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.
Smith RK, Gerard M, Dowling B, Dart AJ, Birch HL, Goodship AE.Over-strain injury of the superficial digital flexor tendon (SDFT) is a common injury in the horse. Tendon appears to adapt to loads placed on it during development, but fatigue damage accumulates after skeletal maturity, which is inadequately repaired and predisposes to clinical tendinitis. In any population of horses, there is a wide variation in SDFT mechanical properties. A noncollagenous protein, cartilage oligomeric matrix protein (COMP), is particularly abundant during growth in the equine SDFT and has been proposed to have an organisational role in the formation of collagenous matrices...
Dahlgren LA, van der Meulen MC, Bertram JE, Starrak GS, Nixon AJ.Flexor tendinitis is a common and debilitating injury of elite and recreational athletes. Healing may be improved through intratendinous injection of insulin-like growth factor-I (IGF-I), which has been shown in vitro to stimulate mitogenesis and enhance tendon matrix production. This study investigated the effects of intratendinous injection of IGF-I on tendon healing in an equine model of flexor tendinitis. Collagenase-induced lesions were created in the tensile region of theflexor digitorum superficialis tendon of both forelimbs of eight horses. Treated tendons were injected with 2 microg r...
Rothaug PG, Boston RC, Richardson DW, Nunamaker DM.To compare the monotonic tensile and fatigue strength of 16-gauge stainless steel wire (SSW) to ultra-high-molecular weight polyethylene (UHMWPE) cable using a transfixed cerclage technique in an in vitro midbody sesamoid osteotomy model. Endoscopic modifications to Martins transfixed cerclage technique were developed. A new suture technique of fixation was compared with the transfixed cerclage technique by measuring gap formation after cyclic testing. Methods: An in vitro biomechanical paired equine cadaver limb study. Methods: Twenty-one paired cadaveric adult equine forelimbs. Methods: Unia...
Kasashima Y, Kuwano A, Katayama Y, Taura Y, Yoshihara T.Six live horses with various stages of acute to chronic superficial digital flexor (SDF) tendinitis were examined using magnetic resonance imaging (MRI). In each case, MRI findings were compared to the corresponding ultrasonographic (USD) and histologic findings, to establish the usefulness of MRI. In the acute cases, lesions characterized by hemorrhage were well defined as high signal intensity on MRI and hypoechoic regions on USD. Chronic tendon fibrosis was slightly hyperechoic and difficult to distinguish from the normal tendon tissue around the original injury by using USD. In contrast, M...
Dowling BA, Dart AJ, Hodgson DR, Rose RJ, Walsh WR.To evaluate the effect of recombinant equine growth hormone (rEGH) on the in vitro biomechanical properties of healing superficial digital flexor tendon (SDFT) in horses. Methods: Completely randomized design. Methods: Twelve Standardbred horses, 3 to 7 years of age, with ultrasonographically normal forelimb SDFT. Methods: One week after induction of collagenase (2,000 U) induced superficial flexor tendonitis, horses were randomly divided into groups of 6. One group was administered intramuscular rEGH (10 microg/kg/day for 1 week, then 20 microg/kg/day for 5 weeks), whereas the other group (co...
Frees KE, Lillich JD, Gaughan EM, DeBowes RM.To determine history, physical and diagnostic examination findings, medical treatment, and outcome of horses with open injuries to the digital flexor tendon sheath treated with the assistance of tenoscopy. Methods: Betrospective study. Methods: 20 horses. Methods: Medical records of 20 horses with open injuries to the digital flexor tendon sheath were reviewed. Signalment, history, physical and diagnostic examination results, bacteriologic culture and susceptibility testing results, surgical and medical treatments, and follow-up examination results were determined. Outcome was determined by us...
Dowling BA, Dart AJ, Hodgson DR, Rose RJ, Walsh WR.To evaluate the effect of recombinant equine growth hormone (rEGH) on the in vitro biomechanical properties of normal adult equine superficial digital flexor tendon (SDFT). Methods: Completely randomized design. Methods: Nine Standardbred horses, 6 to 9 years of age with ultrasonographically normal forelimb SDFT. Methods: Six horses were administered intramuscular (IM) rEGH at 10 microg/kg/day for 1 week, and then 20 microg/kg/day for another 5 weeks; 3 horses (control subjects) were administered an equivalent daily volume of sterile water IM. Horses were killed at the end of the 6-week treatm...
