Low-level Laser Energy Research Articles

Whole-length great saphenous varicose veins thermochemical ablation, a novel technique: safety, efficacy, and mid-term follow-up results

Background Despite all advances in the treatment of varicose veins, recurrence rates are still high, and multiple factors have been incriminated. This study aims to evaluate the safety and efficacy of whole-length great saphenous vein ablation, starting flush with the saphenofemoral junction down to the ankle, using a new technique combining laser and chemical ablations. Patients and methods A prospective study was conducted that included patients with varicose veins who presented to the Vascular Surgery Department, Dr. Soliman Fakeeh Hospital, KSA, in the period from May 2016 to February 2018. All patients were treated with endovenous laser ablation of the whole great saphenous vein starting flush at the saphenofemoral junction using radial fiber combining low-level laser energy with truncal injection sclerotherapy for the below-the-knee vein segment with adjusted linear endovenous energy density. Patients were followed up for 18 months. Chronic venous disease quality of life questionnaire-20 (CIVIQ-20) was obtained before treatment and after 6–12 months. Results This study included 125 patients (132 limbs), their mean age was 40.4±11.8 years, male to female ratio was 1 : 2.4, Clinical, Etiological, Anatomical, Pathological (CEAP) classification was 2–6, the presentation was bilateral in seven (5.6%) patients, technical success was achievable in 99.3% of patients, need for extra-truncal treatment at the same time of ablation (laser, injection, or phlebotomy) in 64 (48.5%) patients, postoperative deep vein thrombosis was seen in 0%, saphenous nerve injury was seen in one (0.7%) case, recanalization at 6–12–18 months was seen in two (1.5%) cases, and improvement in CIVIQ-20 from 71.25±9.6 to 32.4±4.6 and 29.7±1.2 was seen at 6 and 12 months, respectively. Conclusion The use of the radial laser fiber allows safe flush thermal ablation of the great saphenous vein, with the anticipated decrease in groin recurrence, combined with thermochemical ablation of the below-the-knee segment has promising result in short-term and mid-term follow-up.

Painless Laser Acupuncture for Smoking Cessation.

Objective: Traditional Chinese Medicine (TCM) in healthcare is based on the holistic concept of smooth energy flow. The energy helps maintain the circulation of Blood and bodily processes. An efficient supply of consistent energy and good circulation helps support the body's homeostasis. In therapeutics, low-level laser energy can be transferred to the body (via the auricle) to activate or maintain homeostasis through specifically appropriate auricular sites. The goal of this research was to track the effects of painless laser acupuncture (PLA) on a group of highly motivated patients who wanted to quit smoking. Materials and Methods: Executives in their early 30s-50s, who were highly motivated and stressed individuals were treated. Most of these 175 patients smoked 1 pack of cigarettes per day (20 cigarettes), with a few patients smoking more than 1 pack per day. The treatment consisted of PLA applied to both auricular and body acupuncture points in a total of 7 sessions. Results: There was general satisfaction among the patients about the treatment. Of 24 females (13.72%), 21 (87.50%) did not smoke after completing the 7 sessions. Two women reported that despite not having real cravings to smoke, they smoked 1-2 cigarettes per day. One woman (4.12%) reported that she smoked 2-3 cigarettes. Conclusions: The PLA technique for smoking cessation, combined with the principles of TCM, not only helps smokers stop smoking but also restores their homeostasis and good health. By selecting the optimal auricular and body acupuncture points and meridian channels and applying laser energy dosages, the homeostatic hence healing process can be synergized.

Effect of Low-Level Laser Therapy on Bone Regeneration During Osseointegration and Bone Graft.

