Do we need to replace the patella in knee arthroplasty for rheumatoid disease?

We have examined the anterior knee function in two patient groups who had undergone primary knee arthroplasty without patellar resurfacing to identify differences for osteoarthrosis compared with rheumatoid disease. We identified two consecutive series of patients who had undergone knee replacement surgery for either osteoarthritis or rheumatoid disease between 1992 and 1994 under the care of a single surgeon using the same implant and surgical technique. There were 90 patients in each group. All were examined and asked to complete a questionnaire so as to determine Hospital for Special Surgery (HSS) score, Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) score, Bartlett patellar score and a Visual Analogue score (VAS) for any persistent anterior knee pain at rest. We failed to identify any significant differences in terms of anterior knee function between these two groups of patients. The re-operation rate was similar for both groups. It would appear that primary knee replacement for rheumatoid disease is met with a similarly good outcome for anterior knee function despite absence of patellar resurfacing. We would question the contention that patellar resurfacing is necessary for patients undergoing knee replacement for rheumatoid disease.