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.
Lescun TB, Adams SB, Nauman EA, Breur GJ. The aim of this study was to determine how increasing stiffness of fracture site tissues distal to the pins in an equine distal limb transfixation cast influences stress at the bone-pin interface, within the bones distal to the transcortical pins, and contact pressure between the foot and the cast. Methods: A transfixation cast finite element model was used to compare the bone-pin interface stress, pin stress, bone stress distal to the pins and contact pressure between the foot and the cast, using six stiffness values for a composite tissue block representing progressive stages of fractu...
Pérez-Nogués M, Derham A, Marmion J, True Baker W.Shallow lucencies less than 4 mm deep into the medial femoral condyle (MFC) are frequent in Thoroughbred horses undergoing screening sales radiographs. It is unclear if these shallow defects are precursors to larger cystic lesions or if they are fully developed defects that remodel into a flattened femoral condyle. Objective: To evaluate radiological lucencies of the MFC and their progression in size, in a cohort of Thoroughbred horses, ranging from 5 to 18 months of age and to report on the racing careers of these horses compared to their maternal siblings free of stifle pathology. Methods:...
Mageed M, Elfadl A.An 18-year-old Quarter Horse mare was evaluated because of moderate left forelimb lameness of 4 weeks' duration. The clinical evaluation and diagnostic perineural analgesia localized the lameness to the distal portion of the left forelimb. There was swelling on the dorsal and lateral aspect of the coronary band. Radiography, ultrasound, magnetic resonance imaging, and computed tomography of the foot revealed circumscribed well-capsulated soft tissue mass causing a focal deformation of the dorsolateral border of the middle phalanx. The treatment aimed to remove the mass surgically and stabiliz...
Findley JA, O'Neill HD, Bladon BM.A triangular screw configuration has been suggested as preferable for repair of sagittal fractures of the proximal phalanx. Objective: To assess the outcome of a triangular screw construct for repair of incomplete and complete minimally displaced proximal phalanx fractures under standing sedation in a population of Thoroughbred racehorses, compared with a cohort repaired using a linear screw configuration. Methods: Retrospective cohort study. Methods: Medical records and radiographs were accessed to garner clinical data. Date of return to racing was determined from www.racingpost.com. Survival...
Basran PS, Gao J, Palmer S, Reesink HL.Proximal sesamoid bone (PSB) fractures are the most common fatal musculoskeletal injury in North American racehorses. Computed tomography has the potential to detect morphological changes in bone structure but can be challenging to analyse reliably and quantitatively. Objective: To develop a radiomics platform that allows the comparison of features from micro-CTs (µCT) of PSBs in horses that sustained catastrophic fractures with horses that did not. To compare features calculated with a radiomics approach with features calculated from a previously published study that used quantitative µCT i...
Abu-Seida AM, Shamaa AA.Congenital frontal osteoma has not been previously described in horses. This report records-for the first time-a congenital osteoma of the frontal bone in a 4-month-old Arabian filly. The filly had a frontal hard mass that was present at birth and then showed a slow and continuous growth. This mass appeared as a solitary, painless, oval dense tumor of compact bone, about 2 cm in diameter and 3 cm in length. The tumor was asymptomatic, and the skin over the mass was normal. Radiography revealed a well-defined oval, radio-dense mass projecting from the surface of the right frontal bone with no...
Gaul CE, Rich AF, Ressel L, Hinnigan GJ, Owen KR.This study aimed to determine whether a true synovial structure exists over the olecranon tuberosity, which could be attributed to a noninflamed olecranon bursa. Contrast radiography, gross anatomical dissection, and histopathology were used to evaluate the olecranon bursa in horses with no previous elbow pathology. The radiographic study revealed that the contrast was positioned subcutaneously, superficial to the long head of the triceps and its insertion on the olecranon tuberosity and did not extend cranial to the triceps tendon. The contrast region was consistent in shape, size, and locati...
