Extracorporeal Shockwave Therapy (ESWT)

Original Editor - Ayushi Tomer

Top Contributors - Cindy John-Chu, Sue Safadi, Ayushi Tomer, Amanda Ager and Kim Jackson  

History of Extracorporeal Shockwave Therapy

Extracorporeal Shockwave Therapy (ESWT) otherwise referred to as shockwave therapy, was first introduced into clinical practice in 1982 for the management of urologic conditions [1]. The success of this technology for the treatment of urinary stones quickly made it a first-line, noninvasive, and effective method [2]. Subsequently, ESWT was studied in orthopedics where it was identified that it could loosen the cement in total hip arthroplasty revisions[3]. Further, animal studies conducted in the 1980s revealed that ESWT could augment the bone-cement interface, enhance osteogenic response and improve fracture healing [4][5]. While shockwave therapy has been shown to be beneficial in fracture healing, most orthopedic research has focused on upper and lower extremity tendinopathies, fasciopathies, and soft tissue conditions.

Physiology of ESWT

Shockwaves are sound waves that have specific physical characteristics, including nonlinearity, high peak pressure followed by low tensile amplitude, short rise time, and short duration (10 ms). They have a single pulse, a wide frequency range (0-20 MHz), and a high pressure amplitude (0-120 MPa)

These characteristics produce a positive and negative phase of shockwave. The positive phase produces direct mechanical forces, whereas the negative phase generates cavitation and gas bubbles that subsequently implode at high speeds, generating a second wave of shockwaves.[6]

In comparison to ultrasound waves, the shockwave peak pressure is approximately 1000 times greater than the peak pressure of an ultrasound wave.[7]

Mechanism of Action

The effects of ESWT treatment are unknown[8]. However, the proposed mechanisms of action for ESWT include the following: promote neovascularization at the tendon-bone junction [9], stimulate proliferation of tenocytes [10] and osteoprogenitor differentiation [11], increase leukocyte infiltration [12], and amplify growth factor and protein synthesis to stimulate collagen synthesis and tissue remodeling [10] [11] [13] [14].

Principles of Shockwave Therapy

Shockwaves are transient pressure disturbances that propagate rapidly in three-dimensional space. They are associated with a sudden rise from ambient pressure to their maximum pressure. Significant tissue effects include cavitation, which are consequent to the negative phase of the wave propagation.

Direct shockwave and indirect cavitation effects cause hematoma formation and focal cell death, which then stimulate new bone or tissue formation.

Indications for Shockwave Therapy

Shockwave therapy is primarily used in the treatment of common musculoskeletal conditions. These include:

There is no standardized ESWT protocol for the treatment of musculoskeletal conditions.

Contraindications to ESWT in Physiotherapy

  1. Pregnancy
  2. Over major blood vessels and nerves
  3. Pacemakers or other implanted devices
  4. Open wounds
  5. Joint replacements
  6. Epiphysis
  7. Blood clotting disorders including thrombosis
  8. Infection
  9. Cancerous tissues
  10. A compromised mental status of the patient and/or the inability to cooperate.

Differences between ESWT and Therapeutic Ultrasound

  • Therapeutic ultrasound utilises high frequency sound waves, while ESWT utilises lower frequency waves.
  • Ultrasound may produce either thermal or non-thermal effects in tissues, while ESWT does not result in heating effects.

Similarities between Therapeutic Ultrasound and ESWT

  • Both modalities employ acoustic waves to produce therapeutic benefits.
  • They both make use of a coupling medium to transmit sound waves to the tissues being treated.
  • They are both non-invasive forms of treatment.

Evidence-based

According to a study performed by Rompe and coworkers[17], stretching exercises in combination with radial shock wave therapy is more efficient for the treatment of chronic symptoms of proximal plantar fasciopathy than repetitive radial pressure wave therapy alone. Patients were subjected to three sessions of 2000 radial pressure pulses (EFD = 0.16 mJ/mm 2) in weekly intervals, generated with a ballistic device (air compressor pressure 4 bar; rate 8 Hz) manufactured by Electro Medical Systems.

A study to investigate the clinical outcomes of ESWT on calcaneal spurs of 108 patients and its correlation with radiologic changes were reported by Yalcin et al. [18]. All the patients underwent radial pressure wave therapy once a week for 5 weeks (2000 pressure waves starting at an EFD of 0.05 mJ/mm 2 and increasing up to 0.4 mJ/mm 2). After the therapy, approximately 67 % of the patients reported no pain; however, there was no correlation between clinical outcome and radiologic changes. The authors concluded that even without radiologic change.

