Comparison of therapeutic ultrasound and exercises for augmenting tendon healing in rats

Effects of low-density pulsed ultrasound treatment on transforming growth factor-beta, collagen level, histology, biomechanics, and function in repaired rat tendons

Objectives

The aim of this study is to compare the effects of low-density pulsed ultrasound (LIPUS) treatment on growth factors/collagen production, histological, biomechanical, and function of rats with Achilles tendon injury.

Materials and methods

A total of 44 Wistar Albino rats were used in the study between April 2017 and June 2018. The rats were randomized to two treatment groups. Group 1 (n=6) received LIPUS treatment (0.3 Watt/cm2; 1 MHz, 1:5 pulse mode) and Group 2 (n=6)received sham ultrasound (US) treatment following Achilles tendon surgery. Transforming growth factor-beta 1 (TGF-β1) and collagen gene expression levels were evaluated using polymerase chain reaction. The histological evaluation was performed with the Bonar scoring system. The tensile strength was measured by biomechanical testing and the function was evaluated with the Achilles Functional Index (AFI).

Results

Although TGF-β1 expression and tensile strength evaluation showed a tendency to improve in favor of the LIPUS group, no statistically significant difference was found (p=0.065 and p=0.053, respectively). The COL3 gene expression in the LIPUS group and the COL1 expression in the sham US group were significantly higher. Bonar scores and AFI scores showed a statistically significant improvement in the LIPUS group, compared to the sham US group.

Conclusion

Our study results show that LIPUS yields positive effects on tendon histology and functional status in repaired Achilles tendon in rats.

Effects of pulsed electromagnetic field (PEMF) on the tensile biomechanical properties of diabetic wounds at different phases of healing

The present study investigated the effects of pulsed electromagnetic field (PEMF) on the tensile biomechanical properties of diabetic wounds at different phases of healing. Two intensities of PEMF were adopted for comparison.

We randomly assigned 111 10-week-old male streptozotocin-induced diabetic Sprague-Dawley rats to two PEMF groups and a sham control group. Six-millimetre biopsy punched full thickness wounds were made on the lateral side of their hindlimbs. The PEMF groups received active PEMF delivered at 25 Hz with intensity of either 2 mT or 10 mT daily, while the sham group was handled in a similar way except they were not exposed to PEMF. Wound tissues were harvested for tensile testing on post-wounding days 3, 5, 7, 10, 14 and 21. Maximum load, maximum stress, energy absorption capacity, Young’s modulus and thickness of wound tissue were measured.

On post-wounding day 5, the PEMF group that received 10-mT intensity had significantly increased energy absorption capacity and showed an apparent increase in the maximum load. However, the 10-mT PEMF group demonstrated a decrease in Young’s modulus on day 14. The 10-mT PEMF groups showed a significant increase in the overall thickness of wound tissue whereas the 2-mT group showed a significant decrease in the overall maximum stress of the wounds tissue.

The present findings demonstrated that the PEMF delivered at 10 mT can improve energy absorption capacity of diabetic wounds in the early healing phase. However, PEMF (both 2-mT and 10-mT) seemed to impair the material properties (maximum stress and Young’s modulus) in the remodelling phase. PEMF may be a useful treatment for promoting the recovery of structural properties (maximum load and energy absorption capacity), but it might not be applied at the remodelling phase to avoid impairing the recovery of material properties.

Topical Fish Oil Application Coupling with Therapeutic Ultrasound Improves Tendon Healing

Fish oil has been shown to promote collagen synthesis, and hence, connective tissue healing. Therapeutic ultrasound is commonly used to treat soft tissue injuries. This study aimed to investigate the therapeutic effect of topical fish oil on the management of Achilles tendon rupture, comparing normal therapeutic ultrasound with a combination of ultrasound and fish oil. Eighty-five Sprague-Dawley rats underwent surgical hemitenotomy of the right medial Achilles tendon. The rats received daily treatment of either topical placebo ointment (control group [CON]), topical fish oil (FO), therapeutic ultrasound (US) or ultrasound with fish oil as the coupling medium (FU). The treatment started on post-surgical day 2 over a 2-wk or 4-wk period. On days 15 and 29, the rats were sacrificed and their Achilles tendons were tested for structural stiffness, ultimate tensile strength (UTS) and energy absorption capacity. At 2 wk, only US showed higher normalized UTS compared with CON (p < 0.05). At 4 wk, both US and FU demonstrated better UTS (p < 0.05), while both FO and FU had improved in structural stiffness (p < 0.05). Four wk of treatment with ultrasound using fish oil as coupling medium showed improvement in both structural stiffness and UTS (p < 0.05).

