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.
Branch MV, Murray RC, Dyson SJ, Goodship AE.Osteoarthritis (OA) is a common cause of distal tarsal pain, but disease development is poorly understood. Awareness of normal tarsal structure and function is important in order to understand the pathogenesis of OA. Thickening of the subchondral bone (SCB) plate has been related to the development of OA, but SCB plate patterns in the equine tarsus have not been documented. Objective: There is a repeatable pattern of SCB thickness across the distal tarsal joints, and specifically that thickness would be greatest dorsally and laterally. Methods: Twenty cadaver tarsi were collected from mature h...
Devine DV, Moll HD, Bahr RJ.This case report describes chronic sepsis of the right temporomandibular joint in a juvenile horse. Diagnostic work-up included physical examination, radiography, and computed tomography. Humane euthanasia was indicated due to the chronicity of the condition, prognosis, and financial constraints.
Florin M, Arzdorf M, Linke B, Auer JA.To compare the mechanical properties of 4 stabilization methods for equine long-bone fractures: dynamic compression plate (DCP), limited contact-DCPlate (LC-DCP), locking compression plate (LCP), and the clamp-rod internal fixator (CRIF--formerly VetFix). Methods: In vitro mechanical study. Methods: Bone substitute material (24 tubes) was cut at 20 degrees to the long axis of the tube to simulate an oblique mid-shaft fracture. Methods: Tubes were divided into 4 groups (n=6) and double plated in an orthogonal configuration, with 1 screw of 1 implant being inserted in lag fashion through the "fr...
Eby G.Arthritis is inflammation in a joint often with joint damage, usually accompanied by pain, swelling and stiffness, resulting from infection, trauma, degenerative changes, metabolic disturbances, autoimmune or other causes. It occurs in various forms, including rheumatoid arthritis, osteoarthritis, bacterial arthritis and gout. Gallium III can inhibit the production of inflammatory cytokines, such as IL-1beta, produced by macrophage-like cells in vitro. A dose-dependent inhibition of IL-1beta and TPA stimulated MMP activity by gallium nitrate at increasing concentrations occurs, demonstrating t...
Grace ND, Rogers CW, Firth EC, Faram TL, Shaw HL.To measure the nutritive value of pasture in terms of digestible energy intake (DEI) and dry matter (DM) digestibility, and the effects of increased calcium (Ca) intakes on apparent mineral absorption and bone characteristics in grazing weanling Thoroughbreds. Methods: DM intake (DMI) and DEI were determined in 16 weanling Thoroughbreds grazing pasture from their daily faecal DM output, measured over 8 days, divided by the DM indigestible fraction (1-digestible DM) determined in a 6-day digestibility trial. The DM, gross energy content, crude protein, soluble carbohydrate, acid detergent fibre...
Secombe CJ, Firth EC, Perkins NR, Anderson BH.Third carpal bone (C3) disease is a significant cause of lameness in Standardbred and Thoroughbred horses. The bone density of C3 increases as a result of exercise, reducing the compliance of the bone and predisposing it to injury. Currently, the most widely used method of diagnosis is subjective radiography using the tangential view. Radiographically, increases in bone mineral density (BMD) appear as sclerosis but it is not known at what point increases in sclerosis indicate the onset of disease or increased risk of C3 fracture. A quantitative assessment of the BMD of C3 in horses would impro...
Bigley RF, Griffin LV, Christensen L, Vandenbosch R.The interfacial strength of secondary osteons from the diaphysis of the Thoroughbred equine third metacarpal was evaluated using the fiber pushout test. The pushout was performed on 300-500 microm sections of 4x4x15 mm bone blocks machined from four anatomic regions of the cortex. Pushout strength was evaluated from proximal to distal location within the diaphysis on four osteon types classified under polarized light on adjacent histologic sections from each block. The shear strength of the interfaces were estimated from shear lag theory. Differences were found in the interfacial strength of o...
van Veen L, de Greef RJ.A non-displaced radialfracture of a horse was,diagnosed. The horse had an open fracture resulting from external trauma. A diagnosis was made on radiographs taken 48h after trauma. The horse was treated conservatively by box rest and Robert-Jones bandages. After 7 days the wound was opened to let the wound drainage necrotic material and small sequesters and was washed every other day. After 7 weeks, radiographs showed complete consolidation. Four months after the injury the horse was back to work at his former level and is still working two years after the incident.
