Extracorporeal shock wave therapy: an update

Abstract

Extracorporeal shock wave therapy (ESWT) is a safe therapy and there are only a few side effects known (such as pain during ESWT and minor haematomata), but no severe complications are to be expected if it is performed as recommended.Contraindications are severe coagulopathy for high-energy ESWT, and ESWT with focus on the foetus or embryo and focus on severe infection.The effect mechanism of ESWT is still a component of diverse studies, but as far as we can summarize today, it is a similar process to a cascade triggered by mechano-transduction: mechanical energy causes changes in the cellular skeleton, which provokes a reaction of the cell core (for example release of mRNA) to influence diverse cell structures such as mitochondria, endoplasmic reticulum, intracellular vesicles, etc., so the enzymatic response leads to the improvement of the healing process.The usage of ESWT should be taught, to improve the outcome. Courses should be organized by national societies, since the legal framework conditions are different from one country to another.In this update the musculoskeletal indications are addressed (mainly bone and tendons): pseudoarthrosis, delayed fracture healing, bone marrow oedema and osteonecrosis in its early stages, insertional tendinopathies such as plantar fasciitis and Achilles tendon fasciitis, calcifying tendonitis of the rotator cuff, tennis elbow, and wound healing problems. Cite this article: EFORT Open Rev 2020;5:584-592. DOI: 10.1302/2058-5241.5.190067.

Keywords: extracorporeal; indication; pressure; shock wave; therapy.

Fig. 1

Different types of generating pressure waves and shock waves are produced by the diverse devices for ESWT. All these devices produce more or less focused pressure waves and shock waves except the radial devices, which produce pressure waves, which are not focused and have the highest energy in the area where the applicator delivers the mechanical energy into the body, superficially on the skin.

Fig. 2

Comparison of three different acoustic waves: shock waves, diagnostic ultrasound and radial pressure waves. Source. Electro-hydraulic shock wave: MTS Europe GmbH, measurement orthogold100, focused applicator. Diagnostic ultrasound: sine wave, calculated with 1 MPa peak pressure at 2MHz. Radial pressure wave: Cleveland RO, Chitnis PV, McClure SR. Acoustic field of a ballistic shock wave therapy device. Ultrasound Med Biol 2007;33:1327–1335, Figure 6a.