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1.
van der Harst MR van de Lest CH Degroot J Kiers GH Brama PA van Weeren PR 《Equine veterinary journal》2005,37(3):200-206
REASONS FOR PERFORMING STUDY: A detailed and comprehensive insight into the normal maturation process of the different tissues that make up functional units of the locomotor system such as joints is necessary to understand the influence of early training on musculoskeletal tissues. OBJECTIVES: To study simultaneously the maturation process in the entire composite structure that makes up the bearing surface of a joint (cartilage, subchondral and trabecular bone) in terms of biochemical changes in the tissues of juvenile horses at 2 differently loaded sites of the metacarpophalangeal joint, compared to a group of mature horses. HYPOTHESIS: In all the structures described above developmental changes may follow a different timescale. METHODS: Age-related changes in biochemical characteristics of the collagen part of the extracellular matrix (hydroxylysine, hydroxyproline, hydroxypyridinum crosslinks) of articular cartilage and of the underlying subchondral and trabecular bone were determined in a group of juvenile horses (n = 13) (Group 1, age 6 months-4 years) and compared to a group of mature horses (n = 30) (Group 2, >4 years). In both bony layers, bone mineral density, ash content and levels of individual minerals were determined. RESULTS: In cartilage, subchondral bone and trabecular bone, virtually all collagen parameters in juvenile horses were already at a similar (stable) level as in mature horses. In both bony layers, bone mineral density, ash- and calcium content were also stable in the mature horses, but continued to increase in the juvenile group. For magnesium there was a decrease in the juvenile animals, followed by a steady state in the mature horses. CONCLUSIONS: In horses age 6 months-4 years, the collagen network of all 3 layers within the joint has already attained a mature biochemical composition, but the mineral composition of both subchondral and trabecular bone continues to develop until approximately age 4 years. POTENTIAL RELEVANCE: The disparity in maturation of the various extracellular matrix components of a joint can be assumed to have consequences for the capacity to sustain load and should hence be taken into account when training or racing young animals. 相似文献
2.
AIM: To describe features of the morphology of the carpus, quantify the thickness of hyaline and calcified cartilage, and to describe the morphology and density of subchondral bone in the third carpal bone (C3) of young Thoroughbred horses in early training. METHODS: C3 of seven 2-year-old horses in training and seven untrained horses matched for age, sex and breed were assessed by gross appearance, computed tomography, fine-structure radiography, image analysis of high-resolution photographs, and histology. RESULTS: Macroscopic lesions in cartilage were few and mild, and not significantly different between groups. High bone mineral density (BMD), in some cases typical of cortical bone, was confined to the dorsal load path, and was significantly higher in trained than in untrained horses (p<0.01). In the most dorsoproximal aspect of the radial articular facet, apparently outside the dorsal load path, the BMD in both trained and untrained horses was significantly less than in other regions of interest (ROIs). Adaptive increase in density was associated with thickening of the (junctions of) trabeculae oriented proximo-distally. Hyaline cartilage was thicker (p<0.001) in the concavity of the radial articular facet than dorsal or palmar to it, and was thicker in the trained than untrained group (p=0.007). No such differences were detected in the thickness of articular calcified cartilage (ACC). CONCLUSIONS: The rapid response of bone in C3 to relatively small amounts of high-speed exercise was confirmed. A previously unreported increase in thickness of hyaline cartilage was evident, perhaps indicating that this tissue may be more responsive than hitherto thought, at least to particular types of exercise at particular times. These changes occurred with little evidence of abnormality, and thus appeared to be adaptive to the exercise regimen. The model developed should be used for further definition of the exercise stimulus required to produce adaptive, protective changes in sites susceptible to athletic injury. CLINICAL RELEVANCE: The data will serve as reference for use in subsequent imaging studies in which sophisticated aids such as magnetic resonance imaging (MRI) may be used to predict carpal lesions. 相似文献
3.
