Ankylosing spondylitis does not increase the risk of neurogenic heterotopic ossification in patients with a spinal cord injury: a retrospective cohort study.

STUDY

DESIGN

Retrospective chart review.

OBJECTIVES

The present study was performed to analyze the impact of ankylosing spondylitis (AS) in developing heterotopic ossification (HO) in patients following spinal cord injury.

SETTING

Department of Spinal Cord Injury and Department of General and Trauma Surgery, BG-University Hospital Bergmannsheil Bochum, Ruhr-University Bochum, Germany.

MATERIALS AND

METHODS

Between January 2003 and December 2015, 67 patients with AS and SCI were included in the study. The control group consisted of 141 patients with SCI and without AS. The definitive diagnosis of HO was made via magnetic resonance imaging or computed tomography. Primary outcome measure was to analyze the impact of AS on the development of HO.

RESULTS

Fifteen out of 67 AS patients (22.4%) had a diagnosed HO. In the control group, 28 of 141 patients (19.9%) suffered from HO. Patients with AS had no significant higher risk for HO development compared with patients without AS (RR=1.16; 95% CI=0.65-2.09). However, patients with a complete neurological deficit had a twofold higher risk for HO development (RR=2.55; 95% CI=1.26-5.16).

CONCLUSIONS

AS does not increase the risk for HO development in patients with spinal cord injury.