Intramedullary nails may be divided into two categories: unlearned and reamed. reaming effectively lengthens the isthmus of the tibia and thereby extends the number of fractures amenable to this technique, but other studies showed that union impairement and infection rates were relatively high because of reaming destroyed the endosteal blood supply, especially open fractures. Unlearned interlocking nails in open fractures offer the advantage of less damage to the intramedullary blood supply Also lower infection rates have been reported in open fracture when compared with reamed nails.

We analysed 22 cases of tibial shaft fractures managed with interlocking nailing without reaming and experienced treatment of complications since September 1992. Average follow-up period was 13 months ranged 5 to 17 months and results were as follows:

1) We used an unlearned interlocking nails for tibial open fractures, 14 cases(Gustilo-Anderson type: I.3 cases, II.5 cases, III a 4 cases, III b.2 cases)and closed fractures asscciated with combined injuries, 8 cases.

2) Union occurred an average of 5.2 months postoperatively with a range from three to 14 months.

3) The complications were 2 cases of superficial infection and 5 cases of nonunion(3 cases among the 8 cases of closed fracture and 2 cases among the 14 cases of open fracture.

4) The treatment of nonunion was successful with bone graft, additional screw fixation and reinsertion of reamed nail.

5) We concluded that unlearned interlocking nailing was useful method to treat the open tibial shaft fractures in the selected cases, but undesirable to treat closed tibial shaft fractures because considered less mechanical stability.