Low-level light-emitting diode therapy increases mRNA expressions of IL-10 and type I and III collagens on Achilles tendinitis in rats.
Laboratory of Research and Animal Experimentation, Department of Physiotherapy, Federal University of Jequitinhonha and Mucuri Valleys, UFVJM, Rodovia MGT 367, Km 583, no. 5000, 39100-000, Diamantina, Minas Gerais, Brazil, firstname.lastname@example.org.
The present study investigated the effects of low-level light-emitting diode (LED) therapy (880±10 nm) on interleukin (IL)-10 and type I and III collagen in an experimental model of Achilles tendinitis. Thirty male Wistar rats were separated into six groups (n=5), three groups in the experimental period of 7 days, control group, tendinitis-induced group, and LED therapy group, and three groups in the experimental period of 14 days, tendinitis group, LED therapy group, and LED group with the therapy starting at the 7th day after tendinitis induction (LEDT delay). Tendinitis was induced in the right Achilles tendon using an intratendinous injection of 100 L of collagenase. The LED parameters were: optical power of 22 mW, spot area size of 0.5 cm(2), and irradiation time of 170 s, corresponding to 7.5 J/cm(2) of energy density. The therapy was initiated 12 h after the tendinitis induction, with a 48-h interval between irradiations. The IL-10 and type I and III collagen mRNA expression were evaluated by real-time polymerase chain reaction at the 7th and 14th days after tendinitis induction. The results showed that LED irradiation increased IL-10 (p<0.001) in treated group on 7-day experimental period and increased type I and III collagen mRNA expression in both treated groups of 7- and 14-day experimental periods (p<0.05), except by type I collagen mRNA expression in LEDT delay group. LED (880 nm) was effective in increasing mRNA expression of IL-10 and type I and III collagen. Therefore, LED therapy may have potentially therapeutic effects on Achilles tendon injuries.
LLLT improves tendon healing through increase of MMP activity and collagen synthesis.
Department of Anatomy, Cell Biology and Physiology and Biophysics, Institute of Biology, University of Campinas-UNICAMP, CP 6109, Campinas, São Paulo, 13083-970, Brazil, email@example.com.
The Achilles tendon has a high incidence of rupture, and the healing process leads to a disorganized extracellular matrix (ECM) with a high rate of injury recurrence. To evaluate the effects of different conditions of low-level laser (LLL) application on partially tenotomized tendons, adult male rats were divided into the following groups: G1, intact; G2, injured; G3, injured + LLL therapy (LLLT; 4 J/cm(2) continuous); G4, injured + LLLT (4 J/cm(2), 20 Hz); G5, injured; G6, injured + LLLT (4 J/cm(2) continuous); and G7, injured + LLLT (4 J/cm(2), 20 Hz until the 7th day and 2 kHz from 8 to 14 days). G2, G3, and G4 were euthanized 8 days after injury, and G5, G6, and G7 were euthanized on the 15th day. The quantification of hydroxyproline (HOPro) and non-collagenous protein (NCP), zymography for matrix metalloproteinase (MMP)-2 and MMP-9, and Western blotting (WB) for collagen types I and III were performed. HOPro levels showed a significant decrease in all groups (except G7) when compared with G1. The NCP level increased in all transected groups. WB for collagen type I showed an increase in G4 and G7. For collagen type III, G4 presented a higher value than G2. Zymography for MMP-2 indicated high values in G4 and G7. MMP-9 increased in both treatment groups euthanized at 8 days, especially in G4. Our results indicate that the pulsed LLLT improved the remodeling of the ECM during the healing process in tendons through activation of MMP-2 and stimulation of collagen synthesis.
Management of chronic Achilles tendinopathy.
Tendons transmit force between muscles and bones and, when stretched, store elastic energy that contributes to movement.(1) The tendinous portion of the gastrocnemius and soleus muscles merge to form the Achilles tendon, which is the largest and strongest in the body, but one of the most frequently injured.(2,3) Conservative management options for chronic Achilles tendinopathy include eccentric (lengthening) exercises, extracorporeal shockwave therapy (ESWT), topical nitroglycerin, low level laser therapy, orthoses, splints or injections (e.g. corticosteroids, hyperosmolar dextrose, polidocanol, platelet-rich plasma), while a minority of patients require surgery (using open, percutaneous or endoscopic methods).(4-8) Here we assess the management options for patients with chronic Achilles tendinopathy (lasting over 6 weeks).
Photomed Laser Surg. 2012 Mar;30(3):155-9. Epub 2012 Jan 11.
Effects of a therapeutic laser and passive stretching program for treating tendon overuse.
Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong (SAR), China. Gabriel.Ng@inet.polyu.edu.hk
This study investigated the effects of a therapeutic laser, passive stretching, and their combined treatment on the strength of Achilles tendons with overuse pathologies.