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...
Kidd JA, Dyson SJ, Barr AR.Intratendonous infection in the absence of any clinical evidence of a wound has not, to our knowledge, been described previously in horses. This paper reports the clinical features, diagnostic techniques. treatment and outcome in 5 cases of septic flexor tendon core lesions. This condition is characterised by seven lameness and ultrasonographic evidence of a central intratendonous anechoic core lesion which may enlarge rapidly.
Dyson SJ.It was hypothesised that in solar bone images of the front feet of clinically normal horses, or horses with lameness unrelated to the front feet, there would be less than a 10% difference in the ratio of uptake of radiopharmaceutical in either the region of the navicular bone, or the region of insertion of the deep digital flexor tendon (DDFT), compared to the peripheral regions of the distal phalanx. Nuclear scintigraphic examination of the front feet of 15 Grand Prix show jumping horses, all of which were free from detectable lameness, was performed using dorsal, lateral and solar images. Th...
Reiners SR, Jann HW, Stein LE, Good JK, Claypool PL.To compare the healing and mechanical strength of a multiple split autologous tendon graft (MG) to a whole autologous tendon graft (WG) in the deep digital flexor tendon of ponies. Methods: In vitro evaluation of two different tendon-grafting techniques. Methods: Six ponies of mixed gender and age. Methods: Tenotomies performed in forelimb deep digital flexor tendons (DDFT) distal to the insertion of the accessory ligament (AL-DDFT) were repaired with free autologous grafts from the hindlimb lateral digital extensor tendon (LDET). Grafts were either whole (WG) or split into three longitudinal ...
Hammer EJ, Chope K, Lemire TD, Reef VB.This report describes the identification and surgical removal of a lipoma from the extensor tendon sheaths of a horse. To the authors' knowledge, this is the first report of a lipoma of the extensor tendon sheaths of a horse. Ultrasonographic evaluation was crucial to patient management, providing information regarding the soft tissue mass characteristics, tumor margins and synovial involvement prior to surgical exploration. Surgical removal was performed and was curative.
Van Wulfen KK, Bowker RM.To describe microanatomic characteristics of the insertion of the aistal sesamoidean impar ligament (DSIL) and deep digital flexor tendon (DDFT) on the distal phalanx in horses. Methods: Healthy feet obtained from 62 horses of various breeds. Methods: Feet from 23 horses were used to histologically examine the insertion of the DSIL and DDFT (n = 7), its vasculature (10), and neural elements (6). In 39 other horses, the insertion zone was examined for proteoglycan. Results: The insertion of the DSIL and dorsal half of the DDFT contained bundles of collagen fibers with intervening loose connecti...
Van Wulfen KK, Bowker RM.To localize substance P (SP) and neurokinin A (NKA) and their receptors in the insertion of the distal sesamoidean impar ligament (DSIL), deep digital flexor tendon (DDFT), and dorsal hoof wall of healthy feet of horses. Methods: 18 healthy feet from horses. Methods: Samples from the dorsal hoof wall and insertion of the DSIL and DDFT of 10 feet were processed for immunocytochemical analysis, using rabbit polyclonal antisera raised against SP and NKA. Tissue sections from 8 feet were incubated with 125-labeled SP to localize tachykinin receptors and their specificity and with control solutions...
Alexander RM.This research presents the hypothesis and findings that short muscle fibers in horses and other large mammals may protect bones and tendons from damaging vibrations during running, negating the previous […]
Wilson AM, McGuigan MP, Su A, van Den Bogert AJ.The muscular work of galloping in horses is halved by storing and returning elastic strain energy in spring-like muscle-tendon units.These make the legs act like a child's pogo stick that is tuned to stretch and recoil at 2.5 strides per second. This mechanism is optimized by unique musculoskeletal adaptations: the digital flexor muscles have extremely short fibres and significant passive properties, whereas the tendons are very long and span several joints. Length change occurs by a stretching of the spring-like digital flexor tendons rather than through energetically expensive length changes...
Busoni V, Denoix JM.The purpose of this paper is to describe the technique for ultrasonographic examination of the podotrochlear apparatus in the horse using a transcuneal approach. In this study, ultrasound scans were performed in 3 normal cadaver limbs and 5 sound horses and images were compared to anatomic sections to establish the normal ultrasonographic anatomy of the podotrochlear apparatus. Detailed description of transverse and sagittal reference ultrasonographic images of this region is provided. This new imaging technique allows the assessment of the distal sesamoid bone flexor surface, the distal porti...
