[Surgical repair of chronic instabilities of the cruciate ligaments of the knee].

The authors have developped a technique aiming at replacing the anterior cruciate ligament by the tendon of gracilis muscle derouted through the intercondylar region and acting as an active transplant in 32 cases. In 20 other cases replacement of the posterior cruciate ligament was obtained by the use of the tendon of semi tendinosus muscle acting as a passive neo-ligament. The follow-up study demonstrated 87 p. 100 of good results after isolated tears of the anterior ligament and 83 p. 100 after isolated tears of the posterior ligament. 21 times an additional plasty of the medial ligament had to be performed. In these combined lesions results were less favourable.