Photobiomodulation Associated With Conservative Treatment for Achilles Tendon Rupture: A Double-Blind, Superiority, Randomized Controlled Trial

Objective

To investigate the effects of photobiomodulation on Achilles tendon rupture (ATR) treated conservatively.

Design

Prospective, patient- and assessor-blinded, parallel, randomized controlled trial.

Setting

Patients with acute ATR treated conservatively.

Participants

Thirty-four male individuals with acute unilateral ATR treated conservatively (N=34), equally divided in 2 groups: photobiomodulation group (PBMG) and sham group, with mean age of 45.5±9.47 and 48.7±8.38 years, respectively.

Intervention

All participants underwent through an immobilization period, followed by rehabilitation sessions (2 d/wk for 12 weeks) comprising strengthening, range of motion, and balance/weightbearing exercises. In PBMG, the tendon was irradiated with a photobiomodulation cluster (1 904 nm/50 mW infrared laser, 4 858 nm/50 mW infrared diodes, and 4 658 nm/40 mW red diodes; power density of 105 mW/cm² per cluster area) during the immobilization period (2 d/wk for 8 weeks) and the sham group received a simulation of the procedure with no irradiation. Outcomes were assessed at the removal of the immobilization 12 and 16 weeks after tendon rupture.

Main Outcome Measures

Primary outcome was the Achilles Tendon Rupture Score. Secondary outcomes included Numerical Pain Rating Scale at rest and during effort, plantar flexor strength, and ankle range of motion.

Results

Both groups demonstrated an increase in the Achilles Tendon Rupture Score and improvements in range of motion, plantar flexor strength, and pain. There were no significant differences in outcomes between the 2 groups (P>.05) except in pain during walking, which was significantly lower in the PBMG in week 12 (P<.01, effect size=0.56) and week 16 (P<.01, effect size=0.55).

Conclusion

Photobiomodulation associated with conservative treatment is not superior to conservative treatment alone for improving function in patients with acute ATR.

Photobiomodulation Therapy (Light-Emitting Diode 630 nm) Favored the Oxidative Stress and the Preservation of Articular Cartilage in an Induced Knee Osteoarthritis Model

Objective: To evaluate the effects of photobiomodulation (PBM) therapy on oxidative stress and histological aspects of knee osteoarthritis (OA) induced by sodium monoiodoacetate in Wistar rats. Background: OA is a chronic degenerative disease. In addition to the inflammatory role, other factors, such as redox balance, appear to contribute to changes in the articular cartilage, the main articular structure affected. PBM therapy using light-emitting diode (LED) has been proposed to treat the disease by favoring anti-inflammatory effects and modulating markers of oxidative stress, acting on the degenerative process of cartilage. Methods: Twenty-seven male rats were separated into three groups: control (CG), OA (OAG), and LED treatment (LEDG). In the LED group, PBM (LED 630 nm, 300 mW, 9 J/cm², 0.3 W/cm², 30 sec) was applied, starting 24 h after induction, three times per week, for 8 weeks. Cartilage thickness, number of chondrocytes, enzymatic antioxidant defenses [superoxide dismutase (SOD) and catalase (CAT)], oxidative damage [thiobarbituric acid reactive substances (TBARS)], and nonenzymatic defense (ferric reducing antioxidant power) were analyzed. Results: The LEDG had higher average cartilage thickness compared with the OAG and had similar thickness to the CG. Also, the number of chondrocytes was similar to the CG. In the oxidative stress analysis, the LEDG presented antioxidant enzymatic activity (SOD and CAT) higher than the CG, and presented concentration of TBARS lower than the CG and OAG groups. Conclusions: PBM therapy was effective in recovering oxidative stress and preserving the articular cartilage aspects in a knee OA animal model.

