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Professor Emeritus Moira O’Brien

FRCPI, FFSEM, FFSEM (UK), FTCD

Trinity College

Dublin

Clinical Anatomy of Elbow

Injuries to Elbow and Wrist

• Skin

• Bones

• Muscles, tendons

• Nerves

• Blood vessels

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Bones of Elbow

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Elbow Joint

• Synovial hinge joint• One degree of freedom• Uniaxial • The articular surfaces are the

trochlea and the capitulum of the humerus

• The trochlear notch of the ulna • The superior aspect of the

head of the radius

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• When the elbow is extended,

medial epicondyle,

olecranon and

lateral epicondyle

are in a straight line• When flexed, they form a

triangle

Elbow Joint

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Capsule of Elbow Joint

Capsule surrounds the joint• Anteriorly to the margins of the

coronoid and radial fossae of the humerus

• Medially and laterally just beyond the articular margin

• Excluding the medial and lateral epicondyles to which the common flexor and extensor origins are attached

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Capsule of Elbow Joint

Capsule surrounds the joint• Posteriorly to the margins of

the olecranon fossa• Inferiolaterally it is inserted

into the annular ligament of the superior radioulnar joint

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Synovial Membrane

• Lines the capsule and non- articular structures inside the capsule

• Continuous inferiorly with synovial membrane of superior radio-ulnar joints

• Annular ligament covered with articular cartilage

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• Between the capsule and synovial membrane are three other pads of fat

• The largest, at the olecranon fossa, is pressed into it by triceps during flexion

• Two, at the coronoid and radial fossae, are pressed in by brachialis during extension

• They are all slightly displaced in contrary movements

Synovial Membrane MOB TCD

Synovial Membrane

• Smaller synovial-covered tags of fat project into the joint near constrictions flanking the trochlear notch, covering small non-articular areas of bone

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Medial or Ulnar Collateral Ligament

• Thick triangular ligament attached superiorly to the medial epicondyle

• Its anterior band is attached distally to the tubercle on the upper medial margin of the coronoid process

• The posterior band is attached to the medial margin of the olecranon

• A thinner portion, the oblique band, unites both bands

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Medial or Ulnar Collateral Ligament

• The ulnar nerve lies on the medial ligament

• The anterior band may be ruptured in throwing events

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Lateral or Radial Collateral Ligament

• The ligament is attached to the lateral epicondyle

• Fans out to be attached to the upper border of the annular ligament

• The annular ligament is attached to the margins of the radial notch of the ulna

• It is part of the articulation of the superior radioulnar joint

• Covered with articular cartilage

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Medial Structures of Elbow

Common flexor origin, ulnar nerve

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Anterior Relations

• Brachialis lies on capsule• Medial to lateral• Common flexor origin• Median nerve • Brachial artery covered by bicipital

aponeurosis• Biceps• Radial nerve• Superficial • Deep branch is posterior

interosseus nerve

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Posterior Relations

• Triceps• Anconeus• Olecranon bursa• Ulnar nerve posterior to medial

epicondyle• Common extensor origin

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Extensor Tendons

• Brachioradialis• Extensor carpi radialis longus• Extensor carpi radialis brevis*• Extensor digitorum communis • Extensor digiti minimi• Extensor carpi ulnaris

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Posterior Relations

olecranon bursitismedial

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Posterolateral

• Below lateral epicondyle• Head of radius• Behind the extensors of the forearm• Posterior interosseous nerve

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Lateral Elbow MOB TCD

Movements of Elbow Joint

• Flexion and extension• Semiflexion is least pack position• Flexion of the elbow is limited by:• Impact of the radial head in the

radial fossa• Coranoid process against the

coronoid fossa• Tension of posterior part of capsule• Tension of triceps• Apposition (contact) between soft

tissues of forearm and upper arm

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Flexion of Elbow

• Main flexors• Brachialis, musculocutaneous

(C5,6) • Biceps, musculocutaneous

(C5,6) • Weak flexors• Common flexor origin, median

(C6,7)• Except flexor carpi ulnaris,

ulnar nerve (C6,7)• Brachioradialis, radial (C5,6)

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Common Flexor Origin

• Pronator teres • Flexor carpi radialis • Flexor digitorum superficialis• Palmaris longus• Median nerve (C6,7)• Flexor carpi ulnaris• Ulnar nerve (C6,7)

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Elbow

• Biceps brachii Musculocutaneous C5,6• Brachialis Musculocutaneous C5,6• Pronator teres Median C6,7• Supinator posterior Interosseous C5,6Anderson & Hall, 1995

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Extension of Elbow

• Triceps is the main extensor• Weak are extensors from

common extensor origin• Nerve supply radial (C7,8)• Extension of the elbow is

limited by:• Impingement of the olecranon

of the ulna on the olecranon fossa of the humerus

• Tension of the anterior arm muscles and collateral ligaments

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Biceps Brachii

• Crosses shoulder, elbow and superior radioulnar

• A long head arising from the supraglenoid tubercle

• The adjoining portion of the labrum within the capsule of the shoulder joint

• It passes above the head of the humerus

• Leaves the joint below the transverse ligament, which acts as a retinaculum

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Biceps Brachii

• It is surrounded by synovial membrane, which extends inferiorly to the lower margin of the teres major, i.e. the posterior fold of the axilla

