Interspinous spacers versus posterior lumbar interbody fusion for degenerative lumbar spinal diseases: a meta-analysis of prospective studies

Purpose Our aim is to evaluate the safety and effectiveness of interspinous spacers versus posterior lumbar interbody fusion (PLIF) for degenerative lumbar spinal diseases. Methods A comprehensive literature search was performed using PubMed, Web of Science and Cochrane Library through September 2015. Included studies were performed according to eligibility criteria. Data of complication rate, post-operative back visual analogue scale (VAS) score, Oswestry Disability Index (ODI) score, estimated blood loss (EBL), operative time, length of hospital stay (LOS), range of motion (ROM) at the surgical, proximal and distal segments were extracted and analyzed. Results Ten studies were selected from 177 citations. The pooled data demonstrated the interspinous spacers group had a lower estimated blood loss (weighted mean difference [WMD]: −175.66 ml; 95 % confidence interval [CI], −241.03 to −110.30; p < 0.00001), shorter operative time (WMD: −55.47 min; 95%CI, −74.29 to −36.65; p < 0.00001), larger range of motion (ROM) at the surgical segment (WMD: 3.97 degree; 95%CI, −3.24 to −1.91; p < 0.00001) and more limited ROM at the proximal segment (WMD: −2.58 degree; 95%CI, 2.48 to 5.47; p < 0.00001) after operation. Post-operative back VAS score, ODI score, length of hospital stay, complication rate and ROM at the distal segment showed no difference between the two groups. Conclusions Our meta-analysis suggested that interspinous spacers appear to be a safe and effective alternative to PLIF for selective patients with degenerative lumbar spinal diseases. However, more randomized controlled trials (RCT) are still needed to further confirm our results.