To compare the clinical results between Ender nail and interlocking nail in the treatment of infra-isthmic tibial shaft fracture.

The authors analyzed 44 cases of infra-isthmic tibial shaft fracture treated with Ender nail(23 cases) as a group 1 or interlocking nail(21 cases) as a group 2 from 1994 to 1998. Fracture type was divided by AO classification, and measured the fracture level, the time of bone union and angular deformity was checked with roentgenograms. The functional results were compared using the criteria by Klemm and Borner.

Distal end of fracture line from ankle joint shows no difference between two groups(P>0.05). Mean operation time was 96 minutes in group 1 and 140 minutes in group 2(P<0.05). Mean intraoperative blood loss was 103cc in group 1 and 254cc in group 2(P<0.05). Mean bone union time was 19.26 weeks in group 1 and 24.81 weeks in group 2. There was no significant difference between two groups in the angulation(P>0.05) and the functional results by Klemm and Borner.

Ender nail is a good method of treatment in infra-isthmic tibial fracture when isthmic portion of tibia is too narrow, or insertion of distal interlocking screws were too difficult to insert because of the severe soft tissue injury. The stability of fixation can be strengthened with a three point fixation as fanning of the nails in the distal fragments using more than 3 nails selecting a 1cm longer nail than the ordinary nail length for diaphyseal fracture.