Abstract
This chapter describes the effects of a spinal fixation screw on trabecular structural changes in a vertebral body, predicted by a three-dimensional simulation of trabecular remodeling. The entire vertebral body with a fixation screw and bone-screw interface were modeled using voxel finite elements. In the vertebral body, the implantation of the fixation screw caused a change in the mechanical environment of the cancellous bone, leading to trabecular structural changes at the cancellous bone level. The effects of the screw on the trabecular orientation were stronger in the regions above and below the screw compared to those in front of the screw. In the proximity of the bone-screw interface, the trabecular structural changes depended on the direction of the load applied to the screw. The bone resorption, predicted in the pull-out loading, is a candidate cause of screw loosening. The results indicate that the effects of implanted screws on trabecular structural changes are more important for long-term fixation.
This Chapter was adapted from Tsubota et al. (2003) with permission from Springer.
References
An YH (1999) Mechanical properties of bone. In: An H, Draughn RA (eds) Mechanical testing of bone and the bone-implant Interface. CRC, Boca Raton
Beuf O, Newitt DC, Mosekilde L, Majumdar S (2001) Trabecular structure assessment in lumbar vertebrae specimens using quantitative magnetic resonance imaging and relationship with mechanical competence. J Bone Miner Res 16(8):1511–1519. https://doi.org/10.1359/jbmr.2001.16.8.1511
Cowin SC (1985) The relationship between the elasticity tensor and the fabric tensor. Mech Mater 4(2):137–147. https://doi.org/10.1016/0167-6636(85)90012-2
Dalenberg DD, Asher MA, Robinson RG, Jayaraman G (1993) The effect of a stiff spinal implant and its loosening on bone mineral content in canines. Spine (Phila Pa 1976) 18(13):1862–1866
Doblare M, Garcia JM (2001) Application of an anisotropic bone-remodelling model based on a damage-repair theory to the analysis of the proximal femur before and after total hip replacement. J Biomech 34(9):1157–1170
Goel VK, Ramirez SA, Kong W, Gilbertson LG (1995) Cancellous bone Young’s modulus variation within the vertebral body of a ligamentous lumbar spine–application of bone adaptive remodeling concepts. J Biomech Eng 117(3):266–271
Guldberg RE, Richards M, Caldwell NJ, Kuelske CL, Goldstein SA (1997) Trabecular bone adaptation to variations in porous-coated implant topology. J Biomech 30(2):147–153
Hasegawa M, Adachi T, Takano-Yamamoto T (2016) Computer simulation of orthodontic tooth movement using CT image-based voxel finite element models with the level set method. Comput Methods Biomech Biomed Eng 19(5):474–483. https://doi.org/10.1080/10255842.2015.1042463
Hughes TJR, Ferencz RM, Hallquist JO (1987) Large-scale vectorized implicit calculations in solid mechanics on a Cray X-Mp/48 utilizing Ebe preconditioned conjugate gradients. Comput Method Appl M 61(2):215–248
Huiskes R, Hollister SJ (1993) From structure to process, from organ to cell: recent developments of FE-analysis in orthopaedic biomechanics. J Biomech Eng 115(4B):520–527
Huiskes R, Weinans H, Grootenboer HJ, Dalstra M, Fudala B, Slooff TJ (1987) Adaptive bone-remodeling theory applied to prosthetic-design analysis. J Biomech 20(11–12):1135–1150
Kuiper JH, Huiskes R (1997) Mathematical optimization of elastic properties: application to cementless hip stem design. J Biomech Eng 119(2):166–174
Lu WW, Zhu Q, Holmes AD, Luk KD, Zhong S, Leong JC (2000) Loosening of sacral screw fixation under in vitro fatigue loading. J Orthop Res 18(5):808–814. https://doi.org/10.1002/jor.1100180519
Luo G, Sadegh AM, Alexander H, Jaffe W, Scott D, Cowin SC (1999) The effect of surface roughness on the stress adaptation of trabecular architecture around a cylindrical implant. J Biomech 32(3):275–284
McCullen GM, Garfin SR (2000) Spine update: cervical spine internal fixation using screw and screw-plate constructs. Spine (Phila Pa 1976) 25(5):643–652
Mosekilde L (1990) Age-related loss of vertebral trabecular bone mass and structure–biomechanical consequences. In: Mow VC, Ratcliffe A, Woo SL-Y (eds) Biomechanics of Diarthrodial Joints II. Springer, New York
Orr TE, Beaupre GS, Carter DR, Schurman DJ (1990) Computer predictions of bone remodeling around porous-coated implants. J Arthroplast 5(3):191–200
Prendergast PJ (1997) Finite element models in tissue mechanics and orthopaedic implant design. Clin Biomech (Bristol, Avon) 12(6):343–366
Sadegh AM, Luo GM, Cowin SC (1993) Bone ingrowth: an application of the boundary element method to bone remodeling at the implant interface. J Biomech 26(2):167–182
Stanford CM, Brand RA (1999) Toward an understanding of implant occlusion and strain adaptive bone modeling and remodeling. J Prosthet Dent 81(5):553–561
