TKA Extensor Mechanism Complications

In recent years, extensor mechanism complications such as patellar instability, prosthetic wear and loosening, soft tissue impingement, and patellar clunk have overall become a less frequent cause for reoperation after total knee arthroplasty (TKA). Extensor mechanism disruptions however, although rare, remain a challenging problem to treat. These include patellar and quadriceps tendon ruptures and patellar fracture. The diagnosis of these conditions is made clinically, with patients presenting with extensor lag being the most likely candidates for surgery. For both patellar and quadriceps tendon tears, direct repairs have proven unsatisfactory. The most up-to-date literature has demonstrated the effectiveness of Marlex mesh reconstructions. Fractures of the patella occasionally necessitate operative intervention in the form of open reduction and internal fixation (ORIF) or patellar fracture resection with extensor mechanism advancement, but the results remain somewhat unpredictable. This chapter describes various surgical options to address each of these three unique disruptions of the extensor mechanism with an emphasis on the author’s preferred technique of Marlex mesh reconstruction and provides up-to-date literature regarding the effectiveness of various surgical techniques in addition to potential complications that may arise in these patients after surgery.