Joints Of Horses Research Articles

Computed tomographic arthrography, gross anatomy and histology demonstrate a communication between synovial invaginations in the proximal aspect of the third interosseous muscle and the carpometacarpal joint in horses.

This descriptive anatomical study investigates the relationship between the third interosseous muscle, also known as the suspensory ligament, and the carpometacarpal joint in forelimbs of horses, with the hypothesis that there was a direct synovial communication between these structures as shown by computed tomographic arthrography, histology, and gross anatomy sections. Computed tomography of the carpus and metacarpal region was performed on two groups. Group 1 consisted of eight cadaver limbs undergoing computed tomographic arthrography following injection of a mixture of positive contrast medium, saline, and color-pigmented fluid solution into the middle carpal joint. Group 2 consisted of eight forelimbs assessed using plain computed tomography. The images were interpreted subjectively for contrast medium distribution and objectively by comparing Hounsfield values of the proximal suspensory ligament at 0.5 cm intervals starting at the origin and extending 3 cm distal to the proximal subchondral bone plate of the third metacarpal bone. Of the 16 limbs, two were sectioned for gross anatomy and one was documented histologically. The proximal suspensory ligament was visualized with clear margins on computed tomography images. The positive contrast medium was found within the lateral and medial lobes of the suspensory ligament in all eight (100%) limbs. Hounsfield units within the suspensory ligament following contrast injection were significantly higher than in those in the plain CT group between 0.5 and 2.5 cm distal to the proximal subchondral bone plate of the third metacarpal bone (p < 0.05). The gross anatomy sections showed color pigmentation within the suspensory ligament correlating to the contrast medium distribution evident on computed tomography images. Histology confirmed a synovial lined cavity within the suspensory ligament. The demonstration of a direct synovial communication between the internal structure of the proximal suspensory ligament and the carpometacarpal joint in horses offers further explanation for commonly encountered interactions of diagnostic local anesthesia of the carpal and subcarpal regions. When performing diagnostic or therapeutic injections into the middle carpal joint, the likely effect on the proximal suspensory ligament should be considered. Furthermore, as the proximal suspensory ligament was identified clearly on CT images, further studies are needed to elucidate the utility of CT in clinical cases with suspected soft tissue pathology in the subcarpal region.

Diagnostic imaging of the equine cervical spine – Are radiographs enough?

Diagnostic imaging of the equine cervical spine – Are radiographs enough?

Increasing tourniquet number has no effect on amikacin concentration within the radiocarpal joint in horses undergoing intravenous regional limb perfusion.

To determine whether IV regional limb perfusion (IVRLP) performed in the cephalic vein with a wide rubber tourniquet (WRT) applied proximal and distal to the carpus results in a higher peak concentration (Cmax) of amikacin in the radiocarpal joint (RCJ), compared with the Cmax for IVRLP using a single WRT proximal to the carpus. 7 healthy adult horses. Horses underwent IVRLP using standing sedation with 2 g of amikacin sulfate diluted to 60 mL by use of saline (0.9% NaCl) solution in the cephalic vein with 2 different tourniquet techniques; proximal WRT (P) and proximal and distal WRT (PD). Synovial fluid was collected from the RCJ at 5, 10, 15, 20, 25, and 30 minutes after IVRLP. Tourniquets were removed after the 30-minute sample was collected. Blood samples from the jugular vein were collected at 5, 10, 15, 20, 25, 29, and 31 minutes after IVRLP. Amikacin concentration was quantified by a fluorescence polarization immunoassay. Median peak concentration (Cmax) of amikacin and time to maximum drug concentration (Tmax) within the RCJ were determined. Median peak concentration in the RCJ was 1331.4 μg/mL with technique P and 683.1 μg/mL with technique PD. Median Tmax occurred at 30 minutes with technique P and 25 minutes with technique PD. No significant (Cmax, P = 0.18; Tmax, P = 0.6) difference in amikacin Cmax or Tmax between techniques was detected. Placement of 2 WRTs offers no advantage to a single proximal WRT when performing IVRLP to deliver maximal amikacin concentrations to the RCJ using IVRLP.

