The metacarpophalangeal joint, commonly referred to as the fetlock joint, is a critical anatomical structure in horses, located between the metacarpal bone and the proximal phalanx. It plays a significant role in the locomotion and weight-bearing functions of the forelimbs. This synovial joint is composed of several components, including articular cartilage, joint capsule, ligaments, and synovial fluid, all contributing to its function and stability. The joint undergoes substantial stress during movement, making it susceptible to various disorders, such as osteoarthritis, synovitis, and ligament injuries. This page aggregates peer-reviewed research studies and scholarly articles that explore the anatomy, biomechanics, pathology, and treatment options related to the metacarpophalangeal joint in horses.
Adrian M, Grant B, Ratzlaff M, Ray J, Boulton C.Electrogoniometry was used qualitively and quantitatively to assess the movements of the normal and pathologic metacarpophalangeal joints of selected horses. A total of 4 Thoroughbreds, 1 normal and 3 with clinical and radiographic changes in the metacarpophalangeal joints of 1 limb, were evaluated at the walk and trot. Goniograms of the affected joints were compared with those of the normal horse and the normal contralateral metacarpophangeal joint. Qualitative asymmetry was recognized on the goniograms, and the ranges of motion were quantified and related to the clinical and radiologic obser...
Nickels FA, Grant BD, Lincoln SD.Villonodular synovitis was diagnosed as the cause of lameness in 14 horses. The diagnosis was based on the history, clinical signs, and arthrographic findings. Treatment consisted of surgical excision and radiation therapy. The response to treatment was favorable in 13 horses.
In horses, osteoarthritis (OA) mostly affects metacarpophalangeal and metatarsophalangeal (fetlock) joints. The current modalities used for diagnosis of equine limb disorders lack ability to detect early OA. Here, we propose a new alternative approach to assess experimental cartilage damage in fetlock joint using Acoustic Emissions (AE). Objective: To evaluate the potential of AE technique in diagnosing OA and see how AE signals changes with increasing severity of OA. Methods: An in vitro experimental study. Methods: A total of 16 distal limbs (8 forelimbs and 8 hindlimbs) from six Finn horses...
Guillot M, Mespoulhes-Rivière C, Bousquet-Mélou A, Lacroix MZ, Roques BB, Lallemand EA.Intravenous regional limb perfusion (IVRLP) of antibiotics is a therapeutic method used to treat distal limb infections in horses. The objectives of this study were to determine the pharmacokinetic parameters and tolerance of sodium benzylpenicillin (NaBP) administered via IVRLP; to compare the feasibility, tolerance, and efficacy of performing IVRLP on a flexed limb versus a weightbearing limb; and to predict the efficacy of IVRLP using gentamicin or NaBP. A prospective crossover study was conducted with six horses, each undergoing four phases of antibiotic infusion (gentamicin at 2.2 mg/kg ...
Boado A, Pollard D, Dyson S.There are no studies that have investigated factors influencing the outcome of dressage horses with suspensory ligament (SL) branch injuries. The aim was to determine if age, breed, work level, injury severity, anatomical localisation of injury, number of injured branches, periligamentous fibrosis, persistence of power Doppler signal or coexistent osteoarthritis of a metacarpophalangeal (MCP) or metatarsophalangeal (MTP) joint influenced the prognosis of 70 dressage horses. Outcome was defined as good (return to pre-injury level of work or higher), poor (return to a lower level of work) or ret...
Marković L, Vićić I, Lazarević Macanović M, Francuski Andrić J, Kovačević Filipović M, Radaković M.Working horses often develop distinct patterns of joint degeneration, yet research in this population remains limited. This study aimed to characterize degenerative changes in the metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joints of Serbian Mountain Horses using computed tomography (CT) and to explore their associations with synovial fluid (SF) biomarkers. A cross-sectional analysis was conducted on 32 MCP/MTP joints from eight clinically sound horses. Postmortem, joints underwent CT imaging, and SF samples were analyzed for viscosity, protein content, total nucleated cell count (...
Malekipour F, Whitton RC, Muir P, Lee PV.Stress fractures are common in racehorses, with the metacarpophalangeal (MCP) joint being the most frequently affected site as it is subjected to high-magnitude and high-rate cyclic loads during training and racing. These loads lead to repeated compressive stresses, resulting in subchondral bone (SCB) sclerosis, fatigue microcracks, and matrix damage that can progress to parasagittal fractures or palmar osteochondral disease (POD). The present study developed joint-specific 3D FE models and slice-based FE models using standing CT images for three trained racehorses, each presenting distinct SC...
Beggan CP, Panizzi L, Oliver LJ.To measure microsphere recovery following needle-through-and-through lavage (NTAT) of the metacarpo-/metatarsophalangeal joint (fetlock) and digital flexor tendon sheath (DFTS) compared to endoscopic lavage (EL). Methods: Ex vivo experimental study. Methods: Adult equine cadavers immediately following euthanasia (n = 10). Methods: Colored 15 μm microspheres (2 million) were injected into fetlock joints and DFTS. Synovial structures were assigned to NTAT or EL groups. Each lavage was performed using 5 L of 0.9% NaCl, sequentially collecting egress fluid for microsphere quantification. Re...
Vishwanath K, McClure SR, Bonassar LJ.Intra-articular injections of hyaluronic acid (HA) are the cornerstone of osteoarthritis (OA) treatments. However, the mechanism of action and efficacy of HA viscosupplementation are debated. As such, there has been recent interest in developing synthetic viscosupplements. Recently, a synthetic 4 wt% polyacrylamide (pAAm) hydrogel was shown to effectively lubricate and bind to the surface of cartilage in vitro. However, its ability to localize to cartilage and alter the tribological properties of the tissue in a live articulating large animal joint is not known. The goal of this study was to...
