of the prosthetic implants vis-a-vis the forces acting on the knee joints.

Patients With Thumb Carpometacarpal Arthritis Have Quantifiable Characteristic Expectations That Can Be Measured With a Survey.

Science.gov (United States)

Kang, Lana; Hashmi, Sohaib Z; Nguyen, Joseph; Lee, Steve K; Weiland, Andrew J; Mancuso, Carol A

2016-01-01

Although patient expectations associated with major orthopaedic conditions have shown clinically relevant and variable effects on outcomes, expectations associated with thumb carpometacarpal (CMC) arthritis have not been identified, described, or analyzed before, to our knowledge. We asked: (1) Do patients with thumb CMC arthritis express characteristic expectations that are quantifiable and have measurable frequency? (2) Can a survey on expectations developed from patient-derived data quantitate expectations in patients with thumb CMC arthritis? The study was a prospective cohort study. The first phase was a 12-month-period involving interviews of 42 patients with thumb CMC arthritis to define their expectations of treatment. The interview process used techniques and principles of qualitative methodology including open-ended interview questions, unrestricted time, and study size determined by data saturation. Verbatim responses provided content for the draft survey. The second phase was a 12-month period assessing the survey for test-retest reliability with the recruitment of 36 participants who completed the survey twice. The survey was finalized from clinically relevant content, frequency of endorsement, weighted kappa values for concordance of responses, and intraclass coefficient and Cronbach's alpha for interrater reliability and internal consistency. Thirty-two patients volunteered 256 characteristic expectations, which consisted of 21 discrete categories. Expectations with similar concepts were combined by eliminating redundancy while maintaining original terminology. These were reduced to 19 items that comprised a one-page survey. This survey showed high concordance, interrater reliability, and internal consistency, with weighted kappa values between 0.58 and 0.78 (95% CI, 0.39-0.78; p Patients with thumb CMC arthritis volunteer a characteristic and quantifiable set of expectations. Using responses recorded verbatim from patient interviews, a clinically

BIOLOGIC JOINT RECONSTRUCTION: ALTERNATIVES TO ARTHROPLASTY

Directory of Open Access Journals (Sweden)

Brian J. Cole

2009-06-01

Full Text Available A comprehensive source of information in the management of cartilage lesions of major joints using nonoperative or surgical techniques other than total joint replacement. The text also includes chapters in basic sciences, imaging and rehabilitation.The editors are aiming to provide a reference about the latest concepts and techniques in the treatment of cartilage lesions including future aspects by a comprehensive approach to the alternative joint restoration procedures such as biological, pharmacological and surgical techniques of cartilage repairing and partial resurfacing etc.Orthopedic surgeons in sports medicine, orthopedic surgeons performing joint replacements, orthopedic resident and fellows will be the main audiences.The text is 349 pages, divided into 34 chapters in 7 sections. Section I is "Background-articular cartilage and allograft processing" including chapters about pathology, patient evaluation, imaging and allograft processing. Section II is "Nonoperative treatment" including chapters about neutraceuticals, pharmacological treatment and rehabilitation. Section III is "Operative treatment-knee" including chapters about arthroscopic debridment, microfracture, osteochondral autograft transplantation, mosaicplasty, osteochondral autograft transfer, osteochondral allografts, autologous chondrocyte implantation, existing cell-based technologies, minimally invasive second-generation autologous chondrocyte implantation, future development in cartilage repair, meniscus transplantation, management of OCD, patellafemoral chondral disease, proximal tibial and distal femoral osteotomies, unicompartmental arthritis current techniques, unicompartmental knee replacement. Section IV is "Operative treatment-Hip" including chapters about hip arthroscopy and arthroscopic partial resurfacing, related osteotomies. Section V is "operative treatment-shoulder" including chapters about arthroscopic debridment and release, biologic resurfacing and

PEEK Biomaterials in Trauma, Orthopedic, and Spinal Implants

Science.gov (United States)

Kurtz, S. M.; Devine, J. N.

2007-01-01

Since the 1980s, polyaryletherketones (PAEKs) have been increasingly employed as biomaterials for trauma, orthopedic, and spinal implants. We have synthesized the extensive polymer science literature as it relates to structure, mechanical properties, and chemical resistance of PAEK biomaterials. With this foundation, one can more readily appreciate why this family of polymers will be inherently strong, inert, and biocompatible. Due to its relative inertness, PEEK biomaterials are an attractive platform upon which to develop novel bioactive materials, and some steps have already been taken in that direction, with the blending of HA and TCP into sintered PEEK. However, to date, blended HA-PEEK composites have involved a trade-off in mechanical properties in exchange for their increased bioactivity. PEEK has had the greatest clinical impact in the field of spine implant design, and PEEK is now broadly accepted as a radiolucent alternative to metallic biomaterials in the spine community. For mature fields, such as total joint replacements and fracture fixation implants, radiolucency is an attractive but not necessarily critical material feature. PMID:17686513

A contact mechanics model for ankle implants with inclusion of surface roughness effects

International Nuclear Information System (INIS)

Hodaei, M; Farhang, K; Maani, N

2014-01-01

Total ankle replacement is recognized as one of the best procedures to treat painful arthritic ankles. Even though this method can relieve patients from pain and reproduce the physiological functions of the ankle, an improper design can cause an excessive amount of metal debris due to wear, causing toxicity in implant recipient. This paper develops a contact model to treat the interaction of tibia and talus implants in an ankle joint. The contact model describes the interaction of implant rough surfaces including both elastic and plastic deformations. In the model, the tibia and the talus surfaces are viewed as macroscopically conforming cylinders or conforming multi-cylinders containing micrometre-scale roughness. The derived equations relate contact force on the implant and the minimum mean surface separation of the rough surfaces. The force is expressed as a statistical integral function of asperity heights over the possible region of interaction of the roughness of the tibia and the talus implant surfaces. A closed-form approximate equation relating contact force and minimum separation is used to obtain energy loss per cycle in a load–unload sequence applied to the implant. In this way implant surface statistics are related to energy loss in the implant that is responsible for internal void formation and subsequent wear and its harmful toxicity to the implant recipient. (paper)

A contact mechanics model for ankle implants with inclusion of surface roughness effects

Science.gov (United States)

Hodaei, M.; Farhang, K.; Maani, N.

2014-02-01

Total ankle replacement is recognized as one of the best procedures to treat painful arthritic ankles. Even though this method can relieve patients from pain and reproduce the physiological functions of the ankle, an improper design can cause an excessive amount of metal debris due to wear, causing toxicity in implant recipient. This paper develops a contact model to treat the interaction of tibia and talus implants in an ankle joint. The contact model describes the interaction of implant rough surfaces including both elastic and plastic deformations. In the model, the tibia and the talus surfaces are viewed as macroscopically conforming cylinders or conforming multi-cylinders containing micrometre-scale roughness. The derived equations relate contact force on the implant and the minimum mean surface separation of the rough surfaces. The force is expressed as a statistical integral function of asperity heights over the possible region of interaction of the roughness of the tibia and the talus implant surfaces. A closed-form approximate equation relating contact force and minimum separation is used to obtain energy loss per cycle in a load-unload sequence applied to the implant. In this way implant surface statistics are related to energy loss in the implant that is responsible for internal void formation and subsequent wear and its harmful toxicity to the implant recipient.

The Synovial Lining and Synovial Fluid Properties after Joint Arthroplasty

Directory of Open Access Journals (Sweden)

Michael Shang Kung

2015-05-01

Full Text Available The lubrication of the cartilaginous structures in human joints is provided by a fluid from a specialized layer of cells at the surface of a delicate tissue called the synovial lining. Little is known about the characteristics of the fluids produced after a joint arthroplasty procedure. A literature review was carried out to identify papers that characterized the synovial lining and the synovial fluids formed after total hip or knee arthroplasty. Five papers about synovial lining histology and six papers about the lubricating properties of the fluids were identified. The cells making up the re-formed synovial lining, as well as the lining of interface membranes, were similar to the typical Type A and B synoviocytes of normal joints. The synovial fluids around joint replacement devices were typically lower in viscosity than pre-arthroplasty fluids but the protein concentration and phospholipid concentrations tended to be comparable, suggesting that the lining tissue function was preserved after arthroplasty. The widespread, long-term success of joint arthroplasty suggests that the lubricant formed from implanted joint synovium is adequate for good clinical performance in the majority of joints. The role the fluid plays in component wear or failure is a topic for future study.

ISHKS joint registry: A preliminary report

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Jawahir A Pachore

2013-01-01

form can be downloaded from the website www.ishks.com. The information collected includes patient demographics, indication for surgery, implant details and in case of revision arthroplasty: the details of implants removed and the cause of failure of primary arthroplasty. These forms are mailed to the central registry office and the data is fed in computerized registry. Data collection started in October 2006. Results: Joint registry is a very important initiative of ISHKS and till date, have data of 34,478 TKAs and 3604 THAs, contributed by 42 surgeons across India. Some important observations have emerged. Data of 34,478 TKAs was assessed: These included 8612 males (25% and 25,866 females (75%. Average age was 64.4 years (Osteoarthritis range: 45 to 88 years; Rheumatoid arthritis range: 22 to 74 years. Average body mass index was 29.1 (Range: 18.1 to 42.9. The indication for TKA was osteoarthritis in 33,444 (97% and rheumatoid arthritis in 759 (2.2%. Total of 3604 THA procedures were recorded. These included 2162 (60% male patients and 1442 (40% female patients. Average age was 52 years (Range 17 to 85 years and average BMI was 25.8 (Range: 17.3 to 38.5. The indications for THA was AVN in 49%. Conclusion: The registry will become more meaningful in years to come. Active participation of all arthroplasty surgeons across India is vital for the success of the joints registry.

Development and Reliability of the OMERACT Thumb Base Osteoarthritis Magnetic Resonance Imaging Scoring System

DEFF Research Database (Denmark)

Kroon, Féline P B; Conaghan, Philip G; Foltz, Violaine

2017-01-01

: The TOMS assessed the first carpometacarpal (CMC-1) and scaphotrapeziotrapezoid (STT) joints for synovitis, subchondral bone defects (including erosions, cysts, and bone attrition), osteophytes, cartilage, and bone marrow lesions on a 0-3 scale (normal to severe). Subluxation was evaluated only in the CMC......, with better performance for subchondral bone defects, subluxation, and bone marrow lesions. CONCLUSION: A thumb base OA MRI scoring system has been developed. The OMERACT TOMS demonstrated good intrareader and interreader reliability. Longitudinal studies are warranted to investigate reliability of change...

Short Implants: New Horizon in Implant Dentistry.

Science.gov (United States)

Jain, Neha; Gulati, Manisha; Garg, Meenu; Pathak, Chetan

2016-09-01

The choice of implant length is an essential factor in deciding the survival rates of these implants and the overall success of the prosthesis. Placing an implant in the posterior part of the maxilla and mandible has always been very critical due to poor bone quality and quantity. Long implants can be placed in association with complex surgical procedures such as sinus lift and bone augmentation. These techniques are associated with higher cost, increased treatment time and greater morbidity. Hence, there is need for a less invasive treatment option in areas of poor bone quantity and quality. Data related to survival rates of short implants, their design and prosthetic considerations has been compiled and structured in this manuscript with emphasis on the indications, advantages of short implants and critical biomechanical factors to be taken into consideration when choosing to place them. Studies have shown that comparable success rates can be achieved with short implants as those with long implants by decreasing the lateral forces to the prosthesis, eliminating cantilevers, increasing implant surface area and improving implant to abutment connection. Short implants can be considered as an effective treatment alternative in resorbed ridges. Short implants can be considered as a viable treatment option in atrophic ridge cases in order to avoid complex surgical procedures required to place long implants. With improvement in the implant surface geometry and surface texture, there is an increase in the bone implant contact area which provides a good primary stability during osseo-integration.

Influence of Palatal Coverage and Implant Distribution on Implant Strain in Maxillary Implant Overdentures.

Science.gov (United States)

Takahashi, Toshihito; Gonda, Tomoya; Mizuno, Yoko; Fujinami, Yozo; Maeda, Yoshinobu

2016-01-01

Maxillary implant overdentures are often used in clinical practice. However, there is no agreement or established guidelines regarding prosthetic design or optimal implant placement configuration. The purpose of this study was to examine the influence of palatal coverage and implant number and distribution in relation to impact strain under maxillary implant overdentures. A maxillary edentulous model with implants and experimental overdentures with and without palatal coverage was fabricated. Four strain gauges were attached to each implant, and they were positioned in the anterior, premolar, and molar areas. A vertical occlusal load of 98 N was applied through a mandibular complete denture, and the implant strains were compared using one-way analysis of variance (P = .05). The palatolabial strain was much higher on anterior implants than on other implants in both denture types. Although there was no significant difference between the strain under dentures with and without palatal coverage, palateless dentures tended to result in higher implant strain than dentures with palatal coverage. Dentures supported by only two implants registered higher strain than those supported by four or six implants. Implants under palateless dentures registered higher strain than those under dentures with palatal coverage. Anterior implants exhibited higher palatolabial strain than other implants regardless of palatal coverage and implant configuration; it is therefore recommended that maxillary implant overdentures should be supported by six implants with support extending to the distal end of the arch.

Biotribology of Cartilage Wear in Knee and Hip Joints Review of Recent Developments

Science.gov (United States)

Gulsen, Akdogan; Merve, Goncu; Meltem, Parlak

2018-01-01

Nowadays, the problem of wear in the knee and hip joints is an important issue that concerns many people and still requires new solutions. In recent years, researchers dealing with knee and hip articular cartilage erosion continue to investigate the subject in terms of biotribology. In this study, recent developments and studies in this relevant area are been examined. By using the basic principles of tribology, useful new methods that can be used in the field of biotribology can be produced. Artificial joints designed using various materials such as metals, ceramics, polymers and composites are still being studied. New studies in this area will affect the development of implant technology. Different alloys or composites are currently being tested for new implant designs. Moving implants with a risk of wear are tested in laboratory conditions in simulator devices before they are used in the human body. Major topics such as nanotechnology, tissue engineering, orthopedics, tribology, biotribology, lubrication, organ transplantation and artificial organs, which are still important today, will be useful in the search for finding suitable solutions in the future in biotribological studies. This review article aims to provide an overview of in-vitro studies at the theoretical and laboratory conditions that must be performed prior to clinical investigation.

A Midterm Review of Lesser Toe Arthrodesis With an Intramedullary Implant.

Science.gov (United States)

Harmer, James Lee; Wilkinson, Anthony; Maher, Anthony John

2017-10-01

Lesser toe deformities are one of the most common conditions encountered by podiatric surgeons. When conservative treatments fail surgical correction is indicated. Many surgical options have been described to address the complex nature of these deformities but no perfect solution has been reported to date. However, with the continued advancement of internal fixation technology, interphalangeal joint (IPJ) arthrodesis with an intramedullary implant may be a good option. This retrospective study presents patient reported outcomes and complications at 6 months and 3 years following lesser toe proximal interphalangeal joint (PIPJ) arthrodesis with a polyketone intrameduallary implant (Toe Grip, Orthosolutions, UK). Between September 2011 and November 2012, a total of 38 patients attended for second toe PIPJ arthrodesis by means of the Toe Grip device. At 6 months postoperation, 94.7% of patients and at 3 years postoperation, 92.8% of patients felt that their original complaint was better or much better. Health-related quality of life scores continued to improve overtime as measured by the Manchester Oxford Foot Questionnaire. Complications were generally observational and asymptomatic. The most common complications were floating toes (17.8%), mallet deformities (14.2%), metatarsalgia (17.8%), and transverse plane deformity of the toe (10.7%). This study demonstrates excellent patient-eported outcomes with minimal symptomatic complications making the "Toe Grip" implant a safe and effective alternative fixation device for IPJ arthrodesis when dealing with painful digital deformities. Therapeutic, Level IV: Case series.

The effects of bone marrow aspirate, bone graft, and collagen composites on fixation of titanium implants

DEFF Research Database (Denmark)

Babiker, Hassan; Ding, Ming; Sandri, Monica

2012-01-01

Replacement of extensive local bone loss especially in revision joint arthroplasty and spine fusion is a significant clinical challenge. Allograft and autograft have been considered as gold standards for bone replacement. However, there are several disadvantages such as donor site pain, bacterial...... contamination, and non union as well as the potential risk of disease transmission. Hydroxyapatite and collagen composites (HA/Collagen) have the potential in mimicking and replacing skeletal bones. This study attempted to determine the effects of newly developed HA/Collagen-composites with and without bone...... marrow aspirate (BMA) on enhancement of bone implant fixation. Method: Titanium alloy implants were inserted into bilateral femoral condyles of eight skeletally mature sheep, four implants per sheep. The implant had a circumferential gap of 2 mm. The gap was filled with: HA/Collagen; HA...

Thermal characterization of Ag and Ag + N ion implanted ultra-high molecular weight polyethylene (UHMWPE)

Science.gov (United States)

Sokullu Urkac, E.; Oztarhan, A.; Tihminlioglu, F.; Kaya, N.; Ila, D.; Muntele, C.; Budak, S.; Oks, E.; Nikolaev, A.; Ezdesir, A.; Tek, Z.

2007-08-01

Most of total hip joints are composed of ultra-high molecular weight polyethylene (UHMWPE). However, as ultra-high molecular weight polyethylene is too stable in a body, wear debris may accumulate and cause biological response such as bone absorption and loosening of prosthesis. In this study, ultra-high molecular weight polyethylene samples were Ag and Ag + N hybrid ion implanted by using MEVVA ion implantation technique to improve its surface properties. Samples were implanted with a fluence of 1017 ion/cm2 and extraction voltage of 30 kV. Implanted and unimplanted samples were investigated by thermo-gravimetry analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), optical microscopy (OM) and contact Angle measurement. Thermal characterization results showed that the ion bombardment induced an increase in the % crystallinity, onset and termination degradation temperatures of UHMWPE.

Complications after percutaneous placement of totally implantable venous access ports in the forearm

International Nuclear Information System (INIS)

Goltz, J.P.; Petritsch, B.; Thurner, A.; Hahn, D.; Kickuth, R.

2012-01-01

This article focuses on radiological imaging of complications after interventional percutaneous insertion of totally implantable venous access ports (TIVAPs) which were placed in the forearm. Thus far most reviews have dealt with pectorally-placed TIVAPs. Compared with the pectoral approach, implantation in the forearm has been associated with certain complications owing to a longer route of the port catheter within a smaller vein, and owing to the route across the elbow joint, resulting in higher rates of catheter-associated thrombosis and possible mechanical complications. The purpose of this review is to describe the complications after implantation of TIVAPs in the forearm, and to make radiologists familiar with the key findings of the complications during radiological imaging, including colour-coded and compression Duplex ultrasound, computed tomography, and digital subtraction venography.

Application of computer graphics in the design of custom orthopedic implants.

Science.gov (United States)

Bechtold, J E

1986-10-01

Implementation of newly developed computer modelling techniques and computer graphics displays and software have greatly aided the orthopedic design engineer and physician in creating a custom implant with good anatomic conformity in a short turnaround time. Further advances in computerized design and manufacturing will continue to simplify the development of custom prostheses and enlarge their niche in the joint replacement market.

Two-stage revision surgery with preformed spacers and cementless implants for septic hip arthritis: a prospective, non-randomized cohort study

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Logoluso Nicola

2011-05-01

Full Text Available Abstract Background Outcome data on two-stage revision surgery for deep infection after septic hip arthritis are limited and inconsistent. This study presents the medium-term results of a new, standardized two-stage arthroplasty with preformed hip spacers and cementless implants in a consecutive series of adult patients with septic arthritis of the hip treated according to a same protocol. Methods Nineteen patients (20 hips were enrolled in this prospective, non-randomized cohort study between 2000 and 2008. The first stage comprised femoral head resection, debridement, and insertion of a preformed, commercially available, antibiotic-loaded cement hip spacer. After eradication of infection, a cementless total hip arthroplasty was implanted in the second stage. Patients were assessed for infection recurrence, pain (visual analog scale [VAS] and hip joint function (Harris Hip score. Results The mean time between first diagnosis of infection and revision surgery was 5.8 ± 9.0 months; the average duration of follow up was 56.6 (range, 24 - 104 months; all 20 hips were successfully converted to prosthesis an average 22 ± 5.1 weeks after spacer implantation. Reinfection after total hip joint replacement occurred in 1 patient. The mean VAS pain score improved from 48 (range, 35 - 84 pre-operatively to 18 (range, 0 - 38 prior to spacer removal and to 8 (range, 0 - 15 at the last follow-up assessment after prosthesis implantation. The average Harris Hip score improved from 27.5 before surgery to 61.8 between the two stages to 92.3 at the final follow-up assessment. Conclusions Satisfactory outcomes can be obtained with two-stage revision hip arthroplasty using preformed spacers and cementless implants for prosthetic hip joint infections of various etiologies.

Forced-air warming discontinued: periprosthetic joint infection rates drop

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Scott D. Augustine

2017-06-01

Full Text Available Several studies have shown that the waste heat from forced-air warming (FAW escapes near the floor and warms the contaminated air resident near the floor. The waste heat then forms into convection currents that rise up and contaminate the sterile field above the surgical table. It has been shown that a single airborne bacterium can cause a periprosthetic joint infection (PJI following joint replacement surgery. We retrospectively compared PJI rates during a period of FAW to a period of air-free conductive fabric electric warming (CFW at three hospitals. Surgical and antibiotic protocols were held constant. The pooled multicenter data showed a decreased PJI rate of 78% following the discontinuation of FAW and a switch to air-free CFW (n=2034; P=0.002. The 78% reduction in joint implant infections observed when FAW was discontinued suggests that there is a link between the waste FAW heat and PJIs.

Radiology of the hand in progressive systemic sclerosis

Energy Technology Data Exchange (ETDEWEB)

Scutellari, P N; Orzincolo, C; Delli Gatti, I. and others

1986-01-01

Radiographs and xerographs of the hands of 35 patients with progressive systematic sclerosis (PSS), as defined by the ARA, were reviewed. Patients with ''overlap'' syndromes (i.e., mixed connective tissue disease, systemic lupus erythematosus or rheumatoid arthritis) have been excluded. Soft tissue changes included atrophy (hidebound skin), and dystrophic calcifications, particularly in CREST patients (calcinosis, Raynaud phenomenon, esophageal dysmobility, sclerodactily and telangectasia). The most common bony change is resorption of distal phalanges; diffuse osteoporosis is also frequent; the distal interphalangeal and first carpometacarpal joints involvement appear as a distinctive feature of this e....

Capnocytophaga canimorsus - An underestimated cause of periprosthetic joint infection?

Science.gov (United States)

Orth, Marcel; Orth, Patrick; Anagnostakos, Konstantinos

2017-08-01

Periprosthetic joint infection (PJI) is a major clinical problem in orthopedic surgery. Capnocytophaga canimorsus (C. canimorsus) is an unusual and hardly detectable bacterium. A review of the literature indicates that C. canimorsus affects mainly immunocompromised patients. It has not been reported to cause periprosthetic joint infections in immunocompetent patients so far. This case report aims to raise awareness of C. canimorsus in orthopedic surgery with special regard to joint arthroplasty. We report a case of a 54-year-old immunocompetent patient with a late infection after total knee arthroplasty caused by C. canimorsus. The patient underwent two-stage revision with prosthesis explantation, implantation of an antibiotic-impregnated static spacer, intravenous antimicrobial therapy for four weeks with cefuroxime followed by oral antimicrobial therapy with ciprofloxacin for further two weeks and secondary revision total knee arthroplasty. In the present case, we could demonstrate that adequate treatment of C. canimorsus was capable to successfully treat periprosthetic joint infection caused by C. canimorsus in an immunocompetent patient. We feel that C. canimorsus has to be taken into account as a potential pathogen causing periprosthetic joint infection - regardless of the immunological status of the patient and especially when the detection of a pathogen does not succeed. Copyright © 2017 Elsevier B.V. All rights reserved.

Post-operative computed tomographic imaging of the shoulder joint

International Nuclear Information System (INIS)

Helweg, G.; Zur Nedden, D.; Wicke, K.; Knapp, R.; Oberhauser, A.; Resch, H.; Sperner, G.

1992-01-01

Between 1984 and 1990 312 patients underwent surgery for habitual or recurrent shoulder dislocation. Out then, 65 had a post-operative CT examination. This retrospective study was launched to demonstrate the value of CT in post-operative shoulder imaging. In most cases, CT was done using standardised techniques without contrast medium. Except in 4 cases, an intra-articular double-contrast technique was used. Evaluation was focused on 41 cases after implantation of a wedged bone graft in cases of primary or secondary flat glenoid or widening of a small glenoid with cortical consoles and bone block. The results demonstrate the effectiveness of standardised CT technique in that all necessary information concerning stabilisation of the shoulder joint, sufficient implant of bone grafts and assessment of correct inclination after osteotomy were obtained. (orig.)

Most common surgical mistakes with treatment of prosthetic joint infections

Directory of Open Access Journals (Sweden)

Boštjan Kocjančič

2014-08-01

Full Text Available The treatment of infections of orthopedic implants is often difficult and complex, although the chances of successful treatment with properly selected diagnostics, surgical and antibiotic treatment protocol have recently increased significantly. Surgical treatment is a key stone factor in the treatment of infections of orthopedic implants and any errors in it often lead to worse clinical outcomes. The most important and frequent surgical errors include: conservative treatment of periprothetic infections with antibiotics only, to-late surgical revision, insufficient debridement during surgical revision, inadequate intraoperative samples for bacteriological and histological analysis. It is important to have and to follow proper treatment algorithm for periprosthetic joint infection. In this work we present the listed surgical and most illustrative key errors.

Thermal characterization of Ag and Ag + N ion implanted ultra-high molecular weight polyethylene (UHMWPE)

Energy Technology Data Exchange (ETDEWEB)

Sokullu Urkac, E. [Department of Materials Science, Izmir High Technology Institute, Gulbahcekoyu Urla, Izmir (Turkey)]. E-mail: emelsu@gmail.com; Oztarhan, A. [Bioengineering Department, Ege University, Bornova, Izmir 35100 (Turkey); Tihminlioglu, F. [Department of Chemical Engineering, Izmir High Technology Institute, Gulbahcekoyu Urla, Izmir (Turkey); Kaya, N. [Bioengineering Department, Ege University, Bornova, Izmir 35100 (Turkey); Ila, D. [Center for Irradiation of Materials, Alabama A and M University, Normal AL 35762 (United States); Muntele, C. [Center for Irradiation of Materials, Alabama A and M University, Normal AL 35762 (United States); Budak, S. [Center for Irradiation of Materials, Alabama A and M University, Normal AL 35762 (United States); Oks, E. [H C Electronics Institute, Tomsk (Russian Federation); Nikolaev, A. [H C Electronics Institute, Tomsk (Russian Federation); Ezdesir, A. [R and D Department, PETKIM Holding A.S., Aliaga, Izmir 35801 (Turkey); Tek, Z. [Department of Physics, Celal Bayar University, Manisa (Turkey)

2007-08-15

Most of total hip joints are composed of ultra-high molecular weight polyethylene (UHMWPE ). However, as ultra-high molecular weight polyethylene is too stable in a body, wear debris may accumulate and cause biological response such as bone absorption and loosening of prosthesis. In this study, ultra-high molecular weight polyethylene samples were Ag and Ag + N hybrid ion implanted by using MEVVA ion implantation technique to improve its surface properties. Samples were implanted with a fluence of 10{sup 17} ion/cm{sup 2} and extraction voltage of 30 kV. Implanted and unimplanted samples were investigated by thermo-gravimetry analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), optical microscopy (OM) and contact Angle measurement. Thermal characterization results showed that the ion bombardment induced an increase in the % crystallinity, onset and termination degradation temperatures of UHMWPE.

[Hand osteoarthritis].

Science.gov (United States)

Šenolt, Ladislav

Hand osteoarthritis (OA) is a common chronic disorder causing pain and limitation of mobility of affected joints. The prevalence of hand OA increases with age and more often affects females. Clinical signs obviously do not correlate with radiographic findings - symptomatic hand OA affects approximately 26 % of adult subjects, but radiographic changes can be found in up to two thirds of females and half of males older than 55 years.Disease course differ among individual patients. Hand OA is a heterogeneous disease. Nodal hand OA is the most common subtype affecting interphalangeal joints, thumb base OA affects first carpometacarpal joint. Erosive OA represents a specific subtype of hand OA, which is associated with joint inflammation, more pain, functional limitation and erosive findings on radiographs.Treatment of OA is limited. Analgesics and nonsteroidal anti-inflammatory drugs are the only agents reducing symptoms. New insights into the pathogenesis of disease should contribute to the development of novel effective treatment of hand OA.

Porous polymers for repair and replacement of the knee joint meniscus and articular cartilage

NARCIS (Netherlands)

Klompmaker, Jan

1992-01-01

The studies presented here were initiated to answer a variety of questions concerning firstly the repair and replacement of the knee joint meniscus and, secondly, the repair of full-thickness defects of articular cartilage. AIMS OF THE STUDIES I To assess the effect of implantation of a porous

Ion implantation

International Nuclear Information System (INIS)

Dearnaley, Geoffrey

1975-01-01

First, ion implantation in semiconductors is discussed: ion penetration, annealing of damage, gettering, ion implanted semiconductor devices, equipement requirements for ion implantation. The importance of channeling for ion implantation is studied. Then, some applications of ion implantation in metals are presented: study of the corrosion of metals and alloys; influence or ion implantation on the surface-friction and wear properties of metals; hyperfine interactions in implanted metals

Investigation of the effect of conservative interventions in thumb carpometacarpal osteoarthritis: systematic review and meta-analysis.

Science.gov (United States)

Bertozzi, Lucia; Valdes, Kristin; Vanti, Carla; Negrini, Stefano; Pillastrini, Paolo; Villafañe, Jorge Hugo

2015-01-01

The purpose of this study was to conduct a current review of randomized controlled trials regarding the effect of conservative interventions on pain and function in people with thumb carpometacarpal (CMC) osteoarthritis (OA), perform a meta-analysis of the findings and summarize current knowledge. Data were obtained from MEDLINE, CINAHL, Embase, PEDro and CENTRAL databases from their inception to May 2014. Reference lists of relevant literature reviews were also searched. All published randomized trials without restrictions to time of publication or language were considered for inclusion. Study subjects were symptomatic adults with thumb CMC OA. Two reviewers independently selected studies, conducted quality assessment and extracted results. Data were pooled in a meta-analysis, when possible, using a random-effects model. Quality of the body evidence was assessed using GRADE approach. Sixteen RCTs involving 1145 participants met the inclusion criteria. Twelve were of high quality (PEDro score > 6). We found moderate quality evidence that manual therapy and therapeutic exercise combined with manual therapy improve pain in thumb CMC OA at short- and intermediate-term follow-up, and from low to moderate quality evidences that magneto therapy improves pain and function at short-term follow-up. Orthoses (splints) were found to improve function at long-term follow-up and pinch strength at short-term follow-up. Finally, we found from very low to low-quality evidence that other conservative interventions provide no significant improvement in pain and in function at short- and long-term follow-up. Some of the commonly performed conservative interventions performed in therapy have evidence to support their use to improve hand function and decrease hand pain. Additional research is required to determine the efficacy of other therapeutic interventions that are performed with patients with thumb CMC OA. Manual therapy and exercise are an effective means of improving pain and

Modern radiological postoperative diagnostics of the hip joint in children and adults

International Nuclear Information System (INIS)

Weber, M.A.; Thierjung, H.; Kloth, J.K.; Egermann, M.

