2023, Vol. 27 ›› Issue (27): 4271-4276

Finite element analysis of oblique-pulling manipulation in the treatment of lumbar synovial incarceration

Lu Yu1, 2, Xiang Junyi1, 2, Yin Benjing1, 2, Bao Chaoyu1, 2, Bi Heng1, 2, Li Jizheng1, 2, Chen Shuai1, 2, He Guangxiong1, 2, Li Jubao1, 2   

Abstract: BACKGROUND: Oblique-pulling manipulation has a reliable curative effect on lumbar synovial incarceration, and it has been widely used in the clinic. However, the related research on the treatment of lumbar synovial incarceration by oblique-pulling manipulation is still relatively lacking.  
OBJECTIVE: To analyze the biomechanical mechanism and effect of oblique-pulling manipulation in the treatment of lumbar synovial incarceration by three-dimensional finite element method, and provide theoretical basis for the treatment of lumbar synovial incarceration by oblique-pulling manipulation.
METHODS: The CT data of patients with lumbar synovial incarceration were collected, and the three-dimensional finite element model of L4-5 motor unit of spine was established by using Mimics and Ansys software. The operation process of the oblique-pulling manipulation in the left lateral position was simulated, and the influence of the oblique-pulling manipulation on the biomechanics, morphological changes and facet joint contact area of each tissue structure of L4-5 segment of lumbar spine was analyzed.  
RESULTS AND CONCLUSION: (1) A three-dimensional finite element model of lumbar L4-5 segment was established, and the validity of the model was verified. (2) Before and after the oblique-pulling manipulation was applied, the stress of left facet joint cartilage increased from 2.959 MPa to 14.35 MPa; the strain increased from 0.078 34 to 0.345 1, and the contact area of articular cartilage increased from 20.806 2 mm2 to 94.872 7 mm2. On the other hand, the stress of the right facet joint cartilage decreased from 3.127 MPa to 0 MPa; the strain decreased from 0.081 96 to 0, and the articular cartilage contact surface decreased from 16.705 3 mm2 to 0 mm2 on the right. (3) It is concluded that oblique-pulling manipulation has a good effect on patients with lumbar synovial incarceration. It can change the stress and strain of the articular process and the contact area of the upper and lower articular processes, fully release and open the articular process, and achieve the therapeutic purpose of reducing the articular process and relieving the synovial incarceration.

Key words: lumbar facet joint, three-dimensional finite element, synovial incarceration, oblique-pulling manipulation, biomechanics