Abstract
We reviewed the patellofemoral problems of patients who received Mark 3 type total knee arthroplasty (TKA). There were 99 knee joints including 39 osteoarthrosis (OA) and 60 rheumatoid arthritis (RA) patients. Radiograms of all knees were reviewed. In 45 knee joints, clinical examination and radiological measurement were done and JOA scores before and after surgery were compared. The lateral shift ratio was calculated and the thickness of the patella was measured from the skyline view.
There were two patella fractures. One fracture might be attributed to strenuous work as a farmer, and the other might be due to severe osteoporosis with ankylosis in the contralateral knee. Neither patella dislocation nor broken patella component were seen these 99 knees.
Anterior knee pain appeared in only two out of 45 knees. Mean JOA score improved after TKA both in OA (preop. 44, post op. 71) and in RA knees (preop. 33, post op. 72). All 45 knees showed lateral shift of the patella. However, this did not indicate a poor result.
There was no correlation between JOA score and the lateral shift ratio nor between JOA score and thickness of the patella.
