Fracture-dislocation of the proximal aspect of the humerus with remote displacement of the humeral head is exceedingly rare. We are aware of five reports that describe such injuries2,3,5,7,8. In four of them, the injury was an ipsilateral intrathoracic displacement of the humeral head resulting from fracture-dislocation. The fifth, more recent report details a case in which the displaced humeral head was found in the ipsilateral retroperitoneal space8.
We report a case of a four-part fracture-dislocation of the proximal aspect of the humerus with displacement of the humeral head into the contralateral pleural cavity.
*No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. No funds were received in support of this study.
†Department of Orthopaedic Surgery, Rhode Island Hospital/Brown University, 593 Eddy Street, Providence, Rhode Island 02903.
A sixty-four-year-old, right-hand-dominant man fell fifteen feet (4.6 meters) from a ladder while repairing a skylight in his home. He was transported to our level-1 trauma center, where he was evaluated according to Advanced Trauma Life Support protocols1. When he arrived, he was alert and hemodynamically stable and he reported pain in the chest and left shoulder. There was extensive subcutaneous emphysema over both hemithoraces, and the posterior aspects of the ribs were tender bilaterally. The trachea was in the midline, and breath sounds were diminished bilaterally. A radiograph of the chest confirmed bilateral pneumothoraces, and chest tubes were placed.
There was diffuse swelling about the left shoulder girdle. The skin was intact. The left radial pulse was intact, and the pulses on the left and right sides were symmetrical. On neurological examination, there was diminished sensibility to light touch in the axillary nerve distribution and weakness of the deltoid, biceps, and triceps on the left side. Although the examination was limited because the patient had pain and had been sedated, it was possible to palpate the biceps and triceps contracting. Contraction of the deltoid was felt by some examiners but not by others. The patient could contract all distal muscles, although strength testing was again limited by pain.
Radiographs of the left shoulder demonstrated a displaced comminuted fracture of the proximal aspect of the humerus (Fig. 1). The greater and lesser tuberosities were displaced, and the humeral head was absent. Radiographs of the chest demonstrated bilateral pneumothoraces, widening of the mediastinum, and displacement of the humeral head into the apex of the contralateral aspect of the chest (Fig. 2). A computed tomography scan of the chest demonstrated that the humeral head was outside the lung parenchyma in the apex of the right thoracic cavity. An apparent trail of air marking the path of the humeral head was noted to enter the left aspect of the chest through the thoracic inlet, to pass behind the esophagus through the superior mediastinum, and to enter into the right pleural cavity. There was no evidence of aortic injury (Figs. 3-A and 3-B).
The injury was believed to be the equivalent of a zone-I neck injury, and a standard protocol for the evaluation of this kind of injury was followed6. The findings on an arteriogram of the aortic arch were normal, with runoff to the great vessels, and the results of a barium swallow, a bronchoscopy, and an esophagoscopy were all normal as well.
On the fifth day in the hospital, after pulmonary function had stabilized and the patient was cleared for thoracoscopy and open reduction by the trauma team, the patient was taken to the operating room. Initially, he was placed in left lateral decubitus and a right thoracoscopy was performed by a thoracic surgeon. The humeral head was localized adjacent to the lung. There was mild contusion of parenchyma in the right upper lobe. The humeral head was removed through an expanded thoracoscopy portal (Fig. 4).
Immediately following this portion of the procedure, the patient was placed in the beach-chair position for reconstruction of the shoulder. The fracture of the proximal aspect of the humerus was explored through a deltopectoral approach. The tuberosities were found to be displaced and comminuted. The axillary nerve was palpably intact. The pectoralis major and latissimus dorsi insertions were partially avulsed from the humerus. Additionally, there was a fracture of the anterior aspect of the glenoid rim and capsular disruption. The rotator cuff was intact. The shoulder was reconstructed with a modular humeral head replacement. The fracture of the glenoid rim was small; it was reduced and was stabilized with sutures incorporated in the capsular repair. Immediately postoperatively, the neurological findings were unchanged.