The effect of low-level laser therapy (LLLT) on bone regeneration during osseointegration and bone graft is very controversial. Despite many positive reports of in vitro and in vivo studies and more than 50 randomized clinical trials claiming a positive effect of photobiomodulation (PBM), many reports found no significant effect of lasers. The aim of this study was to evaluate studies correlating PBM and bone regeneration and to assesses parameters that produce positive results based on dose and output power used. Four electronic databases were used: PubMed, Springer, Google Scholar, and Cochrane. The research yielded 230 articles. The full texts of all articles were evaluated and scored using eligibility criteria adapted from Cericato et al. After evaluation, only 19 articles met the inclusion criteria. A positive effect of low-level laser energy on bone regeneration within a certain relationship between dose and output power was found. LLLT stimulates cellular metabolism, increasing protein synthesis and subsequent bone regeneration. A high dose combined with low power or a low dose combined with high power appears to produce a positive effect.

Evaluating low-level laser therapy effect on reducing orthodontic pain using two laser energy values: a split-mouth randomized placebo-controlled trial.

No randomized controlled trial before has evaluated the role of low-level laser energy in its analgesic effects in orthodontics. To evaluate the effect of single application of low-level laser with 4-Joule or 16-Joule energy on pain reduction following elastomeric separators placement. A two-arm parallel-group single-blind placebo-controlled randomized controlled trial, with implementation of split-mouth technique in each group. Twenty-six patients in need of orthodontic treatment with a fixed orthodontic appliance were enrolled and randomly allocated to either the 4-Joule or the 16-Joule laser energy group. Elastomeric separators were applied for the mandibular first molars. For each patient one molar received a single low-level laser dose using an 830-nm Ga-Al-As laser device with either 4-Joule or 16-Joule laser beam energy, while the other molar received a placebo treatment by applying the laser device in the same method and parameters as the counterpart molar without emitting the laser beam. The molar to be irradiated was also randomly chosen using simple randomization technique. Allocation was concealed and patients were blinded to which side would receive the laser irradiation. Main outcome measure was the degree of pain scored during mastication for each mandibular first molar after 1, 6, 12, 24, 48, and 72 hours of both laser and placebo treatments application. A questionnaire with an 100-mm Visual Analogue Scale (VAS) was used for pain assessment. Thirty-six patients were evaluated for eligibility, 10 of them were excluded making the final randomized number 26 patients. One patient dropped out later for not completing the questionnaire. Accordingly, the results of 25 patients were statistically analysed. No statistical significance was found for both low-level laser energy values in comparison to the corresponding placebo treatments. No harms were encountered. Intervention provider was not blinded to the intervention. Low-level laser therapy, applied at two different laser energy values, is ineffective in relieving elastomeric separators induced orthodontic pain. This trial was not registered. No funding to be declared.

Analysis of the variation in low-level laser energy density on the crushed sciatic nerves of rats: a morphological, quantitative, and morphometric study.

The objective of this study was to evaluate three energy densities of low-level laser therapy (LLLT, GaAlAs, 780nm, 40mW, 0.04cm2) for the treatment of lesions to peripheral nerves using the sciatic nerve of rats injured via crushing model (15kgf, 5.2MPa). Thirty Wistar rats (♂, 200-250g) were divided into five groups (n = 6): C-control, not injured, and irradiated; L0-injured nerve without irradiation; L4-injured nerve irradiated with LLLT 4J/cm2 (0.16J); L10-injured nerve irradiated with LLLT 10J/cm2 (0.4J); and L50-injured nerve irradiated with LLLT 50J/cm2 (2J). The animals were sacrificed 2weeks after the injury via perfusion with glutaraldehyde (2.5%, 0.1M sodium cacodylate buffer). The nerve tissue was embedded in historesin, cut (3μm), mounted on slides, and stained (Sudan black and neutral red). The morphological and quantitative analysis (myelin and blood capillary densities) and morphometric parameters (maximum and minimum diameters of nerve fibers, axon diameter, G-ratio, myelin sheath thickness) were assessed using the ImageJ software. ANOVA (parametric) or Kruskal-Wallis (nonparametric) tests were used for the statistical analysis. Groups L0, L4, L10, and L50 exhibited diminished values of all the quantitative and morphometric parameters in comparison to the control group. The morphological, quantitative, and morphometric data revealed improvement after injury in groups L4, L10, and L50 (irradiated groups) compared to the injured-only group (L0); the best results, in general, were observed for the L10 group after 15days of nerve injury.

