Topic:Articular Cartilage
Articular cartilage in horses is a specialized connective tissue found at the ends of bones within joints. It provides a smooth, lubricated surface for articulation and facilitates the transmission of loads with a low frictional coefficient. Articular cartilage is primarily composed of chondrocytes, collagen fibers, and proteoglycans, and it lacks blood vessels, nerves, and lymphatics. This avascular nature contributes to its limited capacity for self-repair following injury. The health and integrity of articular cartilage are essential for maintaining joint function and mobility in horses. This page compiles peer-reviewed research studies and scholarly articles that explore the structure, function, and pathological changes of articular cartilage in equine species, as well as advancements in diagnostic and therapeutic approaches for cartilage-related disorders.
The application of an indenter system to measure structural properties of articular cartilage in the horse. Suitability of the instrument and correlation with biochemical data. A recently developed indenter system that aims at determination of local structural properties of the cartilage surface was evaluated for suitability in the horse. To this aim, maximum indenter force was measured of the articular surface and related to biochemical characteristics of the cartilage at different sites of the distal metacarpal bone (MC). Significant topographical variation exists in structural properties of the articular surface of the MC. The dorsal margin showed a significantly lower maximum indenter force than more centrally located areas, indicating an increased compliance und...
The effect of sodium heparin on equine articular cartilage. This study compared the effect of sodium heparin and gentamicin sulphate on equine articular cartilage (AC) explants in order to investigate the possible use of sodium heparin in the treatment of infectious arthritis. Six concentrations of sodium heparin and gentamicin sulphate were tested. The supernatant and explant digest were assayed for glycosaminoglycan (GAG) content with the dimethyl-methylene blue assay and the per cent loss of GAG was calculated. A significant (P< 0.001) increase in percentage GAG loss was noted for the sodium heparin groups when compared to the control, whilst no ...
The surgical technique and the age of the horse both influence the outcome of mosaicplasty in a cadaver equine stifle model. Six pieces of grafts, 6.5 mm in diameter, 20 mm in length, were taken from each of 170 cadaver hindlimbs, using the cranial surface of the medial femoral trochlea for harvesting. The age of the horses varied between 4 months and 23 years. 30 limbs under the age of 12 years were selected for transplantation. Three of six grafts were transplanted into the medial femoral condyle using different combinations of tunnel depth and dilation. With ageing, a significant decline in transplantability was detected. In general, mosaicplasty cannot be recommended in horses above 11 years. Based on a previous...
Scedosporium prolificans infection associated with arthritis and osteomyelitis in a horse. Scedosporium prolificans was associated with arthritis and degenerative osteomyelitis in a 6-year-old Thoroughbred racehorse. The horse was suspected to have an inflammatory lesion of the interosseous tendon, but treatment had resulted in only a minimal response. Shortly after diagnostic arthrocentesis of the left metacarpophalangeal joint was performed, the joint became severely swollen, and radiography of the area revealed lysis of the distal end of the third metacarpal bone, the proximal sesamoid bones, and the proximal end of the proximal phalanx. The horse did not respond to treatment and...
Use of synovial fluid markers of cartilage synthesis and turnover to study effects of repeated intra-articular administration of methylprednisolone acetate on articular cartilage in vivo. In vivo the effects of intra-articular (IA) corticosteroids on articular cartilage remain controversial. This study was designed to examine this issue using synovial fluid (SF) markers of cartilage metabolism. Paired radiocarpal joints, without clinical or radiographic signs of joint disease, were studied in 10 adult horses. Aseptic arthrocentesis was performed weekly for 13 weeks. IA injections of methylprednisolone acetate (MPA) into the treatment joint and the vehicle into the control joint were performed at weeks 3, 5 and 7. We used radioimmunoassays on SF samples which measure a keratan s...
