The use of external fixation in the reconstruction of complex posterior cruciate injuries

Proper immobilization of the knee after repair or reconstruction of the posterior cruciate ligament is difficult because of the tendency of the tibia to sag posteriorly, placing tension on the repaired structures. We describe the use of external fixation to immobilize the knee after repair or reconstruction of the posterior cruciate ligament. In seven patients, external fixation devices were used postoperatively for immobilization. Ail three patients with acute injury had repair of the avulsed ligament and associated ligamentous injuries. Of the four patients with chronic injury, three underwent reconstructive surgery because of significant injury to other ligaments. The average length of immobilization in the fixator was 45.4 days. The range of motion at last followup averaged 5.7° to 103.5°, and followup was from six to 20 months. Two patients had three complications: one had decreased flexion and the other had a pin tract infection and lacked flexion beyond 90°. All patients were satisfied with the result of surgery: three patients had a 1 + posterior drawer and four had a stable posterior cruciate ligament at folfowup examination. External fixation may be useful in complex knee injuries involving rupture of the posterior cruciate ligament.