INFERIOR GLENOHUMERAL DISLOCATION (LUXATIO ERECTA)
INFERIOR GLENOHUMERAL DISLOCATION (LUXATIO ERECTA)
This very rare injury is more common in elderly individuals.
Mechanism of Injury (Fig. 14.13)
The superior aspect of articular surface is directed inferiorly and is not in contact with the inferior glenoid rim. The humeral shaft is directed superiorly.
Rotator cuff avulsion and tear, pectoralis injury, proximal humeral fracture, and injury to the axillary artery or brachial plexus are common.
Clinical Evaluation
Patients typically present in a characteristic “salute” fashion, with the humerus locked in 110 to 160 degrees of abduction and forward elevation. Pain is usually severe.
The humeral head is typically palpable on the lateral chest wall and axilla.
A careful neurovascular examination is essential, because neurovascular compromise almost always complicates these dislocations.
Radiographic Evaluation
Trauma series of the affected shoulder: AP, scapular-Y, and axillary views are taken.
The AP radiograph is typically diagnostic, with inferior dislocation of the humeral head and superior direction of the humeral shaft along the glenoid margin.
The radiograph must be carefully scrutinized for associated fractures, which are common and may be clinically not detected because of a diffusely painful shoulder.
Treatment
Nonoperative
Reduction may be accomplished by the use of traction-countertraction maneuvers.
Axial traction should be performed in line with the humeral position (superolaterally), with a gradual decrease in shoulder abduction. Countertraction should be applied with a sheet around the patient, in line with, but opposite to the traction vector.
The arm should be immobilized in a sling for 3 to 6 weeks, depending on the age of the patient. Older individuals may be immobilized for shorter periods to minimize shoulder stiffness.
Operative
Occasionally, the dislocated humeral head “buttonholes” through the inferior capsule and soft tissue envelope, preventing closed reduction. Open reduction is then indicated with enlarging of the capsular defect and repair of the damaged structures.
Complications
Neurovascular compromise: This complicates nearly all cases of inferior glenohumeral dislocation, but it usually recovers following reduction.