TRABECULAR METAL PATELLA IN TOTAL KNEE ARHROPLASTY

Abstract

Compromised patellar bone stock poses significant the chnical problems in primary and revision knee arthroplasty. In these situations, traditional approaches have included: non resurfacing, patellectomy, patellar bone grafting, ‘Gull-Wing’ osteotomy. A new material (Trabecular Metal) fabricated using a tantalum metal and vapor deposition techhnique that create a metallic strut configuration with 80%porosity, and physical and mechanical properties similar to bone has been introduced. The authors studied the short-term results following patellar resurfacing using trabecular metal patella in primary and revision total knee arhroplasty (TKA).

Nine patients undergoing primary (2 cases) or revision (7 cases) TKA with the use of a trabecular metal patella were evaluated at a mean of 16 months follow-up. All patients had marked patellar bone deficiency precluding resurfacing with a standard cemented patellar button. The all polyethylene patela was cemented into the trabecular metal base and the remaining patella bone stock; additional fixation was provided by # 2 non absorbable sutures through the peripheral holes on the metal shell.

Revision TKA may be complicated by severe patellar bone loss that preclude implantantion of a standard cemented patellar component. Several options including patellectomy, non resurfacing and osteotomy or grafting of remaining bony shell have been proposed. It is rare in primary knee arthroplasty that the patella has been so eroded that resurfacing is not feasible. Trabecular metall patella may be indicate in the complex revision or even primary knee arthroplasty in which all that remains of the patella is a thin shell of anterior cortical. The short-term results of patellar resurfacing with trabecular metal have demonstrated favorable results.