The musculoskeletal system in horses encompasses the bones, muscles, tendons, ligaments, and joints that facilitate movement and provide structural support. This system is essential for locomotion, athletic performance, and overall health in equine species. The equine skeleton consists of approximately 205 bones, which are connected by joints and supported by a network of muscles and connective tissues. Tendons connect muscles to bones, while ligaments link bones to other bones, contributing to joint stability. The musculoskeletal system is subject to various conditions, including injuries, degenerative diseases, and developmental disorders, which can impact a horse's mobility and performance. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, pathology, and treatment of musculoskeletal conditions in horses.
Herszberg B, McCue ME, Larcher T, Mata X, Vaiman A, Chaffaux S, Chérel Y, Valberg SJ, Mickelson JR, Guérin G.Glycogen storage diseases or glycogenoses are inherited diseases caused by abnormalities of enzymes that regulate the synthesis or degradation of glycogen. Deleterious mutations in many genes of the glyco(geno)lytic or the glycogenesis pathways can potentially cause a glycogenosis, and currently mutations in fourteen different genes are known to cause animal or human glycogenoses, resulting in myopathies and/or hepatic disorders. The genetic bases of two forms of glycogenosis are currently known in horses. A fatal neonatal polysystemic type IV glycogenosis, inherited recessively in affected Qu...
Butcher MT, Hermanson JW, Ducharme NG, Mitchell LM, Soderholm LV, Bertram JE.The forelimb digital flexors of the horse display remarkable diversity in muscle architecture despite each muscle-tendon unit having a similar mechanical advantage across the fetlock joint. We focus on two distinct muscles of the digital flexor system: short compartment deep digital flexor (DDF(sc)) and the superficial digital flexor (SDF). The objectives were to investigate force-length behavior and work performance of these two muscles in vivo during locomotion, and to determine how muscle architecture contributes to in vivo function in this system. We directly recorded muscle force (via ten...
Ferguson VL, Bushby AJ, Firth EC, Howell PG, Boyde A.Impact exercise has a profound effect in increasing volumetric density of epiphyseal bone, as clearly shown in 2 year old thoroughbred racehorses from which we derived the tissue studied in the present investigation. Here, we asked the question whether the fabric-level properties of the mineralised tissues immediately below hyaline articular cartilage which transmit the extra loads are themselves altered in consequence. We therefore studied the nanoindentation elastic modulus and its relationship to the concentration of mineral determined by quantitative backscattered electron imaging in the h...
Holopainen JT, Brama PA, Halmesmäki E, Harjula T, Tuukkanen J, van Weeren PR, Helminen HJ, Hyttinen MM.The effects of growth and maturation on the mineral deposition and the collagen framework of equine subchondral bone (SCB) were studied. Methods: Osteochondral specimens (diameter 6 mm) from the left metacarpophalangeal joint of 5-(n=8), 11-(n=8) and 18-month-old (n=6) horses were investigated at two differently loaded sites (Site 1 (S1): intermittent peak loading; Site 2 (S2): habitual loading). The SCB mineral density (BMD) was measured with peripheral quantitative computer tomography (pQCT), and the data were adjusted against the volume fraction (Vv) of the bone extracellular matrix (ECM). ...
The Journal of traumaAugust 13, 2008
Volume 65, Issue 2 447-460 doi: 10.1097/TA.0b013e31817dac43
Loder RT.It was the purpose of this study to review equestrian-related injuries using a large nation wide database and analyze predictors of significant injury. Methods: The National Electronic Surveillance System database was queried for equestrian injuries from 2002 to 2004. The presence of a fracture, dislocation, traumatic brain injury, musculoskeletal injury, orthopedic injury, and spinal injury, as well as injury mechanism, geographical location, and emergency room disposition were noted. Bivariate, cosinor seasonal, and multiple logistic regression analyses were performed. p < 0.01 was considere...
