Page 251 - Advances in Biomechanics and Tissue Regeneration

12.4 DISCUSSION 247

(A) (B)

(C) (D)

(E) (F)
FIG. 12.5 Maximum principal stress in an intact foot with loads of 150 (A), 300 (C), and 375 N (E), respectively, on the Achilles tendon and with
7.5mm bone excision and loads of 150N (B), 300N (D), and 375 N (F), respectively, on the Achilles tendon.

application to the talus and to the calcaneus through traction applied by the Achilles tendon. The results from these
simulations indicate that as the volume of the bone extracted from the calcaneus increases, there is a redistribution of
stresses that differs significantly from an intact foot. This redistribution is further magnified with increasing loads.
Even though an increase in the volume of bone harvest did not significantly affect the maximum stress that we iden-
tified, in cases where the calcaneus was vulnerable to injury, stresses did increase.
This stress redistribution in the calcaneus may create an opportunity for a fracture risk.
The calcaneus consists of a peripheral cortical layer of compact tissue that coats a framework of spongy tissue. This
lamina exists in an orientation to effectively fulfill the functional requirements of the foot [21]. Thus its structure is

I. BIOMECHANICS