Growth plate research

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Found a 2010 article, but results are unequivocal. (attached)

Sheri MorrowDusty, UD, RAStrider and PippinCardigan Welsh Corgis

To: vetrehab Sent: Wednesday, December 28, 2011 2:34:56 PMSubject: RE: Re: Q 1000

Sheri,Thank you for sharing this. My question with this case report is whether it translates to LLLT given that this CO2 LASER burned through tissue and exposed bone, which may mean the growth plate received thermal damage. Thoughts?

To: VetRehab From: msstrider@...Date: Wed, 28 Dec 2011 15:20:51 -0500Subject: Re: Re: Q 1000 [1 Attachment]

[Attachment(s) from Sheri included below] I found an article on Physeal Arrest in a 5 year old following laser treatment of warts. They reference an older article done on Rabbit growth plates. Hope the article attaches.

Sheri MorrowDusty, UD, RAStrider and PippinCardigan Welsh Corgis

> > > > > > > > > > > > > > > > > > > > > > > > > > > I couldn't send an attachment so here is the proceedings. I hope this helps.> > Laurie> > > > Laser as a Therapeutic Modality> > Laurie McCauley, DVM> > TOPS Veterinary Rehabilitation> > Canine Rehabilitation Institute> > > > Laser stands for "light amplification by stimulated emission of radiation." Albert Einstein first introduced this concept in 1917. Low Level Laser Therapy (LLLT) is the stimulation of tissue with low energy lasers to achieve a therapeutic effect. Some of the effects at a cellular level include increased ATP production in the cells, enhancing Na-K pump function, enzymatic activation, macrophage activity, cell proliferation, release of growth factors by fibroblasts, proliferation of T and B lymphocytes, and production of extracellular matrix, . At a tissue level there is decrease in oedema and hyperkeratotic lesion formation, an increase in lymphatic peristalsis, collagen synthesis with matrix-tissue remodeling, lymphatic and vascular regeneration, angiogenesis and circulation. At the patient level there is a reduction in pain via the gate theory and an endorphin release, diminishing or elimination of fibrous tissue, and a stimulation of healing both at a skin level and below. LLLT's most common indications include treating pain associated with degenerative joint disease; IVDD; acute and chronic sprains, strains, tendonitis, and bursitis; acute and chronic otitis and gingivitis; and skin lesions including hot spots, anal gland ruptures, lick granulomas, and clean and contaminated wounds. Lasers can also be utilized to stimulate acupuncture points in patients that can not tolerate needles. Different Laser diodes can only put out a brief spectrum of wavelengths and so you will commonly see wavelengths in the 630-660nm range, 808nm, 904-905nm range, and 970-980nm range being used in therapeutic lasers. Penetration is mostly dependent on wavelength with 630-700nm wavelength penetrating 0.5-1cm, 700-800nm penetrating 2-3 cm, 800-970nm penetrating 3-4 cm, 970-990nm penetrating 1-2 cm, and 990-1200nm penetrating 4-5cm. Absorption of laser energy is dependent on the type and quantity of chromophores present in the tissue. Their composition, which is different depending on the tissue type, determines the response of the tissue itself to the laser radiation at a certain wavelength. Each kind of chromophore absorbs only some specific wavelengths and let the other ones pass. The main chromophores are melanin, hemoglobin, and water. Although water has the least effect of the chromophores, treating a wet patient significantly decreases the amount of penetration. Water absorbs wavelengths most in the 900-1,000nm range. Melanin absorbs more energy at lower wavelengths (600-800nm compared to 800-970nm though it is a linear effect). Darker skin or coated patients will have deeper penetration with higher wavelengths. If you have a lower wavelength, scanning with lower power will allow you to get the desired effect without heating the tissue. Hemoglobin is least absorbed in the 630-830nm wavelength with the most absorption, causing least penetration, in the 900nm and above range. Therefore if your laser is in the 900-1,000nm range, compression of the tissue will be important to allow for best penetration. > > When laser light hits tissue several things happen, we will discuss each one and how to make the most of the energy you are applying. Reflection is when light hits the tissue and bounces off, there is no effect on the tissue. If the laser is 2 cm off of the skin, 20% of the light energy is lost due to reflection. If pressure is utilized, penetration of the laser energy is increased, most likely by physically pushing blood out of the tissue (ischemia) due to the hemoglobin reduction and the physical act of stretching the skin decreasing the melanin concentration. One study showed coupling with pressure increased transmission rate by 51.5% compared with using contact without pressure, and 92.6% compared with using a 2-mm