Joerg Hausdorf- email@example.com
Munich, Marchioninistr. 15
81377 Munich, Germany
Popular version of paper 1aBB3
Presented Monday morning, May 16, 2005
Joint ASA/CAA Meeting, Vancouver, BC
Extracorporal shock waves are transient pressure disturbances
that propagate rapidly in three-dimensional space. For more than 20 years, urologists
have used devices which are able to focus those shock waves onto a small target
to treat kidney stones. Those waves migrate without damage through skin and
soft tissue and set their energy free on the borderline of a tissue with a far
different density like calcified kidney stones ... or bone.
For patients who underwent multiple lithotripsies (shock wave treatment of kidney stones), physicians found new growth of bone in the iliac crest (the major part of the pelvic bone). This phenomenon was recognized as a reaction to the shock waves and researchers began to study those bony reactions. First it was thought that high energy was needed to somehow break the bone and then cause it to heal. But recent studies showed that even lower energy levels, which did not show any destructions of the bone, were able to enhance bone healing.
In our group, which has been working in shock wave research for more than 25 years, we were able to show that at the scale of the cell, our lowest level of biological organization, there is a reaction to shock waves. We applied shock waves to fibroblasts (cells from soft tissue like tendons, ligaments or muscles) and to osteoblasts (cells which form the bone). One day after the treatment we found an increase of a very important bone growth factor (bFGF) identically in both cell types. So for the first time it could be shown that shock waves enhance the production of this bone growth factor in intact human cells (Fig. 1).
So for the femoral head necrosis we wanted to know whether the
shock waves are really able to migrate deeply enough into the bone to reach
the necrotic area. Therefore we measured the pressure inside the femoral head
of cadaver pig bones while shock wave application. And indeed we found even
10 mm beneath the surface still 50 % of the shock wave pressure.