Radiographic Assessment of Glenoid Morphology and Its Association with Proximal Humeral Fracture Configuration

Background: The aim of this study was to investigate the association between glenoid anatomy and proximal humeral fracture geometry and to identify radiographic parameters associated with multi-segment and articular fractures. Methods: In this retrospective observational study, 113 patients treated for proximal humeral fractures between 2016 and 2019, regardless of treatment modality, were included. Demographic characteristics, injury mechanisms, and fracture classifications were recorded. Fracture geometry and complexity were evaluated using the Neer and AO/OTA classification systems. Glenoid anatomy was assessed by measuring the Critical Shoulder Angle (CSA), glenoid inclination, and glenoid version on radiographs. Multivariable ordinal logistic regression was performed to adjust for age, sex, and injury mechanism. Results: Older age was correlated with higher Neer and AO/OTA types (p = 0.031, r = 0.176; p = 0.013, r = 0.208, respectively). Glenoid inclination was correlated with fracture geometry and fragmentation according to the Neer classification (p = 0.007, r = 0.228), while glenoid inclination and version were correlated with the AO/OTA classification (p = 0.028, r = 0.181; p = 0.014, r = -0.207, respectively). However, these associations were not independently associated with fracture configuration after multivariable adjustment, whereas older age remained independently associated with higher AO/OTA classification. Conclusions: Glenoid morphometric parameters showed weak univariate associations with proximal humeral fracture configuration but were not independent predictors after adjustment for age, sex, and injury mechanism. These findings suggest that glenoid morphology is only one of several factors contributing to fracture configuration and warrants further investigation in larger prospective studies.