A specific oblique radiography, and treatment, of a medial coronoid process fracture.

Acute traumatic fracture of the medial coronoid process is rarely reported and has previously only been described in three dogs to date. A three-year-old Schapendoes was presented for an acute non weight-bearing lameness. The definitive diagnosis of a medial coronoid process fracture was delicate and based on the disto-medial proximo-lateral oblique radiographic view (Di35M-PrLO). The surgical removal of the fragment was performed using a medial arthroscopic approach. The outcome was rapidly favourable. Lameness disappeared and the follow-up radiographs three months later revealed minimal reactions of osteoarthrosis.     

RADIOGRAPHIC EVALUATION OF THE CANINE ELBOW JOINT WITH SPECIAL REFERENCE TO THE MEDIAL HUMERAL CONDYLE AND THE MEDIAL CORONOID PROCESS

The results of radiographic examination of clinically affected elbow joints in 14 young, large-breed dogs, including standard and oblique projections and linear tomography, were compared with the findings of medial arthrotomy. Radiographs revealed arthrosis (13 dogs), osteochondrosis of the medial humeral condyle (2 dogs), fragmentation of the medial coronoid process (5 dogs), and a combination of osteochondrosis of the medial humeral condyle and fragmentation of the medial coronoid process (2 dogs). In one dog fissures in the medial coronoid process and in another dog a linear radiopacity along the articular surface of the medial coronoid process were found. In three dogs both medial humeral condyle and medial coronoid process appeared normal. The radiographic findings were confirmed during surgery in 11 dogs. Cartilage erosion of the medial humeral condyle in two dogs and of the medial coronoid process in one dog had not resulted in radiographically visible abnormalities. Radiographic examination of the elbow joints in young, large-breed dogs should include standard mediolateral and craniocaudal projections, a mediolateral projection with the joint maximally extended and the leg supinated 15°, and a craniolateral-to-caudomedial projection.     

Radiographic, computed tomographic and arthroscopic findings in 23 dogs with osteochondrosis of the tarsocrural joint

Twenty-three dogs with osteochondrosis of the tarsocrural joint were evaluated by radiography, computed tomography (CT) and arthroscopy. The radiographic examination included an extended and flexed mediolateral, a plantarodorsal, a flexed dorsoplantar skyline view, and a plantaromedial-dorsolateral and a plantarolateral-dorsomedial view (two oblique views). The CT examination was carried out in ventral recumbency and 1 mm slices were taken with a bone window setting; 31 lesions were identified in the 46 joints examined. The arthroscopic exploration used either a plantar or a dorsal puncture, depending on the site of the lesion. In six cases the lateral, and in 17 cases the medial trochlear ridge was involved. Although the survey radiographs were sufficient to make a diagnosis, the CT examination helped to determine the exact site, and the number and size of the fragments of bone. A four-stage classification system comparable to the one used in man was established. Arthroscopy provided information about synovial inflammation and damage to the joint cartilage, and made it possible to remove fragments of bone from one-third of the cases.     

Radiographic assessment of humeroulnar congruity in a medium and a large breed of dog

Elbow joint incongruity is recognized as an important factor in the development, treatment, and prognosis of canine elbow dysplasia. Elbow incongruity has been measured based on radiographic joint space widths, however these values can be affected by the degree of elbow joint flexion. Recent studies have reported radiographic curvature radii as more precise measures of humeroulnar congruity in dogs. The aim of this prospective observational study was to describe radiographic curvature radii measured from flexed and extended elbow radiographs for a sample of dogs representing a medium breed (Portuguese Pointing Dog) and a large breed (Estrela Mountain Dog). The curvature radii from the ulnar trochlear notch and humeral trochlea were measured in 114 mediolateral elbow extended radiographic views (30 Portuguese Pointing Dog and 27 Estrela Mountain Dog), and 84 mediolateral flexed views (22 Portuguese Pointing Dog and 20 Estrela Mountain Dog). The sampled animals' ages ranged from 12 to 84 months (34.6 ± 17.8 months). Good agreement was observed between curvature radii measurements for flexed vs. extended views in both breed groups. Ulnar trochlear notch curvature radii measurements were greater than humeral trochlea curvature radii measurements in both breed groups. Both curvature radii were greater in the large‐breed dog group vs. the medium‐breed dog group. Both breed groups had ulnar and humeral curves with similar typology. However, the large breed group had greater intermediate differences between the humeroulnar surface curvature radii. Results from this study supported the use of curvature radii as measures of humeroulnar congruity in mediolateral flexed elbow radiographs of medium and large breed dogs.     