A systematic review evaluating the use of ultrasound in the identification of osteochondrosis in horses

Osteochondrosis is commonly encountered in young horses, with welfare, performance, and economic effects. Consequently, pre-purchase radiographic screening for osteochondrosis is routinely performed. Ultrasonographic examination of articular cartilage and osteochondrosis lesions are described in the literature with many case series or single case reports published. This systematic review was undertaken to examine the evidence for using ultrasonography in comparison to traditional radiography, arthroscopy or necropsy findings in the detection of osteochondrosis.The systematic review identified a paucity of studies in which there was marked variation in the populations, sample size, methods and results reported. Currently, there is no strong evidence confirming the diagnostic accuracy and validity of ultrasonography in the detection of osteochondral lesions in the relevant joints in horses.

Four cases of atypical large and abaxial osteochondral fragments of the dorsal articular margin of the proximal phalanx in the metatarsophalangeal joint of Warmblood horses

Four cases of atypical large and abaxial osteochondral fragments of the dorsal articular margin of the proximal phalanx in the metatarsophalangeal joint of Warmblood horses

In vivo joint synovial fluid disposition of a novel sustained-release formulation of diclofenac and hyaluronic acid in horses.

Intra-articular administration of sustained-release anti-inflammatory drugs is indicated in horses suffering from joint inflammation, but no such drugs are labelled for veterinary use. To obtain initial data on synovial disposition and safety of a new sustained-release formulation of diclofenac (SYN321) in the joints of horses, an experimental interventional study of elimination and side effects of intra-articular administration of SYN321 was conducted. Nine clinically sound horses were included in the study, and SYN321 was administered by the intra-articular route. Dose ranges and sampling intervals were established in a pilot study with two horses, and then applied in a main study involving seven horses treated in the fetlock joint. Diclofenac was detected above lower limit of quantification (LOQ: 0.5ng/ml) in synovial fluid throughout the study period (14days), and below LOQ (0.1ng/ml) in plasma after 4days and in urine after 14days. No obvious clinical side effects were detected. Clinical examination and objective lameness evaluation suggested that SYN321has potential as a local joint NSAID treatment with sustained release in horses, but further studies on synovial fluid exposure, safety and clinical efficacy are warranted.

Effects of an articular cartilage lubrication with a viscosupplement in vitro and in vivo following osteochondral fractures in horses.

To assess whether the combination of hyaluronan, sodium chondroitin sulfate, and N-acetyl-d-glucosamine (HCSG) lubricates articular cartilage in vitro and modulates joint lubrication in vivo. 16 healthy adult horses. The effects of HCSG injections on SF lubricant properties and joint health, immediately after injury and 2 weeks later, were analyzed by use an equine osteochondral fracture model of post-traumatic osteoarthritis (OA). Middle carpal joints of adult horses were randomly assigned to 1 of 4 surgical treatment groups as follows: normal nonsurgical group (n = 8), normal sham-surgical group (8), OA-induced surgical group with HCSG injection (8), or OA-induced surgical group with saline (0.9% NaCl) solution injection (8). Synovial fluid was aspirated periodically and analyzed for boundary lubrication function and lubricant molecules. At 17 days, joints were screened for gross pathological changes. Induction of OA led to an impairment of SF lubrication function and diminished hyaluronan concentration in a time-dependent manner following surgery, with HCSG injection lessening these effects. Certain friction coefficients approached those of unaffected normal equine SF. Induction of OA also caused synovial hemorrhage at 17 days, which was lower in joints treated with HCSG. After induction of OA, equine SF lubricant function was impaired. Hyaluronan-sodium chondroitin sulfate-N-acetyl-d-glucosamine injection restored lubricant properties at certain time points and reduced pathological joint changes.

Development and Validation of a Three-Dimensional Printed Training Model to Teach Ultrasound-Guided Injections of the Cervical Articular Process Joints in Horses.

Intra-articular injections are routinely performed to alleviate pain and inflammation associated with osteoarthritis in horses. Intra-articular injections require accurate needle placement to optimize clinical outcomes and minimize complications. This study's objectives were to develop and validate a three-dimensional (3D) printed model of an equine cervical articular process joint to teach ultrasound-guided injections. Five identical models of an equine cervical articular process joint were 3D printed and embedded in 10% ballistic gelatin. Experts' and novices' ability to successfully insert a needle into the joint space of the model using ultrasound guidance was assessed and graded using an objective structured clinical examination (OSCE). Scores from experts and novices were compared to evaluate the construct validity of the model. Participants also answered a survey assessing the face and content validity of the model. Experts required less time (22.51 seconds) for correct needle placement into the model joint space than novices (35.96 seconds); however, this difference was not significant (p = .53). Experts' median total OSCE score (14) was significantly higher (p = .03) than novices' (12), supporting the model's construct validity. Participants agreed on the face and content validity of the model by grading all survey questions greater than 7 on a 10-point Likert-type scale. In summary, we successfully developed a 3D printed model of an equine cervical articular process joint, partially demonstrated the construct validity of the model, and proved the face and content validity of this new training tool.

