Common conditions of the elbow

Question 1

List 5 developmental conditions of the elbow

Answer 1

Medial coronoid disease (MCD)
Ununited anconeal process (UAP)
Osteochondritis dissecans (OCD)
Elbow Incongruency
Humeral Intracondylar Fissure (HIF)

Question 2

List 3 traumatic conditions of the elbow

Answer 2

Condylar fractures
Proximal ulna/radius fractures
Luxation/collateral ligament rupture

Question 3

List 2 degenerative conditions of the elbow

Answer 3

Flexor enthesiopathy
Osteoarthritis

Question 4

How might the subjective gait analysis highlight an elbow condition?

Answer 4

Shortened stance phase
Head lift during stance phase on affected limb

Question 5

Describe the possible findings on the clinical exam of a patient with elbow disease

Answer 5

Muscle atrophy
Joint effusion
Periarticular thickening (chronic)
Pain/crepitus on elbow manipulation
Assess range of motion

Question 6

What should be done before proceeding with diagnostic imaging?

Answer 6

Accurate localisation of lameness

Question 7

Describe the anatomical features of the normal elbow

Answer 7

Humerus
Radius
Ulnar
Coronoid process
Anconeal process
Olecranon
Lateral and medial epicondyle
Humeral condyle

Question 8

How is the anconeal process visualised on radiography?

Answer 8

Flexed mediolateral projection

Question 9

Describe arthroscopy of the elbow joint

Answer 9

• Most sensitive modality
• Requires equipment and expertise
• Can assess cartilage: not possible with radiography or computed tomography
• Allows concurrent diagnostics and surgical intervention

Question 10

Describe arthrocentesis of the elbow

Answer 10

• 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

Question 11

Where are the landmarks for arthrocentesis of the elbow?

Answer 11

Immediately distal to medial or lateral epicondyle
Caudolaterally along anconeal process

Question 12

Which features of synovial fluid can be analysed?

Answer 12

Volume
Colour/turbidity
Total cell counts
Differential cell counts
Cytology

Question 13

How might osteoarthritis appear on cytology compare to IMPA?

Answer 13

OA – low cellularity mononuclear cells predominate
IMPA/BIA – Highly cellular with neutrophilic inflammation

Question 14

In which patients is elbow dysplasia most commonly seen?

Answer 14

A VERY common disease of popular medium-large breed dogs
Labradors, Rottweilers, Bernese Mountain Dogs

Question 15

Name the 4 diseases defined by IEWG that come under the term elbow dysplasia

Answer 15

1. Fragmentation of the medial aspect of the coronoid process/medial coronoid disease
2. OCD of the medial aspect of the humeral condyle
3. Ununited anconeal process
4. Elbow incongruity

Question 16

What are the two causes of elbow incongruency?

Answer 16

Short radius
Short ulna syndrome

Question 17

Describe the features of a short radius

Answer 17

Premature closure of the proximal or distal radial growth plate
Contribution to medial coronoid disease

Question 18

Describe the features of short ulna syndrome

Answer 18

Premature closure of the distal ulna physis
Contribution to medial coronoid disease and ununited anconeal process

Question 19

Describe how elbow incongruency is treated

Answer 19

Bone Lengthening Procedures:
Osteotomies to improve congruency
Needs to be carried out in young dogs
Most common: short ulna syndrome

Question 20

Describe the factors contributing to medial coronoid disease

Answer 20

Genetics
Nutrition
Biomechanics - Sites of greatest load
Gender - Males 2:1 females

Question 21

Describe the pathophysiology of medial coronoid disease

Answer 21

1. Incongruency:
   - Short radius documented in 45% of elbows with MCD
   - Short ulna documented in 14% of elbows with MCD
2. Mechanical overload:
   - Disturbance of normal endochondral ossification
   - Weak points between retained cartilage and subchondral bone
   - Subsequent fissure and fracture formation

Question 22

Describe diagnostic imaging of medial coronoid disease

Answer 22

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

Question 23

How can medial coronoid disease be diagnosed?

Answer 23

CT scan
Arthroscopy

Question 24

Describe conservative management of medial coronoid disease

Answer 24

1. Analgesia
   - NSAIDs
   - Paracetamol/codeine
   - Amantadine, gabapentin, tramadol …
2. Nutraceuticals
3. Weight control
4. Controlled exercise
5. Physio/hydrotherapy

Question 25

Describe surgical management of medial coronoid disease

Answer 25

- Fragment removal - Subtotal coronoidectomy - Biceps ulnar release procedure (BURP) - Load-transfer procedures - Bone resurfacing procedures - Total elbow replacement (TER) - Elbow arthrodesis

Question 26

What are the clinical signs of osteochondritis dissecans?

Answer 26

Lameness Joint effusion

Question 27

How is OCD diagnosed?

Answer 27

Radiography Arthroscopy Arthrotomy

Question 28

Describe the pathogenesis of OCD

Answer 28

- 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

Question 29

How is OCD treated?

Answer 29

- Cartilage flap removal + debridement of subchondral bone - Osteochondral Autogenous Transfer (OATS) = Transfer of host osteochondral graft from unaffected site - Synthetic osteochondral transplant

Question 30

In which patients is ununited anconeal process most commonly seen?

Answer 30

Breeds predisposed include Bassets, GSDs, BMD, mastiffs Bilateral in 20% - 35% of cases Male 2:1 Female

Question 31

Describe the pathogenesis of ununited anconeal process

Answer 31

Secondary centre of ossification only present in 16% of dogs Joint incongruency (short ulna)

Question 32

How will ununited anconeal process present on clinical exam?

Answer 32

Thoracic limb lameness: - Chronic - Exacerbated by exercise Joint effusion larger than that seen with MCD

Question 33

How will ununited anconeal process present on radiography

Answer 33

Flexed mediolateral view Consolidation of AP not present until between 16 & 20 weeks in GSD Earlier in Greyhounds (14 – 15 weeks)

Question 34

How is ununited anconeal process treated?

Answer 34

Conservative if mild lameness (may be especially true with Bassets) Surgery

Question 35

Describe surgery for ununited anconeal process

Answer 35

1. Removal of anconeus - Only considered if other treatment options failed as causes instability - Older dogs with severe OA 2. Anconeal process reattachment 3. Ulnar osteotomy 4. Proximal ulnar osteotomy + reattachment

Question 36

How can you differentiate Incomplete ossification of the humeral condyle (IOHC) from a Humeral Intracondylar Fissure

Answer 36

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

Question 37

How will a patient with a humeral intercondylar fissure present?

Answer 37

Either: - Acute onset lameness typically secondary to fracture - Chronic thoracic limb lameness - Asymptomatic

Question 38

How will a humeral intercondylar fissure present on diagnostic imaging?

Answer 38

Radiography: Large fissures can be seen on standard craniocaudal radiographic projections Computed tomography: - More sensitive than radiography - Allows 3D-Multiplanar Reconstruction

Question 39

What are the surgical indications for humeral intercondylar fissure?

Answer 39

Persistent lameness in the affected limb Early remodeling can be detected on the lateral epicondylar crest