Pulsed Nd: YAGLaser versus Ultrasound in Treatment of Osteoporosis

Anwar Abdel gayed Ebid PhD, PT and Ali Abd El Monsif Thabet PhD, PT. Associate Professor Physical Therapy, Faculty of Applied Medical Science, Umm Al-Qura University, Kingdom of Saudi Arabia. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History

The beneficial effect of ultrasound on bone healing is due to the piezo-electric phenomenon Sheng et al., 2001. Bone is piezo-electric, which means that electric potentials are produced in bone when it is subjected to mechanical stress Hadjiargyrou 1998.
Previous study found that ultrasound stimulate osteogenesisin bone, stimulate osteoblasts to increase collagen productionRutten 2008, inhibiting mature osteoclasts from resorbing bone and stimulating osteoblasts for bone formation Doan 1999,stimulate vascularization Trelles 1987,organization of collagen fibers and ATP levels Garavello-Freitas 2003.
Laser has the ability to stimulate the attachment and proliferation of the human osteoblasts like cells cultured on titanium implant material indicating that LLLT can modulate the activity of cells surrounding implant material Khandra 2008. Also; laser improve collagen fiber deposition at early stages of the healing; increased amount of well-organized bone trabeculae at the end of the experimental period on irradiated animals Márquez 2008.
Laser light affects the mitochondrial respiratory chain and consequently their selective permeability for sodium, potassium and calcium ions, or by increasing the activity of certain enzymes such as cytochrome oxidase and adenosine triphosphatase. It also increases DNA synthesis, collagen and pro-collagen production and may increase the cell proliferation or alter locomotory characteristics of cellsLoevschall 1994. There was no study evaluate the comparison between laser and US.So our study was conducted to compare between pulsed high intensity lase and pulsed ultrasound in treatment of osteoporosis.

Material and methods:-
This was a 12-week randomized study with two measurement points' baseline (pre) and 12 weeks (post). Sixty osteoporotic patients were enrolled in this study. Inclusion Criteria:Their age between 40 to 65 years (to avoid inclusion of older patients with multiple medical problems) with no history of cancer, renal disease, gastrectomy, metabolic bone disease or any condition (such as a neurogenic,myopathic or connective tissue disorder) that could cause secondary osteoporosis. The participants did not intake any medications associated with accelerated bone loss (steroids) or any medications affected bone metabolism (calcium, vitamin D), nonsmoker, and led sedentary life style without participation at any exercise training during this study. All participants were given a full explanation of the treatment protocol and a written informed consent form giving agreement to participation and publication of results was signed by the patients.

Randomization:-
The participants in this study were randomly assigned into one of three groups (three randomized groups in a pretest-posttest design): Pulsed Nd: YAG laser group (LG, n=20), Low intensity ultrasound group (USG, n=20) and control group (CG, n=20). Subject characteristics (Mean ± SD) of all groups were listed in the table (1).
HILT was delivered in two different phases, Initial phase and terminal phase. In initial phase, three sub-phases of fast manual scan (every10 cm scanned in about 1.5 second) was performed to lumber region with increasing fluences (710-910-1530 mj/cm 2 ) and decreasing frequencies (30-20-15Hz) with total energy of 2000 juels reached 938 lumber region. In Final phase: 3 sub-phases of slow scanning (every 10 cm scanned in about three second) with increasing fluences (710-910-1530 mj/cm 2 ) and decreasing frequencies (30-20-15Hz) with total energy of 2000 juels reached lumber region. Scans can be longitudinal or transversal to the anatomical structure to be treated, ideally following a straight lines path. The irradiation was performed contact with the back and done in three phases (initial, intermediate and final phase) according to designed protocol for laser application.
Pulsed low intensity ultrasound:-Ultrasound group received low intensity ultrasound on the lumbar region (L 1-5 ), 3 times/weeks, 10 minutes for 12 weeks. Low intensity ultrasound was composed of a pulse width of 200 μs containing 1.5MHz sine waves, with a repeated frequency of 1.0 kHz with a spatial-averaged temporal-averaged intensity of 30 mW/cm2Warden et al., 2001. Before the application of LIUS, its output characteristics were measured by hydrophonic scanning. The treatment procedure was explained to all subjects. Skin was cleaned with alcohol. During the irradiation, the position of the subjects was the same for both groups (prone lying position with a pillow under her abdomen).
Outcome measures include BMD assessed by DEXA (Dual x-ray Absorptiometry (DXA) (Model QDR-1000W, Hologic, Inc., Waltham, MA) was used for the qualitative assessment of BMD in the vertebral bodies of the lumbar spine for both groups. DEXA performs an imaging test that measures bone density by passing x-rays with two different energy levels through the bone. It is used to diagnose osteoporosis (decrease in bone mass and density). It is also called bone mineral density scan (BMD scan).

