WorldWideScience

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. Cervical Total Disc Arthroplasty

    OpenAIRE

    Basho, Rahul; Hood, Kenneth A.

    2012-01-01

    Symptomatic adjacent segment degeneration of the cervical spine remains problematic for patients and surgeons alike. Despite advances in surgical techniques and instrumentation, the solution remains elusive. Spurred by the success of total joint arthroplasty in hips and knees, surgeons and industry have turned to motion preservation devices in the cervical spine. By preserving motion at the diseased level, the hope is that adjacent segment degeneration can be prevented. Multiple cervical disc...

  3. 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

  4. Lubrication regimes in lumbar total disc arthroplasty.

    Science.gov (United States)

    Shaheen, A; Shepherd, D E T

    2007-08-01

    A number of total disc arthroplasty devices have been developed. Some concern has been expressed that wear may be a potential failure mode for these devices, as has been seen with hip arthroplasty. The aim of this paper was to investigate the lubrication regimes that occur in lumbar total disc arthroplasty devices. The disc arthroplasty was modelled as a ball-and-socket joint. Elastohydrodynamic lubrication theory was used to calculate the minimum film thickness of the fluid between the bearing surfaces. The lubrication regime was then determined for different material combinations, size of implant, and trunk velocity. Disc arthroplasties with a metal-polymer or metal-metal material combination operate with a boundary lubrication regime. A ceramic-ceramic material combination has the potential to operate with fluid-film lubrication. Disc arthroplasties with a metal-polymer or metal-metal material combination are likely to generate wear debris. In future, it is worth considering a ceramic-ceramic material combination as this is likely to reduce wear.

  5. 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.

  6. The artificial disc: theory, design and materials.

    Science.gov (United States)

    Bao, Q B; McCullen, G M; Higham, P A; Dumbleton, J H; Yuan, H A

    1996-06-01

    Low back pain is one of the most common medical conditions in the Western world. Disc degeneration, an inevitable process of aging, of variable rate and degree, is one of the major causes of low back pain. Currently, there are two major surgical interventions for treating conditions related to the degenerative disc: discectomy and fusion. Although discectomy and fusion produce a relatively good short-term clinical result in relieving pain, both these surgical treatments alter the biomechanics of the spine, possibly leading to further degeneration of the surrounding tissues and the discs at adjacent levels. Over the past 35 years, a tremendous effort has been made to develop an artificial disc to replace the degenerated disc. The goal is the restoration of the natural biomechanics of the segment after disc excision, thus relieving pain and preventing further degeneration at adjacent segments. However, the artificial disc faces a complex biomechanical environment which makes replication of the biomechanics difficult and long-term survival challenging to designs and materials. The purpose of this article is to examine the factors of importance in designing a disc replacement. Topics covered include the structure and function of the natural disc, the changes that occur with disc degeneration and existing methods of treatment for the degenerative spine. The progress in achieving a functional, long-lasting disc replacement is outlined.

  7. Discover cervical disc arthroplasty versus anterior cervical discectomy and fusion in symptomatic cervical disc diseases: A meta-analysis

    Science.gov (United States)

    Shangguan, Lei; Ning, Guang-Zhi; Tang, Yu; Wang, Zhe; Luo, Zhuo-Jing; Zhou, Yue

    2017-01-01

    Objective Symptomatic cervical disc disease (SCDD) is a common degenerative disease, and Discover artificial cervical disc, a new-generation nonconstrained artificial disk, has been developed and performed gradually to treat it. We performed this meta-analysis to compare the efficacy and safety between Discover cervical disc arthroplasty (DCDA) and anterior cervical discectomy and fusion (ACDF) for SCDD. Methods An exhaustive literature search of PubMed, EMBASE, and the Cochrane Library was conducted to identify randomized controlled trials that compared DCDA with ACDF for patients suffering SCDD. A random-effect model was used. Results were reported as standardized mean difference or risk ratio with 95% confidence interval. Results Of 33 articles identified, six studies were included. Compared with ACDF, DCDA demonstrated shorter operation time (P 0.05). Subgroup analyses did not demonstrated significant differences. Conclusion In conclusion, DCDA presented shorter operation time, and better ROM at the operative level. However, no significant differences were observed in blood loss, NDI scores, neck and arm pain scores, JOA scores, secondary surgery procedures and adverse events between the two groups. Additionally, more studies of high quality with mid- to long-term follow-up are required in future. PMID:28358860

  8. Biomechanics of a posture-controlling cervical artificial disc: mechanical, in vitro, and finite-element analysis.

    Science.gov (United States)

    Crawford, Neil R; Arnett, Jeffery D; Butters, Joshua A; Ferrara, Lisa A; Kulkarni, Nikhil; Goel, Vijay K; Duggal, Neil

    2010-06-01

    Different methods have been described by numerous investigators for experimentally assessing the kinematics of cervical artificial discs. However, in addition to understanding how artificial discs affect range of motion, it is also clinically relevant to understand how artificial discs affect segmental posture. The purpose of this paper is to describe novel considerations and methods for experimentally assessing cervical spine postural control in the laboratory. These methods, which include mechanical testing, cadaveric testing, and computer modeling studies, are applied in comparing postural biomechanics of a novel postural control arthroplasty (PCA) device versus standard ball-and-socket (BS) and ball-in-trough (BT) arthroplasty devices. The overall body of evidence from this group of tests supports the conclusion that the PCA device does control posture to a particular lordotic position, whereas BS and BT devices move freely through their ranges of motion.

  9. Durability of cervical disc arthroplasties and its influence factors

    Science.gov (United States)

    Chen, Chao; Zhang, Xiaolin; Ma, Xinlong

    2017-01-01

    Abstract Background: The durability of cervical disc arthroplasties (CDA) may vary significantly because of different designs and implanting techniques of the devices. Nevertheless, the comparative durability remains unknown. Objectives: We aimed to assess the durability of CDAs in at least 2-year follow-up. We analyzed the classifications and causes of secondary surgical procedures, as well as the structural designs of the devices that might influence the durability. Methods: PubMed, Medline, Embase, and Cochrane Central Register of Controlled Trials were searched from the inception of each database to September 2015 using the following Keywords: “cervical disc replacement” OR “cervical disc arthroplasty” AND “randomized controlled trial (RCT).” Publication language was restricted to English. The primary outcome was the rate of secondary surgical procedures following CDA or anterior cervical decompression and fusion (ACDF). Pairwise meta-analysis and a Bayesian network meta-analysis were carried out using Review Manager v5.3.5 and WinBUGS version 1.4.3, respectively. Quality of evidence was appraised by Grading of Recommendations Assessment, Development and Evaluation methodology. Results: Twelve RCTs that met the eligibility criteria were included. Follow-up ranged from 2 years to 7 years. A total of 103 secondary surgical procedures were performed. The most frequent classification of secondary surgical procedures was reoperation (48/103) and removal (47/103). Revision (3/103) and supplementary fixation (2/103) were rare. Adjacent-level diseases were the most common cause of reoperations. The rates of secondary surgical procedures were significantly lower in Mobi-C, Prestige, Prodisc-C, Secure-C group than in ACDF group. No significant difference was detected between Bryan, PCM, Kineflex-C, Discover, and ACDF. Mobi-C, Secure-C, and Prodisc-C ranked the best, the second best, the third best, respectively. Conclusions: We concluded that Mobi-C, Secure

  10. 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.

  11. 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.

  12. The effect of single-level, total disc arthroplasty on sagittal balance parameters: a prospective study.

    Science.gov (United States)

    Le Huec, Jc; Basso, Y; Mathews, H; Mehbod, A; Aunoble, S; Friesem, T; Zdeblick, T

    2005-06-01

    A prospective radiographic study of the influence of total disc replacement on spinal sagittal balance. The goal of this study was to prospectively determine the effect of a single-level, total disc replacement on the sagittal balance of the spine, especially on sacral tilt (ST), pelvic tilt (PT), and lumbar lordosis. It has been shown that lumbar fusion may deleteriously alter the sagittal balance of the spine, including a decrease in the ST and lumbar lordosis. Clinically, postfusion pain has been shown to be significantly related to a decreased ST, increased PT, and decreased lumbar lordosis, independent of other factors such as pseudoarthrosis. To our knowledge, the influence of total disc replacement on spinal sagittal balance has not yet been reported in the literature. This is a prospective study of 35 patients who received a single level disc replacement using the Maverick Total Disc Arthroplasty system (Medtronic Sofamor Danek, Memphis, Tennessee) by a single surgeon at one institution from March 2002 to September 2003. The preoperative and postoperative radiographic evaluation included standing anteroposterior and lateral full spine films that included the femoral heads. The parameters studied were ST, PT, global and segmental lordosis, and global kyphosis. The average age of the 35 patients studied was 44.3 years (range 35-57). There were 18 females and 17 males. The disc arthroplasty was performed at the L4-L5 level in 19 patients and at the L5-S1 level in 16 patients. The average follow-up was 14 months (range 6-22 months). The preoperative values of global lordosis, ST, and PT were 51.5 degrees , 37.8 degrees , 16.9 degrees and, at last follow-up, they were 51.4 degrees , 37.4 degrees , and 17.5 degrees , respectively. These changes were not significantly different. When the groups were separated according to the level operated, there was still no statistical difference with regard to the overall lordosis, ST, PT or kyphosis from pre- to postoperative

  13. 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

  14. Lumbar total disc arthroplasty: coronal midline definition and optimal TDA placement.

    Science.gov (United States)

    Marshman, Laurence A G; Friesem, Tai; Rampersaud, Y Raja; Le Huec, Jean-Charles; Krishna, Manoj; Reddy, Guru R

    2008-01-01

    It is a general principle with arthroplasty insertion that precise implant centering is critical for long term function and outcome. Whilst some authors have proclaimed that lumbar total disc arthroplasty (TDA) may be different, and that off -centre placement may be functionally well tolerated, these claims are premature: significantly worse clinical results have already been reported with poorly placed TDA at 2 years. Accurate TDA placement requires a precise and consistent definition of the desired coronal midline target (which is currently lacking), as well as a procedural mechanism to optimize placement at that target. We summarize our experience, as well as others', in achieving these two requirements. Long-term outcomes after lumbar TDA insertion should only be compared with results from fusion where TDAs have been implanted accurately.

  15. 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.

  16. The Incidence of Adjacent Segment Degeneration after Cervical Disc Arthroplasty (CDA): A Meta Analysis of Randomized Controlled Trials

    OpenAIRE

    Baohui Yang; Haopeng Li; Ting Zhang; Xijing He; Siyue Xu

    2012-01-01

    BACKGROUND: Cervical disc arthroplasty is being used as an alternative degenerative disc disease treatment with fusion of the cervical spine in order to preserve motion. However, whether replacement arthoplasty in the spine achieves its primary patient centered objective of lowering the frequency of adjacent segment degeneration is not verified yet. METHODOLOGY: We conducted a meta-analysis according to the guidelines of the Cochrane Collaboration using databases including PubMed, Cochrane Ce...

  17. Medium-term outcomes of artificial disc replacement for severe cervical disc narrowing

    Directory of Open Access Journals (Sweden)

    Chao-Hung Yeh

    2014-01-01

    Conclusions: Acceptable clinical outcome for treatment of severe cervical disc narrowing with cervical disc replacement technique has been performed in current study. Most patients maintained good postoperative mobility and no significant adjacent level degeneration were found. Cervical disc replacement may be applicable in treatment of severe cervical disc narrowing; however, longer follow-ups are required for ensuring the long-term efficacy of cervical disc replacement.

  18. 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.

    Directory of Open Access Journals (Sweden)

    Sheng Shi

    Full Text Available 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.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.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.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.

  19. The incidence of adjacent segment degeneration after cervical disc arthroplasty (CDA: a meta analysis of randomized controlled trials.

    Directory of Open Access Journals (Sweden)

    Baohui Yang

    Full Text Available BACKGROUND: Cervical disc arthroplasty is being used as an alternative degenerative disc disease treatment with fusion of the cervical spine in order to preserve motion. However, whether replacement arthoplasty in the spine achieves its primary patient centered objective of lowering the frequency of adjacent segment degeneration is not verified yet. METHODOLOGY: We conducted a meta-analysis according to the guidelines of the Cochrane Collaboration using databases including PubMed, Cochrane Central Register of Controlled Trials and Embase. The inclusion criteria were: 1 Randomized, controlled study of degenerative disc disease of the cervical spine involving single segment or double segments using Cervical disc arthroplasty (CDA with anterior cervical discectomy and fusion (ACDF as controls; 2 A minimum of two-year follow-up using imaging and clinical analyses; 3 Definite diagnostic evidences for "adjacent segment degeneration" and "adjacent segment disease"; 4 At least a minimum of 30 patients per population. Two authors independently selected trials; assessed methodological quality, extracted data and the results were pooled. RESULTS: No study has specifically compared the results of adjacent segment degenerative; Two papers describing 140 patients with 162 symptomatic cervical segment disorders and compared the rate of postoperative adjacent segment disease development between CDA and ACDF treatments, three publications describing the rate of adjacent-segment surgery including 1273 patients with symptomatic cervical segments. The result of the meta-analysis indicates that there were fewer the rate of adjacent segment disease and the rate for adjacent-segment surgery comparing CDA with ACDF, but the difference was not statistically significant. CONCLUSIONS: Based on available evidence, it cannot be concluded, that CDA can significantly reduce the postoperative rate of the adjacent segment degenerative and adjacent segment disease. However, due

  20. Do design variations in the artificial disc influence cervical spine biomechanics? A finite element investigation

    OpenAIRE

    Faizan, Ahmad; Goel, Vijay K.; Garfin, Steven R.; Serhan, Hassan; Biyani, Ashok; Elgafy, Hossein; Krishna, Manoj; Friesem, Tai; Bono, Christopher M

    2009-01-01

    Various ball and socket-type designs of cervical artificial discs are in use or under investigation. Many artificial disc designs claim to restore the normal kinematics of the cervical spine. What differentiates one type of design from another design is currently not well understood. In this study, authors examined various clinically relevant parameters using a finite element model of C3–C7 cervical spine to study the effects of variations of ball and socket disc designs. Four variations of b...

  1. Medium-term outcomes of artificial disc replacement for severe cervical disc narrowing

    Institute of Scientific and Technical Information of China (English)

    Chao-Hung Yeh; Che-Wei Hung; Cheng-Hsing Kao; Chien-Ming Chao

    2014-01-01

    Objective:To determine if theBryan cervical disc prosthesis could relieve objective neurological symptoms, signs, and restore mobility in patients with severe cervical disc narrowing. Methods:Clinical data of thirty-two patients underwentBryan cervical disc replacement has been collected fromApril2006 toFebruary2010.Severe cervical disc narrowing with gradeV disc degeneration were included in this study.Bryan cervical disc prostheses have been implanted through anterior approach.JapaneseOrthopedicsAssociation(JOA) score, visual analog scale, Odom’s scale, and flexion-extension radiological follow-ups were applied for evaluations. Results:A total of41Bryan disc prostheses from32 patients with an average follow-up duration of33.5 months(range23 to44 months) were evaluated.Clinical functions of patients were significantly improved.Preoperative averaged visual analog scale score of6.3±2.2 was decreased to1.3±1.2(at36 months,P<0.001), while preoperative averagedJOA score of14.4±1.2 was increased to16.3±0.9(at36 months,P<0.001).Thirty of32 patients received excellent to good outcomes inOdom’s scale.Averaged mobility was restored to(9.9±3.2)°at the last follow-up evaluation of36 months.No subsidence or migration of implant was identified. Conclusions:Acceptable clinical outcome for treatment of severe cervical disc narrowing with cervical disc replacement technique has been performed in current study.Most patients maintained good postoperative mobility and no significant adjacent level degeneration were found.Cervical disc replacement may be applicable in treatment of severe cervical disc narrowing; however, longer follow-ups are required for ensuring the long-term efficacy of cervical disc replacement.

  2. Do design variations in the artificial disc influence cervical spine biomechanics? A finite element investigation.

    Science.gov (United States)

    Faizan, Ahmad; Goel, Vijay K; Garfin, Steven R; Bono, Christopher M; Serhan, Hassan; Biyani, Ashok; Elgafy, Hossein; Krishna, Manoj; Friesem, Tai

    2012-06-01

    Various ball and socket-type designs of cervical artificial discs are in use or under investigation. Many artificial disc designs claim to restore the normal kinematics of the cervical spine. What differentiates one type of design from another design is currently not well understood. In this study, authors examined various clinically relevant parameters using a finite element model of C3-C7 cervical spine to study the effects of variations of ball and socket disc designs. Four variations of ball and socket-type artificial disc were placed at the C5-C6 level in an experimentally validated finite element model. Biomechanical effects of the shape (oval vs. spherical ball) and location (inferior vs. superior ball) were studied in detail. Range of motion, facet loading, implant stresses and capsule ligament strains were computed to investigate the influence of disc designs on resulting biomechanics. Motions at the implant level tended to increase following disc replacement. No major kinematic differences were observed among the disc designs tested. However, implant stresses were substantially higher in the spherical designs when compared to the oval designs. For both spherical and oval designs, the facet loads were lower for the designs with an inferior ball component. The capsule ligament strains were lower for the oval design with an inferior ball component. Overall, the oval design with an inferior ball component, produced motion, facet loads, implant stresses and capsule ligament strains closest to the intact spine, which may be key to long-term implant survival.

  3. 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.

  4. Clinical study to evaluate the safety and effectiveness of the Aesculap Activ-L™ artificial disc in the treatment of degenerative disc disease

    Directory of Open Access Journals (Sweden)

    Mo Fred F

    2010-04-01

    Full Text Available Abstract Background The objective of this clinical study is to evaluate the safety and effectiveness of the Activ-L Artificial Disc for treatment of single-level degenerative disc disease of the lumbar spine in patients who have been unresponsive to at least six months of prior conservative care. The hypothesis of the study is that the Activ-L Disc is non-inferior to the control (the Charité® Artificial Disc [DePuy Spine] or ProDisc-L® Total Disc Replacement [Synthes Spine] with respect to the rate of individual subject success at 24 months. Individual subject success is a composite of effectiveness and safety. Methods/Design The study proposed is a prospective, randomized, single-masked, controlled, multi-center clinical trial consisting of an estimated 414 subjects with single-level DDD of the lumbar spine (L4/L5, or L5/S1 who have failed to improve with conservative treatment for at least six months prior to enrollment. After enrollment, subjects will be randomized in a 2:1 ratio to either the Activ-L Disc (investigational device or the control (Charité or ProDisc-L. Radiographic endpoints will be evaluated by an independent reviewer at an imaging core laboratory. Each subject will be followed for 5 years post-treatment. Discussion The safety and effectiveness of the Activ-L Artificial Disc for treatment of single-level degenerative disc disease of the lumbar spine will be equivalent to Charité® Artificial Disc [DePuy Spine] or ProDisc-L® Total Disc Replacement [Synthes Spine] at 24 months. Trial Registration Current Controlled Trials NCT00589797.

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

    Directory of Open Access Journals (Sweden)

    Yue JJ

    2016-05-01

    Full Text Available 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 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 received Food and Drug Administration approval - the activL® Artificial Disc (Aesculap Implant Systems. Compared to previous-generation lumbar TDRs, the activL® Artificial Disc incorporates specific design enhancements that result in a more precise anatomical match and allow a range of motion that better mimics the healthy spine. The results of mechanical and clinical studies demonstrate that the activL® Artificial Disc results in improved mechanical and clinical outcomes versus earlier-generation artificial discs and compares favorably to lumbar fusion. The purpose of this report is to describe the activL® Artificial Disc including implant characteristics, intended use, surgical technique, postoperative care, mechanical testing, and clinical experience to date. Keywords: activL® Artificial Disc, artificial disc, degenerative disc disease, discogenic, implant, lumbar, motion preservation, pain

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

    Science.gov (United States)

    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 received Food and Drug Administration approval - the activL(®) Artificial Disc (Aesculap Implant Systems). Compared to previous-generation lumbar TDRs, the activL(®) Artificial Disc incorporates specific design enhancements that result in a more precise anatomical match and allow a range of motion that better mimics the healthy spine. The results of mechanical and clinical studies demonstrate that the activL(®) Artificial Disc results in improved mechanical and clinical outcomes versus earlier-generation artificial discs and compares favorably to lumbar fusion. The purpose of this report is to describe the activL(®) Artificial Disc including implant characteristics, intended use, surgical technique, postoperative care, mechanical testing, and clinical experience to date.

  7. Does total disc arthroplasty in C3/C4-segments change the kinematic features of axial rotation?

    Science.gov (United States)

    Wachowski, Martin Michael; Wagner, Markus; Weiland, Jan; Dörner, Jochen; Raab, Björn Werner; Dathe, Henning; Gezzi, Riccardo; Kubein-Meesenburg, Dietmar; Nägerl, Hans

    2013-06-21

    We analyze how kinematic properties of C3/C4-segments are modified after total disc arthroplasty (TDA) with PRESTIGE(®) and BRYAN(®) Cervical Discs. The measurements were focused on small ranges of axial rotation (TDA. External parameters: constant axially directed pre-load, constant flexional/extensional and lateral-flexional pre-torque. The applied axial torque and IHA-direction did not run parallel. The IHA-direction was found to be rotated backwards and largely independent of the rotational angle, amount of axial pre-load, size of pre-torque, and TDA. In the intact segments pre-flexion/extension hardly influenced IHA-positions. After TDA, IHA-position was shifted backwards significantly (BRYAN-TDA: ≈8mm; PRESTIGE-TDA: ≈6mm) and in some segments laterally as well. Furthermore it was significantly shifted ventrally by pre-flexion and dorsally by pre-extension. The rate of lateral IHA-migration increased significantly after BRYAN-TDA during rightward or leftward rotations. In conclusion after the TDA the IHA-positions shifted backwards with significant increase in variability of the IHA-positions after the BRYAN-TDA more than in PRESTIGE-TDA. The TDA-procedure altered the segment kinematics considerably. TDA causes additional translations of the vertebrae, which superimpose the kinematics of the adjacent levels. The occurrence of adjacent level disease (ALD) is not excluded after the TDA for kinematical reasons.

  8. 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

  9. Quality of systematic reviews: an example of studies comparing artificial disc replacement with fusion in the cervical spine.

    Science.gov (United States)

    Tashani, Osama A; El-Tumi, Hanan; Aneiba, Khaled

    2015-01-01

    Cervical artificial disc replacement (C-ADR) is now an alternative to anterior cervical discectomy and fusion (ACDF). Many studies have evaluated the efficacy of C-ADR compared with ACDF. This led to a series of systematic reviews and meta-analyses to evaluate the evidence of the superiority of one intervention against the other. The aim of the study presented here was to evaluate the quality of these reviews and meta-analyses. Medline via Ovid, Embase, and Cochrane Library were searched using the keywords: (total disk replacement, prosthesis, implantation, discectomy, and arthroplasty) AND (cervical vertebrae, cervical spine, and spine) AND (systematic reviews, reviews, and meta-analysis). Screening and data extraction were conducted by two reviewers independently. Two reviewers then assessed the quality of the selected reviews and meta-analysis using 11-item AMSTAR score which is a validated measurement tool to assess the methodological quality of systematic reviews. Screening of full reports of 46 relevant abstracts resulted in the selection of 15 systematic reviews and/or meta-analyses as eligible for this study. The two reviewers' inter-rater agreement level was high as indicated by kappa of >0.72. The AMSTAR score of the reviews ranged from 3 to 11. Only one study (a Cochrane review) scored 100% (AMSTAR 11). Five studies scored below (AMSTAR 5) indicating low-quality reviews. The most significant drawbacks of reviews of a score below 5 were not using an extensive search strategy, failure to use the scientific quality of the included studies appropriately in formulating a conclusion, not assessing publication bias, and not reporting the excluded studies. With a significant exception of a Cochrane review, the methodological quality of systematic reviews evaluating the evidence of C-ADR versus ACDF has to be improved.

  10. 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

  11. Long term preservation of motion with artificial cervical disc implants: A comparison between cervical disc replacement and rigid fusion with cage

    Science.gov (United States)

    Cincu, Rafael; Lorente, Francisco de Asis; Gomez, Joaquin; Eiras, Jose; Agrawal, Amit

    2014-01-01

    Background: With the advancement of technologies there is more interest in the maintenance of the spine's biomechanical properties focusing on the preservation of the functional motion segment. In present article we describe our experience with 25 cases managed with artificial cervical discs with 28 Solis cage following cervical discectomy with a mean follow-up period of 7.5 year. Materials and Methods: All surgeries were performed by single surgeon from March 2004 to June 2005 with a follow-up till date. Patients with symptomatic single or multiple level diseases that had no prior cervical surgery were candidates for the study. Cohort demographics were comparable. Standardized clinical outcome measures and radiographic examinations were used at prescribed post-operative intervals to compare the treatment groups. Relief in radicular pain, cervical spine motion, and degenerative changes at follow-up were noted. Results: In a total 53 cases, the mean age in prosthesis group was 47 years (age range: 30-63 years) and mean age in cage group was 44 years (32-62 years). Mean hospital stay was 2.7 days in both the groups. At 4 weeks complete cervical movements could be achieved in 19 cases in artificial disc group. Maintenance of movement after 7.5 years was in 76% of these patients. Lordosis was maintained in all cases till date. There was no mortality or wound infection in our series. Conclusions: We conclude that artificial cervical disc could be an alternative to fixed spinal fusion as it represents the most physiological substitute of disc. However, there is need for further studies to support the use of artificial cervical disc prosthesis. PMID:25685218

  12. Prosthetic Lumbar disc replacement for degenerative disc disease

    Directory of Open Access Journals (Sweden)

    Kulkarni Arvind

    2005-01-01

    Full Text Available Mechanical articulated device to replace intervertebral disc as a treatment for low back pain secondary to disc degeneration has emerged as a promising tool for selected patients. The potential advantages are prevention of adjacent segment degeneration, maintenance of mobility as well as avoidance of all the complications associated with fusion. The short-term results have been comparable to that of fusion, a few mid-term results have shown mixed outcome, but information on long-term results and performance are not available at present. The rationale for lumbar disc arthroplasty, indications, contraindications, the various artificial devices in the market and the concepts intrinsic to each of them, basic technique of insertion, complications are discussed and a brief summary of our experience with one of the devices is presented.

  13. Effect of an artificial disc on lumbar spine biomechanics: a probabilistic finite element study.

    Science.gov (United States)

    Rohlmann, Antonius; Mann, Anke; Zander, Thomas; Bergmann, Georg

    2009-01-01

    The effects of different parameters on the mechanical behaviour of the lumbar spine were in most cases determined deterministically with only one uncertain parameter varied at a time while the others were kept fixed. Thus most parameter combinations were disregarded. The aim of the study was to determine in a probabilistic finite element study how intervertebral rotation, intradiscal pressure, and contact force in the facet joints are affected by the input parameters implant position, implant ball radius, presence of scar tissue, and gap size in the facet joints. An osseoligamentous finite element model of the lumbar spine ranging from L3 vertebra to L5/S1 intervertebral disc was used. An artificial disc with a fixed center of rotation was inserted at level L4/L5. The model was loaded with pure moments of 7.5 Nm to simulate flexion, extension, lateral bending, and axial torsion. In a probabilistic study the implant position in anterior-posterior (ap) and in lateral direction, the radius of the implant ball, and the gap size of the facet joint were varied. After implanting an artificial disc, scar tissue may develop, replacing the anterior longitudinal ligament. Thus presence and absence of scar tissue were also simulated. For each loading case studied, intervertebral rotations, intradiscal pressures and contact forces in the facet joints were calculated for 1,000 randomized input parameter combinations in order to determine the probable range of these output parameters. Intervertebral rotation at implant level varies strongly for different combinations of the input parameters. It is mainly affected by gap size, ap-position and implant ball radius for flexion, by scar tissue and implant ball radius for extension and lateral bending, and by gap size and implant ball radius for axial torsion. For extension, intervertebral rotation at implant level varied between 1.4 degrees and 7.5 degrees . Intradiscal pressure in the adjacent discs is only slightly affected by all

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

    Institute of Scientific and Technical Information of China (English)

    张斌; 周红

    2015-01-01

    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.%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。

  15. Adjacent-level arthroplasty following cervical fusion.

    Science.gov (United States)

    Rajakumar, Deshpande V; Hari, Akshay; Krishna, Murali; Konar, Subhas; Sharma, Ankit

    2017-02-01

    -up period. CONCLUSIONS Artificial cervical disc replacement in patients who have previously undergone cervical fusion surgery appears to be safe, with encouraging early clinical results based on this small case series, but more data from larger numbers of patients with long-term follow-up are needed. Arthroplasty may provide an additional tool for the management of post-fusion adjacent-level cervical disc disease in carefully selected patients.

  16. 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

    Directory of Open Access Journals (Sweden)

    van den Akker Elske

    2010-06-01

    Full Text Available Abstract Background 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 a known entity on the long term. Recently, cervical disc prostheses are developed to maintain motion and possibly reduce the incidence of adjacent disc degeneration. A comparative cost-effectiveness study focused on adjacent segment degeneration and functional outcome has not been performed yet. We present the design of the NECK trial, a randomised study on cost-effectiveness of anterior cervical discectomy with or without interbody fusion and arthroplasty in patients with cervical disc herniation. Methods/Design Patients (age 18-65 years presenting with radicular signs due to single level cervical disc herniation lasting more than 8 weeks are included. Patients will be randomised into 3 groups: anterior discectomy only, anterior discectomy with interbody fusion, and anterior discectomy with disc prosthesis. The primary outcome measure is symptomatic adjacent disc degeneration at 2 and 5 years after surgery. Other outcome parameters will be the Neck Disability Index, perceived recovery, arm and neck pain, complications, re-operations, quality of life, job satisfaction, anxiety and depression assessment, medical consumption, absenteeism, and costs. The study is a randomised prospective multicenter trial, in which 3 surgical techniques are compared in a parallel group design. Patients and research nurses will be kept blinded of the allocated treatment for 2 years. The follow-up period is 5 years. Discussion Currently, anterior cervical discectomy with fusion is the golden standard in the surgical treatment of cervical disc herniation. Whether additional interbody fusion or disc prothesis is necessary and cost-effective will be determined by this trial

  17. 人工椎间盘置换术治疗跳跃型多节段颈椎病的中期疗效%Comparison of the mid-term follow-up results between treatment of Bryan cervical artificial disc replacement and ante-rior cervical decompression and fusion for"skip"cervical spondylosis

    Institute of Scientific and Technical Information of China (English)

    尚子琨; 张英泽; 张迪; 丁文元; 张为; 孟宪中; 王林峰; 申勇

    2014-01-01

    Objective To retrospectively analysis and compareabout Bryan artificial cervical disc arthroplasty with ante-rior cervical decompression and fusion (ACDF) on the clinical efficacy for“Skip”cervical spondylosis. Methods From February 2002 to May 2012, 49 cases were treated with Bryan artificial cervical disc arthroplasty (artificial cervical disc replacement surgery group, 18 cases) or anterior cervical decompression and fusion (ACDF group, 31 cases), 29 males and 20 females. Each case was evaluated at the moment of preoperatively, 3 months, 6 and 12 months and last follow-up after surgery by the Japanese Orthopedic Association (JOA), Neck Disability Index (NDI), Visual Analog Scale (VAS), Cervical sagittal curvature, the total cervical spine range of motion(ROM),middle segments of motion. MRI was also used to assess to adjacent segment disc degeneration, spinal cord compression and signal change situation. Results All patients were followed up for more than 24 months. The score of the JOA, NDI, VAS in the two groups of patients improved significantly after surgery than before surgery. In addition, the VAS score in last follow-up were significantly different between the two groups, but other index each time in the two groups showed no significant difference. In last follow-up, the result of artificial cervical disc arthroplasty group were better than ACDF group on the incidence of axial symptoms, the total cervical spine range of motion (ROM) and middle segments of motion. The incidence of axial symptoms in artificial cervical disc arthroplasty group were 11.1%,ACDF group were 45.2%. ROM in arti-ficial cervical disc arthroplasty group were 35.5°±5.9°,ACDF group were 24.5°±6.2°. Middle segments of motion in artificial cer-vical disc arthroplasty group were 7.3°±1.4°,ACDF group were 10.1°±1.6°. The above comparison of the datas were statistically different. There are two cases of adjacent segment degeneration in ACDF group without need to surgery

  18. 颈椎间盘置换治疗颈椎病的疗效观察%Efficacy evaluation of treating cervical spondylopathy with the Discover artificial cervical disc prosthesis

    Institute of Scientific and Technical Information of China (English)

    方礼明; 张亚军; 张军; 李勤

    2013-01-01

    Objective To explore the clinical and radiological outcomes of Discover artificial cervical disc arthroplasty and the range of motion status on adjacent segments for cervical spondylosis causing radiculopathy or myelopathy.Methods A total of 18 consecutive patients underwent cervical arthroplasty with the Discover artificial cervical disc at our hospital.Clinical and radiological follow-ups were conducted.Their radiographic parameters of treatment and adjacent segments were evaluated at Month 1,3,6,12,18 post-operation.And the Japanese Orthopedic Association (JOA) score,visual analog scale (VAS) pain score and Odom's scale were recorded and analyzed.Results During follow-ups over an average of 15 months,there was no occurrence of vascular injury,severe complications or prosthesis displacement and loosening.The score of JOA was 7.2 ± 1.8 at preoperation and 16.7 ± 4.5 at postoperation.And the score of VAS was 8.15 ± 1.65 at preoperation and 2.03 ± 1.12 at postoperation.Conclusion Discover artificial cervical disc arthroplasty is efficacious and the patients recover quickly.Targeted cervical segments may be stabilized and their physiological ranges of motion preserved.%目的 探讨颈椎人工间盘治疗脊髓型和神经根型颈椎病术后的临床效果.方法 2008年6月至2010年6月,武警北京市总队第二医院骨科18例保守治疗无效的颈椎病患者行DiscoverTM人工颈椎间盘置换术,术后按计划随访术后1、3、6、12、18个月,记录术前和术后每个时间点JOA评分,Odom分级及VAS评分.术前、术后3、6、12、18个月登记颈椎正侧及动力位X线片,分析评价椎间盘的位置.结果 18例患者均获得随访,平均随访15个月,术后未出现血管神经损伤,无严重并发症发生.术后患者未发现假体松动和移位.JOA评分从术前(7.2±1.8)分到术后(16.7±4.5)分,VAS评分从术前(8.4±1.4)分到术后(2.0±1.1)分,术后手术效果按照Odom分级都是优良结果,优16例,良2

  19. 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

  20. 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

  1. Does core mobility of lumbar total disc arthroplasty influence sagittal and frontal intervertebral displacement? Radiologic comparison with fixed-core prosthesis

    Science.gov (United States)

    Delécrin, Joël; Allain, Jérôme; Beaurain, Jacques; Steib, Jean-Paul; Chataigner, Hervé; Aubourg, Lucie; Huppert, Jean; Ameil, Marc; Nguyen, Jean-Michel

    2009-01-01

    Background An artificial disc prosthesis is thought to restore segmental motion in the lumbar spine. However, it is reported that disc prosthesis can increase the intervertebral translation (VT). The concept of the mobile-core prosthesis is to mimic the kinematic effects of the migration of the natural nucleus and therefore core mobility should minimize the VT. This study explored the hypothesis that core translation should influence VT and that a mobile core prosthesis may facilitate physiological motion. Methods Vertebral translation (measured with a new method presented here), core translation, range of motion (ROM), and distribution of flexion-extension were measured on flexion-extension, neutral standing, and lateral bending films in 89 patients (63 mobile-core [M]; 33 fixed-core [F]). Results At L4-5 levels the VT with M was lower than with F and similar to the VT of untreated levels. At L5-S1 levels the VT with M was lower than with F but was significantly different compared to untreated levels. At M levels a strong correlation was found between VT and core translation; the VT decreases as the core translation increases. At F levels the VT increases as the ROM increases. No significant difference was found between the ROM of untreated levels and levels implanted with either M or F. Regarding the mobility distribution with M and F we observed a deficit in extension at L5-S1 levels and a similar distribution at L4-5 levels compared to untreated levels. Conclusion The intervertebral mobility was different between M and F. The M at L4-5 levels succeeded to replicate mobility similar to L4-5 untreated levels. The M at L5-S1 succeeded in ROM, but failed regarding VT and mobility distribution. Nevertheless M minimized VT at L5-S1 levels. The F increased VT at both L4-5 and L5-S1. Clinical Relevance This study validates the concept that the core translation of an artificial lumbar disc prosthesis minimizes the VT. PMID:25802632

  2. Biotribology of a vitamin E-stabilized polyethylene for hip arthroplasty - Influence of artificial ageing and third-body particles on wear.

    Science.gov (United States)

    Grupp, Thomas M; Holderied, Melanie; Mulliez, Marie Anne; Streller, Rouven; Jäger, Marcus; Blömer, Wilhelm; Utzschneider, Sandra

    2014-07-01

    The objective of our study was to evaluate the influence of prolonged artificial ageing on oxidation resistance and the subsequent wear behaviour of vitamin E-stabilized, in comparison to standard and highly cross-linked remelted polyethylene (XLPE), and the degradation effect of third-body particles on highly cross-linked remelted polyethylene inlays in total hip arthroplasty. Hip wear simulation was performed with three different polyethylene inlay materials (standard: γ-irradiation 30 kGy, N2; highly cross-linked and remelted: γ-irradiation 75 kGy, EO; highly cross-linked and vitamin E (0.1%) blended: electron beam 80 kGy, EO) machined from GUR 1020 in articulation with ceramic and cobalt-chromium heads. All polyethylene inserts beneath the virgin references were subjected to prolonged artificial ageing (70°C, pure oxygen at 5 bar) with a duration of 2, 4, 5 or 6 weeks. In conclusion, after 2 weeks of artificial ageing, standard polyethylene shows substantially increased wear due to oxidative degradation, whereas highly cross-linked remelted polyethylene has a higher oxidation resistance. However, after enhanced artificial ageing for 5 weeks, remelted XLPE also starts oxidate, in correlation with increased wear. Vitamin E-stabilized polyethylene is effective in preventing oxidation after irradiation cross-linking even under prolonged artificial ageing for up to 6 weeks, resulting in a constant wear behaviour.

  3. Convergence of simulations of self-gravitating accretion discs II: Sensitivity to the implementation of radiative cooling and artificial viscosity

    CERN Document Server

    Rice, W K M; Forgan, D H; Armitage, P J

    2013-01-01

    Recently it has been suggested that the fragmentation boundary in Smoothed Particle Hydrodynamic (SPH) and FARGO simulations of self-gravitating accretion discs with beta-cooling do not converge as resolution is increased. Furthermore, this recent work suggests that by carefully optimising the artificial viscosity parameters in these codes it can be shown that fragmentation may occur for much longer cooling times than earlier work suggests. If correct, this result is intriguing as it suggests that gas giant planets could form, via direct gravitational collapse, reasonably close to their parent stars. This result is, however, slightly surprising and there have been a number of recent studies suggesting that the result is likely an indication of a numerical problem with the simulations. One suggestion, in particular, is that the SPH results are influenced by the manner in which the cooling is implemented. We extend this work here and show that if the cooling is implemented in a manner that removes a known numer...

  4. 角度人工椎间盘置换后对相邻下位椎间隙应力的影响%Effects of artificial disc replacement with angles on stress of adjacent intervertebral disc

    Institute of Scientific and Technical Information of China (English)

    柏传毅; 张维杰; 卫文博; 凌伟; 田振兴; 党晓谦; 王坤正

    2014-01-01

    Objective:To evaluate stress changes of intervertebral space and adjacent intervertebral space after artificial disc replacement with angles. Methods:Artificial disc replacement with angles were designed according to existing data. Axial pressure,flexion/extension,lateral bending and torsion loading were applied on finite element models of normal cervical discs on C4,5 segments,C4,5 segments with 0°artificial cervical discs and C4,5 segments with 10°artificial cervical discs,then stress changes of C4,5 space was observed. The same loadings were applied on finite element models of normal cervical discs on C 4-C6 segments,C4,5 segments with 0°,C4,5 segments with 10°,then stress changes of replaced segments space and adjacent segment space were observed. Results:For C4,5 segments,80 MPa/0°artificial discs and 80 MPa/10°artificial discs had the similar e-quivalent shear stress(Se),and were both larger than that of normal discs,when lateral bending were performed,80 MPa/0°ar-tificial discs were closed to normal discs when axial pressure and flexion/extension were carried out ,while 80 MPa/10°artifi-cial discs had a larger Se than that of normal ones,when torsion loading were applied,Szx/Szy stress of 80 MPa/0°and 80 MPa/10°artificial discs were closed to normal ones. For C4-C6 segments,the axial pressure,flexion/extension and lateral bend-ing of C5,6 were all lower than normal discs after C4,5 discs were replaced by 80 MPa/10°artificial discs,while Szx/Szy of torsion loading were closed to normal ones. Conclusion:Artificial discs with 10° have less influences on stress of adjacent interverte-bral space and closer to mechanical property after being implanted into intervertebral space.%目的:探讨带角度人工颈椎间盘置换后椎间隙及相邻椎间隙应力变化。方法:根据已有的测量结果,设计角度人工椎间盘。对已建立的C4,5两节段带椎间盘的正常颈椎有限元模型、C4,5置换0°椎间盘假体和置换10

  5. 单节段颈椎人工椎间盘置换术临床疗效探讨%Clinical study of single-level artificial cervical disc replacement for cervical spondylosis

    Institute of Scientific and Technical Information of China (English)

    戚正; 王利民; 谭洪宇; 王卫东

    2011-01-01

    Objective To investigate the curative effect of single-level artifical cervical disc arthroplasty. Methods Thirty-two patients with cervical spondylosis were treated with single-level artifical cervical disc replacement, At 6 weeks, 3, 6, 12 and 18 months after operation, the patients were followed up. The radiography of forward flexion, backward extension, and left and right lateral flexion were obtained atevery follow-up time. The stability of prosthesis, the range of motion status atoperated levelin Active C group were observed. Meanwhile, investigate all patients with complications by follow-up score. Results The incidence rates of early postoperative dysphagia,cervicodynia,brachialgia in the operation group decreased obviously(P<0.05).There was no significant difference in the motion range of adjancent segments before and after Active C replacement(P>0.05). Conclusions Single segment cervial artificial disc replacement can reduce complications in early stage. The adjacent segments postoperative is avoided in mid-term.%目的 探讨单节段颈椎人工椎间盘置换术临床疗效.方法 对我院32例患者经单节段颈椎人工椎间盘(ActivC型)置换术.术后6周、3个月、6个月、12个月、18个月复查拍摄颈椎前屈后伸动力位X线片,观察置换组假体稳定性.同时进行术后系列调查评分,对治疗结果进行回顾性分析.结果 手术组术后早期吞咽困难、颈痛、上肢疼痛等发生率明显降低(P<0.05).人工颈椎间盘置换组置换前后邻近节段活动范围差异无统计学意义(P>0.05).结论 单节段颈椎人工椎间盘置换术后早期并发症减少,中期能保护相邻节段退变.

  6. 颈椎人工椎间盘置换后对相邻节段退变的影响%Effect of cervical disc arthroplasty on adjacent segment degeneration

    Institute of Scientific and Technical Information of China (English)

    孙宇; 赵衍斌; 周非非; 张凤山; 潘胜发; 周方; 刘忠军

    2011-01-01

    Objective:To investigate the adjacent segment degeneration after single level cervical disc arthroplasty. Method : Patients received single level cervical arthroplasty in our institute were reviewed retrospectively. Up to October 2010,a total of 80 patients gained at least 20 months' follow-up.There were 8 cases of C3/4,15 C4/5,49 C5/6 and 8 C6/7.41 patents received Bryan Disc cervical prosthesis and 39 received ProDisc-C prosthesis. Adjacent segment degeneration was evaluated on X-ray and magnetic resonance imaging (MRI) at preoperative and final follow-up.X-ray based adjacent segment degeneration included the presence of aoy of the following parameters:narrowing of disc space>10%,new anterior or/and extended osteophyte formation,calcification of anterior longitudinal ligament. Cervical disc degeneration was evaluated according to Miyazaki's grading system based on T2-weighted MRI.Result:The mean follow-up period was 38 months (range,20-64 months).Of 160 segments at final follow-up,8 distal adjacent segments were excluded due to unavailability of X-ray,adjacent segment degeneration was observed in 21 of 152 segments(13.8%) based on X-ray findings.The rate of adjacent segment degeneration for Bryan disc group was 10.0%,which was lower than that of ProDisc-C group (18.1%).47 patients gained MRI follow-up,and adjacent segment degeneration was observed in 14 of 94 segments (14.9%).The rate of MRI-based adjacent segment degeneration for Bryan Disc group was 12.5%,which was also lower than that of ProDisc-C group (22.7%).No adjacent segment disease developed at final follow-up. Conclusion:Less than 15% cases develop adjacent segment degeneration 38 months after cervical disc arthroplasty,and the effect may vary between different prosthesis.%目的:观察单节段颈椎人工椎间盘置换术后相邻节段退变情况.方法:截止到2010年10月在我院行单节段颈椎人工椎间盘置换术后随访20个月以上且资料完整、既

  7. 颈椎前路减压人工颈椎间盘置换术与融合术治疗单节段颈椎间盘突出症的短期疗效比较%Clinical outcome of Discover artificial cervical disc replacement versus anterior cervical decompression and fusion for single segment cervical disc herniation

    Institute of Scientific and Technical Information of China (English)

    卡哈尔·艾肯木; 楚戈; 王振斌; 陈继征; 顾文飞; 胡雅斌; 涂来勇; 赵疆; 项泽文

    2014-01-01

    Background: The curative effect of anterior cervical discectomy and fusion (ACDF) is satisfactory for the patients with symptomatic cervical disc herniation. However, it can result in stress increase in adjacent segments and speed up the degen-eration of adjacent segments. Artificial cervical disc replacement (ACDR), a typical non-fusion surgical treatment, may be an alternative to ACDF for cervical disc herniation. Objective:To compare the clinical outcomes between ACDR and ACDF for single segmental cervical disc herniation. Methods:From January 2009 to February 2012, 61 patients with single segmental cervical disc herniation were treated in our hospital. Of them, 26 received Discover ACDF (arthroplasty group) and 35 underwent single-level ACDF (fusion group). Visual analogue scale (VAS) neck/arm pain score, Japanese Orthopedics Association (JOA) score and flexion-exten-sion range of motion of operative and adjacent segments were evaluated preoperatively and 1 week and 3, 6, 12, and 24 months postoperatively. Complications and secondary treatment were recorded. Results:A total of 52 patients (29 in arthroplasty group and 23 in fusion group) were followed up. The average follow-up pe-riod was 15.3 months (range, 12-24 months). The VAS scores of neck pain and upper limb pain and JOA score were signifi-cantly improved during follow up as compared with preoperative ones in all patients (P0.05). In arthroplasty group, there was no significant difference in range of motion of opera-tive and adjacent segments before and after treatment (P>0.05). The rate of fusion achievement was 90.5%. In arthroplasy group, prosthesis antedisplacement (<3 mm) in 2 patients at 6 months after surgery, and cerebrospinal fluid leakage oc-curred 1 patient. In fusion group, adjacent segment disease occurred in one patient who underwent secondary operation. Conclusions:Discover cervical disc replacement is a feasible alternative to ACDF for patients with persistent symptomatic cervical disc

  8. Crack Orientation and Depth Estimation in a Low-Pressure Turbine Disc Using a Phased Array Ultrasonic Transducer and an Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Wenshuang Chang

    2013-09-01

    Full Text Available Stress corrosion cracks (SCC in low-pressure steam turbine discs are serious hidden dangers to production safety in the power plants, and knowing the orientation and depth of the initial cracks is essential for the evaluation of the crack growth rate, propagation direction and working life of the turbine disc. In this paper, a method based on phased array ultrasonic transducer and artificial neural network (ANN, is proposed to estimate both the depth and orientation of initial cracks in the turbine discs. Echo signals from cracks with different depths and orientations were collected by a phased array ultrasonic transducer, and the feature vectors were extracted by wavelet packet, fractal technology and peak amplitude methods. The radial basis function (RBF neural network was investigated and used in this application. The final results demonstrated that the method presented was efficient in crack estimation tasks.

  9. Crack orientation and depth estimation in a low-pressure turbine disc using a phased array ultrasonic transducer and an artificial neural network.

    Science.gov (United States)

    Yang, Xiaoxia; Chen, Shili; Jin, Shijiu; Chang, Wenshuang

    2013-09-13

    Stress corrosion cracks (SCC) in low-pressure steam turbine discs are serious hidden dangers to production safety in the power plants, and knowing the orientation and depth of the initial cracks is essential for the evaluation of the crack growth rate, propagation direction and working life of the turbine disc. In this paper, a method based on phased array ultrasonic transducer and artificial neural network (ANN), is proposed to estimate both the depth and orientation of initial cracks in the turbine discs. Echo signals from cracks with different depths and orientations were collected by a phased array ultrasonic transducer, and the feature vectors were extracted by wavelet packet, fractal technology and peak amplitude methods. The radial basis function (RBF) neural network was investigated and used in this application. The final results demonstrated that the method presented was efficient in crack estimation tasks.

  10. 人工颈椎间盘的假体结构及应用特点%Prosthesis structure and application features of artificial cervical disc

    Institute of Scientific and Technical Information of China (English)

    颜端国

    2014-01-01

    背景:目前人工颈椎间盘假体设计和使用都得到了很大的发展,主要有低磨擦滑动面、弹簧系统、橡胶制成的人工颈椎间盘及其他各种弹性假体。目的:总结人工颈椎间盘假体结构特点及在骨科的应用现状。方法:由第一作者以“人工颈椎间盘;假体;椎间盘突出症”和“Artificial Cervical Disc;prosthesis;intervertebral disc herniation;the surgical therapy”为关键词,分别在CNKI(2000至2013年)和PubMed数据库(1960至2013年)http://www.ncbi.nlm.nih.gov/PubMed)检索近年文献,检索内容为人工颈椎间盘假体在骨科的应用。计算机在CNKI数据库检索出200篇文献,在PubMed数据库检索出56篇文献,阅读标题和进行筛选,保留符合纳入标准的40篇归纳总结。结果与结论:人工颈椎间盘假体类似椎间盘生理功能,材料具有耐磨损、耐疲劳、抗腐蚀等特点,它类似于人体椎间盘的生理和生物力学载荷功能,保持了脊柱的稳定和运动功能,避免了邻近节段的退变加速。文章重点对Bryan、Mobi-C、PCM、Prodisc-C、Prestige及CerviCore人工颈椎间盘结构做了介绍。人工颈椎间盘置换的短期疗效已得到认可,但是它不能完全替代颈前路植骨融合内固定,是治疗颈椎退变性椎间盘疾病的又一主要手段。%BACKGROUND:The design and use of artificial cervical disc prosthesis have great development, such as rubber-made artificial cervical disc with low-friction sliding surface and spring system, and other various elastic prostheses. OBJECTIVE:To summarize structural characteristics and present application of artificial cervical disc prosthesis. METHODS:The first author searched CNKI (2000-2013) and PubMed databases (1960-2013) http://www.ncbi.nlm.nih.gov/PubMed for literatures on application of artificial cervical disc prosthesis. The key words included artificial cervical disc, prosthesis, intervertebral disc

  11. 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.

