Extensor mechanism problems are one of the serious complications and an important cause of morbidity in revision knee arthroplasty, having direct consequences on clinical results. Serious complications such as quadriceps and patellar tendon rupture, patella fracture, patellar alignment problems and instability may be seen. In order to avoid legal problems and reduce morbidity rate, surgeons should know the possible complications of the operation and be able to manage them. In this review, causes and solutions of extensor mechanism problems are presented.