The calcar femorale: A new perspective.

It is the role of the hip joint to support the superincumbent body weight while its complex range of movement, under a variety of stresses, allows the individual to undertake a wide range of physical activities. It is then perhaps not surprising that a recent anatomical study shows that the upper femur has a structure commensurate with the complexity of its movements. Mechanically, the upper femur consists of two separate bones: the combined femoral head and neck and the femoral shaft. Both bones consist of a mixture of two different types: cancellous bone and cortical bone, each with its own characteristics. Both bones are subjected to two different forces: those of weight bearing and movement and those of bone modelling. In the face of these complexities, this article tenders some theoretical considerations as to how this region functions and deals with these particular problems. From an anatomical viewpoint, the calcar femorale plays a central role in the mechanical structure of the femoral neck and is pivotal in the management of the stresses to which the region is subjected.