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.
Modransky P, Thatcher CD, Welker FH, Booth LC.This research journal article documents a rare case of a five-day-old foal suffering from a congenitally malformed hoof and the associated lameness. The disorders studied were unilateral navicular bone agenesis […]
Kempson SA.Two types of defect were observed when hoof clippings from horses with brittle feet were viewed in the scanning electron microscope. The first defect showed a loss of structure and horn in the stratum externum. This defect was remedied after biotin treatment. The second defect showed poor attachment of the horn squames and failed to respond to biotin treatment alone. An improvement in this case was achieved by the addition of powdered limestone to the diet.
The Journal of heredityMay 1, 1987
Volume 78, Issue 3 171-177 doi: 10.1093/oxfordjournals.jhered.a110351
Leone NC, Shupe JL, Gardner EJ, Millar EA, Olson AE, Phillips EC.Hereditary multiple exostosis (HME), a bone tumor first described by Virchow, has been studied over a period of 15 years on a comparative basis. The horse, an excellent biomedical model for this physically deforming multiple bone tumor in man, has been utilized in this study. The etiology, hereditary pattern, potential for malignancy and other aspects of this strange affliction need additional clarification. This in-depth study of 261 individuals from 144 families was compared with that of 55 horses bearing the HME trait, selectively bred and studied over the same period. Important information...
Greet TR.The case histories of three young thoroughbred racehorses with displaced lateral condylar fractures combined with an axial fracture of the lateral sesamoid bone are described. In two cases the condylar fracture was repaired surgically but both horses developed severe degenerative joint disease and remained lame. The third horse was destroyed humanely. It is important that axial fractures of the sesamoid bone are recognised so that a poorer prognosis can be given for treatment of condylar fractures in racing thoroughbreds.
Bukowiecki CF, Bramlage LR, Gabel AA.Forty-eight limbs of 12 freshly euthanized horses were used to generate data on the strength of the equine suspensory apparatus. The point of failure of the suspensory apparatus of each limb was determined. Immediately before euthanasia, 6 of the 12 horses (thoroughbreds and standardbreds) had been engaged in active training or racing, and six horses in stall and/or pasture activity. In the actively training or racing horses, the point of acute failure of the suspensory apparatus was within the proximal sesamoid bones in 20 (83%) limbs (resulting in 17 apical fractures, 2 basilar fractures, an...
Auer JA, Watkins JP.Fifteen cases of radial fractures in adult horses weighing more than 300 kg are discussed. Four of the horses were destroyed on humane grounds immediately because of a poor prognosis and expense of internal fixation; and two horses at five days and five weeks, respectively after treatment by cast application was initiated. Internal fixation was used in nine horses but of these only two horses recovered completely and resumed their former activities. In eight cases, two plates were applied, one lateral or medial and the other cranial. The internal fixation techniques of all nine horses were scr...
Kold SE, Hickman J, Meisen F.The quantitative aspects of equine cancellous bone graft incorporation and the possibility of influencing graft incorporation by daily exposure to a pulsed electromagnetic field (PEMF) was studied in eight yearling ponies. In order to be able to quantify formative aspects of graft remodelling, a double and treble tetracycline intravital labelling technique was used. Intravital radiographs were obtained at regular intervals throughout the trial, but were found to be of little assistance in assessing any differences between stimulated and non-stimulated grafts. The ponies were humanely destroyed...
Kold SE, Hickman J, Meisen F.The incorporation of autogenous cancellous bone graft was studied in eight yearling ponies. The site for the defect to be grafted was chosen so that the effect on the graft, of both the host cortical and trabecular bone, could be assessed. To obtain information concerning the vitality of the graft and the dynamic aspects of the modelling and remodelling processes of graft incorporation, a double and treble tetracycline intravital labelling technique was used. Radiographs of the graft and host tissues of all ponies were obtained regularly, but were of little assistance in assessing graft incorp...
