Tendons in horses are fibrous connective tissues that attach muscles to bones, facilitating movement and providing stability to the musculoskeletal system. They are composed primarily of collagen fibers, which confer strength and flexibility, allowing horses to perform various physical activities. Equine tendons are subject to significant mechanical stress during locomotion, making them susceptible to injury, particularly in performance horses. Common tendon injuries include strains, tears, and tendinitis, which can impact a horse's mobility and performance. This page compiles peer-reviewed research studies and scholarly articles that explore the structure, function, and pathology of tendons in horses, as well as advancements in diagnostic and therapeutic approaches for tendon injuries.
Mercati F, Pascucci L, Curina G, Scocco P, Tardella FM, Dall'aglio C, Marini C, Ceccarelli P.The transplantation of multipotent mesenchymal stromal cells (MSCs) is a potentially promising therapy for the treatment of tendon and ligament injuries and some forms of articular pathology in horses. This study investigated the effects of storage conditions on MSCs. Equine adipose tissue-derived MSCs (eAd-MSCs) were stored at 4 °C and at room temperature (RT) for 24 and 48 h, and viability, doubling time, expression of CD44 and CD90 antigens, clonogenic/differentiation potentials, and karyotype were subsequently evaluated. The eAd-MSC viability was significantly affected by the storage ...
Dakin SG, Dudhia J, Smith RK.Injuries to the superficial digital flexor tendon (SDFT) are an important cause of morbidity and mortality in equine athletes, but the healing response is poorly understood. One important drive for the healing of connective tissues is the inflammatory cascade, but the role of inflammation in tendinopathy has been contentious in the literature. This article reviews the processes involved in the healing of tendon injuries in natural disease and experimental models. The importance of inflammatory processes known to be active in tendon disease is discussed with particular focus on recent findings ...
Halper J.Though soft tissue disorders have been recognized and described to some detail in several types of domestic animals and small mammals for some years, not much progress has been made in our understanding of the biochemical basis and pathogenesis of these diseases in animals. Ehlers-Danlos syndrome described in dogs already in 1943 and later in cats affects mainly skin in these animals. The involved skin is thin and hyperextensible with easily inflicted injuries resulting in hemorrhagic wounds and atrophic scars. Joint laxity and dislocation common in people are less frequently found in dogs. No...
Mohanty N, Gulati BR, Kumar R, Gera S, Kumar P, Somasundaram RK, Kumar S.Mesenchymal stem cells (MSCs) isolated from umbilical cord blood (UCB) in equines have not been well characterized with respect to the expression of pluripotency and mesenchymal markers and for tenogenic differentiation potential in vitro. The plastic adherent fibroblast-like cells isolated from 13 out of 20 UCB samples could proliferate till passage 20. The cells expressed pluripotency markers (OCT4, NANOG, and SOX2) and MSC surface markers (CD90, CD73, and CD105) by RT-PCR, but did not express CD34, CD45, and CD14. On immunocytochemistry, the isolated cells showed expression of CD90 and CD73...
Thorpe CT, Riley GP, Birch HL, Clegg PD, Screen HR.Some tendons, such as the human Achilles and equine superficial digital flexor tendon (SDFT), act as energy stores, stretching and recoiling to increase efficiency during locomotion. Our previous observations of rotation in response to applied strain in SDFT fascicles suggest a helical structure, which may provide energy-storing tendons with a greater ability to extend and recoil efficiently. Despite this specialization, energy-storing tendons are prone to age-related tendinopathy. The aim of this study was to assess the effect of cyclic fatigue loading (FL) on the microstructural strain respo...
Dakin SG, Smith RK, Heinegård D, Önnerfjord P, Khabut A, Dudhia J.During inflammatory processes the extracellular matrix (ECM) is extensively remodeled, and many of the constituent components are released as proteolytically cleaved fragments. These degradative processes are better documented for inflammatory joint diseases than tendinopathy even though the pathogenesis has many similarities. The aims of this study were to investigate the proteomic composition of injured tendons during early and late disease stages to identify disease-specific cleavage patterns of the ECM protein cartilage oligomeric matrix protein (COMP). In addition to characterizing fragme...
