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Sample records for artificial disc arthroplasty

  1. Cervical disc arthroplasty with ProDisc-C artificial disc: 5-year radiographic follow-up results

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yan-bin; SUN Yu; ZHOU Fei-fei; LIU ZHONG-jun

    2013-01-01

    Background Cervical disc arthroplasty is an alternative surgery to standard cervical decompression and fusion for disc degeneration.Different types of cervical disc prosthesis are used in China.The aim of this study was to evaluate the radiographic outcomes of cervical arthroplasty using the ProDisc-C prosthesis.Methods Radiographic evaluation,including static and dynamic flexion-extension lateral images,was performed at baseline and at final follow-up.Results Twenty six patients who had single-level ProDisc-C arthroplasty were followed up for a mean period of 63 months (56-76 months).The range of motion at the operated level was 9.3°±3.7° at baseline and 7.3°±3.5° at final follow-up,with a significant difference (P <0.05).Seventeen of 26 levels (65.4%) developed heterotopic ossification:three were classified as grade Ⅱ,13 were classified as grade Ⅲ,and 1 as grade Ⅳ,according to McAfee's classification.Forty nine adjacent segments were evaluated by lateral Ⅹ-ray and 18 (36.7%) segments developed adjacent segment degenerations.Conclusions ProDisc-C arthroplasty had acceptable radiographic results at 5-year follow-up.The range of motion was preserved.However,more than 60% of the patients developed heterotopic ossification.

  2. Clinical and radiographic results of cervical artificial disc arthroplasty: over three years follow-up cohort study

    Institute of Scientific and Technical Information of China (English)

    TIAN Wei; HAN Xiao; LIU Bo; LI Qin; HU Lin; LI Zhi-yu; YUAN Qiang; HE Da; XING Yong-gang

    2010-01-01

    Background Theoretic advantages of cervical disc arthroplasty include preservation of normal motion and biomechanics in the cervical spine, and reduction of adjacent-segment degeneration. The clinical and radiographic effects of cervical disc arthroplasty in short term have been ascertained. The aim of this study is to research the data of mid-term results.Methods In this prospective cohort study, 50 patients who underwent cervical disc arthroplasty from December 2003 to January 2006 were enrolled. There were 39 patients who received 1-level disc arthroplasty, and 11 patients received 2-level disc arthroplasty, with an average age of 50.9 years (range from 29 to 73). The median follow-up was 41.85months (range from 36.00-55.63 months). Patients were followed prospectively with respect to their symptoms,neurologic signs, and radiographic results.Results The median value of Japanese Orthopaedic Association (JOA) score was 14.0 before surgery, and 16.5 at the most recent follow-up (P <0.01). The median value of the recovery rate of the JOA score was 92.2%. The preoperative range of motion (ROM) at the indexed level was (10.40±4.97)°, which has significantly correlated with the most recent follow-up ROM which was (8.56±4.76)° (P <0.05, r=0.33). The ROM at the operative level at the most recent follow-upwas greater than the value at the 3-month follow-up of (7.52±3.37)° (P <0.05). The preoperative functional spinal unit (FSU) angulation was (-0.96±6.52)°, which was not significantly correlated with that of the most recent follow-up value of (-2.65±7.95)° (P <0.01, r=0.53). The preoperative endplate angulation was (2.61±4.85)°, which had no significant correlation with that of the most recent follow-up value of (0.71±6.41)° (p >0.05).Conclusions The clinical and radiographic results of cervical disc arthroplasty are good in mid-term follow-up. The normal range of motion of the operated level and the biomechanics in the cervical spine are well

  3. Total Disc Arthroplasty for Treating Lumbar Degenerative Disc Disease

    OpenAIRE

    Mostofi, Keyvan

    2015-01-01

    Study Design Lumber disc arthroplasty is a technological advancement that has occurred in the last decade to treat lumbar degenerative disk diseases. Purpose The aim of this retrospective study was to establish the impact and outcomes of managing patients with lumbar degenerative disk disease who have been treated with lumbar total disc arthroplasty (TDA). Overview of Literature Several studies have shown promising results following this surgery. Methods We reviewed the files of 104 patients ...

  4. Bryan total disc arthroplasty: a replacement disc for cervical disc disease

    OpenAIRE

    Wenger, Markus

    2010-01-01

    Markus Wenger1, Thomas-Marc Markwalder21Neurosurgery, Klinik Beau-Site and Salem-Spital, Berne, Switzerland; 2Attending Neurosurgeon FMH, Private Practice Spine Surgery, Berne-Muri, SwitzerlandAbstract: Total disc arthroplasty is a new option in the treatment of cervical degenerative disc disease. Several types of cervical disc prostheses currently challenge the gold-standard discectomy and fusion procedures. This review describes the Bryan Cervical Disc System and presents the Bryan prosthes...

  5. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... a total disc replacement arthroplasty on a young patient who has a herniated disc in her neck. ... way in, it’s, you know, I find that patients have very little pain after surgery. And just ...

  6. Artificial Cervical Disc Replacement Improves Mobility

    Science.gov (United States)

    Artificial Cervical Disc Replacement Improves Mobility February 18, 2009 From PinnacleHealth, Harrisburg, PA Welcome to this “OR ... this new technology with the use of an artificial disc has some significant benefits over the previous ...

  7. Heterotopic Ossification Causing Radiculopathy after Lumbar Total Disc Arthroplasty

    OpenAIRE

    Jackson, Keith L.; Hire, Justin M; Jacobs, Jeremy M.; Key, Charles C.; DeVine, John G.

    2015-01-01

    To date, no reports have presented radiculopathy secondary to heterotopic ossification following lumbar total disc arthroplasty. The authors present a previously unpublished complication of lumbar total disk arthroplasty (TDA) secondary to heterotopic ossification (HO) in the spinal canal, and they propose a modification to the McAfee classification of HO. The patient had undergone an L5/S1 lumbar TDA two years prior due to discogenic back pain. His preoperative back pain was significantly re...

  8. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... spine problems in up to date but this new technology with the use of an artificial disc ... of patients for many, many. Prior to this new technology, we would take out that disc and ...

  9. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... problems in up to date but this new technology with the use of an artificial disc has ... patients for many, many. Prior to this new technology, we would take out that disc and then ...

  10. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available Artificial Cervical Disc Replacement Improves Mobility February 18, 2009 From PinnacleHealth, Harrisburg, PA Welcome to this “OR ... this new technology with the use of an artificial disc has some significant benefits over the previous ...

  11. Design concepts in lumbar total disc arthroplasty

    OpenAIRE

    Galbusera, Fabio; Bellini, Chiara M.; Zweig, Thomas; Ferguson, Stephen; Raimondi, Manuela T.; Lamartina, Claudio; Brayda-bruno, Marco; Fornari, Maurizio

    2008-01-01

    The implantation of lumbar disc prostheses based on different design concepts is widely accepted. This paper reviews currently available literature studies on the biomechanics of TDA in the lumbar spine, and is targeted at the evaluation of possible relationships between the aims of TDA and the geometrical, mechanical and material properties of the various available disc prostheses. Both theoretical and experimental studies were analyzed, by a PUBMED search (performed in February 2007, revise...

  12. The Research of Artificial Cervical Disc Replacement

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhua; Qiang Shenb

    2008-01-01

    Cervical arthroplasty after anterior decompression with insertion of a prosthetic total disc replacement has been suggested as an alternate to anterior cervical fusion. It develops quickly during recent years. Currently there are several cervical arthroplasty devices. Each device varies in terms of materials, range of motion and constraint. Early studies suggest that in the short term, the complication rate and efficacy is no worse than fusion surgery. Long-term results have not yet been reported. This review examines the current prostheses as well as discussing issues regarding indications and technique. It is hoped that an improvement of cervical arthroplasty occurs in terms of materials and design as spinal surgeons enter a new dines of the management of cervical spine disease.

  13. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... to date but this new technology with the use of an artificial disc has some significant benefits ... facing straight up. The incision that Dr. Beutler uses is a little over an inch long, and ...

  14. Requirements for an artificial intervertebral disc

    NARCIS (Netherlands)

    Eijkelkamp, MF; van Donkelaar, CC; Veldhuizen, AG; van Horn, [No Value; Huyghe, JM; Verkerke, GJ

    2001-01-01

    Intervertebral disc degeneration is an important social and economic problem. Presently available artificial intervertebral discs (AIDs) are insufficient and the main surgical intervention is still spinal fusion. The objective of the present study is to present a list of requirements for the develop

  15. Heterotopic Ossification Causing Radiculopathy after Lumbar Total Disc Arthroplasty.

    Science.gov (United States)

    Jackson, Keith L; Hire, Justin M; Jacobs, Jeremy M; Key, Charles C; DeVine, John G

    2015-06-01

    To date, no reports have presented radiculopathy secondary to heterotopic ossification following lumbar total disc arthroplasty. The authors present a previously unpublished complication of lumbar total disk arthroplasty (TDA) secondary to heterotopic ossification (HO) in the spinal canal, and they propose a modification to the McAfee classification of HO. The patient had undergone an L5/S1 lumbar TDA two years prior due to discogenic back pain. His preoperative back pain was significantly relieved, but he developed new, atraumatic onset radiculopathy. Radiographs and a computed tomography myelogram revealed an implant malposition posteriorly with heterotopic bone formation in the canal, causing an impingement of the traversing nerve root. Revision surgery was performed with implant extraction, L5/S1 anterior lumbar interbody fusion, supplemental posterior decompression, and pedicle screw fixation. The patient tolerated the procedure well, with complete resolution of the radicular leg pain. At a two-year follow up, the patient had a solid fusion without subsidence or recurrence of heterotopic bone. This case represents a novel pattern of heterotopic ossification, and it describes a previously unreported cause for implant failure in lumbar disc replacement surgery-reinforcing the importance of proper intraoperative component positioning. We propose a modification to the existing McAfee classification of HO after TDA with the addition of Class V and VI HO. PMID:26097664

  16. Frisbee - the first artificial cervical disc of 3RD generation

    OpenAIRE

    Karin Büttner-Janz; Bernhard Meyer; Rafael Donatus Sambale; Hans-Joachim Wilke; Nelli Rüdiger; Eiko Büttner

    2014-01-01

    OBJECTIVE: The current cervical disc arthroplasty is limited by postoperative facet joint arthritis, heterotopic ossification and segmental kyphosis. The total Frisbee disc, which has an upper convex/concave non-spherical surface and a lower flat sliding surface, is a new approach for improved outcomes. Prior to clinical application, safety and suitability tests are required. METHODS: The Frisbee is the first 3rd generation disc according to a new classification of total disc because it can...

  17. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... plate. Obviously that procedure has worked out very well, but there’s probably a lot of really significant ... fusing this area, putting in an artificial disc. Well it allows motion, you know, and there’s been ...

  18. Removal versus preservation of the posterior longitudinal ligament in Bryan cervical disc arthroplasty

    Institute of Scientific and Technical Information of China (English)

    YANG Da-long; DING Wen-yuan; ZHANG Ying-ze; ZHANG Wei; XU Jia-xin; SHEN Yong

    2013-01-01

    Background Bryan cervical disc arthroplasty can be used to restore and maintain the mobility and function of the involved cervical spinal segments.The efficiency of posterior longitudinal ligament (PLL) resection in anterior cervical decompression and fusion has been demonstrated.However,no clinical reports have compared PLL removal with preservation in Bryan cervical disc arthroplasty.This study aimed to assess the role of removal of PLL in Bryan cervical disc arthroplasty at an 18-month follow-up.Methods We performed a prospective investigation of clinical and radiological outcomes in patients after Bryan cervical disc arthroplasty.Sixty patients who underwent Bryan cervical disc arthroplasty were included.The PLL was removed in 35 patients (investigational group) and preserved in 25 patients (control group).All of the patients were followed up for more than 18 months.Clinical (Japanese Orthopedic Association score and Visual Analogue Scale pain score) and radiological (functional spinal unit (FSU) angle,range of movement (ROM),and diameter of the spinal cord) parameters were compared between the two groups before and after surgery (18 months).Results Clinical outcomes in the investigational group were significantly superior to those in the control group.There were no significant differences in the FSU angle and ROM (P=-0.41 and 0.16,respectively) between the two groups.However,the increase in diameter of the spinal cord in the investigational group was significantly greater than that in the control group (P <0.01).Conclusions Removal of the PLL can improve the clinical outcomes of Bryan cervical disc arthroplasty.This procedure does not have a large effect on imbalance and motion of the cervical spine.

  19. Nucleus disc arthroplasty with the NUBAC™ device: 2-year clinical experience

    OpenAIRE

    Balsano, M.; Zachos, A.; Ruggiu, A.; Barca, F.; Tranquilli-Leali, P.; Doria, C.

    2011-01-01

    Low back pain (LBP) due to degenerative disc disease (DDD) is a common condition that can be treated along a continuum of care: from conservative therapies to several surgical choices. Nucleus arthroplasty is an emerging technology that could potentially fill part of the gap in the spine continuum of care. The introduction of recent technologies that allow the replacement of the degenerated disc nucleus using prosthetic devices may be considered an additional therapeutic tool that can be used...

  20. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... over, you know, fusion. People wonder, does it cause problems at the next level up, so if ... a concern. Will the fusion at this disc cause problems at the disc above or the disc ...

  1. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... so much different than the fusion. The ProDisc C total disc replacement from Synthes Spine is an ... intervertebral disc in the cervical spine. The ProDisc C is indicated for patients suffering from intractable symptomatic ...

  2. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... to delineate the exact trajectory into the disc space. So now he’s found the disc space, what he wants to do is confirm it ... has stuck a marker into this actual disc space, and the next thing he is goes to ...

  3. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... implant components work together with the surrounding spinal structures to provide stability and function. The ProDisc C implant is secured to the vertebral bodies above and below the disc space and held in place with two central keels. ...

  4. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... put my handle back on, and meanwhile, the scrub nurse is preparing the actual disc itself because ... was doing that on the back table, the scrub nurse and the circulating nurse were putting together ...

  5. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... the location of the diseased disc, and the soft tissues are moved away from the front of the ... a zero-profile implant that does not contact soft tissue structures after it is implanted. The technical aspect ...

  6. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... wonder, does it cause problems at the next level up, so if I fuse this disc here, ... fusion, then the hope is that the next levels hopefully won’t feel the stress, and by ...

  7. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... the way to do this in the near future of the state of the art. What are ... the-art of treating disc herniations in the future. Thank you. Thank you for watching this “OR ...

  8. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... stress, and by not feeling the stress, they should maintain good discs, hopefully over the lifetime of ... right where it wants to be, and that should be a natural position for the bones of ...

  9. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... implant that is composed of two cobalt chrome alloy end plates and a polyethylene insert. The polyethylene ... the ProDisc C implant have a plasma-sprayed titanium coding to provide bony coating to promote bony ...

  10. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... place with two central keels. All bone contacting surfaces of the ProDisc C implant have a plasma-sprayed titanium coding to provide bony coating to promote bony on growth, providing long-term ...

  11. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... fascia, which is kind of connective tissue that helps hold things together. It’s the very last layer ... placing a marker external to the skin to help to delineate the exact trajectory into the disc ...

  12. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... it out, the patient’s chin is to the right and the chest wall is towards the left, and he’s dissecting up and down. So the ... other nerve, the one that goes down his left arm, and if both are freed up, we’ll put in a piece of disc where we took out our disc right through here. Can I have a nerve fork, ...

  13. Lumbar disc arthroplasty: indications, biomechanics, types, and radiological criteria

    International Nuclear Information System (INIS)

    Lumbar total disc replacement (TDR) was developed to treat a painful degenerative lumbar motion segment while avoiding the disadvantages of fusion surgery, such as adjacent segment instabilities. Early clinical results with TDR have shown a significant reduction in low back pain and a significant improvement in disability scores. When compared to fusion, the results with TDR tend to be superior in the short-term follow-up and initial rehabilitation is faster. The radiological assessment is an integral part of the preoperative work-up. Plain X-rays of the lumbar spine should be complemented by flexion - extension views in order to assess residual segmental mobility. Computed tomography is used to exclude osteoarthritis of the zygapophyseal joints, Baastrup's disease (kissing spines) and other sources of low back pain. Magnetic resonance imaging is useful to exclude substantial disc protrusions; it allows for the detection of disc dehydration and bone marrow edema in the case of activated spondylochondrosis. If osteoporosis is suspected, an osteodensitometry of the lumbar spine should be performed. Postoperative plain X-rays should include antero-posterior and lateral views as well as flexion - extension views in the later postoperative course. Measurements should determine the disc space height in the lateral view, the segmental and total lumbar lordosis as well as the segmental mobility in the flexion - extension views. The ideal position of a TDR is exactly central in the ap-view and close to the dorsal border of the vertebral endplates in the lateral view. Malpositioning may cause segmental hyperlordosis and unbalanced loading of the endplates with the risk of implant subsidence and migration. (orig.)

  14. Artificial cervical disc replacement: Principles, types and techniques

    Directory of Open Access Journals (Sweden)

    Sekhon L

    2005-01-01

    Full Text Available Cervical arthroplasty after anterior decompression with insertion of a prosthetic total disc replacement has been suggested as an alternate to anterior cervical fusion. Currently there are four cervical arthroplasty devices available on the market whose results in clinical use have been reported. Each device varies in terms of materials, range of motion, insertion technique and constraint. It is not known which device is ideal. Early studies suggest that in the short term, the complication rate and efficacy is no worse than fusion surgery. Long-term results have not yet been reported. This review examines the current prostheses available on the market as well as discussing issues regarding indications and technique. Pitfalls are discussed and early experiences reviewed. In time, it is hoped that a refinement of cervical arthroplasty occurs in terms of both materials and design as well as in terms of indications and clinical outcomes as spinal surgeons enter a new era of the management of cervical spine disease.

  15. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... it gets inserted, it’s very rough. It’s titanium plasma sprayed, and this allows for the body to ... surfaces of the ProDisc C implant have a plasma-sprayed titanium coding to provide bony coating to ...

  16. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... diseased disc and releasing pressure on the surrounding nerves and spinal cord. We’re going to do an image ... with that motion is going to push against nerves or the spinal cord. So it’s sometimes a little bit more ...

  17. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... is exactly where I’m putting my instruments right now, and those are small pieces of disc that I’m taking out. I’m obviously going real slow through this area, and the reason is ...

  18. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... ultrahigh molecular weight polyethylene, and it’s a medical-grade plastic that’s really been made to sustain active ... the disc level above and below as well. Good point. It does, and so I’m kind ...

  19. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... the next levels hopefully won’t feel the stress, and by not feeling the stress, they should maintain good discs, hopefully over the ... was an appropriate procedure that would work. These studies turned out well, and the FDA has approved ...

  20. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... the next levels hopefully won’t feel the stress, and by not feeling the stress, they should maintain good discs, hopefully over the ... FDA studies, in our study, in all the literature that I’ve read has been extremely positive ...

  1. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... see it gets inserted, it’s very rough. It’s titanium plasma sprayed, and this allows for the body ... the ProDisc C implant have a plasma-sprayed titanium coding to provide bony coating to promote bony ...

  2. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... That’s the actual disc space right there. It’s beautiful. So I’m going to take a scalpel ... And that’s where I wan it. That looks beautiful, so I’m very pleased about that. I’ ...

  3. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... younger patients, the patients in their 30s and 40s with disc herniations, than an older patient, let’s ... go to the recovery room, spend maybe an hour, hour and 15 minutes in recovery room and ...

  4. Artificial Cervical Disc Replacement Improves Mobility

    Medline Plus

    Full Text Available ... the next levels hopefully won’t feel the stress, and by not feeling the stress, they should maintain good discs, hopefully over the ... cord. So it’s sometimes a little bit more work. Well, there’s the space for where that nerve ...

  5. Heterotopic ossification in cervical disc arthroplasty: Is it clinically relevant?

    OpenAIRE

    Barbagallo, Giuseppe M.; Corbino, Leonardo A.; Olindo, Giuseppe; Albanese, Vincenzo

    2010-01-01

    Study design:  Retrospective cohort study. Objective:  To analyze the presence and clinical relevance of heterotopic ossification (HO) at 3 years mean follow-up. Methods:  Thirty patients suffering from cervical radiculopathy and/or myelopathy treated with anterior disc replacement (ADR) were studied. HO was classified using the McAfee grading system. Range of motion was measured from flexion and extension x-rays. Short-form 36 and neck disability index (NDI) assessed functional outcome. Resu...

  6. Improving the fixation of an artificial intervertebral disc

    NARCIS (Netherlands)

    Eijkelkamp, MF; Hayen, J; Veldhuizen, AG; Van Horn, [No Value; Verkerke, GJ

    2002-01-01

    The fixation of an artificial intervertebral disc has been studied especially with respect to the dimensions, the convexity of the endplates and the size of the fixation elements. From literature and cadaveric vertebrae, the dimensions and shape of the lumbar vertebral endplates were determined and

  7. Frisbee - the first artificial cervical disc of 3RD generation

    Directory of Open Access Journals (Sweden)

    Karin Büttner-Janz

    2014-03-01

    Full Text Available OBJECTIVE: The current cervical disc arthroplasty is limited by postoperative facet joint arthritis, heterotopic ossification and segmental kyphosis. The total Frisbee disc, which has an upper convex/concave non-spherical surface and a lower flat sliding surface, is a new approach for improved outcomes. Prior to clinical application, safety and suitability tests are required. METHODS: The Frisbee is the first 3rd generation disc according to a new classification of total disc because it can precisely mimic the segmental ROM, including the soft limitation of axial rotation. The ISO 18192-1 test was carried out to determine the rate of wear debris. A FE model was used to assess the safety of prosthetic components. In the sagittal plane several variables to determine the most favorable lordotic angle were evaluated. RESULTS: Two angled prosthetic plates are safer than one sliding angled core to prevent the displacement. The lordosis of 7° of the Frisbee leads to kyphosis of no more than 2° without reduction of the ROM. The wear rate of the Frisbee is five times smaller compared to an FDA-approved disc with a spherical sliding surface. CONCLUSIONS: Based on the test results, the clinical application of Frisbee can now be studied. The postoperative kyphosis observed with other devices is not an issue with the Frisbee design. Physiological ROM is combined with the significant reduction of wear debris. For these reasons the Frisbee has the potential to provide a better balanced segmental loading reducing the degeneration of the joint surface and heterotopic ossification.

  8. Biomechanics of a Fixed–Center of Rotation Cervical Intervertebral Disc Prosthesis

    OpenAIRE

    Crawford, Neil R; Baek, Seungwon; Sawa, Anna G.U.; Safavi-Abbasi, Sam; Sonntag, Volker K.H.; Duggal, Neil

    2012-01-01

    Background Past in vitro experiments studying artificial discs have focused on range of motion. It is also important to understand how artificial discs affect other biomechanical parameters, especially alterations to kinematics. The purpose of this in vitro investigation was to quantify how disc replacement with a ball-and-socket disc arthroplasty device (ProDisc-C; Synthes, West Chester, Pennsylvania) alters biomechanics of the spine relative to the normal condition (positive control) and si...

  9. Comparison of 2 Zero-Profile Implants in the Treatment of Single-Level Cervical Spondylotic Myelopathy: A Preliminary Clinical Study of Cervical Disc Arthroplasty versus Fusion

    Science.gov (United States)

    Yang, Li-Li; Liu, Zu-De; Yuan, Wen

    2016-01-01

    Objectives Cervical disc arthroplasty (CDA) with Discover prosthesis or anterior cervical discectomy and fusion (ACDF) with Zero-P cage has been widely used in the treatment of cervical spondylotic myelopathy (CSM). However, little is known about the comparison of the 2 zero-profile implants in the treatment of single-level CSM. The aim was to compare the clinical outcomes and radiographic parameters of CDA with Discover prosthesis and ACDF with Zero-P cage for the treatment of single-level CSM. Methods A total of 128 consecutive patients who underwent 1-level CDA with Discover prosthesis or ACDF with Zero-P cage for single-level CSM between September 2009 and December 2012 were included in this study. Clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) score and Neck Disability Index (NDI). For radiographic assessment, the overall sagittal alignment (OSA), functional spinal unit (FSU) angle, and range of motion (ROM) at the index and adjacent levels were measured before and after surgery. Additionally, the complications were also recorded. Results Both treatments significantly improved all clinical parameters (P 0.05). Besides, no significant differences existed in dysphagia, subsidence, or adjacent disc degeneration between the 2 groups (P > 0.05). However, significant differences occurred in prosthesis migration in CDA group. Conclusions The results of this study showed that clinical outcomes and radiographic parameters were satisfactory and comparable with the 2 techniques. However, more attention to prosthesis migration of artificial cervical disc should be paid in the postoperative early-term follow-up. PMID:27441736

  10. Application of cervical arthroplasty with Bryan cervical disc:long-term X-ray and magnetic resonance imaging follow-up results

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yan-bin; SUN Yu; CHEN Zhong-qiang; LIU Zhong-jun

    2010-01-01

    Background Cervical disc arthroplasty is a new technique for treating degenerative cervical disease. Its goal is to avoid the degeneration of adjacent levels by preserving motion at the treated level. The aims of this study were to evaluate the radiologic outcomes of Bryan cervical disc replacement and the degenerative status of adjacent segments.Methods Twenty-two patients at a single center underwent discectomy and implantation of Bryan cervical disc. The mean follow-up period was 60 months (57-69 months). Twenty patients underwent single-level arthroplasty and two underwent arthroplasty at two levels. The levels of surgery included C3/4 (3 levels), C4/5 (2 levels), C5/6 (18 levels) and C6/7 (1 level). Radiographic evaluation included dynamic X-ray examination and magnetic resonance imaging (MRI) at baseline and at final follow-up.Results On X-ray examination, the range of motion (ROM) at the operated level was 7.2° (2.5°-13.0°) at baseline and 7.8° (1.0°-15.0°) at final follow-up (P >0.05). Heterotopic ossification around the prosthesis was observed in eight levels,and two levels showed loss of motion (ROM <2°). MRI showed worsening by a grade at the upper level in 2/22 patients,and worsening by a grade at the lower level in 3/22, according to Miyazaki's classification. No further impingement of the ligamentum flavum into the spinal canal was observed at adjacent levels, though the disc bulge was slightly increased at both the adjacent upper and lower levels at final follow-up.Conclusions Arthroplasty using Bryan cervical disc prosthesis resulted in favorable radiologic outcomes in this study.Disc degeneration at adjacent levels may be postponed by this technique.

  11. Differences between C3-4 and other subaxial levels of cervical disc arthroplasty: more heterotopic ossification at the 5-year follow-up.

    Science.gov (United States)

    Chang, Peng-Yuan; Chang, Hsuan-Kan; Wu, Jau-Ching; Huang, Wen-Cheng; Fay, Li-Yu; Tu, Tsung-Hsi; Wu, Ching-Lan; Cheng, Henrich

    2016-05-01

    OBJECTIVE Several large-scale clinical trials demonstrate the efficacy of 1- and 2-level cervical disc arthroplasty (CDA) for degenerative disc disease (DDD) in the subaxial cervical spine, while other studies reveal that during physiological neck flexion, the C4-5 and C5-6 discs account for more motion than the C3-4 level, causing more DDD. This study aimed to compare the results of CDA at different levels. METHODS After a review of the medical records, 94 consecutive patients who underwent single-level CDA were divided into the C3-4 and non-C3-4 CDA groups (i.e., those including C4-5, C5-6, and C6-7). Clinical outcomes were measured using the visual analog scale for neck and arm pain and by the Japanese Orthopaedic Association scores. Postoperative range of motion (ROM) and heterotopic ossification (HO) were determined by radiography and CT, respectively. RESULTS Eighty-eight patients (93.6%; mean age 45.62 ± 10.91 years), including 41 (46.6%) female patients, underwent a mean follow-up of 4.90 ± 1.13 years. There were 11 patients in the C3-4 CDA group and 77 in the non-C3-4 CDA group. Both groups had significantly improved clinical outcomes at each time point after the surgery. The mean preoperative (7.75° vs 7.03°; p = 0.58) and postoperative (8.18° vs 8.45°; p = 0.59) ROMs were similar in both groups. The C3-4 CDA group had significantly greater prevalence (90.9% vs 58.44%; p = 0.02) and higher severity grades (2.27 ± 0.3 vs 0.97 ± 0.99; p = 0.0001) of HO. CONCLUSIONS Although CDA at C3-4 was infrequent, the improved clinical outcomes of CDA were similar at C3-4 to that in the other subaxial levels of the cervical spine at the approximately 5-year follow-ups. In this Asian population, who had a propensity to have ossification of the posterior longitudinal ligament, there was more HO formation in patients who received CDA at the C3-4 level than in other subaxial levels of the cervical spine. While the type of artificial discs could have confounded the

  12. Clinical and radiologic comparison of dynamic cervical implant arthroplasty and cervical total disc replacement for single-level cervical degenerative disc disease.

    Science.gov (United States)

    Shichang, Liu; Yueming, Song; Limin, Liu; Lei, Wang; Zhongjie, Zhou; Chunguang, Zhou; Xi, Yang

    2016-05-01

    Anterior cervical discectomy and fusion, to date the most successful spine procedure for the surgical treatment of cervical radiculopathy, has limitations that have led to the development of non-fusion cervical procedures, such as cervical total disc replacement (TDR) and dynamic cervical implant (DCI) arthroplasty. We compared the clinical and radiological results of DCI and cervical TDR for the treatment of single-level cervical degenerative disc disease in Chinese patients. A retrospective review of 179 patients with cervical spondylotic myelopathy who underwent DCI or TDR between April 2010 and October 2012 was conducted, and 152 consecutive patients (67 patients single-level DCI and 85 single-level TDR) who completed at least 2years of follow-up were included. Clinical and radiological assessments were performed preoperatively and at 1week and 3, 6, 12, and 24months postoperatively. The most common operative level was C5/C6 (49.3%). The differences in blood loss, duration of surgery, and duration of hospitalization were not statistically significant. The Japanese Orthopaedic Association scale, Visual Analog Scale, Neck Disability Index, and Short Form-36 scores improved significantly after surgery in both the DCI and TDR groups (P<0.05), but the differences were not statistically significant at the final follow-up. The rate of occurrence of heterotopic ossification was 22.4% and 28.2% in the DCI and TDR groups, respectively. As an effective non-fusion technique, DCI is a more economical procedure. Further prospective, randomized studies with long-term follow-up periods are needed to determine the long-term effects. PMID:26928156

  13. Clinical and radiologic comparison of dynamic cervical implant arthroplasty versus anterior cervical discectomy and fusion for the treatment of cervical degenerative disc disease.

    Science.gov (United States)

    Li, Zhonghai; Yu, Shunzhi; Zhao, Yantao; Hou, Shuxun; Fu, Qiang; Li, Fengning; Hou, Tiesheng; Zhong, Hongbin

    2014-06-01

    This study compared the clinical and radiological outcomes of dynamic cervical implant (DCI; Scient'x, Villers-Bretonneux, France) arthroplasty versus anterior cervical discectomy and fusion (ACDF) for the treatment of cervical degenerative disc disease. This prospective cohort study enrolled patients with single-level cervical degenerative disc disease who underwent DCI arthroplasty or ACDF between September 2009 and June 2011. Patients were followed up for more than 2years. Clinical evaluation included the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), Neck Disability Index (NDI), Japan Orthopedic Association (JOA) score, and visual analog scale (VAS) scores for neck and arm pain. Radiological assessments included segmental range of motion (ROM), overall ROM (C2-C7), disc height (DHI), and changes in adjacent disc spaces. The VAS, SF-36, JOA, and NDI scores improved significantly after surgery in both the DCI and ACDF groups. The VAS, JOA, and SF-36 scores were not significantly different between the DCI and ACDF groups at the final follow-up. The segmental ROM at the treated level and overall ROM increased significantly after surgery in the DCI group, but the ROM in the adjacent cephalad and caudal segments did not change significantly. The mean DHI at the treated level was significantly restored after surgery in both groups. Five patients (12.8%) in the DCI group showed new signs of adjacent segment degeneration. These results indicate that DCI is an effective, reliable, and safe procedure for the treatment of cervical degenerative disc disease. However, there is no definitive evidence that DCI arthroplasty has better intermediate-term results than ACDF. PMID:24411326

  14. Chiropractic management of patients post-disc arthroplasty: eight case reports

    Directory of Open Access Journals (Sweden)

    Descarreaux Martin

    2010-04-01

    Full Text Available Abstract Background When conservative therapies for low back pain (LBP are not effective, elective surgery may be proposed to these patients. Over the last 20 years, a new technology, disc replacement, has become increasingly popular because it is believed to maintain or restore the integrity of spinal movement and minimize the side-effects compared to fusion. Although disc replacement may relieve a patient from pain and related disability, soreness and stiffness of the lumbopelvic region seem to be common aftermaths of the surgery. This prospective case series was undertaken to identify and describe potential adverse events of lumbar spinal manipulation, a common therapy for low back pain, in a group of patients with symptoms after disc prostheses. Cases presentation Eight patients who underwent lumbar spine total disc replacement were referred by an orthopaedic surgeon for chiropractic treatments. These patients had 1 or 2 total lumbar disc replacements and were considered stable according to the surgical protocol but presented persistent, post-surgical, non-specific LBP or pelvic pain. They were treated with lumbar spine side posture manipulations only and received 8 to 10 chiropractic treatments based on the clinical evolution and the chiropractor's judgment. Outcome measures included benign, self-limiting, and serious adverse events after low back spinal manipulative therapy. The Oswestry Disability Index, a pain scale and the fear avoidance belief questionnaire were administered to respectively assess disability, pain and fear avoidance belief about work and physical activity. This prospective case series comprised 8 patients who all had at least 1 total disc replacement at the L4/L5 or L5/S1 level and described persistent post-surgical LBP interfering with their daily activities. Commonly-reported side-effects of a benign nature included increased pain and/or stiffness of short duration in nearly half of the chiropractic treatment period

  15. The activL® Artificial Disc: a next-generation motion-preserving implant for chronic lumbar discogenic pain

    OpenAIRE

    Yue, James J.; Garcia, Rolando; Miller, Larry E.

    2016-01-01

    Degeneration of the lumbar intervertebral discs is a leading cause of chronic low back pain in adults. Treatment options for patients with chronic lumbar discogenic pain unresponsive to conservative management include total disc replacement (TDR) or lumbar fusion. Until recently, only two lumbar TDRs had been approved by the US Food and Drug Administration − the Charité Artificial Disc in 2004 and the ProDisc-L Total Disc Replacement in 2006. In June 2015, a next-generation lumbar TDR receive...

  16. Mid- to Long-Term Outcomes of Cervical Disc Arthroplasty versus Anterior Cervical Discectomy and Fusion for Treatment of Symptomatic Cervical Disc Disease: A Systematic Review and Meta-Analysis of Eight Prospective Randomized Controlled Trials.

    Directory of Open Access Journals (Sweden)

    Yan Hu

    Full Text Available This study aimed to investigate the mid- to long-term outcomes of cervical disc arthroplasty (CDA versus anterior cervical discectomy and fusion (ACDF for the treatment of 1-level or 2-level symptomatic cervical disc disease.Medline, Embase, and the Cochrane Central Register of Controlled Trials databases were searched to identify relevant randomized controlled trials that reported mid- to long-term outcomes (at least 48 months of CDA versus ACDF. All data were analyzed by Review Manager 5.3 software. The relative risk (RR and 95% confidence intervals (CIs were calculated for dichotomous variables. The weighted mean difference (WMD and 95%CIs were calculated for continuous variables. A random effect model was used for heterogeneous data; otherwise, a fixed effect model was used.Eight prospective randomized controlled trials (RCTs were retrieved in this meta-analysis, including 1317 and 1051 patients in CDA and ACDF groups, respectively. Patients after an ACDF had a significantly lower rate of follow-up than that after CDA. Pooled analysis showed patients in CDA group achieved significantly higher rates of overall success, Neck Disability Index (NDI success, neurological success and significantly lower rates of implant/surgery-related serious adverse events and secondary procedure compared with that in ACDF group. The long-term functional outcomes (NDI, Visual Analog Scale (VAS neck and arm pain scores, the Short Form 36 Health Survey physical component score (SF-36 PCS, patient satisfaction and recommendation, and the incidence of superior adjacent segment degeneration also favored patients in CDA group with statistical difference. Regarding inferior adjacent segment degeneration, patients in CDA group had a lower rate without statistical significance.This meta-analysis showed that cervical disc arthroplasty was superior over anterior discectomy and fusion for the treatment of symptomatic cervical disc disease in terms of overall success, NDI

  17. Biomechanics of Artificial Disc Replacements Adjacent to a 2-Level Fusion in 4-Level Hybrid Constructs: An In Vitro Investigation

    OpenAIRE

    Liao, Zhenhua; Fogel, Guy R.; Wei, Na; Gu, Hongsheng; Liu, Weiqiang

    2015-01-01

    Background The ideal procedure for multilevel cervical degenerative disc diseases remains controversial. Recent studies on hybrid surgery combining anterior cervical discectomy and fusion (ACDF) and artificial cervical disc replacement (ACDR) for 2-level and 3-level constructs have been reported in the literature. The purpose of this study was to estimate the biomechanics of 3 kinds of 4-level hybrid constructs, which are more likely to be used clinically compared to 4-level arthrodesis. Mate...

  18. Single-level cervical radiculopathy: clinical outcome and cost-effectiveness of four techniques of anterior cervical discectomy and fusion and disc arthroplasty.

    Science.gov (United States)

    Bhadra, Arup K; Raman, A S; Casey, Adrian T H; Crawford, R J

    2009-02-01

    Although there are several accepted methods of surgical treatment for single-level cervical radiculopathy, the choice depend on the surgeon's preference. The techniques may vary in peri-operative morbidity, short- and long-term outcome, but no study so far has analyzed their cost-effectiveness. This study might give some insight in balancing cost and effectiveness and deciding the right technique. Sixty consecutive patients (15 each group), mean age 36 (range 24-76 years) with single-level cervical disc disease underwent surgical treatment with four different techniques in two centers over the period of 1999-2005. The four groups were--(1) plate and tricortical autograft, (2) plate, cage, and bone substitute, (3) cage only, and (4) disc arthroplasty. The data was collected prospectively according to our protocol and subsequently analyzed. The clinical outcome was assessed comparing visual analog scale (VAS) of neck pain and, short form 12 (SF12) questionnaire both pre- and postoperatively. The radiological assessment was done for fusion rate and postoperative related possible complications at 3 months, 6 months, 1 year, and final follow-up. The cost analysis was done calculating the operative time, hospital stay, implant cost together. The mean follow-up period was 31 months (range 28-43 months). The clinical outcome in terms of VAS of neck and arm pain and SF12 physical and mental score improvement (P=0.001) were comparable with all four techniques. The radiological fusion rate was comparable to current available data. As the hospital stay was longer (average 5 days) with plate and autograft group, the total cost was maximum (average 2,920 pound sterling) with this group. There was satisfactory clinical and radiological outcome with all four techniques. Using the cage alone was the most cost-effective technique, but the disc arthroplasty was comparable to the use of cage and plate. Anterior cervical discectomy and fusion is an established surgical treatment for

  19. 人工全膝关节置换术后功能康复研究进展%Research Progress in Functional Rehabilitation after Artificial Total Knee Arthroplasty

    Institute of Scientific and Technical Information of China (English)

    张斌; 周红

    2015-01-01

    康复治疗是术后膝关节功能可达到预期效果的重要措施,对人工膝关节置换术后的临床效果至关重要。本文分析人工膝关节置换术后肌力训练、关节活动度训练、本体觉训练、行走步态训练的进展,强调人工膝关节置换术后健康教育及功能锻炼的重要性。%Rehabilitation is an important measure for knee joint function after operation to achieve the expected effect, which is crucial for the clini-cal effect of artificial total knee arthroplasty postoperation. This paper analyses the progress in strength training, joint activity training, proprioceptive training and gait training after artificial total knee arthroplasty, emphasizing the importance of health education and functional training after artificial total knee arthroplasty.

  20. Total Disc Arthroplasty and Anterior Cervical Discectomy and Fusion in Cervical Spine: Competitive or Complimentary? Review of the Literature

    OpenAIRE

    Jawahar, Ajay; Nunley, Pierce

    2012-01-01

    Anterior cervical discectomy and arthrodesis has come to represent standard of care for patients with persistent radicular and/or myelopathic symptoms that have failed to improve with conservative treatments. One potential complication of the procedure is the accelerated degeneration of the vertebrae and the intervertebral discs adjacent to the level fused and the effects of fusion on those levels. The concern that fusion may be a contributing factor to accelerated adjacent segment degenerati...

  1. Lumbar disc arthroplasty: indications, biomechanics, types, and radiological criteria; Lumbale Bandscheibenendoprothesen: Indikationen, Biomechanik, Typen und radiologische Kriterien

    Energy Technology Data Exchange (ETDEWEB)

    Baur-Melnyk, A.; Reiser, M.F. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet, Orthopaedische Klinik und Poliklinik, Muenchen (Germany); Birkenmaier, C. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet, Institut fuer Klinische Radiologie, Muenchen (Germany)

    2006-09-15

    Lumbar total disc replacement (TDR) was developed to treat a painful degenerative lumbar motion segment while avoiding the disadvantages of fusion surgery, such as adjacent segment instabilities. Early clinical results with TDR have shown a significant reduction in low back pain and a significant improvement in disability scores. When compared to fusion, the results with TDR tend to be superior in the short-term follow-up and initial rehabilitation is faster. The radiological assessment is an integral part of the preoperative work-up. Plain X-rays of the lumbar spine should be complemented by flexion - extension views in order to assess residual segmental mobility. Computed tomography is used to exclude osteoarthritis of the zygapophyseal joints, Baastrup's disease (kissing spines) and other sources of low back pain. Magnetic resonance imaging is useful to exclude substantial disc protrusions; it allows for the detection of disc dehydration and bone marrow edema in the case of activated spondylochondrosis. If osteoporosis is suspected, an osteodensitometry of the lumbar spine should be performed. Postoperative plain X-rays should include antero-posterior and lateral views as well as flexion - extension views in the later postoperative course. Measurements should determine the disc space height in the lateral view, the segmental and total lumbar lordosis as well as the segmental mobility in the flexion - extension views. The ideal position of a TDR is exactly central in the ap-view and close to the dorsal border of the vertebral endplates in the lateral view. Malpositioning may cause segmental hyperlordosis and unbalanced loading of the endplates with the risk of implant subsidence and migration. (orig.) [German] Die lumbale Bandscheibenendoprothese (LBEP) wurde entwickelt, um ein schmerzhaftes lumbales Bewegungssegment unter Vermeidung der Nachteile einer Fusionsoperation zu behandeln. Erste klinische Ergebnisse der LBEP zeigen eine signifikante Reduktion der

  2. Artificial disc and vertebra system: a novel motion preservation device for cervical spinal disease after vertebral corpectomy

    Directory of Open Access Journals (Sweden)

    Jun Dong

    2015-07-01

    Full Text Available OBJECTIVE: To determine the range of motion and stability of the human cadaveric cervical spine after the implantation of a novel artificial disc and vertebra system by comparing an intact group and a fusion group. METHODS: Biomechanical tests were conducted on 18 human cadaveric cervical specimens. The range of motion and the stability index range of motion were measured to study the function and stability of the artificial disc and vertebra system of the intact group compared with the fusion group. RESULTS: In all cases, the artificial disc and vertebra system maintained intervertebral motion and reestablished vertebral height at the operative level. After its implantation, there was no significant difference in the range of motion (ROM of C3-7 in all directions in the non-fusion group compared with the intact group (p>0.05, but significant differences were detected in flexion, extension and axial rotation compared with the fusion group (p<0.05. The ROM of adjacent segments (C3-4, C6-7 of the non-fusion group decreased significantly in some directions compared with the fusion group (p<0.05. Significant differences in the C4-6 ROM in some directions were detected between the non-fusion group and the intact group. In the fusion group, the C4-6 ROM in all directions decreased significantly compared with the intact and non-fusion groups (p<0.01. The stability index ROM (SI-ROM of some directions was negative in the non-fusion group, and a significant difference in SI-ROM was only found in the C4-6 segment of the non-fusion group compared with the fusion group. CONCLUSION: An artificial disc and vertebra system could restore vertebral height and preserve the dynamic function of the surgical area and could theoretically reduce the risk of adjacent segment degeneration compared with the anterior fusion procedure. However, our results should be considered with caution because of the low power of the study. The use of a larger sample should be

  3. 人工颈椎间盘置换术患者围手术期护理体会%Cervical intervertebral disc arthroplasty patients perioperative nursing experience

    Institute of Scientific and Technical Information of China (English)

    刘丹

    2015-01-01

    颈椎间盘突出症是一种常见的退化性病变,它可以引起脊髓和神经根病变,脊髓病变甚至可能造成四肢运动功能损害、感觉异常等。人工间盘的设计理念之一是保留手术节段的活动,另一设计理念是降低临近节段退变的发生,它既能保持脊柱节段的稳定性和活动功能,又能避免临近关节受到连累,对于提高患者生活质量有实际意义。2013年11月,我科成功为一名严重脊髓型颈椎病患者实施了经颈前路减压、人工椎间盘置换术,围手术期的系统、精密的观察和护理,对手术成功起到重要作用,术后患者恢复良好,患者及其家属对手术效果均感到满意,现总结护理经验如下。%The cervical intervertebral disc herniation is a common degradation lesions, it can cause spinal cord and nerve root lesions, limb motor function caused by spinal cord lesions and may even damage, paresthesia, etc. Between artificial disc is one of the design concept of conservative surgery section of the activity, a design concept is to reduce the happening of the adjacent segment degeneration, it can maintain the stability of the spinal segment and function of activity, and can avoid near joints, small area, to improve the patients quality of life has a practical significance. In November 2013, I division success as a serious spondylotic myelopathy successfully implemented by decompression and anterior portion of artificial intervertebral disc replacement, through system, precision of perioperative observation and nursing care, for the success rate of surgery play an important role, the patient recovered well postoperatively, patients and their families were satisfied with the surgical effects are, summarized nursing experience is as follows.

  4. Biomechanics of Artificial Disc Replacements Adjacent to a 2-Level Fusion in 4-Level Hybrid Constructs: An In Vitro Investigation.

    Science.gov (United States)

    Liao, Zhenhua; Fogel, Guy R; Wei, Na; Gu, Hongsheng; Liu, Weiqiang

    2015-01-01

    BACKGROUND The ideal procedure for multilevel cervical degenerative disc diseases remains controversial. Recent studies on hybrid surgery combining anterior cervical discectomy and fusion (ACDF) and artificial cervical disc replacement (ACDR) for 2-level and 3-level constructs have been reported in the literature. The purpose of this study was to estimate the biomechanics of 3 kinds of 4-level hybrid constructs, which are more likely to be used clinically compared to 4-level arthrodesis. MATERIAL AND METHODS Eighteen human cadaveric spines (C2-T1) were evaluated in different testing conditions: intact, with 3 kinds of 4-level hybrid constructs (hybrid C3-4 ACDR+C4-6 ACDF+C6-7ACDR; hybrid C3-5ACDF+C5-6ACDR+C6-7ACDR; hybrid C3-4ACDR+C4-5ACDR+C5-7ACDF); and 4-level fusion. RESULTS Four-level fusion resulted in significant decrease in the C3-C7 ROM compared with the intact spine. The 3 different 4-level hybrid treatment groups caused only slight change at the instrumented levels compared to intact except for flexion. At the adjacent levels, 4-level fusion resulted in significant increase of contribution of both upper and lower adjacent levels. However, for the 3 hybrid constructs, significant changes of motion increase far lower than 4P at adjacent levels were only noted in partial loading conditions. No destabilizing effect or hypermobility were observed in any 4-level hybrid construct. CONCLUSIONS Four-level fusion significantly eliminated motion within the construct and increased motion at the adjacent segments. For all 3 different 4-level hybrid constructs, ACDR normalized motion of the index segment and adjacent segments with no significant hypermobility. Compared with the 4-level ACDF condition, the artificial discs in 4-level hybrid constructs had biomechanical advantages compared to fusion in normalizing adjacent level motion. PMID:26694835

  5. Comparison of wear behaviors for an artificial cervical disc under flexion/extension and axial rotation motions.

    Science.gov (United States)

    Wang, Song; Song, Jian; Liao, Zhenhua; Feng, Pingfa; Liu, Weiqiang

    2016-06-01

    The wear behaviors of a ball-on-socket (UHMWPE-on-Ti6Al4V) artificial cervical disc were studied with 1.5MC (million cycles) wear simulation under single flexion/extension and axial rotation motion and their composite motion. The wear rates, wear traces, and contact stress were analyzed and contrasted based on mass loss, optical microscopy and SEM as well as 3D profilometer, and ANSYS software, respectively. A much higher wear rate and more severe wear scars appeared under multi-directional motion. Flexion/extension motion of 7.5° lead to more severe wear than that under axial rotation motion of 4°. The above results were closely related to the contact compression stress and shear stress. The wear surface in FE motion showed typical linear wear scratches while revealing obvious arc-shaped wear tracks in AR motion. However, the central zone of both ball and socket components revealed more severe wear tracks than that in the edge zone under these two different motions. The dominant wear mechanism was plowing/scratching and abrasive wear as well as a little oxidation wear for the titanium socket while it was scratching damage with adhesive wear and fatigue wear due to plastic deformation under cyclic load and motion profiles for the UHMWPE ball. PMID:27040218

  6. Quadruple-component superficial circumflex iliac artery perforator (SCIP) flap: A chimeric SCIP flap for complex ankle reconstruction of an exposed artificial joint after total ankle arthroplasty.

    Science.gov (United States)

    Yamamoto, Takumi; Saito, Takafumi; Ishiura, Ryohei; Iida, Takuya

    2016-09-01

    Total ankle arthroplasty (TAA) is becoming popular in patients with rheumatoid arthritis (RA)-associated ankle joint degeneration. However, ankle wound complications can occur after TAA, which sometimes requires challenging reconstruction due to anatomical complexity of the ankle. Superficial circumflex iliac artery (SCIA) perforator (SCIP) flap has been reported to be useful for various reconstructions, but no case has been reported regarding a chimeric SCIP flap for complex ankle reconstruction. We report a case of complex ankle defect successfully reconstructed with a free quadruple-component chimeric SCIP flap. A 73-year-old female patient with RA underwent TAA, and suffered from an extensive ankle soft tissue defect (13 × 5 cm) with exposure of the implanted artificial joint and the extensor tendons. A chimeric SCIP flap was raised based on the deep branch and the superficial branch of the SCIA, which included chimeric portions of the sartorius muscle, the deep fascia, the inguinal lymph node (ILN), and the skin/fat. The flap was transferred to the recipient ankle. The sartorius muscle was used to cover the artificial joint, the deep fascia to reconstruct the extensor retinaculum, the ILN to prevent postoperative lymphedema, and the adiposal tissue to put around the extensor tendons for prevention of postoperative adhesion. Postoperatively, the patient could walk by herself without persistent leg edema or bowstringing of the extensor tendons, and was satisfied with the concealable donor scar. Although further studies are required to confirm efficacy, multicomponent chimeric SCIP has a potential to be a useful option for complex defects of the ankle. PMID:27423250

  7. Early results and review of the literature of a novel hybrid surgical technique combining cervical arthrodesis and disc arthroplasty for treating multilevel degenerative disc disease: opposite or complementary techniques?