  12. The effect of different design concepts in lumbar total disc arthroplasty on the range of motion, facet joint forces and instantaneous center of rotation of a L4-5 segment.

    Science.gov (United States)

    Schmidt, Hendrik; Midderhoff, Stefan; Adkins, Kyle; Wilke, Hans-Joachim

    2009-11-01

    Although both unconstrained and constrained core lumbar artificial disc designs are in clinical use, the effect of their design on the range of motion, center of rotations, and facet joint forces is not well understood. It is assumed that the constrained configuration causes a fixed center of rotation with high facet forces, while the unconstrained configuration leads to a moving center of rotation with lower loaded facets. The authors disagree with both assumptions and hypothesized that the two different designs do not lead to substantial differences in the results. For the different implant designs, a three-dimensional finite element model was created and subsequently inserted into a validated model of a L4-5 lumbar spinal segment. The unconstrained design was represented by two implants, the Charité disc and a newly developed disc prosthesis: Slide-Disc. The constrained design was obtained by a modification of the Slide-Disc whereby the inner core was rigidly connected to the lower metallic endplate. The models were exposed to an axial compression preload of 1,000 N. Pure unconstrained moments of 7.5 Nm were subsequently applied to the three anatomical main planes. Except for extension, the models predicted only small and moderate inter-implant differences. The calculated values were close to those of the intact segment. For extension, a large difference of about 45% was calculated between both Slide-Disc designs and the Charité disc. The models predicted higher facet forces for the implants with an unconstrained core compared to an implant with a constrained core. All implants caused a moving center of rotation. Except for axial rotation, the unconstrained and constrained configurations mimicked the intact situation. In axial rotation, only the Slide- Disc with mobile core reproduced the intact behavior. Results partially support our hypothesis and imply that different implant designs do not lead to strong differences in the range of motion and the location

  13. 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

  14. Current research status of the prosthesis-related complication after cervical disc arthroplasty%颈椎间盘置换术后假体相关并发症的研究现状

    Institute of Scientific and Technical Information of China (English)

    赵郭盛; 张圆; 权正学

    2016-01-01

    近年来,为避免颈椎融合术治疗颈椎退行性疾病所带来的假关节形成及邻近节段退变加速等问题,颈椎间盘置换术作为一种非融合技术广泛应用于临床,其疗效确切,已逐渐成为治疗颈椎退行性疾病的常规手术方式。但随着该技术应用的深入,随访年限的增加,颈椎间盘置换术后与假体相关的一系列特殊并发症逐渐被学者报道。本文就颈椎间盘置换术后假体相关并发症的研究现状作一综述。%Recently,to avoid the adverse effect such as pseudoarthrosis and accelerated degeneration of ad-jacent segments resulting from cervical fusion, cervical disc arthroplasty ( CDA) has been widely used in clinical practice as a procedure in the treatment of cervical degeneration disease.With satisfactory outcomes,CDA has been gradually accepted as a conventional procedure in treating cervical spondylosis.However,with the increased number of the total operations and the accumulation of follow-up information,some complications due to the prosthesis were revealed.Thus,we collect the related references and conduct this study to review the current status of prosthesis-re-lated complications after cervical disc arthoplasty.

  15. 单节段人工椎间盘置换治疗颈椎病的中长期疗效%Medium and long term result of the single level cervical disc arthroplasty for cervical spondylosis meylopathy

    Institute of Scientific and Technical Information of China (English)

    张雪松; 王岩; 张永刚; 肖嵩华; 王征; 陆宁; 毛克亚; 崔庚; 徐辉; 齐登彬

    2012-01-01

    目的:评价单节段颈椎人工椎间盘置换(cervical disc arthroplasty,CDA)对颈椎病的中长期治疗效果.方法:2003年12月~2005年12月采用前瞻、随机、对照研究单节段Bryan假体CDA与传统前路颈椎减压融合(ACDF)手术治疗颈椎病的疗效,所有患者均按统一的纳入、排除标准进入临床研究,共80例,随机分为两组,并进行均衡性检验,一组进行CDA手术,另一组进行ACDF手术,术后经1d、3个月、6个月、1年、2年、5年及2012年6月的末次随访.其中CDA组32例、ACDF组35例完成了随访,应用动力位X线片观察置换间隙活动度,采用McAfee异位骨化分级方法评定颈椎间盘置换术后异位骨化情况,在MRI T2加权像上采用Miyazaki颈椎间盘退变分级方法评定两组相邻节段椎间盘退变情况,采用颈椎活动障碍指数(NDI)和疼痛视觉模拟评分(VAS)评价术后症状改善程度.结果:本组病例随访7.2~9.6年,平均8.8年.CDA组假体位置良好,无塌陷或移位发生,末次随访时矢状面假体置换间隙活动度1.20°~8.20°,平均6.35°±1.45°;32例患者中8例(25%)置换间隙发生异位骨化,其中2例(6.25%)置换节段丧失活动度;翻修3例,1例因头侧邻近间隙退变、颈椎间盘突出压迫脊髓;2例因头侧跳跃间隙后方骨赘压迫脊髓;末次随访时置换间隙相邻的其他63个节段中22个椎间盘退变分级加重1级,8个加重2级,但无相关临床症状出现.ACDF组融合率100%,翻修3例,2例因头侧邻近间隙退变、存在神经症状;1例因尾侧邻近间隙退变,压迫脊髓;其余67个相邻节段中34个椎间盘退变分级加重1级,15个加重2级,但均无相关临床症状出现.末次随访时CDA组的NDI、颈部VAS及上肢VAS评分分别为16.83±3.12、1.17±0.41及1.96±0.51分,ACDF组分别为17.21±3.53、1.23±0.35及1.86±0.62分,较术前均显著改善,但两组间比较无显著性差异(P>0.05).结论:颈椎人工椎间盘置换术

  16. Distraction Arthroplasty

    Science.gov (United States)

    ... arthroplasty? The major goal of this treatment is healing of damaged tissue that occurs from arthritis. Unloading the ankle, along with the use of range of motion activity, is believed to help restore some of the ...

  17. A Meta-analysis of Cervical Disc Arthroplasty Compared to Anterior Cervical Discectomy and Fu-sion for Degenerative Cervical Disc Disease%颈椎间盘置换与融合治疗退变性颈椎间盘疾病的 Meta 分析

    Institute of Scientific and Technical Information of China (English)

    石青鹏; 朱永林

    2016-01-01

    Objective To systematically compare the outcomes of cervical disc arthroplasty with anterior cervical discecto-my and fusion in the treatment of single-level degenerative cervical disc disease. Methods The references concerning cervical disc arthroplasty and anterior cervical discectomy and fusion for the singel-level degenerative cervical disc disease were re-trieved through PubMed,Cochrane Library,Ovid,SpringerLink,the China Biological Medicine Database,Wafang Database and Weipu Database,as well as by manually searching the related journals and literature. The eligible trials were extracted accord-ing to the inclusion and exclusion criteria. The methodological quality of the included trials were evaluated. RevMan5. 1 soft-ware was used for data analysis. Results Eight randomized controlled trials were included in the final Meta-analysis. The re-sults of Meta-analysis showed that statistically difference between these procedures in the SF-36(MD = 0. 98,95% CI:- 0. 33~ - 2. 29,Z = 1. 46,P = 0. 14),complications(OR = 0. 60,95% CI:0. 34 ~ 1. 04,P = 0. 07),reoperation rate(OR = 0. 52, 95% CI:0. 26 ~ 1. 05,Z = 1. 83,P = 0. 07). There were no statistically difference in the neck disability index(MD = - 2. 74, 95% CI:- 4. 57 ~ - 0. 91,Z = 2. 93,P = 0. 003),neck VAS(MD = - 2. 84,95% CI:- 4. 85 ~ - 0. 84,Z = 2. 78,P = 0. 005) and arm pain VAS(MD = - 1. 84,95% CI:- 3. 07 ~ - 0. 61,Z = 2. 92,P = 0. 003). Conclusion In treatment of single-level degenerative cervical disc disease,cervical disc arthroplasty has better outcomes in the improvement of pain symptom and neck function,but no superiority in complications,reoperation rate and SF-36 scores.%目的:系统性评价颈椎间盘置换与颈椎间盘摘除和融合治疗单节段退变性颈椎间盘疾病的效果。方法计算机检索 PubMed、Cochrane Library、Ovid、SpringerLink、中国生物医学文献数据库、万方、维普等数据库,手工检索相关杂志及纳入研究的参考文献,制

  18. 单节段半限制型Activ-C人工椎间盘置换术的早期疗效观察%Observation of early results after single-level semi-constrained Activ-C cervical disc arthroplasty

    Institute of Scientific and Technical Information of China (English)

    李洪珂; 张长江; 王明君; 杨贤玉; 李来好

    2014-01-01

    目的:观察半限制型Activ-C人工椎间盘置换术治疗单节段颈椎病的早期临床疗效。方法2009年7月至2012年9月,在我院接受Activ-C人工椎间盘置换术并获得随访的单节段颈椎病患者共28例,男18例,女10例,年龄32~62岁,平均45.2岁。采用日本骨科协会(Japaneseorthopedicassociation,JOA)评分、颈椎活动障碍指数(neckdisabilityindex,NDI)和疼痛视觉模拟评分(visualanaloguescale,VAS)评价术后症状改善程度,比较手术前后的颈椎曲度、手术节段活动度变化,观察统计手术并发症情况。结果随访时间12~36个月,平均17.8个月,JOA脊髓功能评分从(8.5±2.5)分增加至(14.8±1.5)分,NDI评分从(24.8±6.9)分下降至(7.3±4.8)分,颈部VAS评分从(6.8±1.3)分下降至(1.2±0.4)分,上肢VAS评分从(7.4±1.2)分下降至(1.1±0.4)分,均有明显改善(P<0.05)。置换节段活动度从术前平均(9.6±4.3)°增加至末次随访时平均(10.8±3.5)°,差异无统计学意义(P>0.05);颈椎整体曲度术前为(12.9±10.5)°,末次随访时为(15.4±9.1)°,但差异无统计学意义(P>0.05)。结论单节段半限制型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。%Objective To evaluate the early clinical results of semi-constrained Activ-C cervical disc arthroplasty for single-level cervical spondylosis. Methods From July 2009 to September 2012, 28 patients with single-level cervical spondylosis underwent Activ-C cervical disc arthroplasty and were followed up. There were 18 males and 10 females, whose mean age was 45.2 years old ( range: 32-62 years ). The Japanese Orthopedic Association ( JOA ) scores, Neck Disability Index ( NDI ) and Visual Analogue Scale ( VAS ) were used to evaluate the postoperative improvement of symptoms, compare the preoperative and postoperative cervical curvature and segmental

  19. Wear studies on ZrO2-filled PEEK as coating bearing materials for artificial cervical discs of Ti6Al4V.

    Science.gov (United States)

    Song, Jian; Liu, Yuhong; Liao, Zhenhua; Wang, Song; Tyagi, Rajnesh; Liu, Weiqiang

    2016-12-01

    Polyetheretherketone (PEEK) and its composite coatings are believed to be the potential candidates' bio-implant materials. However, these coatings have not yet been used on the surface of titanium-based orthopedics and joint products and very few investigations on the tribological characteristics could be found in the published literature till date. In this study, the wettabilities, composition and micro-hardness were characterized using contact angle measurement, scanning electron microscopy (SEM) and hardness tester. The tribological tests were conducted using a ball-on-disc contact pair under 25% newborn calf serum (NCS) lubricated condition. For comparison, bare Ti6Al4V was studied. The obtained results revealed that those PEEK/ZrO2 composite coatings could improve the tribological properties of Ti6Al4V significantly. Adhesive wear and mild abrasive wear might be the dominant wear and failure mechanisms for PEEK/ZrO2 composite coatings in NCS lubricated condition. After comprehensive evaluation in the present study, 5wt.% ZrO2 nanoparticles filled PEEK coating displayed the optimum tribological characteristics and could be taken as a potential candidate for the bearing material of artificial cervical disc.

  20. Clinical Effect of Anterior Disc Excision with Bone Graft Fusion and Bryan Artificial Cervical Disc Replacement%颈前路减压植骨融合与Bryan人工颈椎间盘置换疗效比较

    Institute of Scientific and Technical Information of China (English)

    陈昆; 蔡惠民; 陈荣滋

    2014-01-01

    目的:探讨颈椎前路减压植骨融合术( anterior cervical decompression and fusion,ACDF)与Bryan人工颈椎椎间盘置换术( artificial cervical disc replacement,ACDR)两种手术方式用于治疗脊髓型颈椎病及神经根型颈椎病的近期和远期疗效。方法系统分析我院2010年11月至2012年11月70例(70个节段)脊髓型或神经根型颈椎病患者病例资料,将70例(70个节段)脊髓型或神经根型颈椎病患者,通过随机数字表法随机分为ACDF组(35例)及Bryan组(35例)。通过分析术前及术后随访12个月的Odom′s标准评分、活动度( range of motion,ROM)、日本骨科协会( Japa-nese orthopaedic association,JOA)、健康调查简表( the MOS item short from health survey,SF-36)及颈椎残障功能指数( neck disability index,NDI)观察指标的差异,同时对随访12个月的上述各项指标进行两组间比较,比较两者疗效,分析两种术式的优点及他们产生的问题。结果两种手术方式都能取得明确疗效,治疗后患者症状明显缓解( P0.05);JOA评分及SF-36评分两者差异性不显著( P>0.05);而在12个月随访ROM评估及NDI比较有差异,Bryan组数据优于 ACDF组,差异具有统计学意义( P0. 05). JOA score and SF-36 scale had no significant differences(P>0. 05). There was difference between ROM and NDI in the evaluation of 12 month follow-up. Data of Bryan group were better than ACDF group(P<0. 05). Conclusion Bryan artificial cervical disc re-placement(ACDR)is superior to the anterior cervical decompression and fusion(ACDF)in reducing the adjacent segment degeneration of cervical vertebra. Its short-term and mid-term curative effect is superior to the ACDF. But Bryan artificial cervi-cal disc replacement( ACDR)coexist the complications such as incomplete decompression and heterotopic ossification,the long-term curative effect is inferior than ACDF.

  1. 人工颈椎间盘置换术治疗脊髓型颈椎病的近期疗效%Short-term efficacy of Bryan cervical disc arthroplasty in patients with cervical spondylotic myelopathy

    Institute of Scientific and Technical Information of China (English)

    梁英杰; 钟润泉; 郭东明; 温世锋

    2014-01-01

    目的:探讨Bryan人工颈椎间盘置换术治疗脊髓型颈椎病的近期疗效。方法应用Bryan人工颈椎间盘置换术治疗26例脊髓型颈椎病患者,在术前及末次随访时的颈椎X线片上测量置换节段矢状位、冠状位活动度。应用JOA评分评价术后神经功能。结果术后患者症状均明显缓解。26例均获随访,时间29~48个月。末次随访JOA评分由术前平均8.3分±4.6分增加到16.1分±5.3分,置换节段矢状位活动范围4.3°~7.2°(5.6°±2.4°);冠状位左右侧屈活动范围分别为3.1°~4.3°(3.8°±1.1°)和3.1°~4.6°(3.9°±0.9°)。随访期间假体无偏移松动或下沉,无置换节段假体周围异位骨化。结论 Bryan人工颈椎间盘置换术治疗脊髓型颈椎病近期临床效果较好,维持颈椎正常的活动范围、生理曲度和较好的生物力学稳定性。%Objective To discuss the short-term clinical and radiographic outcome of Bryan cervical disc arthroplas-ty.Methods Radiographic and clinical outcomes in 26 patients who received the Bryan cervical disc prosthesis were retrospectively reviewed.Static and dynamic X-ray was taken for measuring the range of motion.Clinical outcomes were assessed using Japanese Orthopedics Academy (JOA)scale.Results The average follow-up time was 29~48 months,and all patients were satisfied with the relief of symptoms.In the last follow-up,the average JOA scale was 16.1 ±5.3 ,while it was 8.3 ±4.6 pre-operation.The sagittal range of motion was 4.3°~7.2°(5.6°±2.4°),and the coronal range of motion was 3.1°~4.3°(3.8°±1.1°)and 3.1°~4.6°(3.9°±0.9°).No heterotopic ossifica-tion,prosthesis loosening,prosthesis migration or other complications occured.Conclusions Arthroplasty using the Bryan disc for cervical spondylotic myelopathy patients seems to be safe and provids encouraging clinical and radiolog-ic outcome in our short-term study.

  2. Evaluation of the Clinical Efficacy of Artificial Total Knee Arthroplasty in the Treatment of Knee Osteoarthritis%人工膝关节置换术治疗膝关节骨性关节炎临床疗效评价

    Institute of Scientific and Technical Information of China (English)

    洪士东; 欧阳晓; 丁允知; 刘晓钟

    2015-01-01

    目的:评价人工膝关节置换术治疗膝关节骨性关节炎的临床疗效。方法随机选取该院自2010年1月—2015年3月收治的60例膝关节骨性关节炎患者作为观察对象,随机分成对照组与实验组,对照组患者与实验组患者各30例,对照组采用药物与运动疗法治疗,实验组采用人工膝关节置换术治疗,对比两组膝关节骨性关节炎患者治疗后的临床疗效。结果对照组的总有效率为70%,实验组的总有效率为90%,对照组膝关节骨性关节炎患者的临床疗效明显低于实验组,两组间临床疗效的差异有统计学意义(P<0.05)。结论人工膝关节置换术治疗膝关节骨性关节炎的临床疗效明显,值得临床推广。%Objective To evaluate the clinical efficacy of artificial total knee arthroplasty in the treatment of knee os-teoarthritis. Methods 60 cases with knee osteoarthritis admitted in our hospital from January 2010 to March 2015 were se-lected as the subjects and randomly divided into the control group and the experimental group with 30 cases in each. Pa-tients in the control group were treated by medication and cinesiotherapy, while those in the control group were treated by artificial total knee arthroplasty. And the clinical efficacy of the two groups was compared. Results The overall response rate was much higher in the experimental group than that in the control group(90%vs 70%) with statistically significant dif-ference (P<0.05). Conclusion Artificial total knee arthroplasty has significant effect in the treatment of knee osteoarthritis, which is worthy of clinical promotion.

  3. 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

  4. 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

  5. 人工全髋置换联合髋臼造盖治疗先天性髋关节脱位★%Artificial total hip arthroplasty and hip-self procedure in the treatment of congenital dislocation of hip

    Institute of Scientific and Technical Information of China (English)

    刘燚; 严建军; 崔志明

    2013-01-01

      背景:以往采用单纯的人工关节置换、截骨重建等治疗成人 CrownⅣ型先天性髋关节脱位的效果都不是很满意。目的:探讨人工全髋置换联合髋臼造盖重建治疗成人CrownⅣ型先天性髋关节脱位的疗效。方法:回顾性分析采用人工全髋置换联合髋臼造盖重建治疗23例成人CrownⅣ型先天性髋关节脱位的患者,其中男2例,女21例,年龄20-35岁,平均(24.26±3.56)岁。重建治疗后按Harrris髋关节功能标准评定术后疗效并进行统计学分析。结果与结论:23例患者均获得随访,随访时间为12-60个月,平均(26.60±13.16)个月。采用SPSS19.0进行统计学比较后发现,手术前后髋关节功能Harrris评分差异有显著性意义(P <0.01)。人工全髋置换联合髋臼造盖能重建髋关节正常结构,缓解疼痛,增加髋关节稳定性,是治疗成人 Crown Ⅳ型先天性髋关节脱位的理想方法。%BACKGROUND:The effects of artificial joint replacement, osteotomy and reconstruction in the treatment of Crown Ⅳ-type congenital dislocation of hip in adult are not very satisfied. OBJECTIVE:To evaluate the effect of artificial total hip arthroplasty and hip-self procedure in the treatment of Crown Ⅳ-type congenital dislocation of hip in adult patients. METHODS:Twenty-three adult patients with Crown Ⅳ-type congenital dislocation of hip were treated with artificial total hip arthroplasty and hip-self procedure. There were 2 males and 21 females with an average age of (24.26±3.56) years ranging 20 to 35 years. The effect was evaluated according to the Harrris evaluation standard, and the statistical analysis was performed. RESULTS AND CONCLUSION:Al of the patients were fol owed-up for 12-60 months, averaged of (26.60±13.16) months. Statistical comparison with the SPSS 19.0 system showed there was significant difference of the Harrris scores between preoperation and postoperation period (P<0.05). The

  6. 人工颈椎间盘结构、材料及体外生物力学的研究进展*★%Research progresses of artificial cervical disc structure, material and in vitro biomechanics

    Institute of Scientific and Technical Information of China (English)

    蒲婷; 原芳; 廖振华; 刘伟强

    2013-01-01

      背景:人工颈椎间盘置换作为颈椎疾病治疗的全新方法,正逐渐得到临床广泛认可,其使用的植入器械——人工颈椎间盘还需更深入研发及验证。目的:综述了现有人工颈椎间盘产品的结构、材料及体外生物力学研究,并对未来发展状态进行展望。方法:以“artificial cervical disc,prothesis,structure,material,biomechanical study”为英文检索词检索Pubmed数据库,以“人工颈椎间盘,假体,结构,材料,生物力学”为检索词检索CNKI数据库,纳入人工颈椎间盘结构设计、材料设计及体外生物力学评估相关工作,主要整理近5年来有关研究,排除重复性工作,重点对36篇文献进行分析讨论。结果与结论:现有人工颈椎间盘产品主要采用金属-聚合物(MOP)结构,以半限制型和非限制型居多,尺寸系列已较完善,且全为进口产品。通过对现有产品进行分析与总结,提出人工颈椎间盘在新结构设计、面向种群设计和材料改进3个方向有重大发展空间,材料改进可以从终板材料、髓核材料、表面喷涂材料几方面考虑。%  BACKGROUND: Artificial cervical disc replacement has been widely used in clinical cervical surgery. Further research of biomechanics of the artificial cervical disc used in the surgery is needed. OBJECTIVE: To review the structure, material types and in vitro biomechanical study of the existed artificial cervical disc, and to prospect the development in the future. METHODS: The PubMed databases and CNKI database were searched with key words of “artificial cervical disc, prosthesis, structure, material, biomechanical study” in English and Chinese respectively. The articles related to artificial cervical disc structure, material, and in vitro biomechanics were included. The researches in the recent 5 years were col ected, and the repetitive studies were excluded. A total of 36

  7. 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.

  8. Finite element analysis of cervical spine following artificial intervertebral disc replacement%颈椎人工椎间盘置换有限元分析

    Institute of Scientific and Technical Information of China (English)

    徐波; 金大地; 张美超

    2013-01-01

    Objective To establish a three-dimensional finite element model of cervical spine C4~5segment following PrestigeTM-LP artificial intervertebral disc replacement and analyze segmental motions.Methods The geometry of C4~5 vertebrae was reconstructed from computer tomography (CT) scan images of an adult male human fresh cervical spinal specimen.A FEM of C4~5 vertebrae and PrestigeTM-LP prosthesis was established and simulated clinical operation by using ANSYS10.0 system.Motions of flexion,extension,lateral bending and axial rotation were determined in physiological loading.Results Detailed geometries of vertebral bodies were modeled including ligaments,facet joints,and uncovertebral joints.Motions of flexion,extension,lateral bending,axial rotation are 5.7°,3.5°,5.0°,11.3°,respectively and conform with what have been reported in the literature.Conclusions The FEM possesses a high precision of geometries of vertebral bodies and biomechanical character.PrestigeTM-LP artificial disc prosthesis well preserves intervertebral segmental motion for cervical spine.%目的 建立C4~5节段PrestigeTM-LP颈椎人工椎间盘植入后的三维有限元模型,进行手术节段的运动分析.方法 采用对成年男性的新鲜尸体的颈椎标本进行CT三维扫描方法建立C4~5节段和PrestigeTM-LP人工间盘有限元,模拟完成C4~5人工椎间盘置换手术.测量生理加载下手术节段前屈/后伸、侧弯及轴向旋转运动角度.结果 有限元模型对颈椎的结构,包括椎体间韧带、颈椎关节突关节、钩椎关节等均进行了精确的重建,并较好地模拟手术操作进行PrestigeTM-LP人工间盘植入.运动加载后运动角度,前屈5.7°,后伸3.5°,侧弯5.0°,旋转11.3°,与文献报道结果较为接近.结论 有限元模型具有精确度高,手术模拟真实的特点,可作为颈椎人工椎间盘生物力学研究的一种较好途径.PrestigeTM-LP颈椎人工椎间盘置换可较好地保留手术节段的运动功能.

  9. 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.

  10. 推拿配合人工牵拉闪压腰法及针刺治疗腰椎间盘突出症%Massage Combined with Artificial Traction Flash Press Waist Method and Acupuncture Treating Lumbar Disc Herniation

    Institute of Scientific and Technical Information of China (English)

    黄利云; 张胜良; 靳伟跃; 杨粉霞; 张志文

    2013-01-01

    目的:探讨中医治疗腰椎间盘突出症的创新方法。方法:152例腰椎间盘突出症患者应用推拿手法及人工牵拉瞬间闪压相应椎旁痛点,并配合针刺治疗。结果:治愈81例,显效35例,好转25例,无效11例,总有效率为92.76%。结论:推拿配合人工牵拉闪压腰法及针刺治疗腰椎盘突出症安全有效,无毒副作用,患者易于接受。%Objective:To explore the innovative methods of traditional Chinese medicine treating lumbar disc herniation. Methods:152 cases of lum-bar disc herniation were applied with massage combined with artificial traction flash pressing corresponding paravertebral point of pain and acupunc-ture. Results:81 cases were cured, 35 cases markedly effective, 25 cases improved, 11 cases ineffective, the total effective rate was 92.76%. Conclu-sion:Massage combined with artificial traction flash press waist method and acupuncture treating lumbar disc herniation is safe and effective, with-out toxic and side effects, easily accepted by patients.

  11. Clinical Analysis of 16 cases of Artificial Knee Joint Arthroplasty%人工膝关节表面置换术16例临床分析

    Institute of Scientific and Technical Information of China (English)

    吴双宝

    2014-01-01

    目的:介绍膝关节表面置换治疗膝关节炎的方法,探讨其疗效.方法:我院自2009年10月~2013年8月,对16例患者22个膝关节施行膝关节表面置换术.结果:随访资料完备,随访5~18个月,平均10.7个月,膝关节(HSS)评分,均增加到80分以上;膝关节活动范围(ROM)增加至90°以上.术中1例发生早期并发症.结论:人工膝关节表面置换术(TEA)可有效缓解关节疼痛,改善膝关节活动度,并矫正膝关节畸形,是治疗终末期膝关节疾病的有效方法,可以在基层医院推广应用.%Objective:To introduce the method of total knee arthroplasty(TEA)in the treatment of knee osteoarthritis, and to investigate its efficacy. Methods:From October 2009 to August 2013, 16 patients(22 knees)were treated with total knee arthroplasty. Results:The follow-up data was complete and the follow-up period was 5 to 18 months with an average of 10.7 months. The patients’hospital for special surgery(HSS)score was increased to 80 points or more;range of motion(ROM)of knee joint increased to 90° or more. Early complications occurred in 1 case. Conclusion:TEA can effectively relieve joint pain, improve knee joint ROM, and correct the knee joint deformity, so it is an effec-tive method for the treatment of end-stage knee joint disease, and it is can be generalized in the primary hospital.

  12. 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

  13. PRELIMINARY CLINICAL STUDY ON ARTIFICIAL CERVICAL DISC REPLACEMENT BY Mobi-C PROSTHESIS%Mobi-C人工颈椎间盘临床应用初步报告

    Institute of Scientific and Technical Information of China (English)

    鲍达; 马远征; 陈兴; 李宏伟; 胡明; 高天君

    2011-01-01

    Objective To study the clinical application of Mobi-C prosthesis in treatment of anterior cervical discectomy and artificial disc replacement (ADR). Methods Between January 2009 and June 2009, 20 cases of degenerative cervical disease were treated with anterior discectomy and ADR by Mobi-C prosthesis, including 13 cases of cervical disc herniation and 7 cases of cervical spondylotic radiculopathy, and 25 Mobi-C prosthesis were implanted. There were 8 males and 12 females, aged 29-54 years (mean, 45.2 years). The disease duration was from 4 days to 5 years (mean, 1.2 years). Affected segments of process included C3, 4 in 1 case, C4, 5 in 2 cases, C5, 6 in 7 cases, C6,7 in 5 cases, C4, 5 and C5, 6 in 2 cases, and C5, 6 and C6, 7 in 3 cases. Radiographs were taken regularly, and cervical range of motion (ROM) on segments of disc replacements were measured. The functions of cervical spinal cord were evaluated by "40 score" system (COA) preoperatively, immediately postoperatively, and at follow-up. The quality of life was evaluated by neck disability index (NDI) and visual analogue scale (VAS) score. Results All incisions healed by first intention. No perioperative complication was found. All cases were followed up 16.5 months on average (range, 14-18 months). There was no significant difference in cervical ROM of operatied segment between preoperation and follow-up duration (t=0.808, P=0.440). No heterotopic ossification was found at follow-up. COA score at last follow-up (38.20 ± 1.14) was significantly higher than preoperative one (32.10 ± 2.96), (t=9.278, P=0.000), and the improvement rate at last follow-up was 77.2% ± 5.4%. VAS score at last follow-up (3.20 ± 1.23) had significant difference when compared with preoperative one (5.10 ± 1.29), (t=10.585, P=0.000). NDI score at last follow-up (29.40 ± 4.55) had significant difference when compared with preoperative one (39.20 ± 3.80), (t=16.039, P=0.000). Conclusion A satisfactory short-term curative effect

  14. Retrospective analysis of multi-level cervical artificial disc replacement compared with nearby segments fused for multi-level disc hernations%人工椎间盘置换与颈前路融合治疗多节段颈椎病回顾性分析

    Institute of Scientific and Technical Information of China (English)

    王衡; 刘英杰; 常江; 张锴; 朱卉敏

    2015-01-01

    目的 对比总结多节段颈椎间盘突出症患者分别实施人工椎间盘置换和颈前路融合固定的效果分析,判断人工椎间盘置换术后效果.方法 自2005年7月对16例多节段颈椎间盘突出患者进行了前路椎间盘切除、Bryan人工椎间盘置换术(A组),观察手术前后VAS评分及颈椎活动度变化,并与同期所做的多节段颈前路融合内固定23例患者(B组)相对照.结果 两组患者术后各时间点疼痛缓解、VAS评分较术前有明显提高(P<0.05),术后两组VAS评分比较差异未见统计学意义(P>0.05).术后12个月及2年时两组间整体活动度比较差异有统计学意义(P<0.05),A组人工椎间盘置换节段术后2年活动度与术前比较差异未见统计学意义(P>0.05).A组末次随访时较术后3d时显著增加(P<0.05);B组术后各时间点比较差异未见统计学意义(P>0.05).结论 人工椎间盘置换治疗多节段颈椎间盘突出症临床效果较好,术后对手术节段的活动度影响较小,是一种解决颈椎活动性与稳定性矛盾的较好的方法.%Objective To evaluate the therapeutic effects of the multi-level cervical artificial disc replacements compared with the anterial cervical artificial fusion on the multi-level disc fusion and to investigate their effect after the treatment.Methods The patient with discectomy underwent cervical artificial disc replacements (group A) in the C3-7 intervertebral discs from July.2005.The VAS score and the range of motion(ROM) of two groups was observed perioperatively.Results The patient could move his neck in all directions without pain.The spinal and neural symptoms were significantly alleviated,and there were obviously elevation in VAS score in each time point (P < 0.05),and there was no significant difference in VAS score between the two groups (P < 0.05).There were significant differences in the range of motion(ROM) of two groups according to the follow-up for 12 month and 2

  15. Functional evaluation of the cervical spine after Bryan artificial disc replacement%Bryan人工颈椎间盘置换对颈椎功能影响的临床分析

    Institute of Scientific and Technical Information of China (English)

    田伟; 刘波; 李勤; 胡临; 李志宇; 袁强; 韩骁

    2008-01-01

    Objective To assess the effect of Bryan cervical disc replacement on the function of the cervical spine.Methods Bryan cervical artificial disc replacement was performed in 164 cases from Dec 2003 to Aug 2007,and all the cases were retrospectively followed up.Among them,1 disc replacement was done in 132 cases,2 discs in 28 cases and 3 discs in 4 eases with a total number of 200 artificial discs. There were 102 male patients and 62 female patients.Their age ranged from 25 to 70 years old(with an average of 47 years old).All the cases were operated according to the standard procedure for Bryan artificial disc replacement,and immobilized in a cervical collar for 2 weeks after operation.Motion of the replaced disc in sagittal direction,JOA score and satisfaction rate of the patients were followed up and evaluated.Results In this group,no acute complications happened during the operation.All patients returned to work 4 to 6 weeks after operation.The postoperative ameliorate rate of JOA score was 56%. Range of motion in sagittal direction of the operated disc was 14.4 degrees before operation,decreased to 5.7 degrees at 1 week after operation,but improved to 14.7 degrees at the time of final follow-up and was not significantly different from preoperative range.Motion in the upper adjacent disc to the replacement level was 10.9 degrees before operation,decreased to 5.5 degrees at 1 week after operation,and improved to 8.2 degees at the time of final follow-up but was significantly smaller than preoperative range.The satisfaction rate of the patients was 94%.Loosening of the prosthesis happened in 1 case 6 months after operation but remained stable afterwards.Subsidence up to 1 mm occurred in another case 7 months after operation but also remained stable afterwards.Automatic posterior union occurred in 3 cases in which relative small size artificial discs were implanted.Conclusions The clinical outcome of Bryan artificial disc replacement was quite

  16. 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.

  17. Local and global subaxial cervical spine biomechanics after single-level fusion or cervical arthroplasty.

    Science.gov (United States)

    Finn, Michael A; Brodke, Darrel S; Daubs, Michael; Patel, Alpesh; Bachus, Kent N

    2009-10-01

    An experimental in vitro biomechanical study was conducted on human cadaveric spines to evaluate the motion segment (C4-C5) and global subaxial cervical spine motion after placement of a cervical arthroplasty device (Altia TDI,Amedica, Salt Lake City, UT) as compared to both the intact spine and a single-level fusion. Six specimens (C2-C7) were tested in flexion/extension, lateral bending, and axial rotation under a +/- 1.5 Nm moment with a 100 N axial follower load. Following the intact spine was tested; the cervical arthroplasty device was implanted at C4-C5 and tested. Then, a fusion using lateral mass fixation and an anterior plate was simulated and tested. Stiffness and range of motion (ROM) data were calculated. The ROM of the C4-C5 motion segment with the arthroplasty device was similar to that of the intact spine in flexion/extension and slightly less in lateral bending and rotation, while the fusion construct allowed significantly less motion in all directions. The fusion construct caused broader effects of increasing motion in the remaining segments of the subaxial cervical spine, whereas the TDI did not alter the adjacent and remote motion segments. The fusion construct was also far stiffer in all motion planes than the intact motion segment and the TDI, while the artificial disc treated level was slightly stiffer than the intact segment. The Altia TDI allows for a magnitude of motion similar to that of the intact spine at the treated and adjacent levels in the in vitro setting.

  18. 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

  19. SHOULDER ARTHROPLASTY RECORDS

    Science.gov (United States)

    Filho, Geraldo Motta; Galvão, Marcus Vinicius; Monteiro, Martim; Cohen, Marcio; Brandão, Bruno

    2015-01-01

    The study's objective is to evaluate the characteristics and problems of patients who underwent shoulder arthroplasties between July 2004 and November 2006. Methodology: During the period of the study, 145 shoulder arthroplasties were performed. A prospective protocol was used for every patient; demographic, clinical and surgical procedure data were collected. All gathered data were included in the data base. The patients were divided in three major groups: fractures, degenerative diseases and trauma sequels. Information obtained from the data base was correlated in order to determine patients' epidemiologic, injuries, and surgical procedure profiles. Results: Of the 145 shoulder arthroplasties performed, 37% presented trauma sequels, 30% degenerative diseases, and 33% proximal humerus fracture. 12% of the cases required total arthroplasties and 88% partial arthroplasties. Five major complications were observed on early postoperative period. Conclusion: Shoulder arthroplasties have become a common procedure in orthopaedic practice. Surgical records are important in evidencing progressive evolution and in enabling future clinical outcomes evaluation. PMID:26998463

  20. Hip resurfacing arthroplasty

    OpenAIRE

    2010-01-01

    Background and purpose Hip resurfacing arthroplasty is claimed to allow higher activity levels and to give better quality of life than total hip arthroplasty. In this literature review, we assessed the therapeutic value of hip resurfacing arthroplasty as measured by functional outcome. Methods An extensive literature search was performed using the PubMed, Embase, and Cochrane databases. Results 9 patient series, 1 case-control study, and 1 randomized controlled trial (RCT) were included. Clin...

  1. 推拿配合人工单下肢牵引治疗腰椎间盘突出症%Manipulation Combined with Artificial Single Lower Limb Traction in the Treatment of Lumbar Disc Herniation

    Institute of Scientific and Technical Information of China (English)

    李宏龙; 平晓慧

    2013-01-01

    Objective:To observe the clinical effect of artificial single lower limb traction combined with manipulation in the treatment of lumbar disc herniation. Methods:96 patients were randomly divided into observation group and control group. Observation group was treated with artificial sin-gle lower limb traction combined with manipulation, while control group was treated with double lower limb hammer traction. The clinical efficacy was compared between the two groups. Results:The total effective rate was 95.83%in observation group and 85.42%in control group with signifi-cant difference (P<0.05). The clinical effect in the observation group was better than that of control group. Conclusion:Artificial single lower limb traction is superior to traditional double lower limb hammer traction in the treatment of lumbar disc herniation.%目的:观察人工单下肢牵引法配合推拿治疗腰椎间盘突出症的疗效。方法:将96例患者随机分为观察组和对照组,观察组采用人工单下肢牵引法配合推拿治疗;对照组采用双下肢重锤牵引法配合推拿治疗,比较两组临床疗效。结果:观察组总有效率为95.83%,高于对照组的85.42%(P<0.05)。结论:人工单下肢牵引法治疗腰椎间盘突出症疗效优于传统的双下肢重锤牵引法。

  2. 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

  3. Unicompartmental knee arthroplasty

    NARCIS (Netherlands)

    Kort, Nanne Pieter

    2007-01-01

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

  4. The short-term efficacy of Prestige LP artificial disc single-level replacement for cervical spondylosis%Prestige LP人工椎间盘置换治疗单节段颈椎病的近期疗效

    Institute of Scientific and Technical Information of China (English)

    黄波; 卢一生; 施建东; 徐静芳; 刘振刚

    2014-01-01

    Objective To evaluate the short-term radiological and functional outcome of artifi-cial disc single-level replacement for cervical disc degenerative diseases. Methods 15 patients with cervical disc degenerative diseases underwent Prestige LP artificial disc replacement were se-lected in this study. There were 8 cases of cervical spondylotic myelopathy and 7 cases of nerve root cervical syndrome. The range of motion(ROM) of the cervical spine,ROM of treated segment and lordosis of cervical spine were reviewed respectively at preoperation and 1 month,3 months and 12 months postoperation,and the NDI scores,VAS for neck and arm pain were also reviewed respectively preoperation and the last follow-up. Results At an average of 16.3 months(range 6-24 months) follow-up,the neurologic symptom and sign in all cases had significant improvement. The NDI was significantly improved from(47.80±11.52)% to(16.20±9.34)%(P<0.05),the VAS for neck and arm pain were all significantly improved from(5.13±1.44) and (6.30±1.51) to (1.46±0. 81) and (1.14 ±0.57) respectively (P<0.05). The lordosis of cervical spine was significantly in-creased at follow up (P<0.05). The ROM of the cervical spine and ROM of treated segment re-covered to the preoperative level. There was no neurological complication during operation,and no ossification in the replaced level and no prosthesis displacement and loosening . Conclusion Our findings suggest that the Prestige LP cervical disc replacement in the treatment of cervical disc degenerative diseases has good functional short-term results, further follow-up is necessary to e-valuate mid- and long-term outcome.%目的:探讨应用Prestige LP人工椎间盘置换治疗单节段颈椎病的近期临床疗效。方法治疗单节段颈椎病患者15例,统计并分析患者术前和术后1、3、12个月随访时JOA评分、NDI脊髓功能评分、颈部及上肢疼痛VAS评分、置换节段活动度、颈椎运动范围、颈椎生理曲度等指标

  5. 人工颈椎间盘置换术治疗脊髓型颈椎病10例临床分析%Artificial cervical disc replacement in the treatment of cervical spondylotic myelopathy clinical analysis of 10 cases

    Institute of Scientific and Technical Information of China (English)

    杨磊; 崔宏勋; 赵庆安; 饶耀剑

    2013-01-01

      目的探讨人工颈椎间盘置换术用于治疗脊髓型颈椎病的临床疗效.方法2010年6月—2012年9月,对10例保守治疗无效患者的11个节段进行了人工颈椎间盘置换术,男6例,女4例;年龄41~61岁,平均(48±0.8)岁.单节段9例,双节段1例,术后随访3~12个月.结果所有患者伤口均I期临床愈合,术中及术后没有神经和血管损伤的并发症,结合术前术后颈椎活动范围检查、神经系统症状、Odom评级、JOA评分及影像学检查,患者神经系统症状均获得满意改善,JOA评分较术前明显升高.颈椎曲度、置换节段功能活动度、置换节段上下位椎体椎间隙高度得到保持.假体未见下沉或偏移,未见异位骨化.结论颈椎人工椎间盘置换术在维持节段运动功能的同时,可取得良好的神经减压效果,人工椎间盘置换术的短中期疗效是令人满意的.%Objective To investigate the artificial cervical disc replacement for the treatment of cervical spondylotic myelopathy. Methods In 2010 June to 2012 September,10 cases of invalid conservative treatment of patients with 11 segments for the artificial cervical disc replacement,6 cases were male,4 female;age 41-61 years,mean 48±0.8 years old. 9 cases of single segment,1 cases of double segments,followed up for 3 months to 12 months. Results All patients were healed wound phase I clinical,intraoperative and postoperative no nerve and blood vessel injury,combined examination of cervical range check, neurological symptoms,Odom rating,JOA score and imaging before and after surgery,patients with nervous system symptoms were satisfactory improvement,JOA score was significantly higher than that before operation. Cervical curvature,replacement of segmental function activity,replacement segment inferior vertebral height is maintained. Prosthesis no sinking or offset, no heterotopic ossification. Conclusion Cervical artificial disc replacement in the maintenance of segmental motion

  6. 骨水泥型人工股骨头置换治疗老年不稳定股骨转子间骨折%Curative effects using cemented artificial femoral head arthroplasty for unstable intertrochanteric fracture in elderly patients

    Institute of Scientific and Technical Information of China (English)

    吕浩; 荆珏华; 周云

    2013-01-01

    Objective To explore the clinical effect of artificial femoral head arthroplasty on unstable intertrochanteric fracture of femur in the elderly patients.Methods 17 cases of the femoral neck fractures in elderly patients was treated with bone cement prosthetic femoral head replacement and intertrochanteric reconstruction.The patients did earliest rehabilitation exercise after operation.Results The operation time was 55 ~ 95min,the intraoperative blood loss was 100 ~500 ml.1 case got involved deep vein thrombosis in lower limb.17 cases were followed up for 8 ~ 21 months.According to the final Harris hip function score,8 cases were excellent,6 good,2 fair,and 1 poor.Conclusions Cemented prosthetic femoral head replacement in the treatment of intertrochanteric femoral fractures can shorten the time in bed,reduce the complications,provide early stage of hip functional exercise to rehabilitation.The curative effect is reliable.%目的 探讨人工股骨头置换治疗老年不稳定股骨转子间骨折的临床效果.方法 对17例老年不稳定股骨转子间骨折患者行骨水泥型股骨头置换及转子间重建,术后早期进行功能锻炼.结果 手术时间55~95 min,术中出血量100~500 ml.1例术后出现下肢静脉血栓.17例均获随访,时间8~21个月.末次随访髋关节功能Harris评分:优8例,良6例,可2例,差1例.结论 应用骨水泥人工股骨头置换治疗不稳定股骨转子间骨折,可缩短患者卧床时间,减少并发症发生;早期进行患髋功能锻炼,有利于康复,且疗效可靠.

  7. Observation on early therapeutic effect of DISCOVER artificial cervical disc replacement for cervical spondylotic myelopathy%DISCOVER人工颈椎间盘置换术治疗脊髓型颈椎病的早期疗效观察

    Institute of Scientific and Technical Information of China (English)

    钱俊; 辛兵; 何玉泽; 郭开今

    2013-01-01

    目的 探讨应用DISCOVER人工颈椎间盘置换术治疗脊髓型颈椎病的早期临床疗效.方法 回顾性分析行DISCOVER人工颈椎间盘置换术的12例脊髓型颈椎病患者的临床资料,统计并分析患者术前和术后神经功能状态JOA评分和颈椎总活动度(ROM),进行早期疗效评估.结果 所有患者随访6个月,术后临床症状和体征明显改善或消失,JOA评分由术前的(6.79±3.62)分提高到末次随访的(15.84 ±0.89)分(P<0.05);ROM术前为(51.3 ±14.2)°,术后末次随访为(49.9±13.8)°,差异无统计学意义(P>0.05).按照Odom评定标准,末次随访时,优9例,良2例,可1例,优良率91.7%.结论 应用DISCOVER人工颈椎间盘置换术治疗脊髓型颈椎病早期疗效良好,远期效果有待进一步观察.%Objective To evaluate the early clinical efficacy of DISCOVER artificial cervical disc replacement sur gery for cervical spondylotic myelopathy. Methods The clinical data of 12 patients with cervical spondylotic myelopathy undergoing DISCOVER artificial cervical disc replacement was analyzed retrospectively. Preoperative and postoperative neurological status JOA scores and cervical range of motion (ROM) were compared and early therapeutic efficacy was e-valuated. Results All patients were followed - up for 6 months. The neurological symptoms and signs were alleviated or disappeared in all cases. The JOA score was significantly improved from 6. 79 ±3. 62 preoperatively to 15. 84 ±0. 89 at the last postoperative follow - up (P 0. 05 ). According to Odom criteria, 9 cases got excellent results, 3 cases got good results, 1 case got fair results. The rate of excellent and good results was 91.7%. Conclusion Our findings suggest that the DISCOVER cervical disc replacement for cervical spondylotic myelopathy may yield good short - term functional results. Further follow - up is necessary to evaluate mid and long - term outcome.

  8. Cross-shear implementation in sliding-distance-coupled finite element analysis of wear in metal-on-polyethylene total joint arthroplasty: intervertebral total disc replacement as an illustrative application.

    Science.gov (United States)

    Goreham-Voss, Curtis M; Hyde, Philip J; Hall, Richard M; Fisher, John; Brown, Thomas D

    2010-06-18

    Computational simulations of wear of orthopaedic total joint replacement implants have proven to valuably complement laboratory physical simulators, for pre-clinical estimation of abrasive/adhesive wear propensity. This class of numerical formulations has primarily involved implementation of the Archard/Lancaster relationship, with local wear computed as the product of (finite element) contact stress, sliding speed, and a bearing-couple-dependent wear factor. The present study introduces an augmentation, whereby the influence of interface cross-shearing motion transverse to the prevailing molecular orientation of the polyethylene articular surface is taken into account in assigning the instantaneous local wear factor. The formulation augment is implemented within a widely utilized commercial finite element software environment (ABAQUS). Using a contemporary metal-on-polyethylene total disc replacement (ProDisc-L) as an illustrative implant, physically validated computational results are presented to document the role of cross-shearing effects in alternative laboratory consensus testing protocols. Going forward, this formulation permits systematically accounting for cross-shear effects in parametric computational wear studies of metal-on-polyethylene joint replacements, heretofore a substantial limitation of such analyses.

  9. 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.

  10. Imaging of knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-05-01

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

  11. 颈椎人工椎间盘置换术与颈前路减压融合内固定术手术疗效比较%Comparing the effects of Bryan cervical Disc arthroplasty with anterior cervical decompres-sion and fusion

    Institute of Scientific and Technical Information of China (English)

    张涛; 王弘; 徐宏光; 李从明

    2016-01-01

    目的:比较颈椎人工椎间盘置换术( cervical disc arthroplasty ,CDA)与颈前路减压融合内固定术( anterior cervical de-compression and fusion ,ACDF)的手术疗效。方法:回顾分析2012年8月~2015年1月收治的退变性颈椎病50例,随机给予CDA(n=23),或者ACDF(n=27)治疗,术后12个月门诊随访。结果:两组术前性别、年龄、手术节段活动度(range of motion, ROM)、VAS( visual analogue scale )及JOA( Japanese orthopaedic association )无统计学差异,CDA组比ACDF组手术时间短,出血量少,具有明显统计学差异( P<0.01),两组住院时间无明显统计学差异。术后12个月,两组手术节段ROM差异具有统计学意义( P<0.01),CDA组ROM较术前得以维持,ACDF组降低。两组JOA及VAS无统计学差异。结论:CDA较ACDF能维持手术节段的活动度,CDA有望取代ACDF。%Objective:To compare curative effects of Bryan cervical disc arthroplasty ( CDA) with those of anterior cervical decompression and fusion ( AC-DF).Methods:A total of 50 patients with cervical spondylotic myelopathy treated in our hospital between August 2012 and January 2015 were randomly as-signed to two groups.One group were treated with CDA (n=23) and another with ACDF(n=27).Two groups of patients were postoperatively followed on outpatient basis for 12 months.Results:The two groups were not significantly different regarding the gender,ages,range of cervical motion(ROM) and sco-ring on visual analogue scale(VAS) and Japanese Orthopedic Association(JOA).CDA group had shorter operative time and intraoperative blood loss than ACDF group,the difference was significant( P<0.01) .The length of hospital stay remained similar for the two groups ,yet the two groups were different con-cerning the ROM 12 month after operation(P<0.01).Postoperative ROM was maintained in patients in CDA group,whereas was decreased in ACDF group. There was no

  12. 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......% reverse shoulder arthroplasties, and 3% total arthroplasties. Median WOOS was 59% (IQR: 37-82). 5% had been revised by the end of June 2010. The most frequent indications for revision were dislocation or glenoid attrition....

  13. 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.