Effects of enrofloxacin and ciprofloxacin hydrochloride on canine and equine chondrocytes in culture. To study chondrotoxic effects of enrofloxacin (ENR) and ciprofloxacin hydrochloride (CFX) on canine and equine articular chondrocytes in culture and to compare the effects with that of cultivation in Mg2+-free medium. Methods: Chondrocytes from articular cartilage of 4- and 6 -month old dogs and 2- to 4- year-old horses. Methods: Chondrocytes were cultivated with 10, 40, 80, and 160 microg of CFX/ml, 10, 50, 100, and 150 microg of ENR/ml, or in Mg2+-free medium. A live-to-dead test was performed to test cytotoxic effects. Morphologic changes were evaluated by electron microscopy. An attachment...
Survey of arthroscopic surgery for carpal chip fractures in thoroughbred racehorses in Japan. Medical and racing records of 155 Thoroughbred racehorses that underwent arthroscopic surgery for carpal chip fractures were investigated. Articular damage for 98.4% of the fractures was classified as G1 or G2 using McIlwraith's criteria. The rate of return to racing after surgery was 82.6%. Evaluation of racing performance after surgery was attempted using a placing index (PI) based on race finish position. There was no significant difference in the PI distribution between horses that underwent surgery and other healthy horses.
Effect of contact stress in bones of the distal interphalangeal joint on microscopic changes in articular cartilage and ligaments. To examine articular cartilage of the distal interphalangeal (DIP) joint and distal sesamoidean impar ligament (DSIL) as well as the deep digital flexor tendon (DDFT) for adaptive responses to contact stress. Methods: Specimens from 21 horses. Methods: Pressure-sensitive film was inserted between articular surfaces of the DIP joint. The digit was subjected to a load. Finite element models (FEM) were developed from the data. The navicular bone, distal phalanx, and distal attachments of the DSIL and DDFT were examined histologically. Results: Analysis of pressure-sensitive film revealed signific...
The role of subchondral bone in joint disease: a review. Subchondral bone plays a role in the pathogenesis of osteochondral damage and osteoarthritis in horses and humans. Osteochondral fragmentation and fracture, subchondral bone necrosis and osteoarthritis are common diseases in athletic horses, and subchondral bone is now thought to play an integral role in the pathogenesis of these diseases. There have been numerous research efforts focused on articular cartilage damage and its pathogenesis, yet comparatively little effort focused on subchondral bone pathology or the coordinated disease states of the osteochondral tissues. The purpose of this re...
Subchondral cystic lesions of the proximal extremity of the tibia in horses: 12 cases (1983-2000). To determine clinical and radiographic features of subchondral cystic lesions (SCL) of the proximal extremity of the tibia in horses that could be used to classify these lesions as being related to osteochondrosis or osteoarthritis and to evaluate results of surgical debridement. Methods: Retrospective study. Methods: 12 horses with 14 SCL. Methods: Medical records and radiographs obtained before and after treatment were reviewed. Results: In 6 young horses (8 lesions), SCL were considered to be related to osteochondrosis; all involved the lateral tibial condyle. The remaining 6 horses were ma...
Effects of enrofloxacin and magnesium deficiency on matrix metabolism in equine articular cartilage. To investigate the effects of enrofloxacin and magnesium deficiency on explants of equine articular cartilage. Methods: Articular cartilage explants and cultured chondrocytes obtained from adult and neonatal horses. Methods: Full-thickness explants and cultured chondrocytes were incubated in complete or magnesium-deficient media containing enrofloxacin at concentrations of 0, 1, 5, 25, 100, and 500 microg/ml. Incorporation and release of sulfate 35S over 24 hours were used to assess glycosaminoglycan (GAG) synthesis and degradation. An assay that measured binding of dimethylmethylene blue dye ...
Contact areas and pressure distribution on the proximal articular surface of the proximal phalanx under sagittal plane loading. The objective of this study was to map topographically contact areas and pressure distributions on the proximal articular surface (PAS) of the proximal phalanx (PI) under various clinically relevant loading conditions. Left and right forelimbs of 13 mature horses were transected halfway down the radius and loaded in a position mimicking the weightbearing attitude close to the midstance phase. Five loads were used which corresponded with loads that can be expected in different gaits or during athletic performance (stance: 1800 N, walk: 3600 N, trot: 5400 N, gallop: 10,500 N and jumping: 12,000 ...
