Prospective stress radiography in 38 old injuries of the ligaments of the knee joint.

In a prospective clinical and stress radiographic study comprising 38 patients, the course of chronic ligament injuries in the knee joint was evaluated. All but five patients had isolated ligament injuries, 16 of which affected the anterior cruciate ligament. The operations were performed from 18 days to 20 years after the injury had occurred. In 13 patients primary suture could be carried out, 12 patients underwent exploratory arthrotomy, and the remainder had relevant ligament repair. After a follow-up period of 7 years the instability had been cured in all patients with medial laxity and in one of two patients with lateral laxity. Nineteen patients had a drawer sign preoperatively. The anterior drawer sign disappeared in practically all patients, while a posterior drawer sign was a constant sequel to injury affecting the posterior cruciate ligament. It was difficult to prevent the development of rotatory instability--which was present in six preoperatively and in 14 at follow-up--and the rotatory instabilities were predominantly marked (greater than 6 mm). Nevertheless, only a few patients had an annoying sensation of instability. By means of ligament reconstruction, it was possible to reduce the preoperative instability appreciably. Passive instability had completely subsided in 40 per cent (15/38). The subjective result was good, only 16 per cent (6/38) having troublesome loss of function.