AIM: To describe features of the morphology of the carpus, quantify the thickness of hyaline and calcified cartilage, and to describe the morphology and density of subchondral bone in the third carpal bone (C3) of young Thoroughbred horses in early training. METHODS: C3 of seven 2-year-old horses in training and seven untrained horses matched for age, sex and breed were assessed by gross appearance, computed tomography, fine-structure radiography, image analysis of high-resolution photographs, and histology. RESULTS: Macroscopic lesions in cartilage were few and mild, and not significantly different between groups. High bone mineral density (BMD), in some cases typical of cortical bone, was confined to the dorsal load path, and was significantly higher in trained than in untrained horses (p<0.01). In the most dorsoproximal aspect of the radial articular facet, apparently outside the dorsal load path, the BMD in both trained and untrained horses was significantly less than in other regions of interest (ROIs). Adaptive increase in density was associated with thickening of the (junctions of) trabeculae oriented proximo-distally. Hyaline cartilage was thicker (p<0.001) in the concavity of the radial articular facet than dorsal or palmar to it, and was thicker in the trained than untrained group (p=0.007). No such differences were detected in the thickness of articular calcified cartilage (ACC). CONCLUSIONS: The rapid response of bone in C3 to relatively small amounts of high-speed exercise was confirmed. A previously unreported increase in thickness of hyaline cartilage was evident, perhaps indicating that this tissue may be more responsive than hitherto thought, at least to particular types of exercise at particular times. These changes occurred with little evidence of abnormality, and thus appeared to be adaptive to the exercise regimen. The model developed should be used for further definition of the exercise stimulus required to produce adaptive, protective changes in sites susceptible to athletic injury. CLINICAL RELEVANCE: The data will serve as reference for use in subsequent imaging studies in which sophisticated aids such as magnetic resonance imaging (MRI) may be used to predict carpal lesions. 相似文献
4.
Lewis CW Williamson AK Chen AC Bae WC Temple MM Wong WV Nugent GE James SP Wheeler DL Sah RL Kawcak CE 《American journal of veterinary research》2005,66(10):1823-1829
OBJECTIVE: To determine and correlate subchondral bone mineral density and overlying cartilage structure and tensile integrity in mature healthy equine stifle (low magnitude loading) and metacarpophalangeal (high magnitude loading) joints. ANIMALS: 8 healthy horses, 2 to 3 years of age. PROCEDURE: Osteochondral samples were acquired from the medial femoral condyle (FC) and medial trochlear ridge (TR) of the stifle joint and from the dorsal (MC3D) and palmar (MC3P) aspects of the distal medial third metacarpal condyles of the metacarpophalangeal joint. Articular cartilage surface fibrillation (evaluated via India ink staining) and tensile biomechanical properties were determined. The volumetric bone mineral density (vBMD) of the underlying subchondral plate was assessed via dual-energy x-ray absorptiometry. RESULTS: Cartilage staining (fibrillation), tensile moduli, tensile strength, and vBMD were greater in the MC3D and MC3P locations, compared with the FC and TR locations, whereas tensile strain at failure was less in MC3D and MC3P locations than FC and TR locations. Cartilage tensile moduli correlated positively with vBMD, whereas cartilage staining and tensile strain at failure correlated negatively with vBMD. CONCLUSIONS AND CLINICAL RELEVANCE: In areas of high joint loading, the subchondral bone had high vBMD and the articular cartilage surface layer had high tensile stiffness but signs of structural wear (fibrillation and low failure strain). The site-dependent variations and relationships in this study support the concept that articular cartilage and subchondral bone normally adapt to physiologic loading in a coordinated way. 相似文献
5.
van der Harst MR DeGroot J Kiers GH Brama PA van de Lest CH van Weeren PR 《American journal of veterinary research》2005,66(7):1238-1246
OBJECTIVE: 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. SAMPLE POPULATION: Right metacarpophalangeal joints from 59 mature warmblood horses. PROCEDURE: 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 previously published values from nonosteoarthritic equine joints. RESULTS: Compared with findings in nonosteoarthritic joints, GAG concentration was lower in cartilage from osteoarthritic joints and there was a loss of site differences in cellularity and lysylpyridinoline (LP) cross-link content. In subchondral bone, LP cross-link content was decreased overall and there was a loss of site differences in osteoarthritic joints; ash content was higher in the osteoarthritic joints. Hydroxyproline content in trabecular bone from osteoarthritic joints was greater than that in nonosteoarthritic trabecular bone. In all 3 layers and at both sites, the linear increase of the pentosidine cross-link content with age had diminished or was not apparent in the horses with osteoarthritic joints. CONCLUSIONS AND CLINICAL RELEVANCE: In equine metacarpophalangeal joints with early osteoarthritis, distinct biochemical changes were detected in the cartilage and subchondral and trabecular bone. The dissimilarity in response of the different tissues and differences between the sites that are affected may be related to differences in biomechanical loading and transmission and dissipation of force. 相似文献
6.