Cross-sectional comparison of synovial fluid biochemical markers in equine osteoarthritis and the correlation of these markers with articular cartilage damage. To investigate the relationship between biochemical markers in the synovial fluid of osteoarthritic and contralateral equine joints and gross articular cartilage pathology. Methods: Twenty-two horses underwent bilateral arthroscopy of their carpal or metacarpophalangeal joints following recent onset lameness. The degree of cartilage damage in each joint was scored and synovial fluid, from both the clinically affected and the contralateral joint, was collected. Bone specific alkaline phosphatase (BAP), 5D4 epitope of keratan sulphate (KS), total glycosaminoglycans (GAG) and hyaluronan (HA) were...
The effects of methylprednisolone on normal and monocyte-conditioned medium-treated articular cartilage from dogs and horses. To study in vitro (1) the dose-response relationships between proteoglycan metabolism in normal and corticosteroid-treated articular cartilage; (2) long-term proteoglycan metabolism after treatment of articular cartilage with corticosteroids; and (3) the effect of corticosteroids on proteoglycan metabolism in articular cartilage treated with monocyte-conditioned medium (MCM). Methods: Equine and canine articular cartilage explants were treated with corticosteroids and MCM. Proteoglycan synthesis and degradation were measured by radioactive labeling in short-term culture, and the long-term effe...
The influence of strenuous exercise on collagen characteristics of articular cartilage in Thoroughbreds age 2 years. In order to assess the influence of strenuous exercise on collagen characteristics of articular cartilage, the response of the collagen network was studied in seven 2-year-old Thoroughbreds subjected to strenuous exercise compared to 7 nontrained individuals. After 13 weeks, the animals were subjected to euthanasia, fetlock joints of the forelimbs were scored macroscopically after Indian Ink staining, and articular cartilage from different locations of the articular surface of the proximal first phalanx was sampled and analysed for water content, collagen content, hydroxylysine content and amo...
The effects of glucosamine derivatives on equine articular cartilage degradation in explant culture. To determine whether glucosamine-3-sulfate, glucose-3-sulfate (control) and N-acetyl glucosamine inhibit experimentally induced degradation of equine articular cartilage explants similar to glucosamine HCl. Methods: Articular cartilage was obtained from the antebrachio-carpal and middle joints of horses (2-8 years old) killed for reasons unrelated to lameness. Cartilage discs were harvested from the weight-bearing region of the articular surface and cultured. Media were exchanged daily and the recovered media stored at 4 degrees C. On days 1 and 2 lipopolysaccharide (LPS, 10 microg/ml) was add...
Metalloproteinases and tumor necrosis factor-alpha activities in synovial fluids of horses: correlation with articular cartilage alterations. Early detection of osteoarthritis in horses represents a challenge for equine practitioners. Several biological markers have been implicated in the pathological processes involved in articular cartilage destruction. To further document cartilage matrix proteases production, synovial fluid was collected from 14 horses (90 joints) before they were subjected to euthanasia. Growth macroscopic examination of the joints gave information on cartilage alterations. Samples were analyzed for matrix metalloproteinase (MMPs) activities by gelatin zymography and tumor necrosis factor alpha (TNF-alpha) cyto...
Ultrasonographic evaluation of tarsocrural joint cartilage in normal adult horses. Ultrasonographic examination of the tarsus was performed on four clinically and radiographically normal limbs of adult horses. Particular attention was paid to the articular cartilage surfaces of the trochlear ridges of the talus and the distal intermediate ridge of the tibia. Two separate measurements of articular cartilage thickness were acquired from a longitudinal view at each site. Anatomy was confirmed with post mortem dissection. Ultrasonography was found to be a practical method for imaging the articular cartilage over the trochlear ridges of the talus and distal intermediate ridge of ...
