Subchondral bone refers to the layer of bone just beneath the cartilage in the joints of horses. It plays a role in supporting the overlying cartilage and distributing loads across the joint surface during movement. Changes or damage to the subchondral bone can affect joint function and are often associated with conditions such as osteoarthritis. In horses, the health of subchondral bone is of interest for understanding joint disorders and improving lameness diagnosis and management. This page compiles peer-reviewed research studies and scholarly articles that examine the structure, function, and pathological changes of subchondral bone in equine joints.
Malekipour F, Oetomo D, Lee PV.Subchondral bone microdamage due to high-impact loading is a key factor leading to post-traumatic knee osteoarthritis. A quantified assessment of the mechanical characteristics of subchondral bone at the tissue-level is essential to study the mechanism of impact-induced microdamage. We combined mechanical impact testing of equine cartilage-bone with µCT image-based finite element models (μFEM) of each specimen to determine subchondral bone (including calcified cartilage: CCSB) elastic tissue modulus and local stresses and strains associated with micro-fractures within the CCSB tissue. The ma...
Stack JD, Levingstone TJ, Lalor W, Sanders R, Kearney C, O'Brien FJ, David F.Osteochondral lesions resulting from osteochondritis dissecans are problematic to treat and present a significant challenge for clinicians. The aims of this study were to investigate the use of a scaffold-assisted microfracture approach, employing a novel, multilayered, collagen-based, osteochondral graft substitute in the treatment of severe osteochondritis dissecans of both lateral femoral trochlear ridges in an equine athlete, and to assess the potential of this novel scaffold to enhance repair of the osteochondral unit. A 15 month-old female filly presented with large osteochondritis diss...
Noble P, Singer ER, Jeffery NS.Sagittal fractures of the first phalanx are a common, potentially catastrophic injury in racehorses. These fractures are often linked to an acute, one time, biomechanical event; however, recent evidence implies that chronic exposure to stress can lead to the accumulation of bony changes that affect the structural integrity of the bone and increase the likelihood of fracture. The aim of the study was to compare variations of two common metrics of bone adaptation - subchondral bone density and thickness across the proximal articular surface of the first phalanx in Thoroughbred horses that (1) ra...
Walker WT, Silverberg JL, Kawcak CE, Nelson BB, Fortier LA.To determine morphological characteristics of subchondral bone cysts (SBCs) in medial femoral condyles (MFCs) of adult horses with orthopedic disease. Methods: CT scans of 7 MFCs with SBCs from 6 adult horses. Methods: CT was used to determine the volume, surface area, and centers of the articular cyst opening and SBC in each MFC. Cysts were ordered from smallest to largest on the basis of volume. Osseous pathological characteristics of the MFC were assessed in the frontal plane. Three-dimensional distance of displacement between the center of the articular cyst opening and center of the cyst ...
Loughridge AB, Hess AM, Parkin TD, Kawcak CE.Changes in subchondral bone density, induced by the repetitive cyclical loading of exercise, may potentiate fatigue damage and the risk of fracture. Objective: To use computed tomography (CT) to characterise bone density patterns at the articular surface of the third metacarpal bone in racehorses with and without lateral condylar fractures. Methods: Case control METHODS: Computed tomographic images of the distal articulating surface of the third metacarpal bone were obtained from Thoroughbred racehorses subjected to euthanasia in the UK. Third metacarpal bones were divided into 3 groups based ...
Boado A, López-Sanromán FJ.Articular osteochondrosis (OC) is commonly reported in horses but there are no reports of its prevalence in the Spanish Purebred (SP). The objective of this study was to assess the prevalence and characteristics of OC of the tarsocrural, dorsal metacarpo-metatarsophalangeal and femoropatellar joints in the SP in a retrospective study. The data were obtained from the radiographs of 309 SP horses and the prevalence and characteristics of lesions were calculated. Osteochondral lesions at predilected sites were diagnosed in 48.8% of the horses. It was more common to find the presence of fragments ...
Bertuglia A, Lacourt M, Girard C, Beauchamp G, Richard H, Laverty S.The role of osteoclasts in osteochondral degeneration in osteoarthritis (OA) has rarely been investigated in spontaneous disease or animal models of OA. Objective: The objectives of the current study were to investigate osteoclast density and location in post-traumatic OA (PTOA) and control specimens from racehorses. Methods: Cores were harvested from a site in the equine third carpal bone, that undergoes repetitive, high intensity loading. Histological and immunohistochemical (Cathepsin K and Receptor-activator of Nuclear Factor kappa-β ligand (RANKL)) stained sections were scored (global an...
