Ligaments in horses are fibrous connective tissues that connect bones to other bones, providing stability and support to the skeletal structure. These structures are integral to maintaining joint function and facilitating movement. In equine anatomy, ligaments are involved in various functions, including supporting the limbs and allowing for efficient locomotion. Common ligaments in horses include the suspensory ligament, which plays a significant role in supporting the fetlock joint, and the nuchal ligament, which supports the head and neck. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, function, injury mechanisms, and rehabilitation of ligaments in horses.
Eren G, López-Albors O, López Corbalán M, Latorre R.Digital technologies have improved the visualization of anatomical structures for veterinary education and clinical practice. In this study, a detailed three-dimensional anatomical model of the equine palmar metacarpal region was generated using E12-based epoxy sheet plastination combined with digital reconstruction in Amira V5.6 software. Serial cross-sections of the metacarpal region provided high-resolution visualization of bones, tendons, ligaments, nerves, vessels, fasciae, and synovial structures, with minimal shrinkage or deformation, ensuring improved anatomical accuracy. These section...
Nelson B.Complications of equine musculoskeletal procedures and surgery are an inevitable occurrence. This article summarizes complications principally encountered by primary equine veterinarians who perform and manage musculoskeletal procedures and surgeries. Topics discussed include complications of musculoskeletal diagnostic procedures, angular/flexural limb deformities, and muscle, tendon, and ligament surgery; surgery of the foot, orthopedic and arthroscopic surgery, and cast management. Each section lists complications encountered and includes diagnostic and treatment considerations. Awareness of...
Samol MA, Barrett MF, Frisbie DD.Significant distal interphalangeal joint (DIPJ) pathology, particularly affecting soft tissue and articular cartilage, is often not identifiable on radiographs but can be accompanied by joint capsule enthesopathy on the middle phalanx (P2), which can be readily identified. Objective: To explore frequency and correlations between DIPJ capsule enthesopathy identified on magnetic resonance imaging (MRI) and radiographs and DIPJ articular cartilage abnormalities and other concurrent soft tissue or osseous pathology within the foot found on MRI. Methods: Retrospective descriptive case series. Metho...
Gutierrez SO, Garcia-Lopez JM, Chope KB, Levine DG, Ortved K, Brown KA.To describe the clinical and ultrasonographic findings in horses with desmopathy of the abaxial palmar/plantar ligament (APL) of the proximal interphalangeal joint and the prevalence of concurrent musculoskeletal injuries in the pastern and foot. Unassigned: Horses presenting to New Bolton Center between March 2017 and November 2022 with an age ranging from 5 to 20 years that underwent lameness evaluation in which lameness was localized to the distal limb and had an ultrasonographic diagnosis of APL desmopathy. Unassigned: Horses included were those that (1) presented for a lameness examinatio...
Freeman KD, Adams MN, Salinger AE, White NA, Barrett JG.Suspensory desmopathy is a frequently documented cause of lameness in performance horses; proximal suspensory desmopathy is the most frequent site of injury in dressage horses [...].
Tommasa SD, Raspe S, Farí G, Imperante A, Brehm W.Tendon and ligament injuries in equine athletes pose significant challenges, often leading to prolonged recovery, reduced performance, and increased risk of reinjury. Current treatment strategies, including conservative and surgical approaches, have shown limited success in fully restoring tendon integrity. Autologous blood derivatives, such as autologous conditioned serum (ACS), have emerged as potential regenerative therapies. However, the clinical efficacy of ACS in the treatment of equine tendinopathies remains under investigation. Unassigned: This study aimed to compare the clinical outco...
Bosch K, Zsoldos RR, Hartig A, Licka T.The influence of soft tissue structures, including ligaments spanning one or more intervertebral junctions and the nuchal ligament, on motion of the equine cervical joints remains unclear. The present study addressed this using four post-mortem horse specimens extending from head to withers with all ligaments intact. Three-dimensional kinematics was obtained from markers on the head and bone-anchored markers on each cervical and the first thoracic vertebra during rotation, lateral bending, flexion and extension of the whole head, and neck segment. Yaw, pitch, and roll angles in 8 cervical join...
