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ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

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Hypertrophic columnar cartilage 0.27 0.13 [16]<br />

5. NUMERICAL RESULTS<br />

Figure 2 illustrates the longitudinal growth of the domain and the number of cells (per<br />

finite element) in the columnar cartilage during 31 days. It is observed that the growth<br />

plate maintains its physiological equilibrium as the number of chondrocytes in the<br />

columnar cartilage remains constant over time. The obtained growth rate was of 59.03<br />

μm / day, which has a numerical error of 7.33 % compared with the real rate of 55 μm /<br />

day [1].<br />

Figure 2: Longitudinal growth of the domain and number of cells per finite element: (a)<br />

5 days, (b) 10 days, (c) 20 days (d) 31 days.<br />

6. CONCLUSION<br />

This work has presented a computational model which describes the growth plate<br />

behavior and its mechanical modulation from a biological point, unlike the existing<br />

models where the bone elongation is simulated suing equivalent thermal deformations<br />

[11]. Based on the experimental data reported by Stokes et al [7], the model includes the<br />

effect of mechanical loading on the final choncrocytic height as a linear function of the<br />

stress modulation over the preferred direction of growth. An UEL was implemented and<br />

it was used to simulate the growth for a 2-years old human distal femur for 31 days,<br />

obtaining a numerical error of 7.32%. The obtained results demonstrate that the model<br />

can simulate the cellular activity of the growth plate if it has reached an equilibrium<br />

condition.<br />

8. REFERENCES<br />

1. Kember, N. F. and Sissons, H. A. Quantitative histology of the human growth plate.<br />

The journal of bone and joint surgery. 1976. 58-B (4): 426-435.<br />

2. Villemure, I. and Stokes I. A. Growth plate mechanics and mechanobiology. A<br />

survey of present understanding. Journal of Biomechanics. 2009. 42: 1793-1803.<br />

3. Kindblom, J. M. , Nilsson, O., Hurme, T., Ohlsson, C. and Savendahl, J. Expression<br />

and localization of Indian Hedgehog (Ihh) and parathyroid hormone related protein<br />

(PTHrP) in the human growth plate during pubertal development. Journal of

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