Firth EC.The site of occurrence of 490 bone sequestra in horses and cattle was investigated. Most sequestra occurred in the proximal half of the third metatarsal bone and the third metacarpal bone. The most common clinical features included swelling, presence of a draining tract, impaired function and delayed wound healing. These diagnostic features, and the preferred time to confirm the diagnosis by radiological examination are discussed. The surgical treatment is relatively simple and the prognosis favourable in most cases. It is suggested that soft tissue injury and the presence of infection are of ...
Bowman KF, Sweeney CL, Tate LP.A medial condylar fracture of the third metatarsal bone in a 2-year-old Thoroughbred filly was repaired successfully by use of compression bone plating. At discharge from the hospital, thickening of the metatarsus was evident, and proliferative changes were associated with the site of bone plate application. It was expected that these changes would limit the filly's use as a racehorse, and a return to training was not recommended. Especially in horses that may return to racing, use of compression bone plating initially should not replace stall rest or lag screw fixation treatment of this type ...
Badoux DM.The morphology of the bones of the equine tarsus has distinct kinematical and kinetic implications which are primarily expressed in the helical motion of the talocrural joint and in the transmission of forces by the rigid conformation of the subtalar articulations.
Caron JP, Barber SM, Doige CE, Pharr JW.This study documented the normal histologic features of the equine metacarpal and metatarsal periosteum and characterized its osteogenic response to surgical manipulation. Two periosteal flaps were elevated from the dorsomedial matacarpal and metatarsal diaphysis in each of three limbs of four yearling and four adult lightbreed horses. The superficial metacarpal cortex under the flap was resected with a bone chisel in one-half of the horses and was undisturbed in the remainder. One periosteal flap in each limb was excised and the other flap was replaced and secured by sutures. All limbs in the...
Cheal EJ, Snyder BD, Nunamaker DM, Hayes WC.The objective of this investigation was to examine the stress-morphology relationships for trabecular bone around implants with different surface characteristics. Stainless steel spheres with either a polished surface or a sintered-bead porous coating were implanted unilaterally into equine patellae and maintained for a 6 month period. Stereological methods were used to quantify the trabecular bone morphology and finite element analyses were performed to predict the trabecular bone stresses. In general, the remodeling response around the smooth implants was greater than that around those porou...
Rose PL, Hightower D, Auer JA, Hulse D, Schenk RK.In the present study, radionuclide scintigraphy and radiography were used to evaluate the rate and degree of healing that occurred in surgically created subchondral bone defects in horses. Following radionuclide scintigraphy and radiography the horses were killed, and histomorphometric analysis was performed on the defect sites. The histomorphometric results were compared to the radionuclide scintigraphic and radiographic results to determine which noninvasive technique provided the most accurate information concerning healing of the bone defects. It was concluded that radionuclide scintigraph...
Firth EC, Greydanus Y.The talus and proximal and distal epiphysis of the humerus, radius, femur, tibia and distal metacarpus of 20 foals aged 0 to 150 days were obtained at necropsy and sawn sagittally into slabs 4 to 8 mm thick. The thickness of the cartilage (articular cartilage and unossified epiphyseal cartilage) was measured in three to five places in each slab, using a sliding calliper. In most epiphyses, the site, or sites, of thickest cartilage was constant in all foals examined. The difference between thickest and thinnest cartilage within one epiphysis was greatest in distal femora and least in distal met...
Vachon A, Bramlage LR, Gabel AA, Weisbrode S.To determine the effect of subchondral bone drilling (forage) on the cartilage repair process after injury has occurred, a cartilage defect (1 cm in diameter) was created on the radial facet of the proximal surface of each third carpal bone in 6 adult horses. In one of the third carpal bones (right or left thoracic limb) of each horse, a 1-cm cartilage defect was created, and 5 holes (1 mm in diameter and 10 mm deep) were drilled through the subchondral bone into the cancellous bone. In the other thoracic limb, an identical defect was created, but not drilled. Analyses of cell numbers and type...