Co-existence of ununited anconeal process and fragmented medial coronoid process of the ulna in the dog

OBJECTIVES: To determine the incidence of fragmented medial coronoid process of the ulna in dogs with ununited anconeal process. The efficacy of presurgical radiography to diagnose the co-existence of these diseases was also investigated. METHODS: One hundred and fifty-five joints from 137 dogs with ununited anconeal process were included in the study. For the radiographic examinations, an extended mediolateral projection and a craniolateral-caudomedial oblique projection of each elbow joint were taken before surgery. Inspection of the medial part of the joint was carried out either by arthrotomy or arthroscopy. RESULTS: Seventy-two per cent of the dogs were German shepherd dogs. In 25 joints (16 per cent) a fragmented medial coronoid process was diagnosed and removed via arthrotomy or arthroscopy. The co-existence of a fragmented medial coronoid process was diagnosed correctly in only 13 cases (52 per cent) by radiography. In five of these cases with advanced osteoarthritis, the fragment was directly visible because of its dislocation. Compared with published information, the occurrence of ununited anconeal process with fragmented medial coronoid process is noted more frequently in the present study. CLINICAL SIGNIFICANCE: It can be summarised that if ununited anconeal process is present, it is not usually possible to clearly identify fragmented medial coronoid process by radiography. Therefore, it is important to be able to inspect the medial aspect of the joint concerned during surgery.     

BONE SCINTIGRAPHY FOR THE DIAGNOSIS OF AN ABNORMAL MEDIAL CORONOID PROCESS IN DOGS

Few reports have been published regarding the use of scintigraphy in the diagnosis of elbow joint lameness in dogs. Some authors have speculated about the potential use of bone scintigraphy and its suspected high sensitivity for the early diagnosis of abnormalities of the medial coronoid process (MCP) in dogs. Scintigraphy is used routinely in our institution in dogs presented for thoracic limb lameness and/or suspected of abnormalities of the MCP when radiographic findings were equivocal. Radiographic, scintigraphic, and surgical findings of the elbow joints of 17 dogs with elbow joint lameness were compared with radiographic, scintigraphic, and necropsy findings of the elbow joints of 12 clinically healthy Labrador Retrievers. Quantitative evaluation of scintigraphic images was performed to determine relative radiopharmaceutical uptake in the region of the MCP. Maximum relative uptake of the coronoid process in the normal dogs was taken as a threshold value to classify elbows as positive or negative for an abnormal MCP after all 24 elbows of the 12 healthy dogs were confirmed as being normal at necropsy. All 17 elbows from lame dogs were positive on scintigraphy and confirmed as having chondromalacia, a fissure, or fragmentation of the MCP. Based on our results, bone scintigraphy may be a valuable diagnostic tool for the diagnosis of abnormalities of the MCP in dogs, and particularly in older dogs where clinical and radiographic changes may be ambiguous.     

Effect of computed tomography display window and image plane on diagnostic certainty for characteristics of dysplastic elbow joints in dogs

OBJECTIVE: To test the effects of computed tomography (CT) image plane and window settings on diagnostic certainty for CT characteristics associated with dysplastic elbow joints (elbow joint dysplasia) in dogs and to provide optimal display guidelines for these CT characteristics. SAMPLE POPULATION: CT images of 50 dysplastic elbow joints from 49 lame dogs and 10 elbow joints from 5 sound dogs. PROCEDURES: CT image data were obtained in transverse, sagittal, and dorsal planes. Each plane was examined by use of 3 Hounsfield unit (HU) window settings. Two veterinary radiologists independently evaluated sets of CT images for evidence of 7 CT characteristics. Effect of elbow joint status, image plane, and window settings on diagnostic certainty for these CT characteristics was tested by use of a visual analogue scale. RESULTS: Diagnostic certainty for abnormalities of the medial coronoid process (MCP) and radial incisure was highest in the transverse plane, subchondral defects or sclerosis of the trochlea humeri was highest in the dorsal plane, and joint incongruity was highest in the sagittal plane. Certainty for hypoattenuating subchondral defects or fissures was highest at 2,500 or 3,500 HUs, whereas certainty for subchondral sclerosis was highest at 1,500 HUs and lowest at 3,500 HUs. CONCLUSIONS AND CLINICAL RELEVANCE: Diagnostic certainty for CT characteristics of elbow joint dysplasia in dogs was affected by image display variables. Diagnostic certainty for altered subchondral bone density was primarily influenced by window settings, whereas structural MCP abnormalities and joint incongruity were influenced most by image plane.     

