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

Use of Ultrasonography in Diagnosis of Medial Compartment Disease of the Elbow in Dogs

OBJECTIVE

 The objective of this prospective study was to evaluate the use of ultrasonography in the diagnosis of medial coronoid process disease in unclear cases.

STUDY DESIGN

 Fifteen elbows (on thirteen dogs) for which radiography and computed tomography did not lead to a clear diagnosis of medial coronoid process disease were included. On each elbow, ultrasonography was performed with a high frequency linear transducer (12-18Hz). Then, arthroscopic examination of the joint was performed by a surgeon who was unaware of ultrasonographic findings to confirm medial coronoid process disease.

RESULTS

 At least one ultrasonographic lesion was detected in 13 out of 15 elbows. The main reported ultrasonographic lesions were joint effusion (10/15 elbows) and an abnormal shape of the medial coronoid process (irregular, ill-defined or fragmented) (9/15).

CONCLUSION

 Ultrasonography can be a helpful additional diagnostic tool to confirm medial coronoid process disease of the elbow joint before performing arthroscopy in unclear cases. Further studies will be needed to evaluate the use of higher frequency transducers and determine if it could improve the diagnostic value of ultrasonography.

Radiographic determination of humeroradial, humeroulnar, and radioulnar subluxation indices to quantify elbow incongruence in dogs confirmed to have medial coronoid disease

Medial coronoid disease and elbow incongruence are common orthopedic problems causing forelimb lameness in large breed dogs. Therefore, the objective of this retrospective clinical study is to radiographically quantify the incongruity of humeroradial, humeroulnar, and radioulnar joints in dogs with confirmed medial coronoid disease compared to controls. Sixty-six (93 elbows) control and 73 (113 elbows) diseased Labrador and Golden Retrievers were enrolled. Our objective was achieved by measuring the central humeroradial, humeroulnar, and radioulnar distances and calculating the corresponding subluxation index of each joint on the extended mediolateral elbow radiograph. The traditional radioulnar step was also measured on the same mediolateral projection. Variables were compared between control and diseased groups, and the significance level was P < .05. The central humeroradial, humeroulnar, and radioulnar distances and corresponding subluxation indices increased significantly (P ≤ .007) in elbows with confirmed medial coronoid disease compared to controls. Radioulnar step increased significantly (P < .0001) in diseased elbows. Elbow incongruence, manifested by increased humeroradial, humeroulnar, and radioulnar subluxation indices, appeared to be consistent with medial coronoid disease in Labrador and Golden Retrievers. An elbow with a humeroradial, humeroulnar, or radioulnar subluxation index >0.15, 0.10, or 0.14, respectively, or radioulnar step >1.4 mm, is more likely to be incongruent and may have a concomitant coronoid disease. However, future validation of the reported measurements is still warranted.

Assessment of medial coronoid disease in 180 canine lame elbow joints: a sensitivity and specificity comparison of radiographic, computed tomographic and arthroscopic findings

Background

Diagnostic imaging is essential to assess the lame patient; lesions of the elbow joint have traditionally been evaluated radiographically, however computed tomography (CT) has been suggested as a useful technique to diagnose various elbow pathologies. The primary objective of this study was to determine the sensitivity and specificity of CT to assess medial coronoid disease (MCD), using arthroscopy as gold standard. The secondary objective was to ascertain the radiographic sensitivity and specificity for MCD compared with CT.

Methods

For this study 180 elbow joints were assessed, of which 141 had been examined with radiography, CT and arthroscopy; and 39 joints, had radiographic and CT assessment. Sensitivity and specificity were calculated for CT and radiographic findings using available statistical software.

Results

Sensitivity and specificity of CT using arthroscopy as gold standard resulted in high values for sensitivity (100 %) and specificity (93 %) for the assessment of MCD. For the radiographic evaluation, a sensitivity of 98 % and specificity of 64 - 69 % using CT as the technique of reference, were found.

Discussion

These results suggest that in case of doubt during radiographic assessment, CT could be used as a non-invasive technique to assess the presence of MCD.

Conclusion

Based on the high sensitivity and specificity obtained in this study it has been considered that CT, rather than arthroscopy, is the preferred noninvasive technique to assess MCD lesions of the canine elbow joint.

Topographic bone density of the radius and ulna in greyhounds and labrador retrievers with and without medial coronoid process disease

OBJECTIVE

To quantify, using computed tomography (CT), cross-sectional ulnar bone density (UBD), and regional radial bone density (RRBD) at the level of the medial coronoid process (MCP) in elbows with and without medial coronoid process disease (MCPD) and with and without fragmentation of MCP (FCP).

STUDY DESIGN

Retrospective clinical case-control and ex vivo study.

