Management of LC Type I (LC-1) Pelvic Injuries with Complete Sacral Fracture: Comparison of Solitary Anterior Fixation with Combined Anterior-Posterior Fixation

Background. Management of LC-1 type pelvic injuries, particularly in patients with complete sacral fracture (LC-1 PICSF, OTA type 61-B2.1), remains controversial. Specific indications for solitary fixation remain unclear, and there is a paucity of outcomes data in comparison to combined fixation. We undertook a retrospective study in patients with LC-1 PICSFs to compare outcomes between solitary anterior fixation and combined anterior-posterior fixation. Methods. A retrospective cohort study was conducted with enrollment from 2016 to 2018 at a single tertiary-referral center in China. Adults with operatively managed LC-1 PICSFs were enrolled. Patients with sacral displacement < 1  cm as assessed by axial CT received solitary anterior ring fixation (group A); patients with displacement ≥ 1  cm received combined fixation of both the anterior and posterior rings (group B). Reduction was confirmed by manipulation under anesthesia. Patients followed up for at least 24 months postoperatively. Primary outcome was function (Majeed score). Secondary outcomes included intraoperative characteristics, pain (VAS score), quality of fracture reduction (Tornetta and Matta radiographic grading), rate of nonunion, early weight-bearing status, and complication rate. Results. 68 (89%) of 76 enrolled patients completed follow-up. Patients in group A exhibited improved operative times, less time under fluoroscopy, and less blood loss as compared to group B. There were no significant differences between groups A and B regarding quality of fracture reduction, rate of union, functional outcomes, or rate of complications. Notably, group B patients were more likely to achieve full early weight-bearing. Conclusion. LC-1 PFCSFs can get benefits from ORIF; the treatment algorithm should be differently made following the degree of the sacral fractures displacement. Less than 1 cm sacral fracture displacement may get good functional outcomes from solitary anterior fixation. However, for the sacral fractures displacement greater or equal to 1 cm, both the anterior and posterior pelvic rings should be surgical stabilization.