    OpenAIRE

    Barbagallo, Giuseppe M. V.; Assietti, Roberto; Corbino, Leonardo; Olindo, Giuseppe; Foti, Pietro V.; Russo, Vittorio; Albanese, Vincenzo

    2009-01-01

    We report the clinical and radiological results on the safety and efficacy of an unusual surgical strategy coupling anterior cervical discectomy and fusion and total disc replacement in a single-stage procedure, in patients with symptomatic, multilevel cervical degenerative disc disease (DDD). The proposed hybrid, single-stage, fusion–nonfusion technique aims either at restoring or maintaining motion where appropriate or favouring bony fusion when indicated by degenerative changes. Twenty-fou...

  8. Analysis of mid-long term clinical efficacy and complications of Bryan artificial cervical disc replacement%Bryan人工颈椎椎间盘置换术后中长期临床疗效及相关问题分析

    Institute of Scientific and Technical Information of China (English)

    蒋涛; 任先军; 王卫东; 初同伟; 李长青

    2011-01-01

    目的 探讨Bryan人工颈椎椎间盘置换术(artificial cervical disc replacement,ACDR)治疗颈椎椎间盘突出症的中长期临床疗效及并发症发生情况.方法 回顾分析13例颈椎椎间盘突出症患者,采用Bryan ACDR治疗,单节段11例,双节段2例,共置换了15个节段.术后定期随访,依照Odom评级和日本骨科学会(Japanese Orthopaedic Association,JOA)评分评定临床疗效和神经功能改善情况,通过影像学资料观察假体位移、假体周围骨吸收、异位骨化、假体活动度及颈椎生理曲度变化.结果 经过5年以上的随访,患者神经症状有明显缓解,Odom评级临床优良率达到92.3%,JOA评分由术前的11.6分增加到的15.6分.术后X线片示假体稳定,没有出现假体前后位移>2mm.术后1例出现自发性融合;1例在置换节段上位椎体前下缘有明显骨吸收,接近2.5mm,并伴椎体后缘的异位骨化.末次随访时置换假体活动度平均为9.2°,邻近节段活动度与术前相当.结论 通过5~7年的中长期随访,Bryan ACDR术治疗颈椎椎间盘突出症具有较好的临床疗效,并发症少,安全可靠.%Objective To evaluate the mid-long term clinical efficacy and complications of Bryan artificial cervical arthro-plasty replacement (ACDR) for treatment of cervical disc herniation. Methods Thirteen cases of cervical disc herniation were retrospectively analyzed. A total of 15 sets of Bryan cervical disc prosthesis were implanted into 13 cases, including single level disc replacement in 11 cases and bi-level in 2 cases. During follow-up, the clinical efficacy and neurological function were evaluated by Odom's criteria and Japanese Orthopaedic Association (JOA)score; the mobility, resorption, heteropic ossification, physiological lordosis and range of motion of the implanted and adjacent segment were observed on dynamic radiograph. Results After more than 5 years of follow-up, all cases showed significant improvement in neurological

  9. The activL® Artificial Disc: a next-generation motion-preserving implant for chronic lumbar discogenic pain

    OpenAIRE

    Yue JJ; Garcia Jr R; Miller LE

    2016-01-01

    James J Yue,1 Rolando Garcia Jr,2 Larry E Miller3 1Department of Orthopaedic Surgery, Yale School of Medicine, New Haven, CT, 2Orthopedic Care Center, Miami, FL, 3Miller Scientific Consulting, Inc., Asheville, NC, USA Abstract: Degeneration of the lumbar intervertebral discs is a leading cause of chronic low back pain in adults. Treatment options for patients with chronic lumbar discogenic pain unresponsive to conservative management include total disc replacement (TDR) or lumbar f...

  10. The activL® Artificial Disc: a next-generation motion-preserving implant for chronic lumbar discogenic pain

    OpenAIRE

    Miller, Larry E.

    2016-01-01

    James J Yue,1 Rolando Garcia Jr,2 Larry E Miller3 1Department of Orthopaedic Surgery, Yale School of Medicine, New Haven, CT, 2Orthopedic Care Center, Miami, FL, 3Miller Scientific Consulting, Inc., Asheville, NC, USA Abstract: Degeneration of the lumbar intervertebral discs is a leading cause of chronic low back pain in adults. Treatment options for patients with chronic lumbar discogenic pain unresponsive to conservative management include total disc replacement (TDR) or ...

  11. Minimizing cryopreservation-induced loss of disc cell activity for storage of whole intervertebral discs

    OpenAIRE

    SCW Chan; SKL Lam; VYL Leung; Chan, D.; KDK Luk; KMC Cheung

    2010-01-01

    Severe intervertebral disc (IVD) degeneration often requires disc excision and spinal fusion, which leads to loss of spinal segment mobility. Implantation of an allograft disc or tissue engineered disc construct emerges as an alternative to artificial disc replacement for preserving the motion of the degenerated level. Establishment of a bank of cadaveric or engineered cryopreserved discs enables size matching, and facilitates clinical management. However, there is a lack of understanding of ...

  12. The NEtherlands Cervical Kinematics (NECK) Trial. Cost-effectiveness of anterior cervical discectomy with or without interbody fusion and arthroplasty in the treatment of cervical disc herniation; A double-blind randomised multicenter study

    NARCIS (Netherlands)

    M.P. Arts (Mark); R. Brand (René); B.W. Koes (Bart); W.C. Peul (Wilco); M.E. van den Akker (Elske)

    2010-01-01

    textabstractBackground. Patients with cervical radicular syndrome due to disc herniation refractory to conservative treatment are offered surgical treatment. Anterior cervical discectomy is the standard procedure, often in combination with interbody fusion. Accelerated adjacent disc degeneration is

  13. Application of finite element analysis in a biomechanical study on artificial lumbar disc%有限元分析在腰椎人工椎间盘生物力学研究中的应用

    Institute of Scientific and Technical Information of China (English)

    陈小龙; 海涌; 关立; 刘玉增

    2015-01-01

    Lumbar disc herniation is one of the major causes of chronic low back pain. Fusion surgery is the gold standard in surgical treatment of the disease, while adjacent segment degeneration is often resulted from the fusion surgery. In order to keep normal motion of the disc, artiifcial disc replacement has been put forward. In the past 50 years, the technology has developed from basic research and animal experiment stage to clinical application stage, which has become a routine treatment option for chronic low back pain. In recent 20 years, there has been many clinical and biomechanical research reports at home and abroad. Along with the advance of the technology, finite element method has been increasingly used in the biomechanical study on artificial lumbar disc. A large number of studies show that the clinical outcomes of disc prostheses are good, while the design and application of artiifcial intervertebral disc remain to be improved. By using three-dimensional ( 3 D ) ifnite element method, the mechanical properties can be obtained through the simulated body condition and simple physical experiment of artiifcialdisc prostheses, so as to reflect the mechanical changes of artificial disc in the process of physiological and pathological processes. The ifnite elementmethod can be used to analyze the stress and strain of components with complex morphology, structure, material and loading condition, with the advantages of comprehensive mechanical properties, repeatability, high-level controllability, etc. In this paper, the characteristics of several kinds of commonly used ifnite element analysis softwares are introduced, and the research results of ifnite elementmethod in artiifcial disc replacement and the effects of artiifcial disc implantation on spinal biomechanics are summarized. When compared with in vitro experiment, the finite element method has its own advantages and disadvantages. It is thought that more meaningful results can be achieved through the

  14. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... you're talking about an arthroplasty, their pain relief is fairly rapid and early on. And the ... body and the arm, and have better pain relief. So, with the arthroplasty, it tends to be ...

  15. Artroplastia total de disco cervical com prótese de Bryan: resultados clínicos e funcionais Artroplastía cervical total con prótesis de Bryan: resultados clínicos y funcionales Cervical total disc arthroplasty with Bryan disc: clinical and functional outcomes

    Directory of Open Access Journals (Sweden)

    Eduardo Machado de Menezes

    2012-09-01

    resultados buenos y excelentes, 10% satisfactorios y el 7% malos. Hubo sólo una complicación (3%, que se revirtió con artrodesis anterior. CONCLUSIONES: La artroplastia discal cervical ha demostrado ser un método seguro y eficaz para el tratamiento de casos seleccionados de hernia de disco cervical asociada a la radiculopatía y/o a compresión de la médula espinal en el corto y mediano plazo.OBJECTIVE: To evaluate results of cervical disc arthroplasty with the Bryan prosthesis for treatment of cervicobrachial pain (radiculopathy and spinal cord compression (myelopathy. METHODS: From 2002 to 2007, the CECOL surgical staff has operated 65 patients. Only 28 patients were found in 2010 to a new data collection. The pre- and post-operative evaluation was conducted using the CSOQ questionnaire (Cervical Spine Outcomes Questionnaire. Odom criteria were used only in the postoperative evaluation. Both were translated and adapted to local culture. RESULTS: There was a significant symptomatic and functional improvement in most patients. The reduction of neck pain (axial and brachial pain (radicular was similar. Odom criteria showed 82.1% good and excellent results, 10% satisfactory and 7% poor. There was only one complication (3% which was reversed with anterior arthrodesis. CONCLUSIONS: The total cervical disc arthroplasty has proved to be a safe and effective method to treat selected cases of cervical disc herniation with radiculopathy and/or myelopathy in the short and medium term.

  16. Fusion around cervical disc prosthesis: case report.

    NARCIS (Netherlands)

    Bartels, R.H.M.A.; Donk, R.

    2005-01-01

    OBJECTIVE AND IMPORTANCE: Cervical arthroplasty is a relatively new method to maintain motion after cervical anterior discectomy. Two cases are presented in which bony fusion occurred around a cervical disc prosthesis. CLINICAL PRESENTATION: A 30-year-old man and a 49-year-old woman underwent a righ

  17. Solid radiographic fusion with a nonconstrained device 5 years after cervical arthroplasty.

    Science.gov (United States)

    Heary, Robert F; Goldstein, Ira M; Getto, Katarzyna M; Agarwal, Nitin

    2014-12-01

    Cervical disc arthroplasty (CDA) has been gaining popularity as a surgical alternative to anterior cervical discectomy and fusion. Spontaneous fusion following a CDA is uncommon. A few anecdotal reports of heterotrophic ossification around the implant sites have been noted for the BRYAN, ProDisc-C, Mobi-C, PRESTIGE, and PCM devices. All CDA fusions reported to date have been in devices that are semiconstrained. The authors reported the case of a 56-year-old man who presented with left C-7 radiculopathy and neck pain for 10 weeks after an assault injury. There was evidence of disc herniation at the C6-7 level. He was otherwise healthy with functional scores on the visual analog scale (VAS, 4.2); neck disability index (NDI, 16); and the 36-item short form health survey (SF-36; physical component summary [PSC] score 43 and mental component summary [MCS] score 47). The patient underwent total disc replacement in which the DISCOVER Artificial Cervical Disc (DePuy Spine, Inc.) was used. The patient was seen at regular follow-up visits up to 60 months. At his 60-month follow-up visit, he had complete radiographic fusion at the C6-7 level with bridging trabecular bone and no motion at the index site on dynamic imaging. He was pain free, with a VAS score of 0, NDI score of 0, and SF-36 PCS and MCS scores of 61 and 55, respectively. Conclusions This is the first case report that identifies the phenomenon of fusion around a nonconstrained cervical prosthesis. Despite this unwanted radiographic outcome, the patient's clinical outcome was excellent. PMID:25303618

  18. Screening of hyaluronic acid-poly(ethylene glycol) composite hydrogels to support intervertebral disc cell biosynthesis using artificial neural network analysis.

    Science.gov (United States)

    Jeong, Claire G; Francisco, Aubrey T; Niu, Zhenbin; Mancino, Robert L; Craig, Stephen L; Setton, Lori A

    2014-08-01

    Hyaluronic acid (HA)-poly(ethylene glycol) (PEG) composite hydrogels have been widely studied for both cell delivery and soft tissue regeneration applications. A very broad range of physical and biological properties have been engineered into HA-PEG hydrogels that may differentially affect cellular "outcomes" of survival, synthesis and metabolism. The objective of this study was to rapidly screen multiple HA-PEG composite hydrogel formulations for an effect on matrix synthesis and behaviors of nucleus pulposus (NP) and annulus fibrosus (AF) cells of the intervertebral disc (IVD). A secondary objective was to apply artificial neural network analysis to identify relationships between HA-PEG composite hydrogel formulation parameters and biological outcome measures for each cell type of the IVD. Eight different hydrogels were developed from preparations of thiolated HA (HA-SH) and PEG vinylsulfone (PEG-VS) macromers, and used as substrates for NP and AF cell culture in vitro. Hydrogel mechanical properties ranged from 70 to 489kPa depending on HA molecular weight, and measures of matrix synthesis, metabolite consumption and production and cell morphology were obtained to study relationships to hydrogel parameters. Results showed that NP and AF cell numbers were highest upon the HA-PEG hydrogels formed from the lower-molecular-weight HA, with evidence of higher sulfated glycosaminoglycan production also upon lower-HA-molecular-weight composite gels. All cells formed more multi-cell clusters upon any HA-PEG composite hydrogel as compared to gelatin substrates. Formulations were clustered into neurons based largely on their HA molecular weight, with few effects of PEG molecular weight observed on any measured parameters. PMID:24859415

  19. 10%盐水冰袋联合弹力绷带持续加压冷敷用于全膝关节置换术后关节肿痛%Continued pressured cold therapy by using elastic bandage to secure 10% saline ice pack for pain and swelling after artificial total knee arthroplasty

    Institute of Scientific and Technical Information of China (English)

    王春萍; 田琴; 李英

    2012-01-01

    Objective To safely and effectively minimize swelling and pain after artificial total knee arthroplasty. Methods Totally, 60 patients with knee joint osteoarthritis scheduled for total knee arthroplasty were divided into 2 groups commensurateiy (odd registration ID number for the observation group, and even number for the control group). After arthroplasty, a common gauze roller bandage was applied to the surgical site of the control group and then a 10% saline ice pack was placed above the bandage. An elastic compression bandage was applied lo the surgical site of the observation group, and was topped by a 10.% saline ice pack, which was secured to the operated knee by another roll of elastic compression bandage. Results Swelling and pain after artificial total knee arthroplasty in the observation group were significantly milder than those in the control group, and the time it took for swelling and pain to subside in the observation group was significantly shortened than in the control group CPartificial to tal knee arthroplasty and boost them to subside.%目的 探讨安全经济有效的减轻全膝关节置换术后关节肿胀及疼痛的方法.方法 将60例膝关节骨性关节炎实施全膝关节置换术患者按住院号单双数分为观察组和对照组各30例.术后对照组采用绷带包扎,10%盐水冰袋冷敷;观察组用弹力绷带包裹患肢后用10%盐水冰袋冷敷,再用弹力绷带加压包扎,均持续3d.结果 观察组下肢肿胀、疼痛程度显著轻于对照组,肿胀及疼痛消退时间显著短于对照组(均P<0.01).结论 10%盐水冰袋联合弹力绷带持续加压冷敷可有效减轻全膝关节置换术后膝关节肿胀和疼痛,加快肿胀、疼痛消退.

  20. Bicompartmental knee arthroplasty

    OpenAIRE

    Sabatini, Luigi; Giachino, Matteo; Risitano, Salvatore; Atzori, Francesco

    2016-01-01

    Total knee arthroplasty (TKA) is the most worldwide practiced surgery for knee osteoarthritis and its efficacy is mightily described by literature. Concerns about the invasiveness of TKA let the introduction of segmental resurfacing of the joint for younger patients with localized osteoarthritis. Bone stock sparing and ligaments preservation are the essence of both unicompartmental knee arthroplasty (UKA) and bicompartmental knee arthroplasty (BKA). Advantages related to BKA are the respect o...

  1. Design principle and development tendency of artificial lumbar disc prosthesis%人工腰椎间盘假体设计原理研究及未来趋势发展

    Institute of Scientific and Technical Information of China (English)

    董可欣; 马德春; 李秋菊; 张丽; 李磊

    2014-01-01

    BACKGROUND:Artificial lumbar disc replacement is a new choice for the treatment of degenerative disc disease, and preserves lumbar vertebra’s biomechanical characteristics during pain elimination. The design of the prosthesis structure and material needs further study and validation. OBJECTIVE:To review the structure and material types of presently designed artificial lumbar discs, then to discuss the trends in the optimization design of prosthesis. METHODS:The PubMed database, China National Knowledge Infrastructure database and Chinese BioMedical Literature Database were searched for related articles concerning artificial lumbar disc and type and biomechanics of nucleus pulposus prosthesis material published from January 2005 to February 2013 by the first author. Key words were“artificial lumbar disc, principle of prosthesis design, structure, material, clinical trials”in Chinese and“artificial lumbar disc, total disc replacement, structure, material, clinical trial”in English. Repetitive and old studies were excluded. 135 articles were found, but 36 articles were included for review. RESULTS AND CONCLUSION:At present, the materials for intervertebral discs include cobalt-chromium al oy, ceramics, stainless steel, titanium al oy and ultrahigh molecular weight polyethylene. Artificial lumbar disc is commonly made by different materials. Bryan prosthesis is most commonly used in the clinic. Three-dimensional finite element analysis, in vitro trial and clinical studies verified its good biomechanical property. The successful rate of replacement was high. Nucleus prosthesis contains prefabricated type and situ polymerization type, and obtains smal injury, so it is a hot focus in present study, but it cannot achieve biomechanical function of human nucleus pulposus. To dig novel material is a future direction for designing individual prosthesis. The prosthetic structure and biomaterial design experience constant improvement and development. This study

  2. Discover人工颈椎间盘置换治疗颈椎间盘退变性疾病的临床疗效%Outcome of discover cervical artificial disc replacement for degenerativedisc disease of the cervical spine

    Institute of Scientific and Technical Information of China (English)

    何智勇; 李开南; 聂海; 母建松; 兰海

    2012-01-01

    Objective To estimate the clinical effects on Discover cervical artificial disc replacement for degenerative disc disease of the cervical spine. Methods A total of 20 patients with cervical disc degeneration, whose pain is not relieved adequately with six weeks of conservative care and daily activities become difficult, were chosed in this study between January 2007 and August 2011. The clinical outcomes were assessed using neck disable index (NDI) and visual analogue scale ( VAS) and Odora scale before surgery and 1、6、12、24 months after surgery. Imageological examination included X ray, cervical CT scanning and MR imaging. Results There are 26 levels in 20 patients performing cervical disc replacement and the follow-up period was 24 months. The NDI, VAS of neck pain, VAS of arm pain were from (23. 82 ±2. 87)、(5.90 ±0. 35)、(5. 91 ±1.63) before sugery to (5. 21 ± 1. 12)、(1. 62 ±0. 87)、(0. 97 ±0. 65) 2 years after sugery. Odom scale were excellent or good in all palienls. The operation time was 60-210 minutes and the estimated blood loss was 70 - 350 milliliter. The motion function of cervical artificial disc implanted was very good with imageology evaluation. The prosthesis moved forward 3 mm in one patient, and another patient had heterotopic ossification 12 months after surgery. Conclusion Discover cervical artificial disc replacement for degenerative disc disease of the cervical spine is safe and effective, however, further study should be conducted to determine the long term outcome.%目的 评价Discover人工颈椎间盘置换治疗颈椎间盘退变性疾病的临床疗效.方法 2007年1月~2011年8月,20例颈椎间盘退变突出经保守治疗无效的患者行人工颈椎间盘置换术.患者术前、术后1、6、12、24个月时使用颈椎功能障碍指数(neck disable index,NDI)、疼痛视觉模拟疼痛量表(visual analogue scale,VAS)进行疗效评估,手术效果采用Odom法评价.影像学检查包括颈椎动力位X

  3. Incidence of secondary surgical procedures after cervical disc arthroplasty compared to fusion: a meta-analysis%颈椎人工椎间盘置换术与前路减压融合固定术再手术率的Meta分析

    Institute of Scientific and Technical Information of China (English)

    姜东杰; 顾庆国; 王占超; 王新伟; 袁文

    2015-01-01

    目的 比较颈椎人工椎间盘置换术与前路减压融合固定术治疗单节段颈椎病术后相邻节段和手术节段再手术的发生率.方法 计算机检索Pubmed、Medline、Ovid、Embase、Cochrane Library和中国生物医学文献数据库、万方、维普等数据库,英文检索词为"cervical"、"replacement OR arthroplasty OR prosthesis’,、"fusion OR arthrodesis","reoperation ORsecondary surgical procedure",中文检索词为"颈椎"、"间盘置换"、"融合"、"再手术".由2名评价者严格按照纳入及排除标准进行文献筛选,收集关于颈椎人工椎间盘置换术与前路减压融合固定术再手术发生率的前瞻性随机对照研究.根据Cochrane Reviews Handbook 5.1.0的RCT偏倚风险评价标准对纳入文献的偏倚风险进行独立评价,并采用Review Manager5.2软件进行统计分析相邻节段和手术节段的再手术发生率.结果12篇文献纳入研究,短期(2年)随机对照研究6篇,中远期(4~8.8年)随机对照研究6篇.4篇为低偏倚风险,7篇为中偏倚风险,1篇为高偏倚风险.Meta分析显示,短期随访结果 中两种术式在相邻节段的再手术发生率无明显差异,而中远期随访结果显示非融合组术后相邻节段再手术率低于融合组;非融合组手术节段再手术率均低于融合组.短期随访中两组患者采用Removal翻修方法的例数无差别;中远期随访中融合组患者采用该翻修方法进行翻修的人数多于非融合组.结论 非融合术式能在一定程度上降低相邻节段再手术的发生率,但是在短期(2年)内对降低邻近节段再手术的发生率效果并不明显.减少融合术后假关节形成是降低融合术式手术节段再手术率的有效方法.%Objective To compare the incidence of secondary surgical procedures after cervical disc arthroplasty vs anterior cervical discectomy with fusion in patients treated for symptomatic single level cervical spondylosis.Methods An online

  4. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... stability and soft tissue envelope. In the early days of reverse arthroplasty, it used to be said ... often we'll drain these patients for a day to try to prevent hematoma formation, especially in ...

  5. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... to conventional arthroplasty, we often use a subscap soft tissue takedown, rather than an osteotomy because of concerns ... the tendon. We've learned that this anterior soft tissue repair is critical for the stability of the ...

  6. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... in the United States. The indications are a patient with painful arthritis, absent rotator cuff, a less ... reverse arthroplasty is indicated for that type of patient. In a younger patient with an intact cuff, ...

  7. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... reverse shoulder arthroplasty for cuff deficient arthritis. You should be aware that I helped design the system ... the delto- pectoral approach. The three features you should watch for in this video are the things ...

  8. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... that we can take them out at the time of antibiotic stoppage. Another question is, why such ... been with your patients? Well, most of the time when you're talking about an arthroplasty, their ...

  9. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... endo button for secure fixation, as well as #5 Ethibond Mason-Allen sutures around the lesser tuberosity ... hemi arthroplasty, or in an anatomic situation, is 5.3 centimeters from the top of the pectoralis ...

  10. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... a friction bite that if you try to work it around the corner, you can get an ... stability and soft tissue envelope. In the early days of reverse arthroplasty, it used to be said ...

  11. Imaging of hip arthroplasty

    International Nuclear Information System (INIS)

    Hip arthroplasty has become a common and still increasing procedure for the treatment of osteoarthritis, advanced head necrosis, post-inflammatory arthritis or rheumatoid arthritis.Radiography is the most important imaging modality for monitoring the normal, asymptomatic hip arthroplasty. Radiographs are obtained at the end of a surgical treatment, to exclude complications like fracture or component misplacement. In the follow-up radiographs are used for the diagnosis of loosening and infection of the hip arthroplasty as well as soft tissue ossification. Together with the history and clinical information, the analysis of morphological findings allows to find the grade of loosening. MRI has been advocated in the diagnosis of infection, in particular in the localisation of soft tissue involvement.Imaging, especially by radiographs, is used for the evaluation of the normal and complicated follow-up of hip arthroplasty. (orig.)

  12. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... to conventional arthroplasty, we often use a subscap soft tissue takedown, rather than an osteotomy because of ... and anteverted, and we worry about crushing that soft bone of the tuberosity later on. So you ...

  13. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... for sort of common cuff arthroplasty in an elderly thin patient where the head is already rising ... cement this case, because in the typical osteoporotic elderly patient with cuff arthropathy, we would do a ...

  14. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... case of reverse shoulder arthroplasty for cuff deficient arthritis. You should be aware that I helped design ... in the last decade for cuff deficient shoulder arthritis in the United States. The indications are a ...

  15. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... here in New York to bring you a video of a recent case of reverse shoulder arthroplasty ... helped design the system that's shown in this video, so I receive royalties and therefore have a ...

  16. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... residents and do receive compensation for that, as well. Now, reverse shoulder arthroplasty is a new option ... t see the neck of the humerus as well, but on the other hand, you have a ...

  17. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... their arm up but they can't do it actively. And the reverse arthroplasty is indicated for ... those. The advantage of a superior approach is it's especially useful if you've had previous open ...

  18. Imaging of hip arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Theodore T., E-mail: millertt@hss.edu [Department of Radiology and Imaging, Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021 (United States)

    2012-12-15

    The imaging evaluation of the prosthetic hip begins with radiography, but arthrography, aspiration, scintigraphy, sonography, CT and MR imaging all have roles in the evaluation of the painful prosthesis. This article will review the appearance of normal hip arthroplasty including hemiarthroplasty, total arthroplasty, and hip resurfacing, as well as the appearances of potential complications such as aseptic loosening and osteolysis, dislocation, infection, periprosthetic fracture, hardware failure, and soft tissue abnormalities.

  19. Arthroplasty register for Germany

    OpenAIRE

    Hagen, Anja; Gorenoi, Vitali; Schönermark, Matthias P.

    2009-01-01

    Scientific background The annual number of joint replacement operations in Germany is high. The introduction of an arthroplasty register promises an important contribution to the improvement of the quality of patient's care. Research questions The presented report addresses the questions on organization and functioning, benefits and cost-benefits as well as on legal, ethical and social aspects of the arthroplasty registers. Methods A systematic literature search ...

  20. Artificial cervical disc replacement and anterior cervical decompression and fusion for the treatment of single segmental cervical disc herniation:a 3-year follow-up%颈椎人工间盘置换与前路减压融合修复单节段颈椎间盘突出症:3年随访

    Institute of Scientific and Technical Information of China (English)

    程俊杰; 眭江涛; 马原; 田慧中

    2015-01-01

    stages. Artificial disc replacement can not only play a role in mitigation of cervical disease neurological symptoms and signs, but also maintain stability and semental activity of cervical spine, and reduce secondary adjacent segmental degeneration. These two methods which applied in cervical degenerative intervertebral disc herniation stil remain controversial. OBJECTIVE:To investigate the short-term effect of artificial cervical disc replacement and anterior cervical decompression and fusion for the treatment of single segmental cervical disc herniation. METHODS:Total y 48 patients with single segment radiculopathy or myelopathy cervical diseases induced by cervical disc herniation that required surgery and received a three-month fol ow-up were included and retrospectively analyzed. These patients were divided into replacement group (n=21) and fusion group (n=27) according to the different repair programs. Patients in the replacement group were subjected to Prestige LP cervical artificial disc replacement, and patients in the fusion group were subjected to disc fusion using interbody fusion cage of Johnson or al ogeneic fibularing. They were fol owed up at 1 week, 3, 6, 12, 24, 36 months after treatment. Complications were recorded during the fol ow-up. The pain of patients was evaluated using neck and upper limb pain visual analogue scale scores. The therapeutic effect was evaluated using Japanese Orthopaedic Association (JOA) score. The clinical symptoms improvement and daily functional status of patients after treatment were evaluated using cervical disability index. RESULTS AND CONCLUSION:During the final fol ow-up, the fusion rate in fusion group was 93%(25/27). Comparisons between groups:at the 1 week and final fol ow-up after treatment, the visual analog scale scores of neck and upper limbs and cervical dysfunction indexes were al lower than those before treatment;the Japanese Orthopaedic Association scores were higher than those before treatment (P0.05). The

  1. Recent development on surface modification of artificial disc material for wear resistance%人工椎间盘关节材料表面耐磨改性研究进展

    Institute of Scientific and Technical Information of China (English)

    王松; 廖振华; 刘宇宏; 刘伟强

    2013-01-01

    Generally titanium alloy and ultra-high molecular weight polyethylene (UHMWPE) are software materials in artificial disc joint material pairing, so their surface modification is important to improve the wear resistance and long-term stability of the prosthesis. The recent development to improve surface hardness and wear resistance of the titanium alloy by using heat treatment, micro-arc oxidation, surface infiltration elements, plated DLC films, laser surface modification and ion implantation technology are reviewed. Then the research to improve surface hardness and wear resistance of UHMWPE by plating DLC films are introduced. At last, the future trends of the artificial disc prosthesis wear resistance are analyzed.%钛合金和超高分子量聚乙烯(UHMWPE)在人工椎间盘关节材料配对中一般是软体材料,其表面改性对提高假体耐磨性能及长期稳定性有重要意义.主要介绍了采用热处理、微弧氧化、表面渗元素、表面镀DLC膜、激光表面改性、离子注入技术提高钛合金表面硬度和耐磨性的研究进展,以及采用表面镀DLC膜等提高UHMWPE表面硬度和耐磨性的研究现状,展望了人工椎间盘假体耐磨性研究的发展趋势.

  2. Failure of cervical arthroplasty in a patient with adjacent segment disease associated with Klippel-Feil syndrome

    Directory of Open Access Journals (Sweden)

    Ioannis D Papanastassiou

    2011-01-01

    Full Text Available Cervical arthroplasty may be justified in patients with Klippel-Feil syndrome (KFS in order to preserve cervical motion. The aim of this paper is to report an arthroplasty failure in a patient with KFS. A 36-year-old woman with KFS underwent two-level arthroplasty for adjacent segment disc degeneration. Anterior migration of the cranial prosthesis was encountered 5 months postoperatively and was successfully revised with anterior cervical fusion. Cervical arthroplasty in an extensively stiff and fused neck is challenging and may lead to catastrophic failure. Although motion preservation is desirable in KFS, the special biomechanical features may hinder arthroplasty. Fusion or hybrid constructs may represent more reasonable options, especially when multiple fused segments are present.

  3. Arthroplasty register for Germany

    Directory of Open Access Journals (Sweden)

    Hagen, Anja

    2009-10-01

    Full Text Available Scientific background: The annual number of joint replacement operations in Germany is high. The introduction of an arthroplasty register promises an important contribution to the improvement of the quality of patient’s care. Research questions: The presented report addresses the questions on organization and functioning, benefits and cost-benefits as well as on legal, ethical and social aspects of the arthroplasty registers. Methods: A systematic literature search was conducted in September 2008 in the medical databases MEDLINE, EMBASE etc. and was complemented with a hand search. Documents describing arthroplasty registers and/or their relevance as well as papers on legal, ethical and social aspects of such registers were included in the evaluation. The most important information was extracted and analysed. Results: Data concerning 30 arthroplasty registers in 19 countries as well as one international arthroplasty register were identified. Most of the arthroplasty registers are maintained by national orthopedic societies, others by health authorities or by their cooperation. Mostly, registries are financially supported by governments and rarely by other sources.The participation of the orthopedists in the data collection process of the arthroplasty registry is voluntary in most countries. The consent of the patients is usually required. The unique patient identification is ensured in nearly all registers.Each data set consists of patient and clinic identification numbers, data on diagnosis, the performed intervention, the operation date and implanted prostheses. The use of clinical scores, patient-reported questionnaires and radiological documentation is rare. Methods for data documentation and transfer are paper form, electronic entry as well as scanning of the data using bar codes. The data are mostly being checked for their completeness and validity. Most registers offer results of the data evaluation to the treating orthopedists and

  4. Bipolar hip arthroplasty.

    Science.gov (United States)

    Chang, Qing; Liu, Shubing; Guan, Changyong; Yu, Fangyuan; Wu, Shenguang; Jiang, Changliang

    2011-12-01

    Our aim was to compare hip arthroplasty with internal screw fixation in the repair of intertrochanteric fractures in elderly patients with osteoporosis. Of 112 included patient, 70 (81.81 ± 4.88 years) received hip arthroplasty with a prosthesis specially designed for intertrochanteric fractures, and 42 (83.46 ± 5.11 years) underwent plate-screw fixation. The hip arthroplasty group had significantly longer operation time, intraoperative blood loss, and total volume of blood transfused but had shorter time to beginning weight-bearing (5.94 ± 2.76 vs 23.68 ± 22.01 days) and higher postoperative Harris hip score (91.37 ± 4.80 vs 86.14 ± 5.46). In the arthroplasty group, there were 2 dislocations; and in the plate-screw fixation group, there were 5 internal fixation failures. Hip arthroplasty is preferable to internal fixation in elderly patients (age >80 years) with osteoporosis. PMID:21530148

  5. Bicompartmental knee arthroplasty

    Science.gov (United States)

    Giachino, Matteo; Risitano, Salvatore; Atzori, Francesco

    2016-01-01

    Total knee arthroplasty (TKA) is the most worldwide practiced surgery for knee osteoarthritis and its efficacy is mightily described by literature. Concerns about the invasiveness of TKA let the introduction of segmental resurfacing of the joint for younger patients with localized osteoarthritis. Bone stock sparing and ligaments preservation are the essence of both unicompartmental knee arthroplasty (UKA) and bicompartmental knee arthroplasty (BKA). Advantages related to BKA are the respect of knee biomechanics, lower complications rates, shorter hospital stay, faster rehabilitation. Moreover, in case of failure of the first implant the conversion to TKA is undemanding and can be compared to a standard prosthesis. Our experience suggest that BKA is a reliable technique in selected cases and especially younger people with higher functional requests can favourably profit from it. Although those results are encouraging, we still need further prospective, randomized, long-term studies to finally assess BKA indications and outcomes. PMID:26855941

  6. Bicompartmental knee arthroplasty.

    Science.gov (United States)

    Sabatini, Luigi; Giachino, Matteo; Risitano, Salvatore; Atzori, Francesco

    2016-01-01

    Total knee arthroplasty (TKA) is the most worldwide practiced surgery for knee osteoarthritis and its efficacy is mightily described by literature. Concerns about the invasiveness of TKA let the introduction of segmental resurfacing of the joint for younger patients with localized osteoarthritis. Bone stock sparing and ligaments preservation are the essence of both unicompartmental knee arthroplasty (UKA) and bicompartmental knee arthroplasty (BKA). Advantages related to BKA are the respect of knee biomechanics, lower complications rates, shorter hospital stay, faster rehabilitation. Moreover, in case of failure of the first implant the conversion to TKA is undemanding and can be compared to a standard prosthesis. Our experience suggest that BKA is a reliable technique in selected cases and especially younger people with higher functional requests can favourably profit from it. Although those results are encouraging, we still need further prospective, randomized, long-term studies to finally assess BKA indications and outcomes. PMID:26855941

  7. 人工颈椎间盘与颈椎动态稳定器治疗颈椎病的早中期临床疗效和影像学分析%A comparison of cervical disc arthroplasty versus dynamic cervial implant in the treatment of cervical spondylopathy:a clinical and radiological study

    Institute of Scientific and Technical Information of China (English)

    关立; 陈小龙; 海涌; 刘玉增; 汪文龙; 于志毅

    2015-01-01

    ;两组患者术后6个月和末次随访与术前比较,差异均有统计学意义(P<0.01),但两组间术前及术后末次随访时差异无统计学意义(P>0.05);两组患者术前、术后6个月及末次随访时对比,手术节段椎间隙高度、手术节段和相邻节段椎间活动度差异无统计学意义(P>0.05)。Prodisc-C 组术后末次随访发现3例异位骨化,2例假体前移1 mm,DCI 组未出现异位骨化和假体移动。结论 Prodisc-C 人工颈椎间盘与 DCI 治疗颈椎病均能保留颈椎活动度,恢复和维持椎间隙高度和颈椎生理弧度,早中期疗效满意。%Objective To evaluate the clinical and radiological outcomes of cervical disc arthroplasty by Prodisc-C versus dynamic cervial implant ( DCI ) in the treatment of cervical spondylopathy.Methods All cervical spondylopathy cases undergoing cervical disc arthroplasty by Prodisc-C or dynamic cervial implant between February 2011 and February 2013 were analyzed retrospectively. There were 16 patients in anterior cervical disc arthroplasty group ( male 8, female 8 ). Age averaged 44 years ( range: 32-54 years ). There were 10 cases with cervical spondylotic myelopathy, and 6 cases with radicular spondylosis. In dynamic cervical implant group were 10 cases ( male 6, female 4 ). Age averaged 44.5 years ( range: 33-55 years ). There were 7 cases of cervical spondylotic myelopathy, and 3 cases of radicular spondylosis. Parameters as gender, age, operation time and blood loss of all the patients were analyzed. The patients were followed 1 month, 3 months, 6 months, 12 months and 24 months postoperatively. Neck disability index ( NDI ), Japanese Orthopaedic Association ( JOA ) Score and Visual Analogue Scale ( VAS ) were used to evaluate the clinical outcomes of the two groups. Anterioposterior and lateral X-ray, hyperextension and hyperflexion X-ray films before and after surgery were analyzed and cervical lordosis, the height of disc, range of motion

  8. Mid-term clinical outcome of Bryan artificial cervical disc replacement for cervical spondylosis and its effect on degeneration of adjacent discs%Bryan人工颈椎椎间盘置换术治疗颈椎病的中期临床效果及对邻近椎间盘退变的影响

    Institute of Scientific and Technical Information of China (English)

    王贝宇; 曾建成; 孔清泉; 刘浩; 丁琛; 胡韬; 石锐; 李涛; 洪瑛; 宋跃明; 刘立岷

    2011-01-01

    Objective To observe the clinical outcome of Bryan artificial cervical disc replacement for cervical spondylo-sis, and to investigate its effect on degeneration of adjacent discs in mid-term study. Methods From November 2004 to December 2007, 34 patients (38 discs) receiving Bryan artificial cervical disc replacement were included in this study. Clinical results were evaluated by SF-36 score, neck disability index (NDI) score, neck/arm pain visual anatague scale (VAS) scores and Odom' s scale. The data were collected before surgery and at 1 week ,3,6, 12, 24, 36, 48 and 60 months after surgery. Adjacent degeneration was assessed by scoring system of cervical disk degeneration based on neutral lateral radiographs before operation and 12, 24, 36, 48 and 60 months after surgery. Incidence of postoperative complications and reoper-ations were also recorded. Results The neurological symptoms of each patient were significantly alleviated in short term after operation. The postoperative SF-36 physical component score and SF-36 mental component score, NDI score and neck/arm pain VAS scores were significantly improved compared with those of pre-operation. In 36 and 48 months after surgey, excellent and good outcomes were observed , though there were some cases with decreased outcomes; sound outcomes were achieved at the final follow-up in all cases. Mild degeneration of adjacent discs occurred after operation, but there was no severe degeneration at the final follow-up. There was no prosthesis subsidence or excursion, no heterotopic ossification or spontaneous fusion, and no reoperation. Conclusion Bryan artificial disc replacement has a sound clinical outcome in mid-term and can protect against acceleration of adjacent discs degeneration.%目的 观察Bryan人工颈椎椎间盘置换术治疗颈椎病的中期临床效果,研究该术对邻近椎间盘的影响.方法 2004年11月~2007年12月间,对34例颈椎间盘突出症患者共38个节段实施Bryan人工颈椎

  9. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available Reverse Shoulder Arthroplasty Zimmer, Inc. New York City, New York March 17, 2010 Welcome to this OR Live presentation, brought to you by Zimmer. Hi. I'm ... my partner, Brad Parsons. We're here in New York to bring you a video of a ...

  10. M obi-C 颈椎人工间盘置换治疗单节段颈椎间盘突出症的效果%Effect of Mobi-C cervical artificial disc replacement in the treatment of single proplase of cervical intervertebral disc

    Institute of Scientific and Technical Information of China (English)

    柳达; 黄瑛; 李彬; 贾长青; 许晓军; 梁峰; 付勤

    2013-01-01

    Objective:To research the short-term effect of Mobi-C cervical artificial disc replacement (CADR) therapy in patients with single proplase of cervical intervertebral disc .Methods:Mobi-C artificial cervical disc was applied to treat 12 cases of single proplase of cervical intervertebral disc .The data about clinical observation , imaging evaluation and questionnaire were collected at preoperative , postoperative ( 1-2 days ) and the end follow-up.Results:The patients were followed up for 6 to 24 months,average 13 months.All the patients were satisfactory to the outcome , excellent in 10 cases and good in 2 cases according to Odom criterion .The pain in upper limb and neck were significantly relieved, the VAS score immediately decreased 5.8 points after operation(P<0.05), and 5.5 points at the last follow-up(P<0.05).NDI and SF-36 improved obviously,which meant the patient′s quality of life improved obviously .Degeneration at the adjacent segments was not found in addition to 3 patient with heterotopic ossification .Conclusions:Mobi-C CADR therapy reserving mobility of cervical spine has a good effect in the early stage , and can improve the quality of life of the patients .%目的:探讨Mobi-C颈椎人工间盘置换治疗单节段颈椎间盘突出症的近期效果。方法:对应用Mobi-C颈椎人工间盘置换治疗的12例单节段颈椎间盘突出症患者于术前、术后(1~2 d )及末次随访时进行全面的影像学和临床评价,并进行问卷调查。结果:本组病例随访6~24月,平均13个月。 Odom临床疗效评价优10例,良2例。患者的颈部及上肢疼痛明显缓解,VAS评分术后下降了5.8分(P<0.05),末次随访时下降了5.5分(P<0.05)。颈椎功能障碍指数(NDI)和SF-36生活质量量表评分明显改善,患者的生活质量明显提高。除3例患者发生异位骨化外,未发现相邻节段退变加速。结论:保留颈椎活动度的Mobi-C颈椎人工间

  11. Artificial cervical disc replacement: range of motion of replacement segment and degeneration of adjacent segments%人工颈椎间盘置换:置换节段活动度及相邻节段退变分析

    Institute of Scientific and Technical Information of China (English)

    陈渲宇; 初冬; 伍骥; 郑超; 黄蓉蓉; 崔玉明; 尚咏; 范恒华; 虞攀峰; 赵旭红

    2015-01-01

    BACKGROUND:In recent years,artificial cervical disc replacement surgery as a new method for the treatment of cervical disease has gradualy been accepted and understood,but relevant complications have gradualy attracted attention.OBJECTIVE:To investigate the clinical outcomes of artificial cervical disc replacement in the treatment of cervical disease and the range of motion of the replacement segment.METHODS: A total of 25 patients with artificial cervical disc replacement in the treatment of cervical spondylosis,who were treated in the Department of Orthopedics,Air Force General Hospital of Chinese PLA from August 2006 to April 2012,were enroled in this study,including 15 males and 10 females,aged 31-76 years,averagely 51.04 years.There were 6 cases of double segments and 19 cases of single segment.They were folowed up for 24 to 93 months.Clinical results were assessed using the Japanese Orthopaedic Association score,cervical dysfunction index and pain visual analog scale scores.Imaging was used to observe range of motion,cervical curvature,heterotopic ossification,and degeneration of adjacent segments.RESULTS AND CONCLUSION:Neurological function in al patients was improved to different degrees.One case suffered from mild heterotopic ossification,but no clinical symptoms were found.No significant difference in range of motion of surgical segment,and range of motion of upper and lower adjacent segments was detected between pre-replacement and final folow-up results (P>0.05).No significant difference in range of motion of C2-C7 was found between pre-replacement and final folow-up results (P>0.05).Japanese Orthopaedic Association score,cervical dysfunction index and pain visual analog scale scores were significantly improved during final folow-up compared with pre-replacement (P<0.05).These results indicated that artificial cervical disc replacement in the treatment of cervical disease can achieve better clinical efficacy,can keep the range of motion of

  12. Clinical outcome of Bryan artificial cervical disc replacement for the treatment of cervical spondylosis: A midterm follow-up%Bryan人工颈椎间盘置换治疗颈椎病的中期临床随访

    Institute of Scientific and Technical Information of China (English)

    丁琛; 孔清泉; 刘浩; 胡韬; 石锐; 李涛; 洪瑛; 宋跃明; 刘立岷; 曾建成

    2011-01-01

    BACKGROUND: Although the short-term clinical efficacy of Bryan artificial cervical disc replacement is generally acknowledged by most spinal surgeons, the midterm and long term clinical results and complications are still unclear.OBJECTIVE: To summarize midterm term clinical results of Bryan artificial cervical disc replacement for the treatment of cervical spondylosis.METHOD: From November 2004 to December 2007, 34 patients had Bryan cervical disc replacement in Department of Orthopedics, West China Hospital were selected, including 30 cases with single replacement and 4 cases with bi-level replacement. Clinical result was evaluated by SF-36 score, JOA score, and neck/arm pain VAS scores. And the data was collected before surgery and at 7 days, 3, 6, 12, 24, 36 and 48 months after surgery. Neutral lateral and dynamic cervical radiographs were made to measure the flexion-extension range of motion (ROM) of operative segment, adjacent segments and C2-7 segment, the intervertebral height of operative and adjacent segments, and the translation of operative level. The intraoperative and postoperative complications were recorded and analyzed.RESULTS AND CONCLUSION: The neurological symptoms of each patient were alleviated notably. The postoperative SF-36physical component score and SF-36 mental component score, JOA score, NDI score and neck/arm pain VAS scores were significantly improved compared with those of the preoperative (P < 0.05), but no statistical significance were noted between each time point after 3-month follow-up (P > 0.05). Each implanted prosthesis preserved the ROM>2° at each follow-up time point,and no heterotopic ossification or spontaneous fusion was found at the operative segment. At 48-month follow-up,flexion-extension ROM of operative segment and C2-7 segment slightly increased but showed no statistical significance compared with the preoperative counterparts (P > 0.05); ROM of upper and lower adjacent segments also showed no statistical

  13. The Danish Shoulder Arthroplasty Registry

    DEFF Research Database (Denmark)

    Rasmussen, Jeppe; Jakobsen, John; Brorson, Stig;

    2012-01-01

    The Danish Shoulder Arthroplasty Registry (DSR) was established in 2004. Data are reported electronically by the surgeons. Patient-reported outcome is collected 10-14 months postoperatively using the Western Ontario osteoarthritis of the shoulder index (WOOS). 2,137 primary shoulder arthroplasties...

  14. 人工腰椎间盘假体位置对活动度的影响%Effect of intervertebral position on range of motion after artificial lumbar total disc replacement and clinical management

    Institute of Scientific and Technical Information of China (English)

    刘艳成; 宁尚龙; 杨强; 夏群; 张继东; 徐宝山; 胡永成; 吉宁; 苗军; 白剑强; 韩岳

    2010-01-01

    Objective To discuss the effect of SB Charité lumbar artificial disc position on intervertebral range of motion(ROM)and clinical management.Methods Between 2004 and 2007, 30 discogenic low back pain patients confirmed by discography underwent 1/2-level total disc replacement (TDR)implantation with 32 prostheses.There were 12 males and 18 females with a mean age of 44 years old (range:28-55).All indexed levels were inserted between L4-S1 involving L4-5(n =9), L5S1(n = 19)and L4-S1(n =2).The clinical outcome was measured by Oswestry disability index(ODI)and visual analogue scale(VAS).Radiographic outcome measures included flexion/extension ROM, restoration of operative level intervertebral disc height, maintenance of disc height at the final follow-up.A technique previously described by McAfee was used to evaluate TDR position in three groups.Paired t test was used to compare the preoperative and postoperative ROM and clinical ODI, VAS scores.Results Twenty-eight patients were followed-up for 24-60 months with an average of 38 months.All the prostheses were solidly immobilized with the vertebral endplate.No disc prosthesis rupture, dislocation, subsidence or heterotopic ossification was observed.Preoperative ODI, VAS back pain and VAS leg pain scores were 70.34 ± 9.21, 7.46 ± 2.65,4.81 ± 2.75;and postoperative corresponding scores 7.65 ± 8.61, 0.68 ± 0.69, 0.35 ± 0.32respectively.The positions of disc prostheses were graded as Group Ⅰ , excellent, n = 17;Group Ⅱ,suboptimal, n = 6;Group Ⅲ, poor, n = 5.Preoperative mean intervertebral flexion/extension ROM (degree)of Group Ⅰ to Group Ⅲ were 9.75 ± 2.80, 10.30 ± 1.20 and 10.08 ± 2.43 respectively.The postoperative mean intervertebral flexion/extension ROM(degree): 6.68 ± 3.83, 4.22 ± 3.51 and 3.48 ± 3.56 respectively.Postoperatively all clinical outcome scores were lower than preoperative ones.Disc height was significantly restored.Mean intervertebral ROM decreased versus preoperative

  15. Herniated lumbar disc

    OpenAIRE

    Jordon, Jo; Konstantinou, Kika; O'Dowd, John

    2011-01-01

    Herniated lumbar disc is a displacement of disc material (nucleus pulposus or annulus fibrosis) beyond the intervertebral disc space. The highest prevalence is among people aged 30 to 50 years, with a male to female ratio of 2:1.

  16. Herniated Lumbar Disc

    Science.gov (United States)

    Herniated Lumbar Disc What is a herniated disc? Nonsurgical treatment Medication and pain management Surgery What can I expect after ... at and just below the waist. A herniated lumbar disc can press on the nerves in the spine ...

  17. Comparison of adjacent segment degeneration five years after single level cervical fusion and cervical arthroplasty:a retrospective controlled study

    Institute of Scientific and Technical Information of China (English)

    SUN Yu; ZHAO Yan-bin; PAN Sheng-fa; ZHOU Fei-fei; CHEN Zhong-qiang; LIU Zhong-jun

    2012-01-01

    Background Cervical arthroplasty is indicated to preserve cervical motion and prevent accelerated adjacent segment degeneration.Whether accelerated adjacent segment degeneration is prevented in the long term is unclear.This trial compared adjacent segment degeneration in Bryan disc arthroplasty with that in anterior cervical decompression and fusion five years after the surgery.Methods We studied patients with single level degenerative cervical disc disease.The extent of adjacent segment degeneration was estimated from lateral X-rays.Results Twenty-six patients underwent single level Bryan disc arthroplasty and twenty-four patients underwent single level anterior cervical decompression and fusion.All patients were followed up for an average of sixty months.In the Bryan arthroplasty group,nine(17.6%)segments developed adjacent segment degeneration,which was significantly lower than that(60.4%)in the anterior cervical decompression and fusion group.Eleven segments in the Bryan arthroplasty group developed heterotopic ossification according to McAfee's classification and two segments had range of motion less than 2°.In the heterotopic ossification group,four(19.5%)segments developed adjacent segment degeneration,similar to the number in the non-heterotopic ossification group(16.7%).Adjacent segment degeneration rate was 50% in gradeⅣ?group but 11.8% in gradeⅡ?to Ⅲ.Conclusions Adjacent segment degeneration was accelerated after anterior cervical decompression and fusion.However,Bryan disc arthroplasty avoided accelerated adjacent segment degeneration by preserving motion.Patients with gradeⅣ?heterotopic ossification lost motion,and the rate of adjacent segment degeneration was higher than that in patients without heterotopic ossification.