2015-01-01

The assessment of bone healing and loosening of endoprosthesis material was long the primary indication for postoperative projection radiography and CT imaging of the hip joint following trauma and endoprosthesis implantation. With the increasing number of joint-preserving surgery, e. g. of surgical hip luxation and hip arthroscopy for the treatment of femoroacetabular impingement (FAI), high-resolution imaging of intra-articular pathologies before and after surgery has become increasingly important. In this review article, diagnostic imaging of the hip joint is presented following common trauma surgery and orthopedic surgery interventions. The imaging modalities of projection radiography, CT and MRI including direct MR-arthrography are discussed with regard to their diagnostic capability in the postoperative assessment of the hip joint. Among others topics, imaging is discussed following hip arthroplasty, following surgical hip luxation and arthroscopic interventions for the treatment of FAI, as well as following core decompression for avascular necrosis of the femoral head. Moreover, orthopedic interventions of the hip joint in children and adolescents are presented and the dedicated reporting of postoperative imaging is outlined.

MR imaging of autologous chondrocyte implantation of the knee

Energy Technology Data Exchange (ETDEWEB)

James, S.L.J.; Connell, D.A.; Saifuddin, A.; Skinner, J.A.; Briggs, T.W.R. [RNOH Stanmore, Department of Radiology, Stanmore, Middlesex (United Kingdom)

2006-05-15

Autologous chondrocyte implantation (ACI) is a surgical technique that is increasingly being used in the treatment of full-thickness defects of articular cartilage in the knee. It involves the arthroscopic harvesting and in vitro culture of chondrocytes that are subsequently implanted into a previously identified chondral defect. The aim is to produce a repair tissue that closely resembles hyaline articular cartilage that gradually becomes incorporated, restoring joint congruity. Over the long term, it is hoped that this will prevent the progression of full-thickness articular cartilage defects to osteoarthritis. This article reviews the indications and operative procedure performed in ACI. Magnetic resonance imaging (MRI) sequences that provide optimal visualization of articular cartilage in the post-operative period are discussed. Normal appearances of ACI on MRI are presented along with common complications that are encountered with this technique. (orig.)

Autologous chondrocyte implantation: superior biologic properties of hyaline cartilage repairs.

Science.gov (United States)

Henderson, Ian; Lavigne, Patrick; Valenzuela, Herminio; Oakes, Barry

2007-02-01

Information regarding the quality of autologous chondrocyte implantation repair is needed to determine whether the current autologous chondrocyte implantation surgical technology and the subsequent biologic repair processes are capable of reliably forming durable hyaline or hyaline-like cartilage in vivo. We report and analyze the properties and qualities of autologous chondrocyte implantation repairs. We evaluated 66 autologous chondrocyte implantation repairs in 57 patients, 55 of whom had histology, indentometry, and International Cartilage Repair Society repair scoring at reoperation for mechanical symptoms or pain. International Knee Documentation Committee scores were used to address clinical outcome. Maximum stiffness, normalized stiffness, and International Cartilage Repair Society repair scoring were higher for hyaline articular cartilage repairs compared with fibrocartilage, with no difference in clinical outcome. Reoperations revealed 32 macroscopically abnormal repairs (Group B) and 23 knees with normal-looking repairs in which symptoms leading to arthroscopy were accounted for by other joint disorders (Group A). In Group A, 65% of repairs were either hyaline or hyaline-like cartilage compared with 28% in Group B. Autologous chondrocyte repairs composed of fibrocartilage showed more morphologic abnormalities and became symptomatic earlier than hyaline or hyaline-like cartilage repairs. The hyaline articular cartilage repairs had biomechanical properties comparable to surrounding cartilage and superior to those associated with fibrocartilage repairs.

Experimental and numerical study of cemented bone-implant interface behaviour

Directory of Open Access Journals (Sweden)

P. Zlamal

2011-01-01

Full Text Available Although the total hip replacement (THR is a long-proven method of surgical treatment of diseases and disorders of the human hip, the surgery brings some risk of long-term instability of the joint. The aim of the research was to investigate the cemented bone-implant interface behavior. The main problems (cement layer degradation and bone-cement interface debonding during physiological loading conditions have been investigated using a custom hip simulator. The experimental setup was designed to allow cyclic loading of the sample of pelvic bone with implanted cemented acetabular component. The hip contact force of required direction and magnitude was applied to the implant using a spherical femoral component head. The most unfavorable activity (downstairs walking was simulated. The process of damage accumulation in the fixation was monitored by repeated scanning using high resolution micro Computed Tomography (µCT. Use of micro-focus source and large high-resolution flat panel detector allows investigation of structural changes and crack propagation both in the cement layer and the trabecular bone.

Radiologic evaluation of wrist arthrography

International Nuclear Information System (INIS)

Park, Yang Hee; Seong, Hyeun Lim; Yang, Jae Beom; Park, Chan Sup; Lee, Sang Seun

1991-01-01

Wrist arthrography allows direct visualization of the cartilage and synovial structure not seen in plain film. Arthrography of the wrist is valuable in evaluating patients with persistent wrist pain and limitation of motion after trauma. Wrist arthrography was performed in the evaluation of 30 patients with rheumatoid arthritis (2 cases), ganglions (12 cases), and wrist trauma (16 cases), and contrast media was injected in radiocarpal joint. The arthrographic findings were analyzed, and the results were as follows: In 16 patients with wrist trauma, 12 cases (75%) of compartment communication was seen including communication with distal radioulnar joint (44%), midcarpal joint (69%), and common carpometacarpal joint (63%). Of the total 30 patients, the pisiform-triquetral joint communicated with the radio carpal joint in 9 cases (30%). In 16 patients with trauma, the findings of post-traumatic arthritis included tendon communication (50%), irregular synovium (31%), and rupture of the joint capsule (25%). There was no lymphatic filling. Of 3 scaphoid fracture patients without bony callus formation, fibrous union was verified in one patient and nouncion in 2. O 12 patients with ganglion, communication between the ganglion and radiocarpal joint was seen in 2 cases and no communication in 10 cases

PERIPROSTHETIC JOINT INFECTION IN PATIENTS WITH RHEUMATIC DISEASES: THE PROBLEMS OF DIAGNOSIS, PREVENTION, AND TREATMENT

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A. E. Khramov

2015-01-01

Full Text Available One of the most menacing complications of large joint total endoprosthesis (TE in patients with rheumatic diseases (RD is the development of periprosthetic infection (PI, progression of which may give rise not only to limb loss, but also death. At the same time, early diagnosis and adequate surgical care make it possible not only to arrest the infectious process, but also to preserve an implanted joint.Objective: to define criteria for the diagnosis, prevention, and treatment of PI after hip and knee joint (HJ and KJ TE in patients with RD.Subjects and methods. In 2009 to 2013, 654 KJ and 549 HJ TE was performed in the V.A. Nasonova Research Instituteof Rheumatology performed KJ (n = 654 and HJ (n = 549 joint ERs.Results and discussion. PI developed in 12 (3.63% and 8 (2.95% patients after KJ and HJ ER, respectively. Early, delayed, and late PI was seen in 11, 6, and 3 patients, respectively. Eleven patients with early PI underwent joint revision/ debridement with preservation of an endoprosthesis and replacement of HJ endoprosthetic inserts and heads. The operations were completed with the collagen hemobiotics being left in the wound and its drainage. Systemic antibiotic therapy was used for 4–6 weeks. No recurrent infection was observed in 9 cases. Two patients underwentresurgery, by setting suction-irrigation systems. Nine patients with delayed or late PI had the following operations: A single-stage revision operation (the endoprosthesis was removed and a new one was implanted was performed in two cases of stable endoprosthetic components and accurately verified low-virulent microorganisms susceptible to certain antibiotics. It was imperative to use cement with an antibiotic, collagen hemobiotics, and systemic antibiotic therapy for 6 weeks. The other 7 patients with unstable endoprosthetic components underwent two-stage revision: Stage 1, endoprosthetic removal and antibiotic-loaded spacer implantation; 6-12 weeks after

Friction in total hip joint prosthesis measured in vivo during walking.

Science.gov (United States)

Damm, Philipp; Dymke, Joern; Ackermann, Robert; Bender, Alwina; Graichen, Friedmar; Halder, Andreas; Beier, Alexander; Bergmann, Georg

2013-01-01

Friction-induced moments and subsequent cup loosening can be the reason for total hip joint replacement failure. The aim of this study was to measure the in vivo contact forces and friction moments during walking. Instrumented hip implants with Al2O3 ceramic head and an XPE inlay were used. In vivo measurements were taken 3 months post operatively in 8 subjects. The coefficient of friction was calculated in 3D throughout the whole gait cycle, and average values of the friction-induced power dissipation in the joint were determined. On average, peak contact forces of 248% of the bodyweight and peak friction moments of 0.26% bodyweight times meter were determined. However, contact forces and friction moments varied greatly between individuals. The friction moment increased during the extension phase of the joint. The average coefficient of friction also increased during this period, from 0.04 (0.03 to 0.06) at contralateral toe off to 0.06 (0.04 to 0.08) at contralateral heel strike. During the flexion phase, the coefficient of friction increased further to 0.14 (0.09 to 0.23) at toe off. The average friction-induced power throughout the whole gait cycle was 2.3 W (1.4 W to 3.8 W). Although more parameters than only the synovia determine the friction, the wide ranges of friction coefficients and power dissipation indicate that the lubricating properties of synovia are individually very different. However, such differences may also exist in natural joints and may influence the progression of arthrosis. Furthermore, subjects with very high power dissipation may be at risk of thermally induced implant loosening. The large increase of the friction coefficient during each step could be caused by the synovia being squeezed out under load.

Friction in total hip joint prosthesis measured in vivo during walking.

Directory of Open Access Journals (Sweden)

Philipp Damm

Full Text Available Friction-induced moments and subsequent cup loosening can be the reason for total hip joint replacement failure. The aim of this study was to measure the in vivo contact forces and friction moments during walking. Instrumented hip implants with Al2O3 ceramic head and an XPE inlay were used. In vivo measurements were taken 3 months post operatively in 8 subjects. The coefficient of friction was calculated in 3D throughout the whole gait cycle, and average values of the friction-induced power dissipation in the joint were determined. On average, peak contact forces of 248% of the bodyweight and peak friction moments of 0.26% bodyweight times meter were determined. However, contact forces and friction moments varied greatly between individuals. The friction moment increased during the extension phase of the joint. The average coefficient of friction also increased during this period, from 0.04 (0.03 to 0.06 at contralateral toe off to 0.06 (0.04 to 0.08 at contralateral heel strike. During the flexion phase, the coefficient of friction increased further to 0.14 (0.09 to 0.23 at toe off. The average friction-induced power throughout the whole gait cycle was 2.3 W (1.4 W to 3.8 W. Although more parameters than only the synovia determine the friction, the wide ranges of friction coefficients and power dissipation indicate that the lubricating properties of synovia are individually very different. However, such differences may also exist in natural joints and may influence the progression of arthrosis. Furthermore, subjects with very high power dissipation may be at risk of thermally induced implant loosening. The large increase of the friction coefficient during each step could be caused by the synovia being squeezed out under load.

3D Analysis of the Proximal Interphalangeal Joint Kinematics during Flexion

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Florian Hess

2013-01-01

Full Text Available Background. Dynamic joint motion recording combined with CT-based 3D bone and joint surface data is accepted as a helpful and precise tool to analyse joint. The purpose of this study is to demonstrate the feasibility of these techniques for quantitative motion analysis of the interphalangeal joint in 3D. Materials and Method. High resolution motion data was combined with an accurate 3D model of a cadaveric index finger. Three light-emitting diodes (LEDs were used to record dynamic data, and a CT scan of the finger was done for 3D joint surface geometry. The data allowed performing quantitative evaluations such as finite helical axis (FHA analysis, coordinate system optimization, and measurement of the joint distances in 3D. Results. The FHA varies by 4.9±1.7° on average. On average, the rotation in adduction/abduction and internal/external rotation were 0.3±0.91° and 0.1±0.97°, respectively. During flexion, a translational motion between 0.06 mm and 0.73 mm was observed. Conclusions. The proposed technique and methods appear to be feasible for the accurate assessment and evaluation of the PIP joint motion in 3D. The presented method may help to gain additional insights for the design of prosthetic implants, rehabilitation, and new orthotic devices.

Morphological parameters for implantation of the screwless spring loop dynamic posterior spinous process stabilizing system.

Science.gov (United States)

Song, Geun Soo; Lee, Yeon Soo

2015-07-01

This study aimed to quantify morphological characteristics of the posterior lumbar spinous process, which may affect stable implantation of screwless wire spring loops. Virtual implantations of a screwless wire spring loop onto pairs of lumbar spinous processes were performed for computed tomography (CT)-derived three-dimensional vertebral models of 40 Korean subjects. Morphological parameters of lumbar vertebrae 1 through 5 (L1-L5) were measured with regard to bone-implant interference. In males, the transspinous process fixation lengths decreased from 57.8±3.0mm to 48.8±3.2mm as the lumbar joints descend from L1-L2 to L4-L5, with those in females about 4.1±0.4mm shorter (pprocess and the greatest (8.1±2.2mm) for the L4 upper spinous process; this was 1.0±10.3mm less than that for males at corresponding levels (p>0.05). The ratio of the spinous process clenched thickness to the transspinous fixation length increased from 0.133±0.016 to 0.196±0.076 for the upper spinous processes as the lumbar joints descend. The ratio of the spinous process clenched thickness to the transspinous fixation length varies, depending on gender and whether the clenched level is the upper or lower spinous process. These parameters related to the clenching fixation stability should be considered in development and implantations of the screwless wire spring loop. Copyright © 2015 Elsevier GmbH. All rights reserved.

A comparative study of zirconium and titanium implants in rat: osseointegration and bone material quality.

Science.gov (United States)

Hoerth, Rebecca M; Katunar, María R; Gomez Sanchez, Andrea; Orellano, Juan C; Ceré, Silvia M; Wagermaier, Wolfgang; Ballarre, Josefina

2014-02-01

Permanent metal implants are widely used in human medical treatments and orthopedics, for example as hip joint replacements. They are commonly made of titanium alloys and beyond the optimization of this established material, it is also essential to explore alternative implant materials in view of improved osseointegration. The aim of our study was to characterize the implant performance of zirconium in comparison to titanium implants. Zirconium implants have been characterized in a previous study concerning material properties and surface characteristics in vitro, such as oxide layer thickness and surface roughness. In the present study, we compare bone material quality around zirconium and titanium implants in terms of osseointegration and therefore characterized bone material properties in a rat model using a multi-method approach. We used light and electron microscopy, micro Raman spectroscopy, micro X-ray fluorescence and X-ray scattering techniques to investigate the osseointegration in terms of compositional and structural properties of the newly formed bone. Regarding the mineralization level, the mineral composition, and the alignment and order of the mineral particles, our results show that the maturity of the newly formed bone after 8 weeks of implantation is already very high. In conclusion, the bone material quality obtained for zirconium implants is at least as good as for titanium. It seems that the zirconium implants can be a good candidate for using as permanent metal prosthesis for orthopedic treatments.

NASA Research Announcement Phase 2 Final Report for the Development of a Power Assisted Space Suit Glove

Science.gov (United States)

Lingo, Robert; Cadogan, Dave; Sanner, Rob; Sorenson, Beth

1997-01-01

The main goal of this program was to develop an unobtrusive power-assisted EVA glove metacarpalphalangeal (MCP) joint that could provide the crew member with as close to nude body performance as possible, and to demonstrate the technology feasibility of power assisted space suit components in general. The MCP joint was selected due to its being representative of other space suit joints, such as the shoulder, hip and carpometacarpal joint, that would also greatly benefit from this technology. In order to meet this objective, a development team of highly skilled and experienced personnel was assembled. The team consisted of two main entities. The first was comprised of ILC's experienced EVA space suit glove designers, who had the responsibility of designing and fabricating a low torque MCP joint which would be compatible with power assisted technology. The second part of the team consisted of space robotics experts from the University of Maryland's Space Systems Laboratory. This team took on the responsibility of designing and building the robotics aspects of the power-assist system. Both parties addressed final system integration responsibilities.

Septic monoarthritis of the first carpo-metacarpal joint caused by Mycobacterium kansasii.

Science.gov (United States)

Brutus, J P; Lamraski, G; Zirak, C; Hauzeur, J P; Thys, J P; Schuind, F

2005-02-01

A case of septic carpal monoarthritis due to Mycobacterium kansasii developing 16 months after accidental inoculation in a healthy laboratory technician is reported. No predisposing factor such as immunosuppression, preexisting degenerative, inflammatory arthritis or cortisone injection was present. Treatment with antituberculous oral medication alone resulted in resolution of the disease. Synovectomy was unnecessary. Ten years after the initial causative event, the patient remains free of symptoms.

Two years follow-up study of the pain-relieving effect of gold bead implantation in dogs with hip-joint arthritis

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Søli Nils

2007-03-01

Full Text Available Abstract Seventy-eight dogs with pain from hip dysplasia participated in a six-month placebo-controlled, double-blinded clinical trial of gold bead implantation. In the present, non-blinded study, 73 of these dogs were followed for an additional 18 months to evaluate the long-term pain-relieving effect of gold bead implantation. The recently-published results of the six month period revealed that 30 of the 36 dogs (83% in the gold implantation group showed significant improvement (p = 0.02, included improved mobility and reduction in the signs of pain, compared to the placebo group (60% improvement. In the long-term two-year follow-up study, 66 of the 73 dogs had gold implantation and seven dogs continued as a control group. The 32 dogs in the original placebo group had gold beads implanted and were followed for a further 18 months. A certified veterinary acupuncturist used the same procedure to insert the gold beads as in the blinded study, and the owners completed the same type of detailed questionnaires. As in the blinded study, one investigator was responsible for all the assessments of each dog. The present study revealed that the pain-relieving effect of gold bead implantation observed in the blinded study continued throughout the two-year follow-up period.

Compressive Strength Evaluation in Brazed ZrO2/Ti6Al4V Joints Using Finite Element Analysis

Science.gov (United States)

Sharma, Ashutosh; Kee, Se Ho; Jung, Flora; Heo, Yongku; Jung, Jae Pil

2016-05-01

This study aims to synthesize and evaluate the compressive strength of the ZrO2/Ti-6Al-4V joint brazed using an active metal filler Ag-Cu-Sn-Ti, and its application to dental implants assuring its reliability to resist the compressive failure in the actual oral environment. The brazing was performed at a temperature of 750 °C for 30 min in a vacuum furnace under 5 × 10-6 Torr atmosphere. The microstructure of the brazed joint showed the presence of an Ag-rich matrix and a Cu-rich phase, and Cu-Ti intermetallic compounds were observed along the Ti-6Al-4V bonded interface. The compressive strength of the brazed ZrO2/Ti-6Al-4V joint was measured by EN ISO 14801 standard test method. The measured compressive strength of the joint was ~1477 MPa—a value almost five times that of existing dental cements. Finite element analysis also confirmed the high von Mises stress values. The compressive strains in the samples were found concentrated near the Ti-6Al-4V position, matching with the position of the real fractured sample. These results suggest extremely significant compressive strength in ZrO2/Ti-6Al-4V joints using the Ag-Cu-Sn-Ti filler. It is believed that a highly reliable dental implant can be processed and designed using the results of this study.

Short dental implants: an emerging concept in implant treatment.

Science.gov (United States)

Al-Hashedi, Ashwaq Ali; Taiyeb Ali, Tara Bai; Yunus, Norsiah

2014-06-01

Short implants have been advocated as a treatment option in many clinical situations where the use of conventional implants is limited. This review outlines the effectiveness and clinical outcomes of using short implants as a valid treatment option in the rehabilitation of edentulous atrophic alveolar ridges. Initially, an electronic search was performed on the following databases: Medline, PubMed, Embase, Cochrane Database of Systematic Reviews, and DARE using key words from January 1990 until May 2012. An additional hand search was included for the relevant articles in the following journals: International Journal of Oral and Maxillofacial Implants, Clinical Oral Implants Research, Journal of Clinical Periodontology, International Journal of Periodontics, Journal of Periodontology, and Clinical Implant Dentistry and Related Research. Any relevant papers from the journals' references were hand searched. Articles were included if they provided detailed data on implant length, reported survival rates, mentioned measures for implant failure, were in the English language, involved human subjects, and researched implants inserted in healed atrophic ridges with a follow-up period of at least 1 year after implant-prosthesis loading. Short implants demonstrated a high rate of success in the replacement of missing teeth in especially atrophic alveolar ridges. The advanced technology and improvement of the implant surfaces have encouraged the success of short implants to a comparable level to that of standard implants. However, further randomized controlled clinical trials and prospective studies with longer follow-up periods are needed.

Number of implants for mandibular implant overdentures: a systematic review

Science.gov (United States)

Lee, Jeong-Yol; Kim, Ha-Young; Bryant, S. Ross

2012-01-01

PURPOSE The aim of this systematic review is to address treatment outcomes of Mandibular implant overdentures relative to implant survival rate, maintenance and complications, and patient satisfaction. MATERIALS AND METHODS A systematic literature search was conducted by a PubMed search strategy and hand-searching of relevant journals from included studies. Randomized Clinical Trials (RCT) and comparative clinical trial studies on mandibular implant overdentures until August, 2010 were selected. Eleven studies from 1098 studies were finally selected and data were analyzed relative to number of implants. RESULTS Six studies presented the data of the implant survival rate which ranged from 95% to 100% for 2 and 4 implant group and from 81.8% to 96.1% for 1 and 2 implant group. One study, which statistically compared implant survival rate showed no significant differences relative to the number of implants. The most common type of prosthetic maintenance and complications were replacement or reattaching of loose clips for 2 and 4 implant group, and denture repair due to the fracture around an implant for 1 and 2 implant groups. Most studies showed no significant differences in the rate of prosthetic maintenance and complication, and patient satisfaction regardless the number of implants. CONCLUSION The implant survival rate of mandibular overdentures is high regardless of the number of implants. Denture maintenance is likely not inflenced substantially by the number of implants and patient satisfaction is typically high again regardless os the number of implants. PMID:23236572

Magnetic resonance imaging in cadaver dogs with metallic vertebral implants at 3 Tesla: evaluation of the WARP-turbo spin echo sequence.

Science.gov (United States)

Griffin, John F; Archambault, Nicholas S; Mankin, Joseph M; Wall, Corey R; Thompson, James A; Padua, Abraham; Purdy, David; Kerwin, Sharon C

2013-11-15

Laboratory investigation, ex vivo. Postoperative complications are common after spinal implantation procedures, and magnetic resonance imaging (MRI) would be the ideal modality to image these patients. Unfortunately, the implants cause artifacts that can render MRI nondiagnostic. The WARP-turbo spin echo (TSE) sequence has been developed to mitigate artifacts caused by metal. The objective of this investigation was to evaluate the performance of the WARP-TSE sequence in canine cadaver specimens after implantation with metallic vertebral implants. Magnetic field strength, implant type, and MRI acquisition technique all play a role in the severity of susceptibility artifacts. The WARP-TSE sequence uses increased bandwidth, view angle tilting, and SEMAC (slice-encoding metal artifact correction) to correct for susceptibility artifact. The WARP-TSE technique has outperformed conventional techniques in patients, after total hip arthroplasty. However, published reports of its application in subjects with vertebral column implants are lacking. Ex vivo anterior stabilization of the atlantoaxial joint was performed on 6 adult small breed (implantation with stainless steel implants. N/A.

Primary prevention of peri-implantitis: managing peri-implant mucositis.

Science.gov (United States)

Jepsen, Søren; Berglundh, Tord; Genco, Robert; Aass, Anne Merete; Demirel, Korkud; Derks, Jan; Figuero, Elena; Giovannoli, Jean Louis; Goldstein, Moshe; Lambert, France; Ortiz-Vigon, Alberto; Polyzois, Ioannis; Salvi, Giovanni E; Schwarz, Frank; Serino, Giovanni; Tomasi, Cristiano; Zitzmann, Nicola U

2015-04-01

Over the past decades, the placement of dental implants has become a routine procedure in the oral rehabilitation of fully and partially edentulous patients. However, the number of patients/implants affected by peri-implant diseases is increasing. As there are--in contrast to periodontitis--at present no established and predictable concepts for the treatment of peri-implantitis, primary prevention is of key importance. The management of peri-implant mucositis is considered as a preventive measure for the onset of peri-implantitis. Therefore, the remit of this working group was to assess the prevalence of peri-implant diseases, as well as risks for peri-implant mucositis and to evaluate measures for the management of peri-implant mucositis. Discussions were informed by four systematic reviews on the current epidemiology of peri-implant diseases, on potential risks contributing to the development of peri-implant mucositis, and on the effect of patient and of professionally administered measures to manage peri-implant mucositis. This consensus report is based on the outcomes of these systematic reviews and on the expert opinion of the participants. Key findings included: (i) meta-analysis estimated a weighted mean prevalence for peri-implant mucositis of 43% (CI: 32-54%) and for peri-implantitis of 22% (CI: 14-30%); (ii) bleeding on probing is considered as key clinical measure to distinguish between peri-implant health and disease; (iii) lack of regular supportive therapy in patients with peri-implant mucositis was associated with increased risk for onset of peri-implantitis; (iv) whereas plaque accumulation has been established as aetiological factor, smoking was identified as modifiable patient-related and excess cement as local risk indicator for the development of peri-implant mucositis; (v) patient-administered mechanical plaque control (with manual or powered toothbrushes) has been shown to be an effective preventive measure; (vi) professional intervention

Biomechanical analysis of acromioclavicular joint dislocation treated with clavicle hook plates in different lengths.

Science.gov (United States)

Shih, Cheng-Min; Huang, Kui-Chou; Pan, Chien-Chou; Lee, Cheng-Hung; Su, Kuo-Chih

2015-11-01

Clavicle hook plates are frequently used in clinical orthopaedics to treat acromioclavicular joint dislocation. However, patients often exhibit acromion osteolysis and per-implant fracture after undergoing hook plate fixation. With the intent of avoiding future complications or fixation failure after clavicle hook plate fixation, we used finite element analysis (FEA) to investigate the biomechanics of clavicle hook plates of different materials and sizes when used in treating acromioclavicular joint dislocation. Using finite element analysis, this study constructed a model comprising four parts: clavicle, acromion, clavicle hook plate and screws, and used the model to simulate implanting different types of clavicle hook plates in patients with acromioclavicular joint dislocation. Then, the biomechanics of stainless steel and titanium alloy clavicle hook plates containing either six or eight screw holes were investigated. The results indicated that using a longer clavicle hook plate decreased the stress value in the clavicle, and mitigated the force that clavicle hook plates exert on the acromion. Using a clavicle hook plate material characterized by a smaller Young's modulus caused a slight increase in the stress on the clavicle. However, the external force the material imposed on the acromion was less than the force exerted on the clavicle. The findings of this study can serve as a reference to help orthopaedic surgeons select clavicle hook plates.

Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection

DEFF Research Database (Denmark)

Starch-Jensen, Thomas; Christensen, Ann-Eva; Lorenzen, Henning

2017-01-01

OBJECTIVES: The objective was to test the hypothesis of no difference in implant treatment outcome after installation of implants with a scalloped implant-abutment connection compared to a flat implant-abutment connection. MATERIAL AND METHODS: A MEDLINE (PubMed), Embase and Cochrane library search...... of suprastructures has never been compared within the same study. High implant survival rate was reported in all the included studies. Significantly more peri-implant marginal bone loss, higher probing depth score, bleeding score and gingival score was observed around implants with a scalloped implant-abutment...... loss around implants with a scalloped implant-abutment connection. CONCLUSIONS: A scalloped implant-abutment connection seems to be associated with higher peri-implant marginal bone loss compared to a flat implant-abutment connection. Therefore, the hypothesis of the present systematic review must...

Total joint Perioperative Surgical Home: an observational financial review.

Science.gov (United States)

Raphael, Darren R; Cannesson, Maxime; Schwarzkopf, Ran; Garson, Leslie M; Vakharia, Shermeen B; Gupta, Ranjan; Kain, Zeev N

2014-01-01

The numbers of people requiring total arthroplasty is expected to increase substantially over the next two decades. However, increasing costs and new payment models in the USA have created a sustainability gap. Ad hoc interventions have reported marginal cost reduction, but it has become clear that sustainability lies only in complete restructuring of care delivery. The Perioperative Surgical Home (PSH) model, a patient-centered and physician-led multidisciplinary system of coordinated care, was implemented at UC Irvine Health in 2012 for patients undergoing primary elective total knee arthroplasty (TKA) or total hip arthroplasty (THA). This observational study examines the costs associated with this initiative. The direct cost of materials and services (excluding professional fees and implants) for a random index sample following the Total Joint-PSH pathway was used to calculate per diem cost. Cost of orthopedic implants was calculated based on audit-verified direct cost data. Operating room and post-anesthesia care unit time-based costs were calculated for each case and analyzed for variation. Benchmark cost data were obtained from literature search. Data are presented as mean ± SD (coefficient of variation) where possible. Total per diem cost was $10,042 ± 1,305 (13%) for TKA and $9,952 ± 1,294 (13%) for THA. Literature-reported benchmark per diem cost was $17,588 for TKA and $16,267 for THA. Implant cost was $7,482 ± 4,050 (54%) for TKA and $9869 ± 1,549 (16%) for THA. Total hospital cost was $17,894 ± 4,270 (24%) for TKA and $20,281 ± 2,057 (10%) for THA. In-room to incision time cost was $1,263 ± 100 (8%) for TKA and $1,341 ± 145 (11%) for THA. Surgery time cost was $1,558 ± 290 (19%) for TKA and $1,930 ± 374 (19%) for THA. Post-anesthesia care unit time cost was $507 ± 187 (36%) for TKA and $557 ± 302 (54%) for THA. Direct hospital costs were driven substantially below USA benchmark levels using the Total Joint-PSH pathway. The incremental

The use of polymer gel dosimetry to measure dose distribution around metallic implants

International Nuclear Information System (INIS)

Nagahata, Tomomasa; Yamaguchi, Hajime; Monzen, Hajime; Nishimura, Yasumasa

2014-01-01

A semi-solid polymer dosimetry system using agar was developed to measure the dose distribution close to metallic implants. Dosimetry of heterogeneous fields where electron density markedly varies is often problematic. This prompted us to develop a polymer gel dosimetry technique using agar to measure the dose distribution near substance boundaries. Varying the concentration of an oxygen scavenger (tetra-hydroxymethyl phosphonium chloride) showed the absorbed dose and transverse relaxation rate of the magnetic resonance signal to be linear between 3 and 12 Gy. Although a change in the dosimeter due to oxidization was observed in room air after 24 hours, no such effects were observed in the first 4 hours. The dose distribution around the metal implants was measured using agar dosimetry. The metals tested were a lead rod, a titanium hip joint, and a metallic stent. A maximum 30% dose increase was observed near the lead rod, but only a 3% increase in the absorbed dose was noted near the surface of the titanium hip joint and metallic stent. Semi-solid polymer dosimetry using agar thus appears to be a useful method for dosimetry around metallic substances. (author)

[The use of polymer gel dosimetry to measure dose distribution around metallic implants].

