Relationship of Sacral Fractures to Nerve Injury: Is the Denis Classification Still Accurate?

OBJECTIVE

Use modern computed tomographic imaging to reassess neurological injury risks associated with zone I-III sacral fractures as originally described by Denis et al.

DESIGN

Retrospective case-control study.

SETTING

University Level I Trauma Center.

PATIENTS/

PARTICIPANTS

One thousand five hundred seven consecutive patients who presented with sacral fractures between January 2000 and August 2012.

MAIN OUTCOME MEASUREMENTS: Patients were stratified based on the diagnosis of acute neurological injury. The risk of severe and complex sacral fractures based on the presence of nerve injury was assessed.

RESULTS

The rate of nerve injury was significantly lower compared with historic data (3.5% vs. 21.6%, P < 0.001). Acute nerve injury was a significant risk factor for displaced (odds ratio [OR]: 8.4, 95% confidence interval [CI], 1.4-51.9) and comminuted (OR: 5.2, 95% CI, 1.7-16.3) sacral fractures as well as zone II (OR: 3.4, 95% CI, 1.1-10.1) and III (OR: 3.9, 95% CI, 1.0-16.4) fractures.

CONCLUSIONS

The incidence of nerve injuries associated with sacral fractures is significantly lower than originally published by Denis et al. Patients with a nerve injury were highly correlated with having a displaced, comminuted, or zone III fracture, or spinopelvic dissociation; the authors recommend a fine cut computerized tomography for further investigation if these findings are not apparent on initial radiographic imaging.

LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.