Joostens Z, Audigié F, de la Rebière de Pouyade G, Garigliany MM, Busoni V.In human medicine, the enthesis, or tendon-to-bone insertion, is generally considered a linked entity or 'enthesis organ' and plays a crucial biomechanical role. This study aimed to histologically assess the equine proximal third interosseus muscle (suspensory ligament) enthesis in 10 pelvic limbs from 7 horses. The area of the proximal third interosseus muscle enthesis was divided into 6 compartments based on post-mortem computed tomography and prepared for histology using haematoxylin/eosin and trichrome staining. The proximal third interosseus muscle enthesis showed a fibrocartilaginous nat...
Durgam S.The mid-metacarpal SDFT, intrasynovial DDFT and suspensory ligament are frequently injured soft tissues in the equine athlete. The mid-metacarpal SDFT exhibits a hierarchical structure and encounters repetitive strains at its functional limit. The intrasynovial DDFT possesses fibrocartilage where opposing bony surfaces to facilitate resistance-free gliding and contains chondrocyte-like cells embedded in a proteoglycan-rich ECM. While suspensory ligament enthesis injuries are common, collagen and non-collagen ECM structure-function specializations at the bone-ligament interface are understudied...
Bertone AL, Reinemeyer C, Tsaprailis G, Ragland D, Leise B.The use of micro-particulate allografts is rising, but knowledge about the protein characterization and biocompatibility of umbilical cord-derived allografts (UC) in vivo is limited. Methods: Proteomic analyses using mass spectrometry (MS) determined equine UC protein relative quantification and functions using total spectral counts (TSC). UC cytokines were quantified by enzyme-linked immunosorbent assay (ELISA). Three in vivo studies assessed recipient clinical and tissue biocompatibility in joints and ligaments. Results: Proteomics revealed 2645 annotated TSCs. Proteins of > 89 TSC we...
Ellis KL, Giancola S.Rehabilitation for tendon/ligament injury requires a multimodal approach to reduce pain, restore range of motion, improve proprioception/neuromotor control, and improve strength/endurance. Multiple tools are available to accomplish these goals. The rehabilitation program must be tailored to the individual patient regardless of injury type in order to return the horse to full athletic activity and reduce the risk of reinjury.
Pluim M, Reynolds A, McClure S.High-power laser therapy and extracorporeal shock wave therapy (ESWT) can be safely used to treat tendon and ligament injuries in horses, and the potential beneficial effects have been described. The power of low level lasers is not sufficient for treatment of tendon and ligament injuries in horses. ESWT is used more often to treat tendon and ligament injuries than it is for any other type of condition in horses, but there is limited supporting scientific evidence. Further research should focus on establishing dosage and treatment protocols for both laser therapy and ESWT in horses with clinic...
Connard SS, Schnabel LV.This review explores the use of biologics in the treatment of tendon and ligament injuries in horses, focusing on current and emerging therapies aimed at enhancing tissue repair and regeneration. It discusses the role of scaffold-based therapies, growth factors, blood-derived and tissue-derived biologics, and gene therapy as biologic regenerative therapies for improving healing outcomes. The review evaluates the mechanisms, efficacy, and challenges of biologics in clinical applications, highlighting recent advances and clinical studies. It provides an overview of current trends and future dire...
Urion R, Lustgarten M, Hostnik ET.Technological developments in imaging modalities have advanced the diagnostic capabilities for equine tendon and ligament injuries beyond the traditional methods. This review examines elastography techniques in ultrasonography that assess tissue stiffness and strain properties, computed tomography (CT) innovations including PET/CT fusion and dual-energy CT, and emerging applications of diffusion-weighted MRI for evaluating fiber microstructure and functionality. These complementary approaches offer veterinarians improved means to detect early injuries, assess structural integrity, monitor heal...
Moreno C, Rice H.Diagnostic and treatment strategies for infectious equine tendon and ligament disorders are continually evolving where recent progress is focused on advanced imaging and evidence supporting endoscopic lavage and regional antimicrobial therapy.
Beasley B.The overall objective of therapeutic farriery for equine tendon and ligament injuries is to provide a biomechanical environment conducive to healing by limiting excessive strain on the injured structure. With an understanding of equine limb anatomy and the pathophysiology of tendon/ligament injuries, the rationale used in therapeutic farriery for soft tissue injuries of the distal limb is quite logical. Through therapeutic farriery, foot manipulation is used to reduce the tension on the injured tendon(s) or ligament(s).
