Elbow Arthrology Flashcards
Three main joints
1) Humero-ulnar Joint
* Articulation between trochlea
of humerus and trochlear notch
of ulna
2) Humero-radial Joint
* Articulation between the
capitulum of humerus and the
head of radius
3) Proximal/Superior Radio-ulnar Joint
* Articulation between the
proximal radius and the radial
notch on the ulna
HUMERO-ULNAR JOINT
(flexion/ extension)
- FLEXION of arm > trochlea of the distal
Humerus and the trochlear notch of the Ulna - Supported by “ledge” on Ulna –
coronoid process - Fits into the coronoid fossa on the Humerus
- EXTENSION of arm > Olecranon fossa of humerus receives the olecranon of the ulna
Synovial Hinge joint
HUMERO-RADIAL JOINT
(flexion and extension)
- Articulation between the head
of the radius and the
capitulum of the humerus - Both joints make up the elbow
joint - Share same capsule
- THINK LEGO! - interlocking
synovial hinge joint
PROXIMAL RADIO-ULNAR JOINT
- Synovial Pivot joint (allows rotation around an axis)
- Articulation between the head of
radius (disc shaped) and the radial
notch on the ulna (medial aspect of
ulna) within the fibro-osseous ring
Radial notch is hyaline-covered and makes up 1/5th of the fibro-osseous ring
Allows movement of pronation and
supination
INTEROSSEOUS
MEMBRANE
- Connects to the interosseous borders of the ulna and radius
- Fibres pass obliquely and medially which act to pass forces from the radius to the ulna
- There are distinct apertures (openings for vessels) to pass through to the posterior
compartment - Provides attachments for muscle
Joint Capsule
(Anterior/Posterior)
Anterior Capsule
* On the Humerus, it
extends superiorly from
the articular margins and
covers the Coronoid and
Radial Fossae anteriorly
and the Olecranon Fossa
posteriorly
* Superior radio-ulnar joint &
the Annular Ligament
Posterior Capsule
* Margins of Olecranon
Fossa
* Below Medial & Lateral Epicondyles
* Annular Ligament
A single fibrous capsule
completely surrounds the
elbow and superior radio-
ulnar joints
