The sternoclavicular (SC) joint is the sole articulation providing continuity between the axial and appendicular skeleton of the upper extremity. Painless range of motion and stability of the joint are important in overall function of the shoulder girdle. It is a pivotal articulation capable of resisting compressive and tensile loads. Its articular surfaces are separated by an intra-articular disc that can often be injured with instability of the joint. Sternoclavicular instability is a painful and often disabling condition that is typically the result of traumatic injury.
The initial presentation of SC instability usually follows some type of traumatic injury. A direct blow to the medial clavicle can result in posterior dislocation. A force delivered to the lateral clavicle or a direct blow to the manubrium can result in anterior displacement of the medial clavicle. Although anterior dislocation is more clearly distinguished on physical exam by a prominent lump, posterior dislocation is often subtle and more difficult to identify. In both cases, pain is localized to the joint, bruising and swelling will be noted, and the arm will often be held close to the body to protect against motion and distraction at the joint.
Posterior dislocations can present with dysphagia, stridor, or shortness of breath – findings which indicate compression of the underlying esophagus and trachea, and should prompt urgent reduction of the joint. It is important to note that the medial physis of the clavicle is the last to fuse. Sternoclavicular dislocations in younger patients can be confused with displaced medial clavicle physeal fractures. Anterior SC instability is more common than posterior SC instability.
Physical exam will show tenderness overlying the SC joint, possibly associated with crepitus. Shoulder motion will be limited by pain at the SC joint. Radiographs of the chest should be obtained to evaluate for associated injury to the chest, such as pneumo/hemothorax or rib fractures. Sensitivity of chest radiograph is poor for detecting SC joint dislocation. The 40 degree cephalic tilt view is more useful. In this view, superior displacement of the clavicle indicates anterior dislocation, and inferior displacement of the clavicle indicates posterior dislocation. Comparison to the adjacent contralateral SC joint makes diagnosis simpler. Computed Tomography (CT) remains the most sensitive modality for identification of SC joint dislocations, and also allows for differentiation from medial clavicle physeal fractures in young patients.
Most anterior SC dislocations can be treated non-operatively, either with symptomatic management or closed reduction. Posterior SC dislocations without tracheal or esophageal compression can be treated with observation.
Patients less than 25 years of age with a medial clavicle physeal fracture (often misdiagnosed as SC dislocation) can be treated non-operatively if they do not have symptoms of tracheal/esophageal compression. The medial clavicle will often remodel and heal in these cases.
In patients with acute anterior (<10 days) dislocation, closed reduction using conscious sedation or general anesthetic can be attempted by applying traction to the abducted arm while applying pressure to the medial clavicle. A bolster or sandbag is placed under the patient between the scapulae to help with scapular retraction during the maneuver. Even after successful reduction, the rate of recurrent instability is high (>50%).
Acute posterior dislocations can be treated with traction on the abducted arm with the shoulder extended, and a towel clamp applied percutaneously to the medial clavicle to pull it anteriorly. This technique can be utilized with conscious sedation, or general anesthesia in the operative theatre.
Indications for Surgery
Absolute indications for surgery include symptoms of tracheal or esophageal compression in the setting of a posterior SC dislocation that has failed closed reduction, or that has been dislocated >10 days. Acute anterior SC dislocations that have failed closed reduction, or chronic injuries with persistent symptoms including pain and instability should also be considered for operative management.
Preoperatively, arrangements should be made with a thoracic surgeon to be immediately available to address any inadvertent injury to the vital structures of the mediastinum, which lie in close proximity to the surgical field for treatment of SC injuries.
The option of a preoperative regional anesthetic may be available, and can help with postoperative pain control. The patient should be positioned supine, with the operative upper extremity sterilely prepped and draped. It is helpful to include the entire upper extremity in the operative field, so that it can be moved to assist with reduction of the SC joint. As a precaution, the sterile field should also include the chest and abdomen to allow for rapid access in case of injury to vital structures of the mediastinum.
