MSD Manual

Please confirm that you are a health care professional

honeypot link

Elbow Dysplasia in Dogs

(Ununited Anconeal Process, Fragmented Medial Coronoid Process, Osteochondrosis of the Humeral Condyle)


Joseph Harari

, MS, DVM, DACVS, Veterinary Surgical Specialists, Spokane, WA

Last full review/revision Nov 2020 | Content last modified Nov 2020
Topic Resources

Ununited Anconeal Process

This results when there is separation of the ossification center of the anconeal process from the proximal ulnar metaphysis. Fusion should be completed by 5–6 months of age. The fracture is postulated to result from a biomechanical imbalance of force and movement in the rapidly growing elbow. Initially, the anconeal process is connected to the ulna by a bridge of fibrous tissue, which fragments to form a pseudoarthrosis, and the elbow becomes unstable. This joint laxity continues to damage the articular cartilage, and secondary osteoarthritis results. A hereditary basis has been implicated but not proved.

Lameness develops insidiously between 4 and 8 months of age; however, some bilateral cases may not be diagnosed until dogs are >1 year old. Affected elbows may deviate laterally, and the range of motion is restricted. Advanced cases have osteoarthritis, joint effusion, and crepitus. Clinical signs are suggestive, and the diagnosis is confirmed by radiography Diagnostic Imaging of Animals Radiography (generation of transmission planar images) is one of the most commonly used diagnostic tools in veterinary practice even though other imaging modalities such as ultrasonography,... read more Diagnostic Imaging of Animals . A lateral radiograph of the elbow in the flexed position allows visualization of the ununited process. Both elbows should be examined because the condition can be bilateral.

Fragmentation of the Medial Coronoid Process

Osteochondrosis of the Medial Humeral Condyle

This results from a disturbed endochondral fusion of the epiphysis of the medial epicondyle with the distal end of the humerus. The exact cause is unknown, but because the carpal and digital flexors originate from the ventral aspect of this structure, it may represent an epiphyseal avulsion. It results in pain on flexion of the elbow or deep digital palpation and is accompanied by soft-tissue swelling. Radiographically, radiodense structures have been seen caudal and distal to the area of the medial epicondyle.


Early surgical treatment is recommended before degenerative joint disease Degenerative Arthritis in Dogs and Cats Degenerative joint disease, ventrodorsal projection, characterized by irregular bone margins in the joint. Degenerative joint disease, lateral projection, characterized by irregular bone margins... read more Degenerative Arthritis in Dogs and Cats develops. For fragmentation of the medial coronoid process, a medial arthrotomy or arthroscopy is performed and the fragmented process removed. For ununited anconeal process Ununited Anconeal Process Ununited anconeal process, characterized by separation or cleavage of the bone tip from the proximal ulna. Elbow dysplasia is a generalized incongruency of the elbow joint in young, large, rapidly... read more Ununited Anconeal Process , either a lateral arthrotomy is performed and the ununited process removed, or a midshaft ulnar osteotomy is performed to relieve asynchronous growth and result in union of the process. Reattachment of the process by screw fixation is also an option. For osteochondrosis Osteochondrosis in Dogs Osteochondrosis of the shoulder in a 5-month-old Irish Wolfhound, characterized by subchondral bone lucency and flattening of the caudal humeral head. Osteochondrosis of the stifle in a dog... read more Osteochondrosis in Dogs , the subchondral bone lesion is curetted to stimulate fibrocartilage formation. Transplantation of cartilage plugs in lieu of curettage has recently been described. Prognosis after surgery is good if degenerative joint disease has not developed in the joint. Aspirin or NSAIDs Nonsteroidal Anti-inflammatory Drugs The importance of pain management and the use of NSAIDs in animals has increased dramatically in recent decades, with use of NSAIDs in companion animals being routine. NSAIDs have the potential... read more Nonsteroidal Anti-inflammatory Drugs (eg, carprofen, deracoxib, firocoxib, meloxicam, tepoxalin) can be used to reduce pain and inflammation Pathophysiology of Inflammation The initial inflammation phase consists of three subphases: acute, subacute, and chronic (or proliferative). The acute phase typically lasts 1–3 days and is characterized by the five classic... read more . Joint-fluid modifiers (glycosaminoglycans, hyaluronic aid) and acupuncture may be useful, although most reports are anecdotal. Joint injection with mesenchymal cells or platelet-rich plasma has also been described; reports are inconclusive.

For More Information

Others also read
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Test your knowledge

In all animals, the motor unit of skeletal muscle consists of the motor neuron, the neuromuscular junction, and muscle fibers. Muscle dysfunction—such as ataxia, paresis, or paralysis—most commonly originates in which of the following locations?
Become a Pro at using our website 

Also of Interest

Become a Pro at using our website