Upper limb

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4 Upper limb

Chapter contents

Humerus

Fractures

Radius

Ulna

Fractures

Hand

Carpal bones
Metacarpal bones
Phalanges
Fractures

Elbow joint

Trauma

Wrist joint

Trauma

First carpometacarpal joint

Fractures

Humerus (Figs 4.1 and 4.2)

Type

Long bone.

image

Fig. 4.1 Right humerus (anterior aspect).

A–Lesser tuberosity (tubercle)

B–Greater tuberosity (tubercle)

C–Intertubercular sulcus (bicipital groove)

D–Deltoid tuberosity

E–Lateral border

F–Lateral supracondylar ridge

G–Lateral epicondyle

H–Radial fossa

I–Capitulum

J–Trochlea

K–Medial epicondyle

L–Coronoid fossa

M–Medial supracondylar ridge

N–Surgical neck

O–Anatomical neck

P–Head of humerus.

image

Fig. 4.2 Right humerus (posterior aspect).

1 – Head of humerus

2 – Anatomical neck

3 – Surgical neck

4 – Medial border

5 – Medial supracondylar ridge

6 – Olecranon fossa

7 – Medial epicondyle

8 – Groove for the ulnar nerve

9 – Trochlea

10 – Lateral epicondyle

11 – Lateral supracondylar ridge

12 – Spiral groove

13 – Greater tuberosity (tubercle).

Position

Largest bone in the upper limb.

Articulations

Head of humerus with the glenoid cavity of the scapula to form the shoulder joint.

Trochlea of the humerus with the trochlear notch of the ulna and the capitulum of the humerus with the head of the radius to form the elbow joint.

Main parts

Features of the upper end of the humerus

Head of humerus –

rounded.

Lesser tuberosity (lesser tubercle) –

anteriorly, the tendon of the subscapularis muscle is attached.

Greater tuberosity (greater tubercle) –

postero-laterally the supraspinatus tendon is attached to the upper aspect, infraspinatus tendon to the middle and the teres minor tendon to the lower, posterior aspect.

Intertubercular sulcus (bicipital groove) –

between the tuberosities. Contains the tendon of the long head of biceps.

Anatomical neck –

adjoining the head.

Surgical neck –

between the upper end and the shaft.

Features of the shaft of the humerus

Deltoid tuberosity –

for the attachment of the deltoid muscle, located on the antero-lateral surface.

Spiral groove –

for the radial nerve.

Medial border

Lateral border

Anterior border

Antero-lateral surface

Antero-medial surface –

in the middle of which is the nutrient foramen.

Posterior surface

Features of the lower end of the humerus

Lateral epicondyle –

above the capitulum.

Medial epicondyle –

above the trochlea.

Lateral supracondylar ridge –

distal end of the lateral border above the lateral epicondyle.

Medial supracondylar ridge –

distal end of the medial border above the medial epicondyle.

Capitulum –

rounded; articulates with the head of radius.

Trochlea –

pulley-shaped; articulates with the trochlear notch of the ulna. Has a large medial lip which forms the ‘carrying angle’ (see elbow joint).

Groove for the ulnar nerve –

posterior aspect, medial to the trochlea.

Olecranon fossa –

posteriorly receives the olecranon process of the ulna when the elbow joint is extended.

Coronoid fossa –

anteriorly receives the coronoid process of the ulna when the elbow joint is fully flexed.

Radial fossa –

anteriorly receives the head of the radius when the elbow joint is flexed.

Ossification

Primary centre

Shaft –

8th week of intrauterine life.

Secondary centres

Upper end –

3 centres:

head appears age 6 months;

greater tuberosity age 1–2;

lesser tuberosity age 4–5.

Fuse together age 6.

Fuse with shaft age 18–20.

Lower end –

4 centres:

capitulum appears age 1;

medial epicondyle age 4–6;

trochlea age 9–10;

lateral epicondyle age 12.

Lateral epicondyle, trochlea and capitulum fuse together at puberty.

Fuse with shaft age 14–16.

Medial epicondyle fuses with the shaft age 20.

Radiographic appearances of the humerus (Figs 4.3 and 4.4)

image

Fig. 4.3 Left humerus: anteroposterior projection.

A–Surgical neck

B–Shaft of humerus

C–Medullary cavity

D–Olecranon

E–Medial epicondyle

F–Head of radius

G–Capitulum

H–Lateral epicondyle

I–Olecranon and coronoid fossae

J–Deltoid tuberosity

K–Intertubercular sulcus (Bicipital groove)

L–Lesser tuberosity

M–Greater tuberosity

N–Anatomical neck

O–Head of humerus.

(From Bryan 1996.)

image

Fig. 4.4 Left humerus: lateral projection.

1 – Lesser tuberosity

2 – Intertubercular sulcus (Bicipital groove)

3 – Radius

4 – Ulna

5 – Olecranon

6 – Trochlea

7 – Epicondyles

8 – Supracondylar ridge

9 – Shaft of humerus

10 – Greater tuberosity

11 – Head of humerus.

