Division of Sports Medicine and Shoulder Surgery, Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, USA.
Division of Sports Medicine and Shoulder Surgery, Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, USA.
J Shoulder Elbow Surg. 2022 Jun;31(6S):S110-S116. doi: 10.1016/j.jse.2022.03.002. Epub 2022 Apr 1.
It is unclear if native glenohumeral anatomic features predispose young patients to instability and if such anatomic risk factors differ between males and females. The purpose of this study was to compare glenoid and humeral head dimensions between patients with a documented instability event without bone loss to matched controls and to evaluate for sex-based differences across measurements. The authors hypothesized that a smaller glenoid width and glenoid surface area would be significant risk factors for instability, whereas humeral head width would not.
A prospectively maintained database was queried for patients aged <21 years who underwent magnetic resonance imaging (MRI) for shoulder instability. Patients with prior shoulder surgery, bony Bankart, or glenoid or humeral bone loss were excluded. Patients were matched by sex and age to control patients who had no history of shoulder instability. Two blinded independent raters measured glenoid height, glenoid width, and humeral head width on sagittal MRI. Glenoid surface area, glenoid index (ratio of glenoid height to width), and glenohumeral mismatch ratio (ratio of humeral head width to glenoid width) were calculated.
A total of 107 instability patients and 107 controls were included (150 males and 64 females). Among the entire cohort, there were no differences in glenoid height, glenoid width, glenoid surface area, humeral head width, or glenoid index between patients with instability and controls. Overall, those with instability had a greater glenohumeral mismatch ratio (P = .029) compared with controls. When stratified by sex, female controls and instability patients showed no differences in any of the glenoid or humerus dimensions. However, males with instability had a smaller glenoid width by 3.5% (P = .017), smaller glenoid surface area by 5.2% (P = .015), and a greater glenohumeral mismatch ratio (P = .027) compared with controls.
Compared with controls, males with instability were found to have smaller glenoid width and surface area, and a glenoid width that was proportionally smaller relative to humeral width. In contrast, bony glenohumeral morphology did not appear to be a significant risk factor for instability among females. These sex-based differences suggest that anatomic factors may influence risk of instability for male and female patients differently.
目前尚不清楚是否存在使年轻患者易发生不稳定的固有盂肱解剖特征，以及这些解剖危险因素在男性和女性之间是否存在差异。本研究的目的是比较有记录的不稳定事件而无骨丢失的患者与匹配对照组之间的肩胛盂和肱骨头尺寸，并评估测量值是否存在性别差异。作者假设较小的肩胛盂宽度和肩胛盂表面积将是不稳定的重要危险因素，而肱骨头宽度则不是。
前瞻性维护的数据库中查询了年龄<21 岁的因肩关节不稳定而行 MRI 的患者。排除有既往肩部手术、骨 Bankart 损伤或肩胛盂或肱骨头骨丢失的患者。通过性别和年龄与无肩关节不稳定病史的对照组患者相匹配。两名独立的盲法测量员在矢状面 MRI 上测量肩胛盂高度、肩胛盂宽度和肱骨头宽度。计算肩胛盂表面积、肩胛盂指数（肩胛盂高度与宽度的比值）和盂肱匹配比（肱骨头宽度与肩胛盂宽度的比值）。
共纳入 107 例不稳定患者和 107 例对照组患者（150 例男性和 64 例女性）。在整个队列中，不稳定患者与对照组之间在肩胛盂高度、肩胛盂宽度、肩胛盂表面积、肱骨头宽度或肩胛盂指数方面无差异。总体而言，不稳定患者的盂肱匹配比更大（P=.029）。按性别分层时，女性对照组和不稳定患者在任何肩胛盂或肱骨头尺寸方面均无差异。然而，男性不稳定患者的肩胛盂宽度小 3.5%（P=.017），肩胛盂表面积小 5.2%（P=.015），盂肱匹配比大 2.7%（P=.027）。
与对照组相比，不稳定患者的肩胛盂宽度和表面积较小，且肩胛盂宽度相对于肱骨头宽度的比例较小。相比之下，骨性盂肱形态似乎不是女性不稳定的重要危险因素。这些基于性别的差异表明，解剖因素可能以不同的方式影响男性和女性患者的不稳定风险。
