A Comparison of Patella Retention versus Resurfacing in Total Knee Arthroplasty: A Minimum 7 Year Follow-up / 대한정형외과학회잡지

ABSTRACT

PURPOSE: To evaluate and report the clinical and radiological results of patients that had undergone patellar retention and resurfacing during total knee arthroplasty. MATERIALS AND METHODS: From July 1993 to December 1999, 54 patients (73 cases) underwent total knee arthroplasty by one surgeon. We divided these patients into the patellar retention group and patellar resurfacing group, and compared the clinical and radiological results of the two groups. The indications of patellar retention were a small patella, nearly normal articular cartilage, minimal preoperative patellofemoral pain, poor patellar bone quality, and young patient age. In these cases, osteophytes of the patella were removed and marginal electrocauterization was performed. There were 32 patients (41 cases) in the patellar retention group and 22 patients (32 cases) in the patellar resurfacing group. The mean follow-up period was 106.7 months in the patellar retention group and 93.6 months in the patellar resurfacing group. We evaluated the patients using the knee rating system of the American Knee Society (knee score and functional score), knee arthroplasty rating system of the Hospital for Special Surgery (HSS score), patellofemoral score, range of motion of the knee joint, and performed a radiological evaluation by use of the radiographical evaluation system of the Knee Society at the last follow-up period. Also, to evaluate patellofemoral congruence, we used Keblish's method. RESULTS: At the last follow-up, the mean knee score and functional score were 90.4 and 75.5 for the patellar retention group, and 86.1 and 70.0 for the patellar resurfacing group, respectively (p=0.29, p=0.27). The HSS score was 85.2 for the patellar retention group and 84.8 for the patellar resurfacing group (p=0.30). The Bristol patellar score and Lonner Patellofemoral score were 8.7 and 82.0 for the patellar retention group and 8.8 and 85.6 for the patellar resurfacing group, repectively (p=0.86, p=0.86). The mean value of the patellofemoral score was slightly higher in the patellar resurfacing group, but statistically there was no difference between the two groups. There were also no statistically differences in the others parameters. CONCLUSION: We obtained favorable results by selective patellar resurfacing total knee arthroplasty, although there were no significant differences for both the patellar retention and resurfacing group. We believe that it may be better to select a proper indication than to just follow the preference of the surgeon for patellar resurfacing.