Ellis K, Van Zeeland EM, Ashton L, Wist S, Broeckling C, Harris M, Frisbie DD, Sikes KJ.To (1) identify tissue-specific metabolic profiles of the superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), and suspensory ligament (SL) and (2) evaluate metabolic profile differences in the SDFT, DDFT, and SL between the equine forelimb and hindlimb. Unassigned: 2 SDFT, DDFT, and SL specimens were collected from the forelimbs and hindlimbs of 10 horses of mixed breed, age, and sex that were euthanized for other reasons. One specimen was processed for histology to confirm that there were no underlying soft-tissue pathologies. One specimen was processed for 2 forms of...
Peeters MWJ, Ott S, van Veggel E, Berner D, Perrier M.Limited reports in the literature are available regarding desmitis of the palmar/plantar ligaments of the proximal interphalangeal joint (PL-PIPJ); the clinical significance of such injuries is unknown. Objective: To describe the ability to differentiate the PL-PIPJ on low-field magnetic resonance (MR) examination. To describe the injury characteristics of the PL-PIPJ on MR examination and the correlation with clinical features and lameness. Methods: Retrospective case series. Methods: Data and MR images of 29 horses were collected from the databases of three institutions. Horses were included...
Quam V.Inflammation plays a role in acute and chronic equine tendon/ligament injury; anti-inflammatories are often indicated. Local corticosteroids provide consistent and profound short-term effects on pain and inflammation across species. However, there is no demonstrated benefit in the long term, and complications can occur. Alternative biologic anti-inflammatory treatments are available and should be used in horses at risk of complications. Nonetheless, corticosteroids remain an affordable and effective anti-inflammatory that, with continued research, may be indicated on a case-by-case basis as pa...
Tress D, Hennessy S, Merle R, Jensen KC, Lischer C, Ehrle A.Impingement of spinous processes (SPs) is commonly diagnosed in the equine athlete. For diagnostic and therapeutic purposes, local injections are performed at the level of the space between adjacent spinous processes in affected horses. Objective: To assess the accuracy of different techniques for the local injection of the interspinal space in the equine thoracolumbar spine. Methods: Ex vivo experimental study. Methods: Equine thoracolumbar spine specimens were used to compare three techniques for needle insertion (midline; bilateral abaxial; unilateral oblique), two needles (20G-1½″; 20G-...
Kirkpatrick CJ, Ernst NS, Trumble TN.Injury to the collateral ligament (CL) of the distal interphalangeal joint (DIPJ) is recognized as a source of lameness in horses. Intralesional injection has been advocated to increase return to performance. This study was a proof-of-concept study in standing horses to evaluate success of a palmar radiographic-guided approach for injecting insertions of the DIPJ CLs previously described in cadaver limbs. Horses were sedated, nerve blocked, and placed on wooden blocks with the limb to be injected staggered approximately 20cm cranially to the other limb. The DIPJ CL insertion was injected, usin...
Cardinaux EM, Oltmanns H, Beineke A, Meißner J, Geburek F.Flexural limb deformities are a widespread condition in foals. Oxytetracycline is a common conservative treatment option with relaxing effects on the muscle-tendon-unit, potentially mediated through a matrix-metalloproteinase (MMP)-inhibitor mechanism. Its high therapeutic dose for this indication, potential negative side effects, and the guidelines for prudent use of antimicrobials make investigating alternatives desirable. In this study, the influence of substances with potentially similar mechanisms of action, however without antimicrobial properties, on viability and proliferation of juven...
Carmona JU, López C.(1) Background: Tendon and ligament injuries are a leading cause of lameness in horses, with significant economic implications. Platelet-rich plasma (PRP) has gained attention for its regenerative potential, but its efficacy remains uncertain due to inconsistent study designs and reporting. (2) Methods: This systematic review, following the PRISMA guidelines, evaluated 22 studies (clinical and experimental) to assess the safety and efficacy of PRP in treating equine tendon and ligament injuries. The risk of bias was analyzed using the ROBINS-I and RoB 2.0 tools. (3) Results: PRP demonstrated a...
