Sternoclavicular Joint Dislocations: Epidemiology, Surgical Anatomy, and Critical Complications
Key Takeaway
Sternoclavicular (SC) joint dislocations are uncommon but critical shoulder girdle injuries, often high-energy. They are classified as anterior (most common) or posterior, with posterior dislocations posing significant "hidden dangers" due to their proximity to vital mediastinal structures like major blood vessels, necessitating thorough clinical assessment for associated life-threatening complications.
A 24-year-old rugby player presents to the ED following a high-impact tackle. He is holding his right arm in slight adduction and reports significant pain over the medial clavicle. You suspect a sternoclavicular (SC) joint injury. How do you approach the initial assessment and diagnostic imaging to rule out the "hidden dangers"?
Candidate: I would perform a primary and secondary survey. I'd specifically check for signs of posterior dislocation like stridor, dysphagia, or absent radial pulses. For imaging, I'd order AP and lateral X-rays, but since they have overlap, I'd prioritize a CT scan to look at the joint and the mediastinum.
Failing to emphasize the "Serendipity view" on X-ray, or worse, ordering an MRI as the initial investigation. Candidates often forget to mention the specific clinical signs of posterior mediastinal impingement (e.g., dyspnea, venous congestion) or fail to declare that a CT-Angiogram is mandatory for posterior injury.
Start with a structured clinical assessment looking for mediastinal compression (dyspnea, dysphagia, hoarseness, venous congestion of the neck). Imaging starts with plain films including the Serendipity view (40° cephalic tilt) to compare symmetry. However, a CT scan is the gold standard. If a posterior dislocation is identified or suspected, a CT-Angiogram (CTA) is mandatory to assess the brachiocephalic/subclavian vessels, trachea, and esophagus before any manipulation is attempted.
The CT scan confirms a posterior SC joint dislocation. The patient is haemodynamically stable with no acute neurological deficit, but there is clear retrosternal displacement. What is your definitive management plan?
Candidate: I would take the patient to the operating theatre for a closed reduction under general anaesthesia with muscle relaxation. I would have vascular and thoracic surgery on standby in case of vascular injury during the reduction.
Suggesting the use of a towel clip for reduction. This is an antiquated and dangerous technique that risks catastrophic injury to underlying great vessels. Also, failing to emphasize that reduction should be performed in a facility with thoracic surgical backup is a major safety oversight.
Management is urgent reduction under GA with full muscle relaxation. The patient must be in an environment with thoracic/vascular surgery backup. I would attempt closed reduction using longitudinal traction in abduction/extension with manual manipulation of the clavicle. Towel clips are contraindicated. If closed reduction fails or if there is vascular/visceral injury, proceed to open reduction. I would explicitly state that K-wire fixation is contraindicated due to the high risk of catastrophic migration into the heart or great vessels.
In a patient with a chronic symptomatic SC joint instability, what are the primary surgical options for reconstruction, and what is your preferred technique?
Candidate: For chronic cases, I would perform a reconstruction using a tendon graft. I'd drill tunnels in the medial clavicle and the manubrium to pass an autograft, like a palmaris longus or semitendinosus, to recreate the costoclavicular ligaments.
Suggesting simple primary suture repair for chronic cases. Chronic tissues are attenuated and scarred; primary repair will inevitably fail. Ignoring the importance of the costoclavicular (rhomboid) ligament is also a significant error in understanding SC joint stability.
The mainstay of treatment is ligamentous reconstruction. I would utilize an autograft (typically semitendinosus or gracilis) to create a figure-of-8 reconstruction, threading the graft through divergent tunnels in the medial clavicle and securing it to the manubrium/first rib to mimic the native Costoclavicular and SC ligaments. If the joint is degenerate, medial clavicle resection arthroplasty may be necessary as a salvage procedure to address intractable pain, though this does not restore full stability.
