Multiple iliosacral screws in a single osseous fixation pathway: Utility and safety

1) To evaluate common characteristics for injuries treated with multiple iliosacral screws in a single sacral osseous pathway to evaluate when it may be useful and 2) to determine whether placing multiple iliosacral screws in a single sacral OFP increases risk for unsafe screws.

Design: Retrospective, combined case-control and cohort analyses Setting: Single, Level 1 regional trauma center Patient Selection Criteria: Treated with iliosacral screws identified by CPT code search 27,216 and 27218 Outcome Measures and Variables: Population was divided into multiple screw (MS) and single screw (SS) groups. Outcomes of interest were factors associated with MS group and screw safety on postoperative CT scan.

There were 133 patients with 53/133 (39.8%) in the MS group and 80/133 (60.2%) in the SS group. On logistic regression, each 2-mm increase in CT measurement was associated with higher odds of receiving multiple screws for sacroiliac style (OR = 1.34, 95% CI 1.05-1.71, p = 0.02) or transsacral if non-dysmorphic (OR = 1.55, 95% CI 1.25-1.93, p < 0.001) in S1. Patients were 3.4 times more likely to be in the MS group with C-type than B-type injuries (OR = 3.40, 95%CI 1.61-7.22, p = 0.0014). MS was not a risk factor for juxtacortical or extraosseous screw placement (RR = 1.93, 95%CI 0.66-5.65, p = 0.23).

The results of this study suggest that surgeons may place multiple iliosacral screws in a single OFP in more complex or unstable injuries and/or when larger safe corridors exist on preoperative imaging and that multiple iliosacral screws may not be associated with an increase in risk for unsafe screw placement.