Hurtig MB, Fretz PB.The radiocarpal and middle carpal joints of 4 clinically normal horses and 24 necropsy specimens were examined with an arthroscope to describe the topographic anatomy of these joints. The carpal bones of the radiocarpal joint had congruent articular surfaces in extension, but carpal flexion resulted in a stairstep between the radial and intermediate carpal bones. The variable surface anatomy, as well as the restricted synovial space and the technical limitations of the arthroscope, contributed to the need for more than one arthroscopic approach to the radiocarpal joint to ensure a thorough exa...
Sanders-Shamis M, Bramlage LR, Gable AA.The case records, radiographs and treatment results of 47 consecutive equine radius fractures presented to The Ohio State University Veterinary Hospital from 1975 to 1985 were examined retrospectively. Chip fractures and incomplete fractures were not considered. Both diaphyseal fractures and fractures involving the physes were included. Diaphyseal fractures were placed into three major categories: comminuted, oblique and transverse; and subclassified as proximal, mid-diaphyseal, or distal. Fractures involving a physis were classified using the Salter-Harris classification system. The horses ra...
Glade MJ, Luba NK, Schryver HF.The application of transmission ultrasonics to the equine cannon holds promise as a method of monitoring metacarpal and metatarsal development, quality and integrity under a variety of experimental and field conditions. The validity of relating the velocities of sound pulses transmitted through the cannon to the mechanical breaking strengths of these bones was tested in two studies. Breaking strengths calculated from the sound velocities through sections of the metacarpal bones from 14 yearling ponies and 12 yearling horses were highly correlated with the mechanical breaking strengths of those...
Hardy J, Marcoux M, Eisenberg H.A suspected lesion of osteochondrosis dissecans involving the anconeal process of the humeroradial joint (elbow) was found in 2 horses. In horse 1, the lesion was found during routine lameness examination, during which alleviation of the lameness was achieved after intra-articular anesthesia of the elbow. In horse 2, the lesion was found at necropsy. Horse 1 responded satisfactorily to intra-articular treatment with hyaluronic acid. Both horses also had other joints affected with osteochondrosis dissecans.
Tozaki T, Miyake T, Kikuchi M, Kakoi H, Hirota KI, Kusano K, Ishikawa Y, Nomura M, Kushiro A, Nagata SI.Thoroughbred racehorses are produced by mating small numbers of Arabian stallions and native British mares, and have been improved by selection of horseracing performance for about 300 years. While these improvements led to good performance as racehorses, they exposed horses to numerous medical disorders, aggravated by extensive exercise. Fractures are frequent medical disorders in Thoroughbred racehorses. In this study, fracture heritability was estimated using 3,927 Japanese Thoroughbred racehorses to elucidate the risk of racehorse fractures. The heritability estimates of all examined frac...
Jukema GN, Settner M, Dunkelmann G, Tilkorn P, Niemeyer OW, Hierholzer G.In a case of I degree open multifragmentary metacarpal fracture of a 4-week-old Arabian foal, an osteosynthesis with the Ilizarov ringfixator was performed. Immediate full weight-bearing (100 kg) was possible, demonstrating the high stability of the Ilizarov ringsystem. After 12 weeks, sufficient bony union was achieved, and the fixator could be removed. At that time, the body weight of the foal was 170 kg. In our opinion, this case proves the high stability and efficiency of the ringsystem under difficult and unusual conditions.
Peterson ML, Srinath S, Murphy J.A new instrument is presented which is capable of high resolution acoustic imaging at relatively low frequencies. This approach results in increased complexity of the signal processing required and reduced throughput of the instrument. However, these disadvantages are amply compensated by the ability to create velocity scan images of materials with either high attenuation or low material velocities. These measurements are not possible using traditional/acoustic microscopes. The initial performance of the new instrument is demonstrated using thin samples of shim materials to show that acceptabl...
Losonsky JM, Kneller SK.Bilateral metacarpophalangeal radiographs of 100 Standardbreds were examined for visualization and location of nutrient foramina of the proximal phalanx. Foramina were located in the dorsal or palmar cortex or were not visible radiographically. Of 100 horses, 45 had bilaterally symmetrical foramina. Left and right proximal phalangeal foramina were asymmetrical in the remaining 55 horses. Of 200 proximal phalangeal foramina (in 100 horses), 78 were in the dorsal cortex, 61 were in the palmar cortex, and 61 were not visible radiographically. A significant (P = 0.05) effect of age or sex could no...
