Biomechanical Evaluation of Spinal Column after Percutaneous Cement Discoplasty: A Finite Element Analysis

• Published in: Orthopaedic surgery Vol. 14; no. 8; pp. 1853 - 1863
• Main Authors: Li, Shuang, Xu, Baoshan, Liu, Yancheng, Zhang, Jingyu, Xu, Guijun, Shao, Pengfei, Li, Xiaoye, Hu, Yongcheng, Ma, Xinlong
• Format: Journal Article
• Language: English
• Published: Melbourne John Wiley & Sons Australia, Ltd 01.08.2022; John Wiley & Sons, Inc; Wiley
• Subjects: Biomechanical; Biomechanics; Bone cement; Finite element analysis; Ligaments; Lumbar spinal stenosis; Older people; Percutaneous cement discoplasty; PMMA; Polymethyl methacrylate; Range of motion; Sliding friction; Software; Spinal stenosis; Surgery; Test systems; Vertebrae; United States > US
• ISSN: 1757-7853; 1757-7861
• DOI: 10.1111/os.13314

Objective To compare the biomechanical properties of percutaneous cement discoplasty (PCD) in the spinal column between different implant‐endplate friction. Methods A validated L3‐Scarumfinite element (FE) model was modified for simulation. In the PCD model, the L4/5 level was modified based on model 1 (M1) and model 2 (M2). In M1, the interaction between bone cement and endplate was defined as face‐to‐face contact with a friction coefficient of 0.3; in M2, the contact was defined as a Tie constraint. 7.5 N m moments of four physiological motions and axial load of 15, 100 and 400 N preload were imposed at the top of L3. The range of motion (ROM) and interface stress analysis of endplates, annulus fibrosus and bone cement of the operated level were calculated for comparisons among the three models. Results The ROM of M1 and M2 increased when compared with the intact model during flexion (FL) (17.5% vs 10.0%), extension (EX) (8.8% vs −8.8%), left bending (LB) (19.0% vs −17.2%) and left axial rotation (LR) (34.6% vs −3.8%). The stress of annulus fibrosus in M1 and M2 decreased in FL (−48.4% vs −57.5%), EX (−25.7% vs −14.7%), LB (−47.5% vs −52.4%), LR (−61.4% vs −68.7%) and axis loading of 100 N (−41.5% vs −15.3%), and 400 N (−27.9% vs −27.3%). The stress of upper endplate of M1 and M2 increased in FL (24.6% vs 24.7%), LB (82.2% vs 89.5%), LR (119% vs 62.4%) and axis loading of 100 N (64.6% vs 45.5%), and 400 N (58.2% vs 24.3%), but was similar in EX (2.9% vs 0.3%). The stress of lower endplate of M1 and M2 increased in FL (170.9% vs 175.0%), EX (180.8% vs 207.7%), LB (302.6% vs 274.7%), LR (332.4% vs 132.8%) and axis loading of 100 N (350.7% vs 168.6%), and 400 N (165.2% vs 106.7%). Conclusion Percutaneous cement discoplasty procedure could make effect on the mobility or stiffness. The fusion of bone cement and endplate might have more biomechanical advantages, including of the decreasing rate of implant subsidence and dislocation, and the increase spine stability. Finite element (FE) models of L3‐S used in this article: (A,B) normal model, (C) model 1, the interaction between bone cement and endplate was defined as face‐to‐face contact; (D) model 2, the interaction was defined as a Tie constraint. 15 N m moments of four physiological motions and axial load of 100 and 400 N preload were imposed at the top of L3. The range of motion (ROM) and interface stress analysis of endplates, annulus fibrous and bone cement for the operated level were calculated for comparisons among the three models. After PCD progress the spine stability was same as normal spine; the implant of bone cement can increase the stress of adjacent vertebrae especially in the upper and lower endplate, and it can be reduced by the way of fusion between bone cement and endplate or fusion.