Cherdchutham W, Meershoek LS, van Weeren PR, Barneveld A.To determine the effects of exercise on biomechanical properties of the superficial digital flexor tendon (SDFT) in foals. Methods: 43 Dutch Warmblood foals. Methods: From 1 week until 5 months of age, 14 foals were housed in stalls and not exercised, 14 foals were housed in stalls and exercised daily, and 15 foals were maintained at pasture. Eight foals in each group were euthanatized at 5 months, and remaining foals were housed together in a stall and paddock until euthanatized at 11 months. After euthanasia, SDFT were isolated and fit in a material testing system. Mean cross-sectional area ...
Meershoek LS, Schamhardt HC, Roepstorff L, Johnston C.Lameness in athletic horses is often caused by forelimb tendon injuries, especially in the interosseus tendon (TI) and superficial digital flexor tendon (SDF), but also in the accessory ligament (AL) of the deep digital flexor tendon (DDF). In an attempt to explain the aetiology of these injuries, the present study investigated the loading of the tendons during landing after a jump. In jumping horses, the highest forces can be expected in the trailing limb during landing. Therefore, landing kinematics and ground reaction forces of the trailing forelimb were measured from 6 horses jumping singl...
Alexander GR, Gibson KT, Day RE, Robertson ID.To measure the effects of transection of the accessory ligament of the superficial digital flexor (SDF) muscle (superior check desmotomy) on flexor tendon and suspensory ligament (SL) strain in vitro. Methods: In vitro experimental biomechanical investigation. ANIMALS USED: Ten equine cadaver forelimbs. Methods: The effects of superior check desmotomy were determined using equine cadaver forelimbs secured in a servocontrolled hydraulic testing machine. Strain sensors were used to measure strain on the superficial and deep digital flexor tendons and SL, and a goniometer was used to measure join...
Eddy AL, Van Hoogmoed LM, Snyder JR.Equine thermography has increased in popularity recently because of improvements in thermal cameras and advances in image-processing software. The basic principle of thermography involves the transformation of surface heat from an object into a pictorial representation. The colour gradients generated reflect differences in the emitted heat. Variations from normal can be used to detect lameness or regions of inflammation in horses. Units can be so sensitive that flexor tendon injuries can be detected before the horse develops clinical lameness. Thermography has been used to evaluate several dif...
Dahlgren LA, Nixon AJ, Brower-Toland BD.To investigate effects of beta-aminopropionitrile and a combination of insulin-like growth factor (IGF)-I and beta-aminopropionitrile on metabolism of equine tendon fibroblasts. Methods: Flexor tendon explants from 3 horses. Methods: Explants received 1 of 4 treatments (control, IGF-I, beta-aminopropionitrile, and IGF-I/beta-aminopropionitrile) for 10 days, and message expression for collagen types I and III was assessed by use of in situ hybridization. Histologic findings, new protein production, and quantitative determinations of glycosaminoglycan, DNA, and de novo collagen synthesis were ma...
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...
Meershoek LS, van den Bogert AJ, Schamhardt HC.To describe a method to calculate flexor tendon forces on the basis of inverse dynamic analysis and an in vitro model of the equine forelimb and to quantify parameters for the model. Methods: 38 forelimbs of 23 horses that each had an estimated body mass of > or = 500 kg. Methods: Longitudinal limb sections were used to determine the lines of action of the tendons. Additionally, limb and tendon loading experiments were performed to determine mechanical properties of the flexor tendons. Results: The study quantified the parameters for a pulley model to describe the lines of action. Furthermo...
Meershoek LS, Lanovaz JL.To test the sensitivity to measurement and modeling errors of a method for noninvasive calculation of flexor tendon forces in the equine forelimb and to calculate tendon forces for Dutch Warmblood horses during trotting. Methods: A normative set of kinematic and ground-reaction force (GRF) data obtained from horses during trotting in another study. Methods: Forces in the flexor tendons were calculated from the data set before and after addition of fixed relative and absolute errors. Amount of error was based on normal accuracy of the variables. A similar analysis was performed for a measure of...
