Inferior angle of scapula fractures: A retrospective case series

Abstract

Background: Inferior angle of scapula fractures (IAS) are rare injuries that result from the periscapular shoulder muscles avulsing the inferior scapula tip. The aim of this study was to investigate the mechanisms of injury, investigations and treatment outcomes, as currently only case reports are available to guide management. Methods: Computered tomography (CT) images were reviewed to identify patients with an IAS fracture. Case notes were reviewed, and patients contacted to gather data relating to the injury, treatment and outcome. Results: Fourteen fractures were identified on CT. Five were missed on the initial radiograph. High energy fractures had an average age of 47.6 years, 90% were male. Low energy fractures had a mean age of 83.6 years 75% were female. All undisplaced fractures had a satisfactory outcome treated non-operatively. Three of six displaced fractures reported an unsatisfactory outcome with non-operative treatment. Subsequent surgical fixation resulted in resolution of symptoms. Conclusions: Inferior angle of scapula fractures are a rare injury that can result from high or low energy trauma. They are easy to miss on plain radiographs. Identification is important as displaced fractures can do poorly when treated non-operatively, but symptoms resolve with surgical fixation. Undisplaced fracture has a satisfactory outcome when treated non-operatively. Evidence: Level IV.

Keywords: Scapula fracture; avulsion fracture; inferior angle of scapula; natural history; trauma.