A hockey stick shaped incision is made over the SC joint, with the transverse portion of the incision following Langer’s skin lines. The vertical portion of the incision is in line with the sternum. A sharp corner should be avoided to prevent wound healing complications at its apex. Dissection should be performed down to the level of the sternocleidomastoid. The sternocleidomastoid’s insertion on the manubrium is elevated subperiosteally. The proximal clavicle is typically easily visualized. After identification of the SC joint capsule, an arthrotomy is made in the longitudinal direction of the clavicle. The capsule is elevated inferiorly and superiorly on both the manubrial and clavicular sides to gain visualization of the SC joint. The intra-articular disc, which is often damaged, is excised.
The shoulder is then placed through a range of motion to evaluate the instability pattern of the SC joint. If the joint is dislocated at the time of surgery, reduction of the joint should be performed at this time. Gentle manipulation using a tenaculum forceps or a pointed towel clamp can be performed. A gentle counter force can be applied to the sternum/manubrium while an anterior directed pull is applied to the clavicle (for a posterior SC dislocation). Stability of the joint should be evaluated after reduction by again testing the shoulder through a full range of motion, and also applying gentle loads to the clavicle. The articular cartilage of the joint should also be assessed, and its condition documented, as arthrosis of the joint can sometimes help explain persistent pain after recovery from the procedure. If significant arthrosis is present, a moderate resection of the proximal clavicle can be performed using a rongeur.
In acute cases of irreducible, SC dislocation, the joint may be stable after reduction. Following reduction, repair of the joint capsule alone may be sufficient. In some acute cases, and most chronic cases of SC instability or dislocation, reconstruction using allograft tissue augmentation may be required.
Soft tissue graft reconstruction requires the drilling of a tunnel through the medial clavicle as well as a tunnel through the manubrium. To safely create the tunnels and avoid injury to the thorax and mediastinum, a malleable retractor is positioned posterior to the manubrium and medial clavicle. Sequentially larger drills and reamers can be used to create the tunnels. Our preferred tunnel diameter is 4 mm. Progressively widening the tunnels, rather than beginning with the desired final reamer size, can reduce the risk of plunging.
A semitendinosus allograft is prepared using two #2 high strength non-absorbable sutures whipstitched from one end to the other (each stitch traverses the entire length of the tendon to avoid stress relaxation of the tendon, and thus weakening of the construct after final tensioning). The tendon is passed through the tunnels in a figure-of-eight fashion, and the ends sutured to each other and to the other limbs of the figure-of-eight construct using 2-0 high strength non-absorbable suture.
The sutures whipped through the allograft are then used to close the SCr arthrotomy in such fashion to overlap the inferior and superior leaflets of the capsule to perform a capsular shift, effectively reducing the joint volume and further stabilizing the construct. The shoulder is taken through a range of motion and stability of the joint is assessed. The skin can be closed in layers in standard fashion. We recommend the use of a running subcuticular stitch for improved cosmesis.
Pearls and Pitfalls of Technique
Always have a thoracic surgeon immediately available for closed reduction or open reduction of the SC joint. They will be unnecessary almost every time, but can help avoid and manage issues if they arise.
During drilling of tunnels in the manubrium and medial clavicle, be sure to place a malleable retractor directly posterior to them to protect the vital vascular structures of the chest that lie in close proximity.
When preparing the allograft, whipstitch the entire length of the graft with #2 high strength non-absorbable suture. The suture will act as an internal fixator, and can prevent stress relaxation of the graft, which could lead to recurrent instability.
Sternoclavicular dislocations are often missed on standard chest or clavicle radiographs. Have a high index of suspicion when symptoms are localized over the SC joint. Do not be fooled by a seemingly normal chest x-ray. Insist on appropriate 40 degree cephalic tilt radiographs, or axial imaging if necessary.
While creating the bony tunnels through the clavicle and manubrium, the surgeon can plunge, while attempting to traverse hard, thick cortical bone. For this reason, we recommend sequentially increasing the size of the drills to progressively expand the diameter of the tunnel. This reduces work required of each drill or reamer, and so decreases the need for excessive force on the drill that can lead to plunging.
