Clinical & Radiological Comparison Between Three Different Minimally Invasive Surgical Fusion Techniques for Single-Level Lumbar Spondylolisthesis: MIS-PLF vs MIS-TLIF vs MIDLF

Presented at SMISS Annual Forum 2016
By Mohamed Elmekaty MD
With Ivan Gonchar MD, Yoshihisa Kotani MD, PhD, Emad Elmehy MD, PhD,

Disclosures: Mohamed Elmekaty MD None Ivan Gonchar MD None, Yoshihisa Kotani MD, PhD B; L&K Biomed. , Emad Elmehy MD, PhD None,

Introduction

Although, several Minimally Invasive Surgical (MIS) techniques for lumbar spine fusion have been reported, no study has compared the efficacy of MIS-Posterolateral Fusion (MIS-PLF) vs MIS-Transforaminal Lumbar Interbody Fusion (MIS-TLIF) vs Midline Lumbar Fusion with modified CBT (MIDLF) for lumbar spondylolisthesis 

Aims/Objectives

To compare clinical and radiographic outcomes of three different MIS fusion techniques for single-level lumbar spondylolisthesis. 

Methods

A total of 103 patients with single-level lumbar spondylolisthesis was included in this study. MIS-PLF, MIS-TLIF and MIDLF group included 22, 15, and 66 cases, respectively. MIS-PLF utilized 4cm midline incision and PPS, achieving small PLF with iliac bone graft. MIS-TLIF group utilized bilateral mini-Wiltse approach and pedicle screws. MIDLF was a TLIF through small midline incision using modified cortical bone trajectory screws. The evaluation parameters were operation time, intraoperative bleeding, serum C-reactive protein (CRP) and creatine kinase (CK) at POD1 and POD7, and overall functional outcome by Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) score. The changes in lumbar lordosis, segmental disc angle and disc height were measured. The fusion rate, screw loosening and % loss of correction were also assessed. 

Results

Mean operation time was significantly shorter in MIDLF (117 min) and in MIS-PLF (132 min) vs MIS-TLIF (167 min). Mean bleeding amount was significantly less in MIDLF (110 ml) vs MIS-PLF (245 ml) and MIS-TLIF (350 ml). Mean CRP values were significantly lower in MIDLF (1.32) at POD1 vs MIS-PLF (3.24) and MIS-TLIF (2.07). Mean CK values were significantly lower in MIDLF at (POD1-7) (329-71) vs MIS-PLF (606-161) and MIS-TLIF (780-117). There was no significant difference between three groups in JOABPEQ score. MIDLF showed more increase of lumbar lordosis angle and segmental disc angle postoperatively. MIDLF and MIS-TLIF showed significant increase of middle disc height vs MIS-PLF. Also, MIDLF showed more increase of posterior disc height. MIDLF showed significant less loss of correction after three months postoperatively (1%) vs MIS-PLF (5%). Fusion rate was 100% in MIDLF and MIS-TLIF and 90% in MIS-PLF. Screw Loosening occurred in 18% of MIS-PLF, 26.6% of MIS-TLIF and 3% of MIDLF. 

Conclusions

MIDLF using modified CBT screws demonstrated higher fusion rate, less screw loosening rate and less invasiveness when compared to other two MIS fusion techniques. Also, MIDLF was more effective in maintaining correction, restoring LL angle, segmental disc angle and disc height, which was attributed to high fixation strength of modified CBT screws.