Missed posterior shoulder fracture dislocations: a new protocol from a London major trauma centre

Abstract

Background: A high incidence of missed posterior shoulder dislocations is widely recognised in the literature. Concern was raised by the upper limb multidisciplinary team at a London major trauma centre that these missed injuries were causing serious consequences due to the need for surgical intervention and poor functional outcome.

Objective: To identify factors contributing to missed diagnosis and propose solutions.

Methods: A local quality improvement report was performed investigating time from admission to diagnosis of simple posterior dislocations and fracture dislocations over a 5-year period. Factors contributing to a delayed diagnosis were analysed.

Results: The findings supported current evidence: a posterior shoulder dislocation was more often missed if there was concurrent fracture of the proximal humerus. Anteroposterior and scapular Y view radiographs were not always diagnostic for dislocation. Axial views were more reliable in assessment of the congruency of the joint and were associated with early diagnosis and appropriate treatment of the injury.

Discussion: As a result of these findings a new protocol was produced by the orthopaedic and radiology departments and distributed to our emergency department practitioners and radiography team. The protocol included routine axial or modified trauma axial view radiographs for all patients attending the emergency department with a shoulder injury, low clinical suspicion for dislocation and a low threshold for CT scan. Reaudit and ongoing data collection have shown significant increase in axial view radiographs and improved diagnosis.

Keywords: continuous quality improvement; diagnostic errors; patient safety; surgery; teamwork.

Figure 1

Light bulb sign due to internal rotation on left compared with posterior dislocation on right.

Figure 2

Anteroposterior (AP) radiograph demonstrating a proximal humerus fracture. There is a concurrent posterior dislocation present though this is not obvious on the single view. The Y view demonstrates it more clearly.

Figure 3

Anteroposterior (AP) radiograph demonstrating a lesser tuberosity fracture. Once again only careful analysis of the Y view reveals the concurrent dislocation.

Figure 4

Axial view radiograph demonstrating obvious posterior dislocation of the humeral head.

Figure 5

Protocol for management of shoulder injuries. AP, anteroposterior; ATLS, Advanced Trauma Life Support; ED, emergency department.

Figure 6

Patient position required to obtain a Velpeau view. The arm can remain in a sling therefore preventing pain.