[Tissue-induced changes of the extracorporeal shockwave]

Extracorporeal shock wave therapy has been applied very frequently for more than 2 decades. Excellent results in clinical application and research led to widespread use of this noninvasive procedure. Until now the actual mode of action and biochemical pathways after extracorporeal shock wave therapy (ESWT) remain unknown. A small number of technical parameters could be determined after improved technical methods and sensor devices had been designed. It is also still unclear how these technical findings apply to the clinical setting. Therefore, we investigated the influence of musculocutaneous tissue on shock wave focus. A tissue thickness of 15 mm significantly influenced focus characteristics. We found distinct spreading and slight lateral deviation of the focus. In the same way, the peak positive pressure was significantly reduced after the shock waves had passed the musculocutaneous model. The study demonstrates that in vitro results could not be transferred directly to clinical or in vivo conditions. The clinical application of extracorporeal shock waves should be modified in intensity and number of shock waves depending on individual anatomic conditions, indication, and location.