The skeletal system in horses comprises a complex structure of bones that provide support, protection, and mobility. Equine bones are involved in various physiological functions, including mineral storage and hematopoiesis. The bone structure in horses is categorized into different types, such as long bones, short bones, flat bones, and irregular bones, each serving specific roles in movement and stability. Research in this area explores topics such as bone development, remodeling, and the impact of nutrition and exercise on bone health. This page gathers peer-reviewed studies and academic articles that focus on the anatomy, physiology, and pathology of bones in horses, offering insights into conditions such as fractures, bone diseases, and the effects of aging on the equine skeletal system.
Jasiński T, Zdrojkowski Ł, Turek B, Kaczorowski M, Pawliński B, Brehm W, Domino M.Computed tomography (CT) is used to support the diagnosis of equine temporomandibular joint (TMJ) disease; however, its diagnostic accuracy remains unclear. This study aimed to evaluate the relationship between CT findings and histopathological manifestations of osteoarthritis (OA) in equine TMJs. A total of 82 TMJs were CT-imaged, sampled, grouped into age-related and OA-related groups, and analyzed for frequency distributions, correlations, and CT-based TMJ OA diagnosis. CT findings were observed in 79% of joints, including 'CT anatomical variations' considering to reflect age-related remode...
Irandoust S, Malekipour F, Whitton C, Muir P, Lee PVS, Henak C.Condylar stress fracture of the third metacarpal bone (MC3) in Thoroughbred racehorses is a common catastrophic injury and identification of horses at heightened risk remains subjective. Standing computed tomography (sCT) is a practical screening tool that enables patient-specific finite element analysis (FEA) of the distal MC3 and prediction of subchondral bone strain, as a potential objective classifier of racehorses at heightened risk. The goal of this study was to compare two independently developed sCT-based subject-specific FEA pipelines for virtual mechanical testing of the distal MC3. ...
Yilmaz İÇ, Güler T, Ekmen EG, Özçelik M.Boron plays significant roles in various biological systems, including mineral, lipid, and energy metabolism, immune and endocrine systems, and brain function. It has been suggested to enhance performance and may prevent conditions such as osteoporosis, osteoarthritis, and arthritis. Despite these known benefits, its effects on growth performance and mineral metabolism in horses remain understudied, particularly in young animals like Purebred Arabian foals. The primary objective of this study was to investigate the effects of different doses of boron supplementation (0, 5, 10, and 15 mg/day ...
Martin JE, Hecht S, Craig L, Durward-Akhurst SA, Marlowe JL, Hines MT.A 12-year-old pony mare was presented for evaluation of dental disease and nasal discharge. At presentation, clinical signs included bilateral nasal discharge, cutaneous masses, and numerous hard enlargements involving the bones of the skull, maxilla, mandible, and cervical vertebrae. Oral exam revealed advanced dental disease with hard enlargements adjacent to and between numerous cheek teeth. Radiographs and computed tomography confirmed the presence of severe dental disease and proliferative bone lesions disseminated along the skull, hyoid apparatus, and cranial cervical vertebrae. The bony...
Smíšek M, Dvořáková R, Kolon T, Hrnčiarik E, Bíšková J, Hanáček F, Klontza-Jaklová V.To evaluate pathological changes identified in a skeleton of a horse from Roman-period Gerulata, Slovakia. Methods: The remains consist of a partially preserved, articulated skeleton of an adult horse from today's southern urban district of Bratislava-Rusovce in southwestern Slovakia. Methods: The specimen underwent macroscopic analysis to assess taxonomic identification, biological profile, and pathological changes. Thoracolumbar lesions were further evaluated using computed tomography (CT). Radiocarbon dating determined the absolute age of the remains. Results: Species determination indicate...
Vanderbiest L, Rousseau L, Renaville B, Aleman M, Finno C, Milan A, Vinardell T.Occipitoatlantoaxial malformations (OAAM) are developmental disorders occurring at the occiput, atlas and axis. OAAM type 1 is a familial disorder affecting Arabian horses. Currently, a single genetic mutation in the HOXD3 gene region can be tested to confirm the diagnosis. This case describes a 3-year-old Arabian gelding affected with OAAM. Clinical examination revealed a proximal cervical deformation on the right side and severe stiffness of the neck in the sagittal plane without associated pain. Neurological examination demonstrated a generalized proprioceptive ataxia. Radiographs revealed ...