Carvalho AM, Yamada AL, Golim MA, Álvarez LE, Hussni CA, Alves AL.Mesenchymal stem cells (MSCs) have been used to treat equine tendonitis with promising results; however, little is known about the potential migration of these cells. Objective: To assess the possible migration of MSCs from an implantation site in the superficial digital flexor tendon (SDFT) to a lesion in the SDFT of the contralateral limb. Methods: In vivo experimental study. Methods: Adipose-derived MSCs were isolated from 4 healthy horses. Lesions were induced in the SDFTs of both forelimbs, followed by intralesional implantation of autologous adipose-derived MSCs labelled with nanocrystal...
Reyes AM, Jahr H, van Schie HT, Weinans H, Zadpoor AA.The elastic strain limit (ESL) of tendons is the point where maximum elastic modulus is reached, after which micro-damage starts. Study of damage progression in tendons under repetitive (fatigue) loading requires a priori knowledge about ESL. In this study, we propose three different approaches for predicting ESL. First, one single value is assumed to represent the ESL of all tendon specimens. Second, different extrapolation curves are used for extrapolating the initial part of the stress-strain curve. Third, a method based on comparing the shape of the initial part of the stress-strain curve ...
Jordana M, Martens A, Duchateau L, Vanderperren K, Saunders J, Oosterlinck M, Pille F.Controversy exists about the desensitisation obtained after diagnostic analgesia of the digital flexor tendon sheath (DFTS) during lameness examinations. Objective: To determine whether DFTS analgesia results in inadvertent desensitisation of the palmar/plantar digital nerves and whether this depends on the injection technique used. Methods: Crossover experimental study. Methods: The DFTS of 9 horses were injected with local anaesthetic solution and radiodense contrast medium using one of the following techniques: Proximal (at lateral proximal recess of the DFTS), Axial (axial to the lateral p...
Patruno M, Martinello T.In order to treat frequently occurring conditions such as traumatic rupture or over-strain tendinopathies, the techniques of tissue engineering and cell-based therapies have become an accepted modus operandi since other available remedies appear to be ineffective in restoring the original structure and function of the injured tissue. However, the mechanisms accounting for the effectiveness of novel regenerative approaches in treating equine tendon and ligament injuries remain poorly characterised. In this review we summarize and discuss the most significant results of our research regarding bi...
Claerhoudt S, Bergman EH, Saunders JH.This study describes a detailed computed tomographic reference of the normal equine foot. Ten forefeet of five adult cadavers, without evidence of orthopaedic disease, were used. Computed tomography (CT) was performed on all feet. Two-millimetre thick transverse slices were obtained, and sagittal and dorsal planes were reformatted. The CT images were matched with the corresponding anatomic slices. The phalanges and the distal sesamoid bone showed excellent detail. The extensor and flexor tendons (including their attachments) could be clearly evaluated. The collateral (sesamoidean) ligaments co...
Tipton TE, Ray CS, Hand DR.To characterize superficial digital flexor (SDF) tendon lesions in the forelimbs of cutting horses and determine recurrence rate and prognosis for this condition. Methods: Retrospective case series. Methods: 19 cutting horses with SDF tendonitis. Methods: Medical records for horses evaluated for SDF tendonitis in 2007 through 2011 were reviewed. Data regarding age, sex, lameness grade, affected limb, and treatment were collected. Ultrasonographic images were reviewed, and lesion characteristics were recorded. Follow-up telephone interviews with owners or trainers were conducted to determine re...
Couppé C, Svensson RB, Sødring-Elbrønd V, Hansen P, Kjaer M, Magnusson SP.Magnetic resonance imaging (MRI) has commonly been applied to determine tendon cross-sectional area (CSA) and length either to measure structural changes or to normalize mechanical measurements to stress and strain. The ability to reproduce CSA measurements on MRI images has been reported, but the accuracy in relation to actual tendon dimensions has never been investigated. The purpose of this study was to compare tendon CSA measured by MRI with that measured in vitro with the mould casting technique. The knee of a horse was MRI-scanned with 1.5 and 3 tesla, and two examiners measured the pate...
Smith RK, Werling NJ, Dakin SG, Alam R, Goodship AE, Dudhia J.Tendon injuries are a common age-related degenerative condition where current treatment strategies fail to restore functionality and normal quality of life. This disease also occurs naturally in horses, with many similarities to human tendinopathy making it an ideal large animal model for human disease. Regenerative approaches are increasingly used to improve outcome involving mesenchymal stem cells (MSCs), supported by clinical data where injection of autologous bone marrow derived MSCs (BM-MSCs) suspended in marrow supernatant into injured tendons has halved the re-injury rate in racehorses....
