Recombinant human bone morphogenetic protein-2-induced radiculitis in elective minimally invasive transforaminal lumbar interbody fusions: a series review.

Study Design: Retrospective single center analysis.

Objective: The purpose of our study is to quantify the development of a postoperative radiculitis in our minimally invasive transforaminal lumbar interbody fusion patient population.

Summary Of Background Data: 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.

Methods: 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.

Results: 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.

Conclusion: 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.