Topic:Carpal Joint
The carpal joint in horses, also known as the knee, is a complex structure composed of bones, cartilage, ligaments, and synovial fluid that facilitates movement and weight-bearing in the forelimb. It consists of three main articulations: the radiocarpal joint, the midcarpal joint, and the carpometacarpal joint. These articulations are supported by a series of ligaments and tendons that provide stability and flexibility. The carpal joint is susceptible to various conditions such as osteoarthritis, fractures, and synovitis, which can affect the horse's mobility and performance. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, biomechanics, common disorders, diagnostic techniques, and treatment options related to the carpal joint in horses.
A retrospective evaluation of the surgical management of equine carpal injury. Records of 220 thoroughbred horses presented to the Randwick Equine Centre or the University of Queensland Veterinary Teaching Hospital for surgical management of carpal injury were reviewed. Details of racing performance were obtained, enabling evaluation of racing success following surgery. Age and sex matched control horses not known to have suffered carpal injury were selected from the Australian Stud Book and the Australian Racehorse Register. Control and treated populations were compared in terms of overall career racing success. Radiographs or xeroradiographs from 198 horses were availa...
Apparent viscosity of the synovial fluid from mid-carpal, tibiotarsal, and distal interphalangeal joints of horses. To compare the apparent viscosity of normal synovial fluid of the mid-carpal, tibiotarsal, and interphalangeal joints of horses. Methods: Viscosity evaluation over a range of shear rates was used to characterize the apparent viscosity of synovial fluids from the 3 joints. Methods: 60 clinically normal adult horses. Methods: Viscosity data for synovial fluid samples were obtained over a shear rate range of 10 to 250/s and apparent viscosity was calculated at 50, 100, 150, 200, and 250/s. Effect of shear rate on apparent viscosity was determined, using a two-way ANOVA, with significant differenc...
Estimation of the heritability of lameness in standardbred trotters. The degree of lameness of 265 randomly selected three-year-old standardbred trotters was assessed on a fixed point scale with 0 indicating soundness and 5 indicating that the animals were not weightbearing. Two variables were used to describe the signs of lameness; one was the continuous variable: the sum of the initial lameness score and the lameness scores after separate flexion tests of the carpal, stifle/tarsal and phalangeal joints and the second was the bivariate variable; the ratio of lame/sound horses. The mean (sd) heritability of the continuous variable was estimated to be 0.25 (0.21...
Radiographic and arthroscopic findings associated with subchondral lucency of the distal radial carpal bone in 71 horses. Case records and radiographs of 71 horses with subchondral lucency, without radiographic evidence of fracture, located on the distal radial carpal bone were examined retrospectively. All horses had lameness and/or joint effusion referable to the carpus. Distal radial carpal bone subchondral lucency was found as a solitary lesion or as a lesion concurrent and symmetric to a contralateral distal radial carpal bone chip fracture. The lesion appeared radiographically as a lucency or shadow on the distal dorsal margin of the radial carpal bone and was most evident on the flexed lateromedial and dor...
Malignant mast cell neoplasia with local metastasis in a horse. A 12-year-old Arab stallion was presented with a chronically swollen right carpus resulting in profound lameness of the same leg. An incisional biopsy of subcutaneous tissue from the right carpus submitted for cytology and histopathology revealed large numbers of eosinophils interspersed by substantial numbers of variably sized and granulated mast cells. Fungal culture of a subcutaneous tissue sample taken from the right carpus was negative. Serial full blood counts revealed persistent mature eosinophilia, not accompanied by a mastocytaemia, neutrophilia without left shift and persistent hyper...
Hyaluronan turnover in the synovial fluid in metacarpophalangeal–and middle carpal joints in standardbred horses. The biological turnover of hyaluronan (sodium hyaluronate) of different molecular weights (0.6 x 10(6) and 2.5 x 10(6) Daltons) was studied in the synovial fluid of the middle carpal and metacarpophalangeal joints of 6 clinically healthy Standardbred horses. The hyaluronan was radioactively labelled with 14C. The biological half-life (t1/2) was calculated from repeated synovial samples after injection of the labelled hyaluronan. The mean t1/2 in the metacarpophalangeal joints was 9.7 h for low molecular weight hyaluronan and 8.9 h for high molecular weight hyaluronan and in the middle carpal j...