Photobiomodulation Before Eccentric Fatigue Protocol in the Control of Pain and Muscle Damage Markers: A Double-Blind, Randomized Controlled Study

Background: Several strategies are used in the management of delayed-onset muscle soreness (DOMS), but there is not always evidence to justify its use. Photobiomodulation (PBM) is a noninvasive means, with promising previous results of its use in this outcome. Objective: This study aimed to identify the effects of PBM in the femoral quadriceps region to reduce DOMS in men undergoing a fatigue protocol. Methods: This is a double-blind, randomized controlled study. The sample consisted of 35 physically active men. The volunteers were divided into two groups: pre-fatigue PBM [Group 1 (G1)] and post-fatigue PMB [Group 2 (G2)]. The fatigue test was conducted at the same time of day. Given this was a crossover study of volunteers, we used at least a 1-week washout to avoid any residual interference from the previous intervention. PBM (active/placebo) was performed 5 min before the start of the fatigue protocol in G1 and immediately after the fatigue protocol in G2. PBM was applied at six points on the femoral quadriceps muscle (cluster laser/light emitting diodes 13, 415 mW, 30.2 J per point, 73 sec per application, and total dose of 181.2 J). In the data analysis, the primary endpoint was DOMS measured using a Numerical Pain Scale, and the secondary outcome was examined on the effects of PMB muscle damage, muscle contraction, and isometric horizontal jump. Results: There were significant differences to PBM compared with the placebo group for DOMS, with no differences between the times of application. For muscle damage, there was significant difference (p > 0.05) when PBM was applied in pre-fatigue. G1 led to an increase of 14.9% in the creatine kinase level when active since the application of placebo PBM increased by 65% (p = 0.04). Conclusions: The PBM applied before eccentric fatigue protocol showed no significant results on DOMS, although there was a positive effect to control muscle damage. Brazilian Registry of Clinical Trials (RBR-7qhddz).

Acute Photobiomodulation Effects Through a Cluster Device on Skeletal Muscle Fatigue of Biceps Brachii in Young and Healthy Males: A Randomized Double-Blind Session

Objective: The aim of this study was to investigate and compare the acute effects of red and infrared photobiomodulation (PBM) using a cluster device on biceps brachii muscle fatigue in young and healthy males. Background: Vigorous physical activity could lead to muscle fatigue, which compromises motor control and muscle strength and consequently impairs performance. The positive effects of PBM in reducing fatigue onset have been highlighted. However, the better wavelength with cluster devices is not yet established. Methods: A randomized double-blind session was used. Thirty-two young and healthy males were randomized into the control group (CG), red PBM group (RPG), and infrared PBM group (IPG). A PBM cluster device [7 visible diodes (630 nm), 7 infrared diodes (850 nm), 100 mW/diode, 2 W/cm² power density, 91 J/cm² energy density, 4 J per point, 28 J total energy, and 40 sec] was applied after muscle fatigue. Muscle fatigue was analyzed by surface electromyography (EMG) recorded from the long head of biceps brachii, blood lactate concentration, and evaluation of the rate of perceived exertion (RPE) using the Borg Scale. The fatigue protocol consisted of a maximum voluntary isotonic contraction of elbow flexion-extension with 75% of one-repetition maximum until exhaustion. The Borg Scale was applied before and at the end of the experiment to measure the RPE. The electromyography fatigue index (EMGFI) was calculated by windows of median frequency from EMG data. Results: EMGFI, blood lactate concentration, and RPE showed no intergroup statistical difference, except the EMGFI delta value that showed a difference between IPG and CG, with a greater value in the CG. However, intragroup comparisons showed that EMGFI decreased in the CG and RPE and lactate concentration increased significantly in all groups. Conclusions: There was no difference between red and infrared PBM in reduction of biceps brachii fatigue. However, the EMGFI delta value was greater in the IPG compared with the CG, suggesting that infrared can be more effective in reducing biceps brachii fatigue.

