Shoulder and Elbow

Question 1

List the two standard projections of the shoulder and one additional projection

Answer 1

1. Mediolateral
2. Cranium medial – Caudolateral oblique

Additional = cranioproximal – craniodistal (skyline)

Question 2

What is the purpose of the cranium medial – caudolateral oblique of the shoulder

Answer 2

Highlights of the lesser and intermediate tubercles, bicipital groove, and deltoid tuberosity

Question 3

What does the cranial proximal – cranial distal oblique (skyline) projection of the shoulder highlight?

What to soft tissue structures run in this area?

Answer 3

Humeral tubercles

Biceps tendon and bursa

Question 4

DJD of the shoulder
relative occurrence
prognosis
typically secondary to what?

Answer 4

Relatively uncommon

Poor prognosis

Common sequela to osteochondrosis but also can be secondary to fracture or sepsis

Question 5

DJD of the shoulder, six typical radiographic findings

Answer 5

– Peri-articulate osteophyte formation 
– enthesophyte formation 
– flattening of the articular surface 
– subchondral sclerosis 
– subchondral license 
– narrowing of the scapulohumeral joint

Question 6

Osteochondrosis of the shoulder – two manifestations and their clinical appearance

Answer 6

OCD of the card off humeral head (glenoid as well) – often lame

Osseous cyst – like lesions of the glenoid cavity or humeral epiphysis – can be an incidental finding

Horse often has advanced DJD before diagnosis is made

Question 7

While fracture of the shoulder is uncommon, where is a relatively most common place for fracture?

What type of fracture is it?

What attaches here and why is that important?

Answer 7

Fracture of the supraglenoid tubercle

Avulsion fracture, maybe simple or comminuted and is generally articular

Biceps brachii tendon attachment site – fraction of this muscle because cranial and distal displacement of the fracture fragment

Question 8

Luxation of the scapulohumeral joint

What breed may be predisposed?

Generally results from what?

What are the two directions possible for the luxation?

How do you tell what is the direction of the luxation?

Answer 8

Shetland pony’s

Traumatic injury

Cranial lateral or cranial medial and need oblique projection

Question 9

Standard projections of the elbow

Answer 9

Mediolateral

Craniocaudal

Question 10

Most common injury of the elbow in a horse

Answer 10

Fracture and infection due to traumatic injury

Question 11

DJD of the elbow in the horse
– relative occurrence
– typically secondary to what three things

Answer 11

Relatively rare, osteochondrosis, infection or articular fracture

Question 12

Five radiographic findings associated with DJD of the elbow

Answer 12

– Osteophytes 
– Enthesophytes
– subchondral bone sclerosis 
– subchondral bone Lysis 
– narrowing of joint space

Question 13

Most common elbow fracture in the horse

most common signalment

important to determine what with the most common fracture type and why

Answer 13

Olecranon

Foals (result of kick)

Must determine if Olecranon fracture involves the articular surface – note in the trochlear notch the distal portion of the notch is nonarticular

Question 14

Osteochondrosis of the elbow
 – most common presentation
 – most common signalment
 – most common location
 – (plus/minus) What other characteristic often seen simultaneously

Answer 14

Osseous cyst – like lesions(geographic lysis),
young horses,
medial aspect of the proximal radial epiphysis,
periosteal reaction at medial collateral ligament insertion