Patil DB, Adamiak Z, Piórek A.The present review informs about the current status regarding use of interlocking nailing for fracture repair in animals. The clinical limitations of interlocking nailing and its subsequent improvement by evolving novel nail design or supplementation with type I ESF using hybrid nail bolt/ESF pin has been dealt. The biomechanical and clinical evaluation of novel interlocking nail supplements and its possible clinical use is included.
Del Bue M, Riccò S, Ramoni R, Conti V, Gnudi G, Grolli S.Equine mesenchymal stem cells (MSC) are of particular interest both for basic research and for the therapeutic approach to musculoskeletal diseases in the horse. Their multilineage differentiation potential gives them the capability to contribute to the repair of tendon, ligament and bone damage. MSCs are also considered a promising therapeutic aid in allogeneic cell transplantation, since they show low immunogenicity and immunomodulating functions.Adipose tissue-derived adult equine stem cells (AdMSC) can be isolated, expanded in vitro and then inoculated into the damaged tissue, eventually i...
McCue ME, Valberg SJ, Lucio M, Mickelson JR.A missense mutation in the GYS1 gene was recently described in horses with polysaccharide storage myopathy (PSSM). Objective: The first objective was to determine the prevalence of the GYS1 mutation in horses with PSSM from diverse breeds. The second objective was to determine if the prevalence of the GYS1 mutation differed between horses diagnosed with PSSM based on grade 1 (typically amylase-sensitive) or grade 2 (typically amylase-resistant) polysaccharide. Methods: Eight hundred and thirty-one PSSM horses from 36 breeds. Methods: Horses with PSSM diagnosed by histopathology of skeletal mus...
Zedda M, Lepore G, Manca P, Chisu V, Farina V.Bone microstructure of domestic herbivores is still not completely understood. Indeed, works focused on the bone histology of numerous Mammalian species frequently led to misunderstandings because of the high number of variations such as the kind of bone, section orientation, species, breed and age. Moreover, attempts to identify the species in archaeozoological studies by a mere qualitative approach have not been encouraging and in recent years quantitative methods, based on image processing and statistical analysis, have appeared. The present study was undertaken to determine whether morphom...
Pollock S, Stover SM, Hull ML, Galuppo LD.The first objective of this study was to experimentally determine surface bone strain magnitudes and directions at the donor site for bone grafts, the site predisposed to stress fracture, the medial and cranial aspects of the transverse cross section corresponding to the stress fracture site, and the middle of the diaphysis of the humerus of a simplified in vitro laboratory preparation. The second objective was to determine whether computing strains solely in the direction of the longitudinal axis of the humerus in the mathematical model was inherently limited by comparing the strains measured...
Pollock S, Hull ML, Stover SM, Galuppo LD.Knowledge of the forces that act upon the equine humerus while the horse is standing and the resulting strains experienced by the bone is useful for the prevention and treatment of fractures and for assessing the proximolateral aspect of the bone as a site for obtaining autogenous bone graft material. The first objective was to develop a mathematical model to predict the loads on the proximal half of the humerus created by the surrounding musculature and ground reaction forces while the horse is standing. The second objective was to calculate surface bone stresses and strains at three cross se...
Vinardell T, David F, Morisset S.To describe a direct arthroscopic approach to the suprapatellar pouch (SPP), its intra-articular anatomy, and report our clinical experience with SPP arthroscopy. Methods: (1) Experimental study and (2) retrospective clinical study. Methods: (1) Cadaveric equine hind limbs (n=24; 14 horses) and (2) 5 horses. Methods: Four femoropatellar joints (FPJ) were dissected or injected with latex to document surface landmarks and topographic anatomy. (1) Arthroscopic exploration of 20 SPP (10 equine cadavers) was performed and described, followed by dissection. (2) Medical records of horses that had FPJ...
Tidswell HK, Innes JF, Avery NC, Clegg PD, Barr AR, Vaughan-Thomas A, Wakley G, Tarlton JF.Fatigue fracture of cuboidal bones occurs in the human foot as well as the equine carpus. The racehorse provides a naturally-occurring model to study the effects of high-intensity exercise on the morphology and metabolism of cuboidal bones. We studied both the mineral and the collagenous matrix of the third (C(3)) and radial (C(r)) carpal bones of raced and non-raced Thoroughbred (TB) horses. We hypothesised that racehorses would show increases in the mineral component of these bones and post-translational modifications of the collagenous matrix alongside changes in markers of collagen remodel...