• Short head arises from the coracoid process with the coracobrachialis

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• The two heads unite to form a fleshy belly, which becomes a tendon, inserted into the posterior aspect of the radial tuberosity

• The bicipital aponeurosis extends from its medial margin, passing anterior to the brachial artery and the median nerve, fuses with deep fascia of the forearm and the medial margin of the ulna

• A bursa separates it from the radius Nerve supply is musculocutaneous nerve C5,6,7

Biceps Brachii MOB TCD

Action of Biceps Muscle

• Helps to stabilise and flex the shoulder

• Its role as a dynamic stabiliser of the gleno-humeral joint is particularly important in the late cocking phase of throwing

• Flexes the elbow• The most powerful supinator

of the forearm when the elbow is flexed

• The action of the biceps is weak at the shoulder and powerful at the elbow

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Brachialis Muscle

• Arises from the anterior aspect of the shaft of the humerus below the deltoid tuberosity

• It is inserted into the anterior aspect of the coranoid process of the ulna and the capsule of the elbow joint

• It lies directly anterior to the elbow joint and is only a flexor of the elbow

• The musculocutaneous nerve

C5,6,7 supplies it

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Coracobrachialis Muscle

• It arises from the coracoid process, together with the short head of the biceps brachii

• Inserts into the middle of the medial surface of the humerus

• Helps to flex and adduct the arm at the shoulder joint

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Coracobrachialis Muscle

• The coracobrachialis muscle also helps to stabilise the shoulder joint

• A persistent lower head may remain as supra-trochlear spur or

• Ligament of Struthers, attached to the medial epicondyle of the humerus

• May compress the median nerve or the brachial artery

• Musculo-cutaneous nerve C5,6,7

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Pain in Elbow and Wrist

• Must rule out referred pain from cervical spine

• Upper thoracic spines• Increased neural tension

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Test for Stability of Elbow

• Varus and valgus stresses• 0 and 30 degrees of flexionBehr & Altchek, 1997

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Adult Elbow Injuries

Fractures• Distal humerus• Radial head and radial neck• OlecranonDislocations• Simple• Fracture, dislocationBehr & Altchek, 1997

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Elbow Pain

• Loose bodies• Pain• Locking

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Medial Elbow Pain

• Referred pain• Medial epicondylitis• Medial collateral ligament

injury• Ulnar nerve injury• Avulsion of medial

epicondyle • Apophysitis • Degenerative changes of

medial elbowBrukner & Khan, 1997

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Test for Medial Epicondylitis

Stabilise flexed elbow• Palpate medial epicondyle• Slowly supinate the forearm• Extend wrist and elbow, while patient resistsAnderson & Hall, 1995

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Lateral Elbow Pain

• Lateral epicondylitis (tennis elbow)

• Entrapment of the radial nerve• Degenerative changes of the

radio-humeral joint• Posterolateral rotatory instability• Cervical spine problemsBehr & Altchek, 1997

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Lateral Epicondylitis

• Extensor carpi radialis brevis in most cases

• Anterior edge of extensor digitorum communis 30%

Less frequently• Extensor carpi radialis longus• Extensor carpi ulnarisNirschl, 1993

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Lateral Epicondylitis; Pathology

Tendonosis

1. Repetitive microtrauma

2. Angioplastic hyperplasia

3. Fibrosis

4. Granulation tissue

5. Mucoid degenerationNirschl, 1993

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• Racquet sports • Backhand• Throwing sports• Golfers• Musicians• Labourers Behr & Altchek, 1997

Lateral Epicondylitis MOB TCD

• Stabilise flexed elbow• Resisted extension and radial deviation of wrist• Passive stretching of wrist extensors• Resisted extension of extensor digitorum communis of

middle finger with wrist extendedAnderson & Hall, 1995

Test for Lateral Epicondylitis MOB TCD

Elbow Nerve Compression

• Radial tunnel syndrome• Posterior interosseous nerve

syndrome• Cubital tunnel syndrome• Pronator syndrome• Anterior interosseous nerve

syndromeBehr & Altchek, 1997

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Test for Ulnar Neuritis

• Tap ulnar nerve on posteromedial aspect of medial epicondyle

• Completely flex elbow and hold for five minutes• Positive = tingling along nerveAnderson & Hall ,995

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Elbow Effusion

• Fullness in the triangular area bounded by

• The radial head• The lateral epicondyle• The tip of the olecranonBehr & Altchek, 1997

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Pediatric Elbow Injuries

• Fractures lateral condyle and olecranon

• Physeal fractures of radial head

• Supracondylar fracture and fracture of radial neck

• ‘Little League elbow’• Osteochondritis

dissecans of capitellumBehr & Altchek, 1997

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• Traction apophysitis ‘Little League elbow’

• Due to repeated stress on medial epicondyle

by contraction of the flexor pronator group

• Valgus loads during late cocking and acceleration stages of throwing

Behr & Altchek, 1997

Pediatric Elbow Injuries MOB TCD

Elbow Dislocation MOB TCD

Osteochondritis Dissecans of Capitellum

• Avascular necrosis of subchondral bone• Repetitive trauma to blood supply in dominant arm in

athletic children >8 years • Female gymnasts• Male baseballPappas, 1982

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