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.
Gates S, Hinnigan G, Rich A, Ricci E, Owen K.This case series discusses the clinical presentation, ultrasonographic findings, treatment, and outcome of 5 horses with superficial digital flexor tendon (SDFT) lesions within the carpal canal. The horses' ages ranged from 11-28 years, and presented with an acute, unilateral forelimb lameness which worsened following proximal limb flexion. The presence of a lesion within the SDFT of the carpal canal was accompanied by a mild swelling of the palmar carpal region in most cases. Diagnostic anesthesia of the ulnar nerve, when performed, abolished the lameness. Ultrasound evaluation revealed an in...
Costa F, Brunsting J, Corrêa F.This case report describes a 16-year-old jumping stallion that had a marked swelling over the left antebrachial area along with substantial lameness after a fall. The horse was weight bearing but lame (4/5; AAEP scale) at the walk with marked enlargement in the caudal aspect of the antebrachial region. After a static musculoskeletal examination, radiography and ultrasonography the horse was diagnosed with flexor muscle myopathy and presumptive extremity compartment syndrome. Following medical treatment, the horse improved clinically over several days. Six-months post injury the horse showed fl...
Yin NH, McCarthy I, Birch HL.Human Achilles tendon is composed of three smaller sub-tendons and exhibits non-uniform internal displacements, which decline with age and after injury, suggesting a potential role in the development of tendinopathies. Studying internal sliding behaviour is therefore important but difficult in human Achilles tendon. Here we propose the equine deep digital flexor tendon (DDFT) and its accessory ligament (AL) as a model to understand the sliding mechanism. The AL-DDFT has a comparable sub-bundle structure, is subjected to high and frequent asymmetric loads and is a natural site of injury similar...
Smith RKW, McIlwraith CW.Tendinopathy remains one of the most common musculoskeletal disorders affecting both human and equine athletes and presents a considerable therapeutic challenge. The following workshop report comes from the third Dorothy Havemeyer Symposium of Tendinopathy which provided a unique overview of our current understanding of both the basic science and the clinical challenges for diagnosing and treating tendinopathy in both species. Pathologically, tendon demonstrates alterations in both cellular, molecular, structural, and biomechanical features, leading to a spectrum of pathological endotypes. To ...
Quam VG, Altmann NN, Brokken MT, Durgam SS.Intrasynovial deep digital flexor tendon (DDFT) injuries occur frequently and are often implicated in cases of navicular disease with poor outcomes and reinjuries. Cell-based approaches to tendon healing are gaining traction in veterinary medicine and ultimately may contribute to improved DDFT healing in horses. However, a better understanding of the innate cellular characteristics of equine DDFT is necessary for developing improved therapeutic strategies. Additionally, fibrocartilaginous, intrasynovial tendons like the DDFT are common sites of injury and share a poor prognosis across species,...
Symons J.Pressure boots are applied to hind limbs of showjumping horses with the intent to enhance jumping form. Manufacturers claim acupressure points enhance proprioception of hind limbs. With this increased awareness, horses are expected to retract their hind limbs to clear jump rails. This research aimed to investigate a more direct, mechanical effect of pressure boots on hind limb biomechanics. Cadaveric hind limbs ( = 6) were mechanically loaded in axial compression (3 cycles at 0.25 Hz, displacement control ~3300 N) with (2 trials) and without (2 trials) a pressure boot applied. During mechanica...
Lapjit C, Charoenchanikran P, Petchkaew P, Sukpipattanamongkol S, Yodsheewan R, Theerapan W, Chanda M.The fetlock joint is a high mobility structure that accommodates enormous loading during locomotion. An injury of the superficial constituent such as subtendinous bursitis may occur due to repeated trauma. An 8-year old school riding horse was presented with dorsomedial distension in the left hindlimb fetlock region. The lesion was noted following routine exercise. The horse demonstrated no lameness and a negative response to the fetlock flexion test. Radiographic findings revealed a smooth surface cortical thickening on the medial aspect of the distal third metatarsal bone. Furthermore, the u...