SAMPLE POPULATION

Labrador Retriever elbows (n = 54) and normal cadaveric Greyhound elbows (11) undergoing elbow CT.

MATERIALS AND METHODS

Labrador Retriever elbows were divided into 2 groups: (1) clinically unaffected and (2) MCPD-affected elbows. This 2nd group was subdivided based on the presence of a displaced FCP. UBD was measured linearly, in Hounsfield units (HU) across the widest part of the ulna incorporating the MCP. The radial head was divided into 6 zones, with mean RRBD (HU) calculated for each group.

RESULTS

MCPD-affected Labrador Retriever elbows had significantly lower UBD within the MCP with a higher UBD in the cranial ulnar medulla. Lower RRBD was also seen in the radial head adjacent to the MCP in MCPD-affected Labrador Retriever elbows with FCP compared with Labrador Retriever elbows without FCP. Greyhounds had consistently lower RRBD and UBD at the apex of the MCP compared with clinically unaffected Labrador Retriever elbows.

CONCLUSIONS

Our results suggest a caudolateral load-transfer shift through the ulna in MCPD-affected elbow joints, unloading the MCP. Changes in regional radial head bone density suggest that the radial head is involved in the pathogenesis of MCPD.

Computed tomography of canine elbow joints affected by primary and concomitant flexor enthesopathy

Flexor enthesopathy is an important differential diagnosis for elbow lameness in dogs. The disorder can be a primary cause of elbow lameness or concomitant with other elbow pathology. Since treatment differs for primary and concomitant forms of flexor enthesopathy, a noninvasive method for distinguishing between them is needed. In the current prospective study, computed tomographic (CT) examination was performed before and after IV injection of contrast in 17 dogs with primary flexor enthesopathy, 24 dogs with concomitant flexor enthesopathy, 13 dogs with elbow dysplasia, and seven normal dogs. Dogs were assigned to groups based on results of clinical examination and at least three other imaging modalities. Computed tomographic lesions consistent with flexor enthesopathy were found in all clinically affected joints with primary flexor enthesopathy and in 29 of the 30 clinically affected joints with concomitant flexor enthesopathy. Those lesions were not found in sound elbows or joints affected by elbow dysplasia. Flexor lesions detected in dogs with primary flexor enthesopathy were not significantly different from those detected in dogs with the concomitant form. Findings indicated that CT can be applied to detect flexor enthesopathy, but a distinction between the primary and concomitant forms was not always possible. Authors recommend the use of multiple diagnostic techniques for treatment planning in affected dogs.

Anatomical study of fibrous structures of the medial aspect of the canine elbow joint

Forces exerted by fibrous structures on the medial aspect of the canine elbow joint have been reported to be involved in elbow pathology. The purpose of this paper is to assess the relationships of the ligamentous and muscular structures of this region of the canine elbow joint, and how they relate to the medial coronoid process. Six cadavers of adult German shepherd cross-breed dogs were used in this study to make intra-articular and vascular injections of this region. Some joints were dissected and some were frozen to saw sagittal or dorsal cryosections to assess the relationships of the myotendinous structures. The brachialis muscle tendon passed through the division of the bicipital tendon of insertion which formed a fibrous tendon sheath that was reinforced by the oblique ligament. The biceps' brachii's main insertion is the radial tuberosity where it inserts along with the cranial branch of the oblique ligament and the cranial branch of the medial collateral ligament. Rotational and compression forces exerted by the insertion of the biceps brachii-brachialis tendon complex onto the ulna might influence medial coronoid disease. Therefore, sectioning these tendons could be considered as a treatment for medial coronoid disease.

Computed tomography of ununited anconeal process in the dog

OBJECTIVE

The purpose of this study was to describe computed tomography (CT) features of the ununited anconeal process and relate them with the following elbow dysplasia signs: medial coronoid disease, medial humeral condyle changes, osteoarthritis (OA), and radioulnar incongruence.

METHODS

Computed tomographic images of dogs older than six months with an ununited anconeal process were evaluated (n = 13). Ununited anconeal process features were described as being complete or incomplete, and the degree of displacement, volume, and presence of cysts and sclerosis were also evaluated. Medial coronoid disease was defined as an irregular medial coronoid process shape, presence of sclerosis and fragmentation. Medial humeral condyle changes were defined as subchondral bone flattening, lucencies, and sclerosis. Osteoarthritis was graded depending on the osteophytes size. Radioulnar incongruence was measured on a sagittal view at the base of the medial coronoid process.

