Influence of extracorporeal shock-wave application on normal bone in an animal model in vivo: SCINTIGRAPHY, MRI AND HISTOPATHOLOGY

There is little information about the effects of extracorporeal shock-wave about application the effects (ESWA) of on normal bone physiology. We have therefore investigated the effects of ESWA on intact distal rabbit femora in vivo. The animals received 1500 shock-wave pulses each of different energy flux densities (EFD) on either the left or right femur or remained untreated. The effects were studied by bone scintigraphy, MRI and histopathological examination. Ten days after ESWA (0.5 mJ/mm 2 and 0.9 mJ/mm 2 EFD), local blood flow and bone metabolism were decreased, but were increased 28 days after ESWA (0.9 mJ/mm 2 ). One day after ESWA with 0.9 mJ/mm 2 EFD but not with 0.5 mJ/mm 2 , there were signs of soft-tissue oedema, epiperiosteal fluid and bone-marrow oedema on MRI. In addition, deposits of haemosiderin were found epiperiosteally and within the marrow cavity ten days after ESWA. We conclude that ESWA with both 0.5 mJ/mm 2 and 0.9 mJ/mm 2 EFD affected the normal bone physiology in the distal rabbit femur. Considerable damaging side-effects were observed with 0.9 mJ/mm 2 EFD on periosteal soft tissue and tissue within the bone-marrow cavity.