Radioulnar joint Flashcards
What type of joint is the radioulnar joint?
A pivot joint.
What movement of the forarm does the radioulnar joint allow?
Pronation and Supination
How many radioulnar joints are there?
- One proximal and one distal.
Where is the proximal radioulnar joint?
Just distal to the elbow.
What forms the proximal radioulnar joint?
The radial head articulating with the radial notch on the ulna.
What holds the radial head in place?
The anular radial ligament. It is lined with synovial membane.
What produces pronation at the proximal radioulnar joint?
Pronator quadratus
pronator teres
What produces supination at the proximal radioular joint?
Supinator
Biceps Brachii
Where is the distal radioulnar joint?
Just proximal to the wrist joint
What articulates in the distal radioulnar joint?
Head of the ulnar and ulnar notch on radius
What does the articular disc do?
Bind the radius and ulna together
Separates the distsal radioulnar joint from the wrist joint
What moves to allow pronation and supination at the distal radioulnar joint?
The ulnar notch on the radius slides anteriorly over the head of the ulna
What causes pronation of the Distal radioulnar joint?
Pronator quadratus
Pronator teres
What causes supination of the distsal radioulnar joint?
Supinator
Biceps Brachii
What is the interosseous membrane?
A sheet of connective tissue that joins the radius and ulna together between the radioulnar joints
Where does the interosseous membrane attach?
Medial border of the radius
Lateral border of the ulna
What is the main functions of the interosseous membrane?
Holding the radius and ulna together during pronation and supination
Provides attachment for muscles
Transfer forces from the radius to the ulna
When thinking of fractures in the forearm, what is important to remember?
That usually the radius and ulna will break together.
What is a Monteggias fracture?
A force from behind the ulna causes the shaft to fracture and a dislocation of the radial head anteriorly at the elbow.
What is a Galeazzi fracture?
There is a fracture of the radius and the ulna head is dislocated at the distal radioulnar joint.
