Effect of Deformity and Malunion of the Anterior Pelvic Ring

Pelvic fractures are common after high-energy trauma and are often associated with ligamentous injury. Treatment is guided by assessing stability of the pelvic ring, and unstable injuries frequently require surgery to achieve a desirable outcome. Assessment of pelvic ring stability is often possible with physical examination and standard imaging studies (plain radiographs and computed tomography); however, these "static" imaging modalities may not adequately identify dynamically unstable pelvic injuries that require surgery. Cadaveric and clinical data suggest that the injured pelvis may recoil significantly from the point of maximal displacement, and some unstable injuries may not be recognized until patients present with clinical symptoms. This article presents the case of a patient who sustained a minimally displaced pelvic ring injury that was stable on bedside examination and static imaging, but ultimately was unstable. She developed a substantial pelvic malunion with significant pain and activity limitations. The patient subsequently underwent successful pelvic ring reconstruction, and she remains asymptomatic at 2 years.