Montano C, Auletta L, Greco A, Costanza D, Coluccia P, Del Prete C, Meomartino L, Pasolini MP.The use of platelet-rich plasma (PRP) to enhance tenodesmic lesion healing has been questioned over the years. The aim of this study was to evaluate current literature to establish the effectiveness of PRP for treating tenodesmic lesions through a systematic review, in accordance with the PRISMA guidelines, and a meta-analysis. Studies comparing PRP with placebo or other treatments for horses with tenodesmic injuries or evaluated PRP effect on tendon and ligament explants were included. Outcomes were clinical, ultrasound, histologic, molecular evaluation, and adverse effects. Two authors indep...
Secchi V, Masala G, Corda A, Corda F, Potop E, Barbero Fernandez A, Pinna Parpaglia ML, Sanna Passino E.Early diagnosis of tendon injuries and accurate long-term monitoring of the healing process are key for equine veterinarians that use conventional ultrasonography. The development of strain elastography could improve the management of clinical cases. The aim of the study was to assess the intraobserver repeatability and interobserver reproducibility of manual measurements of the colored areas of the tendons within elastograms and to standardize this manual modality by comparing the analysis of the images with ImageJ. Twenty elastograms of the injured superficial digital flexor tendons (SDFTs) ...
Osborn ML, Cornille JL, Blas-Machado U, Uhl EW.Navicular syndrome has been traditionally characterized by progressive lameness with chronic degeneration of the navicular bone. Advances in imaging techniques have revealed that its associated soft tissue structures are also affected. This distribution of lesions is explained by conceptualizing the equine navicular apparatus as an enthesis organ that facilitates the dissemination of mechanical stress throughout the tissues of the foot. The navicular apparatus has the same structural adaptations to mechanical stress as the human Achilles tendon complex. These adaptations efficiently dissipate ...
Zetterström SM, Boone LH, Weatherall KM, Caldwell FJ.To describe a minimally invasive technique for semitendinosus tenotomy with ultrasonographic guidance and to evaluate procedural complications. Methods: Experimental study. Methods: Cadaveric equine hind limbs (n = 16). Methods: A stab incision was performed distocaudal to the tibial insertion of the semitendinosus muscle with ultrasonographic assistance. After transection of the tendon with an arthroscopic retrograde knife, the tendon edges palpably retracted, and complete transection was confirmed by ultrasound. Limbs were dissected to confirm the degree of tendon transection and to identify...
Depuydt E, Broeckx SY, Van Hecke L, Chiers K, Van Brantegem L, van Schie H, Beerts C, Spaas JH, Pille F, Martens A. Tendon injuries are very common in horses and jeopardize the athletic performance, and due to the high risk of reinjury may lead to early retirement. The use of mesenchymal stem cells for the treatment of equine tendon disease is widely investigated because of their regenerative potential. The objective of this study is to investigate the safety and efficacy of equine allogeneic tenogenic primed mesenchymal stem cells (tpMSCs) for the management of tendinitis in horses. A core lesion was surgically induced in the superficial digital flexor tendon of both forelimbs of eight horses. After 7 da...
Meeremans M, Van Damme L, De Spiegelaere W, Van Vlierberghe S, De Schauwer C.(1) Background: Tendinopathy is a common injury in both human and equine athletes. Representative in vitro models are mandatory to facilitate translation of fundamental research into successful clinical treatments. Natural biomaterials like gelatin provide favorable cell binding characteristics and are easily modifiable. In this study, methacrylated gelatin (gel-MA) and norbornene-functionalized gelatin (gel-NB), crosslinked with 1,4-dithiotreitol (DTT) or thiolated gelatin (gel-SH) were compared. (2) Methods: The physicochemical properties (H-NMR spectroscopy, gel fraction, swelling ratio, an...
Ferrando Meseguer E, Roig Sánchez S, Pino Almero L, Romano Bataller A, Mínguez Rey MF.Talipes equinovarus or clubfoot is a congenital deformity of the foot with bone, muscle, and tendon involvement. It's one of the most frequent foot malformations in pediatric orthopedics. Although generally idiopathic, it may have a syndromic cause and be associated with musculoskeletal, neurological, or connective tissue conditions. The treatment of choice in idiopathic clubfoot is the Ponseti method based on manipulation and fixation with serial casts that seek progressive correction of the deformity. The Ponseti method effectiveness has been demonstrated in arthrogryposis and myelomeningoce...