Albanese V, Straticò P, Fischer H, Petrizzi L.Injuries to the distal limb are common in horses. The clinical aspect of the lesions is variable based on the structures that are involved. Synovial structures as well as tendons and/or ligaments may be involved in such injuries, affecting treatment modalities and costs, and prognosis. This retrospective study compares wounds involving synovial structures to wounds without such involvement in terms of treatment duration and costs, and prognosis. Synovial wounds were much more expensive to treat and carried a lower prognosis. Involvement of tendons and/or ligaments in the wounds resulted in mor...
Breen LJ, Stack JD, Gillen AM, Baldwin CM.(1) To evaluate the feasibility of needle tenoscopy of the digital flexor tendon sheath (DFTS) using basisesamoid (BS) and proximolateral (PL) approaches in a standing equine cadaver model. (2) To report visualization of intrathecal DFTS anatomy via both approaches. (3) To determine the efficacy of needle scope-guided palmar/plantar annular ligament (PAL) desmotomy. (4) To report any iatrogenic damage associated with the procedure. Methods: Ex vivo experimental. Methods: Ten equine cadaver limbs. Methods: Limbs were placed in a Kimzey leg-saver splint and needle tenoscopy was performed using t...
Dollemore G, McGovern K, Tallon R.Conservative and surgical management of left dorsal displacement and nephrosplenic ligament entrapment of the large colon (NSLE) is well described in horses. Whilst breed factors predispose the development of NSLE, it is unknown if breed affects the likelihood for surgical intervention. Objective: To compare the incidence of surgical intervention and differences in pre-operative parameters between Thoroughbred and non-Thoroughbred horses. The authors hypothesise a higher proportion of Thoroughbreds require surgical intervention. Methods: Retrospective cross-sectional study. Methods: Case recor...
Colla S, Johnson JW, McGilvray KC, Zanotto GM, Seabaugh KA.Therapeutic shoeing for horses is used to affect the palmar angle (PA) of the distal phalanx. These changes may influence the strain on the distal interphalangeal joint collateral ligaments (DIJCLs). This cadaveric study aimed to assess DIJCL strain under varying loads and PA adjustments. Using 26 cadaver forelimbs, eight optical markers were placed on one DIJCL for strain measurement under five different loads (1000-5000 newtons) at a neutral PA, followed by PA increases of 2°, 4°, and 6° and decreases of -2° and -4°. The results indicate that increases in PA corresponded to significantl...
Guest DJ, Birch HL, Thorpe CT.The suspensory ligament (SL) is a key component of the elaborate and highly adapted suspensory apparatus in the horse. In addition to contributing to stabilisation of the metacarpophalangeal joint, the SL has a spring like function to reduce the energetic cost of locomotion. Although the SL is highly prone to injury in horses of all ages and competing in a wide range of disciplines, knowledge regarding fundamental structure-function relationships in the SL is lacking, particularly compared with other injury-prone tendinous structures such as the superficial digital flexor tendon. In this revie...
Hagenbach M, Bierau J, Cruz AM, Koch C, Manso-Díaz G, Büttner K, Staszyk C, Röcken M.In the diagnostics of orthopedic diseases in the horse, diagnostic imaging often plays a decisive role. Cone beam computed tomography (CBCT) imaging is used in both human and small animal medicine and becoming increasingly popular. To see whether CBCT imaging can be useful in the diagnosis of orthopedic diseases of the carpal region of the horse and to explore possible limitations we compared CBCT images with multidetector computed tomography (MDCT) images of the carpal region of equine cadaveric specimens. Unassigned: Twenty-eight forelimbs from fifteen horses, slaughtered for reasons unrelat...
Schnabel LV, Lynch ME, van der Meulen MC, Yeager AE, Kornatowski MA, Nixon AJ.Tendinitis remains a catastrophic injury among athletes. Mesenchymal stem cells (MSCs) have recently been investigated for use in the treatment of tendinitis. Previous work has demonstrated the value of insulin-like growth factor-I (IGF-I) to stimulate cellular proliferation and tendon fiber deposition in the core lesion of tendinitis. This study examined the effects of MSCs, as well as IGF-I gene-enhanced MSCs (AdIGF-MSCs) on tendon healing in vivo. Collagenase-induced bilateral tendinitis lesions were created in equine flexor digitorum superficialis tendons (SDFT). Tendons were treated with ...
