Is a simplified Finite Element model of the gluteus region able to capture the mechanical response of the internal soft tissues under compression?

BACKGROUND Internal soft tissue strains have been shown to be one of the main factors responsible for the onset of Pressure Ulcers and to be representative of its risk of development. However, the estimation of this parameter using Finite Element (FE) analysis in clinical setups is currently hindered by costly acquisition, reconstruction and computation times. Ultrasound (US) imaging is a promising candidate for the clinical assessment of both morphological and material parameters. METHOD The aim of this study was to investigate the ability of a local FE model of the region beneath the ischium with a limited number of parameters to capture the internal response of the gluteus region predicted by a complete 3D FE model. 26 local FE models were developed, and their predictions were compared to those of the patient-specific reference FE models in sitting position. FINDINGS A high correlation was observed (R = 0.90, p-value < 0.01). A sensitivity analysis showed that the most influent parameters were the mechanical behaviour of the muscle tissues, the ischium morphology and the external mechanical loading. INTERPRETATION Given the progress of US for capturing both morphological and material parameters, these results are promising because they open up the possibility to use personalised simplified FE models for risk estimation in daily clinical routine.

[1]  Jean-Sébastien Affagard,et al.  Identification of hyperelastic properties of passive thigh muscle under compression with an inverse method from a displacement field measurement. , 2015, Journal of biomechanics.

[2]  A Gefen,et al.  Pressure ulcers and deep tissue injury: a bioengineering perspective. , 2007, Journal of wound care.

[3]  Hélène Pillet,et al.  Development and evaluation of a new methodology for the fast generation of patient-specific Finite Element models of the buttock for sitting-acquired deep tissue injury prevention. , 2018, Journal of biomechanics.

[4]  C. Oomens,et al.  The effects of deformation, ischemia, and reperfusion on the development of muscle damage during prolonged loading. , 2011, Journal of applied physiology.

[5]  N. Vuillerme,et al.  Biomechanical modeling to prevent ischial pressure ulcers. , 2014, Journal of biomechanics.

[6]  J. B. Reswick,et al.  Experience at Rancho Los Amigos Hospital With Devices and Techniques to Prevent Pressure Sores , 1976 .

[7]  Klaas Nicolay,et al.  Role of ischemia and deformation in the onset of compression-induced deep tissue injury: MRI-based studies in a rat model. , 2007, Journal of applied physiology.

[8]  R. Daniel,et al.  Etiologic factors in pressure sores: an experimental model. , 1981, Archives of physical medicine and rehabilitation.

[9]  E. I. Odell,et al.  Deformations and Stresses in Soft Body Tissues of a Sitting Person , 1978 .

[10]  M. Fink,et al.  Viscoelastic and anisotropic mechanical properties of in vivo muscle tissue assessed by supersonic shear imaging. , 2010, Ultrasound in medicine & biology.

[11]  Frank Baaijens,et al.  Pressure Induced Deep Tissue Injury Explained , 2014, Annals of Biomedical Engineering.

[12]  F P T Baaijens,et al.  Validation of a numerical model of skeletal muscle compression with MR tagging: a contribution to pressure ulcer research. , 2008, Journal of biomechanical engineering.

[13]  C. W. J. Oomens,et al.  Temporal Effects of Mechanical Loading on Deformation-Induced Damage in Skeletal Muscle Tissue , 2010, Annals of Biomedical Engineering.

[14]  Yohan Payan,et al.  Personalized modeling for real-time pressure ulcer prevention in sitting posture. , 2018, Journal of tissue viability.

[15]  D L Bader,et al.  A new MR-compatible loading device to study in vivo muscle damage development in rats due to compressive loading. , 2006, Medical engineering & physics.

[16]  Amit Gefen,et al.  How do microclimate factors affect the risk for superficial pressure ulcers: a mathematical modeling study. , 2011, Journal of tissue viability.

[17]  C. D. Savci-Heijink,et al.  An advanced magnetic resonance imaging perspective on the etiology of deep tissue injury. , 2018, Journal of applied physiology.

[18]  S. Avril,et al.  In vivo Identification of the Passive Mechanical Properties of Deep Soft Tissues in the Human Leg , 2016 .

[19]  M. Fink,et al.  Supersonic shear imaging: a new technique for soft tissue elasticity mapping , 2004, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[20]  Evan Call,et al.  Off loading wheelchair cushion provides best case reduction in tissue deformation as indicated by MRI. , 2017, Journal of tissue viability.

[21]  Y. Itzchak,et al.  Strains and stresses in sub-dermal tissues of the buttocks are greater in paraplegics than in healthy during sitting. , 2008, Journal of biomechanics.

[22]  Yohan Payan,et al.  Clinically oriented real-time monitoring of the individual’s risk for deep tissue injury , 2011, Medical & Biological Engineering & Computing.

[23]  M. Rausch,et al.  Towards understanding pressure ulcer formation: Coupling an inflammation regulatory network to a tissue scale finite element model , 2019, Mechanics Research Communications.

[24]  J. C. Simo,et al.  Quasi-incompressible finite elasticity in principal stretches. Continuum basis and numerical algorithms , 1991 .

[25]  Pierre Badel,et al.  Prediction of the Biomechanical Effects of Compression Therapy on Deep Veins Using Finite Element Modelling , 2015, Annals of Biomedical Engineering.