Resources

[19]

References

  1. Chaussy C, Schmiedt E, Jocham D, Brendel W, Forssmann B, Walther V. First clinical experience with extracorporeally induced destruction of kidney stones by shock waves. Jour Urol 1982;127: 417-420
  2. Argyropoulos AN, Tolley DA. Optimizing shock wave lithotripsy in the 21st century. Eur Urol 2007; 52: 344-352
  3. Park SH, Park JB, Weinstein JN, Loening S. Application of extracorporeal shock wave lithotripter (ECSWL) in orthopedics. I. Foundations and overview. J Appl Biomater 1991; 2:115-126
  4. Weinstein JN, Oster DM, Park JB, Park SH, Loening S. The effect of the extracorporeal shock wave lithotriptor on the bone-cement interface in dogs. Clin Orthop Relat Res 1988; 235:261-267.
  5. Haupt G, Haupt A, Ekkernkamp A, Gerety B, Chvapil M. Influence of shock waves on fracture healing. Urology 1992; 39: 529-532
  6. van der Worp H, van den Akker-Scheek I, van Schie H, Zwerver J. ESWT for tendinopathy: Technology and clinical implications. Knee Surg Sports Traumatol Arthrosc 2013; 21:1451-1458
  7. 7.0 7.1 Wang CJ. Extracorporeal shockwave therapy in musculoskeletal disorders. J Orthop Surg Res 2012; 7:11
  8. Reilly JM, Bluman E, Tenforde AS. Narrative Review on the Effect of Shockwave Treatment for Management of Upper and Lower Extremity Musculoskeletal Conditions PMR 2018; 10(12): 1385-1403.
  9. Wang CJ, Huang HY, Pai CH. Shockwave-enhanced neovascularization at the tendon-bone junction: An experiment in dogs. J Foot Ankle Surg 2002; 41:16-22
  10. 10.0 10.1 Chen YJ, Wang CJ, Yang KD, et al. Extracorporeal shock waves promote healing of collagenase-induced Achilles tendinitis and increase TGF-beta1 and IGF-I expression J Orthop Res 2004; 22: 854-861
  11. 11.0 11.1 Wang FS, Yang KD, Chen RF, Wang CJ, Sheen-Chen SM. Extracorporeal shock wave promotes growth and differentiation of bone-marrow stromal cells towards osteoprogenitors associated with induction of TGF-beta. J Bone Joint Surg Br 2002; 84: 457-46.
  12. Rompe JD, Kirkpatrick CJ, Kullmer K, Schwitalle M, Krischek O. Dose-related effects of shock waves on rabbit tendo Achillis. A sonographic and histological study. J Bone Joint Surg Br 1998; 80: 546-552.
  13. Bosch G, Lin YL, van Schie HT, van De Lest CH, Barneveld A, van Weeren PR. Effect of extracorporeal shock wave therapy on the biochemical composition and metabolic activity of tenocytes in normal tendinous structures in ponies. Equine Vet J 2007; 39: 26-231
  14. Waugh CM, Morrissey D, Jones E, Riley GP, Langberg H, Screen HR. In vivo biological response to extracorporeal shockwave therapy in human tendinopathy. Eur Cell Mater 2015; 29: 268-280.
  15. Vahdatpour B, Taheri P, Zwre Zade A, Moradian S. Efficacy of Extracorporeal Shockwave Therapy in Frozen Shoulder. International Journal of Preventive Medicine 2014; 5(7): 875-881
  16. Wang CJ, Ko JY, Weng LH, Wang JW, Chen JM, Sun YC, Yang YJ. Extracorporeal Shockwave Shows Regression of Osteoarthritis of the Knee in Rats. J Surg Res. 2011; 171(2): 601-608.
  17. Rompe JD, Furia J, Cacchio A, Schmitz C, Maffulli N. Radial shock wave treatment alone is less efficient than radial shock wave treatment combined with tissue-specific plantar fascia-stretching in patients with chronic plantar heel pain. International Journal of Surgery. 2015;24:135-42.
  18. Ogden JA, Tóth-Kischkat A, Schultheiss R. Principles of shock wave therapy. Clinical Orthopaedics and Related Research (1976-2007). 2001; 387:8-17.
  19. Langmore Podiatry. Shockwave Therapy Demonstration. Available from: https://www.youtube.com/watch?v=P5dibaAu7pQ [last accessed 6/17/2018]