To evaluate the union time and nonunion rate after intramedullary nailing of femoral shaft fracture in adult, we would like to analysis the operation techniques, comminution, contact surface and displacement.

We reviewed retrospectively 53 patients undergoing femoral intramedullary nailing at least 2 years postoperatively and analysised the union time and nonunion rate by operation techniques, comminution, contact surface and displacement. Patients were operated by either antegrade or retrograde intramedullary nailing.

There were no differences in nonunion rate, the duration of bony union between antegrade and retrograde intramedullary nail groups. Significant differences were found in the duration of bony union between the Winquist and Hansen type I, II and the type III, IV (p<0.05). There were significant differences in the duration of bony union among simple, comminuted, and segmental fracture groups (p<0.05).

The union time is affected by not operation techniques and fracture displacement, but Winquist-Hansen classification and number of fracture fragments in intramedullary nailing of adult femoral shaft fracture.