Reconstruction of bone loading conditions from in vivo strain measurements

Weinans, Harrie; Blankevoort, Leendert

doi:10.1016/0021-9290(94)00122-k

Cited by 14 publications

(12 citation statements)

References 8 publications

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“…The far-field loading configuration was much simpler than that expected in a real, growing human. During gait in humans and other animals, the compressive joint reaction force is exerted over a range of angles, and bending and torsional moments are exerted on the tibia over a range of directions (Lanyon et al 1975;Weinans and Blankevoort 1995;Peterman et al 2001). In the model used in this study, the entire range of loads was pared down to a single axial compressive load and a torsional moment.…”

Section: Discussionmentioning

confidence: 99%

Computational simulation of spontaneous bone straightening in growing children

Carpenter

Carter

2009

Biomech Model Mechanobiol

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Periosteal surface pressures have been shown to inhibit bone formation and induce bone resorption, while tensile strains perpendicular to the periosteal surface have been shown to inhibit bone resorption and induce new bone deposition. A new computational model was developed to incorporate these experimental findings into simulations of spontaneous bone straightening in children with congenital posteromedial bowing of the tibia. Three-dimensional finite element models of the periosteum were used to determine the relationships between the defect angle and the distribution of bone surface pressures and strains due to growth-generated tensile strains in the periosteum. These relationships were incorporated into an iterative simulation to model development of a growing, bowed tibia with an initial defect angle of 27 degrees. When periosteal loads were included in the simulation, the defect angle decreased to 10 degrees after 2 years, and the bone straightened by an age of 25 years. When periosteal loads were not included in the simulation, the defect angle decreased to 23 degrees after 2 years, and a defect angle of 9 degrees remained at an age of 25 years. A "modeling drift" bone apposition/resorption pattern appeared only when periosteal loads were included. The results suggest that periosteal pressures and tensile strains induced by bone bowing can accelerate the process of bone straightening and lead to more complete correction of congenital bowing defects. Including the mechanobiological effects of periosteal surface loads in the simulations produced results similar to those seen clinically, with rapid straightening during the first few years of growth.

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Section: Discussionmentioning

confidence: 99%

Computational simulation of spontaneous bone straightening in growing children

Carpenter

Carter

2009

Biomech Model Mechanobiol

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“…Other studies attempting to duplicate or calibrate in a mechanical testing machine the strain distributions seen in the live animal (Carter er al. 1981a.b;Weinans and Blankevoort 1995) have avoided the problem of individual variation by using the same bones, with the same strain gauges, for both in vivo, and later, ex vivo strain measurements. In effect, the current study removed differences between individuals in neuromuscular and training factors from consideration by loading each bone in the same way, leaving only the differences in geometry and in the distribution of material properties.…”

Section: Discussionmentioning

confidence: 99%

Ex vivoSimulation ofin vivostrain distributions in the equine metacarpus

Les¹,

Stover²,

Taylor³

et al. 1998

Equine Veterinary Journal

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Summary The objective of this study was to examine several simple ex vivo loading conditions for the equine metacarpus, and to evaluate their ability to reproduce the mid‐diaphyseal bone surface strain distributions previously reported in vivo at the walk and trot. Distributed axial compressive loads, and 9 different axial compressive point loads at −7.5 kN and −15 kN were applied to metacarpal‐distal carpal bone preparations from 6 Thoroughbred horses, aged 1–5 years. The resulting dorsal, medial, palmar, and lateral mid‐diaphyseal bone surface axial and shear strains were compared with previously reported in vivo surface strain distributions using a root mean square error (RMSE) protocol. The effects of loading condition and load magnitude on RMSE were assessed with a mixed‐model analysis of variance. There were significant differences between loading conditions, and, in most cases, between load magnitudes, in the fit of the ex vivo to the in vivo strain distributions. In vivo mid‐diaphyseal bone surface strain distributions at the walk can be well approximated ex vivo by a distributed axial compressive load, or by a point load positioned 0.5 cm mediad to the sagittal midline, at −7.5 kN loads. In vivo mid‐diaphyseal bone surface strain distributions at the trot can be well approximated by the −15 kN loads applied to the same locations. These simplified loading conditions can be used in designing biologically relevant loading protocols for ex vivo mechanical testing studies, as well as in developing boundary conditions for finite element analysis. As such, these loading conditions may be considered as tools to be used as a means of replicating in vivo loading conditions during the intial design and testing stages in the development of fracture fixation devices, as well as in the theoretical mechanical analysis of the metacarpal structure.

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“…To allow for the acquisition of data over time, the specimen was cyclically compressed, and imaging was not performed until a quasi‐steady state load‐deformation response was achieved. The number of cycles required to reach quasi‐steady state was found for loads of one‐times body weight (78 N) (12), which are typical of tibiofemoral joints during the quadruped gait cycle (13), using 11 specimens. Load was applied for 1.5 s during each 10‐s cycle (11).…”

Section: Methodsmentioning

confidence: 99%

Articular cartilage deformation determined in an intact tibiofemoral joint by displacement‐encoded imaging

Chan

Neu

Hull

2009

Magnetic Resonance in Med

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This study demonstrates the in vitro displacement and strain of articular cartilage in a cyclically-compressed and intact joint using displacement-encoded imaging with stimulated echoes (DENSE) and fast spin echo (FSE). Deformation and strain fields exhibited complex and heterogeneous patterns. The displacements in the loading direction ranged from ؊1688 to ؊1481 m in the tibial cartilage and from ؊1601 to ؊764 m in the femoral cartilage. Corresponding strains ranged from ؊9.8% to 0.7% and from ؊4.3% to 0.0%. The displacement and strain precision were determined to be 65 m and less than 0.2%, respectively. Displacement-encoded magnetic resonance imaging is capable of determining the nonuniform displacements and strains in the articular cartilage of an intact joint to a high precision. Knowledge of these nonuniform strains is critical for the in situ characterization of normal and diseased tissue, as well as the comprehensive evaluation of repair constructs designed using regenerative medicine. Magn Reson Med 61:989 -993, 2009.

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Reconstruction of bone loading conditions from in vivo strain measurements

Cited by 14 publications

References 8 publications

Computational simulation of spontaneous bone straightening in growing children

Computational simulation of spontaneous bone straightening in growing children

Ex vivoSimulation ofin vivostrain distributions in the equine metacarpus

Articular cartilage deformation determined in an intact tibiofemoral joint by displacement‐encoded imaging

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