Scotti E, Jeffcott LB.An in vitro study on the calcaneus of adult horses (n = 5) and foals (n = 10) was carried out using radiographic photodensitometry, single photon absorptiometry, transmission ultrasound velocity and chemical analysis. Data for trabecular bone content, ash, calcium and phosphorus levels were obtained. As techniques for assessing bone quality, ultrasound velocity was not sufficiently sensitive nor accurate and radiographic photodensitometry was found to be limited value. Photon absorptiometry was both accurate and reproducible, although some variation in bone mineral content and bone mineral den...
Kraus BM, Ross MW, Boswell RP.Two 2-year-old pacers, a 3-year-old pacer and a 2-year-old-trotter with acute forelimb lameness were admitted for nuclear scintigraphic examination. Horses were grade 3-4/5 lame. There was increased radiopharmaceutical uptake (IRU) in the distal cranial medial aspect of the humerus in one horse and along the caudal humeral cortex in the other three horses. Two of the four horses were affected bilaterally. Radiographic abnormalities consisted of thickening of the caudal cortex of the mid-diaphysis of the humerus but radiographic changes were not present in all horses. All horses were managed wi...
Cassotis NJ, Stick JA, Arnoczky SP.A 4-month-old Quarter Horse colt was admitted for repair of an open, comminuted fracture of the proximal portions of the diaphyses of the left second, third, and fourth metatarsal bones. Initial repair included internal fixation and cancellous bone graft. However, the third metatarsal bone became infected and failed to heal. After removal of infected portions of the bone, a 5-cm, fullthickness cortical allograft was placed in the defect. Rigid internal fixation provided stability for the allograft and remaining fracture fragments so that the horse was able to bear weight on the second and four...
Driesang I, Böhm D.Both hock joints were examined clinically, radiologically and scintigraphically in 80 horses with special regard to bone spavin. The positive x-ray and bone scan results corresponded in most cases. It was evident that there was no correlation between degree of lameness and/or extent of radiological findings and increased radioactive uptake in the joint. Scintigraphic evaluation may demonstrate early changes at the onset of bone spavin as well as the frequent bilateral nature of the condition.
White NA, Blackwell RB, Hoffman PE.Salter-Harris type II proximal tibial fractures were repaired in two 1-month-old foals, using a dynamic compression plate. The plate was placed on the medial aspect of the tibia, and a single cancellous bone screw was used to reduce the proximal fragment displacement. The plate provided fixation during healing and functioned as a transphyseal bridge, which induced a disparity in growth and corrected a slight lateral angulation of the limb. Limb growth after plate removal was normal.
Verdegaal EJ, Kroeze EJ, Dik KJ, van Oijen LA, Sloet van Oldruitenborgh-Oosterbaan MM.A 9-year-old Dutch Warmblood mare was presented with a history of abnormal behaviour and acute facial nerve paralysis on the left side. Clinical examination revealed a slight head tilt and a corneal ulcer of the left eye. The base of the left ear was warm and painful. Endoscopic examination of the left guttural pouch showed thickening of the proximal part of the stylohyoid bone. Computer tomography revealed a left-sided prominent bony enlargement of the middle and proximal part of the stylohyoid bone and the tympanic bulla, fusion of the temporrhoid joint, and osseous proliferation of the pars...
Nevins M, Cappetta EG, Cullum D, Khang W, Misch C, Ricchetti P, Sclar A, Wallace SS, Ho DK, Kim DM.Conventional dentoalveolar osseous augmentation procedures for creating bone volume for dental implant placement often involve the use of grafting materials with or without barrier membranes to foster selective cell and tissue repopulation. A study was conducted to determine the efficacy of equine particulate bone (Equimatrix, Osteohealth) to augment the creation of new bone and preserve the volume of bone at extraction sites for the purpose of placing an implant in an optimal position for restoration. Clinical and histologic evidence supported the suitability of equine particulate bone for ex...