Radius and Ulna Flashcards
What percentage of weight at the elboe is transmitted through the radius and the ulna?
- Radius 51%
- Ulna 49%
The tendons of which muscle insert on the medial side of the radius and ulna?
- Biceps brachii
- Bracialis
What muscles share their origin with both the radius and the ulna in the mid-diaphysis?
- Pronator quadratus
- Deep digital flexor
- Abductor pollicus longus
What is the radioulnar ligament?
Proximal extension of the antebrachiocarpal joint capsule between the radius and ulna. Attaches proximally to the interosseus ligament
How much of the growth below the elbow is the distal ulna physis responsible for?
Proximal radial physis?
- Distal ulnar physis 100%
- Proximal radial physis 30-50%
What age do the physes of the antebrachium close?
222-250d (in Beagles)
What is the mean radial procurvatum of Labs?
26.6 degrees
How do you calculate procurvatum?
On sagittal view:
Procurvatum = CORA magnitude + (90-aCdPRA) + (90-aCdDRA)
What is the sensitivity and specificity of rads for diagnosing radioulnar incongruity?
- Sensitivity 78%
- Specificity 86%
Radial shortening needed to be between 1.5-4mm for a 90% sensitivty
What is the sensitivty and specificity of arthroscopy for diagnosing radioulnar incongruity?
- Sensitivity 94%
- Specificity 81.9%
What it he sensitivity, specificity and interobserver agreement for radioulnar incongruency on 3D printed models with a 1mm incongruence
- Sensitivity 82%
- Specificity 100%
- Interobservor agreement 87%
How much radial lengthening has been reported with the use of an ESF and distraction osteogenesis?
Up to 50% of the original radial length
What are the options for radial lengthening?
- Distraction osteogenesis
- Transverse osteotomy and acute correction
- Sagittal sliding osteotomy (acute correction)
Can alternatively perform ulnar astectomy abover interosseous ligament with an IM pin. Can be left for gradual shortening or can be acutely shortened with hemicerclage
What percentage off physeal insults is made up of distal ulnar physeal injury?
63%
What are the typical changes in the radius secondary to premature closure of the distal ulnar physis?
- Procurvatum
- Shortening
- Distal valgus
- Torsion
What are the surgical options for ulnar lengthening?
- Dynamic ulnar ostectomy/osteotomy
- Distal ulnar ostectomy
- CESF and distraction osteogenesis
- Distracted osteotomy and plating
- Sagittal sliding osteotomy
What can done to aid in stability of a proximal dynamic ulnar osteotomy/ostectomy?
- Oblique cut (proximocaudal to craniodistal)
- IM pin
What methods can reduce the chances of permature healing of the ostectomy?
- Ostectomy gap greater than 1.5x diameter of the bone (Key’s hypothesis)
- Removal of all periosteum in the vicinity
- Insertion of free fat graft into ostectomy
What had been associated with unsuccessful outcomes after a distal ulnar ostectomy to treat ulnar shortening?
Radial valgus greater than 25 degrees
If varus, recurvatum or internal torsion are present then radial corrective measures will be necessary
What is the Heuter-Volkmann law (aka Delpech’s law)?
Physeal growth is slowed by excessive compression and is accelerated by distraction
What percentage of antebrachial deformities are biapical in chondrodystrophic breeds?
80%
What percentage of dogs with an antebrachial deformity corrected with a CESF has improvement in function?
60%
What percentage of radial deformities in an oblique plane were accurately correced using a radial or cylindrical saw?
44%
A true domes osteotomy ascribes to which low of osteotomies?
Paley’s second rule