Firth EC Rogers CW van Weeren PR Barneveld A McIlwraith CW Kawcak CE Goodship AE Smith RK 《Veterinary journal (London, England : 1997)》2012,192(1):34-40
This study recorded the response to training of the diaphysis of the proximal phalangeal bone and the third metacarpal bone (Mc3) and the Mc3 proximal metaphysis. Nineteen 2- and 3-year old horses in training were exposed either to spontaneous exercise at pasture (PASTEX group) or additional imposed exercise (CONDEX group) from a very young age. Quantitative computed tomography scans were analysed for bone mineral content, size, bone mineral density, periosteal and endosteal circumference, cortical thickness and an estimate of bone strength. The bones of the CONDEX horses were bigger and stronger than those of the PASTEX horses at the start of the observation period, and these differences were maintained after adjusting for training workload. Increase in the bone strength index was through size and not density increase. Density increased during training and decreased during paddock rest between the two training campaigns, during which time bone strength continued to increase because of the slow growth that was still occurring. The greatest variance in the response to the training exercise of diaphyseal bone mineral content, bone strength index or cortical thickness was associated with the cumulative workload index at the gallop, although statistically significant unexplained variances remained. There were no differences in bone response to training, with the exception of the endosteal circumference at 55% of the Mc3 length from the carpometacarpal joint space between CONDEX and PASTEX, which indicated that young horses may be able to be exercised slightly more vigorously than currently accepted. 相似文献
7.
Young BD Samii VF Mattoon JS Weisbrode SE Bertone AL 《American journal of veterinary research》2007,68(8):841-849
OBJECTIVE: 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. SAMPLE POPULATION: 8 metacarpophalangeal (MCP) joints (n = 4 horses) without osteoarthritis and 6 osteoarthritis-affected MCP joints (4). PROCEDURES: 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 determined. Data for osteoarthritis-affected and control joints were compared. Histomorphometric point count analyses identified areas of bone density for comparison with CT density measurements. RESULTS: Osteoarthritis-affected condyles had heterogeneous subchondral bone with focal resorptive lesions and patterned sclerosis, whereas control condyles had symmetric bone density distribution. In osteoarthritis-affected condyles, bone density determined via gray scale image density analysis was greater (dorsal and medial pattern), compared with control condyles, and differed among zones because of resorption and sclerosis. With regard to bone density in osteoarthritis-affected condyles, histologic findings correlated with CT images, and bone lesions were significantly correlated with cartilage lesions. CONCLUSIONS AND CLINICAL RELEVANCE: In horses, heterogeneous distribution and greater subchondral bone density were characteristic of osteoarthritis-affected condyles, compared with control condyles. Subchondral bone lesions correlated with overlying cartilage lesions in osteoarthritis-affected MCP joints. Identification of CT image characteristics appears to predict the presence of a cartilage lesion in MCP joints of horses with osteoarthritis. 相似文献
8.
Murray RC Znaor N Tanner KE DeBowes RM Gaughan EM Goodship AE 《Equine veterinary journal》2002,34(3):306-310
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 intra-articular administration of methylprednisolone acetate (MPA). Eight 2-year-old female horses had MPA or diluent administered into contralateral middle carpal joints at 14 day intervals, for a total of 4 treatments per horse. Horses underwent a standard treadmill exercise protocol until euthanasia (Day 70). Standard sites were located on the dorsal aspect of third, radial and intermediate carpal bones. Osteochondral samples from each test site were divided into subchondral bone and cancellous bone portions. These were dried, resin-embedded and gold-coated. Microhardness measurements were obtained at each test site. No significant effect of intra-articular treatment was detected. At each site, cancellous bone trabecular struts had an 18-19% higher microhardness value than the overlying subchondral bone. These findings indicate that intra-articular administration of MPA at this dose has no effect on subchondral or cancellous bone adaptation to short-term exercise and, therefore, on the propensity of carpal bones to injury. Further investigation into the calcified cartilage layer, effect of different corticosteroid preparations and diffusion of medication are required. 相似文献
9.