  14. Bryan人工椎间盘置换术对颈椎曲度影响的研究%Effect of cervical arthroplasty with Bryan disc prosthesis on post-operative cervical curvature

    Institute of Scientific and Technical Information of China (English)

    孙宇; 赵衍斌; 周非非; 张凤山; 潘胜发; 刘忠军

    2011-01-01

    Objective To investigate the angle changes of functional spine unit ( FSU) at operated segment after single-level Bryan disc replacement at different time points after operation. Methods A total of 60 patients receiving single-level Bryan disc replacement between December 2003 and December 2007 were enrolled in this study. The changes of FSU angle were measured and compared on lateral X-ray films. Results All 60 patients were followed up for an average of 32 months ( ranging 3-69 months). The levels of surgery included C3/C4 (2 cases), C4/C3 (14 cases) , C5/C6 (41 cases) and C6/C,7(3 cases). The mean FSU angle was 0. 3° before the surgery, and -0. 5° at the final follow-up, with statistically significant difference found between them ( P < 0.05 ). The patients were divided into three groups according the operation period: early stage group (2003-2004), middle stage group (2005) and late stage group (2006-2007). The average FSU kyphosis was increased by 1.6° after the operation in early stage group, but only by 0.1° in late stage group,and the difference had statistical significance ( P < 0.05 ). Conclusion FSU kyphosis mainly occurs in early stage after Bryan disc replacement. This complication could be avoided with surgical experience accumulation and surgical technique improvement.%目的 观察不同手术时期Bryan人工椎间盘置换术后置换节段脊柱功能单位(functional spine unit,FSU)曲度变化情况.方法 随访2003年12月~2007年12月接受单节段Bryan人工椎间盘置换术的患者,在侧位X线片上测量FSU角度变化.结果 60例患者获得随访,随访3~ 69个月,平均32个月,手术节段包括C3/C4节段2例,C4/C5节段14例,C5/C6节段41例,C6/C7节段3例.术前FSU平均曲度为0.3°,末次随访时为-0.5°(P<0.05).根据手术日期将全部病例分成早期(2003~ 2004年)、中期(2005年)和后期(2006 ~ 2007年)3维,统计分析发现早期病例随访时FSU后凸平均增加1.6°,后

  15. Artificial total hip arthroplasty for proximal femur tumors:clinical efficacy and security%人工全髋关节置换治疗股骨近端骨肿瘤:疗效及安全性分析

    Institute of Scientific and Technical Information of China (English)

    周政; 刘傥

    2014-01-01

    背景:随着医疗水平的提高,肢体恶性肿瘤保肢手术的价值日益提高,目前已替代截肢,成为当今肢体肿瘤外科治疗的主流与发展方向。但目前为止,对股骨近端肿瘤还没有统一的手术适应证,仍存在争议。目的:观察人工全髋关节置换联合瘤段扩大切除治疗股骨近端骨肿瘤的效果。方法:选取中南大学湘雅二医院收治的股骨近端骨肿瘤患者并随机分为对照组和观察组,每组30例。对照组患者根据病情选择病灶刮除,瘤体壁灭活,自体和(或)异体骨、人工骨混合植骨后行植入物内固定治疗。观察组患者接受瘤段扩大切除加人工全髋关节置换治疗。比较两组患者手术时间、术中术后出血量、住院时间及关节功能情况。2年后对患者进行回访,比较两组患者的转移复发率、死亡率以及生活质量。结果与结论:两组患者手术时间及术中出血量间无显著性差异(P>0.05),但观察组患者住院时间短于对照组,关节功能恢复优良率(83%)高于对照组(53%),术后2年内转移复发率(7%)和死亡率(3%)均低于对照组(30%,23%)。观察组患者生活质量各项指标均优于对照组,差异有显著性意义(P0.05). However, hospital stay of patients in the observation group was shorter than the control group. The excellent and good rate of recovery of joint function (83%) was higher in the observation group than in the control group (53%). The metastasis and recurrence rate within 2 years after surgery (7%) and death rate (3%) were lower in the observation group than in the control group (30%, 23%). Various indicators of quality of life of patients in the observation group were significantly better than the control group (P<0.05). These results confirmed that artificial total hip arthroplasty in the treatment of proximal femur tumors is safe and effective.

  16. ADJACENT SEGMENT DEGENERATION AFTER CERVICAL ARTIFICIAL DISC REPLACEMENT AT EARLY MID-TERM FOLLOW-UP%人工颈椎间盘置换术后邻近节段退变情况的早中期随访

    Institute of Scientific and Technical Information of China (English)

    刘雅普; 夏虹; 艾福志; 石林; 隋文渊

    2012-01-01

    Objective To study the effectiveness of artificial disc replacement for cervical diseases and the adjacent segment degeneration. Methods Between January 2008 and October 2010, 39 cases of cervical spondylosis underwent cervical disc replacement. Of them, there were 20 males and 19 females with an average age of 45.7 years (range, 32-60 years) and an average disease duration of 30 months (range, 1 month to 10 years), including 26 cases of cervical myelopathy, 11 cases of nerve root cervical spondylosis, and 2 cases of mixed cervical spondylosis. Single level disc lesion was observed in 27 cases while bi-level lesion in 12 cases. Prestige disc prosthesis was used in 9 patients, Prodisc-C prosthesis in 4 patients, and Discover disc prosthesis in 26 patients. The neurological functional recovery was assessed after operation by Japanese Orthopaedic Association (JOA) score. The range of motion of replaced segment and adjacent segments was measured (Cobb angle), and Kellgren's X-ray assessment was used to evaluate the degree of adjacent segment degeneration. Results The operation was successfully performed in all cases, with primary healing of all the incisions. All patients were followed up from 12 to 36 months with an average of 23.1 months. JOA score was significantly improved at last follow-up when compared with preoperative score (P 0.05). According to the Kellgren's X-ray assessment, degeneration of the adjacent segments occurred in 5 cases at last follow-up, including 3 cases of degeneration from grade 0 to grade 1 or 2, 1 from grade 1 to grade 2, and 1 from grade 2 to grade 3, with a degeneration rate of 12.8%, but no significant difference was found in degeneration degree when compared with preoperative value (X2=1.793, P=0.406). No degeneration of adjacent segments occurred in 32 patients at 15 months after operation. Conclusion Artificial disc replacement has a good effectiveness in treating cervical spondylosis, which can maintain the range of motion of the

  17. Artificial Total Disc Replacement for Lumbar Degenerative Disc Disease: A Systematic Review%人工全椎间盘置换治疗退行性腰椎间盘疾病的系统评价

    Institute of Scientific and Technical Information of China (English)

    何祖胜; 白靖平; 锡林宝勒日; 金格勒; 吴泰相; 李静

    2005-01-01

    目的分析人工全椎间盘置换治疗退行性腰椎间盘疾病的疗效.方法计算机检索Cochrane图书馆(2004年第2期)中的临床对照试验资料库和Cochrane协作网背痛专业试验数据库、MEDLINE(1966~2004)、EMBASE(1980~2004)、中国生物医学文献光盘数据库(CBMdisk,2003),手工检索中文文献(截自2004年6月),并询问相关厂家以及研究者.由两名评价员独立提取资料,并按Cochrane协作网提供的方法对纳入文献进行质量评价和结果分析.结果共纳入3个RCT,包括152例患者.文献质量评价结果显示,3个RCT均可能存在选择性偏倚、实施偏倚和测量偏倚的高度可能性.其中两篇使用ProDisc-Ⅱ人工全椎间盘置换,1篇使用SB-Ⅲ人工全椎间盘置换.3个RCT均未提供详细的原始数据,因此不能进行Meta分析.人工全椎间盘置换组病人术后早期VAS疼痛评分(visual analog scale)和ODI功能评分(oswestry disability index)有改善,但术后6个月与融合组无差异.病人满意率,术后6个月人工全椎间盘置换组有优于融合组的趋势.短期随访显示,人工椎间盘能够保存受累节段的运动功能.两篇RCT报告了相关并发症.结论人工全椎间盘置换短期内能够重建退变节段的高度及生理运动功能,但缺乏长期的随访,尤其对于能否防止毗邻节段的退变缺乏证据.尚需更多设计严格的研究以增加证据的强度.

  18. 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

  19. 与人工髓核置换相关的国人腰椎间盘结构测量%Measurement of lumbar disc related to artificial nucleus pulposus replacement in Chinese

    Institute of Scientific and Technical Information of China (English)

    王子轩; 单涛

    2012-01-01

    BACKGROUND: Surgeons usually predict the size and number of nucleus pulposus (NP) prosthesis before operation according to the diameters of lumbar intervertebral disc measured on medical images.OBJECTIVE: To measure and analyze height of lumbar intervertebral space, lumbar disc and NP diameters in normal for obtaining basic data of intervertebral disc related to artificial prosthetic nucleus.METHODS: Totally 157 lumbar spine X-ray films (Lateral views) of normal adult were randomly selected. Anterior, middle and posterior heights of lumbar intervertebral space were measured on X-ray films. A total of 106 lumbar Magnatic Resonance Imaging (MRI) images of normal adult were randomly selected for measuring transverse diameter and antero-posterior diameter (A-P diameter) of NP and lumbar disc.RESULTS AND CONCLUSION: ? X-ray film: from upper to lower, the height of intervertebral space increased gradually. Posterior height of lumbar intervertebral space was low. It ranged between 7 mm and 9 mm, approximately 50% at L2/3, L3/4, and L4/5, about 39.5% at L5/S1. ? MRI images: from L2/3 to L5/S1, the transverse diameter and A-P diameter of lumbar disc enlarged in turn. About 46.7% A-P diameter of lumbar discs were more than 37 mm. However, only 49.0% were proved that the A-P diameters of NP were more than 24 mm. In this study, the average transverse diameter of NP was 33.5 mm, the average A-P diameter was 23.4 mm. The A-P diameters of NP were all more than 12 mm. Among these, about 22.9% were more than 24 mm. The results indicated that single prosthetic disc nucleus (PDN) is suitable for most Chinese patients, and the height of 7 mm of PDN is commonly chosen. The A-P diameter of lumbar disc ranging from 37 mm is demonstrated unreliable to predict double PDN replacement before operation in Chinese.%背景:临床多根据影像资料中腰椎间盘径线尺寸来选择假体型号和预计置入数量.目的:以X射线片和MRI测量分析正常人腰椎间隙高度、腰椎

  20. Medium term efficacy analysis of bi-level BRYAN artificial cervical disc replacement for the treatment of cervical spondylosis%双节段BRYAN人工颈间盘置换的中期疗效分析

    Institute of Scientific and Technical Information of China (English)

    种涛; 俞兴; 贾育松; 李春根; 柳根哲; 毕连涌; 徐林

    2013-01-01

    [ Objective]To observe the clinical effect and imaging results of the treatment of adjacent segment cervical spon-dylosis in the adjacent bi - level BRYAN cervical disc replacement. [ Method] A retrospective studying was performed on 19 cases of cervical spondylosis receiving adjacent bi - level BRYAN artificial cervical disc replacement and were followed up from January 2006 to February 2009 in our hospital. Clinical outcome of surgery was evaluated by Japanese Orthopaedic Association score (JOA) , neck disability index(NDI) and visual analogue pain scale (VAS)for neck pain before surgery and at 1 week,3, 6,12,24,36 months after surgery respectively. The range of motion (ROM) of the surgical segments, the upper and lower adjacent segments, and C2-7 was assessed by cervical dynamic X - ray film before operation and 3 ,6,12,24,36 months after sugery. Operative adjacent segment degeneration was assessed by X - ray disc degeneration scoring system 12,24 and 36 months after surgery. [Result]The neurological symptoms of each patients were significantly improved. The postoperative JOA score , NDI scores, neck pain VAS scores were improved significantly at each follow - up time point compared with those of preoperation, difference was statistically significant (P 0. 05). ROM of the two operative segment increased significantly compared with the preoperative each time point after 3 - month follow - up (P 0. 05). To the last follow - up, the surgery had not led to adjacent segment disc degeneration exacerbated and no serious complications occurred. [ Conclusion ] The clinical result of BRYAN artificial cervical disc replacement in the treatment of adjacent bi - level cervical degenerative disc disease is good, not only reserving the kinematic characteristics of operative segment, adjacent segments , C2-7 segment but preventing of adjacent segment degeneration. No serious complication occurs during mediterm follow - up.%[目的]观察相邻双节段BRYAN人工颈椎间盘

  1. 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

  2. 人工颈椎间盘置换与前路颈椎间盘切除融合后邻近节段椎间盘应力分布的有限元对比%Comparison of stress distribution of adjacent segments after artificial cervical disc replacement versus anterior cervical discectomy and fusion:a finite element analysis

    Institute of Scientific and Technical Information of China (English)

    刘雅普; 侯秀伟; 吴广良; 夏虹

    2016-01-01

    背景:通过前期的临床随访研究发现,前路颈椎融合后邻近节段椎间盘退变速度要快于人工颈椎间盘置换,人工颈椎间盘置换相较于前路颈椎融合可以保持良好的置换节段活动度,是否置换后邻近椎间盘的应力情况与融合之间存在着差异需要进一步研究。目的:对比人工颈椎间盘置换与前路颈椎间盘切除融合后邻近节段椎间盘的应力分布情况。方法:选择1名30岁健康男性志愿者,人工颈椎间盘和颈椎前路钢板实物进行薄层CT扫描,通过Mimics 10.01及Geomagic Studio.v11软件重建出三维图像,将以上三维数据导入Abaqus 6.9有限元分析软件中进行网格划分、赋值、应力分析。利用有限元方法分析模拟人工颈椎间盘置换及前路颈椎间盘切除融合后邻近节段椎间盘的应力变化。结果与结论:①在相同的预载荷条件下,前屈、后伸、侧屈等运动状态时前路颈椎间盘切除融合后邻近节段椎间盘的应力明显大于正常人相应节段椎间盘应力;而人工椎间盘植入后与正常人相比,在前屈、后伸、侧屈等运动状态时邻近节段椎间盘的应力差异无显著性意义;②前路颈椎间盘切除融合组与人工颈椎间盘置换组相比较,融合组术后邻近节段椎间盘的应力较置换组增大10.3%-51.6%;③有限元分析方法发现,前路颈椎间盘切除融合后邻近节段椎间盘应力大于人工颈椎间盘置换组,随着随访时间的延长,相较于传统前路减压融合,人工颈椎间盘置换可能将更好地发挥其对邻近节段椎间盘的保护作用。%BACKGROUND:Previous clinical fol ow-up study showed that disc degeneration of adjacent segment after anterior cervical discectomy and fusion was faster than that of artificial cervical disc replacement. Compared with the anterior cervical discectomy and fusion, artificial cervical disc replacement can maintain a

  3. Total hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Slavković Nemanja

    2012-01-01

    Full Text Available Total hip arthroplasty is most common reconstructive hip procedure in adults. In this surgery we replace some parts of the upper femur and acetabulum with biocompatible materials. The main goal of this surgery is to eliminate pain and regain full extent of joint motion, maintaining hip stability. Surgical technique, biomaterials, design of the prosthesis and fixation techniques have evolved with time adjusting to each other. After total hip arthroplasty patients’ quality of life should be improved. There are many various postoperative complications. Some of them are fatal, and some are minor, which may become manifested years after surgery. Each next surgical procedure following previous hip surgery is associated with considerably lower chances to be successful. Therefore, in primary total hip arthroplasty, preoperative evaluation and preparation of patients are essential. Every orthopaedic surgeon needs to improve already adopted surgical skills applying them with precision and without compromise, with the main goal to achieve long-term durability of the selected implant. The number of total hip arthroplasties will also increase in future, and newer and higher quality materials will be used.

  4. Bryan人工椎间盘单节段置换治疗颈椎间盘退变性疾病的临床疗效%Clinic Therapeutic Effect of Bryan Artificial Disc Single Level Replacement on Cervical Disc Degenerative Diseases

    Institute of Scientific and Technical Information of China (English)

    石锐; 刘浩; 丁琛; 胡韬; 李涛; 龚全; 宋跃明; 洪瑛

    2011-01-01

    -up visiting at the expected time in the next two years after the operation. Patients' symptom scale, VAS for neck pain, VAS for arm pain, NDI were 2. 80 ±0. 42, 4. 62 ± 1. 84, 5. 01 ±1. 79, and 22. 60±4. 88, respectively before the operation and significantly decreased to 0. 20±0. 42, 1. 01±0. 56, 0. 82±0. 24, and 4. 30+1. 25, respectively at the end of the follow-up. All patients had good or higher score of the Odom score. The ymptoms were completely relieved in eight patients (38. 1%). The mean operation time was (110. 5±42. 6) minutes, the average blood loss was (166. 0±108. 8) mL. The normal motion of the artificial disc was observed. No cervical instability was observed. Two prosthesis migrated slightly. Conclusion Single segmental Bryan disc replacement is safe and effective on the cervical disc degeneration. The two-year follow-up reveales a satisfied clinical outcome.

  5. 人工全髋关节置换术及全膝关节置换术术后隐性失血的临床比较%Clinical comparison of postoperative hidden blood loss by artificial hip replacement and total knee arthro-plasty

    Institute of Scientific and Technical Information of China (English)

    骆雷锋

    2016-01-01

    Objective To investigate the postoperative hidden blood loss by artificial total hip replacement and to -tal knee arthroplasty .Methods Sixty patients accepted total hip arthroplasty from June 2012 to September 2014 were se-lected as the experiment group , the other 72 patients accepted total knee arthroplasty were selected as the control group , ac-cording to Gmss equation , calculated hidden blood loss combination of the patients weight , height, the red blood cell pres-sure before and after operation.Results In experiment group, the hidden blood loss[(482.1 ±42.7)ml] was significant-ly lower than in that incontrol group [(776.1 ±84.8)ml](P0.05).The hidden blood loss of obese and non obese in the group had no significant difference (P>0.05).Conclusions The hidden blood loss after total knee arthroplasty was significantly higher than that after artificial hip replacement , the application of drainage blood transfu-sion cannot meet the body circulation recovery needs , should be timely supplement blood capacity .%目的:探究人工全髋关节置换术及全膝关节置换术术后隐形失血的情况。方法选取周口市中心医院2012年6月至2014年9月收治的60例接受人工全髋关节置换术治疗的患者为实验组,另选择同期来院行人工全膝关节置换术的72例患者为对照组,依据Gmss方程,并结合患者体质量、身高、手术前后红细胞压积,行隐性失血计算。结果实验组隐性失血量为(482.1±42.7)ml,明显低于对照组的(776.1±84.8)ml(P<0.05);而未应用引流血回输者与应用引流血回输者隐性失血比较差异未见统计学意义(P>0.05),组内肥胖者与非肥胖者隐性失血量比较差异未见统计学意义( P>0.05)。结论人工全膝关节置换术后隐性失血量明显高于人工全髋关节置换术,应用引流血回输无法满足机体体循环恢复需要,应及时行血容量补充。

  6. 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

  7. Broken discs: warp propagation in accretion discs

    OpenAIRE

    Nixon, Chris; King, Andrew

    2012-01-01

    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 nonlinear fluid effects, which reduce the effective viscosities in warped regions, can promote the breaking of the disc into two distinct planes. This occurs when the Shakura & Sunyaev dimen...

  8. Primary total elbow arthroplasty

    Directory of Open Access Journals (Sweden)

    Suresh Kumar

    2013-01-01

    Full Text Available Background: Primary total elbow arthroplasty (TEA is a challenging procedure for orthopedic surgeons. It is not performed as frequently as compared to hip or knee arthroplasty. The elbow is a nonweight-bearing joint; however, static loading can create forces up to three times the body weight and dynamic loading up to six times. For elderly patients with deformity and ankylosis of the elbow due to posttraumatic arthritis or rheumatoid arthritis or comminuted fracture distal humerus, arthroplasty is one of the option. The aim of this study is to analyze the role of primary total elbow arthroplasty in cases of crippling deformity of elbow. Materials and Methods: We analyzed 11 cases of TEA, between December 2002 and September 2012. There were 8 females and 3 males. The average age was 40 years (range 30-69 years. The indications for TEA were rheumatoid arthritis, comminuted fracture distal humerus with intraarticular extension, and posttraumatic bony ankylosis of elbow joint. The Baksi sloppy (semi constrained hinge elbow prosthesis was used. Clinico-radiological followup was done at 1 month, 3 months, 6 months, 1 year, and then yearly basis. Results: In the present study, average supination was 70° (range 60-80° and average pronation was 70° (range 60-80°. Average flexion was 135° (range 130-135°. However, in 5 cases, there was loss of 15 to 35° (average 25° of extension (45° out of 11 cases. The mean Mayo elbow performance score was 95.4 points (range 70-100. Arm length discrepancy was only in four patients which was 36% out of 11 cases. Clinico-radiologically all the elbows were stable except in one case and no immediate postoperative complication was noted. Radiolucency or loosening of ulnar stem was seen in 2 cases (18% out of 11 cases, in 1 case it was noted after 5 years and in another after 10 years. In second case, revision arthroplasty was done, in which only ulnar hinge section, hinge screw and lock screw with hexagonal head

  9. Effect of psychological intervention on pain and early rehabilitation of the patients after total artificial hip arthroplasty%疼痛心理干预对人工髋关节置换术后早期康复效果的影响

    Institute of Scientific and Technical Information of China (English)

    帅红; 李安

    2012-01-01

    Objective:To investigate the effect of psychological intervention on pain and early rehabilitation of the patients after total artificial hip arthroplasty. Methods: 60 patients who underwent total artificial hip arthroplasty were randomly divided into the experimental and control groups ( 30 cases in each group ). The patients in the control group were given routine nursing care, health education and analgesic treatment and the patients in the experimental group were additionally given comprehensive psychological interventions, such as cognitive behavior therapy, relaxation and biofeedback therapy and supportive psychotherapy. The degree of postoperative pain and hip joint function were observed in the two groups. Results:The pain scores in the resting and active state respectively in 6,f2,24,48 and 72 hours after operation were lower in the experimental group than the control group ( P <0. 05 ) ;the active exercise times of flexion and rotation of the ankle of the affected limb 2 days after operation were many more in the experimental group than the control group ( P < 0. 01 ); Hams scores of the hip function 2 and 4 weeks after operation were higher in the experimental group than the control group ( P <0. 05 ). Conclusion:The comprehensive psychological intervention can effectively control the postoperative pain of patients and promote early rehabilitation of hip joint function after total artificial hip arthroplasty.%目的:探讨疼痛心理干预对人工髋关节置换术(THA)后早期康复效果的影响.方法:将60例THA患者随机分为实验组和对照组各30例,对照组给予常规护理、健康宣教及疼痛治疗,实验组在对照组基础上给予认知行为疗法、放松与生物反馈疗法、支持心理疗法等疼痛心理干预措施.观察两组术后疼痛程度及髋关节功能.结果:两组比较,实验组术后6、12、24、48、72 h静息及活动状态疼痛评分均低于对照组(P<0.05);实验组术后2 d平均每天完成

  10. 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.

  11. Mortality after shoulder arthroplasty

    DEFF Research Database (Denmark)

    Amundsen, Alexander; Rasmussen, Jeppe Vejlgaard; Olsen, Bo Sanderhoff

    2016-01-01

    BACKGROUND: The primary aim was to quantify the 30-day, 90-day, and 1-year mortality rates after primary shoulder replacement. The secondary aims were to assess the association between mortality and diagnoses and to compare the mortality rate with that of the general population. METHODS: The study...... included 5853 primary operations reported to the Danish Shoulder Arthroplasty Registry between 2006 and 2012. Information about deaths was obtained from the Danish Cause of Death Register and the Danish Civil Registration System. Age- and sex-adjusted control groups were retrieved from Statistics Denmark...

  12. 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

  13. CURBSIDE CONSULTATION IN HIP ARTHROPLASTY

    OpenAIRE

    Sporer, Scott M.; Bernard R. Bach, Jr

    2009-01-01

    DESCRIPTION A user friendly reference for decision making in hip arthroplasty designed in a question formed clinical problem scenarios and answers format .The articles composed of the answers, containing current concepts and preferences of experts in primary and revision hip surgery are enhanced by several images, diagrams and references and written in the form of a curbside consultation by Scott M. Sporer, MD. and his collaborators. PURPOSE By this practical reference of hip arthroplasty, Sc...

  14. Comparison of the mid-term follow-up results between Bryan cervical artificial disc replacement and anterior cervical decompression and fusion for cervical degenerative disc disease%Bryan人工间盘置换与前路减压融合治疗颈椎退行性疾病的中期随访研究

    Institute of Scientific and Technical Information of China (English)

    田伟; 阎凯; 韩骁; 于杰; 靳培浩; 韩晓光

    2013-01-01

    Objective To evaluate the mid-term tollow-up results of cervical artificial disc replacement (CADR) for cervical degenerative disc disease,and to explore whether it can reduce the occurrence of adjacent segment degeneration (ASD).Methods A prospective comparative study of 93 patients who underwent CADR or anterior cervical decompression and fusion (ACDF) for cervical degenerative disc disease were conducted.All patients were followed up for more than 6 years.The Japanese Orthopaedic Association (JOA) score,neck disability index (NDI),Odom's scale,X-rays and magnetic resonance imaging (MRI) were used to evaluate the clinical and radiologic results.Results Twenty eight patients who underwent CADR and 35 patients who underwent ACDF had complete follow-up data.At final follow-up,the JOA score and NDI improved significantly in both groups.Between the two groups,there was no significant difference in terms of JOA score,NDI and Odom's scale.The sagittal alignment was well maintained in both groups.The total cervical spine range of motion (ROM) had no significant change for the CADR group,whereas,it significantly decreased for the ACDF group.The ROM at the replacement level of CADR patients decreased from 9.5° ± 3.7° before operation to 7.0° ± 3.0° 3 months after operation,and it was maintained to 6.6° ± 4.1° at final follow-up without significant decrease.Lateral radiographs and T2-weighted MRI showed the incidence of ASD in CADR group was significantly lower than that in ACDF group.Conclusion The six-year follow-up results of CADR are basically satisfactory.Compared with ACDF,it could better preserve physiological motion and biomechanics of cervical spine,and reduce the incidence of ASD.%目的 评价人工椎间盘置换术治疗颈椎退行性疾病的中期疗效,并探讨其是否可以减少邻近节段退变的发生.方法 前瞻性对比分析接受颈椎人工间盘置换术(置换组,45例)与颈椎前路减压融合术(融合组,48例)治疗的颈椎

  15. Dynamos in accretion discs

    OpenAIRE

    Brandenburg, A.; von Rekowski, B.

    2007-01-01

    It is argued that accretion discs in young stellar objects may have hot coronae that are heated by magnetic reconnection. This is a consequence of the magneto-rotational instability driving turbulence in the disc. Magnetic reconnection away from the midplane leads to heating of the corona which, in turn, contributes to driving disc winds.

  16. Finite element analysis of biomechanical performance of atlanto-axial bony structure following artificial atlanto-odontoid joint arthroplasty%人工寰齿关节置换后寰枢椎骨性结构生物力学性能的有限元分析

    Institute of Scientific and Technical Information of China (English)

    胡勇; 袁振山; 赵红勇; 张美超; 顾勇杰

    2013-01-01

    Objective To investigate the stress characteristics of atlanto-axial bony structure under conditions of anteflexion,posterior extension,lateral flexion,and rotation after artificial atlanto-odontoid joint arthroplasty using three-dimensional finite element method and to improve the orientation of artificial atlantoodontoid joint from perspective of stress.Methods A three-dimensional finite element model of prosthetic atlanto-odontoid joint arthroplasty was created from CT images of the artificial atlantoodontoid joint and cervical vertebrae using software Mimics,Freeform,and Ansys.Stress characteristics of the model dealt with proneness,posterior extension,lateral flexion,or rotation loads were observed.Biomechanical performance of the bony structure of the model was analyzed and the orientation in improving the prosthesis was discussed.Results Anteflexion loading produced a maximum stress of 0.138 ×l08 N/m2 at the junction of lateral mass and posterior arch of the atlas,and 0.201 × 108 N/m2 at axial nail hole,contact point of plates with the axis,and posterior arch of the axis.Posterior extension loading produced a maximum stress of 0.666 × 107 N/m2 at junction of lateral mass and posterior arch of the atlas and 0.254 × 108 N/m2 at arch of the axis.Besides,stress concentration occurred at atlantoaxis nail hole.Right bending produced a maximum stress of 0.124 × 108 N/m2 at nail hole of right mass of atlas and 0.178 × 108 N/m2 at right contact point of the axis with plates.Right rotation produced a maximum stress of 0.847 × 107 N/m2 at junction of lateral mass and posterior arch of the atlas and 0.170 × 109 N/m2 at contact point of the axis with plates.The finite element model comprised 28 620 nodes and 107 441 units and provided good defining of the structural properties of artificial atlanto-odontoid joint arthroplasty.Under different loading conditions,the stress was mainly distributed in contact point of the vertebral body with plates,nail holes

  17. Construction and validation of a finite element model of atlanto-axial joint following artificial atlanto-odontoid joint arthroplasty%人工寰齿关节置换后寰枢关节有限元模型的建立

    Institute of Scientific and Technical Information of China (English)

    胡勇; 赵红勇; 谢辉; 袁振山; 董伟鑫; 张美超

    2013-01-01

    Objective To develop and validate an anatomic detailed finite element model of atlanto-axial joint following artificial atlanto-odontoid joint arthroplasty.Methods The normal fresh human specimens of atlas and axial and artificial atlanto-odontoid joint were subjected to CT scan.Three-dimensional model was established by Mimics software.According to clinical practice,dealing with atlas and axial and assembling artificial atlanto-odontoid joint by Freeform.After constructing the geometric model and meshing the solid model using tetrahedral solid elements,adding the relevant ligament structure,the meshed model was acqujred and finished by Ansys at last.The ligaments were modeled with tension-only spring elements with bilinear modulus of elasticity data according to neutral and elastic zones.The ligaments of model includes:atlantoaxial joint capsule and ligaments,facet joint capsular ligament,interspinous ligament,supraspinous ligament.Sliding contact definitions with friction were used for all the facet joints.In the analysis,the weight of the skull was simulated by applying vertical load of 40 N on the fixed handle,and the inferior surface of the C2 venebral body was fully constrained but the upper part of the atlas without any constraints.Pure moment loading of 1.53 N.m was applied to the fixed handle to simulate various movements of the atlanto-axial joint under flexion,extension,lateral bending and axial rotation configurations.The the range of motion (ROM) of model under different direction were evaluated biomechanically.To validate the finite element model in term of ROM compared against the experimental data by Yong Hu at al.Results The model consists of 26324 nodes and 103053 elements,In the conditions of flexion,extension,righe flexion and right rotatio,the ROM of the artificial atlanto-odontoid joint are 1.6°,5.1 °,4.6 ° and 22.0°,that is correlated well with the results by Yong Hu at al.Conclusion The anatomic detailed finite element model

  18. Transfemoral amputation after failed knee arthroplasty

    DEFF Research Database (Denmark)

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

    2016-01-01

    BACKGROUND: Transfemoral amputation is considered the last treatment option for failed knee arthroplasty. The extent to which this procedure is performed is not well known. The purpose of this study was to identify the incidence and causes of amputation following failure of knee arthroplasty...... in a nationwide population. METHODS: Data were extracted from the Danish Civil Registration System, the Danish National Patient Register, and the Danish Knee Arthroplasty Register. With use of individual data linkage, 92,785 primary knee arthroplasties performed from 1997 to 2013 were identified. Of these, 258...... for causes related to failed knee arthroplasty. The 15-year cumulative incidence of amputation was 0.32% (95% confidence interval [CI], 0.23% to 0.48%). The annual incidence of amputation following arthroplasties performed from 1997 to 2002 was 0.025% compared with 0.018% following arthroplasties performed...

  19. Black hole accretion discs

    CERN Document Server

    Lasota, Jean-Pierre

    2015-01-01

    This is an introduction to models of accretion discs around black holes. After a presentation of the non-relativistic equations describing the structure and evolution of geometrically thin accretion discs we discuss their steady-state solutions and compare them to observation. Next we describe in detail the thermal-viscous disc instability model and its application to dwarf novae for which it was designed and its X-ray irradiated-disc version which explains the soft X--ray transients, i.e. outbursting black-hole low-mass X-ray binaries. We then turn to the role of advection in accretion flow onto black holes illustrating its action and importance with a toy model describing both ADAFs and slim discs. We conclude with a presentation of the general-relativistic formalism describing accretion discs in the Kerr space-time.

  20. MHD disc winds

    CERN Document Server

    Ferreira, J

    2006-01-01

    This is a doctorate level lecture on the physics of accretion discs driving magnetically self-confined jets, usually referred to in the literature as disc winds. I will first review the governing magnetohydrodynamic equations and then discuss their physical content. At that level, necessary conditions to drive jets from keplerian accretion discs can already be derived. These conditions are validated with self-similar calculations of accretion-ejection structures. In a second part, I will critically discuss the biases introduced when using self-similarity as well as some other questions such as: Are these systems really unstable? Can a standard accretion disc provide the conditions to launch jets in its innermost parts? What is the difference between X-winds and disc-winds? Finally, the magnetic interaction between a protostar and its circumstellar disc will be discussed with a focus on stellar spin down.

  1. 两种外展枕用于人工全髋关节置换术后的疗效观察%Effective observation on application of two kinds of abduction pillow in postoperative artificial total hip arthroplasty

    Institute of Scientific and Technical Information of China (English)

    贾尚琼; 徐支南; 李舜尧; 蒋丽华; 罗红梅; 王丽晖

    2012-01-01

    Objective To compare the ettects of two kinds of abduction pillow used in postoperative artificial total hip arthro-plasty(THA). Methods 160 cases of artificial THA in our hospital from January 2007 to October 2010 were divided into two groups,80 cases in each group. The experimental group used the introduced new technological ladder-shaped abduction pillow,and the control group was given the improved abduction pillow. The effects of two kinds of abduction pillow used in postoperative artificial total hip replacement were compared. Results In experimental group, the position turning over took 5 - 10 min,the tolerance time of lateral lying position was (10. 0+1. 3)min. The comfort level and the satisfaction level were 31. 2% and 65. 0%. But in the control group,the position turning over took 3 - 5 min,the tolerance time of lateral lying position was (30. 0±2. L)min. The comfort level and the satisfaction level were 56. 2% and 90. 0%. The results showed statistical difference between the two groups(P< 0. 05). Conclusion The improved abduction pillow is better than introduced new technological ladder-like abduction pillow.%目的 比较两种外展枕用于人工全髋关节置换术(THA)后的效果.方法 选择2007年1月至2010年10月行THA的患者160例随机分为实验组和对照组,每组80例,实验组使用引进的新技术梯形外展枕,对照组为改良后的外展枕.比较两组外展枕用于THA后的效果.结果 实验组患者翻身时间(5~10)min、侧卧耐受时间(10.0±1.3)min,舒适度(31.2%)和满意度(65.0%),与对照组[分别为(3~5)、(30.0±2.1)min、56.2%和90.0%]比较,差异有统计学意义(P<0.05).结论 改良后的外展枕更利于THA后的患者.

  2. Black hole accretion discs

    OpenAIRE

    Lasota, Jean-Pierre

    2015-01-01

    This is an introduction to models of accretion discs around black holes. After a presentation of the non-relativistic equations describing the structure and evolution of geometrically thin accretion discs we discuss their steady-state solutions and compare them to observation. Next we describe in detail the thermal-viscous disc instability model and its application to dwarf novae for which it was designed and its X-ray irradiated-disc version which explains the soft X--ray transients, i.e. ou...

  3. The effect of preoperative factors on the function of the cervical spine after cervical artificial disc replacement:a minimal 3 years follow-up%术前因素对人工颈椎间盘置换术中期疗效的影响

    Institute of Scientific and Technical Information of China (English)

    田伟; 韩骁; 刘波; 李勤; 胡临; 李志宇; 袁强; 何达

    2010-01-01

    目的 探讨术前因素对Bryan人工颈椎间盘置换术中期随访治疗效果的影响.方法 对2003年12月至2006年1月实施的Bryan人工颈椎间盘置换术患者的临床资料进行回顾性分析,共50例患者61个椎间盘,其中单节段颈椎人工椎间盘置换39例,双节段颈椎人工椎问盘置换11例.评估患者病程长短、置换椎间隙高度、置换节段活动度等术前因素对末次随访疗效的影响.结果 截至2009年1月,术后36个月以上的53例患者中50例获得随访.随访时间36.0~55.6个月,呈偏态分布,中位数为41.9个月.术前神经症状时间936个月的患者JOA改善率中位数与≤3个月患者相比,差异具有统计学意义(P0.87的患者相比,末次随访JOA评分改善率及置换节段活动度均较低,差异具有统计学意义(P<0.05).结论 对于颈椎病及颈椎问盘突出症患者,应在神经功能障碍出现后早期行手术治疗.拟手术节段退变严重的患者,是人工椎间盘置换手术的相对禁忌.%Objective To evaluate the effect of preopertative factors on the function of the cervical spine after Bryan artificial disc replacement. Methods Fifty patients who underwent cervical disc replacement from December 2003 to January 2006 were investigated. The preopertative factors such as long course of disease, lose of motion or disc height at the operation level were evaluated for their effects on the motion of the operated disc and clinical results at the time of final follow-up. There were 35 males and 15 females. Thirty-nine patients received one-level disc replacement, 11 patients received two-level disc replacement. The age of patients was from 25 to 73 years, average was 49 years. Results Until January 2009, 50 cases of all the 53 patient who got operation for more than 3 years were followed up. The follow up period was from 36. 0 to 55.6 months, which showed a skewed distribution, with a median of 41.9 months.The patients, who got neural syndrome

  4. 探讨 ProDisc-C 人工颈椎间盘置换术与颈前路椎间盘切除融合治疗颈椎病的临床疗效%To evaluate clinical outcomes of ProDisc-C cervical disc replacement versus fusion for cervical spondylosis

    Institute of Scientific and Technical Information of China (English)

    郭卫春; 黄文俊; 汪光晔

    2015-01-01

    myelopathy or radiculopathy were enrolled in this study .They were randomly assigned to ProDisc-C artificial cervical disc replacement group ( arthroplasty group:24 patients) and anterior cervical discectomy and fusion group (fusion group:22 patients).Operation time,blood loss were compared between the 2 groups.Visual analogue scale(VAS),Japanese Orthopedics Association( JOA) score,Range-of-motion of cervical overall and adjacent intervertebral area near the intervertebral space were evaluated preoperatively and 3,12,months postoperatively.Results A total of 46 patients(100%) were followed up for an aver-age 12 months(range,6~24).No difference was found in the operation time,intraoperative blood loss between 2 groups(P>0.05). VAS and JOA scores were apparently improved after surgery compared with before surgery in each group(P0.05).In ProDisc-C group,pre-and postoperative motion of cervical overall and adjacent intervertebral area near the intervertebral space are remained unchanged at any of the follow-up time (P>0.05).In ACDF group,motion of cervical overall decreased in 3 months after operation but gradually recovered to preoperative level in12 months after operation.Motion of adjacent intervertebral area increased in 12 months (P<0.05).There are 3 cases with dysphagia after operation in ACDF group.Conclusion ProDisc-C artificial cervical disc replacement can achieve similar clinical improvement compared with traditional ACDF for treatment of single segment disc degeneration in Mid term follow up.Artificial cervical disc replacement can effectively retain the cervical range of motion,reduce the degeneration of adjacent segments and the inci-dence of postoperative dysphagia.

  5. Artificial cervical disc prosthesis and zero-profile interbody fixation and fusion system for cervical disease:2-year follow-up%人工颈椎间盘假体联合零切迹椎间融合内固定系统置入治疗颈椎病:2年随访

    Institute of Scientific and Technical Information of China (English)

    董振宇; 楚戈; 黄异飞; 袁凤云

    2015-01-01

    BACKGROUND:Artificial cervical disc prosthesis simulates range of motion and buffer shock function of normal intervertebral discs. Clinical experiments verify that artificial cervical disc prosthesis material has good biocompatibility and mechanical characteristics. OBJECTIVE:To evaluate artificial cervical disc replacement and zero-profile interbody fixation and fusion system for multilevel cervical disease in 2-year folow-up. METHODS:Artificial cervical disc replacement and zero-profile interbody fixation and fusion system were used to treat 42 patients with multilevel cervical disease. The patient presented typical symptoms and signs of spinal cord or nerve root compression. There were 18 cases of cervical myelopathy, 15 cases of nerve root cervical spondylosis and 10 cases of mixed type of cervical spondylosis. After treatment, mean operation time, blood loss and reoperation rate were measured. Postoperative complications, disability index of neck function, visual analog scale, function unit range of corresponding surgery segments of the cervical spine, Cobb angle of C2-C7 vertebral body, range of motion of adjacent segment of proximal and distal vertebral bodies were observed and clinical outcomes were evaluated. RESULTS AND CONCLUSION: Al cases finished the operation and were scored at various time points. After treatment, radiating pain of shoulder and neck and upper extremity were remarkably lessened. Numbness and sensory loss symptoms disappeared obviously. Quality of life elevated noticeably. Visual analog scale and the disability index of neck function score were decreased in final folow-up compared with pre-treatment (P < 0.001). C2-C7 vertebrae Cobb angle, FSU angle, range of motion of proximal surgery adjacent segment and range of motion of the distal surgery adjacent segment were elevated compared with pre-treatment (P < 0.001). These data indicate that cervical spondylosis was improved after treatment. Each index of cervical spondylosis after

  6. Short-and medium-term efficacy of artificial cervical disc replacement versus fusion for cervical spondylosis%人工颈椎间盘置换与融合治疗颈椎病:中短期疗效的比较

    Institute of Scientific and Technical Information of China (English)

    高明勇; 陶海鹰; 卫爱林; 贺斌

    2014-01-01

    BACKGROUND:Recently, non-fusion technology representing as artificial cervical disc replacement continues to improve. On the basis of reconstruction of disc structure and function of involved segments, cervical spine structure of surgery area segment is significantly close to dynamic and static load stress distribution required by natural physiological systems. It effects are apparent in protecting intervertebral facet joints of degenerated segment and structure and function of the cervical spine of adjacent segments and in maintaining cervical dynamic stability, which presented obvious methodological strengths compared with segmental fusion technology. OBJECTIVE:To evaluate the clinical outcomes of anterior cervical discectomy and fusion and Bryan artificial cervical disc replacement in the treatment of single-level cervical spondylotic myelopathy or radiculopathy. METHODS:A total of 43 middle and old age patients with single-level cervical spondylotic myelopathy or radiculopathy, who were treated from March 2010 to March 2012, were enrol ed in this study. They were randomly assigned to anterior cervical discectomy and fusion group (fusion group) and Bryan artificial cervical disc replacement group. Range-of-motion of cervical overal and adjacent intervertebral area near the intervertebral space was observed with radiography. During fol ow-up, postoperative recovery of neurological function was evaluated using Japanese Orthopaedic Association scale, visual analog scale and neck disability index. RESULTS AND CONCLUSION:None patients experienced complications of neurovascular injury during and after the surgery. Range-of-motion of postoperative overal cervical vertebra and adjacent joint was improved in the Bryan artificial cervical disc replacement group compared with the fusion group. Neurological function was apparently improved after surgery in each group. At 3 months after surgery, scores of Japanese Orthopaedic Association, visual analog scale and neck

  7. Short-term follow-up for artificial cervical disc replacement: Changes of stability and range of motion in cervical vertebra%人工颈椎间盘假体置换短期随访:颈椎稳定性及其运动范围变化

    Institute of Scientific and Technical Information of China (English)

    汤雪明; 徐南伟; 周栋; 蒋巍; 李海波

    2012-01-01

    背景:椎间盘摘除减压后的节段融合会限制节段的生理运动,造成邻近节段应力加大而导致其退变加速.目的:观察人工颈椎间盘植入假体治疗颈椎病短期随访中的稳定性及置换节段和颈椎整个节段的运动范围变化.方法:于2010-06/2011-08在常州市第二人民医院骨科共施行PCM钴铬合金颈椎间盘假体置换11例12个节段,男7例,女4例;脊髓型颈椎病8例,外伤性颈椎间盘突出3例.结果与结论:患者随访时间为3~12个月.置换后1,3,6个月以及末次随访时置换节段过屈过伸活动度、左右侧屈活动度与术前接近.置换后1个月、末次随访时患者日本矫形外科协会评分明显升高,而Oswestry颈椎功能障碍指数明显降低(P 0.05),同时X射线未发现假体松动、下沉或异位骨化等不良反应.提示PCM人工颈椎间盘置换后短期颈椎稳定功能活动效果较好.%BACKGROUND: Segment fusion after the discectomy decompression of cervical disc limits the physical exercise of the segment,which causes the accelerated degeneration due to increased stress of adjacent segment.OBJECTIVE: To observe stability and range of motion (ROM) in the replacement segment and cervical segment duringshort-term follow-up using artificial cervical disc replacement for the treatment of cervical disc disease.METHODS: Totally 11 cases (12 segments) who treated with cobalt-chromium alloy PCM cervical disc replacement fromDepartment of Orthopedics, the Second People's Hospital of Changzhou from June 2010 to August 2011 PCM were selectedincluding seven males and four females. Among these cases, there were eight cases with cervical myelopathy, and three caseswith traumatic cervical disc herniation.RESULTS AND CONCLUSION: All cases were followed-up for 3 to 12 months. ROM over flexion and extension, and flexionROM on lateral left and right were similar to preoperation at 1, 3, 6 months and final follow-up after replacement. Japaneseorthopaedic

  8. Current Concepts of Using Large Femoral Heads in Total Hip Arthroplasty

    OpenAIRE

    Cho, Myung-Rae; Choi, Won Kee; Kim, Jae Jung

    2016-01-01

    Instability and dislocation after total hip arthroplasty are the most common causes of revisions and major complications for failure of inserted prostheses, leading to a reduction in quality of life. Because the use of artificial femoral head sizes smaller than patient's own size is the important cause for dislocation, the use of large femoral head have increased. Femoral head sizes greater than 32 mm offer multiple advantages in physical function and activity levels of patients by improving ...

  9. CURBSIDE CONSULTATION IN HIP ARTHROPLASTY

    Directory of Open Access Journals (Sweden)

    Scott M. Sporer

    2009-03-01

    Full Text Available DESCRIPTION A user friendly reference for decision making in hip arthroplasty designed in a question formed clinical problem scenarios and answers format .The articles composed of the answers, containing current concepts and preferences of experts in primary and revision hip surgery are enhanced by several images, diagrams and references and written in the form of a curbside consultation by Scott M. Sporer, MD. and his collaborators. PURPOSE By this practical reference of hip arthroplasty, Scott M. Sporer, MD. and the contributors have aimed providing the reader practical and clinically relevant information, evidence-based advices, their preferences and opinions containing current concepts for difficult and controversial clinical situations in total hip replacement surgery which are often not addressed clearly in traditional references. FEATURES The book is composed of 9 sections and 49 articles each written by a different expert designed in a question and answers format including several images and diagrams and also essential references at the end of each article. In the first section preoperative questions is subjected. Second section is about preoperative acetabulum questions. Third section is about preoperative femur questions. Fourth section is about intraoperative questions. Intraoperative acetabulum question is subjected in the fifth section and the intraoperative femur questions in the sixth section. The seventh section is about postoperative questions. Eighth and ninth sections are about general questions about failure and failure of acetabulum in turn. AUDIENCE Mainly practicing orthopedic surgeons, fellows and residents who are interested in hip arthroplasty have been targeted but several carefully designed scenarios of controversial and difficult situations surrounding total hip replacement surgery and the current information will also be welcomed by experienced clinicians practicing in hip arthroplasty. ASSESSMENT Scott M. Sporer

  10. 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

  11. Applied anatomy of the sciatic nerve injury in the artificial total hip arthroplasty%人工全髋关节置换术中坐骨神经损伤的应用解剖学观察

    Institute of Scientific and Technical Information of China (English)

    杨景武; 史晓林

    2005-01-01

    背景:人工全髋关节置换术(THR)是近年来治疗老年人髋关节疾患的首选方法,按Harri's评分优良率为84%.该手术对坐骨神经损伤发生率国内报道为0.46%,国外报道为0.08%~9.70%.目的:通过解剖位置的分析探讨THR术中坐骨神经损伤的因素.设计:以人体解剖标本为研究对象,单一样本研究.单位:湖州师范学院医学院解剖实验室.对象:实验于2003-03/05在湖州师范学院医学院解剖实验室完成.正常人体成年骨盆标本56具,男27具,女29具.方法:对坐骨神经的来源及走行、坐骨神经与髋臼的关系进行测量分析,并对在THR术中拉钩及螺丝钉固定所致坐骨神经损伤,进行详尽测量分析. 主要观察指标:坐骨神经与髋臼的位置关系.结果:测出坐骨神经至髋臼底的距离左侧为(6.00±0.85)mm,右侧为(6.00±0.71)mm;坐骨神经至髋臼缘的距离左侧为(13.00±0.75)mm,右侧为(14.00±0.06)mm.坐骨神经在髋臼缘处周径左侧为(32.00±0.28)mm,右侧为(31.00±0.68)mm.髋臼底至坐骨大孔的距离为左侧为(29.00±0.36)mm,右侧为(29.00±0.24)mm.结论:确定拉钩及螺丝钉固定在1~3点及5~6点为安全区.在THR术中陈旧髋臼骨折脱位、拉钩的位置不当、螺钉固定髋臼位置不当均可导致医源因素损伤坐骨神经.%BACKGROUND: At present, the artificial total hip replacement(THR) is the first choice of the hip joint disease for the old, and the choiceness rate is 84% according to the Harri' s grade, and the therapeutic effect is content. The occurrence rate of the sciatic nerve injury in the THR is reported to be 0.46% in and 0. 08%-9.7% abroad.OBJECTIVE: To study the influencing factors of the sciatic nerve injury in the THR through the anatomical location analysis.DESIGN: Single sample study based on the human anatomical samples.SETTING: Human Anatomy Laboratory in the Medical Department of the Huzhou Normal University.PARTICIPANTS: The study was completed in the

  12. 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.