Son JK, De Paz P, Kim J, Sanaei R, Ryu S, Bailey S, Davies HMS.The carpal and third metacarpal (MC3) bones of the equine forelimb undergo morphological adaptation during early growth, influenced by developmental and mechanical factors. However, the longitudinal interactions between dorsal carpal morphology and MC3 structural characteristics have not been fully characterized. Improved understanding of these relationships may help identify morphological indicators associated with bone injury risk before training. Objective: To examine the longitudinal associations between dorsal carpal angular morphology and MC3 diaphyseal parameters in growing Thoroughbred...
Putnoki V, Pollard D, Dyson S, Boros K, Nagy A.There are limited data on sequential computed tomographic (CT) evaluation and objective CT assessment of the metacarpal condyles in Thoroughbred racehorses. This longitudinal study aimed to document changes in attenuation of the metacarpal condyles during the first two years of training and racing. Fan-beam CT examination of the metacarpophalangeal regions was performed on 40 non-lame Thoroughbred yearlings, and repeated four more times, approximately six months apart. Mean Hounsfield Unit (HU) measurements were obtained on sagittal reconstructions of the dorsal and palmar halves of the medial...
Skierbiszewska K, Turek B, Jasiński T, Kaczorowski M, Kozłowska N, Higuchi J, Domino M.Bone grafting in equine medicine offers a promising contribution to treating orthopaedic developmental diseases and chondral, osteochondral and segmental bone defects. Among grafts, synthetic bone substitutes-alloplastics-show favourable biological properties addressing numerous limitations presented by autografts, xenografts and allografts. Objective: To compile and disseminate clinical data and research findings from existing publications on the use of alloplastics in horses. Methods: Systematic review. Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-analysis 202...
Kamr A, Fortin-Trahan R, Arroyo LG, Hostnik LD, Gomez DE, Toribio RE.Hypocalcemia is frequent in horses with colitis. Information on serum parathyroid hormone (PTH) concentrations and its association with bone turnover biomarkers in horses with colitis is lacking. We aimed to determine the association between serum bone resorption biomarkers (C-terminal telopeptide of type I collagen [CTX-I]) and bone formation (osteocalcin [OCN]) with blood PTH, total calcium (tCa), ionized calcium (iCa), phosphorus (Pi), and total magnesium (tMg) concentrations, and mortality in horses with acute colitis. A total of 163 horses were divided into colitis (n = 127) and healt...
Folgmann MS, Stock KF, Feige K, Delling U.Current studies on the health status of young German Warmblood stallions are lacking. Objective: To evaluate the prevalence of radiographic findings at licensing examinations of Warmblood candidate stallions and quantify the environmental influences on the distribution of recorded findings. Methods: In this retrospective observational study, records of 1693 radiographic examinations performed on 1678 German Warmblood stallions presented for licensing in 2018-2020 were reviewed. Data were provided by all German Warmblood horse-breeding associations and their official veterinarians. The collecti...
Hall NP, Sweeney DM, Holmströem M, Kim W, Wang Y, Donahue KD, Palmer SE, Lambert DH, Bayly WM.To determine whether targeted lesion-specific algorithms developed from data collected with accelerometer-based inertial measurement units worn by racing Thoroughbreds could retrospectively identify horses at high risk of incurring forelimb condylar or proximal sesamoid fractures. Unassigned: Fracture-specific algorithms were generated from July 2021 to December 2024 with accelerometer data from 42,623 races by 15,755 horses, including 54 races by 23 horses that subsequently suffered condylar fractures and 90 races by 31 horses that later sustained proximal sesamoid fractures. Fracture-specifi...
Ahmed HT, Berner D, Zhang Q, Verheyen K, Llabres-Diaz F, Peter VG, Chang YM.Fractures are a leading cause of morbidity and mortality in Thoroughbred racehorses, posing a significant threat to their welfare and careers. This study introduces a deep learning model specifically designed to facilitate fracture detection in equine athletes. By leveraging extensive training on human fracture data and refining the model with equine imaging, it highlights the transformative potential of transfer learning across species and medical contexts. This approach is not limited to equine fractures but could be adapted for use in detecting injuries or conditions in other veterinary spe...
