Should Posterior Midline Structures Be Preserved in Decompression Surgery for Lumbar Spinal Stenosis?

This was a systematic review and meta-analysis study.The purpose of this study is to evaluate the available evidence on the preservation of posterior midline structures in decompression surgery for lumbar spinal stenosis (LSS).The gold-standard treatment for LSS refractory to conservative management is facet-preserving laminectomy. The question remains whether the midline structures should be preserved in decompression surgery for LSS.We performed a systematic review of the Medline, PubMed, Embase, and Cochrane databases in search of published reports comparing midline structure preservation (MSP) and conventional laminectomy (CL) for LSS. The population was divided into 2 groups: (1) MSP group (intervention) and (2) CL group (control). The various outcome parameters including blood loss, operation time, hospital stay, back and leg pain, functional scores including Oswestry Disability Index (ODI) score, Japanese Orthopedic Association score, and 36-Item Short Form Survey (SF-36) scores, satisfaction, and instability rates were analyzed. Data were extracted and aggregated for meta-analysis.Of the published reports, 16 met our inclusion criteria with an aggregated 540 in the intervention and 538 in the control groups, respectively. The aggregated data demonstrated patients undergoing MSP had significantly decreased back pain Visual Analog Scale compared with CL, regardless of time after surgery ( P =0.007). The MSP group also showed a significantly lower Oswestry Disability Index score and SF-36 Mental Component Summary score ( P =0.005 and 0.03, respectively) and longer 6-month walking distance ( P <0.00001). The patient satisfaction rate was significantly higher in the MSP group ( P =0.02), and the instability rate was significantly lower in the MSP group compared with the CL group ( P <0.0001). At 3 days after surgery, MSP significantly decreased the level of creatinine phosphokinase ( P <0.00001). Regarding intraoperative blood loss, hospital stay, leg pain Visual Analog Scale score, Japanese Orthopedic Association score, and SF-36 Physical Component Summary score, there were no significant differences between the 2 groups. However, MSP showed significantly higher operation time ( P =0.04).We concluded despite heterogenous and limited data, this study suggests that preservation of midline structure leads to less severe back pain, better functional recovery, and satisfaction rate. Meanwhile, it decreases creatinine phosphokinase level and instability rate.Level III-therapeutic.