Retrospective single center analysis.
The purpose of our study is to quantify the development of a postoperative radiculitis in our minimally invasive transforaminal lumbar interbody fusion patient population.
The application of recombinant human Bone Morphogenetic Protein-2 (BMP) in spinal surgery has allowed for greater success in spinal fusions. This has led to the FDA approving its use in anterior lumbar interbody fusion. However, its well-recognized benefits have generated its “off-label” use in the cervical, thoracic, and lumbar spine. Despite its benefits, the adverse effects of its inflammatory properties are just starting to get recognized. Some clear adverse reactions have been documented in the literature in the cervical spine. However, we feel that these inflammatory properties may be present in the lumbar spine as well.
We performed a retrospective chart review of 43 patients who had undergone a minimally invasive transforaminal lumbar interbody fusions. Thirty-five of these patients had BMP and 8 patients did not have BMP. We documented whether there was a preoperative radiculopathy present and whether a radiculopathy was present postoperative. We reviewed radiographic postoperative imaging to establish a structural cause for any radiculopathy. If new or increasing radicular symptoms were present, we attempted to assess the duration of these symptoms.
Our analysis, showed that 0 of the 8 patients of the non-BMP group had new radicular symptoms that were not attributed to structural causes. In the BMP group, 4 of the 35 patients (11.4%) had new radicular symptoms without structural etiology.
Our analysis suggest that patients undergoing minimally invasive transforaminal lumbar interbody fusions procedures have a higher incidence of developing new radicular symptoms that could be attributed to BMP.
Bone morphogenetic protein has been used in an “off-label” manner in minimally invasive transforaminal lumbar interbody fusion. We performed a retrospective analysis of the incidence of radiculitis in this patient population. Our results indicate that there is a 11.4% risk of developing radiculitis when using bone morphogenetic protein in minimally invasive transforaminal lumbar interbody fusions.
From the Department of Neurological Surgery, Northwestern University, Feinberg School of Medicine, Chicago, IL.
Acknowledgment date: August 12, 2008. Revision date: October 5, 2008. Acceptance date: December 19, 2008.
The device(s)/drug(s) that is/are the subject of this manuscript is/are not FDA-approved for this indication.
No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.
Full Institutional Review Board Approval was granted by the Office for the Protection of Research Subjects at Northwestern University with IRB 2323-001.
Stefan A. Mindea, MD, and Patrick Shih, MD, contributed equally to the preparation of this manuscript.
Address correspondence and reprint requests to Patrick Shih, MD, Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, 676 N Clair Street, Suite 2210, Chicago, IL; E-mail: email@example.com