Measurement of diabetic wounds with optical coherence tomography-based air-jet indentation system and a material testing system

OBJECTIVE

Material testing system is a conventional but destructive method for measuring the biomechanical properties of wound tissues in basic research. The recently developed optical coherence tomography-based air-jet indentation system is a non-destructive method for measuring these properties of soft tissues in a non-contact manner. The aim of the study was to examine the correlation between the biomechanical properties of wound tissues measured by the two systems.

METHOD

Young male Sprague-Dawley rats with streptozotocin-induced diabetic were wounded by a 6 mm biopsy punch on their hind limbs. The biomechanical properties of wound tissues were assessed with the two systems on post-wounding days 3, 7, 10, 14, and 21. Wound sections were stained with picro-sirius red for analysis on the collagen fibres. Data obtained on the different days were charted to obtain the change in biomechanical properties across the time points, and then pooled to examine the correlation between measurements made by the two devices. Qualitative analysis to determine any correlation between indentation stiffness measured by the air-jet indentation system and the orientation of collagen fibres.

RESULTS

The indentation stiffness is significantly negatively correlated to the maximum load, maximum tensile stress, and Young's modulus by the material testing system (all p<0.05). The orientation of collagen changes with the indentation stiffness over time.

CONCLUSION

Our findings support the use of optical coherence tomography-based air-jet indentation system to evaluate the biomechanical properties of wounds in a non-contact manner. It is a potential clinical device to examine the biomechanical properties of chronic wounds in vivo in a repeatable manner.

Efficacy of therapeutic ultrasound in pain and joint mobility in whiplash traumatic acute and subacute phases

To determine if ultrasound (US) is effective in reducing pain and mobility limitation in the treatment of traumatic cervical sprain, we performed an experimental study. The sample comprised 54 diagnosed subjects with a mean age of 36.54 y (standard deviation = 12.245), assigned by simple random selection to an experimental group with ultrasound treatment and a control group with placebo ultrasound. Treatment consisted of 10 sessions of an ultrasound treatment protocol, followed by 15 sessions of a protocol identical for both groups without ultrasound. The variables assessed were pain and joint mobility. There was no significant difference (p > 0.05) between groups in the first 10 sessions of treatment. However, there was a statistically significant difference (p < 0.05) between groups on the pain variable, 20 days after completion of the US. High-active ultrasound treatment is more effective than placebo in reducing pain.

In vivo and ex vivo approaches to studying the biomechanical properties of healing wounds in rat skin

An evaluation of wound mechanics is crucial in reflecting the wound healing status. The present study examined the biomechanical properties of healing rat skin wounds in vivo and ex vivo. Thirty male Sprague-Dawley rats, each with a 6 mm full-thickness circular punch biopsied wound at both posterior hind limbs were used. The mechanical stiffness at both the central and margins of the wound was measured repeatedly in five rats over the same wound sites to monitor the longitudinal changes over time of before wounding, and on days 0, 3, 7, 10, 14, and 21 after wounding in vivo by using an optical coherence tomography-based air-jet indentation system. Five rats were euthanized at each time point, and the biomechanical properties of the wound tissues were assessed ex vivo using a tensiometer. At the central wound bed region, the stiffness measured by the air-jet system increased significantly from day 0 (17.2%), peaked at day 7 (208.3%), and then decreased progressively until day 21 (40.2%) as compared with baseline prewounding status. The biomechanical parameters of the skin wound samples measured by the tensiometer showed a marked reduction upon wounding, then increased with time (all p &lt; 0.05). On day 21, the ultimate tensile strength of the skin wound tissue approached 50% of the normal skin; while the stiffness of tissue recovered at a faster rate, reaching 97% of its prewounded state. Our results suggested that it took less time for healing wound tissues to recover their stiffness than their maximal strength in rat skin. The stiffness of wound tissues measured by air-jet could be an indicator for monitoring wound healing and contraction.

