The Inferior Radioulnar Joint

Question 1

Classification of the inferior radioulnar joint.

Answer 1

Synovial pivot joint.

Question 2

Where does articulation occur in this inferior radioulnar joint?

Answer 2

Between the head of the owner and the owner notch on the lower end of the radius.

Question 3

Name the articular surfaces of the radioulnar joint.

Answer 3

Head of the ulna, ulnar notch of the radius, articular disc & interosseous membrane.

Question 4

Describe the head of the ulna as an articular surface.

Answer 4

It is crescent shaped on the lateral and anterior aspects and it is covered in hyaline cartilage. It articulates with the intra-articular disc.

Question 5

Describe the ulnar notch of the radius as an articular surface.

Answer 5

Situated between the two edges of its interosseous border
Faces medially and is covered by highline cartilage.

Question 6

Describe the articular disc as an articular surface.

Answer 6

Triangular fibrocartilaginous articular disc.
Unites the radius and the ulna
Attached by its apex to the lateral side of the root of the ulna styloid process and by its base to the sharp inferior edge of the ulnar notch.

Question 7

Describe the interosseous membrane as an articular surface.

Answer 7

Stretches between the interosseous borders of the radius and ulna.
Passes obliquely downwards and medially from the radius to the ulna
Provides firm connection between the radius and ulna
Separates and increases the area of attachment of deep muscles in the forearm

Question 8

Describe the movements of the inferior radioulnar joint.

Answer 8

Rotation of the distal end of the radius around the head of the ulna during pronation and supination.