Radiologic predictor of intraoperative lateral wall fractures in treatment of pertrochanteric fractures with cephalomedullary nailing

OBJECTIVE: This study was performed to investigate the reliability of the height of pertrochanteric fractures as a predictor of lateral wall fractures after cephalomedullary nailing and provide a simple way to determine the threshold value. METHODS: We performed a prospective randomized clinical study of 50 consecutive patients who underwent measurement of the height of the pertrochanteric fracture and the tangent line to the superior margin of the contralateral femoral neck. The preoperative and postoperative integrity of the lateral wall was evaluated by computed tomography. RESULTS: The pertrochanteric fracture height was significantly lower in patients with than without intraoperative lateral wall fractures (15.6 vs. 28.5 mm, respectively). The threshold value of the fracture height was 20.445 mm, which was not significantly different from the mean height of the tangent line of the superior margin of the contralateral femoral neck (19.4 mm). CONCLUSIONS: Pertrochanteric fractures with the proximal starting point lower than the mirror position of the tangent line to the superior margin of the contralateral femoral neck have a higher risk of intraoperative lateral wall fractures during cephalomedullary nailing.