*Corresponding author: Lionel Thollon, Ifsttar, Laboratoire de Biomécanique Appliquée Marseille, Aix-Marseille Université, France, Tel: +33 4658012; Fax: +33 4658019; E-mail: lionel.thollon@ifsttar.fr Citation: Breda R, Godio-Raboutet Y, Mavrori E, Thollon L (2016) Structural Analysis of the Human Tibia by pQCT. J Orthop Res Physiother 2: 021. Received: 11, December 2015; Accepted: 12, February 2016; Published: 26, February 2016 Introduction e general anatomy of the tibia has long been known, but close microscopic biometric analysis of its actual structure has only been possible since on the one hand the advent of efficient techniques (such as CT scan), and on the other the development of reliable methods of statistical analysis (such as R soſtware). As early as the 17th century, Galileo Galilei demonstrated a relationship between body weight and bone size [1]. e works of Wolff at the end of the 19th century on the stresses exerted by environmental forces on bone trabeculae introduced the notion of bone adaptation without giving a precise explanation [1]. It was not until the end of the 1970s that Frost postulated that bone adapted to external force through a change in structure, a postulate that he clarified 20 years later in his theory of the “bone mechanostat” [2]. is meant that modeling and remodeling of bone could be induced by the forces to which it was subjected. e external forces exerted on each bone are different. In bending, in torsion and in compression, these forces induce changes in bone structure. e ratios between the mass and the resistance of each bone differ. ey depend on the site and on the forces exerted [1]. In order to resist compression forces, highly mineralized bone (pre-eminently cancellous) is developed at the expense of cortical bone. is peripheral cortical bone resists forces of bending and torsion [3]. Frost’s theory is an attractive one to determine some anatomical properties of bone and its adaptation to external forces [2]. Our study sought evidence that bone can adapt to external forces. Vertical stance and bipedal gait cause specific stresses on the long bones. Along the course of human evolution, the tibia has been increasingly subjected to different external forces. Evolution led to adaptation and modification of the structure of this bone. It is commonly accepted that the tibial plateaus, for example, have become thicker because of the increased stresses related to vertical stance. Moreover, the epiphyses of long bones have greater volume than the diaphysis, and their composition of cancellous bone enables them to adapt to compression stresses [2]. Frost postulated that the cancellous bone of the epiphysis and metaphysis allows better dispersal of compression stresses because of its composition and its greater contact surface area [2]. e forces exerted on the tibia commence at the distal epiphysis with the talocrural joint and are then dispersed along the diaphysis, passing proximal to the thigh through the knee. At this joint, these epiphyseal forces are distributed no longer to a single joint surface but to two, thus decreasing the stresses on each joint. Some authors have suggested forces are compressive at the ankle and are bending/torsion forces at the diaphysis [1,3,4]. At the knee, these forces are again compression forces but they are now distributed along two paths [1]. is would confirm the adaptation of tibial bone structure to the external forces acting on it. In the 1980s, some authors carried out anatomical studies of cadaver tibias in order to corroborate this hypothesis [4]. More recently, thanks to modern non-invasive techniques of investigation Breda R, et al., J Orthop Res Physiother 2016, 2: 021 DOI: 10.24966/ORP-2052/100021 HSOA Journal of Orthopedic Research and Physiotherapy Research Article Abstract Purpose The general anatomy of the tibia has long been known, but close microscopic and biometric analysis of its structure has only recently been possible. We wished to study this bone because of the numerous injuries observed during the traumatology, car’s injury or the deck-slap effect observing during war surgery. Materials and methods In order to better understand the mechanism of these injuries, we aimed to map out the tibia to examine more closely the distribution of cortical bone according to several parameters. We retrospectively studied 67 tibias using a high-definition scanner and compared our results with those of the literature. Results In the tibial metaphysis, we observed very high bone density, circularity close to 1, thin cortical bone and the greatest diameters. In the diaphysis, we observed a decrease in periosteal and intramedul- lary diameters, a marked increase in cortical thickness and a change in tibial architecture together with a marked decrease in circularity. These results were similar to those of the literature. Discussion The tibia is subjected to multidirectional forces. It is commonly accepted that each part of the tibia cannot resist all stresses and consequently there is a distribution of resistances in each part of the tibia. The epiphyseal part is subjected to compression forces, whereas the diaphyseal part is more subjected to bending and torsion forces. Conclusion Our study revealed a significant difference between men and women (P < 0.001) showing a discriminant effect of sex on cortical thickness, internal diameter and external diameter of the tibia. Keywords: Anthropometry; Medical imaging - Biomechanics; Tibia Renaud Breda 1 , Yves Godio-Raboutet 2 , Erty Mavrori 3 and Lionel Thollon 2 * 1 Department of Orthopaedic and Traumatological Surgery, Sainte Anne Military Teaching Hospital, Toulon, France 2 Ifsttar, Laboratoire de Biomécanique Appliquée Marseille, Aix-Marseille Université, France 3 Department of Radiology, Sainte Anne Military Teaching Hospital, Toulon, France Structural Analysis of the Human Tibia by pQCT