Comparative Effectiveness of Minimally Invasive Bilateral Transforaminal Lumbar Interbody Fusions Using 2 Intervertebral Titanium Expandable Versus Peek Static Interbody Spacers: 1-year Radiographic Outcomes

Presented at SMISS Annual Forum 2019
By Steven Schopler MD
With Nickul Jain MD, Emily Fish PA-C, Jessica Riggleman BS, Samantha Greeley BS, Charles Ledonio MD, CCRP,

Disclosures: Steven Schopler MD A; Globus Medical. B; Organogenesis, Arthrex. F; RTI Surgical. Nickul Jain MD A; Globus Medical. B; Spineart., Emily Fish PA-C None, Jessica Riggleman BS D; Globus Medical. E; Globus Medical., Samantha Greeley BS D; Globus Medical. E; Globus Medical., Charles Ledonio MD, CCRP E; Globus Medical,


Transforaminal lumbar interbody fusion (TLIF) using static spacers is a recognized procedure for the treatment of degenerative disc disease (DDD) with or without spondylolisthesis, which is commonly performed either as an open or minimally invasive procedure. The advantage of minimally invasive surgery (MIS) has been reported to have less blood loss, minimal tissue disruption, and earlier recovery time. MIS bilateral TLIF with 2 interbody spacers has been developed to improve restoration of sagittal alignment, which is essential for better patient outcomes. As with any new technique, clinical outcome studies are essential to determine its efficacy.


This study compares the radiographic outcomes of patients who underwent bilateral TLIF with 2 intervertebral interbody expandable or 2 static spacers.


This is a single-surgeon, retrospective, Institutional Review Board-exempt chart review of 73 consecutive patients with DDD who underwent single-level bilateral MIS-TLIF using either 2 PEEK static (38) or 2 titanium expandable interbody spacers (35) within the same vertebral level. Mean differences of radiographic outcomes were compared from preoperative to postoperative 12-month follow-up. Statistical results were significant when p<0.05.


Seventy-three consecutive patients were evaluated with an average age of 56.6±14.5 years; 50.7% (37/73) were female. Of the 73 patients, 31.5% had spacers placed at L4-L5 (23/73) and 64.4% (47/73) at L5-S1. Mean improvement of anterior disc height from preoperative to 12 months was higher in the expandable group [93.2% (6.1±5.3mm)] than in the static group [54.7% (4.0±2.7mm)] (p>0.05). For posterior disc height, mean improvement from preoperative to 12 months was significantly higher in the expandable group [234.8% (7.4±2.6)] than in the static group [77.7% (3.7±2.6)] (p<0.05). There was no significant difference in lumbar lordosis between the two groups (p>0.05).


This study showed significant positive radiographic outcomes for patients who underwent MIS bilateral TLIF using 2 intervertebral titanium expandable interbody spacers based on significant changes in disc height compared to PEEK static interbody spacers; with the results sustained up to 12-month follow-up. Further studies with larger sample sizes and longer follow-up are needed to determine the durability of this new procedure.

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