DeClue A, Workman K, May-Davis S.To date, radiographically identifying the bony landmarks relevant to diagnosing the complete C6 aplasia of the caudal lamina ventralis (C6 aCLV4) has not been described. Furthermore, a gross study has identified C6 aCLV4 as the main correlation between transposition of the CLV from C6 to C7, where coinciding neck pain was commonly reported. This study aimed to identify C6 aCLV4 in radiographs, where the outcome might benefit equine practitioners in isolating neck pain. Initially, the relevant bony landmarks were radiographically determined from a normal C6 by applying a lateral 30° dorsal-ven...
Karastoyanova N, Stamberov P, Nikolova S, Leshtakov P.To assess pathological lesions observed in an Early Iron Age (8th-century BCE) horse to gain insight into equine use and management in the past. Methods: The study is based on a nearly complete adult horse skeleton recovered from a pit at an archaeological site near Chirpan, Thracian Valley, southern Bulgaria. The assemblage is radiocarbon dated to the 8th century BCE and represents one of the few well-documented Early Iron Age equine skeletons from Bulgaria. Methods: Preserved skeletal elements were examined macroscopically following standard zooarchaeological and palaeopathological protocols...
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...
Palomino Lago E, Roberts SJ, Orriss IR, Lumsden ES, Guest DJ.Bone is a dynamic tissue that is maintained through the co-ordination of bone resorption and bone formation. An imbalance of these processes can lead to bone disease. In vitro studies of osteoblasts can help to understand bone formation, but primary cells have a limited lifespan in culture. Herein, we report the successful generation of equine immortalized osteoblasts through the stable overexpression of human telomerase reverse transcriptase (hTERT) and Simian virus 40 (SV40) large T-antigen in osteoblasts isolated from trabecular bone taken from the third metacarpal of a two-year-old Thoroug...
Salinas P, Vergara MA, Tapia D.Navicular syndrome (NS) is a chronic, degenerative condition of the equine thoracic limb that compromises the distal sesamoid bone (DSB) and associated structures responsible for stabilization and load absorption during locomotion. Although historically attributed to vascular alterations, its etiology is now recognized as biomechanical, characterized by chronic overload of the deep digital flexor tendon. Conventional diagnostic techniques-radiography, scintigraphy, and ultrasonography-lack the sensitivity and precision required to detect early microarchitectural alterations. This study aimed t...
Brown NL, Irandoust S, Thom EJ, Whitton RC, Henak CR, Muir P.Condylar stress fracture of the third metacarpal bone (MC3) is a common catastrophic injury in Thoroughbred racehorses and is associated with parasagittal groove (PSG) subchondral osteolysis. Standing computed tomography (sCT) imaging enables sensitive identification of this fatigue-induced early subchondral bone injury (SBI), but there is no objective method for identifying racehorses at heightened risk of condylar stress fracture. Objective: To estimate PSG first principal strain in elite Thoroughbred racehorses that have undergone subjective risk assessment using sCT fetlock screening. Meth...
DiBello D, Cassel N, Granacka V, Beard L, Rosado SC, Hill-Thimmesch K, Avellar H.Equine sarcoidosis is an uncommon disease characterized by granulomatous inflammation presenting in a spectrum of body system involvement and severity. Musculoskeletal manifestations are sporadically reported but without correlation between imaging and pathologic findings. In a mature Quarter Horse mare eventually diagnosed with a progressive form of sarcoidosis, phalangeal osteolysis discovered on radiography prompted further evaluation, revealing diffuse, discrete osteolysis throughout the axial skeleton. Due to disease progression, humane euthanasia was elected, and computed tomography and ...
El Brini Z, Mhar I, Bouktaib FE, Piro M, Daniel C, Alyakine H.Working equids are at high risk of musculoskeletal disorders due to strenuous labor, repetitive tasks, and harsh environmental conditions. This retrospective study describes the distribution of radiographically detected musculoskeletal findings in working equids presented to four Society for the Protection of Animals Abroad (SPANA) centers in Morocco, based on 498 animals and 1125 radiographs collected between 2015 and 2022. The study population was mainly composed of horses (78.1%), followed by donkeys (15.3%) and mules (6.6%). Most were males (65.7%), and the majority were between 5 and 15 y...
