Impact of coronal plane fragments and anterior big neck fragments on the occurrence of perioperative lateral wall fractures in AO/OTA 31-A1,2 intertrochanteric fractures treated with cephalomedullary nailing

Abstract

Cephalomedullary nails are used widely today for pertrochanteric fractures, and intraoperative lateral wall fractures can cause adverse effects. Recently, a high incidence of coronal fragments in pertrochanteric fractures was reported when analyzed with 3D CT reconstructions. In this study, we analyzed the association between the type of coronal fragments and perioperative lateral wall fractures. Patients diagnosed with pertrochanteric fractures and treated by cephalomedullary nails at three university hospitals from September 2016 to December 2020 were examined. A total of 463 patients were included. We examined the coronal fragments and divided the patients into two groups according to the involvement of the posteromedial cortex. Postoperative X-rays were scanned for fracture lines at the blade entry site. Twenty-two patients among 463 patients had perioperative lateral wall fractures. The AO type A2 fractures, use of provisional pins, existence of coronal fragments, involvement of the posteromedial cortex, and the existence of anterior big neck fragments were significantly relevant to perioperative lateral wall fractures. 11 of 22 lateral wall fracture patients were delayed fracture patients, identified 4weeks after surgery. A coronal fragment combined by anterior big neck fragments had a 9.24 times higher risk of lateral wall fractures compared to fractures with only coronal fragments. Pertrochanteric fractures with large coronal fragments and anterior big neck fragments have a high risk of perioperative lateral wall fractures when treated by cephalomedullary nails. Surgeons should examine the width of the intact lateral wall, and take caution to preserve its integrity.