- March 2008 - Volume 31 · Issue 3:
Sternoclavicular dislocations are uncommon injuries, representing approximately 3% of all major insults to the shoulder girdle.1 Anterior sternoclavicular dislocations outnumber posterior dislocations by a ratio of 20:1, due in part to the greater strength of the posterior sternoclavicular ligament over its anterior counterpart.2 In fact, posterior sternoclavicular dislocations are so rare that approximately 100 cases have been reported in the literature since first being described in 1824 by Sir Astley Cooper.3 Despite the relative infrequency of posterior sternoclavicular dislocations, early diagnosis and treatment are crucial because of the potential of damage to the great vessels, trachea, and esophagus in the superior mediastinum caused by the posteriorly displaced clavicular head.
The diagnosis of a posterior sternoclavicular dislocation often is difficult and generally requires a high index of suspicion based on the patients history and physical examination. Patients with a posterior sternoclavicular dislocation usually have a history of trauma to either the sternum or scapulothoracic area and may complain of dyspnea, dysphagia, dysphonia, or pain over the clavicular head. A thorough physical examination also may reveal a slight depression of the clavicular head into the superior mediastinum, although swelling over the area can make detection of such a defect virtually impossible.
Patients also may have signs and symptoms of thoracic outlet syndrome, such as an edematous upper extremity, or evidence of brachial plexus palsy. Presenting symptoms can be altered by changes in arm positioning, particularly in chronic dislocations.
Evaluation with anteroposterior radiographs is difficult because of the superimposed ribs and lungs.4 Computed tomography (CT) is required for appropriate evaluation of the injury pattern. Because the medial clavicle is the last bone to fuse (at approximately age 25 years), injury patterns can change depending on patient age, with CT used to distinguish dislocations from medial epiphyseal fractures.
Most posterior sternoclavicular dislocations can be treated effectively with closed reduction and 6 to 8 weeks of immobilization.2,5 Instability presenting as recurrent or chronic dislocation is addressed with open treatment. Precisely which technique should be used to achieve stable internal fixation is controversial, but ligament repair with reconstruction appears to be the most widely accepted.6,7,8 Surgical fixation with Kirschner wires is not recommended and has been associated with fatal hardware migration.9 Medial clavicle resection also has been reported as a treatment option.10 These soft-tissue stabilization procedures all require a prolonged course of immobilization.
Plate stabilization of a pure posterior sternoclavicular dislocation has been reported in the literature for 2 patients using an intrasternal Balser plate.11 This technique offers the advantage of shorter postoperative immobilization and a good functional outcome. Plate removal is recommended approximately 3 months postoperatively to prevent manubrial or retrosternal hook migration.
This article presents 2 cases of posterior sternoclavicular dislocation treated with open reduction and internal fixation using locking plate osteosynthesis.
A 26-year-old nicotine-dependent woman was a restrained driver in a high-speed motor vehicle accident when her car hydroplaned on a wet road and hit a guardrail. She initially was examined at another hospital and was diagnosed with a right radial shaft fracture and a C2 fracture, the latter of which prompted transfer to our level-1 trauma center.
On physical examination, the patient reported pain in her right forearm, right clavicle, and neck with a cervical collar in place. She was breathing comfortably and able to phonate. However, she noted minor difficulty swallowing as well as weakness and paresthesia in her right hand. Removal of the right arm splint revealed closed skin and soft compartments with no gross instability. There was pain with passive movement of the right shoulder and tenderness to palpation over the right sternoclavicular joint with depression noted. No crepitance could be appreciated.
An AP chest radiograph revealed midline deviation of the right medial clavicle without fracture. Forearm radiographs demonstrated a nondisplaced radial shaft fracture with anatomic length and bow. Computed tomography from the transferring hospital that was sent with the patient revealed a nondisplaced C2 fracture and a previously undiagnosed Allman grade III posterior sternoclavicular dislocation with compression of mediastinal structures (Figure 1).
The patient was urgently taken to the operating room, and closed reduction of the dislocation was performed under general anesthesia. After a stable reduction was achieved, the patient was placed into a sling and a short arm splint was reapplied to the right forearm to address the radial shaft fracture.
Postoperatively, the patients dysphagia resolved completely, and she had no dyspnea or dysphonia. She reported mild pain over the right clavicular head despite appropriate anatomic contour. Serial examinations were unchanged for 48 hours. Radiographs and CT confirmed anatomic reduction of the right sternoclavicular joint with no fracture.
The patient was treated with immobilization for 6 weeks. At her 6-week follow-up visit, she reported new-onset dysphagia, particularly with a change in arm position. Physical examination reveled tenderness to medial clavicle palpation with a manubrial prominence. Repeat CT showed recurrent right posterior sternoclavicular dislocation.