Early motion or an accelerated recovery program may seem attractive to the patient, however this can place the patient at increased risk of recurrence. Encourage the patient to be patient and avoid excessive early motion and strengthening.
Potential complications can arise from the injury itself, non-operative management, or operative treatment. Persistent pain, dysphagia, stridor, recurrent dislocation, or instability are possible with any management choice, however reduction of the joint usually resolves the symptoms. Infection and wound healing issues can be associated with open management. Most ominous is the potential for life threatening injury to the major vascular structures of the mediastinum and upper chest.
The shoulder is immobilized in a simple sling for 3 weeks following the procedure. Isometric periscapular exercises with the arm kept at the side can begin on the first day post-operatively. Active range of motion to the level of the shoulder can begin 3 weeks after the procedure, and advance to unrestricted range of motion at 6 weeks post-operatively. Resisted exercises and strengthening using resistance bands is initiated 12 weeks after surgery. Although patients often would prefer to accelerate the protocol, it is important to allow soft tissue healing prior to stressing the stabilization.
Outcomes/Evidence in the Literature
Groh, GI, With, MA.. “Management of traumatic sternoclaviclar joint injuires”. J Am Acad Ortho Surg. vol. 19. 2011. pp. 7(Review article with overview of presentation, diagnosis, and management of SC dislocations.)
Martetschläger, F, Warth, RJ, Millett, PJ. “Instability and Degenerative Arthritis of the Sternoclavicular Joint: A Current Concepts Review”. Am J Sports Med. 2013. (Review of current literature regarding epidemiology, presentation, diagnosis, and treatment of SC joint injuries, including description of a surgical technique for reconstruction of the joint.)
Glass, ER, Thompson, JD, Cole, PA, Gause, TM, Altman, GT. “Treatment of sternoclavicular joint dislocations: a systematic review of 251 dislocations in 24 case series”. J Trauma. vol. 70. 2011. pp. 1294-8. (Systematic review of case series in the literature, comparing functional outcomes for patients with SC dislocations, comparing anterior/posterior, acute/chronic, and non-operative/closed reduction/open treatment methods.)
Guan, JJ, Wolf, BR. “Reconstruction for anterior sternoclavicular joint dislocation and instability”. J Shoulder Elbow Surg. vol. 22. 2013. pp. 775-81. (Article describing a surgical technique for reconstruction of the SC joint, and patient outcomes following the procedure.)
Thut, D, Hergan, D, Dukas, A, Day, M, Sherman, OH. “Sternoclavicular joint reconstruction–a systematic review”. Bull NYU Hosp Jt Dis. vol. 69. 2011. pp. 128-35. (Systematic review of treatment methods for SC injuries, concluding that reconstruction with tendon tissue woven in a figure-of-eight pattern through drill holes in the manubrium and clavicle is stronger than repair with local tissue.)
Sewell, MD, Al-Hadithy, N, Le Leu, A, Lambert, SM. “Instability of the sternoclavicular joint: current concepts in classification, treatment and outcomes”. Bone Joint J. vol. 95-B. 2013. pp. 721-31. (Review article that discusses the anatomy and biomechanics of the SC joint, as well as the classification of SC joint instability and its treatment.)
Van Tongel, A, De Wilde, L. “Sternoclavicular joint injuries: a literature review”. Muscles Ligaments Tendons J. vol. 1. 2012. pp. 100-5. (A review of literature on SC injuries, discussing the diagnosis and treatment of various SC instability patterns.)
Sternoclavicular dislocation can sometimes be a challenging injury to diagnose. Appropriate clinical suspicion and imaging techniques can help avoid missed injuries. Although closed management for acute dislocations is possible, open treatment consisting of reduction of the joint and allograft reconstruction of the SC ligaments may be necessary. Appropriate activity limitations after reduction and reconstruction are necessary to promote success. Careful surgical technique to avoid injury to the adjacent vital vascular structures is necessary, and the immediate availability of a thoracic surgeon during reduction and surgery is highly recommended.
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