  18. Preliminary clinical outcomes of traumatic cervical herniation by artificial cervical disc replacement%人工椎间盘置换治疗外伤性颈椎椎间盘突出症的初期临床疗效

    Institute of Scientific and Technical Information of China (English)

    欧云生; 刘显宏; 权正学; 唐可; 罗小辑; 蒋电明; 安洪

    2011-01-01

    Objective To observe the preliminary outcomes of traumatic cervical hemiation treated by artificial cervical disc replacement (ACDR). Methods Clinical data of 8 patients with traumatic cervical hemiation undergoing ACDR from April 2007 to February 2011 were studied retrospectively. All the patients were assessed by clinical observation and radiological studies preoperatively, in 3 and 6 months postoperatively, and at the end of follow-up. Clinical outcome was evaluated using Japanese Orthopaedic Association (JOA) score, neck disabiliy index (NDI) criteria, and visual analog scale (VAS). Functional spinal unit range of motion (ROM) was also measured in the reontgenographs at anteroposterior and lateral, bending and extending positions. Results All cases were followed up for 6-36 months (mean 15 months). The JOA, NDI, VAS ( neck pain and arm pain) and cervical unit ROM were all significantly improved after operation ( P <0.05). No neurological or vascular complication was found in these 8 cases. The disc height and stability of cervical vertebra were maintained in the reontgenographs taken at the final follow-up. One case was found having artificial cervical prosthesis antedisplacement 1 mm 42 d after operation, and the distance of antedisplacement was not increased at the final follow-up. There was no subsidence, loosening, excursion, or heterotopic ossification in the other 7 patients. Conclusion As long as indication is correctly chosen, satisfactory outcomes will be achieved for traumatic cervical hemiation by ACDR.%目的 观察人工颈椎椎间盘置换术(artificial cervical disc replacement,ACDR)治疗外伤性颈椎椎间盘突出症的初期临床疗效.方法 对8例行ACDR的外伤性颈椎椎间盘突出症患者的临床资料进行随访分析.临床疗效评价包括术前、术后3个月、术后6个月及末次随访时的日本骨科学会(Japanese Orthopaedic Association,JOA)评分、颈椎功能障碍指数( neck disabiliy index,NDI)评分

  19. Spine imaging after lumbar disc replacement: pitfalls and current recommendations

    OpenAIRE

    Sandén Bengt; Robinson Yohan

    2009-01-01

    Abstract Background Most lumbar artificial discs are still composed of stainless steel alloys, which prevents adequate postoperative diagnostic imaging of the operated region when using magnetic resonance imaging (MRI). Thus patients with postoperative radicular symptoms or claudication after stainless steel implants often require alternative diagnostic procedures. Methods Possible complications of lumbar total disc replacement (TDR) are reviewed from the available literature and imaging reco...

  20. Chronic infections in hip arthroplasties

    DEFF Research Database (Denmark)

    Lange, Jeppe; Troelsen, Anders; Thomsen, Reimar W; Søballe, Kjeld

    2012-01-01

    Two-stage revision is regarded by many as the best treatment of chronic infection in hip arthroplasties. Some international reports, however, have advocated one-stage revision. No systematic review or meta-analysis has ever compared the risk of reinfection following one-stage and two-stage revisi......Two-stage revision is regarded by many as the best treatment of chronic infection in hip arthroplasties. Some international reports, however, have advocated one-stage revision. No systematic review or meta-analysis has ever compared the risk of reinfection following one-stage and two......-stage revisions for chronic infection in hip arthroplasties....

  1. Minimally Invasive Total Knee Arthroplasty

    Medline Plus

    Full Text Available ... Institute. We're going to be doing an MIS total knee arthroplasty with the Zimmer mobile bearing ... this point. And there is many recipes for MIS knee surgery as there are surgeons. What’s kind ...

  2. Broken discs: warp propagation in accretion discs

    Science.gov (United States)

    Nixon, Christopher J.; King, Andrew R.

    2012-04-01

    We simulate the viscous evolution of an accretion disc around a spinning black hole. In general, any such disc is misaligned, and warped by the Lense-Thirring effect. Unlike previous studies, we use effective viscosities constrained to be consistent with the internal fluid dynamics of the disc. We find that non-linear fluid effects, which reduce the effective viscosities in warped regions, can promote breaking of the disc into two distinct planes. This occurs when the Shakura & Sunyaev dimensionless viscosity parameter α is ≲0.3 and the initial angle of misalignment between the disc and hole is ≳45°. The break can be a long-lived feature, propagating outwards in the disc on the usual alignment time-scale, after which the disc is fully co-aligned or counter-aligned with the hole. Such a break in the disc may be significant in systems where we know the inclination of the outer accretion disc to the line of sight, such as some X-ray binaries: the inner disc, and so any jets, may be noticeably misaligned with respect to the orbital plane.

  3. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... are your thoughts on that? Well, the more athletic they are, the more I’m going to ... three weeks, and people are back to doing sports like. Now golf is not a very high- ...

  4. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... the patients do so well right off the bat, you know, a little trouble swallowing maybe. I ... operations because they feel well right off the bat. So I’m taking out these pins. I ...

  5. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... play tennis? When I can do things recreationally?” What are your thoughts on that? Well, the more athletic they ... near future of the state of the art. What are your thoughts on that, Bill? I really think this ...

  6. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... Harrisburg, PA Welcome to this “OR Live” webcast presentation brought to you by Pinnacle Health in Harrisburg, ... Thank you for watching this “OR Live” webcast presentation brought to you by Pinnacle Health in Harrisburg, ...

  7. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... Beutler is defining out, that’s the platysma muscle right there. He’ll divide that a little to ... catch on that a little bit different. But right now Dr. Beutler is exposing the spine. He’s ...

  8. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... actually doing an operation like this. But by far and away, the most common problem that you ... technical aspect of putting the implant in is far greater than just putting in a piece of ...

  9. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... to learn more. Just click on the “Request information” button on your screen and open the door ... to learn more, just click on the “Request information” button on your webcast screen and open the ...

  10. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... and tingling in the hands and loss of motor strength. Is that typical of how this patient ... that’s where the problem is. That’s where we start getting patients that have a pinched nerve or ...

  11. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... ultrahigh molecular weight polyethylene, and it’s a medical-grade plastic that’s really been made to sustain active ... bit. That’s just fluid to wash out any blood or bone wax or whatever, pieces of bone. ...

  12. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... piece of what we call -- it’s a medical plastic. It’s ultrahigh molecular weight polyethylene, and it’s a medical-grade plastic that’s really been made to sustain active compression ...

  13. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... which is kind of connective tissue that helps hold things together. It’s the very last layer before ... and allows the vertebrae to lock on or hold the implant tight so it has a good ...

  14. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... pressure off that nerve. So a lot of times these patients present with significant pain not only ... so it doesn’t wiggle out. There are times during this operation we’re going to pushing ...

  15. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... are relatively fragile structures, and I want to protect them as best I can. So we just ... end plates and secure his position. That’s great, Bill. That does look good. Obviously this new technology ...

  16. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... technically there’s sometimes a bit more of a challenge to it because you’re putting something that’s ... Well it’s not something you learn in med school. This is on operation kind that takes ... First, the primary chisel is inserted over the trial and advanced ...

  17. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... everybody in the operating room today. And our staff here has really worked hard to make this ... I want to thank Dr. Beutler and his staff for helping out with a successful procedure. I’ ...

  18. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... biting instrument and remove that. He has a large bone spur right here. This piece of bone ... is exiting right there, and there was a large piece of bone. We were fighting it as ...

  19. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... like. Now golf is not a very high-impact game, but there’s a lot of bending, and ... extremely well. And, again, this is, I think, technology on the forefront that will become the state- ...

  20. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... esophagus and the trachea because they are relatively fragile structures, and I want to protect them as ... an investigational group that was in the United States. There were 20 centers in the United States ...

  1. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... like that. I sometimes tell people it’s crab meat. Do you do that, Walt? Yeah, I do. ... what you said, kind of looks like crab meat when it sticks back. And so what happens ...

  2. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... want to put these in, so patients with osteoporosis or, you know, very, very severe stenosis. What ... this. As you said, if a person has osteoporosis and the bones are thin, or if a ...

  3. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... where I have this awl. This is just something sharp so I can get a screw started ... down here. I’m just getting a little something started there. All right. So what we’re ...

  4. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... Well it’s not something you learn in med school. This is on operation kind that takes experience, ... three weeks, and people are back to doing sports like. Now golf is not a very high- ...

  5. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... at the fascia, which is kind of connective tissue that helps hold things together. It’s the very ... the spine itself. That’s this kind of whitish tissue. Rather than cutting it, I’m just actually ...

  6. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... little smaller one, and this is that sizing business. So what I’m going to look at ... minimally invasive this procedure is. It’s such a small incision and such carpentry that can be done ...

  7. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... he is goes to do is stick a screw into the bottom part of C6 and into ... just something sharp so I can get a screw started and we’ll put a screw in right there, and we’re going to ...

  8. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... little to give him a little more visual aspect, and then he’ll find this sternocleidomastoid. Now ... part to heal. And the third and final aspect that he’s going to do is actually insert ...

  9. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... neck out you can actually make out the definition of that muscle. He will split that muscle ... is an operation that I think will become standard, and state of the art. Right now we’ ...

  10. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... and releasing pressure on the surrounding nerves and spinal cord. We’re going to do an image right ... so he can fully and thoroughly decompress the spinal cord exist. So he is right now working his ...

  11. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... cord. So it’s sometimes a little bit more work. Well, there’s the space for where that nerve ... end plate forms the socket. The implant components work together with the surrounding spinal structures to provide ...

  12. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... Yeah. They look -- the screws look good just looking at the fluoro image there. Why don’t ... incision. Well, it is. You know I guess looking at my thumbs, you can see that the ...

  13. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... in there, but we’re able to avoid these with our dissection, and you’ll see that ... than cutting it, I’m just actually using these cotton balls to push them apart gently, and ...

  14. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... the near future of the state of the art. What are your thoughts on that, Bill? I ... think will become standard, and state of the art. Right now we’re following these patients out ...

  15. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... of the neck. There are some vital anatomic structures in there, but we’re able to avoid these with our ... make any difference. There aren’t really any structures that it would harm in any way. But when it does it in the back of ...

  16. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... a small incision and such carpentry that can be done through a one, one-and-a-half-inch incision. Well, it is. You know I guess looking at ... could go more anterior, but it seems to be recessed. Do you think more anterior? No. Ideally that should work. Well that’s right on the border now. Yeah. Well ...

  17. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... Beutler planned the incision with the use of X-Ray, placing a marker external to the skin to ... he wants to do is confirm it with X-Ray so that there’s no confusion to take the ...

  18. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... screen and open the door to informed medical care. OR Live, the vision of improving health. Hi, ... screen and open the door to informed medical care. “OR Live,” the vision of improving health. 11

  19. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... have to mess with those today or any day. So can I have the nerve fork. I’ ... not to go to work for about ten days. I must say this patient here, he is ... that allow patients to go home the same day after these operations because they feel well right ...

  20. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... screen and open the door to informed medical care. OR Live, the vision of improving health. Hi, my name is Walt Peppelman, and welcome. ... screen and open the door to informed medical care. “OR Live,” the vision of improving health. 11

  1. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... Live” webcast presentation brought to you by Pinnacle Health in Harrisburg, Pennsylvania. “OR Live” makes it easy ... medical care. OR Live, the vision of improving health. Hi, my name is Walt Peppelman, and welcome. ...

  2. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... through a notch and allows the vertebrae to lock on or hold the implant tight so it ... doing now, this is a holding pin. This locks this jig into the vertebral body and allows ...

  3. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... socket implant that is composed of two cobalt chrome alloy end plates and a polyethylene insert. The ... is an operation that I think will become standard, and state of the art. Right now we’ ...

  4. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... your screen and open the door to informed medical care. OR Live, the vision of improving health. ... small piece of what we call -- it’s a medical plastic. It’s ultrahigh molecular weight polyethylene, and it’s ...

  5. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... is go through skin and down through the muscle that he was explaining called the “platysma muscle.” This is a very small muscle, very thin, and actually as you stretch your ...

  6. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... welcome. Today we’re going to have the opportunity to watch Dr. William Beutler perform a total ... of the nerve. So that’s what Dr. Beutler’s job is right now, is to remove all this ...

  7. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... incorporates this implant pretty quickly. Boy, that’s a good point. You know, folks would worry about where does this ... device, but you don’t even need that. You put that in there so good the first time, I don’t even think ...

  8. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... of the neck. There are some vital anatomic structures in there, but we’re able to avoid ... and the trachea because they are relatively fragile structures, and I want to protect them as best ...

  9. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... guy, and he wants to go back to work, you know, within a week or so. And so we’re -- his wife ... little bit. But people are up and at work and doing activities by around two, three weeks, and people are back to doing sports like. ...

  10. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... door to informed medical care. OR Live, the vision of improving health. Hi, my name is Walt ... door to informed medical care. “OR Live,” the vision of improving health. 11

  11. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... quite the opposite. It’s a very, very high success-rate operation. The clinical results and the FDA ... in the way of problems, and long-term success seems to be holding, so I’m very, ...

  12. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... first thing he will do is go through skin and down through the muscle that he was ... X-Ray, placing a marker external to the skin to help to delineate the exact trajectory into ...

  13. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... molecular weight polyethylene, and it’s a medical-grade plastic that’s really been made to sustain active compression and motion on this area for many, many, many year, decades. And so you can see when the components are placed in place that the body is able to maintain motion of the neck ...

  14. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... neck out you can actually make out the definition of that muscle. He will split that muscle ... Beutler is defining out, that’s the platysma muscle right there. He’ll divide that a little to ...

  15. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... Pinnacle Health in Harrisburg, Pennsylvania. “OR Live” makes it easy for you to learn more. Just click ... blood loss with this procedures and this approach. It’s actually a very dry procedure, and he’ll ...

  16. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... It has an outer rim of what we call the “annulus fibrosus.” And then the inside is ... the canal and explore out into what we call the foraminal region to make sure there’s no ...

  17. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... he will do is measure and get a trial implant. This implant will be approximately the size ... to be inserted at. After he places a trial and he’s happy with that, the next thing ...

  18. Artificial Cervical Disc Replacement Improves Mobility

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    Full Text Available ... been utilized to perform anterior cervical discectomies and fusions. The fusion procedure has been the most common way to ... significant benefits over the previous procedure of the fusion, and that is, able to maintain motion of ...

  19. Lumbar disc replacement in adolescents: An initial experience in two cases

    OpenAIRE

    Kasliwal, Manish K.; Harel Deutsch

    2012-01-01

    Management of painful lumbar disc degeneration is one of the most common conditions treated by spine surgeons. Several recent prospective multicenter trials have demonstrated the effectiveness of artificial lumbar disc replacement in treating discogenic lower back pain. Though data on the safety and effectiveness has gradually been accumulated in adults, there is a lack of published data on the effectiveness and feasibility of lumbar artificial disc replacement in adolescents. The authors sha...

  20. In vitro-analysis of kinematics and intradiscal pressures in cervical arthroplasty versus fusion – A biomechanical study in a sheep model with two semi-constrained prosthesis

    OpenAIRE

    Daentzer, Dorothea; Welke, Bastian; Hurschler, Christof; Husmann, Nathalie; Jansen, Christina; Flamme, Christian Heinrich; Richter, Berna Ida

    2015-01-01

    Background As an alternative technique to arthrodesis of the cervical spine, total disc replacement (TDR) has increasingly been used with the aim of restoration of the physiological function of the treated and adjacent motions segments. The purpose of this experimental study was to analyze the kinematics of the target level as well as of the adjacent segments, and to measure the pressures in the proximal and distal disc after arthrodesis as well as after arthroplasty with two different semi-c...

  1. Prodisc-C人工颈椎椎间盘置换的临床疗效观察和运动功能评估%Clinical efficiency and motor function assessment of Prodisc-C artificial cervical disc replacement

    Institute of Scientific and Technical Information of China (English)

    陈道森; 施荣茂; 周强; 罗飞; 代飞; 张劲松; 许建中

    2011-01-01

    目的 通过术后随访评价Prodisc-C人工颈椎椎间盘置换术(artificial cervical disc replacement,ACDR)治疗颈椎病的临床疗效及其对颈椎置换节段、邻近节段运动功能的影响.方法 回顾性分析2009年8月~2011年2月行Prodisc-C ACDR治疗20例颈椎病患者,其中脊髓型9例、神经根型8例、混合型3例,单椎间盘置换17例、双椎间盘置换3例.患者术前行CT、MRI检查明确诊断,术前和术后定期行疼痛视觉模拟量表(visual analogue scale,VAS)和日本骨科学会(Japanese Orthopaedic Association,JOA)及摄颈椎X线片.结果 13例患者获得6~18个月随访.患者术前颈肩背疼痛、上下肢麻木、肌力减弱等不适症状均明显改善.术后VAS及JOA评分均较术前明显改善,差异有统计学意义(P<0.01);置换节段椎间活动度( range of motion,ROM)在术后1、3、6个月显著增大,与术前相比差异有统计学意义(P<0.01);在末次随访时仍大于术前,差异有统计学意义(P<0.05);上下位邻近节段椎间隙高度和椎间ROM与术前相比,差异无统计学意义(P>0.05).所有病例未见假体松动、移位和异位骨化.结论 Prodisc-C ACDR短期随访疗效优良,置换节段ROM增大,邻近节段椎间隙高度和椎间ROM维持在正常水平,但远期疗效还有待进一步随访观察.%Objective To evaluate the clinical efficacy of artificial cervical disc replacement (ACDR) with Prodisc-C and its effects on the motor function of the replaced level and adjacent segments. Methods A total of 20 patients who received ACDR with Prodisc-C from April 2009 to February 2011 were retrospectively analyzed. There were 9 patients with myelopathy, 8 with radiculopa-thy, and the left 3 with both symptoms. There were 17 participators received single level replacement, and the other 3 had 2 levels replaced. All the patients received CT and MRI preoperatively for accurate diagnosis. Visual analogue scale ( VAS) scores for neck and arm

  2. Preliminary results of Activ C artificial disc replacement for cervical spondylosis%Activ C人工椎间盘置换术治疗颈椎病的早期疗效

    Institute of Scientific and Technical Information of China (English)

    赵耀; 刘屹林; 王利民; 谭洪宇; 王卫东; 廖文胜; 鲍恒

    2012-01-01

    目的:观察Activ C人工椎间盘置换术治疗颈椎病的早期临床疗效,分析其临床应用价值.方法:2009年11月~2011年3月在我院接受Activ C人工椎间盘置换术并获得随访的颈椎病患者共43例(45个节段),平均年龄48.3岁,其中男18例,女25例,脊髓型颈椎病22例,神经根型颈椎病16例,混合型颈椎病5例;单节段置换41例(C3/4 2例,C4/5 17例,C5/6 21例,C6/7 1例),双节段置换2例(C4/5和C5/6 1例,C5/6和C6/7 1例).采用日本骨科协会JOA评分、颈椎活动障碍指数(NDI)和疼痛视觉模拟评分(VAS)评价术后症状改善程度,比较手术前后的颈椎曲度、手术节段及邻近上下节段活动度变化,观察统计手术并发症情况.结果:术后随访8~24个月,平均13.8个月.患者的JOA评分、NDI、颈部VAS评分、上肢VAS评分分别由术前的8.2±0.7、35.3±4.7、6.8±1.1和6.5±1.2分显著改善至末次随访时的14.7±0.4、16.2±3.4、1.3±0.8和1.8±0.9分(P均<0.05).颈椎生理曲度术前为7.97°±4.49°,末次随访时为9.15°±3.85°,手术前后无明显差异(P>0.05).置换节段活动度较术前明显增加(P<0.01),邻近上下节段活动度手术前后差异无统计学意义(P>0.05).术后人工椎间盘活动良好,无塌陷或移位,随访期间未见邻近节段明显退变,2例分别在术后7个月和10个月时异位骨化形成.结论:Activ C人工椎间盘置换术可有效改善颈椎病患者的临床症状,维持颈椎的生理曲度和活动度,早期临床疗效满意.%Objectives: To investigate the early clinical effects of cervical Activ C artificial disc replacement. Methods: 43 patients(mean age 48.3 years; 18 males and 25 females) of cervical spondylosis with a total of 45 levels involved underwent anterior cervical decompression and Activ C implantation between November 2009 and March 2011. There were 22 cases of cervical spondylotic myelopathy, 16 cases of cervical spondy-lotic radiculopathy and 5 cases of mixed

  3. Experimental and clinical studies on dynamic circulation of intervertebral discs by radiation clearance method

    International Nuclear Information System (INIS)

    Few studies on the mechanism of dynamic circulation in intervertebral discs are reported. The purpose of this study is to clarify the dynamic mechanism of circulation in the lumbar intervertebra discs with radioisotope clearance, experimentally and clinically. Rabbits were used as experimental animals and were divided into two groups, normal and artificially injured. I131-sodium was injected into them and the clearance was followed. Injected I131-sodium was cleared in the order of; 1) discs with injured annulus fibrosus, 2) discs with injection of α-chymotrypsin, 3) discs with injuries in the border between vertebral body and annulus fibrosus, 4) and normal discs. Human degenerated discs were also used for this study. In the clinical cases, I131-sodium was cleared faster in the degenerated discs than in the normal. The pathway for I131-sodium to be cleared is supposed to be extravascular and interstitial spaces in the disc. (author)

  4. Minimally Invasive Total Knee Arthroplasty

    Medline Plus

    Full Text Available ... the NexGen® LPS-Flex Mobile and LPS-Mobile Bearing Knees March 5, 2009 Welcome to this "OR ... MIS total knee arthroplasty with the Zimmer mobile bearing knee. We invite all of you who have ...

  5. Minimally Invasive Total Knee Arthroplasty

    Medline Plus

    Full Text Available ... NexGen® LPS-Flex Mobile and LPS-Mobile Bearing Knees March 5, 2009 Welcome to this "OR Live" ... re going to be doing an MIS total knee arthroplasty with the Zimmer mobile bearing knee. We ...

  6. Introduction of total knee arthroplasty in Lithuania

    OpenAIRE

    Tarasevicius, Sarunas; Stucinskas, Justinas; Robertsson, Otto; Wingstrand, Hans

    2009-01-01

    Background and purpose We have previously reported that the first 10 years of hip arthroplasty in Lithuania resulted in a higher cumulative revision rate than that observed in Sweden. We thus compared the corresponding results after introduaction of total knee replacement in Lithuania. Methods The 10-year revision rate for the first 595 primary ScanKnee arthroplasties inserted in Klaipeda, Lithuania, was compared to that for the first 1,280 ScanKnee primary arthroplasties inserted in Sweden. ...

  7. Total disc replacement for chronic low back pain: background and a systematic review of the literature

    OpenAIRE

    de Kleuver, M.; F. Oner; W. Jacobs

    2002-01-01

    In this paper the rationale for total disc replacement is discussed, and the authors suggest seven requirements that should be met before the implantation of these devices can be accepted as regular procedures. In an attempt to answer the questions raised, a systematic literature search was performed. The search yielded no controlled trials and nine case series with a total of 564 arthroplasties in 411 patients. The devices used were SB Charité in eight and Acroflex in one study. The percenta...

  8. Revision of the Gunston polycentric knee arthroplasty with total knee arthroplasty.

    Science.gov (United States)

    Memişoğlu, Kaya; Müezzinoğlu, U Sefa; Kesemenli, Cumhur Cevdet

    2010-01-01

    The Gunston polycentric knee arthroplasty, first designed and performed by Frank Gunston in 1971, is the first prosthesis considering the natural knee biomechanics. Although the polycentric knee arthroplasty showed encouraging results to relieve pain and to preserve the preoperative range of motion and joint instability, the improvements in prosthesis design and arthroplasty technology rapidly made the polycentric knee prosthesis obsolete. Herein, we report a 58-year old male patient who had revision of the Gunston polycentric knee arthroplasty with total knee arthroplasty performed 32 years after the initial operation. PMID:21343693

  9. Operative Management of Lumbar Degenerative Disc Disease.

    Science.gov (United States)

    Lee, Yu Chao; Zotti, Mario Giuseppe Tedesco; Osti, Orso Lorenzo

    2016-08-01

    Lumbar degenerative disc disease is extremely common. Current evidence supports surgery in carefully selected patients who have failed non-operative treatment and do not exhibit any substantial psychosocial overlay. Fusion surgery employing the correct grafting and stabilization techniques has long-term results demonstrating successful clinical outcomes. However, the best approach for fusion remains debatable. There is some evidence supporting the more complex, technically demanding and higher risk interbody fusion techniques for the younger, active patients or patients with a higher risk of non-union. Lumbar disc arthroplasty and hybrid techniques are still relatively novel procedures despite promising short-term and mid-term outcomes. Long-term studies demonstrating superiority over fusion are required before these techniques may be recommended to replace fusion as the gold standard. Novel stem cell approaches combined with tissue engineering therapies continue to be developed in expectation of improving clinical outcomes. Results with appropriate follow-up are not yet available to indicate if such techniques are safe, cost-effective and reliable in the long-term. PMID:27559465

  10. Operative Management of Lumbar Degenerative Disc Disease

    Science.gov (United States)

    Lee, Yu Chao; Osti, Orso Lorenzo

    2016-01-01

    Lumbar degenerative disc disease is extremely common. Current evidence supports surgery in carefully selected patients who have failed non-operative treatment and do not exhibit any substantial psychosocial overlay. Fusion surgery employing the correct grafting and stabilization techniques has long-term results demonstrating successful clinical outcomes. However, the best approach for fusion remains debatable. There is some evidence supporting the more complex, technically demanding and higher risk interbody fusion techniques for the younger, active patients or patients with a higher risk of non-union. Lumbar disc arthroplasty and hybrid techniques are still relatively novel procedures despite promising short-term and mid-term outcomes. Long-term studies demonstrating superiority over fusion are required before these techniques may be recommended to replace fusion as the gold standard. Novel stem cell approaches combined with tissue engineering therapies continue to be developed in expectation of improving clinical outcomes. Results with appropriate follow-up are not yet available to indicate if such techniques are safe, cost-effective and reliable in the long-term. PMID:27559465

  11. Wear Performance of UHMWPE and Reinforced UHMWPE Composites in Arthroplasty Applications: A Review

    OpenAIRE

    Juan C. Baena; Jingping Wu; Zhongxiao Peng

    2015-01-01

    As the gold standard material for artificial joints, ultra-high-molecular-weight polyethylene (UHMWPE) generates wear debris when the material is used in arthroplasty applications. Due to the adverse reactions of UHMWPE wear debris with surrounding tissues, the life time of UHMWPE joints is often limited to 15–20 years. To improve the wear resistance and performance of the material, various attempts have been made in the past decades. This paper reviews existing improvements made to enhance i...

  12. Double rupture disc experience

    International Nuclear Information System (INIS)

    Result of these observations, comparisons and evaluations can be summarized in the following list of concerns regarding the use of double rupture discs coupled to the liquid space of a steam generator that is subjected to a large leak sodium water reaction event. Single rupture disc show delayed collapse characteristics in LLTR Series I and double disc assemblies are presumed to be more complex with additional delay before opening to give pressure relief. Delayed failure increases pressures in the IHTS and must be adequately covered by design requirements. With CRBR design, the first disc may fail only partially reducing the loading on the second disc with the result that relief performance may not meet requirements

  13. Imaging of hip joint arthroplasty

    International Nuclear Information System (INIS)

    The hip joint is the largest joint in the human body and consequently, its evaluation by diagnostic imaging is highly important. This includes imaging of hip joint arthroplasty, which is used to avoid joint immobility following a wide spectrum of diseases, such as end-stage degenerative disease, avascular necrosis of the femoral head or post-traumatic fractures. Conventional radiography is still the standard imaging modality for the evaluation of hip arthroplasty both directly following surgery and for periodical follow-up. In the majority of cases conventional radiography enables adequate assessment of early and late complications that can arise following hip arthroplasty, such as loosening, prosthetic or periprosthetic fracture, luxation, infection and soft tissue calcification. If the diagnosis cannot be established by means of radiography, advanced imaging methods such as computed tomography (CT) and magnetic resonance imaging (MRI), with or without injection of contrast media, may provide additional information. This is particularly true for the depiction of inflammatory processes. Regardless of the imaging modality used patients' clinical symptoms must also be taken into account in order to establish the correct diagnosis. (orig.)

  14. Simultaneous and staged bilateral total hip arthroplasty

    DEFF Research Database (Denmark)

    Lindberg-Larsen, Martin; Joergensen, Christoffer Calov; Husted, Henrik;

    2013-01-01

    Bilateral total hip arthroplasty (BTHA) and bilateral simultaneous total hip arthroplasty (BSTHA) are done increasingly. Previous studies evaluating outcomes after bilateral procedures have found different results. The aim of this study was to investigate length of hospital stay (LOS), 30 days...

  15. Optic disc oedema

    DEFF Research Database (Denmark)

    Nielsen, Marianne Kromann; Hamann, Steffen

    2014-01-01

    Optic disc oedema describes the nonspecific, localized swelling of the optic nerve head regardless of aetiology. Therefore, differentiating among the various aetiologies depends on a thorough history and knowledge of the clinical characteristics of the underlying conditions. Papilloedema strictly...... refers to optic disc oedema as a consequence of elevated intracranial pressure. It is usually a bilateral condition and visual function is preserved until late. Optic disc oedema caused by an anterior optic neuropathy is usually unilateral and accompanied by the loss of visual function....

  16. Curative effect evaluation and complication analysis of Bryan artificial cervical disc replacement%Bryan人工颈椎间盘置换术后疗效评价及并发症分析

    Institute of Scientific and Technical Information of China (English)

    蓝旭; 许建中; 刘雪梅; 葛宝丰

    2013-01-01

    To observe the curative effects and complications nf Bryan cervical disc replacement for cervical disc herniation. Methods:From Jannary 2005 to December 2008,39 patients with cervical disc herniation were treated with Bryan cervical disc replacement. There were 20 males and 19 females,with an average age of 47 years old (ranged ,35 to 59). Spinal compression symptom (20 cases) and nerve root symptom (19 eases) were main clinical symptoms. Single level disc was replaced in 35 cases and two-level replaced in 4 cases. Offset and activity of prosthesis, cervical physiological curvature, heterotopic ossification, prosthetic fusion were observed by dynamic X-ray. According to Odom's standard and JOA score, nerve function were evaluated;and depending on NDI standard,clinical symptom and daily function status were recorded. Results: All the patients were followed up from 16 to 36 months with an average of 24 months. Nerve function obviously improved and radiating pain of upper limb completely relieved. No patient with prosthetic anterior-posterior offset more than 2 mm was found. Prosthetic flexion and extention angle was(8.5±1.8)°,left and right flexion range respectively were (3.5±1.2)° and (3.3±1.5)°. Cervical physiological curvature improved obviously or recovered normally. Three cases occurred in heterotopic ossification and 2 cases occurred in prosthetic fusion. According to Odom's standard,25 cases got an excellent results,9 good,5 fair,the rate of excellent and good was 87.2%. JOA score increased from preoperative(8.26±1.32) to (15.71±1.89) at final follow-up and NDI decreased from preoperative (43.7±3.8) to (20.1±2.9) at final follow-up. Conclusion: Treatment of cervical disc herniation with Bryan cervical disc replacement can get the good curative effects,which can obtain good nerve functional recovery,cervical stability and activity. Nevertheless, the operation has typical complication such as heterotopic ossification and prosthetic fusion. Thus.it is

  17. Revision of the Gunston polycentric knee arthroplasty with total knee arthroplasty

    OpenAIRE

    Memisoglu, Kaya; Muezzinoglu, U. Sefa; Kesemenli, Cumhur Cevdet

    2011-01-01

    The Gunston polycentric knee arthroplasty, first designed and performed by Frank Gunston in 1971, is the first prosthesis considering the natural knee biomechanics. Although the polycentric knee arthroplasty showed encouraging results to relieve pain and to preserve the preoperative range of motion and joint instability, the improvements in prosthesis design and arthroplasty technology rapidly made the polycentric knee prosthesis obsolete. Herein, we report a 58-year-old male patient who had ...

  18. LUMBAR DISC HERNIATION

    OpenAIRE

    Vialle, Luis Roberto; Vialle, Emiliano Neves; Suárez Henao, Juan Esteban; Giraldo, Gustavo

    2015-01-01

    Lumbar disc herniation is the most common diagnosis among the degenerative abnormalities of the lumbar spine (affecting 2 to 3% of the population), and is the principal cause of spinal surgery among the adult population. The typical clinical picture includes initial lumbalgia, followed by progressive sciatica. The natural history of disc herniation is one of rapid resolution of the symptoms (four to six weeks). The initial treatment should be conservative, managed through medication and physi...

  19. ANALYSIS OF MONOPOLE ANTENNA ON CIRCULAR DISC BY MODE MATCHING

    Institute of Scientific and Technical Information of China (English)

    Sun Baohua; Zhang Fushun; Liu Qizhong

    2001-01-01

    Mode matching is used for the analysis of monopole antenna on circular disc, which is achieved by developing a novel model consisting of two artificial ground planes above and bellow the monopole antenna. Using this model, the input impedance is computed and compared with measured data reported in literatures, and excellent agreement is observed.

  20. Radicular interdural lumbar disc herniation

    OpenAIRE

    Akhaddar, Ali; Boulahroud, Omar; Elasri, Abad; Elmostarchid, Brahim; Boucetta, Mohammed

    2009-01-01

    Intraradicular lumbar disc herniation is a rare complication of disc disease that is generally diagnosed only during surgery. The mechanism for herniated disc penetration into the intradural space is not known with certainty, but adhesion between the radicular dura and the posterior longitudinal ligament was suggested as the most important condition. The authors report the first case of an intraradicular lumbar disc herniation without subdural penetration; the disc hernia was lodged between t...

  1. Radially truncated galactic discs

    CERN Document Server

    De Grijs, R; Wesson, K H; Grijs, Richard de; Kregel, Michiel; Wesson, Karen H.

    2000-01-01

    We present the first results of a systematic analysis of radially truncatedexponential discs for four galaxies of a sample of disc-dominated edge-onspiral galaxies. Edge-on galaxies are very useful for the study of truncatedgalactic discs, since we can follow their light distributions out to largerradii than in less highly inclined galaxies. The origin of these truncationsand their asymmetry and sharpness are helpful to better constrain theories ofgalaxy formation. In general, the discs of our sample galaxies are truncated at similar radiion either side of their centres. With the exception of the disc of ESO 416-G25,it appears that our sample galaxies are closely symmetric, in terms of both thesharpness of their disc truncations and the truncation length. However, thetruncations occur over a larger region and not as abruptly as found by van derKruit & Searle (KS1-4). We show that the truncated luminosity distributions of our sample galaxies,if also present in the mass distributions, comfortably meet the r...

  2. Total knee arthroplasty in vascular malformation

    Directory of Open Access Journals (Sweden)

    Harish Bhende

    2015-01-01

    Full Text Available In Klippel–Trenaunay syndrome, vascular malformations are not only in skin and superficial soft tissues but also in deep tissues like muscles bones and joints. It is well documemted that these recurrent intraarticular bleeds can cause early arthritis and joint pain. Performing arthroplasty in such patients is difficult and fraught with complications. We describe such a case where navigated total knee arthroplasty was performed with success to avoid the problems of intra medullary alignment used in the presence of intra medullary vascular malformations. We also suggest certain measures when knee arthroplasty is considered in such patients.

  3. Postoperative radiologic imaging of joint arthroplasty

    International Nuclear Information System (INIS)

    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.)

  4. Arthroplasty of the elbow in rheumatoid arthritis.

    Science.gov (United States)

    Kimura, C; Vainio, K

    1976-05-21

    The study consists of 208 elbow arthroplasties performed on rheumatoid arthritic patients. A straight resection of the joint was used in 53 cases and a modified Hass arthroplasty with skin interposition in 155 cases. The average postoperative range of motion in these groups was 100 degrees and 96 degrees respectively. Postoperatively the joint was painless in 81 and 67% of the elbows respectively. The Hass arthroplasty gave a better stability and extension power. The most common complications were paresthesias in the region of the ulnar nerve and bone resorption in the region of the ulnar nerve and bone resorption in the region of the olecranon fossa. PMID:779734

  5. Total Ankle Arthroplasty: An Imaging Overview

    Science.gov (United States)

    Kim, Da-Rae; Potter, Hollis G.; Li, Angela E.; Chun, Ka-Young; Jung, Yoon Young; Kim, Jin-Su; Young, Ki-Won

    2016-01-01

    With advances in implant technology, total ankle arthroplasty (TAA) has become an increasingly popular alternative to arthrodesis for the management of end-stage ankle arthritis. However, reports in the literature do not focus on the imaging features of TAA. Through a literature review, we demonstrate basic design features of the current ankle arthroplasty system, and the normal and abnormal postoperative imaging features associated with such devices. Pre- and postoperative evaluations of ankle arthroplasty mainly include radiography; in addition, computed tomography and magnetic resonance imaging provide further characterization of imaging abnormalities. Familiarization with multimodal imaging features of frequent procedural complications at various postoperative intervals is important in radiological practice. PMID:27134529

  6. Discover颈人工椎间盘置换术联合颈椎前路减压融合术治疗颈椎病的临床疗效%The clinic effect of discover cervical artificial disc replacement combined with anterior cervical decompression and fusion in treatment of cervical spondylosis

    Institute of Scientific and Technical Information of China (English)

    吴兴林

    2014-01-01

    Objective To explore the clinic effect of discover cervical artificial disc replacement combined with anterior cervical decompression and fusion in treatment of cervical spondylosis. Methods 96 patients were selected from our hospital,and the they were evenly divied into two group by random,experimental group patients were treated with discover cervical artificial disc replacement combined with anterior cervical decompression,the control group patients were treated with anterior cervical decompression and fusion.Compared and analyzed the two groups'cervical spine,the average hospital stay,postoperative cervical fixation time,normal activity recovery time and clinical effect after treatment. Results The experimental group's cervical average activity was (44.6±4.7) degree which was higher than control group,and the difference was significantly(P < 0.05);The experimental group was shorter than control group in average hospital stay,postoperative cervical fixation time,normal activity recovery time,and the difference was significantly(P < 0.05);Experimental group's total effective rate was 97.9% which was higher than the control group(87.5%),and the difference was significantly(P<0.05). Conclusion Discover cervical artificial disc replacement combined with anterior cervical decompression and fusion can reduce the average hospital stay,postoperative cervical fixation time,normal activity recovery time,can ensure the patients's cervical average activity to recover normal,and can improve the clinical effect.%目的:探讨分析Discover颈人工椎间盘置换术联合颈椎前路减压融合术的临床疗效。方法选择我院96例患者,将其随机均分为两组,实验组行Discover颈人工椎间盘置换术联和颈椎前路减压融合术治疗;对照组行颈椎前路减压融合术治疗,比较患者术后颈椎活动度、平均住院时间、术后颈椎固定时间、恢复正常活动时间以及患者临床疗效,并进行统计学分析。

  7. Artificial intelligence

    CERN Document Server

    Hunt, Earl B

    1975-01-01

    Artificial Intelligence provides information pertinent to the fundamental aspects of artificial intelligence. This book presents the basic mathematical and computational approaches to problems in the artificial intelligence field.Organized into four parts encompassing 16 chapters, this book begins with an overview of the various fields of artificial intelligence. This text then attempts to connect artificial intelligence problems to some of the notions of computability and abstract computing devices. Other chapters consider the general notion of computability, with focus on the interaction bet

  8. Characterisation of global flow and local fluctuations in 3D SPH simulations of protoplanetary discs

    CERN Document Server

    Arena, Serena

    2013-01-01

    A complete and detailed knowledge of the structure of the gaseous component in protoplanetary discs is essential to the study of dust evolution during the early phases of pre-planetesimal formation. The aim of this paper is to determine if three-dimensional accretion discs simulated by the Smoothed Particle Hydrodynamics (SPH) method can reproduce the observational data now available and the expected turbulent nature of protoplanetary discs. The investigation is carried out by setting up a suite of diagnostic tools specifically designed to characterise both the global flow and the fluctuations of the gaseous disc. The main result concerns the role of the artificial viscosity implementation in the SPH method: in addition to the already known ability of SPH artificial viscosity to mimic a physical-like viscosity under specific conditions, we show how the same artificial viscosity prescription behaves like an implicit turbulence model. In fact, we identify a threshold for the parameters in the standard artificia...

  9. Patients’ decision making in total knee arthroplasty

    OpenAIRE

    Barlow, T.; Griffin, D.; Barlow, D; Realpe, A.

    2015-01-01

    Objectives A patient-centred approach, usually achieved through shared decision making, has the potential to help improve decision making around knee arthroplasty surgery. However, such an approach requires an understanding of the factors involved in patient decision making. This review’s objective is to systematically examine the qualitative literature surrounding patients’ decision making in knee arthroplasty. Methods A systematic literature review using Medline and Embase was conducted to ...

  10. Introduction of total knee arthroplasty in Lithuania

    Science.gov (United States)

    Stucinskas, Justinas; Robertsson, Otto; Wingstrand, Hans

    2009-01-01

    Background and purpose We have previously reported that the first 10 years of hip arthroplasty in Lithuania resulted in a higher cumulative revision rate than that observed in Sweden. We thus compared the corresponding results after introduaction of total knee replacement in Lithuania. Methods The 10-year revision rate for the first 595 primary ScanKnee arthroplasties inserted in Klaipeda, Lithuania, was compared to that for the first 1,280 ScanKnee primary arthroplasties inserted in Sweden. As in the hip replacement study, only patients with osteoarthritis (OA) were included. Primary knee arthroplasties without patellar resurfacing were included, and the endpoint was revision for any reason other than addition of a patellar component. Results We found that the cumulative revision rate was not statistically significantly different between the groups. The revision pattern was different, however, and we observed 24 isolated patellar component additions in Sweden, but none in Klaipeda. Interpretation Contrary to the results of our previous hip arthroplasty study, the cumulative revision rate after total knee arthroplasty was similar in the two groups. This suggests that compared to hip arthroplasty, the outcome of total knee arthroplasty was less dependent on surgical experience. The large difference regarding isolated patellar component additions may be explained by long-term accumulation of severe OA cases in Lithuania. To patients subject to a newly introduced surgical treatment offering great improvement in quality of life, patellofemoral pain may be a minor problem. Furthermore, patellar problems may not have seemed particularly relevant for the surgeons, considering the disability of other patients waiting to be treated. PMID:19297790

  11. Management of complications after total shoulder arthroplasty

    OpenAIRE

    Josef K Eichinger; Galvin, Joseph W.

    2015-01-01

    The outcomes of total shoulder arthroplasty (TSA) for painful arthritis of the glenohumeral joint are excellent with significant improvement in pain and function. Increased use of total shoulder arthroplasty over the past decade has led to identification of common complications. Although the complication rate is low, accurate and timely diagnosis, appropriate management, and implementation of methods for prevention are critical to a successful long-term outcome. The most common complications ...

  12. Polyethylene in knee arthroplasty: A review

    OpenAIRE

    Chakrabarty, Gautam; Vashishtha, Mayank; Leeder, Daniel

    2015-01-01

    Polyethylene (PE) has been used extensively in knee arthroplasty since the mid 20th century. Progress in material manufacturing and processing has led to newer polyethylenes over last few decades with different material properties. It has been established that PE wear in knee arthroplasty causes particle induced osteolysis which is the main reason for late failure and requires revision surgery. Although there are various causes of wear, the properties of PE have long been a matter of investig...

  13. The vibration of rolling discs

    OpenAIRE

    Ferguson, Neil Stuart

    1988-01-01

    The study presented is a fundamental investigation into the vibration of a rolling disc and an analysis of the sound which is then produced by the disc response. In order to characterise the disc's behaviour the free and forced vibration of a thin disc is analysed with the additional conditions which occur in rolling. These conditions include the geometric boundary conditions, the effect of the in-plane load, the change due to rotation of the disc and the effect of contact on the disc which i...

  14. Pseudoenhancement of intervertebral disc herniation

    Energy Technology Data Exchange (ETDEWEB)

    Araki, Y.; Ootani, M.; Furukawa, T.; Tsukaguchi, I. (Dept. of Radiology, Osaka Rosai Hospital (Japan)); Mitomo, M. (Dept. of Radiology, Osaka Univ. Medical School (Japan))

    1992-08-01

    Two patients with intervertebral disc herniation appeared to demonstrate abnormally diffuse and intense enhancement of the disc after intravenous administration of gadolinium-DTPA for MRI. Surgery disclosed a dilated epidural venous plexus in one and vascular granulation tissue in the other, associated with the herniated disc material. The mechanism of this 'pseudoenhancement' of the disc appears to be a partial volume effect of disc material and the adjacent veins or granulation tissue. Pseudoenhancement of a herniated disc should be included in the differential diagnosis of a diffusely enhancing epidural mass. (orig.).

  15. Design of the PROCON trial: a prospective, randomized multi – center study comparing cervical anterior discectomy without fusion, with fusion or with arthroplasty

    Directory of Open Access Journals (Sweden)

    Grotenhuis J André

    2006-11-01

    Full Text Available Abstract Background PROCON was designed to assess the clinical outcome, development of adjacent disc disease and costs of cervical anterior discectomy without fusion, with fusion using a stand alone cage and implantation of a Bryan's disc prosthesis. Description of rationale and design of PROCON trial and discussion of its strengths and limitations. Methods/Design Since proof justifying the use of implants or arthroplasty after cervical anterior discectomy is lacking, PROCON was designed. PROCON is a multicenter, randomized controlled trial comparing cervical anterior discectomy without fusion, with fusion with a stand alone cage or with implantation of a disc. The study population will be enrolled from patients with a single level cervical disc disease without myelopathic signs. Each treatment arm will need 90 patients. The patients will be followed for a minimum of five years, with visits scheduled at 6 weeks, 3 months, 12 months, and then yearly. At one year postoperatively, clinical outcome and self reported outcomes will be evaluated. At five years, the development of adjacent disc disease will be investigated. Discussion The results of this study will contribute to the discussion whether additional fusion or arthroplasty is needed and cost effective. Trial registration Current Controlled Trials ISRCTN41681847

  16. Revision total elbow arthroplasty with the linked Coonrad-Morrey total elbow arthroplasty

    DEFF Research Database (Denmark)

    Plaschke, Hans Christian; Thillemann, Theis; Belling-Sørensen, Anne Kathrine; Olsen, Bo

    2013-01-01

    In this retrospective study we evaluated the short- to medium-term results after 20 Coonrad-Morrey revision total elbow arthroplasties (TEAs).......In this retrospective study we evaluated the short- to medium-term results after 20 Coonrad-Morrey revision total elbow arthroplasties (TEAs)....

  17. Joint Line Reconstruction in Navigated Total Knee Arthroplasty Revision

    Science.gov (United States)

    2012-05-16

    Revision Total Knee Arthroplasty Because of; Loosening; Instability; Impingement; or Other Reasons Accepted as Indications for TKA Exchange.; The Focus is to Determine the Precision of Joint Line Restoration in Navigated vs. Conventional Revision Total Knee Arthroplasty

  18. Composition of Airy disc

    Institute of Scientific and Technical Information of China (English)

    Guoquan Zhou; Xiuxiang Chu; Jun Zheng

    2008-01-01

    The description of a plane wave diffracted by a circular aperture is directly started from the Maxwell's equations. Based on the vector angular spectrum representation of Maxwell's equations, the diffracted plane wave is decomposed into the TE and TM terms. The analytical TE and TM terms in the far field are presented by stationary phase. As the TE and TM terms are orthogonal to each other in the far field, their sum constitutes the so-called Airy disc pattern. Therefore, this research reveals the composition of Airy disc, which is beneficial to deepen and enhance the recognition of the classical diffraction problem.

  19. Artificial Limbs

    Science.gov (United States)

    ... you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which ... activities such as walking, eating, or dressing. Some artificial limbs let you function nearly as well as ...

  20. 人工椎间盘置换加颈前路椎体次全切减压植骨融合术治疗多节段颈椎病%Artificial Disc Replacement Combined with Anterior Cervical Decompression and Autograft Bone Fusion for the Treatment of Multi-segment Cervical Spondylosis

    Institute of Scientific and Technical Information of China (English)

    廖维峰; 肖晟; 黄象望; 刘向阳; 张毅; 向铁城

    2014-01-01

    [目的]探讨人工椎间盘置换加颈前路椎体次全切减压植骨融合术治疗多节段颈椎病的临床疗效。[方法]湖南省人民医院2008年2月至2012年6月收治的12例多节段颈椎病手术病例,均行人工椎间盘置换加颈前路椎体次全切减压植骨融合术,随访时间为12~18个月,平均随访15.5个月,均摄术前、术后及末次随访时的颈椎正侧位及颈椎过伸过屈位X线片及磁共振检查,观察植骨融合、内固定及人工椎间盘的情况,以JO A评分评价神经功能改善情况。[结果]所有病例内置物无松动、移位,植骨融合时间在3~6个月,平均4.9个月。置换间隙活动度术后1年时为12.5°±5.0°,与术前(12.3°±4.9°)比较无统计学差异(P>0.05)。术前JOA 评分平均为9.3分,术后6个月时平均为16.1分,平均改善率为91.2%。[结论]人工椎间盘置换加颈前路椎体次全切减压植骨融合术治疗多节段颈椎病近期疗效满意,是治疗多节段颈椎病的一种可行方法。%[Objective]To explore the clinical efficacy of cervical artificial disc replacement combined with anterior cervical decompression and autograft bone fusion for the treatment of multi -segment cervical spon-dylosis .[Methods]Twelve patients with multi- segment cervical spondylosis operated in Hunan provincial people's hospital from Feb .2008 to June 2012 underwent cervical artificial disc replacement combined with an-terior cervical decompression and autograft bone fusion .The follow up time was 12~18 months(average 15 .5 months) .Cervical MRI and X-ray films of cervical normal lateral position ,hyperextension and hyperflexion position were performed before and after operation and at the last time of follow up .Bone fusion ,internal fixa-tion and artificial disc were observed .JOA score was used to evaluate the improvement of neurological func-tion .[Results]No loosening and displacement of

  1. The growth of planets by pebble accretion in evolving protoplanetary discs

    CERN Document Server

    Bitsch, Bertram; Johansen, Anders

    2015-01-01

    The formation of planets depends on the underlying protoplanetary disc structure, which influences both the accretion and migration rates of embedded planets. The disc itself evolves on time-scales of several Myr during which both temperature and density profiles change as matter accretes onto the central star. Here we use a detailed model of an evolving disc to determine the growth of planets by pebble accretion and their migration through the disc. Cores that reach their pebble isolation mass accrete gas to finally form giant planets with extensive gas envelopes, while planets that do not reach pebble isolation mass are stranded as ice giants and ice planets containing only minor amounts of gas in their envelopes. Unlike earlier population synthesis models, our model works without any artificial reductions in migration speed and for protoplanetary discs with gas and dust column densities similar to those inferred from observations. We find that in our nominal disc model the emergence of planetary embryos pr...

