Albritton Mark J, Graham Robert D, Richards Richard S, Basamania Carl J
Sports Medicine and Shoulder Service, Duke University Medical Center, Durham, NC 27710, USA.
J Shoulder Elbow Surg. 2003 Sep-Oct;12(5):497-500. doi: 10.1016/s1058-2746(03)00182-4.
The purpose of this anatomic study was to assess the risk to the suprascapular nerve by measuring the tension on the nerve and the angle between the nerve and its motor branch at the scapular notch with medial supraspinatus tendon retraction. Twelve shoulders in six cadavers were dissected to evaluate the branching point of the first motor branch of the suprascapular nerve, the change in angle between the nerve and its first motor branch at the scapular notch with retraction of the supraspinatus tendon, and the resulting tension on the nerve. The first motor branch originated at the notch in 9 cadavers, just proximal in 1, and just distal in 2. With the supraspinatus muscle in its anatomic position, the suprascapular nerve and its first motor branch angle measured 142.6 degrees at the scapular notch. After retraction of the supraspinatus, the angle markedly decreased to 98.7 degrees and 34.6 degrees with 1 cm and 5 cm of medial retraction, respectively. The motor branch was taut in all specimens at 2 to 3 cm of retraction. Medial retraction of the supraspinatus tendon drastically changes the course of the suprascapular nerve through the scapular notch, creating increased tension on the nerve. The degree of rotator cuff muscle atrophy frequently observed after a massive tear may be explained by increased tension on the nerve due to muscle retraction.
本解剖学研究的目的是通过测量肩胛上神经的张力以及在肩胛切迹处肩胛上神经与其运动支之间的角度（伴冈上肌内侧肌腱回缩）来评估肩胛上神经所面临的风险。对6具尸体的12个肩部进行解剖，以评估肩胛上神经第一运动支的分支点、冈上肌肌腱回缩时肩胛切迹处神经与其第一运动支之间角度的变化以及由此产生的神经张力。第一运动支在9具尸体中起源于切迹处，在1具尸体中起源于切迹近端，在2具尸体中起源于切迹远端。在冈上肌处于解剖位置时，肩胛上神经与其第一运动支在肩胛切迹处的角度为142.6度。冈上肌回缩后，分别在内侧回缩1 cm和5 cm时，该角度显著减小至98.7度和34.6度。在回缩2至3 cm时，所有标本中的运动支均处于紧张状态。冈上肌肌腱的内侧回缩显著改变了肩胛上神经通过肩胛切迹的走行，使神经张力增加。巨大撕裂后经常观察到的肩袖肌萎缩程度可能是由于肌肉回缩导致神经张力增加所致。