Tendinopathy involving overuse is usually treated with exercise and stretching, but there has been no report on the treatment effect of a therapeutic laser combined with passive stretching on managing this condition. Despite the beneficial effect of a therapeutic laser on healing tendons that have had traumatic injury, its effect on degenerative tendons is not known.
Twenty-five mature Sprague-Dawley (SD) rats were used, with 20 subjected to daily bipedal downhill running for 8 weeks, to induce Achilles overuse, and 5 as normal controls. The exercised rats were divided into four groups: 1, laser treatment; 2, passive stretching; 3, combined laser and stretching; and 4, no treatment, running controls. GaAlAs laser with 660?nm wavelength was applied to both Achilles tendons for 50?sec for Groups 1 and 3. Passive stretching of 20 times/10?sec of maximum ankle plantar flexion was applied to Groups 2 and 3. Treatments were applied after each running session for a a total of 56 treatment sessions. On week 9, the tendons were tested for load-relaxation, stiffness, and ultimate strength.
Stiffness was different (p=0.01), difference in ultimate strength was marginally insignificant (p=0.07), and load-relaxation difference was not significant among groups. Post-hoc analyses revealed that the mean stiffness of all the four exercise groups was lower than the normal control, whereas the ultimate strength from the laser and combined laser and stretching was not different from that of the normal control group, but was higher than that of the passive stretching and no treatment groups.
We conclude that a therapeutic laser and combined laser with passive stretching might slow down the decrease in Achilles tendon strength but would not be able to stop the pathological changes of overuse from developing.
Photomed Laser Surg. 2011 Jun 13. [Epub ahead of print]
Different Power Settings of LLLT on the Repair of the Calcaneal Tendon.
1 Department of Plastic Surgery, Universidade Federal de São Paulo (UNIFESP) , São Paulo, Brazil .
Abstract Objective: The purpose of this study was to evaluate the effect of an 830-nm GaAlAs diode laser operating at output powers of 40, 60, 80, and 100?mW and energy density of 30?J/cm(2) on the repair of partial calcaneal tendon ruptures in rats. Methods: A partial tendon rupture was induced in all animals, which were treated with laser irradiation for 5 consecutive days. Six days after injury, the injured tendons were removed and examined by polarized light microscopy. Collagen fiber organization was evaluated by birefringence measurements, and collagen content was determined by Picrosirius Red staining. Results: It was observed that the higher the output power (60-100?mW) the greater the amount of type III collagen (p<0.01). The amount of type I collagen was significantly greater (p=0.05) in the 80?mW group than in the control group (sham stimulation). A non-statistically significant improvement in the realignment of collagen fibers was observed in the irradiated groups. Conclusions: Low-level laser therapy resulted in significantly greater amounts of type III collagen (output powers of 60?mW or more) and type I collagen (output power of 80?mW), however, no significant differences between groups were found in the realignment of collagen fibers.
Lasers Med Sci. 2011 May 6. [Epub ahead of print]
An experimental study of low-level laser therapy in rat Achilles tendon injury.
Department of Physiotherapy, Faculty of Health and Social Science, Bergen University College, Bergen, Norway, firstname.lastname@example.org
The aim of this controlled animal study was to investigate the effect of low-level laser therapy (LLLT) administered 30 min after injury to the Achilles tendon. The study animals comprised 16 Sprague Dawley male rats divided in two groups. The right Achilles tendons were injured by blunt trauma using a mini guillotine, and were treated with LLLT or placebo LLLT 30 min later. The injury and LLLT procedures were then repeated 15 hours later on the same tendon. One group received active LLLT (??=?904 nm, 60 mW mean output power, 0.158 W/cm(2) for 50 s, energy 3 J) and the other group received placebo LLLT 23 hours after LLLT. Ultrasonographic images were taken to measure the thickness of the right and left Achilles tendons. Animals were then killed, and all Achilles tendons were tested for ultimate tensile strength (UTS). All analyses were performed by blinded observers. There was a significant increase in tendon thickness in the active LLLT group when compared with the placebo group (p?<?0.05) and there were no significant differences between the placebo and uninjured left tendons. There were no significant differences in UTS between laser-treated, placebo-treated and uninjured tendons. Laser irradiation of the Achilles tendon at 0.158 W/cm(2) for 50 s (3 J) administered within the first 30 min after blunt trauma, and repeated after 15 h, appears to lead to edema of the tendon measured 23 hours after LLLT. The guillotine blunt trauma model seems suitable for inflicting tendon injury and measuring the effects of treatment on edema by ultrasonography and UTS. More studies are needed to further refine this model.
Ostomy Wound Manage. 2011 Apr;57(4):32-40.
Conservative Management of Achilles Tendon Wounds: Results of a Retrospective Study.
