J Neurol Neurosurg Spine | Volume 4, Issue 1 | Research Article | Open Access

Static versus Expandable Interbody Spacers: Final 2-Year Clinical and Radiographic Results

Richard Frisch1*, Torrey Shirk2 and Charles Ledoniob2

1Southeastern Spine Institute, USA 2Musculoskeletal Education and Research Center (MERC), USA

*Correspondance to: Richard Frisch 

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Background: Lateral Lumbar Interbody Fusion (LLIF) procedures using large interbody static spacers may require excessive trialing and forceful impaction, leading to iatrogenic endplate disruption, excessive neural retraction, and implant subsidence. The in situ expansion capability offered by expandable interbody spacers facilitates insertion to help reduce endplate damage and optimize endplate contact. Objective: This study reported radiographic and clinical outcomes of static and expandable interbody spacers following LLIF. Methods: This study included 64 patients with degenerative disc disease who underwent LLIF at 1 to 2 contiguous level(s) using a polyether-ether-ketone static or titanium expandable intervertebral spacer. Half (32) of the patients were treated with static spacers, and half (32) with expandable spacers. All spacers were supplemented by posterior screw and rod stabilization. Results: Mean VAS pain and ODI, and RAND 36 scores improved significantly (p<0.05) at 24-month follow-up. Patients treated with expandable implants were found to have significantly lower scores for VAS back and leg pain and ODI at 24-month follow-up compared to static implants. Intervertebral disc height increased significantly (p<0.05) from baseline for expandable and static groups at each follow-up through 24 months. At 12-month follow-up the static group had significantly higher subsidence rates. No new subsidence cases developed between 12-month and 24-month follow-up. Conclusion: In this cohort, clinical use of expandable interbody spacers resulted in better outcomes through 24-month follow-up compared to static interbody spacers, with the expandable group showing significantly greater improvements in pain and disability than the static group at 24 months.


Frisch R, Shirk T, Ledoniob C. Static versus Expandable Interbody Spacers: Final 2-Year Clinical and Radiographic Results. J Clin Neurol Neurosurg Spine. 2019; 4(1): 1018..

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