Reamed intramedullaiy nailing technique leaves the problem of destorying the endosteal blood supply, which associated with delayed union and postoperative infection. Recent reports have shown excellent rate of union and low rate of intection with unlearned interlocking intramedullary nail.

Author reviewed 58 cases of tibia shaft fractures that were treated with unrealned interlocking nail from Feb. 1992 to Feb. 1994.

1. Furty nine fractures were closed and 9 were open (Gustilo-Andersonl;3,II;5, IIIa;1). Thrity one fractures involved the distal portion, 19 fractures the middle portion, 6 fractures tile proximal portion and 2 fractures were segmental.

2. Thirty six cases were male and 22 were female. The most common age was 3rd decade (25.8%).

3. The most common caute was traffic accident.

4. Average interval from injury to operation were 5.7 days in close fracture and 11.3 days in open fracture.

5. The mean duration of bone union were 15.7 weeks in closed fracture and 19.5 wreks in open fracture.

6. Complications include 1 case of delayed union, 1 case of joint stiffness and 1 case of screw failure.

7. According to the functional results by Klemm and Borner, 42 cases were excellent, 15 cases were good and 1 was fair.