Effects of motion segment level, Pfirrmann intervertebral disc degeneration grade and gender on lumbar spine kinematics

MG Muriuki, RM Havey, LI Voronov… - Journal of …, 2016 - Wiley Online Library
MG Muriuki, RM Havey, LI Voronov, G Carandang, MR Zindrick, MA Lorenz, L Lomasney…
Journal of Orthopaedic Research, 2016Wiley Online Library
ABSTRACT MRI allows non‐invasive assessment of intervertebral disc degeneration with
the added clinical benefit of using non‐ionizing radiation. What has remained unclear is the
relationship between assessed disc degeneration and lumbar spine kinematics. Kinematic
outcomes of 54 multi‐segment (L1‐Sacrum) lumbar spine specimens were calculated to
discover if such an underlying relationship exists with degeneration assessed using the
Pfirrmann grading system. Further analyses were also conducted to determine if kinematic …
Abstract
MRI allows non‐invasive assessment of intervertebral disc degeneration with the added clinical benefit of using non‐ionizing radiation. What has remained unclear is the relationship between assessed disc degeneration and lumbar spine kinematics. Kinematic outcomes of 54 multi‐segment (L1‐Sacrum) lumbar spine specimens were calculated to discover if such an underlying relationship exists with degeneration assessed using the Pfirrmann grading system. Further analyses were also conducted to determine if kinematic outcomes were affected by motion segment level, gender or applied compressive preload. Range of motion, hysteresis, high flexibility zone size and rotational stiffness in flexion‐extension, lateral bending and axial rotation were the kinematic outcomes. Caudal intervertebral discs in our study sample were more degenerative than cranial discs. L5‐S1 discs had the largest flexion‐extension range of motion (p < 0.005) and L1‐L2 discs the lowest flexion high flexibility zone size (p < 0.013). No other strict cranial‐caudal differences in kinematic outcomes were found. Low flexibility zone rotational stiffness increased with disc degeneration grade in extension, lateral bending and axial rotation (p < 0.001). Trends towards higher hysteresis and lower range of motion with increased degeneration were observed in flexion‐extension and lateral bending. Applied compressive preload increased flexion‐extension hysteresis and augmented the effect of degeneration on hysteresis (p < 0.0005). Female specimens had about one degree larger range of motion in all rotational modes, and higher flexion extension hysteresis (p = 0.016). These results suggest that gender differences exist in lumbar spine kinematics. Additionally high disc loads, applied compressive preload or applied moment, are needed to kinematically distinguish discs with different levels of degeneration. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1389–1398, 2016.
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