Efeito da fotobiomodulação associada a exercícios na dor e na funcionalidade de pacientes com osteoartrite de joelho: estudo-piloto

RESUMO O objetivo do estudo foi avaliar o efeito da fotobiomodulação associada a exercícios na dor e na funcionalidade de pacientes com osteoartrite de joelho. Para isso foram recrutados 20 pacientes com osteoartrite do joelho uni ou bilateral, que foram distribuídos em dois grupos: grupo-controle (GC), que realizou aplicação de fotobiomodulação (FBM) placebo e um protocolo de exercício; e grupo fotobiomodulação (GF), que realizou aplicação ativa da FBM e o protocolo de exercício, sendo esse realizado duas vezes por semana durante oito semanas e consistindo de alongamentos passivos dos músculos de membros inferiores, straight leg raise, treinamento proprioceptivo e exercícios para o controle da marcha. A FBM foi aplicada com o aparelho cluster contendo quatro diodos de 670 nm e cinco diodos de 850 nm, com uma potência de saída de 540 mW, sendo a dose utilizada de 4 J/cm2. Os grupos foram avaliados pré e pós-tratamento com os questionários SF-36, Lequesne, Tinetti, e por meio da Escala Visual Analógica de dor (EVA). Os dados foram analisados com o método Anova, seguido do Bonferroni. Os dados indicaram melhoras significativas para o GF ao fim do tratamento para as avaliações da EVA (2±1,25 vs. 0,7±0,82; p=0,009). Embora ambos os grupos tenham obtido melhoras significativas ao longo do tratamento, não foi possível observar diferenças significativas entre eles para o restante das avaliações ao final do tratamento. Portanto, conclui-se que o uso da FBM associada a exercícios apresentou melhora da dor nos pacientes com osteoartrite de joelho, embora não tenha sido possível observar diferenças significativas no que diz respeito à funcionalidade.

Investigation of different application techniques for Kinesio Taping® with an accompanying exercise protocol for improvement of pain and functionality in patients with patellofemoral pain syndrome: A pilot study

BACKGROUND

Patellofemoral pain syndrome (PFPS), characterized by retropatellar and peripatellar pain, is a common disorder affecting young women. Treatment has included exercise-based therapy and taping techniques for rapid reduction of symptoms and pain. Although Kinesio Taping® (KT) has been studied as adjunctive therapy, evidence on its effectiveness is limited and conflicting.

OBJECTIVE

To determine the feasibility of performing a double-blind randomized controlled trial (RCT) using KT® for PFPS treatment and to determine an ideal sample size.

DESIGN

Double-blind, randomized, controlled pilot study.

METHOD

Forty-three women (aged 18-45 years) with at least a 3-month history of PFPS were randomized based on the mechanical correction techniques: using KT® for patellar medialization (KT-PM), using KT® for lateral rotation of the femur and tibia (KT-LRFT), and the control group (CG). All groups underwent the same muscle strengthening and motor control procedures for 12 weeks. Knee pain and function were evaluated at baseline, at 6 weeks, at treatment completion (12 weeks), and during the 12-week follow-up using the numerical pain rating scale (NPRS) at rest and during effort, Anterior Knee Pain Scale (AKPS), and single jump hop test.

RESULTS

There were clinically significant differences between the KT-LRFT and the CG in terms of AKPS and NPRS scores during effort at the 6-week and 12-week follow-ups. All groups (within group) showed a significant improvement in pain and function.

CONCLUSIONS

A complete RCT using KT® for the treatment of PFPS is feasible with some changes regarding outcome measures and treatment protocols.