Ellis L.A 19-year-old appendix mare was presented with severe, acute right forelimb lameness and a history of significant hoof wall defect. The defect began as progressive toe separation affecting the dorsal hoof wall, which was eventually resected by a farrier. Placement of bar shoes by a farrier to stabilize the hoof was ineffective. Radiographs showed hoof wall separation, palmar rotation, and displacement of the coffin bone, consistent with failure of the laminar structures. Treatment included phenylbutazone, radiographic-guided therapeutic farriery consisting of derotation with a wedge shoe, and ...
Gough SL, Anderson JDC, Dixon JJ.Three-dimensional computed tomographic (CT) evaluation of the cervical vertebral column enables more accurate identification of osseous and soft tissue lesions than traditional latero-lateral radiography. However, examination of the complete cervical vertebral column has been limited by horse size, preventing evaluation of the caudal cervical vertebrae. Objective: To describe a technique to enable CT myelography of the complete cervical spine and describe the findings in 51 horses. Methods: Records of 51 horses presented for evaluation of cervical vertebral lesions. Methods: A retrospective re...
Leśniak KG, Williams JM.Directionality of limb and facial asymmetries in nonelite equine populations has been previously reported with results indicating strong similarities to those reported in racehorses. This investigation aimed to consider the relationship between the magnitude of the asymmetries presented within the general equine population, and their previously reported directionality. Direct measurements of 15 bilateral traits (four facial and 11 limb) were captured from a mixed population of 100 horses and ponies. The pooled (whole) population was considered further as horse (withers height >148 cm) and ...
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...
Liuti T, Dixon PM.The geometric morphometrics method (GMM) is a technique to study scale and shape relationships of structures using Cartesian geometric coordinates rather than linear, areal (of area), or volumetric variables. GMM has been of great value in many biological studies, but does not appear to have been used to examine equine skulls.In this exploratory study, twenty-nine normal equine heads of three different age groups: 16 years old (N = 10) were examined.Computed tomography (CT) bone window DICOM images were reconstructed into isosurfaces (3-dimensional contoured surfaces), onto which landm...
Ramos S, Pinto A, Cardoso M, Alexandre N, Bettencourt E, Monteiro S, Gama LT.Radiographic prevalence and correlation of radiographic findings has not been performed in Lusitano Purebred horses. The aim of this study was to (1) evaluate the prevalence of primary osteoarthritis radiographic findings in Lusitano Purebred horses; (2) to assess correlations between radiographic findings in different joints of the same limb and different limbs; and (3) elucidate the effect of age in the radiographic findings. A radiographic protocol of the stifle, tarsi, fetlocks and distal limbs was done in 98 Lusitanos and the classification of the radiographs was performed using a 0-4 sc...
Elzer EJ, Bramlage LR.Outcomes have been reported for a limited number of short frontal plane fractures of the proximal phalanx following nonsurgical treatment and internal fixation. Objective: To describe a new approach, arthroscopic debridement, of short frontal plane fractures of the proximal phalanx in flat-racing Thoroughbreds and post-operative racing outcome. Methods: Retrospective case-control study. Methods: Medical records of 81 Thoroughbred racehorses treated with arthroscopic debridement for frontal plane fractures of the proximal phalanx were reviewed. Diagnostic images and operative reports were used ...
Henderson B, Bramlage LR, Koenig J, Monteith G.To assess the influence of humeral stress fracture location on the time to return to racing and postinjury performance of thoroughbred racehorses. Methods: Retrospective study (1992-2015). Methods: Thoroughbred racehorses (n = 131) that presented for lameness with the sole diagnosis of humeral stress fractures in the lame limb, as determined by scintigraphy or radiology. Methods: Sex, fracture site, age, starts, earnings, and average earnings per race were examined for differences in pre-stress and post-stress fracture diagnosis for the entire population as well as individual stress fracture l...
de Preux M, Vidondo B, Koch C.To determine the influence of a purpose-built frame on the accuracy of screw placement during computer-assisted orthopedic surgery (CAOS) of the equine extremity. Methods: Experimental cadaveric study. Methods: Twenty-four paired equine cadaveric limbs obtained from seven horses. Methods: Three 4.5-mm cortex screws were inserted in lag technique in three different planes of orientation in the proximal phalanx (P1) by means of CAOS. In the study group (n = 12 limbs), the tracker was anchored on a purpose-built frame designed to stabilize the extremity. In the control group (n = 12 limbs), a con...
