Geometrical aspects of growth plate modelling using Carter's and Stokes's approaches

• Published in: Acta of bioengineering and biomechanics Vol. 14; no. 1; p. 93
• Main Author: Piszczatowski, Szczepan
• Format: Journal Article
• Language: English
• Published: Poland 2012
• Subjects: Biomechanical Phenomena - physiology; Cartilage - growth & development; Growth Plate - anatomy & histology; Growth Plate - physiology; Humans; Infant; Models, Anatomic; Models, Biological
• ISSN: 1509-409X

Development of the skeleton is a complex mechanobiological process. Shape and size of the majority of bone elements are the result of endochondral growth and ossification occurring during childhood and adolescent period. The influence of mechanical loading acting in the skeletal system on bone development is known since the 19th century, but understanding of such phenomenon seems to be still insufficient. Traditionally accepted Hueter-Volkmann law claims that increased pressure acting on a growth plate retards bone growth and, conversely, reduced pressure or even tension accelerates it. Stokes's approach is directly based on this theory. Carter's model seems to be slightly more complex because takes into account three-dimensional stress state. The subject of the research was to evaluate the mechanobiological condition of endochondral bone growth occurring within the growth cartilage where different geometrical structures (8 models) of the growth plate and various loading conditions (5 variants) were considered. Simulations were made using the finite element method and both Stokes's and Carter's models were used to estimate mechanical stimulation of bone growth. Results indicate non-uniformity of the growth conditions occurring within the growth cartilage when its layer is located between two bone blocks. Non-axial loadings result in dissymmetry of mechanical stimulation of bone growth. In general, its minimum is located in the regions of the cartilage to which maximal loadings were directed. Carter's approach is, however, more sensitive to interrelation between growth plate geometrical structure and loading direction, compared to Stokes's model. Obtained results indicate the necessity of realistic modelling of the growing bone geometrical structure, including the elaboration of custom-made models. Further research is necessary to elaborate the new formula describing mechanical influences on bone growth, taking into account the cyclic loading of a constant direction. In this way it will be possible to overcome the still existing problems with the explanation of numerous clinical phenomena.