There are a number of options available to manage the patella when revising a failed total knee arthroplasty. If the previous
patellar component is well-fixed, undamaged, not worn, and compatible with the femoral revision component, then it can be
retained. When a patellar component necessitates revision and is removed with adequate remaining patellar bone stock, an onlay-type
all-polyethylene cemented implant can be used. Management of the patella with severe bony deficiency remains controversial.
Treatment options for the severely deficient patella include the use of a cemented all-polyethylene biconvex patellar prosthesis,
patellar bone grafting and augmentation, patellar resection arthroplasty (patelloplasty), performing a gull-wing osteotomy,
patellectomy, or the use of newer technology such as a tantalum (trabecular metal) patellar prosthesis. Severe patellar bone
deficiency is a challenging situation because restoration of the extensor mechanism, proper patellar tracking, and satisfactory
anatomic relationships with the femoral and tibial components are critical for an optimal clinical outcome.
Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
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