Mancini IAD, Schmidt S, Brommer H, Pouran B, Schäfer S, Tessmar J, Mensinga A, van Rijen MHP, Groll J, Blunk T, Levato R, Malda J, van Weeren PR.Recent research has been focusing on the generation of living personalized osteochondral constructs for joint repair. Native articular cartilage has a zonal structure, which is not reflected in current constructs and which may be a cause of the frequent failure of these repair attempts. Therefore, we investigated the performance of a composite implant that further reflects the zonal distribution of cellular component both in vitro and in vivo in a long-term equine model. Constructs constituted of a 3D-printed poly(ϵ-caprolactone) (PCL) bone anchor from which reinforcing fibers protruded into ...
Huguet EE, Porter EG, Chapman KA, Saunders FC, Davis B, Berry CR.The radiographic anatomy of the equine distal tibia is complex and is not widely described in the current literature. Superimposition and radiographic similarities between the different osseous structures of the equine distal tibia can make it difficult for anatomic localization of pathology. The purpose of this prospective, descriptive, anatomic study was to detail the normal anatomy of the equine distal tibia using routine radiographic projections and CT of the equine tarsus. Radiographic identification of the different osseous protuberances of the distal tibia on three cadaveric limbs was a...
Zedda M, Sathe V, Chakraborty P, Palombo MR, Farina V.The microstructural features of the tissue of long bones subjected to different biomechanical stresses could be a helpful tool for a better understanding of locomotor behavior in extant and extinct mammals, including equids. However, few researches have attempted to describe the bone tissue of extinct horses. In our study, we analyze and compare the histomorphometric features of the bone tissue in extant modern horses, Equus caballus, and Equus namadicus, a Pleistocene Indian extinct wild horse. The number, position, and size of the osteons and Haversian canals of the bone tissue, classifiable...
Shaktivesh S, Malekipour F, Whitton RC, Hitchens PL, Lee PV.Fatigue-induced subchondral bone (SCB) injuries are prevalent among athletes due to the repetitive application of high magnitude loads on joints during intense physical training. Existing fatigue studies on bone utilize a standard fatigue test approach by applying loads of a constant magnitude and frequency even though physiological/realistic loading is a combination of various load magnitudes and frequencies. Metal materials in implant and aerospace applications have been studied for fatigue behavior under physiological or realistic loading, however, no such study has been conducted on biolog...
Metzger J, Distl O.Orthopedic diseases are a common cause for limited exercise capacity in the horse. They often underlie genetic risk factors, which can affect bone, articular cartilage, tendons, ligaments, and adnexal structures among others. The genetic effects can directly interfere with tissue development and skeletal growth or can trigger degenerative or inflammatory processes. Many of these diseases of the locomotor system like osteochondrosis are complex and can be affected by multifactorial influences. For this reason, it is important for those performing diagnostic procedures to have a comprehensive kn...
Boorman S, Boone L, Weatherall K, Caldwell F.A 7-year-old American Quarter Horse gelding was referred to the JT Vaughan Large Animal Teaching Hospital at Auburn University, College of Veterinary Medicine, for an investigation of a recurrent swelling of the nasofrontal region. Computed tomography examination of the skull was most consistent with a sequestrum of the left nasofrontal suture with associated focal osteomyelitis and left conchofrontal sinusitis. Surgery to remove the sequestrum, debride the devitalized bone, and flush the left conchofrontal sinus was performed. A microbial culture was obtained at the time of surgery, which yie...
Puangthong C, Bootcha R, Petchdee S, Chanda M.A 17-year-old mixed breed pony was presented with intermittent neck stiffness during regular training rides in the six months preceding its admission. All parameters were within the normal range, except for an increase in heart rate (48 bpm) during the examination. Concave areas were observed at the level between the atlas and axis vertebrae (C1-C2) on both the left and right sides of the neck. Radiographs were taken of the laterolateral, left ventrodorsal oblique, and right ventrodorsal oblique projections in the cranial cervical region. The images revealed severe structural disorders, includ...