Goodchild OA, Rosen SN, Mennecart B, Meng J, Tissier J.Perissodactyla, or odd-toed ungulates, are represented today by 16 species of rhinoceroses, tapirs, and horses. Perissodactyls were much more diverse in the past, having a rich fossil record spanning from the earliest Eocene (~56 Ma) to recent, including a myriad of extinct lineages. Despite over a century of study, the inter-relationships of some extinct perissodactyl families remain poorly resolved. New morphological characters are needed to help solve this issue. Recent studies suggest that the ear region, ., the petrosal and the bony labyrinth of the inner ear, is a valuable source of morp...
Gernhardt J, Reuter T, Mählmann K, Schulze N, Lischer CJ.To compare the feasibility and biomechanical stability of two surgical techniques for fixation of vertical plane fractures of the accessory carpal bone (ACB). Methods: Randomized experimental ex vivo study. Methods: Eight equine accessory carpal bones were included in a control group. A total of 20 equine cadaveric forelimbs were randomly assigned into two groups (n = 10 per group). Methods: Vertical plane fractures were created palmar to the extensor sulcus using an oscillating saw. In Group 1 (CS), fractures were stabilized with two 4.5 mm cortical screws in lag fashion. In Group 2 (XP...
Sellke L, Ludewig E, Handschuh S, Witter K.In a previous study on hoof biometry, we found that mathematical correction of measuring results from radiographs did not lead to complete correspondence to computed tomography (CT) results. The present study investigates this finding by comparing 13 measures of six cadaveric equine digits collected with the following workflows: radiographs with 1 and 2 m focus-object distance (FOD) (Xray 1 m/2 m), computed tomography images in planes defined based on anatomical landmarks (CTw), simulated radiographs based on the tomography dataset (virtual 120-mm slabs, Xray Sim) and measurements based ...
Malekipour F, Whitton RC, Muir P, Lee PV.Stress fractures are common in racehorses, with the metacarpophalangeal (MCP) joint being the most frequently affected site as it is subjected to high-magnitude and high-rate cyclic loads during training and racing. These loads lead to repeated compressive stresses, resulting in subchondral bone (SCB) sclerosis, fatigue microcracks, and matrix damage that can progress to parasagittal fractures or palmar osteochondral disease (POD). The present study developed joint-specific 3D FE models and slice-based FE models using standing CT images for three trained racehorses, each presenting distinct SC...
Sohn Y, An SJ, Forbes E, Yoon J, Kim BS, Ryu SH, Lee I.Osteochondritis dissecans (OCD) is a developmental orthopedic condition in young horses. Exercise and management affect OCD development, but the impact of exercise patterns during the 6-12 months growth period remains unclear. This study examined the association between OCD lesions in Thoroughbred foals and irregular exercise patterns. Forty foals wore halter-mounted Global Positioning System devices that recorded velocity every five seconds during turnout. Foals were routinely turned out for approximately 13 h daily, except on rainy days. Radiographs were taken at six and twelve months of a...
Chapple AR, Daglish J, Stover SM, Slipchenko N, Phillips KL.Stress fracture is an important cause of mortality and morbidity in racing Thoroughbreds. Nuclear scintigraphy is the imaging modality of choice for investigating unlocalised stress-related bone remodelling in horses. Stress fractures of the caudal lumbar vertebral column have been previously described in both racing Quarter horses and racing Thoroughbreds post-mortem. There is a lack of literature describing the imaging appearance of vertebral stress fractures in racehorses ante-mortem. Objective: To describe: (1) ante-mortem scintigraphic appearance of presumed thoracolumbar vertebral stress...
Morrice-West AV, Wong ASM, Hitchens PL, Whitton RC.Musculoskeletal injuries (MSI) in racehorses are not typically spontaneous events, but develop gradually through cumulative cycles of loading over time. Stride characteristics can now be recorded with wearable technology, providing opportunity to quantify the skeletal impact of galloping over time. We estimated bone fatigue accumulation based on speed (m/s) and number of strides from n = 3168 race starts by n = 405 Thoroughbreds commencing racing in Tasmania, Australia between 2011 and 2016. The percentage bone fatigue accumulated was divided by various time periods (career, active car...
