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.
Hickman J.Sir Frederick Hobday's service as a Veterinary Officer in the Army Veterinary Corps during the Great War 1914-1918 is recorded. This is followed by a description of the fractures of the distal forelimb which can be treated satisfactorily by surgery, and includes fractures of the carpal, the small metacarpal, the proximal sesamoid bones, the first phalanx and the extensor process of the third phalanx.
Turner AS, Mills EJ, Gabel AA.Strain gauges were successfully bonded in vivo to the cranial, caudal, medial, and lateral aspects of the equine radium and tibia and to the dorsal, palmar, or plantar, medial, the lateral aspects of the metacarpus and metatarsus--all in the mid-diaphyseal region. Various activities were investigated, including walking, trotting or pacing, and standing up from anesthesia. The strain patterns showed that each stride produced a characteristic deformation cycle. The strains were measured and the axial loads were calculated as the horse performed certain activities. The tension band side of each b...
White NA, Wheat JD.Proximal tibial epiphyseal fractures in 2 foals were reduced and stabilized by expansion and compression between 2 transversely placed Steinman pins, one on each side of the fracture. A Charnley apparatus or turnbuckles placed between the pins on each side of the fracture provided the mechanical advantage for repositioning the fracture fragments and achieving rigid fixation during healing. A light cast was applied over the fixation apparatus, keeping the limb in an extended position. The cast and fixation apparatus were removed after 4 weeks. The technique allowed rapid healing and adequate am...
Stashak TS, Adams OR.Autogenous bone grafts were obtained from the tuber coxae of 9 horses. The method used involved an oblique incision to expose the lateral aspect of the tuber coxae. The periosteum was incised and reflected in order to make a 5- by 2.5-cm opening in the lateral cortex for graft retrieval. The method provided good visualization, ample grafting material, and freedom from postsurgical complications.
Turner AS, Gabel AA.Avulsion fractures of the posteromedial eminence of the 2nd phalanx were repaired, using an ASIF cortex screw in 3 reining Quarter Horses. Within 9 and 11 months, respectively, 2 horses were sound and back in competition as reining horses. The other horse was sound for pleasure class showing at 7 months after surgery.
Harrington DD.1. The effects of feeding with a purified magnesium-deficient diet (--Mg, 7-8 mg Mg/kg) on horse foal blood serum and tissue concentrations of Mg, calcium and phosphorus were studied, and the results compared with histopathological findings. 2. Serum concentrations of Ca and P were unaffected by feeding with the --Mg diet, whereas serum Mg concentrations decreased from a mean initial (day o) concentration of 0.78 mmol/l to 0.53 mmol/l 7 d after foals were placed on the -Mg diet, and then continued to decrease at a slower rate. 3. Aorta concentrations of Ca and P, but not Mg, were positively co...
Menschik A.Mobility of the knee of the horse. The modification of medial and lateral femoral condyles by additional movement of the cruciate ligaments shown on the animal joint. Final rotation in the human knee-joint shapes the femoral condyles by additional movement of the cruciate ligaments. The roll-slide movement and final rotation lead to curving of the medial condyle of the femur in the transverse plane. The transition from the roll-slide into a tilting movement in the final phase of ultimate rotation reduces the power of the posterior ligamentous system of the knee-joint when there is a force tend...
Brown MP, MacCallum FJ.Tetracycline-labeled bones of 23 foals from 52 to 104 days old were sectioned and macroscopically examined to assess the extent of ossification or fusion of ossification centers. A grading system was devised with which to record information about the ossification centers and growth plates. The objective was to define anatomic standards which could contribute toward obtaining an accurate radiologic interpretation. Labeled limb bones of 3 neonatal foals were similarly treated, but grading of these was limited to the consideration of whether each site was still cartilaginous or had commenced to o...
Crowhurst RC.Diseases of the back of horse and man are not comparable owing to the great difference in anatomy and posture. Veterinary surgeons, particularly in the United Kingdom, are often requested to account for a poor performance due to suspected "back trouble" but a complete examination of the horse's back is most difficult and care must be taken first to exclude any limb or foot lesions. Diseases of the bones, nerves and muscles are briefly discussed. Diagnosis must be improved by new radiographic and biochemical tests before the significance of back lesions can be assessed or even treated.
Brook D.A case of what can be presumed to be secondary nutritional hyperparathyroidism, due to high phosphorus diet, in a six year old pony is discussed. The findings are compared to those found when the disease occurs in young growing horses.