Achilles tendon wounds are therapeutically challenging. The tendon`s functional importance, the paucity of soft tissue surrounding the ankle, and common patient comorbidities often limit surgical reconstructive procedure options. Depending on wound depth and overall patient health, secondary intention healing of these wounds can take many months. At the authors’ wound care center, patients who are referred with recalcitrant, deep Achilles tendon wounds and who are able to visit the center two to three times per week are offered a protocol of topical hyperbaric oxygen (THBO) followed by low-level laser therapy (LLLT) and moisture-retentive dressings. A retrospective study was conducted to evaluate the outcomes of patients who received treatment for a deep Achilles tendon wound during the years 2004 through 2008. Patients who were seen but did not obtain care at the center were contacted via telephone. Of the 80 patients seen, 15 were referred for amputation, 52 obtained treatment elsewhere, and 13 received the THBO/LLLT protocol. Patient median age was 73 years (range 52-90 years) and most (85%) had diabetes mellitus. Average wound size was 90 cm2 (range 6.25-300 cm2) with an average duration of 11.7 months (range 2-60 months) before treatment. Complete re-epithelialization was achieved in 10 patients (77%) following a mean treatment time of 19 ± 10 weeks (range 5-42 weeks). Of those, seven remained ambulatory and ulcer-free at mean follow-up of 3.3 ± 1.8 years. Eight of the 52 patients (15%) who were not treated in the authors’ center reported their ulcer was healed and 15 (29%) underwent amputation. Considering the severity of these wounds, the observed treatment outcomes are encouraging and may present a reasonable alternative for some patients with Achilles tendon wounds. Research is needed to clarify the role of these modalities in the conservative treatment of patients with Achilles tendon ulceration.
Lasers Surg Med. 2010 Aug;42(6):553-8.
Anti-inflammatory effects of low-level light emitting diode therapy on Achilles tendinitis in rats
Xavier M, David DR, de Souza RA, Arrieiro AN, Miranda H, Santana ET, Silva JA Jr, Salgado MA, Aimbire F, Albertini R.
Institute of Research and Development, IP&D, Vale do Paraiba University, UNIVAP, Av. Shishima Hifumi, 2911, 12244-000 São José dos Campos, São Paulo, Brazil.
BACKGROUND AND OBJECTIVES: The present study investigated the effects of low-level light emitting diode (LED) therapy (880 +/- 10 nm) on inflammatory process in a experimental model of Achilles tendinitis induced by collagenase.
STUDY DESIGN/MATERIALS AND METHODS: Fifty-six male Wistar were separated into seven groups (n = 8), three groups in the experimental period of 7 days and four groups in the experimental period of 14 days, the control group (CONT), tendinitis group (TEND), LED therapy group (LEDT) for both experimental periods, and LED therapy group 7th to 14th day (LEDT delay) for 14 days experimental period. The LED parameters was 22 mW CW of optical output power, distributed in an irradiation area of 0.5 cm(2), with an irradiation time of 170 seconds, the applied energy density was 7.5 J/cm(2) in contact. The therapy was initiated 12 hours after the tendinitis induction, with a 48-hour interval between the irradiations. The histological analysis and inflammatory mediators were quantified.
RESULTS: Our results showed that LED decreases the inflammatory cells influx and mRNA expression to IL-1 beta, IL-6, tumor necrosis factor-alpha (TNF-alpha) in both phase, and cyclooxygenase-2 (COX-2) just in initial phase (P < 0.05).
CONCLUSION: Our results suggest that the anti-inflammatory therapy with low-power LED (880 nm) enhanced the tissue response in all groups. We can conclude that the LED was able to reduce signs of inflammation in collagenase-induced tendinitis in rats by reducing the number of inflammatory cells and decrease mRNA expression of cytokines.
Lasers Surg Med. 2010 Aug;42(6):559-65.
Collagen changes and realignment induced by low-level laser therapy and low-intensity ultrasound in the calcaneal tendon.
Wood VT, Pinfildi CE, Neves MA, Parizoto NA, Hochman B, Ferreira LM.
Division of Plastic Surgery, Universidade Federal de São Paulo (UNIFESP), CEP 04023-002 Sao Paulo, SP, Brazil. email@example.com
BACKGROUND AND OBJECTIVE: The treatment of calcaneal tendon injuries requires long-term rehabilitation. Ultrasound (US) and low-level laser therapy (LLLT) are the most used and studied physical agents in the treatment of tendon injuries; however, only a few studies examined the effects of the combination of US and LLLT. Therefore, the purpose of this study was to investigate which treatment (the exclusive or combined use of US and LLLT) most effectively contribute to tendon healing.