Over the next several days postoperatively, physical examination demonstrated a deterioration in neurological function. Strength was evaluated with manual motor testing. There was no appreciable contraction of the anterior and middle aspects of the deltoid, and there was equivocal contraction of the posterior aspect of the deltoid. With strength graded on a scale ranging from grade 0 to grade 5, the triceps was grade 3; the biceps, grade 4; extension of the wrist, grade 2; flexion of the wrist, grade 3; the first dorsal interosseous muscle, grade 2; and the flexor digitorum sublimis, grade 2. External and internal rotation were grade 2. Sensation to light touch was diminished in the axillary and musculocutaneous distributions. One month after the injury, there appeared to be no improvement in neurological function. Electrodiagnostic studies confirmed a severe injury of the brachial plexus. The electromyographic portion of the study demonstrated an injury of both the posterior and the medial cord of the brachial plexus. Seventeen months after the injury, the brachial plexopathy had partially resolved. Testing of muscle strength revealed that the deltoid was grade 3 of 5; external rotation, grade 4; internal rotation, grade 3; the biceps and triceps, grade 5-; and all distal muscles, grade 5.
Initially, the patient had severe pain in the shoulder, arm, and hand, and he had difficulty using the involved extremity. At the time of the most recent follow-up visit, however, he reported only rare episodes of pain and had no limitation of his routine daily activities.
Remote displacement of a humeral head following fracture or dislocation has been reported infrequently. To our knowledge, this is the first report of displacement of the humeral head to the contralateral side of the body.
Glessner described the case of a seventy-five-year-old woman who sustained a fracture-dislocation into the ipsilateral pleural space and was managed with drainage with a chest tube and reattachment of the rotator cuff to the humeral shaft2. Two years after treatment, the patient was satisfied with the result. Wirth et al. described a case in which the humeral head was displaced into the ipsilateral retroperitoneal space8. The humeral head was retrieved and replaced during open reduction, and it was then internally fixed.
In our patient, the mechanism of injury may have been the direct projection of the articular segment of the humeral head propelled by the humeral shaft. A computed tomography scan of the chest suggested that the path of the humeral head traversed the mediastinum. The avulsions of the pectoralis major and latissimus dorsi insertions from the humerus, in addition to the brachial plexopathy, suggested that the humeral shaft was severely displaced at the time of the injury. We elected to remove the humeral head from the chest in order to prevent the late development of pulmonary problems. Thoracoscopy offered the possibility of a minimally invasive approach4.
The trauma surgery team chose to treat this injury as a zone-I neck injury when evaluating this patient because of the path that the humeral head took through the mediastinum. The neck is commonly divided into three zones. Zone I includes the thoracic outlet, extending from the level of the cricoid cartilage down to the level of the clavicle. Potentially involved structures include the proximal carotid arteries; the subclavian vessels; the major vessels in the chest, lung, and superior mediastinum; the esophagus; the trachea; the thoracic duct; and the brachial plexus. Zone II consists of structures between the cricoid and the mandible, and zone III involves structures superior to the mandible. Patients who have obvious injuries or those who are hemodynamically unstable are often brought directly to the operating room when the injury involves one of these zones. Stable patients are systematically evaluated with use of angiography, endoscopy, contrast studies of the gastrointestinal tract, radiographs of the chest, and computed tomography scans. If the results of all studies are normal, the patient may be observed; otherwise, operative intervention is needed on the basis of the results of the diagnostic tests6. While the results of the studies for our patient did not show evidence of mediastinal injury, the computed tomography study of the chest revealed the proximity of the trachea, esophagus, and great vessels to the path that the humeral head followed. Clearly, injury of any of these structures can be life-threatening and must be actively addressed.
The reason for the deterioration in the neurological status of our patient was not clear. During the operation, the infraclavicular portion of the brachial plexus was explored and was palpably intact. There was no evidence of compression from hematoma. Care was taken to avoid traction on the extremity. As the muscle strength gradually began to improve on repeated postoperative examination, the decision was made not to explore the brachial plexus, as no treatable etiology was clearly evident. Over the course of the patient's recovery, the neurological function has continued to improve.
The patient in the report by Wirth et al. was managed with salvage of the articular segment of the humeral head and open reduction and internal fixation8. Despite this procedure, avascular necrosis occurred. We treated the four-part fracture-dislocation in our patient with a humeral head replacement, as we believed that the complete disruption of the vascular supply to the humeral head segment would have led to avascular necrosis of the humeral head and a potentially poor long-term outcome had we attempted to salvage the segment.