Biewener AA.The stresses acting in muscle-tendon units and ligaments of the forelimb and hindlimb of horses were determined over a range of speed and gait based on recordings of ground reaction forces and limb kinematics. Maximum stresses of 40-50 MPa were calculated to act in several of the principal forelimb (superficial digital flexor (SDF), deep digital flexor (DDF), ulnaris lateralis (UL) and flexor carpi ulnaris/radialis (FCU/R)) and hindlimb tendons (plantaris, DDF) at the fastest galloping speeds recorded (up to 7.4 m s-1). Smaller stresses were found for the gastrocnemius (GAST) tendon (30 MPa) a...
Lomas AJ, Ryan CN, Sorushanova A, Shologu N, Sideri AI, Tsioli V, Fthenakis GC, Tzora A, Skoufos I, Quinlan LR, O'Laighin G, Mullen AM, Kelly JL....Tendon injuries represent a significant clinical burden on healthcare systems worldwide. As the human population ages and the life expectancy increases, tendon injuries will become more prevalent, especially among young individuals with long life ahead of them. Advancements in engineering, chemistry and biology have made available an array of three-dimensional scaffold-based intervention strategies, natural or synthetic in origin. Further, functionalisation strategies, based on biophysical, biochemical and biological cues, offer control over cellular functions; localisation and sustained relea...
Ferris DJ, Frisbie DD, Kisiday JD, McIlwraith CW, Hague BA, Major MD, Schneider RK, Zubrod CJ, Kawcak CE, Goodrich LR.To report outcome of horses with femorotibial lesions (meniscal, cartilage or ligamentous) treated with surgery and intra-articular administration of autologous bone marrow derived mesenchymal stem cells (BMSCs). Methods: Prospective case series. Methods: Horses (n = 33). Methods: Inclusion criteria included horses that had lameness localized to the stifle by diagnostic anesthesia, exploratory stifle arthroscopy and subsequent intra-articular administration of autologous BMSCs. Case details and follow-up were gathered from medical records, owner, trainer or veterinarian. Outcome was defined as...
Thorpe CT, Clegg PD, Birch HL.Tendon injury is one of the most common causes of wastage in the performance horse; the majority of tendon injuries occur to the superficial digital flexor tendon (SDFT) whereas few occur to the common digital extensor tendon. This review outlines the epidemiology and aetiology of equine tendon injury, reviews the different functions of the tendons in the equine forelimb and suggests possible reasons for the high rate of failure of the SDFT. An understanding of the mechanisms leading to matrix degeneration and subsequent tendon gross failure is the key to developing appropriate treatment and p...
Thorpe CT, Godinho MSC, Riley GP, Birch HL, Clegg PD, Screen HRC.While the predominant function of all tendons is to transfer force from muscle to bone and position the limbs, some tendons additionally function as energy stores, reducing the cost of locomotion. Energy storing tendons experience extremely high strains and need to be able to recoil efficiently for maximum energy storage and return. In the equine forelimb, the energy storing superficial digital flexor tendon (SDFT) has much higher failure strains than the positional common digital extensor tendon (CDET). However, we have previously shown that this is not due to differences in the properties of...
Smith RK, Zunino L, Webbon PM, Heinegård D.A protein prominent in guanidine hydrochloride extracts of adult bovine and equine digital flexor tendons was confirmed to be Cartilage Oligomeric Matrix Protein (COMP) by non-reducing and reducing SDS-PAGE, reaction with rabbit anti-COMP polyclonal antiserum on Western blots, trypsin digestion followed by HPLC on a C2/C18 column, and identification of COMP mRNA from tendon on Northern blots. Immunohistochemistry and Western blots of extracts showed COMP to be present in all regions of digital flexor tendons. Equine tendon COMP was purified by ion exchange chromatography and gel filtration and...
Torricelli P, Fini M, Filardo G, Tschon M, Pischedda M, Pacorini A, Kon E, Giardino R.Tissue repair in musculoskeletal injuries is often a slow and sometimes incomplete process. Regenerative medicine based on the use of growth factors (GFs) and cell therapy is aimed at improving the quality and speed of tendon and ligament healing. The aim of this study was to evaluate the potential for the administration of a combination of autologous platelet-rich plasma (PRP) and freshly isolated bone marrow mononucleated cells (BMMNCs) in 13 competition horses affected by overuse musculoskeletal injuries (suspensory ligament desmopathy and superficial flexor tendinopathy) and refractory to ...