Papini L, de Preux M, Pauwels F, Missotten J, Van der Vekens E.(1) Background: Cone beam computed tomography (CBCT) is increasingly used in equine practice to diagnose musculoskeletal injuries, including fractures in the distal limb. However, limited detail in the thick cortical bone of the metacarpus/metatarsus hinders accurate diagnosis. In human medicine, the addition of aluminum filters (AF) enhanced image quality while reducing radiation exposure. This study aimed to evaluate the effect of AF on image quality in CBCT scans of equine distal limbs. (2) Methods: Adult equine cadaver limbs were scanned with a mobile CBCT unit using varying tube currents ...
Micheau L, Audigié F, Moiroud C, Jacquet S.Disuse-induced bone loss during stall confinement and immobilization is a major concern in horses because it impairs recovery and increases susceptibility to further injury. Experimental models are needed to evaluate therapeutic options, but most available equine models rely on cast immobilization, which is technically demanding and may be associated with complications. This study aimed to assess a simpler and less restrictive model to induce a quantifiable decrease in bone density in horses. Six French Standardbred horses underwent eight weeks of stall confinement, with a wooden wedge fitted ...
Frisbie DD, Cross MW, McIlwraith CW.Histological measurements of the thickness of non-calcified and calcified cartilage, as well as the subchondral bone plate in five locations on the femoral trochlea and medial femoral condyles of species were used in preclinical studies of articular cartilage and compared to those of the human knee. Cadaver specimens were obtained of six human knees, as well as six equine, six goat, six dog, six sheep and six rabbit stifle joints (the animal equivalent of the human knee). Specimens were taken from the lateral trochlear ridge, medial trochlear ridge and medial femoral condyle. After histopathol...
Rubin CT, Lanyon LE.Galileo (1638) observed that "nature cannot grow a tree nor construct an animal beyond a certain size, while retaining the proportions which suffice in the case of a smaller structure". However, subsequent measurement has shown that limb bone dimensions are scaled geometrically with body size (Alexander et al., 1979a), and that the material properties of their constituent bone tissue are similar in animals over a wide range of body weight (Sedlin & Hirsch, 1966; Yamada, 1970; Burstein et al., 1972; Biewener, 1982). If, as suggested in previous scaling arguments (McMahon, 1973; Biewener, 19...
Frisbie DD, Trotter GW, Powers BE, Rodkey WG, Steadman JR, Howard RD, Park RD, McIlwraith CW.To evaluate the effect of arthroscopic subchondral bone microfracture on healing of large chondral defects in horses. Methods: Short- (4 months) and long-term (12 months) in vivo experimental chondral defect model. Methods: 10 horses, aged 2 to 5 years. Methods: Each horse had a 1 cm2 full-thickness chondral defect created in both radial carpal bones and both medial femoral condyles. One carpus and one femoral condyle of each horse had the subchondral bone plate under the defect perforated using an orthopedic awl. All horses were exercised, five horses were evaluated after 4 months and five ho...
Hillier ML, Bell LS.This review brings together a complex and extensive literature to address the question of whether it is possible to distinguish human from nonhuman bone using the histological appearance of cortical bone. The mammalian species included are rat, hare, badger, racoon dog, cat, dog, pig, cow, goat, sheep, deer, horse, water buffalo, bear, nonhuman primates, and human and are therefore not exhaustive, but cover those mammals that may contribute to a North American or Eurasian forensic assemblage. The review has demonstrated that differentiation of human from certain nonhuman species is possible, i...
Rubin CT, Lanyon LE.Rosette strain gauges were attached to the midshaft of the radius and tibia of two horses and two dogs, which ran on a treadmill through their entire range of speed and gait. The relative magnitudes of the principal strains on the opposite cortices of each bone remained constant through the stance phase of the stride, and their orientation varied by a maximum of only 14 degrees through the entire speed range. The maximum strain rate increased linearly with speed, but the peak strain magnitude was also dependent upon the gait used, increasing incrementally by up to 59% at the transition from wa...
