The posterior compartment of the forearm - Common extensor origin, anatomical snuffbox, vessels and nerves (dave's notes) Flashcards
What and where is the common extensor origin? What attaches here?
The smooth area on the front of the lateral epicondyle is for the attachment of the common extensor origin
ECRB
ED
EDMinimi
ECU
All tendons are fused with each other and to the deep fascia
What is the anatomical snuffbox?
The concavity between EPL (ulnar side) and EPB/APL (radial side)
What crosses the tendons of the anatomical snuffbox?
The cutaneous branch of the radial nerve
What begins in the anatomical snuffbox?
The cephalic vein
What lies deep to all three tendons of the anatomical snuffbox?
The radial artery
What lies proximal to the anatomical snuffbox?
The radial styloid
What lies distal to the anatomical snuffbox?
Scaphoid, trapezium and then the base of the thumb metacarpal lie distally
Describe the course of the posterior interosseous nerve
The nerve passes through the two layers of the supinator muscle and then appears in the extensor compartment, over abductor pollicis longus to the IO membrane
What does the posterior interosseous nerve supply?
The muscles arising from the common extensor origin, and the deep muscle of the extensor compartment.
Sensory to IO membrane and periosteum
What is the course of the posterior interosseous artery? What does it supply? How is it assisted?
Passes between the bones in the forearm accompanying the posterior interosseous nerve, supplying the deep muscles of the flexor compartment, fades out part way along and is supplemented by the anterior interosseous artery.
