The musculoskeletal system in horses encompasses the bones, muscles, tendons, ligaments, and joints that facilitate movement and provide structural support. This system is essential for locomotion, athletic performance, and overall health in equine species. The equine skeleton consists of approximately 205 bones, which are connected by joints and supported by a network of muscles and connective tissues. Tendons connect muscles to bones, while ligaments link bones to other bones, contributing to joint stability. The musculoskeletal system is subject to various conditions, including injuries, degenerative diseases, and developmental disorders, which can impact a horse's mobility and performance. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, pathology, and treatment of musculoskeletal conditions in horses.
Woods TDC, Dixon J, Fraser BSL, Melvaine C.Exploratory tenoscopy is considered the gold standard technique to identify intrathecal pathology of the equine carpal flexor tendon sheath (CFTS). Preoperative diagnosis allows for more precise prognostication and surgical planning, potentially associated with improved surgical outcomes. This prospective, descriptive, anatomical study aimed to describe the anatomy of the equine CFTS using noncontrast and contrast CT in clinically normal cadaver limbs. Ten pairs of equine forelimbs free of gross external abnormalities were examined from mid-antebrachium to distal metacarpus. Specimens initiall...
Esselman AM, Johnson SA, Hague BA, Frisbie DD.(1) To evaluate the ability of western performance horses diagnosed with chondromalacia to return to performance; Specifically, the relationship between the grade of chondromalacia and the horses' ability to resume work; (2) To determine the impact of postoperative therapy on clinical outcomes. Methods: Retrospective case series. Methods: Horses (n = 34). Methods: Records of western performance horses with lameness localized to the stifle that underwent subsequent arthroscopy with chondromalacia as the most significant diagnosis were reviewed. Chondromalacia was surgeon-graded as slight, m...
Aoun R, Ogunmola Z, Musso A, Taguchi T, Takawira C, Lopez MJ.The shift in vertical forces on the equine hoof surface by heart-bar, egg-bar, and wooden clog shoes can significantly impact gait kinetics. Hypotheses tested in this study were that vertical, braking, and propulsion peak force (PF) and impulse (IMP) are different while shod with heart-bar, egg-bar, open-heel, and wooden clog shoes, or while unshod, and the resultant ground reaction force vector (GRF YZ ) has the longest duration of cranial angulation with open-heel shoes followed by unshod, then egg-bar and heart-bar shoes, and the shortest with wooden clog shoes. Forelimb GRFs were recorded ...
Connaughton MT, MacDonald EJ, Ireland JL, Rocchigiani G, Stack JD.Caudal wedge ostectomy has not been investigated for overriding or impinging spinous processes (SPs). Objective: To establish the feasibility of caudal wedge ostectomy and compare measures of surgical trauma and error between hypothetical caudal and cranial wedge ostectomies on SPs of different inclinations. Methods: Experimental, method comparison study. Methods: Computed tomography and caudal wedge ostectomy surgery were performed on four cadavers. Observations, technical difficulties, and surgical errors were recorded. Radiographs from 67 horses with overriding/impinging SPs were reviewed. ...
de Secondi C, Cantatore F, Marcatili M, Biggi M, Withers J, de Zani D, Zani D.Back pain is a debilitating condition hampering horses' athletic careers. Thoracic spondylosis (TS), a known cause of back pain, leads to osteophytes formation across intervertebral joints. In horses, TS is poorly reported, with anecdotal signs and response to treatment. To report clinical presentation, diagnostic imaging findings, treatment and outcome in horses with TS. The clinical records of horses diagnosed with TS between 2010 and 2023 were reviewed. Signalment, clinical and imaging findings, treatment, and outcome were analysed. Thoracic spondylosis was graded from 1 to 5. Grades, concu...
Velásquez JM, Tamayo-Arango L, Santos-Silva T, Miglino MA.Horse joints are common sites of injury, orthopedic issues, and surgical and clinical interventions. For this reason, a thorough understanding of joint anatomy, including the boundaries of their recesses and their relationships with other structures of the locomotor apparatus, is essential. This study aimed to develop cast anatomical models of the synovial structures of the equine hand and foot, compare different casting materials and visualization methods, and identify the most suitable technique for enhancing the understanding of equine limb arthrology. Additionally, an anatomical descriptio...
Mason SJ, O'Neill HD, Bladon BM.The objective was to investigate synovial sample appearance, total nucleated cell count (TNCC), total protein concentration (TP), and neutrophil percentage in horses with acute articular fractures to aid decision making in acutely lame horses. Methods: Retrospective case series. Methods: Synovial fluid samples (n = 55). Methods: Synovial fluid records were analyzed over an 11 year period from horses undergoing lag screw fixation or arthroscopic fragment removal of intra-articular fractures within 48 h of occurrence. Horses were excluded when presented with wounds close to the joint or ...