Williams RB, Harkins LS, Hammond CJ, Wood JL.For improvements to the safety and welfare of racehorses to be possible, it is essential to have access to basic descriptive information about the veterinary incidents encountered during horseracing. A 3 year surveillance study (1996-1998) was conducted by The Jockey Club into racing injuries, other postrace clinical problems and fatalities from all 59 British racecourses (mainland Britain only) to identify risk factors. During the survey there were 222,993 racing starts: 106,897 starts in flat races on turf (47.9%), 26,519 starts in flat races on all-weather surfaces (11.9%), 30,932 starts in...
Micklethwaite L, Wood AK, Sehgal CM, Polansky M, Dowling BA, Dart AJ, Rose RJ, Hodgson DR.To determine whether quantitative analysis of sonographic brightness could be used to detect healing of an induced injury of the superficial digital flexor tendon in horses and whether rate of healing was influenced by equine recombinant growth hormone. Methods: 8 clinically normal Standardbreds. Methods: A localized injury was created in the left and right superficial digital flexor tendons of each horse by injection of 2,000 units of collagenase. After injury, 4 horses received equine recombinant growth hormone, a possible promoter of tendon healing. Sonographic images (7.5 MHz) of the flexo...
Reef VB.Until recently, it was difficult to critically evaluate tendon healing in vivo. Superficial digital flexor tendon injuries were considered healed when the injured tendon was cold, non-painful, adequate time had passed for tendon healing to occur, and no recurrence of the injury was detected when the horse returned to athletic work. This article discusses how ultrasonography has revolutionized the diagnosis, treatment, and management of tendon injuries.
Meershoek LS, Roepstorff L, Schamhardt HC, Johnston C, Bobbert MF.Tendon injuries are an important problem in athletic horses and are probably caused by excessive loading of the tendons during demanding activities. As a first step towards understanding these injuries, the tendon loading was quantified during jump landings. Kinematics and ground reaction forces were collected from the leading and trailing forelimbs of 6 experienced jumping horses. Joint moments were calculated using inverse dynamic analysis. It was found that the variation of movement and loading patterns was small, both within and between horses. The peak flexor joint moments in the coffin a...
Bernardino PN, Smith WA, Galuppo LD, Mur PE, Cassano JM.Mesenchymal stromal (stem) cells (MSCs) have been studied to treat many common orthopedic injuries in horses. However, there is limited information available on when and how to use this treatment effectively. The aim of this retrospective study is to report case features, treatment protocols, and clinical outcomes in horses treated with MSCs. Methods: 65 horses presenting with tendinous, ligamentous, and articular injuries, and treated with MSCs prepared by a single laboratory between 2016 and 2019. Outcome information was available for 26 horses. Methods: Signalment, clinical signs, diagnosti...
Mason TA.Seven cases of chronic tenosynovitis affecting the extensor carpi radialis or lateral digital extensor tendon and their sheaths are described. All cases were chronic and in 4 of the cases previous treatment by drainage and local corticosteroid injection had been ineffective. Surgical exploration of 6 cases demonstrated a distinct lesion and specific surgical treatment was carried out.
Williams J, Miyabayashi T, Ruggles A, Yamamoto J, Takiguchi M.A 2.5-year-old female Thoroughbred horse was referred to the veterinary teaching hospital for right front limb lameness of 1 year duration. Physical examination and diagnostic nerve blocks failed to localize the origin of the lameness. Scintigraphy with 99mTc-MDP suggested increased radionuclide uptake in the palmar metacarpal soft tissues of the right front limb. Ultrasonographic examination revealed hypoechoic lesions in the superficial digital flexor tendon and the suspensory ligament, suggesting tendinitis and desmitis. Combined imaging modalities improved detection and characterization of...
Chen YT, Mills C, von Rickenbach KJ, McInnis KC.A 61-yr-old female equestrian presented after 2 wks of left medial thigh pain, which developed suddenly while exiting a car. She denied any history of recent trauma or falls. On examination, she was found to have tenderness at the left distal medial thigh with a palpable region of decreased tissue volume at the gracilis myotendinous junction. Point-of-care ultrasound and magnetic resonance imaging confirmed a high-grade partial thickness tear of the left distal gracilis at the myotendinous junction, as well as pes anserine bursal distention. She received physical therapy and underwent a 1-time...