Comparison of radiographic assessments of the tibial plateau slope in dogs

OBJECTIVES: To evaluate the accuracy of 2 radiographic methods used to assess tibial plateau slope (TPS) in dogs and evaluate effects of film digitization and radiographic beam placement on TPS measurements. SAMPLE POPULATION: 16 hind limbs from dog cadavers weighing > 20 kg. PROCEDURES: Radiographs of tibiae were made with the radiographic beam centered over the stifle joint and midshaft of the tibia. Tibiae were collected, the femorotibial contact area was determined, and slope of the medial tibial condyle in relation to the tibial shaft was measured. Radiographs were digitized. Slope of the medial tibial condyle was measured on printed and digitized radiographs read in random order by 6 examiners unaware of anatomic measurements. Three examiners used a conventional measuring technique, and 3 examiners used an alternative measuring technique. RESULTS: Anatomic measurements were significantly higher than radiographic measurements made by use of the conventional interpretation method but did not differ from radiographic measurements made by use of the alternate method. Measurements from printed radiographs were lower than measurements from digitized radiographs for the 4 most experienced examiners. CONCLUSIONS AND CLINICAL RELEVANCE: Measurements made by use of a line tangential to the cranial, linear portion of the medial tibial condyle at the femorotibial contact point were accurate measurements of the anatomic TPS. Measurements made by use of the conventional TPS measurement method underestimated the anatomic TPS. Measurements made on digitized radiographs were typically more accurate than measurements made on printed radiographs.     

The possible role of the tibial plateau angle for the severity of osteoarthritis in dogs with cranial cruciate ligament rupture

The purpose of this study was to determine factors correlated with the severity of radiographic osteoarthritis (OA) scoring in dogs with cranial cruciate ligament rupture (CrCLR). Three radiographs of stifle joints (craniocaudal, mediolateral, and mediolateral radiograph with 90 degree flexion of the stifle and tarsal joints) were obtained from 36 dogs with CrCLR (Clinical group) and from 22 dogs without stifle joint disease (Control group). Information about these dogs was collected from the owners and from medical records. Radiographic OA scores in each dog in the clinical group were determined from radiographs using a numeric grading system previously reported. The tibial plateau angle (TPA) in each dog in both groups was measured on mediolateral radiographs with 90 degree flexion of the stifle and tarsal joints. The Mann-Whitney's U test was used for comparing variables between the clinical group and the control group, and Spearman's rank correlation test was used for evaluating correlations between radiographic OA scores and variables in the clinical group. No significant differences were detected between the clinical group and the control group for any of the variables. There were two positive correlations; one between the radiographic OA score and TPA (r=0.395, p=0.014); and the other between body weight and OA score (r=0.399, p=0.013) in the clinical group. Our results indicate that body weight and TPA could affect the severity of the radiographic OA score in dogs with CrCLR.     

Canine elbow dysplasia and primary lesions in German shepherd dogs in France

Five hundred and twenty German shepherd dogs were screened for elbow dysplasia. The following primary lesions were analysed: joint incongruity (JI), fragmented medial coronoid process (FCP), osteochondrosis or osteochondritis of the medial humeral condyle and ununited anconeal process (UAP). Three radiographic views were used for each joint to achieve a definitive diagnosis. The prevalence of elbow dysplasia was 19.4 per cent. The most frequent lesion was JI (16.3 per cent), followed by FCP (11.3 per cent). UAP was diagnosed rarely (1.1 per cent). Combinations of lesions were very frequent (42.2 per cent of the dysplastic elbows). Although these results may be biased due to prescreening of dogs with UAP, it should be highlighted that JI and FCP occur frequently in German shepherd dogs and are probably the most common primary lesions of elbow dysplasia, although they have been under-reported until now.     

