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.
Lizarraga I, Panizzi L, Gieseg MA, Riley CB, Chambers JP.To evaluate thermal nociceptive thresholds (TNTs) before and after inducing a standardized radiocarpal bone osteochondral fracture (OCF) in horses. Methods: Prospective, controlled, randomized, masked study. Methods: A group of 10 Thoroughbred fillies aged 2 years. Methods: Skin temperature and TNTs were measured on the skin over the triceps brachii muscle in both the thoracic limbs before (week 0) and weekly (weeks 1-8) after unilateral arthroscopic induction of a radiocarpal OCF (n = 4) or sham surgery (n = 6) followed by a standardized exercise programme. The contralateral, non-operated t...
Ferrando Meseguer E, Roig Sánchez S, Pino Almero L, Romano Bataller A, Mínguez Rey MF.Talipes equinovarus or clubfoot is a congenital deformity of the foot with bone, muscle, and tendon involvement. It's one of the most frequent foot malformations in pediatric orthopedics. Although generally idiopathic, it may have a syndromic cause and be associated with musculoskeletal, neurological, or connective tissue conditions. The treatment of choice in idiopathic clubfoot is the Ponseti method based on manipulation and fixation with serial casts that seek progressive correction of the deformity. The Ponseti method effectiveness has been demonstrated in arthrogryposis and myelomeningoce...
Shaffer SK, Sachs N, Garcia TC, Fyhrie DP, Stover SM.To assess the motion of the proximal sesamoid bones (PSBs) relative to the third metacarpal bone (MC3) of equine forelimbs during physiologic midstance loads. Methods: 8 musculoskeletally normal forelimbs (7 right and 1 left) from 8 adult equine cadavers. Methods: Each forelimb was harvested at the mid-radius level and mounted in a material testing system so the hoof could be moved in a dorsal direction while the radius and MC3 remained vertical. The PSBs were instrumented with 2 linear variable differential transformers to record movement between the 2 bones. The limb was sequentially loaded ...
Lee AKK, Uhl EW, Osborn ML.Therapies based upon whole-body biomechanical assessments are successful for injury prevention and rehabilitation in human athletes. Similar approaches have rarely been used to study equine athletic injury. Degenerative osteoarthritis caused by mechanical stress can originate from chronic postural dysfunction, which, because the primary dysfunction is often distant from the site of tissue injury, is best identified through modeling whole-body biomechanics. To characterize whole-body equine kinematics, a realistic skeletal model of a horse was created from equine computed tomography (CT) data t...
Ramírez A CE, Hurtado-Macías A, Talamantes R, Flores E, Ladrón de Guevara HP, Delgado JI, Estrella RA, Riestra JM, Montes JM, Esmonde-White K....Guided bone regeneration surgeries are based on grafting a scaffold in the site to be repaired. The main focus of the scaffold is to provide mechanical support to newly formed blood vessels and cells that will colonize the grafted site, achiving bone regenertation. In this regards, the aim of this study was to characterize the anatomy, structular, surface morphologycal, chemical composition, and nanomechanical properties of ostrich and equine trabecular bone. Ostrich and equine specimens were obtained from a local abattoir and bone was obtained by blunt dissection, n = 5. Tissue bone anatomy...
Shan R, Johnston AS, Rosanowski SM, O'Shea J, Riggs CM.Transverse stress fracture of the palmar cortex of the distal aspect of the third metacarpal bone (TSF PCD McIII) is poorly documented. Objective: To describe the typical signalment of this injury, the common clinical and radiological signs and prognosis. Methods: A retrospective hospital-based case series with follow-up of racing records. Methods: All cases of TSF PCD McIII diagnosed among racehorses in training at the Hong Kong Jockey Club between 2011 and 2019 were identified. Clinical records were reviewed and documented signs were recorded for each case. Findings from a predefined list of...
Tucker R, Hall YS, Hughes TK, Parker RA.Computed tomography (CT) imaging of the cervical spine of mature horses under general anaesthesia is becoming increasingly accessible. Osteochondral fragmentation (OF) of the cervical articular process joints (APJs) has been identified on CT imaging; the prevalence, clinical features and significance of this finding are currently unknown. Objective: To describe the prevalence and clinical features of a population of horses with CT evidence of OF within the cervical APJs. Methods: Retrospective, descriptive case series. Methods: The study population consisted of all horses undergoing CT imaging...