Echigoya Y, Sato T, Itou T, Endo H, Sakai T.To elucidate the molecular properties of the equine glycolytic enzymes equine M(1) (eM(1)) and M(2) (eM(2))-pyruvate kinase (PK), mRNAs were isolated from thoroughbred horse skeletal muscle and hair roots, respectively. The full-length eM(1) and eM(2)-PK cDNAs consist of 2,320 and 2,376 bp, respectively, containing a 1596 bp open reading frame. The cDNAs were mapped to equine chromosome 1, and the equine pyruvate kinase M (PKM) gene consists of twelve exons. Exon 9 of eM(1)-PK and exon 10 of eM(2)-PK were further investigated in five equine species. Out of 55 amino acids encoded by exon 9 in e...
Clayton HM, White AD, Kaiser LJ, Nauwelaerts S, Lavagnino M, Stubbs NC.A lightweight bracelet that provides tactile stimulation to the horse's pastern and coronet induces a higher flight arc of the hoof. This study addresses the pattern of habituation to these devices. Objective: To evaluate short-term habituation to tactile stimulation of the pastern and coronet in trotting horses. Methods: Tactile stimulation was provided by a lightweight (55 g) device consisting of a strap with seven chains that was attached loosely around the pastern. Reflective markers were fixed to the dorsal hoof wall, the forehead and over the tenth thoracic vertebra of eight sound horses...
Merritt JS, Davies HM, Burvill C, Pandy MG.The equine distal forelimb is a common location of injuries related to mechanical overload. In this study, a two-dimensional model of the musculoskeletal system of the region was developed and applied to kinematic and kinetic data from walking and trotting horses. The forces in major tendons and joint reaction forces were calculated. The components of the joint reaction forces caused by wrapping of tendons around sesamoid bones were found to be of similar magnitude to the reaction forces between the long bones at each joint. This finding highlighted the importance of taking into account muscle...
Probst A, Macher R, Hinterhofer C, Polsterer E, Guarda IH, König HE.This study aims to elucidate the topographical anatomy of the carpal flexor retinaculum or palmar anular carpal ligament (PACL) in the horse. Ten specimen of the carpus of five healthy horses were studied by dissection in layers. Slices of 5 mm in thickness facilitated observation of the soft tissues. The superficial layer of the PACL subdivides into five compartments: one for the palmar nerve and the arterial and venous branches, one for only the radial artery, one for the radial vein, and one for the tendon of the radial carpal flexor muscle, and finally for the deep layer that supports all ...
Gehlen H, Oey L, Rohn K, Bilzer T, Stadler P.Chronic pulmonary diseases (recurrent airway obstruction [RAO]) have been reported to alter skeletal muscle cells in humans. The purpose of this study was to evaluate a potential relationship between pulmonary and muscle variables in horses with a clinical diagnosis of RAO. Muscle biopsies from healthy horses and from horses with RAO were investigated and the relationship between the severity of lung disease and the degree of muscular changes was determined. Objective: We hypothesized that chronic pulmonary disease can lead to changes of the skeletal muscle in horses. Methods: Fifteen healthy ...
Waselau M, Sutter WW, Genovese RL, Bertone AL.To determine outcome of Standardbred racehorses with moderate to severe midbody suspensory ligament desmitis (MSD) treated by means of ultrasound-guided intralesional injection of a single dose of platelet-rich plasma (PRP) followed by a program of gradually increased exercise. Methods: Nonrandomized clinical trial. Methods: 9 Standardbred racehorses. Methods: Following injection of PRP, horses were allowed a controlled, gradual return to exercise. Race records for the year prior to injury and for 3 consecutive years after horses returned to racing were reviewed. For comparison purposes, race ...
