SHOCKWAVE: DOES IT WORK?

    1. A Little History
      1. Shockwave therapy, also known as ESWT, EPAT and RSWT. Originally used in the 80’s for kidney stone destruction. But now commonly has gained attention for being effective in treating Tendonopathies, Soft Tissue injuries, Non-Unions, Wound care. The purpose of this blog is to go over the actual biochemistry, application process, healing time and general question people have. 
    2. How It Works?
      1. There are two different types employed in medicine. There is the Focused one used for things like kidney stones and the other is “Non-Focused used for sports medicine application, wound care, non-unions. One way of looking at the difference between the two is to imagine an Olympic diver (focused) V.S. Someone belly flopping (non-Focused) into the water. Both produce the same amount of energy but the area where the energy is dispersed is different. The focused in needed in cases of kidney stones as they lie deeper in our bodies, while most sports medicine injuries are on the surface. Our main focus will be on the Non-focussed shockwave therapy as it applies to podiatric medicine. In our case we employ the use of a pneumatic machine with small hand piece that has a projectile inside it. The projectile rapidly then hits the end of the hand piece that is in contact with the patient’s skin. Creating a shockwave that goes to the affected part of the body.
    3. What Shockwave Do To Help Heal The Damaged Tissue ?
      1. On  a cellular level, these shockwave cause mechanical stress between cells. This is done by changes in pressure conditions. This activates certain chemical signal pathway that changes how cells behave with each other. This can be similar to the stress that an astronaut might feel when returning to earth. The stress from the extra gravity back on earth causes cells to respond by laying down new bone and make up for the bone loss that occurred in space. 

 

      1. From a Biochemistry standpoint many interesting things happen. In our tendon the shockwave causes increased amount TGF or Transforming Growth Factor-B1. This decreases the amount of fibrotic tissue. There is increase in IGF or Insulin Growth Factor-1. This helps promote growth of cells need in healing. There is an increase in PCNA or Proliferating Cellular Nuclear Antigen, which is needed for DNA repair. There is also an increase in Nitric Oxide a vasodilator which helps control inflammation and activates TGF and collagen synthesis. There is the increase in Lubricin, one of the things that make up synovial fluid. The synovial fluid which helps to lubricate and facilitate the movement of the tendons. 
      2. There is evidence which shows that there is a decrease in sensitivity to Substance P, a very potent pain signaling molecule in our body. 
      3. At the Bony Level, there is an increase in production of bone producing precursor cells along with reduction of osteoclasts which destroy bone. In Bone we have seen an increase in growth factors like VEGF, eNOS and PCNA) that are needed for repair and to promote blood flow to the area.
    1. What to Expect During A Shockwave Treatment?
      1. Usually the doctor or a trained medical assistant will perform the treatment. The whole treatment takes about 15-20 minutes each session. We like to ease our patient into the treatment as it can cause some discomfort when we first start. Initially we start with 500-700 pulses to help desensitize the area. From there we increase the intensity. Each treatment can range from 1500-2000 pulses. Patients generally tolerate the treatment very well. It can take up to 3-5 treatment before one starts noticing the results. We also employ other therapies such as icing, stretching and even physical therapy. 
      2. Best part of shockwave therapy, it can delay or completely negate the need for surgical intervention. 

References:

  1. Int J Surg.2015 Dec;24(Pt B):147-53. Shock wave as biological therapeutic tool: From mechanical stimulation to recovery and healing, throughmechanotransduction. d’Agostino MC, Craig K, Tibalt E, Respizzi S
  2. Proceedings of the National Academy of Sciences90 (2): 770–774. (1993). “Transforming growth factor beta 1 null mutation in mice causes excessive inflammatory response and early death.”. Kulkarni, A. B.; Huh, C. G.; Becker, D.; Geiser, A.; Lyght, M.; Flanders, K. C.; Roberts, A. B.; Sporn, M. B.; Ward, J. M.  
  3. Journal of Clinical Investigation110 (6): 771–781. (2002). “Circulating levels of IGF-1 directly regulate bone growth and density”. Yakar S, Rosen CJ, Beamer WG, Ackert-Bicknell CL, Wu Y, Liu JL, Ooi GT, Setser J, Frystyk J, Boisclair YR, LeRoith D
  4. Cell 129 (4): 665–79. (May 18, 2007). “PCNA, the maestro of the replication fork.”. Moldovan GL, Pfander B, Jentsch S 
  5. Am J Vet Res 2005; 66: 1702–1708. Evaluation of analgesia resulting from extracorporeal shock wave therapy and radial pressure wave therapy in the limbs of horses and sheep. McClure SR, Sonea IM, Evans RB, et al.
  6. Cell Tissue res. 346 (2) 2011 NOV, 255-262. Extracorporeal shockwave-induced expression of lubricin in tendons and septa. Znag, D. Kearney, CJ. Cheriyan, T.
  7. Brain2008 May 1;1207:96-101. Extracorporeal shockwave application to the distal femur of rabbits diminishes the number of neurons immunoreactive for substance P in dorsal root ganglia L5. Hausdorf J, Lemmens MA, Kaplan S, Marangoz C, Milz S, Odaci E, Korr H, Schmitz C, Maier M.
  8. Biochem biophys res commun. 287 (3) 2001 sept. 648-655. Physical shock wave mediates membrane hyperpolarization and Ras activation for osteogenesis in human bone marrow stromal cells. Wang, FS, wang CJ, Huang HJ, et al.
  9. JBJS br. 84 (3) 2002 Apr. 457-461. Extracorporeal shock wave promotes growth and differentiation of bone-marrow stromal cells towards osteoprogenitors associated with induction of TGF-beta 1. Wang FS, Yang KD, Chen RF. Et al.
  10. Vet Comp Orthop Traumatol. 2016 Mar 18;29(2):99-107. A review of the cellular and molecular effects of extracorporeal shockwave therapy. Chamberlain GA, Colborne GR