The Clinical Outcome of Patellofemoral Arthroplasty vs Total Knee Arthroplasty in Patients Younger Than 55 Years.

Background: Patellofemoral osteoarthritis affects 10% of patients older than 40 years and is commonly treated by patellofemoral joint 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 in patients younger than 60 years.

Methods: A retrospective case-matched cohort based on age, sex, body mass index, and side of 23 PFAs (in 19 patients) operated on by 2 surgeons and of 23 TKAs (23 patients) operated on by 6 surgeons was included in the study. All patients were younger than 55 years and operated on between March 2010 and September 2015. The Western Ontario and McMaster Osteoarthritic Index, Knee injury and Osteoarthritis Outcome scores, Tegner, and University of California, Los Angeles activity scores were compared between preoperative and minimum 2-year postoperative timepoints between groups.

Results: TKA and PFA were comparable on all patient-reported outcome measures at minimum 2-year follow-up; however, PFA patients exhibited statistically significantly larger improvement between 1 year postoperative and 2 years postoperative timepoints (P < .05). All patients improved between preoperative and postoperative timepoints (P < .05).

Conclusion: 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 patellofemoral osteoarthritis who desire a more conservative, kinematic-preserving approach, PFA continues to be a practical treatment option yielding early outcomes that compare favorably with TKA.