Blikslager AT, Bristol DG.A 3-month-old foal was examined because of lameness and fracture of the left lateral trochlear ridge of the femur. Arthroscopy of the left femoropatellar joint was elected. After induction of general anesthesia and placement of the foal in dorsal recumbency, it was noticed that the left hind limb was extended at the tibiotarsal joint and flexed at the femorotibial joint. Avulsion fracture at the origin of the peroneus tertius tendon was diagnosed. Fracture fragments were excised. The horse had mild left hind limb lameness at the time of follow-up evaluation 1 year after discharge.
Noble P, Lejeune JP, Caudron I, Lejeune P, Collin B, Denoix JM, Serteyn D.Whereas the effect of heel configuration on the tension of the suspensory apparatus is well documented in the literature, there are few reports of joint contact force components in the equine distal forelimb. Objective: To improve understanding of the effect of heel configuration on equine digit joint loading, a sensitivity analysis was performed to compare the effect of a raised heel on joint contact force components in the coffin and fetlock joints during the stance phase of the trot. Methods: Four Warmblood horses were used. An inverse dynamic analysis was carried out using kinematic and ki...
Schnewlin M, Lischer C.This article gives a general overview on a new therapy in equine orthopedics. In human medicine extracorporal shock wave therapy (ESWT) is used for lithotripsy of stones of the urologic system and also in orthopedics. In equine medicine the therapy is almost exclusively applied for the treatment of orthopedic problems. The main indications are proximal suspensory desmitis (PSD), lesions of tendons and ligaments, osteoporotic changes and spavin. In this paper the mode of action of shock waves and the different shock wave devices are discussed. Also, some information about an ongoing clinical tr...
Hago BE, Vaughan LC.Contrast radiography was used to determine the position, shape, relationship and capacity of a number of tendon sheaths and bursae which have clinical significance in the horse. It was possible to establish the normal range of radiographic anatomy for these structures. Some variation in the extent and form of tendon sheaths were found between individual horses and between foals and adults.
Norrie RD.The concept of regenerative healing has been used to manipulate the healing process in experimental animals and clinically to augment bone healing in people after orthopedic operation. An implanted electrical device was used in an attempt to produce regenerative healing in experimentally created equine tendon injury. The bimetallic electrical implant did not produce regenerative healing under the conditions of this experiment. The mechanism of implantation and discussion of the results are included.
Cuevas-Ramos G, Cova M, Arguelles D, Prades M.The function of the popliteal muscle and tendon in horses remains undescribed. In humans, it is considered a stabilizer of the posterior-lateral region of the knee; its function is closely related to that of the lateral collateral ligament (LCL) and meniscus. The popliteal tendon (PopT) constitutes the main proximal attachment of the popliteus muscle to the femur, and in humans, insertional variations have been described. Knowledge of anatomical variations is needed for the correct interpretation of diagnostic images and arthroscopic findings. To elucidate further the anatomy of the equine Pop...
Knudsen O.The paper briefly describes the percutaneous tendon splitting operation as performed in general practice and evaluates its effectiveness on the basis of races run during a 2 year follow-up period. The results are compared with similar figures for normal Standardbred trotters. A higher percentage of horses subjected to splitting of the suspensory ligament failed to remain sound long enough to run more than 10 races during the follow-up period. The percentage of horses returning to racing whose superficial flexor was operated upon was somewhat lower than the control group.
Buchner HH, Savelberg HH, Becker CK.An analysis of joint moments was used to study the biomechanical implications, load redistribution and kinematic pattern following desmotomy of the accessory ligament of the deep digital flexor tendon (AL) in adult horses. Recordings of 6 sound horses were made before and 10 days after desmotomy of the AL of the right forelimb at the walk and the trot. Kinematic recordings of the right forelimb and the left distal forelimb were made using the CODA-3 system. Kinetic recordings of the ground reaction forces in both forelimbs were made using a Kistler force plate simultaneously with the kinematic...
Brown MP, Pool RR.Braided carbon fiber sutures were used to repair surgically transected or lacerated digital flexor tendons of 20 mature horses (10 experimental and 10 clinical cases). In addition, 4 experimental horses had tenectomies that were not surgically repaired; these served as controls for the horses with carbon-implanted tendons. Six of the 10 clinically affected horses were returned to their intended use; 2 were euthanatized because of complications and 2 were still recuperating. The experimental horses were euthanatized at 12 days and 1, 2, 4, 8, and 12 months. Tendon scars were structurally and fu...