Ricco S, Renzi S, Del Bue M, Conti V, Merli E, Ramoni R, Lucarelli E, Gnudi G, Ferrari M, Grolli S.Overstrain tendonitis are common pathologies in the sport horses. Therapeutic approaches to tendon healing do not always result in a satisfactory anatomical and functional repair, and healed tendon is often characterized by functional impairment and high risk of reinjury. Recently, mesenchymal stem cells (MSCs) and platelet rich plasma (PRP) have been proposed as novel therapeutic treatments to improve the tendon repair process. MSCs are multipotent, easy to culture and being originated from adult donors do not pose ethical issues. To date, autologous MSCs have been investigated mainly in the ...
Lustgarten M, Redding WR, Labens R, Morgan M, Davis W, Seiler GS.Tendon and ligament injuries are common causes of impaired performance in equine athletes. Gray-scale ultrasonography is the current standard method for diagnosing and monitoring these injuries, however this modality only provides morphologic information. Elastography is an ultrasound technique that allows detection and measurement of tissue strain, and may provide valuable mechanical information about equine tendon and ligament injuries. The purpose of this study was to determine the feasibility, reproducibility, and repeatability of elastography; and to describe elastographic characteristics...
Tully LJ, Murphy AM, Smith RK, Hulin-Curtis SL, Verheyen KL, Price JS.To explore whether genetic susceptibility is a potential risk factor for superficial digital flexor (SDF) tendinopathy in Thoroughbred (TB) racehorses. Objective: To identify informative single nucleotide polymorphisms (SNPs) that capture genetic diversity across a range of candidate genes and to investigate, in a case-control study, their association with SDF tendinopathy in UK National Hunt TB racehorses in training. Methods: Case-control candidate gene association study. Methods: This study used in silico gene assembly and DNA sequencing to screen candidate genes for SNPs. Seven candidate g...
Rich T, Henderson LB, Becker DL, Cornell H, Patterson-Kane JC.Superficial digital flexor tendon (SDFT) injuries of horses usually follow cumulative matrix microdamage; it is not known why the reparative abilities of tendon fibroblasts are overwhelmed or subverted. Relevant in vitro studies of this process require fibroblasts not already responding to stresses caused by the cell culture protocols. We investigated indicators of replicative damage in SDFT fibroblast monolayers, effects of this on their reparative ability, and measures that can be taken to reduce it. Results: We found significant evidence of replicative stress, initially observing consistent...
Seo JP, Tanabe T, Tsuzuki N, Haneda S, Yamada K, Furuoka H, Tabata Y, Sasaki N.Osteochondrosis (OC) is a common and clinically important joint disorder in horses. However, repair of the OC region is difficult because of the avascular nature of cartilage. This study aimed to evaluate the efficacy of bilayer gelatin/β-tricalcium phosphate (GT) sponges loaded with mesenchymal stem cells (MSCs), chondrocytes, bone morphogenetic protein-2 (BMP-2), and platelet rich plasma (PRP) for the repair of osteochondral defects of the talus in horses. Full-thickness osteochondral defects were created on both the lateral trochlear ridges of the talus (n = 6). In the test group, a basic ...
Bowser JE, Elder SH, Pasquali M, Grady JG, Rashmir-Raven AM, Wills R, Swiderski CE.Hereditary equine regional dermal asthenia (HERDA) is an autosomal recessive disorder of Quarter Horses characterised by skin fragility. Horses with HERDA have a missense mutation in peptidyl-prolyl cis-trans isomerase B (PPIB), which encodes cyclophilin B and alters folding and post translational modifications of fibrillar collagen. Objective: The study aimed to test the hypothesis that tendons, ligaments and great vessels, which, like skin, are rich in fibrillar collagen, will also have abnormal biomechanical properties in horses with HERDA. Methods: Ex vivo biomechanical study comparing...
