Stabilisation of Radial Fractures Flashcards
What are skeletally immature animals with radius/ulna fractures at risk of?
Angular limb deformity
In any dog, and particularly cats, with antebrachial fractures, every effort must be made to maintain the natural motion that occurs between the radius and ulna.
What are we at risk at if not? (2)
- implant failure
- reduced QoL
What is the antebrachium composed of?
Radius and ulna
Proximally, the ulna ‘embraces’ the radial head with? (2)
the medial and lateral coronoid processes.
braces’ the radial head with the medial and lateral coronoid processes. Around 50% of thoracic limb weight-bearing is carried by..?
The proximal radial articular surface at the level of the elbow
Where is the 2nd largest area of the thoracic limb which is weight-bearing?
Ulna
What ligaments of the elbow joint tether the radius and ulna together? (2)
medial and lateral collateral
medial and lateral collateral
medial and lateral radial incisures of the ulna
How do the biceps brachii and brachialis muscles insert?
They have tendons of insertion that bifurcate and insert on the medial surface of radius and the ulna
Distal to the elbow joint the radius and ulna are joined by dense..?
Interosseous ligament
What muscles share their origination between radius and ulna at the level of the mid-diaphysis? (3)
Pronator quadratus,
Deep digital flexor
Abductor pollicis longus muscles.
If the radius and ulna are #, why is it that only the radius may need to be fixed in some cases?
The main weight bearing bone is the radius,
Radial #, Suitable cases for external coaptation? (3)
Isolated fracture of the radial or ulnar diaphysis
Stable fractures involving both radius and ulna
Young, medium-sized or larger dogs, or cats.
When to x-ray following external coaptation of the radius?
Initial, 4 weeks, 6 weeks, 12 weeks
T or F
External coaptation is a suitable method for radial # in toy or small breeds
FALSE - SHOULD NOT BE USED
What # tends to lead to angular limb deformity?
When growth plates involved
The distal ulna growth plate is most prone to injury, due to its conical shape it is prone to..?
Crushing
With growth plate is most prone to injury
Distal ulna
Which area of # is described when describing displacement?
distal component displacement in relation to the proximal component.
Risk of proximal screws becoming a stress riser results in?
Poss #
Standard approach to a radial #?
Medial
How to approach a distal radial #?
Medial combined with cranial
Approach to radius - T or F
Cephalic vein and tendon of abductor pollicis longus muscle may be sacrificed to allow adequate exposure.
True
What is the tension side of the radius?
Cranial
Cranial approach to the radius; only relatively short screws; why?
The cranio-caudal diameter of the distal radius.
Standard site for radial plate?
Cranial
On the cranial approach to the radius; what can become irritated; especially with distal #?
Extensor tendons
Main advantage of a medial plate being applied to the radius?
Longer screws can be used due to shape
What size plate and number of screws for a medial plate application of the radius?
Smaller plate - more screws over same distance
When is it advised to repair the ulna as well as radial #? (2)
- Multiple trauma
- Animals with increased pronation supination and/or high forces acting (e.g., dogs with increased pronation/supination e.g., racing breeds, giant breeds, cats).
What approach allows access to radius and ulna?
Lateral
Minimally invasive application with locking plates: what is this?
The focus is shifted from filling all screw holes to preserving the soft tissue envelope while providing adequate stability.
When can ESF be employed? (2)
Comminuted #
high grade open #
Where is an ESF NOT recommended?
Toy breed
Why do toy breeds provide a greater challenge to surgical repair? (3)
- Antebrachii more susceptible to # due to morphology
- Increased delayed healing; decreased vascular density at distal diaphyseal-metaphyseal junction of radius
- Small cross sectional area of distal radius; adequate bone apposition a challenge
Toy breed; Aim to provide rigid stabilisation, optimise apposition, and preserve blood supply. How can this be done? (3)
Internal fixation is the method of choice.
Consider a bone graft.
Consider how to preserve blood supply (gentle soft tissue handling etc).
Consider staged screw removal to avoid stress protection starting close to fracture site and waiting 3-4 weeks after removal.
Medial approach to the radius:
Patient position?
Position patient in dorsal recumbency with hanging leg.
Medial approach to the radius:
Where is the skin incision?
Skin incision from medial epicondyle of the humerus to styloid process of radius - protect cephalic vein crossing in distal portion.
On the medial approach to the radius, the superficial fascia is incised. Then the deep fascia; this is between which 3 muscles?
Extensor carpi radialis muscle and pronator proximally,
Parallel to extensor muscles distally
Medial approach to radius:
If access to proximal radius required, incise which 2 muscles insertion?
Pronator and supinator muscles
Which nerve (located deep to proximal supinator) needs to be preserved on the medial approach to the radius?
Radial
Lateral approach to the radius:
How is the patient positioned?
Lateral recumbency with hanging leg
Lateral approach to the radius:
Where is the incision
Centre over lateral edge of radius; from radial head to distal radius
Lateral approach to the radius:
Incise deep fascia along radial shaft and cranial border of common digital extensor muscle.
What muscles are then retracted and which direction? (2)
Common and lateral digital extensor
Lateral approach to radius:
Retract which muscle medially or incise along ulna.
Abductor pollicis longus
If there is a # distal ulna, what needs to be thought about whether this may benefit from fixation?
More pronounced movement of the ulna will be present during pronation and supination.