Mirams M, Ayodele BA, Tatarczuch L, Henson FM, Pagel CN, Mackie EJ.During the early stages of articular osteochondrosis, cartilage is retained in subchondral bone, but the pathophysiology of this condition of growing humans and domestic animals is poorly understood. A subtractive hybridization study was undertaken to compare gene expression between the cartilage of early experimentally induced equine osteochondrosis lesions and control cartilage. Of the many putative differentially expressed genes identified, eight were confirmed by quantitative PCR analysis as differentially expressed, in addition to those already known to be associated with early lesions. G...
Seo JP, Kambayashi Y, Itho M, Haneda S, Yamada K, Furuoka H, Tabata Y, Sasaki N.This study aimed to evaluate the efficacy of a synovial flap and gelatin/β-tricalcium phosphate (GT) sponge loaded with mesenchymal stem cells (MSCs), bone morphogenetic protein-2 (BMP-2), and platelet rich plasma (PRP) for repairing of osteochondral defects in horses. Osteochondral defects were created on the medial condyle of both femurs (n=5). In the test group, a GT sponge loaded with MSCs, BMP-2, and PRP (GT/MSCs/BMP-2/PRP) was inserted into the defect and then covered with a synovial flap. In the control group, the defect was treated only with the GT/MSCs/BMP-2/PRP. The test group showe...
McCoy AM.Osteoarthritis (OA) is unquestionably one of the most important chronic health issues in humans, affecting millions of individuals and costing billions of dollars annually. Despite widespread awareness of this disease and its devastating impact, the pathogenesis of early OA is not completely understood, hampering the development of effective tools for early diagnosis and disease-modifying therapeutics. Most human tissue available for study is obtained at the time of joint replacement, when OA lesions are end stage and little can be concluded about the factors that played a role in disease deve...
Laverty S, Lacourt M, Gao C, Henderson JE, Boyde A.We studied changes in articular calcified cartilage (ACC) and subchondral bone (SCB) in the third carpal bones (C3) of Standardbred racehorses with naturally-occurring repetitive loading-induced osteoarthritis (OA). Two osteochondral cores were harvested from dorsal sites from each of 15 post-mortem C3 and classified as control or as showing early or advanced OA changes from visual inspection. We re-examined X-ray micro-computed tomography (µCT) image sets for the presence of high-density mineral infill (HDMI) in ACC cracks and possible high-density mineralized protrusions (HDMP) from the ACC...
Bani Hassan E, Mirams M, Ghasem-Zadeh A, Mackie EJ, Whitton RC.To gain a better understanding of the aetiology of articular surface collapse in horses with palmar osteochondral disease. Objective: To determine whether acceleration of focal bone resorption associated with reduced physical activity contributes to articular surface collapse in racehorses with palmar osteochondral disease. Methods: Cross-sectional study comparing metacarpal bones from horses at varying stages of race training. Methods: Metacarpal bones from 36 racing Thoroughbred horses were examined with high-resolution peripheral quantitative computed tomography to determine the proportion ...
Peloso JG, Vogler JB, Cohen ND, Marquis P, Hilt L.To compare bony changes in the metacarpophalangeal joint (MCPJ) of racehorses with (cases) and without (controls) biaxial proximal sesamoid bone (PSB) fracture as determined by 2 grading scales applied to images of cadaveric forelimbs obtained by means of standing MRI (sMRI). Methods: Case-control study. Methods: Forelimbs from 74 Thoroughbred racehorses (21 cases and 53 controls) that were euthanized at a Florida racetrack. Methods: Both forelimbs were harvested from cases and controls. Each forelimb underwent sMRI to obtain images of the MCPJ. Two grading scales were described and used for i...
Olstad K, Østevik L, Carlson CS, Ekman S.Osteochondrosis arises as a result of focal failure of the blood supply to growth cartilage. The current aim was to examine the pathogenesis of pseudocysts and true cysts in subchondral bone following failure of the blood supply to the articular-epiphyseal cartilage complex in horses. Cases were recruited based on identification of lesions (n = 17) that were considered likely to progress to or to represent pseudocysts or true cysts in epiphyseal bone in histological sections and included 10 horses ranging in age from 48 days to 5 years old. Cases comprised 3 warmbloods, 3 Standardbreds, 1 Quar...
