Research Fellow, Neurosurgery Mayo Clinic Rochester, Minnesota, United States
Introduction: Bone morphogenetic protein (BMP) – an osteoinductive agent commonly used in lumbar arthrodesis – is off-label for cervical arthrodesis. This study aims to identify the effect of BMP use on clinical and radiological outcomes in instrumented cervical arthrodesis.
Methods: A systematic review of the literature was performed to identify studies directly comparing outcomes between cervical arthrodeses with and without BMP. Outcomes were analyzed separately for cases of anterior cervical discectomy and fusion (ACDF) and posterior cervical fusion (PCF).
Results: A total of 21 studies with 6,538 patients (2,172 using BMP, 4,366 without BMP) were included. Among 15 studies on ACDF, BMP was associated with a 10% higher fusion rate [RR=1.12, p=0.01] and a 3% lower reoperation rate [RR=0.48, p=0.04]. However, BMP was also associated with a 16% higher risk of dysphagia [RR=1.93, p=0.01] and a 3.2% higher risk of seroma/fluid collection [RR=5.00, p=0.01]. A higher BMP dose (>=0.9 mg/level) was associated with significantly higher fusion rates [RR=1.12, p=0.02] but not with dysphagia (p=0.12). Fusion or dysphagia rates did not differ based on the mean number of levels fused in ACDF. No significant difference in Neck Disability Index or neck pain Visual Analog Scale scores was observed. Among six studies on PCF, the use of BMP was not associated with significant differences in fusion rates (p=0.38) and reoperation (p=0.89).
Conclusion : Using BMP in ACDF is associated with higher rates of fusion, lower rates of all-cause reoperation, and potentially improved patient-reported outcomes, but also with an increased risk of dysphagia. The use of BMP in PCF seems to have a less important effect on clinical and radiological outcomes.
How to Improve Patient Care: The meta-analysis helps surgeons in the judicious use of BMP to promote fusion In patients with cervical arthrodesis at the risk of dysphagia and reoperations.
