Intervertebral disc degeneration reduces vertebral motion responses

Spine (Phila Pa 1976). 2007 Sep 1;32(19):E544-50. doi: 10.1097/BRS.0b013e318145ac39.

Abstract

Study design: A prospective in vivo experimental animal study.

Objective: To determine the effects of disc degeneration and variable pulse duration mechanical excitation on dorsoventral lumbar kinematic responses.

Summary of background data: In vitro and in vivo biomechanical studies have examined spine kinematics during posteroanterior loading mimicking spinal manipulation therapy (SMT), but few (if any) studies have quantified SMT loading-induced spinal motion responses in the degenerated intervertebral disc.

Methods: Fifteen sheep underwent a survival surgical procedure resulting in chronic disc degeneration of the L1-L2 disc. Ten age- and weight-matched animals served as controls. Uniform pulse dorsoventral mechanical forces (80 N) were applied to the L3 spinous processes using 10-, 100-, and 200-ms duration pulses mimicking SMT. L3 displacement and L2-L1 acceleration in the control group were compared with the degenerated disc group.

Results: Dorsoventral displacements increased significantly (fivefold, P < 0.001) with increasing mechanical excitation pulse duration (control and degenerated disc groups). Displacements and L2-L1 acceleration transfer were significantly reduced (approximately 19% and approximately 50%, respectively) in the degenerated disc group compared with control (100- and 200-ms pulse duration protocols, P < 0.01).

Conclusion: Dorsoventral vertebral motions are dependent on mechanical excitation pulse duration and are significantly reduced in animals with degenerated discs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Models, Animal
  • Intervertebral Disc / diagnostic imaging
  • Intervertebral Disc / physiopathology*
  • Lumbar Vertebrae / diagnostic imaging
  • Lumbar Vertebrae / physiopathology*
  • Manipulation, Spinal*
  • Motion*
  • Radiography
  • Severity of Illness Index
  • Sheep
  • Spinal Diseases / diagnostic imaging
  • Spinal Diseases / physiopathology*
  • Spinal Diseases / therapy
  • Stress, Mechanical
  • Time Factors