O3295: Diagnostic Accuracy and Outcomes of Posterior Sternoclavicular Joint Dislocations in the Pediatric Population

Background: Sternoclavicular (SC) joint dislocations are uncommon injuries and can occur both anteriorly and posteriorly. While rarer, posterior dislocations can be dangerous with the potential to cause associated damage to the esophagus, trachea, and neurovascular structures in the area. Given this, timely diagnosis is of utmost importance. The purpose of this study was to evaluate pediatric and adolescent patients sustaining posterior SC joint dislocations to identify the prevalence of missed diagnoses at initial presentation, as well as the patient characteristics, treatment modalities and outcomes associated with these injuries.

Methods: Retrospective review was conducted on patients at a single institution with a posterior sternoclavicular joint dislocation from October 1, 2015, to November 1, 2024. Patients without a CT scan positive for SC joint dislocation or those with recurrent subluxation without dedicated dislocation were excluded. Patient demographics, injury mechanism, dislocation characteristics, diagnosis timeline, conservative and surgical treatment data, and patient outcomes were collected and analyzed.

Results: 36 patients met study criteria, median age 14.9, majority male (91.7%), white (66.7%), not Hispanic or Latino (91.7%). 13/36 patients (36.1%) had their posterior dislocation missed at initial presentation, which were then diagnosed on CT scan upon subsequent presentation. Most patients presented initially to the Emergency Department (n=30, 83.3%), and the most common injury mechanism was a sports related trauma (86.1%), most often football (n=7), wrestling (n=7) and ice hockey (n=5). Lateral impact to the shoulder was the primary mechanism of dislocation (n=28, 77.8%). Only 2 patients endorsed a fall or blow to the anterior chest as the associated mechanism of injury. All but one patient underwent surgical management via open reduction and internal fixation. The median time from initial presentation to clearance was 182.5 days (IQR 130.0 to 200.0 days). One patient returned following their initial treatment course with complications, sustaining a subsequent fall to the shoulder without repeat dislocation.

Conclusion: Posterior sternoclavicular joint dislocations are a potentially dangerous injury that were found to be most commonly presenting initially to the emergency department, with traumatic injuries during contact sports and a mechanism of a fall on or blow to the lateral shoulder as the most prevalent injury characteristics. Over one third of these dislocations went undiagnosed at patients’ initial presentation and were only identified upon follow-up visit on CT scan. Due to the potential for posterior sternoclavicular joint dislocations to cause damage to the neurovascular and surrounding structures, timely diagnosis and treatment is critical to reduce these risks. A high index of suspicion for posterior dislocation should be given when patients present with anterior chest pain following a lateral blow to the shoulder, and physicians should consider obtaining a CT scan at initial presentation to evaluate for posterior dislocation, as chest and clavicle X-Rays cannot reliably demonstrate these injuries.