Survival Analysis To Assess The Effectiveness And Safety Of Low-dose RhBMP-2 In Cervical Fusion

Objective:Recombinant human bone morphogenetic protein-2 has been employed extensively in bone fusion in recent years.However,the safety of rhBMP-2 in anterior cervical discectomy and fusion has been called into doubt because to a significant number of documented adverse events connected to rhBMP-2.Previous research has found a link between rhBMP-2 dosage and problems,however there is no agreement on the lowest effective dose of rhBMP-2 in ACDF.The aim of this study was to confirm the efficacy of low-dose rhBMP-2 in inducing cervical fusion by survival analysis,and to look into the safety of its use in ACDF.Methods:According to inclusion and exclusion criteria,the clinical data of patients having anterior cervical discectomy and fusion at the Department of Spinal Surgery of the hospital between June 2020 and December 2021 were reviewed,and 46 patients were ultimately included in this study.Based on the bone transplant materials used,they were put into two groups:Group A(25 cases)used only osteophytes from the cervical spine,and Group B(21 cases)used osteophytes from the cervical spine and rhBMP-2.Both groups were followed for at least a year.The patient’s general information was recorded,including gender,age,Body Mass Index and chronic medical history.The perioperative data comprised operation time,intraoperative blood loss,total drainage volume,postoperative hospital stay length and the kind of internal fixation device.Imaging evaluation indices included prevertebral soft tissue thickness at the C6 level before and 3 days after surgery,anterior disc height and C2-7 Cobb Angle before,3 days after,1 month after,and 3 months after surgery.Cervical spine radiography and computed tomography were used to record the fusion state and time at each subsequent time point.JOA ratings assessed clinical efficacy before surgery and at the last follow-up.Early problems were recorded down,and long-term complications were found through outpatient or telephone follow-up.The two groups’ data were compared using statistical methods.Results:In the two groups,there were no appreciable differences in terms of gender,age,BMI,basic medical history,or internal fixation device type(P>0.05).And there was no significant difference between the two groups in perioperative measures such as operation time,blood loss,drainage volume,and postoperative length of hospital stay(P>0.05).The fusion rate of group B(median survival time:3 months,95%CI 2.52-3.48)was quicker than that of group A(median survival time:3.5 months,95%CI 3.01-3.91),and the difference between the two groups was statistically significant(P<0.05).There was a statistically significant(P<0.05)increase in anterior disc height between the before(Group A:3.46±0.26cm,group B:3.62±0.56cm)and after surgery periods(Group A:3.81 ±0.29cm,group B:4.07±0.57cm)in both groups within 3 days following surgery.In each follow-up time point,there was no significant difference between the two groups(P>0.05),both groups lost an average amount of height within three months of surgery,and there was no significant difference in the total amount of height lost between the two groups(P>0.05).In group A,the anterior disc height segment continued to improve 1 and 3 months after surgery,and the difference was statistically significant(P<0.05),whereas in group B,the height returned to preoperative levels 1 and 3 months after surgery(P>0.05).The C2-7 Cobb angles of the two groups at each follow-up time point were not statistically different(P>0.05).It was statistically significant(P<0.05)that the prevertebral soft tissue thickness of C6 in both groups(Group A:1.82±0.38cm,group B:1.79±0.25cm)was increased after surgery(Group A:1.67±0.38cm,group B:1.60±0.19cm).Before and 3 days after surgery,there was no statistically significant difference between the two groups(P>0.05).At the last follow-up,the two groups’ JOA scores were higher than before surgery.When comparing the two groups’ JOA scores and rates of improvement before and after surgery,there were no statistically significant differences(P>0.05).Concerning complications,there was 1 case of pharyngeal pain and dysphagia in group A(4%),3 cases of significant prevertebral soft tissue swelling(12%),and 3 cases of significant cage subsidence(12%).In group B,there were 1 cases of inflammation(4.8%),2 cases of severe prevertebral soft tissue swelling(9.5%),and 5 cases of significant cage subsidence(23.8%).There was no subsequent hospitalization in any of the instances.The administration of low dosage rhBMP-2 was not strongly linked to prevertebral soft tissue swelling or fusion sink,according to a binary Logistic regression analysis(P>0.05).During hospitalization and follow-up,neither group had any complications,such as neurovascular injury,airway injury,seroma,cerebrospinal fluid leakage,wound infection,ectopic ossification,radiculitis,aggravation of cervical contractile deformity,screw looseness and fracture,or adjacent segment disease.Conclusion:In single-segment ACDF,low dosage(0.5 mg/lever)rhBMP-2 can efficiently speed up cervical fusion and is generally safe.The potential benefit of modest doses of rhBMP-2 in patients with multilevel ACDF requires further research to be confirmed.