Lange-Consiglio A, Rossi D, Tassan S, Perego R, Cremonesi F, Parolini O.We have recently demonstrated that heterologous transplantation of horse amniotic membrane-derived mesenchymal cells (AMCs) can be useful for cell therapy applications in tendon diseases, and hypothesized that these cells may promote tendon repair via paracrine-acting molecules targeting inflammatory processes. To test this hypothesis, here we examined the immunomodulatory characteristics of AMCs and of their conditioned medium (AMC-CM) in vitro, and studied the potential therapeutic effect of AMC-CM in thirteen different spontaneous horse tendon and ligament injuries in vivo. Our results demo...
Carvalho Ade M, Badial PR, Álvarez LE, Yamada AL, Borges AS, Deffune E, Hussni CA, Garcia Alves AL.Tendon injury is a major cause of lameness and decreased performance in athletic equines. Various therapies for tendonitis have been described; however, none of these therapies results in complete tissue regeneration, and the injury recurrence rate is high even after long recovery periods involving rest and physiotherapy. Methods: A lesion was induced with collagenase gel in the superficial digital flexor tendon in the center portion of the metacarpal region of eight equines of mixed breed. After two weeks, the lesions of the animals in the treated and control groups were treated through the i...
Sivaguru M, Eichorst JP, Durgam S, Fried GA, Stewart AA, Stewart MC.Injuries and damage to tendons plague both human and equine athletes. At the site of injuries, various cells congregate to repair and re-structure the collagen. Treatments for collagen injury range from simple procedures such as icing and pharmaceutical treatments to more complex surgeries and the implantation of stem cells. Regardless of the treatment, the level of mechanical stimulation incurred by the recovering tendon is crucial. However, for a given tendon injury, it is not known precisely how much of a load should be applied for an effective recovery. Both too much and too little loading...
Calvert N, Grainger N, Hurworth M.Currently, there is a lack of cheap and effective training models to allow orthopaedic surgery trainees to learn the basics of anterior cruciate ligament reconstruction. The aim of this paper was to investigate the viability of using various animal joints as models for the training of anterior cruciate ligament reconstruction. Methods: Equine stifles, bovine stifles and carpal joints, sheep stifles and porcine stifles, were sourced from a local abattoir. Each joint was assessed for the following criteria: suitable tendons for harvesting, ease of arthroscopy access, adequacy of arthroscopy view...
Nemoto M, Kizaki K, Yamamoto Y, Oonuma T, Hashizume K.In vitro cell studies might be a useful tool for studying tendon pathology, but no suitable in vitro models exist for tendon disorders. The purpose of this study was to confirm whether cell scratch culture using tendon-derived fibroblasts can provide a suitable in vitro tendon disorder model. Extracellular matrix components were examined immunohistochemically in tendon tissue, and then their related gene expression levels were analyzed by conventional reverse transcription polymerase chain reaction (RT-PCR) and/or quantitative real-time RT-PCR in tissues and cells. Collagen type I (Col I), col...
Schnabel LV, Fortier LA, McIlwraith CW, Nobert KM.Stem cells are commonly used in equine practice to treat musculoskeletal disorders including tendonitis, osteoarthritis, and more recently laminitis. As the field of regenerative medicine continues to advance, equine practitioners need contemporary information regarding the choice of stem cell type and recommendations regarding clinical implementation of stem cell therapies. Clinicians must also be aware of the limitation in current knowledge regarding stem cells, and the impending regulatory laws that may limit the use of equine stem cells in clinical patients.
Welsh CE, Lewis TW, Blott SC, Mellor DJ, Lam KH, Stewart BD, Parkin TD.A retrospective cohort study of important musculoskeletal conditions of Thoroughbred racehorses was conducted using health records generated over a 15 year period (n=5062, 1296 sires). The prevalence of each condition in the study population was: fracture, 13%; osteoarthritis, 10%; suspensory ligament injury, 10%; and tendon injury, 19%. Linear and logistic sire and animal regression models were built to describe the binary occurrence of these musculoskeletal conditions, and to evaluate the significance of possible environmental risk factors. The heritability of each condition was estimated us...
Lam KK, Parkin TD, Riggs CM, Morgan KL.To identify the risk factors for premature retirement because of tendon injury in a Thoroughbred racehorse population. Methods: 175 Thoroughbred racehorses (cases) at the Hong Kong Jockey Club that were retired from racing because of tendon injury between 1997 and 2004 and for which the last preretirement exercise was at a fast pace were each matched with 3 control horses that were randomly selected from all uninjured horses that had galloped on the same date as that last exercise episode. Methods: Training data for all horses were examined. Conditional logistic regression analyses were perfor...
