Minimally Invasive TLIF With Expandable Articulating Interbody Spacers Significantly Improves Radiographic Outcomes Compared to Static Interbody Spacers

Presented at SMISS Annual Forum 2019
By Anthony Russo MD
With Steven Schopler MD, Katelyn Stetzner FNP-C, Samantha Greeley BS, Torrey Shirk BA, Charles Ledonio MD, CCRP,

Disclosures: Anthony Russo MD A; Globus Medical, Orthofix. B; Globus Medical, Orthofix, SurGenTec. F; Globus Medical. Steven Schopler MD A; Globus Medical. B; Organogenesis, Arthrex. F; RTI Surgical., Katelyn Stetzner FNP-C None, Samantha Greeley BS E; Globus Medical., Torrey Shirk BA E; Globus Medical, Charles Ledonio MD, CCRP E; Globus Medical,


The goal of minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) is to restore and maintain disc height and lordosis until arthrodesis occurs while minimizing muscle disruption and improving recovery time. The radiographic outcomes of an articulating expandable spacer in MIS TLIFs have yet to be thoroughly investigated in comparison to more traditionally used static spacers.


The purpose of this study is to compare the radiographic outcomes of an articulating expandable spacer to a static spacer used in MIS-TLIF.


This was a multi-site, multi-surgeon, retrospective clinical study from a prospectively collected database with Institutional Review Board exemption. It included 48 patients with a diagnosis of degenerative disc disease at one level from L3 to S1 with or without Grade 1 spondylolisthesis who underwent MIS TLIF using either an articulating expandable or static interbody spacer for the treatment of low back pain and/or radiculopathy. Twenty-seven patients were in the articulating expandable interbody spacer group, while 21 patients were in the static interbody spacer group. Radiographic records were assessed for disc height, neuroforaminal height and lordosis at baseline, 3 months, 6 months, and final follow-up.


The articulating expandable spacer group displayed significantly greater improvement in anterior disc height, posterior disc height, and neuroforaminal height from baseline compared to the static spacer group. Increases in intervertebral angle from baseline were significantly greater in the expandable group than the static group at 3 months, 6 months, and final follow-up by averages of 2.5°, 2.8°, and 3.1°, respectively (p<0.05). The articulating expandable spacer group resulted in a significantly greater improvement in lumbar lordosis from baseline to 3 months and 6 months than the static spacer group by 4.4° and 4.0°, respectively (p<0.05).


MIS TLIF with articulating expandable interbody spacers provides significant restoration and maintenance of disc height, neuroforaminal height, and lordosis compared to static spacers in this comparative cohort. Long-term clinical outcomes are needed to correlate with these radiographic improvements.

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