The effect of arthritis in the carpal joint on performance in Norwegian cold-blooded trotters. The purpose of this study was to evaluate the impact of arthritis of the carpal joint on performance of Norwegian cold-blooded trotters. Two performance variables were used in the analyses. The first was the start status, for which horses that had started in one or more races within a certain age received the value 1, and horses that had not raced were correspondingly assigned the value 0. The second variable was the accumulated, transformed and standardized earnings (ATSE), which is the power transformation of earnings (earnings .2, with unraced horses assigned a value of zero) expressed as a...
Biomechanical properties of third carpal articular cartilage in exercised and nonexercised horses. The relevance of site and exercise on the biomechanical properties of the articular cartilage from the equine third carpal bone were assessed by creep indentation testing. Six horses were exercised for 30 minutes three times weekly. Another six horses were housed in box stalls and were not exercised. At the conclusion of the study, one third carpal bone from each horse was harvested and the KLM biphasic material properties of cartilage were determined at 12 sites. There was a significant (p < 0.01) effect of site but not exercise on the cartilage aggregate modulus, which was significantly l...
Miscellaneous conditions of tendons, tendon sheaths, and ligaments. The use of diagnostic ultrasonography has greatly enhances our ability to diagnose injuries of tendons and tendon sheaths that were previously either unrecognized or poorly understood. For may of these injuries, there is currently only a small amount of follow-up data. This article considers injuries of the deep digital flexor tendon and its accessory ligament, the carpal tunnel syndrome soft tissue swellings on the dorsal aspect of the carpus, intertubercular (bicipital) bursitis and bicipital tendinitis, injuries of the gastrocnemius tendon, common calcaneal tendinitis, rupture of peroneus (...
Arthroscopic findings in the carpal joints of lame horses without radiographically visible abnormalities: 41 cases (1986-1991). Arthroscopy was performed in 1 carpal joint unilaterally in 27 horses and either in 2 carpal joints unilaterally or 1 carpal joint bilaterally in 7 horses. All horses were lame, but the cause of lameness could not be determined from radiographs. Twenty-seven carpi did not have radiographically visible abnormalities; the remaining 14 had only mild to moderate lucency or sclerosis of the radial facet of the third carpal bone. The primary abnormalities identified during arthroscopy included a crush fracture of the third carpal bone (7 carpi), an incomplete fracture of the third carpal bone in the...
The function of the equine carpal joint: a review. The most consistent published ideas on the function of the carpal joint of the horse concern the elasticity of the joint, and its limits to extension. Most of these are not well substantiated experimentally. Compression stress appears to be absorbed by the intercarpal ligaments as the carpal bones are separated by a wedge action during loading. Overextension is prevented by occlusion of dorsally located stop facets on the rows of carpal bones, and by the support of a stay apparatus.
A preliminary study of hyperextension of the carpal joint in the racing Thoroughbred. A photographic study of the angles of 71 carpal joints of horses at the end of a race has shown that overextension of the joint is normal at this stage. Further study is needed to determine the factors which may influence hyperextension, and whether they are relevant to carpal injury.
How the horse moves: 1. Significance of graphical representations of equine forelimb kinematics. The kinematics of 24 two-year-old Dutch Warmblood horses were recorded at the trot (4 m/s) on a high-speed treadmill to study the coordination of joints within the equine forelimb. Joint angle-time, angle-angle, stick, and marker diagrams were used to show forelimb motion graphically. Because the kinematic data referred to the joint angles of the horse standing squarely and were time-standardised to the duration of the stride cycle, mean joint curves could be calculated for the total group. The motion of each segment in the equine forelimb during a complete stride is described and its function...
Plasma concentrations and therapeutic efficacy of phenylbutazone and flunixin meglumine in the horse: pharmacokinetic/pharmacodynamic modelling. The purpose of the present study was to establish in the horse the relationship between plasma concentration profiles of phenylbutazone (PBZ) and flunixin meglumine (FM) and their pharmacological effects in order to build a predictive pharmacokinetic/pharmacodynamic (PK/PD) model. In five horses, an experimental arthritis was induced by injecting Freund's adjuvant into a carpal joint. PBZ (4 mg/kg) and FM (1 mg/kg) were injected by the intravenous route as a single intravenous dose in two different trials. Five pharmacodynamic end-points were regularly measured after test article injection usi...
