Comparison between posterior lumbar interbody fusion and posterolateral fusion with transpedicular screw fixation for isthmic spondylolithesis: a meta-analysis

INTRODUCTION: Primary aim of this study was to compare long-term pain relief and quality of life in adults with isthmic spondylolisthesis (IS) who were treated with posterior lumbar interbody fusion (PLIF) and posterolateral fusion (PLF). Secondary aim was to compare the fusion and infection rates of PLIF- or PLF-treated groups. MATERIALS AND METHODS: We searched four databases and the cited reference lists of the included studies. Inclusion criteria were pain assessment with visual analog scale (VAS), and clinical studies that compared long-term pain relief of PLF and PLIF-treated adults with IS. Exclusion criteria were use of only one treatment and non-English language. RESULTS: Three of five included studies used VAS to assess the decline in low back pain, radicular pain, or leg pains in PLF- or PLIF-treated patients during the follow-up periods (0.5–6 years). Long-term pain relief significantly improved in both treatment groups. Pooled differences in mean improvement of Oswestry disability index after the operation revealed no significant difference in pain relief between the PLF and PLIF groups (P = 0.856). The five studies together indicated that fusion rate was significantly greater in the PLIF group than that in the PLF group. CONCLUSIONS: The majority of PLIF- and PLF-treated adults with low-grade IS experienced long-term pain relief to a similar extent in most studies. PLIF treatment provided significantly better fusion rates than PLF treatment. This meta-analysis indicates that the use of separate, well-defined scales for pain relief and functional outcomes are needed in studies of PLF or PLIF-treated patients.