STUDY DESIGN/MATERIALS AND METHODS: This was a controlled laboratory study with 50 rats whose Achilles tendon was injured by direct trauma. The rats were randomly divided into five groups and treated for 5 consecutive days, as follows: group 1 (control) received no treatment; group 2 was treated with US alone; group 3 was treated with LLLT alone; group 4 was treated first with US followed by LLLT; and group 5 was treated first with LLLT followed by US. On the sixth post-injury day, the tendons were removed and examined by polarized light microscopy. The organization of collagen fibers was assessed by birefringence measurements. Picrosirius-stained sections were examined for the presence of types I and III collagen.
RESULTS: There was a significantly higher organization of collagen fibers in group 2 (US) than in the control group (P = 0.03). The amount of type I collagen found in groups 2 (US), 3 (LLLT), and 5 (LLLT + US) was significantly higher than that in the control group (P <or= 0.01), but no significant differences were found between treatment groups. There were no differences in the amount of type III collagen between groups.
CONCLUSION: Ultrasound, LLLT, and the combined use of LLLT and US resulted in greater synthesis of type I collagen; US was also effective in increasing collagen organization in the early stages of the healing process.
Photomed Laser Surg. 2009 Aug 26. [Epub ahead of print]
Low Level Laser Treatment of Tendinopathy: A Systematic Review with Meta-analysis.
Tumilty S, Munn J, McDonough S, Hurley DA, Basford JR, Baxter GD.
1 Centre for Physiotherapy Research, School of Physiotherapy, University of Otago , Dunedin, New Zealand.
Abstract Objectives: To assess the clinical effectiveness of Low Level Laser Therapy (LLLT) in the treatment of tendinopathy. Secondary objectives were to determine the relevance of irradiation parameters to outcomes, and the validity of current dosage recommendations for the treatment of tendinopathy.
Background: LLLT is proposed as a possible treatment for tendon injuries. However, the clinical effectiveness of this modality remains controversial, with limited agreement on the most efficacious dosage and parameter choices.
Method: The following databases were searched from inception to 1(st) August 2008: MEDLINE, PubMed, CINAHL, AMED, EMBASE, All EBM reviews, PEDro (Physiotherapy Evidence Database), SCOPUS. Controlled clinical trials evaluating LLLT as a primary intervention for any tendinopathy were included in the review. Methodological quality was classified as: high (>/=6 out of 10 on the PEDro scale) or low (<6) to grade the strength of evidence. Accuracy and clinical appropriateness of treatment parameters were assessed using established recommendations and guidelines.
Results: Twenty-five controlled clinical trials met the inclusion criteria. There were conflicting findings from multiple trials: 12 showed positive effects and 13 were inconclusive or showed no effect. Dosages used in the 12 positive studies would support the existence of an effective dosage window that closely resembled current recommended guidelines. In two instances where pooling of data was possible, LLLT showed a positive effect size; in studies of lateral epicondylitis that scored >/=6 on the PEDro scale, participants’ grip strength was 9.59 kg higher than that of the control group; for participants with Achilles tendinopathy, the effect was 13.6 mm less pain on a 100 mm visual analogue scale.
Conclusion: LLLT can potentially be effective in treating tendinopathy when recommended dosages are used. The 12 positive studies provide strong evidence that positive outcomes are associated with the use of current dosage recommendations for the treatment of tendinopathy
Lasers Med Sci. 2009 Jul;24(4):659-65. Epub 2008 Sep 16.
The effects of low-level light emitting diode on the repair process of Achilles tendon therapy in rats.
Casalechi HL, Nicolau RA, Casalechi VL, Silveira L Jr, De Paula AM, Pacheco MT.
Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, Urbanova, São José dos Campos, São Paulo, Brazil.
Thirty Wistar rats (350 +/- 20 g) were subjected to total Achilles tendon tenotomy of the right fore limb. They were submitted to a daily dose of 20 J/cm(2) light emitting diode (LED) (640 +/- 20 nm) therapy. The LED was applied punctually and transcutaneously to the lesioned region. The animals were separated into six groups, C1 and L1, C2 and L2, C3 and L3. The C groups were used for control and the L groups, treated for 7, 14 and 21 consecutive days, respectively. The animals were killed on the 7th, 14th and 21st days after surgery. After the animals had been killed, their tendons were extracted and dissected, fixed in formaldehyde at 10%, and sent for histological analysis by light microscopy in which the repair process was analysed. This study demonstrated that LED interfered in the repair process of the tendon tissue, reducing the number of fibroblasts in the initial periods and improving the quality of the repair in all periods studied.
Lasers Surg Med. 2009 Apr;41(4):271-6.
Effect of low level laser therapy (830 nm) with different therapy regimes on the process of tissue repair in partial lesion calcaneous tendon.
Oliveira FS, Pinfildi CE, Parizoto NA, Liebano RE, Bossini PS, Garcia EB, Ferreira LM.
Department of Plastic Surgery, São Paulo Federal University-UNIFESP, São Paulo, SP 04024-900, Brazil.
