Druel Thibault, Buffard Marius, Nové-Josserand Laurent, Walch Arnaud
Centre Orthopédique Santy, Hôpital Privé Jean Mermoz, Ramsay Santé, Lyon, France.
Laboratoire d'Anatomie Médico-Chirurgicale, Faculté de Médecine Lyon-Est, Lyon, France.
JSES Int. 2022 Nov 11;7(2):331-335. doi: 10.1016/j.jseint.2022.10.013. eCollection 2023 Mar.
The middle glenohumeral ligament (MGHL) is one of the three ligaments that stabilize the anterior capsule of the shoulder. Recent work suggests that it inserts distally into the deep layer of the subscapularis tendon. The role of the MGHL remains debated. The hypothesis of this study was that the MGHL plays a significant functional role in limiting external rotation of the shoulder while allowing a wide range of motion through its distal insertion into the subscapularis rather than directly onto the humerus.
In a cadaveric study performed on 20 shoulders (10 subjects), the MGHL and the other anterior structures of the shoulder were successively cut according to a standardized protocol. At each stage, the external rotation range of the shoulder was measured with the arm at the side (ER 1) and in 90° abduction (ER 2) using a goniometer. After dissection, the structure of the MGHL and its distal insertion were analyzed.
Cutting the MGHL led to significant increases in ER 1 but not in ER 2. Shoulder range of motion in ER 1 increased on average by 15 ± 5° ( < .001) after cutting the MGHL and by 21 ± 11° ( < .001) after subscapularis peel. The range of motion in ER 2 increased by 3 ± 4° ( = .048) after cutting the MGHL, by 4 ± 6° ( = .02) after subscapularis peel and by 25 ± 8° ( < .001) after cutting the inferior glenohumeral ligament. The MGHL was present in all dissected shoulders. It was leaf-like in 12 cases, cord-like in 6 cases and had a vestigial appearance in 2 cases. The distal insertion was in all cases in the deep layer of the subscapularis in a thickening of the anterior capsule in the superior part of the muscle, except for two cases in which the tendinous part of the subscapularis was also involved.
The MGHL limited shoulder external rotation by a similar amount as the subscapularis muscle. Further studies are required to understand the clinical relevance of these findings, notably for the treatment of shoulder stiffness.
肩胛下肌中韧带（MGHL）是稳定肩关节前关节囊的三条韧带之一。近期研究表明，它向远端附着于肩胛下肌腱深层。MGHL的作用仍存在争议。本研究的假设是，MGHL在限制肩关节外旋方面发挥重要功能作用，同时通过其向肩胛下肌的远端附着而非直接附着于肱骨，允许肩关节有较大的活动范围。
在对20个肩关节（10名受试者）进行的尸体研究中，按照标准化方案依次切断MGHL及肩关节的其他前部结构。在每个阶段，使用角度计测量手臂位于身体一侧时（ER 1）和外展90°时（ER 2）的肩关节外旋范围。解剖后，分析MGHL的结构及其远端附着情况。
切断MGHL导致ER 1显著增加，但ER 2未增加。切断MGHL后，ER 1的肩关节活动范围平均增加15±5°（P<0.001），肩胛下肌剥离后增加21±11°（P<0.001）。切断MGHL后，ER 2的活动范围增加3±4°（P=0.048），肩胛下肌剥离后增加4±6°（P=0.02），切断肩胛下盂肱韧带后增加25±8°（P<0.001）。所有解剖的肩关节均存在MGHL。其中12例呈叶状，6例呈索状，2例呈退化外观。除2例肩胛下肌腱部分也受累外，所有病例的远端附着均位于肩胛下肌深层，即肌肉上部前关节囊增厚处。
MGHL限制肩关节外旋的程度与肩胛下肌相似。需要进一步研究以了解这些发现的临床相关性，特别是对于肩关节僵硬的治疗。