Usage Patterns and Beliefs about Therapeutic Ultrasound by Canadian Physical Therapists: An Exploratory Population-Based Cross-Sectional Survey

PURPOSE

To explore the frequency and patterns of ultrasound (US) usage among physical therapists, to describe the most common purposes for using therapeutic US, and to investigate beliefs about therapeutic US.

METHODS

A survey was sent to 95% of physical therapists licensed to practise in the province of Alberta, Canada.

RESULTS

Of 2,269 physical therapists to whom email invitations were sent, 438 (19.3%) provided full responses. RESULTS indicate that US is still frequently incorporated into treatment regimens and is widely believed to be effective; however, the study also found a decrease in US usage over the past 15 years. While physical therapists recognize the lack of evidence for the effectiveness of US, many consider it clinically useful. Physical therapists using US rely largely on their clinical experience when making decisions about its use, but this depends on level of education: clinicians with an MScPT degree tended to base more of their US decisions on research evidence, likely because of the increasing emphasis on research evidence in graduate education.

CONCLUSIONS

Despite the questionable effectiveness of therapeutic US, physical therapists still commonly use this treatment modality, largely because of a belief that US is clinically useful. However, US usage has decreased over the past 15 years.

Comparação do ultrassom pulsado e contínuo no reparo tendíneo de ratos

No tratamento de lesões tendíneas, o uso do ultrassom surge como possibilidade terapêutica, apesar de lacunas sobre seus efeitos clínicos. O objetivo foi avaliar dois protocolos de ultrassom terapêutico sobre dor e edema após trauma tendíneo. Vinte e um ratos Wistar foram submetidos a trauma no tendão calcâneo e divididos em três grupos: sham (GS); ultrassom contínuo (GUC); e ultrassom pulsado (GUP). O trauma ocorreu sobre a face lateral do tendão calcâneo direito, com energia de 0,40 J. A dor foi avaliada pelo teste de incapacidade funcional e o edema, pelo diâmetro laterolateral. Foram realizadas avaliações previamente à lesão; após 1 hora da indução da lesão; após o 1º tratamento; 2, 8 e 24 horas após lesão; e após o 5º dia. O tratamento ocorreu em 5 dias, com transdutor de 1 MHz, durante 3 minutos, sobre o local do trauma, com dose de 0,4 W/cm² SATA. Os resultados da incapacidade funcional para GS mostraram aumento da nocicepção. Para GUC houve aumento ao comparar a avaliação 1 (AV1) com as avaliações 2 (AV2), 3 (AV3) e 4 (AV4); ao comparar AV2 com as avaliações 5 (AV5) e 6 (AV6) houve diminuição de valores. Para GUP houve aumento ao comparar AV1 com AV2 e AV3, mas ao comparar AV2 com as seguintes, houve diminuição significativa a partir de AV4. Para o edema, os grupos tratados produziram aumento inicial, com redução nas últimas avaliações. O ultrassom terapêutico produziu diminuição de dor e edema, mais precocemente para a forma pulsada.

The morphology of the healing tendon: a comparison of the effects of intrasound therapy and therapeutic pulsed ultrasound

BACKGROUND AND PURPOSE

This study investigated the effects of low- and high-intensity intrasound therapy (LITR and HITR) and low-intensity pulsed ultrasound (LIPUS) on the morphology of the healing tendon.

METHODS

Forty-five male Sprague-Dawley albino rats, randomized into five groups, were further subdivided into groups A and B except Group 1. Groups 2-5 underwent an induced crush injury to the Achilles tendon. The groups were allocated to serve as controls (Group 1), received no treatment (Group 2), LIPUS once daily (Group 3), LITR twice daily (Group 4), and HITR twice daily (Group 5). Treatment commenced 24 hr post-injury over the first 14 days. Subgroup A animals were killed on day 15 and those in subgroup B were killed on day 31. The tendons were excised and processed for histological studies.

RESULTS

LITR and HITR given twice daily caused a significant (p < 0.05) proliferation of tenoblasts in the proliferative phase and enhanced their terminal differentiation to tenocytes in the remodeling phase compared with the untreated and LIPUS-treated groups. LITR and HITR also resulted in a significant increase in the volume fraction of collagen fibers compared with LIPUS.

