We report a case of a 48-year-old female who presented four months following a low-energy trauma with symptoms most consistent with adhesive capsulitis. An MRI demonstrated extensive patchy areas of intramuscular edema-like signal involving the lateral head of the deltoid with associated muscle atrophy, in keeping with a subacute denervation injury. She was diagnosed with quadrilateral space syndrome (QSS) and successfully treated with an fluoroscopic-guided corticosteroid injection. At her two-year follow-up, the patient had regained full function and had no lasting symptoms. Non-specific symptoms like ill-defined shoulder pain, decreased motor function, and weakness can delay the diagnosis and management of QSS. As there is a lack of a good diagnostic study, fluoroscopic-guided quadrilateral space block should be considered should the diagnosis fit a patient's clinical profile, as this has the potential to be both diagnostic and therapeutic.
Keywords: Adhesive capsulitis; Fluoroscopic-guided block; Quadrilateral space syndrome.