What question did this study set out to answer?

This research aims to assess mid-term outcomes and survivorship of trochlear arthroplasty for isolated patellofemoral arthritis.

March 3, 2026Open Access

Mid-Term Outcomes of Isolated Trochlear Arthroplasty for Patellofemoral Arthritis: A Joint-Preserving Alternative to Complete Patellofemoral Replacement

Key Points

This research aims to assess mid-term outcomes and survivorship of trochlear arthroplasty for isolated patellofemoral arthritis.
Retrospective review of 50 patients who underwent trochlear arthroplasty between 2008 and 2019.
Medial parapatellar approach with intraoperative joint assessment.
Patelloplasty and circum-patellar neurectomy performed without resurfacing.
Implant survival evaluated using Kaplan-Meier analysis and revision factors assessed with Cox proportional hazards modeling.
Kujala score collected from a subset of unrevised patients.
Overall implant survivorship was 82% at a mean follow-up of 9.2 years.
18% of patients required revision, primarily due to progression of tibiofemoral arthritis.
Revision procedures included patellar resurfacing and staged medial unicompartmental knee replacement.
Mean Kujala score for unrevised patients was 56.1, with no instability or significant flexion deficits reported.
Age and sex were not significant predictors of revision outcomes.

Abstract

Background Trochlea-only arthroplasty (TOA) is a conservative surgical approach for isolated patellofemoral arthritis, aimed at preserving the native patella and avoiding complications associated with its resurfacing. This study evaluates the mid-term survivorship, functional outcomes, and revision profile of patients undergoing TOA and compares outcomes with historical data from conventional patellofemoral arthroplasty (PFA). Methods We retrospectively reviewed 50 patients who underwent isolated TOA between 2008 and 2019 by a single surgeon. A medial parapatellar approach was used, with intraoperative assessment of the joint. The decision to retain the native patella was made irrespective of the extent of arthritis in the patella. All patients underwent patelloplasty and circum-patellar neurectomy without resurfacing. Implant survival was evaluated using Kaplan-Meier analysis, and factors influencing revision were assessed using Cox proportional hazards modelling. Patient-reported outcomes were collected using the Kujala score in a subset of patients with unrevised implants. Results The overall implant survivorship was 82% at a mean follow-up of 9.2 years. Nine (18%) patients required revision, most commonly due to progression of tibiofemoral arthritis. Revisions included patellar resurfacing, staged medial unicompartmental knee replacement, and conversion to total knee arthroplasty. Age and sex were not significant predictors of revision. The mean Kujala score in 13 (32%) unrevised patients was 56.1, with no reports of instability or significant flexion deficits. No patients with known revisions were contacted for patient-reported outcomes. Conclusion TOA is a viable joint-preserving surgical option for selected patients with isolated patellofemoral arthritis. It avoids the complications associated with patellar resurfacing and maintains satisfactory mid-term survivorship comparable to published literature. TOA may serve as a procedural bridge between conservative management and full PFA, allowing for a stepwise and anatomically conservative approach. Further prospective studies are warranted to validate these findings.

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