Lee MC, Seonwoo H, Jang KJ, Pandey S, Lim J, Park S, Kim JE, Choung YH, Garg P, Chung JH.Hydroxyapatite (HA) is a representative substance that induces bone regeneration. Our research team extracted nanohydroxyapatite (EH) from natural resources, especially equine bones, and developed it as a molecular biological tool. Polyethylenimine (PEI) was used to coat the EH to develop a gene carrier. To verify that PEI is well coated in the EH, we first observed the morphology and dispersity of PEI-coated EH (pEH) by electron microscopy. The pEH particles were well distributed, while only the EH particles were not distributed and aggregated. Then, the existence of nitrogen elements of PEI ...
Johnston GCA, Ahern BJ, Woldeyohannes SM, Young AC.Equine advanced imaging research involving racehorse fetlock pathology commonly uses cadaver limbs and a freeze-thaw process. The presence of short tau inversion recovery (STIR) signal intensity in the distal third metacarpal/metatarsal bone is of particular interest and may be clinically relevant in the diagnosis of horses at risk of fracture. However, little is known about the effect of the freeze-thaw process on the MRI appearance of STIR hyperintensity in these bones. This study compares the low-field MRI appearance of the distal third metacarpal/metatarsal bone from cadaver limbs of Thoro...
Logan AA, Nielsen BD.Conflicting research and anecdotal evidence have created disagreement among equestrians as to whether two-year-old horses should be trained and raced. The objective of this literature review is to evaluate epidemiological studies, as well as physiological data on equine bone, articular cartilage, and tendons to better determine the impact of training and racing two-year-old horses. The evaluation of numerous studies on the topic provides evidence that a horse which is trained or raced as a two-year-old has a lower risk of injury and better adapted tissues for the rigors of racing. Unfortunatel...
Logan AA, Nielsen BD, Manfredi JM, Robison CI.Short sprints performed during growth can increase bone strength, mineral density, and cortical widths, but their impact on joint health is not fully understood. Some studies have found joints of young animals are damaged by forced sprints, while others found confinement hindered joint development. This study aimed to determine the impact of short sprints on synovial fluid neopeptide collagenase cleavage of type I and II collagen (C1,2C) and cartilage glycosaminoglycan (GAG) content. Calves were used as a model for young horses in this terminal study. Twenty-four Holstein bull calves were assi...
Curtiss AL, Ortved KF, Dallap-Schaer B, Gouzeev S, Stefanovski D, Richardson DW, Wulster KB.Subchondral bone pathology is common in Thoroughbred racehorses and believed to precede more serious injury. Early identification of pathology is critical to allow for intervention. Objective: To determine interobserver variability of fetlock subchondral bone lesions using cone beam and fan beam computed tomography (CBCT, FBCT) and to validate a robotics-controlled CBCT to identify fetlock subchondral bone pathology in the Thoroughbred racehorse. Methods: Prospective cohort study. Methods: FBCT and CBCT images were acquired of 25 metacarpo-/metatarsophalangeal joints of Thoroughbred racehorses...
Fang J, Zhang D, Cao JW, Zhang L, Liu CX, Xing YP, Wang F, Xu HY, Wang SC, Ling Y, Wang W, Zhang YR, Zhou HM.The mechanism of body growth in mammals is poorly understood. Here, we investigated the regulatory networks involved in body growth through transcriptomic analysis of pituitary and epiphyseal tissues of smaller sized Debao ponies and Mongolian horses at the juvenile and adult stages. Results: We found that growth hormone receptor (GHR) was expressed at low levels in long bones, although growth hormone (GH) was highly expressed in Debao ponies compared with Mongolian horses. Moreover, significant downregulated of the GHR pathway components m-RAS and ATF3 was found in juvenile ponies, which slow...
Ravanetti P, Hamon M, Lechartier A, Zucca E.Surgical repair of unicortical fractures of the distal condyles of the third metacarpal/metatarsal bones (MCIII/MTIII) has been described. In the present case, a bioabsorbable screw was used to stabilize a unicortical fracture in the palmar aspect of the medial condyle of MCIII in a National Hunt Thoroughbred racehorse. The clinical, radiographic, and magnetic resonance imaging findings before and after surgery were recorded. Eighteen weeks after surgery, the lameness had resolved and the bone surrounding the fracture had recovered its normal architecture. One year after surgery, the horse was...