Science.gov (United States)

Nagahata, Tomomasa; Yamaguchi, Hajime; Monzen, Hajime; Nishimura, Yasumasa

2014-10-01

A semi-solid polymer dosimetry system using agar was developed to measure the dose distribution close to metallic implants. Dosimetry of heterogeneous fields where electron density markedly varies is often problematic. This prompted us to develop a polymer gel dosimetry technique using agar to measure the dose distribution near substance boundaries. Varying the concentration of an oxygen scavenger (tetra-hydroxymethyl phosphonium chloride) showed the absorbed dose and transverse relaxation rate of the magnetic resonance signal to be linear between 3 and 12 Gy. Although a change in the dosimeter due to oxidization was observed in room air after 24 hours, no such effects were observed in the first 4 hours. The dose distribution around the metal implants was measured using agar dosimetry. The metals tested were a lead rod, a titanium hip joint, and a metallic stent. A maximum 30% dose increase was observed near the lead rod, but only a 3% increase in the absorbed dose was noted near the surface of the titanium hip joint and metallic stent. Semi-solid polymer dosimetry using agar thus appears to be a useful method for dosimetry around metallic substances.

Regenerative strategies for the treatment of knee joint disabilities

CERN Document Server

Reis, Rui

2017-01-01

This book presents regenerative strategies for the treatment of knee joint disabilities. The book is composed of four main sections totaling 19 chapters which review the current knowledge on the clinical management and preclinical regenerative strategies. It examines the role of different natural-based biomaterials as scaffolds and implants for addressing different tissue lesions in the knee joint. Section one provides an updated and comprehensive discussion on articular cartilage tissue regeneration. Section two focuses on the important contributions for bone and osteochondral tissue engineering. Section three overview the recent advances on meniscus repair/regeneration strategies. Finally, section four further discusses the current strategies for treatment of ligament lesions. Each chapter is prepared by world know expert on their fields, so we do firmly believe that the proposed book will be a reference in the area of biomaterials for regenerative medicine.

Tilted Implants for Full-Arch Rehabilitations in Completely Edentulous Maxilla: A Retrospective Study

Directory of Open Access Journals (Sweden)

Nicolò Cavalli

2012-01-01

Full Text Available Purpose. The aims of this study were to assess the treatment outcome of immediately loaded full-arch fixed bridges anchored to both tilted and axially placed implants in the edentulous maxilla and to evaluate the incidence of biological and prosthetic complications. Materials and Methods. Thirty-four patients (18 women and 16 men were included in the study. Each patient received a maxillary full-arch fixed bridge supported by two axial implants and two distal tilted implants. A total of 136 implants were inserted. Loading was applied within 48 hours of surgery and definitive restorations were placed 4 to 6 months later. Patients were scheduled for followup at 6, 12, 18, and 24 months and annually up to 5 years. At each followup plaque level and bleeding scores were assessed and every complication was recorded. Results. The overall follow-up range was 12 to 73 months (mean 38.8 months. No implant failures were recorded to date, leading to a cumulative implant survival rate of 100%. Biological complications were recorded such as alveolar mucositis (11.8% patients, peri-implantitis (5.9% patients, and temporomandibular joint pain (5.9% patients. The most common prosthetic complications were the fracture or detachment of one or multiple acrylic teeth in both the temporary (20.6% patients and definitive (17.7% patients prosthesis and the minor acrylic fractures in the temporary (14.7% patients and definitive (2.9% patients prosthesis. Hygienic complications occurred in 38.2% patients. No patients’ dissatisfactions were recorded. Conclusions. The high cumulative implant survival rate indicates that this technique could be considered a viable treatment option. An effective recall program is important to early intercept and correct prosthetic and biologic complications in order to avoid implant and prosthetic failures.

Effect of Cyclic Loading on Micromotion at the Implant-Abutment Interface.

Science.gov (United States)

Karl, Matthias; Taylor, Thomas D

2016-01-01

Cyclic loading may cause settling of abutments mounted on dental implants, potentially affecting screw joint stability and implant-abutment micromotion. It was the goal of this in vitro study to compare micromotion of implant-abutment assemblies before and after masticatory simulation. Six groups of abutments (n = 5) for a specific tissue-level implant system with an internal octagon were subject to micromotion measurements. The implant-abutment assemblies were loaded in a universal testing machine, and an apparatus and extensometers were used to record displacement. This was done twice, in the condition in which they were received from the abutment manufacturer and after simulated loading (100,000 cycles; 100 N). Statistical analysis was based on analysis of variance, two-sample t tests (Welch tests), and Pearson product moment correlation (α = .05). The mean values for micromotion ranged from 33.15 to 63.41 μm and from 30.03 to 42.40 μm before and after load cycling. The general trend toward reduced micromotion following load cycling was statistically significant only for CAD/CAM zirconia abutments (P = .036) and for one type of clone abutment (P = .012), with no significant correlation between values measured before and after cyclic loading (Pearson product moment correlation; P = .104). While significant differences in micromotion were found prior to load cycling, no significant difference among any of the abutment types tested could be observed afterward (P > .05 in all cases). A quantifiable settling effect at the implant-abutment interface seems to result from cyclic loading, leading to a decrease in micromotion. This effect seems to be more pronounced in low-quality abutments. For the implant system tested in this study, retightening of abutment screws is recommended after an initial period of clinical use.

In vivo analysis of trapeziometacarpal joint arthrokinematics during multi-directional thumb motions.

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Su, Fong-Chin; Lin, Chien-Ju; Wang, Chien-Kuo; Chen, Guan-Po; Sun, Yung-Nien; Chuang, Alan K; Kuo, Li-Chieh

2014-11-01

The investigation of the joint arthrokinematics of the trapeziometacarpal joint is critical to comprehend the causative mechanism underlying this common form of osteoarthritis. Therefore, the purpose of this study is to evaluate the arthrokinematics of the trapeziometacarpal joint during thumb postures in vivo. Fifteen healthy participants were enrolled in this study. Static computed tomography images of the 1st metacarpal bone and trapezium were taken at specific thumb postures during thumb flexion-extension, abduction-adduction, and circumduction motions. Images were analyzed to examine the joint gliding, expressed as displacement of the centroid of the articular surface of the 1st metacarpal bone, relative to the trapezium. The gliding ratio, defined as joint gliding in each direction normalized to the dimension of the trapezium joint surface in the given direction, was computed and compared between different thumb motions. The results indicate that thumb motions influenced joint gliding. The centroids of the articular surface of the 1st metacarpal bone were primarily located at the central and dorsal-radial regions while executing these motions. The maximum joint gliding of the 1st metacarpal bone occurred in the radial-ulnar direction when performing abduction-adduction, and in the dorsal-volar direction while performing flexion-extension and circumduction, with the gliding ratio values of 42.35%, 51.65%, and 51.85%, respectively. Activities that involved abduction-adduction in the trapeziometacarpal joint caused greater joint gliding in the ulnar-radial direction, while flexion-extension resulted in greater joint gliding in the dorsal-volar and distal-proximal directions. Understanding normal joint kinematics in vivo may provide insights into the possible mechanism leading to osteoarthritis of the trapeziometacarpal joint, and help to improve the design of implants. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effects of hydroxyapatite coating and bone allograft on fixation of loaded experimental primary and revision implants.

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Søballe, Kjeld; Mouzin, Olivier R G; Kidder, Louis A; Overgaard, Søren; Bechtold, Joan E

2003-06-01

We used our established experimental model of revision joint replacement to examine the roles of hydroxyapatite coating and bone graft in improving the fixation of revision implants. The revision protocol uses the Søballe micromotion device in a preliminary 8-week period of implant instability for the presence of particulate polyethylene. During this procedure, a sclerotic endosteal bone rim forms, and a dense fibrous membrane is engendered, having macrophages with ingested polyethylene and high levels of inflammatory cytokines. At the time of revision after 8 weeks, the cavity is revised with either a titanium alloy (Ti) or a hydroxyapatite (HA) 6.0 mm plasma-sprayed implant, in the presence or absence of allograft packed into the initial 0.75 mm peri-implant gap. The contralateral limb is subjected to primary surgery with the same implant configuration, and serves as control. 8 implants were included in each of the 8 treatment groups (total 64 implants in 32 dogs). The observation period was 4 weeks after revision. Outcome measures are based on histomorphometry and mechanical pushout properties. The revision setting was always inferior to its primary counterpart. Bone graft improved the revision fixation in all treatment groups, as also did the HA coating. The sole exception was revision-grafted HA implants, which reached the same fixation as primary Ti and HA grafted implants. The revision, which was less active in general, seems to need the dual stimulation of bone graft and HA implant surface, to obtain the same level of fixation associated with primary implants. Our findings suggest that the combination of HA implant and bone graft may be of benefit in the clinical revision implant setting.

Prosthetic joint infection development of an evidence-based diagnostic algorithm.

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Mühlhofer, Heinrich M L; Pohlig, Florian; Kanz, Karl-Georg; Lenze, Ulrich; Lenze, Florian; Toepfer, Andreas; Kelch, Sarah; Harrasser, Norbert; von Eisenhart-Rothe, Rüdiger; Schauwecker, Johannes

2017-03-09

Increasing rates of prosthetic joint infection (PJI) have presented challenges for general practitioners, orthopedic surgeons and the health care system in the recent years. The diagnosis of PJI is complex; multiple diagnostic tools are used in the attempt to correctly diagnose PJI. Evidence-based algorithms can help to identify PJI using standardized diagnostic steps. We reviewed relevant publications between 1990 and 2015 using a systematic literature search in MEDLINE and PUBMED. The selected search results were then classified into levels of evidence. The keywords were prosthetic joint infection, biofilm, diagnosis, sonication, antibiotic treatment, implant-associated infection, Staph. aureus, rifampicin, implant retention, pcr, maldi-tof, serology, synovial fluid, c-reactive protein level, total hip arthroplasty (THA), total knee arthroplasty (TKA) and combinations of these terms. From an initial 768 publications, 156 publications were stringently reviewed. Publications with class I-III recommendations (EAST) were considered. We developed an algorithm for the diagnostic approach to display the complex diagnosis of PJI in a clear and logically structured process according to ISO 5807. The evidence-based standardized algorithm combines modern clinical requirements and evidence-based treatment principles. The algorithm provides a detailed transparent standard operating procedure (SOP) for diagnosing PJI. Thus, consistently high, examiner-independent process quality is assured to meet the demands of modern quality management in PJI diagnosis.

Glenohumeral Joint Preservation: A Review of Management Options for Young, Active Patients with Osteoarthritis

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Olivier A. van der Meijden

2012-01-01

Full Text Available The management of osteoarthritis of the shoulder in young, active patients is a challenge, and the optimal treatment has yet to be completely established. Many of these patients wish to maintain a high level of activity, and arthroplasty may not be a practical treatment option. It is these patients who may be excellent candidates for joint-preservation procedures in an effort to avoid or delay joint replacement. Several palliative and restorative techniques are currently optional. Joint debridement has shown good results and a combination of arthroscopic debridement with a capsular release, humeral osteoplasty, and transcapsular axillary nerve decompression seems promising when humeral osteophytes are present. Currently, microfracture seems the most studied reparative treatment modality available. Other techniques, such as autologous chondrocyte implantation and osteochondral transfers, have reportedly shown potential but are currently mainly still investigational procedures. This paper gives an overview of the currently available joint preserving surgical techniques for glenohumeral osteoarthritis.

Why are mini-implants lost: the value of the implantation technique!

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Romano, Fabio Lourenço; Consolaro, Alberto

2015-01-01

The use of mini-implants have made a major contribution to orthodontic treatment. Demand has aroused scientific curiosity about implant placement procedures and techniques. However, the reasons for instability have not yet been made totally clear. The aim of this article is to establish a relationship between implant placement technique and mini-implant success rates by means of examining the following hypotheses: 1) Sites of poor alveolar bone and little space between roots lead to inadequate implant placement; 2) Different sites require mini-implants of different sizes! Implant size should respect alveolar bone diameter; 3) Properly determining mini-implant placement site provides ease for implant placement and contributes to stability; 4) The more precise the lancing procedures, the better the implant placement technique; 5) Self-drilling does not mean higher pressures; 6) Knowing where implant placement should end decreases the risk of complications and mini-implant loss.

Why are mini-implants lost: The value of the implantation technique!

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Fabio Lourenço Romano

2015-02-01

Full Text Available The use of mini-implants have made a major contribution to orthodontic treatment. Demand has aroused scientific curiosity about implant placement procedures and techniques. However, the reasons for instability have not yet been made totally clear. The aim of this article is to establish a relationship between implant placement technique and mini-implant success rates by means of examining the following hypotheses: 1 Sites of poor alveolar bone and little space between roots lead to inadequate implant placement; 2 Different sites require mini-implants of different sizes! Implant size should respect alveolar bone diameter; 3 Properly determining mini-implant placement site provides ease for implant placement and contributes to stability; 4 The more precise the lancing procedures, the better the implant placement technique; 5 Self-drilling does not mean higher pressures; 6 Knowing where implant placement should end decreases the risk of complications and mini-implant loss.

Primary prevention of peri-implantitis: Managing peri-implant mucositis

OpenAIRE

Jepsen, Søren; Berglundh, Tord; Genco, Robert; Aass, Anne Merete; Demirel, Korkud; Derks, Jan; Figuero, Elena; Giovannoli, Jean Louis; Goldstein, Moshe; LAMBERT, France; Ortiz-Vigon, Alberto; Polyzois, Ioannis; Salvi, Giovanni; Schwarz, Frank; Serino, Giovanni

2015-01-01

Abstract AIMS: Over the past decades, the placement of dental implants has become a routine procedure in the oral rehabilitation of fully and partially edentulous patients. However, the number of patients/implants affected by peri-implant diseases is increasing. As there are--in contrast to periodontitis--at present no established and predictable concepts for the treatment of peri-implantitis, primary prevention is of key importance. The management of peri-implant mucositis is considere...

Chronic Periprosthetic Hip Joint Infection. A Retrospective, Observational Study on the Treatment Strategy and Prognosis in 130 Non-Selected Patients

DEFF Research Database (Denmark)

Lange, Jeppe; Troelsen, Anders; Søballe, Kjeld

2016-01-01

INTRODUCTION: Limited information is available regarding the treatment strategy and prognosis of non-selected patients treated for chronic periprosthetic hip joint infection. Such information is important as no head-to-head studies on treatment strategies are available. The purpose of this study...... is to report on the treatment strategy and prognosis of a non-selected, consecutive patient population. METHODS: We identified 130 patients in the National Patient Registry, consecutively treated for a chronic periprosthetic hip joint infection between 2003-2008 at 11 departments of orthopaedic surgery. We...... extracted information regarding patient demographics, treatment and outcome. 82 patients were re-implanted in a two-stage revision (national standard), the remaining 48 were not re-implanted in a two-stage revision. We were able to collect up-to-date information on all patients to date of death or medical...

Osteogenesis and Morphology of the Peri-Implant Bone Facing Dental Implants

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Marco Franchi

2004-01-01

Full Text Available This study investigated the influence of different implant surfaces on peri-implant osteogenesis and implant face morphology of peri-implant tissues during the early (2 weeks and complete healing period (3 months. Thirty endosseous titanium implants (conic screws with differently treated surfaces (smooth titanium = SS, titanium plasma sprayed = TPS, sand-blasted zirconium oxide = Zr-SLA were implanted in femur and tibiae diaphyses of two mongrel sheep. Histological sections of the implants and surrounding tissues obtained by sawing and grinding techniques were observed under light microscopy (LM. The peri-implant tissues of other samples were mechanically detached from the corresponding implants to be processed for SEM observation. Two weeks after implantation, we observed osteogenesis (new bone trabeculae around all implant surfaces only where a gap was present at the host bone-metal interface. No evident bone deposition was detectable where threads of the screws were in direct contact with the compact host bone. Distance osteogenesis predominated in SS implants, while around rough surfaces (TPS and Zr-SLA, both distance and contact osteogenesis were present. At SEM analysis 2 weeks after implantation, the implant face of SS peri-implant tissue showed few, thin, newly formed, bone trabeculae immersed in large, loose, marrow tissue with blood vessels. Around the TPS screws, the implant face of the peri-implant tissue was rather irregular because of the rougher metal surface. Zr-SLA screws showed more numerous, newly formed bone trabeculae crossing marrow spaces and also needle-like crystals in bone nodules indicating an active mineralising process. After 3 months, all the screws appeared osseointegrated, being almost completely covered by a compact, mature, newly formed bone. However, some marrow spaces rich in blood vessels and undifferentiated cells were in contact with the metal surface. By SEM analysis, the implant face of the peri-implant

Survival of dental implants placed in sites of previously failed implants.

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Chrcanovic, Bruno R; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

2017-11-01

To assess the survival of dental implants placed in sites of previously failed implants and to explore the possible factors that might affect the outcome of this reimplantation procedure. Patients that had failed dental implants, which were replaced with the same implant type at the same site, were included. Descriptive statistics were used to describe the patients and implants; survival analysis was also performed. The effect of systemic, environmental, and local factors on the survival of the reoperated implants was evaluated. 175 of 10,096 implants in 98 patients were replaced by another implant at the same location (159, 14, and 2 implants at second, third, and fourth surgeries, respectively). Newly replaced implants were generally of similar diameter but of shorter length compared to the previously placed fixtures. A statistically significant greater percentage of lost implants were placed in sites with low bone quantity. There was a statistically significant difference (P = 0.032) in the survival rates between implants that were inserted for the first time (94%) and implants that replaced the ones lost (73%). There was a statistically higher failure rate of the reoperated implants for patients taking antidepressants and antithrombotic agents. Dental implants replacing failed implants had lower survival rates than the rates reported for the previous attempts of implant placement. It is suggested that a site-specific negative effect may possibly be associated with this phenomenon, as well as the intake of antidepressants and antithrombotic agents. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Sub-meninges implantation reduces immune response to neural implants.

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Markwardt, Neil T; Stokol, Jodi; Rennaker, Robert L

2013-04-15

Glial scar formation around neural interfaces inhibits their ability to acquire usable signals from the surrounding neurons. To improve neural recording performance, the inflammatory response and glial scarring must be minimized. Previous work has indicated that meningeally derived cells participate in the immune response, and it is possible that the meninges may grow down around the shank of a neural implant, contributing to the formation of the glial scar. This study examines whether the glial scar can be reduced by placing a neural probe completely below the meninges. Rats were implanted with sets of loose microwire implants placed either completely below the meninges or implanted conventionally with the upper end penetrating the meninges, but not attached to the skull. Histological analysis was performed 4 weeks following surgical implantation to evaluate the glial scar. Our results found that sub-meninges implants showed an average reduction in reactive astrocyte activity of 63% compared to trans-meninges implants. Microglial activity was also reduced for sub-meninges implants. These results suggest that techniques that isolate implants from the meninges offer the potential to reduce the encapsulation response which should improve chronic recording quality and stability. Published by Elsevier B.V.

Factors influencing success of cement versus screw-retained implant restorations: a clinical review

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Ahmad Manawar

2012-10-01

Full Text Available Aim: As more and more dental practitioners are focusing on implant-supported fixed restorations, some clinicians favor the use of cement retained restorations while others consider screw retained prosthesis to be the best choice. Discussion: In screw-retained restorations, the fastening screw provides a solid joint between the restoration and the implant abutment, while in cement-retained prostheses the restorative screw is eliminated to enhance esthetics, occlusal stability, and passive fit of the restorations. The factors that influence the type of fixation of the prostheses to the implants like passivity of the framework, ease of fabrication, occlusion, esthetics, accessibility, retention and retrievability are discussed in this article with scientific studies demonstrating superior outcomes of one technique over another. Screwretained implant restorations have an advantage of predictable retention, retrievability and lack of potentially retained subgingival cement. However, a few disadvantages exist such as precise placement of the implant for optimal and esthetic location of the screw access hole and obtaining passive fit. On the other hand, cement retained restorations eliminate unesthetic screw access holes, have passive fit of castings, reduced complexity of clinical and lab procedures, enhanced esthetics, reduced cost factors and non disrupted morphology of the occlusal table. Conclusion: This article compares the advantages, potential disadvantages and limitations of screw and cement retained restorations and their specific implications in the most common clinical situation.

Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection

DEFF Research Database (Denmark)

Starch-Jensen, Thomas; Christensen, Ann-Eva; Lorenzen, Henning

2017-01-01

OBJECTIVES: The objective was to test the hypothesis of no difference in implant treatment outcome after installation of implants with a scalloped implant-abutment connection compared to a flat implant-abutment connection. MATERIAL AND METHODS: A MEDLINE (PubMed), Embase and Cochrane library search......-abutment connection. There were no significant differences between the two treatment modalities regarding professional or patient-reported outcome measures. Meta-analysis disclosed a mean difference of peri-implant marginal bone loss of 1.56 mm (confidence interval: 0.87 to 2.25), indicating significant more bone...... loss around implants with a scalloped implant-abutment connection. CONCLUSIONS: A scalloped implant-abutment connection seems to be associated with higher peri-implant marginal bone loss compared to a flat implant-abutment connection. Therefore, the hypothesis of the present systematic review must...

Imaging of common breast implants and implant-related complications: A pictorial essay.

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Shah, Amisha T; Jankharia, Bijal B

2016-01-01

The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance imaging of silicone breast implants, with its high sensitivity and specificity for detecting implant rupture, is the most reliable modality to asses implant integrity. Whichever imaging modality is used, the overall aim of imaging breast implants is to provide the pertinent information about implant integrity, detect implant failures, and to detect breast conditions unrelated to the implants, such as cancer.

Randomised controlled trial of extraarticular gold bead implantation for treatment of knee osteoarthritis: a pilot study

DEFF Research Database (Denmark)

Nejrup, Kirsten; Olivarius, Niels de Fine; Jacobsen, Judith L.

2008-01-01

The primary objective of this double-blind, randomised, controlled trial was to determine if implanting gold beads at five acupuncture points around the knee joint improves 1-year outcomes for patients with osteoarthritis (OA) of the knee. Participants were 43 adults aged 18-80 years with pain...... and stiffness from non-specific OA of the knee for over a year. The intervention was blinded implantation of gold beads at five acupuncture points around the affected knee through a hypodermic needle, or needle insertion alone. Primary outcome measures were knee pain, stiffness and function assessed...... acupuncture had greater relative improvements in self-assessed outcomes. The treatment was well tolerated. This 1-year pilot study indicates that extraarticular gold bead implantation is a promising treatment modality for patients with OA of the knee. The new treatment should be tested in a larger trial...

Immediate Direct-To-Implant Breast Reconstruction Using Anatomical Implants

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Sung-Eun Kim

2014-09-01

Full Text Available BackgroundIn 2012, a new anatomic breast implant of form-stable silicone gel was introduced onto the Korean market. The intended use of this implant is in the area of aesthetic breast surgery, and many reports are promising. Thus far, however, there have been no reports on the use of this implant for breast reconstruction in Korea. We used this breast implant in breast reconstruction surgery and report our early experience.MethodsFrom November 2012 to April 2013, the Natrelle Style 410 form-stable anatomically shaped cohesive silicone gel-filled breast implant was used in 31 breasts of 30 patients for implant breast reconstruction with an acellular dermal matrix. Patients were treated with skin-sparing mastectomies followed by immediate breast reconstruction.ResultsThe mean breast resection volume was 240 mL (range, 83-540 mL. The mean size of the breast implants was 217 mL (range, 125-395 mL. Breast shape outcomes were considered acceptable. Infection and skin thinning occurred in one patient each, and hematoma and seroma did not occur. Three cases of wound dehiscence occurred, one requiring surgical intervention, while the others healed with conservative treatment in one month. Rippling did not occur. So far, complications such as capsular contracture and malrotation of breast implant have not yet arisen.ConclusionsBy using anatomic breast implants in breast reconstruction, we achieved satisfactory results with aesthetics better than those obtained with round breast implants. Therefore, we concluded that the anatomical implant is suitable for breast reconstruction.

Sporting Activity Is Reduced 11 Years After First-Generation Autologous Chondrocyte Implantation in the Knee Joint.

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Erdle, Benjamin; Herrmann, Simon; Porichis, Stella; Uhl, Markus; Ghanem, Nadir; Schmal, Hagen; Suedkamp, Norbert; Niemeyer, Philipp; Salzmann, Gian M

2017-10-01

Little is known about long-term sporting activity after periosteal autologous chondrocyte implantation (ACI-P) and its correlation to clinical, morphological, and ultrastructural cartilage characteristics on magnetic resonance imaging (MRI). To evaluate long-term sporting activity after ACI-P and to correlate with clinical and MRI findings. Case series; Level of evidence, 4. Patients who underwent ACI-P for isolated cartilage defects of the knee joint between 1997 and 2001 were analyzed for sporting ability for 3 different time points: lifetime until the onset of pain, the year before ACI-P, and 11 years (range, 9.0-13.4 years) postoperatively. Sporting activity was assessed and patients' level of activity scaled using standardized questionnaires. MRI scans of the affected knee joint at follow-up were analyzed using the MOCART (magnetic resonance observation of cartilage repair tissue) score and T2 mapping. Seventy of 86 patients (81% follow-up rate) consisting of 25 female and 45 male patients, with a mean age of 33.3 ± 10.2 years at the time of surgery, mean defect size of 6.5 ± 4.0 cm 2 , and 1.17 treated defects per patient, agreed to participate in the study at a mean 10.9 ± 1.1 years after ACI-P. Fifty-nine patients (69% of total; 84% of follow-up) agreed to MRI, allowing the complete evaluation of 71 transplant sites. Before the onset of symptoms (lifetime), 95.7% of patients played a mean 6.0 sporting activities at a competitive level. In the year before ACI-P, 81.4% of patients played a mean 3.4 sporting activities in 2.4 sessions during 5.4 hours per week at a recreational level. At follow-up, 82.9% of the patients played a mean 3.0 sporting activities in 1.8 sessions during 3.0 hours per week at a recreational level. In contrast to objective factors, 65.6% of the patients felt that their subjective sporting ability had improved or strongly improved after ACI-P, whereas 12.9% felt that their situation had declined or strongly declined, and 21.4% stated

Implants in free fibula flap supporting dental rehabilitation - Implant and peri-implant related outcomes of a randomized clinical trial.

Science.gov (United States)

Kumar, Vinay V; Ebenezer, Supriya; Kämmerer, Peer W; Jacob, P C; Kuriakose, Moni A; Hedne, Naveen; Wagner, Wilfried; Al-Nawas, Bilal

2016-11-01

The objective of this study was to assess the difference in success rates of implants when using two or four implant-supported-overdentures following segmental mandibular reconstruction with fibula free flap. This prospective, parallel designed, randomized clinical study was conducted with 1:1 ratio. At baseline, all participants already had segmental reconstruction of mandible with free fibula flap. The participants were randomized into two groups: Group-I received implant-supported-overdentures on two tissue-level implants and Group-II received implant-supported-overdentures on four tissue-level implants. Success rates of the implants were evaluated at 3 months, 6 months and 12 months following implant loading using marginal bone level changes as well as peri-implant indices (Buser et al., 1990). 52 patients were randomized into two treatment groups (26 each), out of which 18 patients (36 implants) of Group-I and 17 patients (68 implants) of Group-II were evaluated. One implant in Group-I was lost due to infective complications and one patient in the same group had superior barrel necrosis. There was a statistically significant increase at both time points (p = 0.03, p = 0.04 at 6 months, 12 months) in the amount of marginal bone loss in Group-I (0.4 mm, 0.5 mm at 6 months, 12 months) as compared to Group-II (0.1 mm, 0.2 mm at 6 months, 12 months). There were no clinically significant changes peri-implant parameters between both groups. Peri-implant soft tissue hyperplasia was seen in both groups, 32% of implants at 3-months, 26% at 6-months and 3% at 12-months follow-up. The results of this study show that patients with 2-implant-supported-overdentures had higher marginal bone loss as compared to patients with 4-implant-supported-overdentures. There were no clinically significant differences in peri-implant soft tissue factors in patients with 2- or 4-implant-supported-overdentures. Hyperplastic peri-implant tissues are common in the early implant

Impact of an implanted neuroprosthesis on community ambulation in incomplete SCI.

Science.gov (United States)

Lombardo, Lisa M; Kobetic, Rudolf; Pinault, Gilles; Foglyano, Kevin M; Bailey, Stephanie N; Selkirk, Stephen; Triolo, Ronald J

2018-03-01

Test the effect of a multi-joint control with implanted electrical stimulation on walking after spinal cord injury (SCI). Single subject research design with repeated measures. Hospital-based biomechanics laboratory and user assessment of community use. Female with C6 AIS C SCI 30 years post injury. Lower extremity muscle activation with an implanted pulse generator and gait training. Walking speed, maximum distance, oxygen consumption, upper extremity (UE) forces, kinematics and self-assessment of technology. Short distance walking speed at one-year follow up with or without stimulation was not significantly different from baseline. However, average walking speed was significantly faster (0.22 m/s) with stimulation over longer distances than volitional walking (0.12 m/s). In addition, there was a 413% increase in walking distance from 95 m volitionally to 488 m with stimulation while oxygen consumption and maximum upper extremity forces decreased by 22 and 16%, respectively. Stimulation also produced significant (P ≤ 0.001) improvements in peak hip and knee flexion, ankle angle at foot off and at mid-swing. An implanted neuroprosthesis enabled a subject with incomplete SCI to walk longer distances with improved hip and knee flexion and ankle dorsiflexion resulting in decreased oxygen consumption and UE support. Further research is required to determine the robustness, generalizability and functional implications of implanted neuroprostheses for community ambulation after incomplete SCI.

