The role of post-reduction radiographs after shoulder dislocation.

We sought to determine whether post-reduction radiographs add clinically important information to what is seen on pre-reduction X-rays in Emergency Department (ED) patients with anterior shoulder dislocations. In this prospective, observational study, clinicians recorded preliminary pre-reduction and post-reduction X-ray readings on patients with shoulder dislocations. The films were subsequently reviewed by a blinded attending radiologist. Seventy-three patients presented to the ED with shoulder dislocations over an 18-month period; 55 of these patients had pre- and post-reduction X-rays and were included in the study. Eight of these patients had fractures seen on preliminary reading of post-reduction X-rays; one (1.8%, 95% confidence interval [CI] 0-9.7%) of these fractures was not seen on preliminary reading of pre-reduction films. On preliminary reading, all patients' shoulders were relocated on post-reduction X-rays (100%; 95% CI 93.5-100%). Forty of these patients had their X-rays read by a blinded attending radiologist. Sixteen fractures were seen on post-reduction X-rays, of which 6 (15.0%; 95% CI 5.7-29.8%) were not seen on pre-reduction X-rays. All patients (100%; 95% CI 91.2-100%) whose post-reduction films were read by blinded attending radiologists had shoulder relocation confirmed. In conclusion, although the majority (62.5%) of fractures associated with shoulder dislocations are seen on pre-reduction radiographs, more than one-third (37.5%) of fractures may be visible only on post-reduction X-rays. None of the fractures missed on pre-reduction X-rays changed patient management in the ED. There were no persistent shoulder dislocations found on post-reduction films.