An evaluation of chemical arthrodesis of the proximal interphalangeal joint in the horse by using monoiodoacetate. The use of monoiodoacetate (MIA) for arthrodesis of the proximal interphalangeal joint (PIJ) and the effect of exercise on the degree of fusion were investigated. Eight horses received 3 injections (Weeks 0, 3, 6) of MIA (2 mL; 60 mg/mL) into the right or left front PIJ. Peri-operatively, the horses received phenylbutazone, butorphanol, and abaxial sesamoidean nerve blocks to relieve pain. During the study, the horses were monitored for general health, lameness, and swelling around the injection area. Radiographs were taken biweekly to evaluate bony fusion. Horses were randomly divided into no...
Effect of exercise on the proteoglycan metabolism of articular cartilage in growing foals. In this study, the effect of different exercise regimens on proteoglycan metabolism of articular cartilage was examined in 43 newborn foals randomly divided into 3 groups: a) box-rest, b) box-rest with training and c) free pasture exercise. They were subjected to these exercise regimens from ages 1 week to 5 months and at 5 months, 24 foals (8 from each group) were sacrificed to assess short-term exercise effects. The remaining 19 foals were subjected to the same regimen of light exercise for an additional 6 months before being sacrificed to evaluate possible long-term effects. Articular carti...
Fibrous tissue of subchondral cystic lesions in horses produce local mediators and neutral metalloproteinases and cause bone resorption in vitro. To define the release of nitric oxide (NO), prostaglandin E2 (PGE2), and the neutral metalloproteinases (NMPs) in horses with subchondral cystic lesions (SCL) and to study bone resorption triggered by conditioned media of fibrous tissue of SCL in vitro. Methods: Equine explant cultures of fibrous tissue of SCL, and synovial membrane and articular cartilage of normal horses and horses affected with moderate and severe osteoarthritis were performed. NO, PGE2, and NMP concentrations of media samples were measured, and osteoclast formation and activation was studied in vitro. Methods: Experiment 1...
Influence of different exercise levels and age on the biochemical characteristics of immature equine articular cartilage. This study aimed to examine whether biochemical characteristics of juvenile articular cartilage are changing during the first year post partum and whether they can be influenced by exercise at young age. Water, glycosaminoglycan (GAG), DNA, total collagen, hydroxylysine and hydroxylysylpyridinoline (HP) content were measured in articular cartilage of 43 foals that were subdivided into 3 groups (n = 15, 14 and 14) which were subjected to different exercise regimens from one week after birth to age 5 months. At the age of 5 months all foals were weaned and 8 foals were selected randomly from eac...
Early changes in the distal intertarsal joint of Dutch Warmblood foals and the influence of exercise on bone density in the third tarsal bone. It was hypothesised that imposition of different exercise levels at a young age would lead to differences in bone density in the third tarsal bone and to difference in the prevalence of pathological lesions that might contribute to the development of bone spavin later in life. Furthermore, based on earlier literature, it was hypothesised that such lesions could be classified as a manifestation of osteochondrosis. Changes in bone density in the third tarsal bone and early pathological changes in the articular cartilage of the distal intertarsal joint were studied in the offspring of sires with ...
Changes in proteoglycan metabolism in osteochondrotic articular cartilage of growing foals. In osteochondrosis (OC) the process of endochondral ossification is impaired. Proteoglycans form one of the major components of the extracellular matrix of cartilage and are able to bind calcium. For this reason, proteoglycans are thought to play an important role early in the mineralisation process and may, therefore, be important in the pathogenesis of OC. To investigate possible differences in proteoglycan metabolism, normal and osteochondrotic articular-epiphyseal cartilage was harvested from the hock and stifle joints of 43 foals age 5 and 11 months. The samples were cultured as explants ...