  2. Transfusion practice in hip arthroplasty - a nationwide study

    DEFF Research Database (Denmark)

    Jans, Øivind; Kehlet, H; Hussain, Zubair Butt;

    2011-01-01

    Background and Objectives The optimal transfusion strategy in hip arthroplasty remains controversial despite existing guidelines. The aim of this study was to evaluate the transfusion practice in patients undergoing primary total hip arthroplasty (THA) or revision total hip arthroplasty (RTHA) in...

  3. Outcome after total elbow arthroplasty

    DEFF Research Database (Denmark)

    Plaschke, Hans Christian; Thillemann, Theis M; Brorson, Stig;

    2015-01-01

    BACKGROUND: Total elbow arthroplasties (TEAs) are traditionally grouped into linked and unlinked design. The aim was to analyze the difference in clinical outcomes after TEA based on implant design and indication for surgery and to evaluate primary and revision TEAs. METHODS: A total of 167 TEAs...... (126 primary and 41 revision TEAs) in 141 patients were evaluated with patient-reported outcome measure by the Oxford Elbow Score (OES) and clinically assessed with the Mayo Elbow Performance Score (MEPS), range of motion (ROM), and standard radiographs. RESULTS: The mean follow-up was 10.5 years for...... primary and 7.5 years for revision TEAs. There was no difference in OES or MEPS between linked and unlinked primary TEAs. The OES score in the social-psychological domain was significantly lower in TEAs performed due to fracture (67) compared with rheumatoid arthritis (81; P = .025). ROM in extension...

  4. Spontaneously disappearing lumbar disc protrusion

    OpenAIRE

    Ushewokunze, Shungu; Abbas, Naeem; Dardis, Ronan; Killeen, Ian

    2008-01-01

    Spontaneous disappearance of a herniated lumbar disc is known to occur. This case study describes a 45-year-old patient whose symptoms of lumbar radiculopathy resolved and follow-up imaging showed complete disappearance of the disc prolapse. This phenomenon strengthens the role of conservative treatment in the management of lumbar disc protrusions.

  5. How do accretion discs break?

    Science.gov (United States)

    Dogan, Suzan

    2016-07-01

    Accretion discs are common in binary systems, and they are often found to be misaligned with respect to the binary orbit. The gravitational torque from a companion induces nodal precession in misaligned disc orbits. In this study, we first calculate whether this precession is strong enough to overcome the internal disc torques communicating angular momentum. We compare the disc precession torque with the disc viscous torque to determine whether the disc should warp or break. For typical parameters precession wins: the disc breaks into distinct planes that precess effectively independently. To check our analytical findings, we perform 3D hydrodynamical numerical simulations using the PHANTOM smoothed particle hydrodynamics code, and confirm that disc breaking is widespread and enhances accretion on to the central object. For some inclinations, the disc goes through strong Kozai cycles. Disc breaking promotes markedly enhanced and variable accretion and potentially produces high-energy particles or radiation through shocks. This would have significant implications for all binary systems: e.g. accretion outbursts in X-ray binaries and fuelling supermassive black hole (SMBH) binaries. The behaviour we have discussed in this work is relevant to a variety of astrophysical systems, for example X-ray binaries, where the disc plane may be tilted by radiation warping, SMBH binaries, where accretion of misaligned gas can create effectively random inclinations and protostellar binaries, where a disc may be misaligned by a variety of effects such as binary capture/exchange, accretion after binary formation.

  6. Tracing Planets in Circumstellar Discs

    Directory of Open Access Journals (Sweden)

    Uribe Ana L.

    2013-04-01

    Full Text Available Planets are assumed to form in circumstellar discs around young stellar objects. The additional gravitational potential of a planet perturbs the disc and leads to characteristic structures, i.e. spiral waves and gaps, in the disc density profile. We perform a large-scale parameter study on the observability of these planet-induced structures in circumstellar discs in the (submm wavelength range for the Atacama Large (SubMillimeter Array (ALMA. On the basis of hydrodynamical and magneto-hydrodynamical simulations of star-disc-planet models we calculate the disc temperature structure and (submm images of these systems. These are used to derive simulated ALMA maps. Because appropriate objects are frequent in the Taurus-Auriga region, we focus on a distance of 140 pc and a declination of ≈ 20°. The explored range of star-disc-planet configurations consists of six hydrodynamical simulations (including magnetic fields and different planet masses, nine disc sizes with outer radii ranging from 9 AU to 225 AU, 15 total disc masses in the range between 2.67·10-7 M⊙ and 4.10·10-2 M⊙, six different central stars and two different grain size distributions, resulting in 10 000 disc models. At almost all scales and in particular down to a scale of a few AU, ALMA is able to trace disc structures induced by planet-disc interaction or the influence of magnetic fields in the wavelength range between 0.4...2.0 mm. In most cases, the optimum angular resolution is limited by the sensitivity of ALMA. However, within the range of typical masses of protoplane tary discs (0.1 M⊙...0.001 M⊙ the disc mass has a minor impact on the observability. At the distance of 140 pc it is possible to resolve discs down to 2.67·10-6 M⊙ and trace gaps in discs with 2.67·10-4 M⊙ with a signal-to-noise ratio greater than three. In general, it is more likely to trace planet-induced gaps in magneto-hydrodynamical disc models, because gaps are wider in the presence of

  7. Evolution of Protoplanetary Discs with Magnetically Driven Disc Winds

    CERN Document Server

    Suzuki, Takeru K; Morbidelli, Alessandro; Crida, Aurélien; Guillot, Tristan

    2016-01-01

    Aims: We investigate the evolution of protoplanetary discs (PPDs hereafter) with magnetically driven disc winds and viscous heating. Methods: We consider an initially massive disc with ~0.1 Msun to track the evolution from the early stage of PPDs. We solve the time evolution of surface density and temperature by taking into account viscous heating and the loss of the mass and the angular momentum by the disc winds within the framework of a standard alpha model for accretion discs. Our model parameters, turbulent viscosity, disc wind mass loss, and disc wind torque, which are adopted from local magnetohydrodynamical simulations and constrained by the global energetics of the gravitational accretion, largely depends on the physical condition of PPDs, particularly on the evolution of the vertical magnetic flux in weakly ionized PPDs. Results: Although there are still uncertainties concerning the evolution of the vertical magnetic flux remaining, surface densities show a large variety, depending on the combinatio...

  8. Discs in misaligned binary systems

    CERN Document Server

    Rawiraswattana, Krisada; Goodwin, Simon P

    2016-01-01

    We perform SPH simulations to study precession and changes in alignment between the circumprimary disc and the binary orbit in misaligned binary systems. We find that the precession process can be described by the rigid-disc approximation, where the disc is considered as a rigid body interacting with the binary companion only gravitationally. Precession also causes change in alignment between the rotational axis of the disc and the spin axis of the primary star. This type of alignment is of great important for explaining the origin of spin-orbit misaligned planetary systems. However, we find that the rigid-disc approximation fails to describe changes in alignment between the disc and the binary orbit. This is because the alignment process is a consequence of interactions that involve the fluidity of the disc, such as the tidal interaction and the encounter interaction. Furthermore, simulation results show that there are not only alignment processes, which bring the components towards alignment, but also anti-...

  9. Disc-mass distribution in star-disc encounters

    CERN Document Server

    Steinhausen, M; Pfalzner, S

    2011-01-01

    Investigations of stellar encounters in cluster environments have demonstrated their potential influence on the mass and angular momentum of protoplanetary discs around young stars. In this study it is investigated in how far the initial surface density in the disc surrounding a young star influences the outcome of an encounter. Based on a power-law ansatz for the surface density, $\\Sigma(r) \\propto r^{-p}$, a parameter study of star-disc encounters with different initial disc-mass distributions has been performed using N-body simulations. It is demonstrated that the shape of the disc-mass distribution has a significant impact on the quantity of the disc-mass and angular momentum losses in star-disc encounters. Most sensitive are the results where the outer parts of the disc are perturbed by high-mass stars. By contrast, disc-penetrating encounters lead more or less independently of the disc-mass distribution always to large losses. However, maximum losses are generally obtained for initially flat distributed...

  10. Imaging patellar complications after knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-15

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

  11. Fast-track hip and knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Henrik

    2012-01-01

    Fast-track hip and knee arthroplasty aims at giving the patients the best available treatment at all times, being a dynamic entity. Fast-track combines evidence-based, clinical features with organizational optimization including a revision of traditions resulting in a streamlined pathway from...... clinical and organizational aspects of fast-track hip and knee arthroplasty (I–IX). A detailed description of the fast-track set-up and its components is provided. Major results include identification of patient characteristics to predict length of stay and satisfaction with different aspects of the...... hospital stay (I); how to optimize analgesia by using a compression bandage in total knee arthroplasty (II); the clinical and organizational set-up facilitating or acting as barriers for early discharge (III); safety aspects following fast-track in the form of few readmissions in general (IV) and few...

  12. The Mobi-C cervical disc for one-level and two-level cervical disc replacement: a review of the literature

    Directory of Open Access Journals (Sweden)

    Alvin MD

    2014-11-01

    Full Text Available Matthew D Alvin,1,2 Thomas E Mroz1,3,41Cleveland Clinic Center for Spine Health, Cleveland Clinic, Cleveland, OH, USA; 2Case Western Reserve University School of Medicine, Cleveland, OH, USA; 3Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA; 4Department of Neurological Surgery, Cleveland Clinic, Cleveland, OH, USABackground: Cervical disc arthroplasty (CDA is a novel motion-preserving procedure that is an alternative to fusion. The Mobi-C disc prosthesis, one of many Food and Drug Administration (FDA-approved devices for CDA, is the only FDA-approved prosthesis for two-level CDA. Hence, it may allow for improved outcomes compared with multilevel fusion procedures.Purpose: To critically assess the available literature on CDA with the Mobi-C prosthesis, with a focus on two-level CDA.Methods: All clinical articles involving the Mobi-C disc prosthesis for CDA through September 1, 2014 were identified on Medline. Any paper that presented Mobi-C CDA clinical results was included. Study design, sample size, length of follow-up, use of statistical analysis, quality of life outcome scores, conflict of interest, and complications were recorded.Results: Fifteen studies were included that investigated Mobi-C CDA, only one of which was a level Ib randomized control trial. All studies included showed non-inferiority of one-level Mobi-C CDA to one-level anterior cervical discectomy and fusion (ACDF. Only one study analyzed outcomes of one-level versus two-level Mobi-C CDA, and only one study analyzed two-level Mobi-C CDA versus two-level ACDF. In comparison with other cervical disc prostheses, the Mobi-C prosthesis is associated with higher rates of heterotopic ossification (HO. Studies with conflicts of interest reported lower rates of HO. Adjacent segment degeneration or disease, along with other complications, were not assessed in most studies.Conclusion: One-level Mobi-C CDA is non-inferior, but not superior, to one-level ACDF for patients

  13. Total disc replacement.

    Science.gov (United States)

    Vital, J-M; Boissière, L

    2014-02-01

    Total disc replacement (TDR) (partial disc replacement will not be described) has been used in the lumbar spine since the 1980s, and more recently in the cervical spine. Although the biomechanical concepts are the same and both are inserted through an anterior approach, lumbar TDR is conventionally indicated for chronic low back pain, whereas cervical TDR is used for soft discal hernia resulting in cervicobrachial neuralgia. The insertion technique must be rigorous, with precise centering in the disc space, taking account of vascular anatomy, which is more complex in the lumbar region, particularly proximally to L5-S1. All of the numerous studies, including prospective randomized comparative trials, have demonstrated non-inferiority to fusion, or even short-term superiority regarding speed of improvement. The main implant-related complication is bridging heterotopic ossification with resulting loss of range of motion and increased rates of adjacent segment degeneration, although with an incidence lower than after arthrodesis. A sufficiently long follow-up, which has not yet been reached, will be necessary to establish definitively an advantage for TDR, particularly in the cervical spine. PMID:24412045

  14. Apsidal precession, disc breaking and viscosity in warped discs

    CERN Document Server

    Nealon, Rebecca; Price, Daniel J; King, Andrew

    2015-01-01

    We demonstrate the importance of general relativistic apsidal precession in warped black hole accretion discs by comparing three - dimensional smoothed particle hydrodynamic simulations in which this effect is first neglected, and then included. If apsidal precession is neglected, we confirm the results of an earlier magnetohydrodynamic simulation which made this assumption, showing that at least in this case the $\\alpha$ viscosity model produces very similar results to those of simulations where angular momentum transport is due to the magnetorotational instability. Including apsidal precession significantly changes the predicted disc evolution. For moderately inclined discs thick enough that tilt is transported by bending waves, we find a disc tilt which is nonzero at the inner disc edge and oscillates with radius, consistent with published analytic results. For larger inclinations we find disc breaking.

  15. Revision of infected knee arthroplasties in Denmark

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  16. Planet-Disc Interactions in Fully Radiative Discs

    OpenAIRE

    Bitsch, Bertram

    2011-01-01

    In this dissertation the movement of planets in accretion discs surrounding young stars is investigated. The accretion disc surrounds a protostar, which in turn is created due to the gravitational collapse of an interstellar gas cloud. In this accretion disc, small dust particles can grow to larger objects with a size of up to a few kilometers. These objects are called planetesimals. Through collisions, these planetesimals can grow further until they reach the size of a protoplanet. The proto...

  17. Disc-planet interactions in sub-keplerian discs

    OpenAIRE

    Paardekooper, S.-J.

    2009-01-01

    One class of protoplanetary disc models, the X-wind model, predicts strongly subkeplerian orbital gas velocities, a configuration that can be sustained by magnetic tension. We investigate disc-planet interactions in these subkeplerian discs, focusing on orbital migration for low-mass planets and gap formation for high-mass planets. We use linear calculations and nonlinear hydrodynamical simulations to measure the torque and look at gap formation. In both cases, the subkeplerian nature of the ...

  18. Edge-on thick discs

    Science.gov (United States)

    Kasparova, A.; Katkov, I.; Chilingarian, I.; Silchenko, O.; Moiseev, A.; Borisov, S.

    2016-06-01

    Although thick stellar discs are detected in nearly all edge-on disc galaxies, their formation scenarios still remain a matter of debate. Due to observational difficulties, there is a lack of information about their stellar populations. Using the Russian 6-m telescope BTA we collected deep spectra of thick discs in three edge-on early-type disc galaxies located in different environments: NGC4111 in a dense group, NGC4710 in the Virgo cluster, and NGC5422 in a sparse group. We see intermediate age (4 ‑ 5 Gyr) metal rich ([Fe/H] ~ ‑0.2 ‑ 0.0 dex) stellar populations in NGC4111 and NGC4710. On the other hand, NGC5422 does not harbour young stars, its only disc is thick and old (10 Gyr) and its α-element abundance suggests a long formation epoch implying its formation at high redshift. Our results prove the diversity of thick disc formation scenarios.

  19. CT discography for cervical soft disc hernia

    International Nuclear Information System (INIS)

    In this study the effectiveness of computed tomographic discography (CTD) in diagnosing cervical soft disc hernia was evaluated. Twenty-five interververtebral discs of 15 cases with cervical soft disc hernia were examined with a discography and then a CT scan. Results of the CT scan were as follows: three discs were protruded, 12 discs were prolapsed, 6 discs were extruded, and 4 discs were sequestrated. The findings were helpful in determining the location of soft disc hernians between the median and posterolateral discs. They were also valuable in classifying types of hernians and surgical aproaches. (author)

  20. Postero-Lateral Disc Prosthesis Combined With a Unilateral Facet Replacement Device Maintains Quantity and Quality of Motion at a Single Lumbar Level

    OpenAIRE

    Nayak, Aniruddh N.; Doarn, Michael C.; Gaskins, Roger B.; James, Chris R.; Cabezas, Andres F.; Castellvi, Antonio E.; Santoni, Brandon G.

    2014-01-01

    Background Mechanically replacing one or more pain generating articulations in the functional spinal unit (FSU) may be a motion preservation alternative to arthrodesis at the affected level. Baseline biomechanical data elucidating the quantity and quality of motion in such arthroplasty constructs is non-existent. Purpose The purpose of the study was to quantify the motion-preserving effect of a posterior total disc replacement (PDR) combined with a unilateral facet replacement (FR) system at ...

  1. Artificial blood

    Directory of Open Access Journals (Sweden)

    Sarkar Suman

    2008-01-01

    Full Text Available Artificial blood is a product made to act as a substitute for red blood cells. While true blood serves many different functions, artificial blood is designed for the sole purpose of transporting oxygen and carbon dioxide throughout the body. Depending on the type of artificial blood, it can be produced in different ways using synthetic production, chemical isolation, or recombinant biochemical technology. Development of the first blood substitutes dates back to the early 1600s, and the search for the ideal blood substitute continues. Various manufacturers have products in clinical trials; however, no truly safe and effective artificial blood product is currently marketed. It is anticipated that when an artificial blood product is available, it will have annual sales of over $7.6 billion in the United States alone.

  2. Evaluation of Near/Far Field and Directivity of Ultrasonic Transducer for Turbine Rotor Disc

    International Nuclear Information System (INIS)

    Near/far field length and directivity of transducers were investigated for the improvement and evaluation of the detectability of flaws in a disc. The reference block is fabricated for the disc of stage 6 in Yonggwang unit 1. The near/far field and directivity of an ultrasonic transducer with the center frequency of 5MHz were calculated for the inspection of the disc. These values showed good agreements with the experimental results. In the system composed of a wedge and a disc, those are evaluated theoretically and experimentally for the specimen with the artificial flaws of the size 2mm and 4mm and an ultrasonic transducer with the center frequency 5MHz and diameter 0.5 inch. The detectability of keyway-flaw and detectable region for inspection were evaluated by using both tangential 45 .deg. and 90 .deg. transducers located at the distance of 53mm and 75mm from the disc hub, respectively

  3. Development of an Ultrasonic Inspection Technique for LP Turbine Rotor Disc

    International Nuclear Information System (INIS)

    Turbine rotor disc consists of disc, bore, keyway, hub, and rim in which the typical defects are located. And these part of disc has very complicated geometry, therefore proper transducer selection, wedge design, fabrication, classification and evaluation of the signal identification are required. In this research, test block with the artificial flaws at keyway and boresurface parts have been used in order to establish the ultrasonic inspection technique for flaw detectability on disc. The analysis of the signals from the test blocks was performed. The wedges were designed according to the curvature from the discs. All the ultrasonic signals were collected and identified for evaluation. The ultrasonic inspection technique for the flaw-detection was established from this research. And it is proved that the result of this research can be applicable in the field inspection

  4. Dilemmas in Uncemented Total Hip Arthroplasty

    NARCIS (Netherlands)

    Goosen, J.H.M.

    2009-01-01

    In this thesis, different aspects that are related to the survivorship and clinical outcome in uncemented total hip arthroplasty are analysed. In Chapter 2, the survival rate, Harris Hip score and radiographic features of a proximally hydroxyapatite coated titanium alloy femoral stem (Bi-Metric, Bio

  5. Knee Arthroplasty: With or Without Patellar Component?

    Directory of Open Access Journals (Sweden)

    Árpád Sólyom

    2015-09-01

    Full Text Available Arthroplasty is used when there is irreversible damage to the articular cartilage of the knee. It involves implanting a bicompartimental (femoral and tibial components or a tricompartimental (femoral, tibial and patellar components prosthesis. It is a very invasive and costly operation, so our objective was to evaluate the necessity of the patellar component.

  6. Periprosthetic osteolysis after total wrist arthroplasty

    DEFF Research Database (Denmark)

    Boeckstyns, Michel E H; Herzberg, Guillaume

    2014-01-01

    Background and Literature Review Periprosthetic osteolysis (PPO) after second- or third-generation total wrist arthroplasty (TWA), with or without evident loosening of the implant components, has previously been reported in the literature, but rarely in a systematic way. Purpose The purpose of th...

  7. Hip and knee arthroplasty: quo vadis?

    NARCIS (Netherlands)

    Ho, J.; Meis, J.F.G.M.; Nabuurs-Franssen, M.H.; Voss, A.

    2015-01-01

    Despite of the steady decrease of surgical site infection (SSI) over the last two decades, the incidence of SSI after hip and knee arthroplasty has recently surged. This may be explained by technical changes that may result in an increased risk of SSI, such as the broad implementation of fast track

  8. Knee arthroplasty: are patients' expectations fulfilled?

    DEFF Research Database (Denmark)

    Nilsdotter, Anna K; Toksvig-Larsen, Sören; Roos, Ewa

    2009-01-01

    to pain and physical function after knee arthroplasty. PATIENTS AND METHODS: 102 patients (39 men) with knee osteoarthritis and who were assigned for TKR (mean age 71 (51-86) years) were investigated with KOOS, SF-36, and additional questions concerning physical activity level, expectations...

  9. Fast-track revision knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Henrik; Otte, Niels Kristian Stahl; Kristensen, Billy B;

    2011-01-01

    Abstract Background and purpose Fast-track surgery has reduced the length of hospital stay (LOS), morbidity, and convalescence in primary hip and knee arthroplasty (TKA). We assessed whether patients undergoing revision TKA for non-septic indications might also benefit from fast-track surgery...

  10. Relativistic Disc lines

    CERN Document Server

    Fabian, A C; Parker, M L

    2014-01-01

    Broad emission lines, particularly broad iron-K lines, are now commonly seen in the X-ray spectra of luminous AGN and Galactic black hole binaries. Sensitive NuSTAR spectra over the energy range of 3-78 keV and high frequency reverberation spectra now confirm that these are relativistic disc lines produced by coronal irradiation of the innermost accretion flow around rapidly spinning black holes. General relativistic effects are essential in explaining the observations. Recent results are briefly reviewed here.

  11. Prevention of infection after knee arthroplasty

    Directory of Open Access Journals (Sweden)

    Hagen, Anja

    2010-01-01

    Full Text Available Scientific background: Man-made joints (joint endoprostheses, including knee endoprostheses, are used in some irreversible diseases of the human joints. The implantation of joint endoprostheses (arthroplasty is associated with an increased risk for infection. To prevent infections, different interventions without and with the use of antibiotics (hygiene procedures and antibiotic prophylaxis are used. The benefits of these interventions are not clear yet. Research questions: The presented report addresses the questions regarding the medical effectiveness, the cost-effectiveness as well as the ethical, social and legal aspects related to the use of interventions to prevent infections after knee arthroplasty. Methods: A systematic literature search is conducted in the medical electronic databases MEDLINE, EMBASE, SciSearch etc. in June 2009 and has been completed by a hand search. The analysis includes publications which describe and/or evaluate clinical data from randomized controlled trials (RCT, systematic reviews of RCT, registers of endoprostheses or databases concerning interventions to prevent infections after knee arthroplasty. The conducted literature search also aims to identify health-economic studies and publications dealing explicitly with ethical, social or legal aspects in the use of interventions to prevent infections after knee arthroplasty. The synthesis of information from different publications has been performed qualitatively. Results: The systematic literature search yields 1,030 hits. Based on the predefined inclusion and exclusion criteria a total of ten publications is included in the analysis. The presented report does not find evidence of the effectiveness of different hygiene interventions with a high evidence level. Most of the unspecific interventions are recommended on the basis of results from non-RCT, from studies for other clinical indications and/or for clinically not relevant endpoints, as well as on the basis of

  12. Synovial cutaneous fistula complicating a reverse total shoulder arthroplasty.

    Science.gov (United States)

    Letter, Haley P; Limback, Joseph; Wasyliw, Christopher; Bancroft, Laura; Scherer, Kurt

    2016-06-01

    Reverse total shoulder arthroplasty is becoming a common form of shoulder arthroplasty that is often performed in the setting of rotator cuff pathology. Infection is a rare complication but is more common in reverse total shoulder arthroplasty than in hemiarthroplasty or anatomic total shoulder arthroplasty. We present the case of a 69-year-old patient with a reverse total shoulder arthroplasty who presented with purulent drainage from the skin of his anterior shoulder. Computed tomography arthrogram confirmed the presence of a synovial cutaneous fistula. Synovial cutaneous fistula is a rare variant of periprosthetic infection that, to our knowledge, has not been described previously in the setting of a reverse total shoulder arthroplasty. Computed tomography arthrogram proved to be a reliable method for confirming the diagnosis and was used for operative planning to remove the hardware. PMID:27257460

  13. Percutaneous laser disc decompression for cervical disc herniation

    International Nuclear Information System (INIS)

    Objective: To discuss the clinical application of percutaneous laser disc decompression (PLDD) in the treatment of cervical disc herniation. Methods: The region between anterolateral cervical visceral sheath and carotid sheath was used as puncture access. Under C-arm fluoroscopic monitoring, the puncture needle was inserted to the cervical intervertebral space center, then, the photofiber was implanted in PLDD was performed in 32 patients of cervical disc herniation by using SLT30 semiconductor laser device with the laser output of 500-1 000 J. Results: The effective rate was 87.5%. No infection or serious complications occurred. Conclusion: Percutaneous laser disc decompression is a safe, effective and less invasive treatment for cervical disc herniation. (authors)

  14. Artificial intelligence

    CERN Document Server

    Ennals, J R

    1987-01-01

    Artificial Intelligence: State of the Art Report is a two-part report consisting of the invited papers and the analysis. The editor first gives an introduction to the invited papers before presenting each paper and the analysis, and then concludes with the list of references related to the study. The invited papers explore the various aspects of artificial intelligence. The analysis part assesses the major advances in artificial intelligence and provides a balanced analysis of the state of the art in this field. The Bibliography compiles the most important published material on the subject of

  15. Artificial urushi.

    Science.gov (United States)

    Kobayashi, S; Uyama, H; Ikeda, R

    2001-11-19

    A new concept for the design and laccase-catalyzed preparation of "artificial urushi" from new urushiol analogues is described. The curing proceeded under mild reaction conditions to produce the very hard cross-linked film (artificial urushi) with a high gloss surface. A new cross-linkable polyphenol was synthesized by oxidative polymerization of cardanol, a phenol derivative from cashew-nut-shell liquid, by enzyme-related catalysts. The polyphenol was readily cured to produce the film (also artificial urushi) showing excellent dynamic viscoelasticity. PMID:11763444

  16. 46 CFR 64.61 - Rupture disc.

    Science.gov (United States)

    2010-10-01

    ... SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture disc is the only pressure relief device on the tank, the rupture disc must— (a) Rupture at a pressure...

  17. Unfractionated heparin and mechanical thromboprophylaxis in hip arthroplasty

    OpenAIRE

    Garcia, Flávio Luís; Marins, Murilo Humberto Tobias; Raddi, Thiago Bortoletto; Picado, Celso Hermínio Ferraz

    2015-01-01

    OBJECTIVE: To evaluate the efficacy and safety of unfractionated heparin associated with mechanical prophylaxis as a method for preventing venous thromboembolism in hip arthroplasty. METHOD: We retrospectively reviewed the records of 181 hip arthroplasties out of 216 consecutive cases performed over a period of 39 months in our hospital. We excluded 35 cases due to non-adherence to the standardized method of thromboprophylaxis or loss to follow-up. All arthroplasties evaluated completed one-y...

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

    Science.gov (United States)

    Saffo, Zaid; Ognjan, Anthony

    2016-01-01

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

  19. The Results of ulnohumeral arthroplasty in elbow osteoarthritis

    OpenAIRE

    Dehghani, M.; E. Rouzbahani

    2008-01-01

    AbstractBackground and Purpose: Osteoarthritis (OA) of elbow is not common but can be disabling, if it is not responding to non-operative methods. Several surgical methods are suggested (joint debridment, ulnohumeral arthroplasty, fusion and total elbow arthroplasty). In this study, we evaluated the result of ulnohumeral arthroplasty in seven patients.Materials and Methods: Seven patients (5 males and 2 females) mean age 46 years of age (56-43), during 1378-1385 were operated on with the same...

  20. Chemonucleolysis of lumbar disc herniation

    International Nuclear Information System (INIS)

    Chemonucleolysis is an advantageous alternative to surgical treatment of lumbar disc herniation. To achieve the best results the indications must be strictly observed and the procedure itself must be technically perfect. In these circumstances a rapid, non-invasive and less expensive treatment of lumbar disc herniation is possible. (orig.)

  1. Artificial Reefs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An artificial reef is a human-made underwater structure, typically built to promote marine life in areas with a generally featureless bottom, control erosion, block...

  2. Qualifying CT for wrist arthroplasty: extending techniques for total hip arthroplasty to total wrist arthroplasty

    Science.gov (United States)

    Alcala, Yvonne; Olivecrona, Henrik; Olivecrona, Lotta; Noz, Marilyn E.; Maguire, Gerald Q., Jr.; Zeleznik, Michael P.; Sollerman, Christer

    2005-04-01

    The purpose of this study was to extend previous work to detect migration of total wrist arthroplasty non-invasively, and with greater accuracy. Two human cadaverous arms, each with a cemented total wrist implant, were used in this study. In one of the arms, 1 mm tantalum balls were implanted, six in the carpal bones and five in the radius. Five CT scans of each arm were acquired, changing the position of the arm each time to mimic different positions patients might take on repeated examinations. Registration of CT volume data sets was performed using an extensively validated, 3D semi-automatic volume fusion tool in which co-homologous point pairs (landmarks) are chosen on each volume to be registered. Three sets of ten cases each were obtained by placing landmarks on 1) bone only (using only arm one), 2) tantalum implants only, and 3) bone and tantalum implants (both using only arm two). The accuracy of the match was assessed visually in 2D and 3D, and numerically by calculating the distance difference between the actual position of the transformed landmarks and their ideal position (i.e., the reference landmark positions). All cases were matched visually within one width of cortical bone and numerically within one half CT voxel (0.32 mm, p = 0.05). This method matched only the bone/arm and not the prosthetic component per se, thus making it possible to detect prosthetic movement and wear. This method was clinically used for one patient with pain. Loosening of the carpal prosthetic component was accurately detected and this was confirmed at surgery.

  3. Natural - synthetic - artificial!

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2010-01-01

    The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

  4. COMPARION OF GAP ARTHROPLASTY AND INTERPOSITIONAL GAP ARTHROPLASTY ON THE TEMPOROMANDIBULAR JOINT ANKYLOSIS

    Directory of Open Access Journals (Sweden)

    M. Ramezanian T. Yavary

    2006-11-01

    Full Text Available Temporomandibular joint ankylosis causes limitation in mouth opening and establishes severe deformity and asymmetry in patient’s face, especially in children. Surgery is the only treatment. This study was conducted to compare the effect of two surgical approaches, gap arthropasty and interpositional gap arthroplasty, on rate of maximum interincisal opening in temporomandibular joint ankylosis. We also evaluated the relapse rate of these two surgical approaches. A total of 48 patients were enrolled in this cross-sectional experimental study. Range of mouth opening was evaluated before and during and one year after surgery. All other related information was also recorded. Mean age of the study population was 19.5  8.9 years. Of those, 21 (41% were male and 27 (59% were female. For 26 patients (54.2% interpositional gap arthroplasty was accomplished and for 22 patients (45.8% gap arthropasty was performed. Mean range of mouth opening before and after surgery was 10.3  3.9 and 33.9  5.2 in interpositional gap arthroplasty, 8.7  4.9 and 32.1  7.8 in gap arthropasty, respectively. The results showed that the range of mouth opening significantly increases after ankylosis surgery in both surgical approaches but improvement was less in interpositional gap arthroplasty. In regards to recurrence, results of interpositional gap arthroplasty were superior to gap arthropasty.

  5. On disc-planet interactions in sub-keplerian discs

    CERN Document Server

    Paardekooper, S -J

    2009-01-01

    One class of protoplanetary disc models, the X-wind model, predicts strongly subkeplerian orbital gas velocities, a configuration which can be sustained by magnetic tension. We investigate disc-planet interactions in these subkeplerian discs, focusing on orbital migration for low-mass planets and gap formation for high-mass planets. We use linear calculations and non-linear hydrodynamical simulations to measure the torque and look at gap formation. In both cases, the subkeplerian nature of the disc is treated as a fixed external constraint. We show that, depending on the degree to which the disc is subkeplerian, the torque on low-mass planets varies between the usual Type I torque and the one-sided outer Lindblad torque, which is also negative but an order of magnitude larger. In strongly subkeplerian discs, corotation effects can be ignored, making migration fast and inward. Gap formation near the planet's orbit is more difficult in such discs, since there are no resonances close to the planet accommodating ...

  6. Discs in misaligned binary systems

    Science.gov (United States)

    Rawiraswattana, Krisada; Hubber, David A.; Goodwin, Simon P.

    2016-08-01

    We perform SPH simulations to study precession and changes in alignment between the circumprimary disc and the binary orbit in misaligned binary systems. We find that the precession process can be described by the rigid-disc approximation, where the disc is considered as a rigid body interacting with the binary companion only gravitationally. Precession also causes change in alignment between the rotational axis of the disc and the spin axis of the primary star. This type of alignment is of great important for explaining the origin of spin-orbit misaligned planetary systems. However, we find that the rigid-disc approximation fails to describe changes in alignment between the disc and the binary orbit. This is because the alignment process is a consequence of interactions that involve the fluidity of the disc, such as the tidal interaction and the encounter interaction. Furthermore, simulation results show that there are not only alignment processes, which bring the components towards alignment, but also anti-alignment processes, which tend to misalign the components. The alignment process dominates in systems with misalignment angle near 90°, while the anti-alignment process dominates in systems with the misalignment angle near 0° or 180°. This means that highly misaligned systems will become more aligned but slightly misaligned systems will become more misaligned.

  7. Peripheral Disc Margin Shape and Internal Disc Derangement: Imaging Correlation in Significantly Painful Discs Identified at Provocation Lumbar Discography

    OpenAIRE

    Bartynski, W.S.; Rothfus, W.E.

    2012-01-01

    Annular margin shape is used to characterize lumbar disc abnormality on CT/MR imaging studies. Abnormal discs also have internal derangement including annular degeneration and radial defects. The purpose of this study was to evaluate potential correlation between disc-margin shape and annular internal derangement on post-discogram CT in significantly painful discs encountered at provocation lumbar discography (PLD).

  8. Cost Analysis in Shoulder Arthroplasty Surgery

    Directory of Open Access Journals (Sweden)

    Matthew J. Teusink

    2012-01-01

    Full Text Available Cost in shoulder surgery has taken on a new focus with passage of the Patient Protection and Affordable Care Act. As part of this law, there is a provision for Accountable Care Organizations (ACOs and the bundled payment initiative. In this model, one entity would receive a single payment for an episode of care and distribute funds to all other parties involved. Given its reproducible nature, shoulder arthroplasty is ideally situated to become a model for an episode of care. Currently, there is little research into cost in shoulder arthroplasty surgery. The current analyses do not provide surgeons with a method for determining the cost and outcomes of their interventions, which is necessary to the success of bundled payment. Surgeons are ideally positioned to become leaders in ACOs, but in order for them to do so a methodology must be developed where accurate costs and outcomes can be determined for the episode of care.

  9. Heterotopic bone formation following total shoulder arthroplasty

    DEFF Research Database (Denmark)

    Kjaersgaard-Andersen, P.; Frich, Lars Henrik; Sjøbjerg, J.O.;

    1989-01-01

    the glenohumeral and/or the glenoacromial space. There was no correlation between shoulder pain and the development of ossification. Shoulders with grade III heterotopic bone formation had a limited range of active elevation compared with shoulders without or with only a milder lesion. Men and......The incidence and location of heterotopic bone formation following total shoulder arthroplasty were evaluated in 58 Neer Mark-II total shoulder replacements. One year after surgery, 45% had developed some ectopic ossification. In six shoulders (10%) the ossifications roentgenographically bridged...... patients with osteoarthritis of the shoulder joint were significantly disposed to the development of heterotopic bone. Heterotopic bone formation following total shoulder arthroplasty is frequent, but disabling heterotopic ossifications seem to be rare....

  10. Thromboembolism prophylaxis practices in orthopaedic arthroplasty patients.

    LENUS (Irish Health Repository)

    Cawley, D

    2010-10-01

    Thromboembolic events are a post-operative complication of arthroplasty surgery for up to 3 months. The incidence however, is not fully known. Some form of prophylaxis should be provided to all arthroplasty patients. Clinicians are wary of side effects, compliance profile and the associated cost. The objective of this study is to investigate practice patterns and their relevance to 3 risk groups. Ninety questionnaires were sent to orthopaedic surgeons with 3 hypothetical clinical scenarios and 10 prophylaxis regimes for thromboembolism across different risk groups. The response rate was 81\\/90 (90%). The most popular options in all 3 cases were early mobilisation, thrombo-embolism deterrant (TED) stockings and low molecular weight heparin (LMWH) (51\\/81, 62% of all cases). An inconsistent relationship exists between preferred practice and relevant guidelines. Preferred practice does not correlate with each level of risk.

  11. Fast-track revision knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Henrik; Otte, Niels Kristian Stahl; Kristensen, Billy B; Kehlet, Henrik

    2011-01-01

    Abstract Background and purpose Fast-track surgery has reduced the length of hospital stay (LOS), morbidity, and convalescence in primary hip and knee arthroplasty (TKA). We assessed whether patients undergoing revision TKA for non-septic indications might also benefit from fast-track surgery....... Methods 29 patients were operated with 30 revision arthroplasties. Median age was 67 (34-84) years. All patients followed a standardized fast-track set-up designed for primary TKA. We determined the outcome regarding LOS, morbidity, mortality, and satisfaction. Results Median LOS was 2 (1-4) days...... undergoing revision TKA for non-septic reasons may be included in fast-track protocols. Outcome appears to be similar to that of primary TKA regarding LOS, morbidity, and satisfaction. Our findings call for larger confirmatory studies and studies involving other indications (revision THA, 1-stage septic...

  12. Are galaxy discs optically thick?

    International Nuclear Information System (INIS)

    We re-examine the classical optical evidence for the low optical depths traditionally assigned to spiral discs and argue that it is highly model-dependent and unconvincing. In particular, layered models with a physically thin but optically thick dust layer behave like optically thin discs. The opposite hypotheses, that such discs are optically thick is then examined in the light of modern evidence. We find it to be consistent with the near-infrared and IRAS observations, with the surface brightnesses, with the HI and CO column densities and with the Hα measurements. (author)

  13. High Level Lomber Disc Hernias

    OpenAIRE

    Ateş, Özkan; Tarım, Özcan; Koçak, Ayhan; Önal, S. Çağatay; Çaylı, Süleyman R.; Şahinbeyoğlu, Baran; Tektaş, Şevket

    2002-01-01

    Aim: The scope of this study is to investigate the correlation between the clinical and radiological findings of high level lomber disc hernia (L1-2, L2-3, L3-4) and surgical outcome. Material and Method: 23 high level lomber disc hernia out of 262 lomber disc cases operated between January1996 and November 2001 at the department of Neurosurgery , Faculty of Medicine, İnönü Üniversity (Malatya Turkey) were retrospectively reviewed. Results: 39.1% of the cases were male and...

  14. Imaging of hip arthroplasty; Bildgebung bei Hueftprothesen

    Energy Technology Data Exchange (ETDEWEB)

    Breitenseher, M.J. [Abteilung fuer Osteologie, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria); Klinische Abteilung fuer Radiodiagnostik chirurgischer Faecher, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria); Ludwig-Boltzmann-Institut fuer Radiologische Tumordiagnostik, Wien (Austria); Mayerhoefer, M. [Klinische Abteilung fuer Radiodiagnostik chirurgischer Faecher, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria); Gottsauner-Wolf, F. [Universitaetsklinik fuer Orthopaedie, Wien (Austria); Abteilung fuer Orthopaedie, Allgemeines oeffentliches KH, Krems (Austria); Krestan, C.; Imhof, H. [Abteilung fuer Osteologie, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria); Toma, C.D. [Universitaetsklinik fuer Orthopaedie, Wien (Austria)

    2002-06-01

    Hip arthroplasty has become a common and still increasing procedure for the treatment of osteoarthritis, advanced head necrosis, post-inflammatory arthritis or rheumatoid arthritis.Radiography is the most important imaging modality for monitoring the normal, asymptomatic hip arthroplasty. Radiographs are obtained at the end of a surgical treatment, to exclude complications like fracture or component misplacement. In the follow-up radiographs are used for the diagnosis of loosening and infection of the hip arthroplasty as well as soft tissue ossification. Together with the history and clinical information, the analysis of morphological findings allows to find the grade of loosening. MRI has been advocated in the diagnosis of infection, in particular in the localisation of soft tissue involvement.Imaging, especially by radiographs, is used for the evaluation of the normal and complicated follow-up of hip arthroplasty. (orig.) [German] Die Implantation einer Hueftgelenkprothese ist eine immer haeufiger verwendete medizinische Massnahme bei Erkrankungen des Hueftgelenks wie Koxarthrose, Hueftkopfnekrose, postentzuendliche Arthrose oder rheumatoide Arthritis.Von den bildgebenden Methoden ist das konventionelle Roentgen die wichtigste Untersuchung, um den normalen Behandlungsverlauf einer Hueftprothese zu monitieren. Das Roentgen kann fruehzeitige Komplikationen wie Fraktur oder Fehlposition intraoperativ oder eine Luxation postoperativ erfassen. Im laengerfristigen Verlauf ist das Roentgen zur Diagnose von Infektion, Prothesenlockerung und Weichteilverknoecherung geeignet. In Zusammenschau mit der Klinik ermoeglicht die Analyse morphologisch-radiologischer Details, die Wahrscheinlichkeit einer Lockerung abzuschaetzen. Bei Protheseninfektionen ermoeglicht die MRT die Lokalisation von Weichteilentzuendungen.Die Methoden der Bildgebung, besonders das Roentgen, haben in der Beurteilung des normalen und in der Diagnose des komplizierten Verlaufes einen hohen Stellenwert

  15. Proximal humeral fractures treated with arthroplasty

    Institute of Scientific and Technical Information of China (English)

    QIAN Qi-rong; WU Hai-shan; ZHOU Wei-jiang; LI Xiao-hua; WU Yu-li

    2005-01-01

    Objective: To explore arthroplasty in treating 3- and 4-part fractures of the proximal humerus.Methods: A total of 132 patients with proximal humeral fractures were treated in our hospital from July 1997 to February 2003. According to Neer's classification, the fractures of 45 patients (14 males and 31 females, aged 31-78 years, 56.1 years±7.8 years on an average) belonged to 3- or 4-part fractures (10 patients with 4-part fracture and 35 with 3-part comminuted fracture) and they were treated with shoulder joint arthroplasty. Unipolar prosthesis replacement of the head of humerus was made in 28 cases, while bipolar prosthesis replacement in 2 cases and total shoulder joint replacement in 15 cases. Results: During the follow-up period (range: 12-72 months, mean: 37.3 months±4.1 months), among the 45 patients who suffered from fractures of the proximal humerus and underwent arthroplasty surgery, 44 patients (97.8%) had no postoperative pain and were satisfied with the active range of motion and with the whole treatment results. And radiography showed that the prostheses were at their good position. One patient had postoperative pain because he had so narrow medullary cavity that the humeral prosthesis could not be put deeply enough and the prosthesis head was a little higher over the anatomic level. He did not have good postoperative active range of motion, either. Then he received a review surgery and got satisfied results. Temporary shoulder stiffness was observed in one patient. Manual release of these adhesions improved the shoulder function. No evidence of nonunion of the fracture segments around the humeral prosthesis stem was found. Conclusions: Shoulder arthroplasty is a dependable method to restore the comfort and function of the should joints of the patients with 3- or 4-part fractures of the proximal humerus.

  16. Infected total knee arthroplasty treatment outcome analysis

    OpenAIRE

    Radoičić Dragan; Popović Zoran; Barjaktarović Radoslav; Marinković Jugoslav

    2012-01-01

    Background/Aim. Infected total knee arthroplasty (TKA) is a topic of great importance, because its diagnosing and treatment requires a lot of resources, and often has an unsatisfactory outcome. The aim of this study was to analyze the outcome of the treatment of infection developed following TKA. Methods. This retrospective study of infected TKAs was performed in the period from 1998 to 2008 in the Orthopedics & Traumatology Clinic of the Military Medical Academy (MMA) in Belgrade. ...

  17. Future Bearing Surfaces in Total Hip Arthroplasty

    OpenAIRE

    Chang, Jun-Dong

    2014-01-01

    One of the most important issues in the modern total hip arthroplasty (THA) is the bearing surface. Extensive research on bearing surfaces is being conducted to seek an ideal bearing surface for THA. The ideal bearing surface for THA should have superior wear characteristics and should be durable, bio-inert, cost-effective, and easy to implant. However, bearing surfaces that are currently being implemented do not completely fulfill these requirements, especially for young individuals for whom...

  18. Artificial noses.

    Science.gov (United States)

    Stitzel, Shannon E; Aernecke, Matthew J; Walt, David R

    2011-08-15

    The mammalian olfactory system is able to detect many more odorants than the number of receptors it has by utilizing cross-reactive odorant receptors that generate unique response patterns for each odorant. Mimicking the mammalian system, artificial noses combine cross-reactive sensor arrays with pattern recognition algorithms to create robust odor-discrimination systems. The first artificial nose reported in 1982 utilized a tin-oxide sensor array. Since then, however, a wide range of sensor technologies have been developed and commercialized. This review highlights the most commonly employed sensor types in artificial noses: electrical, gravimetric, and optical sensors. The applications of nose systems are also reviewed, covering areas such as food and beverage quality control, chemical warfare agent detection, and medical diagnostics. A brief discussion of future trends for the technology is also provided. PMID:21417721

  19. Intervertebral disc (IVD): Structure, degeneration, repair and regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Whatley, Benjamin R.; Wen Xuejun, E-mail: xjwen@clemson.edu

    2012-02-01

    Low back pain affects a large portion of the population, resulting in high care costs for therapy and treatment. One primary cause of low back pain is the degeneration of the intervertebral disc (IVD) resulting in the compression of the spinal nerves and adjacent vertebrae. Exact causes of degeneration are unknown, but it is thought that natural aging, and both biological and genetic factors may play a significant role in the degenerative process. Conventional methods to alleviate low back pain include spinal fusion and artificial disc replacement. Traditional treatments through spinal fusion may eliminate pain yet do not restore disc function and lead to further degeneration of adjacent levels by altering disc biomechanics and natural kinematics. Recently, artificial IVD replacements have started to gain interest, with two IVD implants currently approved in the United States. Although these implants facilitate the preservation of motions and disc space height, they are unable to sustain compressive forces due to their lack of elasticity. In addition, the implants may produce wear debris that can cause osteolysis and other deleterious effects. As an alternative to these conventional approaches, tissue engineered IVD constructs offer the advantage of biointegration while preserving the essential attributes of natural motion and disc space restoration. There is a great need for the development of tissue engineered scaffolds that simulate the natural 3D morphology and microenvironment of the targeted tissue. Scaffolds should facilitate biological transport to satisfy nutrition and waste removal requirements within the IVD. The discrete tissue architectures of the nucleus pulposus (NP) and annulus fibrosus (AF) have posed great challenges to IVD tissue engineering. Current attempts have not been able to satisfy the biological functions and/or mechanical properties of native tissue. Therefore, these current scaffolds are far from satisfactory. This review highlights the

  20. Intervertebral disc (IVD): Structure, degeneration, repair and regeneration

    International Nuclear Information System (INIS)

    Low back pain affects a large portion of the population, resulting in high care costs for therapy and treatment. One primary cause of low back pain is the degeneration of the intervertebral disc (IVD) resulting in the compression of the spinal nerves and adjacent vertebrae. Exact causes of degeneration are unknown, but it is thought that natural aging, and both biological and genetic factors may play a significant role in the degenerative process. Conventional methods to alleviate low back pain include spinal fusion and artificial disc replacement. Traditional treatments through spinal fusion may eliminate pain yet do not restore disc function and lead to further degeneration of adjacent levels by altering disc biomechanics and natural kinematics. Recently, artificial IVD replacements have started to gain interest, with two IVD implants currently approved in the United States. Although these implants facilitate the preservation of motions and disc space height, they are unable to sustain compressive forces due to their lack of elasticity. In addition, the implants may produce wear debris that can cause osteolysis and other deleterious effects. As an alternative to these conventional approaches, tissue engineered IVD constructs offer the advantage of biointegration while preserving the essential attributes of natural motion and disc space restoration. There is a great need for the development of tissue engineered scaffolds that simulate the natural 3D morphology and microenvironment of the targeted tissue. Scaffolds should facilitate biological transport to satisfy nutrition and waste removal requirements within the IVD. The discrete tissue architectures of the nucleus pulposus (NP) and annulus fibrosus (AF) have posed great challenges to IVD tissue engineering. Current attempts have not been able to satisfy the biological functions and/or mechanical properties of native tissue. Therefore, these current scaffolds are far from satisfactory. This review highlights the

  1. Artificial intelligence

    International Nuclear Information System (INIS)

    A vivid example of the growing need for frontier physics experiments to make use of frontier technology is in the field of artificial intelligence and related themes. This was reflected in the second international workshop on 'Software Engineering, Artificial Intelligence and Expert Systems in High Energy and Nuclear Physics' which took place from 13-18 January at France Telecom's Agelonde site at La Londe des Maures, Provence. It was the second in a series, the first having been held at Lyon in 1990

  2. Artificial Intelligence

    CERN Document Server

    Warwick, Kevin

    2011-01-01

    if AI is outside your field, or you know something of the subject and would like to know more then Artificial Intelligence: The Basics is a brilliant primer.' - Nick Smith, Engineering and Technology Magazine November 2011 Artificial Intelligence: The Basics is a concise and cutting-edge introduction to the fast moving world of AI. The author Kevin Warwick, a pioneer in the field, examines issues of what it means to be man or machine and looks at advances in robotics which have blurred the boundaries. Topics covered include: how intelligence can be defined whether machines can 'think' sensory

  3. Debris disc formation induced by planetary growth

    CERN Document Server

    Kobayashi, Hiroshi

    2014-01-01

    Several hundred stars older than 10 million years have been observed to have infrared excesses. These observations are explained by dust grains formed by the collisional fragmentation of hidden planetesimals. Such dusty planetesimal discs are known as debris discs. In a dynamically cold planetesimal disc, collisional coagulation of planetesimals produces planetary embryos which then stir the surrounding leftover planetesimals. Thus, the collisional fragmentation of planetesimals that results from planet formation forms a debris disc. We aim to determine the properties of the underlying planetesimals in debris discs by numerically modelling the coagulation and fragmentation of planetesimal populations. The brightness and temporal evolution of debris discs depend on the radial distribution of planetesimal discs, the location of their inner and outer edges, their total mass, and the size of planetesimals in the disc. We find that a radially narrow planetesimal disc is most likely to result in a debris disc that ...

