Development and early results of a new patellofemoral arthroplasty.

UNLABELLED: A new patellofemoral arthroplasty is described, based on a previous design of total knee arthroplasty. The indications are for patients with specific isolated patellofemoral disease with advanced chondral or arthritic damage. The design and technique of insertion is detailed. Three hundred six patellofemoral arthroplasties have been done in 240 patients. The initial results show a high level of pain relief and improvement in function. Two-year followup is available for treatment of 124 knees and 5-year followup is available for treatment of 33 knees. There has been no deterioration in pain or function with followup to 5 years, and there were no late complications attributable to the arthroplasty. Disease progression in the tibiofemoral joint has occurred in 14 patients (16 knees, 5%) requiring revision in 10 of these patients (11 knees, 3.6%). Persistent anterior knee pain was recorded in 14 knees (4%). The short-term results using this new design were better than those of the prosthesis that we used previously, especially concerning malalignment and wear. It offers a reasonable alternative to total knee replacement in the small group of patients with isolated patellofemoral disease. LEVEL OF EVIDENCE: Therapeutic study, Level II (prospective cohort study). See the Guidelines for Authors for a complete description of levels of evidence.