elbow

Elbow joint

· hinge joint

· communicates with PRUJ

· capitellum articulates with radial head

· trochlea articulates with proximal ulna

· humeral fossae for ulna

· anterior coronoid fossa

· posterior olecranon fossa

Ligaments

Capsule

· attached to humerus at margins of ends of articular surfaces

· carried up over coronoid and olecranon fossae

· attached to trochlear notch of ulna and annular ligament of PRUJ

· not attached to radius

· capsule and annular ligament lined by synovial membrane

· synovial membrane attaches

· to articular margin of humerus (incl. floor of fossae)

· to articular margin of ulna

· at lower margin of cylindrical articular surface of radius

· bridges gap between radius and ulna

Ulnar collateral ligament

· triangular with 3 bands

Anterior band

· strongest

· from medial epicondyle of humerus

· to sublime tubercle on medial coronoid process

Posterior band

· from medial olecranon

· to sublime tubercle

Middle band

· connects 2 and is more deep

· from medial epicondyle

· to medial olecranon

· ulnar nerve passes over it

Radial collateral ligament

· single band

· from lateral epicondyle

· to annular ligament

Proximal radioulnar joint

ligaments

Annular ligament

· attaches to margins of radial notch of ulna

· encircles head and neck of radius

· does not attach to radius

· blends with capsule of elbow joint proximally

Quadrate ligament

· runs between neck of radius and ulna just distal to radial notch

· supports synovial membrane

Interosseous membrane

· joins interosseous borders of radius and ulna

· runs obliquely down from radius to ulna

· taut in pronation and relaxed in supination

Oblique cord

· runs between radius and ulna

· fibres in opposite direction to IOM

· slopes upward from radial tuberosity to ulnar tuberosity

· posterior interosseous artery runs through gap between interosseous membrane and oblique cord