Izing S, Béni D, Molnár S, Bakos Z, Bodó G.The objectives of this in vivo experimental study were to evaluate the feasibility of cortical screw insertion into the intact distal phalanx in standing sedated horses and to document potential postoperative complications. One cortical screw was randomly inserted in lag fashion into each distal phalanx in 9 horses. The second surgery on the contralateral limbs was performed 2-3 weeks after the first operation, when a 4.5-mm cortical screw was inserted in lag fashion into the distal phalanx of sedated horses following perineural analgesia. Following surgery, the drill hole was filled with an a...
Biedrzycki AH, Kistler HC, Perez-Jimenez EE, Morton AJ. The aim of this study was to evaluate the surgical execution of a virtual surgical plan (VSP) with three-dimensional (3D) guides against a freehand approach in the equine navicular bone using an automated computer analysis technique. Methods: Eight pairs of cadaveric forelimb specimens of adult horses were used in an experimental study design with modelling. Limbs received either a 3.5 mm cortical screw according to a VSP or using an aiming device. Using computed tomography and computer segmentation, a comparison was made between the executed screw and the planned screw using the Ha...
Espinosa-Mur P, Phillips KL, Galuppo LD, DeRouen A, Benoit P, Anderson E, Shaw K, Puchalski S, Peters D, Kass PH, Spriet M.Cervical osteoarthritis (OA) has been documented as a potential source of pain and poor performance in sport horses. Objective: To assess the prevalence of cervical OA in a population of Warmblood jumpers and its correlation with age, level of performance, neck pain and mobility. Methods: Descriptive observational study. Methods: Warmblood jumpers free of lameness or neurological disorders were selected. Cervical pain and range of motion of the neck were subjectively assessed. Left to right lateral views were taken at C3-C4, C4-C5, C5-C6 and C6-C7. The presence of OA at the cervical articular ...
Pauwels FE, Van der Vekens E, Christan Y, Koch C, Schweizer D.To report on the feasibility, indications, and diagnostic yield of cone beam computed tomography (CBCT) of horses' extremities performed under standing sedation. Methods: Retrospective clinical case series. Methods: Fifty-nine CBCT examinations in 58 horses. Methods: Examinations were categorized for indications for CBCT dependent on a suspicion, presence, or absence of a diagnosis prior to CBCT. The number of acquisitions per examination, total time for the examination, diagnostic score of each acquisition (diagnostic, diagnostic-compromised, nondiagnostic), and additional diagnostic informat...
Nottle BF, Tatarniuk DM, Caldwell FJ, Bell CD, Caston SS, Merkatoris PT, Gillen AM, Katzman SA.To describe the presentation, diagnosis, treatment, and outcome for horses with fibro-osseous lesions of the craniofacial complex. Methods: Retrospective multicenter case series. Methods: Thirty horses evaluated for fibro-osseous lesions of the skull from January 1, 2001 through December 31, 2019 in four centers. Methods: Medical records were reviewed for signalment, clinical presentation, histological and diagnostic imaging findings, treatment instituted, and outcome. Long-term outcome information was obtained by owner questionnaire or the medical record. Results: Diagnoses included ossifying...
Olusa TAO, Davies HMS.Finding an appropriate location for perpendicular positioning of the X-ray machine to produce zero lateromedial (ZLM) and zero dorsopalmar (ZDP) carpal images (views) and finding an acceptable range of rotational variations for measurement of carpal conformational parameters were two major challenges identified during field radiography of equine forelimbs. 16 cadaver forelimbs transacted at antebrachial midshaft from 10 horses (aged 9.13 ± 4.59 years) were axially mounted into a custom-built frame, and the radiographic machine and plate were perpendicularly aligned with the limb. Each limb...
Sarin JK, Te Moller NCR, Mohammadi A, Prakash M, Torniainen J, Brommer H, Nippolainen E, Shaikh R, Mäkelä JTA, Korhonen RK, van Weeren PR, Afara IO....To assess the potential of near-infrared spectroscopy (NIRS) for in vivo arthroscopic monitoring of cartilage defects. Sharp and blunt cartilage grooves were induced in the radiocarpal and intercarpal joints of Shetland ponies and monitored at baseline (0 weeks) and at three follow-up timepoints (11, 23, and 39 weeks) by measuring near-infrared spectra in vivo at and around the grooves. The animals were sacrificed after 39 weeks and the joints were harvested. Spectra were reacquired ex vivo to ensure reliability of in vivo measurements and for reference analyses. Additionally, cartilage thickn...
