Turner Biomechanics

Osteoporosis is a disease in which bones become weak and brittle. In the vertebrae of the spine, bone mineral is lost with age and the bone breaking strength is reduced. In some people, the vertebrae are so weak that their spine will fracture even during normal daily activities. Download our article for more about spine fractures.

New treatments under development will make the skeleton stronger by stimulating new bone formation to augment weakened structures within bones. We investigated a new drug called PTH(1-34) or teriparatide. This drug substantially improved bone structure after several months of treatment. For more information, click here.

Sex hormones affect the way the skeleton develops and also play important roles in the development of osteoporosis. For instance, estrogen suppresses bone growth but then preserves bone structure throughout adulthood. At the menopause, estrogen levels drop and the skeleton rapidly loses bone mass. On the other hand estrogen loss allows the periosteal (outside) diameter of bones to grow. For more about this, click here.

Osteoporosis is a multifaceted disease. Bone becomes porous - hence the name of the disease - but in addition there are many changes to bone tissue that alter bone strength. Changes occur in the dimensions of the mineral crystals, in the rigidity of the collagen matrix, in the microarchitecture of trabecular struts, and in the size and shape of the bones. All of these factors contribute to bone fragility and fracture risk. Drug treatments for osteoporosis do not only affect bone porosity but also affect bone size, architecture and mineral. The effects of several osteoporosis drugs are discussed here.

The exponential rise in hip-fracture risk with aging is not fully explained by the corresponding fall in bone mineral density of the proximal femur. Instead, aging affects hip-fracture risk independently of bone mineral density, suggesting that there are other important age-related changes that must be considered. Of course, falls are important. Elderly people are more likely to fall down; therefore their risk of hip fracture should increase. In addition, ageing causes structural changes in the proximal femur that might increase the risk of fracture should someone fall on their side. Over a decade ago, Yoshikawa et al showed that bone loss occurs preferentially on the superior aspect of the femoral neck. This region of the femoral neck is under minimum mechanical stress during walking, whereas a fall on the hip reverses the stress pattern causing high compressive stresses at the superior neck...more