  4. Vortex migration in protoplanetary discs

    Directory of Open Access Journals (Sweden)

    Papaloizou John C. B.

    2013-04-01

    Full Text Available Vortices embedded in protoplanetary discs can act as obstacles to the unperturbed disc flow. The resulting velocity perturbations propagate away from the vortex in the form of density waves that transport angular momentum. Any asymmetry between the inner and the outer density wave means that the region around the vortex has to change its angular momentum. We find that this leads to orbital migration of the vortex. Asymmetric waves always arise except in the case of a disc with constant pressure, for isothermal as well as non-isothermal discs. Depending on the size and strength of the vortex, the resulting migration time scales can be as short as a few thousand orbits.

  5. Cervical Disc Disease: Biomechanical Aspects

    OpenAIRE

    Kolstad, Frode

    2011-01-01

    Degenerative disc disease in the cervical spine may cause significant pain and disability. Patients present themselves with neck pain, radiculopathy, and/or myelopathy. When the symptoms do not improve with conservative treatment, surgical treatment is considered. The goal of surgical treatment is to decompress nervous structures and to restore the normal anatomical conditions of disc height, alignment, and stability.The present thesis concerns four studies involving the treatment of cervical...

  6. Corticosteroids in Lumbar Disc Surgery

    OpenAIRE

    Lundin, Anders

    2005-01-01

    In a prospective randomised double-blind study eighty patients with MRI verified lumbar disc herniation and corresponding clinical findings underwent microscopic disc removal. The patients were peroperatively given systemic and local corticosteroids or placebo, and followed for 2 years. The hospital stay and time to return to full-time work was significantly shorter in the treatment group. Pain measured as worst pain during the last week was also lower in the corticosteroid group. The results...

  7. Artificial sweeteners

    DEFF Research Database (Denmark)

    Raben, Anne Birgitte; Richelsen, Bjørn

    2012-01-01

    Artificial sweeteners can be a helpful tool to reduce energy intake and body weight and thereby risk for diabetes and cardiovascular diseases (CVD). Considering the prevailing diabesity (obesity and diabetes) epidemic, this can, therefore, be an important alternative to natural, calorie-containin...

  8. Artificial photosynthesis

    OpenAIRE

    Andrew C. Benniston; Anthony Harriman

    2008-01-01

    We raise here a series of critical issues regarding artificial photosynthesis with the intention of increasing awareness about what needs to be done to bring about a working prototype. Factors under consideration include energy and electron transfers, coupled redox reactions, repair mechanisms, and integrated photosystems.

  9. Lumbar disc cyst with contralateral radiculopathy

    OpenAIRE

    Kishore Tourani; Belman Murali; Akshay Sahoo; Dandu Ravi Varma; Narayan Prasad

    2012-01-01

    Disc cysts are uncommon intraspinal cystic lesions located in the ventrolateral epidural space. They communicate with the nucleus pulposus of the intervertebral disc and cause symptoms by radicular compression. We report a unique case of lumbar disc cyst that was associated with disc herniation and contralateral radiculopathy. A 22 year old male presented with one month history of back-ache radiating to the left leg. Magnetic Resonance Imaging (MRI) showed L3-L4 disc herniation with annular t...

  10. Counter-Rotating Accretion Discs

    CERN Document Server

    Dyda, Sergei; Ustyugova, Galina V; Romanova, Marina M; Koldoba, Alexander V

    2014-01-01

    Counter-rotating discs can arise from the accretion of a counter-rotating gas cloud onto the surface of an existing co-rotating disc or from the counter-rotating gas moving radially inward to the outer edge of an existing disc. At the interface, the two components mix to produce gas or plasma with zero net angular momentum which tends to free-fall towards the disc center. We discuss high-resolution axisymmetric hydrodynamic simulations of a viscous counter-rotating disc for cases where the two components are vertically separated and radially separated. The viscosity is described by an isotropic $\\alpha-$viscosity including all terms in the viscous stress tensor. For the vertically separated components a shear layer forms between them. The middle of this layer free-falls to the disk center. The accretion rates are increased by factors $\\sim 10^2-10^4$ over that of a conventional disc rotating in one direction with the same viscosity. The vertical width of the shear layer and the accretion rate are strongly dep...

  11. 人工全膝关节置换术治疗35例单侧膝内翻合并屈曲挛缩畸形临床分析%Artificial treatment of 35 cases of unilateral total knee arthroplasty,genu varus combination of flexion contracture deformity clinical a-nalysis

    Institute of Scientific and Technical Information of China (English)

    王晖; 马超; 秦泗通; 王涛; 许永; 那健

    2015-01-01

    Objective The present study evaluated the clinic effect of total knee arthroplasty in the treatment of unilateral knee versus with flexion contracture,thus providing the basis for clinic treatment. Methods The patients,who endure the unilateral knee versus with flexion contracture,were enrolled in the present study,and the sample included 35 cases. The study was carried on form June 2009 to June 2014. All the patients were treated by total knee arthroplasty. The contrastive analysis factors included knee joint tibiofemoral angle,knee flexion contracture, knee flexion mobility and the HSS score. In addition,the lower limb power line recovery and double lower extremities isometric conditions were e-valuated as a supplement with 1 year follow - up. Results The follow - up information of all patientsˋwere obtained for 1 - 3 years. The results suggested that the knee joint tibiofemoral angle,knee flexion contracture,knee flexion mobility of patients recovered form(18. 0 ± 5. 8)°,(19. 7 ± 1. 2)° and(42. 2 ± 17. 5)° to(168. 9 ± 2. 6)°,(1. 3 ± 0. 5)°and(147. 3 ± 22. 7)°,respectively. There was a statistical significance be-fore and after the treatment( P ﹤ 0. 05 ). On the other side,the HSS score and functional score increased from(31. 2 ± 10. 1)and(14. 3 ± 1. 1)to(88. 3 ± 5. 1)and(19. 3 ± 1. 3),respectively. There was a statistical significance before and after the treatment also( P ﹤ 0. 05 ). In ad-dition,the complications,such as limbs length discrepancy,postoperative limp and serious infections,were not observed in the follow - up date, which means that the surgery achieved a satisfactory curative effect. Conclusion As an efficient clinic method in the treatment of unilateral knee versus with flexion contracture,total knee arthroplasty exhibited a significant improvement in knee joint tibiofemoral angle,flexion contracture and knee joint HSS score,thus providing a higher life quality of the patients,which is deserved to be generalized in clinic.%

  12. Reliability and Validity of the Dutch Version of the International Physical Activity Questionnaire in Patients After Total Hip Arthroplasty or Total Knee Arthroplasty

    NARCIS (Netherlands)

    Blikman, Tim; Stevens, Martin; Bulstra, Sjoerd K.; van den Akker-Scheek, Inge; Reininga, Inge H. F.

    2013-01-01

    STUDY DESIGN: Psychometric assessment. OBJECTIVES: To determine test-retest reliability and concurrent validity of the International Physical Activity Questionnaire (IPAQ) in patients after total hip arthroplasty or total knee arthroplasty. BACKGROUND: Despite recognized benefits of regular physical

  13. Artificial Intelligence.

    Science.gov (United States)

    Lawrence, David R; Palacios-González, César; Harris, John

    2016-04-01

    It seems natural to think that the same prudential and ethical reasons for mutual respect and tolerance that one has vis-à-vis other human persons would hold toward newly encountered paradigmatic but nonhuman biological persons. One also tends to think that they would have similar reasons for treating we humans as creatures that count morally in our own right. This line of thought transcends biological boundaries-namely, with regard to artificially (super)intelligent persons-but is this a safe assumption? The issue concerns ultimate moral significance: the significance possessed by human persons, persons from other planets, and hypothetical nonorganic persons in the form of artificial intelligence (AI). This article investigates why our possible relations to AI persons could be more complicated than they first might appear, given that they might possess a radically different nature to us, to the point that civilized or peaceful coexistence in a determinate geographical space could be impossible to achieve. PMID:26957450

  14. Effect of optic disc size or age on evaluation of optic disc variables

    OpenAIRE

    Kee, C.; Koo, H.; Ji, Y; S. Kim

    1997-01-01

    AIMS/BACKGROUND—It has been reported that the number of optic nerve fibres decrease with age, and the cup/disc (C/D) ratio increases as the optic disc size increases. Consequently, the normal value of the optic disc variables measured by an optic disc analyser may change according to the optic disc size or age. The effect of individual variations in optic disc size or age on interpretation of optic disc variables was investigated.
METHODS—Topographic optic disc variables of 104 normal Asian a...

  15. Artificial intelligence

    OpenAIRE

    Duda, Antonín

    2009-01-01

    Abstract : Issue of this work is to acquaint the reader with the history of artificial inteligence, esspecialy branch of chess computing. Main attention is given to progress from fifties to the present. The work also deals with fighting chess programs against each other, and against human opponents. The greatest attention is focused on 1997 and duel Garry Kasparov against chess program Deep Blue. The work is divided into chapters according to chronological order.

  16. Chondrule transport in protoplanetary discs

    Science.gov (United States)

    Goldberg, Aaron Z.; Owen, James E.; Jacquet, Emmanuel

    2015-10-01

    Chondrule formation remains one of the most elusive early Solar system events. Here, we take the novel approach of employing numerical simulations to investigate chondrule origin beyond purely cosmochemical methods. We model the transport of generically produced chondrules and dust in a 1D viscous protoplanetary disc model in order to constrain the chondrule formation events. For a single formation event we are able to match analytical predictions of the memory they retain of each other (complementarity), finding that a large mass accretion rate (≳10-7 M⊙ yr-1) allows for delays on the order of the disc's viscous time-scale between chondrule formation and chondrite accretion. Further, we find older discs to be severely diminished of chondrules, with accretion rates ≲10-9 M⊙ yr-1 for nominal parameters. We then characterize the distribution of chondrule origins in both space and time, as functions of disc parameters and chondrule formation rates, in runs with continuous chondrule formation and both static and evolving discs. Our data suggest that these can account for the observed diversity between distinct chondrite classes, if some diversity in accretion time is allowed for.

  17. Total elbow arthroplasty: a radiographic outcome study

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Xue Susan [University of Washington, Department of Radiology, Box 357115, Seattle, WA (United States); Petscavage-Thomas, Jonelle M. [Penn State Hershey Medical Center, Department of Radiology, Hershey, PA (United States); Ha, Alice S. [University of Washington, Department of Radiology, Box 354755, Seattle, WA (United States)

    2016-06-15

    Total elbow arthroplasty (TEA) is becoming a popular alternative to arthrodesis for patients with end-stage elbow arthrosis and comminuted distal humeral fractures. Prior outcome studies have primarily focused on surgical findings. Our purpose is to determine the radiographic outcome of TEA and to correlate with clinical symptoms such as pain. This is an IRB-approved retrospective review from 2005 to 2015 of all patients with semiconstrained TEA. All available elbow radiographs and clinical data were reviewed. Data analysis included descriptive statistics and Kaplan-Meier survival curves for radiographic and clinical survival. A total of 104 total elbow arthroplasties in 102 patients were reviewed; 75 % were in women and the mean patient age was 63.1 years. Mean radiographic follow-up was 826 days with average of four radiographs per patient. Seventy TEAs (67 %) developed radiographic complications, including heterotopic ossification (48 %), perihardware lucency (27 %), periprosthetic fracture (23 %), hardware subluxation/dislocation (7 %), polyethylene wear (3 %), and hardware fracture/dislodgement (3 %); 56 patients (55 %) developed symptoms of elbow pain or instability and 30 patients (30 %) underwent at least one reoperation. In patients with radiographic complications, 66 % developed elbow pain, compared to 19 % of patients with no radiologic complications (p = 0.001). Of the patients with radiographic complications, 39 % had at least one additional surgery compared to 0 % of patients without radiographic complications (p = 0.056). Radiographic complications are common in patients after total elbow arthroplasty. There is a strong positive association between post-operative radiographic findings and clinical outcome. Knowledge of common postoperative radiographic findings is important for the practicing radiologist. (orig.)

  18. Tidally-induced warps in protostellar discs

    OpenAIRE

    Terquem, C.; Papaloizou, J.; Nelson, R.(University of California, Davis, Davis, USA)

    1998-01-01

    We review results on the dynamics of warped gaseous discs. We consider tidal perturbation of a Keplerian disc by a companion star orbiting in a plane inclined to the disc. The perturbation induces the precession of the disc, and thus of any jet it could drive. In some conditions the precession rate is uniform, and as a result the disc settles into a warp mode. The tidal torque also leads to the truncation of the disc, to the evolution of the inclination angle (not necessarily towards alignmen...

  19. Total Hip Arthroplasty in Mucopolysaccharidosis Type IH

    Directory of Open Access Journals (Sweden)

    S. O'hEireamhoin

    2011-01-01

    Full Text Available Children affected by mucopolysaccharidosis (MPS type IH (Hurler Syndrome, an autosomal recessive metabolic disorder, are known to experience a range of musculoskeletal manifestations including spinal abnormalities, hand abnormalities, generalised joint stiffness, genu valgum, and hip dysplasia and avascular necrosis. Enzyme therapy, in the form of bone marrow transplantation, significantly increases life expectancy but does not prevent the development of the associated musculoskeletal disorders. We present the case of a 23-year-old woman with a diagnosis of Hurler syndrome with a satisfactory result following uncemented total hip arthroplasty.

  20. Navigated minimally invasive unicompartmental knee arthroplasty.

    Science.gov (United States)

    Jenny, Jean-Yves; Müller, Peter E; Weyer, R; John, Michael; Weber, Patrick; Ciobanu, Eugène; Schmitz, Andreas; Bacher, Thomas; Neumann, Wolfram; Jansson, Volkmar

    2006-10-01

    Unicompartmental knee arthroplasty (UKA) is an alternative procedure to high tibial osteotomy. This study assessed the procedure using computer navigation to improve implantation accuracy and presents early radiological results of a group of patients implanted with the univation UKA (B. Braun Aesculap, Tuttlingen, Germany) with navigation instrumentation and a minimally invasive approach. The authors concluded that navigated implantation of a UKA using a nonimage-based system improved radiologic accuracy implantation without significant inconvenience and minimal change in the conventional operating technique. PMID:17407935

  1. Vaginal mass following uncemented total hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Young-Soo Shin

    2014-01-01

    Full Text Available A 53-year-old woman developed a vaginal mass following an uncemented total hip arthroplasty. The mass was in direct communication with the hip through an acetabular medial wall defect after loosening of the acetabular component. The mass formation was caused simultaneously by changes secondary to polyethylene wear, a tiny delamination of the porous titanium mesh coating and a broken antirotational tab on the acetabular cup, all of which may have served as sources of metal particles. A careful evaluation of the patient′s history, symptoms, X-ray findings and computed tomography scans should always be performed to ensure accurate diagnosis.

  2. Hip and knee arthroplasty: quo vadis?

    OpenAIRE

    Ho, J; Meis, J. F. G. M.; Nabuurs-Franssen, M.H.; Voss, A.

    2015-01-01

    Despite of the steady decrease of surgical site infection (SSI) over the last two decades, the incidence of SSI after hip and knee arthroplasty has recently surged. This may be explained by technical changes that may result in an increased risk of SSI, such as the broad implementation of fast track programs, and/or early interventions on suspected SSI. By definition, early intervention may lead to a higher SSI score, even in the absence of a true SSI. In any case, the reverse trend of SSI war...

  3. Snapping Pes Syndrome after Unicompartmental Knee Arthroplasty

    Science.gov (United States)

    Taketomi, Shuji; Yamagami, Ryota; Tahara, Keitaro; Tanaka, Sakae

    2016-01-01

    Snapping pes syndrome is defined as a snapping sensation in the medial knee caused by pes anserinus and rarely occurs. Snapping pes syndrome after unicompartmental knee arthroplasty (UKA) has not been reported yet. We experienced two cases with this syndrome after UKA. Conservative treatment was effective in one case, while surgical excision of the gracilis tendon was necessary to relieve painful snapping in the other case. The main cause of the first case might be posteromedial overhang of the tibial tray that reached up to 5 mm. The probable cause of the second case was posteromedial overhang of the mobile bearing.

  4. Laser engineering of spine discs

    Science.gov (United States)

    Sobol, E.; Zakharkina, O.; Baskov, A.; Shekhter, A.; Borschenko, I.; Guller, A.; Baskov, V.; Omelchenko, A.; Sviridov, A.

    2009-04-01

    The laser engineering of intervertebral discs is one of the branch of medical physics aimed at the development of minimally invasive laser medical techniques based on the effect of the controlled (time- and space-modulated) laser radiation on the structure and the field of mechanical stress of biological tissues. A new method for the laser engineering of the intervertebral discs and the differences of this approach from the existing physical methods of medical treatment are considered. The newly formed tissues of animals and humans are hystologically studied. Possible regeneration processes are discussed. A control system that provides for the treatment efficiency and safety is developed. The new laser medical equipment that is designed for the laser engineering of intervertebral discs is described, and the corresponding results of the clinical application are presented.

  5. Black hole accretion disc impacts

    Science.gov (United States)

    Pihajoki, P.

    2016-04-01

    We present an analytic model for computing the luminosity and spectral evolution of flares caused by a supermassive black hole impacting the accretion disc of another supermassive black hole. Our model includes photon diffusion, emission from optically thin regions and relativistic corrections to the observed spectrum and time-scales. We test the observability of the impact scenario with a simulated population of quasars hosting supermassive black hole binaries. The results indicate that for a moderate binary mass ratio of 0.3, and impact distances of 100 primary Schwarzschild radii, the accretion disc impacts can be expected to equal or exceed the host quasar in brightness at observed wavelength λ = 510 nm up to z = 0.6. We conclude that accretion disc impacts may function as an independent probe for supermassive black hole binaries. We release the code used for computing the model light curves to the community.

  6. Black hole accretion disc impacts

    CERN Document Server

    Pihajoki, Pauli

    2015-01-01

    We present an analytic model for computing the luminosity and spectral evolution of flares caused by a supermassive black hole impacting the accretion disc of another supermassive black hole. Our model includes photon diffusion, emission from optically thin regions and relativistic corrections to the observed spectrum and time-scales. We test the observability of the impact scenario with a simulated population of quasars hosting supermassive black hole binaries. The results indicate that for a moderate binary mass ratio of 0.3, and impact distances of 100 primary Schwarzschild radii, the accretion disc impacts can be expected to equal or exceed the host quasar in brightness at observed wavelength {\\lambda} = 510 nm up to z = 0.6. We conclude that accretion disc impacts may function as an independent probe for supermassive black hole binaries. We release the code used for computing the model light curves to the community.

  7. Current status of the application of antibiotic-loaded bone cements in primary arthroplasty%初次关节置换中抗生素骨水泥的应用现状

    Institute of Scientific and Technical Information of China (English)

    王晓楠; 王金成

    2013-01-01

    Infection is considered to be a serious complication of artificial arthroplasty. Accordingly, infection control becomes a research focus in recent years. In order to reduce its incidence, many doctors use antibiotic-loaded bone cements in primary arthroplasty, especially in those special cases, such as surgery with a long period, or with a high risk of pollution, revision surgery, and for patients with idiopathic or acquired immunodeficiency, patients with rheumatoid diseases or systemic lupus erythematosus, patients treated with radiotherapy or chemotherapy, obese patients, diabetic patients, especially patients with poor glucose control, and patients with previous joint infection or malignancy. However, there exists such problems as higher costs and a single kind of antibiotics in use. At the same time, the release time of antibiotics in bone cements is limited, which determines that the infection is mainly prevented in the introduced pathway after artificial arthroplasty. So it is uncertain whether all types of bacteria entering the human body through the introduced pathway can be included by the antibacterial spectrum of antibiotics in bone cements, and further experiments and studies are needed for doctors to verify the results. In this article, we reviewed the application of antibiotic-loaded bone cements in primary arthroplasty for reference.

  8. Wear Performance of UHMWPE and Reinforced UHMWPE Composites in Arthroplasty Applications: A Review

    Directory of Open Access Journals (Sweden)

    Juan C. Baena

    2015-05-01

    Full Text Available As the gold standard material for artificial joints, ultra-high-molecular-weight polyethylene (UHMWPE generates wear debris when the material is used in arthroplasty applications. Due to the adverse reactions of UHMWPE wear debris with surrounding tissues, the life time of UHMWPE joints is often limited to 15–20 years. To improve the wear resistance and performance of the material, various attempts have been made in the past decades. This paper reviews existing improvements made to enhance its mechanical properties and wear resistance. They include using gamma irradiation to promote the cross-linked structure and to improve the wear resistance, blending vitamin E to protect the UHMWPE, filler incorporation to improve the mechanical and wear performance, and surface texturing to improve the lubrication condition and to reduce wear. Limitations of existing work and future studies are also identified.

  9. Diagnosis of cervical disc disease

    International Nuclear Information System (INIS)

    High resolution CT easily localized lesions including soft tissues of the bone such as disc protrusion and thickening of the yellow ligament. In all cases, myelography demonstrated compression of the nerve roots of the spinal cord which corresponded to CT findings at the level where plain CT revealed a lesion. However, CT metrizamide myelography demonstrated the lesion more clearly than did conventional myelography. CT metrizamide myelography also outlined compression of the nerve roots satisfactorily and demonstrated compressed findings of the spinal cord in the dynamic study. Thus, high resolution CT was useful for screening of cervical disc disease, and CT metrizamide myelography, for identification of lesions of the nerve roots. (Chiba, N.)

  10. Vertebral osteomyelitis without disc involvement

    Energy Technology Data Exchange (ETDEWEB)

    Kamani, I.; Syed, I.; Saifuddin, A. E-mail: asaifuddin@aol.com; Green, R.; MacSweeney, F

    2004-10-01

    Vertebral osteomyelitis is most commonly due to pyogenic or granulomatous infection and typically results in the combined involvement of the intervertebral disc and adjacent vertebral bodies. Non-infective causes include the related conditions of chronic recurrent multifocal osteomyelitis (CRMO) and SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome. Occasionally, these conditions may present purely within the vertebral body, resulting in various combinations of vertebral marrow oedema and sclerosis, destructive lesions of the vertebral body and pathological vertebral collapse, thus mimicking neoplastic disease. This review illustrates the imaging features of vertebral osteomyelitis without disc involvement, with emphasis on magnetic resonance imaging (MRI) findings.

  11. Hydrodynamic instability in eccentric astrophysical discs

    CERN Document Server

    Barker, Adrian J

    2014-01-01

    Eccentric Keplerian discs are believed to be unstable to three-dimensional hydrodynamical instabilities driven by the time-dependence of fluid properties around an orbit. These instabilities could lead to small-scale turbulence, and ultimately modify the global disc properties. We use a local model of an eccentric disc, derived in a companion paper, to compute the nonlinear vertical ("breathing mode") oscillations of the disc. We then analyse their linear stability to locally axisymmetric disturbances for any disc eccentricity and eccentricity gradient using a numerical Floquet method. In the limit of small departures from a circular reference orbit, the instability of an isothermal disc is explained analytically. We also study analytically the small-scale instability of an eccentric neutrally stratified polytropic disc with any polytropic index using a WKB approximation. We find that eccentric discs are generically unstable to the parametric excitation of small-scale inertial waves. The nonlinear evolution o...

  12. Diagnosis of infection after total hip arthroplasty

    International Nuclear Information System (INIS)

    Forty-eight total hip arthroplasties for which revision surgery was performed were reviewed to determine the accuracy of laboratory tests, plain radiographs, hip aspiration, and technetium-99m MDP and gallium-67 scans in demonstrating the presence or absence of infection of the prosthesis. Six of the 48 hips were diagnosed as having an infection at the revision surgery. The erythrocyte sedimentation rate and the C-reactive protein levels were significantly higher in the patients with infected prostheses. The difference in the white blood cell count was not significant. There was no significant relationship between the presence of infection and the severity of loosening and instability of the implants diagnosed by plain radiographs. The accuracy of hip aspiration in diagnosing the infection was 83%, with a sensitivity of 40% and a specificity of 92%. The accuracy of technetium-99m MDP bone scan was 79%, with a sensitivity of 83%, and a specificity of 79%. Gallium-67 scan had an accuracy of 96%, a sensitivity of 67%, and a specificity of 100%. The findings in the present study indicated that diagnostic tests consisting of laboratory tests and plain radiography, followed by hip aspiration and sequential use of technetium-99m MDP and gallium-67 scintigraphies, are suitable for differentiation between mechanical loosening and infection of total hip arthroplasty. (author)

  13. Preoperative Planning in Primary Total Knee Arthroplasty.

    Science.gov (United States)

    Tanzer, Michael; Makhdom, Asim M

    2016-04-01

    Preoperative planning is of paramount importance in primary total knee arthroplasty. A thorough preoperative analysis helps the surgeon envision the operation, anticipate any potential issues, and minimize the risk of premature implant failure. Obtaining a thorough history is critical for appropriate patient selection. The physical examination should evaluate the integrity of the soft tissues, the neurovascular status, range of motion, limb deformity, and the status of the collateral ligaments to help determine the soft-tissue balancing and constraint strategy required. Standard radiographs, with a known magnification, should be obtained for preoperative total knee arthroplasty templating. Routine standing AP, lateral, and skyline radiographs of the knee can help the surgeon plan the bone cuts and tibial slope as well as the implant size and position at the time of surgery. In certain circumstances, such as severe coronal deformities, bone deficiencies, and/or extra-articular deformities, additional measures are frequently necessary to successfully reconstruct the knee. Constrained implants, metal augments, and bone graft must be part of the surgeon's armamentarium. PMID:26990712

  14. Robot-assisted total hip arthroplasty.

    Science.gov (United States)

    Banerjee, Samik; Cherian, Jeffery J; Elmallah, Randa K; Pierce, Todd P; Jauregui, Julio J; Mont, Michael A

    2016-01-01

    Precise and accurate biomechanical reconstruction during total hip arthroplasty (THA) is essential for durable long-term survivorship. Accurate fit of cementless hip implants is also crucial to reduce micromotion between the bone-implant interfaces to allow for stable osseointegration. Robotic technology aims to minimize potential human errors and improve implant alignment and fit, and address persisting concerns with modern-day cementless THA. Although robotic THA dates back to the early 1990s, concerns with increased operating times, costs, and complications led to its withdrawal. However, semi-active systems have renewed interest in robot-assisted joint arthroplasty. We reviewed the current technology, its potential benefits, and the reported clinical and radiographic outcomes. Early evidence suggests that robotic use may lead to more accurate reconstruction of radiographic parameters, such as implant positioning, fit, center-of-rotation, and leg-length discrepancy. Further research is needed to determine if these will translate into better outcomes and improved implant longevity to justify increased costs. PMID:26592900

  15. UnconStrained ShoUlder arthroplasty

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To evaluate the results of 36unconstrained shoulder arthroplasties. Methods: In the series, 24 total and 12 hemiarthroplasties of the shoulders were performed with unconstrained shoulder prostheses in 29 patients who suffered from glenohumeral degenerative arthritis, rheumatoid arthritis, avascular necrosis and proximal fracture of humerus, respectively. Follow-up averaged 6.2years. All patients were evaluated pre- and post-operatively using the rating system of the Society of American Shoulder and Elbow Surgeons which assesses the severity of pain,strength of muscles around shoulder, stability, range of motion and functional activities of daily living. Radiolucent line and migration of prostheses were observed postoperatively on X-rays. Results: Postoperatively, the rate of pain relief was 91.3%, and active range of motion increased by 47° inforward flexion, 43° in abduction , 30° in external rotation,and 4 segments in internal rotation. Preoperatively the average points of 6 functional activities patients could perform was 0.8, and postoperatively 3.1. On postoperative X-ray, proximal migration of the humerus was seen in 8 shoulders, 6 of which had either a torn or absent rotator cuff. Radiolucent lines were seen around 1humeral component and 9 glenoid components. Onehumeral and 2 glenoid components loosened. Conclusions: These results suggest that unconstrained shoulder arthroplasty is a satisfactory and safe technique.

  16. Robot-assisted unicompartmental knee arthroplasty.

    Science.gov (United States)

    Pearle, Andrew D; O'Loughlin, Padhraig F; Kendoff, Daniel O

    2010-02-01

    The outcomes of unicompartmental knee arthroplasties (UKAs) have demonstrated inconsistent long-term survival. We report the first clinical series of UKA using a semiactive robotic system for the implantation of an inlay unicondylar knee arthroplasty. Ten patients were selected for this study. Preoperative mechanical leg alignment values ranged from 0.3 degrees varus to 9.8 degrees varus. A haptic guidance system was used; a detailed description is given in the manuscript. The setup time for the robot was 41 minutes; intraoperative registration process, 7.5 minutes (6-13 minutes); skin incision, 8 cm; robot-assisted burring, 34.8 minutes (18-50 minutes); mean tourniquet time, 87.4 minutes (68-113 minutes); and overall operation time, 132 minutes (118-152 minutes). The planned and intraoperative tibiofemoral angle was within 1 degrees. The postoperative long leg axis radiographs were within 1.6 degrees. Haptic guidance in combination with a navigation module allows for precise planning and execution of both inlay components in UKA. PMID:19056227

  17. The Cruciate Ligaments in Total Knee Arthroplasty.

    Science.gov (United States)

    Parcells, Bertrand W; Tria, Alfred J

    2016-01-01

    The early knee replacements were hinge designs that ignored the ligaments of the knee and resurfaced the joint, allowing freedom of motion in a single plane. Advances in implant fixation paved the way for modern designs, including the posterior-stabilized (PS) total knee arthroplasty (TKA) that sacrifices both cruciate ligaments while substituting for the posterior cruciate ligament (PCL), and the cruciate-retaining (CR) TKA designs that sacrifice the anterior cruciate ligament but retain the PCL. The early bicruciate retaining (BCR) TKA designs suffered from loosening and early failures. Townley and Cartier designed BCR knees that had better clinical results but the surgical techniques were challenging.Kinematic studies suggest that normal motion relies on preservation of both cruciate ligaments. Unicompartmental knee arthroplasty retains all knee ligaments and closely matches normal motion, while PS and CR TKA deviate further from normal. The 15% to 20% dissatisfaction rate with current TKA has renewed interest in the BCR design. Replication of normal knee kinematics and proprioception may address some of the dissatisfaction. PMID:27327919

  18. Whispering galleries and the control of artificial atoms

    Science.gov (United States)

    Forrester, Derek Michael; Kusmartsev, Feodor V.

    2016-01-01

    Quantum computation using artificial-atoms, such as novel superconducting circuits, can be sensitively controlled by external electromagnetic fields. These fields and the self-fields attributable to the coupled artificial-atoms influence the amount of quantum correlation in the system. However, control elements that can operate without complete destruction of the entanglement of the quantum-bits are difficult to engineer. Here we investigate the possibility of using closely-spaced-linear arrays of metallic-elliptical discs as whispering gallery waveguides to control artificial-atoms. The discs confine and guide radiation through the array with small notches etched into their sides that act as scatterers. We focus on π-ring artificial-atoms, which can generate their own spontaneous fluxes. We find that the micro-discs of the waveguides can be excited by terahertz frequency fields to exhibit whispering-modes and that a quantum-phase-gate composed of π-rings can be operated under their influence. Furthermore, we gauge the level of entanglement through the concurrence measure and show that under certain magnetic conditions a series of entanglement sudden-deaths and revivals occur between the two qubits. This is important for understanding the stability and life-time of qubit operations using, for example, a phase gate in a hybrid of quantum technologies composed of control elements and artificial-atoms. PMID:27122353

  19. Whispering galleries and the control of artificial atoms.

    Science.gov (United States)

    Forrester, Derek Michael; Kusmartsev, Feodor V

    2016-01-01

    Quantum computation using artificial-atoms, such as novel superconducting circuits, can be sensitively controlled by external electromagnetic fields. These fields and the self-fields attributable to the coupled artificial-atoms influence the amount of quantum correlation in the system. However, control elements that can operate without complete destruction of the entanglement of the quantum-bits are difficult to engineer. Here we investigate the possibility of using closely-spaced-linear arrays of metallic-elliptical discs as whispering gallery waveguides to control artificial-atoms. The discs confine and guide radiation through the array with small notches etched into their sides that act as scatterers. We focus on π-ring artificial-atoms, which can generate their own spontaneous fluxes. We find that the micro-discs of the waveguides can be excited by terahertz frequency fields to exhibit whispering-modes and that a quantum-phase-gate composed of π-rings can be operated under their influence. Furthermore, we gauge the level of entanglement through the concurrence measure and show that under certain magnetic conditions a series of entanglement sudden-deaths and revivals occur between the two qubits. This is important for understanding the stability and life-time of qubit operations using, for example, a phase gate in a hybrid of quantum technologies composed of control elements and artificial-atoms. PMID:27122353

  20. Resurfacing shoulder arthroplasty for the treatment of severe rheumatoid arthritis

    DEFF Research Database (Denmark)

    Voorde, Pia C Ten; Rasmussen, Jeppe V; Olsen, Bo S; Brorson, Stig

    2015-01-01

    outcome was obtained 1-year postoperatively using the Western Ontario Osteoarthritis of the Shoulder index (WOOS), and rates of revision were calculated by checking revisions reported until December 2011. The patient-reported outcome of RHA was compared to that of SHA using regression analysis with......BACKGROUND AND PURPOSE: There is no consensus on which type of shoulder prosthesis should be used in patients with rheumatoid arthritis (RA). We describe patients with RA who were treated with shoulder replacement, regarding patient-reported outcome, prosthesis survival, and causes of revision, and...... we compare outcome after resurfacing hemi-arthroplasty (RHA) and stemmed hemi-arthroplasty (SHA). PATIENTS AND METHODS: We used data from the national Danish Shoulder Arthroplasty Registry and included patients with RA who underwent shoulder arthroplasty in Denmark between 2006 and 2010. Patient-reported...

  1. Is cold therapy really efficient after knee arthroplasty?

    Directory of Open Access Journals (Sweden)

    Ersin Kuyucu

    2015-12-01

    Conclusion: After knee arthroplasty, the preoperative and postoperative use of cryotherapy is effective in terms of the pain control and functional knee scores without a significant change in surgical blood loss.

  2. Reverse Shoulder Arthroplasty for Trauma: When, Where, and How.

    Science.gov (United States)

    Szerlip, Benjamin W; Morris, Brent J; Edwards, T Bradley

    2016-01-01

    Reverse shoulder arthroplasty has become increasingly popular for the treatment of complex shoulder injuries, including proximal humerus fractures and fixed glenohumeral dislocation, in the elderly population. The early to midterm results of reverse shoulder arthroplasty for the treatment of proximal humerus fractures are promising compared with the results of unconstrained humeral head replacement, and patients may have more predictable improvement with less dependence on bone healing and rehabilitation. However, long-term follow-up is needed, and surgeons must be familiar with various complications that are specific to reverse shoulder arthroplasty. To achieve optimal patient outcomes for the management of traumatic shoulder injuries, surgeons must have a comprehensive understanding of the current implant options, indications, and surgical techniques for reverse shoulder arthroplasty. PMID:27049189

  3. Total knee arthroplasty in patients with a previous patellectomy.

    Science.gov (United States)

    Maslow, Jed; Zuckerman, Joseph D; Immerman, Igor

    2013-01-01

    Post-patellectomy patients represent a specific subgroup of patients that may develop arthritis and persistent knee pain and potentially require treatment with total knee arthroplasty. This article reviews the treatment and functional outcomes following total knee arthroplasty in patients with prior patellectomy. A case report is presented as an example of the clinical management of a post-patellectomy patient with significant knee pain and disability treated with total knee arthroplasty. Emphasis will be placed in decision- making, specifically with the use of a posterior stabilized implant. In addition, postoperative strengthening of the quadriceps is essential to compensate for the lack of the patella and increase the success of total knee arthroplasty in this subgroup of patients. PMID:24151951

  4. Planet formation in evolving protoplanetary discs

    OpenAIRE

    Alexander, Richard

    2013-01-01

    I attempt to summarize our knowledge of planet formation in evolving protoplanetary discs. I first review the physics of disc evolution and dispersal. For most of the disc lifetime evolution is driven by accretion and photoevaporation, and I discuss how the interplay between these processes shapes protoplanetary discs. I also discuss the observations that we use to test these models, and the major uncertainties that remain. I will then move on to consider planet formation and migration in evo...

  5. Proceedings: Fossil steam turbine disc cracking workshop

    Energy Technology Data Exchange (ETDEWEB)

    1991-04-01

    The objectives of the workshop were to review and consolidate the state of the art of cracking in fossil steam turbine discs; to identify further work needed to assist utilities in evaluating fossil turbine discs subject to SCC. Participants included 18 representatives from utilities, 12 representatives from equipment manufacturing organizations, and 5 consultants. Canadian, European, Japanese, and domestic organizations were represented. Topics included: A Review of GE Fossil Shrunk-On Wheel Stress Corrosion Cracking; Effects on Material and Environmental Factors on SCC of NiCrMoV Rotor Steels; SCC Experience of Shrunk On Discs; Studies on SCC For Steam Turbine Rotor and Disc; Advanced Disc-Type LP Turbine Rotors; Recent Experience of Stress Corrosion Cracking in the LP Discs of Fossil-Fired Reheat Turbines; Stress Corrosion of NiCrMoV LP Disc and Shaft Steels Under Cyclic Loading; NYIT'S Focused Approach for Ultrasonically Scanning Steam Turbine Discs; Probabilistic Assessment of Crack Initiation and Growth in Shrunk-On Discs; Low-Pressure Rotor Disc Cracking and Remaining Life Analysis; Assessment of Probability of Survival of Built Up LP Turbine Rotors With Discs Containing Semi-Circular Keyways; Electric Power Research Institute Turbine Disc Inspection Program; Fossil Turbine Disc Inspections--A Utility Dilemma; In-Service Accumulation of Chemicals in the Keyways and Their Effect on Stress Corrosion Cracking of Turbine Discs; Pitting and Compositional Effects on Stress Corrosion Cracking of Turbine Disc Steels; and TVA's Recent Experience With Inspection and Testing of Shrink-On Discs. Individual papers are processed separately for the data bases.

  6. Spontaneous regression of an intraspinal disc cyst

    Energy Technology Data Exchange (ETDEWEB)

    Demaerel, P.; Eerens, I.; Wilms, G. [University Hospital, Leuven (Belgium). Dept. of Radiology; Goffin, J. [Dept. of Neurosurgery, University Hospitals, Leuven (Belgium)

    2001-11-01

    We present a patient with a so-called disc cyst. Its location in the ventrolateral epidural space and its communication with the herniated disc are clearly shown. The disc cyst developed rapidly and regressed spontaneously. This observation, which has not been reported until now, appears to support focal degeneration with cyst formation as the pathogenesis. (orig.)

  7. Association between trochanteric bursitis, osteoarthrosis and total hip arthroplasty,

    OpenAIRE

    Carlos Roberto Schwartsmann; Felipe Loss; Leandro de Freitas Spinelli; Roque Furian; Marcelo Faria Silva; Júlia Mazzuchello Zanatta; Leonardo Carbonera Boschin; Ramiro Zilles Gonçalves; Anthony Kerbes Yépez

    2014-01-01

    OBJECTIVE: this was an epidemiological study on trochanteric bursitis at the time of performing total hip arthroplasty.METHODS: sixty-two sequential patients who underwent total hip arthroplasty due to osteoarthrosis, without any previous history of trochanteric bursitis, were evaluated. The bursas were collected and evaluated histologically.RESULTS: there were 35 female patients (56.5%) and 27 male patients (43.5%), with a mean age of 65 years (±11). Trochanteric bursitis was conformed histo...

  8. TROCHANTERIC ARTHROPLASTY IN THE SEPTIC ARTHRITIC SEOUELA OF THE HIP

    OpenAIRE

    Cakmak, Mehmet; Karamehmetoglu, Mahmut; Taser, Omer; Alturfan, Aziz

    2004-01-01

    7 cases have been treated with trochanteric arthroplasty, in which femoral neads and necks were lost due to the septic arthritic sequela of the hip. These seven cases have been followed for 2,7 years with 1,5 being the youngest 4 the oldest made on the fact that in those cases in which heads and necks are lost in combination, the best solution can be obtained by trochanteric arthroplasty.

  9. Candida glabrata infection following total hip arthroplasty: A case report

    OpenAIRE

    Zhu, Yun; Yue, Chen; Huang, Zeyu; Pei, Fuxing

    2013-01-01

    Candida glabrata infection following total hip arthroplasty is rare and, due to the insufficiency of standardized clinical and evidence-based guidelines, there is no appropriate therapeutic schedule. The present study reports the case of a 44-year-old patient with Candida glabrata infection following a total hip arthroplasty. The patient was successfully treated by administration of intravenous and oral voriconazole without removal of the prosthesis. This case illustrates the significance of ...

  10. Fungal prosthetic joint infection after total knee arthroplasty

    OpenAIRE

    Reddy, Kankanala J; Shah, Jay D; Rohit V Kale; T Jayakrishna Reddy

    2013-01-01

    Fungal prosthetic joint infection after total knee arthroplasty (TKA) is a rare complication. Lacunae exist in the management of this complication. 62 year old lady presented with pain and swelling in left knee and was diagnosed as Candida tropicalis fungal infection after TKA. She underwent debridement, resection arthroplasty and antifungal plus antibiotic loaded cement spacer insertion, antifungal therapy with fluconazole followed by delayed revision TKA and further fluconazole therapy. Tot...

  11. Compartment syndrome and popliteal vascular injury complicating unicompartmental knee arthroplasty

    OpenAIRE

    Kort, Nanne Pieter; Van Raay, Jos J. J. A. M.; van Horn, Jim R.

    2007-01-01

    Popliteal vascular injury and the compartment syndrome of the leg are rare but important complications of knee arthroplasties. Early diagnosis and treatment are of paramount importance in preventing the devastating complications of these conditions. To our knowledge, these complications have not been reported previously after unicompartmental knee arthroplasty in the literature. Low level of suspicion may delay the diagnosis, as popliteal vascular injury and compartment syndrome are not well ...

  12. Popliteal Artery Pseudoaneurysm Following Primary Total Knee Arthroplasty

    OpenAIRE

    Shin, Young-Soo; Hwang, Yeok-Gu; Savale, Abhijit Prakash; Han, Seung-Beom

    2014-01-01

    An early diagnosis of popliteal artery pseudoaneurysm-a sequela of popliteal artery trauma-is difficult owing to its late presentation following total knee arthroplasty. The incidence of a popliteal artery pseudoaneurysm with a hematoma presenting only a peripheral nerve injury after total knee arthroplasty is also uncommon in the absence of common diagnostic features such as a pulsatile swelling with an audible bruit on auscultation. In the present report, we describe popliteal artery pseudo...

  13. The association between metal allergy, total hip arthroplasty, and revision

    OpenAIRE

    Thyssen, Jacob Pontoppidan; Jakobsen, Stig Storgaard; Engkilde, Kåre; Johansen, Jeanne Duus; Søballe, Kjeld; Menné, Torkil

    2009-01-01

    Background and purpose It has been speculated that the prevalence of metal allergy may be higher in patients with implant failure. We compared the prevalence and cause of revisions following total hip arthroplasty (THA) in dermatitis patients suspected to have contact allergy and in patients in general with THA. Furthermore, we compared the prevalence of metal allergy in dermatitis patients with and without THA. Materials and methods The Danish Hip Arthroplasty Registry (DHAR) contained detai...

  14. Systematic review of patellar resurfacing in total knee arthroplasty

    OpenAIRE

    Li, Shuzhen; Chen, Yueping; Su, Wei; Zhao, Jinmin; He, Shunqing; Luo, Xiangping

    2010-01-01

    Controversies existing over resurfacing the patella in total knee arthroplasty remain in the literature. The purpose of this review was to evaluate the effectiveness of resurfacing versus nonresurfacing the patella in total knee arthroplasty. We searched the Cochrane Library, MEDLINE and EMBASE for published randomised clinical trials relevant to patellar resurfacing. The relative risk of reoperation was significantly lower for the patellar resurfacing group than for the nonresurfacing group ...

  15. MOBILE TIBIAL POLYETHYLENE BEARING IN TOTAL KNEE ARTHROPLASTY

    OpenAIRE

    de Araújo Barros Cobra, Hugo Alexandre; da Palma, Idemar Monteiro

    2015-01-01

    Debris of polyethylene tibial bearings have been recognized as a major cause for the onset of the cascade of biological events leading to osteolysis and loosening of prosthetic components after total knee arthroplasty. Since then, research has been focused on alternative bearing surfaces in order to minimize the amount and rate of polyethylene wear off and, in doing so, increasing the survivorship rate for knee arthroplasties. One such option is to have a mobile tibial bearing allowing more c...

  16. COMPARION OF GAP ARTHROPLASTY AND INTERPOSITIONAL GAP ARTHROPLASTY ON THE TEMPOROMANDIBULAR JOINT ANKYLOSIS

    OpenAIRE

    M. Ramezanian T. Yavary

    2006-01-01

    Temporomandibular joint ankylosis causes limitation in mouth opening and establishes severe deformity and asymmetry in patient’s face, especially in children. Surgery is the only treatment. This study was conducted to compare the effect of two surgical approaches, gap arthropasty and interpositional gap arthroplasty, on rate of maximum interincisal opening in temporomandibular joint ankylosis. We also evaluated the relapse rate of these two surgical approaches. A total of 48 patients were enr...

  17. Electromagnetic Levitation of a Disc

    Science.gov (United States)

    Valle, R.; Neves, F.; de Andrade, R., Jr.; Stephan, R. M.

    2012-01-01

    This paper presents a teaching experiment that explores the levitation of a disc of ferromagnetic material in the presence of the magnetic field produced by a single electromagnet. In comparison to the classical experiment of the levitation of a sphere, the main advantage of the proposed laboratory bench is that the uniform magnetic field…

  18. Therapeutic Effect of Artificial Total Hip Arthroplasty for the Treatment of the Hip Lesions in the Patients with Ankylosing Spondylitis%人工全髋关节置换术治疗强直性脊柱炎髋关节病变的临床疗效

    Institute of Scientific and Technical Information of China (English)

    刘亮; 张星火; 于振山; 张亚奎; 赵峰; 刘喜波

    2012-01-01

    目的 观察人工全髋关节置换治疗强直性脊柱炎髋关节病变的手术方法和临床效果.方法 对2001年3月至2009年6月26例(31髋)强直性脊柱炎髋关节病变患者行人工全髋关节置换并随访,置换前患者日常活动均明显受限或者严重疼痛,Harris评分平均(43.2±5.8)分,髋关节活动度平均51.8°±9.7°.记录术后末次随访的Harris评分,X线检查结果,观察假体有无松动、脱位及异位骨化. 结果 所有病例得到随访,平均随访24.9(8 ~125)个月.末次随访患者均疼痛消失,步态正常.Harris评分平均(82.4±4.7)分;髋关节活动度平均148.6°±7.4°;髋关节Harris评分及关节活动度均显著高于置换前(P<0.05).2髋出现异位骨化,为Brooker分级Ⅰ、Ⅲ级.无脱位、骨折及假体松动下沉,无患者进行翻修. 结论 人工全髋关节置换是治疗强直性脊柱炎晚期髋关节病变的有效方法,可以恢复关节功能,缓解关节疼痛并改善患者生活质量.%Objective To investigate the operative methods and clinical outcomes of total hip arthroplas-ty (THA) in the treatment of patients with hip lesions due to ankylosing spondylitis (AS). Methods From March 2001 to June 2009, 26 patients (31 hips) with AS received THA. All the hips were severe pain and an-kylosed in average 51. 8° ± 9. 7° of flexion. Preoperative Harris hip score was (43. 2 ±5.8) points. Radio-graphic examination and last Harris score were performed completely at the last time of follow-up. Results All the patients were followed up for average 24.9(8 ~ 125) month. Postoperatively.all patient get pain free and normal gait. According to Brooker system, 2 hips appeared heterotopic ossification, one was of Brookers Class I and the other Class III. No loosening or subsidence occurred in all patients. Harris hip score at final follow-up was (82.4±4.7) points (P <0.05), range of motion of hip were average 148. 6° ±7.4°(P <0. 05). Conclusion THA is effective

  19. Lumbar Disc Degenerative Disease: Disc Degeneration Symptoms and Magnetic Resonance Image Findings

    OpenAIRE

    Saleem, Shafaq; Aslam, Hafiz Muhammad; Rehmani, Muhammad Asim Khan; Raees, Aisha; Alvi, Arsalan Ahmad; Ashraf, Junaid

    2013-01-01

    Study Design Cross sectional and observational. Purpose To evaluate the different aspects of lumbar disc degenerative disc disease and relate them with magnetic resonance image (MRI) findings and symptoms. Overview of Literature Lumbar disc degenerative disease has now been proven as the most common cause of low back pain throughout the world. It may present as disc herniation, lumbar spinal stenosis, facet joint arthropathy or any combination. Presenting symptoms of lumbar disc degeneration ...

  20. Spontaneous Regression of Herniated Lumbar Disc with New Disc Protrusion in the Adjacent Level

    OpenAIRE

    Hakan, Tayfun; Gürcan, Serkan

    2016-01-01

    Spontaneous regression of herniated lumbar discs was reported occasionally. The mechanisms proposed for regression of disc herniation are still incomplete. This paper describes and discusses a case of spontaneous regression of herniated lumbar discs with a new disc protrusion in the adjacent level. A 41-year-old man was admitted with radiating pain and numbness in the left lower extremity with a left posterolateral disc extrusion at L5-S1 level. He was admitted to hospital with low back pain ...