Imaging of common breast implants and implant-related complications: A pictorial essay

Directory of Open Access Journals (Sweden)

Amisha T Shah

2016-01-01

Full Text Available The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance imaging of silicone breast implants, with its high sensitivity and specificity for detecting implant rupture, is the most reliable modality to asses implant integrity. Whichever imaging modality is used, the overall aim of imaging breast implants is to provide the pertinent information about implant integrity, detect implant failures, and to detect breast conditions unrelated to the implants, such as cancer.

Disease-Associated Particulates and Joint Inflammation; Mechanistic Insights and Potential Therapeutic Targets

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Olwyn R. Mahon

2018-05-01

Full Text Available It is now well established that intra-articular deposition of endogenous particulates, such as osteoarthritis-associated basic calcium phosphate crystals, gout-associated monosodium urate crystals, and calcium deposition disease-associated calcium pyrophosphate crystals, contributes to joint destruction through the production of cartilage-degrading enzymes and pro-inflammatory cytokines. Furthermore, exogenous wear-debris particles, generated from prosthetic implants, drive periprosthetic osteolysis which impacts on the longevity of total joint replacements. Over the last few years, significant insight has been gained into the mechanisms through which these particulates exert their effects. Not only has this increased our understanding of the pathological processes associated with crystal deposition but it has also led to the identification of a number of therapeutic targets to treat particulate-associated disease. In this review, we discuss recent developments regarding the cellular events triggered by joint-associated particulates, as well as future directions in therapy for particulate-related arthropathies.

Retrograde peri-implantitis

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Mohamed Jumshad

2010-01-01

Full Text Available Retrograde peri-implantitis constitutes an important cause for implant failure. Retrograde peri-implantitis may sometimes prove difficult to identify and hence institution of early treatment may not be possible. This paper presents a report of four cases of (the implant placed developing to retrograde peri-implantitis. Three of these implants were successfully restored to their fully functional state while one was lost due to extensive damage. The paper highlights the importance of recognizing the etiopathogenic mechanisms, preoperative assessment, and a strong postoperative maintenance protocol to avoid retrograde peri-implant inflammation.

Sporting Activity Is Reduced 11 Years After First-Generation Autologous Chondrocyte Implantation in the Knee Joint

DEFF Research Database (Denmark)

Erdle, Benjamin; Herrmann, Simon; Porichis, Stella

2017-01-01

BACKGROUND: Little is known about long-term sporting activity after periosteal autologous chondrocyte implantation (ACI-P) and its correlation to clinical, morphological, and ultrastructural cartilage characteristics on magnetic resonance imaging (MRI). PURPOSE: To evaluate long-term sporting...

Hip and knee joint loading during vertical jumping and push jerking.

Science.gov (United States)

Cleather, Daniel J; Goodwin, Jon E; Bull, Anthony M J

2013-01-01

The internal joint contact forces experienced at the lower limb have been frequently studied in activities of daily living and rehabilitation activities. In contrast, the forces experienced during more dynamic activities are not well understood, and those studies that do exist suggest very high degrees of joint loading. In this study a biomechanical model of the right lower limb was used to calculate the internal joint forces experienced by the lower limb during vertical jumping, landing and push jerking (an explosive exercise derived from the sport of Olympic weightlifting), with a particular emphasis on the forces experienced by the knee. The knee experienced mean peak loadings of 2.4-4.6×body weight at the patellofemoral joint, 6.9-9.0×body weight at the tibiofemoral joint, 0.3-1.4×body weight anterior tibial shear and 1.0-3.1×body weight posterior tibial shear. The hip experienced a mean peak loading of 5.5-8.4×body weight and the ankle 8.9-10.0×body weight. The magnitudes of the total (resultant) joint contact forces at the patellofemoral joint, tibiofemoral joint and hip are greater than those reported in activities of daily living and less dynamic rehabilitation exercises. The information in this study is of importance for medical professionals, coaches and biomedical researchers in improving the understanding of acute and chronic injuries, understanding the performance of prosthetic implants and materials, evaluating the appropriateness of jumping and weightlifting for patient populations and informing the training programmes of healthy populations. Copyright © 2012 Elsevier Ltd. All rights reserved.

Value of radiographic examination of the knee joint for the orthopedic surgeon

International Nuclear Information System (INIS)

Pietsch, M.; Hofmann, S.

2006-01-01

Extended radiographic examinations offer excellent options for diagnosis and strategy for treatment of the knee joint. The whole-leg radiograph is indispensable in measuring alignment for osteotomy or total knee arthroplasty (TKA). Fluoroscopically assisted varus-valgus stress radiographs provide the possibility for verifying mechanical function of the implanted knee prosthesis. Ultrasound examinations have been widely replaced by magnetic resonance imaging (MRI). MRI is the golden standard to examine intra-articular structures of the knee (meniscus, ligaments, cartilage) and surrounding soft tissue. For evaluating femoral and tibial torsion and determining axial rotation of TKA, computed tomography (CT) is best qualified. Imaging of the patellofemoral joint (patella instability) is difficult; CT scans in combination with true lateral radiographs seem to be helpful. (orig.) [de

Ceramic-on-ceramic bearing fractures in total hip arthroplasty: an analysis of data from the National Joint Registry.

Science.gov (United States)

Howard, D P; Wall, P D H; Fernandez, M A; Parsons, H; Howard, P W

2017-08-01

Ceramic-on-ceramic (CoC) bearings in total hip arthroplasty (THA) are commonly used, but concerns exist regarding ceramic fracture. This study aims to report the risk of revision for fracture of modern CoC bearings and identify factors that might influence this risk, using data from the National Joint Registry (NJR) for England, Wales, Northern Ireland and the Isle of Man. We analysed data on 223 362 bearings from 111 681 primary CoC THAs and 182 linked revisions for bearing fracture recorded in the NJR. We used implant codes to identify ceramic bearing composition and generated Kaplan-Meier estimates for implant survivorship. Logistic regression analyses were performed for implant size and patient specific variables to determine any associated risks for revision. A total of 222 852 bearings (99.8%) were CeramTec Biolox products. Revisions for fracture were linked to seven of 79 442 (0.009%) Biolox Delta heads, 38 of 31 982 (0.119%) Biolox Forte heads, 101 of 80 170 (0.126%) Biolox Delta liners and 35 of 31 258 (0.112%) Biolox Forte liners. Regression analysis of implant size revealed smaller heads had significantly higher odds of fracture (chi-squared 68.0, p ceramic type. Liner thickness was not predictive of fracture (p = 0.67). Body mass index (BMI) was independently associated with revision for both head fractures (odds ratio (OR) 1.09 per unit increase, p = 0.031) and liner fractures (OR 1.06 per unit increase, p = 0.006). We report the largest independent study of CoC bearing fractures to date. The risk of revision for CoC bearing fracture is very low but previous studies have underestimated this risk. There is good evidence that the latest generation of ceramic has greatly reduced the odds of head fracture but not of liner fracture. Small head size and high patient BMI are associated with an increased risk of ceramic bearing fracture. Cite this article: Bone Joint J 2017;99-B:1012-19. ©2017 The British Editorial Society of Bone & Joint Surgery.

The effect of radial head implant shape on radiocapitellar kinematics during in vitro forearm rotation.

Science.gov (United States)

Shannon, Hannah L; Deluce, Simon R; Giles, Joshua W; Johnson, James A; King, Graham J W

2015-02-01

A number of radial head implants are in clinical use for the management of radial head fractures and their sequelae. However, the optimal shape of a radial head implant to ensure proper tracking relative to the capitellum has not been established. This in vitro biomechanical study compared radiocapitellar joint kinematics for 3 radial head implant designs as well as the native head. Eight cadaveric upper extremities were tested using a forearm rotation simulator with the elbow at 90° of flexion. Motion of the radius relative to the capitellum was optically tracked. A stem was navigated into a predetermined location and cemented in place. Three unipolar implant shapes were tested: axisymmetric, reverse-engineered patient-specific, and population-based quasi-anatomic. The patient-specific and quasi-anatomic implants were derived from measurements performed on computed tomography models. Medial-lateral and anterior-posterior translation of the radial head with respect to the capitellum varied with forearm rotation and radial head condition. A significant difference in medial-lateral (P = .03) and anterior-posterior (P = .03) translation was found between the native radial head and the 3 implants. No differences were observed among the radial head conditions except for a difference in medial-lateral translation between the axisymmetric and patient-specific implants (P = .04). Radiocapitellar kinematics of the tested radial head implants were similar in all but one comparison, and all had different kinematics from the native radial head. Patient-specific radial head implants did not prove advantageous relative to conventional implant designs. The shape of the fixed stem unipolar radial head implants had little influence on radiocapitellar kinematics when optimally positioned in this testing model. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Influence of an interpositional spacer on the behaviour of the tibiofemoral joint: a finite element study.

Science.gov (United States)

Checa, S; Taylor, M; New, A

2008-10-01

Interpositional arthroplasty is considered by many surgeons for the treatment of isolated medial compartment osteoarthritis of the knee. In this procedure, an interpositional spacer is inserted into the medial compartment of the joint with no bone resection and no mechanical fixation. Major problems such as implant dislocation, severe pain or need for revision have been reported post-operatively. In this study, the kinematics of a knee implanted with an interpositional spacer made of either polyurethane or cobalt-chrome during walking, stair ascent and squatting cycles have been predicted and compared to the normal knee using finite element analysis. In addition, articular cartilage stress histories have been examined to obtain distributions of cumulative stress, a measure of the likelihood of articular cartilage degeneration. The insertion of a polyurethane interpositional spacer in the medial side of the knee did not affect knee kinematics as compared to the normal knee, but caused an increase of articular cartilage cumulative contact stress exposures in the medial compartment of the joint. The knee implanted with the Co-Cr spacer exhibited similar trends in knee kinematics, however significantly different ranges of motion were observed during some periods of the activity cycles, specifically during the first half of the walking cycle where lower ranges of motion were predicted. In addition, higher articular cartilage cumulative contact stress exposures were observed in both compartments of the knee. In both cases, cumulative contact stress exposures of the tibial articular cartilage were more affected than those of the femoral articular cartilage. These results suggest implant material as an important parameter in the design phase of interpositional spacers.

Cochlear implants in children implanted in Jordan: A parental overview.

Science.gov (United States)

Alkhamra, Rana A

2015-07-01

Exploring the perspective of parents on the cochlear implant process in Jordan. Sixty parents of deaf children were surveyed on the information gathering process prior to cochlear implant surgery, and their implant outcome expectations post-surgery. Whether child or parent characteristics may impact parents' post-surgical expectations was explored. Although parents used a variety of information sources when considering a cochlear implant, the ear, nose and throat doctor comprised their major source of information (60%). Parents received a range of information prior to cochlear implant but agreed (93.3%) on the need for a multidisciplinary team approach. Post-surgically, parents' expected major developments in the areas of spoken language (97%), and auditory skills (100%). Receiving education in mainstream schools (92%) was expected too. Parents perceived the cochlear implant decision as the best decision they can make for their child (98.3%). A significant correlation was found between parents contentment with the cochlear implant decision and expecting developments in the area of reading and writing (r=0.7). Child's age at implantation and age at hearing loss diagnosis significantly affected parents' post-implant outcome expectations (pparents agree on the need for a comprehensive multidisciplinary team approach during the different stages of the cochlear implant process. Parents' education about cochlear implants prior to the surgery can affect their post-surgical outcome expectations. The parental perspective presented in this study can help professionals develop better understanding of parents' needs and expectations and henceforth improve their services and support during the different stages of the cochlear implant process. Copyright © 2015. Published by Elsevier Ireland Ltd.

Influence of implant neck design on facial bone crest dimensions in the esthetic zone analyzed by cone beam CT: a comparative study with a 5-to-9-year follow-up.

Science.gov (United States)

Chappuis, Vivianne; Bornstein, Michael M; Buser, Daniel; Belser, Urs

2016-09-01

To examine the influence of two different neck designs on facial bone crest dimensions in esthetic single implant sites after a 5-to-9-year follow-up analyzed by cone beam computed tomography (CBCT). Sixty-one patients with an implant-borne single crown following early implant placement in the esthetic zone were enrolled. The test group consisted of a bone level (BL) neck design exhibiting a hydrophilic micro-rough surface combined with a platform-switching interface (PS) (n = 20). The control group comprised a soft tissue level (STL) neck design exhibiting a hydrophobic machined surface with a matching butt-joint interface (n = 41). Standardized clinical, radiologic, and esthetic parameters were applied. The facial bone crest dimensions were assessed by CBCT. Soft tissue parameters and pink esthetic scores yielded no significant differences between the two designs. Major differences were only observed at the implant shoulder level. The height of the facial bone crest for the BL design was located 0.2 mm above the implant shoulder level, whereas for the STL design, its location was 1.6 mm below. The width of the peri-implant saucer-like bone defect was reduced by 40% for the BL implant design. No differences were observed 2 mm below the shoulder level. The results of this comparative study suggest better crestal bone stability on the facial aspect of single implant sites in the esthetic zone for a BL design with a platform-switching concept when compared with STL implants with a butt-joint interface. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Long time follow up of implant therapy and treatment of peri-implantitis.

Science.gov (United States)

Roos-Jansåker, Ann-Marie

2007-01-01

Dental implants have become an often used alternative to replace missing teeth, resulting in an increasing percentage of the adult population with implant supported prosthesis. Although favourable long-term results of implant therapy have been reported, infections occur. Until recently few reports included data on peri-implant infections, possibly underestimating this complication of implant treatment. It is possible that some infections around implants develop slowly and that with time peri-implantitis will be a common complication to implant therapy as an increasing number of patients have had their implants for a long time (>10 years). Data on treatment of peri-implant lesions are scarce leaving the clinician with limited guidance regarding choice of treatment. The aim of this thesis was to study the frequency of implant loss and presence of peri-implant lesions in a group of patients supplied with Brånemark implants 9-14 years ago, and to relate these events to patient and site specific characteristics. Moreover three surgical treatment modalities for peri-implantitis were evaluated. The thesis is based on six studies; Studies I-III included 218 patients and 1057 implants followed for 9-14 years evaluating prevalence of, and factors related to implant loss (Paper I) and prevalence of peri-implant infections and related factors (Paper I-III). Study IV is a review describing different treatment modalities of peri-implant infections. Study V is a prospective cohort study involving 36 patients and 65 implants, evaluating the use of a bone substitute with or without the use of a resorbable membrane. Study VI is a case series with 12 patients and 16 implants, evaluating a bone substitute in combination with a resorbable membrane and submerged healing. This thesis demonstrated that: After 9-14 years the survival rates of dental implants are high (95.7%). Implant loss seems to cluster within patients and are related to periodontitis evidenced as bone loss on

Hip Implant Systems

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... Implants and Prosthetics Metal-on-Metal Hip Implants Hip Implants Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Hip implants are medical devices intended to restore mobility ...

Age at implantation and auditory memory in cochlear implanted children.

Science.gov (United States)

Mikic, B; Miric, D; Nikolic-Mikic, M; Ostojic, S; Asanovic, M

2014-05-01

Early cochlear implantation, before the age of 3 years, provides the best outcome regarding listening, speech, cognition an memory due to maximal central nervous system plasticity. Intensive postoperative training improves not only auditory performance and language, but affects auditory memory as well. The aim of this study was to discover if the age at implantation affects auditory memory function in cochlear implanted children. A total of 50 cochlear implanted children aged 4 to 8 years were enrolled in this study: early implanted (1-3y) n = 27 and late implanted (4-6y) n = 23. Two types of memory tests were used: Immediate Verbal Memory Test and Forward and Backward Digit Span Test. Early implanted children performed better on both verbal and numeric tasks of auditory memory. The difference was statistically significant, especially on the complex tasks. Early cochlear implantation, before the age of 3 years, significantly improve auditory memory and contribute to better cognitive and education outcomes.

Predicting Failure in Early Acute Prosthetic Joint Infection Treated With Debridement, Antibiotics, and Implant Retention: External Validation of the KLIC Score.

Science.gov (United States)

Löwik, Claudia A M; Jutte, Paul C; Tornero, Eduard; Ploegmakers, Joris J W; Knobben, Bas A S; de Vries, Astrid J; Zijlstra, Wierd P; Dijkstra, Baukje; Soriano, Alex; Wouthuyzen-Bakker, Marjan

2018-03-27

Debridement, antibiotics, and implant retention (DAIR) is a widely used treatment modality for early acute prosthetic joint infection (PJI). A preoperative risk score was previously designed for predicting DAIR failure, consisting of chronic renal failure (K), liver cirrhosis (L), index surgery (I), cemented prosthesis (C), and C-reactive protein >115 mg/L (KLIC). The aim of this study was to validate the KLIC score in an external cohort. We retrospectively evaluated patients with early acute PJI treated with DAIR between 2006 and 2016 in 3 Dutch hospitals. Early acute PJI was defined as infection-related death within 60 days after debridement. A total of 386 patients were included. Failure occurred in 148 patients (38.3%). Patients with KLIC scores of ≤2, 2.5-3.5, 4-5, 5.5-6.5, and ≥7 had failure rates of 27.9%, 37.1%, 49.3%, 54.5%, and 85.7%, respectively (P < .001). The receiver-operating characteristic curve showed an area under the curve of 0.64 (95% confidence interval 0.59-0.69). A KLIC score higher than 6 points showed a specificity of 97.9%. The KLIC score is a relatively good preoperative risk score for DAIR failure in patients with early acute PJI and appears to be most useful in clinical practice for patients with low or high KLIC scores. Copyright © 2018 Elsevier Inc. All rights reserved.

Combined arthroscopically assisted coraco- and acromioclavicular stabilization of acute high-grade acromioclavicular joint separations.

Science.gov (United States)

Hann, Carmen; Kraus, Natascha; Minkus, Marvin; Maziak, Nina; Scheibel, Markus

2018-01-01

Due to high rate of persisting dynamic posterior translation (DPT) following isolated coracoclavicular double-button technique for reconstruction of the acromioclavicular (AC) joint reported in the literature, an additional acromioclavicular cerclage was added to the procedure. The aim of this study was to evaluate the clinical and radiological results of patients with high-grade AC-joint instability treated with a double TightRope technique with an additional percutaneous acromioclavicular cerclage. Fifty-nine patients (6 f/53 m; median age 38.3 (range 21.5-63.4 years) who sustained an acute high-grade AC-joint dislocation (Rockwood type V) were treated using the above-mentioned technique. At the final follow-up, the constant score (CS), the subjective shoulder value (SSV), the Taft score (TF) and the acromioclavicular joint instability score (ACJI) as well as bilateral anteroposterior stress views with 10 kg of axial load and bilateral modified Alexander views were obtained. At a median follow-up of 26.4 (range 20.3-61.0) months, 34 patients scored a median of 90 (33-100) points in the CS, 90 (25-100) % in the SSV, 11 (4-12) points in the TF and 87 (43-100) points in the ACJI. The coracoclavicular (CC) distance was 12.1 (6.5-19.8) mm and the CC difference 2.0 (0.0-11.0) mm. Two patients (5.8%) showed a complete DPT of the AC joint, and fourteen patients (41.1%) displayed a partial DPT. The overall revision rate was 11.7%. Two patients presented implant irritation, one patient a recurrent instability, and one patient suffered from a local infection. The arthroscopically assisted and image-intensifier-controlled double TightRope technique with an additional percutaneous acromioclavicular cerclage leads to good and excellent clinical results after a follow-up of 2 years. The incidence of persisting dynamic horizontal translation is lower compared to isolated coracoclavicular stabilization. Thus, we recommend using the double TightRope implant with an additional

Breast reconstruction - implants

Science.gov (United States)

Breast implants surgery; Mastectomy - breast reconstruction with implants; Breast cancer - breast reconstruction with implants ... harder to find a tumor if your breast cancer comes back. Getting breast implants does not take as long as breast reconstruction ...

EPDM Rubber Modified by Nitrogen Plasma Immersion Ion Implantation.

Science.gov (United States)

Kondyurin, Alexey

2018-04-24

Ethylene-propylene diene monomer rubber (EPDM) was treated by plasma immersion ion implantation (PIII) with nitrogen ions of 20 keV energy and fluence from 10 13 to 10 16 ions/cm². The Fourier-transform infrared attenuated total reflection spectra, atomic force microscopy and optical microscopy showed significant structure changes of the surface. The analysis of an interface of PIII treated EPDM rubber with polyurethane binder showed a cohesive character of the adhesion joint fracture at the presence of solvent and interpreted as covalent bond network formation between the PIII treated rubber and the adhesive.

EPDM Rubber Modified by Nitrogen Plasma Immersion Ion Implantation

Directory of Open Access Journals (Sweden)

Alexey Kondyurin

2018-04-01

Full Text Available Ethylene-propylene diene monomer rubber (EPDM was treated by plasma immersion ion implantation (PIII with nitrogen ions of 20 keV energy and fluence from 1013 to 1016 ions/cm2. The Fourier-transform infrared attenuated total reflection spectra, atomic force microscopy and optical microscopy showed significant structure changes of the surface. The analysis of an interface of PIII treated EPDM rubber with polyurethane binder showed a cohesive character of the adhesion joint fracture at the presence of solvent and interpreted as covalent bond network formation between the PIII treated rubber and the adhesive.

Canadian Cardiovascular Society/Canadian Anesthesiologists' Society/Canadian Heart Rhythm Society joint position statement on the perioperative management of patients with implanted pacemakers, defibrillators, and neurostimulating devices.

Science.gov (United States)

Healey, Jeff S; Merchant, Richard; Simpson, Chris; Tang, Timothy; Beardsall, Marianne; Tung, Stanley; Fraser, Jennifer A; Long, Laurene; van Vlymen, Janet M; Manninen, Pirjo; Ralley, Fiona; Venkatraghavan, Lashmi; Yee, Raymond; Prasloski, Bruce; Sanatani, Shubhayan; Philippon, François

2012-01-01

There are more than 200,000 Canadians living with permanent pacemakers or implantable defibrillators, many of whom will require surgery or invasive procedures each year. They face potential hazards when undergoing surgery; however, with appropriate planning and education of operating room personnel, adverse device-related outcomes should be rare. This joint position statement from the Canadian Cardiovascular Society (CCS) and the Canadian Anesthesiologists' Society (CAS) has been developed as an accessible reference for physicians and surgeons, providing an overview of the key issues for the preoperative, intraoperative, and postoperative care of these patients. The document summarizes the limited published literature in this field, but for most issues, relies heavily on the experience of the cardiologists and anesthesiologists who contributed to this work. This position statement outlines how to obtain information about an individual's type of pacemaker or implantable defibrillator and its programming. It also stresses the importance of determining if a patient is highly pacemaker-dependent and proposes a simple approach for nonelective evaluation of dependency. Although the document provides a comprehensive list of the intraoperative issues facing these patients, there is a focus on electromagnetic interference resulting from electrocautery and practical guidance is given regarding the characteristics of surgery, electrocautery, pacemakers, and defibrillators which are most likely to lead to interference. The document stresses the importance of preoperative consultation and planning to minimize complications. It reviews the relative merits of intraoperative magnet use vs reprogramming of devices and gives examples of situations where one or the other approach is preferable. Copyright © 2012 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Implant Optimisation for Primary Hip Replacement in Patients over 60 Years with Osteoarthritis: A Cohort Study of Clinical Outcomes and Implant Costs Using Data from England and Wales.

Directory of Open Access Journals (Sweden)

Simon S Jameson

Full Text Available Hip replacement is one of the most commonly performed surgical procedures worldwide; hundreds of implant configurations provide options for femoral head size, joint surface material and fixation method with dramatically varying costs. Robust comparative evidence to inform the choice of implant is needed. This retrospective cohort study uses linked national databases from England and Wales to determine the optimal type of replacement for patients over 60 years undergoing hip replacement for osteoarthritis.Implants included were the commonest brand from each of the four types of replacement (cemented, cementless, hybrid and resurfacing; the reference prosthesis was the cemented hip procedure. Patient reported outcome scores (PROMs, costs and risk of repeat (revision surgery were examined. Multivariable analyses included analysis of covariance to assess improvement in PROMs (Oxford hip score, OHS, and EQ5D index (9159 linked episodes and competing risks modelling of implant survival (79,775 procedures. Cost of implants and ancillary equipment were obtained from National Health Service procurement data.EQ5D score improvements (at 6 months were similar for all hip replacement types. In females, revision risk was significantly higher in cementless hip prostheses (hazard ratio, HR = 2.22, p<0.001, when compared to the reference hip. Although improvement in OHS was statistically higher (22.1 versus 20.5, p<0.001 for cementless implants, this small difference is unlikely to be clinically important. In males, revision risk was significantly higher in cementless (HR = 1.95, p = 0.003 and resurfacing implants, HR = 3.46, p<0.001, with no differences in OHS. Material costs were lowest with the reference implant (cemented, range £1103 to £1524 and highest with cementless implants (£1928 to £4285. Limitations include the design of the study, which is intrinsically vulnerable to omitted variables, a paucity of long-term implant survival data (reflecting the

[Arthroscopic treatment of chondral lesions of the ankle joint. Evidence-based therapy].

Science.gov (United States)

Thomas, M; Jordan, M; Hamborg-Petersen, E

2016-02-01

Ankle sprains are the most relevant injuries of the lower extremities and can lead to damage to ligaments and osteochondral lesions. Up to 50 % of patients with a sprained ankle later develop a lesion of the cartilage in the ankle joint or an osteochondral lesion of the talus. This can lead to osteoarthritis of the injured ankle joint. Spontaneous healing is possible in all age groups in cases of a bone bruise in the subchondral bone but in isolated chondral injuries is only useful in pediatric patients. In many cases chondral and osteochondral injuries lead to increasing demarcation of the affected area and can result in progressive degeneration of the joint if not recognized in time. There also exist a certain number of osteochondral changes of the articular surface of the talus without any history of relevant trauma, which are collectively grouped under the term osteochondrosis dissecans. Perfusion disorders are discussed as one of many possible causes of these alterations. Nowadays, chondral and osteochondral defects can be treated earlier due to detection using very sensitive magnetic resonance imaging (MRI) and computed tomography (CT) techniques. The use of conservative treatment only has a chance of healing in pediatric patients. Conservative measures for adults should only be considered as adjuvant treatment to surgery.Based on a comprehensive analysis of the current literature, this article gives an overview and critical analysis of the current concepts for treatment of chondral and osteochondral injuries and lesions of the talus. With arthroscopic therapy curettage and microfracture of talar lesions are the predominant approaches or retrograde drilling of the defect is another option when the chondral coating is retained. Implantation of autologous chondral cells or homologous juvenile cartilage tissue is also possible with arthroscopic techniques. Osteochondral fractures (flake fracture) are usually performed as a mini-open procedure supported by

Ion implantation

International Nuclear Information System (INIS)

Johnson, E.

1986-01-01

It is the purpose of the present paper to give a review of surface alloy processing by ion implantation. However, rather than covering this vast subject as a whole, the survey is confined to a presentation of the microstructures that can be found in metal surfaces after ion implantation. The presentation is limited to alloys processed by ion implantation proper, that is to processes in which the alloy compositions are altered significantly by direct injection of the implanted ions. The review is introduced by a presentation of the processes taking place during development of the fundamental event in ion implantation - the collision cascade, followed by a summary of the various microstructures which can be formed after ion implantation into metals. This is compared with the variability of microstructures that can be achieved by rapid solidification processing. The microstructures are subsequently discussed in the light of the processes which, as the implantations proceed, take place during and immediately after formation of the individual collision cascades. These collision cascades define the volumes inside which individual ions are slowed down in the implanted targets. They are not only centres for vigorous agitation but also the sources for formation of excess concentrations of point defects, which will influence development of particular microstructures. A final section presents a selection of specific structures which have been observed in different alloy systems. (orig./GSCH)

Making Sense of Metal Allergy and Hypersensitivity to Metallic Implants in Relation to Hand Surgery.

Science.gov (United States)

Christensen, Thomas J; Samant, Shefali A; Shin, Alexander Y

2017-09-01

All metals implanted into a biological system undergo some degree of corrosion depending upon its composition. The electrochemical process of corrosion produces free metal ions, which may activate the host's immune system through a variety of mechanisms. Whereas dermal metal hypersensitivity is common, affecting 10% to 15% of the population, the immune reaction from implanted metals is much less common (allergy and hypersensitivity producing a multitude of patient symptoms. Superficial symptoms may be mild to severe forms of dermatitis, urticaria, pruritus, and vasculitis, whereas deep sequelae include metallosis-related pseudotumor, implant loosening, and joint stiffness. Currently, there are clinical tests to evaluate patients for metal hypersensitivity, but there is little agreement regarding the ideal timing and clinical situation prompting the work-up of a patient for a metal allergy or hypersensitivity. An understanding of the epidemiology, etiology, basic science, diagnostic testing, and treatment of patients with suspected metal allergy, as it pertains to the current literature, will aid orthopedic and plastic surgeons of all subspecialties in the management of patients requiring metallic implants. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Total carpometacarpal joint dislocation combined with trapezium fracture, trapezoid dislocation and hamate fracture

DEFF Research Database (Denmark)

Gvozdenovic, R; Vadstrup, Lars Soelberg

2015-01-01

and resulted from rupture of both transverse and longitudinal carpal columns. According to the Garcia-Elias classification of axial carpal disruptions, this particular injury mechanism was a combined axial-radial-ulnar type injury. These injuries are extremely rare and are only sporadically described...

In vitro cell quality of articular chondrocytes assigned for autologous implantation in dependence of specific patient characteristics

DEFF Research Database (Denmark)

Pestka, Jan M; Schmal, Hagen; Salzmann, Gian

2011-01-01

OBJECTIVE: Autologous chondrocyte implantation (ACI) is a well-established therapeutic option for the treatment of cartilage defects of the knee joint. Since information concerning the cellular aspects of ACI is still limited, the aim of the present study was to investigate relevant differences...... between chondrocyte quality after in vitro cultivation and possible correlations with patient-specific factors. DESIGN: Cell quality of 252 consecutive ACI patients was assessed after chondrocyte in vitro expansion by determination of the expression of cartilage relevant surface marker CD44 and cartilage......, aggrecan or collagen type II nor cell density or viability after proliferation seemed to correlate with the grade of joint degeneration, defect aetiology or patient gender. However, chondrocytes harvested from the knee joints of patients at less than 20 years of age showed significantly higher expression...

Does the number of implants have any relation with peri-implant disease?