RADIOGRAPHIC AND COMPUTED TOMOGRAPHY FINDINGS IN BELGIAN SHEPHERD DOGS WITH MILD ELBOW DYSPLASIA

We compared computed tomography (CT) and radiographic findings of Belgian shepherds with grade 1 or borderline elbow dysplasia to determine whether the radiopaque area dorsal to the anconeal process and seen in mediolateral 45° flexed radiographs is formed by osteophytes, or whether it is an anatomic variation. Eighteen dogs with screening results 0/1, 1/0, or one or both elbows graded as borderline were studied. The radiographs were evaluated according to International Elbow Working Group guidelines and compared with CT images. A fragmented medial coronoid process was seen in five joints, and remaining 31 joints were considered free of dysplasia based on CT images. In radiographs, height of the radiopaque area on the anconeal process was 0–2.7 mm in dysplastic and 0–3.0 mm in other joints. Sensitivity of this sign as dysplasia indicator was 40% and specificity 29%. All dysplastic joints and three of the other joints had blurring of the cranial edge of the medial coronoid process. Subtrochlear sclerosis was seen in four dysplastic joints and in three other joints. Both changes were significant indicators of dysplasia ( P <0.001). Sensitivity and specificity of these phenomena as dysplasia indicators were 80% and 90%, respectively. We conclude that the radiopaque area on the anconeal process might not always be osteophyte formation in Belgian shepherds and should not be used as the sole criterion for dysplasia. Blurring of the medial coronoid process cranial edge and ulnar trochlear notch sclerosis are reliable signs of elbow dysplasia and may be beneficial in screening protocols.     

Clinical evaluation of dogs after surgical and nonsurgical management of osteochondritis dissecans of the talus

Osteochondritis dissecans of the medial aspect of the talus was diagnosed in 17 joints in 11 dogs. In 10 of the 11 dogs, intermittent lameness had persisted after initial diagnosis and therapy. Radiographs made during the initial examination showed a widening of the medial tarsocrural joint space, with osteophyte formation involving the medial and caudal tarsocrural joint. The follow-up radiographs showed greatest change in the increase in reactive bone formation, especially involving the medial and caudal aspects of the tarsocrural joint and the medial aspect of the talus. Arthrotomy for flap removal and curettage was performed on 11 joints; 6 joints did not receive surgery. After a mean period of 34 months following diagnosis, the dogs were examined clinically and the affected joints were radiographed. The degree of lameness, range of motion, and stability of the tarsocrural joint were graded for each limb. Radiographic determinants that were assessed included: width of the medial tarsocrural joint space, medial tarsocrural osteophyte formation, lateral tarsocrural osteophyte formation, caudal tarsocrural osteophyte formation, medial talus osteophyte formation, lateral talus osteophyte formation, intertarsal osteophyte formation, subchondral sclerosis of the distal end of the tibia, presence of joint bodies, and periarticular soft-tissue thickness. On the basis of clinical and radiographic evaluations, the surgical procedures described in this report did not modify progression of osteoarthritic changes.     

Unipodal stance influences radiographic evaluation of foot balance in horses

Lifting the contralateral forelimb (unipodal stance) is often used as a method of restraint in horses. This experimental one group pretest, posttest study was conducted to evaluate the effects of unipodal stance on quantitative radiographic parameters in equine forefeet. Seven nonlame horses were randomly selected. Lateromedial (LM) and dorsopalmar (DP) projections were acquired for both forefeet, squarely placed on blocks, using two X‐ray generators. Radiographs of each foot were acquired first in a bipodal stance, immediately followed by the same radiographic projections obtained in a unipodal stance. The following measurements were recorded for each stance: distal interphalangeal joint (DIPJ) space width on both projections; mediolateral joint balance as the difference between lateral and medial DIPJ space widths on DP projections; extensor process‐to‐middle phalangeal condyle distance; and deep digital flexor tendon angle on LM projections. A matched pairs design and Student's t‐test with a 95% confidence level were used to test for statistical significance. Compared to a bipodal stance, lateral DIPJ space width was significantly reduced on unipodal DP views, whereas mediolateral joint imbalance and to a lesser extent medial DIPJ space width were significantly increased. On unipodal LM views, there was a significant higher degree of DIPJ flexion. These findings suggest that stance should be carefully taken into consideration when measuring radiographic parameters in equine forefeet, especially if assessing foot balance and conformation, as unipodal stance significantly affects the mediolateral balance of the DIPJ on DP radiographs and significantly alters the phalangeal axis on LM radiographs.     