Logan AA, Nielsen BD.Conflicting research and anecdotal evidence have created disagreement among equestrians as to whether two-year-old horses should be trained and raced. The objective of this literature review is to evaluate epidemiological studies, as well as physiological data on equine bone, articular cartilage, and tendons to better determine the impact of training and racing two-year-old horses. The evaluation of numerous studies on the topic provides evidence that a horse which is trained or raced as a two-year-old has a lower risk of injury and better adapted tissues for the rigors of racing. Unfortunatel...
Ribitsch I, Oreff GL, Jenner F.Musculoskeletal injuries and chronic degenerative diseases commonly affect both athletic and sedentary horses and can entail the end of their athletic careers. The ensuing repair processes frequently do not yield fully functional regeneration of the injured tissues but biomechanically inferior scar or replacement tissue, causing high reinjury rates, degenerative disease progression and chronic morbidity. Regenerative medicine is an emerging, rapidly evolving branch of translational medicine that aims to replace or regenerate cells, tissues, or organs to restore or establish normal function. It...
Yang F, Richardson DW.The tendon is highly prone to injury, overuse, or age-related degeneration in both humans and horses. Natural healing of injured tendon is poor, and cell-based therapeutic treatment is still a significant clinical challenge. In this study, we extensively investigated the expression of tenogenic genes in equine bone marrow mesenchymal stem cells (BMSCs) and tenocyte-derived induced pluripotent stem cells (teno-iPSCs) stimulated by growth factors (TGF-3 and BMP12) combined with ectopic expression of tenogenic transcription factor MKX or cyclic uniaxial mechanical stretch. Western blotting reveal...
Salinas P, Lira-Velásquez D, Bongiorno A, Sandoval C.The aim of this study was to quantify the distribution of aligned and non-aligned collagen in cross-sections of the superficial digital flexor tendon (SDFT) and deep digital flexor tendon (DDFT) in different levels of the distal forelimb of equines diagnosed with NS (Navicular Syndrome). Sixty equine forelimbs were collected. Was compared two groups (NA, Not affected vs. NS-group) by t-Student. Diagnosis of NS was based on clinical and lameness examination, diagnostic analgesia and radiological findings. The proportion of aligned and non-aligned collagens at 2 levels for the SDFT and 3 levels ...
Salcedo-Jiménez R, Koenig JB, Lee OJ, Gibson TWG, Madan P, Koch TG.Extracorporeal shock wave therapy (ESWT) has been shown to induce different biological effects on a variety of cells, including regulation and stimulation of their function and metabolism. ESWT can promote different biological responses such as proliferation, migration, and regenerations of cells. Recent studies have shown that mesenchymal stromal cells (MSCs) secrete factors that enhance the regeneration of tissues, stimulate proliferation and differentiation of cells, and decrease inflammatory and immune reactions. Clinically, the combination of these two therapies has been used as a treatme...
Luesma MJ, Cantarero I, Sánchez-Cano AI, Rodellar C, Junquera C.The three-dimensional ultrastructure of the tendon is complex. Two main cell types are classically supported: elongated tenocytes and ovoid tenoblasts. The existence of resident stem/progenitor cells in human and equine tendons has been demonstrated, but their location and relationship to tenoblasts and tenocytes remain unclear. Hence, in this work, we carried out an ultrastructural study of the equine superficial digital flexor tendon. Although the fine structure of tendons has been previously studied using electron microscopy, the presence of telocytes, a specific type of interstitial cell, ...
Pechanec MY, Boyd TN, Baar K, Mienaltowski MJ.Tendon injuries amount to one of the leading causes of career-ending injuries in horses due to the inability for tendon to completely repair and the high reinjury potential. As a result, novel therapeutics are necessary to improve repair with the goal of decreasing leg lameness and potential reinjury. Small leucine-rich repeat proteoglycans (SLRPs), a class of regulatory molecules responsible for collagen organization and maturation, may be one such therapeutic to improve tendon repair. Before SLRP supplementation can occur in vivo, proper evaluation of the effect of these molecules in vitro n...
