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.     

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.     

COMPUTED TOMOGRAPHIC FINDINGS OF DOGS WITH CUBITAL JOINT LAMENESS

The purpose of this study was to identify the incidence of abnormal computed tomography (CT) findings in dogs with lameness of one or both elbows. CT examinations of 102 elbows in 51 dogs were reviewed individually and by group consensus by 3 examiners and graded for various abnormalities. Frequently encountered abnormalities included abnormal shape and sclerosis of the medial coronoid process of the ulna, irregularity of the radial incisure of the ulna, and ulnar trochlear notch sclerosis. Other abnormalities included distinct/separate or fissure/in situ fragmentation of the medial coronoid; lucency of the radial incisure; ununited anconeal process; sclerosis, lucency, or flattening of the medial aspect of the humeral condyle; osteophyte formation; and joint incongruity. In conclusion, CT of the canine cubital joint is useful in identification of various lesions beyond simple fragmentation of the medial coronoid process of the ulna.     

Phenotypic and genetic evaluation of elbow dysplasia in Dutch Labrador Retrievers, Golden Retrievers, and Bernese Mountain dogs

Canine elbow dysplasia encompasses four developmental diseases: ununited anconeal process, osteochondrosis of the medial part of the humeral condyle, fragmented medial coronoid process (FCP), and incongruity of the elbow joint. Four radiographic views per joint were used to evaluate 2693 Labrador Retrievers (LRs), 1213 Golden Retrievers (GRs), and 974 Bernese Mountain Dogs (BMDs) for the presence of elbow dysplasia between 2002 and 2009 in the Netherlands. The views were also graded for signs of osteoarthritis and sclerosis. FCP was diagnosed most frequently in LRs, GRs and BMDs, with an incidence of 6%, 5%, and 15%, and a heritability of 0.17, 0.24, and 0.06, respectively. Heritabilities were estimated using a sire model and all available ancestors. Sclerosis at the base of the medial coronoid process was the radiographic sign most strongly correlated with FCP (r=0.95, 0.92, and 0.95 in LRs, GRs and BMDs, respectively). The sex of the dog was significantly correlated with the presence of osteoarthritis in LRs, but not in GRs and BMDs. Male LRs were 1.7-fold more frequently, but not more severely, affected by osteoarthritis than female dogs. Age at radiographic examination was significantly associated with osteoarthritis in all three breeds. The heritability estimates in Retrievers were high enough to warrant including FCP findings in the breeding policy, but until the biomechanical and genetic background of elbow dysplasia are better understood, correct phenotyping with a sensitive technique is essential.     

The elbow

Computed tomography (CT) and magnetic resonance imaging (MRI) are noninvasive methods of imaging the canine cubital joint. CT images are typically acquired using contiguous 1-mm slices, a bone reconstruction algorithm, and a field of view large enough to scan both elbows simultaneously. CT provides a detailed assessment of the medial coronoid process (MCP), radial incisure, anconeal process, and trochlear notch of the ulna; the humeral condyle; joint congruity; and osteoarthrosis. With MRI, use of a surface coil and 3D Fourier transformation gradient echo fast imaging sequences allow contiguous thin slices to be obtained. Both imaging techniques appear to be highly effective in the evaluation of elbow dysplasia, particularly for the detection of MCP fragmentation, although MRI is superior to CT for identifying nonmineralized cartilaginous fragments.     

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.     

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.     

Arthroscopic‐guided ulnar distraction for the correction of elbow incongruency in four dogs

Four skeletally immature, small breed dogs (five elbows) with elbow incongruency were evaluated for forelimb lameness. Findings on clinical examination included pain, effusion and decreased range of motion of the affected elbow. Radiography, computed tomography and arthroscopy demonstrated elbow incongruency in all dogs. Fragmented medial coronoid process was diagnosed arthroscopically in three dogs (four elbows). Arthroscopic subtotal coronoidectomy was performed in all cases of fragmented medial coronoid process. Incongruency was corrected with acute ulnar lengthening under arthroscopic visualisation. The ulna was stabilised with a plate following correction. In two elbows an ostectomy of the anconeal process was performed to prevent impingement against the olecranon fossa. All dogs demonstrated improvement in lameness scores and client‐scored visual analogue scale scores. Postoperative computed tomography showed significant improvement in elbow incongruency in all dogs. Arthroscopic‐guided ulnar lengthening may be considered as a valid treatment in severe cases of elbow incongruency .     

