THE INTEGRITY OF THE LATERAL FEMORAL WALL IN INTERTROCHANTERIC HIP FRACTURES: A SIGNIFICANT PREDICTOR FOR RE-OPERATION.

Abstract

Introduction: Re-operations after intertrochanteric fractures (ITF) are often caused by fracture displacement following postoperative mobilisation. The biomechanical complexity of the fracture, implant position, and the patient’s characteristics are known to influence postoperative outcome significantly. We investigated the importance of an intact lateral femoral wall (LFW) for the postoperative displacement after fixation by a sliding compression hip screw (SHS).

Methods: Two hundred and fourteen consecutive patients with ITF fixated by 135° SHS mounted on four hole lateral plates were included between 2002 and 2004. The fractures were preoperatively classified according to the AO/OTA classification system. The status of the greater and lesser trochanter, the integrity of the LFW and implant positioning were assessed postoperatively. Re-operations due to technical failure were recorded for six months.

Results: Only three percent of patients (5/168) with postoperatively intact LFW’s were re-operated within six months, while twenty-two percent (10/46) of patients with fractured LFW’s had been re-operated (p < 0.001). In multivariate logistic regression analyses combining demographic and biomechanical parameters, a compromised LFW was a significant predictor for reoperation (p = 0.010). Seventy-four percent (34/46) of the LFW fractures occurred during the operative procedure itself. Peri-operative LFW fractures only occurred in three percent (3/103) of the AO/OTA type 31A1–A2.1 ITF fractures, compared to thirty-one percent (31/99) of the AO/OTA type 31A2.2–A2.3 fractures (p < 0.001).

Conclusions: A postoperative fractured LFW was found to be the main predictor for reoperation after ITF. Consequently we conclude that patients with pre- or potential postoperative LFW fractures are not treated adequately by SHS. ITF should therefore be classified according to the integrity of the LFW, especially in regard to randomized trials comparing fracture implants.