Suprascapular nerve entrapment syndrome

　　1、Etiology

　　The compression of the suprascapular nerve can be caused by acute injuries such as scapular fractures or glenohumeral joint injuries. Dislocation of the shoulder joint can also damage the suprascapular nerve. Forward flexion of the shoulder, especially when the scapula is fixed, reduces the mobility of the suprascapular nerve, making it easy to be damaged. Tumors, humeral head ossicles, and fibrosis of the suprascapular notch are all main reasons for the compression of the suprascapular nerve. It is reported that the traction during rotator cuff injury can also cause damage to the suprascapular nerve. Various local lipomas and nodules can compress the trunk or subscapular nerve branches of the suprascapular nerve, causing compression.

　　2、Pathogenesis

　　Sunderland believes that the suprascapular nerve is relatively fixed when passing through the suprascapular notch, making it easy to be damaged during repetitive movements. The repetitive movements of the scapula and glenohumeral joint cause friction of the nerve at the notch, resulting in inflammatory reactions and edema, which can lead to compressive damage. It is known that the movement of the distal scapula can cause the suprascapular nerve to be stretched, causing a 'suspension effect', which causes the nerve to be strangled at the notch, leading to nerve lesions. Mizuno et al. reported that after the accessory nerve is paralyzed, the downward and lateral drooping of the scapula can cause the suprascapular nerve to be pulled by the suprascapular transverse ligament. The scapular branch of the suprascapular nerve can cause pain in the glenohumeral joint, which is the most common clinical symptom. Lesions of the suprascapular nerve are mainly unilateral, but there are also reports of bilateral onset.

　　The main complications of this disease are that when the compression is severe and prolonged, it can cause demyelination of nerve fibers, even far-end axon degeneration, and Wallerian degeneration of the myelin sheath. When the nerve fibers in the narrow channel are mechanically stimulated during limb movement, chronic inflammatory injury and edema are caused.-A vicious cycle of ischemia. This can further cause damage, therefore, patients with this disease should be treated actively to prevent the occurrence of complications.

　　1、Patients often have diffuse dull pain in the periscapular area, located in the posterior lateral part of the shoulder, which can radiate to the posterior part of the neck and arm, but the radiation pain is often located in the posterior side of the upper arm. Patients often feel weak in abduction and external rotation of the shoulder, progressive cases can have atrophy of the supraspinatus muscle, however, in most cases, there is no obvious muscle atrophy, so clinical diagnosis is relatively difficult.

　　2、Patients often have a history of trauma or injury, such as direct or indirect injury to the shoulder, such as when reaching out to cause excessive abduction of the shoulder joint during a fall, resulting in sprain; and some patients have excessive wear and tear of the shoulder joint, such as sports-related wear and tear (such as volleyball, basketball, tennis, etc.), and a history of shoulder work-related injury.

　　3、Patients with trauma or injury have sharp pain in the shoulder, which can be exacerbated during shoulder movement. The pain can be persistent, and severe cases can affect sleep. There is no obvious muscle atrophy, difficulty in lifting the arm, or the affected hand cannot reach the opposite shoulder. Some patients have shoulder pain but no other symptoms, and the pain can last for several years.

　　4、Pain at the scapular notch or in the area between the clavicle and the acromion process is the most common sign of scapular neuropathy syndrome. The trapezius area can also have tenderness, such as at the scapular notch where there is compression, the tender point is at the scapular notch, the shoulder is abduced and externally rotated, the muscle strength is weakened; the supraspinatus and infraspinatus muscles atrophy, especially the infraspinatus muscle atrophy; due to the innervation of the scapular joint branch to the acromioclavicular joint, shoulder clavicular joint tenderness may occur, such as compression at the acromial notch, the pain is less than that at the scapular notch, the tenderness is located at the acromial notch, in addition to the atrophy of the infraspinatus muscle, other manifestations are not obvious.

　　Scapular neuropathy can be caused by acute injuries such as scapular fracture or glenohumeral joint injury. Shoulder dislocation can also damage the suprascapular nerve. Therefore, the affected joint should be protected, joint load reduced, weight loss, rest should be taken, long-term carrying and poor posture should be avoided, and crutches, walkers, etc. should be used. Pay attention to keeping the affected joint warm in daily life, and heat can be applied with a hot water bottle, hot towel, etc., and try to avoid direct blowing of air conditioning and electric fans on the joint during hot summer days.

　　1、Electromyography

　　Electromyography and nerve conduction velocity examination are helpful for the diagnosis of scapular neuropathy syndrome. Khaliki found that in patients with scapular neuropathy syndrome, the latency of evoked potentials is prolonged, and the electromyogram of the supraspinatus muscle can show positive waves, fibrillation waves, and decreased or absent motor potentials.

　　2、X-ray examination

　　使肩胛骨在后前位X线片上向尾部倾斜15°～30°，以检查肩胛上切迹的形态，有助于诊断。

　　肩胛上神经卡压症饮食多食两素：两素即维生素和纤维素。尤其是B族维生素，它神经代谢非常重要的物质，维生素C、维生素D，等是人体不可缺的营养物质，有些脂溶性维生素易引起缺乏，所以应适当吃些牛奶粗米、粗面、胡萝卜、新鲜蔬菜和水果来补充，适当吃些坚果，核桃、白果、松子等，它们含丰富的神经代谢营养物质。忌烟、酒、辛、辣、炸烤食物。

　　一、基本要求

　　肩胛上神经卡压的治疗仍以手术松解为主。保守治疗如休息、理疗、止痛药物的应用，以及局部封闭治疗也可选用。对以创伤或牵拉引起的肩胛上神经损伤，早期可保守治疗。如为明确的慢性卡压，应早期手术治疗，进行神经松解及肩胛上切迹扩大术。

　　二、手术疗法.

　　肩胛上神经卡压松解术常采用三种入路：后入路、前入路和颈部入路。后入路是最常用的手术入路，手术步骤如下：

　　1、麻醉与切口

　　（1）麻醉：全身麻醉，取侧卧位。

　　（2）切口：从肩峰开始，沿肩胛冈向内侧延长至肩胛骨的脊柱缘，长约10cm(图1)。

　　2、手术步骤

      游离切口上侧皮缘，切开深筋膜，辨明斜方肌止点，顺切口方向切断该肌止点。找到斜方肌与冈上肌的肌间隙做钝性分离，向下分离达肩胛骨的上界，继续向外侧分离，找到肩胛上神经和肩胛上血管。将肩胛上血管向外侧牵开，充分显露肩胛上神经可能存在的卡压因素，如肩胛上横韧带及各种纤维束带等，并对卡压因素进行松解。将肩胛上神经游离、牵开，用骨凿对肩胛上切迹进行扩大。术后将肢体远端悬吊，并尽早进行功能锻炼。