Female Patients Exhibit a Narrower Glenoid Rim and Lower Bone Density in the Anteroinferior Quadrant Compared With Male Patients.

Abstract

The purpose of this study was to evaluate sex-based differences in glenoid rim morphology and bone density relevant to arthroscopic Bankart repair. This retrospective study assessed differences in glenoid rim morphology between sexes in patients with shoulder instability and uninjured control subjects who underwent a magnetic resonance imaging scan of the shoulder at a single institution between 2014 and 2023. The glenoid neck-to-face ratio was calculated to compare differences in steepness of the glenoid neck. Bone density was analyzed in a separate cohort of uninjured subjects using computed tomography scans, with Hounsfield units measured in the anteroinferior (4-6 o'clock) quadrant and the mid-anterior (3 o'clock) region. A total of 204 patients (51 shoulders per cohort) were included for the glenoid morphology analysis, and a separate group of 102 uninjured patients was included for bone density evaluation. The neck-to-face ratio differed significantly between male patients and female patients in both the instability cohort (P < .001) and the uninjured cohort (P < .001). There were no significant differences between instability and uninjured cohorts of the same sex (P = .22 and P = .43). Bone density in the anteroinferior quadrant of the glenoid was significantly lower in female patients (median: 272.5 HU) compared with male patients (median: 303.0 HU; P = .009), whereas the mid-anterior region showed no significant differences (P = .65). Female patients exhibit a significantly narrower glenoid rim compared with male patients, with no differences between instability and uninjured subjects of the same sex. Bone density at the anteroinferior quadrant (4-6 o'clock) was also lower in female patients, whereas no difference was observed at the mid-anterior region (3 o'clock). Level III, retrospective comparative study.