White LM, Sussman MS, Hurtig M, Probyn L, Tomlinson G, Kandel R.To prospectively assess T2 mapping characteristics of normal articular cartilage and of cartilage at sites of arthroscopic repair, including comparison with histologic results and collagen organization assessed at polarized light microscopy (PLM). Methods: Study protocol was compliant with the Canadian Council on Animal Care Guidelines and approved by the institutional animal care committee. Arthroscopic osteochondral autograft transplantation (OAT) and microfracture arthroplasty (MFx) were performed in knees of 10 equine subjects (seven female, three male; age range, 3-5 years). A site of art...
de Parades V, Bouchard D, Janier M, Berger A.Pilonidal disease is a frequent suppurative condition that occurs twice as often in men as in women, usually between the ages of 15 and 30. Pilonidal disease is located beneath the skin of the sacro-coccygeal region. It presents acutely as an abscess under tension while the chronic form gives rise to intermittent discharge from pilonidal sinus(es). Diagnosis is clinical and usually straightforward. In the large majority of cases, treatment is surgical but there is no consensus as to the 'ideal' technique. Acute abscess must be evacuated and an off-midline incision seems preferable. Excision is...
Johnson BJ, Stover SM, Daft BM, Kinde H, Read DH, Barr BC, Anderson M, Moore J, Woods L, Stoltz J.Necropsies were performed on 496 horses that had a fatal injury or illness at a California racetrack during the period February 20th 1990 to March 1st 1992. The primary cause of death was categorised by breed, activity at time of injury or illness and organ system affected. Most of the submissions were Thoroughbred horses (432) and Quarter Horses (46). Most of the injuries occurred while racing (42%) and in training sessions (39%); with fewer non-exercise (12%) and accident (7%) related injuries or illnesses. Musculoskeletal injuries accounted for 83% of the Thoroughbred and 80% of the Quarter...
Boyde A.This review presents findings made in studies of large mammalian bones, especially from racehorse training experiments (2-8 years old, third metacarpal, tarsal) and human autopsy orthopaedic femoral implant retrievals and other human biopsy and autopsy cases. Samples were cleaned to analyse mineralized matrix in three dimensions, or poly methyl-methacrylate embedded and micromilled to delete topography and study the superficial c. 0.5-microm two-dimensional section using quantitative backscattered electron imaging. With experimental implant studies in rabbits, observations were also made in vi...
Bertuglia A, Lacourt M, Girard C, Beauchamp G, Richard H, Laverty S.The role of osteoclasts in osteochondral degeneration in osteoarthritis (OA) has rarely been investigated in spontaneous disease or animal models of OA. Objective: The objectives of the current study were to investigate osteoclast density and location in post-traumatic OA (PTOA) and control specimens from racehorses. Methods: Cores were harvested from a site in the equine third carpal bone, that undergoes repetitive, high intensity loading. Histological and immunohistochemical (Cathepsin K and Receptor-activator of Nuclear Factor kappa-β ligand (RANKL)) stained sections were scored (global an...
Biewener AA.Measurements of the cross-sectional geometry and length of bones from animals of different sizes suggest that peak locomotory stresses might be as much as nine times greater in the limb bones of a 300 kg horse than those of a 0.10 kg chipmunk. To determine if the bones of larger animals are stronger than those of small animals, the bending strength of whole bone specimens from the limbs of small mammals and bipedal birds was measured and compared with published data for large mammalian cortical bone (horses and bovids). No significant difference (P greater than 0.2) was found in the failure st...
Olstad K, Hendrickson EH, Carlson CS, Ekman S, Dolvik NI.To transect blood vessels within epiphyseal cartilage canals and observe whether this resulted in ischaemic chondronecrosis, an associated focal delay in enchondral ossification [osteochondrosis (OC)] and pathological cartilage fracture [osteochondrosis dissecans (OCD)] in the distal femur of foals, with potential translational value to the pathogenesis of juvenile osteochondritis dissecans (JOCD) in children. Methods: Ten Norwegian Fjord Pony foals were operated at the age of 13-15 days. Two vessels supplying the epiphyseal growth cartilage of the lateral trochlear ridge of the left distal fe...
Verheyen K, Price J, Lanyon L, Wood J.In order to gain insight into those training regimens that can minimise the risk of fracture in athletic populations, we conducted a large epidemiological study in racehorses. Thoroughbred racehorses provide a suitable model for studying fracture development and exercise-related risk factors in physically active populations. They represent a homogeneous population, undertaking intensive exercise programmes that are sufficiently heterogeneous to determine those factors that influence injury risk. Daily exercise information was recorded for a cohort of 1178 thoroughbreds that were monitored for ...