Conclusions regarding the influence of exercise on the development of the equine musculoskeletal system with special reference to osteochondrosis. This paper summarises and interrelates the findings of a large-scale multidisciplinary investigation to assess the influence of exercise on the development of the equine musculoskeletal system in general and of osteochondrosis in particular, up to age 5 months. Forty-three foals, genetically predisposed to develop OC, were divided into 3 exercise groups: box-rest, box-rest with training and free pasture exercise. At 5 months, all foals were weaned and 8 foals per group were subjected to euthanasia for postmortem examination. The remaining 19 foals were placed together and subjected to euthanas...
Effect of transforming growth factor beta1 on chondrogenic differentiation of cultured equine mesenchymal stem cells. To determine the morphologic and phenotypic effects of transforming growth factor beta1 (TGFbeta1) on cultured equine mesenchymal stem cells (MSC) and articular chondrocytes. Methods: Bone marrow aspirates and articular cartilage samples from a 2-year-old and two 8-month-old horses. Methods: After initial isolation and culture, MSC and chondrocytes were cultured in Ham's F-12 medium supplemented with TGF-beta1 at a concentration of 0, 1, 5, or 10 ng/ml. Medium was exchanged on day 2, and cells were harvested on day 4. Medium was assayed for proteoglycan (PG) content. Total RNA was isolated fro...
Comparison of Northern blot hybridization and a reverse transcriptase-polymerase chain reaction technique for measurement of mRNA expression of metalloproteinases and matrix components in articular cartilage and synovial membrane from horses with osteoarthritis. To determine relative amounts of mRNA expression of aggrecan, type-II collagen, matrix metalloproteinase (MMP) 1, and MMP3 in articular cartilage and synovial membrane samples from healthy equine joints and joints with osteoarthritis (OA) and to compare results of Northern blot hybridization with results of a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Methods: Articular cartilage samples from 8 pairs of joints (1 with OA and 1 healthy) from 6 horses and synovial membrane samples from 6 pairs of joints from 5 horses. Methods: RNA was extracted from samples by use of a modif...
Alterations in cartilage type-II procollagen and aggrecan contents in synovial fluid in equine osteochondrosis. The etiology and pathophysiology of osteochondrosis remain poorly understood because it is difficult to obtain material from lesions in the early stage of this disease and because there is no satisfactory experimental animal model. We wished to determine whether there are changes in articular cartilage turnover in equine osteochondrosis, which closely resembles the human disease, by assaying cartilage matrix molecules in synovial fluids. We used immunoassays that measure a keratan sulfate epitope and the epitope 846 on the cartilage proteoglycan aggrecan and the C-propeptide of cartilage type-...
In vitro evaluation of the effect of dimethyl sulfoxide on equine articular cartilage matrix metabolism. To evaluate the effects of dimethyl sulfoxide (DMSO) on equine articular cartilage matrix metabolism. Methods: Using a cartilage explant culture system, proteoglycan (PG) synthesis, PG release, lactate metabolism, chondrocyte viability, and metabolism recovery were determined after cartilage exposure to DMSO. Methods: Cartilage harvested from metacarpophalangeal and metatarsophalangeal joints of 12 horses (age range, 1 to 10 years). Methods: Explants were exposed to concentrations of DMSO (1% to 20%) for variable times (3 to 72 hours). PG synthesis and release were determined by a radiolabel i...
Age-related effects of TGF-beta on proteoglycan synthesis in equine articular cartilage. The synthesis of proteoglycans was measured in normal equine articular cartilage of ages 9 months to 20 years and the effect of TGF-beta1 on this activity was investigated. The rate of incorporation of [(35)S]Na(2)SO(4) decreased with age as did the responsiveness of the tissue to the growth factor. The enhanced synthesis of proteoglycan induced at all ages by TGF-beta1 was down-regulated by IL-1 beta and retinoic acid. The expression of mRNA for TGF-beta1, 2, and 3 was also measured, and although the level of TGF-beta1 was highest at all ages, the expression of each growth factor decreased wi...