Sternoclavicular Joint Dislocation

Sternoclavicular Joint Dislocation is uncommon injury and account for less than 3 % of all injuries to the shoulder girdle.

Due to the strength of its ligamentous stabilizers, subluxation or dislocation of the SC joint typically requires high-energy trauma. In fact, many patients who present with these injuries often sustain other, more dramatic injuries that require more immediate attention. As a result, the diagnosis can be missed which can have devastating consequences, especially in some cases of posterior SC joint dislocation where disruption of the mediastinal vessels may have occurred. Injury to the mediastinal vessels is much more likely when a posterior dislocation results in disruption of the sternohyoid and sternothyroid muscles as evidenced by axial imaging studies.

Sternoclavicular Dislocation Classification

SC joint Instability is typically classified according to:

• Etiology: traumatic versus atraumatic,
• Chronicity: acute versus chronic,
• Direction: anterior versus posterior,
• Severity: sprain, subluxation or complete dislocation.

The most referenced classification system for SC joint instability, developed by Allman in 1967, accounts for the degree of ligamentous disruption:

• Type I injuries represent a simple sprain of the SC capsuloligamentous structures without evidence of increased medial clavicular mobility.
• Type II injuries involve a partial disruption of the SC capsuloligamentous structures and results in anterior or posterior subluxation of the medial clavicle.
• Type III injuries are the most severe and represent a complete rupture of all supporting ligaments which leads to complete anterior or posterior dislocation of the medial clavicle.

It is important to remember that an apparent SC joint injury in a patient younger than 31 years of age may actually represent fracture of the medial clavicular physis (e.g., Salter–Harris type 1 or 2 injury) rather than injury to the capsuloligamentous structures of the SC joint (i.e., “pseudodislocation”).

See Also: Sternoclavicular Joint Anatomy

Physical Examination

In most cases, patients with acute injuries to the SC joint typically complain of pain and swelling in the vicinity of the medial clavicle after a traumatic event.

While anterior dislocations are usually evident due to the prominence of the medial clavicle with scapulohumeral motion, posterior dislocations are less obvious since the medial clavicle has migrated posteriorly and, thus, does not produce an anterior prominence despite the possibility of extensive swelling.

These injuries may be more difficult to recognize in patients with multiple trauma (especially in narcotized and ventilated patients) since other, more dramatic injuries may mask the SC joint injury. Thorough inspection and palpation of the entire clavicle is necessary to rule out concomitant fractures and the possibility of acromioclavicular (AC) joint dislocation (“floating clavicle”).

In patients with Allman type I or II injuries, severe anterior chest and shoulder pain is often exacerbated by arm motion and supine repositioning.

Imaging Study

Standard anteroposterior (AP) radiographs (including a Serendipity view) and a computed tomographic (CT) scan of the chest should always be obtained in the setting of any acute Sternoclavicular Joint Dislocation.

In the case of a posterior dislocation, a CT angiogram should also be obtained and the on call cardiothoracic surgeon should be made aware of the situation.

Sternoclavicular Joint Dislocation Treatment

In acute anterior SC joint dislocations, closed reduction is usually attempted in the emergency room. In most cases, the medial clavicle will reduce when a firm posteriorly directed pressure is applied by the clinician with the patient supine and a thick pad placed beneath the thoracic spine to retract the scapulae. However, spontaneous re-dislocation may occur immediately after the clinician removes this pressure. When maintenance of reduction cannot be safely achieved, outpatient reconstruction of the SC joint may be needed to restore shoulder function, to maintain joint stability and to prevent the progression of post-traumatic osteoarthritis.

Acute posterior SC joint dislocations should always be considered an emergency since up to 30 % of these injuries result in compromise of the mediastinal vasculature. These patients may display evidence of venous congestion in the neck or ipsilateral arm in addition to coughing, dyspnea, hoarseness, or dysphagia which may suggest disruption of airway patency.

Closed reduction of a posterior SC joint dislocation should never be performed in the emergency room without prior consultation with a cardiothoracic surgeon.

Sternoclavicular Joint Arthritis

Progressive articular cartilage degeneration of the SC joint most commonly occurs following an acute injury to surrounding capsuloligamentous structures, especially in cases that were initially treated nonoperatively. On the other hand, Sternoclavicular Joint Arthritis can also have atraumatic etiologies such as SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, osteitis), avascular necrosis, tumors, septic arthritis, and rheumatoid arthritis, among other potential causes. The indications for surgical treatment of these conditions are case-based.

