Lecture 13 - DDx of forelimb lameness in large dogs

Question 1

is the coronoid process a common site for OC?

Answer 1

no, there was a thoery that fracture of coronoid process was due to OC but this has been proven wrong!

Question 2

what is the common location for osteochondrosis desicans (OCD)?

Answer 2

humeral head

Question 3

how to do you differentiate OC from OCD on PE?

Answer 3

the dog will have a weight bearing lameness with OCD. often radiographs will NOT help you to differentiate - but more likely to notice differences on the lateral radiograph

Question 4

what is the treatment for OCD, which joint has the best response, and what is the approach?

Answer 4

tx for OCD is arthroscopy.
shoulder
craniolateral, caudolateral or caudal approach

Question 5

what is the prognosis for OCD?

Answer 5

typically excellent for a normal return of limb function following both arthrotomy and arthroscopy

Question 6

what is the leading cause of forelimb lameness in the dog? especially large breeds?

Answer 6

elbow dysplasia!

Question 7

elbow dysplasia is really an umbrella term for 3 different conditions - what are they and which one is most common?

Answer 7

1. ununited anconeal process (UAP)
2. OC/OCD of the medial humeral condyle
3. fragmented coronoid process (FCP)

Question 8

what breed do we see commonly with elbow dysplasia?

Answer 8

rottweilers - they are famous for the supinated stance

Question 9

what breeds do we commonly see with ununited anconeal process?

Answer 9

GSD and basset hounds

Question 10

how does the anconeal process normally fuse to the olecranon?

Answer 10

there is a separate center of ossification. at 4 - 5 months of age it fuses to the main body of the olecranon (normal when the animal is young)

Question 11

by what age is the anocneal process considered to be ununited to the olecranon?

Answer 11

20 weeks of age

Question 12

describe the proximal diaphyseal ulnar osteotomy

Answer 12

it is a treatment for an ununited anconeal process
if there is incongruity of the proximal raidal head (its too high) –> we raise the ulna by cutting a piece out. this relieves the pressure on the anconeal process.

Question 13

if you have a 7mo dog with an ununited anconeal process, proximal radial head. what surgical tx should you provide?

Answer 13

proximal diaphyseal ulnar osteotomy.

Question 14

OCD lesions of the humeral condyle always effects

Answer 14

the trochlea (medial portion) of the condyle

the point that articulates with the ulna

Question 15

OCD of the humeral condyle occurs most often in what breed?

Answer 15

Labrador retrievers - particularly chocolate labs

see a limping chocolate lab, this should be first on your list

Question 16

which type of elbow dysplasia is often seen in association with a fragmented cornoid process (FCP)?

Answer 16

OCD of the humeral condyle

Question 17

OCD of the humeral condyle is best seen from what view in a radiograph?

Answer 17

craniolateral-caudomedial OBLIQUE projection by about 15 degrees

allows you to highlight the medial aspect of the humeral condyle

Question 18

standard radiographic study of the elbow should include:

Answer 18

• orthogonal views
• flexed lateral view
• craniolateral caudomedial orthogonal view

Question 19

in what disease do we see diffuse microcracks in subchondral bone that is consistent with FATIGUE micordamage?

Answer 19

fragmented coronoid process - medial aspect

Question 20

what is the pathophysiology behind the fragmented coronoid process (FCP)? how does it occur?

Answer 20

most likely from a subtle defect in the overall shape of the trochlear notch of the ulna that creates repetitive overloading on the medial coronoid process that eventually results in fragmentation

Question 21

is arthritis in the dog primary or secondary?

Answer 21

arthritis in the dog is SECONDARY to some underlying cause.

Question 22

what is panosteitis and what part of the bone does it involve?

Answer 22

it is a cyclic or recurring “shifting” lameness whereby DIAPHYSEAL bone becomes abnormal

(NOT physis or metaphysis - just the DIAPHYSIS)

Question 23

what are the cause and clinical signs of panosteitis? how is it treated?

Answer 23

cause - idiopathic
CS - “shifting” lameness, lethargy, anorexia, fever
tx - granular medullary radiopacity on radiographs - easy to recognize

Question 24

was is a common site for OC?

Answer 24

humeral head 
humeral condyle - specifically the MEDIAL aspect
femoral condyles
patella
trochlear ridges of talus