The Clinical Outcome of Patellofemoral Arthroplasty vs Total Knee Arthroplasty in Patients under age 55 with Isolated Patellofemoral Osteoarthritis

Abstract Background Patellofemoral osteoarthritis (PF OA) affects 10% of patients over 40 years of age and is commonly treated by Patellofemoral Arthroplasty (PFA) or a Total Knee Arthroplasty (TKA). PFA is a more conservative approach with documented faster recovery. No study to date has compared both approaches with respect to patient reported outcome measures (PROMs) in patients under 60 years of age. Methods A retrospective case-matched cohort study based on age, sex, BMI, and side, of 23 PFAs (in 19 patients) operated on by two surgeons and 23 TKAs (23 patients) operated on by six surgeons were included in the study. All patients were under the age of 55 and operated on between March 2010 and September 2015. The Western Ontario and McMaster Osteoarthritic Index (WOMAC), Knee injury and Osteoarthritis (KOOS) scores, Tegner, and UCLA were compared between pre-operative and minimum 2-year post-operative timepoints between groups. Results TKA and PFA were comparable on all PROMs at minimum 2-year follow-up, however, PFA patients exhibited statistically significantly larger improvement between 1-year post-op and 2 years post-op (p Discussion Although TKA performed better with respect to functional outcomes at the 1-year mark, at 2-year follow-up, PFA and TKA performed equally well. Our results allow us to conclude that in younger patients with isolated PF OA who desire a more conservative, kinematic-preserving approach, PFA continues to be a practical treatment option yielding early outcomes that compare favorably with TKA.