Efficiency of low-level laser therapy within induced dental movement: A systematic review and meta-analysis

The low level laser is widely used in Dentistry, in particular, to decrease pain and increase the speed of tooth movement. This study was to perform a systematic literature search to investigate the effectiveness of low level laser and low energy density therapy of the induced tooth movement.This research was performed following the PRISMA instructions and was registered in the PROSPERO. The articles were searched in six electronic databases, with no date and language restriction. Only randomized clinical trials were selected. Articles that did not use the extraction of first premolars as orthodontic planning were excluded, as well as articles using high energy density laser therapy. The articles were assessed for risk of bias and individual quality. The results were analyzed using meta-analysis, using randomized effect.The initial sample consisted of 161 articles. Six articles remained eligible for qualitative analysis and five for quantitative analysis. According to the individual quality, most articles were classified as high quality. Three articles detected statistically significant differences in induced movement by comparing the orthodontic movement between the experimental and control groups. For the maxilla, there was a statistically significant influence of the laser in three months and, for the mandible, in one month.It may be concluded that there is no evidence that laser therapy can accelerate the induced tooth movement.

Is Adjuvant Laser Therapy Effective for Preventing Pain, Swelling, and Trismus After Surgical Removal of Impacted Mandibular Third Molars? A Systematic Review and Meta-Analysis

To assess the efficacy and safety of low-level laser energy irradiation (LLEI) for decreasing pain, swelling, and trismus after surgical removal of impacted mandibular third molars (IMTMs). MEDLINE, EMBASE, and the Central Register of Controlled Trials of the Cochrane Library were searched from their inception, and conference proceedings, cross-references, and gray literature were searched for the last 5 years for randomized and quasi-randomized controlled trials that evaluated the effects of any type of LLEI, compared with active or inactive treatments, in patients undergoing surgical removal of IMTMs. Risk of bias in included studies was assessed by 2 independent evaluators using the Cochrane Risk of Bias tool. A random-effects model meta-analysis was used to estimate the mean difference of trismus between the groups. Heterogeneity was assessed using Cochran χ(2) and I(2). Ten eligible trials were included in this systematic review. The included studies overall had a moderate risk of bias. Because of heterogeneity in the intervention and outcomes assessments, pain and swelling outcomes were only qualitatively summarized and indicated no beneficial effects of LLEI over placebo. Patients receiving LLEI had an average of 4.2 mm (95% confidence interval, 1.2 to 7.2) and 5.2 mm (95% confidence interval, 1.8 to 8.2) less trismus than patients receiving no active treatment on the second and seventh day after the surgery, respectively. There was no benefit of LLEI on pain or swelling and a moderate benefit on trismus after removal of IMTMs. It is necessary to standardize the intervention and outcomes assessment and to conduct adequately powered, well-designed trials to evaluate the efficacy of LLEI.

Reduction in thigh circumference and improvement in the appearance of cellulite with dual-wavelength, low-level laser energy and massage

Objectives: This study evaluated the efficacy and safety of a low-level, dual-wavelength laser energy and massage device for improving the appearance of cellulite and reducing thigh circumference. Methods: Subjects (n = 83) with mild to moderate cellulite enrolled in this IRB-approved, open-label, multicenter study. Their right or left thighs received eight treatments with a low-level, dual-wavelength laser and massage device. The untreated contralateral thigh served as a control. Circumferences of the upper, middle, and lower thighs (treated and untreated) were measured before the fifth and eighth treatments and 1 month after the final treatment. Results: Reduction in thigh circumference of the treated areas exceeded those of the control areas for the upper, middle, and lower thigh in most subjects. The maximum reduction (−0.82 cm) occurred in the upper thigh at 1 month. The mean reduction of the upper, middle, and lower thigh circumferences was −0.64 cm for the treated thighs compared to −0.20 cm for untreated thighs. The difference was significant (p < 0.0001). Fifty-nine (71.1%) treatment thighs lost circumference compared to 44 (53.0%) control thighs. Resolution of adverse effects including erythema, swelling, and increased urination was seen within 30 minutes after treatment. All were resolved without sequelae and within the expected duration. Conclusion: The low-level, dual-wavelength laser energy and massage device safely improves the appearance of cellulite while reducing thigh circumference.

