Patient Outcomes Following Posterior Lumbar Interbody Fusion for Adjacent Segment Disease Using VariLift® as a Standalone Expandable Interbody Device

Background: Adjacent segment disease (ASD) is a notable complication following lumbar fusion. Clinicians use various surgical techniques to correct progression of spine deterioration and reduce the risk of continued ASD. The aim of this retrospective case series is to describe patient outcomes following posterior lumbar interbody fusion (PLIF) using the VariLift® standalone expandable interbody device (without supplemental fixation) for the treatment of ASD. Methods: Nine consecutive patients who underwent a single-level PLIF for the treatment of ASD were reviewed. Outcome measures included patient demographics, comorbidities, surgical complications, time to fusion, Visual Analog Scales for Pain (VAS), and overall patient-reported recovery of symptoms. Nine patients (8 males, 1 female) with a mean age of 62.3 (42 to 72) years underwent a single-level procedure. The standalone VariLift expandable interbody fusion system was used in all nine (9) sequential patients, regardless of the type of fusion/fixation instrumentation previously used. Surgical technique consisted of discectomy and generous bilateral laminotomies with medial facetectomies preserving midline ligamentous structures. Results: Radiographic ASD was confirmed in all cases. Each patient had a history of a lumbar fusion. Preoperatively, 89% of patients reported 9-10 VAS back pain levels. All patients experienced symptomatic improvement. By 12 months postoperatively, average VAS back pain score was 2, a significant improvement from baseline (p < 0.05). Solid interbody fusion without implant failure was observed in all cases with averaged time to fusion at 346 days (min = 181 days). Conclusions/Level of Evidence: Posterior lumbar interbody fusion using the VariLift device to treat symptomatic ASD offers significant clinical success and solid fusion rates without the need for supplemental fixation or extension of previous supplemental fixation. Level of evidence IV. Clinical Relevance: This stand-alone expandable fusion device produced high fusion rates and symptomatic improvement in a sample of patients with severe back pain and ASD.