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Chulalongkorn Medical Journal

Abstract

Background: Adjacent syndrome is a widely concerned adverse outcome after spinal fusion. Interspinous distraction device (IDD) has become an interesting device and seems to be the solution by theoretically controlling loads to adjacent levels. Objective: To analyze the effects of a modified U-shape IDD on the intervertebral disc (IVD) pressure atm instrumented and adjacent level of a lumbar spine model. Methods: Three cadaveric specimens using lumbar vertebrae level 1 - 5 (L1 - L5) spines were loaded in neutral, flexion and extension. Needle pressure sensor was applied to measure IVD pressure at anterior annulus, nucleus pulposus, and posterior annulus of the IVD at L2 - L3, L3 - L4, and L4 - L5. Cadaveric specimens were tested in 4 consecutive sequences including intact specimen, bilateral facetectomy at L3 - L4, insertion of the modified U-shape IDD at L3 - L4, and pedicle screw fixation at L3 - L4, respectively. Results: By using the modified U-shape IDD, the IVD pressures at L2 – L3 were decreased when compared to both destabilized specimen and specimen with pedicle screw fixation especially IVD pressure at nucleus pulposus in flexion position of cadaveric specimen (P = 0.021). However, the IVD pressures at L3 – L4 and L4 – L5 were randomly affected by this device. Conclusions: The modified U-shape IDD provides support for the upper adjacent IVD pressures but the effect for the instrumented and lower adjacent level are still unremarkable.

Publisher

Faculty of Medicine, Chulalongkorn University

DOI

10.14456/clmj.2021.17

First Page

121

Last Page

127

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