Does bone morphogenetic protein increase the incidence of perioperative complications in spinal fusion? A comparison of 55,862 cases of spinal fusion with and without bone morphogenetic protein.

STUDY DESIGN

Retrospective review of a multi-institutional, multisurgeon database.

OBJECTIVE

Assess for associations between bone morphogenetic protein (BMP) use and rate of complications in spinal fusion.

SUMMARY OF BACKGROUND DATA

BMP is commonly used in spinal surgery to augment fusion; however, there is limited evidence demonstrating its associated complications.

METHODS

We performed a retrospective analysis of all fusion cases submitted by members of the Scoliosis Research Society from 2004 to 2007. We stratified on the basis of the use of BMP and evaluated for complications and associated characteristics.

RESULTS

A total of 55,862 cases of spinal fusion were identified with BMP used in 21% (11,933) of the cases. Excluding anterior cervical fusions, there were no significant differences between fusions with and without BMP with regard to overall complications (8.4% vs. 8.5%; P = 0.5), wound infections (2.4% vs. 2.4%; P = 0.8), or epidural hematomas/seromas (0.2% vs. 0.2%; P = 0.3). Anterior cervical fusions with BMP were associated with more overall complications (5.8% vs. 2.4%; P < 0.001) and more wound infections (2.1% vs. 0.4%; P < 0.001) than fusions without BMP. On multivariate analysis for thoracolumbar and posterior cervical fusions, BMP use was not a significant predictor of complications (P = 0.334; odds ratio = 1.039; 95% confidence interval = 0.961-1.124; covariates were BMP use, patient age, revision vs. primary surgery). Multivariate analysis for anterior cervical spinal fusion demonstrated that BMP use remained a significant predictor of complications (P < 0.001, odds ratio = 1.6; 95% confidence interval = 1.516-1.721), after adjusting for the effects of patient age and whether the surgery was a revision procedure.

CONCLUSION

BMP use with anterior cervical fusion was associated with an increased incidence of complications. Use of BMP was not associated with more complications in thoracolumbar and posterior cervical fusions.