椎间盘部分切除对腰椎运动特性影响的生物力学研究

Biomechanical Study of Effects of Partial Discectomy on Kinematic Behaviors of Lumbar Spine

This paper is concerned with the biomechanical effects of partial discectomy on the lumbar spine. With application of the measurement and kinematic analysis method for three-dimensional(3-D) motions, the 3-D motions of eight fresh cadaver lumbar motion segments(LMS) are investigated through eight clinically relevant loads for both before and after partial discectomy. Experiment finds, after partial discectomy, that the magnitudes of main motions of LMS significantly increase for all eight loads, and that the apparent asymmetric motions occur. These show that the intervertebral discs play an important role in maintaining the normal kinematic behaviors of the lumbar spine and the partial discectomy will cause instability of the lumbar spine. It is considered that the decrease of disc stiffnesses after partial discectomy is the basic cause to generate the instability of the lumbar spine, and this will result in a load increase on the posterior structures of the lumbar spine, which may be one of the most important reasons for persistent symptoms of low-back pain after partial discectomy.