Stand-alone interspinous spacers versus decompressive surgery in lumbar spinal stenosis: a systematic review and meta-analysis

Purpose: This study aimed to compare the efficacy and safety of stand-alone placement of interspinous spacers (IPS) with decompressive surgery (DS) for the treatment of lumbar spinal stenosis. Methods: Medline, Embase, and the Cochrane Central Register of Controlled Trials databases were searched until February 2016 to identify relevant randomized controlled trials (RCTs) and comparative cohort studies. The relative risk (RR) and 95% confidence intervals (CIs) were calculated for dichotomous variables. The weighted mean difference (WMD) and 95% CIs were calculated for continuous variables. A random effect model was used for heterogeneous data; otherwise, a fixed effect model was used. Results: Four RCTs and four comparative cohort studies with 834 patients in total met the eligibility criteria for this meta-analysis. Overall, there were no significant differences regarding leg pain score and ODI score between the IPS and DS groups. Pooled estimates showed that patients in the IPS group achieved worse low back pain score and higher rate of reoperation. However, IPS group had a significantly lower rate of complications, shorter hospital stay, and shorter operative time. Conclusions: Based on the current literature, we concluded that there were no significant differences regarding leg pain and ODI scores between the IPS and DS groups. Although having a lower rate of complications and shorter hospital stay and operative time, the IPS group resulted in inferiority of low back pain and a higher rate of reoperation. Careful preoperative consideration on indications, benefits and risks of employing this interspinous implant should be made.