  1. Engineered microporosity: enhancing the early regenerative potential of decellularized temporomandibular joint discs.

    Science.gov (United States)

    Juran, Cassandra M; Dolwick, M Franklin; McFetridge, Peter S

    2015-02-01

    The temporomandibular joint (TMJ) disc is susceptible to numerous pathologies that may lead to structural degradation and jaw dysfunction. The limited treatment options and debilitating nature of severe temporomandibular disorders has been the primary driving force for the introduction and development of TMJ disc tissue engineering as an approach to alleviate this important clinical issue. This study aimed to evaluate the efficacy of laser micropatterning (LMP) ex vivo-derived TMJ disc scaffolds to enhance cellular integration, a major limitation to the development of whole tissue implant technology. LMP was incorporated into the decellularized extracellular matrix scaffold structure using a 40 W CO2 laser ablation system to drill an 8×16 pattern with a bore diameter of 120 μm through the scaffold thickness. Disc scaffolds were seeded with human neonatal-derived umbilical cord mesenchymal stem cells differentiated into chondrocytes at a density of 900 cells per mm(2) and then assessed on days 1, 7, 14, and 21 of culture. Results derived from histology, PicoGreen DNA quantification, and cellular metabolism assays indicate that the LMP scaffolds improve cellular remodeling compared to the unworked scaffold over the 21-day culture period. Mechanical analysis further supports the use of the LMP showing the compressive properties of the LMP constructs closely represent native disc mechanics. The addition of an artificial path of infiltration by LMP culminated in improved chondrocyte adhesion, dispersion, and migration after extended culture aiding in recapitulating the native TMJ disc characteristics. PMID:25319941

  2. Disc degeneration: current surgical options

    Directory of Open Access Journals (Sweden)

    C Schizas

    2010-10-01

    Full Text Available Chronic low back pain attributed to lumbar disc degeneration poses a serious challenge to physicians. Surgery may be indicated in selected cases following failure of appropriate conservative treatment. For decades, the only surgical option has been spinal fusion, but its results have been inconsistent. Some prospective trials show superiority over usual conservative measures while others fail to demonstrate its advantages. In an effort to improve results of fusion and to decrease the incidence of adjacent segment degeneration, total disc replacement techniques have been introduced and studied extensively. Short-term results have shown superiority over some fusion techniques. Mid-term results however tend to show that this approach yields results equivalent to those of spinal fusion. Nucleus replacement has gained some popularity initially, but evidence on its efficacy is scarce. Dynamic stabilisation, a technique involving less rigid implants than in spinal fusion and performed without the need for bone grafting, represents another surgical option. Evidence again is lacking on its superiority over other surgical strategies and conservative measures. Insertion of interspinous devices posteriorly, aiming at redistributing loads and relieving pain, has been used as an adjunct to disc removal surgery for disc herniation. To date however, there is no clear evidence on their efficacy. Minimally invasive intradiscal thermocoagulation techniques have also been tried, but evidence of their effectiveness is questioned. Surgery using novel biological solutions may be the future of discogenic pain treatment. Collaboration between clinicians and basic scientists in this multidisciplinary field will undoubtedly shape the future of treating symptomatic disc degeneration.

  3. Fracture of the neck of a femoral component in a total hip arthroplasty: a case report

    OpenAIRE

    Artime, V.; Ramos, J. C.; Fernandez-Medina, J. M.; de Luis, M. C.; Aguilera, L.

    1997-01-01

    Fracture of components of a total hip arthroplasty occur is a recognised complication. We report an unusual case in which the fracture occurred through the neck of a femoral component on a Lord type of total hip arthroplasty.

  4. CT findings of lumbar intervertebral disc: II. Disc herniation (HNP)

    International Nuclear Information System (INIS)

    In lumbar region the epidural fat pad is relatively abundant so that CT can provides sufficient information in diagnosis of lumbar HNP. Many authors have reported on the CT findings of HNP such as focal nodular protrusion of the posterior disc margin, obliteration of epidural fat pad, impingement of dural sac and nerve root, swelling of nerve root, soft tissue density in the spinal canal and calcification of disc. However there was so previous report describing incidence and reliability of the findings. It is the purpose of the present study to survey the frequency, reliability, and limitation of these CT findings. The clinical material was consisted of 30 operatively proven cases of HNP of the lumbar spine. Each lumbar CT scan was reviewed retrospectively and the findings were analysed by two radiologists independently. There were 20 males and 10 females and the mean age was 36.7 years. Involvement of L4-S5 level was 2.3 times more frequent than that of L5-S1 level. Of 30 cases, 22 were unilateral posterolateral types and 8 cases central or unilateral far lateral types. CT findings observed were nodular protrusion of the posterior margin of the disc, obliteration of epidural fat pad, impingement of dural sac or nerve root, soft tissue density in the spinal canal and calcification in the posterior portion of the protruded disc, in order of decreasing frequency. The conclusions are follows: 1. Nodular protrusion of the posterior disc margin accompanied by obliteration of epidural fat pad was observed in every case. The former findings was designated as direct sign and the latter indirect. 2. Obliteration of the epidural fat appears to be significant in lateral recesses especially when it occurs unilaterally. This was not true, however, in the centrally located fat pad. 3. Impingement of the dural sac and nerve root were observed in 90% and 67%, respectively, and were very helpful in establishing HNP diagnosis when the direct and indirect signs were equivocal

  5. MR imaging findings of a sequestered disc in the lumbar spine: a comparison with an extruded disc

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Su Youn; Park, Ji Seon; Ryu, Kyung Nam [Kyung Hee University Medical Center, Seoul (Korea, Republic of); Jin, Wook [Kyung Hee University East-west Neo Medical Center, Seoul (Korea, Republic of)

    2007-10-15

    To compare the MR findings of a sequestered disc with an extruded disc. MR images of 28 patients with a sequestered disc and 18 patients with an extruded disc were retrospectively reviewed. Patients with sequestered discs were divided into two groups whether definite separation from the parent disc was or was not seen. In the latter group (definite separation not seen) and the extruded disc group of patients, the signal intensities of the herniated discs were compared with the signal intensities of the parent discs and were evaluated on T1-and T2-weighted images. We also assessed the presence of a notch within the herniated disc. In the sequestered disc group of patients (28 discs), only 5 discs (18%) showed obvious separation from the parent disc. Among the remaining 23 discs with indefinite separation, the notch was visible in 14 discs (61%) and 9 discs (39%) had no notch. In the extruded disc group (18 discs), the notch was visible in 2 (11%) discs and the difference between the two groups was statistically significant ({rho} 0.0002). The signal intensities of the herniated discs on T1-weighted images were isointense in both the sequestered and extruded discs. The difference of incidence of high signal intensities on T2-weighted images was not statistically significant ({rho} = 0.125). It is necessary to consider the possibility of the presence of a sequestered disc when a herniated disc material shows a notch.

  6. Accretion and plasma outflow from dissipationless discs

    OpenAIRE

    Bogovalov, Sergei; Kelner, Stanislav

    2008-01-01

    We consider an extreme case of disc accretion onto a gravitating centre when the viscosity in the disc is negligible. The angular momentum and the rotational energy of the accreted matter is carried out by a magnetized wind outflowing from the disc. The outflow of matter from the disc occurs due to the Blandford & Payne(1982) centrifugal mechanism. The disc is assumed to be cold. Accretion and outflow are connected by the conservation of the energy, mass and the angular momentum. The basic pr...

  7. On the warping of Be star discs

    OpenAIRE

    Porter, John M.

    1998-01-01

    The theory of radiatively-induced warps in accretion discs is applied to the discs of Be stars. It is found that these discs may develop warps in their inner regions, although once the warp amplitude is large enough then the interaction between the disc and fast radiatively-driven wind will determine its evolution. The warping is shown to be more important for later than earlier B stars. Although the interaction of the fast-wind with the disc will limit the amplitude of the warp, it cannot dr...

  8. Neurologic injuries after primary total ankle arthroplasty: prevalence and effect on outcomes

    OpenAIRE

    Primadi, Andri; Xu, He-Xing; Yoon, Taek-Rim; Ryu, Je-Hwang; Lee, Keun-Bae

    2015-01-01

    Background Neurologic injuries are complications that can arise after total joint arthroplasty. However, no comprehensive study has been conducted on peripheral nerve injuries after total ankle arthroplasty. The purpose of the present study was to identify the prevalence of neurologic injury following primary total ankle arthroplasty, the predisposing factors, and evaluate the effect on clinical outcomes. Methods We retrospectively analyzed 150 consecutive primary total ankle arthroplasty usi...

  9. Three-level cervical disc herniation

    Directory of Open Access Journals (Sweden)

    St. Iencean Andrei

    2015-09-01

    Full Text Available Multilevel cervical degenerative disc disease is well known in the cervical spine pathology, with radicular syndromes or cervical myelopathy. One or two level cervical herniated disc is common in adult and multilevel cervical degenerative disc herniation is common in the elderly, with spinal stenosis, and have the same cause: the gradual degeneration of the disc. We report the case of a patient with two level cervical disc herniation (C4 – C5 and C5 – C6 treated by anterior cervical microdiscectomy both levels and fusion at C5 – C6; after five years the patient returned with left C7 radiculopathy and MRI provided the image of a left C6 – C7 disc herniation, he underwent an anterior microsurgical discectomy with rapid relief of symptoms. Three-level cervical herniated disc are rare in adults, and the anterior microdiscectomy with or without fusion solve this pathology.

  10. Numerical simulations of disc-planet interactions

    CERN Document Server

    Paardekooper, Richard P Nelson Sijme-Jan

    2009-01-01

    The gravitational interaction between a protoplanetary disc and planetary sized bodies that form within it leads to the exchange of angular momentum, resulting in migration of the planets and possible gap formation in the disc for more massive planets. In this article, we review the basic theory of disc-planet interactions, and discuss the results of recent numerical simulations of planets embedded in protoplanetary discs. We consider the migration of low mass planets and recent developments in our understanding of so-called type I migration when a fuller treatment of the disc thermodynamics is included. We discuss the runaway migration of intermediate mass planets (so-called type III migration), and the migration of giant planets (type II migration) and the associated gap formation in the disc. The availability of high performance computing facilities has enabled global simulations of magnetised, turbulent discs to be computed, and we discuss recent results for both low and high mass planets embedded in such...

  11. The growth of planets by pebble accretion in evolving protoplanetary discs

    Science.gov (United States)

    Bitsch, Bertram; Lambrechts, Michiel; Johansen, Anders

    2015-10-01

    The formation of planets depends on the underlying protoplanetary disc structure, which in turn influences both the accretion and migration rates of embedded planets. The disc itself evolves on time scales of several Myr, during which both temperature and density profiles change as matter accretes onto the central star. Here we used a detailed model of an evolving disc to determine the growth of planets by pebble accretion and their migration through the disc. Cores that reach their pebble isolation mass accrete gas to finally form giant planets with extensive gas envelopes, while planets that do not reach pebble isolation mass are stranded as ice giants and ice planets containing only minor amounts of gas in their envelopes. Unlike earlier population synthesis models, our model works without any artificial reductions in migration speed and for protoplanetary discs with gas and dust column densities similar to those inferred from observations. We find that in our nominal disc model, the emergence of planetary embryos preferably should occur after approximately 2 Myr in order to not exclusively form gas giants, but also ice giants and smaller planets. The high pebble accretion rates ensure that critical core masses for gas accretion can be reached at all orbital distances. Gas giant planets nevertheless experience significant reduction in semi-major axes by migration. Considering instead planetesimal accretion for planetary growth, we show that formation time scales are too long to compete with the migration time scales and the dissipation time of the protoplanetary disc. All in all, we find that pebble accretion overcomes many of the challenges in the formation of ice and gas giants in evolving protoplanetary discs. Appendices are available in electronic form at http://www.aanda.org

  12. Determination of the intervertebral disc space from CT images of the lumbar spine

    Science.gov (United States)

    Korez, Robert; Å tern, Darko; Likar, Boštjan; Pernuš, Franjo; Vrtovec, Tomaž

    2014-03-01

    Degenerative changes of the intervertebral disc are among the most common causes of low back pain, where for individuals with significant symptoms surgery may be needed. One of the interventions is the total disc replacement surgery, where the degenerated disc is replaced by an artificial implant. For designing implants with good bone contact and continuous force distribution, the morphology of the intervertebral disc space and vertebral body endplates is of considerable importance. In this study we propose a method for the determination of the intervertebral disc space from three-dimensional (3D) computed tomography (CT) images of the lumbar spine. The first step of the proposed method is the construction of a model of vertebral bodies in the lumbar spine. For this purpose, a chain of five elliptical cylinders is initialized in the 3D image and then deformed to resemble vertebral bodies by introducing 25 shape parameters. The parameters are obtained by aligning the chain to the vertebral bodies in the CT image according to image intensity and appearance information. The determination of the intervertebral disc space is finally achieved by finding the planes that fit the endplates of the obtained parametric 3D models, and placing points in the space between the planes of adjacent vertebrae that enable surface reconstruction of the intervertebral disc space. The morphometric analysis of images from 20 subjects yielded 11:3 +/- 2:6, 12:1 +/- 2:4, 12:8 +/- 2:0 and 12:9 +/- 2:7 cm3 in terms of L1-L2, L2-L3, L3-L4 and L4-L5 intervertebral disc space volume, respectively.

  13. Postoperative pain treatment after total hip arthroplasty

    DEFF Research Database (Denmark)

    Højer Karlsen, Anders Peder; Geisler, Anja; Petersen, Pernille Lykke;

    2015-01-01

    Treatment of postoperative pain should rely on results from randomized controlled trials and meta-analyses of high scientific quality. The efficacy of a particular intervention may depend on the type of surgical procedure, which supports the reporting of "procedure-specific" interventions. The aim...... of this systematic review was to document the procedure-specific evidence for analgesic interventions after total hip arthroplasty (THA). This PRISMA-compliant and PROSPERO-registered review includes randomized placebo-controlled trials (RCTs) of medication-based analgesic interventions after THA...... reporting of adverse events, considerable differences in supplemental analgesic consumption, and basic analgesic regimens generally characterized trials. Meta-analyses of non-steroidal anti-inflammatory drugs, local infiltration analgesia, intrathecal opioids, and lumbar plexus block provided a 24-hour...

  14. Resection arthroplasty for comminuted olecranon fractures.

    Science.gov (United States)

    Compton, R; Bucknell, A

    1989-02-01

    Five cases of comminuted olecranon fractures treated by resection of the proximal fragments are reviewed. The patients' average age was 56 years and all were radiographically osteopenic. The triceps was advanced and attached to the distal olecranon with the elbow flexed at 90 degrees. A standard postoperative regimen was used with immobilization for three weeks in plaster at 45 to 60 degrees of flexion followed by progression to cautious active range of motion exercises. Follow-up of from 18 to 54 months shows an average active range of motion of 10 degrees flexion to 120 degrees flexion. There were no complaints or clinical evidence of instability and minimal degenerative changes were seen on radiography. We conclude that resection arthroplasty of comminuted olecranon fractures yields excellent clinical and functional results in elderly patients. PMID:2927958

  15. Metaphyseal bone loss in revision knee arthroplasty.

    Science.gov (United States)

    Ponzio, Danielle Y; Austin, Matthew S

    2015-12-01

    The etiology of bone loss encountered during revision total knee arthroplasty (TKA) is often multifactorial and can include stress shielding, osteolysis, osteonecrosis, infection, mechanical loss due to a grossly loose implant, and iatrogenic loss at the time of implant resection. Selection of the reconstructive technique(s) to manage bone deficiency is determined by the location and magnitude of bone loss, ligament integrity, surgeon experience, and patient factors including the potential for additional revision, functional demand, and comorbidities. Smaller, contained defects are reliably managed with bone graft, cement augmented with screw fixation, or modular augments. Large metaphyseal defects require more extensive reconstruction such as impaction bone grafting with or without mesh augmentation, prosthetic augmentation, use of bulk structural allografts, or use of metaphyseal cones or sleeves. While each technique has advantages and disadvantages, the most optimal method for reconstruction of large metaphyseal bone defects during revision TKA is not clearly established. PMID:26362647

  16. Pain Management After Total Joint Arthroplasty.

    Science.gov (United States)

    McDonald, Lisa T; Corbiere, Nicole C; DeLisle, Jay A; Clark, Alexander Martin; Kuxhaus, Laurel

    2016-06-01

    Controlling pain after total joint arthroplasty (TJA) is critical to minimizing complications, decreasing costs, and expediting patients' return to function. We implemented a TJA multimodal pain management protocol at a Level III trauma center in a small, rural community in New York. We retrospectively reviewed 266 patient charts and collected patient demographics, pain management information, and discharge data. Our primary goals were to quantify the total number of narcotic medication doses used and length of hospital stay. The multimodal pain management protocol significantly reduced the number of narcotic doses used (P pain management after TJA can reduce narcotic use and hospital length of stay, thereby also reducing the incidence of side effects from narcotics. PMID:27234795

  17. Fracture Blisters After Primary Total Knee Arthroplasty.

    Science.gov (United States)

    Halawi, Mohamad J

    2015-08-01

    Fracture blisters are tense vesicles that arise on markedly swollen skin overlying traumatized soft tissue. While this relatively uncommon complication has been well described in the trauma literature, this article reports for the first time a case of fracture blisters after primary total knee arthroplasty. The fracture blisters developed within 36 hours of surgery and were associated with profound swelling and erythema. There was no evidence of vascular injury, compartment syndrome, iatrogenic fracture, or deep venous thrombosis. The patient was treated with leg elevation, loosely applied nonadhesive dressings, and a short course of oral antibiotics after skin desquamation. Blood-filled blisters required longer time to reepithelialization than fluid-filled blisters. Knee stiffness developed because of pain and fear of participation with physical therapy, but the patient was able to resume intensive rehabilitation after resolution of the blisters. Patient factors, surgical factors, and review of the literature are discussed. PMID:26251947

  18. Implant survival after total elbow arthroplasty

    DEFF Research Database (Denmark)

    Plaschke, Hans Christian; Thillemann, Theis M; Brorson, Stig;

    2014-01-01

    BACKGROUND: Total elbow arthroplasty (TEA) is an established treatment for late-stage arthritis of the elbow. Indications have expanded to osteoarthritis and nonunion in distal humeral fractures. Information on implant survival and risk factors for revision is still sparse. The aim of this study...... was to evaluate implant survival and risk factors for revision of TEAs inserted in patients in the eastern part of Denmark in the period from 1980 until 2008. MATERIAL AND METHODS: The Danish National Patient Register provided personal identification numbers for patients who underwent TEA procedures...... from 1980 until 2008. On the basis of a review of medical reports and linkage to the National Patient Register, we calculated revision rates and evaluated potential risk factors for revision, including, age, sex, period, indication for TEA, and implant design. RESULTS: We evaluated 324 primary TEA...

  19. Debridement arthroplasty for osteoarthritis of the elbow.

    Science.gov (United States)

    Oka, Y; Ohta, K; Saitoh, I

    1998-06-01

    For treatment of osteoarthritis of the elbow, the authors use debridement arthroplasty with a medial or lateral approach. Thirty-eight elbows in 36 patients treated with this procedure were examined. The age of the patients ranged from 20 to 71 years, with a mean age of 41.7 years. Cubital tunnel syndrome was present in 16 of the 38 (42%) elbows. The operations were performed through a lateral approach in four elbows, a lateral approach with medial skin incision for ulnar nerve neurolysis in 16 elbows, a medial approach in 10 elbows, and a medial plus a lateral approach in eight elbows. The followup ranged from 2 years to 12.1 years, with an average of 5.9 years. Complete pain relief or minimal elbow pain was reported in 95% of patients who had surgical treatment. The average gain in motion was 6 degrees extension and 18 degrees flexion. Results for the various surgical approaches did not show a statistically significant difference. Recurrence of bony spurs and ridges was analyzed additionally in 18 selected patients who could be observed more than 5 years after surgery (range, 5-12 years). Redevelopment of bony spurs on the coronoid process and olecranon tip occurred in all 18 patients, but those changes were graded as mild in 13 (74%) patients and moderate in five (16%) patients and were accompanied by no pain or slight pain. Elbow arthroplasty as used by the authors produces stable and reliable results for relief of pain, gains in range of motion, and the absence of recurrence of significant osteoarthritis. PMID:9646755

  20. Souter arthroplasty for elbows with severe destruction.

    Science.gov (United States)

    Ikävalko, Mikko; Belt, Eero A; Kautiainen, Hannu; Lehto, Matti U K

    2004-04-01

    One hundred fifty-eight primary Souter elbow arthroplasties were done on 134 patients (121 women) with severe joint destruction (Larsen Grade 5) or large bone defects or both. Joint replacement operations were done at our institution from 1985-1997. The study group comprised 156 joints in 132 patients with rheumatoid arthritis or other variants of chronic inflammatory joint disease, one in a patient with osteoarthritis, and one patient with posttraumatic arthrosis. The mean age of the patients at the time of surgery was 57 years (range, 26-81 years) and the mean disease duration was 27 years (tinge, 2-70 years). Radiographically, severe bone defects were detected in 100 humeri and 134 ulnas. Retentive (snap-fit) ulnar components were implanted in 110 joints, and bone grafts were used on 26 humeri and 14 ulnas. Major complications led to five early and 16 late reoperations in 19 patients. Four reoperations were done because of dislocation and eight because of aseptic loosening. One reoperation was done because of early infection and five were done because of late infection. One patient had reoperation because of superficial infection in the bursa olecrani and one triceps tendon rupture also was repaired. One patient had wound repair because of marginal necrosis. In the survival analysis, the cumulative success rate without revision for aseptic loosening at 5 years followup was 97%. Despite the demanding nature of these arthroplasties, the primary results are encouraging. Technically, it is possible to do elbow replacement, even on elbows where the humeral condyles or olecranon or both are missing, if there is sufficient bone left on the diaphyseal areas for primary stem fixation. However, in these extreme cases, the poor general condition of the patient or the difficult soft tissue problems in the elbow region may prove to be a contraindication for joint replacement. PMID:15123937

  1. Revision of infected knee arthroplasties in Denmark.

    Science.gov (United States)

    Lindberg-Larsen, Martin; Jørgensen, Christoffer C; Bagger, Jens; Schrøder, Henrik M; Kehlet, Henrik

    2016-08-01

    Background and purpose - The surgical treatment of periprosthetic knee infection is generally either a partial revision procedure (open debridement and exchange of the tibial insert) or a 2-stage exchange arthroplasty procedure. We describe the failure rates of these procedures on a nationwide basis. Patients and methods - 105 partial revisions (100 patients) and 215 potential 2-stage revision procedures (205 patients) performed due to infection from July 1, 2011 to June 30, 2013 were identified from the Danish Knee Arthroplasty Register (DKR). Failure was defined as surgically related death ≤ 90 days postoperatively, re-revision due to infection, or not reaching the second stage for a planned 2-stage procedure within a median follow-up period of 3.2 (2.2-4.2) years. Results - The failure rate of the partial revisions was 43%. 71 of the partial revisions (67%) were revisions of a primary prosthesis with a re-revision rate due to infection of 34%, as compared to 55% in revisions of a revision prosthesis (p = 0.05). The failure rate of the 2-stage revisions was 30%. Median time interval between stages was 84 (9-597) days. 117 (54%) of the 2-stage revisions were revisions of a primary prosthesis with a re-revision rate due to infection of 21%, as compared to 29% in revisions of a previously revised prosthesis (p = 0.1). Overall postoperative mortality was 0.6% in high-volume centers (> 30 procedures within 2 years) as opposed to 7% in the remaining centers (p = 0.003). Interpretation - The failure rates of 43% after the partial revision procedures and 30% after the 2-stage revisions in combination with the higher mortality outside high-volume centers call for centralization and reconsideration of surgical strategies. PMID:26900908

  2. Results of reconstruction for failed total elbow arthroplasty.

    Science.gov (United States)

    Figgie, M P; Inglis, A E; Mow, C S; Wolfe, S W; Sculco, T P; Figgie, H E

    1990-04-01

    Failure of total elbow arthroplasty leads to difficult and complicated surgical reconstruction. This study evaluates the results of reconstruction after implant removal with respect to pain, motion, and functional ability. Between 1978 and 1985, 11 patients required implant removal. Indications for removal were infection for seven, implant fracture for three, and recurrent dislocation for one. The original diagnosis was rheumatoid arthritis in six elbows and traumatic arthritis in five. The average length of the follow-up period was 5.5 years after implant removal (minimum, two years). Treatment consisted of implant removal and soft-tissue arthroplasty combined with external fixation in ten patients, and attempted arthrodesis with external fixation in one. There were four good, one fair, two poor, and four failed results. Satisfactory results were obtained in seven of the eight elbows in which an anatomic arthroplasty was achieved. This consisted of containment of the ulna by the humeral epicondylar remnants. All eight elbows were pain-free with an average arc of motion of 85 degrees (range, 55 degrees to 120 degrees). They had excellent elbow flexion power; however, triceps strength was often compromised. In the three elbows in which anatomic arthroplasty could not be achieved, one was flail, one was later converted to an arthrodesis with a customized plate, and the third required an immediate arthrodesis. All three were rated as failures. Fractures occurred in five of the 11 elbows. One occurred preoperatively, three occurred intraoperatively, and one occurred postoperatively. All healed satisfactorily during the course of immobilization. The importance of an anatomic arthroplasty when removing a total arthroplasty cannot be overemphasized. Retaining the epicondylar segments is important because satisfactory results were obtained in patients in whom entrapment of the olecranon within the epicondylar ridges was obtained. Such patients can achieve a satisfactory

  3. Artificial Economy

    Directory of Open Access Journals (Sweden)

    Alexandru JIVAN

    2011-08-01

    Full Text Available This paper proposes to eliminate, a routine in the economic thinking, claimed to be responsible for the negative essence of economic developments, from the point of view, of the ecological implications (employment in the planetary ecosystem. The methodological foundations start from the natural origins of the functionality of the human economic society according to the originary physiocrat liberalism, and from specific natural characteristics of the humankind. This paper begins with a comment-analysis of the difference between natural and artificial within the economy, and then explains some of the most serious diversions from the natural essence of economic liberalism. It shall be explained the original (heterodox interpretation of the Classical political economy (economics, by making calls to the Romanian economic thinking from aggravating past century. Highlighting the destructive impact of the economy - which, under the invoked doctrines, we call unnatural - allows an intuitive presentation of a logical extension of Marshall's market price, based on previous research. Besides the doctrinal arguments presented, the economic realities inventoried along the way (major deficiencies and effects, determined demonstrate the validity of the hypothesis of the unnatural character and therefore necessarily to be corrected, of the concept and of the mechanisms of the current economy.The results of this paper consist of original heterodox methodspresented, intuitive or developed that can be found conclusively within the key proposals for education and regulation.

  4. Reoperations Following Cervical Disc Replacement

    OpenAIRE

    Skovrlj, Branko; Lee, Dong-Ho; Caridi, John Michael; Cho, Samuel Kang-Wook

    2015-01-01

    Cervical disc replacement (CDR) has emerged as an alternative surgical option to cervical arthrodesis. With increasing numbers of patients and longer follow-ups, complications related to the device and/or aging spine are growing, leaving us with a new challenge in the management and surgical revision of CDR. The purpose of this study is to review the current literature regarding reoperations following CDR and to discuss about the approaches and solutions for the current and future potential c...

  5. Grain charging in protoplanetary discs

    OpenAIRE

    Ilgner, Martin

    2011-01-01

    Recent work identified a growth barrier for dust coagulation that originates in the electric repulsion between colliding particles. Depending on its charge state, dust material may have the potential to control key processes towards planet formation such as MHD (magnetohydrodynamic) turbulence and grain growth which are coupled in a two-way process. We quantify the grain charging at different stages of disc evolution and differentiate between two very extreme cases: compact spherical grains a...

  6. Gravitating discs around black holes

    Czech Academy of Sciences Publication Activity Database

    Karas, Vladimír; Huré, J.-M.; Semerák, O.

    2004-01-01

    Roč. 21, č. 7 (2004), R1-R5. ISSN 0264-9381 R&D Projects: GA ČR GA205/03/0902; GA AV ČR KSK1048102 Institutional research plan: CEZ:AV0Z1003909 Keywords : black holes * accretion discs * general relativity Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.941, year: 2004

  7. The dispersal of protoplanetary discs

    Directory of Open Access Journals (Sweden)

    Ercolano Barbara

    2013-04-01

    Full Text Available Protoplanetary discs are a natural consequence of the star formation process and as such are ubiquitous around low-mass stars. They are fundamental to planet formation as they hold the reservoir of material from which planets form. Their evolution and final dispersal and the timescales that regulate these process are therefore of particular interest. In this contribution I will review the observational evidence for the dispersal of discs being dominated by two timescales and for the final dispersal to occur quickly and from the inside out. I will discuss the current theoretical models, including X-ray photoevaporation, showing that the latter provides a natural explanation to the observed behaviour and review supporting and contrasting evidence. I will finally introduce a new mechanism based on the interaction between planet formation and photoevaporation that may explain a particular class of transition discs with large inner holes and high accretion rates that are problematic for photoevaporation models and planet formation models alone.

  8. Optic Disc Imaging by Heidelberg Retinal Tomogram in Congenital Optic Disc Anomaly

    OpenAIRE

    Kunjam Vallam; Sekhar G

    2004-01-01

    We evaluated two cases of congenital optic disc anomaly with the Heidelberg Retinal Tomograph (HRT) that could be mistaken for glaucomatous optic disc. One was an optic disc coloboma with a visual field defect and the other had an optic disc pit without a visual field defect. HRT was abnormal only in the eye with optic disc pit with normal fields. While HRT can be a valuable adjunct to disc evaluation and follow-up, it cannot be used in isolation in the differentiation of abnormal from normal...

  9. Proto-planetary disc evolution and dispersal

    Science.gov (United States)

    Rosotti, Giovanni Pietro

    2015-05-01

    Planets form from gas and dust discs in orbit around young stars. The timescale for planet formation is constrained by the lifetime of these discs. The properties of the formed planetary systems depend thus on the evolution and final dispersal of the discs, which is the main topic of this thesis. Observations reveal the existence of a class of discs called "transitional", which lack dust in their inner regions. They are thought to be the last stage before the complete disc dispersal, and hence they may provide the key to understanding the mechanisms behind disc evolution. X-ray photoevaporation and planet formation have been studied as possible physical mechanisms responsible for the final dispersal of discs. However up to now, these two phenomena have been studied separately, neglecting any possible feedback or interaction. In this thesis we have investigated what is the interplay between these two processes. We show that the presence of a giant planet in a photo-evaporating disc can significantly shorten its lifetime, by cutting the inner regions from the mass reservoir in the exterior of the disc. This mechanism produces transition discs that for a given mass accretion rate have larger holes than in models considering only X-ray photo-evaporation, constituting a possible route to the formation of accreting transition discs with large holes. These discs are found in observations and still constitute a puzzle for the theory. Inclusion of the phenomenon called "thermal sweeping", a violent instability that can destroy a whole disc in as little as 10 4 years, shows that the outer disc left can be very short-lived (depending on the X-ray luminosity of the star), possibly explaining why very few non accreting transition discs are observed. However the mechanism does not seem to be efficient enough to reconcile with observations. In this thesis we also show that X-ray photo-evaporation naturally explains the observed correlation between stellar masses and accretion

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

    Directory of Open Access Journals (Sweden)

    Joao Gabriel Duarte Paes Pradella

    2013-09-01

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

  11. Hip arthroplasty for failed treatment of proximal femoral fractures.

    Science.gov (United States)

    D'Arrigo, Carmelo; Perugia, Dario; Carcangiu, Alessandro; Monaco, Edoardo; Speranza, Attilio; Ferretti, Andrea

    2010-10-01

    Failed treatment of an intertrochanteric fracture typically leads to profound functional disability and pain. Salvage treatment with hip arthroplasty may be considered. The aim of this study was to evaluate the results and complications of hip arthroplasty performed as a salvage procedure after the failed treatment of an intertrochanteric hip fracture. Twenty-one patients were treated in our hospital with hip arthroplasty for failed treatment of intertrochanteric hip fracture. There were sixteen women and five men with a mean age of 75.8 years (range 61-85 years). Fourteen patients had failure of a previous nail fixation procedure, five had failure of a plate fixation, one of hip screws fixation and one of Ender nail fixation. In 19 out of 21 patients we performed a total hip arthroplasty-14 cases used modular implants with long-stems and five cases used a standard straight stem. In 2 of 21 cases we used a bipolar hemiarthroplasty. A statistically significant improvement was found comparing pre and postoperative conditions (p < 0.05). Our experience confirms that total hip arthroplasty is a satisfactory salvage procedure after failed treatment of an intertrochanteric fracture in elderly patients with few serious orthopaedic complications and acceptable clinical outcomes. PMID:19572131

  12. The Results of ulnohumeral arthroplasty in elbow osteoarthritis

    Directory of Open Access Journals (Sweden)

    M. Dehghani

    2008-01-01

    Full Text Available AbstractBackground and Purpose: Osteoarthritis (OA of elbow is not common but can be disabling, if it is not responding to non-operative methods. Several surgical methods are suggested (joint debridment, ulnohumeral arthroplasty, fusion and total elbow arthroplasty. In this study, we evaluated the result of ulnohumeral arthroplasty in seven patients.Materials and Methods: Seven patients (5 males and 2 females mean age 46 years of age (56-43, during 1378-1385 were operated on with the same approach. Via posterior incision of elbow along with creation of a hole (17mm diameter all of coronoid and olecranon osteophyte were removed.Results: Mean follow-up was 18 months (12-38 months. Patients were evaluated by radiographic, clinical examination and MEPS criteria. Six patients (85% had relief from pain, and obtained good to excellent results, with an increased range of motion at about 53.5 degree. One patient had relative relief of pain and moderate MEPS. After a year, only in one patient osteophyt formation and reduction in range of motion was observed.Conclusion: Due to a good to excellent results of (85%, increased range of motion in the elbow, relief of pain against low cost and short time of hospitalization, ulnohumeral arthroplasty is a suitable method of surgery in osteoarthritis of elbow.Key words: Elbow, Ulnohumeral arthroplasty, OsteoarthritisJ Mazand Univ Med Sci 2008; 18(64: 86-90 (Persian

  13. Fretting and Corrosion in Modular Shoulder Arthroplasty: A Retrieval Analysis

    Science.gov (United States)

    Panzram, Benjamin

    2016-01-01

    Tribocorrosion in taper junctions of retrieved anatomic shoulder arthroplasty implants was evaluated. A comparison of the tribocorrosion between cobalt-chromium and titanium alloy stems was conducted and the observations were correlated with the individual's clinical data. Adverse effects caused by metal debris and subsequent elevated serum metal ion levels are frequently reported in total hip arthroplasty. In total shoulder arthroplasty, to date only a small number of retrieval analyses are available and even fewer address the issue of tribocorrosion at the taper junctions. A total of 36 retrieved hemiarthroplasties and total shoulder arthroplasties were assessed using the modified Goldberg score. The prevalence of fretting and corrosion was confirmed in this cohort. Titanium stems seem to be more susceptible to damage caused by tribocorrosion than cobalt-chromium stems. Furthermore, stemless designs offered less tribocorrosion at the taper junction than stemmed designs. A weak correlation between time to revision and increased levels of tribocorrosion was seen. Whether or not tribocorrosion can lead to adverse clinical reactions and causes failure of shoulder arthroplasties remains to be examined. PMID:27433471

  14. Do We Need Biomarkers for Disc Degeneration?

    Directory of Open Access Journals (Sweden)

    Helen E. Gruber

    2006-01-01

    Full Text Available Disc degeneration plays a major role in this country's medical, social and economic structure. The life-time prevalence of low back pain, which has disc degeneration as its cause, is about 80% in the general population. It is a primary cause of disability and estimated costs related to low back disorders exceed $100 billion per year in the U.S. alone. Biomarkers are becoming increasingly important as indicators of the presence of disease, and in evaluating outcomes during clinical treatment. Cell-based biologic therapies which are currently being developed to treat disc degeneration are going to be most efficacious when applied to the early stages of disc disease. In this article we ask: 1 Whether there are existing biomarkers which could play a role in detecting early stages of disc degeneration, and 2 Highlight exciting potentials in future biomarker screening for disc degeneration.

  15. Large head metal-on-metal cementless total hip arthroplasty versus 28mm metal-on-polyethylene cementless total hip arthroplasty: design of a randomized controlled trial

    OpenAIRE

    van Raaij Jos JAM; Bos Nanne; Zijlstra Wierd P

    2008-01-01

    Abstract Background Osteoarthritis of the hip is successfully treated by total hip arthroplasty with metal-on-polyethylene articulation. Polyethylene wear debris can however lead to osteolysis, aseptic loosening and failure of the implant. Large head metal-on-metal total hip arthroplasty may overcome polyethylene wear induced prosthetic failure, but can increase systemic cobalt and chromium ion concentrations. The objective of this study is to compare two cementless total hip arthroplasties: ...

  16. Stability and Evolution of Galactic Discs

    OpenAIRE

    Sellwood, J. A.

    1999-01-01

    In this review, I discuss just three aspects of the stability and evolution of galactic discs. (1) I first review our understanding of the bar instability and how it can be controlled. Disc galaxies in which the orbital speed does not decrease much towards the centre have no difficulty avoiding bars, even when dark matter makes an insignificant contribution to the inner part of the rotation curve. (2) I then briefly discuss interactions between disturbances in the discs of galaxies and the sp...

  17. CFD design analysis of ventilated disc brakes

    OpenAIRE

    Pulugundla, Gautam

    2008-01-01

    This thesis reports the numerical investigation of the automotive ventilated disc brake rotor. Disc brakes operate on the principle of friction by converting kinetic energy into heat energy. The main objective of a disc brake rotor is to store this heat energy and dissipate it as soon as possible. This work is carried out in a area where there is very limited understanding. Commercial CFD code FLUENT was used for carrying out the simulations with the rotor rotating in still ...

  18. Black hole feedback from thick accretion discs

    OpenAIRE

    Sadowski, Aleksander; Lasota, Jean-Pierre; Abramowicz, Marek A.; Narayan, Ramesh

    2015-01-01

    We study energy flows in geometrically thick accretion discs, both optically thick and thin, using general relativistic, three-dimensional simulations of black hole accretion flows. We find that for non-rotating black holes the efficiency of the total feedback from thick accretion discs is $3\\%$ - roughly half of the thin disc efficiency. This amount of energy is ultimately distributed between outflow and radiation, the latter scaling weakly with the accretion rate for super-critical accretio...

  19. Self-similar relativistic discs with pressure

    International Nuclear Information System (INIS)

    Solutions for discs in equilibrium specified by a constant velocity of rotation and constant velocity dispersions are found. The fluid is not perfect because the stress tensor is anisotropic. These discs are self-similar if they are of infinite extent. The solutions are exact when an equal number of particles move in each sense of rotation so that there is no dragging of the inertial frames. For discs rotating with the small velocity a WKB approximation is used to obtain solutions. (author)

  20. DSC Study of Collagen in Disc Disease

    OpenAIRE

    S. Skrzyński; Sionkowska, A.; A. Marciniak

    2010-01-01

    Differential scanning calorimetry (DSC) has been used to estimate the effect of disc disease on the collagen helix-coil transition and morphology for tissue extracted from patients during surgical operation. Forty discs were obtained from patients with degenerative disc disease undergoing surgery for low back pain. The patients were in the age between 20 and 70 years old. The specimens were kept wet during DSC experiment. The data allow the comparison between thermal stability of collagen ti...

  1. Physiological pattern of lumbar disc height

    International Nuclear Information System (INIS)

    Purpose of this study is to present a new method of quantifying objectively the height of all discs in lateral radiographs of the lumbar spine and of analysing the normal craniocaudal sequence pattern of lumbar disc heights. Methods: The new parameter is the ventrally measured disc height corrected for the dependence on the angle of lordosis by normalisation to mean angles observed in the erect posture of healthy persons. To eliminate radiographic magnification, the corrected ventral height is related to the mean depth of the cranially adjoining vertebra. In this manner lumbar disc heights were objectively measured in young, mature and healthy persons (146 males and 65 females). The craniocaudal sequence pattern was analysed by mean values from all persons and by height differences of adjoining discs in each individual lumbar spine. Results: Mean normative values demonstrated an increase in disc height between L1/L2 and L4/L5 and a constant or decreasing disc height between L4/L5 and L5/S1. However, this 'physiological sequence of disc height in the statistical mean' was observed in only 36% of normal males and 55% of normal females. Conclusion: The radiological pattern of the 'physiological sequence of lumbar disc height' leads to a relevant portion of false positive pathological results especially at L4/L5. An increase of disc height from L4/L5 to L5/S1 may be normal. The recognition of decreased disc height should be based on an abrupt change in the heights of adjoining discs and not on a deviation from a craniocaudal sequence pattern. (orig.)

  2. Propeller outflows from an MRI disc

    OpenAIRE

    Lii, Patrick S.; Romanova, Marina M.; Ustyugova, Galina V.; Koldoba, Alexander V.; Lovelace, Richard V. E.

    2013-01-01

    We present the results of axisymmetric simulations of MRI-driven accretion onto a rapidly rotating, magnetized star accreting in the propeller regime. The stellar magnetosphere corotates with the star, forming a centrifugal barrier at the disc-magnetosphere boundary which inhibits matter accretion onto the star. Instead, the disc matter accumulates at the disc-magnetosphere interface and slowly diffuses into the inner magnetosphere where it picks up angular momentum and is quickly ejected fro...

  3. Debris disc formation induced by planetary growth

    OpenAIRE

    Kobayashi, Hiroshi; Loehne, Torsten

    2014-01-01

    Several hundred stars older than 10 million years have been observed to have infrared excesses. These observations are explained by dust grains formed by the collisional fragmentation of hidden planetesimals. Such dusty planetesimal discs are known as debris discs. In a dynamically cold planetesimal disc, collisional coagulation of planetesimals produces planetary embryos which then stir the surrounding leftover planetesimals. Thus, the collisional fragmentation of planetesimals that results ...

  4. Computed tomography in the diagnosis of the lumbar disc herniation

    Energy Technology Data Exchange (ETDEWEB)

    Iwakura, Yuichiro (Yatsushiro General Hospital, Kumamoto (Japan)); Hayashi, Yasuo; Suzuki, Mutsuaki; Uemura, Mitsuharu; Fukuda, Kazuyuki; Koito, Hirofumi

    1984-06-01

    In this study, effectiveness of computed tomography (CT) in diagnosing lumbar disc herniation was evaluated. Twenty CT examinations which were interpreted as positive for a herniated disc, and were comfirmed by myelography, were reviewed. In 19 patients, CT demonstrated posterior protrusion of the disc but in one normal disc. Three typical cases were described. This study suggests that CT accurately demonstrates lumbar disc herniation.

  5. Long-term outcome after implantation of prosthetic disc nucleus device (PDN) in lumbar disc disease

    OpenAIRE

    Selviaridis, P; Foroglou, N; Tsitlakidis, A; Hatzisotiriou, A; Magras, I; Patsalas, I

    2010-01-01

    Background: The prosthetic disc nucleus (PDN) device offers an adjunct treatment for patients with degenerative disc disease and herniation, who necessitate surgical intervention, avoiding total-disc replacement or fusion. This prospective, clinical study aimed to gauge the long-term effectiveness of microdiscectomy followed by PDN implantation in relieving pain and improving functional status in patients with symptomatic degenerative lumbar disc disease and herniation.

  6. The quiescent phase of galactic disc growth

    Science.gov (United States)

    Aumer, Michael; Binney, James; Schönrich, Ralph

    2016-07-01

    We perform a series of controlled N-body simulations of growing disc galaxies within non-growing, live dark matter haloes of varying mass and concentration. Our initial conditions include either a low-mass disc or a compact bulge. New stellar particles are continuously added on near-circular orbits to the existing disc, so spiral structure is continuously excited. To study the effect of combined spiral and giant molecular cloud (GMC) heating on the discs, we introduce massive, short-lived particles that sample a GMC mass function. An isothermal gas component is introduced for a subset of the models. We perform a resolution study and vary parameters governing the GMC population, the histories of star formation and radial scale growth. Models with GMCs and standard values for the disc mass and halo density provide the right level of self-gravity to explain the age-velocity dispersion relation of the solar neighbourhood (Snhd). GMC heating generates remarkably exponential vertical profiles with scaleheights that are radially constant and agree with observations of galactic thin discs. GMCs are also capable of significantly delaying bar formation. The amount of spiral-induced radial migration agrees with what is required for the metallicity distribution of the Snhd. However, in our standard models, the outward-migrating populations are not hot enough vertically to create thick discs. Thick discs can form in models with high baryon fractions, but the corresponding bars are too long, the young stellar populations too hot and the discs flare considerably.

  7. The quiescent phase of galactic disc growth

    Science.gov (United States)

    Aumer, Michael; Binney, James; Schönrich, Ralph

    2016-04-01

    We perform a series of controlled N-body simulations of growing disc galaxies within non-growing, live dark matter haloes of varying mass and concentration. Our initial conditions include either a low-mass disc or a compact bulge. New stellar particles are continuously added on near-circular orbits to the existing disc, so spiral structure is continuously excited. To study the effect of combined spiral and giant molecular cloud (GMC) heating on the discs we introduce massive, short-lived particles that sample a GMC mass function. An isothermal gas component is introduced for a subset of the models. We perform a resolution study and vary parameters governing the GMC population, the histories of star formation and radial scale growth. Models with GMCs and standard values for the disc mass and halo density provide the right level of self-gravity to explain the age velocity dispersion relation of the Solar neighbourhood (Snhd). GMC heating generates remarkably exponential vertical profiles with scaleheights that are radially constant and agree with observations of galactic thin discs. GMCs are also capable of significantly delaying bar formation. The amount of spiral induced radial migration agrees with what is required for the metallicity distribution of the Snhd. However, in our standard models the outward migrating populations are not hot enough vertically to create thick discs. Thick discs can form in models with high baryon fractions, but the corresponding bars are too long, the young stellar populations too hot and the discs flare considerably.

  8. Computed tomography in lumbar herniated disc

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Chul Soon; Chang, Kee Hyun; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1984-09-15

    197 spine CTs were performed from 29th , March 1982 to 7th March, 1984. Among them, 39 patients preoperatively diagnosed as herniated nucleus pulposus or bulging disc with CT and myelography were operated. 43 disc spaces of disc disease are analysed in true positive and false negative cases. Finally the accuracy, sensitivity and specificity of spine CT and myelography are calculated. The results are as follows: 1. The CT findings of disc diseases are in order of frequency, asymmetrical obliteration of epidural fat (82%) , ventral indentation or compression on dural sac (72%), focal protrusion of disc (64%), root changes - obliteration, displacement, compression, non-filling of metrizamide - (54%), diffuse disc bulging (36%), disc at body level (31%), disc calcifications (26%), disc vacuum (10%) and other associated findings - spinal stenosis, foraminal stenosis, ligament flavum thickening, facet joint hypertrophy (26%). 2. Sensitivities of spine CT and myelography are 95% and 94%, specificities are 67%, 50% and overall accuracies 93%, 87%, respectively. 3. Therefore, it is recommended that the spine CT be used as a primary diagnostic method and the myelography as a secondary complementary study when the CT gives no conclusive findings.

  9. Accretion Discs Show Their True Colours

    Science.gov (United States)

    2008-07-01

    Quasars are the brilliant cores of remote galaxies, at the hearts of which lie supermassive black holes that can generate enough power to outshine the Sun a trillion times. These mighty power sources are fuelled by interstellar gas, thought to be sucked into the hole from a surrounding 'accretion disc'. A paper in this week's issue of the journal Nature, partly based on observations collected with ESO's Very Large Telescope, verifies a long-standing prediction about the intensely luminous radiation emitted by these accretion discs. Uncovering the disc ESO PR Photo 21/08 Uncovering the inner disc "Astronomers were puzzled by the fact that the best models of these discs couldn't quite be reconciled with some of the observations, in particular, with the fact that these discs did not appear as blue as they should be," explains lead-author Makoto Kishimoto. Such a discrepancy could be the signal that there was something very wrong with the models. With his colleagues, he investigated this discrepancy by studying the polarised light from six quasars. This enabled them to demonstrate that the disc spectrum is as blue as predicted. "The crucial observational difficulty here has been that the disc is surrounded by a much larger torus containing hot dust, whose light partly outshines that of the disc," says Kishimoto. "Because the light coming from the disc is scattered in the disc vicinity and thus polarised, by observing only polarised light from the quasars, one can uncover the buried light from the disc." In a similar way that a fisherman would wear polarised sunglasses to help get rid of the glare from the water surface and allow him to see more clearly under the water, the filter on the telescope allowed the astronomers to see beyond surrounding clouds of dust and gas to the blue colour of the disc in infrared light. The observations were done with the FORS and ISAAC instruments on one of the 8.2-m Unit Telescopes of ESO's Very Large Telescope, located in the Atacama

  10. Association between trochanteric bursitis, osteoarthrosis and total hip arthroplasty,

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Schwartsmann

    2014-06-01

    Full Text Available OBJECTIVE: this was an epidemiological study on trochanteric bursitis at the time of performing total hip arthroplasty.METHODS: sixty-two sequential patients who underwent total hip arthroplasty due to osteoarthrosis, without any previous history of trochanteric bursitis, were evaluated. The bursas were collected and evaluated histologically.RESULTS: there were 35 female patients (56.5% and 27 male patients (43.5%, with a mean age of 65 years (±11. Trochanteric bursitis was conformed histologically in nine patients (14.5%, of whom six were female (66.7% and three were male (33.3%.CONCLUSIONS: 14.5% of the bursas analyzed presented inflammation at the time that the primary total hip arthroplasty due to osteoarthrosis was performed, and the majority of the cases of bursitis were detected in female patients.

  11. TMJ ANKYLOSIS: MANAGEMENT WITH RECONSTRUCTION AND INTERPOSITIONAL ARTHROPLASTY.

    Science.gov (United States)

    Madhumati, Singh; Shruthi, R; Mitul, Sojitra; Karan, Abhishek; Aziz, Abdul

    2015-01-01

    Temporomandibular joint (TMJ) ankylosis is a very desolating structural condition that involves fusion of the mandibular condyle to the base of the skull. It causes difficulty in mastication and breathing. Trauma and Infections are usually responsible. If trauma occurs in young age, it leads to disturbance in growth & facial asymmetry. Treatment of temporomandibular joint (TMJ) ankylosis usually requires adequate excision of the involved ankylotic block (arthroplasty) or interpositional arthroplasty using autogenous or alloplastic materials. Early mobilization, physiotherapy & strict follow up are essential to prevent postop adhesions. In our cases fascia lata was used as an interpositional grafting material. One case was treated by gap arthroplasty, second case by costochondral graft & third case was managed with titanium condylar prosthesis. PMID:27487617

  12. The association between metal allergy, total knee arthroplasty, and revision

    DEFF Research Database (Denmark)

    Münch, Henrik J; Jakobsen, Stig Storgaard; Olesen, Jens T; Menné, Torkil; Søballe, Kjeld; Johansen, Jeanne D; Thyssen, Jacob P

    2015-01-01

    Background and purpose - It is unclear whether delayed-type hypersensitivity reactions against implanted metals play a role in the etiopathogenesis of malfunctioning total knee arthroplasties. We therefore evaluated the association between metal allergy, defined as a positive patch test reaction to...... common metal allergens, and revision surgery in patients who underwent knee arthroplasty. Patients and methods - The nationwide Danish Knee Arthroplasty Register, including all knee-implanted patients and revisions in Denmark after 1997 (n = 46,407), was crosslinked with a contact allergy patch test...... database from the greater Copenhagen area (n = 27,020). Results - 327 patients were registered in both databases. The prevalence of contact allergy to nickel, chromium, and cobalt was comparable in patients with and without revision surgery. However, in patients with 2 or more episodes of revision surgery...

