Second-Generation Onlay Patellofemoral Prostheses: 14-Year Outcomes Redefining Isolated Patellofemoral Osteoarthritis Management.

BACKGROUND

Isolated patellofemoral osteoarthritis is a frequent source of anterior knee pain in middle-aged patients. Second-generation onlay patellofemoral prostheses were developed to address limitations of earlier designs and improve clinical outcomes.

METHODS

We conducted a retrospective study of 231 patients (mean age 52.2 years) who underwent patellofemoral arthroplasty with a second-generation onlay implant between 2009 and 2023. Clinical outcomes were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index and Kaplan-Meier survival analysis. Radiological evaluation included signs of loosening, progression of tibiofemoral osteoarthritis, and patellar alignment.

RESULTS

At a mean follow-up of 9.3 years (range: 2-14), Western Ontario and McMaster Universities Osteoarthritis Index scores improved significantly from 92.14 to 8.40 ( < .001). The implant survival rate was 96.6% at the final follow-up. Early clinical gains were significantly influenced by implant type, while long-term outcomes were associated with patient-specific factors such as body mass index and activity level. Radiological progression of tibiofemoral disease was observed in 6.1% of patients.

CONCLUSIONS

Second-generation onlay patellofemoral prostheses yield sustained functional improvement and low complication rates when used in carefully selected patients. These findings support their use as a reliable solution for isolated patellofemoral osteoarthritis.

LEVEL OF EVIDENCE

III.