Bennet ED, Parkin TDH.The Equine Injury Database (EID) is a census-level record of Thoroughbred racing in North America, currently recording 95.6% of all race starts in 2023, along with partial training and veterinary histories of each horse. Objective: To identify horse-, race- and track-level risk factors associated with race-related fatal musculoskeletal injury (MSI) of Thoroughbred racehorses in North America. Methods: Retrospective cohort study. Methods: The study cohort included all race starts made by horses born after 31 December 2006, at tracks that fully report to the EID and consisted of 3,851,659 race s...
Strugava L, Gomes ARC, Lorga AD, Bosak VL, Rossa AP, Janiszewski JDR, Machado M, Dornbusch PT, Moreno JCD.To describe anatomical references and sonoanatomy of an echo-guided injection for blocking the tibial and common fibular nerves with the use of a caudocranial midfemoral approach and to evaluate dye spreading in horse cadavers. Unassigned: 1 horse cadaver preserved in glycerin was used for the anatomical study, and 14 fresh horse cadavers were used for the dye spreading study. The experimental procedures were conducted on the first cadaver on March 25, 2021, and on the last cadaver on October 5, 2022. A glycerin-preserved horse cadaver's pelvic limb was dissected to identify anatomical landmar...
Cameron-Whytock HA, O'Brien D, Lewis V, Parkin T, Bennet ED.To date, industry and research outputs that have aimed to improve safety in equestrian eventing have tended to focus on identifying risk factors for horse falls during cross-country, which have been identified as the greatest risk of injury and fatality for riders. There is an absence of research that investigates fatalities of horses within the sport of eventing. Objective: To use a combination of media reports and eventing federation databases to describe and document equine fatalities in equestrian eventing, including their context, location and a basic pathology. Methods: Descriptive study...
Debald DC, Stanton VL, Sandow CB, Rodgerson DH, Spirito MA, Hunt RJ, Menarim BC.While radiographically evident carpal osteochondral fragments (COF) in Thoroughbred yearlings impair sales, their impact on future racing performance has been minimally investigated. Objective: To assess the impact of COF on Thoroughbred yearling sales and racing performance, and whether these are improved by arthroscopic removal. We hypothesised that surgical removal of COF improves Thoroughbred yearling sales and racing performance. Methods: Retrospective observational. Methods: Using clinical records from years 2015-2018, 46 Thoroughbred yearlings with COF were identified and allocated to a...
Maleas G, Werpy N, Joostens Z, Bladon B, Gerlach K, Mageed M.Navicular intrabursal pathology (NIP) is a common cause of forelimb lameness in horses. An accurate diagnosis of which structure is involved is essential for therapy and prognosis. Objective: The study aimed to compare the diagnostic performance of ultrasonography, bursography and standing magnetic resonance (MRI) imaging as diagnostic tools of the proximal NIP using bursoscopy as the gold standard. Methods: Prospective blinded study. Methods: A total of 21 feet from 17 horses were included. The feet underwent ultrasonography, followed by MRI, and thereafter bursography and bursoscopy. The i...
Beck AA, Paz LB, Frank MI, Pereira RCF, De La Côrte FD.To evaluate the effect of IA injections of botulinum toxin type A (BoNT-A) in horses with chronic, naturally occurring distal tarsal osteoarthritis. Unassigned: 9 horses were selected after physical and radiographic assessments. Horses also underwent an objective lameness examination and were included if they had a hindlimb impact lameness (Pmin ≥ 3 mm), which positively responded (≥ 50%) to the tarsometatarsal and centrodistal joints' anesthetic block. Horses randomly received an intra-articular injection of BoNT-A or an equivalent volume of saline solution. Horses were reevaluated at pos...
Kadic LIM, Liu CC, Riggs LM.The aim of this study was to compare the monotonic tensile strength and fatigue strength of a stainless steel cable (SSC) compared to a human non-metallic polymer cable (NMPC) in an metacarpophalangeal joint arthrodesis model lacking a dorsal plate application.An experimental biomechanical equine cadaver limb study. Ten metacarpophalangeal joints were collected from five adult Thoroughbred horses, euthanatized for reasons unrelated to orthopaedic disease. Each pair of metacarpophalangeal joints was randomly instrumented with either a 1.7-mm SSC or a NMPC. Each construct was tested in cyclic ...
