Paksoy Alp, Busch Irina, Back David Alexander, Dey Hazra Rony-Orijit, Akgün Doruk, Gebauer Henry
Center for Musculoskeletal Surgery, Charité University Hospital, Berlin, Germany.
JSES Int. 2025 Apr 30;9(4):1312-1318. doi: 10.1016/j.jseint.2025.04.005. eCollection 2025 Jul.
The etiology of primary eccentric osteoarthritis (OA) is multifactorial involving glenoid shape alterations, acromion abnormalities, and rotator cuff pathologies. However, none of the changes described for eccentric OA are either consistent or do satisfactorily explain the condition. Up to now, potential individual risk factors contributing to the development of concentric or eccentric OA have been studied mostly independently of each other. This study examined the differences of osseous shoulder morphology and muscle volume in concentric and eccentric OA of the shoulder as a potential risk factor for the development of posterior glenoid wear.
A retrospective, comparative study was conducted, analyzing computed tomography scans of 114 shoulders in 86 patients with primary OA at a single center between 2010 and 2023. These patients were divided into 2 groups-according to an underlying concentric or eccentric OA. As parameters, the osseous shoulder morphology (glenoid offset, glenoid version, posterior humeral head subluxation, anterior acromial coverage, posterior acromial coverage, posterior acromial tilt, posterior acromial height, and critical shoulder angle (CSA)) and muscle volume (subscapularis, infraspinatus/teres minor, supraspinatus), were measured and compared between the groups. Computed tomography images were classified according to the modified Walch classification.
The mean age of the patients was 68.9 ± 9.9 years and 62.3% of the patients were female (54 of 86). A total of 25 shoulders were included in the concentric group and 89 shoulders in the eccentric group. Patients with eccentric OA had a significantly increased glenoid retroversion according to Friedmann (12.6° ± 8.2° vs. 4.3° ± 3.4°; < .001) and relative to scapular blade axis (10.6° ± 7.6° vs. 3.1° ± 3.6°; < .001), increased scapulohumeral subluxation index (0.67 ± 0.01 vs. 0.55 ± 0.05; < 001), increased glenohumeral subluxation index (0.56 ± 0.06 vs. 0.52 ± 0.05; = .004), and increased CSA (26.3° ± 5.0° vs. 23.1° ± 4.2°; = .006) compared to patients with concentric OA. No significant differences in anterior glenoid offset and other parameters of acromial roof morphology were found between the 2 experimental groups. No significant differences in volumes of supraspinatus, subscapularis and infraspinatus/teres minor muscles could be detected between the 2 experimental groups.
Patients with primary eccentric OA show significant differences in glenoid retroversion, posterior scapulohumeral/glenohumeral subluxation, and CSA. However, there are no significant differences regarding the acromion roof morphology and rotator cuff volume compared to patients with concentric OA.
原发性偏心性骨关节炎（OA）的病因是多因素的，涉及肩胛盂形态改变、肩峰异常和肩袖病变。然而，针对偏心性OA所描述的这些变化既不一致，也不能令人满意地解释这种情况。到目前为止，导致同心性或偏心性OA发展的潜在个体危险因素大多是相互独立研究的。本研究调查了肩部同心性和偏心性OA中骨形态和肌肉体积的差异，作为肩胛盂后部磨损发展的潜在危险因素。
进行了一项回顾性比较研究，分析了2010年至2023年期间单一中心86例原发性OA患者的114个肩部的计算机断层扫描（CT）。根据潜在的同心性或偏心性OA，将这些患者分为两组。作为参数，测量并比较两组之间的骨肩部形态（肩胛盂偏移、肩胛盂版本、肱骨头后脱位、肩峰前覆盖、肩峰后覆盖、肩峰后倾斜、肩峰后高度和临界肩角（CSA））和肌肉体积（肩胛下肌、冈下肌/小圆肌、冈上肌）。CT图像根据改良的Walch分类进行分类。
患者的平均年龄为68.9±9.9岁，62.3%的患者为女性（86例中的54例）。同心性组纳入25个肩部，偏心性组纳入89个肩部。与同心性OA患者相比，偏心性OA患者根据Friedmann法测量的肩胛盂后倾显著增加（12.6°±8.2°对4.3°±3.4°；P<0.001），相对于肩胛冈轴测量的肩胛盂后倾也显著增加（10.6°±7.6°对3.1°±3.6°；P<0.001），肩胛肱骨头半脱位指数增加（0.67±0.01对0.55±0.05；P<0.001），肱盂半脱位指数增加（0.56±0.06对0.52±0.05；P=0.004），CSA增加（26.3°±5.0°对23.1°±4.2°；P=0.006）。在两个实验组之间，肩胛盂前偏移和肩峰顶形态的其他参数没有显著差异。在两个实验组之间，未检测到冈上肌、肩胛下肌和冈下肌/小圆肌体积的显著差异。
原发性偏心性OA患者在肩胛盂后倾、肩胛肱骨头/肱盂后脱位和CSA方面存在显著差异。然而，与同心性OA患者相比，肩峰顶形态和肩袖体积没有显著差异。