Desjardin C, Riviere J, Vaiman A, Morgenthaler C, Diribarne M, Zivy M, Robert C, Le Moyec L, Wimel L, Lepage O, Jacques C, Cribiu E, Schibler L.Osteochondrosis (OC(D)) is a juvenile osteo-articular disorder affecting several mammalian species. In horses, OC(D) is considered as a multifactorial disease and has been described as a focal disruption of endochondral ossification leading to the development of osteoarticular lesions. Nevertheless, OC(D) physiopathology is poorly understood. Affected horses may present joint swelling, stiffness and lameness. Thus, OC(D) is a major concern for the equine industry. Our study was designed as an integrative approach using omics technologies for the identification of constitutive defects in epiphy...
Miller RE, Grodzinsky AJ, Barrett MF, Hung HH, Frank EH, Werpy NM, McIlwraith CW, Frisbie DD.The goal of this study was to test the ability of an injectable self-assembling peptide (KLD) hydrogel, with or without microfracture, to augment articular cartilage defect repair in an equine cartilage defect model involving strenuous exercise. Methods: Defects 15 mm in diameter were created on the medial trochlear ridge and debrided down to the subchondral bone. Four treatment groups (n = 8 each) were tested: no treatment (empty defect), only defect filling with KLD, only microfracture, and microfracture followed by filling with KLD. Horses were given strenuous exercise throughout the one-ye...
MacKay AV, Panizzi L, Sparks HD, Barber SM.To report complications of arthrodesis of the carpometacarpal (CMC) joint using a drilling technique in an adult horse. Methods: Case report. Methods: Horse (n = 1). Methods: A 12-year-old Quarter Horse mare with CMC osteoarthritis (CMC-OA) had arthrodesis under general anesthesia in right lateral recumbency. Under fluoroscopic guidance, a 4.5 mm drill bit was inserted at 3 drilling sites 5-6 cm into the CMC joint and was fanned 30-45° in the plane of the joint and 5-10° in the long axis of the limb to destroy articular cartilage and expose the subchondral bone. Results: The horse pr...
Holmes JM, Mirams M, Mackie EJ, Whitton RC.Bone is repaired by remodelling, a process influenced by its loading environment. The aim of this study was to investigate the effect of a change in loading environment on bone remodelling by quantifying bone resorption and formation activity in the metacarpal subchondral bone in Thoroughbred racehorses. Sections of the palmar metacarpal condyles of horses in race training (n = 24) or resting from training (n = 24) were examined with light microscopy and back scattered scanning electron microscopy (BSEM). Bone area fraction, osteoid perimeter and eroded bone surface were measured withi...
Chevrier A, Kouao AS, Picard G, Hurtig MB, Buschmann MD.Microfracture repair tissue in young adult humans and in rabbit trochlea is frequently of higher quality than in corresponding ovine or horse models or in the rabbit medial femoral condyle (MFC). This may be related to differences in subchondral properties since repair is initiated from the bone. We tested the hypothesis that subchondral bone from rabbit trochlea and the human MFC are structurally similar. Trochlea and MFC samples from rabbit, sheep, and horse were micro-CT scanned and histoprocessed. Samples were also collected from normal and lesional areas of human MFC. The subchondral bone...
Desjardin C, Vaiman A, Mata X, Legendre R, Laubier J, Kennedy SP, Laloe D, Barrey E, Jacques C, Cribiu EP, Schibler L.MicroRNAs (miRNAs) are an abundant class of small single-stranded non-coding RNA molecules ranging from 18 to 24 nucleotides. They negatively regulate gene expression at the post-transcriptional level and play key roles in many biological processes, including skeletal development and cartilage maturation. In addition, miRNAs involvement in osteoarticular diseases has been proved and some of them were identified as suitable biomarkers for pathological conditions. Equine osteochondrosis (OC) is one of the most prevalent juvenile osteoarticular disorders in horses and represents a major concern f...
Trope GD, Ghasem-Zadeh A, Anderson GA, Mackie EJ, Whitton RC.High-resolution 3D imaging may improve the prediction and/or early identification of condylar fractures of the distal metacarpus/tarsus and reduce the frequency of breakdown injury in racehorses. Objective: To test the hypotheses that horses suffering condylar fractures have higher bone volume fraction (BV/TV) of the distal metacarpal epiphysis, greater subchondral bone thickness at the fracture site and higher second moment of inertia in the metacarpal midshaft as identified with high-resolution 3D imaging. Methods: Cross-sectional study using cadaver material. Methods: Thoroughbreds that die...
