Retention of the patella in total knee arthroplasty for rheumatoid arthritis.

AIM: To determine whether retention of the native patella during total knee arthroplasty is appropriate in patients with rheumatoid arthritis.
METHODS: All patients undergoing total knee arthroplasty with a diagnosis of rheumatoid arthritis were identified between January 1997 and December 2000. Subsequently, each individual underwent both radiological and clinical assessments at a designated follow-up clinic.
RESULTS: A total of 30 total knee arthroplasties were studied in 28 patients. Twenty-six patients (93%) were female with a mean age of 74.7 years (range 60-83 years). The average post-operative interval was 59.4 months (range 46-82 months). All individuals were noted to have satisfactory patellar tracking and bone stock at the time of surgery. No patient subsequently underwent revision surgery during follow-up and no episodes of implant sepsis were identified. The mean Patellar Score at final follow-up was 26.2 (range 22-30) with an average anterior knee pain score of 14.2 (range 10-15). The mean Oxford Knee Score was 18.7 (range 16-23) with a mean pain score component of 5.9. Patients were finally assessed with respect to the Knee Society Score. The mean Knee Score was 83.8 (range 71-96) with a mean Function Score of 79.7 (range 40-90).
CONCLUSION: By retaining the native patella we were still able to obtain highly satisfactory medium-term results in terms of pain relief and function. In addition, the potential complications associated with prosthetic replacement of the patella were avoided.