[26]  Amit Gefen,et al.  Assessment of the Biomechanical Effects of Prophylactic Sacral Dressings on Tissue Loads: A Computational Modeling Analysis. , 2017, Ostomy/wound management.

[27]  Cwj Cees Oomens,et al.  How does lateral tilting affect the internal strains in the sacral region of bed ridden patients? - A contribution to pressure ulcer prevention. , 2016, Clinical Biomechanics.

[28]  C. Oomens,et al.  The Relative Contributions of Compression and Hypoxia to Development of Muscle Tissue Damage: An In Vitro Study , 2007, Annals of Biomedical Engineering.

[29]  K. Berecek,et al.  Etiology of decubitus ulcers. , 1975, The Nursing clinics of North America.

[30]  Cees W J Oomens,et al.  On the importance of 3D, geometrically accurate, and subject-specific finite element analysis for evaluation of in-vivo soft tissue loads , 2017, Computer methods in biomechanics and biomedical engineering.

[31]  Pengfei Song,et al.  Validation of shear wave elastography in skeletal muscle. , 2013, Journal of biomechanics.

[32]  Matthew P Reed,et al.  Development and Validation of a High Anatomical Fidelity FE Model for the Buttock and Thigh of a Seated Individual , 2016, Annals of Biomedical Engineering.

[33]  David M Brienza,et al.  Feasibility of freehand ultrasound to measure anatomical features associated with deep tissue injury risk. , 2016, Medical engineering & physics.

[34]  Cees W J Oomens,et al.  Adaptation of a MR imaging protocol into a real-time clinical biometric ultrasound protocol for persons with spinal cord injury at risk for deep tissue injury: A reliability study. , 2017, Journal of tissue viability.

[35]  Y. Itzchak,et al.  Assessment of mechanical conditions in sub-dermal tissues during sitting: a combined experimental-MRI and finite element approach. , 2007, Journal of biomechanics.

[36]  William Z Rymer,et al.  Investigation of Soft-Tissue Stiffness Alteration in Denervated Human Tissue Using an Ultrasound Indentation System , 2008, The journal of spinal cord medicine.

[37]  C. Oomens,et al.  The etiology of pressure ulcers: skin deep or muscle bound? , 2003, Archives of physical medicine and rehabilitation.

[38]  Neima Brauner,et al.  Effects of ambient conditions on the risk of pressure injuries in bedridden patients—multi‐physics modelling of microclimate , 2018, International wound journal.

[39]  Amit Gefen,et al.  The contribution of a directional preference of stiffness to the efficacy of prophylactic sacral dressings in protecting healthy and diabetic tissues from pressure injury: computational modelling studies , 2017, International wound journal.

[40]  M. Rausch,et al.  Linking microvascular collapse to tissue hypoxia in a multiscale model of pressure ulcer initiation , 2019, Biomechanics and Modeling in Mechanobiology.

[41]  M. Kosiak,et al.  Etiology and pathology of ischemic ulcers. , 1959, Archives of physical medicine and rehabilitation.

[42]  Jane Nixon,et al.  Effects of intramuscular fat infiltration, scarring, and spasticity on the risk for sitting-acquired deep tissue injury in spinal cord injury patients. , 2011, Journal of biomechanical engineering.

[43]  N. Vuillerme,et al.  Clinical workflow for personalized foot pressure ulcer prevention. , 2016, Medical engineering & physics.

[44]  Dan L Bader,et al.  A theoretical analysis of damage evolution in skeletal muscle tissue with reference to pressure ulcer development. , 2003, Journal of biomechanical engineering.

[45]  P A Dabnichki,et al.  Deformation and Stress Analysis of Supported Buttock Contact , 1994 .

[46]  S. Laporte,et al.  Shear waves elastography for assessment of human Achilles tendon's biomechanical properties: an experimental study. , 2017, Journal of the mechanical behavior of biomedical materials.

[47]  A. Gefen,et al.  Real-Time Finite Element Monitoring of Sub-Dermal Tissue Stresses in Individuals with Spinal Cord Injury: Toward Prevention of Pressure Ulcers , 2009, Annals of Biomedical Engineering.

[48]  J W Steer,et al.  Predictive prosthetic socket design: part 1—population-based evaluation of transtibial prosthetic sockets by FEA-driven surrogate modelling , 2019, Biomechanics and Modeling in Mechanobiology.

[49]  C. Oomens,et al.  Can Loaded Interface Characteristics Influence Strain Distributions in Muscle Adjacent to Bony Prominences? , 2003, Computer methods in biomechanics and biomedical engineering.

[50]  A. Gefen,et al.  Exposure to internal muscle tissue loads under the ischial tuberosities during sitting is elevated at abnormally high or low body mass indices. , 2010, Journal of biomechanics.

[51]  T. Bush,et al.  Initial estimation of the in vivo material properties of the seated human buttocks and thighs , 2018, International Journal of Non-Linear Mechanics.

[52]  C. Vergari,et al.  Feasibility of sub-dermal soft tissue deformation assessment using B-mode ultrasound for pressure ulcer prevention. , 2018, Journal of tissue viability.

[53]  M. Fink,et al.  Ultrasound elastography: principles and techniques. , 2013, Diagnostic and interventional imaging.

[54]  Mickael Tanter,et al.  Intervertebral disc characterization by shear wave elastography: An in vitro preliminary study , 2014, Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine.