Abstract
INTRODUCTION: Reverse humeral avulsion of the glenohumeral ligament (RHAGL) is a rare and frequently overlooked source of shoulder pain, instability, with limited documentation in the literature. In this uncommon injury, the posterior band of the inferior glenohumeral ligament (IGHL) detaches from the humerus, resulting in posterior shoulder instability. This study aims to effectively illustrate the clinical presentation, identify the diagnostic challenges, detail the surgical management, and assess the outcomes for a patient diagnosed with RHAGL who underwent successful arthroscopic treatment. PRESENTATION OF CASE: A 35-year-old man presented with persistent left shoulder pain and dysfunction after a traumatic dislocation. Clinical tests suggested intra-articular injury with significant symptomactic soft-tissue Bankart and RHAGL status, and magnetic resonance imaging (MRI) revealed a labral tear but did not detect RHAGL. Arthroscopy confirmed a complete avulsion of the posterior band of the IGHL, together with a soft-tissue Bankart lesion, both repaired arthroscopically, followed by a structured rehabilitation program. At six months, the patient had full pain-free motion and returned to normal activity without complications or recurrent instability. DISCUSSION: RHAGL frequently presents with non-specific symptoms and is often overlooked on MRI, which may miss up to half of the cases. Early arthroscopic evaluation is crucial for accurate diagnosis and treatment, allowing for direct repair and excellent outcomes. CONCLUSION: RHAGL should be considered in patients with ongoing posterior shoulder symptoms after trauma, especially when imaging is inconclusive. Early arthroscopic intervention can restore shoulder stability and function, underscoring the need for increased clinical awareness of this rare entity.