Patients with degenerative conditions involving the SC joint will generally present with pain and swelling over the medial clavicle in the absence of a recent traumatic injury. The clinician should palpate the SC joint to detect crepitus or microinstability while the shoulder is placed through a range of motion. However, shoulder range of motion is often inhibited due to significant pain, swelling, and crepitation that can often be relieved following injection of local anesthetic and/or corticosteroids.

Although nonoperative treatment is typically the modality of choice, some patients with recalcitrant symptoms may require open or arthroscopic resection arthroplasty of the SC joint to alleviate their symptoms.

See Also: Ac Joint Arthritis

Voluntary Sternoclavicular Joint Dislocation

Voluntary subluxation or dislocation of the SC joint is an extremely rare condition that is most often seen in young patients with multiligamentous laxity. The ability to subluxate the joint with specific positions and movements of the arm is usually discovered during adolescence.

Although the condition is mostly asymptomatic, some patients may develop symptoms related to instability or chondral degeneration due to the high frequency of subluxation, especially in those involved in overhead sports or manual labor.

References

1. Groh GI, Wirth MA. Management of traumatic sternoclavicular joint injuries. J Am Acad Orthop Surg. 2011 Jan;19(1):1-7. doi: 10.5435/00124635-201101000-00001. PMID: 21205762.
2. Panzica M, Zeichen J, Hankemeier S, Gaulke R, Krettek C, Jagodzinski M. Long-term outcome after joint reconstruction or medial resection arthroplasty for anterior SCJ instability. Arch Orthop Trauma Surg. 2010;130(5):657–65.
3. de Jong KP, Sukul DM. Anterior sternoclavicular dislocation: a long term follow-up study. J Orthop Trauma. 1990;4(4):420–3.
4. Wirth MA, Rockwood CA. Disorders of the sternoclavicular joint. In: Rockwood Jr CA, Matsen III FA, Wirth MA, Lippitt SB, editors. The shoulder. 4th ed. Philadelphia: Saunders; 2009. p. 527–60.
5. Chaudhry FA, Killampalli VV, Chowdhry M, Holland P, Knebel RW. Posterior dislocation of the sternoclavicular joint in a young rugby player. Acta Orthop Traumatol Turc. 2011;45(5):376–8.
6. Perron AD. Chest pain in athletes. Clin Sports Med. 2003;22:37–50.
7. Allman Jr FL. Fractures and ligamentous injuries of the clavicle and its articulation. J Bone Joint Surg Am. 1967;49(4):774–84.
8. Iannotti JP, Williams GR. Disorders of the shoulder: diagnosis and management. Philadelphia: Lippincott Williams & Wilkins; 1999. p. 765–813.
9. El Mekkaoui MJ, Sekkach N, Bazeli A, Faustin JM. Proximal clavicle physeal fracture-separation mimicking an anterior sterno-clavicular dislocation. Orthop Traumatol Surg Res. 2011;97(3):349–52.
10. Eni-Olotu DO, Hobbs NJ. Floating clavicle – simultaneous dislocation of both ends of the clavicle. Injury. 1997;28(4):319–20.
11. Sanders JO, Lyons FA, Rockwood Jr CA. Management of dislocations of both ends of the clavicle. J Bone Joint Surg Am. 1990;72(3):399–402.
12. Thomas Jr CB, Friedman RJ. Ipsilateral sternoclavicular dislocation and clavicle fracture. J Orthop Trauma. 1989;3(4):355–7.
13. Lunseth PA, Chapman KW, Frankel VH. Surgical treatment of chronic dislocations of the sternoclavicular joint. J Bone Joint Surg Br. 1975;57(2):193–6.
14. Yeh GL, Williams Jr GR. Conservative management of sternoclavicular injuries. Orthop Clin North Am. 2000;31(2):189–203.
15. Bicos J, Nocholson GP. Treatment and results of sternoclavicular joint injuries. Clin Sports Med. 2003; 22(2):359–70.
16. Eskola A, Vainionpaa S, Vastamaki M, Slatis P, Rokkanen P. Operation for old sternoclavicular dislocation: results in 12 cases. J Bone Joint Surg Br. 1989;71(1):63–5.
17. Rockwood CA, Groh GI, Wirth MA, Grassi FA. Resection arthroplasty of the sternoclavicular joint. J Bone Joint Surg Am. 1997;79(3):387–93.
18. Warth RJ, Lee JT, Campbell KJ, Millett PJ. Arthroscopic sternoclavicular joint resection arthroplasty: a technical note and illustrated case report. Arthrosc Tech. 2014;3(1):e165–73.