Ayodele BA, Hitchens PL, Wong ASM, Mackie EJ, Whitton RC.Proximal sesamoid bone fractures are common catastrophic injuries in racehorses. Understanding the response of proximal sesamoid bones to race training can inform fracture prevention strategies. Objective: To describe proximal sesamoid bone microstructure of racehorses and to investigate the associations between microstructure and racing histories. Methods: Cross-sectional. Methods: Proximal sesamoid bones from 63 Thoroughbred racehorses were imaged using micro-computed tomography. Bone volume fraction (BVTV) and bone material density (BMD) of the whole bone and four regions (apical, midbody d...
Sage SE, Olive J, Lavoie JP.Age of complete ossification of equine occipital condyles has not been published. Consequently, clinical significance of occipital condyle defects on radiographs or CT scans of young horses remains unknown. The goals of this single-center, retrospective, cross-sectional study were to characterize incidental occipital condyle defects and to define the age of complete ossification. The margin of occipital condyles was classified as regular or with defect(s). Analyses were made on 121 horses, including 106 radiographic and 19 CT studies showing the occipital condyles of horses less than 5 years o...
Brown KA, Davidson EJ, Johnson AL, Wulster KB, Ortved K.Standing cone beam computed tomography (CT) provides cross-sectional imaging of the caudal cervical articular process joints (CAPJs) in the sedated horse, though the clinical implications of osteoarthritis (OA) identified on CT in this location are unknown. Increases in concentrations of intra-synovial cytokines could lend support to the clinical significance of CAPJ OA identified on this imaging modality. Objective: Investigate the presence and concentration of intra-synovial inflammatory cytokines in CAPJs with and without standing cone beam CT evidence of OA using an equine specific multipl...
Jaworski K, Pankiewicz A, Chrószcz A, Poradowski D.The following article concerns the functional use of horse bones in the early Middle Ages (mainly in the period from the mid of the 10th to the 12th/13th century). The authors try to explain how such remains were used and how common it was. It is also discussed whether the special role of the horse in medieval societies somehow restricted its post-mortem usage, or perhaps there was no difference between the skeletal remains of horses and other species in this regard. For this purpose, statistical calculations on the use of the bones of various mammals were made. Only the remains of the species...
Johnson KL, Hespel AM, Price JM, de Swarte M.Radiology can be a challenging subject for students and finding new techniques that help improve their understanding could have positive effects in their clinical practice. The purpose of this prospective experimental study was to implement the use of color-coded, three-dimensional-printed, handheld equine carpus models into a radiographic anatomy course and evaluate the impact objectively and subjectively using quizzes and student response surveys. A first-year veterinary class was randomly divided into two similarly sized groups (groups A and B) for an equine normal radiographic anatomy labo...
Pritchard A, Nielsen BD, Robison C, Manfredi JM.As osteoarthritis is a major cause of lameness in horses in the United States, improving collagen health prior to onset and increasing collagen turnover within affected joints could improve health- and welfare-related outcomes. Through its positive effects on bone mineral content and density and its role in increasing collagen synthesis, silicon (Si) may slow the development and progression of osteoarthritis, thereby reducing lameness. This study evaluated the hypothesis that Si supplementation would increase cartilage turnover through increased collagen degradation and formation markers, as w...
Olusa TAO, Ismail SMY, Murray CM, Davies HMS.Carpal conformation is often considered as a contributory factor to performance and lameness in the horse; however, few attempts have been made to objectively measure radiographic variations of carpal conformation in horses due to insufficient measurable carpal parameters. This pilot study used carpal radiographic images acquired from 10 cadaveric equine forelimbs transected at the antebrachial midshaft from 7 adult horses (7.2 ± 2.6 years), positioned at 'zero lateromedial' (ZLM) and 'zero dorsopalmar' (ZDP) views, to investigate the anatomy of the equine carpus and develop parameters tha...
