Subtrochanteric fracture: the effect of cerclage wire on fracture reduction and outcome.

INTRODUCTION: Subtrochanteric neck of femur fractures are a challenge to treat due to anatomical and biomechanical factors. Poor reduction, varus deformity, nonunion and return to theatre risks are high. A cerclage wire can augment an intramedullary nail to help fracture reduction and construct stability. Concerns exist regarding the use of cerclage wire on fracture zone vascularity. The aim of this study was to assess the benefits and adverse outcomes associated with the use of cerclage wiring.

PATIENTS AND METHODS: A 7-year retrospective review of all subtrochanteric fractures at a Level 1 trauma centre was performed. Pathological fractures, those associated with bisphosphonate use and segmental fractures were excluded. A clinical and radiographic review was performed. Our primary outcome measure was a composite of the major complications of this surgery, defined as either return to theatre for fixation failure, nonunion or implant failure. Fracture displacement, angulation and quality of reduction were measured as secondary outcome measures. Specific complications of the use of cerclage wiring were also reported.

RESULTS: One hundred and thirty four cases met the inclusion criteria for primary outcome. Reduction was achieved closed in 51.9% (n=70), open in 33.3% (n=45) and open with cerclage wire in 14.8% (n=20). Overall there were a total of 13 (9.7%) major complications. No cases with cerclage wire had a return to theatre. If cerclage wire was not used the major complication rate was 11.4%. Fracture displacement (11.0mm vs. 7.69mm) and distraction were related to return to theatre (p<0.05). Cerclage wire use improved fracture displacement (3.2mm vs. 8.8mm), angulation and quality of reduction (p<0.05).

CONCLUSIONS: Anatomical reduction is the key to success of subtrochanteric fractures. Cerclage wire use results in better fracture reduction. Some subtrochanteric fractures can be successfully treated with indirect reduction alone. If fractures cannot be reduced closed, reduction should be achieved by open methods. If a fracture is opened, a cerclage wire should be used, if the fracture pattern allows.