The architecture of the proximal femur: an imaging analysis.

The proximal femur is a dynamic region whose internal architecture reflects the biomechanical demands of weight-bearing. It is composed of two major trabecular systems arranged along the lines of compressive and tensile stresses. Adaptive alterations in these trabeculae occur in a variety of disorders, including osteoporosis, osteoarthritis, and ischemic necrosis. Plain film radiography and computed tomography (CT) have been utilized to study these changes and provide insight into the pathophysiology of these disorders. Analysis of the order of resorption of trabeculae in osteoporosis, the proliferation of trabeculae in osteoarthritis, and the reparative changes in ischemic necrosis often allows accurate assessment of the severity of involvement and can give valuable information to aid treatment planning.