Dubois MS, Morello S, Rayment K, Markel MD, Vanderby R, Kalscheur VL, Hao Z, McCabe RP, Marquis P, Muir P.Articular stress fracture arising from the distal end of the third metacarpal bone (MC3) is a common serious injury in Thoroughbred racehorses. Currently, there is no method for predicting fracture risk clinically. We describe an ex-vivo biomechanical model in which we measured subchondral crack micromotion under compressive loading that modeled high speed running. Using this model, we determined the relationship between subchondral crack dimensions measured using computed tomography (CT) and crack micromotion. Thoracic limbs from 40 Thoroughbred racehorses that had sustained a catastrophic in...
Turley SM, Thambyah A, Riggs CM, Firth EC, Broom ND.The palmar aspect of the third metacarpal (MC3) condyle of equine athletes is known to be subjected to repetitive overloading that can lead to the accumulation of joint tissue damage, degeneration, and stress fractures, some of which result in catastrophic failure. However, there is still a need to understand at a detailed microstructural level how this damage progresses in the context of the wider joint tissue complex, i.e. the articular surface, the hyaline and calcified cartilage, and the subchondral bone. MC3 bones from non-fractured joints were obtained from the right forelimbs of 16 Thor...
Ley CJ, Ekman S, Hansson K, Björnsdóttir S, Boyde A.Osteochondral lesions in the joints of the distal tarsal region of young Icelandic horses provide a natural model for the early stages of osteoarthritis (OA) in low-motion joints. We describe and characterise mineralised and non-mineralised osteochondral lesions in left distal tarsal region joint specimens from twenty-two 30 ±1 month-old Icelandic horses. Combinations of confocal scanning light microscopy, backscattered electron scanning electron microscopy (including, importantly, iodine staining) and three-dimensional microcomputed tomography were used on specimens obtained with guidance f...
Desjardin C, Chat S, Gilles M, Legendre R, Riviere J, Mata X, Balliau T, Esquerré D, Cribiu EP, Betch JM, Schibler L.Osteochondrosis (OC) is a developmental bone disorder affecting several mammalian species including the horse. Equine OC is described as a focal disruption of endochondral ossification, leading to osteochondral lesions (osteochondritis dissecans, OCD) that may release free bodies within the joint. OCD lesions trigger joint swelling, stiffness and lameness and affects about 30% of the equine population. OCD is considered as multifactorial but its physiopathology is still poorly understood and genes involved in genetic predisposition are still unknown. Our study compared two healthy and two OC-a...
Harrison SM, Whitton RC, Kawcak CE, Stover SM, Pandy MG.The equine metacarpophalangeal (MCP) joint is frequently injured, especially by racehorses in training. Most injuries result from repetitive loading of the subchondral bone and articular cartilage rather than from acute events. The likelihood of injury is multi-factorial but the magnitude of mechanical loading and the number of loading cycles are believed to play an important role. Therefore, an important step in understanding injury is to determine the distribution of load across the articular surface during normal locomotion. A subject-specific finite-element model of the MCP joint was devel...
Martig S, Lee PV, Anderson GA, Whitton RC.In racehorses, fatigue related subchondral bone injury leads to overt fracture or articular surface collapse and subsequent articular cartilage degeneration. We hypothesised that the fatigue behaviour of equine subchondral bone in compression follows a power law function similar to that observed in cortical and trabecular bone. We determined the fatigue life of equine metacarpal subchondral bone in-vitro and investigated the factors influencing initial bone stiffness. Subchondral bone specimens were loaded cyclically in compression [54MPa (n=6), 66MPa (n=6), 78MPa (n=5), and 90MPa (n=6)] until...
Smith MR, Wright IM.Fractures of the proximal phalanx are generally considered to result from monotonic supraphysiological loads, but radiological observations from clinical cases suggest there may be a stress-related aetiology. Objective: To determine whether there are radiologically identifiable prodromal changes in Thoroughbred racehorses with confirmed parasagittal fractures of the proximal phalanx. Methods: Retrospective cross-sectional study. Methods: Case records and radiographs of Thoroughbred racehorses with parasagittal fractures of the proximal phalanx were analysed. Thickness of the subchondral bone p...
Olstad K, Hendrickson EH, Ekman S, Carlson CS, Dolvik NI.Describe the local morphological response of the articular-epiphyseal cartilage complex to surgical stab incision in the distal femur of foals, with emphasis on the relationship between growth cartilage injury, enchondral ossification, and repair. Methods: Nine foals were induced into general anesthesia at the age of 13 to 15 days. Four full-thickness stab incision defects were created in the cartilage on the lateral aspect of the lateral trochlear ridge of the left distal femur. Follow-up examination was carried out from 1 to 49 days postoperatively, including examination of intact bones, saw...