Pearce GP, May-Davis S, Greaves D.To investigate the occurrence of geometrical asymmetries in the macro-architecture of left and right femurs from Thoroughbred racehorses previously used in competitive training and racing in New South Wales, Australia. Methods: Detailed postmortem measurements were made of 37 characteristics of left and right femurs from eleven Thoroughbred racehorses euthanased for reasons unrelated to the study. Measurements focused on articulating surfaces and sites of attachment of muscles and ligaments known to be associated with hindlimb locomotion. Results: Five measurements were significantly larger in...
Shrivastava SK, Kailash .Extracorporeal shock wave therapy in orthopedics and traumatology is still a young therapy method. Since the last few years the development of shock wave therapy has progressed rapidly. Shock waves have changed the treatment of urolithiasis substantially. Today shock waves are the first choice to treat kidney and urethral stones. Urology has long been the only medical field for shock waves in medicine. Meanwhile shock waves have been used in orthopedics and traumatology to treat insertion tendinitis, avascular necrosis of the head of femur and other necrotic bone alterations. Another field of ...
Davies HM, Watson KM.The aims of this study were to test whether longer third metacarpal (MC3) bones had thicker dorsal cortices in a group of racehorses that were exercising at similar maximum speeds, and to establish if horses with larger differences in length between their right and left MC3 bones showed larger differences in the dorsal cortical thickness between the two limbs. Methods: An observational study. Methods: Forty Thoroughbred racehorses aged between 2 and 6 years and in training at racing speed at two racing stables were used. Two sets of radiographs of each left and right metacarpus of each horse w...
Da Costa Gómez TM, Barrett JG, Sample SJ, Radtke CL, Kalscheur VL, Lu Y, Markel MD, Santschi EM, Scollay MC, Muir P.Functional adaptation of bone normally protects the skeleton from fracture during daily activity. Accumulation of microcracking and loss of osteocytes have been implicated in the regulation and initiation of targeted (reparative) remodeling of bone and, in certain situations, the development of fatigue or stress fracture. We performed a histologic study of the dorsal cortex of the mid-diaphysis of the third metacarpal (Mc-III) bone of Thoroughbred racehorses after bones were bulk-stained in basic fuchsin and transverse calcified sections were prepared. The Thoroughbred racehorse is an extreme ...
Andritzky J, Rossol M, Lischer C, Auer JA.To compare the precision obtained with computer-assisted screw insertion for treatment of mid-sagittal articular fractures of the distal phalanx (P3) with results achieved with a conventional technique. Methods: In vitro experimental study. Methods: Thirty-two cadaveric equine limbs. Methods: Four groups of 8 limbs were studied. Either 1 or 2 screws were inserted perpendicular to an imaginary axial fracture of P3 using computer-assisted surgery (CAS) or conventional technique. Screw insertion time, predetermined screw length, inserted screw length, fit of the screw, and errors in placement wer...
Read EK, Chandler D, Wilson DG.To compare the biomechanical characteristics and mode of failure of 2 techniques using parallel 5.5 mm screws for pastern joint arthrodesis in horses. Methods: Randomized block design, for horse (1-5), method of fixation (two 5.5 mm screws versus three 5.5 mm screws), side (right, left), and end (front, hind). Constructs were tested to failure in 3-point bending. Methods: Twenty limbs (5 cadavers). Methods: A combined aiming device was used to facilitate screw placement. Two parallel 5.5 mm screws were inserted in lag fashion in 1 limb of a pair, and three 5.5 mm screws were inserted in the co...
Morris MD, Matousek P, Towrie M, Parker AW, Goodship AE, Draper ER.Picosecond time-resolved Raman spectroscopy in equine cortical bone tissue is demonstrated. Using 400-nm pulsed laser excitation (1 ps at 1 kHz) it is shown that Kerr cell gating with a 4-ps window provides simultaneously time-resolved rejection of fluorescence and time-resolved Raman scatter enabling depth profiling through tissue. The Raman shifts are the same as those observed by conventional cw Raman spectroscopy using deep-red or near-infrared lasers. The time decay of Raman photons is shown to fit an inverse square root of time function, suggesting propagation by a diffusive mechanism. U...