Effect of conformation of the distal portion of the femur and proximal portion of the tibia on the pathogenesis of cranial cruciate ligament disease in dogs

OBJECTIVE: To evaluate mediolateral radiographic views of stifle joints to identify conformational differences between athletically sound dogs and dogs with cranial cruciate ligament disease (CCLD). SAMPLE POPULATION: Radiographic images of 50 stifle joints of 43 dogs with surgically confirmed CCLD and 50 stifle joints of 38 dogs without clinical signs of stifle joint disease. PROCEDURES: Mediolateral radiographic views of stifle joints were obtained, and long axes of the femur, tibia, and femoral condyles were measured. Angles between long axes of the femur and femoral condyle and between long axes of the femur and tibia were measured. Circles were drawn representing the joint surface of femoral condyles (circle 1), area of contact on the tibial plateau (circle 2), and femoral trochlea (circle 3). Radii of circles 1, 2 (line F), and 3 were measured. Distances between midpoints of circles 1 and 2 (line K) and between midpoint of circle 2 and most cranial aspect of the tibial tuberosity (line G) were measured. To evaluate differences in conformation that could lead to CCLD, quotients derived from measurements were created for comparison; angles were compared between dog groups. RESULTS: Significant differences were found in the quotients created by the lengths of lines G and F and lines G and K between dogs with and without CCLD. CONCLUSIONS AND CLINICAL RELEVANCE: No anatomic differences were detected in the distal portion of the femur between dogs with and without CCLD. Development of the tibial tuberosity and shape (convexity) of tibial condyles may be relevant in the pathogenesis of CCLD.     

Detection of joint effusion on radiographs of horses

Joint effusion is one of the classic radiographic signs of osteoarthritis, but no information is available regarding clinicians' ability to detect joint effusion radiographically. This study determined the accuracy and precision of experienced and inexperienced observers in detecting joint effusion of the distal interphalangeal (DIP), metacarpophalangeal (MCP) and midcarpal joints on radiographs. Fresh cadaverous forelimbs were loaded in a material testing machine to mimic a standing horse. The joints were gradually distended and lateromedial and dorsopalmar radiographs were acquired. The images were assessed by three experienced and three inexperienced observers. This study showed that the sensitivity was high for both groups for all joints and projections. Specificity was high for the experienced group but low for the inexperienced group. There was a significant positive correlation between joint distension and severity of joint effusion when reported by experienced observersfor most views (except DIP joint), but only for the MCP joint for inexperienced observers. Interoperator agreement was poor to fair for the experienced group and poor for the inexperienced group. In conclusion, the accuracy and precision of grading joint effusion on radiographs was highly subjective and related to experience.     

THE SUPINATED MEDIOLATERAL RADIOGRAPH FOR DETECTION OF HUMERAL HEAD OSTEOCHONDROSIS IN THE DOG

Mediolateral and supinated mediolateral radiographs of the shoulder joint were compared in 19 dogs. Twenty shoulders, representing 15 dogs (5 had bilateral lesions), had osteochondrosis of the humeral head. The flattened humeral head and subchondral defect were detectable in both views in all affected shoulders. The lesions were slightly more easily detected in the supinated view. The supinated view more consistently demonstrated the presence of a calcified cartilage flap and therefore, could be useful in determining a course of therapy. In four dogs (8 shoulders) without osteochondrosis and six normal shoulders from affected dogs, there were no instances in which a shoulder appeared normal on one view, but demonstrated a lesion on the other. The supinated view should be obtained in addition to the mediolateral view in dogs with osteochondrosis of the humeral head.     

Comparison of radiography and ultrasonography to detect osteochondrosis lesions in the tarsocrural joint: A prospective study

Reasons for performing study: Lesions located on the medial malleolus of the tarsocrural joint can be difficult to image radiographically. Ultrasonography allows evaluation of articular cartilage and subchondral bone. Objectives: To compare dorso30° lateral‐plantaromedial‐oblique (DL‐PlMO) and dorso45° views to detect lesions on the medial malleolus, to validate the use of ultrasonography to show lesions in the tarsocrural joint and to compare its sensitivity to radiography. Methods: Tarsocrural joints (n = 111) with osteochondrosis were evaluated ultrasonographically and radiographically prior to arthroscopic lesion debridement. A complete radiographic examination was made and the best view to detect each lesion recorded. Longitudinal and transverse ultrasonography of the dorsal aspect of the joint was performed and the best scan plane to image each lesion recorded. Results: There were 94 joints with lesions on the distal intermediate ridge of tibia, 24 with lesions on the medial malleolus, and 4 with lesions on the lateral trochlear ridge. The sensitivity of radiography to detect lesions on the medial malleolus and distal intermediate ridge of tibia was 71 and 96%, respectively. Eighty‐two percent of lesions on the medial malleolus were better imaged on dorso30° view. The sensitivity of ultrasonography to detect lesions on the medial malleolus and distal intermediate ridge of tibia was 83 and 98%, respectively. Ultrasonography was significantly more sensitive than radiography to detect lesions on the medial malleolus and distal intermediate ridge of tibia. Conclusion: Dorso30° lateral‐plantaromedial‐oblique view was the best to image lesions on the medial malleolus. Ultrasonography was a valuable diagnostic tool to diagnose lesions in the tarsocrural joint and was more sensitive than radiography for lesions located on the medial malleolus and distal intermediate ridge of tibia. Clinical relevance: Radiographic examination should include a dorso30° view for detection of lesions on the medial malleolus and ultrasonography should be considered to diagnose osteochondrosis in the tarsocrural joints.     

