WHEN SHOULD PATELLAR RESURFACING BE DONE IN TOTAL KNEE ARTHROPLASTY?

Abstract

Introduction: Patellar resurfacing (pr) in total knee arthroplasty (TKA) is still controversial. Outerbridge classification of cartilage defects in the patella is the most commonly used one in the literature. The purpose of this study is to determine when PR should be done depending on the degree of cartilage involvement of the patella according to Outerbridge classification.

Materials and Methods: Between 1995 and 2000 we performed a prospective randomised study of 500 TKAs. We performed PR or not depending on the Outerbridge classification of the patella at the time of surgery. Patients with grades I, II and III of Outerbridge formed group A, while patients with grade IV formed group B. Within each group resurfacing was completed on one half of the patients. Group A was formed by 328 patients (164 with PR, 164 without PR). In group B there were 172 patients (86 with PR and 86 without PR). In both groups we always used the same prosthetic design. The average follow-up was 7.8 years for both Group A and Group B. At the end of follow-up we assessed the number of patients in each group that required a secondary resurfacing because of patellofemoral pain.

Results: In group A only one patient required a secondary PR (1.2% rate), while in group B ten patients needed PR (9.8% rate).

Conclusions: The findings of this study make us recommend PR in Outerbridge grade IV patellae, but not in grades I, II and III.