Introduction: Anterior cervical discectomy and fusion (ACDF) using rhBMP-2 with a PEEK implant and plate was compared with ACDF using allograft and plate in patients with symptomatic single-level cervical degenerative disc disease.
Methods: Two hundred twenty-four patients were enrolled in a prospective IDE trial evaluating rhBMP-2/ACS in ACDF (0.6mg in 240 patients, 1.05mg in 4 patients). Clinical outcomes in rhBMP-2 patients were compared with those in 486 historical control allograft patients using propensity score technique to minimize bias. Assessments were completed preoperatively, at discharge, and during follow-up visits at 1.5, 3, 6, 12, and 24 months. Adverse events were recorded at every visit.
Results: At 24 months, mean NDI improvement was greater in the rhBMP-2 group (37.1 points) than in the allograft group (31.4 points, p=0.002). Mean arm pain improvement was 11.0 points in the rhBMP-2 group compared with 9.7 points in the allograft group (p=0.031). The overall neurological success rate was significantly higher in the rhBMP-2 group (p<0.001). Neck pain and general health status (SF-36 PCS and MCS) were similar for both groups. The fusion rate in the rhBMP-2 group was 99.4% as determined by an independent radiology group. On reassessment of the allograft control patients, this same group found a fusion rate of 87.2% in contrast to the original fusion rate of 96%, which was assessed by a different radiology group.
Cumulative adverse event rates were similar in the two groups; however, higher rates of some early adverse events--dysphagia, local swelling, and neck pain--were observed in the rhBMP-2 group. Through 24 months, the rate of subjects with any heterotopic ossification was significantly higher in the rhBMP-2 group (p<0.001).
Conclusions: RhBMP-2 was effective in inducing fusion and improving arm pain and function. Higher rates of certain adverse events and heterotopic ossification were observed in the rhBMP-2 group.
Patient Care: In patients undergoing surgery for single-level cervical disc disease, treatment with rhBMP-2 was effective in inducing fusion and improving pain and function.
Learning Objectives: By the end of this presentation, participants should be able to compare the effectiveness of rhBMP-2 with that of allograft in anterior cervical discectomy and fusion and identify potential adverse events.