Topic:Fetlock Joint
The fetlock joint in horses is a complex articulation located between the cannon bone and the proximal phalanx, playing a pivotal role in equine locomotion. This joint is characterized by its hinge-like structure, allowing for flexion and extension movements essential for a horse's gait. The fetlock joint is supported by a network of ligaments, tendons, and synovial fluid that contribute to its stability and function. Common conditions affecting the fetlock joint include inflammation, osteoarthritis, and injuries to the supporting soft tissues. This section provides access to peer-reviewed studies and scholarly articles that explore the anatomy, biomechanics, and pathologies associated with the fetlock joint in horses.
Comparison of equine articular cartilage thickness in various joints. Thicknesses of fresh equine articular cartilage surfaces from the fetlock, carpal and stifle joints were measured employing a needle probe test. Methods: Eighty-seven samples used in measurement were cultivated from fetlock, carpal and stifle joints of 12 deceased within 4 h of death. After approximately three minutes of exposure to air during dissection, all cartilage samples were preserved in a saline solution to keep the articular cartilage hydrated for testing. The thickness was measured on five different spots on the same sample. The thicknesses of the fetlock, carpus and stifle were co...
Concentrations of stromal cell-derived factor-1 in serum, plasma, and synovial fluid of horses with osteochondral injury. To determine whether stromal cell-derived factor-1 (SDF-1) concentrations in serum, plasma, and synovial fluid differed among untrained, race-trained, and osteochondral-injured Thoroughbred racehorses. Methods: 22 racehorses without osteochondral injury and 37 racehorses with osteochondral injury. Methods: Horses without osteochondral injury were examined before and after 5 to 6 months of race training. Horses with osteochondral injury were undergoing arthroscopic surgery for removal of osteochondral fragments from carpal or metacarpophalangeal or metatarsophalangeal joints (fetlock joints). S...
In vivo measurements of flexor tendon and suspensory ligament forces during trotting using the thoroughbred forelimb model. The purpose of this study was to create a lower forelimb model of the Thoroughbred horse for measuring the force in the superficial and deep digital flexor tendons (SDFT and DDFT), and the suspensory ligament (SL) during a trot. The mass, centers of gravity, and inertial moments in the metacarpus, pastern, and hoof segments were measured in 4 Thoroughbred horses. The moment arms of the SDFT, DDFT, and SL in the metacarpophalangeal (fetlock) and distal interphalangeal (coffin) joints were measured in 7 Thoroughbred horses. The relationship between the fetlock joint angle and the force in the SL...
Use of immunohistochemical staining and electron microscopy to aid in diagnosis of soft tissue sarcomas associated with the fetlock joint in two horses. Soft tissue sarcomas of the equine distal limb associated with joints, sheaths, or bursae have rarely been reported. Accurate diagnosis of these tumors is challenging in both human beings and veterinary species. Immunohistochemical staining and transmission electron microscopy have been used in human beings to reduce misdiagnosis. The current report describes 2 mature horses presenting with lameness and swelling associated with the dorsal aspect of the metacarpo(tarso)phalangeal joint. In both cases, surgical excision was performed with subsequent histological analysis of the masses to determi...
Ultrasound assisted arthroscopic approach for removal of basilar sesamoid fragments of the proximal sesamoid bones in horses. To describe an ultrasound assisted arthroscopic approach for removal of non-articular basilar sesamoid fragments in Thoroughbred yearlings. Methods: Thoroughbred yearlings (n = 7). Methods: Basilar sesamoid fragments identified during pre-sale radiographic examination were removed using a palmar/plantar arthroscopic approach to the fetlock joint and ultrasonographic guidance. Complete fragment removal was confirmed by ultrasonography and radiography. Results: Basilar sesamoid fracture fragments were localized and removed successfully using rongeurs and a radiofrequency probe for soft tissu...
Regenerative therapies for equine degenerative joint disease: a preliminary study. Degenerative joint disease (DJD) is a major cause of reduced athletic function and retirement in equine performers. For this reason, regenerative therapies for DJD have gained increasing interest. Platelet-rich plasma (PRP) and mesenchymal stem cells (MSCs) were isolated from a 6-year-old donor horse. MSCs were either used in their native state or after chondrogenic induction. In an initial study, 20 horses with naturally occurring DJD in the fetlock joint were divided in 4 groups and injected with the following: 1) PRP; 2) MSCs; 3) MSCs and PRP; or 4) chondrogenic induced MSCs and PRP. The ho...