Influence of body mass index on patellofemoral pain

Abstract Introduction: Patellofemoral Pain Syndrome is characterized by retro-patellar and peripatellar pain during squatting, kneeling and running whose intensity can be related to Body Mass Index (BMI). Objective: To evaluate the relationship between overweight, pain and function in women with Patellofemoral Pain Syndrome (PFPS). Method: Cross-sectional observational study of fifty-four women with PFPS assessed in the period between January and December 2015, in the physiotherapy outpatient clinic of a tertiary hospital in the city of São Paulo. To verify the variables of pain at rest, at effort and function, the Numerical Pain Rating Scale (NPRS) and the Kujala Anterior Knee Pain Scale (AKPS) were used. The participants were divided into two groups, according to the BMI categories defined by the World Health Organization (WHO): Group 1, composed of women with normal BMI (18-24.9 kg/m²), with 36 patients, and group 2 composed of overweight women (25-29.9 k/m²), with 18 patients. Comparison between groups of pain at rest and effort and AKPS were performed using Student's t-test and Mann-Witney with statistical significance p < 0,05. Results: There was no statistically significant difference between groups for the pain at rest and effort and for AKPS. Conclusion: BMI does not impact pain intensity and function in women with PFPS.

High-energy dose of therapeutic ultrasound in the treatment of patellar tendinopathy: protocol of a randomized placebo-controlled clinical trial

BACKGROUND

Patellar tendinopathy is an extremely debilitating condition and its treatment usually requires a combination of clinical approaches. Therapeutic ultrasound (TUS) is one of the most available electrophysical agent in rehabilitation settings; however, there is also a lack of high-quality studies that test different dosimetric aspects of TUS. Thus, the purpose of this study is to evaluate the short-, medium-, and long-term effects of the combination of high-energy TUS with a rehabilitation program for patellar tendinopathy.

METHODS

This will be a randomized, placebo-controlled trial with blinding of patients, assessors, and therapist. The setting is an outpatient physical therapy clinic. We will recruit 66 participants (male and female) aged between 18 and 40 years and presenting with patellar tendinopathy. A treatment combining high-energy dose TUS and a rehabilitation program for patellar tendinopathy will be delivered twice a week for 8 weeks. The control group will receive the same treatment, but with a placebo TUS. The effectiveness of the intervention will be measured at the beginning (baseline), midpoint (4 weeks), and end of treatment (8 weeks), as well as at 3- and 6-months post-treatment. Primary outcomes will be pain intensity (visual analogue scale, VAS), and VISA-P questionnaire and primary time points will be baseline (T0) and the end of the program (T2). Also, IPAQ-short form questionnaire, muscle strength (manual dynamometry), 2D kinematics, pain pressure threshold (PPT) algometry, thermography, and magnetic resonance imaging (MRI) will be collected.

DISCUSSION

TUS will be applied in an attempt to enhance the results obtained with the rehabilitation program proposed in this study, as well as stimulate some repair responses in individuals undergoing treatment for patellar tendinopathy, which in turn may optimize and improve treatment programs for patellar tendinopathy as well as to establish new guidelines for the application of TUS.

TRIAL REGISTRATION

This study was prospectively registered at April-3rd-2018 and updated at September-1st-2019 in the Brazilian Registry of Clinical Trials (REBEC) under the registration number: RBR-658n6w.

Translation, cross-cultural adaptation and validation of the Norwich Patellar Instability score for use in Brazilian Portuguese

BACKGROUND

The Norwich Patellar Instability (NPI) score is a tool for evaluating the impact of patellofemoral instability on joint function. It has not been translated or culturally adapted for the Brazilian population before.

OBJECTIVE

This study had the aims of translating and culturally adapting the NPI score for use in Brazilian Portuguese and subsequently assessing its validity for this population.

DESIGN AND SETTING

Translation, cross-cultural adaptation and validation study conducted at the State Public Servants' Institute of São Paulo, Brazil.

METHODS

Sixty patients of both sexes (aged 16-40 years) with diagnoses of patellar dislocation were recruited. The translation and cultural adaptation were undertaken through translation into Brazilian Portuguese and back-translation to English by an independent translator. Face validity was assessed by a committee of experts and by 20 patients. Concurrent validity was assessed through comparing the Brazilian Portuguese NPI score with the Brazilian Portuguese versions of the Lysholm knee score and the Kujala patellofemoral disorder score among the other 40 patients. Correlation analysis between the three scores was performed using Pearson correlation coefficients with significance levels of P < 0.05.