Gardner AK, Santschi EM, Mudge MC, Belknap JK, Metzler AG.To describe the repair of unstable facial fractures by using Foley catheter balloons as intrasinus bolsters. Methods: Case report ANIMALS: Two weanling foals with unilateral fractures of the sinus and orbit secondary to kick injuries. Preoperative imaging that included positive contrast dacrocystorhinography and computed tomography confirmed severe comminution of facial fractures and nasolacrimal duct disruption in both foals. Methods: Small bone fragments were surgically removed, and large fragments were retained even when denuded of periosteum. Repair procedures included nasolacrimal canalic...
Diloksumpan P, Bolaños RV, Cokelaere S, Pouran B, de Grauw J, van Rijen M, van Weeren R, Levato R, Malda J.The clinical translation of three-dimensionally printed bioceramic scaffolds with tailored architectures holds great promise toward the regeneration of bone to heal critical-size defects. Herein, the long-term in vivo performance of printed hydrogel-ceramic composites made of methacrylated-oligocaprolactone-poloxamer and low-temperature self-setting calcium-phosphates is assessed in a large animal model. Scaffolds printed with different internal architectures, displaying either a designed porosity gradient or a constant pore distribution, are implanted in equine tuber coxae critical size defec...
Salamanca-Carreño A, Jordana J, Crosby-Granados RA, Bentez-Molano J, Parés-Casanova PM.This is the first morphological comparative study between local horses and mules from Arauca, Colombia. It was realized to compare morphological traits between both species by analysing 15 adult mules (7 males and 8 females) and 150 adult horses (137 males and 13 females), with an age interval from 2 to 22 years. Data consisted of 24 different body quantitative traits which can explain the body conformation: thoracic circumference, body length (BL), thoracic depth and width, withers height (WH), sternum height, shoulders width, chest width, forelimb cannon perimeter and length, head length and...
Rajpar I, Barrett JG.Tendon injury is a significant clinical problem due to poor healing and a high reinjury rate; successful treatment is limited by our poor understanding of endogenous tendon stem cells. Recent evidence suggests that adult stem cells are phenotypically diverse, even when comparing stem cells isolated from the same tissue from the same individual, and may in fact exist on a spectrum of proliferation and differentiation capacities. Additionally, the relationships between and clinical relevance of this phenotypic variation are poorly understood. In particular, tenogenic capacity has not been studie...
Giraldo A, Pinard CL, Plattner BL, Dubois MS.A periocular nodular sarcoid was diagnosed on the right upper eyelid and medial canthus of a 12-year-old Thoroughbred mare. Enucleation was performed and during the procedure the mass was noted to be firmly adhered to the underlying frontal bone. Partial ostectomy of the dorsal orbital rim was performed. Histopathology revealed invasion of the cortical lamellar bone and the bone marrow by neoplastic spindle cells and extension of these cells to multiple surgical margins. Recurrence at the level of the surgical site and its surroundings occurred 3 months after the procedure. The horse was eutha...
Simpson RM, Hodgin EC, Cho DY.Necropsy of a chronically lame 16-year-old thoroughbred gelding revealed granulomatous osteomyelitis and polyarthritis due to a widely disseminated infection by Micronema deletrix. Diagnosis was based upon the nematode's morphology with its characteristic rhabditiform oesophagus. Granulomata, often containing one or more centrally located M. deletrix, were observed histologically in sections prepared from femur, kidney, stomach, lung, adrenal gland and sublumbar lymph nodes. Neither verminous meningo-encephalitis nor cephalic granulomata, which are the more commonly described lesions, was foun...
Nelson BB, Stewart RC, Kawcak CE, Freedman JD, Patwa AN, Snyder BD, Goodrich LR, Grinstaff MW.To investigate the diffusion trajectory of a cationic contrast medium (CA4+) into equine articular cartilage, and to assess normal and degenerative equine articular cartilage using cationic contrast-enhanced computed tomography (CECT). In the first experiment (Exp1), equine osteochondral specimens were serially imaged with cationic CECT to establish the diffusion time constant and time to reach equilibrium in healthy articular cartilage. In a separate experiment (Exp2), articular cartilage defects were created on the femoral trochlea (defect joint) in a juvenile horse, while the opposite joint...
