The effect of supratrochlear foramen on susceptibility of the distal humerus to fracture

Purpose: Supratrochlear foramina (STF) are occasionally encountered in both clinical and anthropological contexts. However, their biomechanical impact on fracture susceptibility in the distal humerus remains poorly understood. This study aimed to evaluate whether the presence of a single STF affects the fracture load of distal HumerusHumerus models under axial loading. Methods: Standardized foam bone models, simulating the distal humerus, were divided into two groups: (1) models with a single STF and (2) control models without STF. Axial compression tests were performed using a universal testing machine, and fracture loads and speciments stiffness were compared using independent t-tests and Mann-Whitney tests. Results: The mean ± SD peak fracture loads were similar with 1160 ± 100 N and 1110 ± 165 N (P = 0.829) for the test and control groups, respectively. The mean fracture loads trended slightly different with 1050 ± 120 N and 960 ± 150 N for the test and control group, with no statistically significant difference (P = 0.060). Both groups displayed similar incomplete transverse fracture patterns and load-displacement behaviors, indicating comparable mechanical responses prior to fracture. Conclusion: The presence of a single STF does not significantly compromise the fracture resistance of distal humerus models under axial loading. These findings provide preliminary biomechanical evidence that STF may be clinically tolerable, though further studies are needed in cadaveric and dynamic loading conditions to confirm these results.