Biomechanical study of proximal adjacent segment degeneration after posterior lumbar interbody fusion and fixation: a finite element analysis

Journal of Orthopaedic Surgery and Research

Shuai Jiang¹  Weishi Li¹ 

[1] 0000 0004 0605 3760, grid.411642.4, Department of Orthopaedics, Peking University Third Hospital, No. 49 North Huayuan Road, Haidian District, 100191, Beijing, China;

关键词: Adjacent segment degeneration;    Finite element analysis;    Range of motion;    Intervertebral disc pressure;   

DOI  :  10.1186/s13018-019-1150-9

来源: publisher

【 摘 要 】

PurposeTo investigate the biomechanical changes in the proximal adjacent segment with different grades of degeneration after posterior lumbar interbody fusion (PLIF).MethodsWe created three finite element models of the L3–5 with different grades of degeneration (healthy, mild, and moderate) at the L3–4 that were developed by changing the disc height and material properties of the nucleus pulposus. The L4–5 were operated by interbody fusion cages and pedicle screws. All models were loaded with a compressive pre-load of 400 N and a bending moment of 10 N a in three planes to recreate flexion, extension, lateral bending, and axial rotation. The range of motion (ROM), nucleus pressure, and annulus fibrosus pressure of the L3–4 were evaluated.ResultsThe ROM, nucleus pressure, and annulus fibrosus pressure increased at the L3–4 after PLIF. As the degeneration progressed in the L3–4, the ROM of the L3–4 decreased while the nucleus pressure and annulus fibrosus pressure increased.ConclusionsAdjacent segment degeneration (ASD) may be related to the ROM and intradiscal pressure after PLIF. However, as the degeneration of the proximal adjacent segment increases, the ROM in the proximal adjacent segment gradually decreases, but the pressure on the nucleus pulposus and annulus fibrosus gradually increases. Degeneration of the proximal adjacent segment before operation is a risk factor for the ASD after PLIF.

【 授权许可】

CC BY