Impact of walking surface on the range of motion of equine distal limb joints for rehabilitation purposes. The aim of this study was to evaluate the effect of three footing surfaces on the flexion/extension, and range of motion (ROM) of the carpus, tarsus and fetlocks in the horse. The percentage of stride spent in the stance phase of sound horses at the walk was also measured. Nine sound horses were walked on hard ground (HD), soft ground (SF) and a land treadmill (LT), and five complete gait cycles were recorded by a digital video camera. Retro-reflective markers were placed on the skin at four anatomical locations on the left fore and hind limbs, and data were analyzed using two-dimensional (2D)...
Longitudinal development of equine forelimb conformation from birth to weaning in three different horse breeds. There is limited published data on conformational changes in the forelimbs of growing foals. This study was designed to describe the changes in conformation of the carpus and distal forelimb from birth to weaning in foals of three different breeds. Evaluation of the conformation of the carpus, fetlock, pastern and foot was carried out in 134 Thoroughbreds, 162 French Trotters and 98 Selle Français (French Warmblood) within 1 month of age and then at approximately 2 month intervals until weaning at approximately 6 months of age. The prevalence of limb deviations decreased from birth to weaning...
Vascular perfusion of the dorsal and palmar condyles of the equine third metacarpal bone. Palmar osteochondral disease (POD) is an overload arthrosis that commonly affects fetlock joints of racing Thoroughbreds (TB) but the aetiopathogenesis of the disease has not been well defined. Objective: The aim of this study was to compare India ink perfusion in the dorsal and palmar condyles of the third metacarpal bone (McIII) in both passively flexed and maximally extended fetlock joints from paired equine cadaver limbs. Methods: Descriptive cadaver study comparing perfusion of condyles of McIII in paired cadaver limbs in flexion (control group) and maximal extension (intervention group)....
Distal hindlimb kinematics of galloping Thoroughbred racehorses on dirt and synthetic racetrack surfaces. The effect of racetrack surface (dirt or synthetic) on distal hindlimb kinematics of racehorses running at competition speeds is not known. Objective: To compare distal hindlimb and hoof kinematics during stance of breezing (unrestrained gallop) racehorses between dirt and synthetic surfaces. Methods: Two-dimensional kinematic video analysis of 5 Thoroughbred racehorses galloping at high speeds (12-17 m/s) on a dirt racetrack and a synthetic racetrack. Methods: The positions of kinematic markers applied to the left hindlimb were recorded at 500 Hz. Position, velocity and acceleration of jo...
Synovial fluid growth factor and cytokine concentrations after intra-articular injection of a platelet-rich product in horses. Platelet-rich plasma (PRP) products may be useful for treatment of joint disease in horses, but may contain undesirable pro-inflammatory cytokines in addition to growth factors. This study investigated whether autologous PRP increases synovial fluid growth factor and cytokine concentrations when injected into normal equine metacarpophalangeal and metatarsophalangeal (fetlock) joints. Fetlock joints of seven healthy horses received one of four treatments: saline, resting PRP, CaCl2-activated PRP or thrombin-activated PRP. Synovial fluid was sampled prior to injection and at 6, 24, 48 and 96 h p...
Prevalence of osteochondral fragments, osteochondrosis dissecans and palmar/plantar osteochondral fragments in Hanoverian Warmblood horses. In this study, the prevalences of osteochondral fragments in the distal (DUI) and proximal interphalangeal joints (PIJ) as well as in the fetlock, hock and stifle joints, of palmar/plantar osteochondral fragments in the fetlock joints (POFs) and of osteochondrosis dissecans (OCD) in fetlock, hock and stifle joints were estimated in a large sample of Hanoverian Warmblood horses. For this purpose, radiographic findings of 9478 Hanoverian Warmblood horses collected from 2005 to 2011 were analyzed. Overall 31.9% of the horses showed one or more osteochondral fragments in at least one joint. The fe...
Equine developmental orthopaedic diseases–a genome-wide association study of first phalanx plantar osteochondral fragments in Standardbred trotters. Palmar/plantar osteochondral fragments (POF) in fetlock joints commonly affect and influence the athletic performance of horses. In this study, we used the Equine SNP50 BeadChip® to perform a genome-wide association study of metatarsophalangeal POF in 176 Norwegian Standardbred trotter yearlings. Putative quantitative trait loci (QTL) for medial and/or lateral POF, and medial POF only were identified on ECA1, 2, 7, 9 and 31, whereas for lateral POF, only on ECA7, 11, 27 and X. The moderate number of QTL evidences a complex inheritance and suggests various genes controlling POF development in ...
Genetic parameters of juvenile osteochondral conditions (JOCC) in French Trotters. Juvenile osteochondral conditions (JOCC) have been defined as lesions resulting from biomechanical influences (compressive, tensional or shear forces) on the developing and growing musculoskeletal system. They include different types of osteochondrosis, osteochondral fragmentation of the articular surface or of the periarticular margins, juvenile subchondral bone cysts, osteochondral collapse, avulsion fractures of epiphyseal (or metaphyseal) ossifying bone and 'physitis'. The aim of this study was to estimate heritability of JOCC in a sample of 2106 French Trotters from four different sources...
