Safe Reconstruction of Posterior Sternoclavicular Dislocation Using a Palmaris Longus Autograft and ACL Tibial Guide Assistance: A Case Report.

Posterior sternoclavicular joint (SCJ) dislocation is an uncommon but clinically significant injury due to its proximity to vital mediastinal structures and delayed or missed diagnosis is not unusual as symptoms may be nonspecific and plain radiographs can appear normal. Surgical stabilization is typically recommended when posterior displacement results in persistent symptoms or a risk to mediastinal anatomy. We report a 32-year-old recreational futsal player with posterior SCJ dislocation who presented with shoulder pain, dyspnea, and mild dysphagia following a posterolateral impact, with imaging confirming the diagnosis. Open reduction and figure-of-eight reconstruction using a palmaris longus autograft was performed, and tunnel placement was controlled using an anterior cruciate ligament (ACL) tibial guide to reduce the risk of posterior cortical breach and mediastinal injury. Respiratory and swallowing symptoms resolved immediately postoperatively, and at 12 months the patient demonstrated full pain-free shoulder function and radiographic joint stability without recurrence, suggesting that this technique may offer a safe and durable option for managing posterior SCJ dislocation.