Predicting surgical outcomes of non-displaced or valgus-impacted femoral neck fractures: A novel preoperative CT-based comprehensive assessment method

The management of non-displaced or valgus-impacted femoral neck fractures remains challenging. The objective of this study was to introduce our novel method for comprehensive assessment of bone quality and fracture displacement using preoperative computed tomography (CT) images, and determine which radiologic parameters significantly predicted fixation failure. A retrospective analysis was performed on 74 cases of non-displaced or valgus-impacted femoral neck fractures. To determine the independent predictors of screw cutout, femoral head necrosis or nonunion, various clinical variables and radiologic variables, including the mean CT value on coronal CT images, the posterior tilt angle (PTA) on axial CT images, and the valgus angle on coronal CT images were analyzed. In this study, with a mean follow-up duration of 18.7 months, screw cutout was observed in 2 cases (2.7%), while avascular necrosis or nonunion occurred in 7 cases (9.5%). Multivariate logistic regression analyses revealed that the coronal Hounsfield unit (HU) value was an independent predictor of screw cutout (OR = .950, 95% CI: 0.869-0.999, P = .044), with a significantly higher risk when the HU value was ≤80.8. Additionally, the PTA was identified as an independent predictor of avascular necrosis or nonunion (OR = 1.164, 95% CI: 1.030-1.367, P = .013), with a significantly increased risk when PTA was ≥20.8°. Preoperative CT imaging plays a critical role in evaluating surgical outcomes for non-displaced or valgus-impacted femoral neck fractures. When the preoperative coronal HU value is <80.8 or the PTA is >20.8°, the incidence of complications after internal fixation increases significantly, and primary hip arthroplasty warrant consideration.