  13. Comparative study of artificial cervical disc replacement verus anterior cervical discectomy and fusion in the treatment of cervical spondylotic myelopathy%人工颈椎间盘置换与颈前路减压融合术治疗脊髓型颈椎病的对照研究

    Institute of Scientific and Technical Information of China (English)

    马晓勇; 陈涛平; 郭志学

    2012-01-01

    目的 比较人工颈椎间盘置换术与颈前路减压融合术治疗脊髓型颈椎病的疗效,评价其优缺点.方法 65例脊髓型颈椎病患者按照手术方式分为人工颈椎间盘置换术组(33例,行Bryan假体置换术)和颈前路减压融合术组(32例,行颈前路减压融合术).观察两组患者住院时间、术后颈部外固定时间以及术后恢复工作时间;两组患者于术前、术后3、6、12个月行日本矫形外科协会(JOA)评分,并行X线检测颈椎活动度(ROM);评价临床疗效及术后并发症.结果 人工颈椎间盘置换术组患者住院时间、术后颈部外固定时间以及术后恢复工作时间均显著短于颈前路减压融合术组(P < 0.01).两组术后12个月JOA评分均较术前明显提高(P < 0.05),两组差异无统计学意义(P > 0.05).人工颈椎间盘置换术组术后12个月单节段及双节段置换ROM较术前无显著改变(P > 0.05),颈前路减压融合术组术后12个月ROM较术前减小(P < 0.05或P < 0.01),且显著小于人工颈椎间盘置换术组(P < 0.05或P < 0.01).两组患者满意率无差异(P > 0.05).两组术后均无严重并发症发生.结论 人工颈椎间盘置换术治疗脊髓型颈椎病患者术后恢复快,住院时间短,颈部外固定时间短,使患者保持正常的颈椎活动度,临床疗效好,值得临床推广使用.%Objective To compare the efficacy of artificial cervical disc replacement verus anterior cervical discectomy and fusion (ACDF) in the treatment of cervical spondylotic myelopathy (CSM), and evaluate their advantages and disadvantages. Methods A total of 65 patients with CSM were divided into artificial cervical disc replacement group (33 patients) and ACDF group (32 patients). The hospital stay, postoperative cervical fixation time and postoperative time returning to work of the two groups were observed; the Japanese Orthopaedic Association (JOA) score and range of motion by X-ray before surgery, 3

  14. [Uncemented arthroplasty of the hip].

    Science.gov (United States)

    von Schulze Pellengahr, C; Fottner, A; Utzschneider, S; Schmitt-Sody, M; Teske, W; Lichtinger, T; Esenwein, S A

    2009-05-01

    Prognosis of cemented total hip replacement seems to be excellent for elderly patients. In younger age the outcome is less favourable and early revision is more common. Thus, different concepts with better prognosis and preservation of bone stock for possible revisions were needed. After more than 30 years of application with excellent short-term and long-term results, uncemented total hip arthroplasty is nowadays generally regarded as the standard procedure for younger patients. New bone-preserving implants, such as surface replacement or short-stemmed femoral shaft prostheses, have been introduced especially for younger patients. Some of these new procedures are still under development, and the long-term results of new implant concepts have to be evaluated over the next decades. Regarding recently published scientific studies an overview about non-cemented total hip arthroplasty is given and current concepts and developments are presented.

  15. Revision of hip resurfacing arthroplasty.

    Science.gov (United States)

    Wera, Glenn D; Gillespie, Robert J; Petty, Carter; Petersilge, William J; Kraay, Matthew J; Goldberg, Victor M

    2010-08-01

    Metal-on-metal (MOM) hip resurfacing has become an increasingly popular treatment for young, active patients with degenerative disease of the hip, as bearing surfaces with better wear properties are now available. One proposed advantage of resurfacing is its ability to be successfully revised to total hip arthroplasty (THA). In addition, radiographic parameters that may predict failure in hip resurfacing have yet to be clearly defined. Seven MOM resurfacing arthroplasties were converted to conventional THAs because of aseptic failure. Using Harris Hip Scores (HHS) and Short Form 12 (SF-12) questionnaire scores, we compared the clinical outcomes of these patients with those of patients who underwent uncomplicated MOM hip resurfacing. In addition, all revisions were radiographically evaluated. Mean follow-up periods were 51 months (revision group) and 43 months (control group). There was no significant difference between the 2 groups' HHS or SF-12 scores. There was no dislocation or aseptic loosening after conversion of any resurfacing arthroplasty. Valgus neck-shaft angle (P hip resurfacing. Conversion of aseptic failure of hip resurfacing to conventional THA leads to clinical outcomes similar to those of patients who undergo uncomplicated hip resurfacing. The orientation of the femur and the components placed play a large role in implant survival in hip resurfacing. More work needs to be done to further elucidate these radiographic parameters.

  16. Humeral windows in revision total elbow arthroplasty

    Science.gov (United States)

    Salama, Amir; Stanley, David

    2016-01-01

    The use of cortical windows for revision elbow arthroplasty has not previously been widely reported. Their use aids safe revision of a well fixed humeral prosthesis and can be used in the setting of dislocation, periprosthetic fracture or aseptic loosening of the ulnar component. We describe our technique and results of cortical windows in the distal humerus for revision elbow arthroplasty surgery. PMID:27583011

  17. Hip Resurfacing Arthroplasty and Perioperative Blood Testing

    Directory of Open Access Journals (Sweden)

    Andrew Cook

    2014-01-01

    Full Text Available It is standard practice in many institutions to routinely perform preoperative and postoperative haemoglobin level testing in association with hip joint arthroplasty procedures. It is our observation, however, that blood transfusion after uncomplicated primary hip arthroplasty in healthy patients is uncommon and that the decision to proceed with blood transfusion is typically made on clinical grounds. We therefore question the necessity and clinical value of routine perioperative blood testing about the time of hip resurfacing arthroplasty. We present analysis of perioperative blood tests and transfusion rates in 107 patients undertaking unilateral hybrid hip resurfacing arthroplasty by the senior author at a single institution over a three-year period. We conclude that routine perioperative testing of haemoglobin levels for hip resurfacing arthroplasty procedures does not assist in clinical management. We recommend that postoperative blood testing only be considered should the patient demonstrate clinical signs of symptomatic anaemia or if particular clinical circumstances necessitate.

  18. Fast-track hip and knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Henrik

    2012-01-01

    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...... thromboembolic complications in particular (V); feasibility studies showing excellent outcomes following fast-track bilateral simultaneous total knee arthroplasty (VI) and non-septic revision knee arthroplasty (VII); how acute pain relief in total hip arthroplasty is not enhanced by the use of local infiltration......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...

  19. Knee Arthrodesis after failure of Knee Arthroplasty

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  20. 人工颈椎间盘置换联合颈前路融合术治疗多节段脊髓型颈椎病%Treatment on multilevel cervical spondylotic myelopathy by artificial cervical disc replace-ment combined with anterior cervical discectomy and fusion

    Institute of Scientific and Technical Information of China (English)

    游新茂; 叶秀益; 宋滇文; 贾连顺

    2014-01-01

    Objective To explore the clinical effects of artificial cervical disc replacement( ACDR) combined with anterior cervical discectomy fusion ( ACDF ) for the treatment of multi-segmental cervical spondylotic myelopathy ( CSM) . Methods 18 cases with multi-segmental CSM which were treated by ACDR combined with ACDF were re-viewed. The stability of artificial disc, internal fixation and bone fusion were evaluated by X-ray films before opera-tive, immediate postoperative and follow-up. The JOA scores was evaluated also at the same time. Results 18 pa-tients were followed up from 24 to 60 months ( averaged 36 ± 9. 6 months) . The range of motion of the replacement segment were 13. 8° ± 6. 5° at preoperative and 12. 5° ± 5. 3° at the final follow-up, and there was no significant difference between them(P>0. 05). The preoperative JOA scores was 9. 5 ± 1. 5, which was improved to 14. 2 ± 2. 2 in 4 months after operation; Preoperative neurological symptoms were obviously alleviated in most patients, and the improvement ratio of JOA was 62. 7% ± 11. 2%. The results were excellent in 9 patients, good in 5, fair in 2 and poor in 2. There were no patient with false of internal fixation, and the position of artificial disc was good. Conclu-sions ACDR combined with ACDF is a good procedure for multi-segmental cervical spondylotic myelopathy, it not only maintain the cervical spine alignment with saving more movement segments,but also reduce the incidence of ad-jacent segment degeneration.%目的:评价人工颈椎间盘置换联合颈前路融合术治疗多节段脊髓型颈椎病的临床效果。方法采用人工颈椎间盘置换联合颈前路融合治疗18例多节段脊髓型颈椎病患者。根据术前、术后、随访时的颈椎X线片观察人工椎间盘、内固定、植骨融合以及JOA评分改善情况。结果18例均获随访,时间24~60(36±9.6)个月。置换间隙平均活动度术前为13.8°±6.5°,末次随访时为12.5°±5.3

  1. 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

  2. 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...

  3. Innervation of ''painful'' lumbar discs

    NARCIS (Netherlands)

    Coppes, MH; Marani, E; Thomeer, RTWM; Groen, GJ

    1997-01-01

    Study Design. The authors investigated the innervation of discographically confirmed degenerated and ''painful'' human intervertebral discs. Objective. To determine the type and distribution patterns of nerve fibers present in degenerated human intervertebral discs. Summary of Background Data. The i

  4. Observation of short-term curative effect of multi-segmental anterior cervical artificial disc replacement under microscope%显微技术下前路多节段颈椎人工椎间盘置换术短期疗效观察

    Institute of Scientific and Technical Information of China (English)

    龙勇; 冯海龙

    2015-01-01

    目的:探讨显微镜下多节段颈椎人工椎间盘置换术的短期疗效,观察术后颈椎活动度及临床功能的变化,为多节段颈椎间盘突出症的外科治疗提供临床依据。方法因颈椎病( cervical spondylosis,CS)行显微镜下多节段颈椎人工椎间盘置换术患者,其中使用颈椎动态稳定器DCI 2例,使用Prestige-LP人工椎间盘3例。患者术前与术后6月均行颈椎正侧位、过伸过屈位X射线片、颈椎MRI检查,测量脊髓功能评分(JOA)和置换节段活动度(range of motion,ROM)。结果显微镜下微创手术未出现手术并发症,神经功能明显改善;术后6月颈椎运动范围与术前比较差异无统计学意义( P>0.05);所有患者的JOA评分较术前均有明显改善( P<0.05)。结论显微镜下手术创伤小,并发症少,多节段颈椎人工椎间盘置换术基本保留了颈椎的稳定性,具有良好的活动度,短期临床效果良好。%Objective To investigate the short-term curative effect of multiple segmental cervical artificial disc replacement ( msCDR) under microscope and observe the changes of postoperative cervical activity and clinical features in order to provide prelimi-nary clinical basis for surgical treatment of the disease.Methods A retrospective analysis of 5 cases of cervical spondylosis treated with microsurgical msCDR,including 2 cases with cervical dynamic implant(DCI)and 3 cases with artificial cervical disc(Prestige-LP) ,was performed.Data included the cervical motion X-ray, cervical MRI, JOA score evaluation and motion of replacement discs ( Range of motion,ROM) before and after 6 months of surgery.Results Minimally invasive surgery under the microscopic manipula-tions has less operative complications compared with“naked-eye” surgery.Neuro-function was significantly improved.The cervical mo-tion after 6 months of operation showed no significant difference when compared to pre

  5. 颈椎人工椎间盘置换与颈前路减压融合术术后轴性症状的分析%The analysis of neck axial symptoms analysis after cervical artificial disc replacement and anterior cervical decompression and fusion

    Institute of Scientific and Technical Information of China (English)

    张杨; 王利民

    2013-01-01

    目的 对比人工椎间盘置换术和颈前路减压融合术术后的早期临床效果及轴性症状,探讨人工椎间盘对术后颈椎轴性症状(AS)的价值.方法 回顾性分析2010年8月至2012年2月间在郑州大学第一附属医院接受治疗的颈椎病患者86例,均为单节段病变.46例患者(ACDF组)行颈前路减压融合内固定术,其中男21例,女25例,平均年龄51.6岁.40例患者(ADR组)行颈椎人工椎间盘置换术,其中男18例,女22例,平均年龄49.1岁.观察两组患者术后随访时JOA评分、Odom评级情况、颈椎曲度指数(CCl)、颈椎总活动度(ROM)的变化情况,对比颈部AS的发生情况,并进行分析.结果 所有患者均获随访,随访时间6~ 24个月,平均15.2个月.术后两组患者JOA评分较术前均有明显改善(P<0.05);术后3、6个月和末次随访时ACDF组与ADR组Odom临床疗效评级优良率比较差异无统计学意义.颈椎曲度ACDF组术后较术前丢失明显(P<0.05),ADR组手术前后无明显变化(P>0.05);ACDF组ROM术前较术后有明显减少(P<0.05),而ADR组与术前相比差异无统计学意义(P>0.05).ACDF组AS发生率为47.83%,ADR组为20.00%,两组相比差异有统计学意义(P>0.05).结论 人工椎间盘置换术能保留颈椎生理曲度及颈椎ROM,未明显增加邻近节段的活动,且无需佩戴颈围领,可早期活动,从而能够有效减少AS的发生.%Objective To compare the early clinical effects and neck axial symptom (AS)after cervical artificial disc replacement and anterior cervical discectomy and fusion,and to explore the value of cervical artificial disc lower the incidence of the postoperative neck AS.Methods To analyse the 86 cases of cervical spondylosis who treated in the first affiliated hospital of Zhengzhou university from August 2010 to February 2012 retrospectively,all of the cases were single segmental lesions.Forty-six patients (ACDF group) underwent anterior cervical discectomy and fusion

  6. Dislocation following revision total hip arthroplasty.

    Science.gov (United States)

    Gioe, Terence J

    2002-04-01

    Dislocation is a relatively common complication following revision total hip arthroplasty. Risk factors include surgical approach, gender, underlying diagnosis, comorbidities, surgical experience, and previous surgery; for later dislocations, risk factors include wear/deformation of polyethylene, trauma, and decreased muscle strength. Prevention and precaution are the watchwords for dislocations following revision total hip arthroplasty. For dislocations that do occur, treatment rests first on identifying the source of instability. Most dislocations can be managed by closed reduction. Constrained components may increase success rates, but only for appropriate indications. Prevention and treatment of dislocations following revision total hip arthroplasty are discussed in this article.

  7. Total Ankle Arthroplasty: An Imaging Overview.

    Science.gov (United States)

    Kim, Da-Rae; Choi, Yun Sun; 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.

  8. Total ankle arthroplasty: An imaging overview

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Da Rae; Choi, Yun Sun; Chun, Ka Young; Jung, Yoon Young; Kim, Jin Su; Young, Ki Won [Eulji Hospital, Eulji University, Seoul (Korea, Republic of); Potter, Hollis G.; Li, Angela E. [Dept. of Radiology and Imaging, Hospital for Special Surgery, New York (United States)

    2016-06-15

    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.

  9. 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.

  10. Artificial Intelligence.

    Science.gov (United States)

    Waltz, David L.

    1982-01-01

    Describes kinds of results achieved by computer programs in artificial intelligence. Topics discussed include heuristic searches, artificial intelligence/psychology, planning program, backward chaining, learning (focusing on Winograd's blocks to explore learning strategies), concept learning, constraint propagation, language understanding…

  11. Optic disc drusen

    DEFF Research Database (Denmark)

    Fledelius, Hans C

    2017-01-01

    , which, in view of the small disc at risk, may seem a paradox. METHODS: This is an observational retrospective study on an eye clinic series (n = 49), focusing on visual acuity, kinetic/static perimetry, and longitudinal trends, to include the question of eventual visual incapacity. RESULTS: Forty...

  12. 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

  13. 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

  14. 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...

  15. Stiffness after total knee arthroplasty.

    Science.gov (United States)

    Manrique, Jorge; Gomez, Miguel M; Parvizi, Javad

    2015-04-01

    Stiffness after total knee arthroplasty (TKA) adversely affects outcome and impacts patient function. Various risk factors for stiffness after TKA have been identified, including reduced preoperative knee range of motion, history of prior knee surgery, etiology of arthritis, incorrect positioning or oversizing of components, and incorrect gap balancing. Mechanical and associated causes, such as infection, arthrofibrosis, complex regional pain syndrome, and heterotopic ossification, secondary gain issues have also been identified. Management of stiffness following TKA can be challenging. The condition needs to be assessed and treated in a staged manner. A nonsurgical approach is the first step. Manipulation under anesthesia may be considered within the first 3 months after the index TKA, if physical therapy fails to improve the range of motion. Beyond this point, consideration should be given to surgical intervention such as lysis of adhesions, either arthroscopically or by open arthrotomy. If the cause of stiffness is deemed to be surgical error, such as component malpositioning, revision arthroplasty is indicated. The purpose of this article is to evaluate the various aspects of management of stiffness after TKA.

  16. Revision of failed humeral head resurfacing arthroplasty

    Directory of Open Access Journals (Sweden)

    Philipp N Streubel

    2016-01-01

    Conclusion: Outcomes of revision of HHR arthroplasty in this cohort did not improve upon those reported for revision of stemmed humeral implants. A comparative study would be required to allow for definitive conclusions to be made.

  17. Counter-Rotating Accretion Discs

    OpenAIRE

    Dyda, Sergei; Lovelace, Richard V. E.; 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 tw...

  18. Total Ankle Arthroplasty: A Brief Review

    OpenAIRE

    Mann, Roger A.; Harrison, Matthew J.

    2012-01-01

    Ankle fusion has long been the standard of treatment for end-stage ankle arthritis, and a successful arthroplasty has been a long sought alternative. It is a motion sparing procedure and may greatly reduce the potential for adjacent level degeneration as seen with arthrodesis. The typical candidate for arthroplasty is a healthy low demand patient, although the indications are widening as the success of the procedure has increased. Nevertheless, it is not fail-safe, technical expertise and exp...

  19. Wear debris in cemented total hip arthroplasty.

    Science.gov (United States)

    Huo, M H; Salvati, E A; Buly, R L

    1991-03-01

    One of the most prevalent clinical problems in long-term follow up of total hip arthroplasty patients is loosening of prosthetic fixation. Factors contributing to mechanical failure of total hip reconstruction are complex and multiple. It has become increasingly apparent that wear debris from the prosthetic components may contribute significantly to this process. The authors summarize some of the current concepts concerning the detrimental effects of metallic debris in total hip arthroplasty.

  20. 单节段颈椎人工椎间盘置换与前路椎间融合内固定:维持颈椎活动度和稳定性的比较%Single level artificial disc replacement versus anterior cervical fusion:range of motion and stability of cervical vertebra

    Institute of Scientific and Technical Information of China (English)

    王威; 王利民; 王卫东; 谭洪宇; 刘屹林; 张书豪

    2014-01-01

    BACKGROUND:Fusion treatment for single segment cervical spondylosis can induce complications such as abnormal enlargement of range of motion in adjacent segments and degenerative manifestations. Recently, scholars began to explore and to use non-fusion technique to replace traditional fusion therapy. Cervical artificial disc replacement as a new anterior non-fusion program has been greatly used in the clinic, not only obtained good clinical therapeutic effects, but also made cervical vertebrae near physiological stability, delayed adjacent segment degeneration and reduced complications. OBJECTIVE:To compare the clinical effects of the single level artificial disc replacement and the anterior cervical decompression and fusion for cervical spondylosis. METHODS:A total of 59 patients with single segment cervical spondylosis, whose clinical signs and symptoms were accorded, were enrol ed from the First Affiliated Hospital of Zhengzhou University, China from May 2011 to May 2013. Imaging revealed that single segment of cervical disc degeneration compressed spinal cord or nerve root. Owing to different surgeries, these patients were divided into artificial disc replacement group (replacement group;n=32) and anterior cervical decompression and fusion group (fusion group;n=27). They were fol owed up at 5 days, 3, 6 and 12 months after treatment. Japanese Orthopaedic Association scores, neck pain, upper extremity pain visual analog scale scores were measured. The range of motion of the replacement segment and its effects on adjacent segments were observed. RESULTS AND CONCLUSION:The postoperative Japanese Orthopaedic Association Scores were improved compared with preoperative scores (P0.05). Range of motion of the replacement segment after treatment was (11.6±3.0)° in the replacement group, showing no significant differences as compared with before surgery (8.8±2.7)° (P>0.05). No significant activity was found at 3 months after treatment in the fusion group. During fol

  1. 冷疗加压系统使用时间对行人工全膝关节置换术患者关节肿胀疼痛与睡眠质量的影响%Influence of cold flow pressurized systemˊs using time on joint swelling and pain and sleep quality of patients with total artificial knee arthroplasty

    Institute of Scientific and Technical Information of China (English)

    贺文

    2016-01-01

    Objective To study the influence of cold flow pressurized systemˊs using time on joint swelling and pain and sleep quality of patients with total artificial knee arthroplasty ( TKA) . Methods A total of 98 patients who were treated with routine artificial total knee replacement lens in our hospital from April 2014 to May 2015 were chosen as the research objects, and were randomly divided into observation group and control group, 49 cases in each group. Patients of the observation group were treated with the circulative pressure cold therapy within 24 hours after the surgery and the time interval was 8 hours at a time, 30 minutes at a time, and were given conventional nursing care;while the patients of the control group underwent circulative pressure cold therapy within 48 hours after the surgery, the time interval was 8 hours at a time, 30 minutes at a time, and were given routine care as well. The visual simulation e-valuation ( visual analogue scale score, VAS) system were used to assess the level of pain 12 hours, 24 hours, 48 hours and 72 hours after the surgery, and swelling degree was assessed by diametersˊdifference between the healthy thigh and diseased thigh, and the sleeping quality was assessed with Pittsburgh Sleep Quality Index ( PSQI) . Results The VAS scores 12 hours, 24 hours and 48 hours after the surgery of the patients of the observation group were significantly lower than that of the control group, and the difference was statistically significant (P<0. 05);the swelling degree 24 hours, 48 hours and 72 hours after the surgery of the patients of the observation group was significantly lower than that of the control group, and the difference was statistically significant (P<0. 05);the sleep quality 2 days and 3 days after sur-gery of the patients of the observation group was better than that of the control group, and the difference was statistically significant ( P<0. 05 ) . Conclusions Circulating intermittent pressure cold treatment applied in

  2. 人工颈椎间盘假体高度对置换节段活动度影响的生物力学研究%Effect of different heights of artificial cervical disc replacement on the range of motion of the treated segment

    Institute of Scientific and Technical Information of China (English)

    娄纪刚; 刘浩; 李元超; 武文杰; 孟阳; 杨运北; 戎鑫

    2016-01-01

    目的 探讨采用不同高度的人工颈椎间盘假体进行间盘置换术后手术节段活动度的变化规律.方法 收集9具男性新鲜尸体颈椎标本,术前均行颈椎正位、侧位X线片,分别测量C5.6椎间隙高度,并筛选高度为5 mm左右的标本3具进行自身对照实验,先后依次进行完整颈椎组、C5.6节段合适高度(5 mm)人工椎间盘置换组、高度增加1 mm(6 mm)人工椎间盘置换组和增加2 mm(7 mm)人工椎间盘置换组颈椎标本模型的生物力学测试.将标本固定于脊柱三维运动试验机,予75 N跟随载荷,前屈、后伸、左/右侧弯、左/右轴向旋转均施加2 Nm纯力矩载荷,在0.2 Nm/S的变化条件下测量手术节段的活动范围.结果 完整组与5 mm组的前屈、后伸、侧弯及轴向旋转活动范围的差异均无统计学意义;6mm组前屈/后伸、侧弯及轴向旋转的活动范围均较5 mm组增加,且更加接近完整组活动范围,但差异无统计学意义;7 mm组屈伸活动范围(9.5°±1.0°)明显小于完整组(12.5°±0.9°)、5 mm组(11.3°±0.8°)和6 mm组(11.6°±0.9°),但轴向旋转活动范围(10.4°±1.4°)明显大于5 mm组(8.6°±0.3°),差异有统计学意义,而侧弯活动范围与其他3组相比差异均无统计学意义.结论 人工颈椎间盘置换术中试模时两个相邻高度间盘假体植入均合适时,选择高度增加1 mm的间盘可一定程度改善手术节段的活动范围;而高度增加2 mm的间盘置换则可导致手术节段屈伸活动范围减小,旋转活动范围则有增加的趋势.%Objective To cxplore the variation of the range of motion (ROM) of operative level after different heights of artificial cervical disc replacement,and to provide guidance for clinical work in selecting appropriate height of artificial cervical disc prosthesis.Methods The preoperative cervical anteroposterior and lateral Ⅹ-rays of 9 fresh male cadaveric cervical spine specimens were obtained to measure the

  3. Vibration analysis of atomising discs

    Energy Technology Data Exchange (ETDEWEB)

    Deng, H; Ouyang, H, E-mail: H.Ouyang@liverpool.ac.u [Department of Engineering, University of Liverpool, Liverpool L69 3GH (United Kingdom)

    2009-08-01

    The centrifugal atomisation of metallic melts using a spinning disc is an important process for powder production and spray deposition. In the manufacturing process the high-temperature melt flows down to the surface of the atomising disc spinning at very high speed. It is observed that there is a hydraulic jump of the melt flow prior to atomisation. In this paper, the dynamic model of the atomising disc as a spinning Kirchhoff plate with this hydraulic jump is established. The flowing melt is modelled as moving mass and weight force in the radial direction. Using a Galerkin method, it is found that the vibration properties of the atomising disc vary with the disc clamping ratio. The amplitude of the vibration is largely raised when the clamping ratio is smaller than the critical jump radius ratio. It is also found that the disc vibration is non-stationary before becoming steady and the amplitude decreases with increasing disc speed.

  4. 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-...

  5. 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;

    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)....

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

    DEFF Research Database (Denmark)

    Husted, Henrik; Jensen, Tim Toftgaard

    2002-01-01

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

  7. 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

  8. Accretion Discs in Blazars

    OpenAIRE

    Jolley, E. J. D.; Kuncic, Z.; Bicknell, G. V.; Wagner, S.(Max-Planck-Institut für Kernphysik, 69117, Heidelberg, Germany)

    2009-01-01

    The characteristic properties of blazars (rapid variability, strong polarization, high brightness) are widely attributed to a powerful relativistic jet oriented close to our line of sight. Despite the spectral energy distributions (SEDs) being strongly jet-dominated, a "big blue bump" has been recently detected in sources known as flat spectrum radio quasars (FSRQs). These new data provide a unique opportunity to observationally test coupled jet-disc accretion models in these extreme sources....

  9. Health-related quality of life in veterans with prevalent total knee arthroplasty and total hip arthroplasty

    OpenAIRE

    Singh, J.A.; Sloan, J.A.

    2008-01-01

    Objective. To study the HRQOL in veterans with prevalent total knee arthroplasty (TKA) or total hip arthroplasty (THA) and compare them with age- and gender-matched US population and control veteran population without these procedures.

  10. 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.

  11. 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.

  12. Mechanics of Actuated Disc Cutting

    Science.gov (United States)

    Dehkhoda, Sevda; Detournay, Emmanuel

    2017-02-01

    This paper investigates the mechanics of an actuated disc cutter with the objective of determining the average forces acting on the disc as a function of the parameters characterizing its motion. The specific problem considered is that of a disc cutter revolving off-centrically at constant angular velocity around a secondary axis rigidly attached to a cartridge, which is moving at constant velocity and undercutting rock at a constant depth. This model represents an idealization of a technology that has been implemented in a number of hard rock mechanical excavators with the goal of reducing the average thrust force to be provided by the excavation equipment. By assuming perfect conformance of the rock with the actuated disc as well as a prescribed motion of the disc (perfectly rigid machine), the evolution of the contact surface between the disc and the rock during one actuation of the disc can be computed. Coupled with simple cutter/rock interaction models that embody either a ductile or a brittle mode of fragmentation, these kinematical considerations lead to an estimate of the average force on the cartridge and of the partitioning of the energy imparted by the disc to the rock between the actuation mechanism of the disc and the translation of the cartridge on which the actuated disc is attached.

  13. The biomechanical research on the changes of pressures in the C7/T1 intervertebral space after C5/6 cervical artificial disc replacement%C5/6人工颈椎间盘置换后C7/T1椎间隙压力变化的生物力学研究

    Institute of Scientific and Technical Information of China (English)

    李康华; 李思鸿; 李国军; 张俊; 黄跃平

    2009-01-01

    Objective To explore the stress changes of C7/T1 intervertebral space pre-and post C5/6 discectomy and artificial disc replacement.Method Eleven healthy adult fresh muhisegmental cadaveric cervical spine segments were utilized in this investigation and biomechanically evaluated under the following C5/6 conditions:intact spine,discectomy,and Bryan Disc prosthesis implantation.The load,of neutrality and pure moments of axial,flexion,extension,and lateral bending were applied on each group.The stress changes of the inferior (C7/T1)interverlebral space was detected by modified cyclo-shaped miniature transducer.Result Under axial,anteflexion,and lateral bending loading,the discectomy indicated a significant increase in the stress of the inferiorer(C7/T1)intervertebral space,compared to intact condition and CADR(P<0.05).Under extension loading,the discectomy indicated an increase in the stress of the inferiorer(C7/T1)intervertebral space,compared to intact condition(P>0.05).Under axial,flexion,extension and lateral bending loading,the Bryan Disc prosthesis implantation indicate minor increase of the stress in the inferior(C7/T1)intervertebral space to intact condition(P>0.05).Conclusion There was no difference between the C5/6 ADR and intact spine group.The discectomy of the Cs/6 can increase the stress of the C7/T1 intervertebral spaoe.%目的 了解G5/6椎间盘髓核摘除、人工颈椎间盘置换对C7/T1椎间隙内压力的影响.方法 11具新鲜青壮年颈椎尸体标本.按测试的先后次序分为C5/6椎间盘完整组、C5/6椎间盘髓核摘除组和C5/6Bryan人工颈椎间盘置换组,在颈椎标本上施加轴向、侧弯、后伸、前屈分级载荷,测量各组C7/T1椎间隙内的压力并进行分析比较.结果 (1)在轴向、前屈、侧弯三种工况相同载荷下,C5/6椎间盘髓核摘除组C7/T1椎间隙内的压力大于人工椎间盘组与椎间盘完整组(P0.05).(3)C5/6人工椎间盘置换组C7/T1椎间隙内的压力在

  14. ARTHROFIBROSIS FOLLOWING TOTAL KNEE ARTHROPLASTY

    Directory of Open Access Journals (Sweden)

    Ravi B. Solanki

    2014-11-01

    Full Text Available Arthrofibrosis following total knee arthroplasty is an uncommon complication defined as less than 80 degrees of knee flexion 6-8 weeks post operatively. It is characterized by abnormal scarring of the joint in which the formation of dense fibrous tissue and tissue metaplasia prevent normal range of motion. Clinical features include limited knee Range of motion with extension deficit, pain with activities of daily living and unusual amount of pain and swelling post operatively in the absence of infection, bleeding or mechanical complications. We present case of 55 years old female who undergone for total knee replacement before 3 months and presented to our department with complain of knee pain and swelling with activities of daily living. She was diagnosed on the basis of clinical examination. Her detailed evaluation was carried out and Physiotherapy treatment was started.

  15. 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

  16. Heat distribution in disc brake

    Science.gov (United States)

    Klimenda, Frantisek; Soukup, Josef; Kampo, Jan

    2016-06-01

    This article is deals by the thermal analysis of the disc brake with floating caliper. The issue is solved by numerically. The half 2D model is used for solution in program ADINA 8.8. Two brake discs without the ventilation are solved. One disc is made from cast iron and the second is made from stainless steel. Both materials are an isotropic. By acting the pressure force on the brake pads will be pressing the pads to the brake disc. Speed will be reduced (slowing down). On the contact surface generates the heat, which the disc and pads heats. In the next part of article is comparison the maximum temperature at the time of braking. The temperatures of both materials for brake disc (gray cast iron, stainless steel) are compares. The heat flux during braking for the both materials is shown.

  17. Dynamics of warped accretion discs

    OpenAIRE

    Tremaine, Scott; Davis, Shane W.

    2013-01-01

    Accretion discs are present around both stellar-mass black holes in X-ray binaries and supermassive black holes in active galactic nuclei. A wide variety of circumstantial evidence implies that many of these discs are warped. The standard Bardeen--Petterson model attributes the shape of the warp to the competition between Lense--Thirring torque from the central black hole and viscous angular-momentum transport within the disc. We show that this description is incomplete, and that torques from...

  18. Numbered nasal discs for waterfowl

    Science.gov (United States)

    Bartonek, J.C.; Dane, C.W.

    1964-01-01

    Numbered nasal discs were successfully used in studies requiring large numbers of individually marked waterfowl. The procedure for constructing these discs is outlined. Blue-winged teal (Anas discors) with 5/8-inch discs, and canvasback (Aythya valisineria) and redhead (A. americana) with 3/4-inch discs can be individually identified up to 50 and 80 yards, respectively, with a gunstock-mounted, 20-power spotting scope. The particular value of these markers is their durability, the number of combinations possible, and the apparent absence of behavioral or mortality influence among such species as the blue-winged teal.

  19. Two-level total disc replacement with Mobi-C(r over 3-years

    Directory of Open Access Journals (Sweden)

    Reginald Davis

    2014-01-01

    Full Text Available Objective: To evaluate the safety and effectiveness of two-level total disc replacement (TDR using a Mobi-C(r Cervical Artificial Disc at the 36 month follow-up. Methods: a Prospective, randomized, controlled, multicenter clinical trial of an artificial cervical disc (Mobi-C(r Cervical Artificial Disc was conducted under the Investigational Device Exemptions (IDE and the U.S. Food & Drug Administration (FDA regulations. A total of 339 patients with degenerative disc disease were enrolled to receive either two-level treatment with TDR, or a two-level anterior cervical discectomy and fusion (ACDF as control. The 234 TDR patients and 105 ACDF patients were followed up at regular time points for three years after surgery. Results: At 36 months, both groups demonstrated an improvement in clinical outcome measures and a comparable safety profile. NDI scores, SF-12 PCS scores, patient satisfaction, and overall success indicated greater statistically significant improvement from baseline for the TDR group, in comparison to the ACDF group. The TDR patients experienced lower subsequent surgery rates and a lower rate of adjacent segment degeneration. On average, the TDR patients maintained segmental range of motion through 36 months with no device failure. Conclusion: Results at three-years support TDR as a safe, effective and statistically superior alternative to ACDF for the treatment of degenerative disc disease at two contiguous cervical levels.

  20. 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.

  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. Artificial blood.

    Science.gov (United States)

    Sarkar, Suman

    2008-07-01

    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.

  3. Effect of clearance on cartilage tribology in hip hemi-arthroplasty.

    Science.gov (United States)

    Lizhang, Jia; Taylor, Simon D; Jin, Zhongmin; Fisher, John; Williams, Sophie

    2013-12-01

    Hemi-arthroplasty of the hip (an artificial femoral head articulating against the natural acetabulum) is used to treat fractured necks of femur; however, there is evidence that articulation causes erosion of the cartilage, resulting in pain for the patient. Parameters that may influence this cartilage erosion include head material and roughness, clearance between the head and acetabulum and activity levels of the patient. This study has assessed the effect of clearance of hemi-arthroplasty articulations on the contact stress, friction and cartilage deformation in an in vitro tribological simulation of the hemi-arthroplasty joint that applied dynamic loads and motion. It has been demonstrated that peak contact stress increased from 5.6 to 10.6 MPa as radial clearance increased from small (1.8 mm). In all samples, friction factor increased with time and was significantly less with extra-large clearances compared to small (<0.6 mm), medium (0.6-1.2 mm) and large (1.2-1.8 mm) clearances. The cartilage deformation observed was significantly greater in acetabulum samples paired to give small or extra-large clearances compared to those with medium or large clearances.

  4. 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.

  5. Primary total hip arthroplasty for acetabular fracture

    Institute of Scientific and Technical Information of China (English)

    WANG Zi-ming; SUN Hong-zhen; WANG Ai-min; DU Quan-yin; WU Siyu; ZHAO Yu-feng; TANG Ying

    2006-01-01

    Objective: To explore the operative indications and operative methods of primary total hip arthroplasty for acetabular fracture and to observe the clinical curative effect.Methods: We retrospectively summarized and analyzed the traumatic conditions, fracture types, complications,operative time, operative techniques, and short-term curative effect of 11 patients( 10 males and 1 female, with a mean age of 42. 4 years ) with acetabular fracture who underwent primary total hip arthroplasty.Results: The patients were followed up for 6-45 months ( mean = 28 months). Their average Harris score of postoperative hip joint was 78.Conclusion: Under strict mastery of indications,patients with acetabular fracture may undergo primary total hip arthroplasty, but stable acetabular components should be made.

  6. Total Ankle Arthroplasty: A Brief Review

    Directory of Open Access Journals (Sweden)

    Roger A. Mann

    2012-12-01

    Full Text Available Ankle fusion has long been the standard of treatment for end-stage ankle arthritis, and a successful arthroplasty has been a long sought alternative. It is a motion sparing procedure and may greatly reduce the potential for adjacent level degeneration as seen with arthrodesis. The typical candidate for arthroplasty is a healthy low demand patient, although the indications are widening as the success of the procedure has increased. Nevertheless, it is not fail-safe, technical expertise and experience are necessary to achieve a successful result. We have been treating ankle arthritis with the Scandinavian Total Ankle Replacement (STAR ankle replacement prosthesis for over ten years. We believe that arthroplasty will surpass arthrodesis as the standard of care for severe ankle arthritis.

  7. Accretion discs trapped near corotation

    NARCIS (Netherlands)

    D'Angelo, C.R.; Spruit, H.C.

    2012-01-01

    We show that discs accreting on to the magnetosphere of a rotating star can end up in a trapped state, in which the inner edge of the disc stays near the corotation radius, even at low and varying accretion rates. The accretion in these trapped states can be steady or cyclic; we explore these states

  8. 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

  9. 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.

  10. Proprioception and Knee Arthroplasty: A Literature Review.

    Science.gov (United States)

    Wodowski, Andrew J; Swigler, Colin W; Liu, Hongchao; Nord, Keith M; Toy, Patrick C; Mihalko, William M

    2016-04-01

    Proprioceptive mechanoreceptors provide neural feedback for position in space and are critical for three-dimensional interaction. Proprioception is decreased with osteoarthritis of the knees, which leads to increased risk of falling. As the prevalence of osteoarthritis increases so does the need for total knee arthroplasty (TKA), and knowing the effect of TKA on proprioception is essential. This article reviews the literature regarding proprioception and its relationship to balance, aging, osteoarthritis, and the effect of TKA on proprioception. Knee arthroplasty involving retention of the cruciate ligaments is also reviewed, as well the evidence of proprioception in the posterior cruciate ligament after TKA.

  11. Total hip arthroplasty after previous fracture surgery.

    Science.gov (United States)

    Krause, Peter C; Braud, Jared L; Whatley, John M

    2015-04-01

    Total hip arthroplasty can be a very effective salvage treatment for both failed fracture surgery and hip arthritis that may occur after prior fracture surgery. The rate of complications is significantly increased including especially infection, dislocation, and loosening. Complications are more likely to occur after failed open reduction and internal fixation than after posttraumatic arthritis. Adequately ruling out infection before hip arthroplasty can be difficult. The best predictor of infection is a prior infection. Long-term outcomes can be comparable to outcomes in other conditions if complications are avoided.

  12. The Nordic Arthroplasty Register Association

    DEFF Research Database (Denmark)

    Havelin, Leif I; Fenstad, Anne M; Salomonsson, Roger

    2009-01-01

    Background and purpose The possibility of comparing results and of pooling the data has been limited for the Nordic arthroplasty registries, because of different registration systems and questionnaires. We have established a common Nordic database, in order to compare demographics and the results...... collaboration has shown differences between the countries concerning demographics, prosthesis fixation, and survival. The large number of patients in this database significantly widens our horizons for future research....... of total hip replacement surgery between countries. In addition, we plan to study results in patient groups in which the numbers are too small to be studied in the individual countries. Material and methods Primary total hip replacements (THRs) from 1995-2006 were selected for the study. Denmark, Sweden......, and Norway contributed data. A common code set was made and Cox multiple regression, with adjustment for age, sex, and diagnosis was used to calculate prosthesis survival with any revision as endpoint. Results 280,201 operations were included (69,242 from Denmark, 140,821 from Sweden, and 70,138 from Norway...

  13. Intraoral micro-identification discs.

    Science.gov (United States)

    Hansen, R W

    1991-12-01

    Intraoral micro-identification discs have recently been utilized to provide a more permanent method of personal identification. A wafer of plastic or metal with a surface area of 2.5 to 5 mm2 and carrying identifying numbers and/or letters (indicia) is bonded to the buccal enamel surface of the posterior teeth. Personal identification can occur after the I.D. disc is identified and the indicia is read. Reading of photoreduced indicia requires the aid of a microscope subsequent to the removal of the microdisc. In situ reading of disc indicia is possible using low power handheld magnifiers if the size of the indicia approximates 0.3 mm. Computerization is an integral part of non-custom alpha/numeric type designs, but a custom disc carries a name, address, and other specific information unique to the manufacturer. The use of a computer improves access to the database and it decreases the amount of data placed on the disc. Microdisc bases may be fabricated using a mylar type plastic or they may be manufactured from a stainless steel blank. Plastic discs are constructed with an internal sandwich containing the photo-reduced indicia. Metal discs are marked with a photochemical etch or engraved with a computer driven YAG laser. Attachment of the disc to the enamel surface is accomplished by conventional etching and bonding techniques and are typically bonded to the buccal surface of the maxillary first permanent molar or the second primary molar. Clear composite bonding material covers the disc so that salivary contamination does not result in degradation of the indicia. Orthodontic style discs with a mesh back carry laser written information that may be cemented with conventional orthodontic bonding cement. Standardization of the indicia and overall design is considered to be an important aspect of patient and professional acceptance.

  14. Evolution of protoplanetary discs with magnetically driven disc winds

    Science.gov (United States)

    Suzuki, Takeru K.; Ogihara, Masahiro; Morbidelli, Alessandro; Crida, Aurélien; Guillot, Tristan

    2016-12-01

    Aims: We investigate the evolution of protoplanetary discs (PPDs) with magnetically driven disc winds and viscous heating. Methods: We considered an initially massive disc with 0.1 M⊙ to track the evolution from the early stage of PPDs. We solved the time evolution of surface density and temperature by taking into account viscous heating and the loss of mass and angular momentum by the disc winds within the framework of a standard α model for accretion discs. Our model parameters, turbulent viscosity, disc wind mass-loss, and disc wind torque, which were 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 that remains, the surface densities show a large variety, depending on the combination of these three parameters, some of which are very different from the surface density expected from the standard accretion. When a PPD is in a wind-driven accretion state with the preserved vertical magnetic field, the radial dependence of the surface density can be positive in the inner region migration of protoplanets. Conclusions: The variety of our calculated PPDs should yield a wide variety of exoplanet systems.

  15. 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...

  16. Artificial Limbs

    Science.gov (United States)

    ... diabetes. They may cause you to need an amputation. Traumatic injuries, including from traffic accidents and military combat Cancer Birth defects If you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which is ...

  17. 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....

  18. Coevolution of Binaries and Gaseous Discs

    CERN Document Server

    Fleming, David P

    2016-01-01

    The recent discoveries of circumbinary planets by $\\it Kepler$ raise questions for contemporary planet formation models. Understanding how these planets form requires characterizing their formation environment, the circumbinary protoplanetary disc, and how the disc and binary interact and change as a result. The central binary excites resonances in the surrounding protoplanetary disc that drive evolution in both the binary orbital elements and in the disc. To probe how these interactions impact binary eccentricity and disc structure evolution, N-body smooth particle hydrodynamics (SPH) simulations of gaseous protoplanetary discs surrounding binaries based on Kepler 38 were run for $10^4$ binary periods for several initial binary eccentricities. We find that nearly circular binaries weakly couple to the disc via a parametric instability and excite disc eccentricity growth. Eccentric binaries strongly couple to the disc causing eccentricity growth for both the disc and binary. Discs around sufficiently eccentri...

  19. Gait Analysis of Conventional Total Knee Arthroplasty and Bicruciate Stabilized Total Knee Arthroplasty Using a Triaxial Accelerometer

    Science.gov (United States)

    Saito, Hidetomo; Aizawa, Toshiaki; Miyakoshi, Naohisa; Shimada, Yoichi

    2016-01-01

    One component of conventional total knee arthroplasty is removal of the anterior cruciate ligament, and the knee after total knee arthroplasty has been said to be a knee with anterior cruciate ligament dysfunction. Bicruciate stabilized total knee arthroplasty is believed to reproduce anterior cruciate ligament function in the implant and provide anterior stability. Conventional total knee arthroplasty was performed on the right knee and bicruciate stabilized total knee arthroplasty was performed on the left knee in the same patient, and a triaxial accelerometer was fitted to both knees after surgery. Gait analysis was then performed and is reported here. The subject was a 78-year-old woman who underwent conventional total knee arthroplasty on her right knee and bicruciate stabilized total knee arthroplasty on her left knee. On the femoral side with bicruciate stabilized total knee arthroplasty, compared to conventional total knee arthroplasty, there was little acceleration in the x-axis direction (anteroposterior direction) in the early swing phase. Bicruciate stabilized total knee arthroplasty may be able to replace anterior cruciate ligament function due to the structure of the implant and proper anteroposterior positioning. PMID:27648328

  20. Recurrent hemarthrosis after total knee arthroplasty.

    Science.gov (United States)

    Rukavina, Alexander; Kerkhoffs, Gino M M J; Schneider, Philipp; Kuster, Markus S

    2010-07-01

    This report describes a case of spontaneous recurrent hemarthrosis of the knee that presented 4 weeks after total knee arthroplasty. Femoral arteriography showed a false aneurysm of a branch of the inferior lateral geniculate artery. Therapeutic embolization of the arterial branch was performed using three platinum coils with good clinical result and good knee joint function. Hemarthrosis has not recurred since embolization.

  1. Recurrent hemarthrosis after total knee arthroplasty

    OpenAIRE

    Rukavina, A.; Kerkhoffs, G. M. M. J.; Schneider, P.; Kuster, M S

    2010-01-01

    This report describes a case of spontaneous recurrent hemarthrosis of the knee that presented 4 weeks after total knee arthroplasty. Femoral arteriography showed a false aneurysm of a branch of the inferior lateral geniculate artery. Therapeutic embolization of the arterial branch was performed using three platinum coils with good clinical result and good knee joint function. Hemarthrosis has not recurred since embolization.

  2. Recurrent hemarthrosis after total knee arthroplasty

    NARCIS (Netherlands)

    Rukavina, A.; Kerkhoffs, G.M.M.J.; Schneider, P.; Kuster, M.S.

    2010-01-01

    This report describes a case of spontaneous recurrent hemarthrosis of the knee that presented 4 weeks after total knee arthroplasty. Femoral arteriography showed a false aneurysm of a branch of the inferior lateral geniculate artery. Therapeutic embolization of the arterial branch was performed usin

  3. SOFT TISSUE BALANCING IN TOTAL HIP ARTHROPLASTY.

    Directory of Open Access Journals (Sweden)

    Pencho Kosev

    2015-03-01

    Full Text Available We present our experience with the soft tissue balancing in total hip arthroplasty. Detailed indications, planning and surgical technique are presented. The described procedures are performed on 278 hips for a period of 6 years (2008-2014. We conclude that the outcome of a THA can be improved by balancing the stability, ROM, muscle strength and limb length equality.

  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. 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...

  6. Knee arthroplasty in Denmark, Norway and Sweden

    Science.gov (United States)

    Bizjajeva, Svetlana; Fenstad, Anne Marie; Furnes, Ove; Lidgren, Lars; Mehnert, Frank; Odgaard, Anders; Pedersen, Alma Becic; Havelin, Leif Ivar

    2010-01-01

    Background and purpose The number of national arthroplasty registries is increasing. However, the methods of registration, classification, and analysis often differ. Methods We combined data from 3 Nordic knee arthroplasty registers, comparing demographics, methods, and overall results. Primary arthroplasties during the period 1997–2007 were included. Each register produced a dataset of predefined variables, after which the data were combined and descriptive and survival statistics produced. Results The incidence of knee arthroplasty increased in all 3 countries, but most in Denmark. Norway had the lowest number of procedures per hospital—less than half that of Sweden and Denmark. The preference for implant brands varied and only 3 total brands and 1 unicompartmental brand were common in all 3 countries. Use of patellar button for total knee arthroplasty was popular in Denmark (76%) but not in Norway (11%) or Sweden (14%). Uncemented or hybrid fixation of components was also more frequent in Denmark (22%) than in Norway (14%) and Sweden (2%). After total knee arthroplasty for osteoarthritis, the cumulative revision rate (CRR) was lowest in Sweden, with Denmark and Norway having a relative risk (RR) of 1.4 (95% CI: 1.3–1.6) and 1.6 (CI: 1.4–1.7) times higher. The result was similar when only including brands used in more than 200 cases in all 3 countries (AGC, Duracon, and NexGen). After unicompartmental arthroplasty for osteoarthritis, the CRR for all models was also lowest in Sweden, with Denmark and Norway having RRs of 1.7 (CI: 1.4–2.0) and 1.5 (CI: 1.3–1.8), respectively. When only the Oxford implant was analyzed, however, the CRRs were similar and the RRs were 1.2 (CI: 0.9–1.7) and 1.3 (CI: 1.0–1.7). Interpretation We found considerable differences between the 3 countries, with Sweden having a lower revision rate than Denmark and Norway. Further classification and standardization work is needed to permit more elaborate studies. PMID:20180723

  7. Accretion discs trapped near corotation

    OpenAIRE

    D'Angelo, C.R.; Spruit, H.C.

    2012-01-01

    We show that discs accreting on to the magnetosphere of a rotating star can end up in a trapped state, in which the inner edge of the disc stays near the corotation radius, even at low and varying accretion rates. The accretion in these trapped states can be steady or cyclic; we explore these states over a wide range of parameter space. We find two distinct regions of instability: one related to the buildup and release of mass in the disc outside corotation, and the other to mass storage with...

  8. 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

  9. Computer-assisted navigation in knee arthroplasty: a critical appraisal.

    Science.gov (United States)

    Venkatesan, Muralidharan; Mahadevan, Devendra; Ashford, Robert U

    2013-10-01

    The purpose of this review was to appraise the use of computer-assisted navigation in total knee arthroplasty and to assess whether this technology has improved clinical outcomes. Studies were identified through searches in MEDLINE, Embase, and PubMed. Numerous studies have shown improved leg and component alignment using navigation systems. However, the better alignment achieved in navigated knee arthroplasty has not been shown to lead to better clinical outcomes. Navigated knee arthroplasty had lower calculated blood loss and lower incidence of fat embolism compared with conventional knee arthroplasty using intramedullary jigs. It may be most valued when dealing with complex knee deformities, revision surgery, or minimally invasive surgery. Navigated knee arthroplasty, however, is only cost-effective in centers with a high volume of joint replacements. Overall, computer-assisted navigated knee arthroplasty provides some advantages over conventional surgery, but its clinical benefits to date are unclear and remain to be defined on a larger scale.

  10. Modelling Neutral Hydrogen Discs of Spiral Galaxies

    Institute of Scientific and Technical Information of China (English)

    林伟鹏; 洪碧海

    2002-01-01

    We present an analytical model of a neutral hydrogen disc in a spiral galaxy. The gas disc of the spiral galaxy isassumed to have an exponential surface density profile and to be ionized by the cosmic ultraviolet background.To compare with observations, we consider the disc position angle and inclination angle for a line of sight goingthrough the galaxy disc. The HI column densities depend on the strength of ionizing field and disc position andinclination. The model was applied to NGC 3198 and the results were compared with observational data. TheHI disc profile at large disc radii can be tested by further HI observations using radio telescopes with a largeraperture than the present facilities. This HI disc model can be used to predict quasar absorption line systems bygalaxy discs if quasar lines of sight go through the discs.

  11. 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 ...