Latimer CA, Wyman M, Diesem CD, Burt JK.The anatomy of the nasolacrimal duct of the horse was studied grossly and radiographically, using barium contrast dacryocystorhinography and methyl methacrylate casts. Radiographic contrast studies were performed on 4 specimens and gross dissections were performed on 6 specimens. Dacryocystorhinography accurately delineated the course of the nasolacrimal duct, as was subsequently demonstrated by gross dissection. A 60% barium sulfate suspension produced good radiographic contrast, allowing critical assessment of the anatomic features of the nasolacrimal duct.
Nunamaker DM, Butterweck DM, Provost MT.Geometric properties of the third metacarpal bone were compared between the young and adult Standardbred and Thoroughbred racehorse. The change in shape during growth and superimposed training was dramatic in both breeds but the Thoroughbred showed the greatest difference in the minimum moment of inertia as the animal matured. Males had larger moments of inertia throughout the length of the diaphysis than did females. The differences in geometric properties of the third metacarpal bone between the Thoroughbred and Standardbred were related to the incidence of fatigue fractures which are common...
Hughes KJ, Laidlaw EH, Reed SM, Keen J, Abbott JB, Trevail T, Hammond G, Parkin TD, Love S.Sagittal ratio values (SRVs) of cervical vertebrae are used for ante-mortem diagnosis of cervical vertebral stenotic myelopathy, but intraobserver and interobserver variability in measurement may influence radiographic interpretation of vertebral stenosis in horses with neurological disease. Objective: To determine intraobserver repeatability in SRVs, intra- and interobserver agreement in SRVs and whether or not agreement was influenced by animal age. Methods: Forty-two horses (>1 year old) with neurological disease from which laterolateral computed radiographic images of C2-C7 were obtained. ...
van Harreveld PD, Lillich JD, Kawcak CE, Turner AS, Norrdin RW.To determine microradiographic appearance, bone histomorphometry, and mineral density of the long bones of the metacarpophalangeal joint in horses after immobilization followed by remobilization. Methods: 5 healthy horses. Methods: One forelimb of each horse was immobilized in a fiberglass cast for 7 weeks, followed by 8 weeks of increasing exercise. Calcein and oxytetracycline were administered IV during the immobilization and exercise phases, respectively, for bone labeling and analysis after euthanasia. Sagittal sections of metacarpal bones and proximal phalanges were examined via radiograp...
Martinelli MJ, Eurell J, Les CM, Fyhrie D, Bennett D.Although there are many studies in the equine literature focused on articular diseases and the aetiology of osteoarthritis, few have concentrated on normal articular structures and how they change with age. The objective of this investigation was to study the thickness and morphology of the calcified cartilage layer of the distal metacarpus over a range of ages. A parasagittal slab of bone was sectioned from the region of sesamoid contact on the medial condyle of the metacarpi from 34 horses. The slab of bone was preserved, dehydrated and embedded, undecalcified, in methylmethacrylate and then...
Vanderperren K, Ghaye B, Snaps FR, Saunders JH.To determine the detailed computed tomography (CT) anatomy of the metacarpophalangeal (MCP) joint in healthy horses. Methods: 10 cadaveric forelimbs from 10 adult horses without orthopedic disease. Methods: CT of the MCP joint was performed on 4 forelimbs. In 1 of the limbs, CT was also performed after intra-articular injection of 30 mL of contrast medium (40 mg of iodine/mL). Transverse slices 1-mm thick were obtained, and sagittal and dorsal planes were reformatted with a slice thickness of 2 mm. The CT images were matched with corresponding anatomic slices from 6 additional forelimbs. Resul...
Govoni KE.Equine bone fractures are often catastrophic, potentially fatal, and costly to repair. Traditional methods of healing fractures have limited success, long recovery periods, and a high rate of reinjury. Current research in the equine industry has demonstrated that stem cell therapy is a promising novel therapy to improve fracture healing and reduce the incidence of reinjury; however, reports of success in horses have been variable and limited. Stem cells can be derived from embryonic, fetal, and adult tissue. Based on the ease of collection, opportunity for autologous cells, and proven success ...
