Quadrilateral space compression syndrome infrequently occurs in active young adults in whom the axillary nerve or the posterior humeral circumflex artery is compressed in the quadrilateral space. The thick tethered fibrous bands in the quadrilateral space are the most common cause of compression. After diagnosis, most patients are treated nonsurgically with reassurance, physical therapy, NSAIDs, and hydrocortisone injections. In patients in whom nonsurgical treatment fails, surgical decompression effectively relieves symptoms and improves function. Adequate surgical exposure and a thorough understanding of the surrounding anatomy are crucial to a successful procedure.

This video provides an overview and case presentation of quadrilateral space decompression via a posterior approach. An overview of the anatomy, pathogenesis, diagnosis, and management of quadrilateral space compression syndrome is provided. The video discusses the case presentation of a 41-year-old male overhead pitcher with right-sided posterior shoulder pain refractory to nonsurgical management. The patient met all three criteria for surgical decompression, including an arteriogram that demonstrated compression of the posterior humeral circumflex artery in the quadrilateral space during dynamic maneuvers. Surgical decompression of the quadrilateral space is performed via a posterior approach. Excellent decompression of the quadrilateral space was achieved intraoperatively after release of dense fibrous bands. Symptomatic relief was achieved by the first postoperative visit.

Quadrilateral space decompression is a reliable treatment option for patients with persistent symptoms of quadrilateral space compression syndrome that are refractory to nonsurgical management. Although studies have demonstrated good outcomes in patients who undergo quadrilateral space decompression, results are contingent on careful dissection and meticulous technique.