Management of Primary Injuries of the Medial Collateral Ligament of the Carpus in Two Horses

A Preliminary Study of the Influence of High Intensity Laser Therapy (HILT) on Skin Surface Temperature and Longissimus Dorsi Muscle Tone Changes in Thoroughbred Racehorses with Back Pain

The reason for undertaking this study was to investigate soft tissue response to high-intensity laser therapy (HILT) by measuring changes in skin surface temperature and longissimus dorsi muscle tone in the thoracolumbar back area in Thoroughbreds with back pain and diagnosed with and without Kissing Spines Syndrome (KSS). Thoroughbreds aged 3-4 years with clinically presented back pain underwent a radiological examination (to assess a lack or presence of KSS) and longissimus dorsi muscle palpation (to assess muscle tone and pain degree). The subjects were divided into two groups, those with KSS (n = 10) and those without KSS (n = 10). A single HILT treatment on the longissimus dorsi muscle, on the left side, was performed. Thermographic examination and palpation were repeated before and after HILT to assess changes in skin surface temperature and muscle pain response. In both groups, HILT caused a significant increase in skin surface temperature of 2.5 °C on average and a palpation score reduction of 1.5 degrees on average (p = 0.005 for both measurements), without differences in any outcome measures between the groups. Furthermore, the correlation between changes in the average skin surface temperature and the average palpation scores in horses with and without KSS were negative (rho = 0.071 and r = -0.180, respectively; p > 0.05). The results of the present study are encouraging, but further studies with larger samples, a longer follow-up period and comparisons with placebo control groups are needed to draw a more valid conclusion.

Effects of High-Intensity Laser Therapy (HILT) on Skin Surface Temperature and Vein Diameter in Healthy Racehorses with Clipped and Non-Clipped Coat

The aim of this study was to investigate the differences in the effects of high-intensity laser therapy (HILT) on skin surface temperature and vein diameter in the carpal joint region in racehorses with clipped and non-clipped treatment areas. The study included 20 Thoroughbreds split into two equal groups: clipped coat and non-clipped coat. Horses underwent thermographic examination to detect changes in skin surface temperature at the medial surface of the carpal joint, followed by ultrasonographic examination to assess changes in the diameter of the medial palmar vein before and after HILT. The increase in skin surface temperature after HILT was significantly lower in the group with clipped coat than in the non-clipped group. The group with clipped coat showed a greater increase in vessel diameter. There was a significantly weak negative correlation between the changes in average skin surface temperature and vein diameter in both groups. In conclusion, an efficient photothermal effect can be achieved in skin with a non-clipped coat and clipping the treatment area increases photobiostimulation of the tissue, while reducing the photothermal effect. Further research is needed to specify the parameters for the treatment of skin with clipped and non-clipped coat in order to perform effective laser therapy.

A Case Series of 11 Horses Diagnosed with Bone Spavin Treated with High Intensity Laser Therapy (HILT)

The aim of this work was to characterize and describe the effect of High Intensity Laser Therapy (HILT) used in the treatment of chronic osteoarthritis in horses. Over a 2 year period, 11 horses with diagnosed bone spavin were treated with HILT as a monotherapy. The horses chosen for this report presented hind limb lameness, were positive in a spavin flexion test and showed improvement after intra-articular anesthesia of the tarsometatarsal joint. Additionally, all the horses presented radiological signs of tarsus osteoarthritis and had not been treated for bone spavin for a minimum of 6 months. Each horse received 10 HILT therapies over 14 days' treatment time with the same laser protocol. At post-treatment orthopedic examination, 4 horses (36%) had improved 2 lameness grades (in the 5 grade American Association of Equine practitioners lameness scale), 4 horses (36%) had improved 1 lameness grade and 3 horses (28%) did not improve. Additionally, 3 horses were totally sound after HILT. Post-treatment spavin test result improvement was observed in 5 horses (45%), and 6 horses (55%) showed the same spavin test grade as before treatment. There were no horses that were sound in the spavin test performed after HILT. Therefore, it seems probable that the application of HILT in horses suffering from bone spavin may decrease joint pain, which influences visual lameness reduction.