  12. Eclipse mapping of accretion discs

    CERN Document Server

    Baptista, R

    2000-01-01

    The eclipse mapping method is an inversion technique that makes use of the information contained in eclipse light curves to probe the structure, the spectrum and the time evolution of accretion discs. In this review I present the basics of the method and discuss its different implementations. I summarize the most important results obtained to date and discuss how they have helped to improve our understanding of accretion physics, from testing the theoretical radial brightness temperature distribution and measuring mass accretion rates to showing the evolution of the structure of a dwarf novae disc through its outburst cycle, from isolating the spectrum of a disc wind to revealing the geometry of disc spiral shocks. I end with an outline of the future prospects.

  13. Face-on accretion onto a protoplanetary disc

    Science.gov (United States)

    Wijnen, T. P. G.; Pols, O. R.; Pelupessy, F. I.; Portegies Zwart, S.

    2016-10-01

    Context. Stars are generally born in clustered stellar environments, which can affect their subsequent evolution. An example of this environmental influence can be found in globular clusters (GCs) harbouring multiple stellar populations. An evolutionary scenario in which a second (and possibly higher order) population is formed by the accretion of chemically enriched material onto the low-mass stars in the initial GC population has been suggested to explain the multiple stellar populations. The idea, dubbed early disc accretion, is that the low-mass, pre-main-sequence stars sweep up gas expelled by the more massive stars of the same generation into their protoplanetary disc as they move through the cluster core. The same process could also occur, to a lesser extent, in embedded stellar systems that are less dense. Aims: Using assumptions that represent the (dynamical) conditions in a typical GC, we investigate whether a low-mass star of 0.4 M⊙ surrounded by a protoplanetary disc can accrete a sufficient amount of enriched material to account for the observed abundances in so-called second generation GC stars. In particular, we focus on the gas-loading rate onto the disc and star, as well as on the lifetime and stability of the disc. Methods: We perform simulations at multiple resolutions with two different smoothed particle hydrodynamics codes and compare the results. Each code uses a different implementation of the artificial viscosity. Results: We find that the gas-loading rate is about a factor of two smaller than the rate based on geometric arguments, because the effective cross-section of the disc is smaller than its surface area. Furthermore, the loading rate is consistent for both codes, irrespective of resolution. Although the disc gains mass in the high-resolution runs, it loses angular momentum on a timescale of 104 yr. Two effects determine the loss of (specific) angular momentum in our simulations: (1) continuous ram pressure stripping and (2

  14. The outcome and influence of artificial cervical disc replacement on adjacent non-responsible segment instability in patients with cervical spondylosis%人工颈椎间盘置换的疗效及其对相邻非责任节段失稳的影响

    Institute of Scientific and Technical Information of China (English)

    种涛; 俞兴; 徐林; 贾育松; 李春根; 毕连涌; 柳根哲

    2012-01-01

    Objectives: To investigate the clinical efficacy and imaging results of the adjacent segment instability in patients with cervical spondylosis treated by Bryan cervical disc replacement. Methods: A retrospective review was performed on 9 cases suffering from adjacent segment instability before surgery. All 9 cases underwent Bryan artificial cervical disc arthoplasty and were followed up from July 2005 to January 2009 in our hospital. There were 4 males and 5 females with an average age of 33.5 years (range, 26-43 years). Japanese Orthopaedic Association(JOA) score was 10.16±3.17(7-13), and visual analogue pain scale(VAS) was 4.3±2.7(l-7) before surgery. All patients underwent cervical flexion and extension plain film and cervical MRI before surgery. Imaging instability was confirmed in the adjacent segment, which was asymptomatic. C4/5 replacement, 1 cases instability in C5/6; C5/6 replacement 4 cases, 3 cases instability in C4/5, 1 cases instability in C6/7; C6/7 replacement, 2 cases instability in C5/6. The double segment replacement 2 cases, each 1 cases instability in C4/5, C5/6 and C5/6, C6/7, which both are adjacent to the head-end segment. Clinical outcome of surgery was evaluated by JOA, neck pain VAS and Odom before surgery and at 1 week, 3, 6, 12, 24, 36 months after surgery respectively; the range of motion(ROM) of the surgical segment, adjacent unstable segment, C2-C7 and cervical malalignment were assessed by cervical dynamic X-ray before operation and 3, 6, 12, 24, 36 months after surgery. Results: The JOA score, neck pain VAS were improved significantly at each follow-up 3 months later after surgery compared with those of preoperation, difference was statistically significant(P0.05), while decreased significantly at 24 and 36 months(P<0.05). ROM of implanted segment and cervical curve at 24 and 36 months after operation increased significantly(P<0.05) compared with preoper-ative ones. The postoperative ROM of C2-C7 remained unchanged at each follow

  15. Photon Bubbles in Accretion Discs

    OpenAIRE

    Gammie, Charles F.

    1998-01-01

    We show that radiation dominated accretion discs are likely to suffer from a ``photon bubble'' instability similar to that described by Arons in the context of accretion onto neutron star polar caps. The instability requires a magnetic field for its existence. In an asymptotic regime appropriate to accretion discs, we find that the overstable modes obey the remarkably simple dispersion relation \\omega^2 = -i g k F(B,k). Here g is the vertical gravitational acceleration, B the magnetic field, ...

  16. Self-gravitating accretion discs

    OpenAIRE

    Lodato, G.

    2008-01-01

    I review recent progresses in the dynamics and the evolution of self-gravitating accretion discs. Accretion discs are a fundamental component of several astrophysical systems on very diverse scales, and can be found around supermassive black holes in Active Galactic Nuclei (AGN), and also in our Galaxy around stellar mass compact objects and around young stars. Notwithstanding the specific differences arising from such diversity in physical extent, all these systems share a common feature whe...

  17. Unexpected wear of an unicompartimental knee arthroplasty in oxidized zirconium.

    Science.gov (United States)

    Luyet, Anais; Fischer, Jean-François; Jolles, Brigitte M; Lunebourg, Alexandre

    2015-12-01

    Unicompartimental knee arthroplasty is a successful procedure for the treatment of localized osteoarthritis to one compartment of the knee with good long-term results. However, several modes of failure of unicompartimental knee arthroplasty have been described, namely aseptic or septic loosening, progression of disease, wear, and instability. Metallosis after unicompartimental knee arthroplasty is rarely reported and is most often related with polyethylene wear or break. We report on a case of rapid failure of unicompartimental knee arthroplasty in oxidized zirconium associated with metallosis secondary to the dislocation of the polyethylene.

  18. Total joint arthroplasties: current concepts of patient outcomes after surgery.

    Science.gov (United States)

    Jones, C Allyson; Beaupre, Lauren A; Johnston, D W C; Suarez-Almazor, Maria E

    2007-02-01

    Total hip and knee arthroplasties are effective surgical interventions for relieving hip pain and improving physical function caused by arthritis. Although the majority of patients substantially improve, not all report gains or are satisfied after receiving total joint arthroplasty. This article reviews the literature on patient outcomes after total hip and knee arthroplasties for osteoarthritis, and the evidence pertaining to factors that affect these patient-centered outcomes. Mounting evidence suggests that no single patient-related or perioperative factor clearly predicts the amount of pain relief or functional improvement that will occur following total hip or knee arthroplasty.

  19. 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

  20. 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......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...

  1. Lumbar disc excision through fenestration

    Directory of Open Access Journals (Sweden)

    Sangwan S

    2006-01-01

    Full Text Available Background : Lumbar disc herniation often causes sciatica. Many different techniques have been advocated with the aim of least possible damage to other structures while dealing with prolapsed disc surgically in the properly selected and indicated cases. Methods : Twenty six patients with clinical symptoms and signs of prolapsed lumbar intervertebral disc having radiological correlation by MRI study were subjected to disc excision by interlaminar fenestration method. Results : The assessment at follow-up showed excellent results in 17 patients, good in 6 patients, fair in 2 patients and poor in 1 patient. The mean preoperative and postoperative Visual Analogue Scores were 9.34 ±0.84 and 2.19 ±0.84 on scale of 0-10 respectively. These were statistically significant (p value< 0.001, paired t test. No significant complications were recorded. Conclusion : Procedures of interlaminar fenestration and open disc excision under direct vision offers sufficient adequate exposure for lumbar disc excision with a smaller incision, lesser morbidity, shorter convalescence, early return to work and comparable overall results in the centers where recent laser and endoscopy facilities are not available.

  2. Resonances in retrograde circumbinary discs

    CERN Document Server

    Nixon, Chris

    2015-01-01

    We analyse the interaction of an eccentric binary with a circular coplanar circumbinary disc that rotates in a retrograde sense with respect to the binary. In the circular binary case, no Lindblad resonances lie within the disc and no Lindblad resonant torques are produced, as was previously known. By analytic means, we show that when the binary orbit is eccentric, there exist components of the gravitational potential of the binary which rotate in a retrograde sense to the binary orbit and so rotate progradely with respect to this disc, allowing a resonant interaction to occur between the binary and the disc. The resulting resonant torques distinctly alter the disc response from the circular binary case. We describe results of three-dimensional hydrodynamic simulations to explore this effect and categorise the response of the disc in terms of modes whose strengths vary as a function of binary mass ratio and eccentricity. These mode strengths are weak compared to the largest mode strengths expected in the prog...

  3. 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...

  4. Disc piezoelectric ceramic transformers.

    Science.gov (United States)

    Erhart, Jirií; Půlpán, Petr; Doleček, Roman; Psota, Pavel; Lédl, Vít

    2013-08-01

    In this contribution, we present our study on disc-shaped and homogeneously poled piezoelectric ceramic transformers working in planar-extensional vibration modes. Transformers are designed with electrodes divided into wedge, axisymmetrical ring-dot, moonie, smile, or yin-yang segments. Transformation ratio, efficiency, and input and output impedances were measured for low-power signals. Transformer efficiency and transformation ratio were measured as a function of frequency and impedance load in the secondary circuit. Optimum impedance for the maximum efficiency has been found. Maximum efficiency and no-load transformation ratio can reach almost 100% and 52 for the fundamental resonance of ring-dot transformers and 98% and 67 for the second resonance of 2-segment wedge transformers. Maximum efficiency was reached at optimum impedance, which is in the range from 500 Ω to 10 kΩ, depending on the electrode pattern and size. Fundamental vibration mode and its overtones were further studied using frequency-modulated digital holographic interferometry and by the finite element method. Complementary information has been obtained by the infrared camera visualization of surface temperature profiles at higher driving power.

  5. The Comparison between Cervical Artificial Disc Arthroplasty and Anterior Cervical Decompression and Fusion on the Influence of the Adjacent Segments Degeneration%颈椎间盘置换术与颈椎前路减压融合术对邻近节段退变情况影响的比较

    Institute of Scientific and Technical Information of China (English)

    王鲲鹏; 邱玉金; 王玉凤; 刘守勇; 吴磊磊

    2013-01-01

    Objective To compare CADR with ACDF on the influence of the adjacent segments degenera-tion.Methods From February 2008 to October 2010,a total of 62 cases of cervical spondylosis was retrospectively re-viewed.All the patients were divided into CADR group and ACDF group ,depending on different surgical methods .The symptoms and neurological function were evaluated by the cervical Japanese Orthopaedic Association ( JOA) Scores and neck disability index ( NDI ) .The Cobb angle of C 2~7 and the mobility of adjacent segments were valuated the cervical range of mobility and degeneration .Results Compared with the preoperation , the last follow-up neurological function significantly improved ,the difference was statistically significant ( P0 .05 ) .At last follow-up Cobb angle of C 2~7 and the mobility of adjacent upper and lower segments in CADR group were similar to the preoperative ,there was no significant difference statistically (P>0.05).And there was significant difference statistically in ACDF group and between the groups ( P<0.05) .Conclusion CADR is less influ-ential on the adjacent segments degeneration postoperative .%目的:比较分析颈椎间盘置换术( CADR )与颈椎前路减压融合术( ACDF )对邻近节段退变情况的影响。方法回顾性分析2008年2月~2011年10月手术治疗的62名患者,根据术式不同,分为CADR组与ACDF组。采用颈椎JOA、NDI评分评价症状及神经功能,C2~7 Cobb角和手术相邻节段活动度评价颈椎活动范围及退变情况。结果与术前比较,末次随访时两组患者神经功能明显改善,组内差异有显著性(P<0.05),但组间比较差异无显著性(P>0.05)。与术前相比,末次随访时CADR组C2~7 Cobb角和手术相邻上、下节段活动度相近,差异无显著性(P>0.05);ACDF组内比较与两组间末次随访时比较C2~7 Cobb角和手术相邻上、下节段活动度,差异有显著性( P<0.05)。结论 CADR术后对邻近节段的退变影响较ACDF小。

  6. Nursing experience of preoperative standardized for patients with total hip arthroplasty.%人工全髋关节置换术前规范化护理体会

    Institute of Scientific and Technical Information of China (English)

    梁勇东

    2012-01-01

    Objective:Through the analysis of artificial total hip arthroplasty in patients' nursing before operations, to discuss the preoperative standardized nursing of artificial total hip arthroplasty. Methods:The adequate preoperative preparation of 108 total hip replacement patients and the strengthening of preoperative rehabilitation guidance. Results:108 artificial total hip replacement patients can tolerate surgery, grasp the rehabilitation guidance content, and actively cooperate with therapy and nursing, no case of complications such as pressure sores and dislocations. Conclusion:Standardized preoperative care is the important prerequisite for success of total hip arthroplasty.%目的:通过回顾分析人工全髋关节置换术患者术前的护理,探讨人工全髋关节置换术前规范化护理方法.方法:对108例人工全髋关节置换术患者进行了充分的术前准备和加强术前康复指导.结果:本组108例患者能耐受手术,能掌握康复指导内容,积极配合治疗和护理,无1例发生压疮、脱位等并发症.结论:规范化的术前护理是人工全髋关节置换术成功的重要前提.

  7. Application of finite element analysis in biomechanics of artiifcial disc replacement%有限元分析法在研究人工椎间盘置换生物力学中的应用

    Institute of Scientific and Technical Information of China (English)

    孔超; 鲁世保; 张美超

    2014-01-01

    As an important means of theoretical research, ifnite element analysis has been widely used in spinal biomechanics, especially in artiifcial disc replacement. Recent application progress of ifnite element analysis in artificial disc replacement were summarized in this paper, including the establishment of spine model, three-dimensional ( 3D ) model of the artiifcial intervertebral disc and 3D model of the artiifcial cervical and lumbar disc replacement. The advantages, disadvantages and development trends of ifnite element analysis applied in artiifcial disc replacement were also explored.

  8. 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.

  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 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...... 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 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. 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.

  11. Artificial ribonucleases.

    Science.gov (United States)

    Morrow, J R

    1994-01-01

    Many inorganic and organic compounds promote the reactions catalyzed by RNase A. Both the transesterification step, where a 2',3'-cyclic phosphate is formed with concomitant cleavage of RNA, and the hydrolysis step, where the 2',3'-cyclic phosphate is converted to a phosphate monoester, may be mimicked with compounds that are readily synthesized in the laboratory. Electrophilic activation of the phosphate ester and charge neutralization are generally important means by which artificial RNases promote phosphate diester displacement reactions. Several artificial RNases operate by a bifunctional general acid/general base mechanism, as does RNase A. Provision of an intramolecular nucleophile appears to be an important pathway for metal complex promoted phosphate diester hydrolysis. In contrast to the successful design of compounds that promote the reactions catalyzed by RNase A, there are no artificial nucleases to date that will cleave the 3' P-O bond of RNA or hydrolyze an oligonucleotide of DNA. Artificial RNases based on both metal complexes and organic compounds have been described. Metal complexes may be particularly effective catalysts for both transesterification and hydrolysis reactions of phosphate diesters. Under physiological conditions (37 degrees C and neutral pH), several metal complexes catalyze the transesterification of RNA. Future work should involve the development of metal complexes which are inert to metal ion release but which maintain open coordination sites for catalytic activity. The design of compounds containing multiple amine or imidazole groups that may demonstrate bifunctional catalysis is a promising route to new artificial RNases. Further design of these compounds and careful placement of catalytic groups may yield new RNase mimics that operate under physiological conditions. The attachment of artificial RNases to recognition agents such as oligodeoxynucleotides to create new sequence-specific endoribonucleases is an exciting field of

  12. 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.

  13. 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

  14. Stemless shoulder arthroplasty: a literature review

    OpenAIRE

    PETRICCIOLI, DARIO; BERTONE, CELESTE; MARCHI, GIACOMO

    2015-01-01

    The design of humeral implants for shoulder arthroplasty has evolved over the years. The new-generation modular shoulder prostheses have an anatomical humeral stem that replicates the three-dimensional parameters of the proximal humerus. An anatomical reconstruction is the best way to restore stability and mobility of the prosthetic shoulder and improve implant durability. However, a perfect anatomical match is not always possible in, for example, patients with post-traumatic osteoarthritis o...

  15. Dilemmas in Uncemented Total Hip Arthroplasty

    OpenAIRE

    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, Biomet) was evaluated. In conclusion, at an average follow-up of 8 years, this proximally HA-coated femoral component showed favorable clinical and radiological outcome and excellent survivorship. In ...

  16. New concepts in revision total knee arthroplasty.

    Science.gov (United States)

    Vince, Kelly G; Droll, Kurt; Chivas, Dan

    2008-01-01

    Revision knee arthroplasty should be regarded as a discipline separate from primary surgery. A disciplined approach to diagnosis is mandatory in which the following categories for failure are useful: (a) sepsis, (b) extensor mechanism rupture, (c) stiffness, (d) instability, (e) periprosthetic fracture, (f) aseptic loosening and osteolysis, (g) patellar complications and malrotation, (h) component breakage, and (i) no diagnosis. In the event of no coherent explanation for pain and disability, the possibilities of chronic regional pain syndrome, hip or spine pathology, and inability of current technology to meet patient expectations should be considered and revision surgery should be avoided. Revision arthroplasty cannot be performed as if it were a primary procedure and indeed will be eight (or more) different surgeries depending on the cause of failure. Though perhaps counterintuitive, there is a logical rationale and empirical evidence to support complete revision in virtually every case. In general, revision implant systems are required. The early dependence on the "joint line" is inadequate, failing as it does to recognize that the level of the articulation is a three-dimensional concept and not simply a "line." The key to revision surgery technique is that the flexion gap is determined by femoral component size and the extension gap by proximal distal component position. Accordingly, a general technical pathway of three steps can be recommended: 1) tibial platform; 2) stabilization of the knee in flexion with (a) femoral component rotation and (b) size selected with evaluation of (c) patellar height as an indication of "joint line" in flexion only; and 3) stabilization of the knee in extension, an automatic step. Stem extensions improve fixation and, if they engage the diaphysis, may be used as a guide for positioning. Porous metals designed as augments for bone defects may prove more important as "modular fixation interfaces." It is postulated that with the

  17. Recurrent hemarthrosis after unicompartmental knee arthroplasty.

    Science.gov (United States)

    Asanuma, Kunihiro; Ito, Haruo; Ogawa, Akito; Asanuma, Yumiko; Yoshikawa, Tomoaki; Hasegawa, Masahiro; Sudo, Akihiro

    2011-09-09

    Recurrent hemarthrosis after knee arthroplasty can be disabling, requiring adequate and immediate diagnosis and treatment for recovery of symptoms and joint function. The most commonly reported cause is impingement of proliferative synovium between prosthetic components. Although various procedures for hemarthrosis have been reported after knee arthroplasty for patients who do not respond to conservative treatment, the recommended first-line therapy is open surgery or embolization. Although hyperplastic synovium was observed during the first and second arthrotomy, in our case, tissue impingement was not detected. We describe a rare case of recurrent hemarthrosis after unicompartmental knee arthroplasty (UKA) and successful treatment by open synovectomy. A 66-year-old woman presented with spontaneous osteonecrosis of the medial femoral condyle in the right leg. She underwent UKA of the right knee of the medial condyle. Eighteen months after UKA, the patient developed recurrent hemarthrosis. Open arthrotomy was performed 22 months after UKA, revealing only hematoma with no obvious hemorrhage or loosening of the prosthesis. No history of trauma or use of anticoagulant medications was present. After a symptom-free period of 8 months, another 2 episodes of hemarthrosis occurred over the course of 8 months. A second open arthrotomy was performed. Hyperplastic synovium with fibrin and hemosiderin pigmentation was observed, again without hemorrhage or loosening. There were no pathological features of pigmented villonodular synovitis. Synovectomy was performed, and no hemarthrosis has recurred for 2 years.

  18. Analysis of the unicompartmental knee arthroplasty results

    Directory of Open Access Journals (Sweden)

    S. A. Firsov

    2015-01-01

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

  19. 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.

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

    NARCIS (Netherlands)

    Horstmann, W.G.

    2011-01-01

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

  1. Patient-reported outcome after fast-track knee arthroplasty

    DEFF Research Database (Denmark)

    Larsen, Kristian; Hansen, Torben B; Søballe, Kjeld;

    2012-01-01

    PURPOSE: The purpose of this study was to describe patient-related functional outcomes after fast-track total knee arthroplasty and unicompartmental knee arthroplasty. Furthermore, we wanted to assess physical areas where an additional need for rehabilitation could be identified, and finally, we...

  2. Artificial blood.

    OpenAIRE

    1983-01-01

    #Blood substitutes have been developed for almost a century. The various type of artificial blood was continuously available on the market. The theme of this report is to identify the best substitute in emergency situation for some patients and science students. The definition of best is given; thus, as the vital part of the report, the comparison between them is described and discussed. Modified hemoglobin, bovine-based hemoglobin and PFCs are three basic types. In terms of the perfor...

  3. Artificial vision.

    Science.gov (United States)

    Zarbin, M; Montemagno, C; Leary, J; Ritch, R

    2011-09-01

    A number treatment options are emerging for patients with retinal degenerative disease, including gene therapy, trophic factor therapy, visual cycle inhibitors (e.g., for patients with Stargardt disease and allied conditions), and cell transplantation. A radically different approach, which will augment but not replace these options, is termed neural prosthetics ("artificial vision"). Although rewiring of inner retinal circuits and inner retinal neuronal degeneration occur in association with photoreceptor degeneration in retinitis pigmentosa (RP), it is possible to create visually useful percepts by stimulating retinal ganglion cells electrically. This fact has lead to the development of techniques to induce photosensitivity in cells that are not light sensitive normally as well as to the development of the bionic retina. Advances in artificial vision continue at a robust pace. These advances are based on the use of molecular engineering and nanotechnology to render cells light-sensitive, to target ion channels to the appropriate cell type (e.g., bipolar cell) and/or cell region (e.g., dendritic tree vs. soma), and on sophisticated image processing algorithms that take advantage of our knowledge of signal processing in the retina. Combined with advances in gene therapy, pathway-based therapy, and cell-based therapy, "artificial vision" technologies create a powerful armamentarium with which ophthalmologists will be able to treat blindness in patients who have a variety of degenerative retinal diseases.

  4. Cervical disc prosthesis: 2-year follow-up

    Directory of Open Access Journals (Sweden)

    Romero Pinto de Oliveira Bilhar

    2015-06-01

    Full Text Available OBJECTIVE: To review the medical records of patients who underwent surgery for placement of cervical disc prosthesis after two years of postoperative follow-up, showing the basic epidemiological data, the technical aspects and the incidence of complications.METHODS: Medical records of seven patients who underwent surgery for placement of cervical disc prosthesis were reviewed after two years of follow-up, at the Institute of Orthopedics and Traumatology, Faculty of Medicine, University of São Paulo.RESULTS: The average age of patients participating in this study was 43.86 years. Six patients (85.7% had one level approached while one patient (14.3% had two levels addressed. The level C5-C6 has been approached in one patient (14.3% while the C6-C7 level was addressed in five patients (71.4%. One patient (14.3% had these two levels being addressed, C5-C6 and C6-C7. The mean operative time was 164.29±40 minutes. Three patients were hospitalized for 2 days and four for 3 days making an average of 2.57±0.535 days. Two patients (28.6% underwent a new surgical intervention due to loosening of the prosthesis. The mean follow-up was 28.14±5.178 months (23-35 months.CONCLUSIONS: Although cervical arthroplasty appears to be a safe procedure and present promising results in our study as well as in many other studies, it requires long-term studies.

  5. 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.

  6. Atomic gas in debris discs

    Science.gov (United States)

    Hales, Antonio S.; Barlow, M. J.; Crawford, I. A.; Casassus, S.

    2017-04-01

    We have conducted a search for optical circumstellar absorption lines in the spectra of 16 debris disc host stars. None of the stars in our sample showed signs of emission line activity in either Hα, Ca II or Na I, confirming their more evolved nature. Four stars were found to exhibit narrow absorption features near the cores of the photospheric Ca II and Na I D lines (when Na I D data were available). We analyse the characteristics of these spectral features to determine whether they are of circumstellar or interstellar origins. The strongest evidence for circumstellar gas is seen in the spectrum of HD 110058, which is known to host a debris disc observed close to edge-on. This is consistent with a recent ALMA detection of molecular gas in this debris disc, which shows many similarities to the β Pictoris system.

  7. Coevolution of binaries and circumbinary gaseous discs

    Science.gov (United States)

    Fleming, David P.; Quinn, Thomas R.

    2017-01-01

    The recent discoveries of circumbinary planets by Kepler raise questions for contemporary planet formation models. Understanding how these planets form requires characterizing their formation environment, the circumbinary protoplanetary disc and how the disc and binary interact and change as a result. The central binary excites resonances in the surrounding protoplanetary disc which drive evolution in both the binary orbital elements and in the disc. To probe how these interactions impact binary eccentricity and disc structure evolution, N-body smooth particle hydrodynamics simulations of gaseous protoplanetary discs surrounding binaries based on Kepler 38 were run for 104 binary periods for several initial binary eccentricities. We find that nearly circular binaries weakly couple to the disc via a parametric instability and excite disc eccentricity growth. Eccentric binaries strongly couple to the disc causing eccentricity growth for both the disc and binary. Discs around sufficiently eccentric binaries which strongly couple to the disc develop an m = 1 spiral wave launched from the 1:3 eccentric outer Lindblad resonance which corresponds to an alignment of gas particle longitude of periastrons. All systems display binary semimajor axis decay due to dissipation from the viscous disc.

  8. [Revision arthroplasty of the ankle joint].

    Science.gov (United States)

    Hintermann, B; Barg, A; Knupp, M

    2011-11-01

    In the last 20 years total ankle replacement has become a viable alternative to arthrodesis for end-stage osteoarthritis of the ankle. Numerous ankle prosthesis designs have appeared on the market in the past and attracted by the encouraging intermediate results reported in the literature, many surgeons have started to perform this procedure. With increased availability on the market the indications for total ankle replacement have also increased in recent years. In particular, total ankle replacement may now be considered even in younger patients. Therefore, despite progress in total ankle arthroplasty the number of failures may increase. Up to now, arthrodesis was considered to be the gold standard for salvage of failed ankle prostheses. Because of extensive bone loss on the talar side, in most instances tibiocalcaneal fusion is the only reliable solution. An alternative to such extended hindfoot fusions would be revision arthroplasty. To date, however, there are no reported results of revision arthroplasty for salvage of a failed ankle replacement.Based on our experience prosthetic components with a flat undersurface are most likely to be able to find solid support on remaining bone stock. The first 83 cases (79 patients, 46 males, 33 females, average age 58.9 years, range 30.6-80.7 years) with a average follow-up of 5.4 years (range 2-11 years) showed excellent to good results in 69 cases (83%), a satisfactory result in 12 cases (15%) and a fair result in 2 cases (2%) and 47 patients (56%) were pain free. Primary loosening was noted in three cases and of these two cases were successfully revised by another total ankle replacement and in one case with arthrodesis. Another case with hematogenous infection was also revised by arthrodesis. At the last follow-up control two components were considered to be loose and the overall loosening rate was thus 6%.This series has proven that revision arthroplasty can be a promising option for patients with failed total

  9. Comparison of effectiveness between high-flexion and ordinary fixing-platform posterior stabilized artificial knee prosthesis of total knee arthroplasty%高屈曲与非高屈曲固定平台稳定型假体行全膝关节置换术后疗效比较

    Institute of Scientific and Technical Information of China (English)

    赵鹏; 殷力

    2015-01-01

    目的 比较高屈曲与非高屈曲固定平台后稳定型假体行人工全膝关节置换术(Total knee arthroplasty,TKA)后的疗效.方法 回顾性比较2006年3月至2009年9月在郑州大学第一附属医院采用高屈曲固定平台后稳定型假体(高屈曲组)与非高屈曲固定平台后稳定型假体(非高屈曲组)行初次单侧人工表面全膝关节置换241例患者的疗效.其中高屈曲组132例,非高屈曲组109例.241例患者随访3~8年(平均4年).对纽约特种外科医院(The Hospital for Special Surgery,HSS)评分及活动度比较.结果 术后两组HSS评分比较,差异无统计学意义,而高屈曲组活动度大于非高屈曲组,差异有统计学意义.结论 高屈曲组TKA术后关节活动度大于非高屈曲组,但膝关节功能评分与非高屈曲组无差异.

  10. Artificial treatment of 35 cases of unilateral total knee arthroplasty,genu varus combination of flexion contracture deformity clinical a-nalysis%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

    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

    目的:探讨人工全膝关节置换术治疗单侧膝内翻合并屈曲挛缩畸形的临床效果,为临床治疗提供依据。方法选择2009年6月至2014年6月收治的35例单侧膝内翻合并屈曲挛缩畸形的患者为研究对象,应用人工全膝关节置换术进行治疗,对比分析治疗前后患者的膝关节股胫角、屈曲挛缩度、膝关节屈伸活动度与膝关节 HSS 评分的变化,同时进行随访,评估患者恢复一年后,下肢力线的恢复情况以及双下肢等长情况。结果经过手术的治疗及12个月的恢复,手术后患者膝关节股胫角、屈曲挛缩度和膝关节屈伸活动度分别为(18.0±5.8)°、(19.7±1.2)°和(42.2±17.5)°,与手术前相比较,[(168.9±2.6)°、(1.3±0.5)°和(147.3±22.7)°],患者的膝关节股胫角和膝关节屈伸活动度均大幅提高,屈曲挛缩度大幅降低,差异具有统计学意义( P ﹤0.05)。经过手术的治疗及12个月的恢复,患者的膝关节 HSS 临床评分和功能评分分别为(88.3±5.1)和(19.3±1.3)分,同术前相比[(31.2±10.1)分、(14.3±1.1)分],均大幅提高,差异有统计学意义( P ﹤0.05)。术后随访发现,患者并无下肢不等长、术后跛行和严重感染情况等并发症的发生。结论人工全膝关节置换术治疗单侧膝内翻合并屈曲挛缩畸形临床效果显著,患者术后膝关节股胫角、屈曲挛缩和膝关节 HSS 评分有显著改善,有效提高了患者的生存质量,值得在临床推广应用。%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

  11. 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.

  12. Dead discs, unstable discs and the stars they surround

    Directory of Open Access Journals (Sweden)

    D’Angelo Caroline

    2014-01-01

    Full Text Available Strong stellar magnetic fields significantly alter the behaviour of surrounding accretion discs. Recent work has demonstrated that at low accretion rates a large amount of mass can remain confined in the disc, contrary to the standard assumption that the magnetic field will expel the disc in an outflow (the “propeller regime”. These “dead discs” often become unstable, causing cycles of accretion onto the central star. Here I present the main predictions of this model, and argue that it provides a good explanation for the peculiar behaviour seen in several accreting sources with strong magnetic fields. I will focus in particular on three accreting millisecond X-ray pulsars: SAX J1808.4-3658, NGC 6440 X-2 and IGR J00291+5934. These sources all show low-frequency quasi-periodic oscillations consistent with a variable accretion rate, as well as unusual outburst patterns that suggest gas is confined in the inner disc regions during quiescence.

  13. Radiation of accretion discs: the eclipses

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzenberg-Czerny, A.

    1984-05-01

    Light curves have been calculated for eclipses of the accretion disc in a cataclysmic binary. The Roche geometry of the cool component was taken into account and the stellar atmospheres were interpolated to provide the local spectrum of the radiation from the disc. The dependence of the light curve on the parameters of the disc is discussed.

  14. Photoevaporating transitional discs and molecular cloud cores

    Science.gov (United States)

    Li, Min; Sui, Ning

    2017-04-01

    We investigate the evolution of photoevaporating protoplanetary discs including mass influx from molecular cloud cores. We examine the influence of cloud core properties on the formation and evolution of transitional discs. We use one-dimensional thin disc assumption and calculate the evolution of the protoplanetary disc. The effects of X-ray photoevaporation are also included. Our calculations suggest that most discs should experience the transitional disc phase within 10 Myr. The formation time of a gap and its initial location are functions of the properties of the cloud cores. In some circumstances, discs can open two gaps by photoevaporation alone. The two gaps form when the gas in the disc can expand to large radius and if the mass at large radius is sufficiently small. The surface density profile of the disc determines whether the two gaps can form. Since the structure of a disc is determined by the properties of a molecular cloud core, the core properties determine the formation of two gaps in the disc. We further find that even when the photoevaporation rate is reduced to 10 per cent of the standard value, two gaps can still form in the disc. The only difference is that the formation time is delayed.

  15. Intervertebral disc degeneration in dogs

    NARCIS (Netherlands)

    Bergknut, Niklas

    2011-01-01

    Back pain is common in both dogs and humans, and is often associated with intervertebral disc (IVD) degeneration. The IVDs are essential structures of the spine and degeneration can ultimately result in diseases such as IVD herniation or spinal instability. In order to design new treatments halting

  16. 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…

  17. Magnetorotational instability in protoplanetary discs

    CERN Document Server

    Salmeron, Roberto Aureliano; Salmeron, Raquel; Wardle, Mark

    2004-01-01

    We investigate the linear growth and vertical structure of the magnetorotational instability (MRI) in weakly ionised, stratified accretion discs. The magnetic field is initially vertical and dust grains are assumed to have settled towards the midplane, so charges are carried by electrons and ions only. Solutions are obtained at representative radial locations from the central protostar for different choices of the initial magnetic field strength, sources of ionisation, and disc surface density. The MRI is active over a wide range of magnetic field strengths and fluid conditions in low conductivity discs. For the minimum-mass solar nebula model, incorporating cosmic ray ionisation, perturbations grow at 1 AU for B < 8 G. For a significant subset of these strengths (0.2 - 5 G), the growth rate is of order the ideal MHD rate (0.75 Omega). Similarly, when cosmic rays are assumed to be excluded from the disc by the winds emitted by the magnetically active protostar, unstable modes grow at this radius for B less...

  18. Constraints on Slim Accretion Discs

    Institute of Scientific and Technical Information of China (English)

    CAI Zhen-Yi; GU Wei-Min; LU Ju-Fu

    2008-01-01

    @@ We show that when the gravitational force in the vertical direction is correctly calculated, the well-known Sshaped sequence of thermal equilibrium solutions can be constructed only for small radii of black hole accretion flows, such that slim accretion discs can possibly exist only in the inner regions of these flows.

  19. 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.

  20. People who undergo revision arthroplasty report more limitations but no decrease in physical activity compared with primary total hip arthroplasty : an observational study

    NARCIS (Netherlands)

    Stevens, Martin; Hoekstra, Tsjerk; Wagenmakers, Robert; Bulstra, Sjoerd K.; van den Akker-Scheek, Inge

    2009-01-01

    Question: Do people who have had revision arthroplasty report more limitations and less physical activity than those after primary total hip arthroplasty? Can degree of limitation and physical activity be predicted by revision arthroplasty, after adjustment for age, gender, and Charnley classificati

  1. Radiation from optically thin accretion discs

    Energy Technology Data Exchange (ETDEWEB)

    Tylenda, R. (Polska Akademia Nauk, Torun. Pracownia Astrofizyki)

    1981-01-01

    Accretion discs in cataclysmic variables with low rates of mass transfer, M < or approx. 10/sup 16/g s/sup -1/, have outer regions optically thin in continuum. A simple approach that allows one to calculate the radiation spectra from such discs is presented. A great number of disc models has been obtained in order to study the influence of various parameters (accretion rate, outer radius of the disc, inclination angle, mass of the accreting degenerate dwarf, viscosity parameter) of discs on the outgoing continuous spectra, emission lines and the UBV colours.

  2. 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.)

  3. Current trends in total hip arthroplasty.

    Science.gov (United States)

    Eingartner, Christoph

    2007-01-01

    After 20 years of application, with excellent short-term and long-term results, uncemented total hip arthroplasty (THA) is now generally regarded as the standard procedure for younger patients undergoing THA. However, expectations regarding hip replacement are continuously rising, along with the increasing number of young and active patients undergoing hip arthroplasty: a complication rate, including postoperative dislocation, close to zero, faster postoperative rehabilitation, low wear even in active patients, high durability and long term survival, etc. Demographic changes in aging societies are also leading to an increased need for cost-effective THA for the low-demand trauma patient. For high-demand patients, modern THA bearings, such as ceramic-ceramic articulations and other improved PE and metal materials, provide high durability and low wear, if the components are properly aligned. Navigation technology has been introduced in THA to ensure perfect component positioning without outliers and concomitant risk of increased wear and implant failure. Minimally and less invasive approaches are becoming increasingly popular in order to facilitate rehabilitation and fast-track surgery in younger patients. Navigation provides assistance for implant positioning in procedures with limited surgical exposure and visibility. New bone-preserving implants, such as surface replacement or short-stemmed femoral shaft prostheses, have been introduced especially for younger patients. Some of these new procedures are still under development,and the long-term results of new implant concepts have to be evaluated over the next decades. Not every modern concept will likely stand the test of time, but some will be beneficial for patients undergoing total hip arthroplasty in the future.

  4. Comparison of Procedural Sedation for the Reduction of Dislocated Total Hip Arthroplasty

    Directory of Open Access Journals (Sweden)

    Jonathan E. dela Cruz

    2014-02-01

    Full Text Available Introduction: Various types of sedation can be used for the reduction of a dislocated total hip arthroplasty. Traditionally, an Opiate/Benzodiazepine combination has been employed. The use of other pharmacologic agents, such as Etomidate and Propofol, has more recently gained popularity. Currently no studies directly comparing these sedation agents have been carried out. The purpose of this study is to compare differences in reduction and sedation outcomes including recovery times of these three different sedation agents. Methods: A retrospective chart review was performed examining 198 patient’s charts who presented with dislocated total hip arthroplasty at two academic affiliated medical centers. The patients were organized into groups according to the type of sedation agent used during their reduction. The percentages of reduction and sedation complications were calculated along with overall recovery times. Reduction complications included fracture, skin or neurovascular injury, and failure of reduction requiring general anesthesia. Sedation complications included use of bag-valve mask and artificial airway, intubation, prolonged recovery, use of a reversal agent, and inability to achieve sedation. The data were then compared for each sedation agent. Results: The reduction complications rates found were 8.7% in the Propofol group, 24.68% in the Etomidate, and 28.85% in the Opiate/Benzodiazepine groups. The reduction complication rate in the Propofol group was significantly different than those of the other two agents (p≤0.01. Sedation complications were found to happen 7.25% of the time in the Propofol group, 11.69% in the Etomidate group, and 21.25% in the Opiate/ Benzodiazepine group with Propofol having complication rates significantly different than that of the Opiate/Benzodiazepine group (p=0.02. Average lengths of recovery were 25.17 minutes for Propofol, 30.83 minutes for Etomidate, and 44.35 minutes for Opiate/ Benzodiazepine with

  5. 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....... Conclusion Periprosthetic loosening is frequent following a TWA. In our series it was not necessarily associated with implant loosening and seemed to stabilize within 3 years. Close and continued observation is, however, recommended. Level of Evidence Therapeutic IV....

  6. 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.

  7. Lower Limb Ischaemia Complicating Total Hip Arthroplasty

    Directory of Open Access Journals (Sweden)

    Shiu-Wai Chan

    2012-06-01

    Full Text Available This article is about two patients having vascular injuries complicating total hip arthroplasty because of intraoperative indirect injuries. One patient had a delayed presentation of acute lower limb ischaemia, in which he required amputation of his left second toe because of ischaemic gangrene. The other patient had acute lower limb ischaemia leading to permanent muscle and nerve damage because of delayed recognition. Both patients had vascular interventions for the indirect vascular injuries. Preoperative workup for suspicious underlying peripheral vascular disease, intraoperative precautions, and perioperative period of vascular status monitoring are essential for prevention and early detection of such sinister events.

  8. The properties of external accretion discs

    Energy Technology Data Exchange (ETDEWEB)

    Pringle, J.E. (Space Telescope Science Inst., Baltimore, MD (USA))

    1991-02-15

    The properties of external accretion discs (discs with a central source of angular momentum) are explored both analytically and numerically. An illustrative example of the effect of a disc of material around a binary star on the stellar separation is considered. We consider a Greens-function-type solution in which an initial ring of matter is put in orbit around the central binary. We find that the solution splits temporally into three parts. First, the disc evolves as a standard accretion disc unaware of the inner boundary condition. Secondly, the disc interacts with the inner boundary and changes its character to become, thirdly, an outflowing disc which is propelled outwards by the source of angular momentum at the centre. (author).

  9. Twisted accretion discs: Pt. 5; Viscous evolution

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. (Max-Planck-Institut fuer Physik und Astrophysik, Garching (Germany, F.R.). Inst. fuer Astrophysik)

    1990-08-15

    The time-dependence of accretion discs with orbits tilted out of the symmetry plane is studied. The effects of mass inflow modulation, and tilt variation at the disc outer edge, are examined for both circumbinary discs and for discs around compact objects. The appendices extend the numerical work to some analytic examples of tilt diffusion and external forcing effects. It is also shown that the disc must not be treated as a rigid tilted object if global angular momentum is to be conserved. These results are relevant to the problem of long-term periodicities of the light curves in Her X1 and {epsilon} Aur, the S-type symmetry of radio jets, warped gas discs in galaxies and polar rings in Neptune. Twisted discs may also arise in star-forming regions. (author).

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Centrifugally exhausting discs: an inverse process of disc-like accretion

    Energy Technology Data Exchange (ETDEWEB)

    Kaburaki, O.

    1989-03-01

    A disc-like mass-loss process from rapidly rotating, highly magnetized objects is investigated. Such a disc may be considered as an inverse-type of magnetized accretion discs. The disc plasma flows out radially with the Alfven velocity while it rotates, in the main part of the disc, with Keplerian velocity. The magnetic stress transfers angular momentum from the central spinner to the disc. A considerable fraction of the rotational energy extracted in association with the angular momentum is liberated in the disc through the (effective) Joule dissipation. An almost self-consistent set of analytic expressions is proposed as a solution to the steady-state, resistive MHD equations which are fairly simplified by the assumption of thin disc. The possibility of finding such discs around young neutron stars is briefly discussed with reference to SN 1987A.

  15. Grain charging in protoplanetary discs

    CERN Document Server

    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 and aggregates with fractal dimension D_f = 2. Applying a simple chemical network that accounts for collisional charging of grains, we provide a semi-analytical solution. This allowed us to calculate the equilibrium population of grain charges and the ionisation fraction efficiently. The grain charging was evaluated for different dynamical environments ranging from static to non-stationary disc configurations. The results show that the adsorption/desorption of neutral gas-phase heavy metals, such as magnesium, effects the ...

  16. Superhumps, resonances and accretion discs

    Energy Technology Data Exchange (ETDEWEB)

    Whitehurst, R.; King, A. (Leicester Univ. (UK). Dept. of Astronomy)

    1991-03-01

    The structure of accretion discs within binary systems is shown to be influenced by the excitation of resonances within the disc. Of particular importance is that near the 3:1 commensurability with the stars' orbit. This can be used to explain the superhump phenomenon of SU Ursae Majoris dwarf novae in superoutburst. This resonance can only appear for mass ratios which satisfy M{sub 2}/M{sub 1} < {approx equal} 0.25-0.33: for larger mass ratios the available resonances are weaker and of the wrong form to produce the superhump phenomenon. The mass-transfer stream is shown to be an important contributor to the growth rate of the resonance. (author).

  17. 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.

  18. Radiographic analysis of shoulder anatomical arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Merolla, Giovanni [Unit of Shoulder and Elbow Surgery, ' D. Cervesi' Hospital, L. Van Beethoven 46 Street, 47841 Cattolica (Italy)], E-mail: gmerolla@shouldertech.it; Di Pietto, Francesco; Romano, Stefania [Department of Diagnostic Imaging, ' A. Cardarelli' Hospital, Naples (Italy); Paladini, Paolo; Campi, Fabrizio; Porcellini, Giuseppe [Unit of Shoulder and Elbow Surgery, ' D. Cervesi' Hospital, L. Van Beethoven 46 Street, 47841 Cattolica (Italy)

    2008-10-15

    Arthroplasty is the standard treatment for advanced shoulder osteoarthritis. Modern prostheses designs have modular features whose size, shaft/head and body morphology can be adjusted. Total Shoulder Arthroplasty (TSA) provides better results. A complete X-ray follow-up is essential to assess the results and evaluate the survival rates of a shoulder prosthesis. Antero-posterior at 40 deg. in both internal and external rotation (true AP view) and axillary view are recommended to assess the following parameters: orientation and translation of the humeral component, offset, size and height of the humeral head, acromio-humeral distance, distribution and fixation of the cement, stress shielding and cortical resorption, radiolucent lines, subsidence and tilt, glenoid wear and 'bone stock', prostheses instability, glenoid component shift. Shoulder hemiarthroplasty can lead to glenoid wear; the true AP film at 40 deg. of internal rotation provides the best profile of gleno-humeral joint to depict glenoid erosion. Shift of the glenoid component in TSA is identified as tilting or medial migration on true AP and axillary views in the early postoperative period (1-2 months) and at minimum of 2 years. An exhaustive radiographic analysis remains essential to monitor the prosthetic implant and detect early and late complications or risk factors of prosthetic loosening.

  19. Wedged tibial components for total knee arthroplasty.

    Science.gov (United States)

    Jeffery, R S; Orton, M A; Denham, R A

    1994-08-01

    Severe coronal deformity of the knee is frequently associated with erosion of one tibial condyle. This can cause problems with fixation and alignment during total knee arthroplasty. If the tibia is cut to the level of the more worn side, valuable bone is sacrificed; if the less worn side is chosen, the deficiency must be filled with bone--graft, cement, or a prosthesis. Tibial components with an integral polyethylene wedge on the undersurface were introduced in 1980 for use in patients with a bony deficit on one tibial condyle. The authors believe that the Denham prosthesis (Biomet, Wales, U.K.) was the first knee arthroplasty to offer such spacers. Twenty-six patients with preoperative varus deformity in whom a wedged component was used were compared with 29 historic control subjects. None of the wedged components loosened after a median follow-up period of 8 years compared with loosening in five of the control subjects (P = .01). In three of the control subjects a fractured triangle of cement was present on the radiographs. Use of the wedges was not accompanied by an improvement in postoperative alignment. The authors conclude that the wedges resulted in improved fixation that was independent of postoperative alignment.

  20. Extensor mechanism allograft in total knee arthroplasty

    Science.gov (United States)

    Helito, Camilo Partezani; Gobbi, Riccardo Gomes; Tozi, Mateus Ramos; Félix, Alessandro Monterroso; Angelini, Fábio Janson; Pécora, José Ricardo

    2013-01-01

    Objective To analyze the experience with allograft transplantation of the extensor mechanism in total knee arthroplasty and compare results with the international experience. Methods We retrospectively evaluated three cases of extensor mechanism allograft after total knee arthroplasty performed in our hospital with the aid of one of the few tissue banks in Brazil and attempt to establish whether our experiences were similar to others reported in the world literature regarding patient indication, techniques, and outcomes. Results Two cases went well with the adopted procedure, and one case showed bad results and progressed to amputation. As shown in the literature, the adequate tension of the graft, appropriate tibial fixation and especially the adequate patient selection are the better predictors of good outcomes. Previous chronic infection can be an unfavorable predictor. Conclusion This surgical procedure has precise indication, albeit uncommon, either because of the rarity of the problem or because of the low availability of allografts, due to the scarcity of tissue banks in Brazil. Level of Evidence IV, Case Series. PMID:24453688

  1. Eclipse mapping of accretion discs

    OpenAIRE

    Baptista, Raymundo

    2000-01-01

    The eclipse mapping method is an inversion technique that makes use of the information contained in eclipse light curves to probe the structure, the spectrum and the time evolution of accretion discs. In this review I present the basics of the method and discuss its different implementations. I summarize the most important results obtained to date and discuss how they have helped to improve our understanding of accretion physics, from testing the theoretical radial brightness temperature dist...

  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.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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 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...

  4. Rural vs. urban utilization of total joint arthroplasty.

    Science.gov (United States)

    Banerjee, Devraj; Illingworth, Kenneth David; Novicoff, Wendy M; Scaife, Steven L; Jones, Braden K; Saleh, Khaled J

    2013-06-01

    The purpose of this study was to analyze the association between patient demographics and hospital demographics on utilization of total joint arthroplasty in rural and urban populations from the National Inpatient Sample database. Any patient that was discharged after a primary total hip or primary total knee arthroplasty was included in this study. Results showed that rural patients living in a Northeastern hospital region compared to West, less than 65 years of age, females, Blacks and Hispanics were less likely to undergo total joint arthroplasty compared to their urban counterparts. Rural patient were more likely to undergo total joint arthroplasty compared to their urban counterparts if they were in the Midwest and had Medicare as their primary payer provider.

  5. Recurrent Hemarthrosis Following Knee Arthroplasty Treated with Arterial Embolization.

    Science.gov (United States)

    Weidner, Zachary D; Hamilton, William G; Smirniotopoulos, John; Bagla, Sandeep

    2015-11-01

    Recurrent hemarthrosis is an uncommon but troublesome complication following knee arthroplasty. This study reports the results for 13 patients with spontaneous recurrent hemarthrosis after knee arthroplasty treated with arterial embolization. The average interval between arthroplasty and embolization was 47 months (range, 2-103 months), and the average time from onset of hemarthrosis to embolization was 4.1 months (range, 1-11 months). Geniculate arterial embolization lead to resolution of hemarthrosis in 12 of 13 patients (92.3%). The one clinical failure likely represented a case of misdiagnosed periprosthetic joint infection. Two patients experienced transient cutaneous ischemia related to distal particulate embolization that resolved spontaneously. Selective geniculate arterial embolization is an effective and safe treatment modality for recurrent hemarthrosis after knee arthroplasty.

  6. Myofascial Pain in Patients Waitlisted for Total Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Richard Henry

    2012-01-01

    Full Text Available BACKGROUND: Knee pain is one of the major sources of pain and disability in developed countries, particularly in aging populations, and is the primary indication for total knee arthroplasty (TKA in patients with osteoarthritis (OA.

  7. 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.

  8. Primary versus secondary distal femoral arthroplasty for treatment of total knee arthroplasty periprosthetic femur fractures.