The effect of collection and extension on tarsal flexion and fetlock extension at trot. A recent epidemiological study indicated that various factors may be related to injury in dressage horses, but the mechanism by which these injuries occur has yet to be determined. The suspensory ligament (SL) is a frequent site of injury, and it is assumed that greatest strain is placed on this structure in collected trot; this has yet to be proved conclusively. The study aimed to investigate the effect of collected and extended trot on the hindlimb movement pattern. Four dressage horses were fitted with markers and inertial motion sensors (IMS). High-speed video was obtained for 2 strides on...
The isolated perfused equine distal limb as an ex vivo model for pharmacokinetic studies. Even though intra-articular injections play an important role in the treatment of joint-related lameness in horses, little is known about pharmacokinetic properties of substances used. Therefore, an ex vivo model for pharmacokinetic studies was developed using distal forelimbs of slaughtered horses. The extremity was perfused with gassed Tyrode solution for up to 8 h. Tissue viability was confirmed by measurements of glucose consumption, lactate production, and lactate dehydrogenase activity in the perfusate. Standard criteria for tissue viability had been determined in preliminary experiments...
Morphometrical study of bony elements of the forelimb fetlock joints in horses. There are many reports describing fractures in the bony elements of the equine fetlock joint and a few of these discuss possible relationships of these fractures to the mechanical loading of these bones. The likelihood of fracture must be related to the size and shape of bones involved, but information concerning the normal range in size and shape of these bones in horses is lacking. This study aimed to identify morphometrical variations of these bones within different groups of horses. Right and left metacarpal, proximal phalangeal and proximal sesamoid bones were collected from 10 Thoroughbr...
Reliability of high- and low-field magnetic resonance imaging systems for detection of cartilage and bone lesions in the equine cadaver fetlock. To determine the reliability of 2 magnetic resonance imaging (MRI) systems for detection of cartilage and bone lesions of the equine fetlock. Objective: To test the hypotheses that lesions in cartilage, subchondral and trabecular bone of the equine fetlock verified using histopathology can be detected on high- and low-field MR images with a low incidence of false positive or negative results; that low-field images are less reliable than high-field images for detection of cartilage lesions; and that combining results of interpretation from different pulse sequences increases detection of cartil...
Ultrasonographic appearance of bony abnormalities at the dorsal aspect of the fetlock joint in geriatric cadaver horses. This article describes the ultrasonographic (US) appearance of bony abnormalities on the dorsal aspect of the third metacarpal/metatarsal bone of the equine fetlock in cadavers with radiographic signs of osteoarthrosis. After US, computed tomography was undertaken to better characterise the lesions. Twelve fetlock joints were collected and all had more than one bone abnormality on US. Normal subchondral bone appeared on US as a well-defined and regular hyperechoic line with distal acoustic shadowing. Bone abnormalities detected on US included (1) gaps in the proximal subchondral bone filled wi...
Prevalence of radiographic changes in yearling and 2-year-old Quarter Horses intended for cutting. There have been many studies that document radiographic findings in young Thoroughbred and Standardbred horses. No such studies have been performed in Quarter Horses. Objective: To describe the prevalence of radiographic changes in the stifles, tarsi, carpi and fetlocks of young Quarter Horses intended for cutting. Methods: Radiographs of yearling and 2-year-old Quarter Horses were obtained from a radiograph repository and a private farm. The carpi, tarsi, fetlocks and stifles were evaluated and radiographic changes categorised by type and location. The frequency of changes was calculated and ...
Goniometry: is it a reliable tool to monitor passive joint range of motion in horses? Simple objective assessment tools are essential to monitor the clinical efficacy of therapeutic interventions used in equine orthopaedics and rehabilitation. In human medicine, goniometry is a validated tool to quantify restrictions in joint range of motion (ROM); however, the technique is not validated in horses. Objective: To validate 2 different goniometry techniques for the measurement of passive flexion of the fetlock, carpus and hock by examining; 1) the intra- and inter-tester reliability; 2) the differences between 2 goniometry techniques and 3) differences between standing and anaesth...
Heel effects on joint contact force components in the equine digit: a sensitivity analysis. Whereas the effect of heel configuration on the tension of the suspensory apparatus is well documented in the literature, there are few reports of joint contact force components in the equine distal forelimb. Objective: To improve understanding of the effect of heel configuration on equine digit joint loading, a sensitivity analysis was performed to compare the effect of a raised heel on joint contact force components in the coffin and fetlock joints during the stance phase of the trot. Methods: Four Warmblood horses were used. An inverse dynamic analysis was carried out using kinematic and ki...