  13. Shoulder arthroplasty. Part 1: Prosthesis terminology and classification

    Energy Technology Data Exchange (ETDEWEB)

    Sheridan, B.D., E-mail: bdsheridan@hotmail.com [Department of Orthopaedic Surgery, Bristol Royal Infirmary, Bristol (United Kingdom); Ahearn, N.; Tasker, A.; Wakeley, C.; Sarangi, P. [Department of Orthopaedic Surgery, Bristol Royal Infirmary, Bristol (United Kingdom)

    2012-07-15

    Shoulder arthroplasty is the third most common joint replacement procedure in the UK, and there are a number of different implant options available to surgeons to treat a variety of shoulder disorders. With an increasing burden placed on clinical follow-up, more patients are remaining under the care of their general practitioners and musculoskeletal triage assessment services and are not necessarily being seen by specialists. Referrals to orthopaedic specialists are therefore often prompted by radiological reports describing evidence of implant failure. This article is the first of two reviews on shoulder arthroplasty, concentrating on implant features and the indications for their use. The second article will address the modes of failure of shoulder arthroplasty and describe the relevant associated radiological features.

  14. Shoulder arthroplasty. Part 1: Prosthesis terminology and classification

    International Nuclear Information System (INIS)

    Shoulder arthroplasty is the third most common joint replacement procedure in the UK, and there are a number of different implant options available to surgeons to treat a variety of shoulder disorders. With an increasing burden placed on clinical follow-up, more patients are remaining under the care of their general practitioners and musculoskeletal triage assessment services and are not necessarily being seen by specialists. Referrals to orthopaedic specialists are therefore often prompted by radiological reports describing evidence of implant failure. This article is the first of two reviews on shoulder arthroplasty, concentrating on implant features and the indications for their use. The second article will address the modes of failure of shoulder arthroplasty and describe the relevant associated radiological features.

  15. Computer-Navigated Total Knee Arthroplasty Utilization.

    Science.gov (United States)

    Bala, Abiram; Penrose, Colin Thomas; Seyler, Thorsten Markus; Mather, Richard Chad; Wellman, Samuel Secord; Bolognesi, Michael Paul

    2016-07-01

    Computer-navigated total knee arthroplasty (CN-TKA) has been used to improve component alignment, though the evidence is currently mixed on whether there are clinically significant differences in long-term outcomes. Given the established increased costs and operative time, we hypothesized that the utilization rate of CN-TKA would be decreasing relative to standard TKA in the Medicare population given the current health care economic environment. We queried 1,914,514 primary TKAs performed in the entire Medicare database from 2005 to 2012. Current Procedural Terminology (CPT) and International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes were used to identify and separate CN-TKAs. Utilization of TKA was compared by year, gender, and region. Average change in cases per year and compound annual growth rate (CAGR) were used to evaluate trends in utilization of the procedure. We identified 30,773 CN-TKAs performed over this time period. There was an increase in utilization of CN-TKA per year from 984 to 5,352 (average = 572/year, R (2) = 0.85, CAGR = 23.58%) from 2005 to 2012. In contrast, there was a slight decrease in overall TKA utilization from 264,345 to 230,654 (average = 4297/year, R (2) = 0.74, CAGR = - 1.69%). When comparing proportion of CN-TKA to all TKAs, there was an increase from 0.37 to 2.32% (average 0.26%/year, R (2) = 0.88, CAGR = 25.70%). CN-TKA growth in males and females was comparable at 24.42 and 23.11%, respectively. The South region had the highest growth rate at 28.76%, whereas the Midwest had the lowest growth rate at 15.51%. The Midwest was the only region that peaked (2008) with a slow decline in utilization until 2012. Despite increased costs with unclear clinical benefit, CN-TKA is increasing in utilization among Medicare patients. Reasons could include patient preference, advertising, proper of coding the procedure, and increased publicly available information about

  16. Follow-up Study on the Motion Range after Treatment of Degenerative Disc Disease with the Bryan Cervical Disc Prosthesis

    Institute of Scientific and Technical Information of China (English)

    YANG Shuhua; HU Yong; ZHAO Jijun; HE Xianfeng; LIU Yong; XU Weihua; DU Jingyuan; FU Dehao

    2007-01-01

    This study examined effect of a new intervertebral cervical disc prosthesis in relieving the neurological symptoms and signs, improving the patients' ability to perform daily activities, reducing pain, and maintaining the stability and segmental motion. From December 2003 to October 2004, 12 patients, who had received 14 replacements of cervical artificial discs, were followed-up for 2 to 8 months (with a mean of 5.2 months). Of them 5 had cervical spondylotic myelopathy and 7 had cervical disc herniation. The patients included 7 males and 5 females, with their age ranging from 35 to 62 y and a mean of 50.3 y. Single-level replacements were performed in 10 cases and 2 cases received two-level replacement. Operation time of the single-level surgery averaged 130±50 min and the time of two-level surgery was 165±53 min on average (from skin incision to skin suturing).Neurological or vascular complications during or after surgery was not observed. Japanese Orthopedic Association scores (JOA scores) increased from 8.6 to 15.8 on average. There was no prothesis subsidence or excursion. Replaced segments were stable and the range of motion was partially restored, being 4.68° (3.6°-6.1°) in flexion and extension position and 3.51° (2.5°-4.6°) 3.42° (2.6°-4.3°) in left and right bending position. No obvious loss of physiological curvature was noted. CT or MRI follow-up showed that excursion was less than 1.5 mm) in 2 of 14 levels and between 1.5 mm and 3 mm) in 1 of 14 levels. No ossification in the replaced levels was observed. It is concluded that satisfactory short-term results were achieved in the 12 cases of artificial disc replacements. Different from anterior cervical discectomy and fusion, the replacement could achieve quick functional recovery and did not lead to the movement limitation of cervical vertebrae. At least a 5-years follow-up was needed to assess the long-term effect of the prosthesis on its neighboring segments.

  17. Evolution of linear warps in accretion discs and applications to protoplanetary discs in binaries

    CERN Document Server

    Foucart, Francois

    2014-01-01

    The existence of warped accretion discs is expected in a wide variety of astrophysical systems, including circumstellar discs in binaries and discs around binary protostars. A common feature of these discs is that they are perturbed by a misaligned external potential. In this paper, we study the long-term evolution of the disc warp and precession in the case of thick discs (with the dimensionless thickness $H/r$ larger than the viscosity parameter $\\alpha$) in which bending waves can propagate. For small warps, such discs undergo approximately rigid-body precession with a coherent global frequency. We derive the analytical expressions for the warp/twist profiles of the disc and the alignment timescale for a variety of disc models/parameters. Applying our results to circumbinary discs, we find that these discs align with the orbital plane of the binary on a timescale comparable to the global precession time of the disc, and typically much smaller than its viscous timescale. The development of parametric instab...

  18. Shoulder arthroplasty. Part 2: Normal and abnormal radiographic findings

    International Nuclear Information System (INIS)

    Frequently, the decision made by general practitioners or musculoskeletal triage assessment services to refer patients for specialist review is initiated by a radiological report. Following shoulder arthroplasty it is important to ensure that any patient with asymptomatic evidence of a failing prosthesis is referred for review so that revision surgery can be contemplated and planned before the situation becomes unsalvageable. The first paper in this series described the various types of shoulder arthroplasty and indications for each. This follow-up paper will concentrate on their modes of failure and the associated radiographic features, and is aimed at radiology trainees and non-musculoskeletal specialist radiologists.

  19. The triceps preserving approach to total elbow arthroplasty.

    Science.gov (United States)

    Pierce, T D; Herndon, J H

    1998-09-01

    Elbow arthroplasty most commonly is performed through a posterior approach by detaching or reflecting the triceps off the olecranon. Surgical approaches to the elbow joint that dissociate the triceps from the olecranon have distinct disadvantages. Triceps avulsion, triceps weakness, and wound healing problems have been reported. Such complications necessitate more surgery and predispose the joint to an infection. To avoid these complications a modified posterior approach to the elbow joint that preserves the triceps muscle insertion on the olecranon was used in 10 consecutive elbow arthroplasties. This method provides adequate exposure, allows early rehabilitation, and avoids triceps weakness. PMID:9755773

  20. Mid-Term Results of Oxford Medial Unicompartmental Knee Arthroplasty

    OpenAIRE

    Choy, Won-Sik; Kim, Kap Jung; Lee, Sang Ki; Yang, Dae Suk; Lee, Neung Ki

    2011-01-01

    Background This study examined the clinical and radiologic mid-term results of patients treated by Oxford minimally invasive unicompartmental knee arthroplasty. Methods One hundred and eighty-eight knees of unicompartmental knee arthroplasties with Oxford Uni® in 166 patients (16 males and 150 females), which were performed between 2002 and 2005, were reviewed. The mean age was 65.3 years (range, 44 to 82 years) and the mean follow-up period was 79.8 months (range, 56 to 103 months). The preo...

  1. Reverse shoulder arthroplasty: radiological and clinical short–term results

    OpenAIRE

    Atalar, Ata Can; Salduz, Ahmet; Cil, Hilal; Sungur, Mustafa; Celik, Derya; Demirhan, Mehmet

    2014-01-01

    Objective: The aim of this study was to examine the radiological and clinical short term results of the patients who underwent reverse shoulder arthroplasty for rotator cuff arthropathy. Methods: The study included 14 (2 male, 12 female) patients who underwent reverse shoulder arthroplasty for rotator cuff arthropathy between 2009 and 2010. The mean age of the patients was 74 (57–80) years and the mean follow–up period was 32 (21–40) months. Radiological methods as well as the range of mot...

  2. Shoulder arthroplasty. Part 2: Normal and abnormal radiographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Sheridan, B.D., E-mail: bdsheridan@hotmail.com [Department of Orthopaedic Surgery, Bristol Royal Infirmary, Bristol (United Kingdom); Ahearn, N.; Tasker, A.; Wakeley, C.; Sarangi, P. [Department of Orthopaedic Surgery, Bristol Royal Infirmary, Bristol (United Kingdom)

    2012-07-15

    Frequently, the decision made by general practitioners or musculoskeletal triage assessment services to refer patients for specialist review is initiated by a radiological report. Following shoulder arthroplasty it is important to ensure that any patient with asymptomatic evidence of a failing prosthesis is referred for review so that revision surgery can be contemplated and planned before the situation becomes unsalvageable. The first paper in this series described the various types of shoulder arthroplasty and indications for each. This follow-up paper will concentrate on their modes of failure and the associated radiographic features, and is aimed at radiology trainees and non-musculoskeletal specialist radiologists.

  3. Wear particles and osteolysis in patients with total wrist arthroplasty

    DEFF Research Database (Denmark)

    Boeckstyns, Michel E H; Toxværd, Anders; Bansal, Manjula; Vadstrup, Lars Soelberg

    2014-01-01

    tissue, the level of chrome and cobalt ions in the blood, and the possible role of infectious or rheumatoid activity in the development of PPO. METHODS: Biopsies were taken from the implant-bone interphase in 13 consecutive patients with total wrist arthroplasty and with at least 3 years' follow...... of the radiolucent zone. The blood levels of chrome and cobalt ions were normal. There was no evidence of infectious or rheumatoid activity. CONCLUSIONS: Polyethylene wear has been accepted as a major cause of osteolysis in total hip arthroplasty, and metallic debris has also been cited to be an...

  4. The constraints on day-case total knee arthroplasty

    DEFF Research Database (Denmark)

    Thienpont, E; Lavand'homme, P; Kehlet, H

    2015-01-01

    Total knee arthroplasty (TKA) is a major orthopaedic intervention. The length of a patient's stay has been progressively reduced with the introduction of enhanced recovery protocols: day-case surgery has become the ultimate challenge. This narrative review shows the potential limitations of day...... in a limited group of patients. The younger, male patient without comorbidities and with an excellent social network around him might be a candidate. Demographic changes, effective recovery programmes and less invasive surgical techniques such as unicondylar knee arthroplasty, may increase the size...

  5. Pharmacological mydriasis and optic disc examination

    Science.gov (United States)

    Kirwan, J.; Gouws, P.; Linnell, A.; Crowston, J.; Bunce, C.

    2000-01-01

    AIM—To determine whether pharmacological mydriasis leads to a significant difference in interobserver agreement of optic disc measurement compared with examination without mydriasis.
METHOD—A cross sectional study was performed with a pair of observers examining the optic disc of two randomised groups of patients, one group before diagnostic mydriasis, and the other afterwards. Horizontal and vertical disc diameters and cup/disc ratios were measured with a 78 dioptre lens. The study was repeated with another observer pair and two further groups of patients.
RESULTS—In study A 86 subjects were examined in total (52 without and 34 with mydriasis). In study B 87 subjects were examined (45 without and 42 with mydriasis). The 95% limits of agreement of the cup/disc ratio measurement differences were significantly larger without mydriasis (p<0.001 for all studies (F test)). For both studies examination after mydriasis gave significantly greater agreement for vertical and horizontal cup/disc ratios. The cases with good agreement (0.1 difference or better) for vertical cup/disc ratios were 37/52 (72%) and 34 /45 (76%) without mydriasis and 33/34 (97%) and 40/42 (95%) respectively with mydriasis. Similar differences were recorded for horizontal cup/disc ratios. Disc diameter measurement results showed similar differences in study A but were not affected by mydriasis in study B.
CONCLUSIONS—Examination of the optic disc without pharmacological mydriasis gives significantly poorer interobserver agreement. In this study, the mean 95% limits of agreement values for all cup/disc ratio values were 0.27 for examination without mydriasis and 0.13 for examination with mydriasis. A measure outside these limits would suggest a real difference. This study indicates that mydriasis is important for reproducible clinical examination in glaucoma.

 PMID:10906099

  6. Emerging technologies in arthroplasty: additive manufacturing.

    Science.gov (United States)

    Banerjee, Samik; Kulesha, Gene; Kester, Mark; Mont, Michael A

    2014-06-01

    Additive manufacturing is an industrial technology whereby three-dimensional visual computer models are fabricated into physical components by selectively curing, depositing, or consolidating various materials in consecutive layers. Although initially developed for production of simulated models, the technology has undergone vast improvements and is currently increasingly being used for the production of end-use components in various aerospace, automotive, and biomedical specialties. The ability of this technology to be used for the manufacture of solid-mesh-foam monolithic and coated components of complex geometries previously considered unmanufacturable has attracted the attention of implant manufacturers, bioengineers, and orthopedic surgeons. Currently, there is a paucity of reports describing this fabrication method in the orthopedic literature. Therefore, we aimed to briefly describe this technology, some of the applications in other orthopedic subspecialties, its present use in hip and knee arthroplasty, and concerns with the present form of the technology. As there are few reports of clinical trials presently available, the true benefits of this technology can only be realized when studies evaluating the clinical and radiographic outcomes of cementless implants manufactured with additive manufacturing report durable fixation, less stress shielding, and better implant survivorship. Nevertheless, the authors believe that this technology holds great promise and may potentially change the conventional methods of casting, machining, and tooling for implant manufacturing in the future. PMID:24764230

  7. DKG statement on the use of metal alloy discs for patch testing in suspected intolerance to metal implants.

    Science.gov (United States)

    Thomas, Peter; Geier, Johannes; Dickel, Heinrich; Diepgen, Thomas; Hillen, Uwe; Kreft, Burkhard; Schnuch, Axel; Szliska, Christiane; Mahler, Vera

    2015-10-01

    Intolerance reactions to metal implants may be caused by metal allergy. However, prior to implantation, 'prophetic'/prophylactic patch testing should not be performed. Pre-implant patch testing should only be done to verify or exclude metal allergy in patients with a corresponding history. In case of implant-related complications - in particular following replacement arthroplasty - such as pain, effusion, skin lesions, reduced range of motion or implant loosening, orthopedic causes should be ruled out first. Workup of suspected metal implant allergy should then be done using the DKG standard series, which includes nickel, cobalt, and chromium preparations. Various studies assessing the usefulness of metal alloy discs for patch testing have shown this particular approach to be ineffective with respect to providing reliable information on metal allergy. Any positive reaction in such tests cannot be assigned to a specific metal contained within the alloy. Furthermore, there is a risk of broad and indiscriminate use of these readily available discs. Accordingly, given the lack of additional benefit compared to patch testing with standardized metal salt preparations, we do not recommend patch testing with metal alloy discs. PMID:26408461

  8. Unusual disc herniation in a dog: a case history report

    International Nuclear Information System (INIS)

    Unusual disc herniation was identified in a dog. Disc herniation was considered unusual because of its displacement into the vertebral endplate of the adjoining vertebra. Unusual disc herniation in this dog was compared with Schmorl's node in humans

  9. Methodology for optic disc localization

    Directory of Open Access Journals (Sweden)

    Marcos A. Leiva-Vasconcellos

    2014-04-01

    Full Text Available The use of digital images in many areas of society is an activity that has reached a remarkable growth in recent years mainly due to the great development that has occurred in technology around the world. These images have a great use in many branches of medicine because they facilitate the diagnosis by specialists and thus help patients to be diagnosed long before symptoms of the disease begin to manifest. For Ophthalmology, one of the most used images are the digital retinography, If it is used properly will allow the occurrence of eye diseases such as glaucoma and diabetic retinopathy. One of the main elements shown on retinal images are the optic disc, the location and detection is of vital importance for working with different parts of the structure o f the eye. This paper proposes two techniques for locating the optic disc in retinal images based on the combination of multiple filters and applying logical operators. To test the algorithms diaretDB0v11 and DRIVE database were used , as a result of the tests are correctly located the 99.091 % of the images from both repo sitories, and were successfully detected 85 % and 87.143 % of images of DRIVE database and diaretDB0v11 respectively.

  10. Changes in disc herniation after CT-guided Percutaneous Laser Disc Decompression (PLDD): MR findings

    Science.gov (United States)

    Brat, Hugues G.; Bouziane, Tarik; Lambert, Jean; Divano, Luisa

    2004-09-01

    The aim of Percutaneous Laser Disc Decompression (PLDD) is to vaporize a small portion of the nucleus pulposus. Clinical efficacy of this technique is largely proven. However, time-evolution of intervertebral disc and its hernia after PLDD is not known. This study analyses changes in disc herniation and its native intervertebral disc at a mean follow-up of 7.5 months after PLDD in asymptomatic patients. Main observations at MRI are appearance of a high signal on T2WI in the hernia in 59%, shrinking of the hernia in 66% and overall stability of disc height.

  11. Perioperative safety of two-team simultaneous bilateral total knee arthroplasty in the obese patient

    Directory of Open Access Journals (Sweden)

    Gaines Steven T

    2010-06-01

    Full Text Available Abstract Background Although the rates of perioperative morbidity and mortality with simultaneous bilateral total knee arthroplasty remain a concern, multiple studies have shown the procedure to be safe in selected patient populations. Evidence also remains mixed regarding the outcomes of total knee arthroplasty in obese patients. The purpose of this paper is to compare the rates of perioperative morbidity and mortality in consecutive obese patients undergoing two-team simultaneous bilateral total knee arthroplasty and unilateral total knee arthroplasty. Methods The records on all two-team simultaneous total knee arthroplasties and unilateral total knee arthroplasties from October 1997 to December 2007 were reviewed. A total of 151 patients with a body mass index (BMI >30 undergoing two-team simultaneous total knee arthroplasty and 148 patients with a BMI >30 undergoing unilateral total knee arthroplasty were retrospectively reviewed and analyzed to determine perioperative morbidity and mortality as well as one-year mortality rates. Results Preoperative patient characteristics did not show any significant differences between groups. The simultaneous bilateral group had significantly longer operative times (127.4 versus 112.7 minutes, p Conclusions Two-team simultaneous total knee arthroplasty appears to be safe in obese patients, with similar complication rates as compared to unilateral procedures. Two-team simultaneous total knee arthroplasty also appears to have potential benefits over a staged procedure in the obese patient, although more study is required regarding this topic.

  12. Thin, thick and dark discs in LCDM

    CERN Document Server

    Read, J I; Agertz, O; Debattista, Victor P

    2008-01-01

    In a LCDM cosmology, the Milky Way accretes satellites into the stellar disc. We use cosmological simulations to assess the frequency of near disc plane and higher inclination accretion events, and collisionless simulations of satellite mergers to quantify the final state of the accreted material and the effect on the thin disc. On average, a Milky Way-sized galaxy has 1.5 subhalos with vmax>80km/s; 5 with vmax>60km/s; and 13 with vmax>40km/s merge at redshift z>1. A third of these merge at an impact angle 20 degrees) are twice as likely as low inclination ones. These lead to structures that closely resemble the recently discovered inner/outer stellar halos. They also do more damage to the Milky Way stellar disc creating a more pronounced flare, and warp; both long-lived and consistent with current observations. The most massive mergers (vmax > 80km/s) heat t he thin disc enough to produce a thick disc. These heated thin disc stars are essential for obtaining a thick disc as massive as that seen in the Milky ...

  13. Modeling quasar accretion disc temperature profiles

    CERN Document Server

    Hall, Patrick B; Chajet, L S; Weiss, E; Nixon, C J

    2013-01-01

    Microlensing observations indicate that quasar accretion discs have half-light radii larger than expected from standard theoretical predictions based on quasar fluxes or black hole masses. Blackburne and colleagues have also found a very weak wavelength dependence of these half-light radii. We consider disc temperature profile models that might match these observations. Nixon and colleagues have suggested that misaligned accretion discs around spinning black holes will be disrupted at radii small enough for the Lense-Thirring torque to overcome the disc's viscous torque. Gas in precessing annuli torn off a disc will spread radially and intersect with the remaining disc, heating the disc at potentially large radii. However, if the intersection occurs at an angle of more than a degree or so, highly supersonic collisions will shock-heat the gas to a Compton temperature of T~10^7 K, and the spectral energy distributions (SEDs) of discs with such shock-heated regions are poor fits to observations of quasar SEDs. T...

  14. Genetic association studies in lumbar disc degeneration

    DEFF Research Database (Denmark)

    Eskola, Pasi J; Lemmelä, Susanna; Kjær, Per;

    2012-01-01

    Low back pain is associated with lumbar disc degeneration, which is mainly due to genetic predisposition. The objective of this study was to perform a systematic review to evaluate genetic association studies in lumbar disc degeneration as defined on magnetic resonance imaging (MRI) in humans....

  15. Cervical disc hernia operations through posterior laminoforaminotomy

    OpenAIRE

    Coskun Yolas; Nuriye Guzin Ozdemir; Hilmi Onder Okay; Ayhan Kanat; Mehmet Senol; Ibrahim Burak Atci; Hakan Yilmaz; Mustafa Kemal Coban; Mehmet Onur Yuksel; Umit Kahraman

    2016-01-01

    Objective: The most common used technique for posterolateral cervical disc herniations is anterior approach. However, posterior cervical laminotoforaminomy can provide excellent results in appropriately selected patients with foraminal stenosis in either soft disc prolapse or cervical spondylosis. The purpose of this study was to present the clinical outcomes following posterior laminoforaminotomy in patients with radiculopathy. Materials and Methods: We retrospectively evaluated 35 patients ...

  16. Forbidden calcium lines as disc tracers

    CERN Document Server

    Aret, Anna

    2015-01-01

    Forbidden emission lines are particularly valuable disc tracers, because their profiles reflect the kinematics within their formation region. Here we present a short excerpt from the results of a spectroscopic survey of evolved massive stars surrounded by high-density discs.

  17. Computing Decoupled Residuals for Compact Disc Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Andersen, Palle;

    2006-01-01

    pair of residuals generated by Compact Disc Player. However, these residuals depend on the performance of position servos in the Compact Disc Player. In other publications of the same authors a pair of decoupled residuals is derived. However, the computation of these alternative residuals has been...

  18. Simulations of the Galactic Centre Stellar Discs In a Warped Disc Origin Scenario

    International Nuclear Information System (INIS)

    The Galactic Center (GC) hosts a population of young stars some of which seem to form a system of mutually inclined warped discs. While the presence of young stars in the close vicinity of the massive black hole is already problematic, their orbital configuration makes the situation even more puzzling. We present a possible warped disc origin scenario for these stars, which assumes an initially flat accretion disc which develops a warp through Pringle instability, or Bardeen-Petterson Effect. By working out the critical radii and the time scales involved, we argue that disc warping is plausible for GC parameters. We construct time evolution models for such discs considering the discs' self-gravity, and the torques exerted by the surrounding old star cluster. Our simulations suggest that the best agreement for a purely self-gravitating model is obtained for a disc-to-black hole mass ratio of Md/Mbh ∼ 0.001.

  19. Simulations of the Galactic Centre Stellar Discs In a Warped Disc Origin Scenario

    Science.gov (United States)

    Ulubay-Siddiki, A.; Bartko, H.

    2012-07-01

    The Galactic Center (GC) hosts a population of young stars some of which seem to form a system of mutually inclined warped discs. While the presence of young stars in the close vicinity of the massive black hole is already problematic, their orbital configuration makes the situation even more puzzling. We present a possible warped disc origin scenario for these stars, which assumes an initially flat accretion disc which develops a warp through Pringle instability, or Bardeen-Petterson Effect. By working out the critical radii and the time scales involved, we argue that disc warping is plausible for GC parameters. We construct time evolution models for such discs considering the discs' self-gravity, and the torques exerted by the surrounding old star cluster. Our simulations suggest that the best agreement for a purely self-gravitating model is obtained for a disc-to-black hole mass ratio of Md/Mbh ~ 0.001.

  20. The Role of Posterior Longitudinal Ligament in Cervical Disc Replacement: An Ovine Cadaveric Biomechanical Analysis.

    Science.gov (United States)

    Yu, Cheng-Cheng; Hao, Ding-Jun; Ma, Yu-Li; Huang, Da-Geng; Li, Hou-Kun; Feng, Hang; Hou, Qian

    2016-01-01

    BACKGROUND Cervical disc replacement (CDR) has been widely used to restore and maintain mobility and function of the treated and adjacent motion segments. Posterior longitudinal ligament (PLL) resection has been shown to be efficient in anterior cervical decompression and fusion. However, less is known about the biomechanical effect of PLL removal versus preservation in cervical disc arthroplasty. MATERIAL AND METHODS Three motion segments of 24 ovine cervical spines (C2-C5) were evaluated in a robotic spine system with axial compressive loads of 50 N. These cervical spines were divided in three groups according to the following conditions: (1) intact spine, (2) C3/C4 CDR with the Prestige LP prosthesis and PLL preservation, and (3) C3/C4 CDR with the Prestige LP prosthesis and PLL removal. The ranges of motion (ROMs) were recorded and analyzed in each group. RESULTS The C3/C4 ROM in group 3 (CDR with PLL removed) increased significantly in flexion-extension and axial rotation compared with group 1 (intact spine). Moreover, in flexion-extension, the mean total ROM was significantly larger in group 3 than in group 1. All the ROM observed in group 2 (CDR with PLL preserved) did not significantly differ from the ROM observed in group 1. CONCLUSIONS Compared with intact spines, CDR with PLL removal partly increased ROM. Moreover, the ROM in CDR with PLL preservation did not significantly differ from the ROM observed in intact spines. The PLL appears to contribute to the balance and stability of the cervical spine and should thus be preserved in cervical disc replacement provided that the posterior longitudinal ligament is not degenerative and the compression can be removed without PLL takedown. PMID:27243444

  1. Strongly magnetized accretion discs require poloidal flux

    Science.gov (United States)

    Salvesen, Greg; Armitage, Philip J.; Simon, Jacob B.; Begelman, Mitchell C.

    2016-05-01

    Motivated by indirect observational evidence for strongly magnetized accretion discs around black holes, and the novel theoretical properties of such solutions, we investigate how a strong magnetization state can develop and persist. To this end, we perform local simulations of accretion discs with an initially purely toroidal magnetic field of equipartition strength. We demonstrate that discs with zero net vertical magnetic flux and realistic boundary conditions cannot sustain a strong toroidal field. However, a magnetic pressure-dominated disc can form from an initial configuration with a sufficient amount of net vertical flux and realistic boundary conditions. Our results suggest that poloidal flux is a necessary prerequisite for the sustainability of strongly magnetized accretion discs.

  2. Hydrodynamic instability in warped astrophysical discs

    CERN Document Server

    Ogilvie, Gordon I

    2013-01-01

    Warped astrophysical discs are usually treated as laminar viscous flows, which have anomalous properties when the disc is nearly Keplerian and the viscosity is small: fast horizontal shearing motions and large torques are generated, which cause the warp to evolve rapidly, in some cases at a rate that is inversely proportional to the viscosity. However, these flows are often subject to a linear hydrodynamic instability, which may produce small-scale turbulence and modify the large-scale dynamics of the disc. We use a warped shearing sheet to compute the oscillatory laminar flows in a warped disc and to analyse their linear stability by the Floquet method. We find widespread hydrodynamic instability deriving from the parametric resonance of inertial waves. Even very small, unobservable warps in nearly Keplerian discs of low viscosity can be expected to generate hydrodynamic turbulence, or at least wave activity, by this mechanism.

  3. Propeller outflows from an MRI disc

    CERN Document Server

    Lii, Patrick S; Ustyugova, Galina V; Koldoba, Alexander V; Lovelace, Richard V E

    2013-01-01

    We present the results of axisymmetric simulations of MRI-driven accretion onto a rapidly rotating, magnetized star accreting in the propeller regime. The stellar magnetosphere corotates with the star, forming a centrifugal barrier at the disc-magnetosphere boundary which inhibits matter accretion onto the star. Instead, the disc matter accumulates at the disc-magnetosphere interface and slowly diffuses into the inner magnetosphere where it picks up angular momentum and is quickly ejected from the system as an outflow. Due to the interaction of the matter with the magnetosphere, this wind is discontinuous and is launched as discrete plasmoids. If the ejection rate is lower than the disc accretion rate, the matter accumulates at the disc-magnetosphere boundary faster than it can be ejected. In this case, accretion onto the star proceeds through the episodic accretion instability in which episodes of matter accumulation are followed by simultaneous accretion and ejection. During the accretion phase of this inst...

  4. Magnetic resonance imaging of intervertebral disc degeneration

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Hiroshi; Noguchi, Masao (Kitakyushu City Yahata Hospital, Fukuoka (Japan)); Kira, Hideaki; Fujiki, Hiroshi; Shimokawa, Isao; Hinoue, Kaichi

    1993-02-01

    The aim of this study was to correlate the degree of lumbar intervertebral disc degeneration with findings of magnetic resonance imaging (MRI). Seventeen autopsied (from 7 patients) and 21 surgical (from 20 patients) intervertebral discs were used as specimens for histopathological examination. In addition, 21 intervertebral discs were examined on T2-weighted images. Histopathological findings from both autopsied and surgical specimens were well correlated with MRI findings. In particular, T2-weighted images reflected increased collagen fibers and rupture within the fibrous ring accurately. However, when severely degenerated intervertebral discs and hernia protruding the posterior longitudinal ligament existed, histological findings were not concordant well with T2-weighted images. Morphological appearances of autopsy specimens, divided into four on T2-weighted images, were well consistent with histological degeneration. This morphological classification, as shown on T2-weighted images, could also be used in the evaluation of intervertebral disc degeneration. (N.K.).

  5. The formation of planets by disc fragmentation

    Directory of Open Access Journals (Sweden)

    Stamatellos Dimitris

    2013-04-01

    Full Text Available I discuss the role that disc fragmentation plays in the formation of gas giant and terrestrial planets, and how this relates to the formation of brown dwarfs and low-mass stars, and ultimately to the process of star formation. Protostellar discs may fragment, if they are massive enough and can cool fast enough, but most of the objects that form by fragmentation are brown dwarfs. It may be possible that planets also form, if the mass growth of a proto-fragment is stopped (e.g. if this fragment is ejected from the disc, or suppressed and even reversed (e.g by tidal stripping. I will discuss if it is possible to distinguish whether a planet has formed by disc fragmentation or core accretion, and mention of a few examples of observed exoplanets that are suggestive of formation by disc fragmentation.

  6. Lumbar Epidural Varix Mimicking Disc Herniation.

    Science.gov (United States)

    Bursalı, Adem; Akyoldas, Goktug; Guvenal, Ahmet Burak; Yaman, Onur

    2016-07-01

    Lumbar radiculopathy is generally caused by such well-recognized entity as lumbar disc herniation in neurosurgical practice; however rare pathologies such as thrombosed epidural varix may mimic them by causing radicular symptoms. In this case report, we present a 26-year-old man with the complaint of back and right leg pain who was operated for right L4-5 disc herniation. The lesion interpreted as an extruded disc herniation preoperatively was found to be a thrombosed epidural varix compressing the nerve root preoperatively. The nerve root was decompressed by shrinking the lesion with bipolar thermocoagulation and excision. The patient's complaints disappeared in the postoperative period. Thrombosed lumbar epidural varices may mimic lumbar disc herniations both radiologically and clinically. Therefore, must be kept in mind in the differential diagnosis of lumbar disc herniations. Microsurgical techniques are mandatory for the treatment of these pathologies and decompression with thermocoagulation and excision is an efficient method. PMID:27446525

  7. Strongly magnetized accretion discs require poloidal flux

    CERN Document Server

    Salvesen, Greg; Simon, Jacob B; Begelman, Mitchell C

    2016-01-01

    Motivated by indirect observational evidence for strongly magnetized accretion discs around black holes, and the novel theoretical properties of such solutions, we investigate how a strong magnetization state can develop and persist. To this end, we perform local simulations of accretion discs with an initially purely toroidal magnetic field of equipartition strength. We demonstrate that discs with zero net vertical magnetic flux and realistic boundary conditions cannot sustain a strong toroidal field. However, a magnetic pressure-dominated disc can form from an initial configuration with a sufficient amount of net vertical flux and realistic boundary conditions. Our results suggest that poloidal flux is a necessary prerequisite for the sustainability of strongly magnetized accretion discs.

  8. Lumbar disc cyst with contralateral radiculopathy

    Directory of Open Access Journals (Sweden)

    Kishore Tourani

    2012-08-01

    Full Text Available Disc cysts are uncommon intraspinal cystic lesions located in the ventrolateral epidural space. They communicate with the nucleus pulposus of the intervertebral disc and cause symptoms by radicular compression. We report a unique case of lumbar disc cyst that was associated with disc herniation and contralateral radiculopathy. A 22 year old male presented with one month history of back-ache radiating to the left leg. Magnetic Resonance Imaging (MRI showed L3-L4 disc herniation with annular tear and cystic lesion in the extradural space anterior to the thecal sac on right side, which increased in size over a period of 3 weeks. L3 laminectomy and bilateral discectomy and cyst excision was done with partial improvement of patients symptoms.

  9. Lumbar Epidural Varix Mimicking Disc Herniation

    Science.gov (United States)

    Bursalı, Adem; Guvenal, Ahmet Burak; Yaman, Onur

    2016-01-01

    Lumbar radiculopathy is generally caused by such well-recognized entity as lumbar disc herniation in neurosurgical practice; however rare pathologies such as thrombosed epidural varix may mimic them by causing radicular symptoms. In this case report, we present a 26-year-old man with the complaint of back and right leg pain who was operated for right L4–5 disc herniation. The lesion interpreted as an extruded disc herniation preoperatively was found to be a thrombosed epidural varix compressing the nerve root preoperatively. The nerve root was decompressed by shrinking the lesion with bipolar thermocoagulation and excision. The patient's complaints disappeared in the postoperative period. Thrombosed lumbar epidural varices may mimic lumbar disc herniations both radiologically and clinically. Therefore, must be kept in mind in the differential diagnosis of lumbar disc herniations. Microsurgical techniques are mandatory for the treatment of these pathologies and decompression with thermocoagulation and excision is an efficient method. PMID:27446525

  10. Strongly magnetized accretion discs require poloidal flux

    Science.gov (United States)

    Salvesen, Greg; Armitage, Philip J.; Simon, Jacob B.; Begelman, Mitchell C.

    2016-08-01

    Motivated by indirect observational evidence for strongly magnetized accretion discs around black holes, and the novel theoretical properties of such solutions, we investigate how a strong magnetization state can develop and persist. To this end, we perform local simulations of accretion discs with an initially purely toroidal magnetic field of equipartition strength. We demonstrate that discs with zero net vertical magnetic flux and realistic boundary conditions cannot sustain a strong toroidal field. However, a magnetic pressure-dominated disc can form from an initial configuration with a sufficient amount of net vertical flux and realistic boundary conditions. Our results suggest that poloidal flux is a necessary prerequisite for the sustainability of strongly magnetized accretion discs.

  11. Magnetic resonance imaging of intervertebral disc degeneration

    International Nuclear Information System (INIS)

    The aim of this study was to correlate the degree of lumbar intervertebral disc degeneration with findings of magnetic resonance imaging (MRI). Seventeen autopsied (from 7 patients) and 21 surgical (from 20 patients) intervertebral discs were used as specimens for histopathological examination. In addition, 21 intervertebral discs were examined on T2-weighted images. Histopathological findings from both autopsied and surgical specimens were well correlated with MRI findings. In particular, T2-weighted images reflected increased collagen fibers and rupture within the fibrous ring accurately. However, when severely degenerated intervertebral discs and hernia protruding the posterior longitudinal ligament existed, histological findings were not concordant well with T2-weighted images. Morphological appearances of autopsy specimens, divided into four on T2-weighted images, were well consistent with histological degeneration. This morphological classification, as shown on T2-weighted images, could also be used in the evaluation of intervertebral disc degeneration. (N.K.)

  12. Spine imaging after lumbar disc replacement: pitfalls and current recommendations

    Directory of Open Access Journals (Sweden)

    Sandén Bengt

    2009-07-01

    Full Text Available Abstract Background Most lumbar artificial discs are still composed of stainless steel alloys, which prevents adequate postoperative diagnostic imaging of the operated region when using magnetic resonance imaging (MRI. Thus patients with postoperative radicular symptoms or claudication after stainless steel implants often require alternative diagnostic procedures. Methods Possible complications of lumbar total disc replacement (TDR are reviewed from the available literature and imaging recommendations given with regard to implant type. Two illustrative cases are presented in figures. Results Access-related complications, infections, implant wear, loosening or fracture, polyethylene inlay dislodgement, facet joint hypertrophy, central stenosis, and ankylosis of the operated segment can be visualised both in titanium and stainless steel implants, but require different imaging modalities due to magnetic artifacts in MRI. Conclusion Alternative radiographic procedures should be considered when evaluating patients following TDR. Postoperative complications following lumbar TDR including spinal stenosis causing radiculopathy and implant loosening can be visualised by myelography and radionucleotide techniques as an adjunct to plain film radiographs. Even in the presence of massive stainless steel TDR implants lumbar radicular stenosis and implant loosening can be visualised if myelography and radionuclide techniques are applied.

  13. Importance of Attenuating Quadriceps Activation Deficits after Total Knee Arthroplasty

    OpenAIRE

    Thomas, Abbey C.; Jennifer E Stevens-Lapsley

    2012-01-01

    Total knee arthroplasty (TKA) is associated with persistent quadriceps dysfunction. Since quadriceps dysfunction impairs functional performance, minimizing quadriceps dysfunction by attenuating central activation deficits early after surgery may improve function later in life. Rehabilitation strategies incorporating neuromuscular electrical stimulation and early, aggressive quadriceps strengthening may prove beneficial. Further, surgical approaches such as minimally invasive TKA may minimize ...

  14. Outcome Assessment after Aptis Distal Radioulnar Joint (DRUJ Implant Arthroplasty

    Directory of Open Access Journals (Sweden)

    Amir Reza Kachooei

    2014-09-01

    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.

  15. Traditions and myths in hip and knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Henrik; Gromov, Kirill; Malchau, Henrik;

    2014-01-01

    NSAIDs, early mobilization, allowing early travel, and a low hemoglobin trigger for transfusion. Interpretation - Revision of traditions and myths surrounding hip and knee arthroplasty towards more contemporary evidence-based principles can be expected to improve early functional recovery, thus reducing...

  16. Early morbidity after simultaneous and staged bilateral total knee arthroplasty

    DEFF Research Database (Denmark)

    Lindberg-Larsen, Martin; Jørgensen, Christoffer Calov; Husted, Henrik;

    2015-01-01

    PURPOSE: The aim of this nationwide study was to investigate the early morbidity after bilateral simultaneous and staged total knee arthroplasty (TKA) in order to clarify potential benefits of a well-established fast-track regime. METHODS: The Danish National Patient Registry was searched for all...

  17. Periprosthetic fractures of the femur after total knee arthroplasty

    OpenAIRE

    McGraw, Phil; Kumar, Arun

    2010-01-01

    Periprosthetic fracture following total knee arthroplasty is a potentially serious complication. This injury can involve the distal femur, proximal tibia or the patella. This review article analyzes the prevalence, risk factors, classification and treatment options for periprosthetic fractures of the femur.

  18. Compartment syndrome and popliteal vascular injury complicating unicompartmental knee arthroplasty

    NARCIS (Netherlands)

    Kort, Nanne Pieter; Van Raay, Jos J. J. A. M.; van Horn, Jim R.

    2007-01-01

    Popliteal vascular injury and the compartment syndrome of the leg are rare but important complications of knee arthroplasties. Early diagnosis and treatment are of paramount importance in preventing the devastating complications of these conditions. To our knowledge, these complications have not bee

  19. Minimally invasive total hip arthroplasty with the anterior approach

    Directory of Open Access Journals (Sweden)

    Bal B

    2008-01-01

    Full Text Available Background: Total hip athroplasty with the anterior surgical approach is advised because the dissection is entirely within intermuscular planes. In this report we describe a minimally invasive technique of anterior total hip arthroplasty, with the early outcomes. Materials and Methods: The technique of minimally invasive total hip arthroplasty with anterior approach (Smith-Petersen is described. We reviewed data on 100 consecutive patients who underwent anterior total hip arthroplasty with uncemented components. Mean patient age was 61 years (range 33-91. Mean patience BMI 29.8 (range 18.1-51.8. Results: Minumum follow up duration is 10 months. The mean duration of surgery was 53 min (range 34-87 with mean blood loss 185 cc (range 65-630, and the mean incision length was 10.4 cm. Clinical and radiographic outcomes were similar to historical outcomes of standard total hip arthroplasty. Conclusions: With proper surgeon training, minimally invasive total hip replacement with the anterior surgical interval is safe and efficacious.

  20. The role of shoulder fusion in the era of arthroplasty

    OpenAIRE

    González-Díaz, R.; Rodríguez-Merchán, E. C.; Gilbert, M. S.

    1997-01-01

    The indications, surgical techniques, results and complications of shoulder fusion are described. The indications are bacterial infection, paralytic disorders in infancy, combined deltoid and rotator cuff paralysis, post-traumatic brachial plexus lesions, inflammatory arthritis with severe rotator cuff involvement, failed arthroplasty, recurrent dislocation, after resection of tumours, irreparable rotator cuff tear, painful arthritis in a patient whose activities requi...

  1. Low manipulation prevalence following fast-track total knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Henrik; Jørgensen, Christoffer C.; Gromov, Kirill;

    2015-01-01

    Background and purpose - Postoperative joint stiffness following total knee arthroplasty (TKA) may compromise the outcome and necessitate manipulation. Previous studies have not been in a fast-track setting with optimized pain treatment, early mobilization, and short length of stay (LOS), which m...

  2. Large head metal-on-metal cementless total hip arthroplasty versus 28mm metal-on-polyethylene cementless total hip arthroplasty : design of a randomized controlled trial

    NARCIS (Netherlands)

    Zijlstra, Wierd P.; Bos, Nanne; van Raaij, Jos J. A. M.

    2008-01-01

    Background: Osteoarthritis of the hip is successfully treated by total hip arthroplasty with metal-on-polyethylene articulation. Polyethylene wear debris can however lead to osteolysis, aseptic loosening and failure of the implant. Large head metal-on-metal total hip arthroplasty may overcome polyet

  3. Artificial Inteligence and Law

    OpenAIRE

    Fuková, Kateřina

    2012-01-01

    Submitted diploma work Artificial Intelligence and Law deals with the rule of law and its position in the process of new advanced technologies in computer cybernetics and further scientific disciplines related with artificial intelligence and its creation. The first part of the work introduces the history of the first imagines about artificial intelligence and concerns with its birth. This chapter presents main theoretical knowledge and hypotheses defined artificial intelligence and progre...

  4. Artificial Skin in Robotics

    OpenAIRE

    Strohmayr, Michael

    2012-01-01

    Artificial Skin - A comprehensive interface for system-environment interaction - This thesis investigates a multifunctional artificial skin as touch sensitive whole-body cover for robotic systems. To further the evolution from tactile sensors to an implementable artificial skin a general concept for the design process is derived. A standard test procedure is proposed to evaluate the performance. The artificial skin contributes to a safe and intuitive physical human robot interaction.

  5. Total Hip Arthroplasty for Hip Fractures

    Science.gov (United States)

    Monzón, Daniel Godoy; Iserson, Kenneth V.; Jauregui, José; Musso, Carlos; Piccaluga, Francisco; Buttaro, Martin

    2014-01-01

    Introduction: This study aimed to determine the dislocation and reoperation rate, functional outcomes, and the survival rate of the unique subset of very old but lucid and independent patients with hip fractures following a total hip arthroplasty (THA) and geriatric team-coordinated perioperative care. Method: Between 2000 and 2006, previously independent ambulatory patients ≥80 years old presenting with an intracapsular hip fracture were given THAs under the care of an integrated orthopedic surgery–geriatric service. Their fracture-related complications, ambulation, mental status, and survival were followed for 5 to 11 years postinjury. Results: Five years postinjury, 57 (61.3%) patients of the original study group were living. In all, 3 (3.2%) patients had postoperative hip dislocations (and 2 patients had dislocation twice) and 2 reoperations were needed within the first postoperative month. There were no hip dislocations or reoperations after the first year. Radiographs obtained on 88% of the surviving patients at 5 years postoperatively showed that all remained unchanged from their immediate postoperative images. Nearly half of the patients were still able to ambulate as they did preoperatively and their mixed-model equation was statistically unchanged. Conclusion: This study of patients >80 years old with previously good functional status demonstrates that with appropriate surgical (best prosthesis, good operating technique, and regional anesthesia) and geriatric (pre- and postoperative assessments, close follow-up, medication adjustments, and fall-prevention instruction) care, they have few hip dislocations and reoperations, survive postfracture at least as long as their noninjured contemporaries, and continue to function and ambulate as they did prior to their injury. PMID:24660092

  6. Infected total knee arthroplasty treatment outcome analysis

    Directory of Open Access Journals (Sweden)

    Radoičić Dragan

    2012-01-01

    Full Text Available Background/Aim. Infected total knee arthroplasty (TKA is a topic of great importance, because its diagnosing and treatment requires a lot of resources, and often has an unsatisfactory outcome. The aim of this study was to analyze the outcome of the treatment of infection developed following TKA. Methods. This retrospective study of infected TKAs was performed in the period from 1998 to 2008 in the Orthopedics & Traumatology Clinic of the Military Medical Academy (MMA in Belgrade. A total of 654 primary and revised TKAs were performed in the said period. We registered and surgically treated 28 infected TKAs (primary TKAs: MMA - 22, other institutions - 6. The incidence of TKA infection in the MMA was 3.36%. The most common pathogens were: Staphylococcus aureus - 14 (50% cases, and Staph. epidermidis - 3 (10.7% cases. Other isolated pathogens were: Enterococcus faecalis, Klebsiella pneum., Klebsiella spp., Streptoccocus viridans, Seratia spp, Micrococcus luteus and Peptostreptococcus spp. In one case we had mixed anaerobic flora, and in 3 cases cultures were negative. We analyzed diagnostic challenges, risk factors (such as age and previous viscosupplementation and treatment outcomes in our series of infected TKAs. Results. In our series 2 infections healed after iv antibiotics and debridement, 1 patient responded to open debridement with component retention, 4 patients responded fully to one-stage reimplantation, 10 cases responded fully to two-stage reimplantation, 11 patients ended with arthrodesis and we had 1 patient with above knee amputation. Conclusion. Two-stage reimplantation remains gold standard for treatment of infected TKA, and we recommend it as treatment of choice for eradication of infection. The antibiotic loaded spacer prothesis concept in most cases allows infection eradication, good function and high patient satisfaction.

  7. Future bearing surfaces in total hip arthroplasty.

    Science.gov (United States)

    Chang, Jun-Dong

    2014-03-01

    One of the most important issues in the modern total hip arthroplasty (THA) is the bearing surface. Extensive research on bearing surfaces is being conducted to seek an ideal bearing surface for THA. The ideal bearing surface for THA should have superior wear characteristics and should be durable, bio-inert, cost-effective, and easy to implant. However, bearing surfaces that are currently being implemented do not completely fulfill these requirements, especially for young individuals for whom implant longevity is paramount. Even though various new bearing surfaces have been investigated, research is still ongoing, and only short-term results have been reported from clinical trials. Future bearing surfaces can be developed in the following ways: (1) change in design, (2) further improvement of polyethylene, (3) surface modification of the metal, (4) improvement in the ceramic, and (5) use of alternative, new materials. One way to reduce wear and impingement in THA is to make changes in its design by using a large femoral head, a monobloc metal shell with preassembled ceramic liner, dual mobility cups, a combination of different bearing surfaces, etc. Polyethylene has improved over time with the development of highly crosslinked polyethylene. Further improvements can be made by reinforcing it with vitamin E or multiwalled carbon nanotubes and by performing a surface modification with a biomembrane. Surface modifications with titanium nitride or titanium niobium nitride are implemented to try to improve the metal bearings. The advance to the fourth generation ceramics has shown relatively promising results, even in young patients. Nevertheless, further improvement is required to reduce fragility and squeaking. Alternative materials like diamond coatings on surfaces, carbon based composite materials, oxidized zirconium, silicon nitride, and sapphire are being sought. However, long-term studies are necessary to confirm the efficacy of these surfaces after enhancements

  8. Gravitoturbulence in magnetised protostellar discs

    CERN Document Server

    Riols, A

    2016-01-01

    Gravitational instability (GI) features in several aspects of protostellar disk evolution, most notably in angular momentum transport, fragmentation, and the outbursts exemplified by FU Ori and EX Lupi systems. The outer regions of protostellar discs may also be coupled to magnetic fields, which could then modify the development of GI. To understand the basic elements of their interaction, we perform local 2D ideal and resistive MHD simulations with an imposed toroidal field. In the regime of moderate plasma beta, we find that the system supports a hot gravito-turbulent state, characterised by considerable magnetic energy and stress and a surprisingly large Toomre parameter $Q~10$. This result has potential implications for disk structure, vertical thickness, ionisation, etc. Our simulations also reveal the existence of long-lived and dense `magnetic islands' or plasmoids. Lastly, we find that the presence of a magnetic field has little impact on the fragmentation criterion of the disk. Though our focus is on...

