PURPOSE

Navigated sacroiliac screw fixation of the posterior pelvic ring has been introduced, providing the surgeon with an improved three-dimensional orientation of the anatomy. The primary aim of this study was to evaluate the influence of navigation on the surgical outcome. The secondary aim was to evaluate the relevance of sacral dysmorphism.

METHODS

A retrospective cohort study of patients from 2014 to 2022 admitted with acute traumatic pelvic ring injuries was performed. Patients aged ≥ 16 years treated electively with posterior pelvic ring screw fixation and at least 12 months follow up and informed consent were included. Patients were stratified according to treatment strategy (NAV: Navigated screws vs. CONV: Conventional screws) and compared regarding implant-related complications. Patients were automatically matched 1:1 according to age, gender and fracture stability.

RESULTS

A total of 208 patients were included (NAV: n = 66, CONV: n = 142). After matching, 132 patients were finally included with 66 patients in each. Transsacral screws were used more often in the navigated group (69.7%; OR = 5.58, p < 0.0001). There were no significant differences regarding hardware complications. However, no malpositioning or foraminal breaching occurred in the navigated group. A back-analysis of the unmatched group with elevated power revealed that malpositioning rate in the navigated group was significantly lower (p = 0.033). The presence of sacral dysmorphism did not affect malpositioning rates yet those patients were less likely to receive a transsacral screw instrumentation.

CONCLUSION

Navigated screw fixation of the posterior pelvic ring resulted in optimal accuracy of screw placement in trauma patients. Sacral dysmorphism scores might support surgical decision-making regarding the choice of screws. Especially patients with poor bone quality might benefit from transsacral screws, which can be introduced more safely using navigation.