Clinical And Radiographic Results Of Minimally Invasive Surgery With Transforaminal Lumbar Interbody Fusion (MIS TLIF) At L5-S1: A Preliminary Result

Presented at SMISS Annual Forum 2014
By Jin-Sung Kim MD, PhD
With

Disclosures: Jin-Sung Kim MD, PhD None

Introduction:
TLIF has gained popularity during recent years as treatment for spondylolisthesis and other degenerative conditions. With TLIF, there is reduced complications related to muscle dissection and neural retraction as compared to traditional posterior approach. Minimally invasive surgery with TLIF (MIS TLIF) further reduces this complications. However, due to anatomic location, MIS TLIF at L5-S1 level has been deemed difficult, and many believe longer level fusion is also mandatory to prevent instability.

Aims/Objectives:
The aim of this study is to evaluate the clinical and radiographic results of MIS TLIF procedure at L5-S1 level.

Methods:
A total of 14 patients were operated by a single surgeon at our institution between May 2012 and April 2014. All approaches were through minimally invasive transforaminal approach using tubular retractors. Mean follow up period was 9.6±3.8 months. Intraoperative and postoperative complications were noted. Patients were followed up at outpatient clinic at 1, 3, 6, and 12 months after surgery. Visual analogue scale(VAS) and modified Oswestry disability index (ODI) were recorded at each visit, as well as plain X-ray. At the last visit, patients’ satisfaction with the surgery and willingness to undergo the same surgery again were also recorded.

Results:
Mean age of patients was 62.1±6.9 years, with mean BMI of 24.3 (±3.4). All procedure was performed in the lumbar spine at L5-S1 exclusively by a single surgeon. Capstone and Opal cages, as well as Sextant and Viper pedicle screw system was allocated to each patient via a randomized method. There were no cases in which operation was aborted due to difficult approach. No significant complication occurred during operation. Mean VAS and ODI decreased from a mean of 6.5 and 29 preoperatively to 4.4 and 22.5 postoperatively (p<0.05). There were two cases in which pain recurred during follow-up period, and 1 case of only partial fusion. 86% were satisfied with the operation.

Conclusions:
Our preliminary results demonstrates MIS TLIF can be performed at L5-S1 level with clinical and radiographic results comparable to the same surgery at other levels. There were no significant difficulties with approach, and no significant complications. Further study with more number of cases will provide better insight into this type of surgery at L5-S1 level.