Aims: The purpose of this study was to determine whether patella replacement or RAP of the patella is advantageous in TKA.

Methods: 100 patients were recruited to enter a randomised, prospective, double blind clinical trial to determine the efþcacy of patellar resurfacing during total knee arthroplasty. All patients receive the same posterior cruciatesparing prosthesis, and all operations were performed by, or under the direct supervision of the þrst author. Evaluation consisted of the determination of the HSS-Score, the knee society scores, speciþc questions relating to patellafemoral symptoms, radiographs, measurement of torques and stability of one leg standing. All knees were followed at 3 month and 18 month postoperatively.

Results: There was no signiþcant difference between the two groups with regard to the HSS-Score, and the KS-scores. Excentric and concentric torques were higher in the group with RAP of the patella. One leg standing was more stable in the group with RAP of the patella. In both groups one patient complained of severe anterior knee pain. The patient with RAP of the patellar was treated successfully with secondary patella resurfacing.

Conclusions: The clinical outcome and the prevalence of anterior knee pain after TKA with the PFC-∑ knee was not inßuenced by whether or not the patella had been resurfaced. Force and balance are slightly better after TKA with RAP of the patella.