RESULTS

The Brazilian Portuguese version of the NPI score showed moderate correlation with the Brazilian Portuguese versions of the Lysholm score (r = -0.56; 95% confidence interval, CI: -0.74 to -0.30; P < 0.01) and Kujala score (r = -0.57; 95% CI: -0.75 to -0.31; P < 0.01).

CONCLUSION

The Brazilian Portuguese version of the NPI score is a validated tool for assessing patient-reported patellar instability for the Brazilian population.

Photobiomodulation of Matrix Metalloproteinases in Rat Calcaneal Tendons

Objective: The main objective was to verify the modulatory effects of MMP-1, MMP-3, and MMP-13 levels on the partially injured calcaneal tendons of rat exposure to photobiomodulation. Background: Photobiomodulation has been shown to have anti-inflammatory and regenerative effects on tendon injuries. However, there is still uncertainty regarding the beneficial effects in matrix metalloproteinase (MMP) levels, especially MMP-1, -3, and -13. Materials and methods: Sixty-five male Wistar rats were used. Sixty were submitted to a direct trauma on the calcaneal tendons and were randomly distributed into the following six groups: LASER 1, 3, and 7 (10 partially injured calcaneal tendons in each group treated with photobiomodulation for 1, 3, and 7 days, respectively) and Sham 1, 3, and 7 (same injury, with simulated photobiomodulation). The remaining five animals were allocated to the normal group (no injury or treatment procedure). The 780 nm low-level laser was applied with 70 mW of mean power and 17.5 J/cm² of fluency for 10 sec, once a day. The tendons were surgically removed and analyzed for MMP-1, MMP-3, and MMP-13 through immunohistochemistry. Results: MMP-3 levels remained close to normal in all experimental groups (p > 0.05); however, reductions (p < 0.05) in MMP-1 and MMP-13 levels were detected in the groups submitted to one, three, and seven low level laser therapy applications. Conclusions: The photobiomodulation protocol was able to reduce MMP-1 and MMP-13 levels in injured calcaneal tendons.

Laser Photobiomodulation in the acute inflammatory response of the calcaneal tendon injury in rats exposed to cigarette smoke

ABSTRACT Nicotine delays the healing process and increases the levels of myeloperoxidase (MPO), an enzyme that plays a key role in the production of reactive oxygen species during the inflammatory process. Laser Photobiomodulation (PBM) is one of the most used electrophysical agents in the treatment of the calcaneal tendon, however, its effects on MPO activity need to be further elucidated. This study aimed to evaluate the effects of laser PBM on MPO activity after inflicting an injury to the calcaneal tendon of rats exposed to cigarette smoke. Thirty-four male Wistar rats with 90 days of age were used. After 14 days of exposure to cigarette smoke, the animals were divided into three experimental groups: control group (CG, n=12), not submitted to injury or treatment; sham group (ShG, n=10), submitted to partial calcaneal tendon injury and laser PBM simulation; and laser PBM group (PBMG, n=12), submitted to partial calcaneal tendon lesion and treated with laser PBM within the first minute after injury. PBM decreased MPO activity levels in PBMG compared to ShG (CG: 1.38±0.69pg/ml; ShG: 3.78±1.09pg/ml; PBMG: 2.58±0.93pg/ml; p<0.005). In conclusion, applying laser PBM immediately after inflicting damage to the calcaneal tendon attenuates acute inflammatory activity in rats exposed to cigarette smoke.

NEUROMUSCULAR ELECTRICAL STIMULATION OF MEDIUM AND LOW FREQUENCY ON THE QUADRICEPS FEMORIS

Objective

The purpose of this study was to investigate the effects of neuromuscular electrical stimulation (NMES) in different frequencies on the quadriceps femoris. A randomized, controlled, blind cross-sectional study.