Pluim M, Martens A, Vanderperren K, van Weeren R, Oosterlinck M, Dewulf J, Kichouh M, Van Thielen B, Koene MHW, Luciani A, Plancke L, Delesalle C.High-power laser therapy is often used as a treatment for human sport injuries but controlled standardized studies on its efficacy are lacking. The technique has also been introduced in the equine field and recently promising results were reported in a retrospective study focusing on 150 sporthorses suffering from tendinopathy and desmopathy of the SDFT, DDFT, suspensory ligament, and suspensory branches. The goal of the present study was to evaluate the effect of high-power laser in a standardized lesion model in horses. Lesions were created in all lateral suspensory branches of 12 warmblood ...
Nocera I, Aliboni B, Sgorbini M, Gracia-Calvo LA, Conte G, Ben David L, Citi S.Ultrasound (US) is a well-established technique for investigating joint diseases in horses, complementary to radiography. Few studies have been performed on the ultrasonographic aspect of the elbow joint in horses and no reports are available on donkeys. The aim of this study is to describe the ultrasonographic appearance of the elbow joint in healthy donkeys. Descriptive cohort study included 34 elbow joints, which were evaluated in 17 donkeys. Inclusion criteria included no lameness or musculoskeletal diseases in the donkeys. The structures evaluated were the lateral and medial collateral li...
O'Brien C, Marr N, Thorpe C.The forelimb superficial digital flexor tendon (SDFT) is an energy-storing tendon that is highly susceptible to injury during activities such as galloping and jumping, such that it is one of the most commonly reported causes of lameness in the performance horse. This review outlines the biomechanical and biothermal effects of strain on the SDFT and how these contribute to the accumulation of microdamage. The effect of age-related alterations on strain response and subsequent injury risk is also considered. Given that tendon is a slowly healing and poorly regenerative tissue, prompt detection o...
Zhang C, Svensson RB, Montagna C, Carstensen H, Buhl R, Schoof EM, Kjaer M, Magnusson SP, Yeung CC.Tendon is a highly organized, dense connective tissue that has been demonstrated to have very little turnover. In spite of the low turnover, tendon can grow in response to loading, which may take place primarily at the periphery. Tendon injuries and recurrence of injuries are common in both humans and animals in sports. It is unclear why some areas of the tendon are more susceptible to such injuries and whether this is due to intrinsic regional differences in extracellular matrix (ECM) production or tissue turnover. This study aimed to compare populations of tenocytes derived from the tendon c...
Javanshir S, Younesi Soltani F, Dowlati G, Parham A, Naderi-Meshkin H.Managing tendon healing process is complicated mainly due to the limited regeneration capacity of tendon tissue. Mesenchymal stem cells (MSCs) have potential applications in regenerative medicine and have been considered for tendon repair and regeneration. This study aimed to evaluate the capacity of equine adipose tissue-derived cells (eASCs) to differentiate into tenocytes in response to platelet-derived growth factor-BB (PDGF-BB) and growth differentiation factor-6 (GDF-6) in vitro. Frozen characterized eASCS of 3 mares were thawed and the cells were expanded in basic culture medium (DMEM...
Paterson YZ, Evans N, Kan S, Cribbs A, Henson FMD, Guest DJ.The transcription factor scleraxis (SCX) is expressed throughout tendon development and plays a key role in directing tendon wound healing. However, little is known regarding its role in fetal or young postnatal tendons, stages in development that are known for their enhanced regenerative capabilities. Here we used RNA-sequencing to compare the transcriptome of adult and fetal tenocytes following SCX knockdown. SCX knockdown had a larger effect on gene expression in fetal tenocytes, affecting 477 genes in comparison to the 183 genes affected in adult tenocytes, indicating that scleraxis-depend...
Sullivan SN, Altmann NN, Brokken MT, Durgam SS.Primary deep digital flexor tendon (DDFT) pathologies and those accompanying degenerative changes of navicular bone fibrocartilage are major causes of lameness associated with navicular disease. Intrasynovial corticosteroids are mainstay in the treatment due to the anti-inflammatory effects, but their effect on DDFT cell biosynthesis are unknown. The objective of this study was to investigate the effects of methylprednisolone acetate (MPA) on cells isolated from the dorsal fibrocartilaginous region of forelimb DDFTs (DDFT-derived cells) of 5 horses (aged 11-17 years). Non-adherent aggregate c...
Zielińska P, Nicpoń J, Kiełbowicz Z, Soroko M, Dudek K, Zaborski D.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 in...
