RT Journal Article SR Electronic T1 Restoration of Spinal Alignment and Disk Mechanics following Polyetheretherketone Wafer Kyphoplasty with StaXx FX JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 1295 OP 1300 DO 10.3174/ajnr.A2484 VO 32 IS 7 A1 S.M. Renner A1 P.P. Tsitsopoulos A1 A.T. Dimitriadis A1 L.I. Voronov A1 R.M. Havey A1 G. Carandang A1 B. McIntosh A1 C. Carson A1 D. Ty A1 J.G. Ringelstein A1 A.G. Patwardhan YR 2011 UL http://www.ajnr.org/content/32/7/1295.abstract AB BACKGROUND AND PURPOSE: EPFs sustained during VCFs degrade the disk's ability to develop IDP under load. This inability to develop pressure in combination with residual kyphotic deformity increases the risk for adjacent vertebral fractures. We tested the hypothesis that StaXx FX reduces kyphosis and endplate deformity following vertebral compression fracture, restoring disk mechanics. MATERIALS AND METHODS: Eight thoracolumbar, 5-vertebrae segments were tested. A void was selectively created in the middle vertebra. The specimens were compressed until EPF and to a grade I–II VCF. PEEK wafer kyphoplasty was then performed. The specimens were then tested in flexion-extension (±6 Nm) under 400-N preload intact, after EPF, VCF, and kyphoplasty. Endplate deformity, kyphosis, and IDP adjacent to the fractured body were measured. RESULTS: Vertebral body height at the point of maximal endplate deformity decreased after EPF and VCF and was partially corrected after StaXx FX, remaining less than intact (P = .047). Anterior vertebral height decreased after VCF (P = .002) and was partially restored with StaXx FX, remaining less than intact (P = .015). Vertebral kyphosis increased after VCF (P < .001) and reduced after StaXx FX, remaining greater than intact (P = .03). EPF reduced IDP in the affected disk in compression-flexion loading (P < .001), which was restored after StaXx FX (P = 1.0). IDP in the unaffected disk did not change during testing (P > .3). CONCLUSIONS: StaXx FX reduced endplate deformity and kyphosis, and significantly increased anterior height following VCF. Although height and kyphosis were not fully corrected, the disk's ability to pressurize under load was restored. EPFendplate fractureIDPintradiskal pressurePEEKpolyetherether-ketoneVCFvertebral compression fracture