Statistical analysis:-
All data were assessed using SPSS version 16.0. Data were tested by Shapiro-Wilk test and were normally distributed. Data were statistically analyzed using repeated measures ANOVA to test hypothesis and to assess both within and between variabilities. Results are reported as means and standard deviations. For all procedures, significance was accepted at the alpha level of 0.05.

Results:-
Sixty subject participated in this study. Their age ranged from 40 to 65 years with a mean (54.47± 5.17). Their weight ranged from 58 to 85 kg with mean weight 76.7 ± 7.4 and their height ranged from 162 to 178 cm with a mean 172.04 ± 5.46 cm. Un paired t-test showed a non-significant difference between the subjects age, weight and height as p value was 0.57, 0.45 and 0.36 respectively, also; there was no significant difference between all groups at baseline values (p=0.2289), table 1. There was a significant increase in T-score after 12-weeks in the laser and ultrasound groups as compared with baseline values. By comparing the two values after 12 weeks there no significant difference in T-score between laser and ultrasound groups (p=0.8453 and t=0.1965) as shown in table 1.

Discussion:-
The result of the this study showed that the HILT and PUS was effective in increasing the bone mineral density after 12 weeks of treatment and the effect of both modality nearly equal without significant difference in between. Many studies have examined possible treatments and prevent ivestrategies to deal with the boneloss in osteoporosis. Low intensity pulsed ultrasound (LIPUS) was proven to enhance fracture healing effectively; also pulsed ultrasound can be applied clinically to enhance both normal and osteoporotic fracture healing The majority of studies conducted over the last thirty years in laser therapy have been carried out with medium and low intensity Laser devices (Low Level Laser Therapy: LLLT), with wavelengths in the infrared and near infrared 600 -900 nm . Within this spectrum the Laser beam is partially absorbed by the natural chromophores, like melanin, which withhold part of the energy irradiated. This study on the other hand is based on the use of Nd: YAG Pulsed High Intensity Laser Therapy (HILT), which characterized by a wavelength 1046 nm that allows it to penetrate and spread more easily through the tissue due to not having an endogenous chromophoreParraetal.

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A study conducted by Paulo Sérgio et al 2012 on the effect of low level laser therapy (LLLT) on osteoprotic rat using two fluence of laser doses and the authors conclude that LLLT improves bone repair in the osteoporotic rats as a result of stimulation of the newly formed bone, fibrovascularization and angiogenesis. Laser light affects the mitochondrial respiratory chain by changing the electric potential of cell membranes and, consequently, their selective permeability for sodium, potassium and calcium ions, or by increasing the activity of certain enzymes such as cytochrome oxidase and adenosine triphosphatase. It also increases DNA synthesis, collagen and pro-collagen production, and may increase the cell proliferation or alter locomotory characteristics of cellsNoble 1992.
Some authors affirm that low laser light treatment can accelerate bone formation by increasing osteoblasticactivity,vascularization, organization of collagen fibers Noble 1992.Recent studies are suggesting the use of higher laser dosages to stimulate bone metabolism Rennó et al., 2006. In an in vitro study, our group comparing the effects of the 830 nm laser, at the dosages of 1, 5 and 10 J/cm2, showed that the higher dosage was more efficient to produce an increase of osteoblast proliferation and alkaline phosphatase activity. These findings further support the notion of cell/tissue, and dose/wavelength specificities. Also; the 830 nm laser irradiation, at 120 J/cm2, was able to increase the biomechanical properties and bone mineral density of osteopenic rats Rennó et al., 2006.

Conclusion:-
Pulsed high intensity Nd: YAG laser photostimulationand pulsed ultrasound have a favorable beneficial effects on bone mineral density in treatment of osteoporosis