New Abdominal Acupuncture: Description With Clinical Examples

Abstract A number of well-known acupuncture microsystems are used in contemporary clinical practice including the auricular acupuncture system of Nogier, the scalp acupuncture system of Yamamoto, and the hand acupuncture system of Yoo. These microsystems are based on the discovery of a somatotopic relationship of a particular body area to functional areas of the cerebral cortex. Zhiyun Bo introduced an abdominal acupuncture microsystem in 1991 and published the first text on this microsystem in 1999. Accurate localization of acupuncture points on any of these microsystems in clinical practice can be difficult. A novel technique to rapidly and accurately localize microsystem acupoints via stimulation of those points with low-level laser energy is described herein. This technique can be used with any acupuncture microsystem and when applied to the abdominal acupuncture microsystem, is termed the New Abdominal Acupuncture (NAAP). NAAP produces rapid clinical improvements with durable results; clinical exampl...

Effects of Laser on the Synovial Fluid in the Inflammatory Process of the Knee Joint of the Rabbit

The purpose of this study was to evaluate the effects of low-level laser (LLL) energy on the clinical signs of inflammation and the cellular composition of synovial fluid (SF) in the inflamed knee of the rabbit. There are few findings related to the effects of LLL on SF in inflammatory processes and there is little knowledge about the optimal parameters for reducing joint inflammation. Inflammation in the right knee of 36 rabbits was induced by intracapsular injection (0.2 mL) of Terebinthina commun (Tc). The animals were randomly assigned to three groups: acute experimental group (AEG), chronic experimental group (CEG), and control group (CG), which only received Tc. Each group was divided in two subgroups of six animals each. The AEG and CEG groups began to receive laser treatment 2 and 5 d after the induction of inflammation, respectively. Laser irradiation at a wavelength of 830 nm, power output of 77 mW, and power density of 27.5 W/cm(2) was applied daily for 7 d for either 0.12 sec or 0.32 sec, resulting in doses of 3.4 J/cm(2) and 8 J/cm(2), respectively. Body mass, joint perimeter, joint temperature, and the morphology of the SF were analyzed. There was no statistically significant differences between groups in the body mass, joint perimeter, and SF morphology. Laser irradiation with the selected parameters produced only a few subtle differences in the inflammatory signs and the SF. The lack of effects may have been due to the short irradiation time.

Low-Power Laser Treatment in Patients with Frozen Shoulder: Preliminary Results

In this study I sought to test the efficacy of low-power laser therapy (LLLT) in patients with frozen shoulder. The use of low-level laser energy has been recommended for the management of a variety of musculoskeletal disorders. Sixty-three patients with frozen shoulder were randomly assigned into one of two groups. In the active laser group (n = 31), patients were treated with a 810-nm Ga-Al-As laser with a continuous output of 60 mW applied to eight points on the shoulder for 30 sec each, for a total dose of 1.8 J per point and 14.4 J per session. In the placebo group (n = 32), patients received placebo laser treatment. During 8 wk of treatment, the patients in each group received 12 sessions of laser or placebo, two sessions per week (for weeks 1-4), and one session per week (for weeks 5-8). Relative to the placebo group, the active laser group had: (1) a significant decrease in overall, night, and activity pain scores at the end of 4 wk and 8 wk of treatment, and at the end of 8 wk additional follow-up (16 wk post-randomization); (2) a significant decrease in shoulder pain and disability index (SPADI) scores and Croft shoulder disability questionnaire scores at those same intervals; (3) a significant decrease in disability of arm, shoulder, and hand questionnaire (DASH) scores at the end of 8 wk of treatment, and at 16 wk posttreatment; and (4) a significant decrease in health-assessment questionnaire (HAQ) scores at the end of 4 wk and 8 wk of treatment. There was some improvement in range of motion, but this did not reach statistical significance. The results suggested that laser treatment was more effective in reducing pain and disability scores than placebo at the end of the treatment period, as well as at follow-up.