Firth EC, Rogers CW, Doube M, Jopson NB.To determine the effect of a known training regimen on the size and mineral content of the third metacarpal (Mc3) and third metatarsal (Mt3) bones of 2-year-old Thoroughbred horses trained on racetracks. Methods: Mc3 and Mt3 of seven horses trained on grass and sand tracks were scanned at several sites using conventional quantitative and peripheral computed tomography (CT). Bone dimensions and density in the diaphysis and epiphysis were compared with those from seven untrained horses. Calcein label was injected in two clusters, during Weeks 9 and 12. The extent and rate of diaphyseal modelling...
Boyde A, Firth EC.To characterise and explain the increase in density evident by computerised tomography (CT) and radiography in companion studies as a response to training, in bone in the palmar and dorsal regions of the condyles of the third metacarpal bone (Mc3) of 2-year-old Thoroughbred horses. Methods: Compositional back-scattered electron (BSE) imaging in scanning electron microscopy (SEM) and confocal scanning laser microscopy (CSLM) were conducted on polymethyl methacrylate (PMMA)-embedded mediolateral slices of the right distal Mc3 from seven 2-year-old Thoroughbred horses trained on a racetrack and s...
Davies HM.To confirm that the midshaft dorsal cortex of the third metacarpal bone experienced higher compressive strains during fast exercise than the medial or lateral cortices, and that the strain peak occurred earlier in the hoof-down phase of the stride on the dorsal cortex than the medial or lateral cortices. Methods: Observations of a single horse. Methods: Strains were collected from a single, sound, 3-year-old Thoroughbred mare during treadmill exercise from rosette strain gauges implanted onto the medial, lateral and dorsal surfaces of the midshaft of the right cannon bone, simultaneously with ...
Firth EC.Detecting changes in bone during growth, training, rest from competition (spelling), and disease in horses requires imaging techniques that have a high level of accuracy and precision. Currently, most imaging techniques used in horses do not possess such characteristics and are more suitable for detecting end-stage disease than subtle changes. Some are incapable of detecting changes in bone size. Non-planar techniques should be used for estimating or determining bone strength. This review outlines available imaging techniques and shows why cross-sectional procedures are required to accurately ...
Secombe CJ, Firth EC, Perkins NR, Bailey D, Anderson BH.To determine whether variation in x-ray-beam angle significantly affected photodensity of the third carpal bone (C3) in the horse using the tangential radiographic view, and indirectly determine whether radioabsorptiometry (RA) could be used to assess differences in bone mineral density (BMD) of C3 between exercised and non-exercised horses. Methods: The left distal carpal row was isolated post-mortem from 2-year-old Thoroughbred horses that had been either exercised (n=7) for up to 14 weeks using a standard training regimen for racehorses, or not exercised (n=7). The effect of variation in x-...
Norrdin RW, Bay BK, Drews MJ, Martin RB, Stover SM.An overload arthrosis occurs consistently in the palmar region of the metacarpal condyle of the equine fetlock (metacarpophalangeal) joint characterized by subchondral bone sclerosis, devitalization and mechanical failure leading to collapse of the overlying articular cartilage. Samples were selected of joints with mild, moderate, and severe subchondral sclerosis, in which cartilage collapse had not yet occurred. An additional group that had severe sclerosis with focal rarefaction suggesting impending collapse was also studied (n=5/group). Parasagittal slices were milled to 2.0 mm thickness an...
Firth EC, Rogers CW, Jopson N.The response of equine bone to training has not been quantified in racetrack trained horses, only in treadmill exercised horses. Seven two-year-old thoroughbred fillies were trained on sand and grass at a racetrack, in a typical New Zealand flatrace training regime. The horses were exercised 6 days per week for up to 13 weeks. During the day the horses were confined in 4 x 4m sand yards, and were stalled at night. Another 7 fillies of the same age were allowed free exercise in grass yards. The bones of the animals were available after the 13 week experimental period, and were examined using a ...