A pendulum test as a tool to evaluate viscous friction parameters in the equine fetlock joint. An equine fetlock joint pendulum test was studied and the influence of post mortem time and intra-articular lipid solvent on the viscous frictional response examined. Fresh equine digits (group 1, n=6 controls; group 2, n=6 lipid solvent) were mounted on a pendulum tribometer. Assuming that pendular joint damping could be modelled by a harmonic oscillator fluid damping (HOFD), damping time (τ), viscous damping coefficient (c) and friction coefficient (μ) were monitored for 5h under experimental conditions (400N; 20°C). In all experiments, pendular joint damping was found to follow an expone...
Effect of needle size and type, reuse of needles, insertion speed, and removal of hair on contamination of joints with tissue debris and hair after arthrocentesis. To assess joint contamination with tissue and hair after arthrocentesis of equine fetlock joints. Methods: Experimental. Methods: Limb specimens from 8 equine cadavers. Methods: Soft tissues including the joint capsule were harvested from the dorsal aspect of the fetlock joints and mounted on a wooden frame. Needles inserted through the joint tissue preparation were flushed into tissue culture plates that were examined for tissue and hair debris. Variables evaluated were gauge and type of needle (16, 18, 20, and 22 G sharp disposable needles and 20 G disposable spinal needles with stylet), num...
Transverse stress fracture of the distal diaphysis of the third metacarpus in six Thoroughbred racehorses. Fractures involving the fetlock region are encountered commonly in Thoroughbred racehorses. Condylar fractures of the distal metacarpus/metatarsus and mid-sagittal fractures of the proximal phalanx account for the majority of fetlock injuries during both racing and training and clinical features, management and outcome of these injuries have been well described. Transverse fractures of the distal diaphysis of the third metacarpus, however, are seldom observed and have received little attention in the literature. This paper describes clinical and radiological findings associated with 6 cases en...
Arthroscopic visualisation of the third metacarpal and metatarsal condyles in the horse. Arthroscopy of the fetlock joints is a routine surgical procedure in the horse. It is unclear how much of the articular surface of the condyles of the metacarpal (MCIII)/metatarsal (MTIII) bone can be visualised using either the dorsal or palmar/plantar arthroscopic approach. Objective: To investigate which part of the articular surface of the MCIII/MTIII condyles of the fetlock joints can be evaluated arthroscopically using: 1) dorsal approach in combination with flexion; 2) standard palmar/plantar approach; or 3) additional portal at the base of the sesamoid bone with joint extension. Method...
Novel optical imaging technique to determine the 3-D orientation of collagen fibers in cartilage: variable-incidence angle polarization-sensitive optical coherence tomography. To investigate a novel optical method to determine the three dimensional (3-D) structure of articular cartilage collagen non-destructively. Methods: Polarization-sensitive optical coherence tomography was used to determine the apparent optical birefringence of articular cartilage for a number of different illumination directions. A quantitative method based on the theory of light propagation in uniaxial crystalline materials was validated on equine flexor tendon. Qualitative maps of fiber polar and azimuthal orientation at sites on the posterior and anterior segments of the equine third metaca...
Diagnostic imaging of the equine fetlock region using radiography and ultrasonography. Part 2: the bony disorders. The metacarpophangeal/metatarsophalangeal (fetlock) joint in the horse is commonly associated with equine lameness and diagnostic imaging is routinely used to investigate disorders of the joint and its surrounding tissues. This review describes the osseous disorders of the fetlock as well as the technical aspects of taking radiographic and ultrasonographic images of the different lesions. In current clinical practice, a combination of radiography and ultrasonography is still the most frequently used approach to arrive at a diagnosis.
Diagnostic imaging of the equine fetlock region using radiography and ultrasonography. Part 1: Soft tissues. The equine fetlock is the joint most commonly associated with lameness. Although the fetlock is regarded as a simple joint, diagnosis of a fetlock disorder can be a challenge and various imaging modalities are routinely used to arrive at an accurate diagnosis. This review describes the principal disorders affecting the soft tissues of the fetlock region and addresses some of the technical aspects involved in taking radiographic and ultrasonographic images of the different soft tissue lesions. A combination of radiography and ultrasonography is still the most commonly used diagnostic approach i...
Articular fetlock injuries in exercising horses. Articular injuries to the fetlock joint can be categorized as injuries to the soft tissues (synovium, ligaments, cartilage) or bone (third metacarpus/metatarsus, first phalanx, proximal sesamoids). This article focuses on the traumatic injuries to the cartilage and bone from anatomic, functional, and pathophysiological perspectives. An understanding of fetlock motion and loading will assist clinicians in the diagnosis, treatment, and, most importantly, prevention of fetlock injury in working horses.