Observations on the anatomy and pathology of the palmar intercarpal ligaments in the middle carpal joints of thoroughbred racehorses. Ten carpi from juvenile Thoroughbred horses were dissected in detail to record the anatomy of the palmar intercarpal ligaments (PICLs). These were found not to be substantially attached to the palmar carpal ligament. The lateral PICL was sited at the convergence of the palmar aspects of the third, fourth, intermediate and ulnar carpal bones and aligned predominantly in a proximodistal direction. The medial PICL had a large origin distally on the lateral aspect of the radial carpal bone (Cr) and attached to third (C3) and second (C2) carpal bones with apparently separate fibre orientations. Fib...
Effect of betamethasone and exercise on equine carpal joints with osteochondral fragments. Osteochondral fragments were created arthroscopically on the distal aspect of both radial carpal bones in 12 horses. On day 14 after surgery, one middle carpal joint of each horse was injected with 2.5 mL Betavet Soluspan (3.9 mg betamethasone sodium phosphate and 12 mg betamethasone acetate per milliliter) and the contralateral joint was injected with 2.5 mL saline as a control. Intra-articular treatments were repeated on day 35. On day 17, six horses began exercising 5 days per week on a high-speed treadmill. The other six horses were kept in box stalls throughout the study as nonexercised c...
Proximodorsal first phalanx osteochondral chip fragmentation in 336 horses. The results of arthroscopic surgery in the treatment of osteochondral fragmentation of the proximodorsal aspect of the first phalanx and the influence of other fetlock joint lesions on prognosis were evaluated in 336 horses. Horses were classified as: 1) returning to previous use at the same or higher class of performance; 2) returning to previous use (regardless of class of performance); or 3) failing to return to previous use. Ninety-six horses (29%) had fragmentation alone; 140 horses (42%) had fragmentation and additional fetlock lesions, and 100 horses (29%) underwent concurrent carpal ar...
Morphological effects of arthroscopic partial synovectomy in horses. Gross and microscopic effects of arthroscopic partial synovectomy on synovium and articular cartilage of middle carpal joints were studied in 15 horses. A 7-mm diameter motorized synovial resector was inserted into each middle carpal joint and arthroscopic partial synovectomy and lavage or arthroscopic lavage alone was performed. Study periods were 0 (three horses), 16 (three horses), and 30 days (six horses). No gross evidence of degenerative joint disease was observed at day 16 or 30. At 30 days, resected areas lacked villi and there was deposition of fibrin on the synovial surface with vary...
Carpal conformation in relation to carpal chip fracture. An objective radiological method of assessing the degree to which horses are conformationally 'back at the knee' (hyper-extended) is described. The effects on the measurements of variations in the direction of the incident X-ray beam and variations in weight bearing by the horse were assessed. A change from a lateromedial projection towards a plamaro-lateral-dorsomedial oblique projection consistently tended to reduce the observed degree of hyperextension of the carpus. Raising the contralateral limb to increase the load on the carpus had little effect on the measurements. The carpi of 21 thor...
Contact area and pressure distribution changes of the equine third carpal bone during loading. Changes in contact area and pressure distribution with loading were evaluated on the proximal articulating surface of the equine third carpal bone using safranin-O dye staining and pressure sensitive film techniques. A significant increase in percentage contact area resulted as the applied load was increased from 3115 to 9000 N (54.93% +/- 7.99 vs 61.43% +/- 7.37 respectively, P = 0.016). The area in contact shifted towards the dorsal aspect of both the radial and intermediate facets of the third carpal bone. Changes were also detected in the mean pressure under the same loading conditions. Th...
Effect of central or marginal location and post-operative exercise on the healing of osteochondral defects in the equine carpus. The effects of osteochondral defect location and post-operative walking exercise on structural repair and recovery of joint function were examined in the midcarpal joints of ponies. Functional recovery was monitored by measuring ground reaction forces using a force plate. Structural repair was evaluated histologically and by measuring the total collagen and uronic acid content and relative proportions of Type I and II collagen in the repair tissue. Central defects tended to cause a more marked functional disturbance but were repaired with fibrocartilage rather than fibrous tissue in 3 out of 6...
