There is currently great interest in the use of Extracorporeal Shock Wave Therapy (ESWT) and in clarifying the mechanisms of action in tendon pathologies. The success rate ranges from 60% to 80% in epicondylitis, plantar fasciitis, cuff tendinitis, trocanteritis, Achilles tendinitis or jumper's knee. In contrast to urological treatments (lithotripsy), where shockwaves are used to disintegrate renal stones, in musculoskeletal treatments (orthotripsy), shockwaves are not being used to disintegrate tissues, but rather to microscopically cause interstitial and extracellular biological responses and tissue regeneration. The researchers are interesting to investigate the biological effects which support the clinical successes. Some authors speculated that shockwaves relieve pain in insertional tendinopathy by hyper-stimulation analgesia. Many recent studies demonstrated the modulations of shockwave treatment including neovascularization, differentiation of mesenchymal stem cells and local release of angiogenetic factors. The experimental findings confirm that ESWT decrease the expression of high levels of inflammatory mediators (matrix metalloproteinases and inter-leukins). Therefore, ESWT produces a regenerative and tissue-repairing effect in musculoskeletal tissues, not merely a mechanical disintegrative effect as generally before assumed. Based on the encouraging results of clinical and experimental studies, the potential of ESWT appears to be emerging. The promising outcome after this non-invasive treatment option in tendinitis care justifies the indication of shockwave therapy. Further studies have to be performed in order or determine optimum treatment parameters and will bring about an improvement in accordance with evidence-based medicine. Finally, meta-analysis studies are necessary to demonstrate the efficacy and safety of ESWT in treating tendinopathies.
Keywords: biological effects; shock waves; tendinopathies; tendon.