O'Brien TR, Hornof WJ, Meagher DM.Subchondral lesions were identified in the distal palmar region of the third metacarpus in 21 fetlock joints of 15 Thoroughbred horses. The lesions were more commonly identified on the lateromedial and flexed lateral projection, with the flexed lateral projection permitting optimal visualization of the lesion. Lesions appeared as poorly marginated, radiolucent defects and were located at the level of the base of the proximal sesamoid bones. The shape and distribution of the radiolucent defects were: crescent, 4; flattened, 4; shallow concavity, 5; deep concavity, 3; oval, 3; and circular, 2. S...
Easley JT, Brokken MT, Zubrod CJ, Morton AJ, Garrett KS, Holmes SP.Fourteen horses with septic arthritis underwent high-field (1.5 T) magnetic resonance imaging (MRI). Septic arthritis was diagnosed based on results from historical and clinical findings, synovial fluid analyses and culture, and radiographic, ultrasonographic, arthroscopic, and histopathologic findings. MR findings included diffuse hyperintensity within bone and extracapsular tissue on fat-suppressed images in 14/14 horses (100%), joint effusion, synovial proliferation, and capsular thickening in 13/14 horses (93%), bone sclerosis in 11/14 horses (79%), and evidence of cartilage and subchondra...
Nation PN, Klavano GG.This account describes two neonatal foals affected with osteopetrosis. One of these foals, a full term Peruvian Paso, was born alive, was bright and alert but was unable to stand and was euthanized at two days of age. The second foal, an Appaloosa, was also born alive at full term and was blind, weak, uncoordinated and unable to stand. Postmortem examination of both foals revealed generalized osteopetrosis and brachygnathia inferior. The osteopetrosis was characterized by failure of bone remodelling resulting in spicules of mineralized and nonmineralized cartilage covered by osteoid occupying ...
Basic life sciencesJanuary 1, 1996
Volume 64 17-27 doi: 10.1007/978-1-4615-5847-7_2
Bacon GE.The familiar extremes of crystalline material are single-crystals and random powders. In between these two extremes are polycrystalline aggregates, not randomly arranged but possessing some preferred orientation and this is the form taken by constructional materials, be they steel girders or the bones of a human or animal skeleton. The details of the preferred orientation determine the ability of the material to withstand stress in any direction. In the case of bone the crucial factor is the orientation of the c-axes of the mineral content-the crystals of the hexagonal hydroxyapatite- and this...
Albu I, Georgia R, Georoceanu M.The Haversian canal system in the diaphysial compacta of the femur in 4 mammalian species (dog, pig, bovine, horse) was studied on the decalcified bone using a method developed by the authors. In the microscopic studies we found that in all species the network aspects vary with the depth of the compacta layer. In all layers, there is a background of longitudinal canals with more or less regular trajectories describing large curves. The anastomoses linking them are main elements that define the variety of the network aspects both from layer to layer and from species to species. The canal densit...
Spoormakers TJP, Wiemer P.To describe a symphyseal osteotomy stabilised with two short locking compression plates (LCPs) for treatment of class 2 malocclusions. Methods: Case series. Methods: Five horses (age range 8 months to 5¾ years) with overjets and/or overbites ranging from 6 to 32 mm and from 0 to 60 mm, respectively, were treated by osteotomy through the caudal third of the mandibular symphysis, cranial to the interdental space. After cranial distraction and ventral rotation of the rostral part of the mandible, two short (5/6 hole), bent 3.5 mm LCPs were applied ventro-laterally and secured with two or three l...
Vanderperren K, Martens AM, Declercq J, Duchateau L, Saunders JH.To compare clinical usefulness of ultrasonography versus radiography for detection of fragmentation of the dorsal aspect of the metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joints in horses. Methods: Cross-sectional study. Methods: 36 horses with fragmentation of the MCP (n = 19) and MTP (29) joints. Methods: In all joints, radiography (4 standard projections) and ultrasonography were performed prior to arthroscopic examination and fragment removal. Number and location of fragments identified radiographically and ultrasonographically were compared with arthroscopic findings. Results...
Schade SM, Arnoczky SP, Bowker RM.To describe the intra-osseous microvasculature of the distal phalanx of the equine forelimb with regard to its potential clinical relevance. Methods: Eleven clinically normal equine forelimbs were used from six adult horses (range: 4 to 18 years old) euthanatized for reasons unrelated to lameness. In each limb the median artery was catheterized at the level of the carpus and India ink was injected under constant manual pressure. The limbs were frozen and 5 mm thick sections of the foot were cut in the sagittal, coronal, or transverse planes on a band saw. The sections were fixed in 10% formali...
