Ch 52 - Surgical Diseases of the Elbow Flashcards
List the extensor muscles of the elbow joint
What innervated these muscles?
Extensors are innervated by the radial nerve and include:
- Triceps brachii
- Tensor fascia antibrachii
- anconeus muscle
List the main flexors of the elbow joint and the associated nerve
- Biceps brachii - musculocutaneous n
- brachialis m - musculocutaneous n
- Extensor carpi radialis - radial n
What is the normal range of motion of the elbow?
At what point of extension does the anconeal process articulate with the olecranon fossa?
Normal range of motion 130 deg
- 36 flexion
- 165 extension
- At 135deg, anconeal process articulates with olecranon fossa
What is the Campbells test?
Testing rotation stability via the collateral ligaments with the elbow and carpus held at 90deg
What are the three regions of conctact in the elbow?
- Craniolateral aspect of anconeal process
- Radius
- Medial coronoid process
How much of the weight through the elbow goes through the radial head?
51%
Which direction is most common for traumatic elbow luxation? Why?
What position does the elbow need to be in to allow for luxation?
Lateral (92 - 100%)
- Relatively large humeral trochlea
- MCL is inherently weaker
Elbow must be flexed beyond 45 degrees to unlock the anconeal process from the olecranon fossa
What percentage of dogs with traumatic elbow luxation will have concurrent collateral ligament damage?
18 - 50%
What approach is recommended for open reduction of elbow luxation?
Caudolateral
What are the options for post-op immobilisations after elbow reduction?
- Spica splint
- ESF (connecting bars can be replaced by tight elastic bands to allow some early motion)
- Potentially also the transarticular fixation (screw or pin)
What are the three types of congenital elbow luxation?
- Type I: Humeroradial
- Type II: Humeroulnar
- Type III: Combined
How do you treat Type I humeroradial luxation?
- Oblique osteotomy or wedge ostectomy of radius with bone plate or ESF
- Reduction maintained with temporary transarticular pin or intraosseous screws between radius and ulna
- Spica spint or carpal flexion bandage
What breed of dogs have the highest odds ration of UAP?
What percentage of dogs with UAP will also have FMCP?
How often is UAP bilateral?
- Bernese Mt Dogs and Mastiffs
- 13 - 30% have concurrenct FMCP
- Bilateral in 20 - 35%
Define positive and negative radioulnar incongruence
- Positive: Ulna longer than the radius
- Negeative: Radius longer than ulna
At what age does the anconeal process growth plate fuse?
- 14-15wk in Greyhounds
- 16-20wk GSD
What are the Tx options for UAP?
- Anconeal process removal (owners satisfied but only 50% free of lameness)
- Reattachment (dogs under 24 weeks with normal trochlear notch, 60% fusion 2-6m)
- Ulnar osteotomy/ostectomy
- Reattachment and ulnar osteotomy/ostectomy (best outcome: fusion 93%)
What are some guidelines for an ulnar osteotomy for the Tx of UAP?
- Most successful in dogs under 7m with firmly attached, non-displaced anconeal process
- Osteotomy located 30-60mm distal to articular surface
- Bi-oblique: proximocaudolateral to distocraniomedial at 40-50 degrees to long axis
- +/- IM pin
What breeds are predisposed to flexor entheseopathy?
Labradors, GSD, English Setter
What percentage of flexor entheseopathy is primary?
15 - 35%