Li Y, Zhang C, Taylor WTT, Chen L, Flad RK, Boivin N, Liu H, You Y, Wang J, Ren M, Xi T, Han Y, Wen R, Ma J.Horseback riding was a transformative force in the ancient world, prompting radical shifts in human mobility, warfare, trade, and interaction. In China, domestic horses laid the foundation for trade, communication, and state infrastructure along the ancient Silk Road, while also stimulating key military, social, and political changes in Chinese society. Nonetheless, the emergence and adoption of mounted horseback riding in China is still poorly understood, particularly due to a lack of direct archaeological data. Here we present a detailed osteological study of eight horse skeletons dated to c...
Kirkland KD, Baker GJ, Manfra Marretta S, Eurell JA, Losonsky JM.To document age-related changes in the morphology of the endodontic system, reserve crown, and roots of equine mandibular cheek teeth. Methods: Equine mandibular cheek teeth from horses of various ages were compared, using radiography, x-ray computed tomography, and histologic examinations. Methods: 48 right hemi-mandibles from horses 2 to 9 years old. Methods: Hemi-mandibles were radiographed, imaged by computed tomographic reconstruction, and reformatted. Histologic examination was used to identify and correlate tissue types. Results: Permanent mandibular cheek teeth of the horse, at the tim...
Sleutjens J, Voorhout G, Van Der Kolk JH, Wijnberg ID, Back W.In dressage, the head and neck position has become an issue of concern as certain extreme positions may imply a welfare risk for the horse. In man, extension and flexion of the cervical spine cause a decrease and increase in intervertebral foramina dimensions, respectively. However, in horses, the influence of flexion and extension on foramina dimensions and its possible interference with peripheral nerve functioning remains unknown. Objective: To determine the effect of ex vivo flexion and extension on intervertebral foramina dimensions in the equine cervical spine. Methods: Computed tomograp...
Haire TJ, Hodgskinson R, Ganney PS, Langton CM.The purpose of this study was to compare the structural parameters of fabric and fractal dimension as predictors of the Young's modulus of equine cancellous bone. Eight 15 mm cubes of cancellous bone were obtained from three equine third metacarpal bones. Young's modulus was determined for the three orthogonal directions. The fabric and fractal dimension were calculated for each of the six exposed faces of each cube. Fractal dimension plus porosity provided a higher explanatory power for Young's modulus (R2 = 78.7%. P < 0.0001) than fabric plus porosity (R2 = 69.2%, P < 0.0001). Fractal ...
Shaffer SK, To C, Garcia TC, Fyhrie DP, Uzal FA, Stover SM.Proximal sesamoid bone (PSB) fracture is the most common fatal injury in Thoroughbred (TB) racehorses in the United States. Epidemiological and pathological evidence indicates PSB fracture is likely the acute culmination of a chronic stress-related process. However, the aetiopathogenesis of PSB fracture is poorly understood. Objective: To characterise bone abnormalities that precede PSB fracture. Methods: Two retrospective case-control groups of PSBs from TB racehorses with, and without, unilateral biaxial PSB fracture. Methods: Proximal sesamoid bones were harvested post-mortem from TB raceho...
Pool RR, Meagher DM, Stover SM.Navicular syndrome is a degenerative disorder of the distal half of the flexor surface of the proximal sesamoid bone that is predisposed by faulty foot conformation. In horses that become symptomatic, the faulty conformation results in sustained application of nonphysiologic pressure by the deep digital flexor tendon against the flexor cortex of the bone. This force stimulates an intense bone remodeling response in order to attenuate the pressure. An unfortunate sequela of this response is active hyperemia and edema formation in the medullary cavity of the bone. The edema is organized by fibro...
Smith MA, Dyson SJ, Murray RC.The appearance of the equine metacarpophalangeal (MCP) joint on high-field (1.5 T) vs. low-field standing (0.27 T) magnetic resonance (MR) images was evaluated. Objectives were (1) to describe the MR appearance of anatomic structures of clinical interest on images of the equine MCP joint obtained from 20 equine cadaver limbs from horses without lameness using high-field and low-field systems, (2) to categorize the clarity of appearance of anatomic structures on low-field MR images in comparison to high-field images as a gold standard. We found that larger anatomic structures were visible with ...
Billinghurst RC, Brama PA, van Weeren PR, Knowlton MS, McIlwraith CW.To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. Methods: 43 Dutch Warmblood foals with varying severity of osteochondrosis. Methods: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined...
