Early Low-Level Laser Therapy Improves the Passive Range of Motion and Decreases Pain in Patients with Flexor Tendon Injury

Effects of photobiomodulation on pain, lactate and muscle performance (ROM, torque, and EMG parameters) of paretic upper limb in patients with post-stroke spastic hemiparesis-a randomized controlled clinical trial

The objective of the study was to investigate the impact of photobiomodulation (PBM) on the paretic upper limb in post-stroke patients with spastic hemiparesis and to understand the potential of PBM as a long-term non-invasive therapy for reducing the side effects caused by spasticity in the hemiparetic upper limb after a stroke. This is a double-blind randomized clinical trial constituted of 27 participants, being Control group (CG = 12 healthy individuals) and PBM group (PBMG = 15 post-stroke individuals). In the CG, the baseline blood lactate (BL) was evaluated, followed by the evaluation of the IC torque of the biceps and triceps muscles, with the isokinetic dynamometer associated with surface electromyography (EMG) and, subsequently, a new measurement of BL. The PBMG received 10 sessions of treatment with PBM (780 nm, Power: 100 mV, Power Density: 3.18 W/cm2, Energy: 4 J, Fluency: 127.4 J/cm2, Time: 40 s per point and 1.280 s total, Spot: 0.0314 cm2, 32 Points: 16 points (brachial biceps) and 16 points (brachial triceps) applied with contact at 90°, Total Energy: 64 J), which in the pre-treatment evaluation measured BL, the visual analogue scale (VAS) of pain; torque and EMG of the same muscles in the IC, subsequently, a new measurement of VAS and BL, and measurement of range of motion (ROM) during the reaching movement. At the conclusion of the ten sessions, all participants underwent a reassessment, wherein all tests originally administered during the initial evaluation were repeated. Subsequently, the data were analyzed using the Shapiro-Wilk normality test. For related data, the paired t-test was used for normal distributions and the Wilcoxon test for non-normal data. For unrelated data, the t test was used for normal distributions and the Mann-Whitney test for non-normal data. Muscle torque was higher for the CG, with a significant difference (CGxPBMG = p < 0.0001). There was no significant difference between the EMG values of the CG in relation to the Pre-PBM phase and with the Post-PBM phase of the PBMG (p > 0.05). On the other hand, there was a 38% reduction in pain reported by hemiparetic patients (p = 0.0127) and a decrease in BL in the PBMG. Post-PBM ROM increased by 46.1% in the elbow extension of the paretic limb. In conclusion, Photobiomodulation (PBM) demonstrated significant improvements in muscle performance, reducing fatigue and pain levels, and enhancing range of motion in post-stroke patients with spastic hemiparesis. These findings support the potential integration of PBM into rehabilitation protocols, but further research and clinical trials are needed to validate and expand upon these promising outcomes.

Outcome measurement in adult flexor tendon injury: A systematic review

BACKGROUND

Defining the optimal, evidence-based management of flexor tendon injury remains challenging. Lack of consensus on which measures to use to assess the outcome of interventions is a key issue, especially with regard to patient-reported outcome measures (PROMs). This systematic review defines the landscape of outcome measurement in studies on interventions for flexor tendon injuries to guide future research.

METHODS

A PRISMA-compliant systematic review was conducted using bespoke search strategies applied to MEDLINE, EMBASE, PsycINFO, CENTRAL, CINAHL and AMED. A protocol was developed and registered prospectively (CRD42020186780). We identified all studies describing adult patients undergoing interventions for acute hand flexor tendon injuries.

RESULTS

Of the 4844 studies, 114 studies met the final inclusion criteria for evaluating the outcomes of 8127 participants with 9071 injured digits. Studies included 24 randomised controlled trials, 19 cohort studies and 61 case series. Nine different PROMs were used in 24 studies (22%): three site-specific PROMs, one generic quality-of-life measure and four visual analogue scales. Clinician-reported outcome measures were used in 103 studies (96%), such as the range of motion reported in 102 studies (94%). Adverse outcomes were reported in 96 studies (89%), with the most frequently reported adverse outcomes being tendon rupture and infection. Re-operation was reported in 21 studies (19%). The most frequently reported health economic outcome measure was the length of work absence, reported in ten studies (9%).