Benninger MI, Deiss E, Ueltschi G.We describe the clinical findings and radiographic abnormalities of a horse with a bipartite distal phalanx and a bipartite navicular bone of the right forelimb. Associated findings including suspected keratoma and degenerative joint disease of the distal interphalangeal joint are described and possible etiologies are discussed.
Barber SM.The horse, a flight animal that is used extensively by man, frequently receives injuries to its neck or head that result mostly from its management and handling. Better facilities, training of the horse, and horsemanship skills of the handler could prevent many of these injuries. Because many body systems can be involved, with potentially major consequences regarding health, performance, and appearance, early recognition of trauma and competent treatment are crucial. Progress has been made in the treatment of some tracheal and esophageal injuries. Severe tracheal trauma and rupture of the esop...
Gibson VA, Stover SM, Gibeling JC, Hazelwood SJ, Martin RB.We hypothesized that recently formed, incompletely mineralized, and thus, relatively deformable osteons in the equine third metacarpus enhance in vitro load-controlled fatigue life in two ways. Macroscopically, there is a compliance effect, because reduced tissue elastic modulus diminishes the stress required to reach a given strain. Microscopically, there is a cement line effect, in which new osteons and their cement lines more effectively serve as barriers to crack propagation. We studied 18 4 x 10 x 100 mm beams from the medial, lateral, and dorsal cortices of metacarpal bones from 6 thorou...
Johnson NL, Galuppo LD, Stover SM, Taylor KT.To compare screw insertion variables and pullout mechanical properties between AO 6.5-mm cancellous and 7.3-mm cannulated bone screws in foal femoral bone. Methods: A paired, in vitro mechanical study. Methods: Seven pairs of femora from immature (1-7 months) foals. Methods: The 6.5 cancellous and 7.3-mm cannulated screws were inserted at standardized proximal and distal metaphyseal, and mid-diaphyseal locations. Insertion torque, force, and time to drill, tap (6.5-mm cancellous), guide wire insertion (7.3-mm cannulated), and screw insertion were measured. Screw pullout properties (yield and f...
Verschooten F, Gasthuys F, De Moor A.An experimental and clinical study to investigate the aetiology of distal splint bone fractures is described. In vitro, extension of the fetlock did not appear to alter the position of the distal ends of the splint bones, although tension in the interosseous tendons increased. Flexion of the fetlock resulted in slight outward displacement of the distal ends of the splint bones. It is suggested that concurrent desmitis of the suspensory ligament can cause movement of the ends of the splint bones thus predisposing to a fatigue fracture. In a clinical study of 87 horses, 114 splint bone fractures...
van den Bogert AJ, van Weeren PR, Schamhardt HC.In movement analysis of the horse, large errors result from movements of the skin with respect to the underlying bones. A generally applicable, two-dimensional, method for correction of these skin-movement errors in kinematic data has been developed. It was tested on a kinematic analysis of the hindlimb in a walking pony. The results indicate that without correction for skin-movement errors, misreadings of up to 15 degrees in the knee angle and 30% in the moment arm of the gastrocnemius muscle can be expected.
Baxter GM, Doran RE, Allen D.Proximal open comminuted fractures of the fourth metatarsal bone (Mt IV) in eight horses were treated by complete removal of the affected bone and antimicrobial therapy. Two horses had concurrent septic arthritis of the tarsocrural or distal tarsal articulations, and five horses had radiographic evidence of osteomyelitis and sequestration of the affected bone. Five horses became athletically sound for their intended use, two horses with septic arthritis had residual lameness but were pasture sound, and one horse was lost to follow-up. Excision of the entire bone appears to be an acceptable tre...
Bassage LH, Ross MW.Ten horses admitted for lameness evaluation including bone scintigraphy had enostosis-like lesions, described scintigraphically as focal or multifocal areas of intense increased radioisotope uptake within the medullary cavity of one or more long bones, and radiographically as one or multiple round to irregularly shaped radiopacities within the medullary cavity, often in close proximity to the nutrient foramen. There were 6 Thoroughbreds, one male, one female and 4 geldings, 3 Standardbreds, all geldings and one Appaloosa gelding; age 3-10 years. Enostosis-like lesions were seen in the tibia (5...
