Clinically significant abnormalities in postreduction radiographs after anterior shoulder dislocation

To determine the incidence of clinically significant fractures or other abnormalities seen on postreduction shoulder radiographs which were not seen on postreduction should radiographs which were not seen on the prereduction films obtained for anterior shoulder dislocations.

Retrospective chart review of 131 patients who presented with a total of 175 anterior shoulder dislocations to the emergency department of an urban, university-affiliated, Level 1 Trauma Center with an emergency medicine residency program. All patients had complete medical records, radiographs before and after reduction, and no fractures reported on the prereduction films.

There were three avulsion fractures (1.7%; 95% confidence interval [CI], 0% to 4.5%) detected on postreduction radiographs. In all three cases, a radiologist who was blinded to the original interpretations and the purpose of the study also noted the fractures on the prereduction films, although these fractures were not detected on the original interpretations. There were 14 new Hill-Sachs deformities (8%; 95% CI, 4% to 12%). In one case (.6%; 95% CI, 0% to 2.8%), the postreduction radiograph demonstrated a persistent dislocation, which was subsequently reduced in the ED. This was the only postreduction finding that altered acute management.

Postreduction radiographs rarely reveal any clinically significant abnormality after an anterior shoulder dislocation has been reduced. Emergency physicians and orthopedic surgeons should question whether the time and expense of obtaining routine postreduction films in the ED for anterior shoulder dislocations is justified. A prospective study is needed to validate our findings.