Aimaletdinov A, Mindubaeva G, Khalikova S, Kabwe E, Salmakova A, Alexandrova N, Rutland C, Rizvanov A, Zakirova E.Tendon injuries are one of the most common causes of orthopedic disorders in horses. Such injuries involve a long course of treatment and recovery. The most promising method of treating these injuries is the use of recombinant proteins and gene therapy. In this work, we evaluated the therapeutic efficacy of plasmid DNA (pDNA) containing two species-specific coding sequences, i.e. vascular endothelial growth factor 164 (VEGF164) and fibroblast growth factor 2 (FGF2), in the treatment of severe damage to the tendon of the superficial digital flexor. A pDNA construct was used to restore the damag...
Patterson-Kane JC, Firth EC.Despite the high incidence of superficial digital flexor tendon (SDFT) injury in racehorses, the pathobiology of the condition is not clearly defined. The SDFT improves locomotor efficiency by storing elastic energy, but as a result it has low mechanical safety margins. As with the Achilles tendon in humans, rupture during athletic activity often follows accumulation of exercise and age-induced degenerative change that is not repaired by tenocytes. There is limited understanding of tenocyte biology and pathology, including responses to high mechanical strains and core temperatures during exerc...
Schramme M, Hunter S, Campbell N, Blikslager A, Smith R.Tendon injuries are common in all athletic activities in both humans and horses. Research of treatment modalities for this disease has typically been performed on a model of collagenase-induced tendonitis. This model has several disadvantages. Our hypothesis was that a reproducible core lesion could be created surgically in superficial digital flexor tendons (SDFT), which could then be evaluated consistently using ultrasonography. Methods: Four horses free of forelimb lameness were used in this study. Each horse underwent general anaesthesia and a synovial resector was used to create a core le...
Riemersa DJ, Schamhardt HC.A clamp designed for holding tendons in force/elongation studies is described. No slippage occurred when tensile forces up to 13,800 N were applied to horses digital flexor tendons fixed in this clamp.
Innes JF, Clegg P.Examples of naturally occurring musculoskeletal disorders are extremely common in veterinary species and provide a valuable comparative research resource, which can provide compelling comparative data on the aetiopathogenesis and treatment of many common human musculoskeletal diseases. In particular, orthopaedic diseases are a common morbidity in both dogs and horses. In this review, we give an overview of the common musculoskeletal diseases encountered in these species: for instance, tendon and ligament injuries, arthropathies and stress fractures, as well as an insight into the basic biology...
Shrivastava SK, Kailash .Extracorporeal shock wave therapy in orthopedics and traumatology is still a young therapy method. Since the last few years the development of shock wave therapy has progressed rapidly. Shock waves have changed the treatment of urolithiasis substantially. Today shock waves are the first choice to treat kidney and urethral stones. Urology has long been the only medical field for shock waves in medicine. Meanwhile shock waves have been used in orthopedics and traumatology to treat insertion tendinitis, avascular necrosis of the head of femur and other necrotic bone alterations. Another field of ...
Clegg PD.Tendon and ligament injuries continue to be one of the most frequent causes of orthopaedic injury and early retirement in the Thoroughbred racehorse. In the UK, the Horserace Betting Levy Board has invested considerable research funding in the last decade in order to investigate aspects of tendon epidemiology, biology and therapy, in order to decrease both the welfare and economic consequence of such injuries. This review summarises key aspects of this research effort and identifies specific research directions for the future.
O'Brien C, Marr N, Thorpe C.The forelimb superficial digital flexor tendon (SDFT) is an energy-storing tendon that is highly susceptible to injury during activities such as galloping and jumping, such that it is one of the most commonly reported causes of lameness in the performance horse. This review outlines the biomechanical and biothermal effects of strain on the SDFT and how these contribute to the accumulation of microdamage. The effect of age-related alterations on strain response and subsequent injury risk is also considered. Given that tendon is a slowly healing and poorly regenerative tissue, prompt detection o...
Spiesz EM, Thorpe CT, Thurner PJ, Screen HRC.Structure-function relationships in tendons are directly influenced by the arrangement of collagen fibres. However, the details of such arrangements in functionally distinct tendons remain obscure. This study demonstrates the use of quantitative polarised light microscopy (qPLM) to identify structural differences in two major tendon compartments at the mesoscale: fascicles and interfascicular matrix (IFM). It contrasts functionally distinct positional and energy storing tendons, and considers changes with age. Of particular note, the technique facilitates the analysis of crimp parameters, in w...