skin-diode distance. > > Transmission is when energy passes through tissue to penetrate to a deeper level. > > Scattering is when energy passes through tissue but changes direction as it goes through. This allows for effects in the tissue adjacent to where treatment takes place. When point to point techniques are used, you place the laser not immediately next to what you have just treated, but past where you expect the radiation to have an effect, so that the tissue in between points is not over treated. Be careful when treating at an angle, for example pointing in toward the CCL, so as not to put too much energy into the tissue as this can cause pain and detrimental effects. > > Absorption is when the energy stops within a cell and where it has the most effect. If too much energy is put into the tissue, there are detrimental effects. According to the Arndt-Schulz law of treating an open ulcer, the most therapeutic effects are at 0.1 to 4J/cm² with detrimental effects just over 10J/cm². > > Penetration depth is defined as the depth after which the intensity of laser light is reduced of a factor = e (=2.718 ~ 3) according to the Lambert Beer Law. From the definition the penetration depth depends on wavelength and tissue type; it is independent on laser power (W) and laser intensity at the tissue surface (W/cm2). Think of this like trying to water the garden with a hose, if more volume (the speed that the water comes out of the hose) is used you will not get the water to soak into the dirt faster and if too much volume is used, damage to the garden occurs. The optimum "volume" is still being determined, but looking at the research, I have found no studies that show 10J/cm² or over to be beneficial and several that show 10J/cm² having detrimental effects. As to how much energy is used to treat different conditions, the research I have found indicates to deliver a fairly low doses over a longer period of time to optimize anti-inflammatory results as well as for the stimulation of cell proliferation. This means that, at least for healing processes, low power over long time is more effective than high power over short time, even if the total energy is the same. This would be the best indication of using a scanning technique. The flip side is true for temporary analgesia of painful conditions, where a high power over short period of time can produce a better effect. This would be a better indication for using a point to point technique. There are of course thresholds of too little or too much energy causing no effect or a detrimental effect. The optimal dose for human musculo-skeletal conditions can be found at www.walt.nu. The interesting thing is that there are different recommendations for J/cm² if you are using a 904nm wavelength vs. an 808nm wavelength laser. For instance, arthritis of the hip, one of the highest dose recommendations, is a minimum 2 points of 2-4 J for the 904nm wavelength lasers and a minimum of 2-4 points of 6 J for the 780-860nm wavelength lasers. A dose range +/- 50% of given dose is acceptable, but outside of this range is not. The website recommends that once inflammation is gone to reduce the power by 30%. This directly contradicts other sources that say that inflammation is best treated with lower amounts of energy. Other recommendations at this website include treating daily for 2 weeks or every other day for 3-4 weeks. > > > > As in all modalities there are contraindications, these include: Over areas of suspicious or known neoplasia so as not to enhance the blood supply to the area and enhance cell proliferation, over areas of active hemorrhage as this could potentiate hemorrhage, over areas injected with steroids in the past 2-3 weeks, over the chest if there is a pacemaker, over prominent nerves, over the carotid sinus region as it could potentially change the patients blood pressure, and over open growth plates as they could prematurely close.> > > > > > > > >> > > > > I have started working at a practice that has a Q1000 laser. It if certified as a Class I laser. Are class I lasers therapeutic?( It has wavelengths ranging form 470 - 940. The power per diode is less than 5 mW. It has 8 light emitting diodes and 12 laser diodes. Total output per cycle is 3-9 J.)> > > > > I wondering if any on has used this laser or is familiar with it. Does it reach a depth that would treat these conditions? I know depth is wavelength dependent but with variable wavelengths how deep am I really treating with the number of Joules put out? If you have one what are you using it for? Currently it's being using at our clinic to help with healing post op. We are looking at getting a class III laser but as the one that does rehab. in the clinic I want to clarify what the lasers do and what their optimal uses are. Thanks for any help.> > > > > > > > > > Dr. Falch> > > > >> > > > > > > >> > >>

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Effect Rat Cartilage_2010_Cressoni.pdf