McGuigan MP, Wilson AM.A horse's legs are compressed during the stance phase, storing and then returning elastic strain energy in spring-like muscle-tendon units. The arrangement of the muscle-tendon units around the lever-like joints means that as the leg shortens the muscle-tendon units are stretched. The forelimb anatomy means that the leg can be conceptually divided into two springs: the proximal spring, from the scapula to the elbow, and the distal spring, from the elbow to the foot. In this paper we report the results of a series of experiments testing the hypothesis that there is minimal scope for muscle cont...
Brossi PM, Moreira JJ, Machado TS, Baccarin RY.This systematic review aimed to present and critically appraise the available information on the efficacy of platelet rich plasma (PRP) in equine and human orthopedic therapeutics and to verify the influence of study design and methodology on the assumption of PRP's efficacy. We searched Medline, PubMed, Embase, Bireme and Google Scholar without restrictions until July 2013. Randomized trials, human cohort clinical studies or case series with a control group on the use of PRP in tendons, ligaments or articular lesions were included. Equine clinical studies on the same topics were included inde...
Ely ER, Avella CS, Price JS, Smith RK, Wood JL, Verheyen KL.While fractures and tendon injuries are known to be important diseases in National Hunt (NH) racehorses during racing, there are no accurate estimates of their incidence in NH training yards. Objective: To estimate the incidence of fractures and tendon and suspensory ligament injuries (TLIs) in NH racehorses in training; to describe the injuries incurred and to compare injury incidence rates by horse age, trainer, gender and background (ex-flat vs. ex-store horses). Methods: Cohort data were collected from 14 UK NH training yards for 2 racing seasons. Daily exercise regimens and details of fra...
Murray RC, Dyson SJ, Tranquille C, Adams V.Although anecdotal reports of increased orthopaedic injury risk in equine sports exist, there is little scientific evidence to support this. Objective: To test whether horses undertaking a single competitive sport have increased risk of specific injuries compared to those used for general purpose riding (GP); and whether injury type varies with sport category and performance level. Methods: Data from 1069 records of horses undergoing orthopaedic evaluation (1998-2003) and meeting inclusion criteria were reviewed. Sport category (GP, showjumping, dressage, eventing, racing), level (nonelite or ...
Del Bue M, Riccò S, Ramoni R, Conti V, Gnudi G, Grolli S.Equine mesenchymal stem cells (MSC) are of particular interest both for basic research and for the therapeutic approach to musculoskeletal diseases in the horse. Their multilineage differentiation potential gives them the capability to contribute to the repair of tendon, ligament and bone damage. MSCs are also considered a promising therapeutic aid in allogeneic cell transplantation, since they show low immunogenicity and immunomodulating functions.Adipose tissue-derived adult equine stem cells (AdMSC) can be isolated, expanded in vitro and then inoculated into the damaged tissue, eventually i...
Waselau M, Sutter WW, Genovese RL, Bertone AL.To determine outcome of Standardbred racehorses with moderate to severe midbody suspensory ligament desmitis (MSD) treated by means of ultrasound-guided intralesional injection of a single dose of platelet-rich plasma (PRP) followed by a program of gradually increased exercise. Methods: Nonrandomized clinical trial. Methods: 9 Standardbred racehorses. Methods: Following injection of PRP, horses were allowed a controlled, gradual return to exercise. Race records for the year prior to injury and for 3 consecutive years after horses returned to racing were reviewed. For comparison purposes, race ...
Burk J, Plenge A, Brehm W, Heller S, Pfeiffer B, Kasper C.Tendon and ligament pathologies are still a therapeutic challenge, due to the difficulty in restoring the complex extracellular matrix architecture and biomechanical strength. While progress is being made in cell-based therapies and tissue engineering approaches, comprehensive understanding of the fate of progenitor cells in tendon healing is still lacking. The aim of this study was to investigate the effect of decellularized tendon matrix and moderate cyclic stretching as natural stimuli which could potentially direct tenogenic fate. Equine adipose-derived mesenchymal stromal cells (MSC) were...
Goodship AE, Birch HL, Wilson AM.Injury of the collagenous structures comprising tendons and ligaments, either from acute trauma or from repetitive strain lesions, results in protracted periods of disability. The resolution of such injuries often fails to restore the normal morphologic and functional characteristics of the structure and, therefore, either compromises the future performance of the individual or predisposes to an increased risk of recurrent injury.