Directory of Open Access Journals (Sweden)

Bernardo Born PASSONI

2014-10-01

Full Text Available Objective: The aim of this study was to evaluate the relationship between the number of pillar implants of implant-supported fixed prostheses and the prevalence of periimplant disease. Material and Methods: Clinical and radiographic data were obtained for the evaluation. The sample consisted of 32 patients with implant-supported fixed prostheses in function for at least one year. A total of 161 implants were evaluated. Two groups were formed according to the number of implants: G1 ≤5 implants and G2 >5 implants. Data collection included modified plaque index (MPi, bleeding on probing (BOP, probing depth (PD, width of keratinized mucosa (KM and radiographic bone loss (BL. Clinical and radiographic data were grouped for each implant in order to conduct the diagnosis of mucositis or peri-implantitis. Results: Clinical parameters were compared between groups using Student’s t test for numeric variables (KM, PD and BL and Mann-Whitney test for categorical variables (MPi and BOP. KM and BL showed statistically significant differences between both groups (p<0.001. Implants from G1 – 19 (20.43% – compared with G2 – 26 (38.24% – showed statistically significant differences regarding the prevalence of peri-implantitis (p=0.0210. Conclusion: It seems that more than 5 implants in total fixed rehabilitations increase bone loss and consequently the prevalence of implants with periimplantitis. Notwithstanding, the number of implants does not have any influence on the prevalence of mucositis.

A new rabbit model of implant-related biofilm infection: development and evaluation

Science.gov (United States)

Chu, Cheng-Bing; Zeng, Hong; Shen, Ding-Xia; Wang, Hui; Wang, Ji-Fang; Cui, Fu-Zhai

2016-03-01

This study is to establish a rabbit model for human prosthetic joint infection and biofilm formation. Thirty-two healthy adult rabbits were randomly divided into four groups and implanted with stainless steel screws and ultra-high molecular weight polyethylene (UHMWPE) washers in the non-articular surface of the femoral lateral condyle of the right hind knees. The rabbit knee joints were inoculated with 1 mL saline containing 0, 102, 103, 104 CFU of Staphylococcus epidermidis ( S. epidermidis) isolated from the patient with total knee arthroplasty (TKA) infection, respectively. On the 14th postoperative day, the UHMWPE washers from the optimal 103 CFU group were further examined. The SEM examination showed a typical biofilm construction that circular S. epidermidis were embedded in a mucous-like matrix. In addition, the LCSM examination showed that the biofilm consisted of the polysaccharide stained bright green fluorescence and S. epidermidis radiating red fluorescence. Thus, we successfully create a rabbit model for prosthetic joint infection and biofilm formation, which should be valuable for biofilm studies.

Tribological properties of nitrogen implanted and boron implanted steels

International Nuclear Information System (INIS)

Kern, K.T.

1996-01-01

Samples of a steel with high chrome content was implanted separately with 75 keV nitrogen ions and with 75 keV boron ions. Implanted doses of each ion species were 2-, 4-, and 8 x 10 17 /cm 2 . Retained doses were measured using resonant non-Rutherford Backscattering Spectrometry. Tribological properties were determined using a pin-on-disk test with a 6-mm diameter ruby pin with a velocity of 0.94 m/min. Testing was done at 10% humidity with a load of 377 g. Wear rate and coefficient of friction were determined from these tests. While reduction in the wear rate for nitrogen implanted materials was observed, greater reduction (more than an order of magnitude) was observed for boron implanted materials. In addition, reduction in the coefficient of friction for high-dose boron implanted materials was observed. Nano-indentation revealed a hardened layer near the surface of the material. Results from grazing incidence x-ray diffraction suggest the formation of Fe 2 N and Fe 3 N in the nitrogen implanted materials and Fe 3 B in the boron implanted materials. Results from transmission electron microscopy will be presented

Cochlear implantation in late-implanted adults with prelingual deafness.

Science.gov (United States)

Most, Tova; Shrem, Hadas; Duvdevani, Ilana

2010-01-01

The purpose of this study was to examine the effect of cochlear implantation (CI) on prelingually deafened participants who were implanted as adults. The effect of the CI was examined with regard to the following variables: communication, family, social skills, education, and work satisfaction with one's life, loneliness, and self-esteem. Thirty-eight adults participated. Four self-report questionnaires were used at 2 points in time: before and after CI. The research findings show significant differences in the reports of most variables before and after implantation. The participants felt better with regard to communication, social skills, education, and work and satisfaction with one's life after implantation in comparison to their feelings before implantation. Furthermore, they felt less lonely after implantation. However, there were no significant differences before and after implantation regarding their feelings within the family and regarding their self-esteem. The results demonstrated the need to evaluate the benefits resulting from the CI not only with traditional clinical measures but with additional measures as well. Furthermore, they demonstrated the benefit of the CI on the positive psychosociological implications of prelingually deafened adults. Copyright © 2010 Elsevier Inc. All rights reserved.

Histology of a dental implant with a platform switched implant-abutment connection

Directory of Open Access Journals (Sweden)

Vittoria Perrotti

2011-10-01

Full Text Available Background: Peri-implant crestal bone must be stable for aesthetic reasons. Aim of this study was a histologic analysis of an implant with a platform switched implant-abutment connection. Materials and methods: A 32-year-old male patient participated in this study. The patient needed a bilateral mandibular restoration. Four implants were used, and were immediately restored and loaded the same day of insertion. After a 6 weeks healing period, one implant with platform-switched abutment was retrieved with trephine. Before retrieval the implant was osseointegrated and not mobile. On one side of the implant, a 1 mm resorption of the crestal bone was present. On the contrary, on the other side no bone resorption had occurred and about 1 mm of bone was present over the implant shoulder. Results: The bone-implant contact percentage was 65.1 ± 6.3 %. Platform- switching could help in maintaining the height of the peri-implant crestal bone.

Effectiveness of Implant Therapy Analyzed in a Swedish Population: Prevalence of Peri-implantitis.

Science.gov (United States)

Derks, J; Schaller, D; Håkansson, J; Wennström, J L; Tomasi, C; Berglundh, T

2016-01-01

Peri-implantitis is an inflammatory disease affecting soft and hard tissues surrounding dental implants. As the global number of individuals that undergo restorative therapy through dental implants increases, peri-implantitis is considered as a major and growing problem in dentistry. A randomly selected sample of 588 patients who all had received implant-supported therapy 9 y earlier was clinically and radiographically examined. Prevalence of peri-implantitis was assessed and risk indicators were identified by multilevel regression analysis. Forty-five percent of all patients presented with peri-implantitis (bleeding on probing/suppuration and bone loss >0.5 mm). Moderate/severe peri-implantitis (bleeding on probing/suppuration and bone loss >2 mm) was diagnosed in 14.5%. Patients with periodontitis and with ≥4 implants, as well as implants of certain brands and prosthetic therapy delivered by general practitioners, exhibited higher odds ratios for moderate/severe peri-implantitis. Similarly, higher odds ratios were identified for implants installed in the mandible and with crown restoration margins positioned ≤1.5 mm from the crestal bone at baseline. It is suggested that peri-implantitis is a common condition and that several patient- and implant-related factors influence the risk for moderate/severe peri-implantitis (ClinicalTrials.gov NCT01825772). © International & American Associations for Dental Research 2015.

Bilateral Poly Implant Prothèse Implant Rupture: An Uncommon Presentation

Directory of Open Access Journals (Sweden)

Peter Mallon

2013-07-01

Full Text Available Summary: A woman in her 50s underwent delayed bilateral Poly Implant Prothèse implant reconstruction following mastectomy for breast cancer. Symptoms of implant rupture developed 43 months after surgery with an erythematous rash on her trunk. The rash then spread to her reconstructed breast mounds. Initial ultrasound scan and magnetic resonance imaging were normal; however, subsequent magnetic resonance imaging demonstrated left implant rupture only. In theater, following removal of both implants, both were found to be ruptured. The rash on her trunk resolved within 3 weeks in the postoperative period. Chemical analyses of silicone in both implants confirmed a nonauthorized silicone source; in addition, the chemical structure was significantly different between the left and right implant, perhaps explaining the variation in presentation.

Axial displacements in external and internal implant-abutment connection.

Science.gov (United States)

Lee, Ji-Hye; Kim, Dae-Gon; Park, Chan-Jin; Cho, Lee-Ra

2014-02-01

The purpose of this study was to evaluate the axial displacement of the abutments during clinical procedures by the tightening torque and cyclic loading. Two different implant-abutment connection systems were used (external butt joint connection [EXT]; internal tapered conical connection [INT]). The master casts with two implant replicas, angulated 10° from each other, were fabricated for each implant connection system. Four types of impression copings were assembled and tightened with the corresponding implants (hex transfer impression coping, non-hex transfer impression coping, hex pick-up impression coping, non-hex pick-up impression coping). Resin splinted abutments and final prosthesis were assembled. The axial displacement was measured from the length of each assembly, which was evaluated repeatedly, after 30 Ncm torque tightening. After 250 N cyclic loading of final prosthesis for 1,000,000 cycles, additional axial displacement was recorded. The mean axial displacement was statistically analyzed (repeated measured ANOVA). There was more axial displacement in the INT group than that of the EXT group in impression copings, resin splinted abutments, and final prosthesis. Less axial displacement was found at 1-piece non-hex transfer type impression coping than other type of impression copings in the INT group. There was more axial displacement at the final prosthesis than resin splinted abutments in the INT and the EXT groups. After 250 N cyclic loading of final prosthesis, the INT group showed more axial displacement than that of the EXT group. Internal tapered conical connection demonstrated a varying amount of axial displacement with tightening torque and cyclic loading. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

Complications after cardiac implantable electronic device implantations

DEFF Research Database (Denmark)

Kirkfeldt, Rikke Esberg; Johansen, Jens Brock; Nohr, Ellen Aagaard

2013-01-01

Complications after cardiac implantable electronic device (CIED) treatment, including permanent pacemakers (PMs), cardiac resynchronization therapy devices with defibrillators (CRT-Ds) or without (CRT-Ps), and implantable cardioverter defibrillators (ICDs), are associated with increased patient...

Management of peri-implantitis

Directory of Open Access Journals (Sweden)

Jayachandran Prathapachandran

2012-01-01

Full Text Available Peri-implantitis is a site-specific infectious disease that causes an inflammatory process in soft tissues, and bone loss around an osseointegrated implant in function. The etiology of the implant infection is conditioned by the status of the tissue surrounding the implant, implant design, degree of roughness, external morphology, and excessive mechanical load. The microorganisms most commonly associated with implant failure are spirochetes and mobile forms of Gram-negative anaerobes, unless the origin is the result of simple mechanical overload. Diagnosis is based on changes of color in the gingiva, bleeding and probing depth of peri-implant pockets, suppuration, X-ray, and gradual loss of bone height around the tooth. Treatment will differ depending upon whether it is a case of peri-implant mucositis or peri-implantitis. The management of implant infection should be focused on the control of infection, the detoxification of the implant surface, and regeneration of the alveolar bone. This review article deals with the various treatment options in the management of peri-implantitis. The article also gives a brief description of the etiopathogenesis, clinical features, and diagnosis of peri-implantitis.

Experimental study on bone tissue reaction around HA implants radiated after implantation

International Nuclear Information System (INIS)

Kudo, Masato; Matsui, Yoshiro; Tamura, Sayaka; Chen, Xuan; Uchida, Haruo; Mori, Kimie; Ohno, Kohsuke; Michi, Ken-ichi

1998-01-01

This study was conducted to investigate histologically and histomorphometrically the tissue reaction around hydroxylapatite (HA) implants that underwent irradiation in 3 different periods in the course of bone healing after implantation. The cylindrical high-density HA implants were implanted in 48 Japanese white rabbit mandibles. A single 15 Gy dose was applied to the mandible 5, 14, or 28 days after implantation. The rabbits were sacrificed 7, 14, 28, and 90 days after irradiation. Nonirradiated rabbits were used as controls. CMR, labeling with tetracycline and calcein, and non-decalcified specimens stained with toluidine blue were used for histological analyses and histomorphometric measurements. The results were as follows: In the rabbits irradiated 5 days after implantation, the HA-bone contact was observed later than that in the controls and the bone-implant contact surface ratio was lower than that in the controls at examination because necrosis of the newly-formed bone occurred just after irradiation. HA-bone contact of the rabbits irradiated 14 and 28 days after implantation was similar to that of the controls. And, bone remodeling was suppressed in rabbits of each group sacrificed at 90 days after irradiation. The results suggested that a short interval between implantation and irradiation causes direct contact between HA implant and bone and a long lapse of time before irradiation hardly affects the bone-implant contact, but delays bone remodeling. Therefore, it is necessary to prevent overloading the HA implants irradiated after implantation and pay utmost attention to conditions around the bone-implant contact. (author)

One-stage explant-implant procedure of exposed porous orbital implants

DEFF Research Database (Denmark)

Toft, Peter B; Rasmussen, Marie L Roed; Prause, Jan Ulrik

2011-01-01

Purpose:  To investigate the risks of implant exposure after a combined explant-implant procedure in patients with an exposed porous orbital implant. Methods:  Twenty-four consecutive patients who had a combined explant-implant procedure of an exposed hydroxyapatite (21) or porous polyethylene (3...... at the same procedure in sockets without profound signs of infection. The procedure carries a possible risk of poor motility....

Two-stage implant systems.

Science.gov (United States)

Fritz, M E

1999-06-01

Since the advent of osseointegration approximately 20 years ago, there has been a great deal of scientific data developed on two-stage integrated implant systems. Although these implants were originally designed primarily for fixed prostheses in the mandibular arch, they have been used in partially dentate patients, in patients needing overdentures, and in single-tooth restorations. In addition, this implant system has been placed in extraction sites, in bone-grafted areas, and in maxillary sinus elevations. Often, the documentation of these procedures has lagged. In addition, most of the reports use survival criteria to describe results, often providing overly optimistic data. It can be said that the literature describes a true adhesion of the epithelium to the implant similar to adhesion to teeth, that two-stage implants appear to have direct contact somewhere between 50% and 70% of the implant surface, that the microbial flora of the two-stage implant system closely resembles that of the natural tooth, and that the microbiology of periodontitis appears to be closely related to peri-implantitis. In evaluations of the data from implant placement in all of the above-noted situations by means of meta-analysis, it appears that there is a strong case that two-stage dental implants are successful, usually showing a confidence interval of over 90%. It also appears that the mandibular implants are more successful than maxillary implants. Studies also show that overdenture therapy is valid, and that single-tooth implants and implants placed in partially dentate mouths have a success rate that is quite good, although not quite as high as in the fully edentulous dentition. It would also appear that the potential causes of failure in the two-stage dental implant systems are peri-implantitis, placement of implants in poor-quality bone, and improper loading of implants. There are now data addressing modifications of the implant surface to alter the percentage of

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.

3D perfusion bioreactor-activated porous granules on implant fixation and early bone formation in sheep.

Science.gov (United States)

Ding, Ming; Henriksen, Susan S; Martinetti, Roberta; Overgaard, Søren

2017-11-01

Early fixation of total joint arthroplasties is crucial for ensuring implant survival. An alternative bone graft material in revision surgery is needed to replace the current gold standard, allograft, seeing that the latter is associated with several disadvantages. The incubation of such a construct in a perfusion bioreactor has been shown to produce viable bone graft materials. This study aimed at producing larger amounts of viable bone graft material (hydroxyapatite 70% and β-tricalcium-phosphate 30%) in a novel perfusion bioreactor. The abilities of the bioreactor-activated graft material to induce early implant fixation were tested in a bilateral implant defect model in sheep, with allograft as the control group. Defects were bilaterally created in the distal femurs of the animals, and titanium implants were inserted. The concentric gaps around the implants were randomly filled with either allograft, granules, granules with bone marrow aspirate or bioreactor-activated graft material. Following an observation time of 6 weeks, early implant fixation and bone formation were assessed by micro-CT scanning, mechanical testing, and histomorphometry. Bone formations were seen in all groups, while no significant differences between groups were found regarding early implant fixation. The microarchitecture of the bone formed by the synthetic graft materials resembled that of allograft. Histomorphometry revealed that allograft induced significantly more bone and less fibrous tissue (p formation was observed in all groups, while the bioreactor-activated graft material did not reveal additional effects on early implant fixation comparable to allograft in this model. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2465-2476, 2017. © 2016 Wiley Periodicals, Inc.

Impact of implant design on primary stability of orthodontic mini-implants.

Science.gov (United States)

Wilmes, Benedict; Ottenstreuer, Stephanie; Su, Yu-Yu; Drescher, Dieter

2008-01-01

Skeletal anchorage with mini-implants has greatly broadened the treatment possibilities in orthodontics over the last few years. To reduce implant failure rates, it is advisable to obtain adequate primary stability. The aim of this study was to quantitatively analyze the impact of implant design and dimension on primary stability. Forty-two porcine iliac bone segments were prepared and embedded in resin. To evaluate the primary stability, we documented insertion torques of the following mini-implants: Aarhus Screw, AbsoAnchor, LOMAS, Micro-Anchorage-System, ORLUS and Spider Screw. In each bone, five Dual Top Screws were inserted for reference purposes to achieve comparability among the specimens. We observed wide variation in insertion torques and hence primary stability, depending on mini-implant design and dimension; the great impact that mini-implant diameter has on insertion torques was particularly conspicuous. Conical mini-implants achieved higher primary stabilities than cylindrical designs. The diameter and design of the mini-implant thread have a distinctive impact on primary stability. Depending on the region of insertion and local bone quality, the choice of the mini-implant design and size is crucial to establish sufficient primary stability.

Effect of implant position, angulation, and attachment height on peri-implant bone stress associated with mandibular two-implant overdentures: a finite element analysis.

Science.gov (United States)

Hong, Hae Ryong; Pae, Ahran; Kim, Yooseok; Paek, Janghyun; Kim, Hyeong-Seob; Kwon, Kung-Rock

2012-01-01

The aim of this study was to analyze and compare the level and distribution of peri-implant bone stresses associated with mandibular two-implant overdentures with different implant positions. Mathematical models of mandibles and overdentures were designed using finite element analysis software. Two intraosseous implants and ball attachment systems were placed in the interforaminal region. The overdenture, which was supported by the two implants, was designed to withstand bilateral and unilateral vertical masticatory loads (total 100 N). In all, eight types of models, which differed according to assigned implant positions, height of attachments, and angulation, were tested: MI (model with implants positioned in the lateral incisor sites), MC (implants in canine sites), MP (implants in premolar sites), MI-Hi (greater height of attachments), MC-M (canine implants placed with mesial inclination), MC-D (canine implants placed with distal inclination), MC-B (canine implants placed with buccal inclination), and MC-L (canine implants placed with lingual inclination). Peri-implant bone stress levels associated with overdentures retained by lateral incisor implants resulted in the lowest stress levels and the highest efficiency in distributing peri-implant stress. MI-Hi showed increased stress levels and decreased efficiency in stress distribution. As the implants were inclined, stress levels increased and the efficiency of stress distribution decreased. Among the inclined models, MC-B showed the lowest stress level and best efficiency in stress distribution. The lowest stress and the best stability of implants in mandibular two-implant overdentures were obtained when implants were inserted in lateral incisor areas with shorter attachments and were placed parallel to the long axes of the teeth.

Intravitreal dexamethasone implants for the treatment of refractory scleritis combined with uveitis in adult-onset Still's disease: a case report.

Science.gov (United States)

Ahn, Seong Joon; Hwang, Sun Jin; Lee, Byung Ro

2016-11-08

Adult-onset Still's disease is a systemic inflammatory disease which presents with uveitis and scleritis in the eye. Intravitreal dexamethasone implants are used for the treatment of refractory uveitis. A 19-year-old woman diagnosed to have adult-onset Still's disease for fevers, joint pain, and a salmon-colored bumpy rash presented with scleritis and uveitis in the left eye. Topical and systemic steroids with oral methotrexate failed to control the inflammation. We performed intravitreal injections of dexamethasone implants for side effects of steroid and refractory ocular inflammation. The therapy resulted in improvements in the patient's uveitis with reductions in scleral vessel engorgement and redness. There was no recurrence of uveitis or scleritis during 4 months following treatment. Intravitreal injections of dexamethasone implants may result in clinical improvements of refractory scleritis combined with uveitis.

Osteogenic protein-1 increases the fixation of implants grafted with morcellised bone allograft and ProOsteon bone substitute: an experimental study in dogs

DEFF Research Database (Denmark)

Jensen, T B; Overgaard, S; Lind, M

2007-01-01

Impacted bone allograft is often used in revision joint replacement. Hydroxyapatite granules have been suggested as a substitute or to enhance morcellised bone allograft. We hypothesised that adding osteogenic protein-1 to a composite of bone allograft and non-resorbable hydroxyapatite granules...... (ProOsteon) would improve the incorporation of bone and implant fixation. We also compared the response to using ProOsteon alone against bone allograft used in isolation. We implanted two non-weight-bearing hydroxyapatite-coated implants into each proximal humerus of six dogs, with each implant...... surrounded by a concentric 3 mm gap. These gaps were randomly allocated to four different procedures in each dog: 1) bone allograft used on its own; 2) ProOsteon used on its own; 3) allograft and ProOsteon used together; or 4) allograft and ProOsteon with the addition of osteogenic protein-1. After three...

A positive bacterial culture during re-implantation is associated with a poor outcome in two-stage exchange arthroplasty for deep infection.

Science.gov (United States)

Akgün, D; Müller, M; Perka, C; Winkler, T

2017-11-01

The aim of this study was to identify the incidence of positive cultures during the second stage of a two-stage revision arthroplasty and to analyse the association between positive cultures and an infection-free outcome. This single-centre retrospective review of prospectively collected data included patients with a periprosthetic joint infection (PJI) of either the hip or the knee between 2013 and 2015, who were treated using a standardised diagnostic and therapeutic algorithm with two-stage exchange. Failure of treatment was assessed according to a definition determined by a Delphi-based consensus. Logistic regression analysis was performed to assess the predictors of positive culture and risk factors for failure. The mean follow-up was 33 months (24 to 48). A total of 163 two-stage revision arthroplasties involving 84 total hip arthroplasties (THAs) and 79 total knee arthroplasties (TKAs) were reviewed. In 27 patients (16.6%), ≥ 1 positive culture was identified at re-implantation and eight (29.6%) of these subsequently failed compared with 20 (14.7%) patients who were culture-negative. The same initially infecting organism was isolated at re-implantation in nine of 27 patients (33.3%). The organism causing re-infection in none of the patients was the same as that isolated at re-implantation. The risk of the failure of treatment was significantly higher in patients with a positive culture (odds ratio (OR) 1.7; 95% confidence interval (CI) 1.0 to 3.0; p = 0.049) and in patients with a higher Charlson Comorbidity Index (OR 1.5; 95% CI 1.6 to 1.8; p = 0.001). Positive culture at re-implantation was independently associated with subsequent failure. Surgeons need to be aware of this association and should consider the medical optimisation of patients with severe comorbidities both before and during treatment. Cite this article: Bone Joint J 2017;99-B:1490-5. ©2017 The British Editorial Society of Bone & Joint Surgery.

Implantation of β-emitters on biomedical implants: 32 P isotropic ion implantation using a coaxial plasma reactor

International Nuclear Information System (INIS)

Fortin, M.A.; Paynter, R.W.; Sarkissian, A.; Stansfield, B.L.; Terreault, B.; Dufresne, V.

2003-01-01

The development of endovascular brachytherapy and the treatment of certain types of cancers (liver, lung, prostate) often require the use of beta-emitters, sometimes in the form of radioisotope-implanted devices. Among the most commonly used isotopes figures 32 P, a pure beta-emitter (maximum energy: 1.7 MeV), of which the path in biological tissues is of a few cm, restricting the impact of electron bombardment to the immediate environment of the implant. Several techniques and processes have been tried to elaborate surfaces and devices showing strongly bonded, or implanted 32 P. Anodizing, vapor phase deposition, grafting of oligonucleotides, as well as ion implantation processes have been investigated by several research groups as methods to implant beta-radioisotopes into surfaces. A coaxial plasma reactor was developed at INRS to implant radioisotopes into cylindrical metallic objects, such as coronary stents commonly used in angioplasty procedures. The dispersion of 32 P atoms on the interior surfaces of the chamber can be investigated using radiographs, contributing to image the plasma ion transport mechanisms that guide the efficiency of the implantation procedure. The amount of radioactivity on the wall liner, on the internal components, and on the biomedical implants are quantified using a surface barrier detector. A comparative study establishes a relationship between the gray scale of the radiographs, and dose measurements. A program was developed to convert the digitized images into maps showing surface dose density in mCi/cm 2 . An integration process allows the quantification of the doses on the walls and components of the reactor. Finally, the resulting integral of the 32 P dose is correlated to the initial amount of radioactivity inserted inside the implanter before the dismantling procedure. This method could be introduced as a fast and reliable way to test, qualify and assess the amount of radioactivity present on the as-produced implants

[Development of polyaxial locking plate screw system of sacroiliac joint].

Science.gov (United States)

Fan, Weijie; Xie, Xuesong; Zhou, Shuping; Zhang, Yonghu

2014-09-01

To develop an instrument for sacroiliac joint fixation with less injury and less complications. Firstly, 18 adult pelvic specimens (8 males and 10 females) were used to measure the anatomical data related to the locking plates and locking screws on the sacrum and ilium, and the polyaxial locking plate screw system of the sacroiliac joint was designed according to the anatomic data. This system was made of medical titanium alloy. Then 4 adult male plevic specimens were harvested and the experiment was divided into 3 groups: group A (normal pelvic), group B (the dislocated sacroiliac joint fixed with sacroiliac screws), and group C (the dislocated sacroiliac joint fixed with polyaxial locking plate screw system). The vertical displacement of sacroiliac joint under the condition of 0-700 N vertical load and the horizontal displacement on angle under the condition of 0-12 N·m torsional load were compared among the 3 groups by using the biological material test system. Finally, the simulated application test was performed on 1 adult male cadaveric specimen to observe soft tissue injury and the position of the locking plate and screw by X-ray films. According to the anatomic data of the sacrum and ilium, the polyaxial locking plate screw system of the sacroiliac joint was designed. The biomechanical results showed that the vertical displacement of the sacroiliac joint under the condition of 0-700 N vertical load in group A was significantly bigger than that in group B and group C (P 0.05). The horizontal displacement on angle under the condition of 0-12 N·m torsional load in group A was significantly less than that in group B and group C (P 0.05). The test of simulating application showed that the specimen suffered less soft tissue injury, and this instrument could be implanted precisely and safely. The polyaxial locking plate screw system of the sacroiliac joint has the advantages of smaller volume and less injury; polyaxial fixation enables flexible adjustment screw

Early implant-associated osteomyelitis results in a peri-implanted bacterial reservoir

DEFF Research Database (Denmark)

Jensen, Louise Kruse; Koch, Janne; Aalbæk, Bent

2017-01-01

weight of Staphylococcus aureus or saline was inserted into the right tibial bone of 12 pigs. The animals were consecutively killed on day 2, 4 and 6 following implantation. Bone tissue around the implant was histologically evaluated. Identification of S. aureus was performed immunohistochemically...... on tissue section and with scanning electron microscopy and peptide nucleic acid in situ hybridization on implants. The distance of the peri-implanted pathological bone area (PIBA), measured perpendicular to the implant, was significantly larger in infected animals compared to controls (p = 0...

99m technetium-MDP bone scintigraphy in evaluation of painful joint prosthesis

International Nuclear Information System (INIS)

Milosevic, D.; Jaukovic, M.; Jaukovic, Lj.; Ajdinovic, B.

2004-01-01

In addition of clinical evaluation and x-ray radiography, the diagnosis of a loose joint prosthesis is often made by nuclear medicine imaging techniques. Differentiation between loosening and infected prosthesis is important for better treatment of those patients. Aim: The aim of this study was to reevaluate the scintigraphic patterns in patients with painful hip of knee arthroplasty. Material and Method: From 1996. to 2003. forty patients aged 49-78 years were referred for evaluation of possible loosening/infection joint prosthesis: 36 pts with 39 total/ partial hip prosthesis, 1 pt with knee prosthesis and 3 pts with history of previously extracted hip prosthesis due to infection. Whole body acquisition had been performed with a single head gamma camera three hours after the injection of 740 MBq 99m Tc-MDP. Scans were classified as: positive for loosening if abnormal uptake was shown at the tip of the prosthesis; positive for infection if diffuse abnormal uptake was shown around the implant; negative and indeterminate scans. Scintigraphic findings were compared to clinical follow up, histology or cultures. Results: Positive findings were found in 17 bone scans strongly suggesting loosening in 10 cases, infection of prosthesis in 4 cases and both loosening/infection in 3 cases. Bone scintigraphy was normal in 11pts. Scans of three pts with previously extracted hip prosthesis and scheduled for reimplatation, showed inhomogeneously and mildly increased uptake in femur. Most of scans classified as indeterminate (n=12) showed slightly increased tracer uptake in region of acetabular roof, greater or lesser tho chanter, suggesting bone remodeling due to the presence of implant, rather than loosening. Conclusion: 99m Tc-MDP bone scintigraphy had a significant role in assessing the painful joint prosthesis. Complementary diagnostic procedures should be considered in indeterminate scintiscans. (authors)

Influence of different implant materials on the primary stability of orthodontic mini-implants

OpenAIRE

Chin-Yun Pan; Szu-Ting Chou; Yu-Chuan Tseng; Yi-Hsin Yang; Chao-Yi Wu; Ting-Hsun Lan; Pao-Hsin Liu; Hong-Po Chang

2012-01-01

This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm). The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm) and stainless steel mini-implants 10 mm in length. The mini-implants w...

Cartilage Health in Knees Treated with Metal Resurfacing Implants or Untreated Focal Cartilage Lesions: A Preclinical Study in Sheep.

Science.gov (United States)

Martinez-Carranza, Nicolas; Hultenby, Kjell; Lagerstedt, Anne Sofie; Schupbach, Peter; Berg, Hans E

2017-07-01

Background Full-depth cartilage lesions do not heal and the long-term clinical outcome is uncertain. In the symptomatic middle-aged (35-60 years) patient, treatment with metal implants has been proposed. However, the cartilage health surrounding these implants has not been thoroughly studied. Our objective was to evaluate the health of cartilage opposing and adjacent to metal resurfacing implants. Methods The medial femoral condyle was operated in 9 sheep bilaterally. A metallic resurfacing metallic implant was immediately inserted into an artificially created 7.5 mm defect while on the contralateral knee the defect was left untreated. Euthanasia was performed at 6 months. Six animals, of similar age and study duration, from a previous study were used for comparison in the evaluation of cartilage health adjacent to the implant. Cartilage damage to joint surfaces within the knee, cartilage repair of the defect, and cartilage adjacent to the implant was evaluated macroscopically and microscopically. Results Six animals available for evaluation of cartilage health within the knee showed a varying degree of cartilage damage with no statistical difference between defects treated with implants or left untreated ( P = 0.51; 95% CI -3.7 to 6.5). The cartilage adjacent to the implant (score 0-14; where 14 indicates no damage) remained healthy in these 6 animals showing promising results (averaged 10.5; range 9-11.5, SD 0.95). Cartilage defects did not heal in any case. Conclusion Treatment of a critical size focal lesion with a metal implant is a viable alternative treatment.