BACKGROUND AND OBJECTIVE: Calcaneous tendon is one of the most damaged tendons, and its healing may last from weeks to months to be completed. In the search after speeding tendon repair, low intensity laser therapy has shown favorable effect. To assess the effect of low intensity laser therapy on the process of tissue repair in calcaneous tendon after undergoing a partial lesion.
STUDY DESIGN/MATERIALS AND METHODS: Experimentally controlled randomized single blind study. Sixty male rats were used randomly and were assigned to five groups containing 12 animals each one; 42 out of 60 underwent lesion caused by dropping a 186 g weight over their Achilles tendon from a 20 cm height. In Group 1 (standard control), animals did not suffer the lesion nor underwent laser therapy; in Group 2 (control), animals suffered the lesion but did not undergo laser therapy; in Groups 3, 4, and 5, animals suffered lesion and underwent laser therapy for 3, 5, and 7 days, respectively. Animals which suffered lesion were sacrificed on the 8th day after the lesion and assessed by polarization microscopy to analyze the degree of collagen fibers organization.
RESULTS: Both experimental and standard control Groups presented significant values when compared with the control Groups, and there was no significant difference when Groups 1 and 4 were compared; the same occurred between Groups 3 and 5.
CONCLUSION: Low intensity laser therapy was effective in the improvement of collagen fibers organization of the calcaneous tendon after undergoing a partial lesion.
Am J Sports Med. 2008 May;36(5):881-7. Epub 2008 Feb 13.
Effects of low-level laser therapy and eccentric exercises in the treatment of recreational atheletes with chronic achilles tendinopathy.
Stergioulas A, Stergioula M, Aarskog R, Lopes-Martins RA, Bjordal JM.
Institute of Physical Therapy, Bergen University College, Mollendalsvn 6, 5009 Bergen, Norway.
BACKGROUND: Eccentric exercises (EEs) are recommended for the treatment of Achilles tendinopathy, but the clinical effect from EE has a slow onset.
HYPOTHESIS: The addition of low-level laser therapy (LLLT) to EE may cause more rapid clinical improvement.
STUDY DESIGN: Randomized controlled trial; Level of evidence, 1.
METHODS: A total of 52 recreational athletes with chronic Achilles tendinopathy symptoms were randomized to groups receiving either EE + LLLT or EE + placebo LLLT over 8 weeks in a blinded manner. Low-level laser therapy (lambda = 820 nm) was administered in 12 sessions by irradiating 6 points along the Achilles tendon with a power density of 60 mW/cm(2) and a total dose of 5.4 J per session.
RESULTS: The results of the intention-to-treat analysis for the primary outcome, pain intensity during physical activity on the 100-mm visual analog scale, were significantly lower in the LLLT group than in the placebo LLLT group, with 53.6 mm versus 71.5 mm (P = .0003) at 4 weeks, 37.3 mm versus 62.8 mm (P = .0002) at 8 weeks, and 33.0 mm versus 53.0 mm (P = .007) at 12 weeks after randomization. Secondary outcomes of morning stiffness, active dorsiflexion, palpation tenderness, and crepitation showed the same pattern in favor of the LLLT group.
CONCLUSION: Low-level laser therapy, with the parameters used in this study, accelerates clinical recovery from chronic Achilles tendinopathy when added to an EE regimen. For the LLLT group, the results at 4 weeks were similar to the placebo LLLT group results after 12 weeks.
Photomed Laser Surg. 2008 Feb;26(1):25-30.
Laser therapy in the treatment of achilles tendinopathy: a pilot study.
Tumilty S, Munn J, Abbott JH, McDonough S, Hurley DA, Baxter GD.
School of Physiotherapy, Centre for Physiotherapy Research, University of Otago, Dunedin, New Zealand. firstname.lastname@example.org
OBJECTIVE: To test the feasibility of a randomized controlled trial to assess the clinical effectiveness of low-level laser therapy (LLLT) when used in addition to eccentric exercise in the management of Achilles tendinopathy.
BACKGROUND DATA: LLLT has emerged as a possible treatment modality for tendon injuries. Over the past 20 years only three human studies have investigated LLLT for Achilles tendinopathy.
MATERIALS AND METHODS: Twenty patients were randomized into an active laser or placebo group; all patients, therapists, and investigators were blinded to allocation. All patients were given a 12-week eccentric exercise program and irradiated three times per week for 4 wk with either an active or placebo laser at standardized points over the affected tendons. Irradiation parameters in the active treatment group were: 810 nm, 100 mW, applied to six points on the tendon for 30 s, for a total dose of 3 J per point and 18 J per session. Outcome measures were the VISA-A questionnaire, pain, and isokinetic strength. Patients were measured before treatment and at 4 and 12 wk. Analysis of covariance was used to analyze data, using the effects of baseline measurements as a covariate.