Montesso F, Wright IM.Clinical and radiographic examinations of three horses with histories of trauma and/or wounds to the stifle revealed chip fractures from the medial trochlear ridge of the femur of one of them and from the lateral ridges of the femurs of the others. The joints were evaluated and the fragments of bone were removed by arthroscopy. The results were good in all three horses.
Moreno CR, Santschi EM, Janes J, Liu J, Kim DG, Litsky AS.Determine compression generated by lag and neutral screws over 12 h using two bone analogs. Methods: Experimental study. Methods: Bone analogs were made of composite synthetic bone (CSB) or three-dimensional printed polylactic acid (PLA). Analogs had a 2 mm exterior shell with a 10 mm thick internal layer of open-cell material. Methods: Bone analogs were opposed, making a 4-sided box with open ends. A central channel contained the sensor and the screws passed through it to engage both paired analogs. Four screw/analog conditions were tested: neutral and lag screw with bicortical engageme...
Hunt WF, Thomas VG, Stiefel W.Studies of growth and conformation require statistical methods that are not applicable to subjective conformation standards used by breeders and trainers. A new system was developed to provide an objective approach for both science and industry, based on analysis of video images to measure aspects of conformation that were represented by angles or lengths. A studio crush was developed in which video images of horses of different sizes were taken after bone protuberances, located by palpation, were marked with white paper stickers. Screen pixel coordinates of calibration marks, bone markers and...
Kristoffersen M, Hetzel U, Parkin TD, Singer ER.To investigate whether microfractures and alterations in the trabecular bone area are associated with catastrophic bi-axial proximal sesamoid bone fractures (PSBF). Methods: Proximal sesamoid bones (PSB) from 10 racehorses with PSBF and from 10 control racehorses without musculoskeletal injury were examined using the bulk basic fuchsin method. Bone histomorphometric and microfracture analysis was performed, and cases and controls compared using two-sample t-test, paired t-test, and Mann-Whitney U test. Results: There was no significant difference in the microfracture density and the trabecular...
Ramzan PHL.Some sagittal plane fractures of the equine third carpal bone are difficult to detect with conventional radiographic projections. Objective: To describe a novel radiographic projection for the detection of sagittal plane slab fractures of the equine third carpal bone. Methods: Retrospective study of radiological records. Methods: From a first opinion Thoroughbred racehorse caseload, cases were included for analysis if sagittal fracture of the third carpal bone was evident on a dorsoproximal lateral-palmarodistal medial oblique (DPrL-PDiMO) projection of the distal row of carpal bones and not v...
Park RD, Morgan JP, O'Brien T.The incidence of chip fractures in carpal bones and the distal end of the radius in the horse was determined. The radial carpal bone was involved 50% of the time, with the distal end of the radius and intermediate and 3rd carpal bones being involved less frequently. Nine locations were designated where chip fractures in the carpus occurred most often.
A higher incidence of fractures was noticed from the right carpus, with slab fractures of the 3rd carpal bone being noticed more frequently on the right front limb.
Jalim SL, McIlwraith CW, Goodman NL, Anderson GA.The effectiveness and best method to manage dorsal cortical stress fractures is not clear. This study was performed to evaluate the success of lag screw fixation of such fractures in a population of Thoroughbred racehorses. Objective: Lag screw fixation of dorsal cortical stress fractures is an effective surgical procedure allowing racehorses to return to their preoperative level of performance. Methods: The records of 116 racehorses (103 Thoroughbreds) admitted to Equine Medical Centre, California between 1986 and 2008 were assessed. Information obtained from medical records included subject ...
Adiloglu S, Giray CB, Kulac I, Usubutun A, Aktas A.To compare the performance of collagenated bone graft substances with different collagen ratios after sinus floor augmentation. Methods: The cross-sectional study was conducted at Hacettepe University, Ankara, Turkey, from September 2011 to September 2013. Sinus floor augmentation was done with two different equinederived xenografts in patients before dental implant application. Of the two randomised groups, one was treated with 100% collagenated bone mix (Group A), and the other half with 90% collagenated bone mix + 10% collagen gel (Group B).Six months after sinus augmentation, prior to dent...
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.