Vanderperren K, Saunders JH.The metacarpophangeal/metatarsophalangeal (fetlock) joint in the horse is commonly associated with equine lameness and diagnostic imaging is routinely used to investigate disorders of the joint and its surrounding tissues. This review describes the osseous disorders of the fetlock as well as the technical aspects of taking radiographic and ultrasonographic images of the different lesions. In current clinical practice, a combination of radiography and ultrasonography is still the most frequently used approach to arrive at a diagnosis.
Charman RE, Vasey JR.Carpal flexural deformities (CFD) are frequently encountered in the horse, with both congenital and acquired forms described. The success of surgical correction of CFD, both in terms of the ability to achieve a straight palmar carpal angle and the impact on future athletic performance, requires further investigation. Objective: To report the surgical management and outcome of treatment of flexural deformity of the carpus in 72 horses up to 12 months of age. Methods: Information was obtained from the medical records of horses surgically treated for CFD and through follow-up contact with owners....
Morello SL, Ducharme NG, Hackett RP, Warnick LD, Mitchell LM, Soderholm LV.To determine the phase and quantitate the electromyographic (EMG) activity of the genioglossus, geniohyoideus, hyoepiglotticus, omohyoideus, sternohyoideus, sternothyroideus, and thyrohyoideus muscles of clinically normal horses during strenuous exercise. Methods: 7 clinically normal adult horses (2 Thoroughbreds and 5 Standardbreds). Methods: Bipolar electrodes were surgically implanted in the aforementioned muscles, and horses were subjected to an incremental exercise test on a high-speed treadmill. The EMG, heart rate, respiratory rate, and static pharyngeal airway pressures were measured d...
Vanderperren K, Saunders JH.The equine fetlock is the joint most commonly associated with lameness. Although the fetlock is regarded as a simple joint, diagnosis of a fetlock disorder can be a challenge and various imaging modalities are routinely used to arrive at an accurate diagnosis. This review describes the principal disorders affecting the soft tissues of the fetlock region and addresses some of the technical aspects involved in taking radiographic and ultrasonographic images of the different soft tissue lesions. A combination of radiography and ultrasonography is still the most commonly used diagnostic approach i...
Cercone M, Olsen E, Perkins JD, Cheetham J, Mitchell LM, Ducharme NG.Exercise induced intermittent dorsal displacement of the soft palate (DDSP) is a common cause of airway obstruction and poor performance in racehorses. The definite etiology is still unclear, but through an experimental model, a role in the development of this condition was identified in the dysfunction of the thyro-hyoid muscles. The present study aimed to elucidate the nature of this dysfunction by investigating the spontaneous response to exercise of the thyro-hyoid muscles in racehorses with naturally occurring DDSP. Intramuscular electrodes were implanted in the thyro-hyoid muscles of nin...
Schooley EK, Hendrickson DA.Tumors of the musculoskeletal system are rare in horses; however, they must be taken seriously. Diagnosis requires observation of clinical signs, radiographic findings, and histological examination. Veterinarians must realize prognosis is not favorable for most tumors; however, some of these tumors can be treated or at least ameliorated. Tumors discussed in this article include: osteoma and osteosarcoma; osteoblastoma; chondrosarcoma; fibroma and fibrosarcoma; plasma cell myeloma; synovioma; rhabdomyosarcoma and tumors metastatic to the musculoskeletal system.
Gabel AA.Since horses ridden at a gallop have a high incidence of bone spavin, and harness horses (Standardbred pacers and trotters) have a different
syndrome, they will be discussed separately. Osteoarthritis (bone spavin) apparently is caused by impact and compression on the distal tarsal
bones, which occurs most forcefully at the gallop (canter). Shear stresses, which occur in the joint between these bones, are most severe at the trot
or pace, and probably cause the usual cunean-tarsitis problem in
Standardbreds. Obviously some of each force occurs at each gait.
