The interlocking IM nailing is one of the most commonly used treatment method of the femoral shaft fracture. Althrough it has many advantages, but various complications is reported including delayed union, nonunion, malunion, interlocking nail or screw breakage, joint stiffness and infection.

In order to evaluate the complications we reviewed 38 cases in treated with interlocking IM nailing in femoral shaft fracture from january, 1991 to december, 1995 in Hangang Sacred-Heart hospital. The average follow up duration was 14 months (range ; 6 months to 38 months).

The following results are obtained

1. There were 1 cases of nonunion. Nonunion was of no analytic significance in sex, age, the fracture site and associated fracture (P=0.186), but significant in segmental fracture (P=0.02). Because of the small number group, we considered that it would be necessary more clinical expenence.

2. There were 3 cases interlocking screw breakage, all of which were occured in proximal screw. Partial weight bearing was permitted average postoperation 4.3 months. Average duration between operation and screw breakage was 1.3 months, between operation and bone union was 11.7 months.

3. There was 1 case of interlocking nail breakage. we considered that it was resulted from usage of relatively small nail(11 mm) and postoperative early weight bearing(8 weeks).