A 35-year-old male wrestler is admitted to the emergency department with excruciating pain in his right shoulder and proximal arm. During physical examination the patient clutches the arm at the elbow with his opposite hand and is unable to move the injured limb. Radiographic studies show that the patient has a dislocation of the humerus at the glenohumeral joint. Which of the following conditions is the most likely?
The head of the humerus is displaced inferiorly because in that location it is not supported by rotator cuff muscle tendons or the coracoacromial arch. It is also pulled anteriorly beneath the coracoid process by pectoralis and subscapularis muscles. It would not be displaced posteriorly because it is supported by the teres minor and infraspinatus muscle tendons. It would not be displaced superiorly because the acromioclavicular ligament and supraspinatus reinforce in that direction. A medial dislocation is blocked by the subscapularis tendon.
The head of the humerus is displaced anteriorly.
The head of the humerus is displaced posteriorly.
The head of the humerus is displaced inferiorly.
The head of the humerus is displaced superiorly.
Upper Extremity