In the era of recombinant BMP, does additional anterior stabilization add value to a posterolateral fusion?

ABSTRACT Study design: Retrospective cohort study. Clinical question or objective: Is there a benefit to additional transforaminal lumbar interbody fusion (TLIF) if a solid posterolateral (PL) fusion can be achieved with routine bone morphogenetic protein (BMP) use in low-grade spondylolisthesis? Methods: We performed a retrospective review of patients who had undergone surgery for grade I or II lumbar spondylolisthesis stratified into two groups. Group 1 had 46 patients who underwent TLIF along with PL instrumented fusion. Group 2 had 40 patients who underwent PL instrumented fusion alone. In both groups, adequate posterior decompression with pedicle screw instrumentation was performed and rhBMP-7 was used. All patients were evaluated clinically using the Oswestry Disability Index (ODI) and by independent radiological examination at 3 and 12 months. Results: At a minimum follow-up of 12 months, there was no statistically significant difference in the rate of fusion. In addition, there were no differences in the proportion of patients who had a minimal clinically significant difference in their ODI. There was a similar rate of complications between each cohort. Conclusions: The use of BMP was associated with a high rate of PL lumbar fusion. In the presence of a PL fusion, there appears to be little clinical benefit to additional anterior TLIF in degenerative spondylolisthesis. Final class of evidence-treatment Study design RCT Cohort • Case control Case series Methods Concealed allocation (RCT) Intention to treat (RCT) Blinded/independent evaluation of primary outcome F/U ≥ 85% • Adequate sample size • Control for confounding Overall class of evidence III The definiton of the different classes of evidence is available here.