After treatment options were discussed with the patient, open reduction and internal fixation of the dislocation was performed using locking plate osteosynthesis. No damage to the mediastinal structures was noted. Anatomic reduction was stabilized with application of precontoured locking plates placed at 90° to increase the construct strength and resist rotational forces (Figure 2).
Range-of-motion testing of the arm revealed no interfragmentary movement and confirmed stable anatomic reduction. An intraoperative chest radiograph and postoperative CT demonstrated stable reduction with appropriate position of hardware and no evidence of pneumothorax.
The patients postoperative period was unremarkable, and she began formal physical therapy postoperatively with no initial weight bearing because of her the right radial shaft fracture, which was treated conservatively. She reported no dysphagia, dysphonia, or dyspnea, and she had excellent cosmesis with no prominent hardware.
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Figure 1: CT scan shows a posterior dislocation of the right medial clavicle without evidence of medial clavicle physeal fracture. Figure 2: Intraoperative photograph shows the 3.5-mm reconstruction locking plate placed superiorly with 2 screws in the manubrium and 3 screws in the clavicle.
The patient progressed well with physical therapy and returned to work as a manual laborer. Her primary complaint after returning to work was contralateral shoulder and clavicle pain with sleeping on the right shoulder. She also had some pain in her right shoulder with full range of motion.
After discussing treatment options, the patient opted to proceed with elective removal of hardware. Five months following surgical fixation, the hardware was removed, revealing a stable, reduced sternoclavicular joint. The patient has returned to full active duty as a manual laborer with full range of motion of her right shoulder joint and resolution of her contralateral shoulder and clavicle pain.
A 48-year-old nicotine-dependent woman fell down several flights of stairs at home. She presented to the emergency department at another hospital with right shoulder pain. She was diagnosed with a clavicle fracture and was discharged home with a sling for comfort. The following day, the patient received a phone call from the emergency department notifying her to present to our facility for a complex clavicle fracture.
On physical examination, the patient had no dyspnea, dysphonia, or dysphagia. Loss of the normal anatomical contour with depression of the right medial clavicle into the superior mediastinum was noted. A vascular examination was normal, with intact radial, ulnar, median, and axillary nerve sensation and function. Review of the CT sent from original hospital revealed a fracture-dislocation of the medial clavicle with displacement of the medial clavicular fragment posterior to the manubrium (Figure 3).
Figure 3: Two slices starting from posterior (A) to anterior (B) of a preoperative CT showing comminution at the medial clavicle with posterior displacement of the medial clavicle.
After treatment options were discussed with the patient, open reduction and internal fixation of the fracture-dislocation was performed using locking plate osteosynthesis. Intraoperatively, no damage to the mediastinal structures was noted. Anatomic reduction was stabilized, and the precontoured locking plates were placed at 90· to increase the construct strength and resist rotational forces.
Medial clavicular bone loss was restored with demineralized bone matrix graft. Range-of-motion testing in the arm revealed no interfragmentary movement and stable anatomic reduction. Intraoperative and postoperative radiographs demonstrated anatomic reduction with no evidence of pneumothorax.
Postoperatively, the patient had no complaints and continued to use nicotine products. She returned to full weight bearing at 3 weeks and was even able to resume bowling at that time. She underwent physical therapy and has regained full function. The fracture has healed, and the patient reports no dysphagia, dysphonia, or dyspnea (Figure 4). Six months postoperatively, she did not wish to proceed with elective removal of hardware.
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Figure 4: Intraoperative photograph shows the locking plate construct with bone grafting of the medial clavicle comminution (A). Postoperative radiograph shows the anatomic reduction and the position of the hardware (B).
Posterior dislocations of the sternoclavicular joint are rare yet potentially life-threatening injuries because of the proximity of the sternoclavicular joint to anatomic structures in the superior mediastinum. Physical examination can yield limited findings, and a high index of suspicion is warranted for this injury pattern, especially with impingement signs and symptoms such as dyspnea, dysphagia, dysphonia, brachial plexus injury, and vascular alterations.
Diagnosis of posterior sternoclavicular dislocations with plain radiographs can be difficult because of superimposition of the lungs and rib structures; therefore, CT is the diagnostic modality of choice.4 Computed tomography defines the injury pattern and differentiates dislocations from medial clavicle physeal separations.11 It is particularly important to make such a distinction in individuals <25 years.
After diagnosis of a posterior sternoclavicular dislocation, closed reduction should be attempted as quickly as possible with a thoracic surgeon on standby because of the high risk for mediastinal injury. Most posterior sternoclavicular dislocations can be treated with closed reduction and 6 to 8 weeks of immobilization in a figure-of-8 bandage.2,5
Recurrent dislocations or chronic dislocations require open treatment for stabilization. Soft-tissue stabilization procedures require a prolonged course of postoperative immobilization and include repair of the surrounding ligaments and reconstruction with fascia lata, subclavius, or gracilis tendon.12 Stabilization also has been reported using replacement of the sternoclavicular ligament with carbon fiber,13 suturing of the medial aspect of the clavicle into the sternum,14 and resection of the head of the clavicle.11,15 Retrosternal dissection is required by these techniques.
