[Tendinitis of the knee].

The diagnostic criteria for tendinitis of the knee are: (1) strict localization of the pain in the whole length of the tendon from its body to its end; (2) recrudescence of pain during movements that stretch or rub the tendon, and (3) positive local anaesthesia test if needed. Only this approach makes it possible not to miss a tendinitis of the extensor system in a so-called femoro-patellar syndrome, or to misdiagnose a tendinitis of the sartorius, gracilis and semitendinosus muscles when confronted with an osteoarticular pathology of the medial femoro-tibial compartment.