Background Traditional screw or plate fixation options can be used to fix the majority of sacral fractures. However, these techniques are unreliable with dysmorphic upper sacral segments, U-fractures, osseous compression of neural elements, and previously failed fixation. Lumbopelvic fixation can potentially address these injuries but is a technically demanding procedure requiring spinal and pelvic fixation and it is unclear whether it reliably corrects the deformity and restores function. Questions/purposes We therefore assessed reduction quality and loss of fixation, pain related to prominent hardware, subjective dysfunction measured by the Short Musculoskeletal Function Assessment (SMFA), and complications. Methods We retrospectively reviewed 15 patients with unstable sacral fractures treated with lumbopelvic fixation between 2002 and 2010. Patients had radiographic monitoring regarding reduction quality and loss of fixation and clinical followup using the SMFA. The minimum followup was 12 months (mean, 23 months; range, 12–41 months). Results Posterior reduction quality was 11 of 15 with less than 5 mm persistent displacement and four of 15 with 5 to 10 mm displacement. Loss of fixation was observed in one patient as a result of a technical error. Prominent hardware resulted in greater pain. Despite daily activity and bother subscores improving over time, we found long-term dysfunction in the SMFA. Eleven of the 15 patients were able to return to previous work or activities. Conclusion Complex posterior pelvic ring injuries of the sacrum not amenable to traditional fixation options can be salvaged with adherence to the technical details of lumbopelvic fixation. Hardware prominence and pain are markedly reduced with screw head recession. Long-term impairment is noted in patients with complex pelvic ring injuries requiring lumbopelvic fixation compared with normative data. Level of Evidence Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.