Chronic Irreducible Anterior Shoulder Dislocation With Axillary Vein Compression: A Case Report Highlighting Multidisciplinary Management With Reverse Total Shoulder Arthroplasty.

Introduction: Anterior shoulder dislocations are the most common major joint dislocation encountered in clinical practice. Although typically reducible, chronic irreducible anterior dislocations are rare and pose significant diagnostic and management challenges. Contributing factors include rotator cuff pathology, soft tissue interposition, and bony fragments. Vascular complications, while infrequent, must also be considered, particularly in chronic presentations. Case Report: We report the case of a 61-year-old female who sustained an anterior shoulder dislocation after falling on ice 8 weeks prior to presentation. She had a history of a previously canceled rotator cuff repair 3 years earlier. Multiple closed reduction attempts in the emergency department and operating room were unsuccessful. Magnetic resonance imaging (MRI) revealed a chronic massive rotator cuff tear with subscapularis interposition and the humeral head abutting the neurovascular bundle. Computed tomography angiography (CTA) demonstrated axillary vein compression without contrast opacification distal to the axilla. The patient was evaluated by vascular surgery prior to intervention, and an in-clinic venous duplex ultrasound confirmed the chronicity of the occlusive thrombus. Due to the risk of intraoperative complications, a vascular surgeon remained on standby during arthroplasty. Given the irreducibility, chronicity of rotator cuff pathology, and vascular involvement, a reverse total shoulder arthroplasty (rTSA) was performed with vascular surgery support. The patient experienced pain relief and modest improvements in range of motion and Patient-Reported Outcomes Measurement Information system (PROMIS) outcomes postoperatively, though persistent limitations necessitated a revision rTSA. Conclusion: This case underscores the importance of considering vascular compression in chronic irreducible shoulder dislocations. While axillary artery injury is well-documented, chronic axillary vein compression and thrombosis remain underreported. Advanced imaging, particularly CTA, should be utilized when the humeral head lies in close proximity to vascular structures. Such complex cases require management in a tertiary care setting with access to vascular surgery. Multidisciplinary planning, timely diagnosis, and appropriate surgical intervention are essential to optimize outcomes in these high-risk patients.