Photothermal Effects of High-Intensity Laser Therapy on the Superficial Digital Flexor Tendon Area in Clinically Healthy Racehorses

The aim of the present study was to assess the photothermal effects of high-intensity laser therapy (HILT) on the superficial digital flexor tendon (SDFT) of the hindlimb in racehorses. It was conducted on 18 clinically healthy thoroughbreds that were subjected to thermographic examination to measure surface temperature changes in the SDFT. This was performed before and immediately after HILT. This revealed statistically significant differences in the temperature of the skin surface overlying the flexor tendons (p < 0.001). The surface temperature of the area examined was higher by an average of 3.5 °C after HILT, compared with the temperature measured before HILT. Our results prove that HILT has a photothermal effect in treating soft tissue. This finding can be helpful in determining the appropriate parameters for monitoring the short- and long-term effects of HILT.

Histological tissue healing following high-power laser treatment in a model of suspensory ligament branch injury

BACKGROUND

High-power laser therapy gained popularity recently as a regenerative treatment for tendinitis and desmitis in the horse. However, studies evaluating effects of laser therapy on tissue repair at histological level in large mammals are lacking.

OBJECTIVES

To evaluate effects of high-power laser therapy on suspensory desmitis healing, using a model of suspensory ligament branch injury.

STUDY DESIGN

In vivo experiments.

METHODS

Standardised lesions were surgically induced in all 4 lateral suspensory branches of twelve healthy Warmblood horses. Laser therapy (class 4, 15W) was applied daily on 2 of 4 induced lesions for 4 consecutive weeks. Horses were randomly assigned to either short-term study (horses were sacrificed after 4 weeks) or long-term study (6 months). Suspensory ligament samples were scored after staining with haematoxylin-eosin and immunostaining for collagen 1- collagen 3- and factor VIII.

RESULTS

In the short-term study, significantly better (lower) scores for variation in density (17% above cut-off score in treated lesions vs. 31% above cut-off score in controls, p=0.03), shape of nuclei (54% vs. 92%, p=0.02), fibre alignment (32% vs. 75%, p=0.003) and fibre structure (38% vs. 71%, p=0.02) were found in laser treated lesions when compared to controls. Collagen 3 expression was significantly higher (32% vs. 19%, p=0.006) in control lesions. In both short- and long-term studies combined, parameters lesion size (44% vs. 56%, p=0.02) and shape of nuclei (53% vs. 84%, p=0.05) scored significantly better in treated lesions. Long-term, significantly better (lower) scores were found in the laser-treated group for lesion size (15% vs. 45%, p=0.008) and a higher percentage above cut-off score for density of the nuclei (27% vs. 9%, p=0.02), compared to controls.

MAIN LIMITATIONS

The model of suspensory branch injury is not an exact representation of clinical overstrain lesions.

CONCLUSIONS

These results suggest that high-power laser therapy enables better lesion healing than conservative treatment.

Comparison of the Effect of High-Intensity Laser Therapy (HILT) on Skin Surface Temperature and Vein Diameter in Pigmented and Non-Pigmented Skin in Healthy Racehorses

Simple Summary

High-intensity laser therapy (HILT) is used in the treatment of horses, but little is known about the differences in the impact of HILT performed on pigmented and non-pigmented skin. The aim of this study was to assess differences in the influence of HILT on skin surface temperature and vein diameter in a group of healthy racehorses with pigmented and non-pigmented skin in the treatment area. The hypothesis was that HILT would cause a greater increase in skin surface temperature and vein diameter in horses with pigmented skin compared to non-pigmented skin. Ten Thoroughbreds with pigmented skin and ten Thoroughbreds with non-pigmented skin in the treatment area received HILT. Changes in the vein diameter and skin surface temperature of the irradiated area were measured before and after HILT. The HILT treatment caused an increase in the pigmented skin surface temperature and a decrease in the non-pigmented skin surface temperature, while the vein diameter increased in both groups. In conclusion, melanin content in the epidermis plays an important role in light energy absorption and photothermal effects. Determining the physiological and clinical effects of HILT performed on pigmented and non-pigmented skin will help clinicians choose appropriate HILT parameters.