Ligament Augmentation and Reconstruction System Failures in Repair of Grade V Acromioclavicular Joint Dislocation

Directory of Open Access Journals (Sweden)

Martin K.-H. Li

2017-01-01

Full Text Available The Ligament Augmentation and Reconstruction System® (LARS® represents a popular synthetic anatomical reduction method for acromioclavicular joint dislocation by means of coracoclavicular ligament reconstruction. To our knowledge, no early failure has been documented in the literature. We present two unusual cases of LARS failure, one at four months after implant and the other at three weeks, without obvious causes, requiring re-do reconstruction, and discuss potential contributory factors.

Influence of different implant materials on the primary stability of orthodontic mini-implants.

Science.gov (United States)

Pan, Chin-Yun; Chou, Szu-Ting; Tseng, Yu-Chuan; Yang, Yi-Hsin; Wu, Chao-Yi; Lan, Ting-Hsun; Liu, Pao-Hsin; Chang, Hong-Po

2012-12-01

This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm). The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm) and stainless steel mini-implants 10 mm in length. The mini-implants were inserted into artificial bones with a 2-mm-thick cortical layer and 40 or 20 lb/ft(3) trabecular bone density at insertion depths of 2, 4, and 6 mm. The resonance frequency of the mini-implants in the artificial bone was detected with the Implomates(®) device. Data were analyzed by two-way analysis of variance followed by the Tukey honestly significant difference test (α = 0.05). Greater insertion depth resulted in higher resonance frequency, whereas longer mini-implants showed lower resonance frequency values. However, resonance frequency was not influenced by the implant materials titanium alloy or stainless steel. Therefore, the primary stability of a mini-implant is influenced by insertion depth and not by implant material. Insertion depth is extremely important for primary implant stability and is critical for treatment success. Copyright © 2012. Published by Elsevier B.V.

Influence of different implant materials on the primary stability of orthodontic mini-implants

Directory of Open Access Journals (Sweden)

Chin-Yun Pan

2012-12-01

Full Text Available This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm. The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm and stainless steel mini-implants 10 mm in length. The mini-implants were inserted into artificial bones with a 2-mm-thick cortical layer and 40 or 20 lb/ft3 trabecular bone density at insertion depths of 2, 4, and 6 mm. The resonance frequency of the mini-implants in the artificial bone was detected with the Implomates® device. Data were analyzed by two-way analysis of variance followed by the Tukey honestly significant difference test (α = 0.05. Greater insertion depth resulted in higher resonance frequency, whereas longer mini-implants showed lower resonance frequency values. However, resonance frequency was not influenced by the implant materials titanium alloy or stainless steel. Therefore, the primary stability of a mini-implant is influenced by insertion depth and not by implant material. Insertion depth is extremely important for primary implant stability and is critical for treatment success.

Society position statement : Canadian Cardiovascular Society/Canadian Anesthesiologists' Society/Canadian Heart Rhythm Society joint position statement on the perioperative management of patients with implanted pacemakers, defibrillators, and neurostimulating devices.

Science.gov (United States)

Healey, Jeff S; Merchant, Richard; Simpson, Chris; Tang, Timothy; Beardsall, Marianne; Tung, Stanley; Fraser, Jennifer A; Long, Laurene; van Vlymen, Janet M; Manninen, Pirjo; Ralley, Fiona; Venkatraghavan, Lashmi; Yee, Raymond; Prasloski, Bruce; Sanatani, Shubhayan; Philippon, François

2012-04-01

There are more than 200,000 Canadians living with permanent pacemakers or implantable defibrillators, many of whom will require surgery or invasive procedures each year. They face potential hazards when undergoing surgery; however, with appropriate planning and education of operating room personnel, adverse device-related outcomes should be rare. This joint position statement from the Canadian Cardiovascular Society (CCS) and the Canadian Anesthesiologists' Society (CAS) has been developed as an accessible reference for physicians and surgeons, providing an overview of the key issues for the preoperative, intraoperative, and postoperative care of these patients. The document summarizes the limited published literature in this field, but for most issues, relies heavily on the experience of the cardiologists and anesthesiologists who contributed to this work. This position statement outlines how to obtain information about an individual's type of pacemaker or implantable defibrillator and its programming. It also stresses the importance of determining if a patient is highly pacemaker-dependent and proposes a simple approach for nonelective evaluation of dependency. Although the document provides a comprehensive list of the intraoperative issues facing these patients, there is a focus on electromagnetic interference resulting from electrocautery and practical guidance is given regarding the characteristics of surgery, electrocautery, pacemakers, and defibrillators which are most likely to lead to interference. The document stresses the importance of preoperative consultation and planning to minimize complications. It reviews the relative merits of intraoperative magnet use vs reprogramming of devices and gives examples of situations where one or the other approach is preferable.

A novel aragonite-based scaffold for osteochondral regeneration: early experience on human implants and technical developments.

Science.gov (United States)

Kon, Elizaveta; Robinson, Dror; Verdonk, Peter; Drobnic, Matej; Patrascu, Jenel Mariano; Dulic, Oliver; Gavrilovic, Gordon; Filardo, Giuseppe

2016-12-01

Chondral and osteochondral lesions represent a debilitating disease. Untreated lesions remain a risk factor for more extensive joint damage. The objective of this clinical study is to evaluate safety and early results of an aragonite-based scaffold used for osteochondral unit repair, by analysing both clinical outcome and MRI results, as well as the benefits of the procedure optimization through novel tapered shaped implants. A crystalline aragonite bi-phasic scaffold was implanted in patients affected by focal chondral-osteochondral knee lesions of the condyle and trochlea. Twenty-one patients (17 men, 4 women with a mean age of 31.0 ± 8.6 years) without severe OA received tapered shaped implants for the treatment of 2.5 ±1.7 cm 2 sized defects. The control group consisted of 76 patients selected according to the same criteria from a database of patients who previously underwent implantation of cylindrical-shaped implants. The clinical outcome of all patients was evaluated with the IKDC subjective score, the Lysholm score, and all 5 KOOS subscales administered preoperatively and at 6 and 12 months after surgery, while MRI evaluation was performed at the 12 month follow-up. A statistically significant improvement in all clinical scores was documented both in the tapered implants and the cylindrical group. No difference could be detected in the comparison between the improvement obtained with the two implant types, neither in the clinical nor in imaging evaluations. A difference could be detected instead in terms of revision rate, which was lower in the tapered implant group with no implant removal - 0% vs 8/76-10.5% failures in the cylindrical implants. This study highlighted both safety and potential of a novel aragonite-based scaffold for the treatment of chondral and osteochondral lesions in humans. A tapered shape relative to the cylindrical shaped implant design, improved the scaffold's safety profile. Tapered scaffolds maintain the clinical improvement

Metacarpophalangeal joint of the thumb arthrodesis using intramedullary interlocking screws XMCP™.

Science.gov (United States)

Novoa-Parra, C N; Montaner-Alonso, D; Morales-Rodríguez, J

2017-09-04

The study objective was to assess the results of a thumb metacarpophalangeal joint (MCPJ) arthrodesis using intramedullary interlocking screws at 25°, XMCP ™ (Extremity Medical, Parsippany, NJ). Radiographs evaluated the angle of arthrodesis, time of fusion and fixation of the implant. Clinical and functional outcomes were assessed using the DASH questionnaire and the VAS scale. Any complications found during surgery or the follow-up period were noted. We studied 9 patients. The mean follow-up was 27.6 months. Patients showed clinical and radiological evidence of fusion in an average of 8 weeks, the angle of fusion was 25°. There were no complications and no implant had to be removed. The XMCP™ system provides a reliable method for MCPJ arthrodesis for several indications and can be used with other procedures in the complex hand. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

In-vivo evaluation of the kinematic behavior of an artificial medial meniscus implant: A pilot study using open-MRI.

Science.gov (United States)

De Coninck, Tineke; Elsner, Jonathan J; Linder-Ganz, Eran; Cromheecke, Michiel; Shemesh, Maoz; Huysse, Wouter; Verdonk, René; Verstraete, Koenraad; Verdonk, Peter

2014-09-01

In this pilot study we wanted to evaluate the kinematics of a knee implanted with an artificial polycarbonate-urethane meniscus device, designed for medial meniscus replacement. The static kinematic behavior of the implant was compared to the natural medial meniscus of the non-operated knee. A second goal was to evaluate the motion pattern, the radial displacement and the deformation of the meniscal implant. Three patients with a polycarbonate-urethane implant were included in this prospective study. An open-MRI was used to track the location of the implant during static weight-bearing conditions, within a range of motion of 0° to 120° knee flexion. Knee kinematics were evaluated by measuring the tibiofemoral contact points and femoral roll-back. Meniscus measurements (both natural and artificial) included anterior-posterior meniscal movement, radial displacement, and meniscal height. No difference (P>0.05) was demonstrated in femoral roll-back and tibiofemoral contact points during knee flexion between the implanted and the non-operated knees. Meniscal measurements showed no significant difference in radial displacement and meniscal height (P>0.05) at all flexion angles, in both the implanted and non-operated knees. A significant difference (P ≤ 0.05) in anterior-posterior movement during flexion was observed between the two groups. In this pilot study, the artificial polycarbonate-urethane implant, indicated for medial meniscus replacement, had no influence on femoral roll-back and tibiofemoral contact points, thus suggesting that the joint maintains its static kinematic properties after implantation. Radial displacement and meniscal height were not different, but anterior-posterior movement was slightly different between the implant and the normal meniscus. Copyright © 2014 Elsevier Ltd. All rights reserved.

Imaging of common breast implants and implant-related complications: A pictorial essay

OpenAIRE

Shah, Amisha T; Jankharia, Bijal B

2016-01-01

The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance i...

Dental Implant Surgery

Science.gov (United States)

... here to find out more. Dental Implant Surgery Dental Implant Surgery Dental implant surgery is, of course, ... to find out more. Wisdom Teeth Management Wisdom Teeth Management An impacted wisdom tooth can damage neighboring ...

[Clinical application of individualized three-dimensional printing implant template in multi-tooth dental implantation].

Science.gov (United States)

Wang, Lie; Chen, Zhi-Yuan; Liu, Rong; Zeng, Hao

2017-08-01

To study the value and satisfaction of three-dimensional printing implant template and conventional implant template in multi-tooth dental implantation. Thirty cases (83 teeth) with missing teeth needing to be implanted were randomly divided into conventional implant template group (CIT group, 15 cases, 42 teeth) and 3D printing implant template group (TDPIT group, 15 cases, 41 teeth). Patients in CIT group were operated by using conventional implant template, while patients in TDPIT group were operated by using three-dimensional printing implant template. The differences of implant neck and tip deviation, implant angle deviation and angle satisfaction between the two groups were compared. The difference of probing depth and bone resorption of implant were compared 1 year after operation between the two groups. The difference of success rate and satisfaction of dental implantation were compared 1 year after operation between the two groups. SPSS19.0 software package was used for statistical analysis. The deviation direction of the neck and the tip in disto-mesial, bucco-palatal, vertical direction and angle of implants in disto-mesial and bucco-palatal direction in TDPIT group were significantly lower than in CIT group (P0.05). The difference of the cumulative success rate in dental implantation at 3 months and 6 months between the two groups were not significant (P>0.05), but the cumulative success rate of TDPIT group was significantly higher than CIT group at 9 months and 1 year (90.48% vs 100%,P=0.043). The patients' satisfaction rate of dental implantation in TDPIT group was significantly higher than in CIT group (86.67% vs 53.33%, P=0.046). Using three-dimensional printing implant template can obtain better accuracy of implant, higher implant success rate and better patients' satisfaction than using conventional implant template. It is suitable for clinical application.

Osseointegration of zirconia implants: an SEM observation of the bone-implant interface.

Science.gov (United States)

Depprich, Rita; Zipprich, Holger; Ommerborn, Michelle; Mahn, Eduardo; Lammers, Lydia; Handschel, Jörg; Naujoks, Christian; Wiesmann, Hans-Peter; Kübler, Norbert R; Meyer, Ulrich

2008-11-06

The successful use of zirconia ceramics in orthopedic surgery led to a demand for dental zirconium-based implant systems. Because of its excellent biomechanical characteristics, biocompatibility, and bright tooth-like color, zirconia (zirconium dioxide, ZrO2) has the potential to become a substitute for titanium as dental implant material. The present study aimed at investigating the osseointegration of zirconia implants with modified ablative surface at an ultrastructural level. A total of 24 zirconia implants with modified ablative surfaces and 24 titanium implants all of similar shape and surface structure were inserted into the tibia of 12 Göttinger minipigs. Block biopsies were harvested 1 week, 4 weeks or 12 weeks (four animals each) after surgery. Scanning electron microscopy (SEM) analysis was performed at the bone implant interface. Remarkable bone attachment was already seen after 1 week which increased further to intimate bone contact after 4 weeks, observed on both zirconia and titanium implant surfaces. After 12 weeks, osseointegration without interposition of an interfacial layer was detected. At the ultrastructural level, there was no obvious difference between the osseointegration of zirconia implants with modified ablative surfaces and titanium implants with a similar surface topography. The results of this study indicate similar osseointegration of zirconia and titanium implants at the ultrastructural level.

Pre-operative Asymptomatic Bacteriuria: A Risk Factor For Prosthetic Joint Infection?

Science.gov (United States)

Weale, R; El-Bakri, F; Saeed, Kordo

2018-04-13

Infection is a rare complication following implantation of prosthetic material into a joint. The impact of asymptomatic bacteriuria (ASB) before elective operations and the subsequent risk of prosthetic joint infection (PJI) are not well understood. • Assess the prevalence of ASB amongst patients undergoing total arthroplasty of the hip and knee. • Determine the rates of PJI diagnosed within two years of the arthroplasty and if ASB is an independent risk factor for developing PJI. Patients who had total/unicondylar knee or total hip arthroplasty were retrospectively reviewed over a five-year period. Pre-operative urine samples within one year of surgery were analysed and those with ASB identified. Primary outcome was prosthetic joint infection (PJI) within the first postoperative year. 5542 patients were included. 4368 had a pre-operative urine culture recorded. The prevalence of ASB was 140 of 4368 (3.2%). The overall PJI rate was 56 of 5542 (1.01%). Of those with a PJI, 33 had a pre-operative urine sample recorded. The infection rate in the ASB group was 5% (7 of 140), in the no-ASB group it was 0.61% (26 of 4228) and in the group without a urine sample it was 1.96% (23 of 1174) (p value prosthetic joint, suggestive the relationship is unlikely causal. Copyright © 2018. Published by Elsevier Ltd.

Gel-type autologous chondrocyte (Chondron™ implantation for treatment of articular cartilage defects of the knee

Directory of Open Access Journals (Sweden)

Chun Chung-Woo

2010-05-01

Full Text Available Abstract Background Gel-type autologous chondrocyte (Chondron™ implantations have been used for several years without using periosteum or membrane. This study involves evaluations of the clinical results of Chondron™ at many clinical centers at various time points during the postoperative patient follow-up. Methods Data from 98 patients with articular cartilage injury of the knee joint and who underwent Chondron™ implantation at ten Korean hospitals between January 2005 and November 2008, were included and were divided into two groups based on the patient follow-up period, i.e. 13~24-month follow-up and greater than 25-month follow-up. The telephone Knee Society Score obtained during telephone interviews with patients, was used as the evaluation tool. Results On the tKSS-A (telephone Knee Society Score-A, the score improved from 43.52 ± 20.20 to 89.71 ± 13.69 (P Conclusion Gel-type autologous chondrocyte implantation for chondral knee defects appears to be a safe and effective method for both decreasing pain and improving knee function.

Complications with computer-aided designed/computer-assisted manufactured titanium and soldered gold bars for mandibular implant-overdentures: short-term observations.

Science.gov (United States)

Katsoulis, Joannis; Wälchli, Julia; Kobel, Simone; Gholami, Hadi; Mericske-Stern, Regina

2015-01-01

Implant-overdentures supported by rigid bars provide stability in the edentulous atrophic mandible. However, fractures of solder joints and matrices, and loosening of screws and matrices were observed with soldered gold bars (G-bars). Computer-aided designed/computer-assisted manufactured (CAD/CAM) titanium bars (Ti-bars) may reduce technical complications due to enhanced material quality. To compare prosthetic-technical maintenance service of mandibular implant-overdentures supported by CAD/CAM Ti-bar and soldered G-bar. Edentulous patients were consecutively admitted for implant-prosthodontic treatment with a maxillary complete denture and a mandibular implant-overdenture connected to a rigid G-bar or Ti-bar. Maintenance service and problems with the implant-retention device complex and the prosthesis were recorded during minimally 3-4 years. Annual peri-implant crestal bone level changes (ΔBIC) were radiographically assessed. Data of 213 edentulous patients (mean age 68 ± 10 years), who had received a total of 477 tapered implants, were available. Ti-bar and G-bar comprised 101 and 112 patients with 231 and 246 implants, respectively. Ti-bar mostly exhibited distal bar extensions (96%) compared to 34% of G-bar (p overdentures supported by soldered gold bars or milled CAD/CAM Ti-bars are a successful treatment modality but require regular maintenance service. These short-term observations support the hypothesis that CAD/CAM Ti-bars reduce technical complications. Fracture location indicated that the titanium thickness around the screw-access hole should be increased. © 2013 Wiley Periodicals, Inc.

Mathematical modeling of chemotaxis and glial scarring around implanted electrodes

International Nuclear Information System (INIS)

Silchenko, Alexander N; Tass, Peter A

2015-01-01

It is well known that the implantation of electrodes for deep brain stimulation or microelectrode probes for the recording of neuronal activity is always accompanied by the response of the brain’s immune system leading to the formation of a glial scar around the implantation sites. The implantation of electrodes causes massive release of adenosine-5′-triphosphate (ATP) and different cytokines into the extracellular space and activates the microglia. The released ATP and the products of its hydrolysis, such as ADP and adenosine, become the main elements mediating chemotactic sensitivity and motility of microglial cells via subsequent activation of P2Y 2,12 as well as A3A/A2A adenosine receptors. The size and density of an insulating sheath around the electrode, formed by microglial cells, are important criteria for the optimization of the signal-to-noise ratio during microelectrode recordings or parameters of electrical current delivered to the brain tissue. Here, we study a purinergic signaling pathway underlying the chemotactic motion of microglia towards implanted electrodes as well as the possible impact of an anti-inflammatory coating consisting of the interleukin-1 receptor antagonist. We present a model describing the formation of a stable aggregate around the electrode due to the joint chemo-attractive action of ATP and ADP and the mixed influence of extracellular adenosine. The bioactive coating is modeled as a source of chemo-repellent located near the electrode surface. The obtained analytical and numerical results allowed us to reveal the dependences of size and spatial location of the insulating sheath on the amount of released ATP and estimate the impact of immune suppressive coating on the scarring process. (paper)

Influence of controlled immediate loading and implant design on peri-implant bone formation.

Science.gov (United States)

Vandamme, Katleen; Naert, Ignace; Geris, Liesbet; Vander Sloten, Jozef; Puers, Robert; Duyck, Joke

2007-02-01

Tissue formation at the implant interface is known to be sensitive to mechanical stimuli. The aim of the study was to compare the bone formation around immediately loaded versus unloaded implants in two different implant macro-designs. A repeated sampling bone chamber with a central implant was installed in the tibia of 10 rabbits. Highly controlled loading experiments were designed for a cylindrical (CL) and screw-shaped (SL) implant, while the unloaded screw-shaped (SU) implant served as a control. An F-statistic model with alpha=5% determined statistical significance. A significantly higher bone area fraction was observed for SL compared with SU (pimplant contact occurred was the highest for SL and significantly different from SU (pimplant contact was observed, a loading (SL versus SU: p=0.0049) as well as an implant geometry effect (SL versus CL: p=0.01) was found, in favour of the SL condition. Well-controlled immediate implant loading accelerates tissue mineralization at the interface. Adequate bone stimulation via mechanical coupling may account for the larger bone response around the screw-type implant compared with the cylindrical implant.

Influence of Implant Positions and Occlusal Forces on Peri-Implant Bone Stress in Mandibular Two-Implant Overdentures: A 3-Dimensional Finite Element Analysis.

Science.gov (United States)

Alvarez-Arenal, Angel; Gonzalez-Gonzalez, Ignacio; deLlanos-Lanchares, Hector; Brizuela-Velasco, Aritza; Dds, Elena Martin-Fernandez; Ellacuria-Echebarria, Joseba

2017-12-01

The aim of this study was to evaluate and compare the bone stress around implants in mandibular 2-implant overdentures depending on the implant location and different loading conditions. Four 3-dimensional finite element models simulating a mandibular 2-implant overdenture and a Locator attachment system were designed. The implants were located at the lateral incisor, canine, second premolar, and crossed-implant levels. A 150 N unilateral and bilateral vertical load of different location was applied, as was 40 N when combined with midline load. Data for von Mises stress were produced numerically, color coded, and compared between the models for peri-implant bone and loading conditions. With unilateral loading, in all 4 models much higher peri-implant bone stress values were recorded on the load side compared with the no-load side, while with bilateral occlusal loading, the stress distribution was similar on both sides. In all models, the posterior unilateral load showed the highest stress, which decreased as the load was applied more mesially. In general, the best biomechanical environment in the peri-implant bone was found in the model with implants at premolar level. In the crossed-implant model, the load side greatly altered the biomechanical environment. Overall, the overdenture with implants at second premolar level should be the chosen design, regardless of where the load is applied. The occlusal loading application site influences the bone stress around the implant. Bilateral occlusal loading distributes the peri-implant bone stress symmetrically, while unilateral loading increases it greatly on the load side, no matter where the implants are located.

Effect of lateralized design on muscle and joint reaction forces for reverse shoulder arthroplasty.

Science.gov (United States)

Liou, William; Yang, Yang; Petersen-Fitts, Graysen R; Lombardo, Daniel J; Stine, Sasha; Sabesan, Vani J

2017-04-01

Manufacturers of reverse shoulder arthroplasty (RSA) implants have recently designed innovative implants to optimize performance in rotator cuff-deficient shoulders. These advancements are not without tradeoffs and can have negative biomechanical effects. The objective of this study was to develop an integrated finite element analysis-kinematic model to compare the muscle forces and joint reaction forces (JRFs) of 3 different RSA designs. A kinematic model of a normal shoulder joint was adapted from the Delft model and integrated with the well-validated OpenSim shoulder model. Static optimizations then allowed for calculation of the individual muscle forces, moment arms, and JRFs relative to net joint moments. Three-dimensional computer models of 3 RSA designs-humeral lateralized design (HLD), glenoid lateralized design, and Grammont design-were integrated, and parametric studies were performed. Overall, there were decreases in deltoid and rotator cuff muscle forces for all 3 RSA designs. These decreases were greatest in the middle deltoid of the HLD model for abduction and flexion and in the rotator cuff muscles under both internal rotation and external rotation. The JRFs in abduction and flexion decreased similarly for all RSA designs compared with the normal shoulder model, with the greatest decrease seen in the HLD model. These findings demonstrate that the design characteristics implicit in these modified RSA prostheses result in mechanical differences most prominently seen in the deltoid muscle and overall JRFs. Further research using this novel integrated model can help guide continued optimization of RSA design and clinical outcomes. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Tribology considerations for hip joint articulations in relation to the "new orthopaedic patient".

Science.gov (United States)

Rieker, C B

2006-01-01

The purpose of this review is to examine alternative bearings used in total hip arthroplasty (THA) and discuss the specific tribologic needs of the "New Orthopaedic Patient". As orthopaedic patients today are younger and more active, there is a clear need for hip joint implants and articulations minimising the amount of wear and guarantying better stability. Recent modern developments in tribology with highly cross-linked polyethylenes and hard-on-hard bearings allow the safe and effective use of larger diameter articulations in THA.

CLINICAL CONSIDERATIONS OF DENTAL IMPLANT SYSTEM IN IMMEDIATE LOADING IMPLANT CASES

Directory of Open Access Journals (Sweden)

Carolina Damayanti Marpaung

2015-06-01

Full Text Available Immediate loading of dental implant has been researched intensively in the development of Branemark’s early concept of 2 stages implant placement. This was embarked from both patients and practiitioner’s convenience towards a simpler protocol and shorter time frame. Many recent researchers later found that micromotions derived from occlusal loading for a certain degree, instead of resulting a fibrous tissue encapsulation, can enhance the osseointegration process. Dental Implant system enhancement towards maximizing the primary stability held a key factor in Branemark’s concept development. Surgical protocol and implant design was found to give a significant contribution to the prognosis of immediate-loading implants.

An in-fiber Bragg grating sensor for contact force and stress measurements in articular joints

International Nuclear Information System (INIS)

Dennison, Christopher R; Wild, Peter M; Wilson, David R; Gilbart, Michael K

2010-01-01

We present an in-fiber Bragg grating-based sensor (240 µm diameter) for contact force/stress measurements in articular joints. The contact force sensor and another Bragg grating-based pressure sensor (400 µm diameter) are used to conduct the first simultaneous measurements of contact force/stress and fluid pressure in intact cadaveric human hips. The contact force/stress sensor addresses limitations associated with stress-sensitive films, the current standard tools for contact measurements in joints, including cartilage modulus-dependent sensitivity of films and the necessity to remove biomechanically relevant anatomy to implant the films. Because stress-sensitive films require removal of anatomy, it has been impossible to validate the mechanical rationale underlying preventive or corrective surgeries, which repair these anatomies, by conducting simultaneous stress and pressure measurements in intact hips. Methods are presented to insert the Bragg grating-based sensors into the joint, while relevant anatomy is left largely intact. Sensor performance is predicted using numerical models and the predicted sensitivity is verified through experimental calibrations. Contact force/stress and pressure measurements in cadaveric joints exhibited repeatability. With further validation, the Bragg grating-based sensors could be used to study the currently unknown relationships between contact forces and pressures in both healthy and degenerated joints

In vitro fatigue tests and in silico finite element analysis of dental implants with different fixture/abutment joint types using computer-aided design models.

Science.gov (United States)

Yamaguchi, Satoshi; Yamanishi, Yasufumi; Machado, Lucas S; Matsumoto, Shuji; Tovar, Nick; Coelho, Paulo G; Thompson, Van P; Imazato, Satoshi

2018-01-01

The aim of this study was to evaluate fatigue resistance of dental fixtures with two different fixture-abutment connections by in vitro fatigue testing and in silico three-dimensional finite element analysis (3D FEA) using original computer-aided design (CAD) models. Dental implant fixtures with external connection (EX) or internal connection (IN) abutments were fabricated from original CAD models using grade IV titanium and step-stress accelerated life testing was performed. Fatigue cycles and loads were assessed by Weibull analysis, and fatigue cracking was observed by micro-computed tomography and a stereomicroscope with high dynamic range software. Using the same CAD models, displacement vectors of implant components were also analyzed by 3D FEA. Angles of the fractured line occurring at fixture platforms in vitro and of displacement vectors corresponding to the fractured line in silico were compared by two-way ANOVA. Fatigue testing showed significantly greater reliability for IN than EX (pimplant fixture platforms. FEA demonstrated that crack lines of both implant systems in vitro were observed in the same direction as displacement vectors of the implant fixtures in silico. In silico displacement vectors in the implant fixture are insightful for geometric development of dental implants to reduce complex interactions leading to fatigue failure. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Psychological intervention following implantation of an implantable defibrillator

DEFF Research Database (Denmark)

Pedersen, Susanne S.; van den Broek, Krista C; Sears, Samuel F

2007-01-01

The medical benefits of the implantable cardioverter defibrillator (ICD) are unequivocal, but a subgroup of patients experiences emotional difficulties following implantation. For this subgroup, some form of psychological intervention may be warranted. This review provides an overview of current ...

Precision analysis of a multi-slice ultrasound sensor for non-invasive 3D kinematic analysis of knee joints.

Science.gov (United States)

Masum, Md Abdullah; Lambert, Andrew J; Pickering, Mark R; Scarvell, J M; Smith, P N

2012-01-01

Currently the standard clinical practice for measuring the motion of bones in a knee joint with sufficient precision involves implanting tantalum beads into the bones to act as fiducial markers prior to imaging using X-ray equipment. This procedure is invasive in nature and exposure to ionizing radiation imposes a cancer risk and the patient's movements are confined to a narrow field of view. In this paper, an ultrasound based system for non-invasive kinematic evaluation of knee joints is proposed. The results of an initial analysis show that this system can provide the precision required for non-invasive motion analysis while the patient performs normal physical activities.

Vitamin E Phosphate Coating Stimulates Bone Deposition in Implant-related Infections in a Rat Model.

Science.gov (United States)

Lovati, Arianna B; Bottagisio, Marta; Maraldi, Susanna; Violatto, Martina B; Bortolin, Monica; De Vecchi, Elena; Bigini, Paolo; Drago, Lorenzo; Romanò, Carlo L

2018-06-01

Implant-related infections are associated with impaired bone healing and osseointegration. In vitro antiadhesive and antibacterial properties and in vivo antiinflammatory effects protecting against bone loss of various formulations of vitamin E have been demonstrated in animal models. However, to the best of our knowledge, no in vivo studies have demonstrated the synergistic activity of vitamin E in preventing bacterial adhesion to orthopaedic implants, thus supporting the bone-implant integration. The purpose of this study was to test whether a vitamin E phosphate coating on titanium implants may be able to reduce (1) the bacterial colonization of prosthetic implants and (2) bone resorption and osteomyelitis in a rat model of Staphylococcus aureus-induced implant-related infection. Twelve rats were bilaterally injected in the femurs with S aureus UAMS-1-Xen40 and implanted with uncoated or vitamin E phosphate-coated titanium Kirschner wires without local or systemic antibiotic prophylaxis. Eight rats represented the uninfected control group. A few hours after surgery, two control and three infected animals died as a result of unexpected complications. With the remaining rats, we assessed the presence of bacterial contamination with qualitative bioluminescence imaging and Gram-positive staining and with quantitative bacterial count. Bone changes in terms of resorption and osteomyelitis were quantitatively analyzed through micro-CT (bone mineral density) and semiquantitatively through histologic scoring systems. Six weeks after implantation, we found only a mild decrease in bacterial count in coated versus uncoated implants (Ti versus controls: mean difference [MD], -3.705; 95% confidence interval [CI], -4.416 to -2.994; p E-treated group compared with uncoated implants (knee joint: MD, -11.88; 95% CI, -16.100 to -7.664; p E-coated nails compared with the uncoated nails. These preliminary findings indicate that vitamin E phosphate implant coatings can exert a

[Trochanteric femoral fractures: anatomy, biomechanics and choice of implants].

