The superficial part of the back and the scapular region pdf - Upper limb

358

CHAPTER 9

and are described in detail in Chapter 12.

The underlying bones of the back are shown in Figure 9.27

axillary lymph nodes.

level of the iliac crests is upward into the posterior group of

of the skin of the back above the

lymph drainage

The

into the azygos veins and the inferior vena cava.

bar arteries. The veins correspond to the arteries and drain

branches of the posterior intercostal arteries and the lum

to the skin is from the posterior

blood supply

The

buttock.

bar nerves run downward to supply the skin over the

the skin, and the posterior rami of the upper three lum

1.24). The 1st and 8th cervical nerves do not supply

from the posterior rami of the spinal nerves (see Fig.

to the skin of the back is

sensory nerve supply

The

The Upper Limb

The Superficial Part of the Back and

the Scapular Region

Skin

Bones of the Back

Examination of the Axillary Lymph Nodes

The examination of the axillary lymph nodes always forms part of

examining hand high up in the axilla to the outer border of the

The examiner then gently places the tips of the fingers of the

der muscles and let the upper limb hang down at the side.

may be palpated against the medial side of

lateral nodes

forward against the posterior surface of the pectoralis major

With the patient standing or sitting, he or she is asked to place

the hand of the side to be examined on the hip and push hard

medially. This action of adduction of the shoulder joint causes

the pectoralis major muscle to contract maximally so that it

becomes hard like a board. The examiner then palpates the axil-

lary nodes (Fig. 9.26) as follows:

■

The anterior (pectoral) nodes may be palpated by pressing

muscle on the anterior wall of the axilla.

■

The posterior (subscapular) nodes may be palpated by

pressing backward against the anterior surface of the sub-

scapularis muscle on the posterior wall of the axilla.

■

The

the axillary vein. The examiner’s fingers are pressed laterally

against the subclavian vein and the pulsating axillary artery.

■

The central nodes may be palpated in the center of the ax-

illa between the pectoralis major (anterior wall) and the sub-

scapularis (posterior wall).

■

For the apical nodes, the patient is asked to relax the shoul-

first rib. If the nodes are enlarged, they can be felt.

the clinical examination of the breast.

C L I N I C A L N O T E S

superior nuchal line external occipital protuberance

mastoid process

spines of cervical vertebrae

first thoracic spine

spines of lumbar vertebrae

iliac crest

infraspinous fossa

spine of scapula

greater
tuberosity

acromion

clavicle

supraspinous fossa

seventh

third

FIGURE 9.27

Bones of the back.

Basic Anatomy

the thoracic wall and the vertebral column are shown in

The muscles on the back connecting the upper limb to

359

Muscles

Figure 9.28 and are described in Tables 9.1 and 9.2, and the

with the cervical nerves, supplies the trapezius muscle.

at the junction of its middle and lower thirds and, together

beneath the anterior border of the trapezius muscle (Fig. 9.28)

third and fourth cervical nerves. The accessory nerve runs

It is accompanied by branches from the anterior rami of the

posterior triangle of the neck on the levator scapulae muscle.

The spinal part of the accessory nerve runs downward in the

Nerve XI)

Spinal Part of the Accessory Nerve (Cranial

vessels pass backward through this space (Fig. 9.29).

The axillary nerve and the posterior circumflex humeral

neck of the humerus.

by the long head of the triceps and laterally by the surgical

below by the teres major muscle. It is bounded medially

by the subscapularis and capsule of the shoulder joint and

immediately below the shoulder joint. It is bounded above

The quadrangular space is an intermuscular space, located

Quadrangular Space

weakness.

cuff is deficient inferiorly, and this is a site of potential

anterior, superior, and posterior aspects of the joint. The

movements at the shoulder joint. The cuff lies on the

the humerus in the glenoid cavity of the scapula during

The tone of these muscles assists in holding the head of

very important role in stabilizing the shoulder joint.

sule of the shoulder joint (Fig. 9.34). The cuff plays a

minor muscles, which are fused to the underlying cap

subscapularis, supraspinatus, infraspinatus, and teres

The rotator cuff is the name given to the tendons of the

in Figure 9.29 and are described in Table 9.3.

muscles connecting the scapula to the humerus are shown

Rotator Cuff

Nerves

semispinalis capitis

splenius capitis

levator scapulae

spinal part of accessory nerve

supraspinatus

infraspinatus

deltoid

teres minor

teres major

postvertebral muscles

external intercostal

serratus posterior inferior

latissimus dorsi

gluteus maximus

cutaneous branches of posterior rami

of upper three lumbar nerves

internal oblique of abdomen

external oblique of abdomen

lumbar fascia

latissimus dorsi

cutaneous branches of posterior rami of thoracic nerves

lateral and long heads

of triceps

deltoid

infraspinatus

rhomboid major

rhomboid minor

posterior rami of cervical nerves

trapezius

splenius capitis

third occipital nerve

sternocleidomastoid

greater occipital nerve

trapezius

FIGURE 9.28

Superficial and deep muscles of the back.

360

CHAPTER 9

The Upper Limb

circumflex scapular artery

levator scapulae

supraspinatus

rhomboid minor

rhomboid major

infraspinatus

latissimus dorsi

teres major

long head of triceps

lateral head of triceps

profunda artery

radial nerve

posterior circumflex

humeral artery

upper lateral cutaneous

nerve of arm

deltoid

axillary nerve

teres minor

infraspinatus

supraspinatus tendon

suprascapular ligament

suprascapular nerve and artery

deep branch of superficial cervical artery

dorsal scapular nerve

FIGURE 9.29

y nerve to the

Muscles, nerves, and blood vessels of the scapular region. Note the close relation of the axillar

shoulder joint.

