Pharmacological management of aseptic osteonecrosis in children

Aseptic osteonecrosis (AON) in children can progress during ossification of cartilage in periods of increased growth or excessive physical stain and may occur in various locations in the skeleton. Disturbance of blood supply to the bone has been suggested as the main pathological mechanism involved in AON, which is characterised by the death of bone marrow and trabecular bone. The extent and development of osteonecrosis and the duration of disease until restorative healing, depend on the formation of new blood vessels, the spreading of vessels in the affected bony areas, the absorption of osteonecrotic tissue and the structure of new bone. Conservative and operative treatment options for AON vary according to the location and development of the disease and the age of the patient. The goal of all treatment options currently used today is to achieve relief of physical load in the affected bone and to promote and regulate blood supply. Treatment should be started early in order to minimise the extent of osteonecrosis and allow restorative healing. As the processes of myelopoiesis, myelophthisis and fracture healing become more clear, interest has focused on advances in the utilisation of bioactive factors to salvage bone in children affected by AON. Such methods include the use of osteoinductive agents, such as cytokines and bone morphogenetic proteins, as well as factors that stimulate angiogenesis and regulate blood supply. Currently, the prostacyclin analogue, iloprost (Ilomedin, Schering AG), has been successfully used in a pilot study in children suffering from early stages of AON.