Department of Orthopaedic Surgery, Kaisei Hospital, Obihiro, Japan.
Upper Extremity Center of Joint Replacement and Endoscopic Surgery, Hokushin Orthopaedic Hospital, Sapporo, Japan.
J Shoulder Elbow Surg. 2022 Jul;31(7):1442-1450. doi: 10.1016/j.jse.2021.12.035. Epub 2022 Jan 31.
Articular-side tear at the upper border of the subscapularis (SSC-AST) is often detected during shoulder arthroscopic surgery, although its exact pathology remains unknown. The purpose of this study was to investigate the correlation between various characteristics of the coracoid process, including classification of the morphology of the coracoid process tip, and the presence of SSC-AST.
This retrospective, case-controlled study included patients who underwent arthroscopic subacromial decompression with or without rotator cuff repair between January 2018 and September 2021. A total of 130 shoulders in 124 patients, including 77 male and 53 female shoulders (mean age at surgery, 64 years [range, 39-88 years]), were included in this study. Three-dimensional (3D) computed tomography examination was performed preoperatively, and the following indices were measured: coracoid proximal length, coracoid distal length, coracoid angle, coracoglenoid angle, offset of the coracoid process and glenoid (anterior, lateral, and superior offset), and coracoid base angle. The morphology of the tip of the coracoid process was classified into 3 types according to 3D reconstructed views: flat type, round type, and beak type. The presence of SSC-AST was intraoperatively evaluated arthroscopically via a posterior glenohumeral portal. Morphologic risk factors for SSC-AST were evaluated between SSC-AST cases (group T) and non-SSC-AST cases (group N) by multivariable logistic analysis. In addition, the correlation between the incidence of SSC-AST and classification of the tip of the coracoid process was analyzed.
SSC-AST was present in 53 shoulders (40.8%). Group T patients were significantly older than group N patients (68.4 ± 10.0 years vs. 61.5 ± 11.8 years, P < .001). No sex difference was detected between the 2 groups (28 male and 25 female shoulders in group T vs. 49 male and 28 female shoulders in group N, P = .28). Multivariate analysis of morphologic parameters between the 2 groups detected a smaller superior offset as a risk factor for SSC-AST (odds ratio, 0.91; 95% confidence interval, 0.84-0.98; P = .01). No significant differences were found in the other parameters. Regarding classification of the tip of the coracoid process, round- and beak-type coracoid tips had a significantly higher rate of SSC-AST than flat-type tips (flat type, 21.8%; round type, 64.7%; and beak type, 46.3%) (P < .001).
Evaluation of the correlation between the morphology of the coracoid process on 3D computed tomography and the presence of SSC-AST visualized during arthroscopy indicated a significant association between SSC-AST and the morphology of the coracoid process.
在肩关节关节镜手术中，经常会发现肩胛下肌上缘的关节侧撕裂（SSC-AST），尽管其确切的病理学仍然未知。本研究的目的是探讨喙突的各种特征，包括喙突尖端形态的分类，与 SSC-AST 的存在之间的相关性。
这是一项回顾性病例对照研究，纳入了 2018 年 1 月至 2021 年 9 月期间接受关节镜下肩峰下减压术伴或不伴肩袖修复的患者。共纳入了 124 名患者的 130 个肩关节，包括 77 名男性和 53 名女性（手术时的平均年龄为 64 岁[范围，39-88 岁]）。所有患者术前均行三维（3D）计算机断层扫描检查，并测量以下指标：喙突近端长度、喙突远端长度、喙突角、喙肱关节角、喙突与关节盂的前后侧、外侧和上侧偏移以及喙突基底部角度。根据 3D 重建视图将喙突尖端的形态分为 3 种类型：平型、圆型和喙型。通过后路关节镜下肱盂关节门评估 SSC-AST 的存在。通过多变量逻辑分析评估 SSC-AST 病例（组 T）和非 SSC-AST 病例（组 N）之间的 SSC-AST 形态学危险因素。此外，还分析了 SSC-AST 的发生率与喙突尖端分类之间的相关性。
53 个肩关节（40.8%）存在 SSC-AST。组 T 患者的年龄明显大于组 N 患者（68.4±10.0 岁 vs. 61.5±11.8 岁，P<0.001）。两组间性别无差异（组 T 中 28 名男性和 25 名女性肩关节，组 N 中 49 名男性和 28 名女性肩关节，P=0.28）。对两组间形态参数的多变量分析检测到，上侧偏移较小是 SSC-AST 的危险因素（比值比，0.91；95%置信区间，0.84-0.98；P=0.01）。其他参数无显著差异。关于喙突尖端的分类，圆型和喙型喙突尖端的 SSC-AST 发生率明显高于平型（平型 21.8%，圆型 64.7%，喙型 46.3%）（P<0.001）。
评估 3D 计算机断层扫描上喙突形态与关节镜下观察到的 SSC-AST 之间的相关性表明，SSC-AST 与喙突形态之间存在显著相关性。