Science.gov (United States)

Bonnaire, F; Lein, T; Bula, P

2011-06-01

The objective of any surgical care of a trochanteric femoral fracture should be the achievement of a stable osteosynthesis that allows early full weight-bearing mobilisation of the patient, because long-term immobilisation soon becomes a vital threat to the affected patients who are usually elderly with correlating comorbidities. The anatomical references of the proximal femur and the structure of the hip joint contain some specifics that play an essential role in the incurrence of a trochanteric femoral fracture and the planning of the osteosynthesis as well. With reposition and fracture stabilisation particular importance must be attached to the collo-diaphyseal and the antetorsion angle so that they do not interfere with the functional interaction of the hip and knee joint. Uncomplex trochanteric fractures ordinarily stabilise sufficiently after reposition so that even an extramedullary implant can ensure full weight-bearing stability. With evermore distal fracture course and intertrochanteric comminution zone, rotational instability and pivot transfer of the fracture area to lateral and caudal are followed by an increase of the dislocating forces. These kinds of fractures (A2 and A3 according to the AO/ASIF classification) profit from an intramedullary and rotationally stable osteosynthesis. Basically primary total hip arthroplasty is a potential option for surgical care of a trochanteric fracture in elderly patients with relevant coxarthrosis. However this procedure can only be recommended in cases of a stable uncomplex fracture. The more the medial interlocking of the proximal femur is destroyed the more difficult it will be to primarily implant a total hip prosthesis with good offset and without a varus and rotational failure in the fracture zone.The current studies in the main show disadvantages due to increased complications in these patients, so that in cases of an unstable trochanteric fracture a primary osteosynthesis should be performed followed by

Prevalence of Peri-Implant Mucositis and Peri-Implantitis in Patients Treated with a Combination of Axial and Tilted Implants Supporting a Complete Fixed Denture

Directory of Open Access Journals (Sweden)

Nicolò Cavalli

2015-01-01

Full Text Available Objectives. The aim of this retrospective study was to assess the incidence and prevalence of peri-implant mucositis and peri-implantitis in patients with a fixed full-arch prosthesis supported by two axial and two tilted implants. Materials and Methods. Sixty-nine patients were included in the study. Each patient received a fixed full-arch prosthesis supported by two mesial axial and two distal tilted implants to rehabilitate the upper arch, the lower arch, or both. Three hundred thirty-six implants for 84 restorations were delivered. Patients were scheduled for follow-up visits every 6 months in the first 2 years and yearly after. At each follow-up visit peri-implant mucositis and peri-implantitis were diagnosed if present. Results. The overall follow-up range was from 12 to 130 months (mean 63,2 months. Three patients presented peri-implantitis. The prevalence of peri-implant mucositis ranged between 0 and 7,14% of patients (5,06% of implants while the prevalence of peri-implantitis varied from 0 to 4,55% of patients (3,81% of implants. Conclusions. The prevalence and incidence of peri-implant mucositis and peri-implantitis are lower than most of the studies in literature. Therefore this kind of rehabilitation could be considered a feasible option, on the condition of adopting a systematic hygienic protocol.

A new system of implant abutment connection: how to improve a two piece implant system sealing.

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Grecchi, F; DI Girolamo, M; Cura, F; Candotto, V; Carinci, F

2017-01-01

Implant dentistry has become one of the most successful dentistry techniques for replacing missing teeth. The success rate of implant dentistry is above 80%. However, peri-implantitis is a later complication of implant dentistry that if untreated, can lead to implant loss. One of the hypotized causes of peri-implantis is the bacterial leakage at the level of implant-abutment connection. Bacterial leakage is favored to the presence of a micro gap at the implant-abutment interface, allowing microorganisms to penetrate and colonize the inner part of the implant leading to biofilm accumulation and consequently to peri-implantitis development. To identify the capability of the implant to protect the internal space from the external environment, the passage of genetically modified Escherichia coli across implant-abutment interface was evaluated. Implants were immerged in a bacterial culture for twenty-four hours and then bacteria amount was measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 9%. The reported results are better to those of previous studies carried out on different implant systems. Until now, none implant-abutment system has been proven to seal the gap between implant and abutment.

Prosthetic joint infection caused by Granulicatella adiacens: a case series and review of literature.

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Quénard, Fanny; Seng, Piseth; Lagier, Jean-Christophe; Fenollar, Florence; Stein, Andreas

2017-06-23

Bone and joint infection involving Granulicatella adiacens is rare, and mainly involved in cases of bacteremia and infectious endocarditis. Here we report three cases of prosthetic joint infection involving G. adiacens that were successfully treated with surgery and prolonged antimicrobial treatment. We also review the two cases of prosthetic joint infection involving G. adiacens that are reported in the literature. Not all five cases of prosthetic joint infection caused by G. adiacens were associated with bacteremia or infectious endocarditis. Dental care before the onset of infection was observed in two cases. The median time delay between arthroplasty implantation and the onset of infection was of 4 years (ranging between 2 and 10 years). One of our cases was identified with 16srRNA gene sequencing, one case with MALDI-TOF mass spectrometry, and one case with both techniques. Two literature cases were diagnosed by 16srRNA gene sequencing. All five cases were cured after surgery including a two-stage prosthesis exchange in three cases, a one-stage prosthesis exchange in one case, and debridement, antibiotics, irrigation, and retention of the prosthesis in one case, and prolonged antimicrobial treatment. Prosthetic joint infection involving G. adiacens is probably often dismissed due to difficult culture or misdiagnosis, in particular in the cases of polymicrobial infection. Debridement, antibiotics, irrigation, and retention of the prosthesis associated with prolonged antimicrobial treatment (≥ 8 weeks) should be considered as a treatment strategy for prosthetic joint infection involving G. adiacens.

Poly Implants Prosthèse Breast Implants: A Case Series and Review of the Literature.

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Klein, Doron; Hadad, Eran; Wiser, Itay; Wolf, Omer; Itzhaki Shapira, Ortal; Fucks, Shir; Heller, Lior

2018-01-01

Silicone breast implants from the French manufacturer Poly Implants Prosthèse (PIP) were recalled from the European market after the French regulator has revealed the implants contain non-medical-grade silicone filler. In December 2011, following a large increase in reported rupture rate and a possible cancer risk, the French Ministry of Health recommended consideration of the PIP explantation, regardless of their condition. In 2012, the Israel Ministry of Health recommended to replace the implants only upon suspected implant rupture. The aims of this study were to characterize breast-augmented Israeli patients with PIP implants, compare their outcomes with those of breast-augmented patients with different implant types, and review the current PIP literature. Breast-augmented patients who underwent an elective breast implant exchange in Israel between January 2011 and January 2017 were included in the study. Data were collected from electronic and physical medical files. There were 73 breast-augmented female patients with 146 PIP breast implants included in this study. Average implant age was 6.7 ± 2.79 years. Mean implant size was 342.8 ± 52.9 mL. Fourteen women (19 implants [16%]) had a high-grade capsular contracture (Baker grade 3-4). During exchange, 28 implants were found to be ruptured (19.2%). Less than 10 years following breast augmentation, PIP implants demonstrated higher rupture rate compared with other implants. Our data are comparable to overall available rupture rate. Among patients with definitive rupture diagnosis, an elective implant removal should be recommended. In cases of undamaged implants, plastic surgeons should also seriously consider PIP implant explantation. When the patient does not desire to remove the implant, an annual physical examination and breast ultrasound are recommended, beginning a year after augmentation.

Ion implantation into diamond

International Nuclear Information System (INIS)

Sato, Susumu

1994-01-01

The graphitization and the change to amorphous state of diamond surface layer by ion implantation and its characteristics are reported. In the diamond surface, into which more than 10 16 ions/cm 2 was implanted, the diamond crystals are broken, and the structure changes to other carbon structure such as amorphous state or graphite. Accompanying this change of structure, the electric conductivity of the implanted layer shows two discontinuous values due to high resistance and low resistance. This control of structure can be done by the temperature of the base during the ion implantation into diamond. Also it is referred to that by the base temperature during implantation, the mutual change of the structure between amorphous state and graphite can be controlled. The change of the electric resistance and the optical characteristics by the ion implantation into diamond surface, the structural analysis by Raman spectroscopy, and the control of the structure of the implanted layer by the base temperature during implantation are reported. (K.I.)

Impact of cone-beam computed tomography on implant planning and on prediction of implant size

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Pedroso, Ludmila Assuncao de Mello; Silva, Maria Alves Garcia Santos, E-mail: ludmilapedroso@hotmail.com [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Odontologia; Garcia, Robson Rodrigues [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Odontologia. Dept. de Medicina Oral; Leles, Jose Luiz Rodrigues [Universidade Paulista (UNIP), Goiania, GO (Brazil). Fac. de Odontologia. Dept. de Cirurgia; Leles, Claudio Rodrigues [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Odontologia. Dept. de Prevencao e Reabilitacao Oral

2013-11-15

The aim was to investigate the impact of cone-beam computed tomography (CBCT) on implant planning and on prediction of final implant size. Consecutive patients referred for implant treatment were submitted to clinical examination, panoramic (PAN) radiography and a CBCT exam. Initial planning of implant length and width was assessed based on clinical and PAN exams, and final planning, on CBCT exam to complement diagnosis. The actual dimensions of the implants placed during surgery were compared with those obtained during initial and final planning, using the McNemmar test (p < 0.05). The final sample comprised 95 implants in 27 patients, distributed over the maxilla and mandible. Agreement in implant length was 50.5% between initial and final planning, and correct prediction of the actual implant length was 40.0% and 69.5%, using PAN and CBCT exams, respectively. Agreement in implant width assessment ranged from 69.5% to 73.7%. A paired comparison of the frequency of changes between initial or final planning and implant placement (McNemmar test) showed greater frequency of changes in initial planning for implant length (p < 0.001), but not for implant width (p = 0.850). The frequency of changes was not influenced by implant location at any stage of implant planning (chi-square test, p > 0.05). It was concluded that CBCT improves the ability of predicting the actual implant length and reduces inaccuracy in surgical dental implant planning. (author)

Metals for bone implants. Part 1. Powder metallurgy and implant rendering.

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Andani, Mohsen Taheri; Shayesteh Moghaddam, Narges; Haberland, Christoph; Dean, David; Miller, Michael J; Elahinia, Mohammad

2014-10-01

New metal alloys and metal fabrication strategies are likely to benefit future skeletal implant strategies. These metals and fabrication strategies were looked at from the point of view of standard-of-care implants for the mandible. These implants are used as part of the treatment for segmental resection due to oropharyngeal cancer, injury or correction of deformity due to pathology or congenital defect. The focus of this two-part review is the issues associated with the failure of existing mandibular implants that are due to mismatched material properties. Potential directions for future research are also studied. To mitigate these issues, the use of low-stiffness metallic alloys has been highlighted. To this end, the development, processing and biocompatibility of superelastic NiTi as well as resorbable magnesium-based alloys are discussed. Additionally, engineered porosity is reviewed as it can be an effective way of matching the stiffness of an implant with the surrounding tissue. These porosities and the overall geometry of the implant can be optimized for strain transduction and with a tailored stiffness profile. Rendering patient-specific, site-specific, morphology-specific and function-specific implants can now be achieved using these and other metals with bone-like material properties by additive manufacturing. The biocompatibility of implants prepared from superelastic and resorbable alloys is also reviewed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

New biomaterials for orthopedic implants

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Ong KL

2015-09-01

Full Text Available Kevin L Ong, Brian Min Yun, Joshua B WhiteExponent, Inc., Philadelphia, PA, USAAbstract: With the increasing use of orthopedic implants worldwide, there continues to be great interest in the development of novel technologies to further improve the effective clinical performance of contemporary treatment modalities and devices. Continuing research interest also exists in developing novel bulk biomaterials (eg, polycarbonate urethanes, silicon or novel formulations of existing but less widely used biomaterials (eg, polyaryletherketones, polyetheretherketone. There is also growing focus on customizing the material properties of bioabsorbables and composite materials with fillers such as bioactive ceramics. In terms of tissue engineering, more recent developments have focused on basic engineering and biological fundamentals to use cells, signaling factors, and the scaffold material itself to better restore tissue and organ structure and function. There has also been recent controversy with the use of injectables as a nonsurgical approach to treat joint disorders, but more attention is being directed toward the development of newer formulations with different molecular weights. The industry has also continuously sought to improve coatings to supplement the function of existing implants, with the goal of improving their osseointegrative qualities and incorporating antimicrobial properties. These include the use of bone morphogenetic protein, bisphosphonates, calcium phosphate, silicon nitride, and iodine. Due to the widespread use of bone graft materials, recent developments in synthetic graft materials have explored further development of bioactive glass, ceramic materials, and porous titanium particles. This review article provides an overview of ongoing efforts in the above research areas.Keywords: coatings, scaffolds, bioabsorbables, bone graft, injectables

An analysis of a joint shear model for jointed media with orthogonal joint sets

International Nuclear Information System (INIS)

Koteras, J.R.

1991-10-01

This report describes a joint shear model used in conjunction with a computational model for jointed media with orthogonal joint sets. The joint shear model allows nonlinear behavior for both joint sets. Because nonlinear behavior is allowed for both joint sets, a great many cases must be considered to fully describe the joint shear behavior of the jointed medium. An extensive set of equations is required to describe the joint shear stress and slip displacements that can occur for all the various cases. This report examines possible methods for simplifying this set of equations so that the model can be implemented efficiently form a computational standpoint. The shear model must be examined carefully to obtain a computationally efficient implementation that does not lead to numerical problems. The application to fractures in rock is discussed. 5 refs., 4 figs

Cobalt Alloy Implant Debris Induces Inflammation and Bone Loss Primarily through Danger Signaling, Not TLR4 Activation: Implications for DAMP-ening Implant Related Inflammation

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Samelko, Lauryn; Landgraeber, Stefan; McAllister, Kyron; Jacobs, Joshua; Hallab, Nadim James

2016-01-01

Cobalt alloy debris has been implicated as causative in the early failure of some designs of current total joint implants. The ability of implant debris to cause excessive inflammation via danger signaling (NLRP3 inflammasome) vs. pathogen associated pattern recognition receptors (e.g. Toll-like receptors; TLRs) remains controversial. Recently, specific non-conserved histidines on human TLR4 have been shown activated by cobalt and nickel ions in solution. However, whether this TLR activation is directly or indirectly an effect of metals or secondary endogenous alarmins (danger-associated molecular patterns, DAMPs) elicited by danger signaling, remains unknown and contentious. Our study indicates that in both a human macrophage cell line (THP-1) and primary human macrophages, as well as an in vivo murine model of inflammatory osteolysis, that Cobalt-alloy particle induced NLRP3 inflammasome danger signaling inflammatory responses were highly dominant relative to TLR4 activation, as measured respectively by IL-1β or TNF-α, IL-6, IL-10, tissue histology and quantitative bone loss measurement. Despite the lack of metal binding histidines H456 and H458 in murine TLR4, murine calvaria challenge with Cobalt alloy particles induced significant macrophage driven in vivo inflammation and bone loss inflammatory osteolysis, whereas LPS calvaria challenge alone did not. Additionally, no significant increase (p500pg/mL). Therefore, not only do the results of this investigation support Cobalt alloy danger signaling induced inflammation, but under normal homeostasis low levels of hematogenous PAMPs (<2pg/mL) from Gram-negative bacteria, seem to have negligible contribution to the danger signaling responses elicited by Cobalt alloy metal implant debris. This suggests the unique nature of Cobalt alloy particle bioreactivity is strong enough to illicit danger signaling that secondarily activate concomitant TLR activation, and may in part explain Cobalt particulate associated

Novel implant design improves implant survival in multirooted extraction sites: a preclinical pilot study.

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Sivan-Gildor, Adi; Machtei, Eli E; Gabay, Eran; Frankenthal, Shai; Levin, Liran; Suzuki, Marcelo; Coelho, Paulo G; Zigdon-Giladi, Hadar

2014-10-01

The primary aim is to evaluate clinical, radiographic, and histologic parameters of novel implants with "three roots" design that were inserted into fresh multirooted extraction sockets. A secondary aim is to compare this new implant to standard root-form dental implants. Immediate implantation of novel or standard design 6 × 6-mm implants was performed bilaterally into multirooted sockets in mandibles of mini-pigs. Twelve weeks later, clinical, radiographic, stability, histomorphometric, and microcomputed tomography (micro-CT) analyses were performed. Survival rates were significantly higher in the test implants compared with control (92.8% versus 33.3%, respectively; P micro-CT analyses demonstrated bone fill in the inner part of the test implants. Moreover, bone-to-implant contact was higher in the test implants (55.50% ± 3.68% versus 42.47% ± 9.89%). Contrary to the clinical, radiographic, and histomorphometric results, resonance frequency analysis measurements were greater in the control group (77.74 ± 3.21 implant stability quotient [ISQ]) compared with the test group (31.09 ± 0.28 ISQ), P = 0.008. The novel design implants resulted in significantly greater survival rate in multirooted extraction sites. Further studies will be required to validate these findings.

Group D. Initiator paper. Implants--peri-implant (hard and soft tissue) interactions in health and disease: the impact of explosion of implant manufacturers.

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Ivanovski, Saso

2015-01-01

1. The best-documented implants have a threaded solid screw-type design and are manufactured from commercially pure (grade IV) titanium. There is good evidence to support implants ≥ 6 mm in length, and ≥ 3 mm in diameter. 2. Integrity of the seal between the abutment and the implant is important for several reasons, including minimization of mechanical and biological complications and maintaining marginal bone levels. Although the ideal design features of the implant-abutment connection have not been determined, an internal connection, micro-grooves at the implant collar, and horizontal offset of the implant-abutment junction (platform switch) appear to impart favorable properties. 3. Implants with moderately rough implant surfaces provide advantages over machined surfaces in terms of the speed and extent of osseointegration. While the favorable performances of both minimally and moderately rough surfaces are supported by long-term data, moderately rough surfaces provide superior outcomes in compromised sites, such as the posterior maxilla. 4. Although plaque is critical in the progression of peri-implantitis, the disease has a multi-factorial aetiology, and may be influenced by poor integrity of the abutment/implant connection. Iatrogenic factors, such as the introduction of a foreign body. (e.g., cement) below the mucosal margin, can be important contributors. 5. Clinicians should exercise caution when using a particular implant system, ensuring that the implant design is appropriate and supported by scientific evidence. Central to this is access to and participation in quality education on the impact that implant characteristics can have on clinical outcomes. Caution should be exercised in utilizing non-genuine restorative componentry that may lead to a poor implant-abutment fit and subsequent technical and biological complications.

Structure of ion-implanted ceramics

International Nuclear Information System (INIS)

Naramoto, Hiroshi

1983-01-01

The variation of structure of LiF, MgO, Al 2 O 3 and TiO 2 accompanying annealing after ion implantation is explained. The analysis of structure is usually made by the perturbed gamma ray angular correlation, the internal electron Moessbauer method, or the ion scattering method. The results of analyses are discussed for alkali ion implantation, Fe-ion implantation, In-ion implantation, Au-ion implantation, Pt-ion implantation, Pb-ion implantation and transition metal ion implantation. The coupling of the implanted elements with lattice defects and matrix elements, and the compatibility between deposited elements and matrix crystal lattice were studied. The variation of physical properties due to ion implantation such as phase transition, volume change, the control of single crystal region, and the variation of hardness near surface were investigated, and the examples are presented. (Kato, T.)

A comparative study of gold UCLA-type and CAD/CAM titanium implant abutments

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Park, Ji-Man; Lee, Jai-Bong; Heo, Seong-Joo

2014-01-01

PURPOSE The aim of this study was to evaluate the interface accuracy of computer-assisted designed and manufactured (CAD/CAM) titanium abutments and implant fixture compared to gold-cast UCLA abutments. MATERIALS AND METHODS An external connection implant system (Mark III, n=10) and an internal connection implant system (Replace Select, n=10) were used, 5 of each group were connected to milled titanium abutment and the rest were connected to the gold-cast UCLA abutments. The implant fixture and abutment were tightened to torque of 35 Ncm using a digital torque gauge, and initial detorque values were measured 10 minutes after tightening. To mimic the mastication, a cyclic loading was applied at 14 Hz for one million cycles, with the stress amplitude range being within 0 N to 100 N. After the cyclic loading, detorque values were measured again. The fixture-abutment gaps were measured under a microscope and recorded with an accuracy of ±0.1 µm at 50 points. RESULTS Initial detorque values of milled abutment were significantly higher than those of cast abutment (P.05). After cyclic loading, detorque values of cast abutment increased, but those of milled abutment decreased (Pabutment group and the cast abutment group after cyclic loading. CONCLUSION In conclusion, CAD/CAM milled titanium abutment can be fabricated with sufficient accuracy to permit screw joint stability between abutment and fixture comparable to that of the traditional gold cast UCLA abutment. PMID:24605206

New orthopaedic implant management tool for computer-assisted planning, navigation, and simulation: from implant CAD files to a standardized XML-based implant database.

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Sagbo, S; Blochaou, F; Langlotz, F; Vangenot, C; Nolte, L-P; Zheng, G

2005-01-01

Computer-Assisted Orthopaedic Surgery (CAOS) has made much progress over the last 10 years. Navigation systems have been recognized as important tools that help surgeons, and various such systems have been developed. A disadvantage of these systems is that they use non-standard formalisms and techniques. As a result, there are no standard concepts for implant and tool management or data formats to store information for use in 3D planning and navigation. We addressed these limitations and developed a practical and generic solution that offers benefits for surgeons, implant manufacturers, and CAS application developers. We developed a virtual implant database containing geometrical as well as calibration information for orthopedic implants and instruments, with a focus on trauma. This database has been successfully tested for various applications in the client/server mode. The implant information is not static, however, because manufacturers periodically revise their implants, resulting in the deletion of some implants and the introduction of new ones. Tracking these continuous changes and keeping CAS systems up to date is a tedious task if done manually. This leads to additional costs for system development, and some errors are inevitably generated due to the huge amount of information that has to be processed. To ease management with respect to implant life cycle, we developed a tool to assist end-users (surgeons, hospitals, CAS system providers, and implant manufacturers) in managing their implants. Our system can be used for pre-operative planning and intra-operative navigation, and also for any surgical simulation involving orthopedic implants. Currently, this tool allows addition of new implants, modification of existing ones, deletion of obsolete implants, export of a given implant, and also creation of backups. Our implant management system has been successfully tested in the laboratory with very promising results. It makes it possible to fill the current gap

Ion implantation technology

CERN Document Server

Downey, DF; Jones, KS; Ryding, G

1993-01-01

Ion implantation technology has made a major contribution to the dramatic advances in integrated circuit technology since the early 1970's. The ever-present need for accurate models in ion implanted species will become absolutely vital in the future due to shrinking feature sizes. Successful wide application of ion implantation, as well as exploitation of newly identified opportunities, will require the development of comprehensive implant models. The 141 papers (including 24 invited papers) in this volume address the most recent developments in this field. New structures and possible approach

Individual titanium zygomatic implant

Science.gov (United States)

Nekhoroshev, M. V.; Ryabov, K. N.; Avdeev, E. V.

2018-03-01

Custom individual implants for the reconstruction of craniofacial defects have gained importance due to better qualitative characteristics over their generic counterparts – plates, which should be bent according to patient needs. The Additive Manufacturing of individual implants allows reducing cost and improving quality of implants. In this paper, the authors describe design of zygomatic implant models based on computed tomography (CT) data. The fabrication of the implants will be carried out with 3D printing by selective laser melting machine SLM 280HL.

A 5-year randomized trial to compare 1 or 2 implants for implant overdentures.

Science.gov (United States)

Bryant, S R; Walton, J N; MacEntee, M I

2015-01-01

The hypothesis of this 5-y randomized clinical trial was that there would be no significant difference in the satisfaction of edentulous participants with removable complete overdentures attached to 1 or 2 mandibular implants. Secondary aims were to test changes in satisfaction between and within the groups from baseline to 5 y and differences between the groups in implant survival and prosthodontic maintenance over 5 y. Each of the 86 participants (mean age, 67 y) was randomly allocated to receive either 1 implant in the midline (group 1) or 2 implants in the canine areas (group 2) attached to a mandibular overdenture opposing a maxillary complete denture. Satisfaction was self-assessed by participants on a visual analog scale at baseline prior to implants, as well as at 2 mo and 1, 3, and 5 y with implant overdentures, whereas implant survival and prosthodontic maintenance were assessed by clinical examination. After 5 y, 29 participants in group 1 and 33 in group 2 were available, with most dropouts due to death. Satisfaction with the implant denture after 5 y was significantly (P overdentures retained by 1 implant or 2 implants. Additional research is required to confirm long-term treatment effectiveness of single-implant dentures and the implications of prosthetic maintenance with implant overdentures (ClinicalTrials.gov: NCT02117856). © International & American Associations for Dental Research 2014.

Recent advances in dental implants.

Science.gov (United States)

Hong, Do Gia Khang; Oh, Ji-Hyeon

2017-12-01

Dental implants are a common treatment for the loss of teeth. This paper summarizes current knowledge on implant surfaces, immediate loading versus conventional loading, short implants, sinus lifting, and custom implants using three-dimensional printing. Most of the implant surface modifications showed good osseointegration results. Regarding biomolecular coatings, which have been recently developed and studied, good results were observed in animal experiments. Immediate loading had similar clinical outcomes compared to conventional loading and can be used as a successful treatment because it has the advantage of reducing treatment times and providing early function and aesthetics. Short implants showed similar clinical outcomes compared to standard implants. A variety of sinus augmentation techniques, grafting materials, and alternative techniques, such as tilted implants, zygomatic implants, and short implants, can be used. With the development of new technologies in three-dimension and computer-aided design/computer-aided manufacturing (CAD/CAM) customized implants can be used as an alternative to conventional implant designs. However, there are limitations due to the lack of long-term studies or clinical studies. A long-term clinical trial and a more predictive study are needed.

Comparison of Reconstructive Outcomes in Breast Cancer Patients With Preexisting Subpectoral Implants: Implant-Sparing Mastectomy With Delayed Implant Exchange Versus Immediate Tissue Expander Reconstruction.

Science.gov (United States)

Parabkaharan, Sangeetha; Melody, Megan; Trotta, Rose; Lleshi, Amina; Sun, Weihong; Smith, Paul D; Khakpour, Nazanin; Dayicioglu, Deniz

2016-06-01

Women who have undergone prior augmentation mammoplasty represent a unique subset of breast cancer patients with several options available for breast reconstruction. We performed a single institution review of surgical outcomes of breast reconstruction performed in patients with breast cancer with prior history of subpectoral breast augmentation. Institutional review board-approved retrospective review was conducted among patients with previously mentioned criteria treated at our institution between 2000 and 2014. Reconstructions were grouped into 2 categories as follows: (1) removal of preexisting subpectoral implant during mastectomy with immediate tissue expander placement and (2) implant-sparing mastectomy followed by delayed exchange to a larger implant. We reviewed demographics, tumor features, and reconstruction outcomes of these groups. Fifty-three patients had preexisting subpectoral implants. Of the 63 breast reconstructions performed, 18 (28.6%) had immediate tissue expander placed and 45 (71.4%) had implant-sparing mastectomy followed by delayed implant exchange. The groups were comparable based on age, body mass index, cancer type, tumor grade, TNM stage at presentation, and hormonal receptor status. No significant difference was noted between tumor margins or subsequent recurrence, mastectomy specimen weight, removed implant volume, volume of implant placed during reconstruction, or time from mastectomy to final implant placement. Rates of complications were significantly higher in the tissue expander group compared to the implant-sparing mastectomy group 7 (38.9%) versus 4 (8.9%) (P = 0.005). Implant-sparing mastectomy with delayed implant exchange in patients with preexisting subpectoral implants is safe and has fewer complications compared to tissue expander placement. There was no difference noted in the final volume of implant placed, time interval for final implant placement, or tumor margins.

Effect of implant design and bioactive glass coating on biomechanical properties of fiber-reinforced composite implants.

Science.gov (United States)

Ballo, Ahmed M; Akca, Eralp; Ozen, Tuncer; Moritz, Niko; Lassila, Lippo; Vallittu, Pekka; Närhi, Timo

2014-08-01

This study aimed to evaluate the influence of implant design and bioactive glass (BAG) coating on the response of bone to fiber-reinforced composite (FRC) implants. Three different FRC implant types were manufactured for the study: non-threaded implants with a BAG coating; threaded implants with a BAG coating; and threaded implants with a grit-blasted surface. Thirty-six implants (six implants for each group per time point) were installed in the tibiae of six pigs. After an implantation period of 4 and 12 wk, the implants were retrieved and prepared for micro-computed tomography (micro-CT), push-out testing, and scanning electron microscopy analysis. Micro-CT demonstrated that the screw-threads and implant structure remained undamaged during the installation. The threaded FRC/BAG implants had the highest bone volume after 12 wk of implantation. The push-out strengths of the threaded FRC/BAG implants after 4 and 12 wk (463°N and 676°N, respectively) were significantly higher than those of the threaded FRC implants (416°N and 549°N, respectively) and the nonthreaded FRC/BAG implants (219°N and 430°N, respectively). Statistically significant correlation was found between bone volume and push-out strength values. This study showed that osseointegrated FRC implants can withstand the static loading up to failure without fracture, and that the addition of BAG significantly improves the push-out strength of FRC implants. © 2014 Eur J Oral Sci.

Cochlear Implants

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... implant, including: • How long a person has been deaf, •The number of surviving auditory nerve fibers, and • ... Implant, Severe Sensoryneurial Hearing Loss Get Involved Professional Development Practice Management ENT Careers Marketplace Privacy Policy Terms ...

The clinical implications of poly implant prothèse breast implants: an overview.

