Exogen is a pulsed ultrasound device. The unit has a small transducer which is placed on the skin above the broken bone and emits low-intensity, pulsed ultrasound (LIPUS) waves through the skin and soft tissue to penetrate the bone.
I must apply the Exogen device on the blue X on my foot for 20 minutes a day for 4-months. If I start today, my treatment will be complete August 30, 2013. I needed to understand the science behind it because it seemed ridiculous to me that some ultrasounds would stimulate growth of bone until I understood the concept of piezoelectricity and the colagen in my bones.
I do not understand why people do not take the time to explain the science behind things. Once you understand the science, your outlook becomes more positive, you believe the treatment will work and if you believe, the chances of success increase.
Here is what the device will supposedly do:
•Early: The ultrasound waves encourage cells to remove cell debris and bacteria.
•Middle: The pulses stimulate the bone marrow to produce immature bone cells and cartilage cells. These two types of cells are essential to bone regrowth.
•Late: The pulsed waves stimulate the membrane around the bone to ‘seal up’ the fracture, allowing immature bone cells to collect and grow. The ultrasound signals also encourage the newly formed bone cells to mature more rapidly.
As to the science behind the invetion, all facts I will indicate below were pulled from:
In “Method for healing bone fractures with ultrasound” by Luiz R. Duarte (Source: http://www.google.ca/patents?hl=en&lr=&vid=USPAT4530360&id=Cj8aAAAAEBAJ&oi=fnd&dq=ultrasound+bone+healing&printsec=abstract#v=onepage&q=ultrasound%20bone%20healing&f=false)
Luiz Duarte States that the nominal frequency is 1.5 megahertz. The width of each pulse will vary between 10 and 2000 microseconds. The pulse repetitions will oscillate between 100 and 1,000 Hz. The power level of ultrasound is maintained below 100 miliwatts per square centimeter. The ultrasound, when it comes in contact with the bone, gets converted into an electric current which promotes Healing.
Piezoelectricity is an electric charge that accumulates in certain solid materials in response to applied mechanical stress. The Piezoelectricity concept was discovered by Jacques and Pierre Curie. Collagen is the element in bone in which piezoelectricity manifests itself. Collagen exhibits the polar uniaxial orientation of molecular dipoles in its structure and can be considered as bioelectret, a sort of dielectric material exhibiting quasipermanent space charge and dipolar charge. Potentials are thought to occur when a number of collagen molecules are stressed in the same way displacing significant numbers of the charge carriers from the inside to the surface of the specimen. Piezoelectricity of single individual collagen fibrils was measured using piezoresponse force microscopy, and it was shown that collagen fibrils behave predominantly as shear piezoelectric materials. The piezoelectric effect is generally thought to act as a biological force sensor. This effect was exploited by research conducted at the University of Pennsylvania. the late 1970s and early 1980s, which established that sustained application of electrical potential could stimulate both resorption and growth (depending on the polarity) of bone in-vivo. (Sources: Wikipedia: http://en.wikipedia.org/wiki/Piezoelectricity#Bone; http://en.wikipedia.org/wiki/Piezoelectricity)
In terms of statistics, studies of patients with previously unhealed broken bones that had not healed within one year showed successful heal rates of 86%. (Source: 3.Nolte PA, van der Krans A, Patka P, Janssen IMC, Ryaby JP, Albers GHR. (2001) Low-intensity pulsed ultrasound in the treatment of nonunions. J Trauma 51(4): 693-703)
My would is 5 weeks old and is not healing. I’m still young. I still have plenty of collagen in my bones. My body has not started to demineralize. All these factors will contribute to improving my chances of success. Now that I understand the science behind it, I’m very keen to start my treatment.
In layman’s terms, the ultrasound will convert into electricity within my fifth metatarsal which will activate the collagen which will regenerate new cells as a result of piezoelectricity. Simpler still, the device will stimulate bone growth.
I’m looking forward to walking, jogging, dancing, swimming, cycling, hiking and becoming self-reliant again.
Exogen, bring it on baby. Zap my X. Make my bone zing.