Lacourt M, Gao C, Li A, Girard C, Beauchamp G, Henderson JE, Laverty S.To correlate degenerative changes in cartilage and subchondral bone in the third carpal bone (C3) of Standardbred racehorses with naturally occurring repetitive trauma-induced osteoarthritis. Methods: Fifteen C3, collected from Standardbred horses postmortem, were assessed for cartilage lesions by visual inspection and divided into Control (CO), Early Osteoarthritis (EOA) and Advanced Osteoarthritis (AOA) groups. Two osteochondral cores were harvested from corresponding dorsal sites on each bone and scanned with a micro-computed tomography (CT) instrument. 2D images were assembled into 3D reco...
Randall C, Bridges D, Guerri R, Nogues X, Puig L, Torres E, Mellibovsky L, Hoffseth K, Stalbaum T, Srikanth A, Weaver JC, Rosen S, Barnard H....A novel, hand-held Reference Point Indentation (RPI) instrument, measures how well the bone of living patients and large animals resists indentation. The results presented here are reported in terms of Bone Material Strength, which is a normalized measure of how well the bone resists indentation, and is inversely related to the indentation distance into the bone. We present examples of the instrument's use in: (1) laboratory experiments on bone, including experiments through a layer of soft tissue, (2) three human clinical trials, two ongoing in Barcelona and at the Mayo Clinic, and one comple...
Kon E, Muttini A, Arcangeli E, Delcogliano M, Filardo G, Nicoli Aldini N, Pressato D, Quarto R, Zaffagnini S, Marcacci M.The present in vivo preliminary experiment is aimed at testing mechanical and biological behaviour of a new nano-structured composite multilayer biomimetic scaffold for the treatment of chondral and osteochondral defects. The three-dimensional biomimetic scaffold (Fin-Ceramica Faenza S.p.A., Faenza-Italy) was obtained by nucleating collagen fibrils with hydroxyapatite nanoparticles, in two configurations, bi- and tri-layered, to reproduce, respectively, chondral and osteochondral anatomy. Chondral defects (lateral condyle) and deep osteochondral defects (medial condyle) were made in the distal...
Martig S, Chen W, Lee PV, Whitton RC.Musculoskeletal injuries are a common cause of lost training days and wastage in racehorses. Many bone injuries are a consequence of repeated high loading during fast work, resulting in chronic damage accumulation and material fatigue of bone. The highest joint loads occur in the fetlock, which is also the most common site of subchondral bone injury in racehorses. Microcracks in the subchondral bone at sites where intra-articular fractures and palmar osteochondral disease occur are similar to the fatigue damage detected experimentally after repeated loading of bone. Fatigue is a process that h...
Muir P, McCarthy J, Radtke CL, Markel MD, Santschi EM, Scollay MC, Kalscheur VL.The mechanisms that regulate functional adaptation of the articular ends of long bones are poorly understood. However, endochondral ossification of articular cartilage and modeling/remodeling of the subchondral plate and epiphyseal trabeculae are important components of the adaptive response. We performed a histologic study of the distal end of the third metacarpal/metatarsal bone of Thoroughbreds after bones were bulk-stained in basic fuchsin and calcified sections were prepared. The Thoroughbred racehorse is a model of an extreme athlete which experiences particularly high cyclic strains in ...
Reilly GC, Currey JD.During locomotion, the anterior cortex of the equine radius is loaded predominantly in tension, the posterior predominantly in compression. The anterior cortex is relatively strong in tension, the posterior in compression. We investigated the pattern of failure of specimens from the two cortices using laser scanning confocal microscopy. All specimens were loaded in four-point bending to increasingly higher loads. We quantified the amount of diffuse microcracking on the tensile side of these specimens by observing the amount of light emitted under laser illumination. The amount of light emitted...
Nieminen HJ, Ylitalo T, Karhula S, Suuronen JP, Kauppinen S, Serimaa R, Hæggström E, Pritzker KP, Valkealahti M, Lehenkari P, Finnilä M....Collagen distribution within articular cartilage (AC) is typically evaluated from histological sections, e.g., using collagen staining and light microscopy (LM). Unfortunately, all techniques based on histological sections are time-consuming, destructive, and without extraordinary effort, limited to two dimensions. This study investigates whether phosphotungstic acid (PTA) and phosphomolybdic acid (PMA), two collagen-specific markers and X-ray absorbers, could (1) produce contrast for AC X-ray imaging or (2) be used to detect collagen distribution within AC. Methods: We labeled equine AC sampl...