CONCLUSION

Intrasound therapy has a better morphological effect on the healing tendon than LIPUS and may be an option to consider in the treatment of acute tendon injuries.

Therapeutic modalities--an updated review for the hand surgeon

The number of therapeutic modalities available to the hand surgeon has greatly increased over the past several decades. A field once predicated only on heat, massage, and cold therapy now uses electrical stimulators, ultrasound, biofeedback, iontophoresis, phonophoresis, mirror therapy, lasers, and a number of other modalities. With this expansion in choices, there has been a concurrent effort to better define which modalities are truly effective. In this review, we aim to characterize the commonly used modalities and provide the evidence available that supports their continued use.

Low-intensity pulsed ultrasound accelerates healing in rat calcaneus tendon injuries

STUDY DESIGN

Controlled laboratory study.

OBJECTIVE

To evaluate the effect of low-intensity therapeutic ultrasound on the murine calcaneus tendon healing process.

BACKGROUND

Therapeutic ultrasound promotes formation and maturation of scar tissue.

METHODS

Calcaneus tendon tenotomy and tenorrhaphy was performed on 28 Wistar rats. After the procedure, the animals were randomly divided into 2 groups. The animals in the experimental group received a 5-minute ultrasound application, once a day, at a frequency of 1 MHz, a spatial average temporal average intensity of 0.1 W/cm2, and a spatial average intensity of 0.52 W/cm2 at a 16-Hz frequency pulse mode (duty cycle, 20%). Data for the injured side were normalized in relation to the data from the contralateral healthy calcaneus tendon (relative values). The animals in the control group received sham treatment. After a 28-day treatment period, the animals were sacrificed and their tendons surgically removed and subjected to mechanical stress testing. The parameters analyzed were cross-sectional area (mm2), ultimate load (N), tensile strength (MPa), and energy absorption (mJ).

RESULTS

A significant difference between groups was found for the relative values of ultimate load and tensile strength. The mean ± SD ultimate load of the control group was -3.5% ± 32.2% compared to 33.3% ± 26.8% for the experimental group (P = .005). The mean tensile strength of the control group was -47.7% ± 19.5% compared to -28.1% ± 24.1% for the experimental group (P = .019). No significant difference was found in cross-sectional area and energy absorption.

CONCLUSION

Low-intensity pulsed ultrasound produced by a conventional therapeutic ultrasound unit can positively influence the calcaneus tendon healing process in rats.

O ultra-som terapêutico não aumentou as propriedades mecânicas de tendões flexores após reparo

OBJETIVO: Estudo experimental idealizado para investigar as propriedades mecânicas de tendões flexores profundos de coelhos submetidos à tenotomia seguida de tenorrafia e aplicação precoce de ultra-som terapêutico com diferentes intensidades, em comparação com tendões submetidos somente à tenorrafia. MATERIAL E MÉTODOS: Quarenta e quatro coelhos foram divididos em quatro grupos experimentais de acordo com a aplicação do ultra-som. Todos foram submetidos a uma secção do tendão flexor profundo na zona 2 e imobilizados com uma órtese mantida durante todo o experimento. O grupo A recebeu tratamento ultra-sônico com uma intensidade de 1,4 W/cm², o grupo B com 0,6 W/cm², ambos no modo contínuo, o grupo C com 0,6 W/cm² SATA, no modo pulsado à 50% e o grupo D não recebeu tratamento ultra-sônico algum. A frequência ultra-sônica empregada foi de 1 MHz. Após a eutanásia os tendões foram dissecados e submetidos ao ensaio mecânico de tração e análise histológica qualitativa. As propriedades mecânicas avaliadas foram: força máxima, deformação na força máxima e rigidez. RESULTADO: Não houve diferença estatisticamente significante entre os grupos experimentais. CONCLUSÃO: O ultra-som terapêutico não melhorou as propriedades mecânicas dos tendões flexores após reparo.