RESULTS: Within groups, there were significant improvements (p < 0.05) at 4 and 12 wk for all outcome measures, except eccentric strength for the placebo group at 4 wk (p = 0.11). Based on the results of the current study, recruitment of 20 subjects per group would be required to perform an adequately powered study based on minimally important clinical differences in VISA-A scale.
CONCLUSION: This study has demonstrated the feasibility of undertaking a randomized controlled trial of LLLT for Achilles tendinopathy. Conclusions regarding effectiveness cannot be made due to the low statistical power of this pilot study.
Br J Sports Med. 2006 Jan;40(1):76-80; discussion 76-80.
A randomised, placebo controlled trial of low level laser therapy for activated Achilles tendinitis with microdialysis measurement of peritendinous prostaglandin E2 concentrations.
Bjordal JM, Lopes-Martins RA, Iversen VV.
Physiotherapy Science, University of Bergen, Bergen, Norway. email@example.com
BACKGROUND: Low level laser therapy (LLLT) has gained increasing popularity in the management of tendinopathy and arthritis. Results from in vitro and in vivo studies have suggested that inflammatory modulation is one of several possible biological mechanisms of LLLT action.
OBJECTIVE: To investigate in situ if LLLT has an anti-inflammatory effect on activated tendinitis of the human Achilles tendon.
SUBJECTS: Seven patients with bilateral Achilles tendinitis (14 tendons) who had aggravated symptoms produced by pain inducing activity immediately before the study.
METHOD: Infrared (904 nm wavelength) LLLT (5.4 J per point, power density 20 mW/cm2) and placebo LLLT (0 J) were administered to both Achilles tendons in random blinded order.
RESULTS: Ultrasonography Doppler measurements at baseline showed minor inflammation through increased intratendinous blood flow in all 14 tendons and measurable resistive index in eight tendons of 0.91 (95% confidence interval 0.87 to 0.95). Prostaglandin E2 concentrations were significantly reduced 75, 90, and 105 minutes after active LLLT compared with concentrations before treatment (p = 0.026) and after placebo LLLT (p = 0.009). Pressure pain threshold had increased significantly (p = 0.012) after active LLLT compared with placebo LLLT: the mean difference in the change between the groups was 0.40 kg/cm2 (95% confidence interval 0.10 to 0.70).
CONCLUSION: LLLT at a dose of 5.4 J per point can reduce inflammation and pain in activated Achilles tendinitis. LLLT may therefore have potential in the management of diseases with an inflammatory component.
Lasers Surg Med. 2005 Oct;37(4):293-300
Low-level laser therapy (LLLT) prevents oxidative stress and reduces fibrosis in rat traumatized Achilles tendon.
Fillipin LI, Mauriz JL, Vedovelli K, Moreira AJ, Zettler CG, Lech O, Marroni NP, González-Gallego J.
Department of Physiology, Universidade Federal de Rio Grande do Sul, Brazil.
BACKGROUND AND OBJECTIVES: The present study investigated the effects of low-level laser therapy (LLLT) on oxidative stress and fibrosis in an experimental model of Achilles tendon injury induced by a single impact trauma.
STUDY DESIGN/MATERIALS AND METHODS: Male Wistar rats were randomly divided into four groups (n = 8): control, trauma, trauma+LLLT for 14 days, and trauma+LLLT for 21 days. Achilles tendon traumatism was produced by dropping down a load with an impact kinetic energy of 0.544 J. A low level Ga-As laser was applied with a 904 nm wavelength, 45 mW average power, 5 J/cm(2) dosage, for 35 seconds duration, continuously. Studies were carried out at day 21.
RESULTS: Histology showed a loss of normal architecture, with inflammatory reaction, angiogenesis, vasodilatation, and extracellular matrix formation after trauma. This was accompanied by a significant increase in collagen concentration when compared the control group. Oxidative stress, measured by the concentration of thiobarbituric acid reactive substances and hydroperoxyde-initiated chemiluminiscence, was also significantly increased in the trauma group. Administration of LLLT for 14 or 21 days markedly alleviated histological abnormalities reduced collagen concentration and prevented oxidative stress. Superoxide dismutase activity was significantly increased by LLLT treatment over control values.
CONCLUSION: LLLT by Ga-As laser reduces histological abnormalities, collagen concentration, and oxidative stress in an experimental model of Achilles tendon injury. Reduction of fibrosis could be mediated by the beneficial effects on the oxidant/antioxidant balance.
Lasers Surg Med. 2004;35(1):84-9.
Comparison of the effects of laser, ultrasound, and combined laser + ultrasound treatments in experimental tendon healing.
Demir H, Menku P, Kirnap M, Calis M, Ikizceli I.
