Management of the patella during revision total knee replacement arthroplasty.

Managing the patella and balancing the patellofemoral joint space is one of the most difficult aspects of performing a primary total knee replacement (TKR). The situation is compounded in the revision situation. Unfortunately, an otherwise well-performed TKR will fail because of problems with the patella or the extensor mechanism. This article discusses various aspects of the management of the patella and extensor mechanism during revision TKR with an objective of minimizing complications and maximizing functional outcomes. The topics covered include exposure of the patella and extensor mechanism during revision surgery, whether or not to remove all prior patellar implants, the technique for removal of a prior implant, the management of bone loss or fractures of the patella during revision TKR, the insertion (or noninsertion) and fixation of a new implant, and the balance of the patellofemoral joint space, including avoidance of patella baja or patella alta. A compilation of scientific and "no-so" scientific data and experience gleaned over the past 26 years of total knee replacement surgery will be presented.