Comparison Between the Effect of Low-Level Laser Therapy and Low-Intensity Pulsed Ultrasonic Irradiationin Vitro

The objective of this study was to compare the effect of low-level laser therapy (LLLT) and low-intensity pulsed ultrasound (LIPUS) on fibroblast cell culture. Several methods, including ultrasound treatment and LLLT, are being used to facilitate tissue repair and healing processes. L929 fibroblast cell cultures were irradiated with low-level laser energy and LIPUS. Cultures irradiated with ultrasound were divided into five groups: group 1: control (did not receive irradiation); group 2: 0.2 W/cm(2) in pulsed mode at 10% (1:9 duty cycle); group 3: 0.6 W/cm(2) in pulsed mode at 10% (1:9 duty cycle); group 4: 0.2 W/cm(2) in pulsed mode at 20% (2:8 duty cycle); and group 5: 0.6 W/cm(2) in pulsed mode at 20% (2:8 duty cycle). Cultures irradiated with laser energy were divided into three groups: group 1: control (did not receive irradiation); group 2: 6 J/cm(2); and group 3: 50 mJ/cm(2). Each group was irradiated at 24-h intervals, with the following incubation periods post-irradiation: 24, 48, and 72 h; after each irradiation cycle the cultures were analyzed using MTT [3-(4.5-dimethylthiazol-2-yl)-2.5 diphenyltetrazolium bromide]. Analysis of results after LLLT and LIPUS demonstrated that the effect of laser therapy on fibroblast cell culture was greater than that of LIPUS (p < 0.05). Results demonstrated that LLLT significantly increased fibroblastic activity more than LIPUS. Therefore, in the first and second phases of tissue repair, laser treatment may be more effective than ultrasound treatment.

The effect of 880 nm low level laser energy on human fibroblast cell numbers: a possible role in hypertrophic wound healing

Low level lasers (LLLs) have been shown to induce therapeutic effects in wound healing. However, there have been few LLL studies on burn wounds which may become unsightly, hypertrophic and impair function. Inhibitory effects on the healing of fibrotic wounds, prone to hypertrophy may be expected to reasonably reduce the problems accompanying hypertrophic scarring. The effects of LLL wavelengths and treatment parameters on wound healing cells in vitro often demonstrate meaningful results and without concurrent ethical difficulties of clinical trials. This experiment investigated the effect of an 880 nm, 16 mW GaAlAs diode at 2.4 and 4 J/cm 2 on cell numbers of two human fibroblast cell lines, derived from hypertrophic scar (HF) and normal dermal explants (NF), respectively. After irradiation by 880 nm LLL, cell numbers were measured utilising methylene blue bioassay and read by the spectrophotometer in the same microculture plates. HF and NF exhibited decreased cell numbers as compared to sham-irradiated controls. HF cell number, after 2.4 J/cm 2, was significantly lower on day 5 ( P<0.05). The NF cell numbers were significantly lower on day 4 and/or day 5 ( P<0.05). The results have implications on hypertrophic wound healing and further studies are required.

Fat liquefaction: effect of low-level laser energy on adipose tissue.

