Common conditions of the elbow Flashcards
List 5 developmental conditions of the elbow
Medial coronoid disease (MCD)
Ununited anconeal process (UAP)
Osteochondritis dissecans (OCD)
Elbow Incongruency
Humeral Intracondylar Fissure (HIF)
List 3 traumatic conditions of the elbow
Condylar fractures
Proximal ulna/radius fractures
Luxation/collateral ligament rupture
List 2 degenerative conditions of the elbow
Flexor enthesiopathy
Osteoarthritis
How might the subjective gait analysis highlight an elbow condition?
Shortened stance phase
Head lift during stance phase on affected limb
Describe the possible findings on the clinical exam of a patient with elbow disease
Muscle atrophy
Joint effusion
Periarticular thickening (chronic)
Pain/crepitus on elbow manipulation
Assess range of motion
What should be done before proceeding with diagnostic imaging?
Accurate localisation of lameness
Describe the anatomical features of the normal elbow
Humerus
Radius
Ulnar
Coronoid process
Anconeal process
Olecranon
Lateral and medial epicondyle
Humeral condyle
How is the anconeal process visualised on radiography?
Flexed mediolateral projection
Describe arthroscopy of the elbow joint
- Most sensitive modality
- Requires equipment and expertise
- Can assess cartilage: not possible with radiography or computed tomography
- Allows concurrent diagnostics and surgical intervention
Describe arthrocentesis of the elbow
- Simple and quick diagnostic test
- Aseptic preparation of skin
- Typically use 1” – 1.5” 21g - 23g hypodermic needle
- Collect sample in EDTA
- Prepare smear on a slide
Where are the landmarks for arthrocentesis of the elbow?
Immediately distal to medial or lateral epicondyle
Caudolaterally along anconeal process
Which features of synovial fluid can be analysed?
Volume
Colour/turbidity
Total cell counts
Differential cell counts
Cytology
How might osteoarthritis appear on cytology compare to IMPA?
OA – low cellularity mononuclear cells predominate
IMPA/BIA – Highly cellular with neutrophilic inflammation
In which patients is elbow dysplasia most commonly seen?
A VERY common disease of popular medium-large breed dogs
Labradors, Rottweilers, Bernese Mountain Dogs
Name the 4 diseases defined by IEWG that come under the term elbow dysplasia
- Fragmentation of the medial aspect of the coronoid process/medial coronoid disease
- OCD of the medial aspect of the humeral condyle
- Ununited anconeal process
- Elbow incongruity
What are the two causes of elbow incongruency?
Short radius
Short ulna syndrome
Describe the features of a short radius
Premature closure of the proximal or distal radial growth plate
Contribution to medial coronoid disease
Describe the features of short ulna syndrome
Premature closure of the distal ulna physis
Contribution to medial coronoid disease and ununited anconeal process
Describe how elbow incongruency is treated
Bone Lengthening Procedures:
Osteotomies to improve congruency
Needs to be carried out in young dogs
Most common: short ulna syndrome
Describe the factors contributing to medial coronoid disease
Genetics
Nutrition
Biomechanics - Sites of greatest load
Gender - Males 2:1 females
Describe the pathophysiology of medial coronoid disease
- Incongruency:
- Short radius documented in 45% of elbows with MCD
- Short ulna documented in 14% of elbows with MCD - Mechanical overload:
- Disturbance of normal endochondral ossification
- Weak points between retained cartilage and subchondral bone
- Subsequent fissure and fracture formation
Describe diagnostic imaging of medial coronoid disease
Do not expect to see the fragment on standard radiographic views
- can look normal
- may see osteophyte formation on the radial head and caudal aspect of the anconeal process
How can medial coronoid disease be diagnosed?
CT scan
Arthroscopy
Describe conservative management of medial coronoid disease
- Analgesia
- NSAIDs
- Paracetamol/codeine
- Amantadine, gabapentin, tramadol … - Nutraceuticals
- Weight control
- Controlled exercise
- Physio/hydrotherapy
Describe surgical management of medial coronoid disease
- Fragment removal
- Subtotal coronoidectomy
- Biceps ulnar release procedure (BURP)
- Load-transfer procedures
- Bone resurfacing procedures
- Total elbow replacement (TER)
- Elbow arthrodesis
What are the clinical signs of osteochondritis dissecans?
Lameness
Joint effusion
How is OCD diagnosed?
Radiography
Arthroscopy
Arthrotomy
Describe the pathogenesis of OCD
- Interruption to the blood supply going to cartilage
- So cartilage doesn’t become bone
- Instead get the formation of a cartilage cleft within the growing bone
- Cartilage derives its nutrition from joint fluid not blood supply so when there is more cartilage its harder for the joint fluid to diffuse
- Area of cartilage becomes necrotic and mechanically unstable -> fissure formation
How is OCD treated?
- Cartilage flap removal + debridement of subchondral bone
- Osteochondral Autogenous Transfer (OATS) = Transfer of host osteochondral graft from unaffected site
- Synthetic osteochondral transplant
In which patients is ununited anconeal process most commonly seen?
Breeds predisposed include Bassets, GSDs, BMD, mastiffs
Bilateral in 20% - 35% of cases
Male 2:1 Female
Describe the pathogenesis of ununited anconeal process
Secondary centre of ossification only present in 16% of dogs
Joint incongruency (short ulna)
How will ununited anconeal process present on clinical exam?
Thoracic limb lameness:
- Chronic
- Exacerbated by exercise
Joint effusion larger than that seen with MCD
How will ununited anconeal process present on radiography
Flexed mediolateral view
Consolidation of AP not present until between 16 & 20 weeks in GSD
Earlier in Greyhounds (14 – 15 weeks)
How is ununited anconeal process treated?
Conservative if mild lameness (may be especially true with Bassets)
Surgery
Describe surgery for ununited anconeal process
- Removal of anconeus - Only considered if other treatment options failed as causes instability - Older dogs with severe OA
- Anconeal process reattachment
- Ulnar osteotomy
- Proximal ulnar osteotomy + reattachment
How can you differentiate Incomplete ossification of the humeral condyle (IOHC) from a Humeral Intracondylar Fissure
Humeral condyle formed from two separate centres of ossification:
Fusion typically occurs at ~12 weeks of age
Adult onset of clinical signs - ?stress fracture aetiology
How will a patient with a humeral intercondylar fissure present?
Either:
- Acute onset lameness typically secondary to fracture
- Chronic thoracic limb lameness
- Asymptomatic
How will a humeral intercondylar fissure present on diagnostic imaging?
Radiography: Large fissures can be seen on standard craniocaudal radiographic projections
Computed tomography:
- More sensitive than radiography
- Allows 3D-Multiplanar Reconstruction
What are the surgical indications for humeral intercondylar fissure?
Persistent lameness in the affected limb
Early remodeling can be detected on the lateral epicondylar crest
