Between 2000 and 2006, eight patients (ten shoulders) underwent scapulothoracic fusion at our institution. There were four men and four women, with a mean age of 38.4 years (range, nineteen to sixty-one years). The most common indications for surgery were refractory symptomatic scapular winging secondary to fascioscapulohumeral muscular dystrophy in five shoulders, anterior serratus muscle paralysis secondary to long thoracic nerve palsy in one shoulder, and trapezius muscle paralysis secondary to spinal accessory nerve injury in two shoulders. In two of the eight patients (two shoulders), the procedure was performed to treat symptoms following resection of the medial portion of the clavicle. The presentation of these two patients was markedly different from that of the other patients, and their degree of disability and pain was profound. We are not aware of any similar cases that have been published previously in the literature. The two patients were informed that data concerning the case would be submitted for publication, and they consented.
Case 1. A twenty-nine-year-old right-hand-dominant woman presented with disabling right shoulder pain of one-year duration. The patient had a history of a completely asymptomatic congenital pseudarthrosis of the right clavicle. One year before presentation, she fell from a motorcycle, injuring her right shoulder. Radiographs and initial evaluation elsewhere demonstrated no acute fracture; however, she had pain over the pseudarthrosis site. Treatment elsewhere consisted of an attempted open reduction and internal fixation with bone-grafting to the medial clavicular pseudarthrosis. During surgery, severe bleeding was encountered, necessitating emergency resection of a medial section of the clavicle in order to control the bleeding with ligation of the subclavian vein at its junction with the innominate vein. The patient required multiple transfusions but ultimately recovered after a lengthy stay in the intensive care unit.
The patient then presented to our shoulder service one year later with chronic and intolerably severe pain. She reported an inability to perform activities of daily living and described a sensation of aching and tingling along the entire arm. She had tried periscapular strengthening exercises before she presented to us, but she was not able to tolerate any type of exercises, specifically strengthening exercises, because of the severe pain about the shoulder.
The physical examination demonstrated substantial ptosis and medial collapse of the shoulder. The right shoulder appeared to be lower than the left and shorter from lateral to medial. There was an obvious deformity of the sternoclavicular joint region along with loss of its normal contour. Flexion of the affected shoulder was limited to only 80° as compared with 150° in the contralateral shoulder, and the patient had profound scapular winging with any attempt to raise the arm. With application of the scapular compression test12, in which the scapula is manually maintained compressed by the examiner against the chest wall, the pain decreased substantially and the arm could be flexed to 140°. The patient also described dysesthetic sensations radiating down the arm, which were also reduced when the scapula was stabilized against the chest wall manually. Tests for thoracic outlet syndrome were too painful for this patient to perform.
Radiographs and computed tomography of the shoulder showed a comminuted fracture of the medial part of the clavicle and a >5-cm area of resection (Fig. 1). The patient underwent venography, which demonstrated occlusion of the right subclavian vein along with formation of collateral vessels. The findings on electrodiagnostic studies were normal.
The decision to perform a scapulothoracic fusion in this patient was based on restoring the normal scapulothoracic position and eliminating what appeared to be thoracic outlet dysfunction, which was a consequence of collapse of the shoulder girdle. We believed that an attempt to reconstruct the medial portion of the clavicle would be unsuccessful and dangerous due to scarring from the prior surgery and the inability to stabilize the clavicle due to severe bone loss.
Case 2. A forty-three-year-old right-hand-dominant woman sustained a compression injury to the right shoulder when the inner tube on which she was riding at a water park flipped and collided with an immovable object. This resulted in a posterior fracture dislocation of the right sternoclavicular joint along with compression of the clavicle against the trachea and symptomatic labored breathing. The patient was taken to another institution, where she was treated emergently with open reduction and resection of approximately 4 cm of the medial part of the clavicle. Although this operation alleviated the respiratory symptoms, severe pain subsequently developed about the ipsilateral shoulder. Three years following the injury, the patient presented to our shoulder service with a description of chronic and severe pain that precluded use of the arm for all activities of daily living. The pain was described as radiating from the sternoclavicular region into the scapula and down the arm, similar to the symptoms reported by the patient in Case 1. The patient described dysesthesias radiating down the arm and into the hand and, similar to the patient in Case 1, had tried periscapular strengthening exercises before she presented to us, but she was not able to tolerate any type of exercises because of severe pain about the shoulder.
