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

Jung, Yung Bok; Yum, Jae Kwang; Lee, Jin Woo; Jang, Eui Chan

Abstract

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.