Patella Resurfacing Versus Nonresurfacing in Bilateral Total Knee Arthroplasty

Bae, Dae Kyung; Lee, Dong Hee; Baek, Chang Hee; Cho, Jong Hoon

Abstract

Patellofemoral complications are the most frequent problems in total knee arthroplasty. In the literature, the subject of patella resurfacing and nonresurfacing is controversial. Twenty-seven osteoarthritic patients who received bilateral total knee prostheses were studied to evaluate the advantages and disadvantages of patella resurfacing prospectively. Only patients with mild patellofemoral disease were included in the study. The Ortholoc modular implant was used in all cases. Cementless femoral and tibial component were used. But, if we resurfaced the patella, cement was used. In all patients, patella resurfacing had been done in the left knee but not in the right knee. For the clinical analysis, We used Knee Rating Score of the Hospital for Special Surgery(HSS), For the roentgenographic analysis, We used Laurin's lateral patellofemoral angle & Merchant's congruence angle. In the follow up, blind test for patellar pain was performed to compare between right and left knee joint clinically. The average age was 61 years(range 28-72 years) and the average follow up was 21 months(range 12-27 months). Preoperative ROM was 104.4 degrees in right side and 106.7 degrees in left side. Postoperative ROM was 112.7 degrees in right side and 109.6 degrees in left side. Preoperative HSS Knee Rating Score was 53.1 point in right side and 54.8 point in left side. Postoperative HSS Knee Rating Score was 81.5 point in right side and 81.2 point in left side. In the plain knee AP view, preoperative tibiofemoral angle was varus 7.0 degrees in right side and varus 5.6 degrees in left side. Postoperative tibiofemoral angle was valgus 5.1 degrees in right side and valgus 4.9 degrees in left side. Preoperative Merchant's congruence angle was 14.9 degrees in right side and 15.3 degrees in left side. Postoperative Merchant's congruence angle was -2.2 degrees in right side and -0.6 degrees in left side. Range of motion, Knee Rating Score, and X-ray findings revealed no distinct differences. In the blind test of the last follow up, six patients preferred the knee with the unresurfaced patella over the resurfaced knee, three patients preferred the knee with the resurfaced patella and 18 patients responded to be equal.