Diagnosis, management, and outcome in 19 horses with deltoid tuberosity fractures

Objective: To describe the diagnosis and treatment of fractures of the deltoid tuberosity. Study Design: Case series. Methods: Medical records (1992–2009) of 19 horses with radiographic confirmation of deltoid tuberosity fractures were reviewed. Data retrieved included signalment, clinical and diagnostic imaging findings, and treatment. Outcome was determined by telephone questionnaire of owners and referring veterinarians. Results: Most horses were markedly lame on admission and 53% had reduced protraction of the affected limb. All fractures were identified on a cranio45° medial‐caudolateral oblique projection; however, only 32% (6 horses) were detected on a mediolateral projection whereas 86% were evident ultrasonographically. Treatment by local wound care and stall rest resulted in return to athletic function without lameness for 13 of 14 horses that had follow‐up. Conclusions: A cranio45° medial‐caudolateral oblique radiographic view was better than a mediolateral projection for identification of deltoid tuberosity fractures. Ultrasonographic detection of fractures was similar except when gas accumulation obscured the fracture site. Deltoid tuberosity fractures can cause severe lameness but can be treated successfully with conservative management.     

CORRELATION OF RADIOGRAPHIC, NECROPSY AND HISTOLOGIC FINDINGS IN 8 DOGS WITH ELBOW DYSPLASIA

Elbow dysplasia is osteoarthrosis/degenerative joint disease due to abnormal development of the elbow joint. The abnormaldevelopment is the result of specific inherited etiologies alone or in combination. This paper attempts to clarify the diagnosis of elbow dysplasia based on the presence of degenerative joint disease by correlating rediographic necropsy, necropsy, and histopathologic results using elbows from 8 German Shepherd dogs. All elbows had radiographic changes consistent with osteoarthrosis/degenerativejoint disease which were identified best on the flexedmedial-lateral projection. Radiographically, a specific diagnosis was made inseven elbows; ununited anconeal process(6) and osteochondrosis (1). At necropsy these lesions were confirmed plus 14 elbows were identified that had fragmented medial coronoid process (6), abnormally shaped medial coronoid processes of fissures in the articualr cartilage of the medial coronoid process (8). additionally, histopathologically there was proliferative synovitis at the radial notch of the ulna and degenerative changes on the proximal, nonarticualr surface of the anconeal process at the site of insertion of the olecranon ligament and joint capsule.Therefore, for screening the elbow joint to identify elbow dysplasia, the recognition of osteoarthrosis/degenerative joint disease on an extreme flexed mediolateral rediograph appears to be sufficient.     

Correlation of ultrasonographic observations with anatomic features and radiography of the elbow joint in dogs

OBJECTIVE: To define the ultrasonographic appearance of the elbow joint of dogs and to develop an ultrasonographic imaging protocol to reliably accomplish complete evaluation of that joint. ANIMALS: 11 clinically normal mixed-breed dogs. PROCEDURE: Ultrasonographic observations (by use of a 5 to 10 MHz linear array probe) were made of 22 elbow joints in cadaveric forelimbs from clinically normal dogs. Images in standard anatomic planes were recorded with a multi-image camera, on videotape, or onto a computer. The anatomic plane of the ultrasonographic beam and position of the ultrasonographic probe were also recorded. Dissection of each elbow joint was performed, and anatomic features were correlated with ultrasonographic images. RESULTS: Structures clearly identified ultrasonographically included the lateral and medial humeral epicondyles, the humeroradial and humeroulnar joints, anconeal process, medial coronoid process, hyaline cartilage covering the proximal articular surface of the radius, collateral ligaments, tendons of triceps brachii and supinator muscles, and the supinator tendon and sesamoid in the supinator cartilage. An ultrasonographic imaging protocol for examination of the elbow joint was developed. CONCLUSIONS AND CLINICAL RELEVANCE: Precise correlations were established between the gross anatomic appearance of the elbow joint and the ultrasonographic images of its component structures. The ultrasonographic imaging protocol will enable complete examination of all regions of the joint for detection of pathologic lesions.