Meta-analysis Of Posterolateral Versus Posterior Lumbar Interbody Fusion For Low-grade Lumbar Isthmic Spondylolisthesis

Objective: Taking meta-analysis measures to evaluate the clinical efficacy andcomplications of posterolateral versus posterior lumbar interbody fusion for low-gradelumbar isthmic spondylolisthesis to supply further evidences for clinical decisions.Method: A systematic computer-based search（from January1983to December2012） of China biological Medicine Database, Chinese National KnowledgeInfrastructure, CNKI, Ovid of medline, MEDLINE, Cochrane Central Register ofcontrolled trial, EMbase, Web of Science Direct, Google Scholar， Web ofSpringerLink, and manual search of related journals like JBJS, Spine, Euro Spine,Chinese journal of spine and spinal cord, Chinese journal of Orthopedics, Chinesejournal of bone and joint and the journal of cervicodynia&lumbodynia wereperformed for collecting controlled trials on posterior lumbar interbody fusion(PLIF)versus posterolateral fusion(PLF) for low-grade lumbar isthmic spondylolisthesis. Themethodology of the included trials was evaluated. After heterogeneity analysis,RevMan5.0.24software was used for data analysis. To compare the results of PLIFand PLF on clinical efficacy (VAS scores, ODI scores, JOA scores), X-rays radiology(pedicle screws fracture rate, fusion rate, and lordosis angle correction), loss of bloodand operation time. The average follow-up time was2.32years.Results: Five eligible randomized control studies were identified. Three areprospective and two are retrospective ones. In total292(male137female155) patientswere identified,153with PLIF and139with PLF. Aging from18yrs to72yrs. Allstudies showed improvement in validated outcome scores during the latest follow-ups.Pooled data based on clinical efficacy (JOA scores, ODI scores, VAS scores), X-raysradiology (pedicle screws fracture rate, fusion rates and lordosis angle correction), theloss of blood and operation time of PLIF treatment were compared with PLFtreatment showed that statistical heterogeneity after pooled data was low (p=0.930,I-squared0.0). Meta analysis showed that the average loss of blood was comparable[MD=15.50，95%C（I-544.07，575.07），P>0.05].The average operation time in PLIF group was longer than PLF group [MD=36.70，95%CI（7.89，65.51），P<0.05]. Thefracture rate of pedicle screws in PLIF group was lower than PLF group [OR=0.14，95%CI （0.02，0.78），P<0.05].The fusion rate in PLIF group was higher than PLFgroup [OR=4.18，95%CI（1.38，12.65），P=0.01]. The ODI scores between twogroups were comparable [MD=-2.14，95%C（I-6.97，2.68），P>0.05]. The VAS scoresbetween two groups showed no statistical significances [MD=-4.79，95%CI（-13.02，3.45），P>0.05].The JOA scores in PLIF group was higher than PLF group[OR=1.18，95%CI（1.11，1.26），P<0.05]. The lordosis angle correction with PLIFwas better than with PLF [MD=1.64，95%CI （0.08，3.21），P<0.05].Conclusion: Despite the evidence level was relatively low, PLIF and PLF bothare effective for low grade isthmic spondylolisthesis. PLIF confers superiormechanical strength in correction, maintenance of spinal stability and improvement oflumbar sagittal balance.PLF had significant loss of reduction and high hardwarefailure rate, but the clinical outcome was not influenced. Although there are moreadvantages on PLIF, more high quality RCTs are needed to be performed for furtherguides to the clinical decisions.