Abstract

The aim of the study was to assess differences in the influence of high-intensity laser therapy (HILT) on the skin surface temperature and vein diameter of the lateral fetlock joint region in a group of racehorses with pigmented and non-pigmented skin in the treatment area. Twenty Thoroughbreds were divided into two equal groups: pigmented and non-pigmented skin groups. Each horse received the same HILT treatment. Just before and immediately after HILT, thermographic examination was performed to measure the skin surface temperature and ultrasonographic examination assessed the lateral digital palmar vein diameter. After HILT, the pigmented skin surface temperature increased, while the non-pigmented skin surface temperature decreased, and the difference between both groups was significant (p < 0.001). The vein diameter increased after HILT in horses with pigmented and non-pigmented skin, but the difference between both groups was not significant (p = 0.14). In conclusion, melanin content in the epidermis plays an important role in light energy absorption and photothermal effects. The vein diameter changes after HILT application indicated that the increase in vessel diameter may partly depend on photothermal mechanisms occurring in irradiated tissue. Further research is necessary to describe the physiological and clinical effects of HILT performed on pigmented and non-pigmented skin.

Effects of High Intensity Laser Therapy in the Treatment of Tendon and Ligament Injuries in Performance Horses

Simple Summary

High intensity laser therapy (HILT) has been introduced as a non-invasive therapy for musculoskeletal diseases in horses, but little is known about the impact of HILT in the treatment of tendon and ligament injuries. The aim of this study was to evaluate the effects of HILT on tendon and ligament injury treatment in horses. Twenty six horses with tendinopathies and desmopathies were randomly assigned to a HILT treated or to a non-treated group. Each horse from the treatment group underwent a series of fifteen HILT treatments. Clinical and ultrasound assessments were carried out. Clinical evaluation included: pain, swelling and lameness of the affected limb. The ultrasound examination evaluated lesion echogenicity and lesion percentage. In our study, HILT promoted analgesic and anti-oedema effects, with visual lameness reduction in horses with tendon and ligament injuries, and reduced lesion percentage but did not influence change in lesion echogenicity. HILT appears justifiable for its anti-inflammatory effects and can be used as a physiotherapeutic technique for supportive treatment of tendon and ligament injuries in horses. The introduction of laser therapy to veterinary medicine, particularly to analgesic therapy in horses, gives hope of improving the quality of life of patients with chronic musculoskeletal pain.

Abstract

The aim of this study was to evaluate the effects of high intensity laser therapy (HILT) on tendon and ligament injury treatment in horses. Twenty six horses with tendinopathies were randomly assigned to a HILT treated or to a non-treated group. Each horse was subjected to the same rehabilitation programme. Horses from the treatment group underwent a series of fifteen HILT treatments with the same parameters. Clinical and ultrasound assessments were performed by the same veterinarian and were carried out before (day 0), during (day 13–15) and after treatment (day 38–40). Clinical evaluation included: pain, swelling and lameness of the affected limb. The ultrasound examination evaluated lesion echogenicity and lesion percentage. After the treatment, pain, swelling and lameness were significantly improved by HILT compared with the control group (p = 0.023, 0.008 and 0.044, respectively). No significant changes were found in lesion echogenicity degree between both groups in measurements taken during treatment (p = 0.188) and after treatment (p = 0.070). For lesion percentage reduction, the statistical modelling showed a significant improvement in the HILT group compared with the control group during (p = 0.038) and after treatment (p = 0.019). In conclusion, HILT promoted analgesic and anti-oedema effects, with visual lameness reduction in horses with tendon and ligament injuries, and reduced lesion percentage but did not influence change in lesion echogenicity.