SB The elbow joint and cubital fossa

Coronoid fossa

Trochlea

Coronoid process of ulna

Fig.36.1

The bones of the elbow joint; the dotted lines represent the attachments of the capsular ligament

Attachment of capsular ligament

Radial fossa

Capitulum Head of radius

Radial tuberosity

Fig.36.1

The bones of the elbow joint; the dotted lines represent the attachments of the capsular ligament

Biceps ■ Brachialis

Biceps tendon

Brachioradialis

Pronator teres

Fig.36.3

Flexor Carpi Ulnaris Aponeurosis

Triceps tendon

Medial ligament

Annular ligament

Ulna

Median nerve Brachial artery Medial epicondyle

Bicipital aponeurosis

Flexor carpi radialis Palmaris longus Flexor carpi ulnaris

Lax part of capsule Annular ligament

Tendon of biceps Radius

Interosseous membrane Ulna

Cubital Joint Capsule

Fig.36.2

The ligaments of the elbow joint and the superior radio-ulnarjoint

Triceps tendon

Fig.36.2

The ligaments of the elbow joint and the superior radio-ulnarjoint

The cubital fossa. It is crossed by the median cubital vein

The elbow joint (Figs 36.1 and 36.2)

• Type: synovial hinge joint. At the elbow the humeral capitulum articulates with the radial head, and the trochlea of the humerus with the trochlear notch of the ulna. Fossae immediately above the trochlea and capitulum admit the coronoid process of the ulna and the radial head, respectively, during full flexion. Similarly the olecranon fossa admits the olecranon process during full elbow extension. The elbow joint communicates with the superior radio-ulnar joint.

• Capsule: the capsule is lax in front and behind to permit full elbow flexion and extension. The non-articular medial and lateral epicondyles are extracapsular.

• Ligaments (Fig. 36.2): the capsule is strengthened medially and laterally by collateral ligaments.

• The medial collateral ligament is triangular and consists of anterior, posterior and middle bands. It extends from the medial epi-condyle of the humerus and the olecranon to the coronoid process of the ulna. The ulnar nerve is adjacent to the medial collateral ligament as it passes forwards below the medial epicondyle. Owing to the close proximity of the ulnar nerve to the humerus it is at risk in many types of injury, e.g. fracture dislocations, compression and even during surgical explorations.

• The lateral collateral ligament extends from the lateral epicondyle of the humerus to the annular ligament. The annular ligament is attached medially to the radial notch of the ulna and clasps, but does not attach to, the radial head and neck. As the ligament is not attached to the head this is free to rotate within the ligament.

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