Elbow Joint

Question 1

Type of Joint

Answer 1

Humeral-ulnar:
Synovial hinge capable of one degree of freedom
Between trochea of distal humerus and trochlea notch of prox ulna

Humero-radial:
Modified ball and socket between head of radius and capitulum of humerus

Capable of one degree of freedom - flex/ext of forearm
Flex= ~145deg
Ext= 0-5deg

Question 2

Supporting Ligaments

Answer 2

MCL (ulnar) -

• from med epicondyle of humerus
• to med edge of coronoid process (ant band) and med edge of olecranon process (post band)
• transverse band passes between distal attachments of the two

LCL (radial) -
-from lat epicondyle to annular ligt of sup RU jt: ant/post margins attach to margins of radial notch of ulna

Question 3

Capsule and Bursae

Answer 3

Surrounds joint and sup RU blending with:
Med- MCL
Lat- LCL
Ant- brachioradialis (deep fibres)
Post- triceps (deep fibres)
-deep fibres prevent capsule becoming trapped during movement

Bursae:
Intratendinous – within tendon of triceps brachii
Subtendinous – between olecranon and tendon of triceps brachii (reduces F between the two during ext/flex of arm)
Subcutaneous (olecranon) bursa – between olecranon and overlying CT (implicated in olecranon bursitis)

Question 4

Cubital Fossa

Answer 4

Apex - Imaginary line connecting med and lat epicondyles
Med border - pronator teres
Lat border - brachioradialis
Floor - brachialis and supinator
Roof - skin and fascia of arm/forearm, reinforced by bicipital aponeurosis (sheet of tendon-like material arises from tendon of biceps brachii).
-bicipital aponeurosis forms partial protective covering to median nerve, brachial, ulnar and radial arteries