Gaughan EM, Nixon AJ, Krook LP, Yeager AE, Mann KA, Mohammed H, Bartel DL.Sodium hyaluronate reduces adhesions after tendon repair in rodents and dogs, and has been used in limited clinical trials in people. To evaluate its effect on tendon healing and adhesion formation in horses and to compare these effects with those of a compound of similar visco-elastic properties, a study was performed in horses, using a model of collagenase injection in the flexor tendons within the digital sheath. Eight clinically normal horses were randomly allotted to 2 groups. Adhesion formation between the deep digital flexor tendon and the tendon sheath at the pastern region was induced...
Lacitignola L, Crovace A, Rossi G, Francioso E.To compare cultured bone marrow mesenchymal cells (cBMSC), bone marrow mononucleated cells (BMMNCs), and placebo to repair collagenase-induced tissue damage in an equine model of experimental tendonitis, 6 Standardbred horses with no signs of previous SDF tendon injury have been recruited. Three weeks after collagenase treatment an average of either 5.5 x 10(6) cBMSCs or 122.3 x 10(6) BMMNCs, saline solution (placebo) or fibrin glue were injected intralesionally in random order. Horses were stall rested for 21 weeks, and tendon ultrasound scans performed before and during this period. Horses w...
Roth SP, Brehm W, Groß C, Scheibe P, Schubert S, Burk J.Transforming growth factor beta 3 (TGFβ3) promotes tenogenic differentiation and may enhance tendon regeneration in vivo. This study aimed to apply TGFβ3 absorbed in decellularized equine superficial digital flexor tendon scaffolds, and to investigate the bioactivity of scaffold-associated TGFβ3 in an in vitro model. TGFβ3 could effectively be loaded onto tendon scaffolds so that at least 88% of the applied TGFβ3 were not detected in the rinsing fluid of the TGFβ3-loaded scaffolds. Equine adipose tissue-derived multipotent mesenchymal stromal cells (MSC) were then seeded on scaffolds loa...
van Schie HT, Bakker EM, Cherdchutham W, Jonker AM, van de Lest CH, van Weeren PR.To evaluate quantitative ultrasonography for objective monitoring of the healing process and prognostication of repair quality in equine superficial digital flexor (SDF) tendons. Methods: 6 horses with standardized surgical lesions in SDF tendons of both forelimbs. Methods: Healing was monitored for 20 weeks after surgery by use of computerized ultrasonography. Pixels were categorized as C (intact fasciculi), B (incomplete fasciculi), E (accumulations of cells and fibrils), or N (homogenous fluid or cells). Four scars with the best quality of repair (repair group) and 4 scars with the lowest q...
Patterson-Kane JC, Parry DA, Birch HL, Goodship AE, Firth EC.The superficial digital flexor tendon is the most commonly injured tendon in the racing Thoroughbred. Despite the clinical significance of this structure, only limited data exist regarding normal age-related morphology of the tensile units, the collagen fibrils. The age at which these collagen fibrils become mature in composition and structure may be of importance. Consequently, the association of age and collagen fibril crosslink composition, diameter distribution and crimp morphology in the superficial and deep digital flexor tendons of Thoroughbreds up to and including three years of age ha...
Oreff GL, Fenu M, Vogl C, Ribitsch I, Jenner F.For research on tendon injury, many different animal models are utilized; however, the extent to which these species simulate the clinical condition and disease pathophysiology has not yet been critically evaluated. Considering the importance of inflammation in tendon disease, this study compared the cellular and molecular features of inflammation in tenocytes of humans and four common model species (mouse, rat, sheep, and horse). While mouse and rat tenocytes most closely equalled human tenocytes' low proliferation capacity and the negligible effect of inflammation on proliferation, the wound...
Paris DB, Stout TA.Cartilage and tendon injuries are a significant source of animal wastage and financial loss within the horse-racing industry. Moreover, both cartilage and tendon have limited intrinsic capacity for self-repair, and the functionally inferior tissue produced within a lesion may reduce performance and increase the risk of reinjury. Stem cells offer tremendous potential for accelerating and improving tissue healing, and adult mesenchymal stem cells (MSCs) are already used to treat cartilage and tendon injuries in horses. However, MSCs are scarce in the bone marrow isolates used, have limited poten...