Drum MG, Kawcak CE, Norrdin RW, Park RD, McIlwraith CW, Les CM.Comparison of subchondral bone density determined by quantitative computed tomography (CT) with gross and histopathologic changes have not been made in horses. The goal of this study was to determine if mean quantitative CT density and mean voxel standard deviation are associated with the presence and severity of osteochondral lesions in the palmar aspect of the distal third metacarpal bone in racing horses. Metacarpophalangeal joints from nine racehorses were imaged using CT and scored for gross damage. Four-millimeter-thick sagittal and 30 degrees palmar dorsal plane sections were cut, decal...
Young BD, Samii VF, Mattoon JS, Weisbrode SE, Bertone AL.To evaluate and correlate patterns of subchondral bone density and articular cartilage degeneration (derived by use of gross, histologic, and computed tomographic [CT] examinations) in equine third metacarpal condyles with and without osteoarthritis. Methods: 8 metacarpophalangeal (MCP) joints (n = 4 horses) without osteoarthritis and 6 osteoarthritis-affected MCP joints (4). Methods: Horses were euthanized. The third metacarpal condyles of the joints were examined grossly and via CT (3 slice images/condyle). For 6 condylar zones, mean bone density and pattern of density distribution were dete...
Dykgraaf S, Firth EC, Rogers CW, Kawcak CE.The objective was to determine the effects of early exercise on the articular cartilage and subchondral bone at specific sites of the distal third metacarpal and metatarsal bones of 12 young Thoroughbred horses allowed free choice exercise at pasture. Six of the horses had additional controlled exercise 5 days per week from mean age of 21+/-20 days of age (range: 3-83 days) until 17.1 months of age. Confocal laser scanning microscopy was used to quantify viable and non-viable chondrocytes. Proteoglycan scoring and modified Mankin scoring was performed and subchondral bone mineral density measu...
Brama PA, TeKoppele JM, Bank RA, Barneveld A, van Weeren PR.Subchondral bone provides structural support to the overlying articular cartilage, and plays an important role in osteochondral diseases. There is growing insight that the mechanical features of bone are related to the biochemistry of the collagen network and the mineral content. In the present study, part of the normal developmental process and the influence of physical activity on biochemical composition of subchondral bone was studied. Water content, calcium content and characteristics of the collagen network (collagen, hydroxylysine, lysylpyridinoline (LP) and hydroxylysylpyridinoline (HP)...
Nixon AJ, Cummings JF.Serial sections of bone and soft tissue from the metacarpophalangeal joints of 2 mature and 2 immature horses were evaluated for substance P immunoreactive sensory nerve fibers. Formalin-fixed specimens were sectioned, either nondemineralized or demineralized with formic acid or EDTA. Rabbit antiserum to substance P (SP) was used in the streptavidin-biotin-peroxidase complex method for immunolocalization of SP antigen, and staining with 3,3'-diaminobenzidine was used for permanent identification of SP fibers. Abundant sensory nerve fibers were identified in the joint capsule, synovial membrane...
Olive J, Serraud N, Vila T, Germain JP.The metacarpal condyle has received extensive attention as a predominant site of overload arthropathy in racehorses. However, detailed descriptions of MRI lesion patterns for the metacarpophalangeal joint and comparisons between types of racing horses are currently lacking. Aims of this retrospective, cross-sectional study were to describe and compare standing low-field magnetic resonance findings in the metacarpophalangeal joints for groups of Standardbreds and Thoroughbreds using systematic semiquantitative scores. Data archives at the Clinique Vétérinaire Equine de Chantilly and Imavet we...
Morrice-West AV, Hitchens PL, Walmsley EA, Tasker K, Lim SL, Smith AD, Whitton RC.Fatigue life (FL) is the number of cycles of load sustained by a material before failure, and is dependent on the load magnitude. For athletes, 'cycles' translates to number of strides, with load proportional to speed. To improve previous investigations estimating workload from distance, we used speed (m/s, x) per stride collected using 5 Hz GPS/800 Hz accelerometer sensors as a proxy for limb load to investigate factors associated with FL in a Thoroughbred race start model over 25,234 race starts, using a combination of mathematical and regression modelling. Fore-limb vertical force (NKg) w...
