Deformation and stress distribution of the human foot after plantar ligaments release: A cadaveric study and finite element analysis

Abstract

The majority of foot deformities are related to arch collapse or instability, especially the longitudinal arch. Although the relationship between the plantar fascia and arch height has been previously investigated, the stress distribution remains unclear. The aim of this study was to explore the role of the plantar ligaments in foot arch biomechanics. We constructed a geometrical detailed three-dimensional (3-D) finite element (FE) model of the human foot and ankle from computer tomography images. The model comprised the majority of joints in the foot as well as bone segments, major ligaments, and plantar soft tissue. Release of the plantar fascia and other ligaments was simulated to evaluate the corresponding biomechanical effects on load distribution of the bony and ligamentous structures. These intrinsic ligaments of the foot arch were sectioned to simulate different pathologic situations of injury to the plantar ligaments, and to explore bone segment displacement and stress distribution. The validity of the 3-D FE model was verified by comparing results with experimentally measured data via the displacement and von Mise stress of each bone segment. Plantar fascia release decreased arch height, but did not cause total collapse of the foot arch. The longitudinal foot arch was lost when all the four major plantar ligaments were sectioned simultaneously. Plantar fascia release was compromised by increased strain applied to the plantar ligaments and intensified stress in the midfoot and metatarsal bones. Load redistribution among the centralized metatarsal bones and focal stress relief at the calcaneal insertion were predicted. The 3-D FE model indicated that plantar fascia release may provide relief of focal stress and associated heel pain. However, these operative procedures may pose a risk to arch stability and clinically may produce dorsolateral midfoot pain. The initial strategy for treating plantar fasciitis should be non-operative. The plantar fascia, or plantar aponeurosis, is the investing fascial layer of the plantar aspect of the foot, and forms part of the retinacular system, consisting of a network of connective and adipose tissues that supports and protects underlying vital structures of the body. The anatomy of the plantar fascia has been well described by Sarrafian [1] and others [2][3][4][5]. Partial or total plantar fascia release may relieve metatarsal and calcaneal stresses and painful heel syndromes of plantar fasciitis. However, reduction of plantar fascia stiffness may have a significant impact on arch stability, resulting in a more deformable longitudinal arch. Cadaveric studies have been performed to examine biomechanical consequences of release of the plantar ligaments. Huang [6] reported that the average vertical displacements

Biomechanical comparison of locking plate and crossing metallic and absorbable screws fixations for intra-articular calcaneal fractures

“…This criterion was widely adopted for biomechanical analysis (Chen et al, 2014;Liang et al, 2011;Ni et al, 2015;Niu et al, 2014;Tupis et al, 2012). Our simulation showed that the maximum stress exerted on the metallic and absorbable screws was less than the bending strength and shear strength of titanium and PLLA (Chen et al, 2014;Fu et al, 2013;van Dijk et al, 2002).…”

“…Finite-element (FE) analysis is a powerful tool for handling clinical biomechanical problems (Huang et al, 2013;Liang et al, 2011;Niu et al, 2014;Ren et al, 2015;Wong et al, 2015). Therefore, the purpose of our study was to evaluate and compare the biomechanics of plate fixation, crossing metallic screw fixation, and crossing absorbable screw fixation by using FE analysis.…”

Studying Maximum Plantar Stress per Insole Design Using Foot CT-Scan Images of Hyperelastic Soft Tissues

“…FEM is capable of filling the gap and calculating inner stress between the soft and bony tissue of foot and, as a result, is suitable for design of insoles. There are a number of studies on FEM analysis of stress distribution in foot, including improper stress distribution in patients suffering from walking disorder after cerebral accidents [8], stress distribution and equivalent stress in injured foot [9], and studying the effect of tendons on stress distribution [10]. In particular, the foot stress distribution with respect to the design and material of the insole has been examined by FEM, considering linear and elastic properties [11].…”

Effects of Bone Young’s Modulus on Finite Element Analysis in the Lateral Ankle Biomechanics

“…Finite element analysis (FEA) has been widely used in biomechanics [1][2][3][4][5][6][7][8] organs all have very complicated shapes, structures and mechanical properties. These characters make the application of FEA in biomechanics very challenging [9][10][11]. In the FEA modeling, the mechanical properties of various biological tissues are mostly from experimental data in published documents.…”