Biomechanical Study in the Calcaneus Bone After an Autologous Bone Harvest

The calcaneus bone can be used to obtain autologous tissue for ankle and feet surgery, but fracture after harvesting the bone is one of the most severe complications. We sought to determine the biomechanical characteristics of the calcaneus bone while simulating small and large pieces of bone removal at the dorsal aspect of the calcaneal tuberosity. We also evaluated mechanical properties of the foot with increasing traction forces assigned to the Achilles. We used computational tomography images from an individual with no local or systematic pathology to design a finite element (FE) model of the foot. To evaluate principal stress and translations, we measured six conditions using the intact foot as a reference and a model where a piece of bone of variable depth (maximum 7.5 mm) had been removed. The results indicated that as the volume of calcaneus bone extracted increased, there was a redistribution of stresses that differed significantly from an intact foot and was further magnified with increasing loads. Maximum stresses identified in this study were not significantly affected by an increase in the volume of bone harvest; however, stresses increased in areas of the calcaneus are vulnerable to injury.