Introduction: Osteocel-plus and BMP-Formagraft (12% bovine-derived collagen and 88% of hydroxyapatite and beta tricalcium phosphate) are used as fusion extenders to promote bony fusion. Their comparative cost and effectiveness have not been studied so far. We present our analysis based on 36 patients.
Methods: A retrospective chart review on patients who underwent one level elective lateral lumbar interbody fusion surgery (XLIF) using a combination of BMP-FG versus OC+ were evaluated. The formation of trabecular bone for fusion onset, height of disc space and graft subsidence into the vertrbral body were evaluated independently by radiologist and the senior author (SV) based on follow-up Xrays at approximately 3,12 and 24months.
Results: We had 18 patients who received OC+. So we analyzed 18 patients in chronological order with the same start date for BMP-FG one level fusion. Extra-small BMPs with large strips of Formagraft were used in this cohort of patients. All patients had robust fusion with formation of bridging bone. The cost of extra-small BMP was $1,726 and large strip of Formagraft was $1,649. The total cost for biologics for one level fusion using BMP-FG was $3375 (1726+1649). Prior to BMP-FG usage, we used small BMP only which cost $3,451. In contrast, 5cc of Osteocel-plus was used per level which cost $2,756.
Subsidence for Osteocel-plus patients were 2mm (n= 2) and zero (n=16) with no change in the disc height. The subsidence of BMP was zero (n=8), 2(n=1), 3(n=1), 4(n=2), 5(n=2) and 6mm(n=3) with similar reduction in disc heights.
Conclusions: Although both groups of patients has similar outcome with respect to days of hospital stay, bony fusion and wound healing, we noted that the Osteocel-plus cost 18% less. In addition, there was increase in the subsidence with BMP-FG patients but was not statistically significant. Subsidence can be affected by several variables like osteoporosis, minor intra-operative endplate breach, age and sex of the patients. Further studies are required to evaluate this further.
Patient Care: 1. It enables the surgeon to make decision based on the cost of these substitutes for interbody fusion 2. Osteocel is a good
alternative as a fusion substrate with minimal side effect profile 3. BMP needs to be used with caution on patients with severe osteoporosis for risk of subsidence
Learning Objectives: BMP with formagraft versus osteocel plus have similar outcome on patients undergoing spine fusion BMP had more number of
patients with subsidence but was not statistically significant BMP- Formagraft was more expensive than Osteocel plus for interbody fusion
References: 1. Promoting fusion in minimally invasive lumbar interbody stabilization with low-dose bone morphogenic protein-2--but what is the cost? Mannion RJ, Nowitzke AM, Wood MJ. Spine J. 2011 Jun;11(6):527-33. PMID: 20739225
2. The role of Osteocel Plus as a fusion substrate in minimally invasive instrumented transforaminal lumbar interbody fusion. Ammerman JM, Libricz J, Ammerman MD. Clin Neurol Neurosurg. 2013 Jul;115(7):991-4. PMID: 23182179