Kirkpatrick CJ, Ernst NS, Trumble TN.Injury to the collateral ligament (CL) of the distal interphalangeal joint (DIPJ) is recognized as a source of lameness in horses. Intralesional injection has been advocated to increase return to performance. This study was a proof-of-concept study in standing horses to evaluate success of a palmar radiographic-guided approach for injecting insertions of the DIPJ CLs previously described in cadaver limbs. Horses were sedated, nerve blocked, and placed on wooden blocks with the limb to be injected staggered approximately 20cm cranially to the other limb. The DIPJ CL insertion was injected, usin...
Kerbert MP, Delling U, Verhaar N.To investigate the computed tomography (CT) and gross anatomy of the equine medial digital flexor tendon sheath (MDFTS), and the endoscopic anatomy and approach to the MDFTS. Methods: Ex vivo experimental study and one clinical case. Methods: Twelve clinically normal cadaveric hindlimbs. Methods: Dissection, native and contrast CT scans were conducted to evaluate the anatomy of the MDFTS. Based on these findings, the portal locations for the endoscopic approaches were determined. Six hindlimbs were used in the pilot phase and another six limbs were selected for the main study. Endoscopic image...
Albanese V, Straticò P, Fischer H, Petrizzi L.Injuries to the distal limb are common in horses. The clinical aspect of the lesions is variable based on the structures that are involved. Synovial structures as well as tendons and/or ligaments may be involved in such injuries, affecting treatment modalities and costs, and prognosis. This retrospective study compares wounds involving synovial structures to wounds without such involvement in terms of treatment duration and costs, and prognosis. Synovial wounds were much more expensive to treat and carried a lower prognosis. Involvement of tendons and/or ligaments in the wounds resulted in mor...
Cole RC, DeGraves FJ, Brown J, Schumacher J.To compare the effect of 2.5 mL 2% mepivacaine to the effect of 0.5 mL 2% mepivacaine administered over each palmar digital nerve, as an abaxial sesamoid nerve block (ASNB), to 6 horses lame because of naturally occurring digital pain. Unassigned: In a crossover study design with 3 horses in each group, the trotting gait of the horses was analyzed with an inertial sensor-based, motion-analysis system (Q with Lameness Locator; Equinosis LLC) immediately before and after treatment with either 0.5 or 2.5 mL mepivacaine administered over each nerve near the base of the proximal sesamoid bone of th...
Hansen S, Hopster-Iversen C, Berg L, Fjeldborg J, Massey C, Piercy RJ, Carstensen H.Exertional myopathies are recognised as a cause of poor performance in equines. In Icelandic horses presenting reduced performance and/or multi-limb lameness, no specific myopathy has been identified. Objective: To characterise the clinical presentation and histopathological findings in muscle biopsy samples from Icelandic horses demonstrating poor performance. Methods: Case series. Methods: Phenotypic characteristics, clinical examination and diagnoses of 17 Icelandic horses were studied. All horses had a resting serum creatine kinase (CK) and aspartate transaminase activities measured, and C...
Shokry M, Ali LB, El-Sharkawy M.Showjumping athletic horses are frequently affected by back pain, which in turn influences their performance and equestrian activities. Unassigned: The aim of the present study was to determine the etiological factors predisposing to back problems in show jumping horses and how to diagnose, and manage them. Unassigned: A total of 75 cases (45 geldings and 30 mares, aged between 8 and 23 years and weighing 420-550 Kg) with histories suggestive of back problems and low competitive ability as show jumping were used in this study. The evaluation of data was based on the inputs of case history, cli...
Drahonovska A, Bladon BM, O'Neill HD.To describe a technique and report outcomes for internal fixation of short frontal-plane fractures involving the dorsoproximal articular surface of the proximal phalanx (P1) in standing horses. Methods: Short case series. Methods: Six Thoroughbred racehorses with short, frontal plane fractures involving the dorsoproximal P1. Methods: All fractures were located in the hindlimb. Horses presented with moderate lameness and marked effusion of the affected metatarsophalangeal joint. Fractures had a medial bias extending from the central aspect of proximal P1 to involve the dorsomedial prominence. F...
Bernick A, Krohn J, Wehrend A.Patent urachus is a common disease in newborn foals. However, despite its frequency, studies investigating symptoms, comorbidities, treatment and prognosis in a large number of affected foals have rarely been conducted. This study aimed to describe the clinical symptoms, laboratory diagnostic findings and prognosis of foals with patent urachus. Data from 101 foals with a patent urachus from 2006 to 2017 were analysed. Patent urachus occurred at a frequency of 7.8% of all foals up to the 14th day of life during the study period. More colts (74.3%) than fillies (25.7%) were affected. In those wi...