Evaluation of the in vitro effects of local anesthetics on equine chondrocytes and fibroblast-like synoviocytes.

To investigate the in vitro effects of clinically relevant concentrations of the local anesthetics (LAs) bupivacaine, lidocaine, lidocaine with preservative (LP), mepivacaine, and ropivacaine on equine chondrocyte and fibroblast-like synoviocyte (FLS) viability. Chondrocytes and FLSs of the metacarpophalangeal joints of 4 healthy adult horses. Viability of chondrocytes and FLSs was determined with 3 assays: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), and trypan blue (TB) exclusion (only FLS). Viability was assessed after 30- and 60-minute exposures to 0.0625%, 0.125%, and 0.25% bupivacaine; 0.25%, 0.5%, and 1% lidocaine; 0.25%, 0.5%, and 1% LP; 0.25%, 0.5%, and 1% mepivacaine; and 0.125%, 0.25%, and 0.5% ropivacaine. Viability of chondrocytes was significantly decreased with exposure to 0.25% bupivacaine, 1% lidocaine, 1% LP, 1% mepivacaine, and 0.25% ropivacaine. Viability of FLSs was significantly decreased with exposure to 0.25% bupivacaine, 1% mepivacaine, 1% LP, and 0.5% ropivacaine. Clinically relevant concentrations of LAs had in vitro time- and concentration-dependent cytotoxicity for chondrocytes and FLSs isolated from the metacarpophalangeal joints of healthy horses. Bupivacaine was more toxic to chondrocytes than lidocaine, mepivacaine, and ropivacaine, whereas bupivacaine, LP, mepivacaine, and ropivacaine were more toxic to FLSs than preservative-free lidocaine. Several LAs may negatively affect chondrocyte and FLS viability.

Elastosonographic features of the metacarpophalangeal joint capsule in horses

BackgroundCapsulitis leads to the release of inflammatory mediators in the joint, causing capsular fibrosis and osteoarthritis (OA). Strain elastosonography (SE) measures the elasticity of tissue by evaluating its strain in operator-dependent deformation. The aims of the study were to assess the feasibility, repeatability, and reproducibility of SE for imaging the distal attachment of the joint capsule (DJC) of metacarpophalangeal joints in sound horses (Group S) and in horses with metacarpophalangeal OA (Group P) and to evaluate differences in the elastosonographic patterns of these horses. After a whole lameness examination, fore fetlock DJCs were assigned to Group S and Group P and were thereafter examined by two operators using SE. Qualitative (i.e., colour grading score) and semi-quantitative (i.e., elasticity index (EI) and strain ratio (SR)) methods were used to evaluate the elastograms. The inter-rater reliability (IRR), intraclass correlation coefficient (intra-CC) and interclass correlation coefficient (inter-CC) were used to compare colour grading scores and the repeatability and reproducibility of EI and SR outcomes. The same parameters were compared between groups. P < 0.05 indicated a significant finding.ResultsForty-one horses were included: 11 were in Group S and 30 were in Group P (16 with bilateral OA, 8 with left OA and 6 with right OA). IRR outcomes ranged from good to excellent. For transverse and longitudinal ultrasound scans, the colour grading score of Group S was significantly higher than the metacarpophalangeal DJCs of Group P. Both Inter-CC and intra-CC were higher in Group S than in Group P, with values always > 0.8. Significative differences in EI and SR were detected between groups and between Group S and the affected limb of Group P; values were lower in Group S than in Group P.ConclusionsSE can be a useful technique for evaluating DJCs, with good repeatability and reproducibility. DJCs appear softer in sound horses.