Roth SP, Schubert S, Scheibe P, Groß C, Brehm W, Burk J.Age-related degenerative changes in tendon tissue represent a common cause for acute tendon pathologies. Although the regenerative potential of multipotent mesenchymal stromal cells (MSC) was reported to restore functionality in injured tendon tissue, cellular mechanisms of action remain partly unclear. Potential tenogenic differentiation of applied MSC is affected by various intrinsic and extrinsic factors. The current study presents an in vitro model to evaluate the combined extrinsic effects of decellularized equine tendon matrix, transforming growth factor beta 3 (TGFβ3) and bone morphoge...
Durgam SS, Stewart AA, Sivaguru M, Wagoner Johnson AJ, Stewart MC.Tendinitis is a common and a performance-limiting injury in athletes. This study describes the value of intralesional tendon-derived progenitor cell (TDPC) injections in equine flexor tendinitis. Collagenase-induced tendinitis was created in both front superficial digital flexor (SDF) tendons. Four weeks later, the forelimb tendon lesions were treated with 1 × 10 autogenous TDPCs or saline. Tendinitis was also induced by collagenase in one hind SDF tendon, to study the survival and distribution of DiI-labeled TDPCs 1, 2, 4, and 6 weeks after injection. The remaining normal tendon was used...
Vergari C, Pourcelot P, Holden L, Ravary-Plumioën B, Gerard G, Laugier P, Mitton D, Crevier-Denoix N.Excessive axial tension is very likely involved in the aetiology of tendon lesions, and the most appropriate indicator of tendon stress state is the true stress, the ratio of instantaneous load to instantaneous cross-sectional area (CSA). Difficulties to measure tendon CSA during tension often led to approximate true stress by assuming that CSA is constant during loading (i.e. by the engineering stress) or that tendon is incompressible, implying a Poisson's ratio of 0.5, although these hypotheses have never been tested. The objective of this study was to measure tendon CSA variation during qua...
Ashraf Kharaz Y, Zamboulis D, Sanders K, Comerford E, Clegg P, Peffers M.Exploring the tendon proteome is a challenging but important task for understanding the mechanisms of physiological/pathological processes during ageing and disease and for the development of new treatments. Several extraction methods have been utilised for tendon mass spectrometry, however different extraction methods have not been simultaneously compared. In the present study we compared protein extraction in tendon with two chaotropic agents, guanidine hydrochloride (GnHCl) and urea, a detergent, RapiGest™, and their combinations for shotgun mass spectrometry. An initial proteomic analysi...
Clayton HM, Larson B, Kaiser LJ, Lavagnino M.This study investigated the horse's contribution to tension in the reins. The experimental hypotheses were that tension in side reins (1) increases biphasically in each trot stride, (2) changes inversely with rein length, and (3) changes with elasticity of the reins. Eight riding horses trotted in hand at consistent speed in a straight line wearing a bit and bridle and three types of side reins (inelastic, stiff elastic, compliant elastic) were evaluated in random order at long, neutral, and short lengths. Strain gauge transducers (240 Hz) measured minimal, maximal and mean rein tension, rate ...
Kovac M, Litvin YA, Aliev RO, Zakirova EY, Rutland CS, Kiyasov AP, Rizvanov AA.This clinical study describes the intralesional application of the plasmid DNA encoding two therapeutic species-specific growth factors: vascular endothelial growth factor (VEGF164) and fibroblast growth factor 2 (FGF2) in seven horses to restore naturally occurring injuries of the superficial digital flexor tendon (SDFT) (tendinitis) and in three horses with suspensory ligament branch desmitis. Following application all horses were able to commence a more rapid exercise program in comparison to standardized exercise programs. Clinical observation and ultrasonic imaging was used to evaluate th...
Lovati AB, Corradetti B, Cremonesi F, Bizzaro D, Consiglio AL.Adult bone marrow mesenchymal stem cells (BM-MSCs) are a potential cell source for tendon repair in direct cell therapy and tissue engineering investigations. The purpose of this study was to evaluate the tenogenic induction of undifferentiated BM-MSCs under indirect co-culture technique with trimmed native tendon tissue. Since the horse represents a preferred species to study tendon regenerative strategies, this work was conducted on equine BM-MSCs. Methods: Equine BM-MSCs were co-cultured in a transwell system with tendon tissue fragments. The BM-MSC tenogenic differentiation was evaluated b...
