Elbow & Radioulnar Joints Flashcards
What nerve is behind the medial epicondyle?
the ulnar nerve
Which is medial - the trochlea or the capitulum?
the trochlea
Where does the lateral collateral ligament of the elbow attach?
To the lateral epicondyle proximally and the annular ligament distally
What is the annular ligament?
a ligament that encloses the head of the radius
What movement does the attachment of the lateral collateral to the annular ligament permit?
pronation and supination
What movement do collateral ligaments resist?
abduction and adduction
In what orientation is the elbow joint most secure?
extension
What is the carrying angle?
valgus angulation of the forearm relative to the arm
What does increased valgus angulation cause?
stretching of the medial collateral ligament and the ulnar nerve
What is the key feature of the proximal radioulnar joint?
it is in the same joint capsule as the elbow joint
What movement do the radioulnar joints cause?
pronation and supination
What is the function of the interosseus membrane?
transmits forces between the radius and the ulna and provides a surface for muscle attachment
What does the interosseus membrane mean for a fracture in the radius?
It will likely be accompanied by a fracture in the ulna and vice versa
What is the key feature of the distal radioulnar joint?
a fibrocartilage disc - more likely to perforate with age
What muscles act as pronators and supinators?
pronator teres, pronator quadratus, supinator, biceps
Why is a pulled elbow more likely in children?
Their annular ligament is weaker
When is a posterior dislocation of the elbow likely to occur?
In a backwards fall with a flexed elbow
What will a posterior dislocation of the elbow joint cause?
fracture of the coronoid process
What may also be caused by elbow dislocation?
Volkmann’s ischaemia - avascular necrosis of the muscles of the forearm due to spasm of the brachial artery limiting blood supply to the ulnar artery
What is tennis elbow?
lateral epicondylitis - tendinitis of wrist extensor muscles due to extension, pronation and wrist flexion
What structure is vulnerable in a fracture of the medial epicondyle?
the ulnar nerve