Osteochondrosis developed from the early growing process of articular cartilage at the caudal-central region of the medial femoral condyle in rats. Articular cartilage was thick at the region. Mineralization of the matrix in the thick deep zone was incomplete and major parts remained unmineralized. Cavity formation in the mineralized matrix resulting in osteochondrotic lesions was present in the deep zone at 6 weeks of age and was followed by an appearance of viable chondrocytes around it. Osteochondrotic lesions were present from the age of 10 weeks for females and 12 weeks for males. Cavities were expanded and increased in number, and eosinophilic necrotic foci were additionally seen. These changes were extended throughout the deep zone, and viable chondrocytes were also increased in number. The thick deep zone was retained and had no detectable invasions of blood vessels from the subchondral bone. At 20 weeks of age, necrotic areas containing large clefts were present in the basal layer of the thick deep zone and fibrotic lesions were seen beneath them. In normal cases, invasions of blood vessels were seen in the basal layer of the deep zone and also in the cavities of the cartilage; the deep zone was markedly thinned at 20 weeks of age. 相似文献
10.
K Ohshima S Satake M Ono T Ajito K Okada S Numakunai 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1990,52(1):129-136
A pathological study was performed on osteoarthrosis detected at autopsy in 20 horses whose ages ranged from 21 days to 17 years old. They were asymptomatic on the joints except in 3 animals, and autopsied after death or sacrificed due to accidental fracture or other diseases. Lesions of osteoarthrosis were recognized in all horses, which tended to increase in incidence and severity according to age. Lesions were concentrated at hinged joints such as the elbow, fetlock, and hock. Synovial fossae and ulcerative lesions were observed on each opposite articular cartilage, forming the so-called mirror image. Linear erosions regarded as a secondary one were frequently observed on the cartilages. Histologically, the lesions were classified into 4 phases, 1) edematous degeneration, 2) crevice formation, focal necrosis, erosion of cartilage, 3) ulcerative changes, 4) regenerative changes of cartilage in foals and proliferation of fibrous or adipose tissue on the denuded subchondral bone in aged horses. By toluidine blue stain, decreased acid mucopolysaccharide was suggested in cartilaginous matrix around the lesions. From the results, it was concluded that the disease was a disorder of articular cartilage accompanied with hypoplasia of articular subchondral bone. 相似文献
11.
12.
J P Morgan R R Pool T Miyabayashi 《Journal of the American Veterinary Medical Association》1987,190(5):531-540
Shoulder joints of 149 Beagles over 8 years old at the time of death (mean age, 13.8 years +/- 3.21), were examined radiographically throughout their life-times for the frequency of degenerative joint disease (DJD). Clinical histories revealed no underlying cause for DJD. The shoulder joints of a subgroup of 18 dogs were examined at necropsy, and thin sections of the joints were evaluated radiographically and histologically. Serial clinical radiographic studies indicated that normal shoulder joint development during the first year of life was followed by the appearance of subchondral bone sclerosis and bony remodeling of normal joint contour, and by the formation of periarticular osteophytes and enthesiophytes. All changes were progressive with age and typical for DJD in dogs. Bilateral involvement was common. Evaluation of specimens obtained at necropsy revealed: articular cartilage change with roughening of the surface layer, degeneration and death of superficial chondrocytes, exposure of deeper layers of chondrocytes that had proliferated with fissuring of the damaged cartilage, total cartilage loss with polishing of the exposed subchondral bone, mixed patterns of subchondral bone sclerosis and osteoporosis, change in contour of the articular surfaces, and formation of periarticular osteophytes and enthesiophytes. Joint capsule thickening, synovitis, pannus formation, and synovial chondroma formation were observed. Because of the available clinical information, in addition to the typical changes of DJD, it was thought that the changes were primary. Instability appeared to play a role in the pathogenesis of the joint disease described; however, it was not clear whether the instability caused abnormal forces on healthy cartilage or whether the primary cartilage wear caused the instability. 相似文献
13.