    Science.gov (United States)

    Chen, Antonia F; Choi, Lisa E; Colman, Matthew W; Goodman, Mark A; Crossett, Lawrence S; Tarkin, Ivan S; McGough, Richard L

    2013-10-01

    Current methods of fixing periprosthetic fractures after total knee arthroplasty (TKA) are variable, and include open reduction and internal fixation (ORIF) via plating, retrograde nailing, or revision using standard revision TKA components or a distal femoral arthroplasty (DFA). The purpose of this study is to compare patients who failed plating techniques requiring subsequent revision to DFA to patients who underwent primary DFA. Of the 13 patients (9.2%) who failed primary ORIF, causes included nonunion (53.8%), infection (30.8%), loosening (7.7%), and refracture (7.7%). There were significantly more surgical procedures for ORIF revision to DFA compared to primary DFA. Complications for patients who underwent primary reconstruction with DFAs included extensor mechanism disruption (8.3%), infection (5.6%), and dislocation (2.8%). Primary reconstruction via ORIF is beneficial for preserving bone stock, but primary DFA may be preferred in osteopenic patients, or those at high risk for nonunion.

  9. 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...

  10. Preoperative Patient Education for Hip and Knee Arthroplasty: Financial Benefit?

    Science.gov (United States)

    Tait, Mark A; Dredge, Carter; Barnes, C Lowry

    2015-01-01

    Of 904 patients who underwent primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) at the same hospital, 802 participated in a preoperative education day called "Joint Academy" (JA). The length of stay of JA participants was 2.12 days (49.5%) less than patients who did not attend a JA (p education program may significantly reduce overall costs for primary TKA and THA procedures.

  11. Readmissions after fast-track hip and knee arthroplasty

    DEFF Research Database (Denmark)

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

    2010-01-01

    With the implementation of fast-track surgery with optimization of both logistical and clinical features, the postoperative convalescence has been reduced as functional milestones have been achieved earlier and consequently length of stay (LOS) in hospital has been reduced. However, it has been s...... speculated that a decrease in LOS may be associated with an increase in readmissions in general, including risk of dislocation after total hip arthroplasty (THA) or manipulation after total knee arthroplasty (TKA)....

  12. 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.

  13. Artificial neural networks in neurosurgery.

    Science.gov (United States)

    Azimi, Parisa; Mohammadi, Hasan Reza; Benzel, Edward C; Shahzadi, Sohrab; Azhari, Shirzad; Montazeri, Ali

    2015-03-01

    Artificial neural networks (ANNs) effectively analyze non-linear data sets. The aimed was A review of the relevant published articles that focused on the application of ANNs as a tool for assisting clinical decision-making in neurosurgery. A literature review of all full publications in English biomedical journals (1993-2013) was undertaken. The strategy included a combination of key words 'artificial neural networks', 'prognostic', 'brain', 'tumor tracking', 'head', 'tumor', 'spine', 'classification' and 'back pain' in the title and abstract of the manuscripts using the PubMed search engine. The major findings are summarized, with a focus on the application of ANNs for diagnostic and prognostic purposes. Finally, the future of ANNs in neurosurgery is explored. A total of 1093 citations were identified and screened. In all, 57 citations were found to be relevant. Of these, 50 articles were eligible for inclusion in this review. The synthesis of the data showed several applications of ANN in neurosurgery, including: (1) diagnosis and assessment of disease progression in low back pain, brain tumours and primary epilepsy; (2) enhancing clinically relevant information extraction from radiographic images, intracranial pressure processing, low back pain and real-time tumour tracking; (3) outcome prediction in epilepsy, brain metastases, lumbar spinal stenosis, lumbar disc herniation, childhood hydrocephalus, trauma mortality, and the occurrence of symptomatic cerebral vasospasm in patients with aneurysmal subarachnoid haemorrhage; (4) the use in the biomechanical assessments of spinal disease. ANNs can be effectively employed for diagnosis, prognosis and outcome prediction in neurosurgery.

  14. DSC Study of Collagen in Disc Disease

    OpenAIRE

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

    2009-01-01

    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...

  15. Biomechanical study of intervertebral disc degeneration

    OpenAIRE

    González Guitiérrez, Ramiro Arturo

    2012-01-01

    Degeneration and age affect the biomechanics of the intervertebral disc, by reducing its stiffness, flexibility and shock absorption capacities against daily movement and spinal load. The biomechanical characterization of intervertebral discs is achieved by conducting mechanical testing to vertebra-disc-vertebra segments and applying axial, shear, bend and torsion loads, statically or dynamically, with load magnitudes corresponding to the physiological range. However, traditional testing does...

  16. The Roles of Discs for Planetary Systems

    CERN Document Server

    Yeh, L C; Yeh, Li-Chin; Jiang, Ing-Guey

    2007-01-01

    It is known that the discs are detected for some of the extra-solar planetary systems. It is also likely that there was a disc mixing with planets and small bodies while our Solar System was forming. From our recent results, we conclude that the discs play two roles: the gravity makes planetary systems more chaotic and the drag makes planetary systems more resonant.

  17. DISC1 genetics, biology and psychiatric illness

    OpenAIRE

    2013-01-01

    Psychiatric disorders are highly heritable, and in many individuals likely arise from the combined effects of genes and the environment. A substantial body of evidence points towards DISC1 being one of the genes that influence risk of schizophrenia, bipolar disorder and depression, and functional studies of DISC1 consequently have the potential to reveal much about the pathways that lead to major mental illness. Here, we review the evidence that DISC1 influences disease risk through effects u...

  18. DSC Study of Collagen in Disc Disease

    Directory of Open Access Journals (Sweden)

    S. Skrzyński

    2009-01-01

    Full Text Available 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 tissue from healthy patients and from patients suffering from disc disease. In the paper the comparison between thermal helix-coil transition for collagen fibers from patients suffering from disc disease and collagen fibers from healthy organisms has been discussed. The heating rate has an influence on the position on denaturation temperatures of collagen in disc tissues. Higher helix-coil transition temperature of collagen in degenerated disc suggests that additional intermolecular cross linking of collagen fibers occurs. Denaturation temperatures of collagen in degenerated male disc possess smaller values than in female ones. Disc disease induces changes in collagen structure and leads to formation of additional crosslinks between collagen fibers.

  19. 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.

  20. 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

  1. 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.

  2. RECENT VIEW AT UNICOMPARTMENTAL KNEE ARTHROPLASTY AMONG OTHER SURGICAL APPROACHES TO PATIENTS WITH KNEE OSTEOARTHRITIS

    Directory of Open Access Journals (Sweden)

    N. N. Kornilov

    2012-01-01

    Full Text Available In the article recent publications dedicated to unicompartmental knee arthroplasty are analyzed. Evolution of indications and contraindications, mid- and late term results, difference in functional outcomes in comparison with total knee arthroplasty are discussed. Taking into consideration all relevant information unicompartmental knee arthroplasty may be considered as effective and reliable method of treatment of patients with knee osteoarthrosis and osteonecrosis.

  3. 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...

  4. Circumplanetary discs around young giant planets: a comparison between core-accretion and disc instability

    Science.gov (United States)

    Szulágyi, J.; Mayer, L.; Quinn, T.

    2017-01-01

    Circumplanetary discs can be found around forming giant planets, regardless of whether core accretion or gravitational instability built the planet. We carried out state-of-the-art hydrodynamical simulations of the circumplanetary discs for both formation scenarios, using as similar initial conditions as possible to unveil possible intrinsic differences in the circumplanetary disc mass and temperature between the two formation mechanisms. We found that the circumplanetary discs' mass linearly scales with the circumstellar disc mass. Therefore, in an equally massive protoplanetary disc, the circumplanetary discs formed in the disc instability model can be only a factor of 8 more massive than their core-accretion counterparts. On the other hand, the bulk circumplanetary disc temperature differs by more than an order of magnitude between the two cases. The subdiscs around planets formed by gravitational instability have a characteristic temperature below 100 K, while the core-accretion circumplanetary discs are hot, with temperatures even greater than 1000 K when embedded in massive, optically thick protoplanetary discs. We explain how this difference can be understood as the natural result of the different formation mechanisms. We argue that the different temperatures should persist up to the point when a full-fledged gas giant forms via disc instability; hence, our result provides a convenient criterion for observations to distinguish between the two main formation scenarios by measuring the bulk temperature in the planet vicinity.

  5. 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. Endpoints were......, and lumbar plexus block reduced nausea and pruritus. The GRADE-rated quality of evidence ranged from low to very low throughout the analyses. This review demonstrated, that some analgesic interventions may have the capacity to reduce mean opioid requirements and/or mean pain intensity compared with controls...

  6. Extensor mechanism disruption after total knee arthroplasty.

    Science.gov (United States)

    Bates, Michael D; Springer, Bryan D

    2015-02-01

    Extensor mechanism disruption is a rare and potentially devastating complication associated with total knee arthroplasty. Disruption can occur at the quadriceps or patellar tendons or, in the setting of a fracture, at the patella. Recognition of the risk factors for disruption and prevention via meticulous surgical technique are critical to avoid this complication. Various management techniques and the challenges associated with treatment have been described. Nonsurgical management consists of the use of walking aids and/or knee braces, which may not be acceptable for the active patient. Surgical options include primary repair and reconstructive techniques using allograft, autograft, synthetic material, and gastrocnemius rotational flaps. However, no single method has reliably demonstrated satisfactory outcomes. Although research on reconstructive procedures with synthetic materials has been promising, further study is need to assess the use of these materials.

  7. Noise measurement in total knee arthroplasty

    Directory of Open Access Journals (Sweden)

    Lukas A Holzer

    2014-01-01

    Full Text Available Few studies have been performed to analyze noise levels produced by various surgical instruments in the operating room (OR. The highest levels of noise that have been described were due to instruments used for total knee arthroplasty (TKA. These high levels of noise might be a potential health hazard for patients and medical staff. Therefore, we aimed to measure noise levels of current instruments that are widely used worldwide. During a conventional primary TKA the levels of noise in the OR were measured using a Class 1 integrating-averaging sound level meter. The highest A-weighted equivalent level was produced when using a hammer during the implantation of the femoral and tibial components with 90.2 dBA. In total surgical instruments were used for about 10% of the total time of surgery. Noise exposure due to instrument use during TKA does not seem to be a potential health hazard for medical staff or patients.

  8. 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.

  9. 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...... 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...

  10. Total hip arthroplasty in heart transplant patients.

    Science.gov (United States)

    León, José Luis; Resines, Carlos; Zafra, Alberto

    2007-12-01

    Avascular necrosis of the femoral head (AVNFH) is a known complication after heart transplantation. In order to assess the efficacy and complications of cementless total hip arthroplasty (THA) in this population, the authors analysed 24 cementless THAs in 18 patients with advanced AVNFH (stage II affecting more than 15% of the articular surface, stage III and IV according to the Ficat-Arlet classification) after a heart transplant procedure. Average duration of follow-up was 35.4 months (range: 16 to 66). Pain and function scores (Harris Hip Score and WOMAC arthritis index) showed significant improvement from the preoperative levels. There was no evidence of component loosening, heart-related complications or infection following the THA. Cementless THA is a reasonable treatment option for advanced avascular necrosis of the femoral head following heart transplant procedures.

  11. Endotoxins in surgical instruments of hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Vania Regina Goveia

    2016-06-01

    Full Text Available Abstract OBJECTIVE To investigate endotoxins in sterilized surgical instruments used in hip arthroplasties. METHOD A descriptive exploratory study conducted in a public teaching hospital. Six types of surgical instruments were selected, namely: acetabulum rasp, femoral rasp, femoral head remover, chisel box, flexible bone reamer and femoral head test. The selection was based on the analysis of the difficulty in removing bone and blood residues during cleaning. The sample was made up of 60 surgical instruments, which were tested for endotoxins in three different stages. The EndosafeTM Gel-Clot LAL (Limulus Amebocyte Lysate method was used. RESULT There was consistent gel formation with positive analysis in eight instruments, corresponding to 13.3%, being four femoral rasps and four bone reamers. CONCLUSION Endotoxins in quantity ≥0.125 UE/mL were detected in 13.3% of the instruments tested.

  12. Favorable results after total wrist arthroplasty

    DEFF Research Database (Denmark)

    Boeckstyns, Michel E. H.; Herzberg, G.; Merser, Søren

    2013-01-01

    Background and purpose During the past 40 years, several attempts have been made with total wrist arthroplasty to avoid fusion in severely destroyed wrists. The results have often been disappointing. There is only modest clinical documentation due to the small number of patients (especially non....... The wrists had been reviewed annually and analysis was done on the latest follow-up data. Results 60 patients had been operated (5 bilaterally), 5 wrists had been revised, and 52 were available for follow-up (with the revised cases excluded). The pain scores, QuickDASH scores, ulnar flexion, and supination...... for the whole group were statistically significantly better at follow-up. There were no statistically significant differences between the rheumatoid and the non-rheumatoid patients except for motion, which was better in the non-rheumatoid group. The motion obtained depended on the preoperative motion. Implant...

  13. [Standardized terminology for disc disease].

    Science.gov (United States)

    Sánchez Pérez, M; Gil Sierra, A; Sánchez Martín, A; Gallego Gómez, P; Pereira Boo, D

    2012-01-01

    This article reviews the terminology used to describe morphological alterations in the intervertebral discs. Radiologists must be able to communicate information about the type, location, and severity of these alterations to medical and surgical clinicians. It is crucial to use simple, standard, and unified terminology to ensure comprehension not only among radiologists but also with professionals from the different specialties for whom the radiology reports are written (fundamentally traumatologists and neurosurgeons). This terminology will help ensure a more accurate diagnosis and better patient management.

  14. Minimally invasive total hip arthroplasty: in opposition.

    Science.gov (United States)

    Hungerford, David S

    2004-06-01

    At the Knee Society Winter Meeting in 2003, Seth Greenwald and I debated about whether there should be new standards (ie, regulations) applied to the release of information to the public on "new developments." I argued for the public's "right to know" prior to the publication of peer-reviewed literature. He argued for regulatory constraint or "proving by peer-reviewed publication" before alerting the public. It is not a contradiction for me to currently argue against the public advertising of minimally invasive (MIS) total hip arthroplasty as not yet being in the best interest of the public. It is hard to remember a concept that has so captured both the public's and the surgical community's fancy as MIS. Patients are "demanding" MIS without knowing why. Surgeons are offering it as the next best, greatest thing without having developed the skill and experience to avoid the surgery's risks. If you put "minimally invasive hip replacement" into the Google search engine (http://www.google.com), you get 5,170 matches. If you put the same words in PubMed (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi), referencing the National Library of Medicine database, you get SEVENTEEN; none is really a peer-reviewed article. Most are 1 page papers in orthopedics from medical education meetings. On the other hand, there are over 6,000 peer-reviewed articles on total hip arthroplasty. Dr. Thomas Sculco, my couterpart in this debate, wrote an insightful editorial in the American Journal of Orthopedic Surgery in which he stated: "Although these procedures have generated incredible interest and enthusiasm, I am concerned that they may be performed to the detriment of our patients." I couldn't agree with him more. Smaller is not necessarily better and, when it is worse, it will be the "smaller" that is held accountable.

  15. Drain tip culture following total knee arthroplasty

    Directory of Open Access Journals (Sweden)

    Bahubali Aski

    2015-02-01

    Full Text Available Background: Placing a suction drain following total knee replacement is usual practice which is been followed by many surgeons. Closed suction drainage following arthroplasty is a routine with the aim of preventing wound hematoma and thereby reducing the risk of infection. Surgical site infections in orthopaedic surgeries are disastrous and often lead to significant morbidity and mortality. Usefulness of drain tip culture in predicting the wound infection is been tested but results are controversial. Methods: It is a prospective study of 546 drains (352 patients who underwent unilateral or bilateral Total Knee Arthroplasty (TKA. The drain tip was sent for culture at the time of removing. Cultures from the SSI (surgical site infection were also collected. Cases that had at least six months of follow up were included in the study. However in one patient with superficial infection, the drain tip culture was negative. Results: Drain tip culture was positive in total of 18 patients. Three patients had developed deep infection and 10 patients had superficial infection. All three patients with deep infection and 9 out of 10 patients of superficial infection were culture positive. Out of 8 culture positive superficial infections, one had different bacteria identified from the site. Drain tip culture was positive in 3.39% of drains and infection rate was positive in 1.88% of wounds. On statistical analysis we found drain tip culture sensitivity of 90%, specificity of 98.46%, positive predictive value of 52.9% and negative predictive value of 99.8%. Conclusion: Drain tip culture positivity helps in predicting the future chance of developing the infection. If drain tip culture is negative, then there is almost near nil chances of infection. [Int J Res Med Sci 2015; 3(2.000: 409-411

  16. Minimum weight design of inhomogeneous rotating discs

    Energy Technology Data Exchange (ETDEWEB)

    Jahed, Hamid [Department of Mechanical Engineering, Iran University of Science and Technology, Tehran 16844 (Iran, Islamic Republic of); Farshi, Behrooz [Department of Mechanical Engineering, Iran University of Science and Technology, Tehran 16844 (Iran, Islamic Republic of)]. E-mail: farshi@iust.ac.ir; Bidabadi, Jalal [Department of Mechanical Engineering, Iran University of Science and Technology, Tehran 16844 (Iran, Islamic Republic of)

    2005-01-01

    There are numerous applications for gas turbine discs in the aerospace industry such as in turbojet engines. These discs normally work under high temperatures while subjected to high angular velocities. Minimizing the weight of such items in aerospace applications results in benefits such as low dead weights and lower costs. High speed of rotation causes large centrifugal forces in a disc and simultaneous application of high temperatures reduces disc material strength. Thus, the latter effects tend to increase deformations of the disc under the applied loads. In order to obtain a reliable disc analysis and arrive at the corresponding correct stress distribution, solutions should consider changes in material properties due to the temperature field throughout the disc. To achieve this goal, an inhomogeneous disc model with variable thickness is considered. Using the variable material properties method, stresses are obtained for the disc under rotation and a steady temperature field. In this paper this is done by modelling the rotating disc as a series of rings of different but constant properties. The optimum disc profile is arrived at by sequentially proportioning the thicknesses of each ring to satisfy the stress requirements. This method vis-a-vis a mathematical programming procedure for optimization shows several advantages. Firstly, it is simple iterative proportioning in each design cycle not requiring involved mathematical operations. Secondly, due to its simplicity it alleviates the necessity of certain simplifications that are common in so-called rigorous mathematical procedures. The results obtained, compared to those published in the literature show agreement and superiority. A further advantage of the proposed method is the independence of the end results from the initially assumed point in the iterative design routine, unlike most methods published so far.

  17. 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.

  18. Post-Main Sequence Evolution of Debris Discs

    OpenAIRE

    Bonsor, Amy; Wyatt, Mark

    2010-01-01

    The population of debris discs on the main sequence is well constrained, however very little is known about debris discs around evolved stars. In this work we provide a theoretical framework that considers the effects of stellar evolution on debris discs; firstly considering the evolution of an individual disc from the main sequence through to the white dwarf phase, then extending this to the known population of debris discs around main sequence A stars. It is found that discs around evolved ...

  19. Genetic association studies in lumbar disc degeneration

    DEFF Research Database (Denmark)

    Eskola, Pasi J; Lemmelä, Susanna; Kjaer, 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....

  20. The maximum rotation of a galactic disc

    NARCIS (Netherlands)

    Bottema, R

    1997-01-01

    The observed stellar velocity dispersions of galactic discs show that the maximum rotation of a disc is on average 63% of the observed maximum rotation. This criterion can, however, not be applied to small or low surface brightness (LSB) galaxies because such systems show, in general, a continuously

  1. The inner cavity of the circumnuclear disc

    Science.gov (United States)

    Blank, M.; Morris, M. R.; Frank, A.; Carroll-Nellenback, J. J.; Duschl, W. J.

    2016-06-01

    The circumnuclear disc (CND) orbiting the Galaxy's central black hole is a reservoir of material that can ultimately provide energy through accretion, or form stars in the presence of the black hole, as evidenced by the stellar cluster that is presently located at the CND's centre. In this paper, we report the results of a computational study of the dynamics of the CND. The results lead us to question two paradigms that are prevalent in previous research on the Galactic Centre. The first is that the disc's inner cavity is maintained by the interaction of the central stellar cluster's strong winds with the disc's inner rim, and secondly, that the presence of unstable clumps in the disc implies that the CND is a transient feature. Our simulations show that, in the absence of a magnetic field, the interaction of the wind with the inner disc rim actually leads to a filling of the inner cavity within a few orbital time-scales, contrary to previous expectations. However, including the effects of magnetic fields stabilizes the inner disc rim against rapid inward migration. Furthermore, this interaction causes instabilities that continuously create clumps that are individually unstable against tidal shearing. Thus the occurrence of such unstable clumps does not necessarily mean that the disc is itself a transient phenomenon. The next steps in this investigation are to explore the effect of the magnetorotational instability on the disc evolution and to test whether the results presented here persist for longer time-scales than those considered here.

  2. Hygroviscoelasticity of the Human Intervertebral Disc.

    Science.gov (United States)

    1980-07-01

    hernia - tion with age depends on the biochemical changes that occur in the material of the disc during its maturation process. However, a careful machanics...EFFORT One of the recurring pieces of information required in disc response is the intra- discal pressure when the spine is loaded axially. This

  3. Feature Based Control of Compact Disc Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh

    Two servo control loops are used to keep the Optical Pick-up Unit focused and radially on the information track of the Compact Disc. These control servos have problems handling surface faults on the Compact Disc. In this Ph.D thesis a method is proposed to improve the handling of these surface...

  4. Hydromagnetic Flow between Two Rotating Coaxial Discs

    Directory of Open Access Journals (Sweden)

    Abdul Aleem Khan

    1970-01-01

    Full Text Available This paper relates to the steady flow of an electrically incompressible viscous fluid between two parallel coaxial rotating discs with a transverse magnetic field when the discs are rotating in the same direction with the same velocity and there is a source at the centre.

  5. Twisted accretion discs: Pt. 4. Alignment in polytropic discs and low. cap alpha. limit

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S.

    1988-07-01

    Twisted thin accretion discs are of interest in explaining long-term periodicities in X-ray binaries, the eclipse in Epsilon Aurigae, and perhaps precessing radio jets and possible warped molecular outflows in star-forming regions. Earlier results used isothermal discs to determine the alignment radius, Rsub(a). Now we see how polytropic discs effect earlier results for discs around compact objects and around close binaries. We find that Rsub(a) for polytropic discs can be up to an order of magnitude larger, depending on the polytropic index, the viscosity parameter and the precession mechanism. There is little change in the earlier conclusion that the case for alignment in Her X-1 is marginal, while there is substantial alignment in epsilon Aur. A lower limit is put on ..cap alpha.. for isothermal discs, which is expected to hold for polytropic discs as well. A bound is put on the energy of the perturbed flows.

  6. On the reliability of protostellar disc mass measurements and the existence of fragmenting discs

    CERN Document Server

    Dunham, Michael M; Arce, Héctor G

    2014-01-01

    We couple non-magnetic, hydrodynamical simulations of collapsing protostellar cores with radiative transfer evolutionary models to generate synthetic observations. We then use these synthetic observations to investigate the extent to which a simple method for measuring protostellar disc masses used in the literature recovers the intrinsic masses of the discs formed in the simulations. We evaluate the effects of contamination from the surrounding core, partially resolving out the disc, optical depth, fixed assumed dust temperatures, inclination, and the dust opacity law. We show that the combination of these effects can lead to disc mass underestimates by up to factors of 2-3 at millimeter wavelengths and up to an order of magnitude or larger at submillimeter wavelengths. The optically thin portions of protostellar discs are generally cooler in the Class I stage than the Class 0 stage since Class I discs are typically larger and more optically thick, and thus more shielded. The observed disc mass distribution ...

  7. Conversion paralysis after cervical spine arthroplasty: a case report and literature review.

    Science.gov (United States)

    Boudissa, M; Castelain, J E; Boissière, L; Mariey, R; Pointillart, V; Vital, J M

    2015-09-01

    We report a case of conversion paralysis after cervical spine arthroplasty performed in a 45-year-old woman to treat cervico-brachial neuralgia due to a left-sided C6-C7 disc herniation. Upon awakening from the anaesthesia, she had left hemiplegia sparing the face, with normal sensory function. Magnetic resonance imaging (MRI) of the brain ruled out a stroke. MRI of the spinal cord showed artefacts from the cobalt-chrome prosthesis that precluded confident elimination of mechanical spinal cord compression. Surgery performed on the same day to substitute a cage for the prosthesis ruled out spinal cord compression, while eliminating the source of MRI artefacts. Findings were normal from follow-up MRI scans 1 and 15days later, as well as from neurophysiological testing (electromyogram and motor evoked potentials). The deficit resolved fully within the next 4days. A psychological assessment revealed emotional distress related to an ongoing divorce. The most likely diagnosis was conversion paralysis. Surgeons should be aware that conversion disorder might develop after a procedure on the spine, although the risk of litigation requires re-operation. Familiarity with specific MRI sequences that minimise artefacts can be valuable. A preoperative psychological assessment might improve the detection of patients at high risk for conversion disorder.

  8. A preliminary report of patellofemoral arthroplasty in isolated patellofemoral arthritis

    Institute of Scientific and Technical Information of China (English)

    GAO Xiang; XU Zheng-jian; HE Rong-xin; YAN Shi-gui; WU Li-dong

    2010-01-01

    Background Isolated patellofemoral osteoarthritis is not uncommon. Surgical treatment of isolated patellofemoral arthritis remains controversial and poses a challenging treatment dilemma. The present study aimed to evaluate the short-term results of patellofemoral arthroplasty for patients with isolated patellofemoral osteoarthritis.Methods We analyzed 11 patellofemoral arthroplasties performed from March 2006 to September 2009 in 11 patients with isolated patellofemoral arthritis. The patients comprised 2 males and 9 females with an average age of 53.7 years (range, 46-74 years). Standard weightbearing radiographs were taken in the anteroposterior, lateral, and 45° axial views.The knee pain and functional status were evaluated by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scales and American Knee Society (AKS) scores. For comparison, 23 total knee arthroplasties in 23 patients with primary tibiofemoral osteoarthritis were matched according to age, gender, bilaterality and body mass index.The duration of follow-up was 23.7 months (range, 12-47 months).Results The majority of the 11 patients experienced improvement in their patellofemoral symptoms after patellofemoral arthroplasty. The WOMAC scores improved considerably by 7.4 points with respect to pain and by 5.2 points with respect to function. The AKS scores also improved considerably by 23.9 points with respect to pain and 44.3 points with respect to function. Although the clinical outcomes after patellofemoral arthroplasty were not better than those after total knee arthroplasty, patellofemoral arthroplasty exhibited advantages in the shorter operation time, lower blood loss and increased postoperative range of motion. At the latest follow-up, there was no clinical or radiographic evidence of patellofemoral maltracking, loosening or wear.Conclusions On the basis of our experience in this relatively small series of patients with a short-term follow-up,patellofemoral arthroplasty

  9. 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.).

  10. 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.

  11. 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.

  12. Angular momentum transport in protostellar discs

    CERN Document Server

    Salmeron, Roberto Aureliano; Wardle, M; Salmeron, Raquel; Konigl, Arieh; Wardle, Mark

    2006-01-01

    Angular momentum transport in protostellar discs can take place either radially, through turbulence induced by the magnetorotational instability (MRI), or vertically, through the torque exerted by a large-scale magnetic field that threads the disc. Using semi-analytic and numerical results, we construct a model of steady-state discs that includes vertical transport by a centrifugally driven wind as well as MRI-induced turbulence. We present approximate criteria for the occurrence of either one of these mechanisms in an ambipolar diffusion-dominated disc. We derive ``strong field'' solutions in which the angular momentum transport is purely vertical and ``weak field'' solutions that are the stratified-disc analogues of the previously studied MRI channel modes; the latter are transformed into accretion solutions with predominantly radial angular-momentum transport when we implement a turbulent-stress prescription based on published results of numerical simulations. We also analyze ``intermediate field strength'...

  13. 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.

  14. About detection of precessing circumpulsar discs

    Science.gov (United States)

    Grimani, Catia

    2016-08-01

    Detections of circumpulsar discs and planetary systems through electromagnetic observations appear quite rare. In the case of PSR 1931+24 and B0656+14, the hypothesis of a precessing disc penetrating the pulsar light cylinder is found consistent with radio and gamma observations from these stars. Disc self-occultation and precession may affect electromagnetic measurements. We investigate here under which conditions gravitational waves generated by circumpulsar disc precession may be detected by the proposed second-generation space interferometers DECI-hertz Interferometer Gravitational Wave Observatory and Big Bang Observer. The characteristics of circumpulsar detectable precessing discs are estimated as a function of distance from the Solar system. Speculations on detection rates are presented.

  15. 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.

  16. 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.

  17. Properties of HI discs in the Auriga cosmological simulations

    Science.gov (United States)

    Marinacci, Federico; Grand, Robert J. J.; Pakmor, Rüdiger; Springel, Volker; Gómez, Facundo A.; Frenk, Carlos S.; White, Simon D. M.

    2017-01-01

    We analyse the properties of the HI gas distribution in the Auriga project, a set of magnetohydrodynamic cosmological simulations performed with the moving-mesh code AREPO and a physics model for galaxy formation that succeeds in forming realistic late-type galaxies in the 30 Milky Way-sized haloes simulated in this project. We use a simple approach to estimate the neutral hydrogen fraction in our simulation set, which treats low-density and star-forming gas separately, and we explore two different prescriptions to subtract the contribution of molecular hydrogen from the total HI content. The HI gas in the vast majority of the systems forms extended discs although more disturbed morphologies are present. Notwithstanding the general good agreement with observed HI properties - such as radial profiles and the mass-diameter relation - the Auriga galaxies are systematically larger and more gas-rich than typical nearby galaxies. Interestingly, the amount of HI gas outside the disc plane correlates with the star formation rate, consistent with a picture where most of this extra-planar HI gas originates from a fountain-like flow. Our findings are robust with respect to the different assumptions adopted for computing the molecular hydrogen fraction and do not vary significantly over a wide range of numerical resolution. The HI modelling introduced in this paper can be used in future work to build artificial interferometric HI data cubes, allowing an even closer comparison of the gas dynamics in simulated galaxies with observations.

  18. 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.

  19. A review of ceramic bearing materials in total joint arthroplasty.

    Science.gov (United States)

    Bal, B S; Garino, J; Ries, M; Rahaman, M N

    2007-01-01

    Bearings made of ceramics have ultra-low wear properties that make them suitable for total hip arthroplasty (THA) and total knee arthroplasty (TKA). When compared to cobalt chrome (CoCr)-on-polyethylene (PE) articulations, ceramics offer drastic reductions in bearing wear rates. Lower wear rates result in fewer wear particles produced by the articulating surfaces. In theory, this should reduce the risk of periprosthetic osteolysis and premature implant loosening, thereby contributing to the longevity of total joints. In addition to ceramics, other alternative bearing couples, such as highly cross-linked PE (XLPE) and metal-on-metal also offer less wear than CoCr-on-PE articulations in total joint arthroplasty. Alumina and zirconia ceramics are familiar to orthopaedic surgeons since both materials have been used in total joints for several decades. While not new in Europe, alumina-on-alumina ceramic total hips have only recently become available for widespread use in the United States from various orthopaedic implant manufacturers. As the search for the ideal total joint bearing material continues, composite materials of existing ceramics, metal-on-ceramic articulations, and new ceramic technologies will offer more choices to the arthroplasty surgeon. The objective of this paper is to present an overview of material properties, clinical applications, evolution, and limitations of ceramic materials that are of interest to the arthroplasty surgeon.

  20. 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.

  1. Biomechanical Analysis of a Novel Prosthesis Based on the Physiological Curvature of Endplate for Cervical Disc Replacement.

    Directory of Open Access Journals (Sweden)

    Cheng-Cheng Yu

    Full Text Available Biomechanical analysis of a novel prosthesis based on the physiological curvature of endplate was performed.To compare the biomechanical differences between a novel prosthesis based on the physiological curvature of the endplate and the Prestige LP prosthesis after cervical disc replacement (CDR.Artificial disc prostheses have been widely used to preserve the physiological function of treated and adjacent motion segments in CDR, while most of those present a flat surface instead of an arcuate surface which approximately similar to anatomic structures in vivo. We first reported a well-designed artificial disc prosthesis based on the physiological curvature of the endplate.Three motion segments of 24 ovine cervical spines (C2-5 were evaluated in a robotic spine system with axial compressive loads of 50N. Testing conditions were as follows: 1 intact, 2 C3-4 CDR with artificial disc prosthesis based on the physiological curvature of the endplate, and 3 C3-4 CDR with the Prestige LP prosthesis. The range of motion (ROM and the pressures on the inferior surface of the two prostheses were recorded and analyzed.As compared to the intact state, the ROM of all three segments had no significant difference in the replacement group. Additionally, there was no significant difference in ROM between the two prostheses. The mean pressure on the novel prosthesis was significantly less than the Prestige LP prosthesis.ROM in 3 groups (intact group, CDR group with novel prosthesis and CDR group with Prestige LP showed no significant difference. The mean pressure on the inferior surface of the novel prosthesis was significantly lower than the Prestige LP prosthesis. Therefore, the novel artificial disc prosthesis is feasible and effective, and can reduce the implant-bone interface pressure on the endplate, which may be one possible reason of prosthesis subsidence.

  2. Inferior outcome after hip resurfacing arthroplasty than after conventional arthroplasty. Evidence from the Nordic Arthroplasty Register Association (NARA) database, 1995 to 2007

    DEFF Research Database (Denmark)

    Johanson, Per-Erik; Fenstad, Anne Marie; Furnes, Ove;

    2010-01-01

    The reported outcomes of hip resurfacing arthroplasty (HRA) vary. The frequency of this procedure in Denmark, Norway, and Sweden is low. We therefore determined the outcome of HRA in the NARA database, which is common to all 3 countries, and compared it to the outcome of conventional total hip...

  3. Generation of highly inclined protoplanetary discs through single stellar flybys

    CERN Document Server

    Xiang-Gruess, Meng

    2015-01-01

    We study the three-dimensional evolution of a viscous protoplanetary disc which is perturbed by a passing star on a parabolic orbit. The aim is to test whether a single stellar flyby is capable to excite significant disc inclinations which would favour the formation of so-called misaligned planets. We use smoothed particle hydrodynamics to study inclination, disc mass and angular momentum changes of the disc for passing stars with different masses. We explore different orbital configurations for the perturber's orbit to find the parameter spaces which allow significant disc inclination generation. Prograde inclined parabolic orbits are most destructive leading to significant disc mass and angular momentum loss. In the remaining disc, the final disc inclination is only below $20^\\circ$. This is due to the removal of disc particles which have experienced the strongest perturbing effects. Retrograde inclined parabolic orbits are less destructive and can generate disc inclinations up to $60^\\circ$. The final disc...

  4. 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...

  5. Trends in Artificial Intelligence.

    Science.gov (United States)

    Hayes, Patrick

    1978-01-01

    Discusses the foundations of artificial intelligence as a science and the types of answers that may be given to the question, "What is intelligence?" The paradigms of artificial intelligence and general systems theory are compared. (Author/VT)

  6. Lumbar herniated disc: spontaneous regression

    Science.gov (United States)

    Yüksel, Kasım Zafer

    2017-01-01

    Background Low back pain is a frequent condition that results in substantial disability and causes admission of patients to neurosurgery clinics. To evaluate and present the therapeutic outcomes in lumbar disc hernia (LDH) patients treated by means of a conservative approach, consisting of bed rest and medical therapy. Methods This retrospective cohort was carried out in the neurosurgery departments of hospitals in Kahramanmaraş city and 23 patients diagnosed with LDH at the levels of L3−L4, L4−L5 or L5−S1 were enrolled. Results The average age was 38.4 ± 8.0 and the chief complaint was low back pain and sciatica radiating to one or both lower extremities. Conservative treatment was administered. Neurological examination findings, durations of treatment and intervals until symptomatic recovery were recorded. Laségue tests and neurosensory examination revealed that mild neurological deficits existed in 16 of our patients. Previously, 5 patients had received physiotherapy and 7 patients had been on medical treatment. The number of patients with LDH at the level of L3−L4, L4−L5, and L5−S1 were 1, 13, and 9, respectively. All patients reported that they had benefit from medical treatment and bed rest, and radiologic improvement was observed simultaneously on MRI scans. The average duration until symptomatic recovery and/or regression of LDH symptoms was 13.6 ± 5.4 months (range: 5−22). Conclusions It should be kept in mind that lumbar disc hernias could regress with medical treatment and rest without surgery, and there should be an awareness that these patients could recover radiologically. This condition must be taken into account during decision making for surgical intervention in LDH patients devoid of indications for emergent surgery. PMID:28119770

  7. Patient-reported outcome measures in arthroplasty registries

    DEFF Research Database (Denmark)

    Rolfson, Ola; Bohm, Eric; Franklin, Patricia

    2016-01-01

    unsatisfied, dissatisfied, neutral, satisfied, or very satisfied). Survey logistics include patient instructions, paper- and electronic-based data collection, reminders for follow-up, centralized as opposed to hospital-based follow-up, sample size, patient- or joint-specific evaluation, collection intervals......The International Society of Arthroplasty Registries (ISAR) Patient-Reported Outcome Measures (PROMs) Working Group have evaluated and recommended best practices in the selection, administration, and interpretation of PROMs for hip and knee arthroplasty registries. The 2 generic PROMs in common use...... are the Short Form health surveys (SF-36 or SF-12) and EuroQol 5-dimension (EQ-5D). The Working Group recommends that registries should choose specific PROMs that have been appropriately developed with good measurement properties for arthroplasty patients. The Working Group recommend the use of a 1-item pain...

  8. 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.

  9. Radiographic and scintigraphic evaluation of total knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, R.; Soudry, M.

    1986-04-01

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

  10. Stemless shoulder arthroplasty-current results and designs.

    Science.gov (United States)

    Churchill, R Sean; Athwal, George S

    2016-03-01

    Stemless shoulder arthroplasty was originally introduced in 2004 by a single manufacturer. Now, over a decade later, numerous designs are available outside the USA, but as yet, only one implant has been cleared by the Food and Drug Administration (FDA) and is available for use within the USA. Often referred to as "canal sparing," these implants are designed for metaphyseal fixation to minimize humeral bone removal, avoid intraoperative and postoperative humeral fracture complications, and to decrease morbidity associated with revision operations. Recently, the second generation of stemless arthroplasty, a convertible implant allowing use in either anatomic or reverse arthroplasty configuration, was released for use outside the USA. This paper will review the available designs, reported results, and raise potential concerns for this emerging technology.

  11. 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.

  12. Early total hip arthroplasty for severe displaced acetabular fractures

    Institute of Scientific and Technical Information of China (English)

    YANG Shu-hua; ZHANG Yu-kun; XU Wei-hua; LI Jin; LIU Guo-hui; YANG Cao; LIU Yong; TIAN Hong-tao

    2006-01-01

    Objective : To investigate the effect of early total hip arthroplasty for severe displaced acetabular fractures.Methods: Total hip arthroplasty was performed on 17 cases of severe fracture of the acetabulum from 1997 to 2003. The mean follow-up was 2.1 years (1-6 years) and the average period from fracture to operation was 8 days (5-21 day). The average age of the patients was 53 years (26-69 years).Results: At the final follow-up the Harris hip score averaged 82(69-100) points and 15 cases have got a good outcome. There was one case of heterotopic bone formation. There were no radiographic evidences of late loosening of the prosthesis. One patient had severe central displacement of the cup.Conclusions: In patients with severe displaced acetabular fractures, particularly in elderly patients, early total hip arthroplasty is probably an alternative efficient way to achieve a painless and stable hip.

  13. 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...

  14. Stellar irradiated discs and implications on migration of embedded planets II: accreting-discs

    CERN Document Server

    Bitsch, Bertram; Lega, Elena; Crida, Aurélien

    2014-01-01

    The strength and direction of migration of embedded low mass planets depends on the disc's structure. It has been shown that, in discs with viscous heating and radiative transport, the migration can be directed outwards. In this paper we investigate the influence of a constant dM/dt-flux through the disc, as well as the influence of the disc's metallicity on the disc's thermodynamics. We focus on dM/dt discs, which have a net mass flux through them. Utilizing the resulting disc structure, we determine the regions of outward migration in the disc. We perform numerical hydrosimulations of dM/dt discs with viscous heating, radiative cooling and stellar irradiation in 2D in the r-z-plane. We use the explicit/implicit hydrodynamical code FARGOCA that includes a full tensor viscosity and stellar irradiation, as well as a two temperature solver that includes radiation transport in the flux-limited diffusion approximation. The migration of embedded planets is studied by using torque formulae. For a disc of gas surfac...

  15. Artificiality in Social Sciences

    OpenAIRE

    Rennard, Jean-Philippe

    2007-01-01

    This text provides with an introduction to the modern approach of artificiality and simulation in social sciences. It presents the relationship between complexity and artificiality, before introducing the field of artificial societies which greatly benefited from the computer power fast increase, gifting social sciences with formalization and experimentation tools previously owned by "hard" sciences alone. It shows that as "a new way of doing social sciences", artificial societies should undo...

  16. Artificial life and Piaget.

    Science.gov (United States)

    Mueller, Ulrich; Grobman, K H.

    2003-04-01

    Artificial life provides important theoretical and methodological tools for the investigation of Piaget's developmental theory. This new method uses artificial neural networks to simulate living phenomena in a computer. A recent study by Parisi and Schlesinger suggests that artificial life might reinvigorate the Piagetian framework. We contrast artificial life with traditional cognitivist approaches, discuss the role of innateness in development, and examine the relation between physiological and psychological explanations of intelligent behaviour.

  17. Stem cells sources for intervertebral disc regeneration

    Institute of Scientific and Technical Information of China (English)

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

    2016-01-01

    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.

  18. 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...

  19. The tidal disruption of protoplanetary accretion discs

    CERN Document Server

    Larwood, J D

    1997-01-01

    In this paper we revisit the problem of the tidal interaction occuring between a protostellar accretion disc and a secondary point mass following a parabolic trajectory. We model the disc response analytically and we compare our results with three-dimensional SPH simulations. Inviscid as well as viscous hydrodynamics is considered. We show that in a viscous system the response derived from inviscid considerations is predominant even for the highest estimates of an anomalous disc shear viscosity. The angular momentum lost from the disc during the encounter is derived from linear theory, for distant fly-bys, as well as the changes to the disc orientation expected in non-coplanar encounters. It is shown that the target discs can become warped and precess by a small amount during non-coplanar encounters. This small precession is shown to give rise to a relative tilt of the disc which is always more important for determining its final orientation than is the change to the orbital inclination. We discuss the implic...

  20. 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.

  1. Optically-thick accretion discs with advection

    Institute of Scientific and Technical Information of China (English)

    陈林红; 吴枚; 尚仁成

    2002-01-01

    The structures of optically-thick accretion discs with radial advection have been investigated by the iteration and integration algorithms. The advective cooling term changes mostly the inner part of disc solution, and even results in an optically-thick advection-dominated accretion flow (ADAF). Three distinct branches-the outer Shakura-Sunyaev disc (SSD), the inner ADAF and the middle transition layer-are found for a super-Eddington disc. The SSD-ADAF transition radius can be estimated as 18(M/ME)RG where RG is the Schwarzschild radius, M is the mass accretion rate and ME is the Eddington accretion rate. SSD solutions calculated with the iteration and integration methods are identical, while ADAF solutions obtained by these two methods differ greatly. Detailed algorithms and their differences have been analysed. The iteration algorithm is not self-consistent, since it implies that the dimensionless advection factor ξ is invariant, but in the inner ADAF region the variation of ξ is not negligible. The integration algorithm is always effective for the whole region of an optically-thick disc if the accretion rate is no smaller than 10-4ME. For optically-thin discs, the validity of these two algorithms is different. We suggest that the integration method be employed to calculate the global solution of a disc model without assuming ξ to be a constant. We also discuss its application to the emergent continuum spectrum in order to explain observational facts.

  2. 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 ...

  3. Structure of radiation dominated gravitoturbulent quasar discs

    CERN Document Server

    Shadmehri, Mohsen; Dib, Sami

    2016-01-01

    Self-gravitating accretion discs in a gravitoturbulent state, including radiation and gas pressures, are studied using a set of new analytical solutions. While the Toomre parameter of the disc remains close to its critical value for the onset of gravitational instability, the dimensionless stress parameter is uniquely determined from the thermal energy reservoir of the disc and its cooling rate. Our solutions are applicable to the accretion discs with dynamically important radiation pressure like in the quasars discs. We show that physical quantities of a gravitoturbulent disc in the presence of radiation are significantly modified compared to solutions with only gas pressure. We show that the dimensionless stress parameter is an increasing function of the radial distance so that its steepness strongly depends on the accretion rate. In a disc without radiation its slope is 4.5, however, we show that in the presence of radiation, it varies between 2 and 4.5 depending on the accretion rate and the central mass....

  4. Revision reverse shoulder arthroplasty in failed shoulder arthroplasties for rotator cuff deficiency

    Science.gov (United States)

    RANDELLI, PIETRO; RANDELLI, FILIPPO; COMPAGNONI, RICCARDO; CABITZA, PAOLO; RAGONE, VINCENZA; PULICI, LUCA; BANFI, GIUSEPPE

    2015-01-01

    Purpose the aim of this systematic literature review is to report clinical outcomes of reverse shoulder arthroplasty (RSA) used as a revision surgery following failure of the primary implant due to rotator cuff insufficiency. Methods a systematic review was performed using the following key words: revision, shoulder, rotator cuff deficiency, outcome assessment, treatment outcome, complications. Studies eligible for inclusion in the review were clinical trials investigating patients in whom a primary shoulder arthroplasty implant with an incompetent rotator cuff was replaced with a reverse shoulder prosthesis. Results nine articles were identified and further reviewed. The results refer to a total of 226 shoulders that were treated with RSA as revision surgery. The patients in the studies had a mean age ranging from 64 to 72 years and the longest follow-up was 3.8 years. Improvements in function and reduction of pain were shown by many studies, but the mean Constant score ranged from 44.2 to 56. High complication rates (of up to 62%) were recorded, and a mean reoperation rate of 27.5%. Conclusions RSA as revision surgery for patients with rotator cuff deficiency is a valid option, and often the only solution available, but it should be limited to elderly patients with poor function and severe pain. Level of evidence level IV, systematic review of level I–IV studies. PMID:26151037

  5. Functional Outcomes of Revision Total Knee Arthroplasty Following Failed Unicompartmental Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Chris Ironside

    2014-12-01

    Full Text Available Introduction: Unicompartmental knee arthroplasty (UKA can be used to treat medial compartment osteoarthritis of the knee. Some of these knees will eventually fail, and need to be revised. There is controversy about using UKA in younger patients as a definitive procedure or as a means to delay total knee arthroplasty (TKA because the outcomes of subsequent revision surgery may be inferior to a primary TKA. Methods: We retrospectively reviewed a series of 46 revision TKA patients following failed UKA (UKA revisions using functional outcomes questionnaires and compared the results with a cohort of age and gender matched primary TKA patients. Our hypothesis was that UKA revision surgery would be inferior to primary TKA surgery. Results: Data was collected on 33 knees after a mean follow-up period of five years. There was no significant difference in the Oxford Knee Score (33.7 vs 37.1, p = 0.09 or the Western Ontario and MacMasters Universities Arthritis Index (WOMAC (24.8 vs. 19.1, p = 0.22. A subgroup analysis demonstrated that UKAs, which fail early, are more likely to produce an inferior outcome following revision surgery than those that survive more than five years. Discussion: We conclude that UKA can be used effectively in appropriately selected patients, as the functional outcome of their subsequent revision to TKA is not significantly inferior to a primary TKA.

  6. The role of cryopreservation in the biomechanical properties of the intervertebral disc

    Directory of Open Access Journals (Sweden)

    SKL Lam

    2011-12-01

    Full Text Available Implantation of intervertebral disc (IVD allograft or tissue engineered disc constructs in the spine has emerged as an alternative to artificial disc replacement for the treatment of severe degenerative disc disease (DDD. Establishment of a bank of cryopreserved IVD allografts enables size matching and facilitates logistics for effective clinical management. However, the biomechanical properties of cryopreserved IVDs have not been previously reported. This study aimed to assess if cryopreservation with different concentrations of cryopreservant agents (CPA would affect the dynamic viscoelastic properties of the IVD. Whole porcine lumbar IVDs (n = 40 were harvested and processed using various concentrations of CPA, 0 % CPA, 10 % CPA and 20 % CPA. The discs were cryopreserved using a stepwise freezing protocol and stored in liquid nitrogen. After four weeks of storage, the cryopreserved IVDs were quickly thawed at 37 °C for dynamic viscoelastic testing. The apparent modulus, elastic modulus (G’, viscous modulus (G” and loss modulus (G”/G’ were calculated and compared to a fresh control group. Cryopreserved IVD without cryopreservants was significantly stiffer than the control. In the dynamic viscoelastic testing, cryopreservation with the use of CPA was able to preserve both G’ and G” of an IVD. No significant differences were found between fresh IVD and IVD cryopreserved with 10 % CPA or 20 % CPA. This study demonstrated that CPAs at an optimal concentration could preserve the mechanical properties of the IVD allograft and can provide further credence for the application of long-term storage of IVD allografts for disc transplantation or tissue engineered construct applications.

  7. 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.

  8. 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.

  9. Oxidized Zirconium Bearing Surfaces in Total Knee Arthroplasty: Lessons Learned.

    Science.gov (United States)

    Schüttler, Karl Friedrich; Efe, Turgay; Heyse, Thomas J; Haas, Steven B

    2015-10-01

    Polyethylene wear in total knee arthroplasty is a still unsolved problem resulting in osteolysis and long-term failure of knee joint replacement. To address the problem of polyethylene wear, research aimed for an optimal implant design and for an optimal combination of bearing surfaces. Oxidized zirconium was introduced to minimize surface wear and thus potentially increase long-term implant survival. This review comprises the current literature related to in vitro and in vivo studies evaluating performance of oxidized zirconium total knee arthroplasty and results from retrieval analyses.

  10. History and factors of survival of total hip arthroplasty.

    Science.gov (United States)

    Kolundžić, Robert; Trkulja, Vladimir; Orlić, Dubravko

    2012-02-01

    Since the 1960s total hip arthroplasty (THA) has represented one of the greatest accomplishments in orthopedic surgery. It improves the functionality, working ability and quality of life of patients with non-functional hip joint due to various reasons. This article reviews general and regional history of THA, current knowledge and concepts regarding the long-term outcomes of the procedure and emphasizes the need for establishing national (and international) THA registries as an essential way of gathering data critical for decision making in daily practice as well as in defining national healthcare policies in respect to arthroplasty procedures.

