A case report of acute posterior dislocation of shoulder with fracture of greater tubercle of humerus / 中华骨科杂志

ABSTRACT

A case of acute posterior dislocation of shoulder with fracture of greater tubercle of humerus was reported. The patient came to hospital complaining pain and limited motion of left shoulder caused by traffic accident. The diagnosis of posterior dislocation of the left shoulder and fracture of the greater tubercle was confirmed by medical history, physical examination and imaging. After the failure of manual reduction under anesthesia, MRI was conducted which revealed that the biceps brachii longus and supraspinatus and infraspinatus muscle were embedded between the head of humerus and glenoid scapula. Then open reduction and internal fixation was performed. The biceps brachii longus was cut off and then fixed in the inter nodal groove. After the rotator cuff was relieved from the impaction, the dislocation of the humeral head was successfully reduced and the fracture of the greater tubercle was reduced and fixed. According to the operation process, the possible trauma mechanism is discussed as follows the displaced fracture of the greater tubercle destroyed the integrity of the lateral wall of the inter tubercular groove, and the biceps brachii longus slipped out of the inter tubercular groove and shifted to the medial side, which was embedded between the humeral head and the scapular glenoid, thus forcing the humeral head to fall posteriorly, and causing the fracture of the greater tubercle to move anteriorly and inferiorly. Attention should be paid to the possible acute dislocation of shoulder joint for the patients with high energy injury. The only way to avoid missed diagnosis is to combine with multi-directional X-ray or CT examination of shoulder. MRI should be used to determine whether there is tendon incarceration of rotator cuff and/or biceps brachii longus in patients with acute posterior dislocation of shoulder. Anatomic reduction of tubercle fracture is the key to recover the range of motion and muscle strength of shoulder joint.