E. de Bakker

Medial humeral epicondylar lesions in the canine elbow: a review of the literature

A calcified fragment near the medial epicondyle of the humerus was originally described as an ununited medial epicondyle in 1966. Since then several papers reported similar lesions as a cause of elbow lameness. The aetiology and clinical significance of those lesions is poorly known. This paper gives an overview of the veterinary and human literature in an attempt to explain the aetiology and to suggest a diagnostic protocol and treatment plan.

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.

Primary flexor enthesopathy of the canine elbow: imaging and arthroscopic findings in eight dogs with discrete radiographic changes

OBJECTIVE To describe the radiographic, ultrasonographic, computed tomography (CT), magnetic resonance imaging (MRI), and arthroscopic findings in eight dogs with elbow lameness caused by primary flexor enthesopathy. STUDY DESIGN Clinical study. ANIMALS Eight client-owned dogs. METHODS In all dogs, lameness was localized to the elbow by clinical examination. Radiographic examination, ultrasound, CT and MRI were performed prior to arthroscopy. In seven dogs, surgical treatment and subsequent histopathology were performed. RESULTS Primary enthesopathy of the medial epicondyle was diagnosed in eight dogs (13 joints) by combining the minimal radiographic changes with specific ultrasonographic, CT, MRI and arthroscopic findings at the medial epicondyle. In all joints, any other pathology could be excluded. Histopathology of the affected tissue revealed degeneration and metaplasia in the flexor muscles. CONCLUSIONS Primary flexor enthesopathy at the medial epicondyle is an unrecognized condition and is a possible cause of elbow lameness in the dog. Diagnosis is based on specific imaging and arthroscopic findings. CLINICAL RELEVANCE The most important cause of elbow lameness in dogs is medial coronoid disease. Often this condition presents with minimal radiographic and arthroscopic changes. In these cases, primary enthesopathy of the medial epicondyle should be considered as a differential diagnosis, in order to make the correct treatment decision.

Primary and concomitant flexor enthesopathy of the canine elbow

OBJECTIVES To report the characteristics of two types of flexor enthesopathy, primary and concomitant, based on different diagnostic techniques. MATERIALS AND METHODS Over a period of three years a prospective study was performed on dogs admitted for the complaint of elbow lameness. Based on the radiographic findings a selection of dogs underwent a complete series of different imaging modalities. With each technique, pathology of the medial epicondyle and the presence of other elbow disorders were recorded. All joints with signs of flexor pathology apparent with at least three techniques were selected. A distinction was made between primary and concomitant flexor enthesopathy based on the absence or presence of other elbow disorders. RESULTS Primary flexor enthesopathy was diagnosed in 23 joints and concomitant flexor enthesopathy in 20 joints. In 43% of the joints with primary and in 75% of the joints with concomitant flexor enthesopathy, pathology at the medial epicondyle was demonstrated by all techniques. All joints with concomitant flexor enthesopathy had a diagnosis of medial coronoid disease, osteochondritis dissecans, or both. CLINICAL SIGNIFICANCE Pathology at the medial epicondyle is a sign of flexor enthesopathy. It may be present as the only sign in a joint with primary flexor enthesopathy or concomitant with other elbow pathology. In both groups flexor lesions can be demonstrated with different imaging techniques. The distinction between the primary and concomitant form is based on the presence or absence of other elbow pathology, mainly medial coronoid disease. Recognizing both types is important for a correct treatment decision.

Arthroscopic treatment of fragmented coronoid process with severe elbow incongruity. Long-term follow-up in eight Bernese Mountain Dogs.

The purpose of this study was to investigate the long-term treatment results of fragmented coronoid process (FCP) in joints with a radio-ulnar step greater than 3 mm. Treatment of these patients only consisted of fragment removal, without correction of the incongruity. The eight Bernese Mountain Dogs (11 joints) included in this study showed obvious clinical signs of elbow disease and were diagnosed with severe elbow incongruity and concomitant FCP in the time period from 1999-2003. At that time, elbow radiography, computed tomography, and arthroscopy were performed. The mean follow-up period was 5.6 years. The follow-up consisted of a telephone questionnaire combined with a clinical and radiographic re-evaluation at our clinic. The questionnaire revealed that all dogs were either free of lameness or only lame following heavy exercise. One dog sporadically required medication after heavy exercise. The owner satisfaction rate was 100%. The clinical re-evaluation did not reveal any signs of pain or lameness in all cases. Range-of- motion was decreased in nine of the 11 elbows. Radiographs revealed an increase in severity of osteoarthritis in every case.In this case series, arthroscopic fragment removal without treatment of incongruity was demonstrated to be a valuable treatment option and may provide a satisfactory long-term outcome.

