PhD defence D.M. (Denise) van de Laarschot

Dissertation in short:

Osteoporosis is a public health problem. Osteoporotic fractures affect 1 in 3 women and 1 in 5 men over the age of 50. Bisphosphonates are used by millions of patients worldwide for the treatment of osteoporosis. Atypical femur fractures are considered rare side effects of bisphosphonates. These are fractures of the thigh bone that occur spontaneously and often heal slowly. Fear of this rare complication can lead to undertreatment of osteoporosis. Unfortunately, the cause of atypical femur fractures is unknown. In this thesis, we investigate the possibility of a genetic background to atypical femur fractures. We investigate families that have multiple family members with atypical femur fractures to find a genetic cause. An underlying genetic bone disease, could be a risk factor for atypical femur fractures. Secondly, we present DXA scanning as a screening tool to timely diagnose atypical femur fractures. A DXA scan of the hip is routinely made in patients with osteoporosis. By scanning the whole leg, we can look for the beginning atypical femur fracture and hopefully prevent a complete fracture by stopping the bisphosphonates. Lastly, we present recommendations for medical treatment after a patient has had an atypical femur fracture. Bisphosphonates may worsen the atypical fracture or increase the risk of an atypical fracture of the other leg. We discuss the alternative osteoporosis drugs for the prevention of osteoporotic fractures.