Ununited anconeal process - UAP

Question 1

What disease complex is UAP a part of?

Answer 1

ED

Question 2

What is the primary stabilizer in pronation?

Answer 2

The anconeal process -> failure of this -> instability of joint and OA

Question 3

Development of anconeal process?

Answer 3

1. by direct extention of the proximal ulna
2. in large breed dogs (GSD) - separate center of ossification
   - fusion begins: 10-13w
   - fusion complete: 12-20w (4,5m)

Question 4

When can diagnosis of UAP be made based on timeline?

Answer 4

at 20 weeks

Question 5

Aetiology of UAP?

Answer 5

Hypothesis:
1) Osteochondrosis
2) joint incongruity
- unerdevelopment of trochlear notch
- radioulnar incongruence

Question 6

Breeds predisposed?

Answer 6

GSD

Other large/medium breeds

Chondrodystrophic breeds - Bassett hound

Question 7

Age of presentation?

Answer 7

5-18 months, uni or bilateral

Question 8

Clinical presentation

Answer 8

marked effusion
Muscle atrophy
Reduced ROM
pain, crepitus - flexion and extention

Question 9

Concurrent pathology?

Answer 9

FCP in 16% of UAP
Short ulna 50%

Question 10

Diagnosis?

Answer 10

XR - lateral or flexed, schlerosis, osteophytosis

OBS! Also look for FCP -> CT or during surgery

Question 11

Unilateral? Bilateral?

Answer 11

Bilateral in 11-47% of cases

Question 12

Treatment?

Answer 12

Surgical
1. Fragment removal - joint instability, OA
2. Screw fixation
3. Screw and pin fixation, ulnar osteotomy - young only!
4. Ulnar osteotomy - young only!
5. Conservative treatment - when minimal instability