Availability of Patella Resurfacing in Primary Total Knee Arthroplasty Through Evaluation and Analysis of the Patella in Revision Total Knee Arthroplasty / 대한정형외과연구학회지

PURPOSE: The aim of this study was to discuss about availability of patella resurfacing in primary total knee arthroplasty through evaluation and analysis of the patella in revision total knee arthroplasty. MATERIALS AND METHODS: The study was performed for 27 patients who could be followed up more than 12 months after having the revision TKA from March, 2004 to July 2008 among 105 patients (145 knees) who could be followed up more than 5 years after having primary TKA due to degenerative arthritis from 1989 to 1997. There were Group A (15 knees) which had patella resurfacing in revision TKA without patella resurfacing in primary TKA, Group B (12 knees) which had patella resurfacing in primary TKA, but didn't have patella resurfacing in revision TKA. There was difference of mean 11.2 years (6~15 years) between the time that the patients had primary TKA and the time that the patients had revision TKA. The patients consisted of 3 males and 24 females. The average age of the patients who had revision TKA was 76.2 years old (68~87). The Feller's patella score was used as clinical evaluation system after primary TKA, before and after revision TKA, and last follow-up. Ahlback's score was used by for the radiological evaluation of preoperative and postoperative outcome. And Outerbridge classification was used for the evaluation of group A which about wear of articular surface of patellofemoral joint in primary TKA and revision TKA, and positions of wear were classified. RESULTS: The Feller's patella score of group A, The outcome before revision TKA, 14.5 points, after 3 months TKA, 22.6 points, and 12 months follow-up, 24.2 points. The Feller's patella score of group B, The outcome before revision TKA, 24.2 points, after 3 months TKA, 24.3 points, and 12 months 24.8 points. The Ahlback score of group A decreased from 3.4 to 1.7 points, group B decreased from 1.6 to 1.5 points and group C decreased from 3.8 to 1.7 points. The Outerbridge classification of group A was mean 1.9 grade in primary TKA, and mean 3.6 grade in revision TKA. The wear of patella mainly occurred at medial facet. CONCLUSION: The patella resurfacing in primary TKA is considered as a useful treatment on the basis of these clinic and radiologic evaluation.

Comparison of Patella Retention Versus Resurfacing in Total Knee Arthroplasty: Preliminary report / 대한정형외과학회잡지

There is a controversy in patella retention or resurfacing in total knee arthroplasty (TKA) till today. Authors studied 52 cases of 45 patients recieved total knee arthroplasty with patella retention (Group 1, twenty-five cases) or patella resurfacing (Group 2, twenty-seven cases) in patients with osteoarthritis. All operations were done by senior surgeon and the implants used were LCS type (33 cases), AMK type (12 cases), Genesis type (5 cases) and Tricon M type (2 cases). The indications of patella retention were small patella, nearly normal articular cartilage, minimal pre-operative patellofemoral pain, poor patellar bone quality and young patients. Patella retention were performed only with LCS prosthesis, which patella groove of the femoral component is deep and anatomical. The operative approaches used were medial parapatella approach in neutral or varus knee and lateral parapatella approch for severe valgus knee and tilting or lateral subluxation of the patella. The mean follow-up period was 24 months (range 12 months to 5 years). The method for clinical evaluation was Hospital for Special Surgery (HSS) knee scoring (consisted of pain, function, range of motion). The method for radiographical evaluation was Knee societys radiologic evaluation system for tibial and femoral alignment, and Keblishs method for patello-femoral congruence. The clinical HSS knee score was average 90.9 points in both groups, and 91.9 points in group 1, 90.0 points in group 2, and there was no statistically difference in HSS knee score between the two groups (P<0.05). The radiologic results had no significant difference in alignment and patello-femoral congruence between the two groups (P<0.05). But the complications were one case of patella fracture, one patella tendon rupture, one anterior instability and two cases of infection in group 2. In conclusion, the results of both groups were satisfactory. We think that it have relation to strict selection of the patients for patella retension and the use of prosthesis that the patella groove of femoral component is deep and anatomical.