Evaluation of Villus Synovium From Unaffected Metacarpophalangeal Joints of Adult and Juvenile Horses

Horses are a widely accepted model for osteoarthritis (OA) research. Synovial tissue sampling is commonly used in studies to evaluate and grade the progress of OA or to assess treatment effects. Synovial explants play an important role in ex-vivo studies, increasingly replacing the use of living animals. To understand histomorphological changes in the process of joint-related diseases such as OA, detailed information about histomorphometric parameters of unaffected synovial villi is necessary.The objective of the present study was to evaluate the mean width of the intimal synovial lining and its cellularity as well as the vascularization of the subintimal layer in juvenile and adult horses not affected by a joint-related disease.One hundred synovial samples from both metacarpophalangeal joints from 25 horses (one day to 24 years old) were collected to evaluate the following parameters on digitalized hematoxylin-eosin stained samples: Width of intimal synovial lining measured by the distance from the inner joint surface to the subintimal layer; density of the cells making up the intimal synovial lining by counting cell nuclei; vascularization of the subintimal layer measured by the number and size of vessels in relation to the subintimal area.The median width of the intimal lining did not differ among juvenile (22.34 µm) and adult (23.34 µm) horses. The cellularity of the intimal lining was significantly lower in juvenile (one cell/143.8 µm2) than in adult (one cell /188.7µm2), (P < .001) horses as well as the density of blood vessels per mm2 within the subintimal layer (juveniles 1/mm2 vs. adults 0.05/mm2), (P < .001).This study provides morphometric data regarding synovial intimal width, intimal cellularity, and vascularization of equine synovial villi of unaffected horses. For future studies, age-related characteristics should be taken into consideration when synovial tissue samples are used for in-vivo and in-vitro studies.

Features of ultrasonographic examination of the shoulder joint in dogs and horses

Shoulder problems in dogs and horses are a common problem, especially in sport, hunting and service animals. Timely accurate diagnosis and early start of treatment can significantly reduce the duration of therapy and increase its effectiveness. Despite the fact that there are a large number of generally accepted methods of instrumental diagnostics of shoulder joint pathologies, ultrasound examinations in veterinary medicine remain uncovered today. This article highlights the algorithms of ultrasound diagnostics developed by us and the features of the study associated with the species differences between dogs and horses. The article also presents the main necessary projections, as well as the qualitative ultrasound characteristics of the structures of the investigated area in dogs and horses. The result of this study is the formation of a logical algorithm for conducting ultrasound examinations of dogs and horses.

Needle Arthroscopy of the Scapulohumeral Joint and Bicipital BURSA in Horses: An Ex Vivo Study

To evaluate the feasibility of performing needle arthroscopy of the scapulohumeral joint and bicipital bursa in standing horses by using the thoracic limbs of euthanized horses. To that purpose, this experimental study was designed. Ten thoracic limbs, five left and five right from euthanized horses were retained in an upright position to simulate a standing horse. The craniolateral and lateral scapulohumeral arthroscopic portals were used to access the articular structures. A third (caudal) portal was also identified and described. The degree of difficulty in accessing the articular space and the optic maneuverability within the joint were compared between portals. The needle arthroscopy image lacks in quality, but the procedure was considered useful as a diagnostic aid for examination of the scapulohumeral joint of horses. Needle arthroscopy of the bicipital bursa was not possible. Needle arthroscopy has a great diagnostic potential for lesions in the scapulohumeral joint of horses. A new access (caudal) to the scapulohumeral joint of horses has been identified.

Biogeography a key influence on distal forelimb variation in horses through the Cenozoic.

Locomotion in terrestrial tetrapods is reliant on interactions between distal limb bones (e.g. metapodials and phalanges). The metapodial-phalangeal joint in horse (Equidae) limbs is highly specialized, facilitating vital functions (shock absorption; elastic recoil). While joint shape has changed throughout horse evolution, potential drivers of these modifications have not been quantitatively assessed. Here, I examine the morphology of the forelimb metacarpophalangeal (MCP) joint of horses and their extinct kin (palaeotheres) using geometric morphometrics and disparity analyses, within a phylogenetic context. I also develop a novel alignment protocol that explores the magnitude of shape change through time, correlated against body mass and diet. MCP shape was poorly correlated with mass or diet proxies, although significant temporal correlations were detected at 0-1 Myr intervals. A clear division was recovered between New and Old World hipparionin MCP morphologies. Significant changes in MCP disparity and high rates of shape divergence were observed during the Great American Biotic Interchange, with the MCP joint becoming broad and robust in two separate monodactyl lineages, possibly exhibiting novel locomotor behaviour. This large-scale study of MCP joint shape demonstrates the apparent capacity for horses to rapidly change their distal limb morphology to overcome discrete locomotor challenges in new habitats.

Use of autologous products for the treatment of joint and soft tissue disease in horses: A systematic review.