Erciyes University Medical Faculty, Department of Physical Medicine & Rehabilitation, Kayseri, Turkey. firstname.lastname@example.org
BACKGROUND AND OBJECTIVE: Therapeutic ultrasound (US) and laser (L) treatments accelerate and facilitate wound healing, and also have beneficial effects on tendon healing. This randomized control study was designed to evaluate the effects of low-intensity US and low-level laser therapy (LLLT) on tendon healing in rats.
STUDY DESIGN/MATERIALS AND METHODS: Eighty-four healthy male Swiss-Albino rats were divided into three groups consisting of 28 rats, the left Achilles tendons were used as treatment and the right Achilles tendons as controls. The right and left Achilles tendons of rats were traumatized longitudinally. The treatment was started on postinjury day one. We applied the treatment protocols including low-intensity US treatment in Group I (US Group), Sham US in Group II (SUS Group), LLLT in Group III (L Group), Sham L in Group IV (SL Group), US and LLLT in Group V (US + L Group), and Sham US and Sham L in Group VI (SUS + SL Group). The US treatment was applied with a power of 0.5 W/cm2, a frequency of 1 MHz, continuously, 5 minutes daily. A low-level Ga-As laser was applied with a 904 nm wavelength, 6 mW average power, 1 J/ cm2 dosage, 16 Hz frequency, for 1 minute duration, continuously. In the control groups, the similar procedures as in the corresponding treatment groups were applied with no current (Sham method). The treatment duration was planned for 9 days (sessions) in all groups, except the rats used for biochemical evaluation on the 4th day of treatment, which were treated for 4 days. We measured the levels of the tissue hydroxyproline for biochemical evaluation on the 4th, 10th, and 21st days following the beginning of treatment and the tendon breaking strength on the 21st day following the beginning of treatment for biomechanical evaluation. Seven rats in each group were killed on the 4th, 10th, and 21st days for biochemical evaluation and on the 21st day for biomechanical evaluation.
RESULTS: The hydroxyproline levels were found to be significantly increased in the treatment groups on the 10th and 21st days compared to their control groups (P < 0.05). In comparison of the treatment groups on the 4th, 10th, and 21st days of the treatment, the levels of tissue hydroxyproline were found to be more increased in combined US+L Group compared with US Group and L Group, but the difference was not significant (P > 0.05). In comparison of the tendon breaking strengths, it was found as significantly increased in the treatment groups compared with their control groups (P < 0.05), although there was no significant difference between the treatment groups.
CONCLUSIONS: Although US, L, and combined US + L treatments increased tendon healing biochemically and biomechanically more than the control groups, no statistically significant difference was found between them. Also we did not find significantly more cumulative positive effects of combined treatment. As a result, both of these physical modalities can be used successfully in the treatment of tendon healing.
|Lasers Surg Med. 2003;32(4):286-93.|
THE INFLUENCE OF LOW LEVEL INFRA RED LASER THERAPY ON THE REGENERATION OF CARTILAGE TISSUE
P.Lievens , Ph.van der Veen
This study concerns the influence of Laser treatment on the regeneration process of cartilage tissue. There is no need saying that the regeneration of cartilage tissue is a very big problem in rheumatic diseases for example. The lack of blood supply is one of the most important factors involved. Lots of previous publications give us proof of the regeneration capacities of Laser therapy (in wound healing, bone repair etc.)
In this study we have chosen to experiment on cartilage tissue of the ear of mice. We are aware of the fact that the elastic cartilage tissue of the ear is not totally comparable with the hyaline cartilage of articulations. For technical reasons however and because of the fact that the chondrocytes are comparable, we decided to use mice ears in our experiment. A 0,4 mm hole was drilled in both ears on 30 mice. The right ears remain untreated, while the left ears were treated daily with IR-Laser (904 nm) for 3 minutes. Macroscopical as well as histological evaluations were performed on the cartilage regeneration of both ears.
Our results show that after one day postsurgery no differences were found between the irradiated and the non-irradiated group. After the second day, only in the irradiated group there is a clear activation of the perichondrium. After four days, there is a significant ingrowth of the perichondrium into the drill hole in the experimental group and there is only an active perichondrium zone in our control group.
Wound Repair Regen. 1999 Nov-Dec;7(6):518-27.
Matrix remodeling in healing rabbit Achilles tendon.
Reddy GK, Stehno-Bittel L, Enwemeka CS.