Hitchens PL, Pivonka P, Malekipour F, Whitton RC.In Thoroughbred racehorses, fractures of the distal limb are commonly catastrophic. Most of these fractures occur due to the accumulation of fatigue damage from repetitive loading, as evidenced by microdamage at the predilection sites for fracture. Adaptation of the bone in response to training loads is important for fatigue resistance. In order to better understand the mechanism of subchondral bone adaptation to its loading environment, we utilised a square root function defining the relationship between bone volume fraction [Formula: see text] and specific surface [Formula: see text] of the ...
Fuerst A, Derungs S, von Rechenberg B, Auer JA, Schense J, Watson J.To describe the treatment of a subchondral bone cyst in the proximal phalanx with parathyroid hormone peptide-enriched fibrin hydrogel in a warmblood filly. The cyst was localized with computer-assisted orthopaedic surgery, then curetted and finally filled with parathyroid hormone fragment peptide 1-34 (PTH(1-34)) covalently attached to a fibrin hydrogel. The cyst healed quickly without any complications. This result supports the hypothesis that PTH(1-34) delivered locally in a fibrin hydrogel may improve the postoperative prognosis of surgical management of subchondral bone cysts in horses. S...
Easton KL, Kawcak CE.To quantitatively evaluate contact area under 2 loads and subjectively compare contact areas with subchondral bone (SCB) density patterns in intact metacarpophalangeal joints of horses. Methods: 6 forelimbs from horses without musculoskeletal disease. Methods: Computed tomographic scans of intact metacarpophalangeal joints were analyzed to obtain SCB density measurements. Each limb was loaded on a materials testing system to 150 degrees and 120 degrees extension in the metacarpophalangeal joint, and the joint was stained via intra-articular injection with safranin-O or toluidine blue, respecti...
Te Moller NCR, Mohammadi A, Plomp S, Serra Bragança FM, Beukers M, Pouran B, Afara IO, Nippolainen E, Mäkelä JTA, Korhonen RK, Töyräs J....This study aimed to quantify the long-term progression of blunt and sharp cartilage defects and their effect on joint homeostasis and function of the equine carpus. In nine adult Shetland ponies, the cartilage in the radiocarpal and middle carpal joint of one front limb was grooved (blunt or sharp randomized). The ponies were subjected to an 8-week exercise protocol and euthanized at 39 weeks. Structural and compositional alterations in joint tissues were evaluated in vivo using serial radiographs, synovial biopsies, and synovial fluid samples. Joint function was monitored by quantitative gait...
Valdés-Martínez A.Computed tomographic arthrography is an imaging technique used for the evaluation of the internal structures of a joint, especially the soft tissues and subchondral bone defects that may communicate with the joint space. Clinical indications, technical aspects, principles of image interpretation, and advantages and disadvantages of this imaging technique for the evaluation of the equine stifle joint are discussed in this article.
Journal of biomechanicsDecember 24, 2019
Volume 100 109594 doi: 10.1016/j.jbiomech.2019.109594
Malekipour F, Hitchens PL, Whitton RC, Lee PV.Subchondral bone (SCB) microdamage is prevalent in the joints of human athletes and animals subjected to high rate and magnitude cyclic loading of the articular surface. Quantifying the effect of such focal in vivo fatigue-induced microdamage on the mechanical response of the tissue is critical for the understanding of joint surface injury and the development of osteoarthritis. Thus, we aimed to quantify the mechanical properties of cartilage-bone from equine third metacarpal (MC3) condyles, which is a common area of accumulated microdamage due to repetitive impact loading. We chose a non-dest...
Zubrod CJ, Schneider RK.When medical therapy and surgical treatments of an injured joint fail to return the animal to athletic performance or comfortable use of the limb, arthrodes is is a final option for some joints. Arthrodesis refers to the surgical fusion of a joint, resulting in bony ankylosis. Successful arthrodesis requires debridement of the articular cartilage through the calcified cartilage layer, exposing the subchondral bone; alignment of the joint into a weight-bearing position; and stabilization. The methods by which these steps are accomplished are variable, depending on the individual joint. There ar...
Murray RC, Znaor N, Tanner KE, DeBowes RM, Gaughan EM, Goodship AE.Dorsal carpal osteochondral injury is a major cause of lameness in horses undergoing high intensity training. Intra-articular corticosteroid treatment is used commonly to manage exercise-associated articular pain, but its use remains highly controversial in the equine athlete. This project, therefore, aimed to compare the mechanical properties of intra-articular MPA and diluent-treated middle carpal subchondral and cancellous bone in horses undergoing a short-term treadmill exercise programme. It was hypothesised that subchondral and cancellous bone mechanical properties are influenced by intr...
