Fragmented coronoid process - FCP

Question 1

What is the most common dysplastic lesion of the elbow, occuring in how many percent of cases?

Answer 1

FCP, 65%

Question 2

What is the most common cause of juvenile canine forelimb lameness?

Answer 2

FCP

Question 3

What is the characteristics of FCP?

Answer 3

Fissure and fragmentation of catilage and subchondral bone in lateral aspect of medial coronoid
Erosion of cartilage - chondromalacia - exposure of subchondral bone

Question 4

Where is pathology initiated?

Answer 4

In the subchondral bone, propogating up into the articular cartilage

Question 5

What is kissing lesions?

Answer 5

Lissiong lesions - can occur on the opposing medial humeral condyle, unclear if consequence of incongruity or representing mild primary osteochondrosis of humeral condyle

Question 6

Pathogenesis?

Answer 6

Genetics
Nutrition
Excercise

Anatomic incongruity -> increased load -> FCP

Question 7

What type of anatomic incongruity can give FCP?

Answer 7

1. Radioulnar incongruity - step defect
2. Humeroulnar incongruity

Question 8

Detection of incongruity?

Answer 8

Can be challenging even with XR or CT due to being small

Question 9

What causes pain in FCP?

Answer 9

Subchondral pathology, cartilage damage, osteoarthritis, joint capsule distention, fragment/fracture of fragment

Question 10

Breed and gender of FCP?

Answer 10

Labrador retriever
Bernese mountain dog
Rottweiler
Golden retriever

Male

Question 11

Presentation of FCP?

Answer 11

4-5 months of age (or any time after this)
Unilateral or bilateral lameness with exercise intolerance, inactivity stiffness
Outrotated limb during rest and walk

Question 12

Physical examination?

Answer 12

Muscle atrophy - spina scapula
Effusion - caudolaterally
Pain on elvow extention
Pain on pronation/suppination
Pain on digital palpation of medial compartment

Question 13

Diagnosis of FCP?

Answer 13

XR
CT - gold standard
Arthroscopy - dx and tx - gold standard (in combo)

Question 14

Findings on XR?

Answer 14

Subtle ulnar notch sklerosis
Blunting of the coronoid
New bone formation on radial head and anconeal process
CrCa/Cacr: Lipping and osteophytosis in the region of the medial coronoid process and epicodyles

Question 15

Treatment?

Answer 15

Conservative: NSAID, neutraceutical, BCS control, rest
Surgical:
- Arthroscopy - fragment removement, debridement
- CUE - canine unicompartmental elbow replacement
- PAUL - prox abducting ulnar osteotomy
- SHO - sliding humeral osteotomy
- AA - Abrasion arhtroplasty
- SCO - Subtotal coronoidectomy
- DUO - dynamic ulna osteotomy
- BURP - biceps brachial ulnar release
- OATS - osteochondral autograft transfer system

Question 16

Prognosis?

Answer 16

Very individual

If FCP + severe medial compartment disease -> other surgical techniques might be required

Question 17

Late onset FCP - when does it present?

Answer 17

2-4 years old - no XR abnormalities or clinical signs as puppy

Question 18

Late onset FCP - which breeds?

Answer 18

Labrador retriever

Question 19

Late onset FCP - presentation?

Answer 19

Lameness after activity, poorly responsive to exercise restriction and analgesics
Clinical signs: Elbow pain, minimal joint effusion, thickening or discomfort

Question 20

Late onset FCP - image modality?

Answer 20

XR - mild changes
CT, arthroscopy: Fissure of medial coronoid process

Question 21

Late onset FCP - treatment?

Answer 21

Arthroscopic fragment removal