A novel classification system based on the lateral view of 3D-CT for predicting the reducibility of intertrochanteric fractures: a retrospective study

Objective Current classifications for intertrochanteric fractures poorly predict the difficulty of achieving closed reduction. This study aimed to develop and validate a novel classification system based on the lateral view of three-dimensional computed tomography (3D-CT) to preoperatively assess reducibility.Methods We retrospectively reviewed 609 patients with intertrochanteric fractures. After screening, 318 cases (117 AO/OTA 31-A1 and 201 AO/OTA 31-A2) were included. Based on preoperative 3D-CT, fracture morphology was categorized as flexed, neutral, or extended types. The intraoperative outcome of closed reduction was used to define fractures as reducible or irreducible.Results Among the 318 fractures, 174 (54.7%) were reducible and 144 (45.3%) were irreducible. The reducible group included 105 flexed, 21 neutral, and 48 extended types. The irreducible group comprised 90 flexed-type and 54 extended-type fractures. Irreducible flexed-type and extended-type fractures were further subdivided into 3 distinct subtypes each, based on characteristic radiological features.Conclusion The proposed classification system, which integrates the AO/OTA framework with 3D-CT morphology, effectively identifies fractures at high risk for irreducible closed reduction. This system can help surgeons avoid futile reduction attempts and guide the choice of an appropriate reduction strategy.