Background: Limited data are available on return to sports and patient psychometric ratings of success after patellofemoral arthroplasty (PFA) in younger patients with high expectations to return to an active lifestyle.
Purpose/hypothesis: The purpose of this article was to determine the role of PFA and its success in meeting patient expectations regarding the return to low-impact recreational sports and an active lifestyle in younger, active patients. It was hypothesized that PFA would allow younger patients to return to low-impact sports and an active lifestyle and achieve high patient psychometric ratings.
Study design: Case series; Level of evidence, 4.
Methods: In this 10-year prospective study (2009-2018), robotic-assisted PFA was performed on 44 patients (32 women and 12 men; n = 51 consecutive knees), with a mean age of 37.2 years (range, 21-50 years). The follow-up rate was 98%, with a mean of 5.3 years (range, 2-9.3 years). Primary clinical outcomes were as follows: the validated Cincinnati Knee Rating System sports activity and symptom rating scales, patient psychometric ratings of the substantial clinical benefit (SCB), and the Patient Acceptable Symptom State (PASS). Secondary outcomes were the Cincinnati Knee Rating System occupational rating, visual analog pain scale, and the 12-Item Short Form Health Survey. Survivorship was defined by conversion to total knee replacement (TKR).
Results: Before PFA, 78% of patients (35/45 knees) were symptomatic and unable to perform recreational sports, with only 20% of patients (9/45 knees) performing some low-impact sports. After PFA, 80% of patients (36/45 knees) were able to perform low-impact sports, and 7% (3/45 knees) performed jumping-pivoting sports (P < .001). The SCB scored by the patient showed 87% of knees as good, very good, or normal. On the PASS analysis, 89% of patients (95% CI, 76%-96%) were "pleased," and 93% (95% CI, 82%-99%) would undergo surgery again. There were clinically relevant improvements in symptoms of pain, swelling, and giving way (P = .0001). Preoperatively, 91% of knees had moderate to severe pain with activities of daily living, and only 11% of knees had pain at the follow-up. Five of the 50 knees (10%) underwent TKR conversion with one patient lost to follow-up.
Conclusion: PFA resulted in a high return of patients to low-impact sports with high SCB and PASS psychometric ratings. The robotic-assisted 3-dimensional preoperative planning allowed precise intraoperative trochlear implant alignment in knees with severe trochlear dysplasia. PFA is recommended as an alternative treatment in younger patients with end-stage symptomatic patellofemoral arthritis.
Registration: NCT02738476 (ClinicalTrials.gov identifier).
Keywords: extensor mechanism malalignment; patellofemoral osteoarthritis; robotic patellofemoral arthroplasty; trochlear dysplasia.