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Flashcards in Elbow disease Deck (42)
1

1

Why are the individual pathologies in elbow dysplasia grouped?

Elbow dysplasia is a "catch all" diagnosis that is comprised of several similar, but separate, diagnoses for which the pathology is not as well understood.  The different pathologies that make up elbow dysplasia tend to occur together, tend to occur in the same sorts of patients, and tend to occur at the same age.  All have some similarities in diagnosis and treatment, and also tend to cause arthritis over time.

2

What are the individual components of elbow dysplasia?

  • Ununited anconeal process (UAP)
  • Fragmented medial coronoid (FCP)
  • Osteochondritis dissecans (OCD)
  • Joint incongruity

3

Label the structures of the elbow:

4

Where does OCD of the elbow generally occur?

Trochlear ridge of the medial humeral condyle

5

T/F: Incongruity is a thing that happens

TRUE (direct quote from Dundas)

Sometimes incongruity happens by itself and sometimes it happens in combination with other pathologies (particularly UAP and FCP); It's a complex relationship, much like the long distance relationships of Ross students

 

6

What is the (simple) definition of incongruity?

Mismatch in articular surfaces

Can take many forms, including a discrepency in length between the radius and ulna

7

Why do uneven joint surfaces result in DJD?

Uneven joint surfaces --> uneven joint forces --> stress focused on specific areas of cartilage --> uneven wear on the cartilage --> DJD

8

T/F: The individual pathologies of elbow dysplasia always occur together

FALSE--may appear together or singly

It's best to assume there are multiple problems in the joint and be pleasantly surprised when there aren't

9

How does the phrase "developmental orthopedic disease" apply to patients with elbow dysplasia?

Elbow dysplasia is a developmental orthopedic disease, meaning it first manifests prior to skeletal maturity.  Even when the lameness seems to resolve, these diseases often lead to secondary effects (leading to DJD in the long term).  When patients present later in life it is due to the secondary effects rather than the primary 

10

T/F: Dogs with elbow dysplasia should not be bred

TRUE

Elbow dysplasia is hereditary

11

Describe a typical patient with elbow dysplasia

  • Young
  • Male
  • Large/giant breed dogs

12

T/F: Elbow disease is commonly seen bilaterally, meaning dogs should be screened for bilateral disease

TRUE

13

What is the typical history of a dog with elbow dysplasia?

  • Must present from 5-12mo of age
  • Chronic, progressive lameness
    • Might be intermittent (aggravated by activity)
    • Bilateral disease can mask lameness

14

T/F: Younger dogs might try to "power through" the lameness because they want to play, creating more subtle signs of elbow disease

TRUE

15

What are the typical PE findings in a dog with elbow dysplasia?

  • Gait and posture
    • Elbow lameness
    • "Down on sound"
      • Head drops as weight is put on the "good" leg
  • Pain on manipulation of elbow joint
    • UAP: pain on extension (anconeal pressure)
    • FCP: flexion + supination (medial compartment)
  • Thickening (fibrosis) in joint 
  • Crepitus on range of motion (if chronic)

16

What is the characteristic posture of elbow dysplasia?

Toes pointed out at an angle due to varying degree of external rotation of the antebrachium

Hold elbow in toward the body (adduction)

Postural changes serve to help offload the painful medial side of the joint, and shift the weight toward the lateral side

17

What is the proposed cause of UAP in general terms?

  • Radioulnar incongruity--length discrepancy
    • Shortened ulna displaces humerus proximally
    • Excess force on developing anconeal process
    • Ossification fails (disrupted microcirculation)
    • Focused stresses --> separation

18

What is the difference in ossification pattern of the ulna between breeds susceptible to UAP and those that are not?

  • Separate center of ossification in the anconeal process in susceptible breeds
  • Not present in unaffected breeds

19

T/F: Any dog with a separate center of ossification in the anconeal process will automatically go on to develop UAP

FALSE

20

When can UAP be diagnosed (comfortably)?

24 weeks

21

What is the proposed etiology of FCP?

Microtrauma

Presumed to be caused by incongruity

22

What is the relevance of radiographs in the diagnosis of individual components of elbow dysplasia?

  • Often used as first line of defense (non-invasive, inexpensive)
  • Some components are readily identified while others are more subtle

23

What radiographic views are necessary when diagnosing UAP?

OCD?

FCP?

  • UAP = flexed lateral
  • OCD = (well positioned) craniocaudal
  • FCP = sclerosis may be only sign
    • Coronoid overlies radial head (lateral view)
    • Coronoid lies partially over ulna (craniocaudal)

24

Diagnosis?

Ununited anconeal process

*Note the line of separation between the relatively large anconeal fragment and the underlying unla

**Flexed lateral view**

25

Diagnosis?

Osteochondrosis dissecans

 

26

What can be used to diagnose FCP?

CT (least invasive), arthroscopy

27

What is the role of arthroscopy in evaluating a joint for elbow dysplasia?

  • Comprehensive view of all the joint surfaces
  • Incongruity can be diagnosed
  • Also therapeutic 
  • Full evaluation

28

What are the 2 most common treatments for UAP?

Fragment excision

Osteotomy + fixation

29

In which patients would fragment excision be applicable for the treatment of UAP? Why?

  • Older dogs w/ DJD
  • Instability remains
  • Not done in younger dogs--will disrupt growth/stability of joint

30

In which dogs is osteotomy + fixation an appropriate treatment for UAP?

Dogs without OA

31

How does the osteotomy/fixation approach to treating UAP address the role of incongruity?

  • Restoration of congruity--ulna "lengthens"
  • Encourages union of anconeal process
  • Fragment may not fuse long-term

32

What is the typical treatment protocol for FCP and OCD?

  • Arthroscopic treatment is gold standard
    • Fragment removal
    • Debridement of lesion bed

33

What is the prognosis for elbow dysplasia?

  • Early intervention is the best chance
    • Does not prevent DJD
  • Tx via arthrotomy is worse than via arthroscopy
  • Medical management expected long-term

34

Why isn't simple fragment excision sufficient for treatment of elbow dysplasia?

Incongruity remains

DJD, loss of ROM is usually progressive

35

T/F: The typical treatment for FCP and OCD is often combined with treatment for incongruity

TRUE

36

What is incomplete ossification of the humeral condyle?

Failure of union between the medial and lateral portions of the humeral condyle

Fusion normally completed at 12wks

37

What breeds are predisposed to IOHC?

Spaniel breeds (males >> females)

38

What are the 3 ways in which IOHC might present?

  • No clinical signs--incidental finding
  • Mild lameness--indicates micromotion
    • Wt.-bearing lameness
    • Worse after activity
  • Acute NWB lameness
    • Indicates pathologic fracture
    • Historical lameness usually present

39

Diagnosis?

IOHC

40

T/F: When assessing limbs for IOHC (or any elbow disease) you should ALWAYS assess the contralateral limb

TRUE

41

T/F: Medical therapy of IOHC is contraindicated

TRUE