Professor Mayo Clinic Rochester Rochester, Minnesota, United States
Introduction: Outcomes and complications involving the off-label use of bone morphogenetic protein (BMP) in cervical spine surgeries have not clearly defined. This study aims to compare clinico-radiological outcomes in instrumented fusion of cervical spine with and without the usage of BMP.
Methods: A systematic review of the literature was performed to identify studies directly comparing outcomes of using BMP in cervical spine fusion surgeries. 21 studies with 6780 patients (2298 using BMP, 4482 without using BMP) were included. Subgroup analysis based on the type of approach was conducted among the anterior cervical discectomy with fusion (ACDF) and posterior cervical fusion (PCF) cases.
Results: Significantly higher rates of fusions were achieved when using BMP [RR=1.09, 95% CI (1.02, 1.16), p=0.01), but the risk ratio for developing dysphagia with BMP versus without was 1.90 [95% CI (1.09, 3.32), p=0.03]. ACDF cases using BMP had 10.7% more fusion rates [RR=2.21, p=0.014] with 3% lesser reoperation rates [RR=0.48, p=0.04] but had 12% higher incidence of dysphagia [RR=2.21, 95% CI (1.30, 3.78), p=0.01). Rates of fusion, reoperation or dysphagia in PCF surgeries with or without BMP did not show any statistically significant difference. There was no significant change observed in post-operative visual analogue score for neck pain [mean difference: -0.27, 95% CI (-1.15, 0.61), p=0.55] or neck disability index [mean difference: -4.08, 95% CI (-8.20, 0.03), p=0.052] compared to pre-operative status.
Conclusion : Using BMP in cervical spine surgeries is associated with higher rates of fusion although with no meaningful change in patient-reported neck pain score or disability index but is associated with significantly high dysphagia rates, especially in ACDF.