Crevier-Denoix N, Pourcelot P, Ravary B, Robin D, Falala S, Uzel S, Grison AC, Valette JP, Denoix JM, Chateau H.Although track surfaces are a risk factor of tendon injuries, their effects on tendon loading at high speed are unknown. Using a noninvasive ultrasonic technique, it is now possible to evaluate the forces in the superficial digital flexor tendon (SDFT) in exercise conditions. Objective: To compare the effects of an all-weather waxed track (W) vs. a crushed sand track (S), on the SDFT loading in the trotter horse at high speed. Methods: Two trotter horses were equipped with the ultrasonic device (1 MHz ultrasonic probe, fixed on the palmar metacarpal area of the right forelimb). For each trial,...
Paterson YZ, Cribbs A, Espenel M, Smith EJ, Henson FMD, Guest DJ.Tendon injuries occur frequently in human and equine athletes. Treatment options are limited, and the prognosis is often poor with functionally deficient scar tissue resulting. Fetal tendon injuries in contrast are capable of healing without forming scar tissue. Embryonic stem cells (ESCs) may provide a potential cellular therapeutic to improve adult tendon regeneration; however, whether they can mimic the properties of fetal tenocytes is unknown. To this end, understanding the unique expression profile of normal adult and fetal tenocytes is crucial to allow validation of ESC-derived tenocytes...
Geburek F, Stadler P.Conventional treatments of equine tendon injuries lead to an unsatisfactory healing process that usually results in a relatively high recurrence rate. Therefore, in recent years so-called regenerative therapeutics were studied scientifically in vitro and in laboratory animals. These include substances that ideally lead to the formation of replacement tissue, which in contrast to the low quality scar, has similar functional properties as the original intact tendon. Currently, a plethora of different substrates is either commercially available or can be produced in practice with the help of kits...
Genovese RL, Rantanen NW, Hauser ML, Simpson BS.In our 3 years of clinical experience, we have found that diagnostic ultrasound provides the veterinarian with a valuable diagnostic tool. It allows the clinician to quantify morphologic change that has occurred as a result of soft-tissue injuries, even when the clinical findings are ambiguous or insufficient. In cases in which aggressive postinjury therapy has been instituted prior to presentation, diagnostic ultrasound is often the only noninvasive method that can ascertain the extent of the horse's injury. Diagnostic ultrasound provides the technology to detect injuries before they become p...
Meershoek LS, Lanovaz JL, Schamhardt HC, Clayton HM.To calculate forces in the flexor tendons and the influence of heel wedges in affected and contralateral (compensating) forelimbs of horses with experimentally induced unilateral tendinitis of the superficial digital flexor (SDF) tendon. Methods: 5 Warmblood horses. Procedure-Ground reaction force and kinematic data were obtained during a previous study while horses were trotting before and after induction of tendinitis in 1 forelimb SDF and after application of 6 degrees heel wedges to both forehooves. Forces in the SDF, deep digital flexor (DDF), and the suspensory ligament (SL) and strain i...
McClellan A, Paterson YZ, Paillot R, Guest DJ.In horses and humans, tendon injuries are a significant problem. Not only can they occur in both athletes and nonathletes, they require lengthy periods of recuperation and undergo poor natural regeneration, which leads to high reinjury rates. Embryonic stem cells (ESCs) may provide a renewable source of allogeneic cells to use in clinical applications to aid tissue regeneration. Equine ESCs can undergo tenocyte differentiation in vivo and in vitro, but the immune properties of tenocytes isolated from either ESCs or tissues have not previously been characterized. Here, we demonstrate that equin...
Roth SP, Burk J, Brehm W, Troillet A.Mesenchymal stromal cells (MSC) represent a promising treatment option for tendon disorders and joint diseases, primarily osteoarthritis. Since MSC are highly context-sensitive to their microenvironment, their therapeutic efficacy is influenced by their tissue-specific pathologically altered targets. These include not only cellular components, such as resident cells and invading immunocompetent cells, but also components of the tissue-characteristic extracellular matrix. Although numerous models have already shown potential MSC-related mechanisms of action in tendon and joint diseases, only a...
