The shaft of tibia is prone to the open wounds owing to the subcutaneous location and poor muscular envelope. The open wounds frequently result in the severe complications and major disabilities, such as infection, delayed union and nonunion. The choice of treatment should be considered cautiously. The intramedullary fixation of the shaft has the advantage of early weight bearing as well as relative firm fixation. Sixty four cases of fracture of the tibia shaft were treated with interlocking IM nail(38 cases) or Ender nail(26 cases) from December 1985 to January 1993.

1. The most common causes of the tibia fracture were the pedestrian injury and motorcycle accident.

2. There was no difference in operation time between interlocking IM nail group and 5 weeks in Ender nail group. the average time of operation was about 70 minutes.

3. The mean time of cast support was 2.5 weeks in interlocking IM nail group and 5 weeks in Ender nail group. The mean duration of nonweight bearing was 7.6 weeks in interlocking IM nail group,9.2 weeks in Ender nail group.

4. The mean duration of bone union was 18.7 weeks in interlocking IM nail group,21.4 weeks in Ender nail group. The interlocking IM nail group seemed to obtain earlier bone union(2.5 weeks) than Ender nail group, but there was no significance in statistical analysis in the bone union time between two groups.

5. Angular deformities were found in 3 cases in interlocking IM nail group and 4 cases in Ender nail group, which occured in the communited fracture and both ends fracture of the tibia shaft, segmental fractures. Delayed union was also occured in 5 cases in Ender nail group and 3 cases in interlocking IM nail group.