  11. Modeling and Thermal Analysis of Disc

    OpenAIRE

    Brake Praveena S; Lava Kumar M

    2014-01-01

    The disc brake is a device used for slowing or stopping the rotation of the vehicle. Number of times using the brake for vehicle leads to heat generation during braking event, such that disc brake undergoes breakage due to high Temperature. Disc brake model is done by CATIA and analysis is done by using ANSYS workbench. The main purpose of this project is to study the Thermal analysis of the Materials for the Aluminum, Grey Cast Iron, HSS M42, and HSS M2. A comparison between ...

  12. 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.

  13. A lumbar disc surgery predictive score card.

    Science.gov (United States)

    Finneson, B E

    1978-06-01

    A lumbar disc surgery predictive score card or questionnaire has been developed to assess potential candidates for excision of a herniated lumbar disc who have not previously undergone lumbar spine surgery. It is not designed to encompass patients who are being considered for other types of lumbar spine surgery, such as decompressive laminectomy or fusion. In an effort to make the "score card" usable by almost all physicians who are involved in lumbar disc surgery, only studies which have broad acceptance and are generally employed are included. Studies which have less widespread use such as electromyogram, discogram, venogram, special psychologic studies (MMPI, pain drawings) have been purposely excluded.

  14. 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

  15. 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

  16. 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.

  17. The femoral sulcus in total knee arthroplasty.

    Science.gov (United States)

    Lingaraj, Krishna; Bartlett, John

    2009-05-01

    The position of the femoral sulcus relative to the midline of the distal femoral resection in total knee arthroplasty (TKA) was studied to determine if centralized placement of the femoral component on the distal femur was justified in terms of aligning the prosthetic sulcus with the native femoral sulcus. The location of the femoral sulcus was studied in 112 consecutive patients undergoing TKA. The mean sulcus position was 0.7 mm lateral to the midline of the distal femoral resection (SD 1.4, 95% CI, 0.5-1.0 mm). However, the variation in sulcus positions ranged from 4 mm medial to 4 mm lateral to the midline. The mean sulcus position in valgus knees was 1.0 mm lateral to the midline (SD 1.8), and that in varus knees was 0.7 mm lateral to the midline (SD 1.2) (P = 0.501). It appears prudent to centre the femoral component on the native sulcus rather than the midline of the distal femoral resection, so as to ensure accurate alignment of the prosthetic sulcus with the native sulcus and to encourage normal patella tracking.

  18. Muscular strength after total hip arthroplasty

    Science.gov (United States)

    Winther, Siri B; Husby, Vigdis S; Foss, Olav A; Wik, Tina S; Svenningsen, Svein; Engdal, Monika; Haugan, Kristin; Husby, Otto S

    2016-01-01

    Background and purpose Minimizing the decrease in muscular strength after total hip arthroplasty (THA) might allow patients to recover faster. We evaluated muscular strength in patients who were operated on using 3 surgical approaches. Patients and methods In a prospective cohort study, 60 patients scheduled for primary THA were allocated to the direct lateral, posterior, or anterior approach. Leg press and abduction strength were evaluated 2 weeks or less preoperatively, 2 and 8 days postoperatively, and at 6-week and 3-month follow-up. Results Differences in maximal strength change were greatest after 2 and 8 days. The posterior and anterior approaches produced less decrease in muscular strength than the direct lateral approach. 6 weeks postoperatively, the posterior approach produced greater increase in muscular strength than the direct lateral approach, and resulted in a greater increase in abduction strength than the anterior approach. At 3-month follow-up, no statistically significant differences between the groups were found. The operated legs were 18% weaker in leg press and 15% weaker in abduction than the unoperated legs, and the results were similar between groups. Interpretation The posterior and anterior approaches appeared to have the least negative effect on abduction and leg press muscular strength in the first postoperative week; the posterior approach had the least negative effect, even up to 6 weeks postoperatively. THA patients have reduced muscle strength in the operated leg (compared to the unoperated leg) 3 months after surgery. PMID:26141371

  19. Total Knee Arthroplasty in the Combined Contracture

    Directory of Open Access Journals (Sweden)

    O.J. Voskresensky

    2009-09-01

    Full Text Available We have offered modified access to a knee to work out a method for restoration of extensive apparatus of the knee. 91 patients with degenerative damages of the knee were under out su-pervision. All patients were differentiated in groups according to the form of access and pa-thology of the knee. At all stages of studying the following method of investigation were made: goniometry — for estimation of the knee functional condition; electroneiromyography — for reveling deficiency of muscular activity and determination of its kind. Patient's satisfac-tion by operation was defined by means of WOMAC scale subjective indexes. The received digital material was subjected to statistical processing. Thus, it has been proved that applica-tion of the modified access to a knee offered by us in total knee arthroplasty in patients with combined contracture in comparison with traditionally applied technologies of extensive ap-paratus releasing allows in short terms to restore the volume and force of movements in a knee that reduces time of rehabilitation and improves quality of patient's life

  20. Can technology improve alignment during knee arthroplasty.

    Science.gov (United States)

    Thienpont, Emmanuel; Fennema, Peter; Price, Andrew

    2013-09-01

    Component malalignment remains a concern in total knee arthroplasty (TKA); therefore, a series of technologies have been developed to improve alignment. The authors conducted a systematic review to compare computer-assisted navigation with conventional instrumentation, and assess the current evidence for patient-matched instrumentation and robot-assisted implantation. An extensive search of the PubMed database for relevant meta-analyses, systematic reviews and original articles was performed, with each study scrutinised by two reviewers. Data on study characteristics and outcomes were extracted from each study and compared. In total 30 studies were included: 10 meta-analyses comparing computer-assisted navigation and conventional instrumentation, 13 studies examining patient-matched instrumentation, and seven investigating robot-assisted implantation. Computer-assisted navigation showed significant and reproducible improvements in mechanical alignment over conventional instrumentation. Patient-matched instrumentation appeared to achieve a high degree of mechanical alignment, although the majority of studies were of poor quality. The data for robot-assisted surgery was less indicative. Computer-assisted navigation improves alignment during TKA over conventional instrumentation. For patient-matched instrumentation and robot-assisted implantation, alignment benefits have not been reliably demonstrated. For all three technologies, clinical benefits cannot currently be assumed, and further studies are required. Although current technologies to improve alignment during TKA appear to result in intra-operative benefits, their clinical impact remains unclear, and surgeons should take this into account when considering their adoption.

  1. Continuous cold therapy in total knee arthroplasty.

    Science.gov (United States)

    Leutz, D W; Harris, H

    1995-01-01

    This article describes a retrospective study that assessed 52 consecutive patients who underwent total knee arthroplasty (TKA) between January 1, 1992 and September 15, 1992. Thirty-three patients underwent TKA and received cold therapy pads placed over a thin dressing in the operating room. Nineteen patients underwent TKA using an identical operative and postoperative procedure, but did not receive continuous cold therapy. Continuous cold therapy consisted of two sterile plastic pads connnected by rubber hoses containing cool water from an electric main unit that maintained a constant temperature of 42 degrees F for the immediate postoperative period. Cold therapy pads were used an average of 3 days and removed with the first dressing change. Patients who had continuous cold therapy averaged a 200 cc decrease in postoperative blood loss. There was no significant difference in the amount of narcotic use, transfusion requirements, or hospital stay between the two groups. Postoperative swelling and range of motion were not consistently recorded. Twenty-eight other variables also examined not significant. Based on these results, we cannot recommend continuous cold therapy or justify the extra expense for all patients who undergo TKA.

  2. Investigation of the coatings applied onto brake discs on disc-brake pad pair

    Directory of Open Access Journals (Sweden)

    I. Kiliçaslan

    2009-07-01

    Full Text Available While braking, according to the severity of it, thermal, metallurgical, constructive and tribological occurrences emerge on the brake disc-pad interface. In this study, NiCr was sprayed as bonding layer onto the discs, one ofwhich was coated with Al2O3-TiO2 by plasma spray and the other was coated with NiCr-Cr3C2 by High Velocity Oxygen Fuel (HVOF. In addition, the discs were tested with inertia dynamometer according to SAE’s J2522 testing procedure. The measurements showed that although the pads of the coated discs were exposed to higher braking temperatures, friction coefficient of the disc coated with NiCr- Cr3C2 was obtained 6 % higher compared to the original disc.

  3. Stellar irradiated discs and implications on migration of embedded planets I: equilibrium discs

    CERN Document Server

    Bitsch, Bertram; Morbidelli, Alessandro; Kley, Willy; Dobbs-Dixon, Ian

    2012-01-01

    The strength and direction of migration of low mass planets depends on the disc's thermodynamics. In discs where the viscous heating is balanced by radiative transport, the migration can be directed outwards, a process which extends the lifetime of growing planetary embryos. We investigate the influence of opacity and stellar irradiation on the disc thermodynamics. Utilizing the resulting disc structure, we determine the regions of outward migration. We perform two-dimensional numerical simulations of equilibrium discs with viscous heating, radiative cooling and stellar irradiation. We use the hydrodynamical code NIRVANA that includes a full tensor viscosity and stellar irradiation, as well as a two temperature solver that includes radiation transport in the flux-limited diffusion approximation. The migration is studied by using torque formulae. In the constant opacity case, we reproduce the analytical results of a black-body disc: the stellar irradiation dominates in the outer regions -- leading to flaring -...

  4. Burned-out discs stop hurting: fact or fiction?

    DEFF Research Database (Denmark)

    Bendix, Tom; Kjaer, Per; Korsholm, Lars

    2008-01-01

    ). The risk for LBP during the past year attributed to black discs was 11%. CONCLUSION: The data could not support the hypothesis that severely degenerated discs are "burned out" and become less painful. People with black discs had a higher prevalence of LBP compared to those with grey or normal discs...

  5. Prevalence of adjacent segment disc degeneration in patients undergoing anterior cervical discectomy and fusion based on pre-operative MRI findings.

    Science.gov (United States)

    Lundine, Kristopher M; Davis, Gavin; Rogers, Myron; Staples, Margaret; Quan, Gerald

    2014-01-01

    Anterior cervical discectomy and fusion (ACDF) is a widely accepted surgical treatment for symptomatic cervical spondylosis. Some patients develop symptomatic adjacent segment degeneration, occasionally requiring further treatment. The cause and prevalence of adjacent segment degeneration and disease is unclear at present. Proponents for motion preserving surgery such as disc arthroplasty argue that this technique may decrease the "strain" on adjacent discs and thus decrease the incidence of symptomatic adjacent segment degeneration. The purpose of this study was to assess the pre-operative prevalence of adjacent segment degeneration in patients undergoing ACDF. A database review of three surgeons' practice was carried out to identify patients who had undergone a one- or two-level ACDF for degenerative disc disease. Patients were excluded if they were operated on for recent trauma, had an inflammatory arthropathy (for example, rheumatoid arthritis), or had previous spine surgery. The pre-operative MRI of each patient was reviewed and graded using a standardised methodology. One hundred and six patient MRI studies were reviewed. All patients showed some evidence of intervertebral disc degeneration adjacent to the planned operative segment(s). Increased severity of disc degeneration was associated with increased age and operative level, but was not associated with sagittal alignment. Disc degeneration was more common at levels adjacent to the surgical level than at non-adjacent segments, and was more severe at the superior adjacent level compared with the inferior adjacent level. These findings support the theory that adjacent segment degeneration following ACDF is due in part to the natural history of cervical spondylosis.

  6. 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.

  7. 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.

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

    Science.gov (United States)

    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 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.

  9. 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.)

  10. CFD Analysis Of Straight Ventilated Disc Brake

    Directory of Open Access Journals (Sweden)

    Nikhil K

    2016-05-01

    Full Text Available Brakes are the key pieces of a vehicle that plays an active role in safety and performance of the system. The study of aerodynamic cooling of a disc brake in real working condition of vehicle is important in present situations. Brake discs get very hot quickly, so it should be dissipated properly through different modes of heat transfer. Contributions of these heat transfer modes are different in different type of problems. The cooling transfer rates are different in vane surface and frictional surface of a disc brake. Also the temperature varies in each small interval of braking time. So a transient problem simulation is important to study the cooling of a disc brake when a vehicle decelerates from a particular speed. ANSYS CFX tool is used for the simulation of this transient problem.

  11. Stellar Wind Erosion of Protoplanetary Discs

    CERN Document Server

    Schnepf, Neesha R; Romanova, Marina

    2014-01-01

    An analytic model is developed for the erosion of protoplanetary gas discs by high velocity magnetized stellar winds. The winds are centrifugally driven from the surface of rapidly rotating, strongly magnetized young stars. The presence of the magnetic field in the wind leads to Reynolds numbers sufficiently large to cause a strongly turbulent wind/disk boundary layer which entrains and carries away the disc gas. The model uses the conservation of mass and momentum in the turbulent boundary layer. The time-scale for significant erosion depends on the disc accretion speed, accretion rate and on the wind mass loss rate. The time-scale is estimated to be ~2E6 yr. The stellar wind erosion may act in conjunction with photo-evaporation of the discs.

  12. Magnetic Field Amplification via Protostellar Disc Dynamos

    CERN Document Server

    Dyda, Sergei; Ustyugova, Galina V; Koldoba, Alexander V; Wasserman, Ira

    2015-01-01

    We model the generation of a magnetic field in a protostellar disc using an \\alpha-dynamo and perform axisymmetric magnetohydrodynamics (MHD) simulations of a T Tauri star. We find that for small values of the dimensionless dynamo parameter $\\alpha_d$ the poloidal field grows exponentially at a rate ${\\sigma} \\propto {\\Omega}_K \\sqrt{\\alpha_d}$ , before saturating to a value $\\propto \\sqrt{\\alpha_d}$ . The dynamo excites dipole and octupole modes, but quadrupole modes are suppressed, because of the symmetries of the seed field. Initial seed fields too weak to launch MHD outflows are found to grow sufficiently to launch winds with observationally relevant mass fluxes of order $10^{-9} M_{\\odot}/\\rm{yr}$ for T Tauri stars. For large values of $\\alpha_d$ magnetic loops are generated over the entire disc. These quickly come to dominate the disc dynamics and cause the disc to break up due to the magnetic pressure.

  13. Modeling and Thermal Analysis of Disc

    Directory of Open Access Journals (Sweden)

    Brake Praveena S

    2014-10-01

    Full Text Available The disc brake is a device used for slowing or stopping the rotation of the vehicle. Number of times using the brake for vehicle leads to heat generation during braking event, such that disc brake undergoes breakage due to high Temperature. Disc brake model is done by CATIA and analysis is done by using ANSYS workbench. The main purpose of this project is to study the Thermal analysis of the Materials for the Aluminum, Grey Cast Iron, HSS M42, and HSS M2. A comparison between the four materials for the Thermal values and material properties obtained from the Thermal analysis low thermal gradient material is preferred. Hence best suitable design, low thermal gradient material Grey cast iron is preferred for the Disc Brakes for better performance.

  14. Clumps and Axisymmetric Features in Debris Discs

    CERN Document Server

    Jiang, Ing-Guey

    2013-01-01

    This paper studied the structures of debris discs, focusing on the conditions that can form an axisymmetric-looking outer disc from systems with inner clumps. The main conclusion was that as long as the dominated dust grains are smaller than the blowout size, it is easy to form an axisymmetric-looking outer debris disc, which is part of a quasi-steady state of the whole system. This quasi-steady state is established through the balance between grain generations and a continuous out-going grain flow. Assuming there is an event that starts planetesimal collisions and the corresponding grain generations, this balance can be approached in a few thousand years. This result suggested that a quasi-steady-state picture could solve the possible mass budget problem of Vega's outer debris disc.

  15. Spiral shocks and accretion in discs

    Energy Technology Data Exchange (ETDEWEB)

    Spruit, H.C.; Matsuda, T.; Inoue, M.; Sawada, K.

    1987-12-01

    Recent numerical and analytical results on disc-like accretion with shock waves as the only dissipation mechanism are compared. The global properties of the process are similar to those of the viscous (..cap alpha..) disc model, but precise values of the effective ..cap alpha.. value as a function of the accretion rate can be calculated. At low values of the ratio of specific heats (..gamma.. < 1.45) accretion is possible without radiative losses. Such adiabatic accretion can occur in practice at high accretion rates on to low mass objects and may be important in the formation of planets. Following previous authors, it is pointed out that non-axisymmetric perturbations in the outer parts of a disc increase in amplitude as they propagate in and cause spiral shocks more easily in a disc than perturbations originating in the inner parts.

  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. Genetics Home Reference: intervertebral disc disease

    Science.gov (United States)

    ... Ikegawa S. The genetics of common degenerative skeletal disorders: osteoarthritis and degenerative disc disease. Annu Rev Genomics Hum ... article on PubMed Central Reviewed : October 2016 Published : March 21, 2017 The resources on this site should ...

  18. [Disc electrophoresis of collagen protein (author's transl)].

    Science.gov (United States)

    Reitmayr, P; Verzár, F

    1975-01-01

    The composition of proteins extracted from tendon collagen is investigated by disc electrophoresis. No qualitative differences can be demonstrated between young and old collagen. The action of formaldehyde and methionine on the tendons has no effect on the electrophoretic picture.

  19. Hybrid Surgery Versus Anterior Cervical Discectomy and Fusion in Multilevel Cervical Disc Diseases: A Meta-Analysis.

    Science.gov (United States)

    Zhang, Jianfeng; Meng, Fanxin; Ding, Yan; Li, Jie; Han, Jian; Zhang, Xintao; Dong, Wei

    2016-05-01

    To investigate the outcomes and reliability of hybrid surgery (HS) versus anterior cervical discectomy and fusion (ACDF) for the treatment of multilevel cervical spondylosis and disc diseases.Hybrid surgery, combining cervical disc arthroplasty (CDA) with fusion, is a novel treatment to multilevel cervical degenerated disc disease in recent years. However, the effect and reliability of HS are still unclear compared with ACDF.To investigate the studies of HS versus ACDF in patients with multilevel cervical disease, electronic databases (Medline, Embase, Pubmed, Cochrane library, and Cochrane Central Register of Controlled Trials) were searched. Studies were included when they compared HS with ACDF and reported at least one of the following outcomes: functionality, neck pain, arm pain, cervical range of motion (ROM), quality of life, and incidence of complications. No language restrictions were used. Two authors independently assessed the methodological quality of included studies and extracted the relevant data.Seven clinical controlled trials were included in this study. Two trials were prospective and the other 5 were retrospective. The results of the meta-analysis indicated that HS achieved better recovery of NDI score (P = 0.038) and similar recovery of VAS score (P = 0.058) compared with ACDF at 2 years follow-up. Moreover, the total cervical ROM (C2-C7) after HS was preserved significantly more than the cervical ROM after ACDF (P = 0.000) at 2 years follow-up. Notably, the compensatory increase of the ROM of superior and inferior adjacent segments was significant in ACDF groups at 2-year follow-up (P multilevel cervical spondylosis to preserve cervical ROM and reduce the risk of adjacent disc degeneration. Nonetheless, more well-designed studies with large groups of patients are required to provide further evidence for the benefit and reliability of HS for the treatment of cervical disk diseases.

  20. The Annulus Property of Simple Holomorphic Discs

    CERN Document Server

    Zehmisch, Kai

    2010-01-01

    We show that any simple holomorphic disc admits the annulus property, i.e., each interior point is surrounded by an arbitrary small annulus consisting entirely of injective points. As an application we show that interior singularities of holomorphic discs can be resolved after slight perturbation of the involved almost complex structure. Moreover, for boundary points the analogue notion, the half-annulus property, is introduced and studied in detail.

  1. The annulus property of simple holomorphic discs

    OpenAIRE

    Zehmisch, Kai

    2013-01-01

    We show that any simple holomorphic disc admits the annulus property, i.e., each interior point is surrounded by an arbitrary small annulus consisting entirely of injective points. As an application we show that interior singularities of holomorphic discs can be resolved after slight perturbation of the almost complex structure. Moreover, for boundary points the analogue notion, the half-annulus property, is introduced and studied in detail.

  2. Massive thin accretion discs. Pt. 2; Polarization

    Energy Technology Data Exchange (ETDEWEB)

    Laor, A.; Netzer, H. (Tel Aviv Univ. (Israel)); Piran, T. (Hebrew Univ., Jerusalem (Israel). Racah Inst. of Physics)

    1990-02-15

    Thin accretion discs around massive black holes are believed to produce much of the observed optical-UV emission from AGN. Classical calculations predict that this radiation is highly polarized at large inclination angles, in contrast to observations of quasars and Seyfert galaxies. We have calculated the spectrum and polarization of such discs using an improved radiative transfer method with all the relevant opacity sources, and a full general relativistic treatment of the radiation propagation. (author).

  3. Lyman edges in AGN accretion discs

    Energy Technology Data Exchange (ETDEWEB)

    Czerny, B. (Copernicus Astronomical Center, Warsaw (Poland)); Pojmanski, G. (Warsaw Univ. (Poland). Obserwatorium Astronomiczne)

    1990-07-01

    We show that the basic difference in the two principal approaches to predictions of the Lyman edge in an accretion disc lies in the implicit assumption about the density of the radiating gas. Independent from the details, models predict a broad range of the edge sizes, both in absorption and in emission. Observed spectra do not exhibit any strong feature at 912 A but may still be consistent with an accretion disc mechanism if more advanced theory is developed. (author).

  4. Gene expression profile analysis of human intervertebral disc degeneration

    OpenAIRE

    Kai Chen; Dajiang Wu; Xiaodong Zhu; Haijian Ni; Xianzhao Wei; Ningfang Mao; Yang Xie; Yunfei Niu; Ming Li

    2013-01-01

    In this study, we used microarray analysis to investigate the biogenesis and progression of intervertebral disc degeneration. The gene expression profiles of 37 disc tissue samples obtained from patients with herniated discs and degenerative disc disease collected by the National Cancer Institute Cooperative Tissue Network were analyzed. Differentially expressed genes between more and less degenerated discs were identified by significant analysis of microarray. A total of 555 genes were signi...

  5. 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.

  6. Turbulent drag reduction through oscillating discs

    CERN Document Server

    Wise, Daniel J

    2014-01-01

    The changes of a turbulent channel flow subjected to oscillations of wall flush-mounted rigid discs are studied by means of direct numerical simulations. The Reynolds number is $R_\\tau$=$180$, based on the friction velocity of the stationary-wall case and the half channel height. The primary effect of the wall forcing is the sustained reduction of wall-shear stress, which reaches a maximum of 20%. A parametric study on the disc diameter, maximum tip velocity, and oscillation period is presented, with the aim to identify the optimal parameters which guarantee maximum drag reduction and maximum net energy saving, computed by taking into account the power spent to actuate the discs. This may be positive and reaches 6%. The Rosenblat viscous pump flow is used to predict the power spent for disc motion in the turbulent channel flow and to estimate localized and transient regions over the disc surface subjected to the turbulent regenerative braking effect, for which the wall turbulence exerts work on the discs. The...

  7. 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...

  8. The maximum rotation of a galactic disc

    CERN Document Server

    Bottema, R

    1997-01-01

    The observed stellar velocity dispersions of galactic discs show that the maximum rotation of a disc is on average 63% of the observed maximum rotation. This criterion can, however, not be applied to small or low surface brightness (LSB) galaxies because such systems show, in general, a continuously rising rotation curve until the outermost measured radial position. That is why a general relation has been derived, giving the maximum rotation for a disc depending on the luminosity, surface brightness, and colour of the disc. As a physical basis of this relation serves an adopted fixed mass-to-light ratio as a function of colour. That functionality is consistent with results from population synthesis models and its absolute value is determined from the observed stellar velocity dispersions. The derived maximum disc rotation is compared with a number of observed maximum rotations, clearly demonstrating the need for appreciable amounts of dark matter in the disc region and even more so for LSB galaxies. Matters h...

  9. Radio Monitoring of Protoplanetary Discs

    Science.gov (United States)

    Ubach, C.; Maddison, S. T.; Wright, C. M.; Wilner, D. J.; Lommen, D. J. P.; Koribalski, B.

    2017-01-01

    Protoplanetary disc systems observed at radio wavelengths often show excess emission above that expected from a simple extrapolation of thermal dust emission observed at short millimetre wavelengths. Monitoring the emission at radio wavelengths can be used to help disentangle the physical mechanisms responsible for this excess, including free-free emission from a wind or jet, and chromospheric emission associated with stellar activity. We present new results from a radio monitoring survey conducted with Australia Telescope Compact Array over the course of several years with observation intervals spanning days, months and years, where the flux variability of 11 T Tauri stars in the Chamaeleon and Lupus star forming regions was measured at 7 and 15 mm and 3 and 6 cm. Results show that for most sources are variable to some degree at 7 mm, indicating the presence of emission mechanisms other than thermal dust in some sources. Additionally, evidence of grain growth to cm-sized pebbles was found for some sources that also have signs of variable flux at 7 mm. We conclude that multiple processes contributing to the emission are common in T Tauri stars at 7 mm and beyond, and that a detection at a single epoch at radio wavelengths should not be used to determine all processes contributing to the emission.

  10. Clumpy Disc and Bulge Formation

    CERN Document Server

    Perez, J; Tissera, P; Michel-Dansac, L

    2013-01-01

    We present a set of hydrodynamical/Nbody controlled simulations of isolated gas rich galaxies that self-consistently include SN feedback and a detailed chemical evolution model, both tested in cosmological simulations. The initial conditions are motivated by the observed star forming galaxies at z ~ 2-3. We find that the presence of a multiphase interstellar media in our models promotes the growth of disc instability favouring the formation of clumps which in general, are not easily disrupted on timescales compared to the migration time. We show that stellar clumps migrate towards the central region and contribute to form a classical-like bulge with a Sersic index, n > 2. Our physically-motivated Supernova feedback has a mild influence on clump survival and evolution, partially limiting the mass growth of clumps as the energy released per Supernova event is increased, with the consequent flattening of the bulge profile. This regulation does not prevent the building of a classical-like bulge even for the most ...

  11. 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 may...

  12. Total knee arthroplasty after high tibial osteotomy. A systematic review

    NARCIS (Netherlands)

    T.M. van Raaij (Tom); M. Reijman (Max); A. Furlan (Alessandro); J.A.N. Verhaar (Jan)

    2009-01-01

    textabstractBackground: Previous osteotomy may compromise subsequent knee replacement, but no guidelines considering knee arthroplasty after prior osteotomy have been developed. We describe a systematic review of non-randomized studies to analyze the effect of high tibial osteotomy on total knee art

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

    DEFF Research Database (Denmark)

    Münch, Henrik J; Jakobsen, Stig Storgaard; Olesen, Jens T;

    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 ...

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

    NARCIS (Netherlands)

    Koeter, S.; Jackson, R.W.

    2006-01-01

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

  15. Gluteal tendon reconstruction in association with hip arthroplasty.

    Science.gov (United States)

    Bajwa, Ali S; Campbell, David G; Comely, Andrew S; Lewis, Peter L

    2011-01-01

    We studied a prospective cohort of patients in whom gluteal tendon reconstruction was undertaken in association with hip arthroplasty. Over the course of 10 years, 24 patients had gluteal tendon reconstruction performed either at the time of hip arthroplasty or post-operatively, using the Ligament Augment and Reconstruction System (LARS), suture anchors, direct suture to bone, or a combination of these techniques. All patients were assessed clinically and by patient-centred outcome measures, including the hip disability and osteoarthritis score (HOOS). The mean post-operative HOOS was significantly better than pre-operative score (p pain, activities of daily living (ADL), sports and quality of life (QoL) was 72 (SD 12.8), 73 (SD 15.9), 71 (SD 11.8), 54 (SD 22.6) and 57 (SD 21.76) respectively. There were two failures of gluteal tendon reconstruction which required revision using LARS. One patient died of an unrelated cause. Surgical intervention should be considered in gluteal tendinopathy at the time of hip arthroplasty or when symptoms occur following arthroplasty.

  16. 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.

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

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Jakobsen, Stig Storgaard; Engkilde, Kåre;

    2009-01-01

    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 detailed information on 90,697 operations. The Gentofte patch-test database contained test results...

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

    DEFF Research Database (Denmark)

    Boeckstyns, Michel E H; Toxværd, Anders; Bansal, Manjula;

    2014-01-01

    PURPOSE: To determine whether the amount of polyethylene debris in the interphase tissue between prosthesis and bone in patients with total wrist arthroplasty correlated with the degree of periprosthetic osteolysis (PPO); and to investigate the occurrence of metal particles in the periprosthetic...

  19. Nationwide trends in total shoulder arthroplasty and hemiarthroplasty for osteoarthritis.

    Science.gov (United States)

    Trofa, David; Rajaee, Sean S; Smith, Eric L

    2014-04-01

    Recent literature reports an increase in the rate of shoulder arthroplasties, particularly total shoulder arthroplasties (TSAs), being performed in the United States. However, the national epidemiology of use of hemiarthroplasty (HA) and TSA as treatments for glenohumeral osteoarthritis has not been elucidated. We conducted a study to analyze trends in using HA and TSA as treatments for glenohumeral osteoarthritis from 2000 to 2010, and to compare patient characteristics and inpatient complications. US Nationwide Inpatient Sample patients with a primary inpatient diagnosis of shoulder arthritis and a principal procedure of HA or TSA were identified using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedural codes. From 2000 to 2010 the nationally adjusted population rate of shoulder arthroplasty performed for osteoarthritis increased 3.7-fold. Specifically, the population rate of TSA increased 5.0-fold, and that of HA increased 1.9-fold. In 2010, 80.3% of patients having shoulder arthroplasty for arthritis underwent TSA. TSA patients were older (P < .0001) and had a higher mean number of chronic illnesses (P = .034). TSA-associated discharges had a higher rate of surgical and medical care complications (P = .011) and blood transfusions (P = .041) after adjusting for comorbidities.

  20. Criteria used when deciding on eligibility for total knee arthroplasty

    DEFF Research Database (Denmark)

    Skou, Søren Thorgaard; Ross, Ewa M.; Laursen, Mogens Berg;

    2016-01-01

    BACKGROUND: Clinical decision-making in total knee arthroplasty (TKA) is a complex process needing further clarification. The aim of this study was to compare TKA eligibility criteria considered most important by orthopedic surgeons (OSs) to characteristics of patients with knee osteoarthritis (OA...

  1. Fast-track knee arthroplasty – status and future challenges

    DEFF Research Database (Denmark)

    Kehlet, Henrik; Thienpont, Emmanuel

    2013-01-01

    Fast-track programs have been developed for different surgical procedures leading to higher patient satisfaction and lower morbidity. This concept has been extended to knee arthroplasty in recent years. The purpose of this narrative review was to discuss the different aspects of fast-track knee a...

  2. 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

  3. Navigation improves accuracy of rotational alignment in total knee arthroplasty.

    Science.gov (United States)

    Stöckl, Bernd; Nogler, Michael; Rosiek, Rafal; Fischer, Martin; Krismer, Martin; Kessler, Oliver

    2004-09-01

    Successful total knee arthroplasty is dependent on the correct alignment of implanted prostheses. Major clinical problems can be related to poor femoral component positioning, including sagittal plane and rotational malalignment. A prospective randomized study was designed to test whether an optical navigation system for total knee arthroplasty achieved greater implantation precision than a nonnavigated technique. The primary variable was rotation of the femoral component in the transverse plane, measured from postoperative radiographs and computed tomography images. Sixty-four patients were included in the study. All patients received the Duracon total knee prosthesis. The patients were randomly divided into two groups: Group C patients had conventional total knee arthroplasty without navigation; Group N patients had total knee arthroplasty using a computer-assisted knee navigation system. Analysis showed that patients in Group N had significantly better rotational alignment and flexion angle of the femoral component than patients in Group C. In addition, superior postoperative alignment of the mechanical axis, posterior tibial slope, and rotational alignment was achieved for patients in Group N. The use of a navigation system provides improved alignment accuracy, and can help to avoid femoral malrotation and errors in axial alignment.

  4. Alpine Skiing With total knee ArthroPlasty (ASWAP)

    DEFF Research Database (Denmark)

    Kristensen, M.; Pötzelsberger, B.; Scheiber, P.;

    2015-01-01

    We investigated the effect of alpine skiing for 12 weeks on skeletal muscle characteristics and biomarkers of glucose homeostasis and cardiovascular risk factors. Twenty-three patients with a total knee arthroplasty (TKA) were studied 2.9 ± 0.9 years (mean ± SD) after the operation. Fourteen...

  5. Alpine Skiing With total knee ArthroPlasty (ASWAP)

    DEFF Research Database (Denmark)

    Koesters, A.; Poetzelsberger, B.; Dela, F.

    2015-01-01

    The aim of this study was to monitor the long-term effects of skiing on health-related parameters and implant related factors like loosening and wear in patients with total knee arthroplasty. This paper describes the overall study design, general demographics, and physiological demand of the inte...

  6. 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

  7. The role of disc self-gravity in circumbinary planet systems - I. Disc structure and evolution

    Science.gov (United States)

    Mutter, Matthew M.; Pierens, Arnaud; Nelson, Richard P.

    2017-03-01

    We present the results of two-dimensional hydrodynamic simulations of self-gravitating circumbinary discs around binaries whose parameters match those of the circumbinary planet-hosting systems Kepler-16, Kepler-34 and Kepler-35. Previous work has shown that non-self-gravitating discs in these systems form an eccentric precessing inner cavity due to tidal truncation by the binary, and planets which form at large radii migrate until stalling at this cavity. Whilst this scenario appears to provide a natural explanation for the observed orbital locations of the circumbinary planets, previous simulations have failed to match the observed planet orbital parameters. The aim of this work is to examine the role of self-gravity in modifying circumbinary disc structure as a function of disc mass, prior to considering the evolution of embedded circumbinary planets. In agreement with previous work, we find that for disc masses between one and five times the minimum mass solar nebula (MMSN), disc self-gravity affects modest changes in the structure and evolution of circumbinary discs. Increasing the disc mass to 10 or 20 MMSN leads to two dramatic changes in disc structure. First, the scale of the inner cavity shrinks substantially, bringing its outer edge closer to the binary. Secondly, in addition to the eccentric inner cavity, additional precessing eccentric ring-like features develop in the outer regions of the discs. If planet formation starts early in the disc lifetime, these changes will have a significant impact on the formation and evolution of planets and precursor material.

  8. Dynamic, six-axis stiffness matrix characteristics of the intact intervertebral disc and a disc replacement.

    Science.gov (United States)

    Holsgrove, Timothy P; Gill, Harinderjit S; Miles, Anthony W; Gheduzzi, Sabina

    2015-11-01

    Thorough pre-testing is critical in assessing the likely in vivo performance of spinal devices prior to clinical use. However, there is a lack of data available concerning the dynamic testing of lumbar (porcine model) total disc replacements in all six axes under preload conditions. The aim of this study was to provide new data comparing porcine lumbar spinal specimen stiffness between the intact state and after the implantation of an unconstrained total disc replacement, in 6 degrees of freedom. The dynamic, stiffness matrix testing of six porcine lumbar isolated disc specimens was completed using triangle waves at a test frequency of 0.1 Hz. An axial preload of 500 N was applied during all testing. Specimens were tested both in the intact condition and after the implantation of the total disc replacement. Sixteen key stiffness terms were identified for the comparison of the intact and total disc replacement specimens, comprising the 6 principal stiffness terms and 10 key off-axis stiffness terms. The total disc replacement specimens were significantly different to the intact specimens in 12 of these key terms including all six principal stiffness terms. The implantation of the total disc replacement resulted in a mean reduction in the principal stiffness terms of 100%, 91%, and 98% in lateral bending, flexion-extension, and axial rotation, respectively. The novel findings of this study have demonstrated that the unconstrained, low-friction total disc replacement does not replicate the stiffness of the intact specimens. It is likely that other low-friction total disc replacements would produce similar results due to stiffness being actively minimised as part of the design of low-friction devices, without the introduction of stiffening elements or mechanisms to more accurately replicate the mechanical properties of the natural intervertebral disc. This study has demonstrated, for the first time, a method for the quantitative comparative mechanical function

  9. CUSTOMIZED ACETABULAR COMPONENTS IN REVISION HIP ARTHROPLASTY

    Directory of Open Access Journals (Sweden)

    G. M. Kavalersky

    2016-01-01

    Full Text Available In recent years, there is a trend of increasing demand for revision hip arthroplasty. Among these patients there are many with complex acetabular defects, including patients with pelvic discontinuity. To ensure stability for revised acetabular components in such cases becomes a challenging or unachievable task. Such defects give indications for printing customized tri-flange acetabular component. The authors analysed own experience of creating and applying custom made acetabular components in 3 patients with complex acetabular defects. Material and methods. Among the patients there were 2 women and 1 man. Average age was 60,3±19,4 years (38 to 78 years. Two patients had III B defects with pelvic discontinuity and one patient had III A defect by Paprosky classification. As the first step, the authors in collaboration with engineers printed a plaster full size pelvic 3D model, as the second step a customized tri-flange acetabular component was designed and printed. Harris Hip Score was evaluated preoperatively and 3 months postoperatively. Results. Average follow-up period was 5,3±2,5 months (3 to 8 months. The authors observed no cases of implant loosening, dislocation or deep periprosthetic infection. Average Harris Hip Score before surgery was 27,13 and after surgery – 74,1 indicating a significant improvement in 3 months postoperatively. Conclusion. Indications for use of individual acetabular components in reported patients correspond to indications formulated by Berasi et al. The authors obtained encouraging early follow-up outcomes that correspond to data of other authors. In one patient certain difficulties were reported due to insufficient pelvic distraction. Component’s flanges prevented achieving adequate pelvic distraction. Nevertheless, good primary stability was achieved. Modern software and 3D metal printers can significantly reduce the production cost of customized acetabular components. Application of this technology can be

  10. Salvage arthrodesis for failed total ankle arthroplasty

    Science.gov (United States)

    Zürcher, Arthur W

    2010-01-01

    Background and purpose Total ankle arthroplasty (TAA) has gained popularity in recent years. If it fails, however, salvage arthrodesis must be reliable as a rescue procedure. We therefore investigated the clinical, radiographic, and subjective outcome after salvage arthrodesis in a consecutive group of patients, and concentrated on the influence of the method of fixation on union rate and on salvage in inflammatory joint disease. Patients and methods Between 1994 and 2005, salvage arthrodesis was performed on 18 ankles (18 patients). Diagnosis was inflammatory joint disease (IJD) in 15 cases and osteoarthritis (OA) in 3. Tibio-talar fusion was performed in 7 ankles, and tibio-talocalcaneal fusion in 11. Serial radiographs were studied for time to union. Clinical outcome at latest follow-up was measured by the AOFAS score, the foot function index (FFI) and by VAS scores for pain, function, and satisfaction. Results Blade plates were used in 7 ankles (4 IJD, 3 OA); all united. Nonunion developed in 7 of the 11 rheumatic ankles stabilized by other methods. 11 patients (8 fused ankles, 3 nonunions) were available for clinical evaluation. Their mean AOFAS score was 62 and mean overall FFI was 70. VAS score for pain was 20, for function 64, and for satisfaction 74. The scores were similar in united and non-united ankles. Interpretation Blade plate fixation is successful in salvage arthrodesis for failed TAA. A high nonunion rate was found after salvage ankle arthrodesis in IJD with other methods of fixation. Clinical results were fair to good. PMID:20175648

  11. Periacetabular bone mineral density changes after resurfacing hip arthroplasty versus conventional total hip arthroplasty. A randomized controlled DEXA study

    NARCIS (Netherlands)

    Smolders, J.M.; Pakvis, D.F.M.; Hendrickx, B.W.; Verdonschot, N.J.; Susante, J.L.C. van

    2013-01-01

    A randomized controlled trial was performed to evaluate acetabular bone mineral density (BMD) changes after hip resurfacing (RHA) versus an established conventional total hip arthroplasty (THA). A total of 71 patients were allocated randomly to receive either an RHA press-fit cobalt-chromium cup (n=

  12. Periacetabular Bone Mineral Density Changes After Resurfacing Hip Arthroplasty Versus Conventional Total Hip Arthroplasty. A Randomized Controlled DEXA Study

    NARCIS (Netherlands)

    Smolders, J.M.H.; Pakvis, D.F.; Hendrickx, B.W.; Verdonschot, N.J.J.; Susante, van J.L.C.

    2013-01-01

    A randomized controlled trial was performed to evaluate acetabular bone mineral density (BMD) changes after hip resurfacing (RHA) versus an established conventional total hip arthroplasty (THA). A total of 71 patients were allocated randomly to receive either an RHA press-fit cobalt–chromium cup (n

  13. Long-term results of patellofemoral arthroplasty - A report of 56 arthroplasties with 17 years of follow-up

    NARCIS (Netherlands)

    Kooijman, HJ; Driessen, APPM; van Horn, [No Value

    2003-01-01

    We studied retrospectively the outcome of patellofemoral arthroplasty (PFA) using the Richards prosthesis in 51 patients (56 knees). Their mean age was 50 years (30 to 77). In 43 patients (45 knees), the American Knee Society score and the patients' subjective judgement were assessed. Excellent or g

  14. Difference in clinical outcome between total shoulder arthroplasty and reverse shoulder arthroplasty used in hemiarthroplasty revision surgery

    NARCIS (Netherlands)

    Hartel, B.P.; Alta, T.D.; Sewnath, M.E.; Willems, W.J.H.

    2015-01-01

    INTRODUCTION: The increase of shoulder replacements will lead to a higher revision rate of shoulder arthroplasties. The aim of this study is to evaluate the clinical results of revision surgery performed in our hospital, distinguish the differences in clinical outcome according to revision indicatio

  15. Artificial cognition architectures

    CERN Document Server

    Crowder, James A; Friess, Shelli A

    2013-01-01

    The goal of this book is to establish the foundation, principles, theory, and concepts that are the backbone of real, autonomous Artificial Intelligence. Presented here are some basic human intelligence concepts framed for Artificial Intelligence systems. These include concepts like Metacognition and Metamemory, along with architectural constructs for Artificial Intelligence versions of human brain functions like the prefrontal cortex. Also presented are possible hardware and software architectures that lend themselves to learning, reasoning, and self-evolution

  16. A Simulation Model of Focus and Radial Servos in Compact Disc Players with Disc Surface Defects

    DEFF Research Database (Denmark)

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

    2004-01-01

    Compact Disc players have been on the market in more than two decades.As a consequence most of the control servo problems have been solved. A large remaining problem to solve is the handling of Compact Discs with severe surface defects like scratches and fingerprints. This paper introduces a method...

  17. Evolution from protoplanetary to debris discs: The transition disc around HD 166191

    CERN Document Server

    Kennedy, G M; Lisse, C M; Ménard, F; Sitko, M L; Wyatt, M C; Bayliss, D D R; DeMeo, F E; Crawford, K B; Kim, D L; Rudy, R J; Russell, R W; Sibthorpe, B; Skinner, M A; Zhou, G

    2013-01-01

    HD 166191 has been identified by several studies as hosting a rare and extremely bright warm debris disc with an additional outer cool disc component. However, an alternative interpretation is that the star hosts a disc that is currently in transition between a full gas disc and a largely gas-free debris disc. With the help of new optical to mid-IR spectra and Herschel imaging, we argue that the latter interpretation is supported in several ways: i) we show that HD 166191 is co-moving with the ~4 Myr-old Herbig Ae star HD 163296, suggesting that the two have the same age, ii) the disc spectrum of HD 166191 is well matched by a standard radiative transfer model of a gaseous protoplanetary disc with an inner hole, and iii) the HD 166191 mid-IR silicate feature is more consistent with similarly primordial objects. We note some potential issues with the debris disc interpretation that should be considered for such extreme objects, whose lifetime at the current brightness is mush shorter than the stellar age, or i...

  18. Hip arthroplasty in patients with complex femoral deformity after surgical treatment of dysplasia

    OpenAIRE

    V. V. Bliznyukov; R. M. Tikhilov; I. I. Shubnyakov; A. O. Denisov; V. A. Shilnikov; A. Z. Chernyi; S. S. Bilyk

    2014-01-01

    Objective - based on the analysis of remote results of total hip arthroplasty in patients with complex deformities of the femur to compare the effectiveness of operations with standard cases and identify the factors that determine the surgery effectiveness. Material and methods. in Vreden clinic 73 patients with complex deformities of the femur underwent surgical treatment between 2001 and 2013 by various surgical interventions: arthroplasty without femoral osteotomy (23); arthroplasty accomp...

  19. Malnutrition in Joint Arthroplasty: Prospective Study Indicates Risk of Unplanned ICU Admission

    OpenAIRE

    2016-01-01

    Background: Malnutrition has been linked to poor outcomes after elective joint arthroplasty, but the risk of unplanned postoperative intensive care unit (ICU) admission in malnourished arthroplasty patients is unknown. Methods: 1098 patients were followed as part of a prospective risk stratification program at a tertiary, high-volume arthroplasty center. Chronic malnutrition was defined as preoperative albumin Results: The overall incidence of malnutrition was 16.9% (primary and revision arth...

  20. Shoulder arthroplasty in osteoarthritis: current concepts in biomechanics and surgical technique

    OpenAIRE

    MEROLLA, GIOVANNI; Nastrucci, Guglielmo; Porcellini, Giuseppe

    2013-01-01

    Shoulder arthroplasty is a technically demanding procedure to restore shoulder function in patients with severe osteoarthritis of the glenohumeral joint. The modern prosthetic system exploit the benefits of modularity and the availibility of additional sizes of the prosthetic components. In this paper we describe the biomechanics of shoulder arthroplasty and the technique for shoulder replacement including total shoulder arthroplasty (TSA) with all-polyethylene and metal-backed glenoid compon...

  1. Imaging evaluation of complications of hip arthroplasty: review of current concepts and imaging findings.

    Science.gov (United States)

    Awan, Omer; Chen, Lina; Resnik, Charles S

    2013-11-01

    Total hip arthroplasty has evolved along with improvements in component materials and design. The radiologist must accurately diagnose associated complications with imaging methods and stay informed about newer complications associated with innovations in surgical technique, prosthetic design, and novel materials. This pictorial essay presents clinical and imaging correlation of modern hip arthroplasty complications, with an emphasis on the most common complications of instability, aseptic loosening, and infection as well as those complications associated with contemporary metal-on-metal arthroplasty.

  2. Stem cell horizons in intervertebral disc degeneration

    Directory of Open Access Journals (Sweden)

    Joseph Ciacci

    2009-01-01

    Full Text Available Joseph Ciacci1, Allen Ho1,2, Christopher P Ames3, Rahul Jandial41Division of Neurosurgery, University of California, San Diego, La Jolla, California, USA; 2Del E Webb Neurosciences, Aging and Stem Cell Research Center, The Burnham Institute for Medical Research, La Jolla, California, USA; 3Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA; 4Division of Neurosurgery, Department of Surgery, City of Hope Cancer Center, Duarte, CA, USAAbstract: Intervertebral disc degeneration remains a pervasive and intractable disease arising from a combination of aging and stress on the back and spine. The growing field of regenerative medicine brings the promise of stem cells in the treatment of disc disease. Scientists and physicians hope to employ stem cells not only to stop, but also reverse degeneration. However, there are many important outstanding issues, including the hostile avascular, apoptotic physiological environment of the intervertebral disc, and the difficulty of obtaining mesenchymal stem cells, and directing them towards chondrocytic differentiation and integration within the nucleus pulposus of the disc. Given the recent advances in minimally invasive spine surgery, and developing body of work on stem cell manipulation and transplantation, stem cells are uniquely poised to bring about large-scale improvements in treatment and outcomes for degenerative disc disease. In this review we will first discuss the cellular and molecular factors influencing degeneration, and then examine the efficacy and difficulties of stem cell transplantation.Keywords: intervertebral disc degeneration, stem cells, disc disease, mesenchymal stem cells, stem cell transplantation

  3. Cervical disc hernia operations through posterior laminoforaminotomy

    Directory of Open Access Journals (Sweden)

    Coskun Yolas

    2016-01-01

    Full Text Available 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 diagnosed with posterolateral cervical disc herniation and cervical spondylosis with foraminal stenosis causing radiculopathy operated by the posterior cervical keyhole laminoforaminotomy between the years 2010 and 2015. Results: The file records and the radiographic images of the 35 patients were assessed retrospectively. The mean age was 46.4 years (range: 34-66 years. Of the patients, 19 were males and 16 were females. In all of the patients, the neurologic deficit observed was radiculopathy. The posterolaterally localized disc herniations and the osteophytic structures were on the left side in 18 cases and on the right in 17 cases. In 10 of the patients, the disc level was at C5-6, in 18 at C6-7, in 2 at C3-4, in 2 at C4-5, in 1 at C7-T1, in 1 patient at both C5-6 and C6-7, and in 1 at both C4-5 and C5-6. In 14 of these 35 patients, both osteophytic structures and protruded disc herniation were present. Intervertebral foramen stenosis was present in all of the patients with osteophytes. Postoperatively, in 31 patients the complaints were relieved completely and four patients had complaints of neck pain and paresthesia radiating to the arm (the success of operation was 88.5%. On control examinations, there was no finding of instability or cervical kyphosis. Conclusion: Posterior cervical laminoforaminotomy is an alternative appropriate choice in both cervical soft disc herniations and cervical stenosis.

  4. Pre-operative ambulatory measurement of asymmetric leg loading during sit to stand in hip arthroplasty patients

    NARCIS (Netherlands)

    Martínez-Ramírez, Alicia; Weenk, Dirk; Lecumberri, Pablo; Verdonschot, Nico; Pakvis, Dean; Veltink, Peter H.

    2013-01-01

    Total hip arthroplasty is a successful surgical procedure to treat patients with hip osteoarthritis. Clinicians use different questionnaires to evaluate these patients. Gait velocity and these questionnaires; usually show significant improvement after total hip arthroplasty. This clinical evaluation

  5. Crystallization of Self-Propelled Hard Discs

    Science.gov (United States)

    Briand, G.; Dauchot, O.

    2016-08-01

    We experimentally study the crystallization of a monolayer of vibrated discs with a built-in polar asymmetry, a model system of active liquids, and contrast it with that of vibrated isotropic discs. Increasing the packing fraction ϕ , the quasicontinuous crystallization reported for isotropic discs is replaced by a transition, or a crossover, towards a "self-melting" crystal. Starting from the liquid phase and increasing the packing fraction, clusters of dense hexagonal-ordered packed discs spontaneously form, melt, split, and merge, leading to a highly intermittent and heterogeneous dynamics. For a packing fraction larger than ϕ*, a few large clusters span the system size. The cluster size distribution is monotonically decreasing for ϕ ϕ*, and is a power law at the transition. The system is, however, never dynamically arrested. The clusters permanently melt from place to place, forming droplets of an active liquid which rapidly propagate across the system. This self-melting crystalline state subsists up to the highest possible packing fraction, questioning the stability of the crystal for active discs unless it is at ordered close packing.