Methods

Thirty subjects (12 men and 18 women), with an average age of 24.67 years, weight of 65.62 kg and height of 1.69 m were evaluated. Three random test conditions were applied: maximum voluntary isometric contraction (MVIC), maximum voluntary isometric contraction with medium frequency current (MVIC-MF) and maximum voluntary isometric contraction with low frequency current (MVIC-LF). Four MVICs were applied in each situation. The time between different isometric contraction types was 90 seconds while the time between the same conditions of contraction was 10 seconds.

Results

Two-way ANOVA test showed that MVIC-MF had higher values for peak torque than MVIC-LF (p=0.02). Significant statistical results were found when comparing MVIC-MF and MVIC (p=0.03), but not for MVIC and MVIC-LF (p=0.52).

Conclusion

Maximum voluntary isometric contraction associated with medium-frequency electrical stimulation was more effective than other NMES conditions. Level of Evidence II, Therapeutic Studies - Investigation of treatment results.

Prevalence of musculoskeletal injuries and a proposal for neuromuscular training to prevent lower limb injuries in Brazilian Army soldiers: an observational study

BACKGROUND

The activities carried out by soldiers in the army involve great physical demands and require intense trainings to perform combat-specific tasks. Musculoskeletal injury is a potential threat to the health and physical integrity of the soldier. This study aimed to evaluate the prevalence of lower limb musculoskeletal injuries among soldiers and to propose a training protocol to prevent the most frequent injuries.

METHODS

This observational (cross-sectional) study recruited a sample of 103 soldiers who required medical attention, from a total 202 new battalion soldiers. The medical records (paper and online) had a form of running text. All data collected were recorded by the registered physicians of the battalion medical post. The records were analyzed by the following variables: medical diagnosis, injury site, mechanism, type of treatment, time loss, existence of previous injury, and recurring injury.

RESULTS

A total of 112 musculoskeletal injuries were diagnosed in 71 soldiers, and other types of diseases/injuries were diagnosed in the other soldiers. Joint pain accounted for 55.4% of the diagnoses. The knee was the most affected site, while trauma and overload were the most common mechanisms of injury. Drug treatment was used most frequently, accounting for 58% of the cases. The majority of the sample obtained a temporary leave of absence for 1 to 6 days or not at all. Previous injuries and recurrence were not presented as risk factors for injury. With the data received, a protocol for the prevention of injuries to the lower limbs was proposed.

CONCLUSION

This study indicated that the most frequent site of injury is the knee, and joint pain is the most common diagnosis. These results may support the necessity to develop a neuromuscular training protocol to prevent lower limb injuries, which we suggest to be applied in future studies.

Achilles Tendon Vascularization of Proximal, Medial, and Distal Portion Before and After Partial Lesion in Rats Treated with Phototherapy

BACKGROUND

The Achilles tendon is one of the tendons most commonly injured by microtraumas and overuse during sports practice. This tendon is especially fragile because of the low blood supply in its central part. Nevertheless, the literature does not offer enough scientific support to explain the composition and vascular dynamic of animal tendons, despite the relevance of being able to observe if the animal tendon undergoes the same processes of vascularization in different regions, as occurs in humans.

METHODS

We used 28 rats weighing 280 ± 20 g, which were divided into four groups with seven animals each (control, sham, 830 nm, 660 nm). The laser parameters were: power output 60 mW for both lasers, 40 J/cm(2) of energy density, total energy 1.1 J, power density 2.14 W/cm(2), and application time 18.6 sec. This study evaluated the vascular constitution of healthy and injured calcaneous tendons. The tendons of each animal were processed to be embedded in Paraplast and, after that, they were divided into three parts: proximal, medial, and distal. Afterwards, they were cut in slices of 6 μm were made, then they were stained with hematoxylin and eosin. Using an ocular lens reticulated with magnification × 400, we analyzed the number and the area density of the blood vessels using morphometric methods. Data were analyzed with the Shapiro-Wilk test, followed by Tukey, considering p as <0.05.