CONCLUSIONS

There is variability in the use of outcome measures used to study interventions for flexor tendon injuries. An independent systematic review of the psychometric properties of the identified outcome measures and a specific multi-stakeholder consensus process may support optimal choice and standardisation for future studies.

Rehabilitation following surgery for flexor tendon injuries of the hand

BACKGROUND

Various rehabilitation treatments may be offered following surgery for flexor tendon injuries of the hand. Rehabilitation often includes a combination of an exercise regimen and an orthosis, plus other rehabilitation treatments, usually delivered together. The effectiveness of these interventions remains unclear.

OBJECTIVES

To assess the effects (benefits and harms) of different rehabilitation interventions after surgery for flexor tendon injuries of the hand.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, MEDLINE, Embase, two additional databases and two international trials registries, unrestricted by language. The last date of searches was 11 August 2020. We checked the reference lists of included studies and relevant systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs that compared any postoperative rehabilitation intervention with no intervention, control, placebo, or another postoperative rehabilitation intervention in individuals who have had surgery for flexor tendon injuries of the hand. Trials comparing different mobilisation regimens either with another mobilisation regimen or with a control were the main comparisons of interest. Our main outcomes of interest were patient-reported function, active range of motion of the fingers, and number of participants experiencing an adverse event.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, extracted data, assessed risk of bias and assessed the quality of the body of evidence for primary outcomes using the GRADE approach, according to standard Cochrane methodology.

MAIN RESULTS

We included 16 RCTs and one quasi-RCT, with a total of 1108 participants, mainly adults. Overall, the participants were aged between 7 and 72 years, and 74% were male. Studies mainly focused on flexor tendon injuries in zone II. The 17 studies were heterogeneous with respect to the types of rehabilitation treatments provided, intensity, duration of treatment and the treatment setting. Each trial tested one of 14 comparisons, eight of which were of different exercise regimens. The other trials examined the timing of return to unrestricted functional activities after surgery (one study); the use of external devices applied to the participant to facilitate mobilisation, such as an exoskeleton (one study) or continuous passive motion device (one study); modalities such as laser therapy (two studies) or ultrasound therapy (one study); and a motor imagery treatment (one study). No trials tested different types of orthoses; different orthosis wearing regimens, including duration; different timings for commencing mobilisation; different types of scar management; or different timings for commencing strengthening. Trials were generally at high risk of bias for one or more domains, including lack of blinding, incomplete outcome data and selective outcome reporting. Data pooling was limited to tendon rupture data in a three trial comparison. We rated the evidence available for all reported outcomes of all comparisons as very low-certainty evidence, which means that we have very little confidence in the estimates of effect. We present the findings from three exercise regimen comparisons, as these are commonly used in clinical current practice. Early active flexion plus controlled passive exercise regimen versus early controlled passive exercise regimen (modified Kleinert protocol) was compared in one trial of 53 participants with mainly zone II flexor tendon repairs. There is very low-certainty evidence of no clinically important difference between the two groups in patient-rated function or active finger range of motion at 6 or 12 months follow-up. There is very low-certainty evidence of little between-group difference in adverse events: there were 15 overall. All three tendon ruptures underwent secondary surgery. An active exercise regimen versus an immobilisation regimen for three weeks was compared in one trial reporting data for 84 participants with zone II flexor tendon repairs. The trial did not report on self-rated function, on range of movement during three to six months or numbers of participants experiencing adverse events. The very low-certainty evidence for poor (under one-quarter that of normal) range of finger movement at one to three years follow-up means we are uncertain of the finding of zero cases in the active group versus seven cases in the immobilisation regimen. The same uncertainty applies to the finding of little difference between the two groups in adverse events (5 tendon ruptures in the active group versus 10 probable scar adhesion in the immobilisation group) indicated for surgery. Place and hold exercise regimen performed within an orthosis versus a controlled passive regimen using rubber band traction was compared in three heterogeneous trials, which reported data for a maximum of 194 participants, with mainly zone II flexor tendon repairs. The trials did not report on range of movement during three to six months, or numbers of participants experiencing adverse events. There was very low-certainty evidence of no difference in self-rated function using the Disability of the Arm, Shoulder and Hand (DASH) functional assessment between the two groups at six months (one trial) or at 12 months (one trial). There is very low-certainty evidence from one trial of greater active finger range of motion at 12 months after place and hold. Secondary surgery data were not available; however, all seven recorded tendon ruptures would have required surgery. All the evidence for the other five exercise comparisons as well as those of the other six comparisons made by the included studies was incomplete and, where available, of very low-certainty.