Ainsworth DM, Eicker SW, Nalevanko ME, Ducharme NG, Hackett RP, Snedden K.Horses chronically-instrumented with costal diaphragmatic electromyographic electrodes were studied during exercise while unencumbered by a breathing mask. Exercise-associated changes in esophageal (Pes), gastric (Pga) and transdiaphragmatic (Pdi) pressures were measured and related to diaphragmatic electromyographic activity (CS EMG) and to left forelimb impact. In all breaths examined, CS EMG always coincided with decrements in Pes. For all exercise trials, linear increases in CS EMG, Pga and Pdi and linear decreases in Pes, as a function of exercise intensity, always occurred. During all ga...
Dodman NH, Williams R, Court MH, Norman WM.Five horses that underwent prolonged anesthesia (greater than 3 hours) in dorsal recumbency for a surgical procedure were unable to stand after recovery and were euthanatized. A provisional diagnosis of postanesthetic myopathy was confirmed at necropsy in all 5 horses. However, distribution of affected muscles in these horses was atypical, because there was bilateral hind limb adductor muscle involvement.
Stock KF, Hamann H, Distl O.Factors associated with the prevalence of osseous fragments (OF) in fetlock and hock joints were investigated in a population of young Hanoverian Warmblood horses selected for sale at auction from 1991 to 1998. The study was based on results of a standardized radiological examination of 3127 horses. The prevalences of OF in the two joints were significantly dependent on the date, type and quality of the auction, the region of origin and on the anticipated suitability of the horses for dressage and/or show-jumping. The probability of finding OF increased with wither-height. Furthermore, there w...
Gaschen L, Burba DJ.Adaptive and nonadaptive stress remodeling in Thoroughbred racehorses leads to most of their musculoskeletal injuries, and imaging plays an important role in its detection. Bone scintigraphy is important for detecting stress remodeling and stress fractures and aids in decision making when more than one lesion is present on MRI or radiographic examinations. MRI likely represents the best modality for the assessment of osteoarthritis of the metacarpophalangeal and metatarsophalangeal joints. Ultrasonography remains important as the first modality for the assessment of tendon and ligamentous inju...
Sato T, Itou T, Sato G, Kobayashi Y, Endo H, Sakai T.In order to investigate the utilization of glucose in equine skeletal muscle, we determined the coding and proximal promoter sequences of the hexokinase type II (HKII) gene in thoroughbred horse, Grevy's zebra and Hartmann's mountain zebra. The deduced amino acid sequence of thoroughbred horse HKII showed 100, 100, 94.4, 92.7 and 92.6% identities with Grevy's zebra, Hartmann's mountain zebra, human, mouse and rat HKIIs, respectively. In equine HKIIs, specific amino acid substitutions, Ile 159 and Arg 610, were found in the potential binding site for glucose. In addition, the nucleotide sequenc...
van Ginneken MM, Keizer HA, Wijnberg ID, van Dam KG, Schaart G, de Graaf-Roelfsema E, van der Kolk JH, van Breda E.To investigate whether protein kinase C (PKC) isoforms are expressed in equine skeletal muscle and determine their distribution in various types of fibers by use of immunofluorescence microscopy. Methods: 5 healthy adult Dutch Warmblood horses. Methods: In each horse, 2 biopsy specimens were obtained from the vastus lateralis muscle. Cryosections of equine muscle were stained with PKC isoform (alpha, beta1, beta2, delta, epsilon, or zeta)-specific polyclonal antibodies and examined by use of a fluorescence microscope. Homogenized muscle samples were evaluated via western blot analysis. Results...
Melo e Silva SR, Vulcano LC.Collateral cartilage ossification of the distal phalanx in the Brazilian Jumper horse is a common finding. The objective of this study was to evaluate the prevalence and the degree of ossification of the collateral cartilages of the distal phalanx in Brazilian Jumper horses. In an analysis of 652 collateral cartilages from the front feet of 163 horses, 93% of these cartilages had collateral cartilage ossification (P < 0.005), and 7% of these cartilages did not have any type of ossification. In ossified cartilages, 86.4% had ossification beginning from the base, and 6.6% had a separate cente...