Wulster KB.This article discusses the basis of image formation of radiography, scintigraphy, PET, computed tomography (fan beam and cone beam), and magnetic resonance as it relates to imaging of musculoskeletal injury in the sport horse. The benefits and drawbacks of each modality are discussed with particular emphasis on sensitivity, specificity, and accuracy of identification of subchondral bone injury. Examples of straightforward as well as confounding lesions are provided, emphasizing the need for appropriate clinical workup and diagnostic analgesia, where appropriate.
Labens R, Jermyn K.To assess suspensory ligament extensor branch location and fracture gap reduction with simulation of standing and recumbent cortical bone screw repair of experimental incomplete parasagittal proximal phalanx (P1) fractures. Methods: Controlled laboratory study. Methods: Twenty equine cadaver forelimbs. Methods: Simulated fractures were repaired twice in random order. A proximal cortical bone screw was placed in lag fashion with the limb unloaded (simulated recumbent repair) and loaded to 38% of body weight (range, 375-568 kg; simulated standing repair). Changes in fracture gap width were ass...
Spriet M, Espinosa-Mur P, Zhang X, Berg E, Bec J, Katzman S, Galuppo L.The combination of F-Sodium Fluoride ( F-NaF) and F-FluoroDeoxyGlucose ( F-FDG) for positron emission tomography (PET) imaging of the equine foot is appealing for detection of both osseous and soft tissue lesions in a single scan. As the combination of tracers could lead to a loss of information, a sequential approach, consisting in imaging with one tracer prior to injecting the second tracer, might be valuable. The goals of this prospective, methods comparison, exploratory study were to establish the order of tracer injection and timing for imaging. Six research horses were imaged under...
Claerhoudt S, Pille F, Vanderperren K, Hauspie S, Duchateau L, Van der Vekens E, Saunders JH.To investigate whether in navicular bones (NB) from warmbloods, distal border fragmentation is associated with the shape of the proximal articular border or other radiological findings. Methods: Radiographs of the front feet of 325 normal, subadult horses presented for admission as breeding stallions were reviewed. Results: The proximal articular border of the total of 650 NB was classified as straight (n = 278), convex (n = 184), undulating (n = 147) or concave (n = 41). Distal border fragments were present in 57 NB (8.8%). They were significantly more prevalent in NB with a concave (9/41; 22...
Doyle-Jones PS, Sullins KE, Saunders GK.To compare synovial regeneration in the equine carpus after mechanical or CO(2) laser synovectomy. Methods: Arthroscopic partial synovectomy was performed in the radiocarpal and intercarpal joints. Methods: Twelve horses, 3 to 6 years of age, were randomly divided into 3 groups. Methods: The antebrachiocarpal and intercarpal joints in each horse were randomly assigned a treatment such that each horse had one joint treated as a control (arthroscopic lavage), one in which a mechanical or CO(2) laser partial dorsal carpal synovectomy was performed, and one in which a combination of the mechanical...
Rose RJ.Three of the standard radiographic views of the navicular bone were assessed in normal horses and horses with navicular disease to determine the most effective radiographic positioning. Using the upright pedal view, a pastern angulation of 20 degrees from the vertical produced the optimum result when radiographs were taken using a grid. The best result using the high coronary view was obtained with an anode-film distance of 1 1000 mm, and a tube-head angle of 50 degrees from the vertical. When the special navicular view described by Morgan was examined, the most satisfactory projection was obt...
Stewart HL, Kawcak CE, Inscoe CR, Puett C, Lee YZ, Lu J, Zhou OZ, Selberg KT.To describe the technique and assess the diagnostic potential and limitations of tomosynthesis for imaging of the metacarpophalangeal joint (MCPJ) of equine cadavers; compare the tomosynthesis appearance of pathological lesions with their conventional radiographic, CT, and MRI appearances; and evaluate all imaging findings with gross lesions of a given MCPJ. Methods: Distal portions of 4 forelimbs from 4 equine cadavers. Methods: The MCPJs underwent radiography, tomosynthesis (with a purpose-built benchtop unit), CT, and MRI; thereafter, MCPJs were disarticulated and evaluated for the presence...