  6. The inner cavity of the circumnuclear disc

    CERN Document Server

    Blank, Marvin; Frank, Adam; Carroll-Nellenback, Jonathan J; Duschl, Wolfgang J

    2016-01-01

    The circumnuclear disc (CND) orbiting the Galaxy's central black hole is a reservoir of material that can ultimately provide energy through accretion, or form stars in the presence of the black hole, as evidenced by the stellar cluster that is presently located at the CND's centre. In this paper, we report the results of a computational study of the dynamics of the CND. The results lead us to question two paradigms that are prevalent in previous research on the Galactic Centre. The first is that the disc's inner cavity is maintained by the interaction of the central stellar cluster's strong winds with the disc's inner rim, and second, that the presence of unstable clumps in the disc implies that the CND is a transient feature. Our simulations show that, in the absence of a magnetic field, the interaction of the wind with the inner disc rim actually leads to a filling of the inner cavity within a few orbital time-scales, contrary to previous expectations. However, including the effects of magnetic fields stabi...

  7. Structures induced by companions in galactic discs

    CERN Document Server

    Kyziropoulos, P; Gravvanis, G; Patsis, P

    2016-01-01

    Using N-body simulations we study the structures induced on a galactic disc by repeated flybys of a companion in decaying eccentric orbit around the disc. Our system is composed by a stellar disc, bulge and live dark matter halo, and we study the system's dynamical response to a sequence of a companion's flybys, when we vary i) the disc's temperature (parameterized by Toomre's Q-parameter) and ii) the companion's mass and initial orbit. We use a new 3D Cartesian grid code: MAIN (Mesh-adaptive Approximate Inverse N-body solver). The main features of MAIN are reviewed, with emphasis on the use of a new Symmetric Factored Approximate Sparse Inverse (SFASI) matrix in conjunction with the multigrid method that allows the efficient solution of Poisson's equation in three space variables. We find that: i) companions need to be assigned initial masses in a rather narrow window of values in order to produce significant and more long-standing non-axisymmetric structures (bars and spirals) in the main galaxy's disc by t...

  8. The quiescent phase of galactic disc growth

    CERN Document Server

    Aumer, Michael; Schönrich, Ralph

    2016-01-01

    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 ...

  9. Dynamical instabilities in disc-planet interactions

    CERN Document Server

    Lin, Min-Kai

    2012-01-01

    Protoplanetary discs may become dynamically unstable due to structure induced by an embedded giant planet. In this thesis, I discuss the stability of such systems and explore the consequence of instability on planetary migration. I begin with non-self-gravitating, low viscosity discs and show that giant planets induce shocks inside its co-orbital region, leading to a profile unstable to vortex formation around a potential vorticity minimum. This instability is commonly known as the vortex or Rossby wave instability. Vortex-planet interaction lead to episodic phases of migration, which can be understood in the framework of type III migration. I then examine the effect of disc self-gravity on gap stability. The linear theory of the Rossby wave instability is extended to include disc gravity, which shows that self-gravity is effective at stabilising the vortex instability at small azimuthal wavenumber. This is consistent with the observation that more vortices develop with increasing disc mass in hydrodynamic si...

  10. Artificial life and life artificialization in Tron

    Directory of Open Access Journals (Sweden)

    Carolina Dantas Figueiredo

    2012-12-01

    Full Text Available Cinema constantly shows the struggle between the men and artificial intelligences. Fiction, and more specifically fiction films, lends itself to explore possibilities asking “what if?”. “What if”, in this case, is related to the eventual rebellion of artificial intelligences, theme explored in the movies Tron (1982 and Tron Legacy (2010 trat portray the conflict between programs and users. The present paper examines these films, observing particularly the possibility programs empowering. Finally, is briefly mentioned the concept of cyborg as a possibility of response to human concerns.

  11. 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

  12. 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

  13. Registro de artroplastias do ombro Shoulder arthroplasty records

    Directory of Open Access Journals (Sweden)

    Geraldo Motta Filho

    2009-04-01

    Full Text Available OBJETIVO: Determinar as características clínico-cirúrgicas referentes a 145 artroplastias do ombro realizadas no período entre julho de 2004 a dezembro de 2006. MÉTODOS: No período de estudo foram realizadas 145 artroplastias de ombro. Através de protocolo prospectivo, informações demográficas, da anamnese, exame físico e exame radiográfico foram armazenadas em um banco de dados. Os dados coletados foram organizados em três grandes grupos: doenças articulares degenerativas, fraturas e seqüelas traumáticas. Esses dados foram correlacionados a fim de definir o perfil epidemiológico dos pacientes, das lesões e artroplastias. RESULTADOS: Das 145 artroplastias de ombro realizadas 37% foram por seqüelas traumáticas, 30% por doença articular degenerativa e 33% com diagnóstico de fratura. Foram 12% artroplastias totais e 88% parciais. Ocorreram cinco complicações no pós-operatório recente. CONCLUSÃO: As artroplastias de ombro tornaram-se um procedimento frequente na prática ortopédica. Registros cirúrgicos são importantes a fim de demonstrar essa evolução progressiva e permitir avaliações de resultados clínicos no futuro.OBJECTIVE: The study's objective is to evaluate the characteristics and problems of patients who underwent shoulder arthroplasties between July 2004 and November 2006. METHODOLOGY: During the period of the study, 145 shoulder arthroplasties were performed. A prospective protocol was used for every patient; demographic, clinical and surgical procedure data were collected. All gathered data were included in the data base. The patients were divided in three major groups: fractures, degenerative diseases and trauma sequels. Information obtained from the data base was correlated in order to determine patients' epidemiologic, injuries, and surgical procedure profiles. RESULTS: Of the 145 shoulder arthroplasties performed, 37% presented trauma sequels, 30% degenerative diseases, and 33% proximal humerus

  14. Onion artificial muscles

    Science.gov (United States)

    Chen, Chien-Chun; Shih, Wen-Pin; Chang, Pei-Zen; Lai, Hsi-Mei; Chang, Shing-Yun; Huang, Pin-Chun; Jeng, Huai-An

    2015-05-01

    Artificial muscles are soft actuators with the capability of either bending or contraction/elongation subjected to external stimulation. However, there are currently no artificial muscles that can accomplish these actions simultaneously. We found that the single layered, latticed microstructure of onion epidermal cells after acid treatment became elastic and could simultaneously stretch and bend when an electric field was applied. By modulating the magnitude of the voltage, the artificial muscle made of onion epidermal cells would deflect in opposing directions while either contracting or elongating. At voltages of 0-50 V, the artificial muscle elongated and had a maximum deflection of -30 μm; at voltages of 50-1000 V, the artificial muscle contracted and deflected 1.0 mm. The maximum force response is 20 μN at 1000 V.

  15. Signatures of massive collisions in debris discs

    CERN Document Server

    Kral, Quentin; Augereau, Jean-Charles; Boccaletti, Anthony; Charnoz, Sebastien

    2014-01-01

    Violent stochastic collisional events have been invoked as a possible explanation for some debris discs displaying pronounced asymmetries or having a great luminosity excess. So far, no thorough modelling of the consequences of such events has been carried out, mainly because of the extreme numerical challenge of coupling the dynamical and collisional evolution of dust. We perform the first fully self-consistent modelling of the aftermath of massive breakups in debris discs. We follow the collisional and dynamical evolution of dust released after the breakup of a Ceres-sized body at 6 AU from its central star. We investigate the duration, magnitude and spatial structure of the signature left by such a violent event, as well as its observational detectability. We use the recently developed LIDT-DD code (Kral et al., 2013), which handles the coupled collisional and dynamical evolution of debris discs. The main focus is placed on the complex interplay between destructive collisions, Keplerian dynamics and radiat...

  16. OPTIC DISC MELANOCYTOMA: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Sahiba Bedi

    2016-08-01

    Full Text Available Melanocytoma of the optic disc is a rare ophthalmic tumour that arises from melanocytes and is a variant of the melanocytic nevus. It occurs on the optic disc and often extends into the peripapillary retina and choroid. It appears as a dark brown or black lesion, typically small and is almost always unilateral. Although traditionally believed to be a relatively stationary lesion, it is now known to exhibit minor enlargement in 10–15% of cases and can cause minor visual loss by a variety of mechanisms. 1-2% cases can transform to malignant melanoma. We present a case report of a 65-year-old female whose dilated fundus examination of the right eye revealed a circular, pigmented and elevated lesion about 1.5 mm in size covering almost whole of the optic nerve head except for the superior rim, suggestive of optic disc melanocytoma.

  17. Black hole feedback from thick accretion discs

    CERN Document Server

    Sadowski, Aleksander; 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 accretion rates, and returned to the interstellar medium. Accretion on to rotating black holes is more efficient because of the additional extraction of rotational energy. However, the jet component is collimated and likely to interact only weakly with the environment, whereas the outflow and radiation components cover a wide solid angle.

  18. Satellites in discs regulating the accretion luminosity

    CERN Document Server

    Syer, D; Syer, Dave; Clarke, Cathie

    1995-01-01

    We demonstrate, using a simple analytic model, that the presence of a massive satellite can globally modify the structure and emission properties of an accretion disc to which it is tidally coupled. We show, using two levels of numerical approximation, that the analytic model gives reasonable results. The results are applicable to two astrophysical situations. In the case of an active galactic nucleus, we consider the case of a \\sim 10^3\\Msun compact companion to the central black-hole and show that it could modulate the emitted spectrum on a timescale of \\sim10^5 years. In the case of a T Tauri accretion disc, a satellite such as a sub-dwarf or giant planet could modify the disc spectral energy distribution over a substantial fraction of the T Tauri star lifetime.

  19. The debris disc around HIP 17439

    Science.gov (United States)

    Schüppler, Christian; Löhne, Torsten; Krivov, Alexander

    2013-07-01

    In the framework of the Herschel Open Time Key Programme DUNES the debris disc around the K2 V star HIP 17439 was observed. In PACS images the disc emission is spatially clearly extended. A simultaneous analysis of photometric observations and radial brightness profiles from the resolved images provides valuable hints for the disc structure. In an analytical model we adopted power laws for the size and radial distribution of the circumstellar dust and tested two different scenarios: (1) a broad dust ring with a radial extent of about 200AU, (2) two independent dust rings separated by a gap of several tens of AU. Both models fit the spectral energy distribution and the radial profiles quite well. In case (1) the parameters found are consistent with dust stemming from an outer planetesimal belt at ~140AU and strong transport mechanisms that drag the particles inward. Model (2) would imply two planetesimal belts, producing a narrow inner and wider outer distribution of dust.

  20. Discs of Satellites: the new dwarf spheroidals

    CERN Document Server

    Metz, Manuel; Jerjen, Helmut

    2009-01-01

    The spatial distributions of the most recently discovered ultra faint dwarf satellites around the Milky Way and the Andromeda galaxy are compared to the previously reported discs-of-satellites (DoS) of their host galaxies. In our investigation we pay special attention to the selection bias introduced due to the limited sky coverage of SDSS. We find that the new Milky Way satellite galaxies follow closely the DoS defined by the more luminous dwarfs, thereby further emphasizing the statistical significance of this feature in the Galactic halo. We also notice a deficit of satellite galaxies with Galactocentric distances larger than 100 kpc that are away from the disc-of-satellites of the Milky Way. In the case of Andromeda, we obtain similar results, naturally complementing our previous finding and strengthening the notion that the discs-of-satellites are optical manifestations of a phase-space correlation of satellite galaxies.

  1. Effects of disc midplane evolution on CO snowline location

    Science.gov (United States)

    Panić, O.; Min, M.

    2017-01-01

    Temperature changes in the planet forming disc midplanes carry important physico-chemical consequences, such as the effect on the locations of the condensation fronts of molecules - the snowlines. Snowlines impose major chemical gradients and possibly foster grain growth. The aim of this paper is to understand how disc midplane temperature changes with gas and dust evolution, and identify trends that may influence planet formation or allow to constrain disc evolution observationally. We calculate disc temperature, hydrostatic equilibrium and dust settling in a mutually consistent way from a grid of disc models at different stages of gas loss, grain growth and hole opening. We find that the CO snowline location depends very strongly on disc properties. The CO snowline location migrates closer to the star for increasing degrees of gas dispersal and dust growth. Around a typical A type star, the snowline can be anywhere between several tens and a few hundred au, depending on the disc properties such as gas mass and grain size. In fact, gas loss is as efficient as dust evolution in settling discs, and flat discs may be gas-poor counterparts of flared discs. Our results, in the context of different pre-main sequence evolution of the luminosity in low- and intermediate-mass stars suggests very different thermal (and hence chemical) histories in these two types of discs. Discs of T Tauri stars settle and cool down while discs of Herbig Ae stars may remain rather warm throughout the pre-main sequence.

  2. Effect of continuous lumbar traction on the size of herniated disc material in lumbar disc herniation.

    Science.gov (United States)

    Ozturk, Bulent; Gunduz, Osman Hakan; Ozoran, Kursat; Bostanoglu, Sevinc

    2006-05-01

    We investigated the effects of continuous lumbar traction in patients with lumbar disc herniation on clinical findings, and size of the herniated disc measured by computed tomography (CT). In this prospective, randomized, controlled study, 46 patients with lumbar disc herniation were included, and randomized into two groups as the traction group (24 patients), and the control group (22 patients). The traction group was given a physical therapy program and continuous lumbar traction. The control group was given the same physical therapy program without traction, for the same duration of time. Data for the clinical symptoms and signs were collected before and after the treatment together with calculation of a herniation index, from the CT images that showed the size of the herniated disc material. In the traction group, most of the clinical findings significantly improved with treatment. Size of the herniated disc material in CT decreased significantly only in the traction group. In the traction group the herniation index decreased from 276.6+/-129.6 to 212.5+/-84.3 with treatment (p0.05). Patients with greater herniations tended to respond better to traction. In conclusion, lumbar traction is both effective in improving symptoms and clinical findings in patients with lumbar disc herniation and also in decreasing the size of the herniated disc material as measured by CT.

  3. Cometary ices in forming protoplanetary disc midplanes

    Science.gov (United States)

    Drozdovskaya, Maria N.; Walsh, Catherine; van Dishoeck, Ewine F.; Furuya, Kenji; Marboeuf, Ulysse; Thiabaud, Amaury; Harsono, Daniel; Visser, Ruud

    2016-10-01

    Low-mass protostars are the extrasolar analogues of the natal Solar system. Sophisticated physicochemical models are used to simulate the formation of two protoplanetary discs from the initial prestellar phase, one dominated by viscous spreading and the other by pure infall. The results show that the volatile prestellar fingerprint is modified by the chemistry en route into the disc. This holds relatively independent of initial abundances and chemical parameters: physical conditions are more important. The amount of CO2 increases via the grain-surface reaction of OH with CO, which is enhanced by photodissociation of H2O ice. Complex organic molecules are produced during transport through the envelope at the expense of CH3OH ice. Their abundances can be comparable to that of methanol ice (few per cent of water ice) at large disc radii (R > 30 au). Current Class II disc models may be underestimating the complex organic content. Planet population synthesis models may underestimate the amount of CO2 and overestimate CH3OH ices in planetesimals by disregarding chemical processing between the cloud and disc phases. The overall C/O and C/N ratios differ between the gas and solid phases. The two ice ratios show little variation beyond the inner 10 au and both are nearly solar in the case of pure infall, but both are subsolar when viscous spreading dominates. Chemistry in the protostellar envelope en route to the protoplanetary disc sets the initial volatile and prebiotically significant content of icy planetesimals and cometary bodies. Comets are thus potentially reflecting the provenances of the midplane ices in the solar nebula.

  4. Natural course of lumber disc herniation

    Energy Technology Data Exchange (ETDEWEB)

    Tokioka, Takamitsu; Shimada, Kimio; Tanaka, Yuzo; Oshige, Toshihisa; Miyakoshi, Koichi [Okayama Rosai Hospital (Japan)

    1998-09-01

    Thirty-two cases of lumbar disc herniation were sequentially followed by MR imagings in order to ascertain its natural course. Herniation consisted of protrusion in 6 cases, extrusion in 13 cases, and sequestration in 13 cases. We analysed the durations until the herniation regressed more than 50% of its A-P diameter. The mean duration was 8.2 months for extrusion, and 5.3 months for sequestration. Only 2 cases of protrusion regressed within 12 months. Huge disc herniations with central protrusion in particular showed slight spontaneous regression. (author)

  5. Cells and Biomaterials for Intervertebral Disc Regeneration

    CERN Document Server

    Grad, Sibylle

    2010-01-01

    Disorders related to the intervertebral disc (IVD) are common causes of morbidity and of severe life quality deterioration. IVD degeneration, although in many cases asymptomatic, is often the origin of painful neck and back diseases. In Western societies IVD related pain and disability account for enormous health care costs as a result of work absenteeism and thus lost production, disability benefits, medical and insurance expenses. Although only a small percentage of patients with disc disorders finally will undergo surgery, spinal surgery has been one of the fastest growing disciplines in th

  6. Disc-Capped ZnO Nanocombs

    Institute of Scientific and Technical Information of China (English)

    LI Xin; XU chun-xiang; ZHU Guang-Ping; YANG Yi; LIU Jin-Ping; SUN Xiao-Wei; CUI Yi-Ping

    2007-01-01

    Nanocombs with a disc cap structure of ZnO have been synthesized on si substrates by using pure Zinc powders as the source materials based on a vapour-phase transport process.The morphology and the microstructure are investigated by a scanning electron microscopy and x-ray diffraction.Based on the transmission electron microscopy and selected area electron diffraction analysis,the growth directions of three representative parts,nanoribbon stem,nanorod branch and nanodisc cap of the nanocomb are revealed.The growth mechanism of the disc-capped nanocombs is discussed based on the self-catalyzed vapour-liquid-solid process.

  7. A rolling-gliding wear simulator for the investigation of tribological material pairings for application in total knee arthroplasty

    Directory of Open Access Journals (Sweden)

    Denkena Berend

    2010-06-01

    Full Text Available Abstract Background Material wear testing is an important technique in the development and evaluation of materials for use in implant for total knee arthroplasty. Since a knee joint induces a complex rolling-gliding movement, standardised material wear testing devices such as Pin-on-Disc or Ring-on-Disc testers are suitable to only a limited extent because they generate pure gliding motion only. Methods A rolling-gliding wear simulator was thus designed, constructed and implemented, which simulates and reproduces the rolling-gliding movement and loading of the knee joint on specimens of simplified geometry. The technical concept was to run a base-plate, representing the tibia plateau, against a pivoted cylindrical counter-body, representing one femur condyle under an axial load. A rolling movement occurs as a result of the friction and pure gliding is induced by limiting the rotation of the cylindrical counter-body. The set up also enables simplified specimens handling and removal for gravimetrical wear measurements. Long-term wear tests and gravimetrical wear measurements were carried out on the well known material pairings: cobalt chrome-polyethylene, ceramic-polyethylene and ceramic-ceramic, over three million motion cycles to allow material comparisons to be made. Results The observed differences in wear rates between cobalt-chrome on polyethylene and ceramic on polyethylene pairings were similar to the differences of published data for existing material-pairings. Test results on ceramic-ceramic pairings of different frontal-plane geometry and surface roughness displayed low wear rates and no fracture failures. Conclusions The presented set up is able to simulate the rolling-gliding movement of the knee joint, is easy to use, and requires a minimum of user intervention or monitoring. It is suitable for long-term testing, and therefore a useful tool for the investigation of new and promising materials which are of interest for application in

  8. Conventional Versus Cross-Linked Polyethylene for Total Hip Arthroplasty.

    Science.gov (United States)

    Surace, Michele F; Monestier, Luca; Vulcano, Ettore; Harwin, Steven F; Cherubino, Paolo

    2015-09-01

    The clinical and radiographic outcomes of 88 patients who underwent primary total hip arthroplasty with either conventional polyethylene or cross-linked polyethylene (XLPE) from the same manufacturer were compared. There were no significant differences between the 2 subpopulations regarding average age, gender, side affected, or prosthetic stem and cup size. The average follow-up was 104 months (range, 55 to 131 months). To the authors' knowledge, this is the longest follow-up for this particular insert. Clinical and radiographic evaluations were performed at 1, 3, 6, and 12 months and then annually. Results showed that XLPE has a significantly greater wear reduction than that of standard polyethylene in primary total hip arthroplasty. At the longest available follow-up for these specific inserts, XLPE proved to be effective in reducing wear.

  9. [Modern tribology in total hip arthroplasty: pros and cons].

    Science.gov (United States)

    Gómez-García, F

    2014-01-01

    The wear products and adverse reactions that occur on bearing surfaces represent one of the greatest challenges in prosthetic replacements, as the latter experience increasing demands due to the large number of young and older adult patients that have a long life expectancy and remarkable activity. The purpose of this review is to analyze the pros and cons of the new advances in the bearing components of the articular surfaces of current total hip arthroplasties. We also discuss the strategies used historically, their problems, results and the surgeon's role in prescribing the tribologic couple that best fits each patient's needs. We conclude with practical recommendations for the prescription and management of the latest articular couples for total hip arthroplasty.

  10. The use of postoperative suction drainage in total hip arthroplasty.

    Science.gov (United States)

    Acus, R W; Clark, J M; Gradisar, I A; Kovacik, M W

    1992-11-01

    Two hundred eight primary total hip arthroplasties were reviewed to evaluate the effect of closed suction drainage. This review included 45 hips in which closed drains were used and 163 hips in which drains were not used. These two groups were compared for possible differences in wound problems, temperature elevations, changes in Hgb/Hct, and the need for transfusions. There was no statistically significant difference in postoperative temperatures or decrease in Hgb. However, there were four superficial wound infections in the drained group and three superficial wound infections in the non-drained group (P < .025). There were no deep infections in either group. These findings suggest closed suction drainage provides no apparent advantage in uncomplicated primary total hip arthroplasty.

  11. Nursing in fast-track total hip and knee arthroplasty

    DEFF Research Database (Denmark)

    Specht, Kirsten; Kjaersgaard-Andersen, Per; Kehlet, Henrik

    2015-01-01

    AIM: To describe the increased activity in total hip arthroplasty (THA) and total knee arthroplasty (TKA) from 2002 to 2012 in a single orthopaedic department, the organisation of fast-track and its consequences for nursing care. METHODS: Retrospective, descriptive design. Data collection; from...... the hospital administrative database, local descriptions of fast-track, personal contact and discussion with staff. RESULTS: The number of operations increased threefold from 351 operations in 2002 to 1024 operations in 2012. In 2012, THA/TKA patients had a postoperative mean LOS of 2.6/2.8 days. Nurses had......, be considered a worthwhile investment to employ expert/highly qualified professional nurses in fast-track THA and TKA units....

  12. Prediction of Wear in Crosslinked Polyethylene Unicompartmental Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Jonathan Netter

    2015-05-01

    Full Text Available Wear-related complications remain a major issue after unicompartmental arthroplasty. We used a computational model to predict knee wear generated in vitro under diverse conditions. Inverse finite element analysis of 2 different total knee arthroplasty designs was used to determine wear factors of standard and highly crosslinked polyethylene by matching predicted wear rates to measured wear rates. The computed wear factor was used to predict wear in unicompartmental components. The articular surface design and kinematic conditions of the unicompartmental and tricompartmental designs were different. Predicted wear rate (1.77 mg/million cycles was very close to experimental wear rate (1.84 mg/million cycles after testing in an AMTI knee wear simulator. Finite element analysis can predict experimental wear and may reduce the cost and time of preclinical testing.

  13. Knitted outer gloves in primary hip and knee arthroplasty.

    Science.gov (United States)

    Tanner, J; Wraighte, P; Howard, P

    2006-01-01

    A randomised trial was carried out to determine the rate of perforation to inner gloves when comparing latex with knitted gloves during hip and knee arthroplasty. Members of the surgical team were randomised to wear either two pairs of latex gloves (standard double gloving) or a knitted glove on top of a latex glove. In addition, participants completed a visual analogue assessment of their overall satisfaction with the gloves. A total of 406 inner gloves were tested for perforations over a four-month period: 23% of inner gloves were perforated when latex outer gloves were used and 6% of inner gloves were perforated when knitted outer gloves were used. In total, there were 64 perforations to the inner gloves; only one of these perforations was detected by the glove wearer. Wearing knitted outer gloves during hip and knee arthroplasty statistically significantly reduces the risk of perforation to inner latex gloves (p<0.0001).

  14. In vivo determination of total knee arthroplasty kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Komistek, Richard D [ORNL; Mahfouz, Mohamed R [ORNL; Bertin, Kim [Utah Bone & Joint Center, Salt Lake City, Utah (USA); Rosenberg, Aaron [Rush-Presbyterian-St. Luke' s Med Center, Chicago IL (USA); Kennedy, William [Kennedy-White Orthopaedic Center, Sarasota, FL (USA)

    2008-01-01

    The objective of this study was to determine if consistent posterior femoral rollback of an asymmetrical posterior cruciate retaining (PCR) total knee arthroplasty was mostly influenced by the implant design, surgical technique, or presence of a well-functioning posterior cruciate ligament (PCL). Three-dimensional femorotibial kinematics was determined for 80 subjects implanted by 3 surgeons, and each subject was evaluated under fluoroscopic surveillance during a deep knee bend. All subjects in this present study having an intact PCL had a well-functioning PCR knee and experienced normal kinematic patterns, although less in magnitude than the normal knee. In addition, a surprising finding was that, on average, subjects without a PCL still achieved posterior femoral rollback from full extension to maximum knee flexion. The findings in this study revealed that implant design did contribute to the normal kinematics demonstrated by subjects having this asymmetrical PCR total knee arthroplasty.

  15. Improved radiographic outcomes with patient-specific total knee arthroplasty.

    Science.gov (United States)

    Ivie, Conrad B; Probst, Patrick J; Bal, Amrit K; Stannard, James T; Crist, Brett D; Sonny Bal, B

    2014-11-01

    Patient-specific guides can improve limb alignment and implant positioning in total knee arthroplasty, although not all studies have supported this benefit. We compared the radiographs of 100 consecutively-performed patient-specific total knees to a similar group that was implanted with conventional instruments instead. The patient-specific group showed more accurate reproduction of the theoretically ideal mechanical axis, with fewer outliers, but implant positioning was comparable between groups. Our odds ratio comparison showed that the patient-specific group was 1.8 times more likely to be within the desired +3° from the neutral mechanical axis when compared to the standard control group. Our data suggest that reliable reproduction of the limb mechanical axis may accrue from patient-specific guides in total knee arthroplasty when compared to standard, intramedullary instrumentation.

  16. Risk Prediction Tools for Hip and Knee Arthroplasty.

    Science.gov (United States)

    Manning, David W; Edelstein, Adam I; Alvi, Hasham M

    2016-01-01

    The current healthcare environment in America is driven by the concepts of quality, cost containment, and value. In this environment, primary hip and knee arthroplasty procedures have been targeted for cost containment through quality improvement initiatives intended to reduce the incidence of costly complications and readmissions. Accordingly, risk prediction tools have been developed in an attempt to quantify the patient-specific assessment of risk. Risk prediction tools may be useful for the informed consent process, for enhancing risk mitigation efforts, and for risk-adjusting data used for reimbursement and the public reporting of outcomes. The evaluation of risk prediction tools involves statistical measures such as discrimination and calibration to assess accuracy and utility. Furthermore, prediction tools are tuned to the source dataset from which they are derived, require validation with external datasets, and should be recalibrated over time. However, a high-quality, externally validated risk prediction tool for adverse outcomes after primary total joint arthroplasty remains an elusive goal.

  17. Discordance between patient and surgeon satisfaction after total joint arthroplasty.

    Science.gov (United States)

    Harris, Ian A; Harris, Anita M; Naylor, Justine M; Adie, Sam; Mittal, Rajat; Dao, Alan T

    2013-05-01

    We surveyed 331 patients undergoing total hip or knee arthroplasty pre-operatively, and patients and surgeons were both surveyed 6 and 12 months post-operatively. We identified variables (demographic factors, operative factors and patient expectations) as possible predictors for discordance in patient-surgeon satisfaction. At 12 months, 94.5% of surgeons and 90.3% of patients recorded satisfaction with the outcome. The discordance between patient and surgeon satisfaction was mainly due to patient dissatisfaction-surgeon satisfaction. In an adjusted analysis, the strongest predictors of discordance in patient-surgeon satisfaction were unmet patient expectations and the presence of complications. Advice to potential joint arthroplasty candidates regarding the decision to proceed with surgery should be informed by patient reported outcomes, rather than the surgeon's opinion of the likelihood of success.

  18. Be discs in binary systems I. Coplanar orbits

    CERN Document Server

    Panoglou, Despina; Vieira, Rodrigo G; Cyr, Isabelle H; Jones, Carol E; Okazaki, Atsuo T; Rivinius, Thomas

    2016-01-01

    Be stars are surrounded by outflowing circumstellar matter structured in the form of decretion discs. They are often members of binary systems, where it is expected that the decretion disc interacts both radiatively and gravitationally with the companion. In this work we study how various orbital (period, mass ratio, eccentricity) and disc (viscosity) parameters affect the disc structure in coplanar systems. We simulate such binaries with the use of a smoothed particle hydrodynamics code. The main effects of the secondary on the disc are its truncation and the accumulation of material inwards of truncation. In circular or nearly circular prograde orbits, the disc maintains a rotating, constant in shape, configuration, which is locked to the orbital phase. The disc is smaller in size, more elongated and more massive for low viscosity parameter, small orbital separation and/or high mass ratio. Highly eccentric orbits are more complex, with the disc structure and total mass strongly dependent on the orbital phas...

  19. ALGEBROIDAL FUNCTION AND ITS DERIVED FUNCTION IN UNIT CIRCULAR DISC

    Institute of Scientific and Technical Information of China (English)

    Huo Yingying; Sun Daochun

    2009-01-01

    In this article, the authors define the derived function of an algeboidal function in the unit disc, prove it is an algabriodal function, and study the order of algebroidal function and that of its derived function in unit circular disc.

  20. Post-Main Sequence Evolution of Debris Discs

    CERN Document Server

    Bonsor, Amy

    2010-01-01

    The population of debris discs on the main sequence is well constrained, however very little is known about debris discs around evolved stars. In this work we provide a theoretical framework that considers the effects of stellar evolution on debris discs; firstly considering the evolution of an individual disc from the main sequence through to the white dwarf phase, then extending this to the known population of debris discs around main sequence A stars. It is found that discs around evolved stars are harder to detect than on the main sequence. In the context of our models discs should be detectable with Herschel or Alma on the giant branch, subject to the uncertain effect of sublimation on the discs. The best chances are for hot young white dwarfs, fitting nicely with the observations e.g the helix nebula (Su et al. 2007) and 9 systems presented by Chu & Bilikova.

  1. Relationship of condylar position to disc position and morphology

    Energy Technology Data Exchange (ETDEWEB)

    Incesu, L.; Taskaya-Yilmaz, N. E-mail: nergizy@omu.edu.tr; Oeguetcen-Toller, M.; Uzun, E

    2004-09-01

    Introduction/objective: The purpose of this study was to assess whether condylar position, as depicted by magnetic resonance imaging, was an indicator of disc morphology and position. Methods and material: One hundred and twenty two TMJs of 61 patients with temporomandibular joint disorder were examined. Condylar position, disc deformity and degree of anterior disc displacement were evaluated by using magnetic resonance imaging. Results and discussion: Posterior condyle position was found to be the main feature of temporomandibular joints with slight and moderate anterior disc displacement. No statistical significance was found between the condylar position, and reducing and nonreducing disc positions. On the other hand, superior disc position was found to be statistically significant for centric condylar position. Conclusion: It was concluded that posterior condyle position could indicate anterior disc displacement whereas there was no relation between the position of condyle and the disc deformity.

  2. Increasing risk of prosthetic joint infection after total hip arthroplasty

    DEFF Research Database (Denmark)

    Dale, Håvard; Fenstad, Anne M; Hallan, Geir;

    2012-01-01

    Background and purpose The risk of revision due to infection after primary total hip arthroplasty (THA) has been reported to be increasing in Norway. We investigated whether this increase is a common feature in the Nordic countries (Denmark, Finland, Norway, and Sweden). Materials and methods The...... explain this increase. We believe that there has been an actual increase in the incidence of prosthetic joint infections after THA....

  3. Gait and postural control after total knee arthroplasty

    OpenAIRE

    Bjerke, Joakim

    2014-01-01

    The aim of the thesis was to investigate deficits and compensatory strategies after total knee arthroplasty (TKA) in different conditions during gait and quiet standing. Although TKA is considered the gold standard treatment for end-stage knee osteoarthritis, it is associated with a number of implications. Reduced physical function after osteoarthritis is partly, but apparently not fully, remedied by surgery. The two most common deficits are reduced knee muscle strength and limited range of k...

  4. Can pelvic tilting be ignored in total hip arthroplasty?

    Directory of Open Access Journals (Sweden)

    Won Yong Shon

    2014-01-01

    CONCLUSION: The sagittal position of pelvis is a key factor in impingement and dislocation after total hip arthroplasty. Pelvic tilting affects the position of acetabular component in the sagittal plane of the body as compared with its anatomic position in the pelvis. We suggest a preoperative lateral view of spine-pelvis, in upright and supine position for evaluation of a corrective adaptation of the acetabular cup accordingly with pelvic balance.

  5. Total ankle arthroplasty in end-stage ankle arthritis

    OpenAIRE

    Demetracopoulos, Constantine A.; Halloran, James P.; Maloof, Paul; Samuel B Adams; Parekh, Selene G.

    2013-01-01

    Recent advancements in ankle prosthesis design, combined with improved surgical techniques for correction of coronal plane deformity and ligamentous balancing, have led to a resurgence of interest in total ankle arthroplasty for the treatment of end-stage ankle arthritis. Although ankle arthrodesis has long been considered the gold standard treatment for ankle arthritis, recent studies have shown that patients who undergo total ankle replacement have equivalent pain relief and improved functi...

  6. FAST TRACK SURGERY IN TOTAL KNEE ARTHROPLASTY - A REVIEW.

    OpenAIRE

    2015-01-01

    The number of orthopedic surgeons who are convinced in the need for significant changes in planned total knee arthroplasty (TKA) is increasing slowly and steadily. A new approach to pain control has been developed over the past 10-15 years, and the introduction of techniques to reduce perioperative stress, and the use of minimally invasive surgical techniques can help limit postoperative complications and shorten recovery time. This type of optimization is regarded as Fast-track Care program,...

  7. Intraoperative Hypothermia in Total Hip and Knee Arthroplasty.

    Science.gov (United States)

    Frisch, Nicholas B; Pepper, Andrew M; Rooney, Edward; Silverton, Craig

    2016-10-25

    Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common and successful orthopedic procedures, and as their frequency continues to increase substantially, the focus on limiting perioperative complications heightens. Intraoperative normothermia is recommended to minimize additional complications, but limited evidence exists regarding the effect of hypothermia on orthopedic patients. The purpose of this retrospective study was to determine the incidence of perioperative hypothermia in the setting of TKA and THA, and to evaluate its impact on complications and outcomes. The clinical records of 2580 consecutive patients who underwent TKA or THA at a single institution between January 1, 2011, and December 31, 2013 were reviewed. After excluding patients with complex or revision procedures, a total of 2397 patients comprised the study population. Patient demographic data, surgery-specific data, postoperative complications, length of hospital stay, and 30-day readmission were recorded. Patients with a mean intraoperative temperature less than 36°C were identified as hypothermic. Statistical analysis evaluated associations with hypothermia and the effect on complications and outcomes. The incidence of mean intraoperative hypothermia was 37%, 43.9%, and 32.6% for arthroplasty, THA, and TKA, respectively. General anesthesia was significantly associated with hypothermia (P<.001). Women and THA patients were at higher risk for hypothermia. In the arthroplasty and THA cohorts, longer operating room time and re-warmer use were associated with hypothermia (P=.010). Overall, hypothermia was associated with increased estimated blood loss, but no increase in associated transfusion was demonstrated (P=.006). Hypothermia was not associated with postoperative complications. [Orthopedics. 201x; xx(x):xx-xx.].

  8. Stress fracture of the proximal fibula after total knee arthroplasty.

    Science.gov (United States)

    Vaish, Abhishek; Vaishya, Raju; Agarwal, Amit Kumar; Vijay, Vipul

    2016-04-22

    We report a rare case of proximal fibular fatigue fracture developing 14 years after total knee arthroplasty in a known case of rheumatoid arthritis. A valgus deformity of the knee can put abnormal stress on the upper fibula leading to its failure. We believe that, as the fibula acts as an important lateral strut, its disruption due to a fracture led to rapid progress of the valgus deformity of the knee in this patient.

  9. Spontaneous arteriorrhexis in affected lower limb following total knee arthroplasty

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ya-feng; JIANG Qing; WANG Jun-fei

    2008-01-01

    @@ Total knee arthroplasty ( TKA) is now a standard treatment for serious osteoarthritis all over the world. Although it is a standard treatment, it has many complications, among which deep vein thrombosis ( DVT) is the exclusive blood vessel complication that has been reported.1,2 However, we found a new blood vessel complication of TKA in this study, which is spontaneous arteriorrhexis in the affected lower limb.

  10. Changes in knee kinematics following total knee arthroplasty.

    Science.gov (United States)

    Akbari Shandiz, Mohsen; Boulos, Paul; Saevarsson, Stefan Karl; Yoo, Sam; Miller, Stephen; Anglin, Carolyn

    2016-04-01

    Total knee arthroplasty (TKA) changes the knee joint in both intentional and unintentional, known and unknown, ways. Patellofemoral and tibiofemoral kinematics play an important role in postoperative pain, function, satisfaction and revision, yet are largely unknown. Preoperative kinematics, postoperative kinematics or changes in kinematics may help identify causes of poor clinical outcome. Patellofemoral kinematics are challenging to record since the patella is obscured by the metal femoral component in X-ray and moves under the skin. The purpose of this study was to determine the kinematic degrees of freedom having significant changes and to evaluate the variability in individual changes to allow future study of patients with poor clinical outcomes. We prospectively studied the 6 degrees of freedom patellofemoral and tibiofemoral weightbearing kinematics, tibiofemoral contact points and helical axes of rotation of nine subjects before and at least 1 year after total knee arthroplasty using clinically available computed tomography and radiographic imaging systems. Normal kinematics for healthy individuals were identified from the literature. Significant differences existed between pre-TKA and post-TKA kinematics, with the post-TKA kinematics being closer to normal. While on average the pre-total knee arthroplasty knees in this group displayed no pivoting (only translation), individually only five knees displayed this behaviour (of these, two showed lateral pivoting, one showed medial pivoting and one showed central pivoting). There was considerable variability postoperatively as well (five central, two lateral and two medial pivoting). Both preop and postop, flexion behaviour was more hinge-like medially and more rolling laterally. Helical axes were more consistent postop for this group. An inclusive understanding of the pre-TKA and post-TKA kinematics and changes in kinematics due to total knee arthroplasty could improve implant design, patient diagnosis and

  11. Artificial intelligence in medicine.

    Science.gov (United States)

    Ramesh, A. N.; Kambhampati, C.; Monson, J. R. T.; Drew, P. J.

    2004-01-01

    INTRODUCTION: Artificial intelligence is a branch of computer science capable of analysing complex medical data. Their potential to exploit meaningful relationship with in a data set can be used in the diagnosis, treatment and predicting outcome in many clinical scenarios. METHODS: Medline and internet searches were carried out using the keywords 'artificial intelligence' and 'neural networks (computer)'. Further references were obtained by cross-referencing from key articles. An overview of different artificial intelligent techniques is presented in this paper along with the review of important clinical applications. RESULTS: The proficiency of artificial intelligent techniques has been explored in almost every field of medicine. Artificial neural network was the most commonly used analytical tool whilst other artificial intelligent techniques such as fuzzy expert systems, evolutionary computation and hybrid intelligent systems have all been used in different clinical settings. DISCUSSION: Artificial intelligence techniques have the potential to be applied in almost every field of medicine. There is need for further clinical trials which are appropriately designed before these emergent techniques find application in the real clinical setting. PMID:15333167

  12. Temporomandibular joint disc; a proposed histopathological degeneration grading score system

    OpenAIRE

    2010-01-01

    Summary. Aims: The purpose of this study was to draw up a TMJ disc histopathological score that is a semiquantitative transcription of the entire spectrum of TMJ disc degenerative diseases related to changes in disc tissue, and then validate the proposed grading, in order to contribute to a standardized histopathological diagnosis. Methods: Sections from sixty two temporomandibular joint disc specimens affected by tissue degenerative changes and stained with Hematox...

  13. MRI and discography in traumatic intervertebral disc lesions

    Energy Technology Data Exchange (ETDEWEB)

    Ghanem, Nadir; Uhl, Markus; Elgeti, Florian; Pache, Gregor; Kotter, Elmar; Langer, Mathias [University Hospital Freiburg, Departments of Diagnostic Radiology, Freiburg (Germany); Mueller, Christoph; Markmiller, Max [University Hospital Freiburg, Traumatology, Freiburg (Germany)

    2006-11-15

    In this study we evaluated magnetic resonance imaging (MRI) in trauma patients for assessing traumatised adjacent discs of fractured vertebrae before dorsoventral stabilisation. In a prospective study, MRI of 54 discs was performed with a 1.5-T MRI unit. The preoperative MRI with sagittal T1-W-SE and T2-W-TSE was compared to intraoperative discography, which was carried out on both intervertebral discs adjacent to the fractured vertebrae. Signal alterations, morphological changes in the adjacent discs, fractured vertebrae and associated ligament injuries were evaluated. In 47/54 (87%) of the intervertebral discs, the results of both imaging findings were concordant. The discs adjoining vertebral fractures were normal in 18 cases. Regarding the positive concordant imaging findings, MRI and discography revealed traumatised adjacent cranial and caudal discs in 22 discs. In 7 cases, only the cranial adjacent disc was affected. Moreover, 17 cases of intradiscal bleeding, 13 intraosseous herniations into the fractured vertebrae and 20 anuluar tears were visualised in MRI. Associated ligament injuries were detected in 18 cases. Findings were discordant in eight discs. In six discs, MRI was abnormal, demonstrating signal alterations suggestive of positive imaging findings, whereas discography demonstrated no disc injury. MRI failed to detect disc injury in two discs, whereas discography was positive, showing an irregular intradiscal contrast media distribution. MRI, as a non-invasive method for assessing fractures of the thoraco-lumbar spine, may detect traumatised adjacent intervertebral discs. MRI is superior to intraoperative discography. The performance of MRI of the thoraco-lumbar spine is recommended before dorsoventral stabilisation in trauma patients, as it can reveal additional preoperative information such as fractures, disc and associated ligament injuries. (orig.)

  14. Evaluation of the color stability of two techniquesfor reproducing artificial irides after microwave polymerization

    Directory of Open Access Journals (Sweden)

    Marcelo Coelho Goiato

    2011-06-01

    Full Text Available The use of ocular prostheses for ophthalmic patients aims to rebuild facial aesthetics and provide an artificial substitute to the visual organ. Natural intemperate conditions promote discoloration of artificial irides and many studies have attempted to produce irides with greater chromatic paint durability using different paint materials. OBJECTIVES: The present study evaluated the color stability of artificial irides obtained with two techniques (oil painting and digital image and submitted to microwave polymerization. MATERIAL AND METHODS: Forty samples were fabricated simulating ocular prostheses. each sample was constituted by one disc of acrylic resin N1 and one disc of colorless acrylic resin with the iris interposed between the discs. The irides in brown and blue color were obtained by oil painting or digital image. The color stability was determined by a reflection spectrophotometer and measurements were taken before and after microwave polymerization. Statistical analysis of the techniques for reproducing artificial irides was performed by applying the normal data distribution test followed by 2-way ANOVA and Tukey HSD test (α=.05. RESULTS: Chromatic alterations occurred in all specimens and statistically significant differences were observed between the oil-painted samples and those obtained by digital imaging. There was no statistical difference between the brown and blue colors. Independently of technique, all samples suffered color alterations after microwave polymerization. CONCLUSION: The digital imaging technique for reproducing irides presented better color stability after microwave polymerization.

  15. DIAGNOSTIC AND THERAPEUTIC ARTHROSCOPY IN SYMPTOMATIC PATIENTS AFTER KNEE ARTHROPLASTY

    Science.gov (United States)

    Severino, Fabricio Roberto; Souza, Clodoaldo José Duarte de; Severino, Nilson Roberto

    2015-01-01

    Objectives: Assess the worthiness of arthroscopy in investigating and treating knee pain after arthroplasty unexplained by clinical and subsidiary examinations. Methods: Among 402 patients submitted to total or unicompartimental arthroplasty between September 2001 and April 2007 at a public university hospital, 17 presented with pain on prosthetic articulation, without clear diagnosis by clinical, X-ray, laboratory, scintiscan, or nuclear magnetic resonance tests. All patients were submitted to arthroscopy and symptoms were assessed by using the Lysholm scale, comparing pre-and post-arthroscopy periods. Peroperative findings have been recorded. Results: The procedure was effective for pain relief in 14 of 17 patients (82.35%). The median for Lysholm scale climbed from 36 points before arthroscopy to 94 points after the procedure (p < 0.001). Most of the patients (12) were arthroscopically diagnosed with fibrosis known as “cyclop”; on the remaining five patients, anterior synovitis was found. All patients were treated by resection. Conclusions: Knee arthroscopy after arthroplasty in patients presenting unclear persistent pain shows localized arthrofibrosis (“cyclops”) or synovitis, which can be treated by using the same procedure, resulting in pain relief. PMID:27022517

  16. [Periprosthetic humeral fractures: Strategies and techniques of revision arthroplasty].

    Science.gov (United States)

    Kirchhoff, C; Beirer, M; Brunner, U

    2016-04-01

    The primary aims when performing revision arthroplasty of periprosthetic humeral fractures (PHF) are preservation of bone stock, achieving fracture healing and preserving a stable prosthesis with the focus on regaining the preoperative shoulder-arm function. The indications for revision arthroplasty are given in PHF in combination with loosening of the stem. In addition, further factors must be independently clarified in the case of an anatomical arthroplasty. In this context secondary glenoid erosion as well as rotator cuff insufficiency are potential factors for an extended revision procedure. For the performance of revision surgery modular revision sets including long stems, revision glenoid and metaglene components as well as plate and cerclage systems are obligatory besides the explantation instrumentation. Despite a loosened prosthesis, a transhumeral removal of the stem along with a subpectoral fenestration are often required. Length as well as bracing of revision stems need to bridge the fracture by at least twice the humeral diameter. Moreover, in many cases a combined procedure using an additional distal open reduction and internal fixation (ORIF) plus cable cerclages as well as biological augmentation might be needed. Assuming an adequate preparation, the experienced surgeon is able to achieve a high fracture union rate along with an acceptable or even good shoulder function and to avoid further complications.

  17. [Recovery from total knee arthroplasty through continuous passive motion].

    Science.gov (United States)

    Sánchez Mayo, B; Rodríguez-Mansilla, J; González Sánchez, B

    2015-01-01

    The purpose of this study was to know the effects of continuous passive mobilization in patients who underwent total knee arthroplasty. A search strategy was developed to retrieve all clinical trials, written in English and/or Spanish, published in the electronic search databases PubMed, Cochrane Library Plus, Dialnet, CSIC and PEDro. The inclusion criteria were: clinical trials published from January 2000 until November 2014 in English or Spanish. Out of 537 clinical trials that were potentially relevant, a total of 12 were included in this review. The evaluation of 1,153 patients shows that there is no significant difference in improving the range of the joint, pain, balance, motion, healing and hospital stay using continuous passive mobilization against the regular physiotherapy treatment for total knee arthroplasty. The application of continuous passive mobilization in the long-term does not provide any benefit in terms of the breadth of the range of the joint, pain and improvement of standing and motion in comparison with conventional postoperative physiotherapy treatment in total knee arthroplasty. In the short term an improvement is obtained in the range of joint motion in knee flexion.

  18. Review of Arthroscopic and Histological Findings Following Knee Inlay Arthroplasty.

    Science.gov (United States)

    Markarian, Gregory G; Kambour, Michael T; Uribe, John W

    2016-01-01

    The phenomenon of cartilage rim loading in defects exceeding the threshold diameter of 10 mm is well documented. Contoured defect fill off-loads the perimeter and counteracts further delamination and progression of defects. When biological procedures have failed, inlay arthroplasty follows these concepts. The human biological response to contoured metallic surface implants has not been described. Four patients underwent non-implant-related, second-look arthroscopy following inlay arthroplasty for bi- (n=3) and tricompartmental (n=1) knee arthrosis without subchondral bone collapse. Arthroscopic probing of the implant-cartilage interface of nine prosthetic components did not show signs of implant-cartilage gap formation, loosening, or subsidence. The implant periphery was consistently covered by cartilage confluence leading to a reduction of the original defect size diameter. Femoral condyle cartilage flow appeared to have more hyaline characteristics. Trochlear cartilage flow showed greater histological variability and less organization with fibrocartilage and synovialized scar tissue. This review reconfirmed previous basic science results and demonstrated effective defect fill and rim off-loading with inlay arthroplasty.

  19. Erythrocyte deformability and aggregation responses to intermittent and continuous artificial gravity exposure

    Science.gov (United States)

    Marijke, Grau; Vera, Abeln; Tobias, Vogt; Wilhelm, Bloch; Stefan, Schneider

    2017-02-01

    Artificial gravity protocols are used to improve g-tolerance of aviators and discussed as countermeasure during prolonged space flight. Little is known about the impact of artificial gravity on the red blood cells (RBC). The purpose of the study was to test how artificial gravity affects RBC deformability and aggregation, which are important determinants of microcirculation. Nine male subjects were exposed to two hypergravity protocols using a short arm human centrifuge: a continuous (CONT) protocol with constant +2 Gz for 30 min and an intermittent (INTER) protocol with repeated intervals of +2 Gz and rest. Blood was sampled pre and post interventions to measure basal blood parameters, RBC nitrite, RBC deformability, aggregation, and to determine the shear rate balancing aggregation and disaggregation (γ at dIsc min). To test for orthostasis effects, five male subjects were asked to stay for 46 min, corresponding to the length of the centrifuge protocols, with blood sampling pre and post intervention. Artificial gravity programs did not affect basal blood parameters or RBC nitrite levels; a marker for RBC deformability influencing nitric oxide. The INTER program did not affect any of the tested parameters. The CONT program did not remarkably affect RBC deformability or γ at dIsc min but significantly aggravated aggregation. Orthostasis effects were thus excluded. The results indicate that continuous artificial gravity, especially with higher g-forces applied, may negatively affect the RBC system and that for a prolonged space flight intermittent but not continuous artificial gravity might represent an appropriate countermeasure.

  20. Loosening of Total Knee Arthroplasty after Brucellosis Infection: A Case Report

    Science.gov (United States)

    Sazegari, Mohammad Ali; Bahramian, Fateme; Mirzaee, Fateme; Zafarani, Zohreh; Aslani, Hamidreza

    2017-01-01

    In this report we describe a 78-year-old man whose total knee arthroplasty showed the symptoms of infection with brucella with radiographic signs of loosening 5 years after the index surgery. The patient was treated successfully after a 2-stage revision arthroplasty surgery along with using rifampicin and doxycycline for 8 weeks. PMID:28271092