RESULTS

Eleven elbows had a complete and two had an incomplete ununited anconeal process. All ununited anconeal processes had cystic and sclerotic lesions. Seven ununited anconeal processes were displaced and six were non-displaced. Mean ununited anconeal process volume was 1.35 cm3 (0.61 cm³ - 2.08 cm³). Twelve elbows had signs of medial coronoid disease (4 of them with a fragmented medial coronoid process), and one elbow did not show any evidence of medial coronoid disease. Ten elbows had medial humeral condyle changes. One elbow had grade 1 OA, seven elbows had grade 2, and five elbows grade 3. All elbows had radioulnar incongruence: three elbows had a negative and 10 elbows had a positive radioulnar incongruence. Mean radioulnar incongruence was 1.49 mm (0.63 mm - 2.61 mm). Computed tomographic findings were similar in the majority of the elbows studied: complete ununited anconeal processes with signs of medial coronoid disease, positive radioulnar incongruence, high grade of OA, sclerotic medial humeral condyle changes, and large ununited anconeal process volumes.

CLINICAL SIGNIFICANCE

Incomplete small ununited anconeal process volumes could be associated with a lower incidence of medial coronoid disease or medial humeral condyle changes. We recommend performing preoperative CT of elbows with an ununited anconeal process to evaluate concurrent lesions.

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.

Topographic and age-dependent distribution of subchondral bone density in the elbow joints of clinically normal dogs

OBJECTIVE

To investigate topographic and age-dependent adaptation of subchondral bone density in the elbow joints of healthy dogs by means of computed tomographic osteoabsorptiometry (CTOAM). Animals-42 elbow joints of 29 clinically normal dogs of various breeds and ages.

PROCEDURES

Subchondral bone densities of the humeral, radial, and ulnar joint surfaces of the elbow relative to a water-hydroxyapatite phantom were assessed by means of CTOAM. Distribution patterns in juvenile, adult, and geriatric dogs (age, < 1 year, 1 to 8 years, and > 8 years, respectively) were determined and compared within and among groups.

RESULTS

An area of increased subchondral bone density was detected in the humerus distomedially and cranially on the trochlea and in the olecranon fossa. The ulna had maximum bone densities on the anconeal and medial coronoid processes. Increased bone density was detected in the craniomedial region of the joint surface of the radius. A significant age-dependent increase in subchondral bone density was revealed in elbow joint surfaces of the radius, ulna, and humerus. Mean subchondral bone density of the radius was significantly less than that of the ulna in paired comparisons for all dogs combined and in adult and geriatric, but not juvenile, dog groups.

CONCLUSIONS AND CLINICAL RELEVANCE

An age-dependent increase in subchondral bone density at the elbow joint was revealed. Maximal relative subchondral bone densities were detected consistently at the medial coronoid process and central aspect of the humeral trochlea, regions that are commonly affected in dogs with elbow dysplasia.

Fragmented coronoid process in the dog: a heritable disease

Fragmented coronoid process (FCP) is one of the main diseases associated with elbow dysplasia. FCP is often diagnosed in medium-to-large breed dogs with front leg lameness, for instance in Rottweilers, Labrador Retrievers and Bernese Mountain dogs. Dogs with FCP develop osteoarthrosis of the elbow joint despite conservative or surgical treatment. Although FCP is considered a hereditary condition, the gene or genes causing FCP have yet to be identified. This article provides an overview of different aspects of FCP, including elbow joint development, hypotheses about disease pathogenesis, the genetic background of FCP, and genetic methodology to identify gene or genes responsible for FCP.

Diagnostic imaging of canine elbow dysplasia: a review

Canine elbow dysplasia (CED) is a common developmental disorder of the cubital joint of dogs. CED is comprised of fragmented medial coronoid process (FMCP), ununited anconeal process (UAP), osteochondrosis (OC), and elbow incongruity. Multiple imaging modalities have been used to assess this complex of disorders and the severity of the pathologic changes. Radiography has been used as a surveying tool for assessment of CED for many years. Recently, alternate techniques and modalities have expanded our knowledge of CED and our clinical approach to this disorder. Nuclear medicine has been used to aid in localizing lameness to the elbow joint. Ultrasonography has proven helpful for imaging the soft tissue structures adjacent to the joint as well as superficial bone abnormalities, including visualization of FMCP. Computed tomography and magnetic resonance imaging are advanced imaging modalities that allow visualization of the elbow in multiple planes and into three-dimensional reconstructions, thus allowing lesions to be more accurately and comprehensively visualized. Assessment of elbow incongruity in particular has been benefitted by these advanced imaging techniques because of the importance of sagittal and dorsal plane imaging and reconstructions for accurately determining the relationships between radial and ulnar articular surfaces. Comparative studies using multiple techniques and imaging modalities with correlation to reference standards and patient outcomes will be vital to continued progress in this area.