Chapter 96 - Radius and Ulna Flashcards
Classification scheme for ulnar fractures. Type 1a, fracture along the apophyseal physis;
Type 1b Articular, fracture starting out along the apophyseal physis and then breaking into the metaphyseal part of olecranon process and finally entering the elbow joint;
Type 1b Nonarticular, fracture starting out along the apophyseal physis and breaking out the cranial cortex of the olecranon proximal to the anconeal process;
Type 2, simple fracture through the body of the olecranon with articular involvement;
Type 3, simple fracture through the body of the olecranon without articular involvement;
Type 4, multifragment fracture of the olecranon with or without articular involvement;
Type 5, distal oblique ulnar fracture with marginal articular involvement.
What comprises the equine antebrachium?
Radius and Ulna
Which bone in the antebrachium is the major weight-supporting bone?
Radius
What is the primary function of the olecranon?
Acts as a lever arm during elbow and carpal extension
How common are fractures of the ulna in horses?
Relatively common
What is the treatment of choice for fractures of the ulna in horses?
Fracture fixation using a bone plate as a tension band
What is the structure of the ulna in horses?
Triangular in cross-section and tapers distally
What is the olecranon in relation to the ulna?
The proximal part of the ulna
What can result from disturbances in the growth of the olecranon physis?
Development of elbow dysplasia
What is the most common cause of fractures of the ulna in horses?
Direct blow from a kick or fall
Where do fractures often occur when a foal rears up and falls?
The body of the ulna or the olecranon
What is a common fracture type in horses less than one year of age?
A. Type 1b fracture
B. Type 2 fracture
C. Type 3 fracture
D. Type 5 fracture
A. Type 1b fracture
What is the most common fracture configuration in neonates?
A. Physeal separations (type 1a)
B. Transverse fractures (type 2)
C. Nonarticular, nonphyseal fractures (type 3)
D. Comminuted fractures (type 4)
Physeal separations (type 1a)
What kind of fractures are encountered commonly in horses over one year of age?
Distal olecranon-proximal ulnar body fractures
What is a typical presentation of a horse with nondisplaced olecranon fractures?
Dropped elbow and lameness is the primary complaint
What type of radiograph is necessary for complete visualization of the cubital joint and proximal olecranon?
Medial to lateral projection
Which diagnostic tool is occasionally indicated to determine communication between a soft tissue wound and the cubital joint?
Contrast arthrogram
What indicates the severity of soft tissue injury accompanying an olecranon fracture?
A. Degree of lameness
B. Size of the wound
C. Displacement of the fracture
D. Swelling in the humeral region
C. Displacement of the fracture
What is the first step in the initial care for horses with a fractured ulna accompanied by a wound?
Wound therapy with hair removal at the wound margins
What may be used in extensive soft tissue wounds to reduce bacterial numbers?
A. Antibiotic ointments
B. Sterile saline solution
C. Antimicrobial-impregnated PMMA beads
D. Anti-inflammatory drugs
C. Antimicrobial-impregnated PMMA beads
What is a common problem in horses with displaced fractures?
they cannot engage their stay apparatus
What is the purpose of splinting the carpus in extension in horses with a dropped elbow?
To allow weight to be supported on the affected limb
what is the artery responsable for the scapulohumeral joint?
brachia artery and vein
axillary artery and vein
the cephalic vein diverges from external jugular and continues distad in the groove between (name the 2 muscles)
Brachiocephalicus
descending pectoral