Indications for Patella Resurfacing in Total Knee Arthroplasty

Abstract

There is no consensus on whether the patella should be resurfaced in total knee arthroplasty (TKA) at present. Therefore, the indications for patellar resurfacing in TKA were evaluated in this study.
Sixty-seven knees that were received TKA between 1996 and 1998 were studied. The patella were resurfaced in 26 knees, but were not resurfaced in 41 knees. The mean age of the patients was 71 years, and the follow-up period ranged between 24 months and 60 months, with a mean period of 41 months.
The Japanese Orthopaedic Association (JOA) scores, patella scores, and plain radiographs were evaluated. In the non-resurfacing group, the deformation of the patellofemoral joint was investigated, and the patella scores and femoral rotational alignment were evaluated by the degree of congruity between the patellofemoral joint.
Although there were no significant differences between two groups in JOA scores, in those cases with rheumatoid arthritis, the resurfacing group was significantly higher than the non-resurfacing group in patella scores. Anterior knee pain tended to appear more often in the non-resurfacing group. In the resurfacing group, we observed more progressive deformation of the patellofemoral joint and lower patella scores when the congruity between the patellofemoral joints were not good. This trend was more pronounced in those cases with rheumatoid arthritis. In the cases with low femoral rotational alignment scores, the joints were incongruity.
In those cases with osteoarthritis, resurfacing of patella is not necessary in the long term if the femoral rotation is adjusted adequately and the patellofemoral joint is congruent. However, in those cases with rheumatoid arthritis, patellar resurfacing is recommended because the deformation of the joint progresses, and the frequency of pain increases with time even when the patellofemoral joints are congruent.