Science.gov (United States)

Wazir, Umar; Kasem, Abdul; Mokbel, Kefah

2015-01-01

Mammary implants marketed by Poly Implant Prothèse (PIP) were found to contain industrial grade silicone and this caused heightened anxiety and extensive publicity regarding their safety in humans. These implants were used in a large number of patients worldwide for augmentation or breast reconstruction. We reviewed articles identified by searches of Medline, PubMed, Embase, and Google Scholar databases up to May 2014 using the terms: "PIP", "Poly Implant Prothèse", "breast implants" and "augmentation mammoplasty" "siloxanes" or "silicone". In addition the websites of regulating bodies in Europe, USA, and Australia were searched for reports related to PIP mammary implants. PIP mammary implants are more likely to rupture than other implants and can cause adverse effects in the short to the medium term related to the symptoms of rupture such as pain, lumps in the breast and axilla and anxiety. Based on peer-reviewed published studies we have calculated an overall rupture rate of 14.5% (383/2,635) for PIP implants. However, there is no evidence that PIP implant rupture causes long-term adverse health effects in humans so far. Silicone lymphadenopathy represents a foreign body reaction and should be treated conservatively. The long-term adverse effects usually arise from inappropriate extensive surgery, such as axillary lymph node dissection or extensive resection of breast tissue due to silicone leakage.

The Clinical Implications of Poly Implant Prothèse Breast Implants: An Overview

Directory of Open Access Journals (Sweden)

Umar Wazir

2015-01-01

Full Text Available Mammary implants marketed by Poly Implant Prothèse (PIP were found to contain industrial grade silicone and this caused heightened anxiety and extensive publicity regarding their safety in humans. These implants were used in a large number of patients worldwide for augmentation or breast reconstruction. We reviewed articles identified by searches of Medline, PubMed, Embase, and Google Scholar databases up to May 2014 using the terms: "PIP", "Poly Implant Prothèse", "breast implants" and "augmentation mammoplasty" "siloxanes" or "silicone". In addition the websites of regulating bodies in Europe, USA, and Australia were searched for reports related to PIP mammary implants. PIP mammary implants are more likely to rupture than other implants and can cause adverse effects in the short to the medium term related to the symptoms of rupture such as pain, lumps in the breast and axilla and anxiety. Based on peer-reviewed published studies we have calculated an overall rupture rate of 14.5% (383/2,635 for PIP implants. However, there is no evidence that PIP implant rupture causes long-term adverse health effects in humans so far. Silicone lymphadenopathy represents a foreign body reaction and should be treated conservatively. The long-term adverse effects usually arise from inappropriate extensive surgery, such as axillary lymph node dissection or extensive resection of breast tissue due to silicone leakage.

Silver oxide-containing hydroxyapatite coating supports osteoblast function and enhances implant anchorage strength in rat femur.

Science.gov (United States)

Eto, Shuichi; Miyamoto, Hiroshi; Shobuike, Takeo; Noda, Iwao; Akiyama, Takayuki; Tsukamoto, Masatsugu; Ueno, Masaya; Someya, Shinsuke; Kawano, Shunsuke; Sonohata, Motoki; Mawatari, Masaaki

2015-09-01

Antibacterial silver with hydroxyapatite (Ag-HA) is a promising coating material for imparting antibacterial properties to implants. We previously reported that 3% (w/w) silver with HA (3% Ag-HA) has both antibacterial activity and osteoconductivity. In this study, we investigated the effects of Ag-HA on the in vitro osteoblast function and the in vivo anchorage strength and osteoconductivity of implants. Production of the osteoblast marker alkaline phosphatase, but not cytotoxicity, was observed in cells of the osteoblast cell line MC3T3-E1 cultured on the 3% Ag-HA-coated surface. These results were similar to those observed with silver-free HA coating. In contrast, a significant high level of cytotoxicity was observed when the cells were cultured on a 50% Ag-HA-coated surface. The anchorage strength of implants inserted into the femur of Sprague-Dawley (SD) rats was enhanced by coating the implants with 3% Ag-HA. On the 3% Ag-HA-coated surface, both metaphyseal and diaphyseal areas were largely covered with new bone and had adequate osteoconductivity. These results suggest that 3% Ag-HA, like conventional HA, promotes osteogenesis by supporting osteoblast viability and function and thereby contributes to sufficient anchorage strength of implants. Application of 3% Ag-HA, which combines the osteoconductivity of HA and the antibacterial activity of silver, to prosthetic joints will help prevent postoperative infections. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Management of peri-implant infections

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K L Vandana

2015-01-01

Full Text Available The ever-increasing popularity of dental implants in recent years has been associated with the reported incidence of short-term and long-term complications such as peri-implant mucositis and peri-implantitis. Therapies proposed for treating peri-implantitis are based on the evidence available for the treatment of periodontitis, and are aimed at reducing the bacterial load within peri-implant pockets and decontaminating implant surfaces, and, in some cases, attempting afterward to bring about bone regeneration. The treatment of peri-implant infections comprises conservative (nonsurgical and surgical approaches. This paper reviews various treatment strategies used for the treatment of peri-implant diseases. There are many approaches suggested by various authors for the treatment of peri-implant diseases, but there is no “ideal peri-implant therapy” that has been described in the literature. There is no consensus regarding the treatment protocol as the studies conducted so far have had varying study designs, small sample sizes, and short follow-up periods.

An in vivo assessment of the effects of using different implant abutment occluding materials on implant microleakage and the peri-implant microbiome

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Rubino, Caroline

Microleakage may be a factor in the progression of peri-implant pathology. Microleakage in implant dentistry refers to the passage of bacteria, fluids, molecules or ions between the abutment-implant interface to and from the surrounding periodontal tissues. This creates a zone of inflammation and reservoir of bacteria at the implant-abutment interface. Bone loss typically occurs within the first year of abutment connection and then stabilizes. It has not yet been definitively proven that the occurrence of microleakage cannot contribute to future bone loss or impede the treatment of peri-implant disease. Therefore, strategies to reduce or eliminate microleakage are sought out. Recent evidence demonstrates that the type of implant abutment channel occluding material can affect the amount of microleakage in an in vitro study environment. Thus, we hypothesize that different abutment screw channel occluding materials will affect the amount of observed microleakage, vis-a-vis the correlation between the microflora found on the abutment screw channel occluding material those found in the peri-implant sulcus. Additional objectives include confirming the presence of microleakage in vivo and assessing any impact that different abutment screw channel occluding materials may have on the peri-implant microbiome. Finally, the present study provides an opportunity to further characterize the peri-implant microbiome. Eight fully edentulous patients restored with at dental implants supporting screw-retained fixed hybrid prostheses were included in the study. At the initial appointment (T1), the prostheses were removed and the implants and prostheses were cleaned. The prostheses were then inserted with polytetrafluoroethylene tape (PTFE, TeflonRTM), cotton, polyvinyl siloxane (PVS), or synthetic foam as the implant abutment channel occluding material and sealed over with composite resin. About six months later (T2), the prostheses were removed and the materials collected. Paper

Biodegradable radioactive implants for glaucoma filtering surgery produced by ion implantation

Energy Technology Data Exchange (ETDEWEB)

Assmann, W. [Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, 85748 Garching (Germany)]. E-mail: walter.assmann@lmu.de; Schubert, M. [Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, 85748 Garching (Germany); Held, A. [Augenklinik, Technische Universitaet Muenchen, 81675 Munich (Germany); Pichler, A. [Augenklinik, Technische Universitaet Muenchen, 81675 Muenchen (Germany); Chill, A. [Zentralinstitut fuer Medizintechnik, Technische Universitaet Muenchen, 85748 Garching (Germany); Kiermaier, S. [Zentralinstitut fuer Medizintechnik, Technische Universitaet Muenchen, 85748 Garching (Germany); Schloesser, K. [Forschungszentrum Karlsruhe, 76021 Karlsruhe (Germany); Busch, H. [NTTF GmbH, 53619 Rheinbreitbach (Germany); Schenk, K. [NTTF GmbH, 53619 Rheinbreitbach (Germany); Streufert, D. [Acri.Tec GmbH, 16761 Hennigsdorf (Germany); Lanzl, I. [Augenklinik, Technische Universitaet Muenchen, 81675 Munich (Germany)

2007-04-15

A biodegradable, {beta}-emitting implant has been developed and successfully tested which prevents fresh intraocular pressure increase after glaucoma filtering surgery. Ion implantation has been used to load the polymeric implants with the {beta}-emitter {sup 32}P. The influence of ion implantation and gamma sterilisation on degradation and {sup 32}P-fixation behavior has been studied by ion beam and chemical analysis. Irradiation effects due to the applied ion fluence (10{sup 15} ions/cm{sup 2}) and gamma dose (25 kGy) are found to be tolerable.

Trends in cochlear implants.

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Zeng, Fan-Gang

2004-01-01

More than 60,000 people worldwide use cochlear implants as a means to restore functional hearing. Although individual performance variability is still high, an average implant user can talk on the phone in a quiet environment. Cochlear-implant research has also matured as a field, as evidenced by the exponential growth in both the patient population and scientific publication. The present report examines current issues related to audiologic, clinical, engineering, anatomic, and physiologic aspects of cochlear implants, focusing on their psychophysical, speech, music, and cognitive performance. This report also forecasts clinical and research trends related to presurgical evaluation, fitting protocols, signal processing, and postsurgical rehabilitation in cochlear implants. Finally, a future landscape in amplification is presented that requires a unique, yet complementary, contribution from hearing aids, middle ear implants, and cochlear implants to achieve a total solution to the entire spectrum of hearing loss treatment and management.

Micro-cutting of silicon implanted with hydrogen and post-implantation thermal treatment

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Jelenković, Emil V.; To, Suet; Sundaravel, B.; Xiao, Gaobo; Huang, Hu

2016-07-01

It was reported that non-amorphizing implantation by hydrogen has a potential in improving silicon machining. Post-implantation high-temperature treatment will affect implantation-induced damage, which can have impact on silicon machining. In this article, a relation of a thermal annealing of hydrogen implanted in silicon to micro-cutting experiment is investigated. Hydrogen ions were implanted into 4″ silicon wafers with 175 keV, 150 keV, 125 keV and doses of 2 × 1016 cm-2, 2 × 1016 cm-2 and 3 × 1016 cm-2, respectively. In this way, low hydrogen atom-low defect concentration was created in the region less than ~0.8 μm deep and high hydrogen atom-high defect concentration was obtained at silicon depth of ~0.8-1.5 μm. The post-implantation annealing was carried out at 300 and 400 °C in nitrogen for 1 h. Physical and electrical properties of implanted and annealed samples were characterized by secondary ion mass spectroscopy (SIMS), X-ray diffraction (XRD), Rutherford backscattering (RBS) and nanoindentation. Plunge cutting experiment was carried out in and silicon crystal direction. The critical depth of cut and cutting force were monitored and found to be influenced by the annealing. The limits of hydrogen implantation annealing contribution to the cutting characteristics of silicon are discussed in light of implantation process and redistribution of hydrogen and defects generation during annealing process.

Modification of implant material surface properties by means of oxide nano-structured coatings deposition

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Safonov, Vladimir; Zykova, Anna; Smolik, Jerzy; Rogowska, Renata; Lukyanchenko, Vladimir; Kolesnikov, Dmitrii

2014-08-01

The deposition of functional coatings on the metal surface of artificial joints is an effective way of enhancing joint tribological characteristics. It is well-known that nanostructured oxide coatings have specific properties advantageous for future implant applications. In the present study, we measured the high hardness parameters, the adhesion strength and the low friction coefficient of the oxide magnetron sputtered coatings. The corrosion test results show that the oxide coating deposition had improved the corrosion resistance by a factor of ten for both stainless steel and titanium alloy substrates. Moreover, the hydrophilic nature of coated surfaces in comparison with the metal ones was investigated in the tensiometric tests. The surfaces with nanostructured oxide coatings demonstrated improved biocompatibility for in vitro and in vivo tests, attributed to the high dielectric constants and the high values of the surface free energy parameters.

Do the radial head prosthesis components fit with the anatomical structures of the proximal radioulnar joint?

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Wegmann, Kilian; Hain, Moritz K; Ries, Christian; Neiss, Wolfram F; Müller, Lars P; Burkhart, Klaus J

2015-09-01

The fitting accuracy of radial head components has been investigated in the capitulo-radial joint, and reduced contact after prosthetic replacement of the radial head has been observed. The kinematics of the proximal radioulnar joint (PRUJ) are affected by radial head arthroplasty as well, but have not yet been investigated in this regard. The elbow joints of 60 upper extremities of formalin-fixed body donors were disarticulated to obtain a good view of the PRUJ. Each specimen was mounted on the examining table and radial head position in the native PRUJ was assessed in neutral position, full pronation, and full supination. Measurements were repeated after implantation of mono- and bi-polar prostheses. Analysis of the distribution of the joint contacts in the compartments showed significant differences after radial head replacement. In comparison to the native joint, after bipolar and monopolar radial head replacement, the physiological shift of the proximal radius was altered. The physiological shift of the joint contact of the radial head from anterior to posterior during forearm rotation that was found in the native joint in our cadaver model was not observed after prosthetic replacement. With higher conformity and physiological kinematic of radial head prostheses, possibly lower shear forces and lower contact pressures would be generated. The tested radial head prostheses do not replicate the physiological kinematics of the radial head. Further development in the prosthesis design has to be made. The meticulous reconstruction of the annular ligament seems to be of importance to increase joint contact.

Chimeric Peptides as Implant Functionalization Agents for Titanium Alloy Implants with Antimicrobial Properties

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Yucesoy, Deniz T.; Hnilova, Marketa; Boone, Kyle; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

2015-04-01

Implant-associated infections can have severe effects on the longevity of implant devices and they also represent a major cause of implant failures. Treating these infections associated with implants by antibiotics is not always an effective strategy due to poor penetration rates of antibiotics into biofilms. Additionally, emerging antibiotic resistance poses serious concerns. There is an urge to develop effective antibacterial surfaces that prevent bacterial adhesion and proliferation. A novel class of bacterial therapeutic agents, known as antimicrobial peptides (AMPs), are receiving increasing attention as an unconventional option to treat septic infection, partly due to their capacity to stimulate innate immune responses and for the difficulty of microorganisms to develop resistance towards them. While host and bacterial cells compete in determining the ultimate fate of the implant, functionalization of implant surfaces with AMPs can shift the balance and prevent implant infections. In the present study, we developed a novel chimeric peptide to functionalize the implant material surface. The chimeric peptide simultaneously presents two functionalities, with one domain binding to a titanium alloy implant surface through a titanium-binding domain while the other domain displays an antimicrobial property. This approach gains strength through control over the bio-material interfaces, a property built upon molecular recognition and self-assembly through a titanium alloy binding domain in the chimeric peptide. The efficiency of chimeric peptide both in-solution and absorbed onto titanium alloy surface was evaluated in vitro against three common human host infectious bacteria, Streptococcus mutans, Staphylococcus epidermidis, and Escherichia coli. In biological interactions such as occur on implants, it is the surface and the interface that dictate the ultimate outcome. Controlling the implant surface by creating an interface composed chimeric peptides may therefore

Congenital cheek teratoma with temporo-mandibular joint ankylosis managed with ultra-thin silicone sheet interpositional arthroplasty.

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Bhatnagar, Ankur; Verma, Vinay Kumar; Purohit, Vishal

2013-01-01

Primary cheek teratomas are rare with joint ankylosis (TMJA). The fundamental aim in the treatment of TMJA is the successful surgical resection of ankylotic bone, prevention of recurrence, and aesthetic improvement by ensuring functional occlusion. Early treatment is necessary to promote proper growth and function of mandible and to facilitate the positive psychological development of child. Inter-positional arthroplasty with ultra-thin silicone sheet was performed. Advantages include short operative time, less foreign material in the joint space leading to negligible foreign body reactions and least chances of implant extrusion. Instead of excising a large bony segment, a thin silicone sheet was interposed and then sutured ensuring preservation of mandibular height. Aggressive post-operative physiotherapy with custom made dynamic jaw exerciser was used to prevent recurrence.

Immediately loaded mini dental implants as overdenture retainers: 1-Year cohort study of implant stability and peri-implant marginal bone level.

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Šćepanović, Miodrag; Todorović, Aleksandar; Marković, Aleksa; Patrnogić, Vesna; Miličić, Biljana; Moufti, Adel M; Mišić, Tijana

2015-05-01

This 1-year cohort study investigated stability and peri-implant marginal bone level of immediately loaded mini dental implants used to retain overdentures. Each of 30 edentulous patients received 4 mini dental implants (1.8 mm × 13 mm) in the interforaminal mandibular region. The implants were immediately loaded with pre-made overdentures. Outcome measures included implant stability and bone resorption. Implant stability was measured using the Periotest Classic(®) device immediately after placement and on the 3rd and 6th weeks and the 4th, 6th and 12th months postoperatively. The peri-implant marginal bone level (PIBL) was evaluated at the implant's mesial and distal sides from the polished platform to the marginal crest. Radiographs were taken using a tailored film holder to reproducibly position the X-ray tube at the 6th week, 4th and 12th months postoperatively. The primary stability (Periotest value, PTV) measured -0.27 ± 3.41 on a scale of -8 to + 50 (lower PTV reflects higher stability). The secondary stability decreased significantly until week 6 (mean PTV = 7.61 ± 7.05) then increased significantly reaching (PTV = 6.17 ± 6.15) at 12 months. The mean PIBL measured -0.40 mm after 1 year of functional loading, with no statistically significant differences at the various follow-ups (p = 0.218). Mini dental implants placed into the interforaminal region could achieve a favorable primary stability for immediate loading. The follow-up Periotest values fluctuated, apparently reflecting the dynamics of bone remodeling, with the implants remaining clinically stable (98.3%) after 1 year of function. The 1-year bone resorption around immediately loaded MDIs is within the clinically acceptable range for standard implants. Copyright © 2014 Elsevier GmbH. All rights reserved.

Comparative silicone breast implant evaluation using mammography, sonography, and magnetic resonance imaging: experience with 59 implants.

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Ahn, C Y; DeBruhl, N D; Gorczyca, D P; Shaw, W W; Bassett, L W

1994-10-01

With the current controversy regarding the safety of silicone implants, the detection and evaluation of implant rupture are causing concern for both plastic surgeons and patients. Our study obtained comparative value analysis of mammography, sonography, and magnetic resonance imaging (MRI) in the detection of silicone implant rupture. Twenty-nine symptomatic patients (total of 59 silicone implants) were entered into the study. Intraoperative findings revealed 21 ruptured implants (36 percent). During physical examination, a positive "squeeze test" was highly suggestive of implant rupture. Mammograms were obtained of 51 implants (sensitivity 11 percent, specificity 89 percent). Sonography was performed on 57 implants (sensitivity 70 percent, specificity 92 percent). MRI was performed on 55 implants (sensitivity 81 percent, specificity 92 percent). Sonographically, implant rupture is demonstrated by the "stepladder sign." Double-lumen implants may appear as false-positive results for rupture on sonography. On MRI, the "linguine sign" represents disrupted fragments of a ruptured implant. The most reliable imaging modality for implant rupture detection is MRI, followed by sonogram. Mammogram is the least reliable. Our study supports the clinical indication and diagnostic value of sonogram and MRI in the evaluation of symptomatic breast implant patients.

The Efficacy of Supportive Peri-Implant Therapies in Preventing Peri-Implantitis and Implant Loss: a Systematic Review of the Literature

Directory of Open Access Journals (Sweden)

Ausra Ramanauskaite

2016-09-01

Full Text Available Objectives: To study the efficacy of supportive peri-implant therapies in preventing clinical and radiological signs of peri-implantitis and implant loss. Material and Methods: Longitudinal human studies, published between January 1, 2006, and February 1, 2016, were included based on an electronic search using MEDLINE and EMBASE databases and complemented by a manual search. Articles were included only if 1 they comprised a group of patients involved in/adhering to regular supportive peri-implant therapies (SPTs and a control group without such therapies or with poor adherence to them, 2 the protocol of the SPTs was clearly described and 3 the outcome was indicated by means of clinical/radiological changes or implant loss. Results: After initially identifying a total of 710 titles and abstracts, 12 full text articles were selected for eligibility assessment. Seven studies, three prospective and four retrospective, fulfilled the inclusion criteria for this review. The frequency of recall visits varied between the studies from a minimum of one visit every three months to an individually tailored regimen. In all the studies a lack of SPTs or poor adherence to them resulted in significantly higher frequencies of sites with mucosal bleeding, deepened peri-implant pockets or alveolar bone loss. In line with the above, a lack of/poor adherence to SPTs was associated with higher implant loss. Conclusions: To prevent peri-implantitis, an individually tailored supportive programme based on patient motivation and re-instruction in oral hygiene measures combined with professional implant cleaning seem to be crucial.

Anatomical principles for minimally invasive reconstruction of the acromioclavicular joint with anchors.

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Xiong, Chuanzhi; Lu, Yaojia; Wang, Qiang; Chen, Gang; Hu, Hansheng; Lu, Zhihua

2016-11-01

The aim of this study was to evaluate the outcome of a minimally invasive surgical technique for the treatment of patients with acromioclavicular joint dislocation. Sixteen patients with complete acromioclavicular joint dislocation were enrolled in this study. All patients were asked to follow the less active rehabilitation protocol post-operatively. Computed tomography with 3-D reconstruction of the injured shoulder was performed on each patient post operatively for the assessment of the accuracy of the suture anchor placement in the coracoid process and the reduction of the acromioclavicular joint. Radiographs of Zanca view and axillary view of both shoulders were taken for evaluating the maintenance of the acromioclavicular joint reduction at each follow-up visit. The Constant shoulder score was used for function assessment at the final follow-up. Twenty seven of the 32 anchors implanted in the coracoid process met the criteria of good position. One patient developed complete loss of reduction and another had partial loss of reduction in the anteroposterior plane. For the other 14 patients, the mean Constant score was 90 (range, 82-95). For the patients with partial and complete loss of reduction, the Constant score were 92 and 76 respectively. All of them got nearly normal range of motion of the shoulders and restored to pre-operative life and works. With this minimally invasive approach and limited exposure of the coracoid, a surgeon can place the suture anchors at the anatomical insertions of the coracoclavicular ligament and allow the dislocated joint reduced and maintained well. Level IV, Case series; therapeutic study.

Hip Joint Replacement Using Monofilament Polypropylene Surgical Mesh: An Animal Model

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Jacek Białecki

2014-01-01

Full Text Available Hip joint dysplasia is a deformation of the articular elements (pelvic acetabulum, head of the femur, and/or ligament of the head of the femur leading to laxity of the hip components and dislocation of the femoral head from the pelvic acetabulum. Diagnosis is based on symptoms observed during clinical and radiological examinations. There are two treatment options: conservative and surgical. The classic surgical procedures are juvenile pubic symphysiodesis (JPS, triple pelvic osteotomy (TPO, total hip replacement (THR, and femoral head and neck resection (FHNE. The aim of this experiment was to present an original technique of filling the acetabulum with a polypropylene implant, resting the femoral neck directly on the mesh. The experiment was performed on eight sheep. The clinical value of the new surgical technique was evaluated using clinical, radiological, and histological methods. This technique helps decrease the loss of limb length by supporting the femoral neck on the mesh equivalent to the femoral head. It also reduces joint pain and leads to the formation of stable and mobile pseudarthrosis. The mesh manifested osteoprotective properties and enabled the formation of a stiff-elastic connection within the hip joint. The method is very cost-effective and the technique itself is simple to perform.

Repair of articular osteochondral defects of the knee joint using a composite lamellar scaffold.

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Lv, Y M; Yu, Q S

2015-04-01

The major problem with repair of an articular cartilage injury is the extensive difference in the structure and function of regenerated, compared with normal cartilage. Our work investigates the feasibility of repairing articular osteochondral defects in the canine knee joint using a composite lamellar scaffold of nano-ß-tricalcium phosphate (ß-TCP)/collagen (col) I and II with bone marrow stromal stem cells (BMSCs) and assesses its biological compatibility. The bone-cartilage scaffold was prepared as a laminated composite, using hydroxyapatite nanoparticles (nano-HAP)/collagen I/copolymer of polylactic acid-hydroxyacetic acid as the bony scaffold, and sodium hyaluronate/poly(lactic-co-glycolic acid) as the cartilaginous scaffold. Ten-to 12-month-old hybrid canines were randomly divided into an experimental group and a control group. BMSCs were obtained from the iliac crest of each animal, and only those of the third generation were used in experiments. An articular osteochondral defect was created in the right knee of dogs in both groups. Those in the experimental group were treated by implanting the composites consisting of the lamellar scaffold of ß-TCP/col I/col II/BMSCs. Those in the control group were left untreated. After 12 weeks of implantation, defects in the experimental group were filled with white semi-translucent tissue, protruding slightly over the peripheral cartilage surface. After 24 weeks, the defect space in the experimental group was filled with new cartilage tissues, finely integrated into surrounding normal cartilage. The lamellar scaffold of ß-TCP/col I/col II was gradually degraded and absorbed, while new cartilage tissue formed. In the control group, the defects were not repaired. This method can be used as a suitable scaffold material for the tissue-engineered repair of articular cartilage defects. Cite this article: Bone Joint Res 2015;4:56-64. ©2015 The British Editorial Society of Bone & Joint Surgery.

Fixation of Hydroxyapatite-Coated Revision Implants Is Improved by the Surgical Technique of Cracking the Sclerotic Bone Rim

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Elmengaard, Brian; Bechtold, Joan E.; Chen, Xinqian; Søballe, Kjeld

2013-01-01

Revision joint replacement has poorer outcomes that have been associated with poorer mechanical fixation. We investigate a new bone-sparing surgical technique that locally cracks the sclerotic bone rim formed during aseptic loosening. We inserted 16 hydroxyapatite-coated implants bilaterally in the distal femur of eight dogs, using a controlled weight-bearing experimental model that replicates important features of a typical revision setting. At 8 weeks, a control revision procedure and a crack revision procedure were performed on contralateral implants. The crack procedure used a splined tool to perform a systematic local perforation of the sclerotic bone rim of the revision cavity. After 4 weeks, the hydroxyapatite-coated implants were evaluated for mechanical fixation by a push-out test and for tissue distribution by histomorphometry. The cracking revision procedure resulted in significantly improved mechanical fixation, significantly more bone ongrowth and bone volume in the gap, and reduced fibrous tissue compared to the control revision procedure. The study demonstrates that the sclerotic bone rim prevents bone ingrowth and promotes fixation by fibrous tissue. The effect of the cracking technique may be due to improved access to the vascular compartment of the bone. The cracking technique is a simple surgical method that potentially can improve the fixation of revision implants in sclerotic regions important for obtaining the fixation critical for overall implant stability. PMID:19148940

Transcription factor ERG and joint and articular cartilage formation during mouse limb and spine skeletogenesis.

Science.gov (United States)

Iwamoto, Masahiro; Tamamura, Yoshihiro; Koyama, Eiki; Komori, Toshihisa; Takeshita, Nobuo; Williams, Julie A; Nakamura, Takashi; Enomoto-Iwamoto, Motomi; Pacifici, Maurizio

2007-05-01

Articular cartilage and synovial joints are critical for skeletal function, but the mechanisms regulating their development are largely unknown. In previous studies we found that the ets transcription factor ERG and its alternatively-spliced variant C-1-1 have roles in joint formation in chick. Here, we extended our studies to mouse. We found that ERG is also expressed in developing mouse limb joints. To test regulation of ERG expression, beads coated with the joint master regulator protein GDF-5 were implanted close to incipient joints in mouse limb explants; this led to rapid and strong ectopic ERG expression. We cloned and characterized several mammalian ERG variants and expressed a human C-1-1 counterpart (hERG3Delta81) throughout the cartilaginous skeleton of transgenic mice, using Col2a1 gene promoter/enhancer sequences. The skeletal phenotype was severe and neonatal lethal, and the transgenic mice were smaller than wild type littermates and their skeletons were largely cartilaginous. Limb long bone anlagen were entirely composed of chondrocytes actively expressing collagen IX and aggrecan as well as articular markers such as tenascin-C. Typical growth plates were absent and there was very low expression of maturation and hypertrophy markers, including Indian hedgehog, collagen X and MMP-13. The results suggest that ERG is part of molecular mechanisms leading chondrocytes into a permanent developmental path and become joint forming cells, and may do so by acting downstream of GDF-5.

Effect of wrist and interphalangeal thumb movement on zone T2 flexor pollicis longus tendon tension in a human cadaver model.

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Rappaport, Patricia O; Thoreson, Andrew R; Yang, Tai-Hua; Reisdorf, Ramona L; Rappaport, Stephen M; An, Kai-Nan; Amadio, Peter C

2015-01-01

Therapy after flexor pollicis longus (FPL) repair typically mimics finger flexor management, but this ignores anatomic and biomechanical features unique to the FPL. We measured FPL tendon tension in zone T2 to identify biomechanically appropriate exercises for mobilizing the FPL. Eight human cadaver hands were studied to identify motions that generated enough force to achieve FPL movement without exceeding hypothetical suture strength. With the carpometacarpal and metacarpophalangeal joints blocked, appropriate forces were produced for both passive interphalangeal (IP) motion with 30° wrist extension and simulated active IP flexion from 0° to 35° with the wrist in the neutral position. This work provides a biomechanical basis for safely and effectively mobilizing the zone T2 FPL tendon. Our cadaver study suggests that it is safe and effective to perform early passive and active exercise to an isolated IP joint. NA. Copyright © 2015 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Benefits and Risks of Cochlear Implants

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... and Medical Procedures Implants and Prosthetics Cochlear Implants Benefits and Risks of Cochlear Implants Share Tweet Linkedin ... the Use of Cochlear Implants What are the Benefits of Cochlear Implants? For people with implants: Hearing ...

An economic evaluation of maxillary implant overdentures based on six vs. four implants.

Science.gov (United States)

Listl, Stefan; Fischer, Leonhard; Giannakopoulos, Nikolaos Nikitas

2014-08-18

The purpose of the present study was to assess the value for money achieved by bar-retained implant overdentures based on six implants compared with four implants as treatment alternatives for the edentulous maxilla. A Markov decision tree model was constructed and populated with parameter estimates for implant and denture failure as well as patient-centred health outcomes as available from recent literature. The decision scenario was modelled within a ten year time horizon and relied on cost reimbursement regulations of the German health care system. The cost-effectiveness threshold was identified above which the six-implant solution is preferable over the four-implant solution. Uncertainties regarding input parameters were incorporated via one-way and probabilistic sensitivity analysis based on Monte-Carlo simulation. Within a base case scenario of average treatment complexity, the cost-effectiveness threshold was identified to be 17,564 € per year of denture satisfaction gained above of which the alternative with six implants is preferable over treatment including four implants. Sensitivity analysis yielded that, depending on the specification of model input parameters such as patients' denture satisfaction, the respective cost-effectiveness threshold varies substantially. The results of the present study suggest that bar-retained maxillary overdentures based on six implants provide better patient satisfaction than bar-retained overdentures based on four implants but are considerably more expensive. Final judgements about value for money require more comprehensive clinical evidence including patient-centred health outcomes.