A twenty-two-year-old, right-hand-dominant man was seen in the emergency department of a large hospital after he was involved in a motorcycle accident. The patient was managed for multiple injuries, including a head injury with loss of consciousness, amnesia, impairment of hearing, and numbness on the left side of the face; fractures of the ribs, the right foot, and the ankle; and lacerations of the left foot. He also reported pain in the left shoulder. A diagnosis of a possible fracture of the left scapular body was made on the basis of a single anteroposterior radiograph of the left shoulder (Fig. 1). The left upper limb was immobilized in a sling, and the patient was discharged from the hospital after ten days.
Approximately two weeks after the accident, the patient was assessed by an orthopaedic surgeon because of continued pain in the left shoulder. A repeat anteroposterior radiograph was interpreted as showing a possible acromioclavicular disruption. The patient was advised to continue to wear the sling and to begin early passive range-of-motion exercises as tolerated.
Six days later, the patient consulted another orthopaedic surgeon, who ordered transthoracic, axillary lateral, and repeat anteroposterior radiographs of the left shoulder. Although the transthoracic and anteroposterior radiographs were difficult to interpret with respect to the glenohumeral joint and the proximal aspect of the humerus, the axillary radiograph showed a two-part posterior fracture-dislocation of the anatomical neck (Fig. 2). The patient was referred to the senior one of us (C. A. R., Jr.) for evaluation and management.
Physical examination revealed some swelling and diffuse tenderness about the left shoulder, with active elevation in the plane of the scapula to 40 degrees, external rotation to neutral (0 degrees), and internal rotation to the level of the greater trochanter. The function of the axillary, musculocutaneous, radial, ulnar, and median nerves on the left side was normal, as were the distal arterial pulses. The patient reported no previous or recent injuries of the left shoulder other than the one sustained at the time of the motorcycle accident.
The patient was admitted to Bexar County Hospital for open reduction and internal fixation of the posterior fracture-dislocation of the left shoulder. Through an anterior deltopectoral approach that preserved the deltoid and pectoralis major muscles, the interval between the superior border of the subscapularis tendon and the anterior margin of the supraspinatus tendon was developed to allow entry into the joint. It was not necessary to release any of the rotator cuff tendons. The humeral head was found to be dislocated posteriorly, with some capsular attachments to its posterior and inferior aspects. The head was reduced into the glenoid with use of a combination of external pressure over the posterior aspect of the joint, where the head was palpable, and intra-articular leverage with a long Darrach retractor. It then was realigned with the proximal aspect of the humerus and fixed with two threaded Steinmann pins, which were passed percutaneously in a lateral-to-medial direction to engage the subchondral bone of the humeral head (Fig. 3). Percutaneous Steinmann pins were chosen for fixation because they offered a simple method of stabilization and because their subsequent removal would avoid the possible problem of secondary impingement. The left upper limb was immobilized in a type of modified shoulder-spica cast (an above-the-elbow cast connected to an abdominal cast) with the shoulder in neutral rotation and 15 degrees of abduction.
The patient wore the cast for four weeks and then wore a sling for an additional four weeks. During the period of immobilization in the sling, the patient was instructed to use the left arm for gentle activities of daily living, such as dressing and eating. The Steinmann pins were removed eight weeks after the operation. An intensive program of rehabilitation was started at the time of removal of the cast, and strengthening exercises were added at twelve weeks postoperatively. The patient reported good progress, but he failed to return for follow-up.
Despite numerous attempts to arrange a follow-up examination, the patient did not return until fifteen years after the injury and operation. He had been employed as a manual laborer at an ironworks facility since the accident. The patient had mild pain and a popping sensation in the left shoulder with overhead lifting and noticed occasional exacerbation of the pain with changes in the weather. He occasionally had sharp pain that necessitated the oral use of over-the-counter, non-narcotic analgesics; such pain occurred approximately once every two to four months and usually lasted two to three days. The patient believed the left shoulder to be weaker than the right shoulder and to have a decreased range of motion. Clinical examination revealed mild atrophy of the deltoid, supraspinatus, and infraspinatus muscles on the left side compared with those on the right. Range-of-motion measurements demonstrated 140 degrees of flexion, 45 degrees of external rotation, and internal rotation to the twelfth thoracic level on the left compared with 160 degrees of flexion, 45 degrees of external rotation, and internal rotation to the seventh thoracic level on the right.
Radiographs showed good maintenance of the contour of the anatomical neck. Posttraumatic and perhaps ischemic changes were observed in the superior aspect of the humeral head and neck, but there were no areas of major segmental collapse of the humeral head (Figs. 4-A and 4-B).
Displaced fracture of the anatomical neck with dislocation of the humeral head is a rare injury1,3,5,7,8. Jakob et al. reported four such injuries in a series of 730 proximal humeral fractures5. The rarity of this injury may cause the diagnosis to be delayed or missed1,8. However, as with posterior dislocation of the glenohumeral joint without fracture, a frequent cause of misdiagnosis is the failure to make adequate radiographs9. The critical element in the assessment of any injured shoulder is the standard trauma series, which includes anteroposterior, axillary lateral, and scapular lateral radiographs1,8. If the diagnosis cannot be confirmed with these radiographs, then computerized tomography should be performed.
In 1908, Buchanan reported the case of a patient who had an inferior dislocation of the humeral head and reviewed the available literature on twenty-nine patients in whom such an injury had been documented at the time of an operation or autopsy2. Buchanan managed his patient with excision of the humeral head and noted a poor functional result six months after the injury. Kofoed reported on two patients, both of whom were more than sixty years old, in whom a three or four-part fracture-dislocation of the humeral head was treated with open reduction and internal fixation6. In both patients, the humeral head was noted to be completely devoid of soft-tissue attachments at the time of the operation. Neither patient had evidence of avascular necrosis after two years of follow-up. On the basis of his findings, Kofoed suggested that revascularization of the humeral head occurs by "creeping substitution." Swamy and Schemitsch described a patient who had a posterior fracture-dislocation in which a single fragment containing more than half of the articular surface of the humeral head was found to have no soft-tissue attachments10. The fragment was reduced and fixed with Herbert screws, and no evidence of avascular necrosis was observed at the time of the two-year follow-up10.
The fifteen-year results for our patient support the concept that revascularization of the humeral head occurs through a process of so-called creeping substitution. It is likely that accurate reduction and stable internal fixation enhances the probability of successful revascularization of the humeral head. Open reduction and internal fixation in the presence of nearly complete devascularization of the humeral head does not always make avascular necrosis and sequential collapse inevitable. We agree with the principle of attempted internal fixation of these fractures in young patients.