Clegg PD, Strassburg S, Smith RK.Injuries to tendons are common in both human athletes as well as in animals, such as the horse, which are used for competitive purposes. Furthermore, such injuries are also increasing in prevalence in the ageing, sedentary population. Tendon diseases often respond poorly to treatment and require lengthy periods of rehabilitation. The tendon has a unique extracellular matrix, which has developed to withstand the mechanical demands of such tensile-load bearing structures. Following injury, any repair process is inadequate and results in tissue that is distinct from original tendon tissue. There ...
Birch HL, Bailey JV, Bailey AJ, Goodship AE.Specific tendons show a high incidence of partial central core rupture which is preceded by degeneration. In the performance horse, the superficial digital flexor tendon (SDFT) is most often affected. We have described previously the molecular changes that are associated with degeneration in the central core region of the equine SDFT. The pathophysiological mechanism leading to change in synthetic activity of central zone cells in degenerated tendons is not known. In this study, we test the hypothesis that ageing results in matrix composition changes within the central zone of the SDFT. Extrac...
Reed SA, Johnson SE.Mesenchymal stem cells (MSCs) offer promise as therapeutic aids in the repair of tendon, ligament, and bone damage suffered by sport horses. The objective of the study was to identify and characterize stem-like cells from newborn foal umbilical cord blood (UCB). UCB was collected and MSC isolated using human reagents. The cells exhibit a fibroblast-like morphology and express the stem cell markers Oct4, SSEA-1, Tra1-60 and Tra1-81. Culture of the cells in tissue-specific differentiation media leads to the formation of cell types characteristic of mesodermal and endodermal origins. Chondrogenic...
Fortier LA, Smith RK.After tendon injury, the scar tissue that replaces the damaged tendon results in a substantial risk for reinjury. The goal of regenerative therapies is to restore normal structural architecture and biomechanical function to an injured tissue. Successful restoration processes for any tissue are thought to recapitulate those of development, in which there are spatial and temporal interactions between scaffold, growth factors, and cell populations.
Mesenchymal stem cells (MSCs) offer promise as therapeutic aids in the repair of tendon and ligament disorders in sport horses. Equine allogeneic MSCs derived from umbilical cord blood (eUCB-MSCs) can be obtained in a minimally invasive fashion with successful propagation of MSCs. Objective: The objective of this study was to determine the applicability and therapeutic effect of eUCB-MSCs on tendinitis of the superficial digital flexor tendon, desmitis of the suspensory ligament, tendinitis of the deep digital flexor tendon, and desmitis of the inferior check ligament in clinical cases. Method...
Bosch G, de Mos M, van Binsbergen R, van Schie HT, van de Lest CH, van Weeren PR.Extracorporeal shock wave therapy (ESWT) is frequently used in equine practice, but little is known about its biological action. Objective: To study the effects of ESWT on matrix structure and gene expression levels in normal, physiologically loaded tendinous structures in ponies. Methods: Six Shetland ponies, free of lameness and with ultrasonographically normal flexor and extensor tendons and suspensory ligaments (SL), were used. ESWT was applied at the origin of the suspensory ligament and the mid-metacarpal region of the superficial digital flexor tendon (SDFT) 6 weeks prior to sample taki...
Becerra P, Valdés Vázquez MA, Dudhia J, Fiske-Jackson AR, Neves F, Hartman NG, Smith RK.This study aimed to investigate immediate cell survival and distribution following different administration routes of mesenchymal stem cells (MSCs) into naturally occurring tendon injuries. Ten million MSCs, labeled with technetium-99m hexamethylpropyleneamine oxime, were implanted into 13 horses with naturally occurring tendon or ligament injuries intra-lesionally, intravenously and by regional perfusion, and traced for up to 48 h using planar gamma scintigraphy. Labeling efficiencies varied between 1.8% and 18.5% (mean 9.3%). Cells were retained in the damaged area after intra-lesional adm...
