Elbow Complex Flashcards
What is the carrying angle and why is it formed?
5-20 degrees
Trochlea of the humerus extends further distally than does the capitulum
What is the structure of the elbow?
Compound joint
Stable bony arrangement
What is the flexible ROM at the elbow?
145 degrees
How many joints make up the elbow complex? What are they called?
3
Radio-humeral
Superior radio-ulnar
Humeral-ulnar joint
All surrounded by loose capsule
What makes up the humero-ulnar joint? What plane is it in?
Hinge joint between trochlear notch and trochlea of humerus
Not in ant-post plane and so carrying angle in extension/sup formed
What does the semi lunar joint do?
Prevents lateral movement in humero-ulnar joint
What prevents lateral movement at humero-ulnar joint?
Semi lunar notch ulna
Anatomy of the radiohumeral joint?
Limited ball and socket hinge joint
How is the HOR held in the radial notch?
Annular ligament
Structure of radio ulnar joint?
Covers 80% of radial head
Thicker posteriorly > ant
What does the radio ulnar joint allow?
Together allow supination and pronation
What are the four major ligaments of the elbow?
Ulnar collateral
Radial collateral
Annular
Quadrate
What makes up the ulnar collateral ligament?
Anterior oblique band
Posterior band
Intermediate band
Where is the anterior oblique band?
Anterior medial epicodyle to coronoid process
Ulnar nerve crosses this section
Where is the posterior band of the ulnar collateral ligament?
Posterior medial epicodyle to coracoid process
Where is the intermediate band of the ulnar collateral ligament?
Varies
What does the ulnar collateral ligament do?
Resists abduction force
What levels is the ulnar nerve, where is it in the brachial plexus?
C8-T1
Part of medial cord of the brachial plexus
What is the path if the ulnar nerve?
Descends on the posteromedial aspect of the humerus
Travels through cubital fossa at elbow
Enters the anterior (flexor) compartment of the forearm through the two heads of FCU and runs alongside the ulna
What do the lateral and medial cords of the brachial plexus form?
Median nerve
What cord/s of the brachial plexus form/s the median nerve?
lateral and medial
What is the course of the median nerve?
Enters from axilla at inferior margin of teres major
Passes vertically down and courses with brachial artery on medial side of arm between biceps and brachialis
What forms the radial nerve?
C5, C6, C7, C8, T1.
posterior cord of the brachial plexus
What does the radial nerve supply?
3 heads of triceps
12 muscles in posterior aspect of forearm
What is the course of the radial nerve?
Travels through quadrangular space in axilla around the spiral groove humerus a emerges laterally.
- Pierces latral intermuscular septum/branches and travels between brachialis and brachioradialis
- In distal humerus travels anterior to lateral epicondle.
- Pierces forearm divides into 2 branches
What does the radial nerve divide into?
superficial (brachioradialis)
Deep (pierces supinator
What is the largest unprotected nerve in the body?
Ulnar
What supplies the anterior elbow?
musculocutaneus, median and radial nerves