Morphological characterization of femoral head is predictive for femoral neck fracture: radiographic analyses of 209 patients with femoral head fractures (Preprint)

BACKGROUND The injury degree of the femoral head is a significant predictor of femoral neck fracture (FNF) incidence in patients with femoral head fractures (FHFs). However, the exact measurement methods have yet been clearly defined. OBJECTIVE To design a new measurement for the injury degree of the femoral head and investigate its association with FHFs with FNF. METHODS A consecutive series of 209 patients with FHFs was assessed regarding patient characteristics, computed tomography images, and rate of FNF. New parameters for injury degree of femoral head, including percentage of maximum defect length (PMDL) in 2D parameter and percentage of fracture area (PFA) in 3D parameter, were respectively measured. Reliability tests for all parameters were evaluated in 100 randomly selected patients. The sensitivity, specificity, likelihood ratios, and positive and negative predictive values for different parameter cut-off values were employed to test the diagnostic accuracy for FNF prediction. RESULTS Intra- and inter-class coefficients for all parameters were ≥ 0.887. The results of logistic regression analysis showed that average PMDL across all three planes and PFA were the significant predictors of FNF (p < 0.05). Areas under curves (AUCs) of all parameters were ≥ 0.719 (p < 0.05). The cutoff values of the average PMDL across all three planes and PFA were 91.65% and 29.68%. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, predictive positive value and negative predictive value of 2D (3D) parameters were 91.7% (83.3%), 93.4% (58.4%), 13.8 (2.0), 0.09 (0.29), 45.83% (10.87%) and 99.46% (98.29%). CONCLUSIONS The new measurement for injury degree of femoral head appears to be reliable and indicates strong emergence of femoral neck fracture in patients with femoral head fractures. 2D and 3D parameters in FHFs have been proposed in this study, which were a feasible adjunctive diagnostic tool in identifying FNFs. CLINICALTRIAL N/A.