The Experts below are selected from a list of 18177 Experts worldwide ranked by ideXlab platform
Mitsuo Ochi - One of the best experts on this subject based on the ideXlab platform.
-
quantitative stress radiography of the Patella and evaluation of Patellar laxity before and after lateral release for recurrent dislocation Patella
Knee Surgery Sports Traumatology Arthroscopy, 2014Co-Authors: Takuya Niimoto, Masataka Deie, Nobuo Adachi, Muhammad Usman, Mitsuo OchiAbstract:The aims of the present controlled clinical study were to (1) compare Patella laxity determined in the outpatient clinic with that in anaesthetized patients and (2) evaluate Patella laxity before and after lateral release. The study evaluated data on 33 knees from 33 patients (average age 19.7 years) between 2007 and 2011. All patients were diagnosed with recurrent dislocation of the Patella. Patellar stability was evaluated in each patient thrice: Patellas were first imaged in the outpatient clinic prior to surgery at 45° knee flexion with 20 N stress from the medial to lateral side and from the lateral to medial side; then, at the time of surgery, Patella stress images were obtained in the same manner before and after the lateral release procedure. Radiological assessments were performed using the medial stress shift ratio (MSSR) and lateral stress shift ratio (LSSR). There were no significant differences in the LSSR and MSSR before surgery (outpatient data) and in anaesthetized patients before the lateral release procedure. Furthermore, there was no significant difference in MSSR at the time of surgery before and after the lateral release procedure. However, LSSR increased significantly after the lateral release procedure. The results of the present study suggest that quantitative Patella stress radiography in the outpatient clinic is useful when it comes to investigating laxity of the Patella, and that lateral release significantly increases lateral, but not medial, laxity in patients with recurrent Patellar dislocation. IV.
-
A long-term follow-up study after medial patellofemoral ligament reconstruction using the transferred semitendinosus tendon for Patellar dislocation
Knee Surgery Sports Traumatology Arthroscopy, 2005Co-Authors: Masataka Deie, Mitsuo Ochi, Nobuo Adachi, Yoshio Sumen, Kenji Kobayashi, Masanori YasumotoAbstract:The management of Patellar dislocation syndrome has traditionally been difficult. There are no golden standard methods for Patellar dislocations probably due to the many etiologies. However, it is known that medial patellofemoral ligament (MPFL) is damaged when the Patella is dislocated. The purpose of this study is to examine whether our method of MPFL reconstruction is useful for the treatment of dislocated Patellae and unstable Patellae. Forty-six knees (43 patients) of 68 knees (65 patients) that were operated on using our surgical procedure for MPFL reconstruction with the advancement of the vastus medialis or the MPFL reconstruction with Insall’s procedure were followed up for at least 5 years. The patient age ranged from 6 to 43 years. These knees consisted of six habitual dislocation Patellae, twenty-six recurrent dislocation Patellae, ten traumatic dislocation Patellae, and four unstable Patellae. The patients were evaluated pre-operatively and more than three times post-operatively at 6, 12, 36, 60, or 120 months. No patient experienced Patellar dislocation after surgery. Their post-operative Kujala’s scores were significantly improved. On conventional X-ray and on stress X-ray evaluations, the mean values for congruence angle, tilting angle, lateral shift ratio, medial stress shift ratio, and lateral stress shift ratio at the final follow-up (60 or 120 months) were demonstrated to be within the normal range. We conclude that our MPFL reconstruction method with the advancement of the vastus medialis or with Insall’s procedure might be recommended for the treatment of habitual, recurrent, and indeed any other type of Patellar dislocation, as well as for unstable Patellae.
Mark J Spangehl - One of the best experts on this subject based on the ideXlab platform.
-
international rates of Patellar resurfacing in primary total knee arthroplasty 2004 2014
Journal of Arthroplasty, 2017Co-Authors: James F Fraser, Mark J SpangehlAbstract:Abstract Background Patella resurfacing is performed in >80% of primary total knee arthroplasties (TKAs) in the United States, yet far fewer Patellae are resurfaced internationally. Recent registry data have begun to question the long-held belief that Patellar resurfacing yields lower revision rates. Multiple current meta-analyses have not shown a difference in patient satisfaction, anterior knee pain, or knee society scores based on Patellar resurfacing. Methods We sought to determine how the rates of Patellar resurfacing have changed over the past 10 years worldwide (2004-2014). Data were abstracted from the annual reports of 7 national joint registries, literature review, or via direct correspondence with registry administrators. Results Average rates of Patellar resurfacing from 2004 to 2014 ranged from 4% (Norway) to 82% (United States). The largest decrease in resurfacing rates was in Sweden (15%-2%), whereas the biggest increase was in Australia (44%-59%). In 2010, only 48,367 of 137,813 (35%) primary TKAs from all registries outside the United States were resurfaced. Meta-analyses have demonstrated no difference in anterior knee pain or satisfaction scores but do consistently report increased revision rates for unresurfaced Patellae. Recent Swedish registry data, however, showed a reverse trend toward higher revision rates after resurfacing. Conclusion Despite recent registry data and meta-analyses demonstrating equivalent outcomes among resurfaced and unresurfaced Patellae in primary TKA, worldwide trends in Patellar resurfacing have changed little over the past decade. Most countries outside the United States continue to resurface a much smaller proportion of Patellae.
