Quadrilateral Space Syndrome

　　1. Etiology

　　The pathogenesis of this syndrome is due to the fact that when the shoulder joint is abduced and externally rotated, all the muscles composing the quadrilateral space are stretched, exerting pressure on the quadrilateral space from three directions, leading to the occurrence of this syndrome.

　　2. Pathogenesis

　　The quadrilateral space is an anatomical space composed of the small round muscle, the large round muscle, the triceps muscle, and the medial edge of the surgical neck of the humerus. There is a layer of fascial tissue between the small and large round muscles. After the axillary nerve is emitted from the posterior bundle, it斜向后行, passing through the quadrilateral space along the superior edge of the quadrilateral space and continuing to the outside and front along the deep deltoid muscle. The cutaneous branches that支配the sensory sensation of the lateral skin of the shoulder and arm exit the muscle and enter the subcutaneous tissue. The long head of the triceps muscle originates from the posterior aspect of the inferior angle of the scapula and merges with the other two heads to terminate at the olecranon of the ulna. When the shoulder joint is abduced and externally rotated, these three muscles are all stretched, exerting pressure on the quadrilateral space from above, below, and inside.

　　Patients with quadrilateral space syndrome should pay attention to a light diet, stay away from spicy and刺激性 foods, and at the same time, reduce the intake of greasy foods. During the treatment period, pay attention to supplementing sufficient nutrition to help the body recover better.

　　1. Symptoms:It mainly occurs in the dominant limb, but can also occur in both limbs. Initially, there is intermittent pain and numbness in the upper limb, which spreads to the upper arm, forearm, and hand. The symptoms worsen when the shoulder joint is flexed, abduced, and externally rotated. Some cases have a history of nocturnal pain, and the symptoms of most cases worsen without notice. Trauma is a common cause. Johnson believes that the injection of drugs in the posterior axilla may cause axillary nerve injury. Cormier and Redier each reported 1 case of baseball pitcher with this disease, the main manifestation of which is progressive shoulder pain, which is not fixed in front of the shoulder, and 1 case radiates to the arm and hand. The symptoms of the affected limb are exacerbated when it is abduced and externally rotated.

　　2. Signs:Neurological examination often shows no abnormalities, the deltoid muscle may atrophy, other muscles are normal, shoulder abduction may be limited, or the strength of abduction may decrease, the sensation on the lateral side of the shoulder and arm may be dull or absent, and there is a distinct localized tenderness area when pressing on the quadrilateral space from behind, the tenderness area may be biased to the lateral side of the hole, placing the affected limb in abduction and external rotation for 1 minute can induce the appearance of symptoms.

　　In life and work, pay attention to the combination of work and rest, high-risk workers should take corresponding safety measures, and oral anti-inflammatory analgesics, local closure with corticosteroids, physical therapy, etc. If conservative treatment is ineffective, surgical treatment can be performed.

　　I. Electrophysiological Examination:It can be found that the deltoid muscle has denervated potential, and the conduction velocity of the axillary nerve is slowed down.

　　II. Angiography:Understand whether the axillary nerve is compressed by observing the shadowing of the posterior humeral artery.

　　I. What foods are good for the body for the quadrangular space syndrome

　　It is advisable to eat light, eat more vegetables and fruits, such as bananas, strawberries, apples, etc. Because they are rich in nutrients, eat more immune-boosting foods such as propolis to enhance personal disease resistance. In daily life, it is also necessary to reasonably match the diet and pay attention to adequate nutrition.

　　II. What foods should be avoided for the best prognosis of the quadrangular space syndrome

　　Avoid smoking and drinking after surgery. Avoid greasy, spicy, smoking and drinking. Avoid eating cold food. To avoid the recurrence of the disease.

　　I. Treatment

　　I. Conservative Treatment:Including oral anti-inflammatory analgesics, local closure with corticosteroids, physical therapy, etc. If conservative treatment is ineffective, surgical treatment can be performed.

　　II. Surgical Method:Choose an incision parallel to the scapular spine, extending downward along the posterior humerus to the subacromial region, forming a 'one' shape, exposing the large and small round muscles and the long head of the triceps. Cut the fascia below the deltoid muscle, and cut off the origin of the muscle on the scapular spine, fully exposing the quadrangular space. Cut the muscle at the origin of the small round muscle, cut off the oblique fiber bundle and fascial tissue inside the hole, enter the quadrangular space, then identify the nerve vessel bundle, carefully protect and trace the anatomy, pay attention not to damage the accompanying vein, so as not to make it difficult to distinguish the nerve vessel bundle due to bleeding. Use fingers through the quadrangular space to cut off all the fiber bundles that limit and block the fingers. If the quadrangular space decompression is complete, the pulsation of the posterior humeral artery can still be felt when the shoulder is abducted and externally rotated.

　　II. Prognosis

　　The prognosis is good.