Plate stabilization of posterior dislocations initially was reported by Franck et al11 as a way to avoid retrosternal dissection and allow for postoperative physiotherapy. However, damage to mediastinal structures can be encountered because of the anteriorly placed screw fixation, with pneumothorax being the most frequent complication. Locking plate osteosynthesis has the advantage of allowing for unicortical screw fixation in this region, whereas bicortical drill or screw penetration can result in damage to the mediastinal structures.
Locking plate technology is rapidly gaining acceptance for multiple fracture patterns. It uses double-threaded screws that lock to both the plate and the bone, creating an internal-external fixator that is less biologically damaging to periosteal blood flow than conventional plate fixation. Because unicortical screws can be used, it has an advantage in an area such as the mediastinum where damage can occur to structures from drill and screw placement.
Both of our patients were treated with locking plate stabilization and had a full return to function with limited outcome reference data. Franck et al11 used a Balser plate in 2 patients and reported both patients had a stable reduction and early return to normal function at 1 year of follow-up.
Plate stabilization of the sternoclavicular joint is appealing as it avoids retrosternal dissection and a prolonged postoperative immobilization period. The use of locking plates also offers the advantage of allowing for unicortical screw stabilization in this particularly sensitive mediastinal area. Although locked plating is a promising alternative, long-term follow-up is needed before it can be deemed as a replacement or as equivalent to soft-tissue repair procedures used to stabilize the sternoclavicular joint.
- Wettstein M, Borens O, Garofalo R, Kombot C, Chevalley F, Mouhsine E. Anterior subluxation after reduction of a posterior traumatic sterno-clavicular dislocation: a case report and a review of the literature. Knee Surg Sports Traumatol Arthrosc. 2004; 12(5):453-456.
- Nettles JL, Linscheid R. Sternoclavicular dislocations. J Trauma. 1968; 8(2):158-164.
- Rajaratnam S, Kerins M, Apthorp L. Posterior dislocation of the sternoclavicular joint: a case report and review of the clinical anatomy of the region. Clin Anat. 2002; 15(2):108-111.
- Burnstein MI, Pozniak MA. Computed tomography with stress maneuver to demonstrate sternoclavicular joint dislocation. J Comput Assist Tomogr. 1990; 14(1):159-160.
- Leighton RK, Buhr AJ, Sinclair AM. Posterior sternoclavicular dislocations. Can J Surg. 1986; 29(2):104-106.
- Fery A, Sommelet J. Sternoclavicular dislocations: observations on the treatment and result of 49 cases [in French]. Int Orthop. 1988; 12(3):187-195.
- Barth E, Hagen R. Surgical treatment of dislocations of the sternoclavicular joint. Acta Orthop Scand. 1983; 54(5):746-753.
- Burrows H. Tenodesis of subclavius in the treatment of recurrent dislocation of the sterno-clavicular joint. J Bone Joint Surg Br. 1951; 33(2):240-243.
- Venissac N, Alifano M, Dahan M, Mouroux J. Intrathoracic migration of Kirschner pins. Ann Thorac Surg. 2000; 69(6):1953-1955.
- Rockwood CA Jr, Odor JM. Spontaneous atraumatic anterior subluxation of the sternoclavicular joint. J Bone Joint Surg Am. 1989; 71(9):1280-1288.
- Franck W, Jannasch O, Siassi M, Hennig FF. Balser plate stabilization: an alternate therapy for traumatic sternoclavicular instability. J Shoulder Elbow Surg. 2003; 12(3):276-281.
- Martinez A, Rodriguez A, Gonzalez G, Herrera A, Domingo J. Atraumatic spontaneous posterior subluxation of the sternoclavicular joint. Arch Orthop Trauma Surg. 1999; 119(5-6):344-346.
- Burri C, Neugebauer R. Carbon fiber replacement of the ligaments of the shoulder girdle and the treatment of lateral instability of the ankle joint. Clin Orthop Relat Res. 1985; (196):112-117.
- Nicholas JA, Hershman EB. The Upper Extremity in Sports Medicine. St Louis, MO: Mosby; 1990.
- Acus RW III, Bell RH, Fisher DL. Proximal clavicle excision: an analysis of results. J Shoulder Elbow Surg. 1995; 4(3):182-187.
Drs Shuler and Pappas are from the Department of Orthopedics and Rehabilitation, Division of Orthopedic Trauma, Vanderbilt University Medical Center, and Dr Pappas is a medical student, Vanderbilt University, Nashville, Tennessee.
Drs Shuler and Pappas have no relevant financial relationships to disclose.
Correspondence should be addressed to: Nick Pappas, MD, Department of Orthopedic Surgery, University of Pennsylvania, Philadelphia, PA 19104.