Injury of knee ligament associated with ipsilateral femoral shaft fractures and with ipsilateral femoral and tibial shaft fractures.

A series of 110 patients with 114 fractures of the femur were reviewed an average of 3.9 years after injury. Demonstrable knee ligament laxity was present in 31 (27 per cent) of these patients, while 13 (11 per cent) complained of instability. Thirty-three patients with 34 ipsilateral femoral and tibial shaft fractures were examined an average of 3.7 years after injury. Demonstrable knee ligament laxity was present in 18 (53 per cent) of these patients, while 6 (18 per cent) complained of instability. Most of the patients with instability had a rupture of the anterior cruciate ligament with or without damage to other ligaments. We conclude that knee ligament injury is more common with ipsilateral fracture of the femur and tibia than with just a single ipsilateral femoral fracture. We advocate careful assessment of the knee in all cases of fracture of the femur.