A Systematic Review of Acute Irreducible Shoulder Dislocations in the 21st Century.

Background: Rarely, closed reduction cannot be achieved in patients with acute shoulder dislocation, necessitating open management. A paucity of literature exists regarding these cases. Purpose: To perform a systematic review on the mechanism, management, and outcome data of acute irreducible shoulder dislocations. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review of the literature was performed using the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed, and MEDLINE between 2000 and 2020. Inclusion criteria were as follows: human participants, acute irreducible shoulder dislocation requiring open management, English language, and publication within the past 20 years. We excluded basic science articles, technique articles, reviews, editorials, and studies of chronic shoulder dislocations or dislocations with ipsilateral humeral shaft fractures. Results: Twelve articles fit the inclusion criteria and were considered for review. All studies were single case reports (level 4 evidence). Ten of the 12 studies were of male patients. The direction of dislocation included 7 anterior/anteroinferior, 2 posterior, 1 inferior, 1 bilateral inferior, and 1 superolateral. Most dislocations were irreducible owing to a mechanical block to reduction. The most common type of block was an incarcerated long head of the biceps tendon, followed by interposition of 1 of the rotator cuff tendons. The axillary and musculocutaneous nerves, displaced fracture fragments, and Hill-Sachs and bony Bankart lesions were other causes of blocks to reduction. Eleven patients were treated with open surgery, while 1 patient was treated arthroscopically. Procedures performed were dependent on concurrent pathology. Final follow-up ranged from 6 weeks to 2 years, with no repeat dislocation episodes reported. Complications after open reduction included 1 case of brachial plexopathy (posterior cord) and 1 case of musculocutaneous nerve palsy. Conclusion: There is a paucity of literature on the management of irreducible acute shoulder dislocations. The most common irreducible dislocation found in this systematic review was anterior with a mechanical block attributed to interposition of the long head of the biceps tendon. When patients were treated with an open or arthroscopic procedure, recurrence was low, with none reporting recurrent dislocation in limited follow-up.