Genovese RL, Rantanen NW, Simpson BS, Simpson DM.A method to quantitate as well as to document SDFT pathology has been described. This report indicates that computer-assisted evaluation of SDFT damage can improve the accuracy of prognosis in clinical practice. It would appear that a 3.8 severity rating is a limit past which prognosis for successful racing starts to worsen rapidly.
Turlo AJ, Mueller-Breckenridge AJ, Zamboulis DE, Tew SR, Canty-Laird EG, Clegg PD.The main challenge in tendon injury management is suboptimal tissue healing that fails to re-establish original tendon function. Tissue bioengineering is a promising approach for tendon therapy, with potential to improve its functional outcomes. However, evaluation criteria for tissue-engineered tendon are unclear due to the lack of specific markers of differentiated tendon. The study aim was to identify a panel of genes that characterised tendons in comparison to cartilage or muscles and validate those genes, both in human and key species used as models for tendon diseases. Gene expression pr...
Puchalski SM, Galuppo LD, Drew CP, Wisner ER.We compared contrast-enhanced computed tomography (CT) and high field magnetic resonance (MR) imaging in a horse with deep digital flexor tendonopathy. Lesions in the distal extremity were documented grossly and histopathologically. In contrast-enhanced CT, the deep digital flexor tendon lesions were markedly contrast enhancing with evidence of angiogenesis in the core and dorsal border lesions. The lesion morphology was clearly delineated on MR imaging, but without contrast media angiogenesis cannot be identified. Gross examination, histopathologic examination, and CD31 immunohistochemistry c...
Cherdchutham W, Becker CK, Spek ER, Voorhout WF, van Weeren PR.To determine the effects of exercise on collagen fibril diameter distribution in the superficial digital flexor tendon (SDFT) of foals. Methods: 43 Dutch Warmblood foals. Methods: From 1 week until 5 months of age, group-1 foals (n = 14) were housed in stalls and not exercised, group-2 foals (14) were housed in stalls but were exercised, and group-3 foals (15) were maintained at pasture. Biopsy specimens were collected from the SDFT at 2 months, and 8 foals in each group were euthanatized at 5 months. Remaining foals were housed together in a loose stall and paddock until euthanatized at 11 mo...
Hosaka Y, Teraoka H, Yamamoto E, Ueda H, Takehana K.The aim of the present study was to clarify the presence and determine the role of apoptosis in the degenerative process of the superficial digital flexor tendon (SDFT) in the horse. Samples were obtained from normal and inflamed SDFTs of horses. To detect apoptosis and to identify apoptotic cells, the samples were subjected to immunohistochemical labelling and Western blot analysis. Although a large number of cells in degenerate areas showed positive reactions with caspase-3 and single stranded DNA antibodies, cells in normal tendon samples showed very weak reactions. Excessive apoptosis was ...
Riemersma DJ, van den Bogert AJ, Schamhardt HC, Hartman W.Strains of the suspensory ligament and deep digital flexor, superficial digital flexor, and long digital extensor tendons in the equine (pony) hind limb were recorded in vivo, using implanted strain gauges consisting of silicone rubber tubes filled with mercury. The relationship between strain gauge signals and tendon strains was obtained from tension-strain tests performed on isolated tendons after death of the ponies. During normal walking, maximal tendon strain (elongation over initial length, relative to the length of the structures at first ground contact) was 3.1% in the suspensory ligam...
Roberts JH, Halper J.Repair and healing of injured and diseased tendons has been traditionally fraught with apprehension and difficulties, and often led to rather unsatisfactory results. The burgeoning research field of growth factors has opened new venues for treatment of tendon disorders and injuries, and possibly for treatment of disorders of the aorta and major arteries as well. Several chapters in this volume elucidate the role of transforming growth factor β (TGFß) in pathogenesis of several heritable disorders affecting soft tissues, such as aorta, cardiac valves, and tendons and ligaments. Several member...
Scharf A, Holmes SP, Thoresen M, Mumaw J, Stumpf A, Peroni J.Ultrasound-guided intralesional injection of mesenchymal stem cells (MSCs) is held as the benchmark for cell delivery in tendonitis. The primary objective of this study was to investigate the immediate cell distribution following intralesional injection of MSCs. Unilateral superficial digital flexor tendon (SDFT) lesions were created in the forelimb of six horses and injected with 10 × 10 MSCs labeled with superparamagnetic iron oxide nanoparticles (SPIOs) under ultrasound guidance. Assays were performed to confirm that there were no significant changes in cell viability, proliferation, migra...
