RECOMBINANT HUMAN BONE MORPHOGENIC PROTEIN IS SAFE TO USE IN POSTEROLATERAL SPINAL FUSION SURGERY AND IS ASSOCIATED WITH BETTER LEG PAIN SCORES AT LATE FOLLOW UP

Abstract

Introduction: Recombinant human bone morphogenic protein-2 (rhBMP-2) eliminates the need for iliac crest bone graft and has superior fusion rates in anterior interbody fusion1. Post-operative neck swelling has precluded its use in cervical fusion2. Peri-rhBMP-2 oedema is a proposed cause of neuropathic leg pain in posterolateral lumbar fusion. We aimed to compare the incidence of leg pain in a rhBMP-2 treated cohort with a control group following posterolateral lumbar fusion and to determine radiological evidence of a mechanical cause for leg pain in either group.

Methods and Results: A single surgeon, multi-centre elective practice was retrospectively reviewed over a four-year period. All rhBMP-2 treated patients were included. Control patients included all primary instrumented lumbar fusions. Endpoints included single observer recorded leg pain. There were 64 and 40 patients in the rhBMP-2 treated and control group respectively. Pre-operative demographics and diagnoses were similar. Inter-body cages were used equally. Three patients had non-mechanical leg pain in the control group versus eleven in the rhBMP-2 group of which 6 were revision surgeries. None of the control group had previous lumbar fusion (p< 0.05). Within the rhBMP-2 group, cage use was similar for leg pain (31%) and non-leg pain (29%).

Conclusion: In primary lumbar fusion surgery, there is no significant difference in post-operative MRI-identifiable mechanical leg pain between rhBMP-2 treated and non-treated groups. RhBMP-2 loaded cages do not increase the risk of leg pain. Recombinant hBMP-2 is safe to use in posterolateral lumbar surgery.

Conflicts of Interest: None

Source of Funding: None