Bani Hassan E, Mirams M, Ghasem-Zadeh A, Mackie EJ, Whitton RC.To gain a better understanding of the aetiology of articular surface collapse in horses with palmar osteochondral disease. Objective: To determine whether acceleration of focal bone resorption associated with reduced physical activity contributes to articular surface collapse in racehorses with palmar osteochondral disease. Methods: Cross-sectional study comparing metacarpal bones from horses at varying stages of race training. Methods: Metacarpal bones from 36 racing Thoroughbred horses were examined with high-resolution peripheral quantitative computed tomography to determine the proportion ...
Bertuglia A, Basano I, Pagliara E, Bottegaro NB, Spinella G, Bullone M.To compare the effects of tiludronate disodium and 3 other medical treatments on clinical and radiographic findings and biomarkers of disease progression in horses with osteoarthritis of the fetlock joint. 100 Standardbred racehorses with spontaneous traumatic injury of the fetlock joint. Horses were retrospectively grouped by whether they received tiludronate IV or triamcinolone acetonide and hyaluronan, polysulfated glycosaminoglycan, or interleukin-1 receptor antagonist protein intra-articularly. Data were collected on clinical, radiographic, and ultrasonographic findings and results for se...
Anastasiou A, Skioldebrand E, Ekman S, Hall LD.The distal row of carpal bones (C2, C3, and C4) from eight left intercarpal joints--four from Standardbred Trotters and four from Swedish Warmblood horses--were used to assess the potential of magnetic resonance (MR) imaging to detect cartilage and bone lesions. The joints used in the study were classified by macroscopic and radiographic examinations as having normal, mild, moderate, or severe articular cartilage lesions and bone sclerosis. Those classifications correlated well with the appearance of the MR images. Bone sclerosis in the MR images was observed as regions of decreased signal int...
Nixon AJ, Fortier LA, Goodrich LR, Ducharme NG.Debridement of osteochondritis dissecans (OCD) cartilage lesions results in fibrocartilage and imperfect hyaline repair tissue, and forms a permanent irregularity to the subchondral bone plate. Objective: To evaluate the clinical, radiographic and outcome effects of OCD cartilage flap reattachment for select lesions as an alternative to OCD debridement. Objective: Separated cartilage flaps resulting from OCD lesions may be re-incorporated into the hyaline cartilage surface by reattachment rather than debridement and removal. Methods: Resorbable polydioxanone pins were used to reattach OCD flap...
Ravanetti P, Lechartier A, Hamon M, Zucca E.In the last 30 years, several treatments have been proposed to treat subchondral cystic lesions (SCLs) but there have been no randomised studies to compare different methods and there is no consensus as to the optimal treatment. Objective: To evaluate a biocompatible absorbable implant for the treatment of SCLs in young horses in different anatomical locations. Methods: Retrospective case series. Methods: Horses with SCLs were treated with debridement through a trans-cortical extra-articular approach and an absorbable implant was inserted in the cavity. Clinical and radiographic follow-up was...
Malekipour F, Whitton CR, Lee PV.Subchondral bone injury due to high magnitude and repetition of compressive loading is common in humans and athletic animals such as Thoroughbred racehorses. Repeated loading of the joint surface may alter the subchondral bone microstructure and initiate microdamage in the bone adjacent to the articular cartilage. Understanding the relationship between microdamage, microstructure and mechanical properties of the subchondral bone adjacent to the articular cartilage is, therefore, essential in understanding the mechanism of subchondral bone injury. In this study, we used high-resolution µCT sca...
Rubio-Martínez LM, Cruz AM, Gordon K, Hurtig MB.To characterize the microstructure of subchondral bone (SCB) plate and trabecular bone (TBB) of the distopalmar aspect of the condyles of third metacarpal bones (MC3s) from Thoroughbred racehorses at 2 different stages of SCB disease via micro-computed tomography (CT). Methods: 12 pairs of MC3s from Thoroughbred racehorses euthanized for various reasons. Methods: MC3s were collected from horses with mild (n = 6) or severe (6) SCB disease, as determined via micro-CT. Cubic (6 x 6 x 6-cm) specimens of SCB plate and TBB were cut from the palmar aspect of condyles and sagittal ridges and examined ...
Schneider RK, Jenson P, Moore RM.To evaluate clinical findings and response to treatment in horses in which cartilage lesions on the medial femoral condyle were a cause of lameness. Methods: Retrospective case series. Methods: Medical records of 11 horses that had cartilage lesions on the medial femoral condyle detected during arthroscopy of the stifle. Methods: Signalment, history, lameness examination, response to intra-articular anesthesia, radiographs of the stifle, observations during diagnostic arthroscopy, and treatment were extracted from the medical record of each horse. Follow-up examinations and outcome were availa...
