Camp 9 Orthopedic Clinic, Hwaseong, Korea.
Assistive Technology Research Team for Independent Living, Research Institute, National Rehabilitation Center, Seoul, Korea.
Yonsei Med J. 2022 Jul;63(7):657-664. doi: 10.3349/ymj.2022.63.7.657.
We aimed to analyze changes in suprascapular nerve (SSN) position within the suprascapular notch during in vivo shoulder abduction.
Three-dimensional models of the shoulder complex were constructed based on magnetic resonance imaging of the brachial plexus (BP-MR) in a patient diagnosed with SSN dysfunction but normal scapular movement. Using BP-MR in neutral position and computed tomography data on shoulder abduction, shoulder abduction was simulated as the transition between two positions of the shoulder complex with overlapping of a neutral and abducted scapula. SSN movement during abduction was evaluated using the finite element method. Contact stress on the SSN was measured in the presence and absence of the transverse scapular ligament (TSL).
In the neutral position, the SSN ran almost parallel to the front of the TSL until entering the suprascapular notch and slightly contacted the anterior-inferior border of the TSL. As shoulder abduction progressed, contact stress decreased due to gradual loss of contact with the TSL. In the TSL-free scapula, there was no contact stress on the SSN in the neutral position. Towards the end of shoulder abduction, contact stress increased again as the SSN began to contact the base of the suprascapular notch in both TSL conditions.
We identified changes in the position of the SSN path within the suprascapular notch during shoulder abduction. The SSN starts in contact with the TSL and moves toward the base of the suprascapular notch with secondary contact. These findings may provide rationale for TSL release in SSN entrapment.
我们旨在分析活体肩关节外展过程中肩胛上神经（SSN）在肩胛上切迹内位置的变化。
根据臂丛磁共振成像（BP-MRI）构建了一位被诊断为 SSN 功能障碍但肩胛骨运动正常的患者的肩胛带复合体三维模型。在中立位时使用 BP-MR 和肩关节外展的 CT 数据，模拟肩关节从中立位到外展位的转换，即肩胛骨重叠的两个位置。使用有限元法评估 SSN 在肩部外展过程中的运动。测量有和无横肩胛韧带（TSL）时 SSN 上的接触压力。
在中立位时，SSN 几乎与 TSL 的前表面平行运行，直到进入肩胛上切迹，并稍微接触 TSL 的前下边界。随着肩关节外展的进行，由于与 TSL 的接触逐渐丧失，接触压力减小。在无 TSL 的肩胛骨中，SSN 在中立位时没有接触压力。当肩关节外展接近结束时，由于 SSN 开始接触 TSL 条件下肩胛上切迹的底部，接触压力再次增加。
我们确定了肩关节外展过程中 SSN 路径在肩胛上切迹内位置的变化。SSN 首先与 TSL 接触，并随着二次接触向肩胛上切迹的底部移动。这些发现可能为 TSL 释放治疗 SSN 嵌压提供了依据。
