Revision Total Knee Arthroplasty: Surgical Technique in Dealing with Extensor Mechanism Failure

Abstract

Extensor mechanism failure is a challenging issue after total knee arthroplasty. Under this term, several scenarios can be included, varying from patellar instability to patellar fracture or loosening and patellar or quadriceps tendon failure. Most of these complications may have a devastating influence on limb function with a major impact on the quality of life. Since the etiology is often multifactorial, patient’s history as well as clinical presentation must be carefully evaluated. Imaging study may be an additional tool in doubtful cases. The choice between conservative or surgical treatment must take into account all these aspects. However, whereas conservative management of patellar fractures is usually successful, patellar or quadriceps tendon ruptures often require surgical repair or reconstruction. In the same way, patellar loosening requires surgical approach. The treatment of patellar instability is complex and requires the precise definition of the risk factors. However, since the majority of these factors are related to poor surgical technique at the time of the first implant, revision of the femoral and tibial components is often required.