Influence of loading direction due to physical activity on proximal femoral growth tendency. (April 2021)

• Record Type: Journal Article
• Authors: Yadav, Priti; Fernández, Marta Peña; Gutierrez-Farewik, Elena M.
• Is Part Of: Medical engineering & physics. Volume 90(2021)
• Page Start: 83
• Page End: 91
• Publication Date: 2021-04
• Subjects: Osteogenic index -- Octahedral shear stress -- Hydrostatic stress -- Joint contact force -- Acetabular forces; Biomedical engineering -- Periodicals; Biomedical Engineering -- Periodicals; Physics -- Periodicals; Génie biomédical -- Périodiques; Biomedical engineering; Electronic journals; Periodicals; 610.28
• DOI: 10.1016/j.medengphy.2021.02.008
• Languages: English
• ISSNs: 1350-4533

Abstract

Highlights: Subject-specific pediatric femur and growth plate models were developed based on MRI data of one 6-year old child. Bone growth was simulated for different physical activities (walking, hip flexion, hip fast flexion-extension, hip fast adduction-abduction, stairs up-down, jumping jack, cycling, heel-to-knee running, and heel-to bottom-running). Growth was simulated in the principal stress growth direction. Most physical activities evaluated induce the expected femur growth tendencies in an able-bodied child. Abstract: Longitudinal bone growth is regulated by mechanical forces arising from physical activity, whose directions and magnitudes depend on activity kinematics and intensity. This study aims to investigate the influence of common physical activities on proximal femoral morphological tendency due to growth at the femoral head growth plate. A subject-specific femur model based on magnetic resonance images of one able-bodied 6-year old child was developed, and the directions of hip contact force were described as load samples at a constant magnitude. Finite element analysis was performed to predict growth rate and growth direction, and expected changes in neck-shaft angle and femoral anteversion were computed corresponding to circa 4 months of growth. For most loading conditions, neck-shaft angle and femoral anteversion decreased during growth, corresponding to the femur's natural course during normal growth. The largest reduction in neck-shaft angle and femoral anteversion was approximately 0.25° and 0.15°. Our results suggest that most common physical activities induce the expected morphological changes in normal growth in able-bodied children. Understanding the influence of contact forces during less common activities on proximal femoral development might provide improved guidelines and treatment planning for children who have or are at risk of developing a femoral deformity.