Progressive displacement of scapula fractures

Background: Historically, minimally to moderately displaced extra-articular scapula fractures have been managed conservatively. It is possible that operative criteria could be met for a given patient if progressive displacement were to occur. We hypothesize that certain displaced scapula fractures progressively displace in early postinjury period. Methods: A consecutive series of 49 patients with operatively managed extra-articular scapula fractures was evaluated to identify patients initially managed nonoperatively and later operatively because of progressive displacement. Three examiners then independently analyzed radiographs to measure the displacement between injury films and the films used to determine operative indications. A standard method for radiographic measurement of deformity was developed and was used to determine the degree of deformity at injury and at follow-up time when operative care was decided. Results: Eight patients met inclusion criteria. All sustained a specific extra-articular transverse fracture pattern Arbeitsgemeinschaft für Osteosynthefragen/Orthopaedic Trauma Association (AO/OTA) Type A3, Ada-Miller Type IIC). Mean time interval between injury and repeat radiographs was 11.3 (range, 9-15) days. All patients displayed progressive displacement in at least one of the four measured parameters (medial/lateral displacement, angulation, translation, and glenopolar angle), according to the three independent examiners. Predominantly "good" inter- and intraobserver scores were achieved. Conclusions: Certain extra-articular scapula fractures may displace in postinjury period. We recommend close monitoring of conservatively treated fractures to screen for progressive displacement.