Augmenting posterolateral fusion with transforaminal lumbar interbody fusion cage improves clinical outcome, but not fusion rate, of posterior decompression

OBJECTIVE: This study was performed to compare fusion rates and clinical outcomes of posterior decompression by posterolateral fusion (PLF) versus transforaminal lumbar interbody fusion (TLIF) for treatment of lumbar spinal stenosis. METHODS: This retrospective cohort study involved 157 patients with lumbar spinal stenosis treated with instrumented PLF alone or instrumented PLF combined with TLIF from 2010 to 2018. The patients were divided into two groups: the PLF group (Group A), in which posterior decompression with instrumented PLF was performed, and the cage-augmented group (Group B), in which TLIF was added to the procedures described for the PLF group. Patient outcomes (Oswestry Disability Index, visual analog scale score, and 36-Item Short-Form Health Survey scores) and fusion rates were compared. RESULTS: The fusion rate was similar between the two groups. Among patients with two- and three-level fusion, improvements in the clinical outcome scores were significantly greater in Group B than Group A. CONCLUSION: Combining TLIF with PLF provides better clinical outcomes than PLF alone when multilevel fusion is indicated. TLIF augmentation does not improve the fusion rates in either single- or multi-level surgery.