Rotator Cuff Tendinitis

deltoid can then take over and complete the movement to a

the arm is passively assisted for the first 15° of abduction, the

tendon is unable to initiate abduction of the arm. However, if

ment of abduction. The patient with a ruptured supraspinatus

the main function of the supraspinatus muscle is to hold the

movement of the shoulder joint. It will be remembered that

of the tendon seriously interferes with the normal abduction

spinatus tendon can become calcified or rupture. Rupture

without surgery using nonsteroidal anti-inflammatory drugs and

the deltoid. Degenerative changes in the bursa are followed by

During abduction of the shoulder joint, the supraspinatus tendon

presses the humeral head into the glenoid cavity. Lesions of the

The rotator cuff, consisting of the tendons of the subscapularis,

supraspinatus, infraspinatus, and teres minor muscles, which

are fused to the underlying capsule of the shoulder joint, plays

an important role in stabilizing the shoulder joint. The rotator cuff

cuff are a common cause of pain in the shoulder region.

Failure of the cuff is due to either wear or tear. Wear is age

related. Excessive overhead activity of the upper limb may be the

cause of tendinitis, although many cases appear spontaneously.

is exposed to friction against the acromion (Fig. 9.30). Under nor-

mal conditions, the amount of friction is reduced to a minimum

by the large subacromial bursa, which extends laterally beneath

degenerative changes in the underlying supraspinatus tendon,

and these may extend into the other tendons of the rotator cuff.

Clinically, the condition is known as subacromial bursitis, supra-
spinatus tendinitis, or pericapsulitis. It is characterized by the

presence of a spasm of pain in the middle range of abduction

(Fig. 9.30), when the diseased area impinges on the acromion.

Extensive acute traumatic tears are best repaired surgically as

soon as possible. Small chronic cuff injuries are best managed

muscle exercises.

Rupture of the Supraspinatus Tendon

In advanced cases of rotator cuff tendinitis, the necrotic supra-

head of the humerus in the glenoid fossa at the commence-

right angle.

C L I N I C A L N O T E S

Basic Anatomy

361

130

FIGURE 9.30

Subacromial bursitis, supraspinatus tendinitis,

The axillary nerve has the following branches:

Branches

rior branches (Fig. 9.29).

humerus. It terminates by dividing into anterior and poste

joint and with the medial side of the surgical neck of the

ship with the inferior aspect of the capsule of the shoulder

nerve passes through the space, it comes into close relation

the posterior circumflex humeral artery (Fig. 9.29). As the

passes backward and enters the quadrangular space with

brachial plexus (C5 and 6) in the axilla (see page XXX). It

The axillary nerve arises from the posterior cord of the

Axillary Nerve

the shoulder joint.

supplies the supraspinatus and infraspinatus muscles and

ular notch, to reach the supraspinous fossa (Fig. 9.29). It

which bridges the suprascap

suprascapular ligament,

neck. It runs downward and laterally and passes beneath

brachial plexus (C5 and 6) in the posterior triangle in the

The suprascapular nerve arises from the upper trunk of the

Suprascapular Nerve

or pericapsulitis showing the painful arc in the middle range

of abduction, when the diseased area impinges on the

lateral edge of the acromion.

the

Arterial Anastomosis and Ligation of the Axillary

The existence of the anastomosis around the shoulder joint

Artery

is vital to preserving the upper limb should it be necessary to

ligate the axillary artery.

C L I N I C A L N O T E S

Accessory Nerve Injury

The accessory nerve can be injured as the result of stab

wounds to the neck.

C L I N I C A L N O T E S

Axillary Nerve Injury

The axillary nerve can be injured in dislocations of the shoul-

der joint.

C L I N I C A L N O T E S

■

around the surgical neck of the humerus (Fig. 9.31).

Both the circumflex arteries form an anastomosing circle

posterior circumflex humeral artery

The

anterior circumflex humeral artery

The

of the scapula, respectively.

branch supply the subscapular and infraspinous fossae

and its circumflex scapular

subscapular artery

The

Branches from the Axillary Artery

branch that runs down the medial border of the scapula

which gives off a deep

superficial cervical artery,

The

supraspinous and infraspinous fossae of the scapula

which is distributed to the

suprascapular artery,

The

Branches from the Subclavian Artery

tive of the position of the arm (Fig. 9.31).

quate blood flow takes place into the upper limb irrespec

artery and the axillary artery, thus ensuring that an ade

anastomosis exists between the branches of the subclavian

of its lumen. To compensate for this, an important arterial

kinking of the axillary artery and a temporary occlusion

The extreme mobility of the shoulder joint may result in

the deltoid muscle.

joint, two muscles, and the skin covering the lower half of

It is thus seen that the axillary nerve supplies the shoulder

(Fig. 9.29)

upper lateral cutaneous nerve of the arm

then emerges from the posterior border of the deltoid as

and a few branches to the deltoid,

the teres minor muscle

branch to

which gives off a

posterior terminal branch,

lower part.

cle; it supplies the deltoid and the skin that covers its

surgical neck of the humerus beneath the deltoid mus

which winds around the

anterior terminal branch,

to the shoulder joint

articular branch

■

the

Arterial Anastomosis around the

Shoulder Joint

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-

■