Trabecular metal patella in total knee arthroplasty with patella bone deficiency

This study evaluates results following patellar resurfacing using trabecular metal (TM) patella in marked deficiency or weakness of patellar bone that precludes patellar resurfacing with a standard cemented patellar button. Ten consecutive patients undergoing primary (3 cases) or revision (7 cases) total knee arthroplasty with patella augmentation were evaluated at a mean follow-up of 45 months (range 18-65). Nine patients had marked patellar bone deficiency and one had had previous patellectomy. No intra-operative complications occurred. There was no displacement of the patellar component and no patellar fractures when at least 50% of bone contact was possible. We observed loosening of the patella augmentation 17 months after the index procedure only in the case of previous patellectomy. When bone was present the fixation appeared excellent by radiographic evaluation already at 3 to 6 months after surgery; afterward bone contact was uniform in the peripheral regions in both lateral and Merchant radiographic views without signs of loosening. Finally, the mean Knee Society scores improved in all patients.