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...
Goodship AE, Brown PN, Yeats JJ, Jenkins DH, Silver IA.The results of an assessment of carbon fibre for biological use are given, with particular reference to the clinical use of the material in the treatment of equine tendon injury. Biocompatability of the fibres is assessed using fibroblast cell cultures and replacement of normal tendon with carbon fibre prostheses in experimental animals. The rationale and technique for using this material in clinical cases of tendon injury in the racehorse are described. Results are given from 62 implant operations in a limited series of 40 horses.
Clayton HM, Schamhardt HC, Willemen MA, Lanovaz JL, Colborne GR.To determine whether analysis of net joint moments and joint powers is a suitable technique for evaluation of mechanics and energetics of lameness in horses and to measure effects of superficial digital flexor tendinitis. Methods: 6 sound horses. Methods: Horses were evaluated before (sound evaluation) and after (lame evaluation) induction of superficial digital flexor tendinitis in 1 forelimb by injection of collagenase. Recordings were made with an optoelectronic system and a force plate as horses trotted. Net joint moments and joint powers in the sagittal plane at each joint in the forelimb...
Chesen AB, Dabareiner RM, Chaffin MK, Carter GK.To determine clinical signs, ultrasonographic findings, and outcome of horses with tendinitis of the proximal portion of the superficial digital flexor tendon (SDFT; group A horses) and to compare signalment, horse use, and outcome in these horses with that of horses with tendinitis of the midmetacarpal region of the SDFT (group B horses). Methods: Retrospective case series. Methods: 12 group A horses and 22 group B horses. Methods: Medical records were reviewed for signalment, horse use, and outcome information; data for group A horses also included severity of lameness, diagnostic results, a...
Kohama M, Nio J, Hashimoto Y, Iwanaga T.The intimal lining cells of the synovium in joints have been studied morphologically and histochemically and shown to consist of macrophagic cells (type A) and fibroblast-like cells (type B). It is believed that the structure of the synovium in the tendon sheath is similar to that in the joint, but there have been only a few morphological studies of the tendon sheath. The present study revealed the cellular architecture of synovium in the tendon sheath of horses by histochemistry and scanning electron microscopy (SEM). Like the joint, the inner surface of the tendon sheath was covered with a c...
Spadari A, Spinella G, Romagnoli N, Valentini S.Rupture of the lateral lobe of the proximal tendon of the biceps brachii muscle was diagnosed in an Arabian horse. To the authors' knowledge, this is the only report of this condition in horses. Although clinical signs were helpful in the identification of the location of disease, ultrasonographic examination was a more definitive and non- invasive means of diagnosing the pathological condition. Bursoscopic examination of the intertubercular bursa was also useful in obtaining confirmation of the diagnosis, and for debridement and lavage of the bursa.
Shoemaker RS, Bertone AL, Mohammad LN, Arms SW.Effects of longitudinal compression before and after transection of the accessory ligament of the superficial digital flexor (SDF) muscle were measured in eight equine cadaver forelimbs. When compression was increased from 890 N to 3115 N, the metacarpophalangeal (MCP) and carpal joints hyperextended 20 degrees and 4 degrees, respectively, and strain in the SDF and deep digital flexor tendons was increased 3.5% and 1.4%, respectively. The accessory ligament did not elongate. Immediately after transection of the accessory ligament at 3115 N load, a 2.8 mm gap formed between the transected ends ...
Vilar JM, Rivero MA, Arencibia A, Morales I, Pinedo M.The authors propose a standard protocol of ultrasonographic exploration of the tarsal region in transversal and longitudinal planes, with the aim to spread with an accurate location of the anatomical structures. For this study, 10 adult horses of different races and ages (ranged 5-10 years) were used, with the characteristic of not having suffered any kind of tarsic pathology. The equipment was a real time ultrasound machine with a 7.5 mHz lineal transducer. Some different anatomical structures in this region of the hind-limb such as the tendons, ligaments, muscles and articular components wer...
Koch DW.Our understanding of tendon homeostasis and repair following injury has made great strides through basic science, clinical veterinary medicine, and preclinical translational research. We have now gleaned a greater understanding of the cellular and matrix dynamics that are being orchestrated within the tendon, which provide therapeutic opportunities. This article will focus on how utilizing the horse and equine tissues have advanced our understanding of tendinopathy and the cellular and matrix dynamics at play while also identifying continued gaps in our knowledge where the horse as a veterinar...