Ultrasound phonophoresis of panax notoginseng improves the strength of repairing ligament: a rat model

This study examined the phonophoretic effect of a therapeutic ultrasound coupled with a Panax notoginseng (PN) gel and compared it with a therapeutic ultrasound alone for medial collateral ligament repair in rats. Twenty mature male Sprague-Dawley rats receiving surgical transection to the left medial collateral ligament (MCL) were divided randomly into three groups: ultrasound (US, n = 7), ultrasound with PN coupling gel (PNUS, n = 7) and control (n = 6). The treatments started on day 3 after surgery for six days per week over a two-week period. The US group received 4 min of pulsed ultrasound (1 MHz) at the intensity of 0.5W/cm(2) with a normal ultrasonic coupling gel. The PNUS group received the same ultrasound treatment, but with a coupling gel that contained PN extract. The control group received a placebo ultrasound treatment similar to the other two groups. On day 17, the ligaments were mechanically tested for load-relaxation, stiffness and ultimate tensile strength (UTS). Values of the left side were normalized against that of the right side of each animal for analysis. Results revealed significantly higher normalized stiffness (p = 0.009) and UTS (p = 0.022) in the PNUS group than the other two groups, but insignificant difference in load-relaxation among all groups. This study reveals a positive ultrasonic phonophoretic effect of Panax notoginseng extract for improving the strength of ligament repair than ultrasound therapy alone.

Sonographically guided percutaneous needle tenotomy for treatment of common extensor tendinosis in the elbow: is a corticosteroid necessary?

OBJECTIVE

Chronic refractory common extensor tendinosis of the lateral elbow has been shown to respond to sonographically guided percutaneous needle tenotomy (PNT) followed by corticosteroid injection. In this analysis, we attempted to determine whether the corticosteroid is a necessary component of the procedure.

METHODS

We performed PNT on 57 consecutive patients (age range, 34-61 years) with persistent pain and disability resulting from common extensor tendinosis. Under a local anesthetic and sonographic guidance, a needle was advanced into the tendon, and the tip of the needle was used to fenestrate the tendinotic tissue, break up any calcifications, and abrade the adjacent bone. After the procedure, patients underwent a specified physical therapy protocol. During a subsequent telephone interview, patients answered questions about their symptoms, the level of functioning, and perceptions of the procedure outcome.

RESULTS

Of the 52 patients who agreed to participate in the study, 30 (57.7%) reported excellent outcomes, 18 (34.6%) good, 1 (1.9%) fair, and 3 (5.8%) poor. The average follow-up time from the date of the procedure to the telephone interview was 22 months (range, 7-38 months). No adverse events were reported, and 90% stated that they would refer a friend or close relative for the procedure.

CONCLUSIONS

Sonographically guided PNT for refractory lateral elbow tendinosis is an effective procedure, and subsequent corticosteroid injection is not necessary.

The effect of therapeutic ultrasound intensity on the ultrastructural morphology of tendon repair

This study evaluated the effects of ultrasound intensity on the ultrastructural morphology of Achilles tendon healing. Twenty Sprague-Dawley rats with surgically hemi-transected Achilles tendons were randomly assigned into four groups of 0, 0.5, 1.2 and 2 W/cm(2) for ultrasound treatment, with five rats in each group. The treatments were administered with 1 MHz continuous ultrasound daily starting from day 5 after injury. On day 30, ultrathin slides of the Achilles tendons were prepared and examined with transmission electron microscopy. Results showed that the mean collagen fibril size of all treatment groups was higher than the control (p < 0.05). There was no significant difference in the collagen fibril size among the treatment groups. These findings suggest that therapeutic ultrasound can enhance the maturation of collagen fibrils of repairing tendons, and this was not dependent on the intensity of ultrasound applied.

Eccentric calf muscle training compared with therapeutic ultrasound for chronic Achilles tendon pain--a pilot study

A number of studies have indicated that eccentric calf muscle training has beneficial effects in the management of Achilles tendon pain for recreational athletes. The purpose of this prospective randomised single blind pilot study was to investigate their potential effectiveness compared with therapeutic ultrasound in subjects with relatively sedentary lifestyles in an NHS hospital setting. Eleven men and five women (mean age 53+/-21 years) with Achilles tendon pain of minimum duration 4 months were randomised to one of two treatment groups; either eccentric loading or ultrasound. Administration of ultrasound and regular supervision of exercises occurred over a period of 6 weeks, with unsupervised exercises continuing for another 6 weeks. Outcome measurements were taken prior to and after 2, 4, 6 and 12 weeks after commencing treatment. They included: pain on a visual analogue scale, functional index of the leg and lower limb, and the five question EuroQol generalised health questionnaire. The difference in mean score was calculated together with 95% confidence intervals assuming a normal distribution. There were no statistically significant differences between groups or clear trends over time. In addition there was considerable overlap between the confidence intervals. This is not unexpected given the small sample size. Both interventions proved acceptable to the patients with no adverse effects. On this basis we intend conducting a full multi-centred study.