The use of planar bone scintigraphy and HiSPECT for diagnosis of primary and concomitant flexor enthesopathy in the canine elbow

OBJECTIVE To investigate the possibilities and limitations of planar bone scintigraphy and high resolution single photon emission computed tomography (HiSPECT) to diagnose flexor enthesopathy and to distinguish primary flexor enthesopathy from the concomitant form. MATERIALS AND METHODS A prospective study of 46 dogs with primary flexor enthesopathy, concomitant flexor enthesopathy, medial coronoid disease, and normal elbows was performed. All dogs underwent planar bone scintigraphy and HiSPECT imaging. The obtained images were visually scored for increased radiopharmaceutical uptake in the medial humeral epicondylar and medial coronoid process region using a score from 1-3. RESULTS Planar bone scintigraphy demonstrated increased radiopharmaceutical uptake in all diseased elbow joints, except for one. HiSPECT demonstrated increased radiopharmaceutical uptake of the medial humeral epicondyle in nearly all clinically affected joints with primary and concomitant flexor enthesopathy. Additional uptake of the medial coronoid process was recorded in all clinically affected joints with concomitant flexor enthesopathy and in six out of 18 with primary flexor enthesopathy. No difference in intensity of the uptake was noticed. CLINICAL SIGNIFICANCE Planar bone scintigraphy allows the attribution of lameness to the elbow joint in cases of primary flexor enthesopathy with minimal or even absent radiographic changes. The more detailed HiSPECT enables the localization of pathology within the elbow joint and is a sensitive technique to detect flexor enthesopathy. However HiSPECT is insufficient to distinguish primary from concomitant flexor enthesopathy.

Arthroscopic features of primary and concomitant flexor enthesopathy in the canine elbow

OBJECTIVES To investigate the possibilities and limitations of arthroscopy to detect flexor enthesopathy in dogs and to distinguish the primary from the concomitant form. MATERIALS AND METHODS Fifty dogs (n = 94 elbow joints) were prospectively studied: dogs with primary flexor enthesopathy (n = 29), concomitant flexor enthesopathy (n = 36), elbow dysplasia (n = 18), and normal elbow joints (n = 11). All dogs underwent an arthroscopic examination of one or both elbow joints. Presence or absence of arthroscopic characteristics of flexor enthesopathy and of other elbow disorders were recorded. RESULTS With arthroscopy, several pathological changes of the enthesis were observed in 100% of the joints of both flexor enthesopathy groups, but also in 72% of the joints with elbow dysplasia and 25% of the normal joints. No clear differences were seen between both flexor enthesopathy groups. CLINICAL SIGNIFICANCE Arthroscopy allows a sensitive detection of flexor enthesopathy characteristics, although it is not very specific as these characteristics may also be found in joints without flexor enthesopathy. The similar aspect of both forms of flexor enthesopathy and the presence of mild irregularities at the medial coronoid process in joints with primary flexor enthesopathy impedes the arthroscopic differentiation between primary and concomitant forms, requiring additional diagnostic techniques to ensure a correct diagnosis.

The use of the HiSPECT bone scan in canine flexor enthesopathy and coronoid pathology

In this study the use of the high resolution Micro-Single Photon Emission Tomography (HiSPECT) system with a radioactive bonemarker, (99m)Tc-oxidronate, was evaluated in dogs with coronoid pathology and/or flexor enthesopathy. Sixty-five elbows of 34 dogs were included. CT and HiSPECT were performed on all elbows, arthroscopy on 59. Tracer uptake in 8 anatomical regions was graded according to two models. Increased activity in the medial epicondylar region was associated with flexor pathology on CT (P=0.0002) and arthroscopy (P<0.0001) and increased uptake in the medial coronoid (P<0.0001) and the medial condylar area (P<0.013) with coronoid pathology. Uptake in the remaining areas was not associated with both pathologies. In conclusion, the improved resolution of the HiSPECT system allows identification of increased tracer uptake in the anatomical regions involved in coronoid pathology and flexor enthesopathy. This modality may improve the diagnostic potential of the bone scan in canine elbow disease.

Canine synovial fluid biomarkers for early detection and monitoring of osteoarthritis

Secondary, non-inflammatory osteoarthritis (OA) is a common disorder in dogs. Its silent onset prevents early diagnosis and delays treatment. Synovial fluid biomarkers can detect OA at an early stage, before the presence of radiographic signs. In addition, these local biomarkers can aid prognosis of the disease, monitor the response to treatment and can be used to assess the degree of OA. Currently three groups of canine synovial fluid biomarkers have been the focus of research: proinflammatory mediators, enzymes and their inhibitors, and extracellular cartilage degeneration products. These have been investigated in the elbow, hip and stifle joints of both normal dogs and dogs with naturally occurring and experimentally induced OA. None of these biomarkers are currently used in practice for the detection of canine OA at an early stage. A positive relationship between canine synovial fluid biomarkers and OA has been demonstrated, yet no molecular diagnostic test has been developed so far.

Assessment of specific muscle tension in dogs through functional electrical stimulation of the gastrocnemius muscle

• Experimental determination of specific muscle tension in dogs based on in vivo muscle forces