From the first investigation of the application of shock waves in medicine until today is a very short time. During the Second World War it was observed that the lung of castaways was cracked because of the explosion of waterbombs although no outer symptoms of violence existed. This was the first time that the influence of shock waves, created by the exploding bombs, on tissue was observed.
In the 50'ies the first systematic investigations for the use of shock waves in medicine have been performed. For example it was published that electrohydraulic generated shock waves were able to crush ceramic plates in water. In the USA the first patent of an electrohydraulic shock wave generator was accepted (Frank Rieber, New York, Patent No. 2.559.277). End of the 50'ies the physical properties of electromagnetic generated shock waves have been described.
In 1966 the interest in shock waves on human was stimulated accidentally at Dornier company. During experiments with high velocity projectiles an employee touched the plate in the very moment where the projectile hit the plate. He felt something in his body like an electrical shock. Measurements show that no electricity was present. The generated shock wave traveled from the plate over the hand in the body. From 1968 until 1971 the interaction between shock waves and biological tissue in animals was investigated in Germany. The Department of Defense of Germany financed this program. The result was that high-energy shock waves cause effects in the organism over long distances. Particularly the effects of interfaces in the organism were investigated together with the difference and damping of the shock wave on its way through living tissue. Another field of interest was the transition of the shock wave into the body. It was observed that shock waves create low side effects on the way through muscles, fat- and connective tissue. Intact bone tissue remains unharmed under shock wave burden. The danger for the lung, brain, abdomen and other organs was part of the investigation in this program. The best transition media for the shock wave was water and gelatin because of the similarity in the acoustic impedance to the tissue.
These investigations and cooperation with physicians lead to the idea to disintegrate kidney stones with extracorporeal generated shock waves. In the beginning the technical and medical realization of the idea was not very clear but the idea was born. 1971 Haeusler and Kiefer reported about the first in-vitro disintegration of a kidney stone with shock waves without direct contact to the stone. Further in-vitro experiments of contact-free stone disintegration followed. In 1974 the Department of Research and Science of Germany financed the research program "Application of the ESWL". Participants on this program were for example Eisenberger, Chaussy, Brendel, Forßmann and Hepp. 1980 the first patient with a kidney stone was treated in Munich with a prototype machine called Dornier Lithotripter HM1. In 1983 the first commercial lithotripter (HM3, Dornier) was installed in Stuttgart/Germany. In the next years in-vivo and in-vitro experiments with extracorporeal generated shock waves with the goal to disintegrate gallstones were carried out.
In 1985 the first clinical treatment of a gallbladder stone with ESWL was performed in Munich/Germany. One year later a prototype of a lithotripter without a bathtub was tested in Mainz. Today the treatment of kidney and ureteral stones with extracorporeal shock waves is the treatment of the first choice. Modern lithotripters work without a bathtub and without anesthesia. For localization of stones lithotripters are equipped with x-ray and/or ultrasound localization systems. In the last 16 years more than 3 Million patients have been treated. The shock wave therapy is safe and effective but nevertheless careless applied shock wave therapy has the potential to cause severe damage.
Urology is not the only field in medicine where shock waves were used successfully. In 1985 the first experiments were carried out to investigate the influence of shock waves on bones. The reason for this research was the apprehension that shock waves could damage the hip as a result of shock wave therapy on lower ureteral stones. The result of these experiments was that on an intact bone no considerable alteration was observed. Further animal experiments showed that shock waves have osteogenetic potential and stimulate fracture healing. Histological investigations confirmed the influence of shock waves on the activation of osteoblasts.
In 1988 the first shock wave treatment of non-union in human was successfully performed in Bochum/Germany. At the same time Valchanow et. al. reported about shock wave therapy on non-unions and delayed unions. His success rate was 85% but the requirements of his clinical study were not exactly specified. In the next years different clinical studies reported about success rates between 60% and 90%. Two essential circumstances exert influence on the success of the shock wave therapy on non-unions or delayed unions. The influence of shock waves on hypertrophic non-unions seems to be more effective as on atrophic non-unions. The stabilization of the fracture after shock wave therapy seems to be an essential condition for the success of the therapy. As side effects local haematomas, petechial hemorrhage and local swelling were found. These side effects disappeared within a few days without any complications.
The first investigations and treatments on humans were performed with lithotripters, which are designed for the requirements of shock wave application in urology. Because of the anatomical decentralization of the therapy areas (shoulder to food) it was necessary to develop a special orthopedic shock wave device. In 1993 a special orthopaedic shock wave device, OssaTron (HMT AG) with a free moveable therapy head became available.
At the beginning of the 90'ies the first reports about shock wave therapy on tendinitis calcarea were published. Further investigations lead to successful treatment of epicondylitis and heel spur with reported success rates between 70% and 80%. Because of the increasing significance of shock wave therapy on soft tissue diseases, HMT developed a special shock wave device, the ReflecTron. The new concept of its electrode (ReflecTrode) is an increased durability of 50000 shock waves. For the scientific evaluation of the ESWT for orthopedic diseases many clinical studies and publications are available. Design, protocol and contents of the published studies are different but all publications agree that ESWT show high efficiency but very low complications and side effects.