Brown NA, Pandy MG, Kawcak CE, McIlwraith CW.A detailed musculoskeletal model of the distal equine forelimb was developed to study the influence of musculoskeletal geometry (i.e. muscle paths) and muscle physiology (i.e. force-length properties) on the force- and moment-generating capacities of muscles crossing the carpal and metacarpophalangeal joints. The distal forelimb skeleton was represented as a five degree-of-freedom kinematic linkage comprised of eight bones (humerus, radius and ulna combined, proximal carpus, distal carpus, metacarpus, proximal phalanx, intermediate phalanx and distal phalanx) and seven joints (elbow, radiocarp...
Bosch G, René van Weeren P, Barneveld A, van Schie HT.The effectiveness of new therapies to treat tendon injuries is difficult to determine and is often based on semi-quantitative methods, such as grey level analysis of ultrasonographic images or subjective pain scores. The alternatives are costly and long-lasting end-stage studies using experimental animals. In this study, a method of ultrasonographic tissue characterisation (UTC), using mathematical analysis of contiguous transverse ultrasonographic images, was used for intra-vital monitoring of the healing trajectory of standardised tendon lesions treated with platelet rich plasma (PRP) or pla...
Georg R, Maria C, Gisela A, Bianca C.This case report describes the intralesional application of autologous conditioned plasma (ACP) in seven horses as treatment of severe tendinitis of the superficial digital flexor tendon, deep digital flexor tendon, or desmitis of the inferior check ligament. Follow-up data of the horses revealed a positive outcome in 10 to 13 months post injury. All horses treated with ACP were either performing in their previous work-load or were back in full training. Further studies with long-term follow-up will have to be performed to support these clinical intermediate-term observations.
Brown NA, Kawcak CE, McIlwraith CW, Pandy MG.Articular injuries in athletic horses are associated with large forces from ground impact and from muscular contraction. To accurately and noninvasively predict muscle and joint contact forces, a detailed model of musculoskeletal geometry and muscle architecture is required. Moreover, muscle architectural data can increase our understanding of the relationship between muscle structure and function in the equine distal forelimb. Muscle architectural data were collected from seven limbs obtained from five thoroughbred and thoroughbred-cross horses. Muscle belly rest length, tendon rest length, m...
Docking SI, Daffy J, van Schie HT, Cook JL.Investigations into the response of the superficial digital flexor tendon (SDFT) of the Thoroughbred horse to mechanical stimuli have been limited to in vitro cell culture studies focused primarily on gene expression of critical matrix proteins. It is uncertain how well in vitro outcomes translate to the tendon of the horse during exercise. The current study examined changes in tendon structure in response to maximal exercise using ultrasound tissue characterisation (UTC) to scan the SDFT prior to and after competitive racing. UTC uses contiguous transverse ultrasound images to assess the dyna...
Patterson-Kane JC, Wilson AM, Firth EC, Parry DA, Goodship AE.This study was undertaken to test the hypothesis that collagen fibrils, the submicroscopic units of strength in tendon, would hypertrophy in response to a specific defined training programme. Fibril diameters were measured in central and peripheral regions of superficial digital flexor tendon (SDFT) samples from five 18-month-old horses which underwent a subsequent 18 month training programme and 6 age- and sex-matched controls. Central region fibrils from the trained horses had a mass-average diameter (MAD) of 105.3 nm, which was significantly lower (P < 0.01) than that of 131.7 nm for the...
Goodman SA, May SA, Heinegård D, Smith RK.The effect of strain and transforming growth factor beta on equine tendon fibroblasts (tenocytes) was assessed in vitro. Tenocytes were isolated from flexor and extensor tendons of horses from foetal to 10 years of age. These cells were cultured until confluent on collagen-coated silicone dishes. Cyclic biaxial strain of 9+/-1% was applied at 0.5 Hz for 24 hours with or without added TGFbeta1 or 3 (10 ng/ml). Proliferation and synthetic responses were dependent on the tendon of origin. Neither strain nor TGFbeta caused flexor tenocytes to proliferate significantly, while strain alone did proli...