Yin NH, Parker AW, Matousek P, Birch HL.The lack of clinical detection tools at the molecular level hinders our progression in preventing age-related tendon pathologies. Raman spectroscopy can rapidly and non-invasively detect tissue molecular compositions and has great potential for in vivo applications. In biological tissues, a highly fluorescent background masks the Raman spectral features and is usually removed during data processing, but including this background could help age differentiation since fluorescence level in tendons increases with age. Therefore, we conducted a stepwise analysis of fluorescence and Raman combined s...
Bellefeuille M, Peters DF, Nolin M, Slusarewicz P, Telgenhoff D.Collagen cross-linking is an attractive therapeutic route aimed at supplementing natural collagen stabilisation. In this study the toxicity of the cross-linker genipin (GP) was examined in avascular (tendon) and vascular (dermis) tissue. Methods: High doses of GP were injected intratendinously into three yearling horses and evaluated at various time points up to 30 days. A second group of three yearlings were injected into the dermis and evaluated at various time points up to 1 year. Metrics used included lameness, circumferential swelling, ultrasound evaluation, microscopic morphology, collag...
Zarucco L, Wisner ER, Swanstrom MD, Stover SM.Biomechanical models that compute the lengths and forces of muscle-tendon units are broadly applicable to the study of factors that promote injury and the planning and effects of orthopedic surgical procedures in equine athletes. A three-dimensional (3D) generic musculoskeletal model of the equine forelimb comprised of bony segment, muscle-tendon, and ligament information, was developed based on high-resolution computed tomographic (CT) and T1-weighted magnetic resonance (MR) images from an isolated forelimb of a Thoroughbred racehorse. Image fusion was achieved through coregistration of CT an...
Bertone AL, Tremaine WH, Macoris DG, Simmons EJ, Ewert KM, Herr LG, Weisbrode SE.To evaluate clinical safety of administration of injectable enrofloxacin. Methods: Randomized controlled clinical trial. Methods: 24 adult horses. Methods: Healthy horses were randomly allocated into 4 equal groups that received placebo injections (control) or IV administration of enrofloxacin (5 mg/kg [2.3 mg/lb], 15 mg/kg [6.8 mg/lb], or 25 mg/kg [11.4 mg/lb] of body weight, q 24 h) for 21 days. Joint angles, cross-sectional area of superficial and deep digital flexor and calcaneal tendons, carpal or tarsal osteophytes or lucency, and midcarpal and tarsocrural articular cartilage lesions wer...
O'Brien EJO, Smith RKW.Tendon/ligament mineralization is recognized in horses but information regarding its clinical significance is limited. The aims of this observational study were to report the structures most commonly affected by ultrasonographically detectable mineralization and, for these, determine frequency of diagnosis and key clinical features. Cases presented at our hospital in April 1999-April 2013 and September 2014-November 2015 were included: a total of 27 horses (22 retrospective, five prospective). Mineralizations were most common in deep digital flexor tendons (10) and suspensory ligament branches...
Spriet M, Espinosa P, Kyme AZ, Stepanov P, Zavarzin V, Schaeffer S, Katzman SA, Galuppo LD, Beylin D.Positron emission tomography (PET) is a highly sensitive, noninvasive imaging technique for quantifying biological functions of tissues. However, at the time of this study, PET imaging applications had not been reported in the horse. The aim of this exploratory study was to determine whether a portable high-resolution PET scanner could be used to image the equine distal limb. Images of the front feet and fetlocks of three research horses, with known lesions localized to the distal front limbs, were acquired under general anesthesia after administration of 18 F-fluorodeoxyglucose (18 F-FDG), wi...
Bowser JE, Elder SH, Pasquali M, Grady JG, Rashmir-Raven AM, Wills R, Swiderski CE.Hereditary equine regional dermal asthenia (HERDA) is an autosomal recessive disorder of Quarter Horses characterised by skin fragility. Horses with HERDA have a missense mutation in peptidyl-prolyl cis-trans isomerase B (PPIB), which encodes cyclophilin B and alters folding and post translational modifications of fibrillar collagen. Objective: The study aimed to test the hypothesis that tendons, ligaments and great vessels, which, like skin, are rich in fibrillar collagen, will also have abnormal biomechanical properties in horses with HERDA. Methods: Ex vivo biomechanical study comparing...