Riggs CM, Vaughan LC, Evans GP, Lanyon LE, Boyde A.Mechanical test specimens were prepared from the cranial and caudal cortices of radii from eight horses. These were subjected to destructive tests in either tension or compression. The ultimate stress, elastic modulus and energy absorbed to failure were calculated in either mode of loading. Analysis was performed on the specimens following mechanical testing to determine their density, mineral content, mineral density distribution and histological type. A novel technique was applied to sections from each specimen to quantify the predominant collagen fibre orientation of the bone near the plane...
Olstad K, Ytrehus B, Ekman S, Carlson CS, Dolvik NI.Pathological changes in the blood supply to growth cartilage have been implicated in the pathogenesis of osteochondrosis (OC) in horses, but have not been reported using vascular perfusion techniques. Objective: To describe the developmental pattern of cartilage canal vessels in the distal tibial epiphysis and talar growth cartilage of foals. Methods: Nine foals bred from parents with OC were sacrificed between the ages of 0 and 7 weeks to undergo a barium perfusion procedure. The distal end of the tibia and the entire talus were cleared in methyl salicylate and perfused vessels studied in the...
Nunamaker DM, Butterweck DM, Provost MT.The North American Thoroughbred racehorse was chosen as a model to study the pathogenesis of fatigue failure of bone. This species has a high incidence of spontaneous fatigue failure of bone (bucked shins) during its early training. In vivo strain gauge studies of the third metacarpal bone of four young racehorses running at racing speeds showed high principal compressive strains [-4,841 +/- 572 (SD) microstrain] while two older horses had lower principal compressive strains (-3,317 microstrain measured at racing speed, -3,250 microstrain extrapolated from a slower speed run). Previously repor...
Mancini IAD, Schmidt S, Brommer H, Pouran B, Schäfer S, Tessmar J, Mensinga A, van Rijen MHP, Groll J, Blunk T, Levato R, Malda J, van Weeren PR.Recent research has been focusing on the generation of living personalized osteochondral constructs for joint repair. Native articular cartilage has a zonal structure, which is not reflected in current constructs and which may be a cause of the frequent failure of these repair attempts. Therefore, we investigated the performance of a composite implant that further reflects the zonal distribution of cellular component both in vitro and in vivo in a long-term equine model. Constructs constituted of a 3D-printed poly(ϵ-caprolactone) (PCL) bone anchor from which reinforcing fibers protruded into ...
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...
Les CM, Keyak JH, Stover SM, Taylor KT, Kaneps AJ.The purpose of this study was to investigate the relationships between data obtained from quantitative computed tomography and mechanical properties in the equine metacarpus, as measured in vitro in bone specimens. Three hundred and fifty-five bone specimens from the metacarpi of 10 horses were machined into right cylinders aligned with the long axis of the bone. A computed tomographic scan of the specimens, along with a Cann-Genant K2HPO4 calibration standard, was obtained. The specimens then were compressed to failure, and the elastic modulus, yield stress, yield strain, strain energy densit...
Parkin TD, Clegg PD, French NP, Proudman CJ, Riggs CM, Singer ER, Webbon PM, Morgan KL.The risk of fatal distal limb fractures in thoroughbreds racing in the UK was calculated and shown to vary considerably between the different types of race. Flat turf racing was associated with the lowest risk (0.4 per 1000 starts) and national hunt flat racing was associated with the highest risk (2.2 per 1000 starts). The types of fracture were classified by detailed radiographic and postmortem examinations of all the cases recorded over two years, and the distribution of the different types of fracture in the five main types of racing was examined. Overall, lateral condylar fractures of the...
Boyde A, Firth EC.To characterise and explain the increase in density evident by computerised tomography (CT) and radiography in companion studies as a response to training, in bone in the palmar and dorsal regions of the condyles of the third metacarpal bone (Mc3) of 2-year-old Thoroughbred horses. Methods: Compositional back-scattered electron (BSE) imaging in scanning electron microscopy (SEM) and confocal scanning laser microscopy (CSLM) were conducted on polymethyl methacrylate (PMMA)-embedded mediolateral slices of the right distal Mc3 from seven 2-year-old Thoroughbred horses trained on a racetrack and s...