Shaktivesh S, Malekipour F, Whitton RC, Hitchens PL, Lee PV.Fatigue-induced subchondral bone (SCB) injuries are prevalent among athletes due to the repetitive application of high magnitude loads on joints during intense physical training. Existing fatigue studies on bone utilize a standard fatigue test approach by applying loads of a constant magnitude and frequency even though physiological/realistic loading is a combination of various load magnitudes and frequencies. Metal materials in implant and aerospace applications have been studied for fatigue behavior under physiological or realistic loading, however, no such study has been conducted on biolog...
Murray RC, Tranquille CA, Walker VA, Milmine RC, Bak L, Tacey JB, Bolas NM.Standing magnetic resonance (MR) images of proximal metacarpal/metatarsal regions are increasingly being acquired. This study aimed at describing ranges of abnormalities detected in sport/racehorses, using retrospective evaluation of magnetic resonance imaging (MRI) reports from horses with lameness isolated to proximal metacarpal/metatarsal regions with images acquired standing. It was hypothesized that MRI features are different between metacarpal and metatarsal regions and between horses doing different sports. Reports from 359 forelimbs and 64 hindlimbs were included. Palmar/plantar metaca...
Mahdavi FS, Salehi A, Seyedjafari E, Mohammadi-Sangcheshmeh A, Ardeshirylajimi A.Horses with big bone fractures have low chance to live mainly due to the lake of a proper treatment strategy. We believe that further attempts in equine bone tissue engineering will probably be required to meet all the needs for the lesion therapies. Therefore in this study we aimed to investigate the osteogenic differentiation capacity of equine adipose-derived stem cells (e-ASCs) on nano-bioactive glass (nBGs) coated poly(l-lactic acid) (PLLA) nanofibers scaffold (nBG-PLLA). Using electrospinning technique, PLLA scaffold was prepared successfully and coated with nBGs. Fabricated nanofibers w...
Riggs CM.Fractures are the cause of considerable morbidity and mortality among Thoroughbred racehorses. A significant proportion of these injuries occur in the absence of any particular traumatic incident. Evidence of prefracture pathology interpreted as fatigue damage has been identified in some such cases, but the aetiology of many of these so-called 'spontaneous' fractures remains obscure. Parasagittal fractures of the third metacarpal (McIII) and third metatarsal (MtIII) bones are one of the more common fractures to affect Thoroughbred racehorses. The configuration of each of these fracture types i...
Reed SR, Jackson BF, Wood JL, Price JS, Verheyen KL.The aim of this study was to identify exercise-related risk factors for carpal and metacarpo- and metatarso-phalangeal (MCP/MTP) joint injury occurrence in young Thoroughbreds in flat race training. In a 2-year prospective cohort study, daily exercise and joint injury data were collected from horses in 13 training yards in England. Four injury categories were defined: (1) localised to a carpal or MCP/MTP joint based on clinical examination and/or use of diagnostic analgesia with no diagnostic imaging performed; (2) localised to a carpal or MCP/MTP joint with no abnormalities detected on diagno...
Sherlock CE, Mair TS, Ter Braake F.We report the use of low-field standing magnetic resonance imaging in the standing horse for the diagnosis of osseous lesions in the metacarpophalangeal (MCP) or metatarsophalangeal (MTP) joint that were not apparent using standard radiography. Thirteen horses were studied and all had thickening of the subchondral bone plate and abnormal signal intensity in the adjacent spongiosa in either the condyles of metacarpal/metatarsal III or the proximal phalanx or both. Abnormalities were characterized by diffuse decreased signal intensity on T1-weighting adjacent to the subchondral bone and within t...
Tucker RL, Sande RD.There is a growing interest in the use of computed tomography (CT) and magnetic resonance (MR) imaging in equine orthopedic patients. It is well established that CT and MR imaging offer superior diagnostic information in a wide variety of musculoskeletal injuries in human beings and small animals. The highly detailed cross-sectional images obtained with these two modalities can often demonstrate pathologic changes undetected with other common imaging techniques. Based on their multiple applications in human beings and small animals, CT or MR imaging may prove to be the optimal diagnostic imagi...
