Comparison of transforaminal lumbar interbody fusion outcomes in patients receiving rhBMP-2 versus autograft

Publication date: Available online 18 August 2017
Source:The Spine Journal
Author(s): Taleef R. Khan, Kalin R. Pearce, Steven J. McAnany, Colleen M. Peters, Munish C. Gupta, Lukas P. Zebala
Background ContextRecombinant human bone morphogenetic protein 2 (rhBMP-2) plays a pivotal role in complex spine surgery. Despite its limited approval, the off-label use of rhBMP-2 is prevalent, particularly in transforaminal lumbar interbody fusions (TLIF)PurposeTo determine the effectiveness and safety of rhBMP-2 use in TLIF procedures versus autograft.Study DesignRetrospective Cohort StudyPatient SamplePatients older than 18 years undergoing spine surgery for lumbar degenerative spine disease at a single academic institution.Outcome MeasuresClinical outcome was determined according to: patient records. Radiographic outcome was determined according to: plain x-rays and computed tomography (CT).MethodsA retrospective study from 1997-2014 was conducted on 191 adults undergoing anterior-posterior instrumented spinal fusion with TLIF at a single academic institution. Patient data was gathered from operative notes, follow up clinic notes and imaging studies to determine complications and fusion rates. One hundred eight-seven patients fit criteria, which included patients with a minimum of one TLIF, and had a minimum 2-year radiographic and clinical follow-up. Patients were further classified into a BMP group (n=83) or non-BMP group (n=104). Three logistic regression models were run using rhBMP-2 exposure as the independent variable. The respective outcome variables were TLIF-related complications (radiculitis, seroma, osteolysis, and ectopic bone), surgical complications, and all complications.ResultsBMP (n=83) and non-BMP (n=104) groups had similar baseline demographics (sex, diabetes, pre-existing cancer). On average, the BMP and non-BMP groups were similarly aged (51.9 vs. 47.9 years, p>0.05), but the BMP group had a shorter follow-up time (3.03 vs. 4.06 years; p<0.001) and fewer smokers (8 vs. 21 patients; p<0.048). The fusion rate for the BMP and non-BMP groups was 92.7% and 92.3%, respectively. The pseudoarthrosis rate was 7.5% (14/187 patients). Radiculitis was observed in 7 patients in the BMP group (8.4%) and 2 patients in the non-BMP group (1.9%) in the non-BMP group. Seroma was observed in 2 patients in the BMP group (2.4%) and none in the non-BMP group. No deep infections were observed in the BMP group and 1 patient in the non-BMP group (0.96%). While patients exposed to BMP were at a significantly greater risk of developing radiculitis and seroma (OR=4.53, CI=1.42 – 14.5), BMP exposure was not a significant predictor of surgical complications (OR=0.32, CI=0.10 – 1.00) or overall complications (OR=1.11, CI=0.53 – 2.34). The outcome of TLIF-related complications was too rare and the confidence interval too wide for practical significance of the first model.ConclusionEvidence supports the hypothesis that off-label use of rhBMP-2 in TLIF procedures is relatively effective for achieving bone fusion at rates similar to patients receiving autograft. Patients exhibited similar complication rates between the two groups, with the BMP group exhibiting slightly higher rates of radiculitis and seroma.



http://ift.tt/2uY1MGc