  9. Spontaneous Regression of Herniated Lumbar Disc with New Disc Protrusion in the Adjacent Level.

    Science.gov (United States)

    Hakan, Tayfun; Gürcan, Serkan

    2016-01-01

    Spontaneous regression of herniated lumbar discs was reported occasionally. The mechanisms proposed for regression of disc herniation are still incomplete. This paper describes and discusses a case of spontaneous regression of herniated lumbar discs with a new disc protrusion in the adjacent level. A 41-year-old man was admitted with radiating pain and numbness in the left lower extremity with a left posterolateral disc extrusion at L5-S1 level. He was admitted to hospital with low back pain due to disc herniation caudally immigrating at L4-5 level three years ago. He refused the surgical intervention that was offered and was treated conservatively at that time. He had no neurological deficit and a history of spontaneous regression of the extruded lumbar disc; so, a conservative therapy, including bed rest, physical therapy, nonsteroidal anti-inflammatory drugs, and analgesics, was advised. In conclusion, herniated lumbar disc fragments may regress spontaneously. Reports are prone to advise conservative treatment for extruded or sequestrated lumbar disc herniations. However, these patients should be followed up closely; new herniation at adjacent/different level may occur. Furthermore, it is important to know which herniated disk should be removed and which should be treated conservatively, because disc herniation may cause serious complications as muscle weakness and cauda equine syndrome. PMID:27429818

  10. Spontaneous Regression of Herniated Lumbar Disc with New Disc Protrusion in the Adjacent Level

    Directory of Open Access Journals (Sweden)

    Tayfun Hakan

    2016-01-01

    Full Text Available Spontaneous regression of herniated lumbar discs was reported occasionally. The mechanisms proposed for regression of disc herniation are still incomplete. This paper describes and discusses a case of spontaneous regression of herniated lumbar discs with a new disc protrusion in the adjacent level. A 41-year-old man was admitted with radiating pain and numbness in the left lower extremity with a left posterolateral disc extrusion at L5-S1 level. He was admitted to hospital with low back pain due to disc herniation caudally immigrating at L4-5 level three years ago. He refused the surgical intervention that was offered and was treated conservatively at that time. He had no neurological deficit and a history of spontaneous regression of the extruded lumbar disc; so, a conservative therapy, including bed rest, physical therapy, nonsteroidal anti-inflammatory drugs, and analgesics, was advised. In conclusion, herniated lumbar disc fragments may regress spontaneously. Reports are prone to advise conservative treatment for extruded or sequestrated lumbar disc herniations. However, these patients should be followed up closely; new herniation at adjacent/different level may occur. Furthermore, it is important to know which herniated disk should be removed and which should be treated conservatively, because disc herniation may cause serious complications as muscle weakness and cauda equine syndrome.

  11. The properties of discs around planets and brown dwarfs as evidence for disc fragmentation

    CERN Document Server

    Stamatellos, Dimitris

    2015-01-01

    Direct imaging searches have revealed many very low-mass objects, including a small number of planetary mass objects, as wide-orbit companions to young stars. The formation mechanism of these objects remains uncertain. In this paper we present the predictions of the disc fragmentation model regarding the properties of the discs around such low-mass objects. We find that the discs around objects that have formed by fragmentation in discs hosted by Sun-like stars (referred to as 'parent' discs and 'parent' stars) are more massive than expected from the ${M}_{\\rm disc}-M_*$ relation (which is derived for stars with masses $M_*>0.2 {\\rm M}_{\\odot}$). Accordingly, the accretion rates onto these objects are also higher than expected from the $\\dot{M}_*-M_*$ relation. Moreover there is no significant correlation between the mass of the brown dwarf or planet with the mass of its disc nor with the accretion rate from the disc onto it. The discs around objects that form by disc fragmentation have larger than expected m...

  12. Chemical separation of disc components using RAVE

    CERN Document Server

    Wojno, Jennifer; Steinmetz, Matthias; McMillan, Paul J; Matijevič, Gal; Binney, James; Wyse, Rosemary F G; Boeche, Corrado; Just, Andreas; Grebel, Eva K; Siebert, Arnaud; Bienaymé, Olivier; Gibson, Brad K; Zwitter, Tomaž; Bland-Hawthorn, Joss; Navarro, Julio F; Parker, Quentin A; Reid, Warren; Seabroke, George; Watson, Fred

    2016-01-01

    We present evidence from the RAdial Velocity Experiment (RAVE) survey of chemically separated, kinematically distinct disc components in the solar neighbourhood. We apply probabilistic chemical selection criteria to separate our sample into $\\alpha$-low (`thin disc') and $\\alpha$-high (`thick disc') components. Using newly derived distances, which will be utilized in the upcoming RAVE DR5, we explore the kinematic trends as a function of metallicity for each of the disc components. For our thin disc stars, we find a negative trend in the mean rotational velocity ($V_{\\mathrm{\\phi}}$) as a function of iron abundance ([Fe/H]). We measure a positive trend in $\\partial V_{\\mathrm{\\phi}}$/$\\partial$[Fe/H] for the thick disc, consistent with results from high-resolution surveys. We also find differences between the chemical thin and thick discs in all three components of velocity dispersion. We discuss the implications of an $\\alpha$-low, metal-rich population originating from the inner Galaxy, where the orbits of ...

  13. Stem cells sources for intervertebral disc regeneration.

    Science.gov (United States)

    Vadalà, Gianluca; Russo, Fabrizio; Ambrosio, Luca; Loppini, Mattia; Denaro, Vincenzo

    2016-05-26

    Intervertebral disc regeneration field is rapidly growing since disc disorders represent a major health problem in industrialized countries with very few possible treatments. Indeed, current available therapies are symptomatic, and surgical procedures consist in disc removal and spinal fusion, which is not immune to regardable concerns about possible comorbidities, cost-effectiveness, secondary risks and long-lasting outcomes. This review paper aims to share recent advances in stem cell therapy for the treatment of intervertebral disc degeneration. In literature the potential use of different adult stem cells for intervertebral disc regeneration has already been reported. Bone marrow mesenchymal stromal/stem cells, adipose tissue derived stem cells, synovial stem cells, muscle-derived stem cells, olfactory neural stem cells, induced pluripotent stem cells, hematopoietic stem cells, disc stem cells, and embryonic stem cells have been studied for this purpose either in vitro or in vivo. Moreover, several engineered carriers (e.g., hydrogels), characterized by full biocompatibility and prompt biodegradation, have been designed and combined with different stem cell types in order to optimize the local and controlled delivery of cellular substrates in situ. The paper overviews the literature discussing the current status of our knowledge of the different stem cells types used as a cell-based therapy for disc regeneration. PMID:27247704

  14. Shear Mechanics of the TMJ Disc

    Science.gov (United States)

    Juran, C.M.; Dolwick, M.F.; McFetridge, P.S.

    2012-01-01

    The temporomandibular joint (TMJ) is a complex hinge and gliding joint that induces significant shear loads onto the fibrocartilage TMJ disc during jaw motion. The purpose of this study was to assess regional variation in the disc’s shear loading characteristics under physiologically relevant loads and to associate those mechanical findings with common clinical observations of disc fatigue and damage. Porcine TMJ discs were compressed between an axially translating bottom platen and a 2.5-cm-diameter indenter within a hydrated testing chamber. Discs were cyclically sheared at 0.5, 1, or 5 Hz to 1, 3, or 5% shear strain. Within the anterior and intermediate regions of the disc when sheared in the anteroposterior direction, both shear and compressive moduli experienced a significant decrease from instantaneous to steady state, while the posterior region’s compressive modulus decreased approximately 5%, and no significant loss of shear modulus was noted. All regions retained their shear modulus within 0.5% of instantaneous values when shear was applied in the mediolateral direction. The results of the disc’s regional shear mechanics suggest an observable and predictable link with the common clinical observation that the posterior region of the disc is most often the zone in which fatigue occurs, which may lead to disc damage and perforation. PMID:23166043

  15. Have proto-planetary discs formed planets?

    CERN Document Server

    Greaves, J S

    2010-01-01

    It has recently been noted that many discs around T Tauri stars appear to comprise only a few Jupiter-masses of gas and dust. Using millimetre surveys of discs within six local star-formation regions, we confirm this result, and find that only a few percent of young stars have enough circumstellar material to build gas giant planets, in standard core accretion models. Since the frequency of observed exo-planets is greater than this, there is a `missing mass' problem. As alternatives to simply adjusting the conversion of dust-flux to disc mass, we investigate three other classes of solution. Migration of planets could hypothetically sweep up the disc mass reservoir more efficiently, but trends in multi-planet systems do not support such a model, and theoretical models suggest that the gas accretion timescale is too short for migration to sweep the disc. Enhanced inner-disc mass reservoirs are possible, agreeing with predictions of disc evolution through self-gravity, but not adding to millimetre dust-flux as t...

  16. TOTAL KNEE ARTHROPLASTY IN A PATIENT WITH HOFFA FRACTURE PSEUDARTHROSIS: CASE REPORT

    OpenAIRE

    Rodrigo Pires e Albuquerque; Giordano, Vincenzo; Amaral, Ney Pecegueiro do; Carvalho, Antônio Carlos Pires; Barretto, João Maurício

    2015-01-01

    A rare occurrence of a case of Hoffa fracture pseudarthrosis in an alcoholic patient with genu valgum associated with venous insufficiency who underwent total knee arthroplasty is reported. The literature is reviewed and the main factors for surgical indication of total knee arthroplasty after a fracture of the knee are discussed. Total knee arthroplasty was a viable option in a 60-year-old patient with Hoffa fracture pseudarthrosis and comorbidities.

  17. Revision to reverse shoulder arthroplasty with retention of the humeral component

    OpenAIRE

    Werner, Birgit S.; Boehm, Dorota; Gohlke, Frank

    2013-01-01

    Background Revision in failed shoulder arthroplasty often requires removal of the humeral component with a significant risk of fracture and bone loss. Newer modular systems allow conversion from anatomic to reverse shoulder arthroplasty with retention of a well-fixed humeral stem. We report on a prospectively evaluated series of conversions from hemiarthroplasty to reverse shoulder arthroplasty. Methods In 14 cases of failed hemiarthroplasty due to rotator cuff deficiency and painful pseudopa...

  18. Atraumatic patellar prosthesis dislocation with patellar tendon injury following a total knee arthroplasty: a case report

    OpenAIRE

    Singh Alka; Singh Yashwant; Singh Pankaj; Singh Vinay; Javed Sadaf; Abdunabi Murad

    2010-01-01

    Abstract Introduction Total knee arthroplasty is a well-established procedure with gratifying results. There is no consensus in the literature whether to routinely resurface the patella while performing total knee arthroplasty or not. Although an extremely rare occurrence in clinical practice, patellar prosthesis dislocation is a possible complication resulting from total knee arthroplasty. Case presentation We report a rare case of atraumatic spontaneous dislocation of patellar prosthesis in...

  19. Endoscopic anterior decompression in cervical disc disease

    Directory of Open Access Journals (Sweden)

    Yad Ram Yadav

    2014-01-01

    Full Text Available Background: Although microscopic anterior cervical discectomy with or without fusion are common surgical procedures for treatment of cervical herniated discs, loss of disc height, pseudarthrosis, and adjacent disc degeneration are some of the problems associated with it. This study is aimed to evaluate results of endoscopic microforaminotomy in cervical disc diseases. Materials and Methods: A prospective study of 50 patients of mono segmental soft or hard disc causing myeloradiculopathy was undertaken. A visual analogue scale (VAS for neck and arm pain and functional outcomes using the Nurick grading system were assessed. There were 28, 12, 8, and 2 patients at C5-6, C6-7, C4-5, and C3-4 levels disc diseases, respectively. Patients with two or more level disc, instabilities, disc extending more than half vertebral body height, and previous operation at the same segment were excluded. Results: Age ranged from 21 to 67 years. Average postoperative reduction in disc height, operating time, and blood loss was 1.1 mm, 110 minutes, and 30 ml, respectively. Average pre-operative VAS score for arm pain and Nurick grading was 7.6 and 2.7, which improved to 1.9 and 0.82, respectively. All patients improved; 1, 2, 3 grade improvement was seen in 10, 27, and 10 patients, respectively. There was no significant complication or any mortality. Conclusion: Although longer follow up of large number of patients is required, endoscopic microforaminotomy is a safe and an effective alternative to microscopic anterior discectomy with or without fusion.

  20. Magnetic resonance imaging of artificial lumbar disks: safety and metal artifacts

    Institute of Scientific and Technical Information of China (English)

    YANG Chang-wei; LIU Liu; WANG Jian; DONG Ai-sheng; LU Jian-ping; HE Shi-sheng; LI Ming

    2009-01-01

    Background This study was to investigate the safety of two types of commercially available lumbar artificial discs (CHARITE and PRODISC -L) during a magnetic resonance imaging (MRI) procedure in a 1.5-Tesla MR system, and to evaluate the size of metal artifacts on the MR image for different sequences.Methods A 1.5-Tesla clinical MR imaging system was used. The degree of deflection of the endplates of two artificial discs was evaluated by an angle-measurement instrument at the portals of the MRI scanner. The heating effect of the radio frequency (RF) magnetic field was evaluated by using "worst-case" imaging sequences on a human cadaver implanted with an artificial lumbar disc at the L5/S1 intervertebral disc location. The temperatures of the tissue adjacent to the implant, and of the L4/L5 intervertebral disc (used as a control) were measured, respectively, using a digital probe thermometer before and after the MRI scan sequence. A rectangular water phantom was designed to evaluate the metal artifacts of these two artificial discs under different MR imaging sequences.Results The maximal deflection angle of the endplate of the implants under a static MR field was 7.5 and 6.0 degrees, for the CHARITE and PRODISC -L, respectively. The difference between temperature rise of tissue adjacent to the two types of artificial discs and the temperature rise of the L4/L5 control location was 0.4 and 0.6℃, respectively. The size of metal artifacts on images of TSE (T1/T2-weighted), STIR and Turbo Dark Fluid sequences were relatively less than those of TSE fat saturation, Flash and SE (T1-weighted) sequences.Conclusions The CHARITE and the PRODISC -L artificial disc do not present an additional hazard or risk to a patient undergoing an MRI procedure using a scanner operating with a static magnetic field of 1.5T or lower. Image artifacts from the implants may present problems if the anatomical region of interest is in or near the area where these implants are located (e

  1. [Lumbar disc herniation and andrological diseases].

    Science.gov (United States)

    Jin, Bao-fang

    2015-10-01

    Lumbar disc herniation is a common male disease. In the past, More academic attention was directed to its relationship with lumbago and leg pain than to its association with andrological diseases. Studies show that central lumber intervertebral disc herniation may cause cauda equina injury and result in premature ejaculation, erectile dysfunction, chronic pelvic pain syndrome, priapism, and emission. This article presents an overview on the correlation between central lumbar intervertebral disc herniation and andrological diseases, focusing on the aspects of etiology, pathology, and clinical progress, hoping to invite more attention from andrological and osteological clinicians. PMID:26665671

  2. Spectroscopic properties of stars with debris discs

    International Nuclear Information System (INIS)

    The question of the origin and evolution of planetary systems is of fundamental importance for astrophysics. Dusty debris discs are signatures of planetary systems and, therefore, constitute valuable tools to provide new light in our understanding of how planetary systems form and evolve. We present the first results of a spectroscopic programme of a sample of stars with debris discs. High-resolution echelle spectra are used to determine metallicities and abundances. Properties of stars with debris discs, are compared with those of stars hosting planets, as well as 'normal' stars.

  3. Groups, cacti and framed little discs

    CERN Document Server

    Hepworth, Richard

    2010-01-01

    Let G be a topological group. Then the based loopspace of G is an algebra over the cacti operad, while the double loopspace of the classifying space of G is an algebra over the framed little discs operad. This paper shows that these two algebras are equivalent, in the sense that they are weakly equivalent E-algebras, where E is an operad weakly equivalent to both framed little discs and cacti. We recover the equivalence between cacti and framed little discs, and Menichi's isomorphism between the BV-algebras obtained by taking the homology of the loopspace of G and of the double loopspace of BG.

  4. Spectroscopic Parameters of Lumbar Intervertebral Disc Material

    Science.gov (United States)

    Terbetas, G.; Kozlovskaja, A.; Varanius, D.; Graziene, V.; Vaitkus, J.; Vaitkuviene, A.

    2009-06-01

    There are numerous methods of investigating intervertebral disc. Visualization methods are widely used in clinical practice. Histological, imunohistochemical and biochemical methods are more used in scientific research. We propose that a new spectroscopic investigation would be useful in determining intervertebral disc material, especially when no histological specimens are available. Purpose: to determine spectroscopic parameters of intervertebral disc material; to determine emission spectra common for all intervertebral discs; to create a background for further spectroscopic investigation where no histological specimen will be available. Material and Methods: 20 patients, 68 frozen sections of 20 μm thickness from operatively removed intervertebral disc hernia were excited by Nd:YAG microlaser STA-01-TH third harmonic 355 nm light throw 0, 1 mm fiber. Spectrophotometer OceanOptics USB2000 was used for spectra collection. Mathematical analysis of spectra was performed by ORIGIN multiple Gaussian peaks analysis. Results: In each specimen of disc hernia were found distinct maximal spectral peaks of 4 types supporting the histological evaluation of mixture content of the hernia. Fluorescence in the spectral regions 370-700 nm was detected in the disc hernias. The main spectral component was at 494 nm and the contribution of the components with the peak wavelength values at 388 nm, 412 nm and 435±5 nm were varying in the different groups of samples. In comparison to average spectrum of all cases, there are 4 groups of different spectral signatures in the region 400-500 nm in the patient groups, supporting a clinical data on different clinical features of the patients. Discussion and Conclusion: besides the classical open discectomy, new minimally invasive techniques of treating intervertebral disc emerge (PLDD). Intervertebral disc in these techniques is assessed by needle, no histological specimen is taken. Spectroscopic investigation via fiber optics through the

  5. Fast track in total hip and knee arthroplasty--experiences from Hvidovre University Hospital, Denmark

    DEFF Research Database (Denmark)

    Husted, Henrik; Holm, Gitte

    2006-01-01

    This study investigated whether unselected patients operated on with total hip arthroplasty (THA) or total knee arthroplasty (TKA) could accomplish a self-developed accelerated track, ANORAK-HH, with a planned length of stay (LOS) of maximum 5 days and patient satisfaction at all parts of the track....... 307 patients who sustained 329 hip and knee arthroplasties were included in the study with the main material constituted from 243 primary unilateral THA and TKA arthroplasties. ANORAK-HH includes pre-operative patient clinic, patient motivation, dedicated staff, unchanged criteria for discharge and a...

  6. Transradicular lumbar disc herniation: An extreme variant of intraradicular disc herniation

    OpenAIRE

    Kasliwal, Manish K.; Shimer, Adam L

    2015-01-01

    Intradural or intraradicular lumbar disc herniation (IDH) is a relatively rare condition often diagnosed intraoperatively. We encountered an extreme variant of IDH - a transradicular herniation as the disc material extruded through the lumbar nerve root through a split essentially transecting the nerve root. While failure to recognize intradural and intraradicular disc herniation can lead to failed back surgery, the variant described in the present case could lead to iatrogenic injury and com...

  7. Archival-grade optical disc design and international standards

    Science.gov (United States)

    Fujii, Toru; Kojyo, Shinichi; Endo, Akihisa; Kodaira, Takuo; Mori, Fumi; Shimizu, Atsuo

    2015-09-01

    Optical discs currently on the market exhibit large variations in life span among discs, making them unsuitable for certain business applications. To assess and potentially mitigate this problem, we performed accelerated degradation testing under standard ISO conditions, determined the probable disc failure mechanisms, and identified the essential criteria necessary for a stable disc composition. With these criteria as necessary conditions, we analyzed the physical and chemical changes that occur in the disc components, on the basis of which we determined technological measures to reduce these degradation processes. By applying these measures to disc fabrication, we were able to develop highly stable optical discs.

  8. BIOLOGIC JOINT RECONSTRUCTION: ALTERNATIVES TO ARTHROPLASTY

    Directory of Open Access Journals (Sweden)

    Brian J. Cole

    2009-06-01

    limited prosthetic resurfacing. Section VI is "Operative treatment-elbow" including chapters arthroscopy, nonprosthetic elbow arthroplasty, biological resurfacing. The Section VII is "Operative treatment-foot and ankle" including chapters about ankle arthroscopy and cartilage repair in the ankle.The text is one of the most comprehensive and up-to-date references in the treatment of cartilage pathologies and biological joint reconstruction. Some other minimal invasive surgical techniques such as prosthetic partial resurfacing or some osteotomies are also subjected as other alternative treatments for joint restoration. Basic sciences, diagnostic imaging, pharmacological treatment and neutraceuticals, and rehabilitation are making the text. The chapter about future developments in cartilage repair is not only describing the recent technology, different types of tissue engineering and related centers in the world but also gives an idea for the possibilities of future in cartilage repair. Chapters about surgical techniques and procedures are uniformly composed of parts including introduction, preoperative evaluation, surgical technique, postoperative issues, results and references in which the techniques and management described in detail. Numerous high quality images, rich illustrations and figures, page design and also colored tables about key points, protocols, or helpful hints makes the reading and understanding easier

  9. Femoral component loosening after hip resurfacing arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Zustin, Jozef; Sauter, Guido [University Medical Centre Hamburg-Eppendorf, Institute of Pathology, Hamburg (Germany); Hahn, Michael [University Medical Centre Hamburg-Eppendorf, Center for Biomechanics and Skeletal Biology, Hamburg (Germany); Morlock, Michael M. [TUHH Hamburg University of Technology, Biomechanics Section, Hamburg (Germany); Ruether, Wolfgang [University Medical Centre Hamburg-Eppendorf, Department of Orthopaedics, Hamburg (Germany); Amling, Michael [University Medical Centre Hamburg-Eppendorf, Center for Biomechanics and Skeletal Biology, Hamburg (Germany); University Medical Centre Hamburg-Eppendorf, Department of Trauma, Hand and Reconstructive Surgery, Hamburg (Germany)

    2010-08-15

    Before the re-introduction of the current generation of total hip resurfacing arthroplasty, component loosening and osteolysis were of great concern to the orthopaedic community. Early, mid- and long-term clinical results are encouraging, but component loosening still exists. Macroscopic, contact radiographic and histopathological analyses after undecalcified preparation of bone tissue specimens were performed. To investigate the frequency and morphological patterns of the loosening of the femoral component, we analysed a series of 190 retrieved femoral remnants that were revised for aseptic failures. Thirty-five (18.4%) hips were revised for clinical and/or radiographic loosening of the femoral component. Pseudoarthrosis (n = 17; median in situ time: 16 weeks, interquartile range [IQR]: 9 to 34), collapsed osteonecrosis (n = 5; median in situ time: 79 weeks, IQR: 63 to 97), cement-socket debonding (n = 3; median in situ time: 89 weeks, IQR: 54 to 97) and at later follow-up bone-cement loosening (n = 10; median in situ time: 175 weeks; IQR 112 to 198; p =0.005) were distinct patterns of the femoral remnant-implant loosening. Fibrocartilaginous metaplasia of interface bone trabeculae (n = 38; median in situ time: 61 weeks, IQR: 32 to 138) was strongly associated with femoral component loosening (p = 0.009). Both the trabecular hyperosteoidosis (n = 32; median in situ time: 71 weeks, IQR 50 to 129) and excessive intraosseous lymphocyte infiltration (n = 12; median in situ time: 75 weeks, IQR 51 to 98) at the bone-cement interface correlated strongly with fibrocartilaginous metaplasia (p = 0.001 and p = 0.016 respectively) and all three lesions were associated with the female gender (p = 0.021, p = 0.009, and p = 0.051). Femoral component loosening at early follow-up was mostly caused by pathological changes of the femoral remnant bone tissue: pseudoarthrosis and collapsed osteonecrosis. Fibrocartilaginous metaplasia was frequently observed in hips with femoral

  10. [Diagnosis in patients with a painful arthroplasty].

    Science.gov (United States)

    Carrega, Giuliana; Antonini, Andrea; Burastero, Giorgio; Casalino-Finocchio, Giorgetta; Ronca, Agostina; Salomone, Carlo; Riccio, Giovanni

    2015-06-01

    The differential diagnosis between asepting loosening or prosthetic joint infection is not always easy. Tc-99m-labelled leucocyte scans, frozen section and histology can help recognise doubtful cases. We report the experience of the Unit for Infectious Diseases and Septic Orthopaedics of the ASL-2 Liguria, Italy, with a Tc-99m-labelled leucocyte scan and intraoperative frozen section to choose the best therapeutic approach: one-stage or two-stage exchange or arthrodesis-arthroplastica. All cases underwent histology and intraoperative cultures to confirm the diagnosis, and the effectiveness of the approach was evaluated at follow up after 18 months. From January 2011 to December 2012, 36 patients were evaluated (21 hip and 15 knee arthroprosthesis). The Tc-99m-labelled leukocyte scan was positive in 31 and negative in 5 patients. Frozen section was negative in 7 patients. Five of them were patients with a negative Tc-99m-labelled leucocyte scan and were treated successfully with one-stage exchange, even if, in one of them, Enterococcus faecalis was isolated at replacement and suppressive antibiotic treatment was needed. The other 31 patients were treated with arthrodesis arthroplasty (3 patients) or a two-stage exchange. In this group the Tc-99m-labelled leucocyte scan was positive in all patients and the frozen section was positive in 29/31 cases with 6% false negative. Histology was positive in 27/31 with 13% of false negative. The sensitivity and specificity value was respectively 90% and 100% in the frozen section, 84% and 100% in histology. Cultures were positive in 23/31 cases. Patients subjected to two-stage exchange were evaluated again during prosthesis replacement but the results of the Tc-99m-labelled leucocyte scan and histology showed unclear results more frequently: the Tc-99m-labelled leucocyte scan was positive in two cases, the frozen section in three and histology in seven in spite of positive culture in three cases and one relapse in a patient

  11. Treatment of lumbar disc herniation by percutaneous laser disc decompression (PLDD) and modified PLDD

    Science.gov (United States)

    Chi, Xiao fei; Li, Hong zhi; Wu, Ru zhou; Sui, Yun xian

    2005-07-01

    Objective: To study the micro-invasive operative method and to compare the effect of treatment of PLDD and modified PLDD for Lumbar Disc Herniation. Method: Vaporized part of the nucleus pulposus in single or multiple point after acupuncture into lumbar disc, to reach the purpose of the decompression of the lumbar disc. Result: Among the 19 cases of the regular PLDD group, the excellent and good rate was 63.2%, and among the 40 cases of the modified PLDD group, the excellent and good rate was 82.5%. Conclusion: The modified PLDD has good effect on the treatment for lumbar disc herniation.

  12. Transradicular lumbar disc herniation: An extreme variant of intraradicular disc herniation

    Directory of Open Access Journals (Sweden)

    Manish K Kasliwal

    2015-01-01

    Full Text Available Intradural or intraradicular lumbar disc herniation (IDH is a relatively rare condition often diagnosed intraoperatively. We encountered an extreme variant of IDH - a transradicular herniation as the disc material extruded through the lumbar nerve root through a split essentially transecting the nerve root. While failure to recognize intradural and intraradicular disc herniation can lead to failed back surgery, the variant described in the present case could lead to iatrogenic injury and complication if not recognized. A unique case of transradicular lumbar disc herniation in a 25-year-old patient is presented with the depiction of intraoperative images supplementing the text.

  13. Axial T2* mapping in intervertebral discs: a new technique for assessment of intervertebral disc degeneration

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, Sven; Quirbach, Sebastian; Krause, Fabian G.; Benneker, Lorin M. [Inselspital, Berne University Hospital, Department of Orthopaedic Surgery, Berne (Switzerland); Mamisch, Tallal C. [Inselspital, Berne University Hospital, Department of Radiology, Berne (Switzerland); Werlen, Stefan [Clinic Sonnenhof, Department of Radiology, Berne (Switzerland)

    2012-09-15

    To demonstrate the potential benefits of biochemical axial T2* mapping of intervertebral discs (IVDs) regarding the detection and grading of early stages of degenerative disc disease using 1.5-Tesla magnetic resonance imaging (MRI) in a clinical setting. Ninety-three patients suffering from lumbar spine problems were examined using standard MRI protocols including an axial T2* mapping protocol. All discs were classified morphologically and grouped as ''healthy'' or ''abnormal''. Differences between groups were analysed regarding to the specific T2* pattern at different regions of interest (ROIs). Healthy intervertebral discs revealed a distinct cross-sectional T2* value profile: T2* values were significantly lower in the annulus fibrosus compared with the nucleus pulposus (P = 0.01). In abnormal IVDs, T2* values were significantly lower, especially towards the centre of the disc representing the expected decreased water content of the nucleus (P = 0.01). In herniated discs, ROIs within the nucleus pulposus and ROIs covering the annulus fibrosus showed decreased T2* values. Axial T2* mapping is effective to detect early stages of degenerative disc disease. There is a potential benefit of axial T2* mapping as a diagnostic tool, allowing the quantitative assessment of intervertebral disc degeneration. circle Axial T2* mapping effective in detecting early degenerative disc disease. (orig.)

  14. Axial T2* mapping in intervertebral discs: a new technique for assessment of intervertebral disc degeneration

    International Nuclear Information System (INIS)

    To demonstrate the potential benefits of biochemical axial T2* mapping of intervertebral discs (IVDs) regarding the detection and grading of early stages of degenerative disc disease using 1.5-Tesla magnetic resonance imaging (MRI) in a clinical setting. Ninety-three patients suffering from lumbar spine problems were examined using standard MRI protocols including an axial T2* mapping protocol. All discs were classified morphologically and grouped as ''healthy'' or ''abnormal''. Differences between groups were analysed regarding to the specific T2* pattern at different regions of interest (ROIs). Healthy intervertebral discs revealed a distinct cross-sectional T2* value profile: T2* values were significantly lower in the annulus fibrosus compared with the nucleus pulposus (P = 0.01). In abnormal IVDs, T2* values were significantly lower, especially towards the centre of the disc representing the expected decreased water content of the nucleus (P = 0.01). In herniated discs, ROIs within the nucleus pulposus and ROIs covering the annulus fibrosus showed decreased T2* values. Axial T2* mapping is effective to detect early stages of degenerative disc disease. There is a potential benefit of axial T2* mapping as a diagnostic tool, allowing the quantitative assessment of intervertebral disc degeneration. circle Axial T2* mapping effective in detecting early degenerative disc disease. (orig.)

  15. Appearance of Keplerian discs orbiting Kerr superspinars

    CERN Document Server

    Stuchlik, Zdenek; 10.1088/0264-9381/27/21/215017

    2011-01-01

    We study optical phenomena related to appearance of Keplerian accretion discs orbiting Kerr superspinars predicted by the string theory. The superspinar exterior is described by the standard Kerr naked singularity geometry breaking the black hole limit on the internal angular momentum (spin). We construct local photon escape cones for a variety of orbiting sources that enable to determine the superspinars silhouette in the case of distant observers. We show that the superspinar silhouette depends strongly on the assumed edge where the external Kerr spacetime is joined to the internal spacetime governed by the string theory and significantly differs from the black hole silhouette. The appearance of the accretion disc is strongly dependent on the value of the superspinar spin in both their shape and frequency shift profile. Apparent extension of the disc grows significantly with growing spin, while the frequency shift grows with descending spin. This behavior differs substantially from appearance of discs orbit...

  16. Eclipse Mapping: Astrotomography of Accretion Discs

    CERN Document Server

    Baptista, Raymundo

    2015-01-01

    The Eclipse Mapping Method is an indirect imaging technique that transforms the shape of the eclipse light curve into a map of the surface brightness distribution of the occulted regions. Three decades of application of this technique to the investigation of the structure, the spectrum and the time evolution of accretion discs around white dwarfs in cataclysmic variables have enriched our understanding of these accretion devices with a wealth of details such as (but not limited to) moving heating/cooling waves during outbursts in dwarf novae, tidally-induced spiral shocks of emitting gas with sub-Keplerian velocities, elliptical precessing discs associated to superhumps, and measurements of the radial run of the disc viscosity through the mapping of the disc flickering sources. This chapter reviews the principles of the method, discusses its performance, limitations, useful error propagation procedures, as well as highlights a selection of applications aimed at showing the possible scientific problems that ha...

  17. Only marginal alignment of disc galaxies

    CERN Document Server

    Andrae, Rene

    2011-01-01

    Testing theories of angular-momentum acquisition of rotationally supported disc galaxies is the key to understand the formation of this type of galaxies. The tidal-torque theory tries to explain this acquisition process in a cosmological framework and predicts positive autocorrelations of angular-momentum orientation and spiral-arm handedness on distances of 1Mpc/h. This disc alignment can also cause systematic effects in weak-lensing measurements. Previous observations claimed discovering such correlations but did not account for errors in redshift, ellipticity and morphological classifications. We explain how to rigorously propagate all important errors. Analysing disc galaxies in the SDSS database, we find that positive autocorrelations of spiral-arm handedness and angular-momentum orientations on distances of 1Mpc/h are plausible but not statistically significant. This result agrees with a simple hypothesis test in the Local Group, where we find no evidence for disc alignment. Moreover, we demonstrate tha...

  18. The lowest surface brightness disc galaxy known

    International Nuclear Information System (INIS)

    The discovery of a galaxy with a prominent bulge and a dominant extremely low surface brightness disc component is reported. The profile of this galaxy is very similar to the recently discovered giant low surface brightness galaxy Malin 1. The disc central surface brightness is found to be ∼ 26.4 Rμ, some 1.5 mag fainter than Malin 1 and thus by far the lowest yet observed. (author)

  19. Low back pain and degenerative disc disease

    OpenAIRE

    Jandrić Slavica; Antić Branislav

    2006-01-01

    Introduction. Various clinical conditions can cause low back pain, and in most cases it is of a degenerative origin. Degenerative disc disease is a common condition which affects young to middle-aged men and women equally. Changes in the mechanical properties of the disc lead to degenerative arthritis in the intervertebral joints, osteophytes, and narrowing the intervertebral foramen or the spinal canal. Pathophysiology. Degenerative cascade, described by Kirkaldy-Willis, is the widely accept...

  20. Mach disc formation in cylindrical recovery systems

    Energy Technology Data Exchange (ETDEWEB)

    Morris, C.E.; McQueen, R.G.; Marsh, S.P.

    1983-01-01

    Cylindrical recovery systems have been used to shock-load polymers to pressures exceeding 50 GPa. In order to determine the pressures generated in these recovery systems the formation of the Mach disc on axis and its approach to steady state was monitored. The relation of the Mach disc diameter to the lateral dimension of the high explosive used to compress the polymer samples was also investigated.

  1. Activ C cervical disc replacement for myelopathy

    Directory of Open Access Journals (Sweden)

    L McGonagle

    2011-01-01

    Full Text Available Background: Cervical disc replacement is becoming an increasingly popular treatment option for cervical myelopathy. It retains motion at the affected segment, unlike anterior cervical discectomy and fusion. The aim of this study is to assess the outcomes of a series of patients who underwent Activ C disc replacement for cervical myelopathy. Materials and Methods: A series of patients at the above Trust with clinical and radiological evidence of cervical myelopathy who were suitable for cervical disc replacement from 2007 to 2009 were included. Implants were inserted by one of two consultant surgeons {IMS, MO′M}. Patients were assessed preoperatively and at six, 12 and 24 months, postoperatively, with a visual analogue score (VAS for neck and arm pain severity and frequency, the Neck Disability Index questionnaire (NDI and the Centre for Epidemiologic Studies Depression questionnaire (CES-D. Results: Ten patients underwent surgery between May 2007 and July 2009, 6 women, and 4 men. Average age was 54 years (40-64. Disc levels replaced were: four at C4-5; eight at C5-6; seven at C6-7. Three patients had one disc replaced, five patients had two discs replaced, and two patients had three discs replaced. The VAS for neck pain improved from 5.9 pre-operatively to 1.4-24 months postoperatively and the VAS arm pain improved from 5.4 to 2.6. The NDI improved from 51% preoperatively to 26.8% at 24 months postoperatively. The CES-D showed a slight increase from 19.5 preoperatively to 21.7 at 24 months, postoperatively. Conclusion: Cervical decompression and disc replacement improves pain and function in patients with cervical myelopathy. This benefit is maintained at 24 months post op, with no cases requiring revision.

  2. Do We Need Biomarkers for Disc Degeneration?

    OpenAIRE

    Gruber, Helen E.; Edward N. Hanley, Jr.

    2007-01-01

    Disc degeneration plays a major role in this country's medical, social and economic structure. The life-time prevalence of low back pain, which has disc degeneration as its cause, is about 80% in the general population. It is a primary cause of disability and estimated costs related to low back disorders exceed $100 billion per year in the U.S. alone. Biomarkers are becoming increasingly important as indicators of the presence of disease, and in evaluating outcomes during clinical treatment. ...

  3. Mach disc formation in cylindrical recovery systems

    International Nuclear Information System (INIS)

    Cylindrical recovery systems have been used to shock-load polymers to pressures exceeding 50 GPa. In order to determine the pressures generated in these recovery systems the formation of the Mach disc on axis and its approach to steady state was monitored. The relation of the Mach disc diameter to the lateral dimension of the high explosive used to compress the polymer samples was also investigated

  4. Hard Discs on the Hyperbolic Plane

    OpenAIRE

    Modes, Carl D.; Kamien, Randall D.

    2007-01-01

    We examine a simple hard disc fluid with no long range interactions on the two dimensional space of constant negative Gaussian curvature, the hyperbolic plane. This geometry provides a natural mechanism by which global crystalline order is frustrated, allowing us to construct a tractable model of disordered monodisperse hard discs. We extend free area theory and the virial expansion to this regime, deriving the equation of state for the system, and compare its predictions with simulation near...

  5. Inflammation in intervertebral disc degeneration and regeneration

    OpenAIRE

    Molinos, Maria; Almeida, Catarina R.; Caldeira, Joana; Cunha, Carla; Gonçalves, Raquel M.; Barbosa, Mário A.

    2015-01-01

    Intervertebral disc (IVD) degeneration is one of the major causes of low back pain, a problem with a heavy economic burden, which has been increasing in prevalence as populations age. Deeper knowledge of the complex spatial and temporal orchestration of cellular interactions and extracellular matrix remodelling is critical to improve current IVD therapies, which have so far proved unsatisfactory. Inflammation has been correlated with degenerative disc disease but its role in discogenic pain a...

  6. Influence of degenerative changes of intervertebral disc

    OpenAIRE

    Wang, Yi; Chen, Hai-Bin; Zhang, Ling; ZHANG Li-ying; Liu, Jing-cheng; WANG Zheng-guo

    2012-01-01

    【Abstract】Objective: To investigate the material properties of normal and degenerated intervertebral discs (IVDs) and examine the effect of degenerative changes on IVD pathology. Methods: A computer-based online search was under-taken to identify English articles about material properties of IVDs published from January 1950 to 2011 in PubMed database. The retrieved keywords included material properties, intervertebral disc and degeneration. Based on the principle...

  7. Material Science in Cervical Total Disc Replacement

    OpenAIRE

    Pham, Martin H.; Mehta, Vivek A.; Alexander Tuchman; Hsieh, Patrick C.

    2015-01-01

    Current cervical total disc replacement (TDR) designs incorporate a variety of different biomaterials including polyethylene, stainless steel, titanium (Ti), and cobalt-chrome (CoCr). These materials are most important in their utilization as bearing surfaces which allow for articular motion at the disc space. Long-term biological effects of implanted materials include wear debris, host inflammatory immune reactions, and osteolysis resulting in implant failure. We review here the most common ...

  8. Accretion Disc Evolution in Single and Binary T Tauri Stars

    OpenAIRE

    Armitage, Philip J.; C.J. Clarke; Tout, C.A.

    1998-01-01

    We present theoretical models for the evolution of T Tauri stars surrounded by circumstellar discs. The models include the effects of pre-main-sequence stellar and time dependent disc evolution, and incorporate the effects of stellar magnetic fields acting on the inner disc. For single stars, consistency with observations in Taurus-Auriga demands that disc dispersal occurs rapidly, on much less than the viscous timescale of the disc, at roughly the epoch when heating by stellar radiation firs...

  9. MOND predictions of "halo" phenomenology in disc galaxies

    OpenAIRE

    Milgrom, Mordehai; Sanders, Robert H.

    2004-01-01

    We examine two corollaries of MOND pertaining to the properties of the equivalent dark-matter halo. MOND predicts for pure exponential discs a tight relation involving the halo and disc scale lengths and the mean acceleration in the disc, which we find to test favorably against the Verheijen sample of Ursa Major galaxies. A correlation between halo and disc length scales is also apparent when the "maximum disc" contribution is assumed, but we demonstrate that this follows from the more genera...

  10. Spontaneous Regression of a Large Lumbar Disc Extrusion

    OpenAIRE

    Ryu, Sung-Joo; Kim, In Soo

    2010-01-01

    Although the spontaneous disappearance or decrease in size of a herniated disc is well known, that of a large extruded disc has rarely been reported. This paper reports a case of a spontaneous regression of a large lumbar disc extrusion. The disc regressed spontaneously with clinical improvement and was documented on a follow up MRI study 6 months later. The literature is reviewed and the possible mechanisms of spontaneous disc regression are discussed.

  11. Density waves in debris discs and galactic nuclei

    OpenAIRE

    Jalali, Mir Abbas; Tremaine, Scott

    2011-01-01

    We study the linear perturbations of collisionless near-Keplerian discs. Such systems are models for debris discs around stars and the stellar discs surrounding supermassive black holes at the centres of galaxies. Using a finite-element method, we solve the linearized collisionless Boltzmann equation and Poisson's equation for a wide range of disc masses and rms orbital eccentricities to obtain the eigenfrequencies and shapes of normal modes. We find that these discs can support large-scale `...

  12. MR imaging of cervical disc disease

    International Nuclear Information System (INIS)

    Since magnetic resonance imaging (MRI) technology has been greatly improved, MRI for cervical disc disease has become widely used in many facilities. Among non-invasive procedures, MRI is regarded as one of the most useful ones. Conventional myelography, CT myelography, and MRI were performed on 10 patients with cervical disc disease. The authors discussed the correlation between conventional myelography, CT myelography, and MRI as regards their ability to determine the localization and the laterality of disc protrusion and osteophyte. In our MRI study, we use both short-echo (SE) images and GRASS images. The parameters of our GRASS included 5 mm-thick sections. TR=200, TE=20, and flip angles of 10deg. This pulse sequence generates images with high signal cerebrospinal fluid (CSF), resulting in a high-contrast CSF-spinal cord, osteophyte, and disc protrusion. As yet, although it easily shows the localization and laterality of the disc and/or osteophyte, image quality of the GRASS is not yet sufficient to allow us to evaluate detailed deformity of the spinal cord and nerve root. The authors stress the usefulness of this GRASS image for the evaluation of suspected cervical disc disease. (author)

  13. Magnetic white dwarfs with debris discs

    CERN Document Server

    Külebi, Baybars; Lorén-Aguilar, Pablo; Isern, Jordi; García-Berro, Enrique

    2013-01-01

    It has long been accepted that a possible mechanism for explaining the existence of magnetic white dwarfs is the merger of a binary white dwarf system, as there are viable mechanisms for producing sustainable magnetic fields within the merger product. However, the lack of rapid rotators in the magnetic white dwarf population has been always considered a problematic issue of this scenario. Smoothed Particle Hydrodynamics simulations show that in mergers in which the two white dwarfs have different masses a disc around the central compact object is formed. If the central object is magnetized it can interact with the disc through its magnetosphere. The torque applied by the disc changes the spin of the star, whereas the transferred angular momentum from the star to the disc determines the properties of the disc. In this work we build a model for the disc evolution under the effect of magnetic accretion, and for the angular momentum evolution of the star, which can be compared with the observations. Our model pre...

  14. Rapid radiative clearing of protoplanetary discs

    CERN Document Server

    Haworth, Thomas J; Owen, James E

    2015-01-01

    The lack of observed transition discs with inner gas holes of radii greater than ~50AU implies that protoplanetary discs dispersed from the inside out must remove gas from the outer regions rapidly. We investigate the role of photoevaporation in the final clearing of gas from low mass discs with inner holes. In particular, we study the so-called "thermal sweeping" mechanism which results in rapid clearing of the disc. Thermal sweeping was originally thought to arise when the radial and vertical pressure scale lengths at the X-ray heated inner edge of the disc match. We demonstrate that this criterion is not fundamental. Rather, thermal sweeping occurs when the pressure maximum at the inner edge of the dust heated disc falls below the maximum possible pressure of X-ray heated gas (which depends on the local X-ray flux). We derive new critical peak volume and surface density estimates for rapid radiative clearing which, in general, result in rapid dispersal happening less readily than in previous estimates. Thi...

  15. CT findings of calcified herniated lumbar disc

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hyo Kun; Lee, Jun Hyung [Chang Dong Armed Forces Evacuation Hospital, Seoul (Korea, Republic of)

    1987-12-15

    Computed tomography (CT) of 10 calcified herniated lumber discs among 46 operated cases were analysed at the aspects of incidence, location, shape, etc. The results are as follows: 1. The incidence of calcification is 22% (10/46). 2. Among 10 cases, 3 cases are at the level of L4-5 disc space and 7 cases are at the level of L5-S1 disc space. 3. Central herniation (8 cases) are more common than posterolateral herniation (2 cases). 4. Linear or band-like calcifications in the periphery of herniated disc (annulus fibrosus type) are 6 cases and dense patchy calcification in the central portion of herniated disc (nucleus pulposus type) are 4 cases. 5. Two cases (50%) of 4 cases with nucleus pulposus type calcification were found to be ruptured at operation, but none of 6 annulus fibrous calcification types showed rupture. 6. Because more wide operation field and invasive exploration were required in calcified cases than non-calcified cases, it is suggested to evaluate the presence, location, and type of calcification in herniated disc in detail.

  16. Testing protoplanetary disc dispersal with radio emission

    CERN Document Server

    Owen, James E; Ercolano, Barbara

    2013-01-01

    We consider continuum free-free radio emission from the upper atmosphere of protoplanetary discs as a probe of the ionized luminosity impinging upon the disc. Making use of previously computed hydrodynamic models of disc photoevaporation within the framework of EUV and X-ray irradiation, we use radiative transfer post-processing techniques to predict the expected free-free emission from protoplanetary discs. In general, the free-free luminosity scales roughly linearly with ionizing luminosity in both EUV and X-ray driven scenarios, where the emission dominates over the dust tail of the disc and is partial optically thin at cm wavelengths. We perform a test observation of GM Aur at 14-18 Ghz and detect an excess of radio emission above the dust tail to a very high level of confidence. The observed flux density and spectral index are consistent with free-free emission from the ionized disc in either the EUV or X-ray driven scenario. Finally, we suggest a possible route to testing the EUV and X-ray driven disper...

  17. The diversity of thick galactic discs

    Science.gov (United States)

    Kasparova, Anastasia V.; Katkov, Ivan Yu.; Chilingarian, Igor V.; Silchenko, Olga K.; Moiseev, Alexey V.; Borisov, Svyatoslav B.

    2016-07-01

    Although thick stellar discs are detected in nearly all edge-on disc galaxies, their formation scenarios still remain a matter of debate. Due to observational difficulties, there is a lack of information about their stellar populations. Using the Russian 6-m telescope BTA we collected deep spectra of thick discs in three edge-on S0-a disc galaxies located in different environments: NGC 4111 in a dense group, NGC 4710 in the Virgo cluster, and NGC 5422 in a sparse group. We see intermediate age (4-5 Gyr) metal rich ([Fe/H] ˜- 0.2…0.0 dex) stellar populations in NGC 4111 and NGC 4710. On the other hand, NGC 5422 does not harbour young stars, its disc is thick and old (10 Gyr), without evidence for a second component, and its α-element abundance suggests a 1.5-2 Gyr long formation epoch implying its formation at high redshift. Our results suggest the diversity of thick disc formation scenarios.

  18. The Diversity of Thick Galactic Discs

    CERN Document Server

    Kasparova, Anastasia V; Chilingarian, Igor V; Silchenko, Olga K; Moiseev, Alexey V; Borisov, Svyatoslav B

    2016-01-01

    Although thick stellar discs are detected in nearly all edge-on disc galaxies, their formation scenarios still remain a matter of debate. Due to observational difficulties, there is a lack of information about their stellar populations. Using the Russian 6-m telescope BTA we collected deep spectra of thick discs in three edge-on S0-a disc galaxies located in different environments: NGC4111 in a dense group, NGC4710 in the Virgo cluster, and NGC5422 in a sparse group. We see intermediate age (4-5 Gyr) metal rich ([Fe/H] $\\sim$ -0.2 - 0.0 dex) stellar populations in NGC4111 and NGC4710. On the other hand, NGC5422 does not harbour young stars, its disc is thick and old (10 Gyr), without evidence for a second component, and its $\\alpha$-element abundance suggests a 1.5-2 Gyr long formation epoch implying its formation at high redshift. Our results suggest the diversity of thick disc formation scenarios.

  19. Tidally distorted accretion discs in binary stars

    Science.gov (United States)

    Ogilvie, G. I.

    2002-03-01

    The non-axisymmetric features observed in the discs of dwarf novae in outburst are usually considered to be spiral shocks, which are the non-linear relatives of tidally excited waves. This interpretation suffers from a number of problems. For example, the natural site of wave excitation lies outside the Roche lobe, the disc must be especially hot, and most treatments of wave propagation do not take into account the vertical structure of the disc. In this paper I construct a detailed semi-analytical model of the non-linear tidal distortion of a thin, three-dimensional accretion disc by a binary companion on a circular orbit. The analysis presented here allows for vertical motion and radiative energy transport, and introduces a simple model for the turbulent magnetic stress. The m=2 inner vertical resonance has an important influence on the amplitude and phase of the tidal distortion. I show that the observed patterns find a natural explanation if the emission is associated with the tidally thickened sectors of the outer disc, which may be irradiated from the centre. According to this hypothesis, it may be possible to constrain the physical parameters of the disc through future observations.

  20. Proteomic signature of the murine intervertebral disc.

    Directory of Open Access Journals (Sweden)

    Matthew R McCann

    Full Text Available Low back pain is the most common musculoskeletal problem and the single most common cause of disability, often attributed to degeneration of the intervertebral disc. Lack of effective treatment is directly related to our limited understanding of the pathways responsible for maintaining disc health. While transcriptional analysis has permitted initial insights into the biology of the intervertebral disc, complete proteomic characterization is required. We therefore employed liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS protein/peptide separation and mass spectrometric analyses to characterize the protein content of intervertebral discs from skeletally mature wild-type mice. A total of 1360 proteins were identified and categorized using PANTHER. Identified proteins were primarily intracellular/plasma membrane (35%, organelle (30%, macromolecular complex (10%, extracellular region (9%. Molecular function categorization resulted in three distinct categories: catalytic activity (33%, binding (molecule interactions (29%, and structural activity (13%. To validate our list, we confirmed the presence of 14 of 20 previously identified IVD-associated markers, including matrix proteins, transcriptional regulators, and secreted proteins. Immunohistochemical analysis confirmed distinct localization patterns of select protein with the intervertebral disc. Characterization of the protein composition of healthy intervertebral disc tissue is an important first step in identifying cellular processes and pathways disrupted during aging or disease progression.