RESULTS

The area density and the number of blood vessels in the proximal part were 36% and 42%, respectively, of the values found in the medial part. The distal part had 64% more vessels and 52.8% more area density (p < 0.05) than the medial part.

CONCLUSIONS

Low-level laser therapy (LLLT) had no effect on the studied parameters. The vascularization of rat tendon is similar to that of humans, which contributes to the studies of therapies that have been applied in humans.

High voltage pulsed current in collagen realignment, synthesis, and angiogenesis after Achilles tendon partial rupture

Objective

To verify the efficacy of high voltage pulsed current in collagen realignment and synthesis and in angiogenesis after the partial rupturing of the Achilles tendon in rats.

Method

Forty male Wistar rats were randomized into four groups of 10 animals each: sham, cathodic stimulation, anodic stimulation, and alternating stimulation. Their Achilles tendons were submitted to direct trauma by a free-falling metal bar. Then, the treatment was administered for six consecutive days after the injury. In the simulation group, the electrodes were positioned on the animal, but the device remained off for 30 minutes. The other groups used a frequency of 120 pps, sensory threshold, and the corresponding polarity. On the seventh day, the tendons were removed and sent for histological slide preparation for birefringence and Picrosirius Red analysis and for blood vessel quantification.

Results

No significant difference was observed among the groups regarding collagen realignment (types I or III collagen) or quantity of blood vessels.

Conclusion

High voltage pulsed current for six consecutive days was not effective in collagen realignment, synthesis, or angiogenesis after the partial rupturing of the Achilles tendon in rats.

Low-Level Laser Therapy (780 nm) on VEGF Modulation at Partially Injured Achilles Tendon

OBJECTIVE

The aim of this study was to analyze the modulatory effects of near infrared (780 nm) low-level laser therapy (LLLT) on the presence of the vascular endothelial growth factor (VEGF) in the partially injured Achilles tendons of rats.

BACKGROUND

LLLT stimulates the healing process for Achilles tendon injuries, although the extent of the modulatory effect of LLLT on the VEGF levels found in the injured tendons remains unclear.

METHODS

Sixty-five male Wistar rats were distributed in the following seven groups: LASER 1, 3, and 7 (10 partially injured Achilles tendons in each group, which were treated with LLLT for 1, 3, and 7 days, respectively); Sham 1, 3, and 7 (same injury, with simulated LLLT); Control group containing the five remaining animals and in which no procedures were performed. LLLT was applied once a day for 10 sec, with a mean power of 70 mW and fluency of 17.5 J/cm(2). After euthanasia, all of the Achilles tendons were surgically removed and the VEGF levels were analyzed using immunohistochemistry.

RESULTS

The VEGF levels remained close to normal (p > 0.05) when comparing the experimental groups (LASER and Sham: 1, 3, and 7) with the Control group.

CONCLUSION

LLLT did not stimulate the expression of VEGF in the treated Achilles tendons.

Low-level laser therapy in IL-1β, COX-2, and PGE2 modulation in partially injured Achilles tendon

This study evaluated IL-1β, COX-2, and PGE2 modulation in partially injured Achilles tendons treated with low-level laser therapy (LLLT). Sixty-five male Wistar rats were used. Sixty were submitted to a direct injury on Achilles tendon and then distributed into six groups: LASER 1 (a single LLLT application), LASER 3 (three LLLT applications), and LASER 7 (seven LLLT applications) and Sham 1, 3, and 7 (the same injury but LLLT applications were simulated). The five remaining animals were allocated at control group (no procedure performed). LLLT (780 nm) was applied with 70 mW of mean power and 17.5 J/cm(2) of fluency for 10 s, once a day. The tendons were surgically removed and assessed immunohistochemically for IL-1β, COX-2, and PGE2. In comparisons with control (IL-1β: 100.5 ± 92.5 / COX-2: 180.1 ± 97.1 / PGE2: 187.8 ± 128.8) IL-1β exhibited (mean ± SD) near-normal level (p > 0.05) at LASER 3 (142.0 ± 162.4). COX-2 and PGE2 exhibited near-normal levels (p > 0.05) at LASER 3 (COX-2: 176.9 ± 75.4 / PGE2: 297.2 ± 259.6) and LASER 7 (COX-2: 259.2 ± 190.4 / PGE2: 587.1 ± 409.7). LLLT decreased Achilles tendon's inflammatory process.