AUTHORS' CONCLUSIONS

There is a lack of evidence from RCTs on most of the rehabilitation interventions used following surgery for flexor tendon injuries of the hand. The limited and very low-certainty evidence for all 14 comparisons examined in the 17 included studies means that we have very little confidence in the estimates of effect for all outcomes for which data were available for these comparisons. The dearth of evidence identified in this review points to the urgent need for sufficiently powered RCTs that examine key questions relating to the rehabilitation of these injuries. A consensus approach identifying these and establishing minimum study conduct and reporting criteria will be valuable. Our suggestions for future research are detailed in the review.

Photobiomodulation does not influence maturation and mildly improves functional healing of mouse achilles tendons

Tendon rupture can occur at any age and is commonly treated nonoperatively, yet can result in persisting symptoms. Thus, a need exists to improve nonoperative treatments of injured tendons. Photobiomodulation (PBM) therapy has shown promise in the clinic and is hypothesized to stimulate mitochondrial-related metabolism and improve healing. However, the effect of PBM therapy on mitochondrial function during tendon maturation and healing are unknown, and its effect on tendon structure and function remain unclear. In this study, near-infrared light (980:810 nm blend, 2.5 J/cm² ) was applied at low (30 mW/cm² ) or high (300 mW/cm² ) irradiance to unilateral Achilles tendons of CD-1 mice during postnatal growth (maturation) as well as adult mice with bilateral Achilles tenotomy (healing). The chronic effect of PBM therapy on tendon structure and function was determined using histology and mechanics, and the acute effect of PBM therapy on mitochondrial-related gene expression was assessed. During maturation and healing, collagen alignment, cell number, and nuclear shape were unaffected by chronic PBM therapy. We found a sex-dependent effect of PBM therapy during healing on mechanical outcomes (eg, increased stiffness and Young's modulus for PBM-treated females, and increased strain at ultimate stress for PBM-treated males). Mitochondria-related gene expression was marginally influenced by PBM therapy for both maturation and healing studies. This study was the first to implement PBM therapy during both growth and healing of the murine tendon. PBM therapy resulted in marginal and sex-dependent effects on the murine tendon. Clinical significance: PBM may be beneficial for tendon healing because functional remodeling improves without adverse effects.

Analysis of low-level laser transmission at wavelengths 660, 830 and 904 nm in biological tissue samples

BACKGROUND

In recent decades, low-level laser therapy (LLLT) has occupied a prominent position and has been studied in various fields of knowledge, and your effects have been widely observed in studies about numerous tissues, such as tendons, peripheral nerves, cutaneous tissue, bone, and muscle, in different fields of knowledge.

PURPOSE

To analyze the power transmitted by low-level laser therapy (LLLT) to different tissue samples by using distinct wavelengths.

METHODS

Skin samples of rat (n = 7, 1.17-1.63 mm) and pig (n = 10; 1.20-2.30 mm); pig fat (n = 10; 2.71-14.01 mm) and pig muscle (n = 10; 1.91-8.91 mm) were analyzed and interposed between the emitter and the power analyzer sensor. All the samples were irradiated sequentially three times, at five equidistant points and average power levels of 35.34(±1.03), 32.40(±0.70), and 42.32(±0.82) mW, for the wavelengths 660, 830, and 904 nm, respectively. Transmitted radiation was measured with a power analyzer connected to a laser emitter. Statistical analysis was performed with a Shapiro-Wilk test followed by ANOVA with Tukey's post hoc test, with a significance level of 5%.

RESULTS

The transmitted power of LLLT on skin, fat, and muscle of tissues decreases with the increase of thicknesses, presenting minor attenuation on rat skin, pig fat, and pig muscle for 904 nm. The pig skin has the slight attenuation for 830 nm.

CONCLUSION

The LLLT should be applied after considering the transmission loss taking place in different anatomical structures, following the Beer-Lambert law and attenuation coefficient presented for more practical application in many fields.