Prevalence and risk factors in serous arthritis in the carpal joint of Norwegian coldblooded trotters. Of 508 four-year-old coldblooded trotters examined for carpitis, 135 (27%) had the condition. Thirty horses had unilateral carpitis on the left frontlimb, 52 on the right frontlimb and 53 had bilateral carpitis. Of these horses, 105 were stallions, 135 were geldings and 269 were mares. The prevalence of carpitis in these three groups was 25%, 25% and 28%, respectively. Information was obtained on the training regimes in four periods of the life of 378 horses. The odds ratios for the training variables were of the same order in all four periods. In logistic regression analyses on the training v...
Synovial fluid and clinical changes after arthroscopic partial synovectomy of the equine middle carpal joint. Changes in synovial fluid and clinical variables after arthroscopic partial synovectomy of the middle carpal joint were studied in 12 normal horses. A 7 mm motorized synovial resector was inserted into each middle carpal joint; one middle carpal joint of each horse was randomly selected to have arthroscopic synovectomy (treated) and the opposite joint was lavaged (control). Lameness examinations and synovial fluid analyses were performed before operation and at 8, 14, 21, and 28 days after operation. Lameness variables did not differ between treated and control legs. Middle carpal and carpomet...
Neuropeptidergic innervation of equine synovial joints. Immunocytochemical analysis of equine synovial membranes revealed presence of several neuropeptides, including substance P (SP), neurokinin A, and neuropeptide Y, in nerves of the radiocarpal, middle carpal, and metacarpophalangeal (fetlock) joints. Within the subsynovium, these neuropeptides were located perivascularly, whereas in the fronds, only neuropeptide Y was restricted to the vessels of the synovial membrane. Only SP and neurokinin A were found in the intimal layer. The intimal layer of the metacarpophalangeal joint contained more SP-immunoreactive fibers than were observed in the int...
Effects of exercise and polysulfated glycosaminoglycan on the development of osteoarthritis in equine carpal joints with osteochondral defects. This study assessed the effects of postoperative exercise and intra-articular polysulfated glycosaminoglycan (PSGAG) on the repair of osteochondral defects in the carpal joints of ponies. Eighteen ponies with normal carpi had osteochondral defects (mean dimensions 2.4 cm x 0.9 cm) created arthroscopically on the dorsal aspect of the distal articular surface of the radial carpal bone. The ponies were randomized (while balancing for age [range, 2 to 15 years; median, 5.0 years]) to two groups--nine ponies were exercised and nine were stall confined. Beginning at surgery, six ponies in each group...
Effects of hylan on amphotericin-induced carpal lameness in equids. In this double-blind study, the effectiveness of and dose response to intra-articular administration of modified hyaluronan (hylan) was determined in an equine carpal lameness model over a 23-day period, using a computerized three-dimensional motion analysis system, synovial fluid variables, and synovial histologic examination. In 24 clinically sound horses, baseline motion data was acquired from horses trotting at 4 m/s on a high-speed treadmill. Then, to induce lameness, 25 mg of amphotericin B in 5 ml of sterile water was injected into the left middle carpal joint of each horse every other ...
Computer-assisted three-dimensional gait analysis of amphotericin-induced carpal lameness in horses. Motion of 6 clinically sound horses trotting at a speed of 4 m/s on a treadmill was captured by video cameras before and 9, 16, and 23 days after amphotericin-induced lameness to determine the quantitative variables of three-dimensional computer-assisted image analysis that objectively describe carpal lameness. Amphotericin-B was used to induce lameness, and phenylbutazone (2.2 mg/kg of body weight, PO, once) and butorphanol tartrate (0.1 mg/kg IM, q 6 h, to effect) were used to control discomfort. Four 60-Hz cameras were symmetrically placed around the treadmill to capture 6 seconds of images...
Removal of a fracture fragment from the palmar aspect of the intermediate carpal bone in a horse. A 10-year-old Dutch Warmblood gelding sustained a fracture of the palmar tuberosity of the intermediate carpal bone 2 weeks prior to admission. The dorsolateral-palmaromedial oblique and flexed lateromedial radiographic views revealed the fracture line. The palmar fracture fragment from the intermediate carpal bone was removed by arthrotomy of the palmar intercarpal joint, which was approached through the carpal canal. Twenty months after surgery, the horse was show jumping without evidence of lameness.