The roles of serum alkaline and bone alkaline phosphatase levels in predicting heterotopic ossification following spinal cord injury.

STUDY DESIGN

Retrospective chart review.

OBJECTIVES

To analyze the usefulness of serum alkaline phosphatase (AP) and bone alkaline phosphatase (BAP), as well as C-reactive protein (CRP) levels in predicting heterotopic ossification (HO).

SETTING

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

METHODS

Between January 2003 and December 2013, 87 patients with HO around the hips met the inclusion criteria and were included in the study. Alkaline phosphatase, CRP and BAP were assessed and interpreted at the time of HO diagnosis and after radiation therapy in all patients.

RESULTS

At the time of HO diagnosis, 49 out of 87 patients (49.4%) had elevated alkaline phosphatase levels and 39 out of 87 patients (44.8%) had elevated BAP levels. Elevated CRP values were found in 67 patients (77.0%). Within 3 days after single-dose radiation therapy, elevated AP levels persisted in 38 patients (43.7%) and elevated BAP levels in 28 patients (32.2%).

CONCLUSIONS

The results obtained show that the determination of CRP, AP and BAP levels may not be considered a reliable screening method for early HO detection, subsequent to spinal cord injury.