Sonographically guided percutaneous needle tenotomy for treatment of common extensor tendinosis in the elbow

OBJECTIVE

Chronic tendinosis of the common extensor tendon of the lateral elbow can be a difficult problem to treat. We report our experience with sonographically guided percutaneous needle tenotomy to relieve pain and improve function in patients with this condition.

METHODS

We performed sonographically guided percutaneous needle tenotomy on 58 consecutive patients who had persistent pain and disability resulting from common extensor tendinosis. Under a local anesthetic and sonographic guidance, a needle was advanced into the common extensor tendon, and the tip of the needle was used to repeatedly fenestrate the tendinotic tissue. Calcifications, if present, were mechanically fragmented, and the adjacent bony surface of the apex and face of the epicondyle were abraded. Finally, the fenestrated tendon was infiltrated with a solution containing corticosteroid mixed with bupivacaine. After the procedure, patients were instructed to perform passive stretches and to undergo physical therapy. During a subsequent telephone interview, patients answered questions about their experience, their functioning level, and their perceptions of procedure outcome.

RESULTS

Fifty-five (95%) of 58 patients were contacted by telephone and agreed to participate in the study. Thirty-five (63.6%) of 55 respondents reported excellent outcomes, 16.4% good, 7.3% fair, and 12.7% poor. The average follow-up time from the date of the procedure to the date of the interview was 28 months (range, 17-44 months). No adverse events were reported; 85.5% stated that they would refer a friend or close relative for the procedure.

CONCLUSIONS

Sonographically guided percutaneous needle tenotomy for lateral elbow tendinosis is a safe, effective, and viable alternative for patients in whom all other nonsurgical treatments failed.

Ultrasound Therapy in Tendinous Injury Healing in Goats

The effect of ultrasound therapy on tendon injury healing was studied on 12 locally available non-descript adult goats of either sex divided equally in two groups (I and II) consisting of six animals each. The superficial digital flexor tendon (SDFT) was transected and immediately repaired with nylon (2/0) using a locking loop suture pattern under atropine-triflupromazine-lignocaine epidural analgesia and strict aseptic condition. A full limb plaster of Paris cast was applied to immobilize the operated limb for 3 days. Postoperative care was similar in both the groups. In group I, the operated limb was allowed to heal without ultrasound therapy. In group II, pulsed ultrasound therapy was started 3 days after repair of tendinous injury at an intensity of 1 W/cm(2) for 10 min daily for 10 consecutive days. The animals of both groups were evaluated clinically and haemato-biochemically on days 1, 3, 7, 15, 20 and 30 postoperatively. Air tendonograms and ultrasonography were performed on days 0, 10, 20 and 30 post-tenorrhaphy. Histopathological examination of tendon biopsy samples was performed on day 30 post-tenorrhaphy. Resolution of inflammatory swelling, pain, weight bearing and tendon gliding movement was earlier in the test group than control. Rectal temperature, total leucocyte count and differential leucocyte count did not vary significantly at various stages of observation in both the groups. Serum glucose, cortisone and serum alkaline phosphatase levels increased significantly after tendon injury repair in all the animals and decreased slowly at all subsequent intervals in control group, whereas, it was near normal in the treatment group on day 30 post-tenorrhaphy. Air tendenograms and ultrasonography examinations in the test group revealed that there was a marked regression of peritendinous adhesion between the tendon and skin on day 30 post-tendon injury repaired and the tendon at the reconstructive site attained near normal thickness and density. Adhesions were present in the reconstructed site of SDFT in all animals of the control group. Histopathologically, the granulation tissue was comparatively bettered organized at the healing site in the ultrasound-treated animals.