Martinez-Saez L, Marín-García PJ, Llobat ML.Osteochondrosis (OC) is a frequent manifestation of developmental orthopaedic disease, and its severe clinical presentation is known as OC dissecans (OCD). OC is defined as a disruption of the endochondral ossification process in the epiphyseal cartilage, and this disease has been reported in different mammalian species, including humans, dogs, pigs, and horses. OCD is an important cause of lameness in sport horses and is a common cause of impaired orthopaedic potential, whose clinical signs may be of minimal magnitude or manifest as severe joint effusion or clinically noticeable lameness. The...
Findley JA, Bladon BM, O'Neill HD.Sagittal plane fractures of the proximal phalanx (P1) are commonly observed in the UK Thoroughbred racehorse, with the technique and outcome following standing lag screw fixation widely reported. Long frontal plane P1 fractures propagating from the central third of the proximal articular surface occur less frequently, with information concerning repair methods and outcomes currently lacking. Objective: To describe a surgical technique for standing lag screw fixation of long frontal P1 fractures and report on post-operative performance in a UK Thoroughbred population. Methods: Single centre ret...
Sohn Y, An SJ, Forbes E, Kim BS, Jeon HS, Ryu SH, Lee I.The lateral trochlear ridge of the stifle joint is highly susceptible to developing Osteochondrosis (OC)/Osteochondritis dissecans (OCD) lesions. This retrospective study evaluated the medical and racing outcomes of 75 Thoroughbreds who underwent arthroscopic OCD removal at the Jeju Stud Farm Equine Hospital from 2015 to 2017. The analysis included medical records, radiographic assessments, and race performance data, comparing 75 horses that underwent surgery with 257 control horses selected as siblings from the same dam. The surgical group had comparable racehorse registration rates (89.3 %...
Scharf A, Acutt E, Bills K, Werpy N.Deep digital flexor (DDF) tendinopathy is a significant cause of lameness and poor performance in equine athletes with substantial implications for their return to athletic performance. Magnetic resonance imaging (MRI) is increasingly integrated into the diagnostic workup of horses with foot pain and has revolutionised the diagnosis and management of these injuries. This review discusses the principles of MRI in the context of deep digital flexor tendon (DDFT) injury, comparing high-field and low-field systems and highlighting the clinical relevance of technical parameters, including field str...
Ostmeier M, Schellenberger F, Troillet A, Scharner D.Mouth specula with incisor bite plates shift the pressure from all teeth exclusively to the incisors in the opening phase which leads to increased forces on dental, osseous, and soft tissue structures of the horse's head. The potentially pathological character of these forces is described clinically by single reports of maxilla and mandible fractures occurring during the use of opened mouth specula. This study describes these forces on incisor teeth in horses during odontoplasty of cheek teeth under sedation. Measurements were documented using a modified "Günther" mouth speculum fitted with a...
Swezey E, Szydziak E, Angus LDG, Mehta V, Cardozo-Stolberg S.Equestrian trauma is recognized as a high-risk injury mechanism with the potential for significant morbidity and mortality. Although horse-related injuries are more frequently seen in a rural environment, they can also occur in urban settings. Urban physicians should be mindful of these potential cases. Methods: A retrospective review was performed on all patients treated at Nassau University Medical Center, East Meadow, New York, for equestrian-related trauma from January 1, 2000, to December 31, 2024. Results: Twenty-nine equestrian trauma patients ages 10-70 were included, with injuries ob...
Cardinaux EM, Oltmanns H, Beineke A, Meißner J, Geburek F.Flexural limb deformities are a widespread condition in foals. Oxytetracycline is a common conservative treatment option with relaxing effects on the muscle-tendon-unit, potentially mediated through a matrix-metalloproteinase (MMP)-inhibitor mechanism. Its high therapeutic dose for this indication, potential negative side effects, and the guidelines for prudent use of antimicrobials make investigating alternatives desirable. In this study, the influence of substances with potentially similar mechanisms of action, however without antimicrobial properties, on viability and proliferation of juven...
England D, Newsom L, White C, McKenzie E.Site selection for cervical stabilization surgery in horses with spinal ataxia frequently relies on measurements derived from radiographic myelography. A variety of measurement criteria exist and can provide conflicting results. The main objectives of this study were to assess the correlation between two commonly used myelographic measures, dorsal contrast column reduction (DCCR) and dural diameter reduction (DDR), and their association with previously selected operative sites in a population of horses operated at a tertiary clinic. Secondary objectives were to determine if articular process j...