The physical examination was notable for marked ptosis of the involved shoulder along with the appearance of shortening of the shoulder. When any attempt was made to raise the arm, the scapula winged markedly and the patient achieved a maximum of 120° of flexion in the involved shoulder as compared with 150° of flexion in the contralateral shoulder. Any attempt to bring the arm across the chest caused marked pain in the sternoclavicular joint region. Neurovascular examination of the distal aspects of the upper extremities revealed that the neurovascular function was intact. Adson's maneuver and Wright's test for thoracic outlet syndrome were too painful for the patient to tolerate on testing13. The scapular stabilization test12 alleviated the dysesthesias in the arm and allowed the patient to flex the shoulder to 150° with minimal pain.
A computed tomography scan with three-dimensional reconstructions demonstrated loss of the medial 4 cm of the clavicle.
Electrodiagnostic studies, including electromyography and nerve conduction studies of the long thoracic and spinal accessory nerves, revealed normal findings.
Our interpretation of the symptomatic winging was that it was secondary to loss of the lateral strut support normally provided by the medial portion of the clavicle. In other words, the shoulder collapsed inward, allowing the scapula to wing away from the thorax. Moreover, a postural thoracic outlet syndrome seemed to develop as a consequence of the ptosis and medial collapse of the shoulder. Scapulothoracic fusion was chosen as a treatment in order to restore the normal position of the shoulder and eliminate the deformity.
Surgical Procedure
The procedure of scapulothoracic fusion has been described elsewhere10. Our version of this surgical method is described below.
The patient is positioned prone on the operating table. The entire hemithorax and back are sterilely prepared down to and including the iliac crest and then draped, and the arm is also prepared and draped so that it can be moved freely during the operation. The arm can thus be placed into a position of maximum internal rotation, which allows the scapula to wing away from the chest wall, thereby improving exposure for the removal of the periscapular muscles. Arm boards are placed so that the arm can be brought into an optimal position for fusion, which is about 100° of abduction and 20° of forward flexion with the elbow flexed to 90°.
After prophylactic intravenous antibiotics are given, an approximately 15-cm-long incision is made over the medial border of the scapula. Skin flaps are raised. The trapezius and rhomboid muscles are detached from the scapula and reflected medially. The supraspinatus and infraspinatus are elevated out of their respective fossae and pushed laterally in order to allow room for placement of the plate. The arm is then placed in a position of maximum internal rotation by placing the patient's hand on his or her lower back. This positioning allows the scapula to wing away from the chest. The serratus anterior and the subscapularis muscles are then resected, with careful attention paid to systematic control of bleeding, as many large vessels traverse these muscles. Depending on the size of the subscapularis, the medial one-third to one-half of that muscle is resected in order to ensure full contact between the anterior osseous aspect of the scapula and the chest wall without interposition of soft tissue. The serratus muscle is similarly removed.
The third, fourth, fifth, and sixth thoracic ribs are then identified and, with use of an electrocautery, cleared of soft tissue. Some of the intercostal muscles, if prominent, are carefully removed to ensure the ready availability of an adequate amount of bone surface for fusion. The undersurface of the scapula in the subscapularis fossa is then decorticated with a dental burr, as are the exposed ribs. Eighteen-gauge wire loops are then passed around the third, fourth, fifth, and sixth thoracic ribs. This maneuver is performed with use of special elevators similar to those used in laminectomies in spine surgery. Careful attention is taken to ensure that these wires remain extrapleural. After the wires are passed, sterile saline solution is applied to the chest wall and the anesthesiologist is instructed to give the patient positive pressure ventilation so that any pleural leak can be identified and treated.