Loughridge AB, Hess AM, Parkin TD, Kawcak CE.Changes in subchondral bone density, induced by the repetitive cyclical loading of exercise, may potentiate fatigue damage and the risk of fracture. Objective: To use computed tomography (CT) to characterise bone density patterns at the articular surface of the third metacarpal bone in racehorses with and without lateral condylar fractures. Methods: Case control METHODS: Computed tomographic images of the distal articulating surface of the third metacarpal bone were obtained from Thoroughbred racehorses subjected to euthanasia in the UK. Third metacarpal bones were divided into 3 groups based ...
De Angelis N, Scivetti M.This paper reports on a patient who underwent horizontal ridge augmentation using recombinant human platelet-derived growth factor BB (rhPDGF-BB) in combination with a collagenate equine block. Ninety days after the first surgery, 8 mm of new bone was noted on a computed tomography scan, and three 5-mm implants were placed. Histology, performed using confocal laser scanning microscopy, showed a large amount of newly formed bone well characterized with osteon and resorption lacunae, which demonstrated the intense bone remodeling. This study supports the use of rhPDGF-BB in combination with allo...
McCarthy RN, Jeffcott LB, McCartney RN.Ultrasound speed, as measured by a transmission technique in equine cortical bone, was found to vary markedly with the direction of the ultrasound path through the bone. Using bone samples from the mid-site of the third metacarpus of 20 horses, the ultrasound speed was measured as 4125 m s-1 in the longitudinal direction, 3442 m s-1 in the circumferential or transverse direction, and 3428 m s-1 in the radial direction. These results confirm the anisotropic properties of compact bone. Ultrasound speed had a positive linear relationship when compared with bone specific gravity of cortical bone (...
Mori R, Kodaka T, Sano T, Yamagishi N, Asari M, Naito Y.Laminar bone or primary plexiform tissue, not Haversian bone, shows an alternative concentric pattern of laminar-bone units or plates around the bone marrow periphery of long bones, although the laminar bone is gradually replaced by osteons during the growth period. One laminar-bone unit is constructed with a hypercalcified line in the center, woven bone on both sides of the line, and lamellar bone with laminated appositional lines. Such a laminar bone showing a homogeneous calcification has been reported in young calves and some young large animals, but it has not been reported in foals altho...
Peloso JG, Cohen ND, Vogler JB, Marquis PA, Hilt L.OBJECTIVE To compare bony changes of the third metacarpal bone (MC3) of Thoroughbred racehorse cadavers with (cases) or without (controls) catastrophic condylar fracture by use of standing MRI. SAMPLE 140 forelimbs from 26 case horses (both forelimbs) and 88 control horses (single forelimb). PROCEDURES Bone marrow lesions (BMLs), identified as a decrease in T1-weighted (T1W) signal and increases in T2*-weighted (T2*W) and short tau inversion recovery (STIR) signals, and dense bone volume percentage (DBVP), identified as decreases in T1W, T2*W, and STIR signals, in the distopalmar aspect of MC3...
Whitton RC, Walmsley EA, Wong ASM, Shannon SM, Frazer EJ, Williams NJ, Guerow JF, Hitchens PL.Long bone fractures in racehorses may present as stress fractures which have a good prognosis, or complete fractures, which often result in a fatal outcome. In order to identify differences in modifiable management practices that may contribute to these outcomes, racing histories of horses with humeral or tibial fractures and of matched controls were examined. A retrospective case-control study of Australian Thoroughbred racehorses diagnosed with a fracture of the humerus or tibia by scintigraphy or at post-mortem between 2002 and 2016 was undertaken. Control horses were matched from the same ...
Tsuzuki N, Otsuka K, Seo J, Yamada K, Haneda S, Furuoka H, Tabata Y, Sasaki N.This study evaluated the therapeutic effects of a gelatin-β-TCP sponge (sponge) incorporating BMP-2 (BMP-2/sponge) on bone regeneration in equines. Six bone defects were created in third metacarpals of five thoroughbred horses, and a total of six treatments were applied in a randomized manner. The treatments were BMP-2/sponge, BMP-2/gelatin hydrogel sheet (sheet), free BMP-2, bFGF/sheet, plain sponge, and plain sheet. The defects were monitored for 16 weeks by radiography and then examined by histological analysis. Radiographic evaluation scores of bone regeneration revealed significantly gre...