Alrtib AM, Philip CJ, Abdunnabi AH, Davies HM.There are many reports describing fractures in the bony elements of the equine fetlock joint and a few of these discuss possible relationships of these fractures to the mechanical loading of these bones. The likelihood of fracture must be related to the size and shape of bones involved, but information concerning the normal range in size and shape of these bones in horses is lacking. This study aimed to identify morphometrical variations of these bones within different groups of horses. Right and left metacarpal, proximal phalangeal and proximal sesamoid bones were collected from 10 Thoroughbr...
Liuti T, Smith S, Dixon PM.Equine cheek teeth disorders, especially pulpar/apical infections, can have very serious consequences due to the frequent extension of infection to the supporting bones and/or adjacent paranasal sinuses. Limited studies have assessed the accuracy of computed tomographic (CT) imaging in the diagnosis of these disorders, and no study has directly compared imaging and pathological findings of the alveoli of diseased equine cheek teeth. Objective: To validate the accuracy of CT and radiographic imaging of cheek teeth disorders by comparing CT and radiographic imaging, gross and histological findin...
Ringer SK, Lischer CJ, Ueltschi G.To monitor the effect of focused extra-corporeal shock wave therapy (ESWT) on bone and bone-tendon junction of horses without lameness by use of nuclear scintigraphy and thermography. Methods: 6 warmblood horses without lameness. Methods: The origin of the suspensory ligament at the metacarpus (OSL-MC) and the fourth metatarsal bone were treated at 2 time points (days 0 and 16) with 2,000 shocks applied by a focused ESWT device at an energy flux density of 0.15 mJ/mm2. One forelimb and 1 hind limb were treated, and the contralateral limbs served as controls. To document the effect of focused E...
Rothaug PG, Boston RC, Richardson DW, Nunamaker DM.To compare the monotonic tensile and fatigue strength of 16-gauge stainless steel wire (SSW) to ultra-high-molecular weight polyethylene (UHMWPE) cable using a transfixed cerclage technique in an in vitro midbody sesamoid osteotomy model. Endoscopic modifications to Martins transfixed cerclage technique were developed. A new suture technique of fixation was compared with the transfixed cerclage technique by measuring gap formation after cyclic testing. Methods: An in vitro biomechanical paired equine cadaver limb study. Methods: Twenty-one paired cadaveric adult equine forelimbs. Methods: Unia...
Zedda M, Lepore G, Biggio GP, Gadau S, Mura E, Farina V.A high number of differences exist in bone histological features depending on the species, breed, age and bone. Moreover, osteon distribution may vary in the different sides of a bone as a consequence of different biomechanical strains. The aim of this work was to study the distribution and morphology of osteons in different sides of the equine femoral diaphysis with the attempt to correlate them to the main strains operating on them. The following parameters of secondary osteons and Haversian canals were measured in the transverse sections of diaphyses: perimeter, area, minimum and maximum di...
Southwood LL, Kawcak CE, Hidaka C, McIlwraith CW, Werpy N, Macleay J, Frisbie DD.To evaluate gene transfer in an equine metacarpal IV (MCIV) ostectomy model using adenoviral vectors encoding the human bone morphogenetic protein-2 and protein-7 gene (Ad-BMP-2/-7). Methods: Healthy adult horses (n = 15). Methods: A plate stabilized, critical size 1.5 cm ostectomy was created in left and right MCIV. The ostectomy site was injected with either Ad-green fluorescent protein (Ad-GFP) or Ad-hBMP-2/-7 at completion of surgery; the same treatment was assigned to both the left and right forelimb of each horse (n = 5 horses/group). Bone healing was evaluated radiographically every 2 w...
Rodríguez MJ, Latorre R, López-Albors O, Soler M, Aguirre C, Vázquez JM, Querol M, Agut A.The equine temporomandibular joint (TMJ) and its surrounding structures can be difficult to investigate in cases with a clinical problem related to the region. Little previous attention has been given either to a computed tomographic (CT) imaging protocol for the joint or an interpretation of the structures displayed in CT images of the normal joint. Objective: To provide a CT atlas of the normal cross-sectional anatomy of the equine TMJ using frozen and plastinated sections as anatomical reference. Methods: Eight TMJs from 4 immature pure-bred Spanish horses were examined by helical CT. Scans...
