Patellar resurfacing in total knee arthroplasty - A prospective, randomized, double-blind study with five to seven years of follow-up

Background: Whether to resurface the patella during a primary total knee ar throplasty performed for the treatment of degenerative osteoarthritis remai ns a controversial issue. Parameters that have been suggested as being usef ul in guiding this decision include patient height and weight, the presence of anterior knee pain preoperatively, and the grade of chondromalacia enco untered intraoperatively. The purpose of this study was to determine whethe r these parameters were predictive of the clinical result following total k nee arthroplasty with or without patellar resurfacing. Methods: Eighty-six patients (118 knees) undergoing primary total knee arth roplasty for the treatment of osteoarthritis were enrolled in a prospective , randomized, double-blind study. All patients received the same posterior- cruciate-sparing total knee prosthetic components. Patients were randomized to treatment with or without resurfacing of the patella. Evaluations consi sted of the determination of a Knee Society clinical score, the completion of a patient satisfaction questionnaire, specific questions relating to pat ellofemoral symptoms, and radiographs. Sixty-seven patients (ninety-three k nees) were followed for a minimum of five years (range, sixty to eighty-fou r months; average, 70.5 months). Results: With the numbers available, there was no significant difference be tween the groups treated with and without resurfacing with regard to the ov erall Knee Society score or the pain and function subscores. Obesity, the d egree of patellar chondromalacia, and the presence of preoperative anterior knee pain did not predict postoperative clinical scores or the presence of postoperative anterior knee pain. Conclusions: The occurrence of anterior knee pain could not be predicted wi th any clinical or radiographic parameter studied. On the basis of these re sults, it seems likely that postoperative anterior knee pain is related eit her to the component design or to the details of the surgical technique, su ch as component rotation, rather than to whether or not the patella is resu rfaced.