Horne CR, Redding WR.The location of a suspensory ligament (SL) injury heavily influences the clinical presentation, prognosis, and treatment options. Diagnostic imaging is necessary to provide an accurate diagnosis and is critical to ensure the institution of the most appropriate treatment. The hindlimb proximal SL in particular can be challenging to diagnosis, carries a guarded prognosis, and typically requires aggressive treatment to achieve soundness.
Spriet M, Zwingenberger A.Hyperintense signal is sometimes observed in ligaments and tendons of the equine foot on standing magnetic resonance examination without associated changes in size and shape. In such cases, the presence of a true lesion or an artifact should be considered. A change in position of a ligament or tendon relative to the magnetic field can induce increased signal intensity due to the magic angle effect. Objective: To assess if positional rotation of the foot in the solar plane could be responsible for artifactual changes in signal intensity in the collateral ligaments of the distal interphalangeal ...
Smith RKW, Schramme MC.Superficial digital flexor tendinopathy is one of the most common orthopedic soft tissue injuries in horses. The veterinary challenge for this condition is less related to identifying the presence of the injury (as it is usually readily evident clinically) but more related to improving the healing process so that the healed tendon is more like normal tendon in biology and function in order to reduce reinjury, which is the key adverse consequence of the injury. Diagnostic imaging has improved in recent years to aid with treatment choices and monitoring the healing process.
Hill AE, Blea JA, Arthur RM, McIlwraith CW.Private-practice racetrack veterinarians in southern California recorded non-fatal injuries meeting defined criteria in Thoroughbreds for 1 year. Injury incidence was 2.29 injury events per 100 horse-months, which was lower than other studies where trainer reported injury data were collected. Of 477 injuries recorded, 344 (72.1%) were acute and 133 (27.9%) were chronic. Fractures were common (47.6% of injuries), with stress fractures accounting for 14% of injuries. Superficial digital flexor tendonitis and suspensory ligament desmitis accounted for 15.3 and 11.5% of injuries, respectively. Agr...
Weaver JC, Stover SM, O'Brien TR.The sites of bony attachment of the tendons, ligaments, and fibrous portion of the joint capsules of the equine metacarpophalangeal (fetlock) joint region were determined by gross dissection. These sites were transposed to standard radiographic views of the fetlock joint to yield illustrations that can be used as an aid in the diagnosis of soft tissue pathology from radiographs. Evidence of direct attachment of the common digital extensor tendon to the proximal phalanx was not found. Branches of the superficial digital flexor tendon were found to insert only on the middle phalanx. The recently...
Lin YL, Brama PA, Kiers GH, van Weeren PR, DeGroot J.The objectives of the present study were to test the hypotheses that: (1) the composition of the extracellular matrix of the equine superficial digital flexor tendon (SDFT) shows great functional similarities with articular cartilage, i.e. that significant differences exist in biochemical composition of differently loaded areas (which in the case of tendons may be more apparent as tendon shows more obvious differences than cartilage); and (2) that, as in articular cartilage, no substantial alterations in biochemical composition take place during ageing once adulthood has been attained. Tendon ...
Cauvin ER, Tapprest J, Munroe GA, May SA, Schramme MC.This study was designed to develop a reliable technique for endoscopic examination of the tarsal sheath of the lateral digital flexor tendon of horses. The anatomy of the tendon sheath and associated structures was studied in detail in cadavers before determining portals for the insertion of an arthroscope into the sheath. Approaches into the sheath through the proximal pouch and through the flexor retinaculum, at the level of the sustentaculum tali, were performed and compared in cadavers. The proximal pouch portal permitted visualisation only of the proximal half of the sheath, while the app...
Chambers JP, Livingston A, Waterman AE, Goodship AE.This study was undertaken to assess the analgesia provided by detomidine (20 micrograms kg-1 intravenously) in thoroughbred horses. Pain thresholds to a mechanical noxious stimulus were measured before and after a period of mild chronic pain in one foreleg. Detomidine was a good analgesic in control animals; their pain thresholds were significantly elevated for about 60 minutes. After injury, the injured leg had a significantly lower pain threshold and the intensity and duration of analgesia provided by detomidine were significantly reduced. The analgesia in the opposite (sound) leg was also r...
