Nonoperative treatment of select LC-II pelvic ring injuries (OTA/AO 61B2.2) results in a low rate of radiographic displacement.

Objectives: to quantify radiographic outcomes and identify predictors of late displacement in the nonoperative treatment of LC-2 pelvic ring injuries. Design Retrospective review. Setting Two level 1 trauma centers. Patients/participants Thirty eight patients ≥18 years old with LC-2 pelvic ring injuries. Intervention Nonoperative treatment. Main outcome measurements Crescent fracture displacement measured on initial axial Computed Tomography. Change in pelvic ring alignment measured by the Deformity Index, Simple Ratio, Inlet and Outlet Ratios on successive plain radiographs. Results Patients in this study had minimally displaced LC-2 pelvic ring injuries, with median initial crescent fracture displacement of 2mm and median initial Deformity Index of 2%. No patient had a ≥10 percentage point change in Deformity Index over the treatment period, but small amounts of displacement were seen on the other ratios. No patients initially selected for nonoperative treatment converted to operative treatment. No radiographic predictors of late displacement were identified. Bilateral pubic rami fractures and the presence of a complete sacral fracture ipsilateral to the crescent fracture were not associated with late displacement. Conclusions A spectrum of injury severity and stability exists in the LC-2 pattern. Nonoperative treatment of LC-2 injuries with low initial deformity and crescent fracture displacement results in minimal subsequent displacement. Level of evidence Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.