ALAN J. NIXON BVSc ms Diplomate acvs LENNART P. KROOK dvm PhD JEROME E. ROTH dvm JOHN M. KING dvm PhD 《Veterinary surgery : VS》1991,20(3):200-208
A pulsed carbon dioxide laser was used to vaporize articular cartilage in four horses, and perforate the cartilage and subchondral bone in four horses. Both intercarpal joints were examined arthroscopically and either a 1 cm cartilage crater or a series of holes was created in the third carpal bone of one joint. The contralateral carpus served as a control. After euthanasia at week 8, the treated and control joints were examined for gross changes, and samples of cartilage and subchondral bone, synovial membrane, and peripheral lymph nodes were examined histologically. Depletion of cartilage matrix glycosaminoglycan was assessed by safranin-O histochemical staining of the laser site and adjacent cartilage. Cartilage removal by laser vaporization resulted in rapid regrowth, with fibrous and fibrovascular tissue and occasional regions of fibrocartilage at week 8. The subchondral bone, synovial membrane, and draining lymph nodes appeared essentially unaffected by the laser cartilage vaporization procedure. Conversely, carbon dioxide laser drilling of subchondral bone resulted in poor penetration, extensive areas of thermal necrosis of bone, and significant secondary damage to the apposing articular surface of the radial carpal bone. 相似文献
14.
Lesions of the lateral trochlear ridge (LTR) of the distal femur were investigated in four pony or pony cross horses. The animals were all geldings and were six to 15 months of age. Lesions were bilateral in three ponies and unilateral in one. Femoropatellar joint effusion and lameness were present in two ponies; clinical signs were absent in the others. The proximal LTR was affected in all four animals. The radiographic appearance of the lesions was a subchondral defect containing mineralised bodies. Arthroscopic and postmortem examination findings included an osteochondral flap, a fissured or irregular articular surface and a smooth surface overlying focally thickened cartilage that extended into subchondral bone. Thickened articular cartilage was a histological feature of all the lesions. Among the other histological features, the most common were chondronecrosis, chondrocyte clusters, phenotypically abnormal chondrocytes, horizontal fissures at the osteochondral junction and retained blood vessels. The signalment of the four ponies, their clinical signs and the pathological features of their lesions were consistent with osteochondrosis of the LTR in horses. The use of multiple criteria was considered to be important in making a specific diagnosis. 相似文献
15.
Early exercise advances the maturation of glycosaminoglycans and collagen in the extracellular matrix of articular cartilage in the horse 总被引：1，自引：0，他引：1
van Weeren PR Firth EC Brommer B Hyttinen MM Helminen AE Rogers CW Degroot J Brama PA 《Equine veterinary journal》2008,40(2):128-135
REASON FOR PERFORMING STUDY: Training at a very young age may influence the characteristics of the collagen network of articular cartilage extracellular matrix (ECM) in horses. OBJECTIVES: To investigate whether increasing workload of foals results in significant changes in the biochemical composition of articular cartilage ECM. METHODS: Thoroughbred foals (n = 33) were divided into 2 different exercise groups from age 10 days-18 months. One group (PASTEX; n = 15) was reared at pasture; the other (CONDEX; n = 18) underwent a specific additional training programme that increased workload by 30%. At mean age 18 months, 6 animals from each group were subjected to euthanasia. The proximal articular surface of the proximal phalanx of the right hindlimb was examined for the presence of damage using the cartilage degeneration index (CDI). Samples were taken from 2 sites with known different loading patterns. Slices were analysed for DNA, glycosaminoglycans (GAG), collagen and post translational modifications of collagen (formation of hydroxylysylpyridinoline [HP] and pentosidine crosslinks, and hydroxylysine [Hyl]), and exercise groups and different sites compared. RESULTS: There were no differences in CDI between PASTEX and CONDEX animals, indicating the absence of extra joint damage due to the exercise regimen. There were site-related differences for most biochemical variables, corroborating earlier reports. All biochemical variables showed differences between PASTEX and CONDEX groups at one of the sites, and some at both. GAG and collagen levels were lower in the CONDEX group whereas Hyl, HP crosslinks and pentosidine crosslinks were higher. CONCLUSIONS AND POTENTIAL RELEVANCE: A measurable effect of the conditioning exercise was demonstrated. The margin between too much and too little work when training foals may be narrower than intuitively presumed. 相似文献
16.
