Outcomes Of Minimally Invasive Transforaminal Lumbar Interbody Fusion Via MAST Quadrant Retractor Versus Conventional Posterior Open Surgery For Degenerative Lumbar Spine Disease

Objective: To compare clinical outcomes of minimally invasive transforaminallumbar interbody fusion(MIS-TLIF group) via MAST Quadrant retractor vs conventionalposterior open surgery(open group) for degenerative lumbar spine disease.Methods: From March2008to June2012,80patients with single-level lumbardegenerative disease and failed to conservative treatment were enrolled in this study, allcases were divided into two groups randomly, with each group of40patients. There wasno significant difference in age, gender, body weight, clinical diagnosis and the segmentfor treatment between the two groups (P>0.05). Minimally invasive transforaminallumbar interbody fusion via MAST Quadrant retractor or the conventional posterior opensurgery were performed randomly. The operative time, blood loss, postoperative drainage,hospital stay, creatine phosphokinase (CPK) in serum, MRI-T2relaxation time, visual analogue scores (VAS) for back and leg pain, Oswestry disability index (ODI), and fusionrate by24~36months follow-up(mean time was29-month) between two groups werecompared.Results: The MIS-TLIF group had similar operative time compared with the opensurgery group (141.0±27.3min vs139.5±33.7min, P>0.05).Intra-operative blood loss,post-operative drainage in MIS-TLIF group were268.0±122.2ml and25.6±32.4ml, whichwas significantly less than the open group of370.0±147.1ml and277.8±167.4ml,respectly (P <0.05); postoperative hospitalization time in MIS-TLIF group wasshorter than open group (7.3±3.2d vs9.5±2.7d, P <0.05). The VAS and ODI were lower at1,3,6,12,24months postoperatively than preoperative ones in both groups(P﹤0.05). At1month, the MIS-TLIF group had lower VAS score than open surgery group(P﹤0.05),while no significant differences with respect to VAS for back and leg pain at24-month andODI at1,3,6,12,24months was noted between the two groups(P>0.05). CPK levelswere significantly higher at1,3,5days after surgery(P <0.05), and peaked at1day aftersurgery, and back to normal at7days after surgery. Meanwhile, which were significantlylower in the MIS-TLIF group than the open group at1,3days after surgery(P﹤0.05). TheMRI-T2relaxation time of the multifidus muscle was significantly better in the MIS-TLIFgroup than the open surgery group at3months after surgery(P <0.05). Radiologicalanalysis showed similar fusion rate at6,24months after suergery(P﹥0.05).Conclusion: Minimally invasive transforaminal lumbar interbody fusion via MASTQuadrant retractor surgery and conventional posterior open surgery both can achieve agood efficiency, but the former surgery had less soft tissue intervention, and conducive toearly functional recovery.