In vitro effect of 470 nm LED (Light Emitting Diode) in keloid fibroblasts

PURPOSE

To quantify keloid fibroblasts after irradiation with 470nm blue LED, in vitro.

METHODS

Fibroblasts from keloid and adjacent skin have been obtained from 6 patients. Cells have been cultivated and maintained in DMEM culture medium. In Petri dishes, they were irradiated with energy doses of 6J, 12J and 18J. After 24 h, counting was done by the average of the triplicates for each sample.

RESULTS

There were no significant differences in the number of irradiated keloid fibroblasts at the studied doses (p=0.261). In adjacent skin fibroblasts, differences were observed (p=0.025) concerning the doses of 18 J and 6 J (p=0.03).

CONCLUSIONS

There was a reduction in the number of adjacent skin fibroblasts irradiated with 470nm blue LED at the energy dose of 18 J compared to the ones irradiated at the energy dose of 6 J. There were no changes in keloid fibroblasts counting at any of the doses applied, 24 h after irradiation.

Different power settings of LLLT on the repair of the calcaneal tendon

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.

Mechanical stimulation improves survival in random-pattern skin flaps in rats

This was a study on the effects of 3-MHz ultrasound at 16- and 100-Hz pulse repetition frequencies on angiogenesis and viability of random-pattern skin flaps in rats. A cranially-based dorsal skin flap was raised in 60 EPM-Wistar rats, which were randomly divided into four groups: control, sham, 16-Hz and 100-Hz groups. The mean percentage of necrosis was as follows: control, 42% ± 13%; sham, 18% ± 13%; 16-Hz group, 13% ± 10%; and 100-Hz group, 15% ± 7%, with significant differences between the control and the other groups (p < 0.001). The mean vascular density was as follows: control, 5% ± 2%; sham, 7% ± 2%; 16-Hz group, 21% ± 4%; and 100-Hz group, 24% ± 10%, with significant differences between control and ultrasound groups, and between the sham and ultrasound groups (p < 0.001). Both ultrasound treatments (16- and 100-Hz PRFs) induced angiogenesis, and sham and ultrasound treatments improved viability of random-pattern skin flaps in rats.

Experimental model for low level laser therapy on ischemic random skin flap in rats

PURPOSE: To develop an experimental model to be used in the study of low level Laser therapy on viability of random skin flap in rats. METHODS: The sample was 24 Wistar-EPM rats. The random skin flap measured 10 x 4 cm and a plastic sheet was interposed between the flap and donor site. Group 1 (control) underwent sham irradiation with diode laser (830 nm). Group 2 was submitted to laser irradiation with diode laser (830 nm). The animals were submitted to Laser therapy with 36 J/cm² energy density (72 seconds) immediately after the surgery and on the four subsequent days. The probe was usually held in contact with the skin flap surface on a point at 2.5 cm cranial from the flap base. On the seventh postoperative day, the percentage of necrotic area was measured and calculated. RESULTS: Group 1 reached an average necrotic area of 48.86%, Group 2 - 23.14%. After the statistic analysis, compared with the control group, Group 2 showed a statistically significant increase in survival area (p<0.001). CONCLUSION: The experimental model proved to be reliable to be used in the study of effects of low level laser therapy in random skin flap in rats.