Tomita K, Kawahara N, Baba H, Tsuchiya H, Fujita T, Toribatake Y (1997) Total en bloc spondylectomy. A new surgical technique for primary malignant vertebral tumors. Spine (Phila Pa 1976) 22(3):324–333
Tsubota K, Adachi T, Tomita Y (2003) Effects of a fixation screw on trabecular structural changes in a vertebral body predicted by remodeling simulation. Ann Biomed Eng 31(6):733–740. https://doi.org/10.1114/1.1574028
Vaccaro AR, Garfin SR (1995) Internal fixation (pedicle screw fixation) for fusions of the lumbar spine. Spine (Phila Pa 1976) 20(24 Suppl):157S–165S
van Rietbergen B, Huiskes R, Weinans H, Sumner DR, Turner TM, Galante JO (1993) ESB Research Award 1992. The mechanism of bone remodeling and resorption around press-fitted THA stems. J Biomech 26(4–5):369–382
van Rietbergen B, Weinans H, Huiskes R, Odgaard A (1995) A new method to determine trabecular bone elastic properties and loading using micromechanical finite-element models. J Biomech 28(1):69–81
van Rietbergen B, Majumdar S, Pistoia W, Newitt DC, Kothari M, Laib A, Ruegsegger P (1998) Assessment of cancellous bone mechanical properties from micro-FE models based on micro-CT, pQCT and MR images. Technol Health Care 6(5–6):413–420
Zankl M, Wittmann A (2001) The adult male voxel model “golem” segmented from whole-body CT patient data. Radiat Environ Biophys 40(2):153–162
Zioupos P, Smith CW, An YH (1999) Factors affecting mechanical properties of bone. In: An H, Draughn RA (eds) Mechanical testing of bone and the bone-implant Interface. CRC, Boca Raton
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Appendix: Cancellous Bone Remodeling in a Normal Vertebral Body
Appendix: Cancellous Bone Remodeling in a Normal Vertebral Body
In the case of a normal vertebral body, the trabecular surface remodeling simulation was conducted using a half-voxel model of a human L3 vertebral body (model N), as shown in Fig. 14.7a. The cortical shape of the model in the midsagittal plane was determined based on the photograph of the cross-section of the human vertebral body, available in the literature (Mosekilde 1990), as shown in Fig. 14.7b. Rotating the midsagittal section with regard to the central longitudinal axis, the three-dimensional shape of the cortical bone was constructed as an axisymmetric shell. The vertebral body diameter was 50 mm in the bilateral and anteroposterior directions, and its height was 25 mm in the axial direction.
The cancellous bone part was filled with toroidal trabeculae to a bone volume fraction of BVF = 0.46 and the degree of structural anisotropy of H 1/H 3 = 1.04, in which H 1 and H 3 were the maximum and minimum principal values of the fabric ellipsoid (Cowin 1985), respectively. As indicated by the fabric ellipsoid and by the image of the X 2 − X 3 cross-section in Fig. 14.7a, the trabecular structure was initially isotropic. The number of voxels for describing the bone was approximately 0.85 million, and the volume of each element was 250 μm × 250 μm × 250 μm. The bone part was assumed to be homogeneous and isotropic, and Young’s modulus E and Poisson’s ratio ν were set as E b = 20 GPa and ν b = 0.3 (An 1999; Zioupos et al. 1999). As a boundary condition , uniform compressive displacement U 3 was applied to the upper plane at X 3 = 25 mm to apply the total load F 1 = 588 N as a body weight. The lower plane at X 3 = 0 mm was fixed. The model parameters in the remodeling rate equation (Chap. 9) were set constant as threshold values Γ u = 1.0 and Γ l = − 1.25, and the sensing distance was l L = 2.5 mm.
In remodeling simulation, an anisotropic trabecular structure was obtained owing to the trabecular formation and resorption for converging to a local state of uniform stress, as indicated by the image of the X 2 − X 3 cross-section and fabric ellipsoid of the trabecular structure in Fig. 14.8. The angle Θ 3 between the maximum principal direction of the fabric ellipsoid and the X 3 axis was 3∘, consistent with the observation that the trabeculae in the vertebral body are oriented along the axial direction (Mosekilde 1990). The bone volume fraction BVF decreased to 0.37, and the degree of structural anisotropy H 1/H 3 increased to 1.47. The structural parameters BVF and H 1/H 3 obtained in the simulation better captured the experimental observation (Beuf et al. 2001) than the parameters of the initial isotropic structure.
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Kameo, Y., Tsubota, Ki., Adachi, T. (2018). Trabecular Structural Changes in a Vertebral Body with a Fixation Screw. In: Bone Adaptation. Frontiers of Biomechanics, vol 2. Springer, Tokyo. https://doi.org/10.1007/978-4-431-56514-7_14
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