A 38-year-old female presents to your clinic now 1 year after diagnosis with an APC Type I pelvic ring injury that was managed nonoperatively. The patient remains neurovascularly intact with a primary complaint of continued groin pain with activity.
Which radiographic view is most effective at elucidating residual pelvic instability?
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Standing obturator oblique pelvic view
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Supine AP, inlet, and outlet pelvic series
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Weight-bearing double leg iliac inlet pelvic view
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Standing single leg AP pelvic view
Discussion
The correct answer is (D). Seigel et al. describe the utility of single-leg stance AP pelvic radiographs in evaluating for pelvic instability. These standing films were able to elucidate pelvic instability (defined as ≥0.5 cm vertical translation of the symphyseal bodies). This study directly compared the single-leg views to a supine pelvic series. The views described in choices A through C were not included in this evaluation.
What percentage of patients presenting with unstable SI injury or symphyseal disruption will have concomitant displaced acetabular fracture?
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1% to 3%
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5% to 7%
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15% to 20%
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>30%
Discussion
The correct answer is (B). Letournel and more recently Suzuki et al. have described the rate of displaced acetabular fractures in the setting of a displaced pelvic ring injury at 6.7% and 5.1%, respectively.
Objectives: Did you learn...?
Radiographic examination to diagnose residual pelvic instability?
