The effect of early operative stabilization on late displacement of zone I and II sacral fractures.

Introduction: This study was designed to evaluate the effect on displacement of early operative stabilization on unstable fractures when compared to stable fractures of the sacrum.

Methods: Patient consisted of those sustaining traumatic pelvic fractures that also included sacral fractures of Denis type I and type II classification, who were over 18 at the time of the study. Patients were managed emergently, as judged appropriate at the time and then subsequently divided into two cohorts, comprising those who were either treated operatively or non-operatively. The operative group comprised those treated with either internal fixation or external fixation.

Results: Twenty-eight patients had zone II fractures, and 20 had zone I fractures. Zone II fractures showed average displacements of 6.5mm and 6.9mm in the rostral-caudal and anteroposterior directions, respectively, at final follow up. Zone I fractures had average displacements of 6.6mm and 6.1mm in both directions. There were no significant differences between zone I and II sacral fractures (rostral-caudal P=0.74, anteroposterior P=0.24). Average changes in fracture displacement in patients with zone I fractures were 0.6-1.0mm in both directions. Average changes in zone II fractures were 1.8-1.5mm in both directions. There were no significant differences between the average changes in zone I and II fractures in any direction (rostral-caudal P=0.64, anteroposterior P=0.68) or in average displacements at final follow up in any of zone or the entire cohort. Statistically significant differences were noted in average changes in displacement in zone II fractures in the anteroposterior plane (P=0.03) and the overall cohort in the anteroposterior plane (P=0.02).

Conclusion: Operative fixation for unstable sacral fractures ensures displacement at follow up is comparable with stable fractures treated non operatively.