Low-level laser energy has been increasingly used in the treatment of a broad range of conditions and has improved wound healing, reduced edema, and relieved pain of various etiologies. This study examined whether 635-nm low-level lasers had an effect on adipose tissue in vivo and the procedural implementation of lipoplasty/liposuction techniques. The experiment investigated the effect of 635-nm, 10-mW diode laser radiation with exclusive energy dispersing optics. Total energy values of 1.2 J/cm(2), 2.4 J/cm(2), and 3.6 J/cm(2) were applied on human adipose tissue taken from lipectomy samples of 12 healthy women. The tissue samples were irradiated for 0, 2, 4, and 6 minutes with and without tumescent solution and were studied using the protocols of transmission electron microscopy and scanning electron microscopy. Nonirradiated tissue samples were taken for reference. More than 180 images were recorded and professionally evaluated. All microscopic results showed that without laser exposure the normal adipose tissue appeared as a grape-shaped node. After 4 minutes of laser exposure, 80 percent of the fat was released from the adipose cells; at 6 minutes of laser exposure, 99 percent of the fat was released from the adipocyte. The released fat was collected in the interstitial space. Transmission electron microscopic images of the adipose tissue taken at x60,000 showed a transitory pore and complete deflation of the adipocytes. The low-level laser energy affected the adipose cell by causing a transitory pore in the cell membrane to open, which permitted the fat content to go from inside to outside the cell. The cells in the interstitial space and the capillaries remained intact. Low-level laser-assisted lipoplasty has a significant impact on the procedural implementation of lipoplasty techniques.

Fat Liquefaction: Effect of Low-Level Laser Energy on Adipose Tissue

Fat Liquefaction: Effect of Low-Level Laser Energy on Adipose Tissue

Radiothérapie bifractionnée et chimiothérapie par cisplatine et 5-fluoro-uracile concomitantes dans les carcinomes épidermoïdes localement évolués non résécables du pharynx : dix ans d’expérience au centre Antoine Lacassagne

Purpose. – Patients suffering from locally advanced unresectable squamous cell carcinoma of the oropharynx and hypopharynx treated with radiotherapy alone have a poor prognosis. More than 70% of patients die within 5 years mainly due to local recurrences. The aim of this study was to evaluate retrospectively the Antoine Lacassagne Cancer Center’s experience in a treatment by concomitant bid radiotherapy and chemotherapy. Evaluation was based on analysis of the toxicity, the response rates, the survival, and the clinical prognostic factors. Patients and methods. – From 1992 to 2000, 92 consecutive patients were treated in our single institution. All of them had stage IV, unresectable squamous cell carcinoma of the pharynx and they received continuous bid radiotherapy (two daily fractions of 1.2 Gy, 5 days a week, with a 6-h minimal interval between fractions). Total radiotherapy dose was 80.4 Gy on the oropharynx and 75.6 Gy on the hypopharynx. Two or three chemotherapy courses of cisplatin (CP) -5-fluorouracil (5FU) were given during radiotherapy at 21-day intervals (third not delivered after the end of the radiotherapy). CP dose was 100 mg/m 2 (day 1) and 5-FU was given as 5-day continuous infusion (750 mg/m 2/day at 1st course; 430 mg/m 2/day at 2nd and 3rd courses). Special attention was paid to supportive care, particularly in terms of enteral nutrition and mucositis prevention by low-level laser energy. Results. – Acute toxicity was marked and included WHO grade III/IV mucositis (89%, 16% of them being grade IV), WHO grade III dermatitis (72%) and grade III/IV neutropenia (61%). This toxicity was significant but manageable with optimised supportive care, and never led to interruption of treatment for more than 1 week, although there were two toxic deaths. Complete global response rate at 6 months was 74%. Overall global survival at 1 and 2 years was 72% and 50% respectively, with a median follow-up of 17 months. Prognostic factors for overall survival were the Karnofsky index (71% survival at 3 years for patients with a Karnofsky index of 90–100% versus 30% for patients with a Karnofsky index of 80% versus 0% for patients with a Karnofsky index of 60-70%, p = 0.0001) and tumor location (55% at 3 years for oropharynx versus 37% for panpharynx versus 28% for hypopharynx, p = 0.009). Conclusion. – These results confirm the efficacy of concomitant bid radiotherapy and chemotherapy in advanced unresectable tumor of the pharynx. The improvement in results will essentially depend on our capacity to restore in a good nutritional status the patients before beginning this heavy treatment.