Smith MR, Wright IM.Fractures of the proximal phalanx are generally considered to result from monotonic supraphysiological loads, but radiological observations from clinical cases suggest there may be a stress-related aetiology. Objective: To determine whether there are radiologically identifiable prodromal changes in Thoroughbred racehorses with confirmed parasagittal fractures of the proximal phalanx. Methods: Retrospective cross-sectional study. Methods: Case records and radiographs of Thoroughbred racehorses with parasagittal fractures of the proximal phalanx were analysed. Thickness of the subchondral bone p...
Seo JP, Kambayashi Y, Itho M, Haneda S, Yamada K, Furuoka H, Tabata Y, Sasaki N.This study aimed to evaluate the efficacy of a synovial flap and gelatin/β-tricalcium phosphate (GT) sponge loaded with mesenchymal stem cells (MSCs), bone morphogenetic protein-2 (BMP-2), and platelet rich plasma (PRP) for repairing of osteochondral defects in horses. Osteochondral defects were created on the medial condyle of both femurs (n=5). In the test group, a GT sponge loaded with MSCs, BMP-2, and PRP (GT/MSCs/BMP-2/PRP) was inserted into the defect and then covered with a synovial flap. In the control group, the defect was treated only with the GT/MSCs/BMP-2/PRP. The test group showe...
Murray RC, Whitton RC, Vedi S, Goodship AE, Lekeux P.Carpal osteochondral injury is frequently observed in strenuously trained horses. It is clear that the integrity of articular cartilage and subchondral bone are intimately related, although there is controversy about which component is the most important. Calcified cartilage provides the mechanical link between soft hyaline cartilage and stiff subchondral bone so it is essential to understand the tissue's response to exercise. Middle carpal calcified and uncalcified (hyaline) cartilage thickness was investigated in horses undergoing high- and low-intensity exercise. Twelve untrained horses (18...
van der Harst MR, DeGroot J, Kiers GH, Brama PA, van de Lest CH, van Weeren PR.To assess whether site-related changes in biochemical composition are present in the cartilage and subchondral and trabecular bone of the metacarpophalangeal joint of horses with early osteoarthritis. Methods: Right metacarpophalangeal joints from 59 mature warmblood horses. Methods: Biochemical data (cross-link, amino acid, DNA, and ash contents; denatured collagen and glycosaminoglycan [GAG] concentrations; bone mineral density; and mineral composition) were obtained from 2 differently loaded sites of phalanx I cartilage and subchondral and trabecular bone samples; data were compared with pr...
Frazer LL, Santschi EM, Fischer KJ.To predict the bone formation stimulus of a transcondylar screw across an equine subchondral bone cyst (SBC) in an equine medial femoral condyle (MFC). Methods: Finite element modeling (FEM) of an equine MFC with a 2 cm SBC under several transcondylar screw conditions. Methods: The right stifle of a yearling thoroughbred without stifle disease that had been euthanized for reasons unrelated to this study and donated to the University. Methods: The FEM was derived from computed tomography of a yearling thoroughbred and analyzed in ABAQUS v6.14. The transcondylar screw was modeled as a 4.5-mm s...
Scott GS, Crawford WH, Colahan PT.To determine arthroscopic findings in lame horses with subtle radiographic lesions of the medial femoral condyle. Methods: Retrospective study. Methods: 15 horses examined because of lameness that had subtle radiographic evidence of osteochondral lesions involving the medial femoral condyle in at least 1 joint. Methods: Medical records were reviewed, and results of physical examination, radiography, and arthroscopy were recorded. Follow-up information was obtained through reexamination of the horses or telephone conversations with the referring veterinarians, owners, or trainers. Results: Lame...
Bani Hassan E, Mirams M, Mackie EJ, Whitton RC.To investigate the prevalence of microscopic subchondral bone injury in the distal metacarpi/tarsi of Thoroughbred racehorses and associations with recent and cumulative training history. Methods: Metacarpi/metatarsi were obtained from postmortem examination of Thoroughbred racehorses. The severity of palmar/plantar osteochondral disease (POD) was graded in forelimbs from 38 horses and in hindlimbs from a separate cohort of 45 horses. Forelimb samples were embedded in methyl methacrylate and examined using backscattered scanning electron microscopy. Microfracture density in the condylar subcho...
