Effect of fragmentary displacement and morphology in the treatment of comminuted femoral shaft fractures with an intramedullary nail.

Abstract

Our study aimed to determine whether the displacement and morphology of a fragment in femur fracture with Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association/32-B/32-C (AO/OTA/32-B/32-C) classification affect the outcomes following closed reduction and internal fixation with an interlocking nail. This was a retrospective study. The study was conducted at a Level III trauma centre. A total of 50 consecutive patients presenting femoral shaft fracture with AO/OTA-type 32-B/32-C were included in the present study. Patients were divided into two groups according to the displacement of the fragments. In the large displacement group, patients were further subgrouped according to whether a reversed morphology of the fragment was present. The radiographic union score of femur (RUSF), the mean union time and the re-operation rate were assessed. The union rate of small- and large-gap groups at 12 months postoperatively was 75.9% and 21.1%, respectively (p=0.000). The mean union time of those union cases in these two groups was 7.8 and 13.0 months, respectively (p=0.000). The union rate of the non-reversed and reversed groups at 12 months postoperatively was 30% and 11.1%, respectively (p=0.179). The mean RUSF at 12 months in the non-reversed and reversed groups was 8.8 and 8.3, respectively (p=0.590). However, we found that patients presenting a reversed fragment had an increased risk of more than one re-operation (p=0.030). A fragmentary displacement of >1cm in AO/OTA-type 32-B/32-C femoral shaft fracture after nailing affected bone healing. Among the large-gap group patients, an unreduced reverse fragment presented a negative prognostic factor for re-operation. Prognostic level III.