Soft tissue injuries and joint disease are the predominate causes of lameness in the equine athlete and these pathologies carry a guarded prognosis for a return to previous performance. Recently the use of autologous products has become more widespread as a treatment in equine sports medicine. However, the efficacy of these products is yet to be fully established. To evaluate the current published evidence base regarding the efficacy of autologous products in soft tissue injuries and joint disease. A systematic review of English articles using MEDLINE, EMBASE and Web of Science databases from 1980 to 2017. The search strategy identified 1594 papers for review. Fifty-eight papers were included in this review, 28 of which were randomised controlled trials. Significant benefit was reported under several parameters, most notably in the use of autologous chondrocytes in artificially induced cartilage defects on histology. One paper documented a significant clinical response under lameness examination. The current literature shows that the treatment of soft tissue injury and cartilage disease with autologous products is safe and that the use of some products can give significant benefit on some outcome measures. True clinical significance is yet to be demonstrated with any product.

Biomechanical and wearability testing of novel legwear for variably limiting extension of the metacarpophalangeal joint of horses.

To evaluate the ability of novel legwear designed to limit extension of the metacarpophalangeal joint (MCPJ) to redirect loading forces from the flexor apparatus during walk, trot, and canter on a treadmill and during unrestrained and restrained activity in a stall. 6 adult horses without musculoskeletal disease. Legwear-derived force data were recorded under 4 conditions: inactive state (unlimited legwear extension) and 3 active (restrictive) states (mild, 30° extension; moderate, 20° extension; or maximum, 10° extension). Associations between peak legwear loads and torques among legwear states and treadmill gaits and stall activities were assessed. The hair coat and skin of the forelimbs were examined for any legwear-induced adverse effects after testing. During the treadmill exercises, moderate restriction of legwear extension resulted in significantly higher peak load and torque than mild restriction, and faster speeds (canter vs walk or trot and trot vs walk) yielded significantly higher peak load and torque. During in-stall activity, maximum restriction of legwear extension yielded significantly higher peak load and torque than moderate restriction. Unrestrained in-stall activity resulted in significantly higher peak load and torque than restrained activity. The legwear caused minimal adverse effects on the hair coat and skin of the forelimbs. Findings suggested that the legwear variably reduced peak loads on the flexor apparatus. Extension of the MCPJ may be incrementally adjusted through the legwear such that return to activity may be controlled, and controlled return to activity is crucial for rehabilitating flexor apparatus injuries.

Risk Factors for the Occurrence of Desmopathy of the Collateral Ligaments of the Distal Interphalangeal Joint in Equines – A Cross-Sectional Study

Abstract Desmopathy of the collateral ligaments of the distal interphalangeal joint (CL-DIPJ) has been increasingly relevant in equine sports medicine. However, the risk factors for the development of such desmopathy are not well established. In the literature, what has been described about it, is based on the clinical conditions observed in animals diagnosed with this disorder. Considering this scenario, the aim of this study was to verify which possible extrinsic or intrinsic risk factors may influence the occurrence of disorders in the collateral ligaments of the distal interphalangeal joint in polo horses. Twenty-five horses from the same equestrian team, all competing in polo, were evaluated via ultrasonography. The outcome was defined as changes in echogenicity and/or boundaries of the CL-DIPJ of the thoracic limbs of the horses evaluated. The intrinsic factors considered in this study were age, the presence of angular deviations and gender. As extrinsic factors, the parameters taken into consideration were the handicap in which the animals played and the type of training to which these horses were previously submitted in their professional athletic career. The prevalence ratio was used to verify the association between risk factor and outcome. The result of this evaluation was considered significant when the confidence interval value did not involve the value 1. Positive and significant association was observed only for age. Playing in different handicaps did not influence the presence of ligament disorders. The other factors evaluated revealed a positive but not significant association. Thus, it was concluded that animals aged nine years or older present a higher risk of CL-DIPJ disorders.

Arthroscopic evaluation of the metacarpophalangeal and metatarsophalangeal joints in horses with parasagittal fractures of the proximal phalanx.