Computed tomography versus arthroscopy for detection of canine elbow dysplasia lesions

Objective— To describe associations between computed tomography (CT) and arthroscopy in dogs with elbow dysplasia lesions.
Study Design— Retrospective clinical study.
Sample Population— Canine elbows (n=101) investigated by CT and arthroscopy.
Methods— CT scans were reviewed for 10 predetermined CT signs and graded for osteophyte size. Surgical reports were reviewed for specific disease features and cartilage erosion grades. Associations between variables were investigated with multivariate logistic regression and correlation between osteophyte size and cartilage erosion with Spearman's rank order correlation.
Results— Medial coronoid process (MCP) fragment on CT was significantly associated with the arthroscopic identification of a displaced MCP fragment, cartilage erosion affecting the MCP, and cartilage erosion affecting the humeral condyle. Irregular radial incisure of the ulna on CT was significantly associated with the arthroscopic identification of cartilage erosion affecting the MCP. Osteophytes on CT were significantly associated with an abnormal arthroscopic examination. There was a moderately significant correlation between CT osteophyte grade and cartilage erosion grades for areas of the medial joint compartment (r_s=0.44–0.48).
Conclusion— Some CT signs are significantly associated with arthroscopic features of elbow dysplasia lesions in dogs; however, other CT signs were not associated with arthroscopic findings, and CT and arthroscopy can provide contradictory information. Osteophyte size is moderately correlated with cartilage erosion of the medial joint compartment.
Clinical Relevance— CT can provide valuable information for the investigation of dogs with elbow dysplasia, but the absence of CT signs (or the absence of arthroscopic abnormalities) does not rule out elbow lesions.     

RADIOGRAPHIC FEATURES OF PRIMARY AND CONCOMITANT FLEXOR ENTHESOPATHY IN THE CANINE ELBOW

Primary flexor enthesopathy is a recently recognized elbow disorder and should be considered in the differential diagnosis of elbow lameness. For treatment planning purposes, it is important to make a distinction between primary and concomitant forms of the disease. The purpose of this prospective study was to compare radiographic findings for dogs with primary flexor enthesopathy (n = 17), concomitant flexor enthesopathy (n = 24), elbow dysplasia (n = 13), and normal dogs (n = 7). All dogs underwent a complete radiographic examination and each radiographic image was evaluated for the presence or absence of following characteristics: irregular medial humeral epicondyle, spur and calcified body. Additionally, the presence or absence of other elbow disorders (medial coronoid process disease, osteochondritis dissecans, ununited anconeal process, incongruity, subtrochlear sclerosis, and osteoarthritis) was recorded. Radiographic characteristics of flexor enthesopathy were found in 86% of painful joints in the primary flexor enthesopathy group and in 100% of painful joints in the concomitant flexor enthesopathy group. Radiographic characteristics of flexor enthesopathy were not found in sound elbow and elbow dysplasia groups. Frequencies and details of individual radiographic characteristics did not differ between primary and concomitant flexor enthesopathy groups. Findings support the use of radiography as a first screening method for detection of flexor enthesopathy, but not as a technique for distinguishing primary vs. concomitant forms.     

Radiographic changes in elbow dysplasia following ulnar osteotomy--a case report and review of the literature

This case report describes the results of bilateral elbow arthrotomy and a unilateral ulnar osteotomy in a 10-month-old dog with bilateral elbow dysplasia. Fragmented coronoid processes were removed from both joints via bilateral medial arthrotomies. On the right side an ulnar osteotomy was also performed using a caudolateral approach. Bilateral flexed lateral elbow radiographs taken before surgery and 5 months postoperatively were assessed for changes in osteophyte size on the anconeal process, caudal epicondylar ridge and radial head. Osteophytes on the anconeal process and caudal epicondylar ridge disappeared over the postoperative period in the joint that received an ulnar osteotomy. In the contralateral joint the size of the oesteophytes on the anconeal process and caudal epicondylar ridge increased in size during the same period.     

COMPUTED TOMOGRAPHIC FINDINGS IN CANINE ELBOWS ARTHROSCOPICALLY DIAGNOSED WITH EROSION OF THE MEDIAL COMPARTMENT: AN ANALYTICAL METHOD COMPARISON STUDY

Medial compartment erosion is an advanced stage of medial coronoid disease, an important cause of elbow lameness in dogs, with treatment and the expected prognosis depending on the extent of the cartilage lesions. The identification of specific computed tomographic (CT) findings might facilitate the nonsurgical diagnosis and add to treatment decision making. Aims of this retrospective, analytical, method comparison study were to describe CT findings in elbows of dogs arthroscopically diagnosed with medial compartment erosion and to compare CT vs. arthroscopic findings. A total of 56 elbows met inclusion criteria. Elbows with focal (n = 13), diffuse (n = 11), and complete (n = 32) erosion were compared. Prevalence findings for CT lesions were as follows: periarticular osteophytosis (100%), abnormal shape of the medial coronoid process of the ulna (96.4%), and subchondral bone defect of the medial part of the humeral condyle (MHC; 96.4%). The three groups significantly differed for presence of medial coronoid process fragmentation, radial head subchondral bone sclerosis, and widening of the humeroulnar joint space. No significant agreement was found between CT and arthroscopy for presence of a subchondral bone defect of the MHC. A significant agreement was found between CT and arthroscopy for presence of fragmentation of the medial coronoid process. However, some of the calcified body/fragment(s) visualized on CT in the region of the medial coronoid process could not be identified via arthroscopy. Findings indicated that an accurate estimation of the extent of the elbow cartilage lesions still requires arthroscopic joint inspection.     

