Bone morphogenic protein is a viable adjunct for fusion in minimally invasive transforaminal lumbar interbody fusion

Abstract

Study Design: Comparison of prospectively collected data of patients undergoing minimally invasive surgery transforaminal lumbar interbody fusion (MIS-TLIF) with and without recombinant human bone morphogenic protein 2 (BMP). Purpose: To compare the clinical, radiological outcome and complications of patients undergoing MIS-TLIF with and without BMP. Overview of Literature: BMP is an effective fusion enhancer with potential complications. Direct comparison of MIS-TLIF with and without BMP is limited to retrospective studies with short follow-up. Methods: From June 2005 to February 2011, consecutive cases of MIS-TLIF performed by a single surgeon were included. North American Spine Society (NASS) score, Oswestry disability index (ODI), Short Form-36 (SF-36), and visual analogue score (VAS) were assessed preoperatively and at 6 and 24 months postoperatively. Fusion rates and complications were noted. Results: The 252 cases comprised 104 non-BMP and 148 BMP cases. The BMP group was significantly older (mean age, 60.2 vs. 53.9; p <0.01). Preoperative scores were similar. Immediate postoperative morphine usage was significantly lower in the BMP group (12.4 mg vs. 20.1 mg, p <0.01). At 6 months, the BMP group had lower VAS back and leg pain scores (p <0.01). At 2 years, the BMP group had better leg pain scores (p <0.01), ODI (15.4 vs. 20.3, p =0.04) and NASS scores (8.8 vs. 15.8, p <0.01). Both groups showed significant clinical improvement compared to their preoperative levels. The BMP group attained a significantly higher rate of fusion at 6 months follow-up (88.4% vs. 76.8%, p =0.016) with no difference at 2 years. The non-BMP and BMP group had 12 (11.5%) and 9 (6.1%) complications and 5 (4.8%) and 2 (1.4%) reoperations, respectively. Conclusions: The use of BMP to augment fusion in MIS-TLIF is an acceptable alternative that has potential benefits of less pain in early and intermediate postoperative follow-up.