Curtiss AL, Ortved KF, Dallap-Schaer B, Gouzeev S, Stefanovski D, Richardson DW, Wulster KB.Subchondral bone pathology is common in Thoroughbred racehorses and believed to precede more serious injury. Early identification of pathology is critical to allow for intervention. Objective: To determine interobserver variability of fetlock subchondral bone lesions using cone beam and fan beam computed tomography (CBCT, FBCT) and to validate a robotics-controlled CBCT to identify fetlock subchondral bone pathology in the Thoroughbred racehorse. Methods: Prospective cohort study. Methods: FBCT and CBCT images were acquired of 25 metacarpo-/metatarsophalangeal joints of Thoroughbred racehorses...
Bentley VA, Sample SJ, Livesey MA, Scollay MC, Radtke CL, Frank JD, Kalscheur VL, Muir P.Failure of functional adaptation to protect the skeleton from damage is common and is often associated with targeted remodeling of bone microdamage. Horses provide a suitable model for studying loading-related skeletal disease because horses are physically active, their exercise is usually regulated, and adaptive failure of various skeletal sites is common. We performed a histologic study of the navicular bone of three groups of horses: (1) young racing Thoroughbreds (n = 10); (2) young unshod ponies (n = 10); and (3) older horses with navicular syndrome (n = 6). Navicular syndrome is a painfu...
Martig S, Hitchens PL, Lee PVS, Whitton RC.Subchondral bone injuries often precede articular cartilage damage in osteoarthritis and are common in thoroughbred racehorses due to the accumulation of fatigue damage from high speed racing and training. Thus, racehorses provide a model to investigate the role of subchondral bone in joint disease. We assessed the association of horse and racing related factors and micro-CT based micromorphology of three separate subchondral bone layers with the initial stiffness and compressive fatigue life of bone plugs. Furthermore, we investigated three different definitions of fatigue failure of subchond...
Wilson G, Pritchard PP, Papageorgiou C, Phillips S, Kumar P, Langan-Evans C, Routledge H, Owens DJ, Morton JP, Close GL.The present study assessed the effects of a diet and exercise intervention in jockeys on body composition, metabolism, bone and mental health. 10 jockeys followed an individually prescribed 6-wk diet (Carbohydrate=2.5-3.5 g/kg, Protein=2.5 g/kg, Fat=1.0 g/kg). Body mass (59.2±4.6 vs. 57.6±4.5 kg), fat mass (7.5±3.5 vs. 6.2±2.6) and body fat (13.1±5.9 vs. 11.5±4.9%) all decreased (P<0.05) from pre to post-intervention whilst lean mass (47.1±5.3 vs. 47.0±5.5 kg) was maintained (P=0.80). RMR (1703±329 vs. 1975±313 kcal.d(-1)), VO2max (3.8±0.8 vs. 4.1±0.7 L/min(- 1))...
Martin RB, Gibson VA, Stover SM, Gibeling JC, Griffin LV.In studying the flexural fatigue properties of the equine third metacarpal (cannon) bone, we previously found that the dorsal region was weaker monotonically, but more fatigue resistant, than the lateral region. Fatigue resistance was associated with fracture surfaces which demonstrated that secondary osteons had "pulled out" of the surrounding matrix; this never happened in lateral specimens. We therefore became interested in the osteonal structure of this bone, and began to study its birefringence patterns in circularly polarized light. We found that the predominant type of secondary osteon ...
Mézière F, Juskova P, Woittequand J, Muller M, Bossy E, Boistel R, Malaquin L, Derode A.In this paper, ultrasound measurements of 1:1 scale three-dimensional (3D) printed trabecular bone phantoms are reported. The micro-structure of a trabecular horse bone sample was obtained via synchrotron x-ray microtomography, converted to a 3D binary data set, and successfully 3D-printed at scale 1:1. Ultrasound through-transmission experiments were also performed through a highly anisotropic version of this structure, obtained by elongating the digitized structure prior to 3D printing. As in real anisotropic trabecular bone, both the fast and slow waves were observed. This illustrates the p...