Radiographic diagnosis and surgical management of fragmented medial coronoid process in dogs

The diagnosis of fragmented (ununited) medial coronoid process was made in 21 dogs, with 10 dogs having bilateral lesions. Ten of these dogs were presented to surgery. The diagnosis of fragmented medial coronoid process was made in young and middle-aged large- and giant-breed dogs with a history of intermittent or persistent lameness. Diagnosis was based on history as well as results of clinical examination and radiographic study of both elbows. Concomitant elbow lesions seen with fragmented medial coronoid processes were ununited anconeal process and osteochondritis dissecans of the medial humeral condyle. Avulsion of the medial epicondyle and posteromedial supracondylar ridge of the humerus were thought not to have occurred in these cases. Instead, dystrophic ossification of the synovial membrane and periosteal proliferation on the medial epicondyle and posteromedial supracondylar ridge had taken place. It was concluded that, with a questionable radiographic diagnosis of fragmented medial coronoid process, exploratory arthrotomy may be necessary to confirm the diagnosis. Without surgery, the eventual outcome of fragmented coronoid process is degenerative joint disease. Even with degenerative joint disease, however, clinical improvement was seen following removal of the fragment of the medial coronoid process.     

ULTRASONOGRAPHIC ANATOMY OF THE CANINE ELBOW

To produce detailed ultrasonographic images of the soft tissue structures around the canine elbow joint, a series of greyhound cadaver limbs were scanned both intact and dissected in a water bath. Suitable transducer positions and bone landmarks are described and the ultrasonographic appearance of the lateral collateral ligament, anconeal process, triceps tendon, origin of olecranon ligament, biceps tendon insertion, medial collateral ligament, and medial coronoid process are illustrated. Improved understanding of the anatomy of the canine elbow will support clinical ultrasonography of this region.     

Computed tomographic evaluation of canine radioulnar incongruence in vivo

OBJECTIVE: To compare radioulnar incongruence (RUI) of normal canine elbows and elbows with arthroscopically confirmed medial compartment disease in vivo using systematic computed tomography (CT) measurements. STUDY DESIGN: Prospective comparison of RUI measurements in normal and dysplastic canine elbows. SAMPLE POPULATION: Right elbows of 25 medium-large breed, adult dogs with medial compartment disease and 9 medium-large breed, adult dogs with no elbow disease. METHODS: Transverse CT images of proximal radioulnar articulation were reformatted to dorsal and sagittal planes. RUI in 3 locations of the forelimb's medial coronoid was measured. Arthroscopy confirmed diagnosis of medial compartment disease in the diseased group. RUI measurements of the diseased and normal elbows were compared. RESULTS: Cumulative statistical analysis of RUI in all planes revealed no significant difference between the normal and abnormal elbows (P = .61). The abnormal elbows had negative mean RUI at the mid (P = .56) and cranial (P = .24) coronoid regions that were not significantly different from normal elbows and mean positive RUI at the base coronoid that was significantly greater than in normal elbows (P = .00082). CONCLUSION: Canine elbows with established medial compartment disease do not have significant RUI at the medial coronoid region at the time of diagnosis when compared with normal elbows. CLINICAL RELEVANCE: If RUI is a significant factor in the pathophysiology of medial compartment elbow disease in the dog, it does not appear to be present at the time of diagnosis of disease. Ulnar or radial osteotomies do not appear to be indicated for restoration of normal radioulnar articular surface alignment.     

Radiographic findings of the medial humeral epicondyle in 200 canine elbow joints