(From Bryan 1996.)

Fractures

Surgical neck

Cause –

fall on an outstretched hand. Common in elderly people.

Example of treatment –

sling.

Shaft

Usually the middle third.

Spiral

Cause –

fall on the hand with a twisting force.

Example of treatment –

sling.

Transverse

Cause –

fall on the elbow with the arm abducted.

Example of treatment –

manipulation under anaesthesia.

Comminuted –

transverse or short oblique.

Cause –

direct blow on the arm.

Example of treatment –

plaster of Paris either to elbow or axilla to mid-forearm, with the elbow flexed.

Pathological –

proximal half of the shaft.

Cause –

underlying pathology.

Example of treatment –

sling; conservative treatment to alleviate pain.

Supracondylar

Cause –

fall on the hand with elbow flexed. Distal bone fragment is displaced backwards with the risk of damage to the brachial artery. Common injury in children.

Example of treatment –

reduction of the displaced fracture under anaesthesia. Limb immobilised in plaster of Paris with elbow flexed.

Condyles

Cause –

relatively uncommon and occurs mainly in children.

Example of treatment –

plaster of Paris.

Radius (Figs 4.5 and 4.6)

Type

Long bone.

image

Fig. 4.5 Right radius (anterior aspect).

A–Head of radius

B–Neck of radius

C–Radial tuberosity

D–Oblique line

E–Lateral border

F–Interosseous border

G–Lower end of radius

H–Radial styloid process.

Right ulna (anterior aspect).

I–Ulnar styloid process

J–Medial border

K–Interosseous border

L–Ulnar tuberosity

M–Coronoid process

N–Trochlear notch

O–Olecranon process

P–Radial notch.

image

Fig. 4.6 Right radius (posterior aspect).

1 – Head of radius

2 – Neck of radius

3 – Radial tuberosity

4 – Lateral border

5 – Interosseous border

6 – Radial styloid process

7 – Ulnar notch.

Right ulna (posterior aspect).

8 – Ulnar styloid process

9 – Head of ulna

10 – Interosseous border

11 – Medial border

12 – Olecranon process.

Position

Lateral bone of the forearm.

Articulations

Head of radius with the radial notch of the ulna to form the superior radio-ulnar joint and with the capitulum of the humerus to form part of the elbow joint.

Lower end of the radius with the head of ulna to form the inferior radio-ulnar joint and with the scaphoid and lunate to form part of the wrist joint.

Main parts

Features of the upper end of the radius

Head –

rounded, with a concave superior surface and an articular circumference.

Neck –

narrow portion, inferior to the head.

Radial tuberosity –

medial aspect, below the neck, provides attachment for the biceps brachii muscle.

Features of the shaft of the radius

Anterior border

Posterior border

Interosseous border –

attached to the lateral aspect of the ulna by an interosseous membrane to form the middle radio-ulnar joint.

Anterior surface –

the location of the nutrient foramen.

Posterior surface

Lateral surface

Features of the lower end of radius

Ulnar notch –

located on the medial aspect; articulates with head of ulna to form part of the inferior radio-ulnar joint.

Radial styloid process –

prominent process on the lateral aspect which can be palpated.

Distal surface –

for articulation with the carpal bones.

Ossification

Primary centre

Shaft –

8th week of intrauterine life.

Secondary centres

2 centres:

lower end of radius appears age 1;

head of radius appears age 4–5.

Head of radius unites with the shaft age 14–17.

Lower end of the radius unites with the shaft age 17–19.

Ulna (Figs 4.5 and 4.6)

Type

Long bone.

Position

Medial bone of the forearm.

Articulations

Radial notch of the ulna with the head of the radius to form the superior radio-ulnar joint.

Head of ulna with the ulnar notch of the radius to form part of the inferior radio-ulnar joint.

Trochlear notch of the ulna with the trochlea of the humerus to form part of the elbow joint.

(The head of the ulna is covered with an articular disc and therefore does not directly take part in the formation of the wrist joint.)

Main parts

Features of the upper end of the ulna

Olecranon process –

postero-superior projection. It can be palpated on the posterior aspect of the elbow joint; it gives attachment to the triceps tendon.

Coronoid process –

anterior projection.

Ulnar tuberosity –

situated on the anterior surface of the coronoid process; provides attachment to the brachialis muscle.

Trochlear notch –

between the coronoid and olecranon processes; articulates with the trochlea of the humerus.

Radial notch –

depression on the lateral aspect of the coronoid process; articulates with the head of radius.

Features of the shaft of the ulna

Anterior border

Posterior border

Interosseous border –

attached to the medial aspect of the radius by an interosseous membrane.

Anterior surface –

the location of the nutrient foramen.

Medial surface

Posterior surface

Features of the lower end of the ulna

Head –

small and rounded.

Ulnar styloid process –

prominent process which can be palpated on the medial aspect of the wrist joint.

Ossification

Primary centre

Shaft –

8th week of intrauterine life.

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