Labens R, Schramme MC, Murray RC, Bolas N.High-field MRI of the proximal metacarpal/metatarsal region has been associated with great diagnostic potential and clinical reports of standing low-field MRI of the forelimb suggest the same. To better understand diagnostic outcomes with standing low-field MRI of the proximal suspensory region, a prospective survey study was conducted and users of a widely available system questioned on their experience, operating procedures, and interpretation of standing low-field MRI findings. Response data included scores on a modified Likert scale from which weighted ratings were calculated for statistic...
Noble P, Singer ER, Jeffery NS.Sagittal fractures of the first phalanx are a common, potentially catastrophic injury in racehorses. These fractures are often linked to an acute, one time, biomechanical event; however, recent evidence implies that chronic exposure to stress can lead to the accumulation of bony changes that affect the structural integrity of the bone and increase the likelihood of fracture. The aim of the study was to compare variations of two common metrics of bone adaptation - subchondral bone density and thickness across the proximal articular surface of the first phalanx in Thoroughbred horses that (1) ra...
Silver K, Desormaux A, Freeman LC, Lillich JD.Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used drugs for the suppression of inflammation and pain. However, the analgesic properties of NSAIDs are also associated with significant negative side effects, most notably in the gastrointestinal (GI) tract. Increasingly, evidence indicates that the ulcerogenic properties of some NSAIDs are not exclusively the result of inhibition of cyclooxygenase isoforms in the GI tract, and other mechanisms, including inhibition of cell migration and epithelial restitution, are being explored. Recently, microarray analysis was used ...
Fortier LA, Nixon AJ.Osteochondritis dissecans (OCD) and subchondral bone cysts (SBCs) occur commonly and at many different locations in equine limbs and can lead to secondary osteoarthritis when left untreated. Depending on the location and extent of the lesion, arthroscopic surgical debridement may be an effective treatment for returning a horse to athletic soundness. In many cases, however, additional techniques to improve the healing response in bone and cartilage are needed so as to preserve articular function. Methods for improving cartilage repair (ie, restoration of damaged cartilage)or regeneration (ie, r...
Raes EV, Bergman EH, van der Veen H, Vanderperren K, Van der Vekens E, Saunders JH.To compare computed tomography (CT) images of equine tarsi with cross-sectional anatomic slices and evaluate the potential of CT for imaging pathological tarsal changes in horses. Methods: 6 anatomically normal equine cadaveric hind limbs and 4 tarsi with pathological changes. Methods: Precontrast CT was performed on 3 equine tarsi; sagittal and dorsal reconstructions were made. In all limbs, postcontrast CT was performed after intra-articular contrast medium injection of the tarsocrural, centrodistal, and tarsometatarsal joints. Images were matched with corresponding anatomic slices. Four tar...
Vail TB, Trotter GW, Powers BE.The osteoinductive capability of four particle sizes of equine demineralized bone matrix (DBM) was evaluated. Matrix particles were implanted in brachiocephalicus muscle pouches in six horses and were harvested 8 weeks later. Matrix particle sizes of 2.0 mm3 to 4.0 mm3 and 5.0 mm3 to 10.0 mm3 were associated with osteoinductive activity and minimal signs of local inflammation. The two smaller particle sizes (0.425 mm3 to 0.850 mm3 and 0.850 mm3 to 2.0 mm3) were minimally osteoinductive and were associated with a greater local inflammatory response. Microscopic events associated with new bone p...
McCarty CA, Thomason JJ, Gordon KD, Burkhart TA, Milner JS, Holdsworth DW.To assess whether the transient stresses of foot impact with the ground are similar to those found during midstance loading and if the location of high stress correlate with the sites most commonly associated with mechanically induced osteoarthritis (OA). We compared impact stresses in subchondral bone between two subject-specific, three-dimensional, finite-element models of the equine metacarpophalangeal (MCP) joint-one with advanced OA and one healthy, and with similar published data on the stresses that occur at midstance. Methods: Two right MCP joints (third metacarpal and proximal phalanx...
Fleck C, Eifler D.Despite its clinical importance, the fatigue behaviour of cortical bone has not been examined as widely as its static behaviour. In the present study, specimens from the tibiae of horses have been subjected to load-controlled single step tests. The cyclic deformation behaviour was described by the development of stress-strain hysteresis parameters over the lifetime. The fatigue behaviour of bone is characterised by cyclic softening which is most distinctive towards the end of the lifetime. The microstructural damage accumulated during cyclic loading results in a loss of stiffness, asymmetrical...