Objectives: To determine the frequency and radiographic aspect of medial humeral epicondylar lesions as a primary or concomitant finding and to evaluate the association with osteoarthritis. Methods: Medical records of dogs diagnosed with elbow lameness were reviewed. Inclusion criteria for this study were a complete clinical examination, a complete set of digital radiographs and a final diagnosis made by computed tomography or magnetic resonance imaging and arthroscopy. Changes of the medial humeral epicondyle were recorded and correlated with the radiographic osteoarthritis and final diagnosis. Results: Eighty of the 200 elbows showed changes of the medial humeral epicondyle. In 12 of these 80 elbows, changes of the medial epicondyle were the only findings within the joint, and these elbows were diagnosed with primary flexor enthesopathy. In the remaining 68 elbows, other concomitant elbow pathologies were found. In those cases of concomitant epicondylar changes, high grades of osteoarthritis were recorded, while most elbows with primary flexor enthesopathy showed a low grade of osteoarthritis. Clinical significance: Changes of the medial humeral epicondyle are often considered clinically unimportant and are regarded as an expression of osteoarthritis. This study showed the relatively frequent presence of epicondylar changes of which the majority were considered concomitant to a primary elbow problem. If changes of the medial humeral epicondyle are the only pathologic finding (primary flexor enthesopathy) they should be considered as the cause of lameness and not as a sign of osteoarthritis.     

Variation in the ossification process of the anconeal and medial coronoid processes of the canine ulna

This morphological and radiographic study investigates the ossification process of the anconeal and medial coronoid processes of the ulna in a sample of 142 dogs ranging in age from neonatal to 44 weeks. The anconeal process was noted to develop by appositional ossification, formation of a separate ossification center, or a combination of both. Several developmental stages of the ossification center of the anconeal process as well as its anatomic position and radiographic appearance are described. Differences have been noted in the shape of this ossification center as well as the ossification process itself. The medial coronoid process develops exclusively by appositional ossification. Unlike ossification of the anconeal process, ossification of the medial coronoid process was completed earlier (p < 0.05) in smaller than in the larger dogs. In smaller dogs, both the medial coronoid and anconeal processes were found to be mature by the age of 16 weeks. In the larger dogs, ossification of the anconeal process was completed not before 14 weeks of age and ossification of the medial coronoid process was completed about 6 weeks later.     

Osteochondrosis of the elbow joint in young dogs

Osteochondrosis is a failure of the normal process of endochondral ossification. In the elbow joint there are three manifestations of osteochondrosis, namely osteochondritis dissecans of the medial condyle of the humerus, ununited coronoid process and ununited anconeal process. This paper describes a series of sixty-eight cases diagnosed at a referral centre over a 10-year period. Ununited coronoid process and OCD of the medial condyle are not readily diagnosed because the lesions are difficult to demonstrate radiographically, but signs of degenerative joint disease of the elbow in young dogs of the medium to large breeds is strongly suggestive. Surgical treatment is indicated and the surgical approach to the medial aspect of the joint is described.     

Surgical treatment for multiple lesions of elbow dysplasia in two dogs

The presence of an ununited coronoid process, an ununited anconeal process and an ectopic proximolateral radial ossification center are described in a single elbow joint of a ten month old unspayed Great Dane. This animal and a nine month old spayed Saint Bernard, also with an ununited coronoid process, both had marked degenerative osteoarthritis associated with the instabilities.

Chronic lameness and significant palpable elbow joint enlargement(s) were apparent in both dogs. Radiography was used to identify the lesions and surgical treatment produced satisfactory remission of signs.

     

Histomorphometry of fragmented medial coronoid process in dogs: a comparison of affected and normal coronoid processes

OBJECTIVE: To determine if fatigue microdamage is associated with fragmented medial coronoid process (FMCP). STUDY DESIGN: Prospective study. ANIMALS: Thirty-eight dogs were admitted for subtotal coronoid ostectomy as treatment for FMCP. Surgical specimens of medial coronoid process (MCP) were retrieved from treated dogs. Normal MCP were collected from 5 age- and breed-matched dogs and 2 age-matched research beagles that were euthanatized for reasons other than elbow disease. METHODS: MCP specimens from affected elbows were classified into 4 groups based on disease severity. Specimens were bulk-stained for microdamage using 1% basic fuchsin, embedded in polymethylmethacrylate and sectioned at 130 microm. Specimens were evaluated using epifluorescent microscopy (425-440 excitation, 475 nm barrier filter) for diffuse damage (D.DX), osteocyte loss, and porosity. Cartilage thickness was evaluated using bright field microscopy. Qualitative observations were also made. RESULTS: MCP specimens from affected elbows had increased D.Dx, increased osteocyte loss, and greater porosity than normal groups. Specimens classified as severe FMCP (Classes 3, 4) had the most fatigue microdamage. Some Class 1 specimens, defined as having no visible fissuring of the articular cartilage (AC), had large microcracks in trabecular bone. CONCLUSIONS: Accumulation of subchondral fatigue microdamage, is associated with MCP fragmentation. Fissuring occurs in the subchondral bone before gross fibrillation of articular cartilage develops. CLINICAL RELEVANCE: Accumulation of fatigue microdamage in the MCP is important in the pathogenesis of FMCP. The underlying cause of this microdamage accumulation must be identified before treatment plans that will prevent further osteoarthritis of the elbow joint can be designed.