Autogenous corticocancellous strips and cancellous bone are then harvested from the ipsilateral iliac crest and mixed with allograft bone chips. The bone graft is then placed over the exposed ribs. A four or five-hole dynamic compression plate (Synthes, Paoli, Pennsylvania) is placed over the medial part of the scapula in the infraspinatus fossa, approximately 2 to 3 cm from the medial, thicker edge of the scapula. The plate is used mainly to support the thin scapular bone and act as a large washer that supports the bone during fixation to withstand the force of compression between the scapula and the ribs. Holes are then drilled through the holes in the plate as the scapula is aligned with the ribs and wires to ensure the best compression of the scapula against the chest wall. During placement of the plate, the arm is positioned on the arm board in the position noted above, thereby optimally positioning the scapula for fusion. The wires around the fourth, fifth, and sixth thoracic ribs are then brought through the holes in the plate, while the wire around the third thoracic rib is brought through the supraspinatus fossa and over the spine of the scapula. All of the wires are then tightened with use of a wire-tightening device while compression of the scapula to the ribs is carefully confirmed (Fig. 2). The rhomboids and trapezius are then repaired to the infraspinatus and supraspinatus so that there is a muscular cushion overlying the plate and bone. The wound is then closed in a routine fashion over a suction drain.
Postoperatively, a shoulder immobilizer (UltraSling; DonJoy, Carlsbad, California) is worn for twelve weeks. At that time, a computed tomography scan of the shoulder is obtained to evaluate the status of the osseous integration between the scapula and ribs. The performance of gentle passive and active assisted range-of-motion exercises and activities of daily living can begin after the sling is discarded. Strengthening does not start until solid fusion is confirmed by computed tomography scan, which may have to be repeated at five or six months after surgery for this reason (Fig. 3).
Both patients were evaluated at two weeks, six weeks, three months, six months, one year, and two years postoperatively, and the patient in Case 1 was seen also at four years postoperatively. Outcome measures that were used included preoperative and postoperative pain scores, range- of-motion assessment, and Constant scores14. Standard shoulder radiographs were made at the time of each follow-up visit. A computed tomography scan was also acquired at the time of the three-month follow-up to document osseous healing of the fusion and was repeated at the time of the six-month follow-up for the patient in Case 1 for the purpose of confirming a complete scapulothoracic fusion.
Case 1. This patient did not experience any perioperative or postoperative complications. The examination at the most recent evaluation (four years after surgery) showed restoration of the normal contour of the right shoulder. The pain on a scale from 1 to 10 was, on the average, 9 before surgery and 0 after surgery. She had complete resolution of the numbness and tingling that radiated down the involved upper extremity. Shoulder flexion changed from a very painful active flexion of 80° before surgery to a painless flexion of 90° after surgery. The Constant score improved from 25 before surgery to 48 after surgery. Overall, the patient was very happy with the pain resolution and believed that the surgery did help her, despite the fact that shoulder motion had not improved substantially.
Case 2. This patient also did not experience any perioperative or postoperative complications. The examination at the most recent evaluation (twenty-five months after surgery) showed restoration of the normal contour of the right shoulder. The pain on a scale of 1 to 10 was, on the average, 9 before surgery and 4 after surgery, and it was mostly localized to the back of the shoulder at the site of the operation. The patient had almost complete resolution of the preoperative shoulder pain and the numbness and tingling that radiated to the upper extremity. Although the postoperative range of active flexion did not change from that seen before surgery (120°), it could now be achieved painlessly. The Constant score improved from 42 before surgery to 81 after surgery. Overall, the patient was satisfied and believed that the surgery had helped her.