Southwood LL, McIlwraith CW.To determine the outcome of horses with basal fractures of the proximal sesamoid bone from which a fracture fragment involving a portion of the base of the bone was removed arthroscopically and to determine whether fragment size was associated with outcome. Methods: Retrospective study. Methods: 26 horses. Methods: Dorsopalmar and axial-abaxial lengths of the fracture fragment were measured on the dorsopalmar and mediolateral radiographic views, respectively, and percentage of the base of the sesamoid bone involved was estimated. Fractures were classified as grade 1 ( 25% but < 100% of the ...
Gonçalves LM, Pozzobon R, Dos Anjos BL, Pellegrini DCP, Azevedo MS, Dau SL, Oliveira GP, Klaus R.The term juvenile osteochondral condition (JOCC) has been used to identify developmental changes in the growth plates. The condition is characterized by a set of changes with similar pathogenesis that affect the immature skeleton and joints of growing foals. The aim of the current study is to investigate the prevalence and degree of severity of osteochondral changes in Brazilian warmblood (BW) foals in two farms in the south of Brazil. Radiological evaluation was applied to the metacarpophalangeal (MCP), carpal (C), metatarsophalangeal (MTP), tarsal (T), and femorotibiopatellar (FTP) joints of...
Baccarin RY, Martins EA, Hagen SC, Silva LC.A controlled study was designed in order to evaluate the effects of medial patellar desmotomy (MPD), combined with exercise restriction, on clinically and radiographically normal femoropatellar joints, and to identify the patellar instability by radiographic examination. MPD was performed on the right hind limb and the horses were rested for 120 days. Both hind limbs were radiographed before surgery and at 15, 30, 60, 90, and 120 days after MPD, obtaining lateromedial, flexed lateromedial, caudocranial and cranioproximal-craniodistal (skyline) views. The femorotibial and femoropatellar angles ...
Rapoff AJ, Markel MD, Vanderby R.By use of wire ropes as the transosseous component, an external skeletal fixator for the repair of long bone fractures in horses and cattle has been designed and tested in axial compression. Theoretical methods were used in the design process to size fixator components; however, our results suggest that conventional methods of analyzing the displacement of the transosseous component may not apply to wire ropes. Large pretensions in the wire ropes are necessary to obtain functional stiffnesses for fracture fixation. Therefore, a method was sought for terminating the ropes so that an appropriate...
Lewis CW, Williamson AK, Chen AC, Bae WC, Temple MM, Wong WV, Nugent GE, James SP, Wheeler DL, Sah RL, Kawcak CE.To determine and correlate subchondral bone mineral density and overlying cartilage structure and tensile integrity in mature healthy equine stifle (low magnitude loading) and metacarpophalangeal (high magnitude loading) joints. Methods: 8 healthy horses, 2 to 3 years of age. Methods: Osteochondral samples were acquired from the medial femoral condyle (FC) and medial trochlear ridge (TR) of the stifle joint and from the dorsal (MC3D) and palmar (MC3P) aspects of the distal medial third metacarpal condyles of the metacarpophalangeal joint. Articular cartilage surface fibrillation (evaluated via...
Misheff MM, Stover SM, Pool RR.Unicortical corticocancellous bone biopsy specimens 4.5 mm and 6.5 mm in diameter were obtained without long-term complications from the 12th rib in eight standing horses. However, the bone specimens were unsuitable for histologic or histomorphometric evaluation. In in vitro comparisons of biopsy specimens 6.5 mm and 12 mm in diameter, and of unicortical and transcortical biopsy specimens, 12 mm transcortical specimens yielded the most cancellous bone. Transcortical bone biopsy specimens 12 mm in diameter were obtained from eight horses by using power-assisted trephination. The surgical proced...
Nocera I, Sorvillo B, Sgorbini M, Aliboni B, Citi S.Few studies have established the normal radiographic anatomical development of the donkey foal and, to date, no data are available for mules. Our aim was thus to evaluate the radiographic development of the fore digit and carpal joint in the mule foal from 0 to 3 months of age. Ten forelimbs of five healthy full-term mule foals were included. Radiographs of the fore digit lateromedial and dorsopalmar and the carpus dorsopalmar were performed weekly for the first month of age, and bi-monthly during the following two months. Fore digit growth plate closure times, morphological, angular, and line...