Department of Physical Therapy, University of Kansas Medical Center, Kansas City 66160-4568, USA. email@example.com
Biochemical, biomechanical and ultrastructural properties of the connective tissue matrix were investigated during the early remodeling phase of tissue repair in experimentally tenotomized and repaired rabbit Achilles tendons. Sterile surgical tenotomy was performed on the right Achilles tendons of 14 rabbits and allowed to heal for 15 days. The animals were euthanized and the Achilles tendons excised from both limbs. The left contralateral Achilles tendon of each rabbit was used as a control in the experiments. Prior to biochemical analysis, both intact and healing tendons were tested for their biomechanical integrity. The results revealed that the healing tendons had regained some of their physicochemical characteristics, but differed significantly from the intact left tendons. The healing tendons regained 48% tensile strength, 30% energy absorption, 20% tensile stress, and 14% Young’s modulus of elasticity of intact tendons. In contrast, biochemical analysis showed that the healing tendons had 80% of the collagen and 60% of the collagen crosslinks (hydroxypyridinium) of normal tendons. Sequential extraction of collagen from the tissues yielded more soluble collagen in the healing tendons than intact tendons, suggesting either an increase in collagen synthesis and/or enhanced resorption of mature collagen in healing tendons compared to intact tendons. Electron microscopic studies revealed remarkable differences in the ultrastructure between intact and healing tendons. These observations could explain, in part, the connective tissue response to healing during the early phases of tissue remodeling.
Lasers Surg Med. 1998;22(5):281-7.
Laser photostimulation of collagen production in healing rabbit Achilles tendons.
Reddy GK, Stehno-Bittel L, Enwemeka CS.
Department of Physical Therapy, University of Kansas Medical Center, Kansas City 66160-7601, USA.
BACKGROUND AND OBJECTIVE: Low energy laser photostimulation at certain wavelengths can enhance tissue repair by releasing growth factors from fibroblasts and stimulate the healing process. This study was designed to evaluate the influence of laser photostimulation on collagen production in experimentally tenotomized and repaired rabbit Achilles tendons.
STUDY DESIGN/MATERIALS AND METHODS: A total of 24 male New Zealand rabbits, ages 10-12 weeks, were used. Following tenotomy and repair, the surgical hind limbs of the rabbits were immobilized in customized polyurethane casts. The experimental animals were treated with a 632.8 nm He:Ne laser daily at 1.0 J cm(-2) for 14 days. Control animals were sham treated with the laser head. On the fifth day after repair, the casts were removed to allow the animals to bear weight on the lower extremity. The animals were euthanized on the 15th postoperative day, then, the Achilles tendons were excised, processed and analyzed.
RESULTS: Biochemical analyses of the tendons revealed a 26% increase in collagen concentration with laser photostimulation indicating a more rapid healing process in treated tendons compared to controls. Sequential extractions of collagen from regenerating tissues revealed that the laser photostimulated tendons had 32% and 33% greater concentrations of neutral salt soluble collagen and insoluble collagen, respectively, than control tendons suggesting an accelerated production of collagen with laser photostimulation. A significant decrease (9%) in pepsin soluble collagen was observed in laser-treated tendons compared to controls. There were no statistically significant differences recorded in the concentrations of hydroxypyridinium crosslinks and acid soluble collagen between treated and control tendons.
CONCLUSION: This study of laser photostimulation on tendon healing in rabbits suggests that such therapy facilitates collagen production in a manner that enhances tendon healing.
Am J Phys Med Rehabil. 1997 Jul-Aug;76(4):288-96.
Combined ultrasound, electrical stimulation, and laser promote collagen synthesis with moderate changes in tendon biomechanics.
Gum SL, Reddy GK, Stehno-Bittel L, Enwemeka CS.
Department of Physical Therapy, University of Kansas Medical Center, Kansas City 66160-7601, USA.
The biomechanical, biochemical, and ultrastructural effects of a multitherapeutic protocol were studied using regenerating rabbit Achilles tendons. The multitherapeutic protocol was composed of low-intensity Ga:As laser photostimulation, low intensity ultrasound, and electrical stimulation. Achilles tendons of 63 male New Zealand rabbits were tenotomized, sutured, immobilized, and subjected to the multitherapeutic protocol for five days, after which casts were removed and the therapy was continued for nine more days without electrical stimulation. The tendons were excised and compared with control tendons. Multitherapy treatment produced a 14% increase in maximal strength, a 42% increase in load-at-break, a 20% increase in maximal stress, a 45% increase in stress-at-break, a 21% increase in maximal strain, and a 14% increase in strain-at-break. Similarly, multitherapy treatment was associated with an increase in Young’s modulus of elasticity of 31%, an increase in energy absorption at maximum load of 9%, and an increase in energy absorption at load-at-break of 11%. Biochemical analysis of the tendons showed an increase of 23% in the total amount of collagen in the multitherapy-treated tendons, with fewer mature crosslinks (decrease of 6%). Electron micrographs revealed no ultrastructural or morphologic changes in the tendon fibroblasts or in the extracellular matrix. The improvements measured in tendons receiving multitherapy were consistent but less remarkable compared with our earlier works with single modality protocols. The results warrant the hypothesis that the beneficial effects of ultrasound and laser photostimulation on tendon healing may counteract one another when applied simultaneously.