Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Review of Technical Nuances to Improve Clinical Outcomes and Fusion Rate

Presented at SMISS Annual Forum 2014
By Jorge Mendoza-Torres Spine Fellow, MD
With Mick Perez-Cruet MD, MS, Moumita Chaoudhury MD, Clara Seijo MD,

Disclosures: Jorge Mendoza-Torres Spine Fellow, MD None Mick Perez-Cruet MD, MS None, Moumita Chaoudhury MD None, Clara Seijo MD None,

Introduction:
Minimally Invasive Transforaminal Lumbar Interbody Fusion (MI-TLIF) has gained popularity among spine surgeons and patients, However, more evidence is needed to evaluate novel techniques and technology that improve the efficacy, safety, and patient outcome in MI-TLIF.

Aims/Objectives:
Our aim is to critically review a consecutive series of patients showing technical nuances that facilitate the MI-TLIF procedure while improving disc and foraminal height as well as canal diameter. These procedures were then correlated with clinical outcomes to determine the best technique for optimizing clinical outcomes.

Methods:
A series of 73 consecutive patients, 48 female and 25 male, average age of 64 years old; from November 2011 to August 2013, underwent for MI-TLIF and percutaneous pedicle screws instrumentation. Comparative pre-operative, intra-operative and post-operative variable analyzed included: disc and foraminal height restoration, sagittal re-alignment, interbody bone graft utilized, optimal interbody device height, operative times, estimated blood loss, hospital stays, and complication rates. These variable were then correlated with pre- and post-operative outcome variables including: Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), SF-36 scores.

Results:
94% of the patients had a good to excellent outcome at average 12 month follow-up. Disc height and interpedicular distance were increased by 73% and 31% (P=0.001) respectively. Complications seen in 2 cases; one of them had superficial wound infection and another patient had postoperative left L5 radicular pain due to misplacement of one pedicle screw. The average preoperative Visual Analogue Scale (VAS) reduced from 7 to 3.5 (P=0.013). The preoperative Oswestry Disability Index (OSI) decreased from 45.5% to 37% (P=0.003). the fusion rate at 12 month evaluation was 96.5% of the plane xray, including flexion, extension views.

Conclusions:
MIS-TLIF with instrumented pedicle screw placement is a safe procedure, with more than 90% of positive outcome and very low rate of complication (6%) compared with complications (40%) reported previously.