Olive J, Vila T, Serraud N.To compare navicular bone marrow lesion (BML) conspicuity in the feet of horses as determined via 2 fat-suppressed MRI techniques, including standard short tau inversion recovery (STIR) and inversion recovery gradient echo (IRGE). Methods: Feet (n = 150) of horses with lameness referable to the distal portion of the digit. Methods: STIR and IRGE sequences were obtained prospectively in all feet with a standing low-field equine MRI system. Presence of a BML was ascertained by identification of a characteristic combination of marrow alterations in T1-weighted, T2*-weighted, T2-weighted, and STIR...
Sporn A, Berner D, Winter K, Mageed M, Brehm W, Gerlach K.Scintigraphic examination of the thoracic spine is well documented. However, there is limited information about the effects of time on image quality in the period following injection of radionuclide. This study aimed to determine the optimal time point after injection of (99m)Tc-HDP (hydroxymethylene-diphosphonate) to achieve scintigraphic images with the best possible contrast and adequate count rates. Scintigraphic images of the thoracic spine of 21 horses were acquired two, four and six hours after administering (99m)Tc-HDP. Eight regions of interest were drawn in the images, four in the sp...
Schneider RK, Ratzlaff MC, White KK, Hopper SA.To determine effect of 3 half-limb casts on bone strains recorded from the proximal phalanx (P-1) and third metacarpal bone (MCIII) of equine cadaver limbs, using a mechanical testing machine. Methods: 12 equine cadaver limbs and 4 live horses. Methods: Bone strains were recorded at middorsal P-1 and the dorsal cortical aspect of the distal third of MCIII while limbs were variably loaded with 100 to 1,000 lb of force. To determine ability of the cast to protect the distal portion of the limb from weight-bearing loads, strains were recorded with the limb in 1 of the 3 casts and with it unsuppor...
Peeters MWJ, Thursby JJ, Watson HE, Berner D.Palmaroproximal-palmarodistal oblique (PaPr-PaDiO) radiographs are regularly obtained for a full evaluation of the navicular bone (NB). Despite their routine use, different acquisition techniques are described. Objective: To determine optimal foot placement and beam angle for obtaining PaPr-PaDiO views. Methods: In vitro experiment. Methods: A convenience sample of 26 disarticulated forelimbs were placed in six different positions using a leg press to mimic the weight-bearing position. In each position, navicular PaPr-PaDiO images were obtained with eight different beam angles. The resulting 1...
Körber HD.Radiographic examination is a valuable means for the identification of ossified lateral cartilage. The extent and stages of development of the ossification can be determined. The active stage of development of ossified lateral cartilage, which by itself can provoke lameness, can be defined. By means of the X-ray it is tried to differentiate the three kinds of ossification: the enchondral, the peri- and parachondral ossification of the lateral cartilage. Centres of ossification and fractures of the ossified lateral cartilage are described.
Cornelissen BP, Rijkenhuizen AB, Kersten W, Németh F.In chronical proximal sesamoid bone lameness it is difficult to localise the exact site of pain. A specific diagnostic analgesia is not available because of a deficiency of detailed information about the nerve supply to the proximal sesamoid bones and surrounding area. A macroscopic study of the nerve distribution to the proximal sesamoid bones of 10 foals and 5 adult horses revealed that these bones are innervated by two branches, in this study called the medial and lateral sesamoidean nerve, respectively, originating from the medial and lateral palmar nerve. Histology of the left forelimbs o...
Baxter GM, Moore JN, Budsberg SC.An open radial fracture in an adult horse (450 kg) was repaired by internal fixation, using two 18-hole 4.5-mm broad dynamic compression plates and 5.5- and 4.5-mm bone screws. The fracture healed completely, but when evaluated 9 months after surgery, the horse was lame on the fractured limb at a trot. Local infiltration of anesthesia along the distal half of the bone plates greatly ameliorated the lameness, suggesting that the plates were irritating the soft tissues and extensor tendons along the cranial and lateral aspects of the antebrachium. Both bone plates were removed simultaneously wit...
Cole R, Taintor J, Hanson R.An adult gelding was evaluated for bilateral intermittent forelimb lameness of approximately 2 years duration. The horse was found to have grade 2/5 upper motor neuron-general proprioception ataxia with no cranial nerve deficits. During radiographic and gross necropsy examinations a novel atlanto-axial malformation of possible congenital etiology was found. Un hongre adulte a été évalué pour une boiterie intermittente de la jambe avant présente depuis environ 2 ans. On a constaté que le cheval avait une ataxie de proprioception générale des motoneurones supérieurs de grade 2/5 sans d...
