Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2015 May 26:8:219-30.
doi: 10.2147/MDER.S84715. eCollection 2015.

The VariLift(®) Interbody Fusion System: expandable, standalone interbody fusion

Erik Emstad  1 , Diana Cardenas Del Monaco  1 , Louis C Fielding  2 , Jon E Block  2
Affiliations
Review

The VariLift(®) Interbody Fusion System: expandable, standalone interbody fusion

Erik Emstad et al. Med Devices (Auckl). .

Abstract

Intervertebral fusion cages have been in clinical use since the 1990s. Cages offer the benefits of bone graft containment, restored intervertebral and foraminal height, and a more repeatable, stable procedure compared to interbody fusion with graft material alone. Due to concerns regarding postoperative stability, loss of lordosis, and subsidence or migration of the implant, interbody cages are commonly used with supplemental fixation such as pedicle screw systems or anterior plates. While providing additional stability, supplemental fixation techniques increase operative time, exposure, cost, and morbidity. The VariLift(®) Interbody Fusion System (VariLift(®) system) has been developed as a standalone solution to provide the benefits of intervertebral fusion cages without the requirement of supplemental fixation. The VariLift(®) system, FDA-cleared for standalone use in both the cervical and lumbar spine, is implanted in a minimal profile and then expanded in situ to provide segmental stability, restored lordosis, and a large graft chamber. Preclinical testing and analyses have found that the VariLift(®) System is durable, and reduces stresses that may contribute to subsidence and migration of other standalone interbody cages. Fifteen years of clinical development with the VariLift(®) system have demonstrated positive clinical outcomes, continued patient maintenance of segmental stability and lordosis, and no evidence of implant migration. The purpose of this report is to describe the VariLift(®) system, including implant characteristics, principles of operation, indications for use, patient selection criteria, surgical technique, postoperative care, preclinical testing, and clinical experience. The VariLift(®) System represents an improved surgical option for a stable interbody fusion without requiring supplemental fixation.

Keywords: ACDF; PLIF; TLIF; standalone cage.

PubMed Disclaimer

Figures

Figure 1
Figure 1
VariLift®-L (A) and VariLift®-C (B). Abbreviations: VariLift®-L, VariLift® Lumbar Interbody Fusion System; VariLift®-C, VariLift® Cervical Interbody Fusion System.
Figure 2
Figure 2
Posterior lumbar interbody fusion procedure highlights: (A) implant site preparation; (B) sizing; (a) depth collar allows controlled depth of sizing instrument; (b) magnified cross-section view of PLIF sizing instrument; (C) implant insertion and expansion; (a) lateral cross-section; (b) axial cross-section; and (D) bone graft placement, with magnified-oblique view of the expanded cages packed with bone graft (inset). Arrows indicate insertion directions. Abbreviation: PLIF, posterior lumbar interbody fusion.
Figure 3
Figure 3
Transforaminal lumbar interbody fusion procedure highlights: (A) implant site preparation; (B) sizing; (C) implant insertion and expansion; and (D) bone graft placement. Insets illustrate magnified and cross-sectional views.
Figure 4
Figure 4
Cervical procedure highlights: (A) sizing and disk opening preparation with cervical tap; (B) bilateral placement; (C) unilateral placement; (D) implant insertion and expansion; and (E) bone graft placement.
Figure 5
Figure 5
Mechanical test setups for (A) static and dynamic axial compression testing and (B) compressive shear testing.
Figure 6
Figure 6
Finite element model of L4-L5 segment and (A) BAK cage and (B) VariLift®-L. Note: The larger contact area and graft fenestrations of the VariLift®-L compared to the BAK can be clearly appreciated. Abbreviations: BAK, Bagby and Kuslich; VariLift®-L, VariLift® Lumbar Interbody Fusion System.
Figure 7
Figure 7
Twelve-month postoperative radiograph of (A) VariLift®-L at L4-L5 and (B) VariLift®-C at C5-C6. Abbreviations: VariLift®-C, VariLift® Cervical Interbody Fusion System; VariLift®-L, VariLift® Lumbar Interbody Fusion System.
See this image and copyright information in PMC

References

    1. Cloward RB. The treatment of ruptured lumbar intervertebral discs by vertebral body fusion. I. Indications, operative technique, after care. J Neurosurg. 1953;10(2):154–168. - PubMed
    1. Cloward RB. The anterior approach for removal of ruptured cervical disks. J Neurosurg. 1958;15(6):602–617. - PubMed
    1. Bagby GW. Arthrodesis by the distraction-compression method using a stainless steel implant. Orthopedics. 1988;11(6):931–934. - PubMed
    1. FDA . Premarket Approval of BAK™ Interbody Fusion System with Instrumentation. Silver Spring; United States Food and Drug Administration: 1996. p. 950002.
    1. Kuslich SD, Ulstrom CL, Griffith SL, Ahern JW, Dowdle JD. The Bagby and Kuslich method of lumbar interbody fusion. History, techniques, and 2-year follow-up results of a United States prospective, multicenter trial. Spine (Phila Pa 1976) 1998;23(11):1267–1278. discussion 1279. - PubMed

LinkOut - more resources