Dahlgren LA, Mohammed HO, Nixon AJ.he treatment of overuse tendon injuries with exogenous growth factors such as insulin-like growth factor-I (IGF-I) may facilitate an improved return to sustained athletic function. The biological effects of IGF-I are exerted under the control of a complex of IGF receptors, binding proteins, and proteases. This IGF system includes a family of six structurally related high-affinity IGF binding proteins (IGFBPs) that protect IGF-I from local proteases and restrict access of IGF-I to its receptor. This study describes the expression of the IGFBPs in flexor tendon after acute injury and during heal...
Sivaguru M, Eichorst JP, Durgam S, Fried GA, Stewart AA, Stewart MC.Injuries and damage to tendons plague both human and equine athletes. At the site of injuries, various cells congregate to repair and re-structure the collagen. Treatments for collagen injury range from simple procedures such as icing and pharmaceutical treatments to more complex surgeries and the implantation of stem cells. Regardless of the treatment, the level of mechanical stimulation incurred by the recovering tendon is crucial. However, for a given tendon injury, it is not known precisely how much of a load should be applied for an effective recovery. Both too much and too little loading...
Dabbene I, Bullone M, Pagliara E, Gasparini M, Riccio B, Bertuglia A.Information on interference injuries in racehorses is lacking. Objective: To describe clinical findings and prognosis of palmar forelimb interference injuries in Standardbreds. Methods: Retrospective cohort study. Methods: Records of 74 racehorses sustaining palmar forelimb interference injuries were studied; 7 occurred during training and 67 during racing. The number of starts before injury, hind shoeing status, gait penalties and racing speeds in cases occurring during racing were compared with negative controls (67 age, sex and speed category matched horses) from the same races. The number ...
Smith MR, Wright IM, Minshall GJ, Dudhia J, Verheyen K, Heinegård D, Smith RK.To evaluate digital flexor tendon sheath (DFTS) synovial fluid cartilage oligomeric matrix protein (COMP) concentrations as a molecular marker for intrathecal pathology. Methods: Case control study. Methods: Horses (n=46) with DFTS tenosynovitis; 23 fresh cadaver horses. Methods: DFTS synovial fluid samples were collected from clinical cases with noninfected DFTS tenosynovitis and from control DFTS. Clinical and surgical findings were recorded, and dissection of control limbs was performed to confirm the DFTS to be grossly normal. Synovial fluid COMP was quantified using a homologous competiti...
Shrestha K, Gilkerson JR, Stevenson MA, Flash ML.The destinations of Thoroughbred (TB) racehorses exiting the racing industry is a high-profile issue with ethical and welfare implications of interest to both animal welfare groups and racing regulators. This cross-sectional study investigated the reasons that TBs temporarily or permanently exited racing and training in Australia in the 2017-2018 racing season and the outcomes for these horses post-racing. An online questionnaire was sent to the last registered trainers of a representative sample of 2,509 'inactive' TBs. Inactive horses were defined as those horses that were recorded as 'activ...
Addis PR, Lawson SE.The flexor tendons support the metacarpophalangeal (MCP) and distal interphalangeal (DIP) joints during stance phase and since tendon stiffness and strain changes with age, it is likely that kinematics are also age-dependent. Objective: Maximum MCP and DIP angles decrease in the young horse, plateau in the mature horse and increase towards senescence. Methods: The distal limbs of 57 walking horses age 3-212 months were filmed and digitised with an automated tracking system. Maximum MCP and DIP angles during stance phase were used to calculate strain in the superficial and deep digital flexor t...
Mohanty N, Gulati BR, Kumar R, Gera S, Kumar S, Kumar P, Yadav PS.Mesenchymal stem cells (MSCs) offer promise as therapeutic aid in the repair of tendon and ligament injuries in race horses. Fetal adnexa is considered as an ideal source of MSCs due to many advantages, including non-invasive nature of isolation procedures and availability of large tissue mass for harvesting the cells. However, MSCs isolated from equine fetal adnexa have not been fully characterized due to lack of species-specific markers. Therefore, this study was carried out to isolate MSCs from equine umbilical cord blood (UCB) and characterize them using cross-reactive markers. The plastic...
