Lecture 6 1/30/25 Flashcards
What are the differentials for disorders of the elbow joint?
-elbow luxation
-fragmented coronoid process
-osteochondritis dissecans of the medial aspect of humeral condyle
-ununited anconeal process
-ununited medial humeral epicondyle
-trauma/fracture
What are the components of elbow dysplasia?
-fragmented medial coronoid process
-OCD of the medial condyle of the humerus
-ununited anconeal process
-elbow incongruity
What is a fragmented medial coronoid process?
separation of medial coronoid process from the ulna caused by microfractures
What is ununited anconeal process?
separation of ossification enter of the anconeal process
What is elbow incongruity?
incongruity within the joint as a result of abnormal development of the radius, ulna, and/or humerus
What is the typical signalment and signs of elbow dysplasia?
-large breed dogs
-signs starting at 4-8 months; lameness at middle age
-typically male
-affects both elbows 30-70% of time
-intermittent lameness, decreased ROM, and joint swelling
-subtle gait changes/circumduction of the affected limb(s)
-osteoarthritis development
What is assessed when palpating the elbow?
-effusion in the craniomedial and caudolateral compartments
-ability to extend and flex joint
Which movement/pain is associated with ununited anconeal process (UAP)?
-pain on hyperextension
Which movements/pains are associated with OCD of the elbow or fragmented coronoid process (FCP)?
-pain on flexion
-pain on internal and external rotation with digital pressure applied medially to joint
What are the characteristics of radiographs for assessment of the elbow dysplasia?
-extreme flexed medio-lateral view is best for diagnosing degenerative change
-rads are required by the OFA and recommended by the International Elbow Working Group
-mostly interested in the appearance of the anconeal process of the ulna
What are the characteristics of fragmented medial coronoid process?
-may be bilateral
-more common in males
-clinical signs of lameness begin at 5-8 months
Which breeds most commonly present with fragmented medial coronoid process?
-basset hound
-bernese mountain dog
-bullmastiff
-chow chow
-german shepherd
-gordon setter
-irish wolfhound
-mastiff
-newfoundland
-retrievers
-rottweiler
-saint bernard
What causes pain in dogs with fragmented medial coronoid process?
pressure applied to the loose fragment by the radius
What is the pathophysiology of fragmented medial coronoid process?
-recently identified to be caused by microfractures
-often presents with full thickness cartilage wearing/”kissing” lesions on humerus
-incongruity between ulna and radius may contribute
-often occurs bilaterally
-high heritability rate
-environmental factors like diet and mechanical overload also contribute
What are the ancillary tests for fragmented medial coronoid process?
-radiographs: looking for secondary changes
-CT
-diagnostic arthroscopy: gold standard
What are the characteristics of radiographs as a diagnostic tool for fragmented medial coronoid process?
-want to take lateral, flexed lateral, VD, and oblique views
-signs are often nonspecific and typically reflect secondary OA changes
-may see blunting in the “beak” region of the MCP
What are the signs to look for on radiographs that may indicate FCP?
-osteophytes on anconeal process
-sclerosis around trochlear notch of ulna
-blunting of the MCP
What are the characteristics of FCP treatment?
-surgical treatment recommended as soon as diagnosis is made
-better prognosis with surgery if FCP is removed prior to development of advanced OA
-can perform an arthrotomy with muscle splitting or an arthroscopy
-must manage elbow for rest of dog’s life
What are the steps of FCP surgery?
-removal of the fragment
-evaluation for incongruity; possible removal of base of MCP to prevent contact with humeral condyle
-removal of loose or impinging osteophytes
-evaluation for concurrent OCD lesions on humeral condyle
What is the purpose of an ulnar ostectomy procedure?
helps to treat elbow incongruity and allows for the ulna to be pulled into proper position
What are the characteristics of the PAUL procedure?
-for mild cases of elbow incongruity
-unloads the medial compartment
-shifts weight bearing to lateral compartment
When is a sliding humeral osteotomy performed?
severe cases of elbow incongruity
What is a CUE procedure?
partial elbow replacement
What are the characteristics of aftercare and prognosis for elbow surgery?
-soft padded bandage over site of arthrotomy if performed
-leash walks only for 4 weeks
-NSAIDs, adequan, and nutraceuticals used
-alteration of diet/weight loss
-somewhat guarded prognosis; early treatment better
-OA will progress
What are the characteristics of OCD of the medial humeral condyle?
-occurs at medial humeral trochlear ridge
-caused by failure of endochondral ossification of the epicondylar-epiphyseal complex
-may be secondary to ulnar overgrowth and elbow incongruity; places abnormal stress on medial trochlear ridge
What is the typical signalment for OCD of the medial humeral condyle?
-males more likely than females
-signs begin at 5-8 months of age
Which breeds typically present with OCD of the medial humeral condyle?
-chow chow
-german shepherd
-great dane
-rottweiler
-newfoundland
-retrievers
What are the components of the multifactorial etiology of OCD of the medial humeral condyle?
-breed-related
-consistent age of onset
-associated with musculoskeletal development/growth
-consistent clinical course
-genetic background suspected
-rapid growth, trauma, and imbalanced nutrition also implicated
What are the ancillary tests for OCD of the medial humeral condyle?
-radiographs
-CT
-diagnostic arthroscopy: gold standard
What are the characteristics of treatment for OCD of the medial humeral condyle?
-surgical removal of flap if clinically lame; possible to do via arthroscopy
-must remove flap early; erosion can lead to synovitis and arthritis
-often occurs with FCP; need to treat both
-OA invariably progresses
-OA may be the cause of lameness in older dogs rather than flap
What is the aftercare and prognosis for OCD treatment?
-leash walks only for 2 weeks
-good prognosis when flap is removed in dogs less than 8-9 months of age
-secondary OA changes makes surgery in older dogs less favorable
What are the characteristics of ununited anconeal process?
-failure of anconeal process to unite with olecranon
-most common in large/giant breeds and chondrodystrophic breeds
-normal growth plate closure occurs around 5-6 months; persistence of open growth plate is pathologic
-more common in males
Which breeds most commonly develop UAP?
-german shepherd*
-basset hound*
-bernese mountain dog
-chow chow
-mastiff
-newfoundland
-pomeranian
-retrievers
-rottweiler
-saint bernard
-sharpei
What are the characteristics of UAP diagnosis?
-typically diagnosed between 5 and 8 months of age
-clinical signs may not present until after a jumping incident or until degenerative changes occur
-insidious lameness
-soft tissue swelling
-rare for dog to have full function of limb; decreased ROM and circumduction of limb are common
What is the treatment for UAP?
-surgical removal of loose fragment
-ulnar osteotomy in early cases
-potential for primary fixation with a screw, but more likely to fail in later cases
What are the characteristics of aftercare and prognosis for UAP treatment?
-soft padded bandage for 7 days
-leash walks only for 4 weeks
-continue to treat OA
-low impact activity and swimming
-fair prognosis for acute pain reduction
-degenerative OA will still occur
What are the characteristics of ununited medial humeral condyle?
-unknown cause
-trauma may cause bone to be present in the soft tissue of flexor muscles
What can cause elbow incongruity?
-breed-related
-trauma to the growth plate(s)