In the normal shoulder, motion is distributed synergistically between three joints and one fascial articulation. These structures are the sternoclavicular joint, the acromioclavicular joint, the glenohumeral joint, and the scapulothoracic articulation15. The balanced coordination of all of these components ensures smooth and stable functional motion16. An abnormality of any of these components, including scapular malpositioning17, may affect overall shoulder motion. The most common cause of disruption of the stability of the scapulothoracic articulation is the loss of the dynamic function of the muscles that stabilize the scapula to the chest wall18. This loss can be the result of injury to muscles, osseous structures, or nerves.
Disabling scapular winging secondary to loss of the medial clavicular strut support is a rare problem in our practice, and we are unaware of any previous reports of this problem in the literature. Our patients had symptomatic scapular winging in the absence of neurological injury to the muscles that control scapular motion. In both patients, the problem was secondary to loss of stability of the clavicle (the normal lateral strut for the shoulder girdle), which was the result of resection of the medial one-third of the clavicle. Thus, tendon transfer for the treatment of scapular dysfunction did not seem to be an option12,18.
Anatomically, it is evident that when a major segment of the medial part of the clavicle is removed, all supporting ligaments between the medial part of the clavicle and the sternum are lost. In a study of eighty-six cadaveric sternoclavicular joints, Bisson et al. measured the distance from the inferior articular surface of the medial end of the clavicle to the most medial insertion of the costoclavicular ligament and found that the safe distance at which the medial end of the clavicle could be resected without injuring the costoclavicular ligament was, on the average, 1.2 cm in men and 1.0 cm in women19. In a separate study, Cave found that the measurement of the costoclavicular ligament averaged 1.3 cm in length, 1.9 cm in width, and 1.3 cm in thickness20. Thus, if we combine the length of the safe zone of resection of the medial end of the clavicle with the average length of the costoclavicular ligament, we can conclude that resection of >2.5 cm of the medial part of the clavicle may completely disrupt the costoclavicular ligament as well as the sternoclavicular ligament, thereby resulting in the loss of the only articulation that connects the shoulder girdle to the chest15.
The consequences of loss of the sternoclavicular joint can be insignificant, as is seen in many patients who have cleidocranial dysostosis but who remain completely asymptomatic throughout their lives21. In addition, several authors have reported a good-to-excellent outcome after complete clavicular excision for neurovascular exposure, excision of tumor, or the treatment of infection22-25. However, in none of these reports was claviculectomy used to treat severe loss of scapular control and abnormal shoulder position. Wessel and Schaap reported different outcomes in a recent article on total claviculectomy25. Six patients underwent total claviculectomy for various reasons. The outcome was good for the one patient with chronic infection and the two patients with tumor; however, it was poor for the three patients in whom surgery was performed for persistent pain following trauma. The status of the scapulothoracic articulation was not discussed in that paper.
We did not believe that complete claviculectomy was an option for our two patients. Both patients had a probable functional thoracic outlet syndrome, which we believed would worsen with clavicular resection. In addition, both patients had relief of pain and better shoulder motion preoperatively with manual stabilization of the scapula and support of the arm. This indicated that they both needed some form of scapular stabilization to support the shoulder. After scapulothoracic fusion, both patients had reduction of pain and resolution of the radiating numbness and tingling to the ipsilateral involved extremity. Neither patient had much improvement in shoulder motion, but shoulder contour and the ability to perform most activities of daily living were improved.
Many complications are reported secondary to scapulothoracic fusion4-6. These include nonunion, pneumothorax, pleural effusion, and fractures of the scapula and/or ribs. To avoid the fixation loss and nonunion that can occur with fracture, Rush pins or a metal plate can be used to augment the strength of wire fixation7,9,10. In addition, bone grafts can be used to enhance the fusion. In both of our patients, plates, wires, and augmentation of the fusion site with a mixture of autogenous and allogeneic bone grafts were used and a solid fusion was achieved.
In summary, disabling scapular winging secondary to resection of the medial end of the clavicle is a rare and very challenging problem. Scapulothoracic fusion is a salvage procedure that should be considered as a last resort to manage this complicated problem. 