Whitton RC, Mirams M, Mackie EJ, Anderson GA, Seeman E.Bone remodelling is inhibited by high repetitive loading. However, in subchondral bone of racehorses in training, eroded surface doubled in association with fatigue fracture and there was greater surrounding trabecular bone volume suggesting trabecular modelling unloads the bone focally, allowing damage repair by remodelling. Background: Remodelling replaces damaged bone with new bone but is suppressed during high magnitude repetitive loading when damage is most likely. However, in cortical bone of racehorses, at sites of fatigue fracture, focal porosity, consistent with remodelling, is observ...
Palmer JL, Bertone AL, Litsky AS.Changes in contact area and pressure distribution with loading were evaluated on the proximal articulating surface of the equine third carpal bone using safranin-O dye staining and pressure sensitive film techniques. A significant increase in percentage contact area resulted as the applied load was increased from 3115 to 9000 N (54.93% +/- 7.99 vs 61.43% +/- 7.37 respectively, P = 0.016). The area in contact shifted towards the dorsal aspect of both the radial and intermediate facets of the third carpal bone. Changes were also detected in the mean pressure under the same loading conditions. Th...
Changoor A, Hurtig MB, Runciman RJ, Quesnel AJ, Dickey JP, Lowerison M.To improve osteochondral graft reconstruction of subchondral cystic lesions in the medial and lateral femoral condyles by matching the material properties of donor and recipient sites. Objective: To measure biomechanical and biochemical parameters that influence the function and healing of osteochondral grafts used to reconstruct subchondral cystic lesions. Objective: Suitable donor sites are available within the stifle joint for reconstructing the femoral condyles, despite considerable regional property variation. Methods: Fifty-six osteochondral cores were harvested from 6 distal femurs for ...
Nagy A, Dyson S.While low-field magnetic resonance (MR) images can provide useful information in the investigation of proximal metacarpal region pain, an in-depth knowledge of anatomy and comparison with more detailed high-field images are essential to understand the meaning of different signal intensities within tissues. This anatomic description is based on low-field and high-field MR examination of 30 cadaver metacarpal regions of mature horses with no history of carpal or proximal metacarpal pain. Normal MR anatomy is described and is illustrated by high-field and low-field MR images in transverse, sagitt...
Firth EC, Rogers CW.This paper summarises and presents in context the main findings of an extensive series of studies of early training lasting 13 weeks in which the tissue responses of 2-year-old Thoroughbred horses were assessed using a combination of methods. Negligible clinical injury was detected and thus the study fulfilled the intention of investigating adaptive change rather than injury. Cancellous and cortical bone, some digital tendons, and articular cartilage responded to early training exercise to a greater or lesser degree. Clinical examination and ancillary diagnostic aids currently in veterinary cl...
Firth EC, Delahunt J, Wichtel JW, Birch HL, Goodship AE.This study was performed to test the hypothesis that a localised bone hypertrophy could occur within the subchondral cancellous architecture of the third and radial carpal bones. Using 2 levels of controlled and defined exercise, it was observed that a high intensity treadmill exercise protocol resulted in functional adaptation of the carpal bones. The increase in trabecular thickening and density was seen to be localised to those regions underlying common sites of cartilage degradation, the interface of the thickened trabeculae with the normal architecture in the third carpal bone was coincid...
Pollitt CC, Collins SN.The suspensory apparatus of the distal phalanx (SADP) is functionally and clinically important. Objective: To investigate SADP form and function and the microanatomy of its insertion zone. Methods: Descriptive gross and microanatomy. Methods: The feet of 6 normal Standardbred horses were sectioned into blocks along the traditional perpendicular transverse axis and along functional axes of the SADP, decalcified and processed for staining with haematoxylin and eosin, Jones' periodic acid silver methenamine or Masson's trichrome stains. Results: In traditional midline toe transverse plane section...
