General Session: Thoraco-Lumbar Degenerative

Presented by: J.H. Tan - View Audio/Video Presentation (Members Only)

Author(s):

J.H. Tan(1), G. Liu(1), R. Ng(2), N. Kumar(1), H.K. Wong(1)

(1) National University Health System, Orthopaedic Surgery, Singapore, Singapore
(2) National University of Singapore, Singapore, Singapore

Abstract

Introduction: The prevalence of obesity has increased over the years. Obesity increases the risk of intra-operative complications such as difficulties in anesthesia, intravenous access, and identification of anatomical landmarks. While both minimally invasive Transforaminal Lumbar Interbody Fusion (MIS-TLIF) and open TLIF (O-TLIF) are reported to have comparably good long-term outcomes for non-obese patients, no consensus has been reached for outcomes in obese patients. A meta-analysis was performed to answer this clinical question. Methodology: A comprehensive search of the published literature was performed in the following databases: PubMed, Scopus, Web of Science and Cochrane Central Register of Controlled Trials database in accordance to the PRISMA 2009 checklist. We used the following search terms in this systematic review: (TLIF OR (transforaminal lumbar interbody fusion) OR (instrumentation and fusion)) AND (obesity OR obese OR overweight). Search terms were kept broad to encompass all relevant articles. We included articles that directly compared outcomes of obese patients who underwent either O-TLIF or MIS-TLIF. When comparing between the O-TLIF and the MIS-TLIF group, the absolute mean difference or the odds ratio was used as the summary statistic for continuous data or binary data, respectively. Publication bias was studied with funnel plot analysis.

Results: 68 articles were identified from PubMed, 68 articles from Web of Science, 3 articles from Cochrane and 724 articles from Scopus after the initial search. Using the pre-defined inclusion and exclusion criteria, a total of 4 articles were selected for the meta-analysis. The study population consisted of a total of 430 patients, of which 217(50.5%) underwent the O-TLIF and 213(49.5%) underwent MIS-TLIF. 194(45.1%) of them were males, while 236(54.9%) were females. The average age was 54.8±12.0 years. The mean BMI was 33.0±4.5kg/m2. The pooled OR of dural tear intra-operatively from 4 studies involving 430 patients was 3.98(95% CI:1.61 - 9.87) p=0.003, in favour of MIS-TLIF (I2:0.00%). The pooled mean difference intra-operative blood loss from 3 studies involving 282 patients was 383.44mls(95% CI:329.5 - 437.4), p< 0.00001, in favour of MIS-TLIF (I2:1%). The pooled mean difference for hospitalization stay from 2 studies involving 201 patients was 1.21days(95%CI:0.80 - 1.62), p< 0.00001, in favour of MIS-TLIF. The calculated I2 was 46.0%. The pooled OR for post-operative wound infection from 4 studies involving 430 patients was 1.60(95%CI:0.54 - 4.75), p=0.40. (I2:36%). There was no difference between O-TLIF and MIS-TLIF. The pooled mean difference for pre and post-operative VAS from 3 studies involving 303 patients was -0.27(95% CI:-0.64 - 0.11), p=0.16 (I2:89%).There was no difference between O-TLIF and MIS-TLIF. The pooled mean difference for pre and post-operative ODI from 3 studies involving 303 patients was 0.62(95%CI:-3.90 - 5.13), p=0.79 (I2:96%). There was no difference between O-TLIF and MIS-TLIF.

Discussion: MIS-TLIF is superior to O-TLIF in obese patients. Obese patients who underwent O-TLIF are 4 times more likely to have intra-operative dural tear, stayed 1.2 more days in hospital, and had 380mls more blood loss. No difference was found between MIS-TLIF and O-TLIF for wound infection, post-operative VAS and ODI scores. We conclude that MIS-TLIF should be offered to obese patients.