Ross Crawford - One of the best experts on this subject based on the ideXlab platform.
-
the outcome of total knee arthroplasty with and without Patellar resurfacing up to 17 years a report from the australian orthopaedic association national joint replacement registry
Journal of Arthroplasty, 2020Co-Authors: Joseph A Coory, Kelvin G Tan, Sarah L Whitehouse, Alesha Hatton, Stephen E Graves, Ross CrawfordAbstract:Abstract Background Patellar resurfacing in total knee arthroplasty (TKA) remains a controversial issue after more than 4 decades of TKA. Despite a growing body of evidence from registry data, resurfacing is still based largely on a surgeon’s preference and training. The purpose of this study is to provide long-term outcomes for Patellar resurfaced compared to when the Patella is not resurfaced. Methods Data from the Australian Orthopaedic Association National Joint Replacement Registry (1999-2017) were used for this study. The analysis included 570,735 primary TKAs undertaken for osteoarthritis. Hazard ratios (HRs) and 17-year cumulative percent revision rates were used to compare revision rates between 4 subgroups: minimally stabilized (MS) Patellar resurfacing, posterior stabilized (PS) Patellar resurfacing, MS unresurfaced, and PS unresurfaced Patella. Additional analyses of the Patellar implant type and a comparison of inlay and onlay Patellar resurfacing were also performed. Results For all primary TKA, procedures where the Patella was not resurfaced have a higher rate of revision compared to procedures where the Patella was resurfaced (HR, 1.31; confidence interval, 1.28-1.35; P Conclusion Resurfacing the Patella reduces the rate of revision for both MS and PS knees. MS knees with Patellar resurfacing have the lowest rate of revision. Onlay Patella designs are associated with a lower revision rate compared to inlay Patella designs.
Masataka Deie - One of the best experts on this subject based on the ideXlab platform.
-
quantitative stress radiography of the Patella and evaluation of Patellar laxity before and after lateral release for recurrent dislocation Patella
Knee Surgery Sports Traumatology Arthroscopy, 2014Co-Authors: Takuya Niimoto, Masataka Deie, Nobuo Adachi, Muhammad Usman, Mitsuo OchiAbstract:The aims of the present controlled clinical study were to (1) compare Patella laxity determined in the outpatient clinic with that in anaesthetized patients and (2) evaluate Patella laxity before and after lateral release. The study evaluated data on 33 knees from 33 patients (average age 19.7 years) between 2007 and 2011. All patients were diagnosed with recurrent dislocation of the Patella. Patellar stability was evaluated in each patient thrice: Patellas were first imaged in the outpatient clinic prior to surgery at 45° knee flexion with 20 N stress from the medial to lateral side and from the lateral to medial side; then, at the time of surgery, Patella stress images were obtained in the same manner before and after the lateral release procedure. Radiological assessments were performed using the medial stress shift ratio (MSSR) and lateral stress shift ratio (LSSR). There were no significant differences in the LSSR and MSSR before surgery (outpatient data) and in anaesthetized patients before the lateral release procedure. Furthermore, there was no significant difference in MSSR at the time of surgery before and after the lateral release procedure. However, LSSR increased significantly after the lateral release procedure. The results of the present study suggest that quantitative Patella stress radiography in the outpatient clinic is useful when it comes to investigating laxity of the Patella, and that lateral release significantly increases lateral, but not medial, laxity in patients with recurrent Patellar dislocation. IV.