Stimulatory effect of 660 nm low level laser energy on hypertrophic scar‐derived fibroblasts: possible mechanisms for increase in cell counts

Stimulatory effect of 660 nm low level laser energy on hypertrophic scar‐derived fibroblasts: possible mechanisms for increase in cell counts

Stimulatory effect of 660 nm low level laser energy on hypertrophic scar-derived fibroblasts: possible mechanisms for increase in cell counts.

Varying effects of red light wavelengths on in vitro cells have been reported. Low level lasers (LLL) are employed to assist wound healing especially for indolent ulcers. On healing, burn wounds may become hypertrophic, resulting in excessive wound contraction, poor cosmesis, and functional impairment. This study enquired whether 660 nm LLL affected hypertrophic scar-derived fibroblasts. The experiments investigated the effect of a 660 nm, 17 mW laser diode at dosages of 2.4 J/cm2 and 4 J/cm2 on cell counts of two human fibroblast cell lines, derived from hypertrophic scar tissue (HSF) and normal dermal (NDF) tissue explants, respectively. The protocol avoided transfer of postirradiated cells. Estimation of fibroblasts utilized the methylene blue bioassay. The post-660 nm-irradiated HSFs exhibited very significantly higher cell counts than controls P < 0.01 on days 1-4 (Mann-Whitney U-test), and P < 0.01 on days 1-3 for similarly irradiated NDFs.

The use of lasers in operative orthopedics – an update

In laser-assisted arthroscopic knee surgery, clinical outcome and experimental results are quite different. After laser treatment of local chondromalacia, large cartilage lesions with less tendency towards repair were more often seen than after conventional arthroscopic treatment. Therefore, laser treatment of chondromalacia cannot be recommended. Compared with conventional meniscectomy, laser-assisted meniscal surgery has some advantages, but there is also some risk of inducing gonarthrosis. Some studies show a good hemostatic effect of the laser and the feasibility of precise tissue cutting. On the other hand, laser treatment causes alteration of the tissue. The meniscal tissue becomes stiffer, which may promote the manifestation of gonarthrosis. Percutaneous laser disc decompression has been in successful clinical use since 1986 in the treatment of intervertebral disc prolapses. Studies of multiple orthopedic departments worldwide show a success rate of 75%. To guarantee the success the indications must be observed. The use of lasers in the arthroscopic treatment of outlet impingement syndrome have some advantages, too. The outcome is better than that of other arthroscopic techniques and there are fewer complications because of the hemostatic effect and the improved vision. Laser-assisted capsular shrinkage combined with arthroscopic labrum reattachment allows conventional laser use. Capsular shrinkage can be achieved with low-level laser energy. If this treatment is not successful, other operative techniques can be performed without restrictions.

Low‐energy helium‐neon laser irradiation and the tensile strength of incisional wounds in the rat

Low-level laser energy has been reported to modulate the wound healing process in some but not all studies. To examine this hypothesis, we investigated incisional wounds made on the dorsal pelt of rats for changes in the healing produced by low-level irradiation with a helium-neon laser. The incisions were made with a scalpel and closed with sutures. The rats were irradiated daily for 12 days with four levels of laser light (0.0, 0.47, 0.93, and 1.73 J/cm(2)). Analysis of wound tensile strength indicated a possible strengthening of fresh wounds at the highest levels of irradiation (1.73 J/cm(2)). No change was observed in the tensile strength of formalin-fixed wounds. The distribution of measured tensile strengths did not follow normal statistics; instead they showed a platykurtic distribution. Using resampling statistics, where no assumption is made as to the nature of the distribution, we found that the results were contrary to other studies: no biostimulatory effect was seen.