Luxatio Erecta

While jogging in a park, a 45-year-old man tripped and fell on his outstretched hand. As he fell, he tried to catch himself on a nearby park bench but was unsuccessful. He felt that his shoulder was out of place, and he was unable to adduct his arm from its erect position. A witness called for an ambulance, and the man was taken to the emergency department. On arrival, the patient was in extreme pain; his arm was elevated above his head. Initial attempts to adduct the arm were met with resistance from the patient, who stated that this maneuver significantly increased his level of discomfort. Radiographs were then obtained to further evaluate his physical deformity. The patient’s plain radiograph demonstrates luxatio erecta, which is an inferior dislocation of the humeral head (A ,yellow arrow). The dislocation can be seen in relation to the glenoid fossa (black arrows); the distal humerus is also directed superiorly. This relatively rare shoulder dislocation is caused by hyperabduction (an abduction of nearly 180 degrees). An MRI scan obtained after reduction of the patient’s glenohumeral dislocation revealed findings characteristic of inferior shoulder dislocation- bone marrow edema in the regions of the greater tuberosity of the humerus and the inferior portion of the glenoid along with an impaction fracture of the superolateral humeral head. The T1-weighted image (B) shows the greater tuberosity fracture (arrow). In the T2-weighted image (C), edema along the fracture line (white arrow) and adjacent to the fracture (red arrows) can be seen. A torn inferior glenohumeral ligament (yellow arrow) and a small amount of fluid in the subacromial bursa (orange arrow) are also visible. Douglas P. Beall, MD, of Oklahoma City and John Whyte, MD, of Rockville, Md, write that luxatio erecta is distinguished from other shoulder dislocations by the significant superior orientation of the humeral shaft. In almost 50% of cases, the axillary nerve is compressed as a result of inferior displacement of the humeral head after dislocation. The nerve involvement usually resolves spontaneously over time with minimal sequelae. Luxatio erecta is treated with reduction. Typically, the shoulder is easily reduced, as was the case in this patient. He underwent physical therapy and had an unremarkable recovery.