Fractures of the proximal phalanx are one of the most common long bone fractures of Thoroughbred racehorses. Although the degree of disruption and damage to the articular surface is generally considered a major prognostic determinant, associated arthroscopic findings have not previously been reported. To describe the metacarpo/metatarsophalangeal (MCP/MTP) joint lesions associated with parasagittal fractures of the proximal phalanx arthroscopically identified at the time of fracture repair and compare radiographic and arthroscopic appearance of complete fractures. Retrospective case series. Case records and arthroscopic images of horses with parasagittal fractures of the proximal phalanx admitted to Newmarket Equine Hospital from 2007 to 2017 were analysed. 81 MCP/MTP joints in 78 horses underwent arthroscopic evaluation concurrent to parasagittal fracture repair. Tears of the joint capsule and dorsal synovial plica were noted in 43 cases. Arthroscopy identified articular incongruity in three horses where fracture displacement was not predicted at all on pre-operative radiographs, and incongruity in additional plane(s) to the radiographic displacement in 14 horses. Concurrent osteochondral fragmentation and disruption of cartilage were present in some cases. As a retrospective study, the arthroscopic data available for review were variable. Arthroscopic assessment of fracture reduction and joint congruency was evaluated in all cases but there was variation in the completeness of evaluation of the entire dorsal joint space of the fetlock joint. This may have led to the underestimation of soft tissue lesions in these cases. Some horses suffering from parasagittal proximal phalanx fractures have concurrent tearing of the joint capsule and/or dorsal plica, which may have relevance in the acute course of events resulting in the development of fractures. Fracture displacement and incongruency at the articular surface cannot confidently be excluded pre-operatively by radiographs alone.

Comparison of a 3-hole 4.5-mm Dynamic Compression Plate and a 7-hole 5.5-mm Y Locking Compression Plate for Arthrodesis of the Proximal Interphalangeal Joint in Horses—an Ex Vivo Biomechanical Study

The objective of this study was to compare the biomechanical properties in a single cycle axial loading test and the types of failures in two constructs (a 3-hole 4.5-mm dynamic compression plate (DCP) and 7-hole 5.5-mm Y locking compression plate (Y-LCP)) in equine proximal interphalangeal joint (PIJ) arthrodesis. One limb in each pair was randomly assigned to PIJ arthrodesis using a 3-hole 4.5-mm DCP combined with two transarticular 5.5-mm cortical screws, whereas the contralateral limb was submitted to PIJ arthrodesis using a 7-hole Y-shaped 5.0-mm LCP in conjunction with one transarticular 4.5-mm cortical screw inserted through the central plate hole. Cortical screws were inserted in lag fashion. Constructs were submitted to a single axial load cycle to failure. Construct stiffness, load, and deformation were analyzed. Dynamic compression plate and Y-LCP arthrodesis constructs did not differ significantly and were equally resistant to axial loading under the conditions studied (DCP and Y-LCP group stiffness, 5685.22 N/mm and 6591.10 N/mm, respectively). Arthrodesis of the PIJ using a DCP and two transarticular 5.5-mm cortical screws or a Y-LCP yielded biomechanically equivalent outcomes under the test conditions considered. However, Y-LCP provides less impact in the palmar/plantar bone. Application of Y-LCP with unicortical screws has equivalent biomechanical characteristics of DCP and may be a safe option for PIJ arthrodesis, where potential trauma secondary to applying bicortical screws in the palmar/plantar aspect of the pastern can be avoided.

Ultrasonographic Appearance of Elbow Joints in a Population of Amiata Donkeys

Ultrasound (US) is a well-established technique for investigating joint diseases in horses, complementary to radiography. Few studies have been performed on the ultrasonographic aspect of the elbow joint in horses and no reports are available on donkeys. The aim of this study is to describe the ultrasonographic appearance of the elbow joint in healthy donkeys. Descriptive cohort study included 34 elbow joints, which were evaluated in 17 donkeys. Inclusion criteria included no lameness or musculoskeletal diseases in the donkeys. The structures evaluated were the lateral and medial collateral ligaments, ulnaris lateralis proximal tendon, distal biceps brachii tendon, triceps brachii tendon, and the articular space. For each structure, one good-quality image was recorded. The structures were retrospectively assessed for echogenicity, fiber orientation, bone appearance, and shape. The prevalence of the visualized structures was calculated. Cohen κ coefficient was calculated for the repeatability (intraoperator agreement), the reproducibility (interoperator agreement), and the influence of the operator’s experience in US examination. The US appearance of the structures was described. Statistical analysis showed scarce-to-moderate agreement concerning the repeatability and mostly scarce-to-good agreement concerning the reproducibility of the US examination; finally, low-to-discrete agreement concerning the operator’s experience. Technical difficulties precluded an accurate description of the medial collateral ligament. The healthy animals included were limited. The US examination of the elbow joint in donkeys were similar to the features reported in horses. Individual experience partially influences the execution and the assessment of the US images.