2023, Vol. 27 ›› Issue (13): 2011-2015

Finite element comparative analysis on treatment of lumbar disc herniation by the oblique wrench method and the combination of traction, pressing, and oblique pulling

Lu Yu1, 2, Xiang Junyi1, 2, Yin Benjing1, 2, Bi Heng1, 2, Li Jizheng1, 2, Wei Jiajia1, 2, Jia Tao1, 2, Li Pengfei1, 2, Li Jubao1, 2   

Abstract: BACKGROUND: Traditional Chinese medicine manipulation for the treatment of lumbar intervertebral disc herniation has a long history, wide application and remarkable curative effect, and is favored by the majority of patients. However, there are various specific methods of use, and the advantages and disadvantages of various methods and the differences in efficacy are not yet clear.   
OBJECTIVE: To compare the biomechanical mechanism and efficacy of the oblique wrench method and the combined manipulation of traction, pressing, and oblique pulling in the treatment of lumbar disc herniation using the three-dimensional finite element analysis.
METHODS:   Based on the CT images of the lumbar spine in patients with lumbar disc herniation, three-dimensional finite element models of the L4-5 motor function unit in patients with lumbar disc herniation were established. The oblique wrench method and the combination of oblique wrench method and the combined manipulation of traction, pressing, and oblique pulling were simulated to analyze the influence of different methods on the stress, strain and displacement of each tissue of the lumbar motor unit, so as to compare the mechanical mechanism and evaluate the difference in efficacy.   
RESULTS AND CONCLUSION: (1) The three-dimensional finite element model of the L4-5 segment was successfully established and its effectiveness was verified. (2) When the oblique wrench method was applied, the stress in the front of the intervertebral disc was largest, and the stress in the protruding position was smallest; the strain direction of the annulus fibrosus in the posterior right side was rightward and backward, and the strain direction of the annulus fibrosus in the posterior part of the left (protruding side) was rightward and anterior. The intervertebral disc moved forward and rightward, the left nerve root moved forward, and the right nerve root moved backward. (3) When the combination of traction, pressing, and oblique pulling was applied, the stress distribution, strain trend and displacement direction were similar to those of the oblique wrench method, but the stress, strain and displacement were larger. (4) It is indicated that the oblique wrench method and the combination of traction, pressing, and oblique pulling have a good effect on lumbar disc herniation patients, which can shrink and retract the herniated intervertebral disc, increase the distance between the disc and the nerve root, relieve the symptoms of nerve compression. The combined manipulation is more effective.
Key words: lumbar disc herniation, three-dimensional finite element, oblique wrench method, combination of traction, pressing, and oblique pulling, biomechanics