-
A long-term follow-up study after medial patellofemoral ligament reconstruction using the transferred semitendinosus tendon for Patellar dislocation
Knee Surgery Sports Traumatology Arthroscopy, 2005Co-Authors: Masataka Deie, Mitsuo Ochi, Nobuo Adachi, Yoshio Sumen, Kenji Kobayashi, Masanori YasumotoAbstract:The management of Patellar dislocation syndrome has traditionally been difficult. There are no golden standard methods for Patellar dislocations probably due to the many etiologies. However, it is known that medial patellofemoral ligament (MPFL) is damaged when the Patella is dislocated. The purpose of this study is to examine whether our method of MPFL reconstruction is useful for the treatment of dislocated Patellae and unstable Patellae. Forty-six knees (43 patients) of 68 knees (65 patients) that were operated on using our surgical procedure for MPFL reconstruction with the advancement of the vastus medialis or the MPFL reconstruction with Insall’s procedure were followed up for at least 5 years. The patient age ranged from 6 to 43 years. These knees consisted of six habitual dislocation Patellae, twenty-six recurrent dislocation Patellae, ten traumatic dislocation Patellae, and four unstable Patellae. The patients were evaluated pre-operatively and more than three times post-operatively at 6, 12, 36, 60, or 120 months. No patient experienced Patellar dislocation after surgery. Their post-operative Kujala’s scores were significantly improved. On conventional X-ray and on stress X-ray evaluations, the mean values for congruence angle, tilting angle, lateral shift ratio, medial stress shift ratio, and lateral stress shift ratio at the final follow-up (60 or 120 months) were demonstrated to be within the normal range. We conclude that our MPFL reconstruction method with the advancement of the vastus medialis or with Insall’s procedure might be recommended for the treatment of habitual, recurrent, and indeed any other type of Patellar dislocation, as well as for unstable Patellae.
Pieter J Erasmus - One of the best experts on this subject based on the ideXlab platform.
-
comparison of commercial patellofemoral arthroplasty systems on the basis of Patella kinematics peri Patellar soft tissue tension and prosthesis design
Journal of Mechanics in Medicine and Biology, 2012Co-Authors: Jacobus H Muller, Pieter J Erasmus, Cornie SchefferAbstract:Patellofemoral arthroplasties are desirable when treating isolated patellofemoral osteoarthritis, due to preservation of the tibiofemoral joint. Since few studies report on new commercial patellofemoral prosthesis biomechanics, a musculoskeletal model enabling analysis of subject-specific knee biomechanics was used to compare four patellofemoral replacement systems (A, B, C, and D) to one another. The prostheses were implanted according to manufacturer guidelines, after which the knee flexed and extended under active muscle loading. An increased patellotrochlear index enabled early Patella-trochlear groove engagement. The resurfaced Patellae were stable in mediolateral shift and anteroposterior displacement, but only Prosthesis A and D provided a smooth transition between the distal prosthesis border and femoral cartilage. A reduction in the anteroposterior condylar distance displaced the Patella posteriorly, resulting in reduced peri-Patellar soft tissue tension but an increased Patella tendon–quadriceps tendon ratio. The tibial tubercle–trochlear groove distance became pathologic in all replacements. The Patella will be stable irrespective of the prosthesis used, but Prosthesis A and D seem to provide a better fit to the trochlear groove anatomy. The increased tibial tubercle–trochlear groove distance emphasizes the importance of extensor alignment in combination with the placement of the prosthesis: an increased Q-angle might lead to excessive lateral wear on the Patella button. The extensor mechanism load will increase post-surgery based on the rise in the Patella tendon–quadriceps tendon ratio which points to a reduced moment arm. This work provides insight into the dynamic biomechanical function and the design of current commercial patellofemoral replacement systems.
-
recurrent Patellar dislocation after medial patellofemoral ligament reconstruction
Knee Surgery Sports Traumatology Arthroscopy, 2008Co-Authors: Mathieu Thaunat, Pieter J ErasmusAbstract:We report on three cases of recurrent lateral Patellar dislocation following a medial patellofemoral ligament (MPFL) reconstruction for Patellar instability. In all three cases, an isolated MPFL reconstruction was performed with a double autogenous gracilis graft. The Patellar fixation was done through bone tunnels. All three patients presented with a definite moderate to severe traumatic episode resulting in a recurrent Patella dislocation and a transverse avulsion fracture at the medial rim of the Patella. All three were treated by an open reduction and internal fixation with good results. No complication or recurrent dislocations occurred. We suggest that this complication is caused by the original underlying pathology such as dysplastic trochlea, abnormal TT–TG, Patella alta and hyperlaxity, resulting a greater reliance upon the reconstructed MPFL for Patellar stability. When subjected to a severe stress, the graft, which is stronger and stiffer than the original MPFL, will cause a fracture through the medial edge of the Patella. This weak area results from the previous drill holes, which act as stress risers.
