Department of Orthopaedics and Sports Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, USA.
J Anat. 2022 Aug;241(2):453-460. doi: 10.1111/joa.13685. Epub 2022 May 17.
The proximal long head of the biceps tendon (LHBT) has been recognized as a well-known cause of anterior shoulder pain. Previous studies have identified a heterogeneous distribution of nerve fibers in the tendon, with a higher abundance of fibers in the proximal and distal thirds of the tendon. This suggests that the proximal portion of the long head biceps tendon may have a different source of innervation than the distal portion. The purpose of this study was to review the innervation of the superior shoulder and identify the proximal source of sensory innervation of the LHBT. The relevant hypothesis was that the suprascapular nerve (SSN) was the proximal source of sensory innervation to the LHBT. Gross and microdissection of eight fresh human cadaver shoulders were performed, with a focus on the distal articular branches of suprascapular nerve (SSN). Utilizing 3.5× magnification loupes, the medial subacromial branch (MSAb), lateral subacromial branch (LSAb), and posterior glenohumeral branch (PGHb) were identified and followed distally to their terminal branches. In all specimens, terminal branches of the lateral subacromial branch supplied the proximal LHBT and the superior labrum. Terminal branches of the posterior glenohumeral branch supplied the posterosuperior labrum and, to a lesser extent, the labral attachment of the LHBT. These findings confirm branches of the suprascapular nerve as the proximal source of sensory innervation to the LHBT. Identification of the suprascapular nerve as a source of proximal innervation of the LHBT may influence clinical decisions related to nonsurgical and surgical intervention, nerve blocks, and nerve ablation procedures.
肱二头肌长头腱（LHBT）的近端已被认为是引起肩部前痛的一个常见原因。先前的研究已经确定肌腱中的神经纤维具有异质性分布，在腱的近端和远端三分之一处纤维更为丰富。这表明长头腱的近端部分可能具有与远端部分不同的神经支配来源。本研究的目的是回顾肩部的神经支配，并确定 LHBT 的近端感觉神经支配的来源。相关假设是，肩胛上神经（SSN）是 LHBT 的近端感觉神经支配的来源。对八个新鲜的人体尸体肩部进行了大体和显微解剖，重点是肩胛上神经的远端关节支（SSN）。利用 3.5×放大放大镜，识别并追踪内侧肩峰下支（MSAb）、外侧肩峰下支（LSAb）和后肩胛盂支（PGHb）的远端分支。在所有标本中，外侧肩峰下支的终末支供应 LHBT 的近端和上盂唇。后肩胛盂支的终末支供应后上盂唇，并且在较小程度上供应 LHBT 的盂唇附着处。这些发现证实了肩胛上神经分支是 LHBT 的近端感觉神经支配的来源。确定肩胛上神经作为 LHBT 的近端神经支配的来源，可能会影响与非手术和手术干预、神经阻滞和神经消融程序相关的临床决策。