REASONS FOR PERFORMING STUDY: This study was designed to examine a new role for cysteine proteinases in the process of endochondral ossification. OBJECTIVES: The aim of the present study was to investigate the presence and distribution of cathepsin B and cathepsin L in equine articular cartilage during development. METHODS: Full-depth cartilage samples from a total of 40 horses (age range: 4 month fetuses to 2 years) were examined and enzymes detected by immunocytochemical localisation. RESULTS: Observations on the presence of cathepsins B and L revealed significant age-related differences, resulting in clear division of the animals into 2 age groups: i) fetuses and neonates; ii) young growing horses (age 4 weeks to 2 years). Cathepsin B was not detected in cartilage from the majority of fetuses and neonates but was located characteristically in chondrocytes at the articular surface and hypertrophic zone in all growing horses. In contrast, cathepsin L was predominantly present in fetal and neonatal cartilage, located primarily in proliferating chondrocytes. CONCLUSIONS: This study is the first to demonstrate differential and site-specific roles for cathepsin B and cathepsin L in skeletal development in the horse. Potential relevance: The demonstrated involvement of cathepsins B and L in endochondral ossification is of relevance to developmental orthopaedic diseases such as osteochondrosis in which there is a focal failure of bone formation. 相似文献
17.
Radtke CL Danova NA Scollay MC Santschi EM Markel MD Da Costa Gómez T Muir P 《American journal of veterinary research》2003,64(9):1110-1116
OBJECTIVE: To determine changes in the distal ends of the third metacarpal and metatarsal bones (MCIII and MTIII) of Thoroughbred racehorses that had sustained a catastrophic condylar fracture during high-speed exercise. SAMPLE POPULATION: Fractured and contralateral MCIIIs and MTIIIs from 11 Thoroughbred racehorses that sustained a displaced condylar fracture during racing, both MCIIIs from 5 Thoroughbred racehorses euthanatized because of a catastrophic injury other than a condylar fracture, and both MCIIIs from 5 horses of other breeds that had not been professionally trained or raced. PROCEDURE: Macroscopic observations were made of the distal ends of the bones before and after digestion of the articular cartilage with NaOH. RESULTS: In all 11 racehorses with a displaced condylar fracture, the fracture was associated with a branching array of cracks in the condylar groove. In this region, fracture margins were smooth, and there was loss of subchondral bone. Comminution of the dorsal cortex was also seen. Parasagittal linear wear lines in the articular cartilage, erosions in the articular cartilage of the condyles, loss of the underlying subchondral bone, and cracking of condylar grooves were all more severe in the Thoroughbred racehorses than in the horses that had not been professionally trained or raced. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that condylar fractures in horses are pathologic fatigue or stress fractures that arise from a preexisting, branching array of cracks in the condylar groove of the distal end of MCIII or MTIII. 相似文献
18.
H.S. Spooner MS B.D. Nielsen PhD A.D. Woodward MS D.S. Rosenstein DVM P.A. Harris PhD 《Journal of Equine Veterinary Science》2008,28(6):359-362
Although previous research suggests that short bouts of high-speed exercise will increase bone mass in horses, little research has been conducted to determine the impact of endurance exercise on bone. Although many in the equine industry believe that months of slow training will increase bone strength, we hypothesized that endurance training would not alter bone mineral content as determined through optical density. Eleven 2-year-old Arabians were split into two groups, Exercised (E, 6 geldings) or Control (C, 5 fillies), with radiographs taken on day 0 for estimation of bone mineral content by radiographic bone aluminum equivalence (RBAE). The E horses were then trained on a high-speed treadmill for 90 days; training consisted of walking (1.6 m/second), trotting (4 m/second) and cantering (8 m/second) at increasing distances until the target of 60 km/day was met. On day 90, E horses were confined to 9 × 14 m dry lots and placed on a regular exercise schedule, including a 60-km endurance test once every 3 weeks. The C horses remained on pasture throughout the study. On day 162, radiographs were made again on all 11 horses. No differences between treatments, days, or interactions were noted in any cortex or the total RBAE, suggesting that endurance exercise does little to alter bone optical density compared with free-choice exercise on pasture. 相似文献
19.
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 clinical use are not sufficient to detect early abnormalities in metacarpo-phalangeal joint (MCPJ) cartilage found in both trained and untrained horses. Future work should centre on detection of such changes, on the precise registration of training workload, and on the manipulation of the responses of musculoskeletal tissues by careful investigation of the effects of introducing conditioning exercise at a young age. 相似文献
20.
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 clinical use are not sufficient to detect early abnormalities in metacarpo-phalangeal joint (MCPJ) cartilage found in both trained and untrained horses. Future work should centre on detection of such changes, on the precise registration of training workload, and on the manipulation of the responses of musculoskeletal tissues by careful investigation of the effects of introducing conditioning exercise at a young age. 相似文献