Parry DA, Craig AS, Barnes GR.A study has been made of the ultrastructural organization of the collagen fibrils and elastic fibres in tendons and ligaments from horses of ages ranging from 2 months premature to 19 years. Diameter distributions of the collagen fibrils in the common digital extensor tendon, the superficial flexor tendon and the suspensory ligament are unimodal in the foetal tissue and at birth, and at these stages of development the three collagenous tissues are virtually indistinguishable. However, at maturity, the ligament and flexor tendon have bimodal distributions similar to that found for rat-tail tend...
Lange-Consiglio A, Tassan S, Corradetti B, Meucci A, Perego R, Bizzaro D, Cremonesi F.This is the first study to compare the treatment of horse tendon and ligament injuries with the use of mesenchymal stromal cells (MSCs) obtained from two different sources: amniotic membrane (AMSCs) and bone marrow (BM-MSCs). The objective was to prove the ability of AMSCs to exert beneficial effects in vivo. Methods: Five million allogeneic frozen-thawed AMSCs or autologous fresh BM-MSCs were injected intralesionally in horses belonging to group A (51 horses) and group B (44 horses). The interval lesion/implantation was of 6-15 days for the AMSCs and 16-35 days for the BM-MSCs. Healing was as...
Evans CH, Chevalier X, Wehling P.Autologous conditioned serum was developed in the mid 1990s as an expeditious, practical, and relatively inexpensive means of generating the interleukin-1 receptor antagonist, a naturally occurring inhibitor of the cytokine interleukin-1. The latter is thought to be an important mediator of inflammation, pain, and tissue destruction in musculoskeletal conditions. ACS has been widely and successfully used in the local treatment of human and equine osteoarthritis and radicular compression; it has also shown promise in treating tendinopathies, muscle injuries, and tunnel widening after reconstruc...
Crevier-Denoix N, Collobert C, Pourcelot P, Denoix JM, Sanaa M, Geiger D, Bernard N, Ribot X, Bortolussi C, Bousseau B.The objective of this study was to mechanically characterise superficial digital flexor tendon (SDFT) lesions. Eight pathological SDFTs, isolated from 6 adult horses, were tested in traction until rupture (at 1 mm/s). The stresses and strains simultaneously undergone by each of the 7 segments of a tendon were determined throughout the test, and the modulus of elasticity of each segment was evaluated from the segmental stress-strain curve thus obtained. These mechanical data were compared to those obtained on 10 normal SDFTs. After the test, the tendinous segments were submitted to a histologic...
Beerts C, Suls M, Broeckx SY, Seys B, Vandenberghe A, Declercq J, Duchateau L, Vidal MA, Spaas JH.Poor healing of tendon and ligament lesions often results in early retirement of sport horses. Therefore, regenerative therapies are being explored as potentially promising treatment for these injuries. In this study, an intralesional injection was performed with allogeneic tenogenically induced mesenchymal stem cells and platelet-rich plasma 5-6 days after diagnosis of suspensory ligament (SL) (n = 68) or superficial digital flexor tendon (SDFT) (n = 36) lesion. Clinical, lameness and ultrasonographic evaluation was performed at 6 and 12 weeks. Moreover, a survey was performed 12 ...
Plaas A, Sandy JD, Liu H, Diaz MA, Schenkman D, Magnus RP, Bolam-Bretl C, Kopesky PW, Wang VM, Galante JO.We describe analysis of suspensory ligaments from horses with advanced degenerative suspensory ligament desmitis (DSLD) to identify the major proteoglycans (PGs), ADAMTS-aggrecanases and inter-alpha-trypsin inhibitor (IαI) components associated with ligament degeneration. Specific anatomical regions of suspensory ligaments from two normal horses and four diagnosed with DSLD were analyzed by Western blot and immunohistochemistry for the following: aggrecan, aggrecan fragments, decorin, ADAMTS4, ADAMTS5, and IαI components. When compared to normal, DSLD ligaments showed about a 15-fold increas...
Ortved KF.Tendon and ligament injuries are a common source of lameness in the athletic horse. Although tendons and ligaments have the ability to spontaneously heal, lesions tend to fill with biomechanically inferior fibrous tissue such that the horse is prone to reinjury. Regenerative medicine is used to improve quality of repair tissue and prevent reinjury. Platelet-rich plasma, stem cells, and autologous conditioned serum are the most commonly used orthobiologics in the horse. A tailored rehabilitation program is key to returning horses to athleticism following injury. The specifics of regenerative me...
