Biomechanical modelling of growth modulation following rib shortening or lengthening in adolescent idiopathic scoliosis

Carrier, Julie; Aubin, Carl‐Éric; Villemure, Isabelle

doi:10.1007/bf02350997

Cited by 28 publications

(23 citation statements)

References 31 publications

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“…The method proposed in this study for the choice of weights in the objective function formulation (specified by the surgeon) was used to avoid the arbitrary choice proposed in other optimization studies [7,20,43] and to identify the best compromises available considering all aspects of the correction.…”

Section: Discussionmentioning

confidence: 99%

Computer simulation for the optimization of instrumentation strategies in adolescent idiopathic scoliosis

Majdouline

Aubin

Sangole

2009

Med Biol Eng Comput

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Recent studies reveal a large variability of instrumentation strategies in adolescent idiopathic scoliosis (AIS). Determination of the optimal configuration remains controversial. This study aims to develop a method to define the optimal surgical instrumentation strategy using a computer model implemented in a spine surgery simulator (S3). A total of 702 different strategies were simulated on a scoliotic patient using S3. Each configuration was assessed using objective functions that represented different correction objectives. Twelve geometric parameters were used in the three anatomic planes and mobility, and their relative weights were defined by a spine surgeon according to his objectives for correction of scoliosis. Six instrumentation parameters were manipulated in a uniform experimental design framework. An interpolation technique was used to build an approximation model from the simulation results and to locate instrumentation parameters minimizing the objective function. Small or no differences in the correction between the simulated optimal strategy and the real postoperative results of the instrumented segments were observed in the three planes. But the same overall correction was obtained by using fewer implants (only screws) and less instrumented levels. This study demonstrates the potential and feasibility of using a spine surgery simulator to optimize the planning of surgical instrumentation in AIS.

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Section: Discussionmentioning

confidence: 99%

Computer simulation for the optimization of instrumentation strategies in adolescent idiopathic scoliosis

Majdouline

Aubin

Sangole

2009

Med Biol Eng Comput

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“…The representation of the wedge shape of the intervertebral discs following a biomechanical stimulus can still be achieved by modeling the disc in a similar fashion to the vertebral bodies (i.e. center element with beams distributed along the edge) [3] in order to enable the evaluation of internal stresses variation within the disc.…”

Section: Discussionmentioning

confidence: 99%

“…Finite element (FE) models of the spine integrating growth and growth modulation have been used to understand the process of curve progression [3,24,28] and to evaluate different hypotheses for the pathogenesis of AIS [29]. Pathogenesis studied by Villemure et al [29] consisted of shift or rotation at T8, which was assumed to be the apical vertebra of the future scoliosis.…”

Section: Introductionmentioning

confidence: 99%

Pedicle growth asymmetry as a cause of adolescent idiopathic scoliosis: a biomechanical study

et al. 2006

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Over the last century the neurocentral junction (NCJ) has been identified as a potential cause of adolescent idiopathic scoliosis (AIS). Disparate growth at this site has been thought to lead to pedicle asymmetry, which then causes vertebral rotation and ultimately, the development of scoliotic curves. The objectives of this study are (1) to incorporate pedicle growth and growth modulation into an existing finite element model of the thoracic and lumbar spine already integrating vertebral body growth and growth modulation; (2) to use the model to investigate whether pedicle asymmetry, either alone or combined with other deformations, could be involved in scoliosis pathomechanisms. The model was personalized to the geometry of a nonpathological subject and used as the reference spinal configuration. Asymmetry of pedicle geometry (i.e. initial length) and asymmetry of the pedicle growth rate alone or in combination with other AIS potential pathogenesis (anterior, lateral, or rotational displacement of apical vertebra) were simulated over a period of 24 months. The Cobb angle and local scoliotic descriptors (wedging angle, axial rotation) were assessed at each monthly growth cycle. Simulations with asymmetrical pedicle geometry did not produce significant scoliosis, vertebral rotation, or wedging. Simulations with asymmetry of pedicle growth rate did not cause scoliosis independently and did not amplify the scoliotic deformity caused by other deformations tested in the previous model. The results of this model do not support the hypothesis that asymmetrical NCJ growth is a cause of AIS. This concurs with recent animal experiments in which NCJ growth was unilaterally restricted and no scoliosis, vertebral wedging, or rotation was noted.

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“…In Stokes's model, the sensitive factor b l was assumed 1.2 MPa -1 , based on an experimentally determined range of 0.4-1.71 MPa -1 [4,31]. The longitudinal baseline growth for thoracic vertebrae was taken as Gm = 0.8 mm year -1 according to the published data on vertebral growth in adolescents [7].…”

Section: Integration Of Mechanobiological Growth In the Finite Elemenmentioning

confidence: 99%

“…The sensitivity factor b l is determined from experimental data and is considered independent of the external environment. This modeling approach was integrated in beam-type finite element models by simulating the resulting strain increments as thermal loadings or equivalent forces to carry out bone geometrical changes [4,27,36,37].…”

Section: Introductionmentioning

confidence: 99%

Mechanobiological bone growth: comparative analysis of two biomechanical modeling approaches

Lin

Aubin

Parent

et al. 2008

Med Biol Eng Comput

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Mechanobiological growth is the process whereby bone growth is modulated by mechanical loading. Analytical formulations of mechanobiological growth have been developed by Stokes et al. (J Orthop Res 17(5):646-653, 1990) and Carter et al. (J Orthop Res 6:804-816, 1988). The purpose of this study was to compare these two modeling approaches in a finite element model of a vertebra to investigate whether growth pattern induced by these models were equivalent. A finite element model of a thoracic vertebra, integrating a conceptual model of the growth plate, was developed and combined with the mechanobiological growth models. This model was further used to simulate vertebral growth modulation resulting from different physiological loading conditions. Different growth magnitudes were obtained under compression and combined tension/shear loading, whereas dissimilar growth patterns were triggered by shear forces and combined compression/shear. These two models represent mechanobiological bone growth under limited mechanical environment. Carter's model takes into account three-dimensional stress stimuli, but does not intrinsically incorporate the resulting growth orientation. Stokes' model adequately represents the mechanobiological contribution of axial stresses but does not take into account the contribution of non-axial stresses, which can occur in complex mechanical environment.

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Biomechanical modelling of growth modulation following rib shortening or lengthening in adolescent idiopathic scoliosis

Cited by 28 publications

References 31 publications

Computer simulation for the optimization of instrumentation strategies in adolescent idiopathic scoliosis

Computer simulation for the optimization of instrumentation strategies in adolescent idiopathic scoliosis

Pedicle growth asymmetry as a cause of adolescent idiopathic scoliosis: a biomechanical study

Mechanobiological bone growth: comparative analysis of two biomechanical modeling approaches

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