The role of plain films and computed tomography in the evaluation of scapular neck fractures

Objective: To assess the ability of plain films and computed tomography scans to show the pattern, displacement, and angulation of scapular neck fractures. To assess the ability of computed tomography to identify concomitant occult shoulder injuries. Design: Masked retrospective radiographic review. Setting: Level I trauma center. Participants: Three orthopaedic surgeons (two attending physicians and one senior resident) and one musculoskeletal radiology attending physician reviewed the imaging studies of scapula neck fractures in twenty patients treated at our institution. Main Outcome Measures: Kappa analysis of agreement of fracture characteristics and benefits of computed tomography for scapular neck fractures. Results: The mean weighted kappa coefficient for interobserver reliability of fracture displacement was 0.49 when the fractures were assessed by plain films alone. 0.5 when they were assessed by computed tomography scans alone, and 0.35 when they were assessed by plain films and computed tomography scans. The mean weighted kappa coefficients for fracture angulation were 0.30, 0.23, and 0.16, respectively. The mean simple kappa coefficients for fracture classification were 0.81. 0.20, and 0.33, respectively. Concomitant injury to the superior shoulder suspensory complex was seen in 57 percent of cases, including nine clavicle fractures, one coracoid fracture. and three acromion process fractures. The coracoid fracture and two of the acromion process fractures were minimally displaced and seen on computed tomography scans only. Conclusion: Scapular neck fracture displacement, angulation, and anatomic classification showed moderate interobserver reliability by plain films but were not enhanced by computed tomography. Computed tomography confused, rather than clarified, the assessment of these characteristics. Computed tomography may be useful to identify associated injuries to the superior shoulder suspensory complex, which can be missed by plain films alone. Routine computed tomography in patients with scapular neck fractures cannot be recommended based on this study. Computed tomography of scapular neck fractures may be useful in selected cases in which intraarticular extension is noted on plain films.