A 64-year-old woman fell down the stairs and was admitted to the emergency department with severe left shoulder pain. Upon examination, her shoulder showed signs of dislocation and swelling below the clavicle. Tests also revealed sensory deficits in the skin of her left arm, forearm, hand and fingers, indicating damage to the axillary and radial nerves. The physician diagnosed a subcoracoid dislocation of the left shoulder joint complicated by damage to the axillary and radial nerves, caused by the initial trauma and further displacement of the humerus by the pulling muscles. A thorough knowledge of shoulder anatomy and nerve distribution was required to make this diagnosis and interpret the clinical findings.

1. A 64-year-old woman fell down the stairs and was admitted to the emergency department with severe left shoulder pain.
While she was sitting up, her left arm was by her side and her left elbow was flexed and supported by her right hand.
Inspection of the left shoulder showed loss of the normal rounded curvature and evidence of a slight swelling below the
left clavicle. The physician then systematically tested the cutaneous sensibility of the left upper limb and found severe
sensory deficits involving the skin of the back of the arm down as far as the elbow, the lower lateral surface of the arm
down to the elbow, the middle of the posterior surface of the forearm as far as the wrist, the lateral half of the dorsal
surface of the hand, and the dorsal surface of the lateral three and a half fingers proximal to the nail beds.
A diagnosis of subcoracoid dislocation of the left shoulder joint was made, complicated by damage
to the axillary and radial nerves.
The head of the humerus was displaced downward to below the coracoid process of the scapula
by the initial trauma and was displaced further by the pull of the muscles (subscapularis,
pectoralis major).
The loss of shoulder curvature was caused by the displacement of the humerus (greater
tuberosity) medially so that it no longer pushed the overlying muscle (deltoid) laterally. The
extensive loss of skin sensation to the left upper limb was the result of damage to the axillary
and radial nerves.
For a physician to be able to make a diagnosis in this case and to be able to interpret the clinical findings, he or she must
have considerable knowledge of the anatomy of the shoulder joint. Furthermore,
the physician must know the relationship of the axillary and radial nerves to the joint and the
distribution of these nerves to the parts of the upper limb.
Adopted from Snell ANATOMY………………………..

2. ARTERIAL SUPPLY TO
THE UPPER LIMB
5 main vessels (proximal to distal)
Subclavian artery
Axillary artery
Brachial artery
Radial artery
Ulnar artery
mnemonic…”SUBAR”

4. On the right, Subclavian artery arises from the brachiocephalic
trunk, on the left, it branches directly from the arch of aorta
It travels laterally towards the axilla and enters the axilla at the
lateral border of the first rib and is renamed as axillary artery
Subclavian artery

6. Axilla: Axillary artery and its
branches
Lies deep to the pectoralis minor and the 3 cords of brachial
plexus
It is divided into 3 parts based on its relative position to the p.
minor
1st part…proximal to p. minor (superior thoracic artery)
2nd part…posterior to p. minor (thoracoacromial artery)
3rd part…distal to p. minor (subscapular artery , anterior and
posterior circumflex arteries)

8. Cont’d
The anterior and posterior circumflex humeral arteries form an
anastomotic network around the surgical neck of the humerus and
can be damaged in cases of fracture
At the lower border of the teres major muscle, the axillary artery
is renamed the brachial artery.
CLINICAL RELEVANCE...the axillary artery may be dilated to
morethan twice each original size, hence compressing the brachial
plexus producing neurological symptoms such as paraesthesia and
muscle weakness.

9. Brachial artery
It is a continuation of the axillary artery past the lower border of
teres major. It is the main supply of blood to the arm
Immediately distal to the teres major, the brachial artery gives rise
to the profunda brachii(deep artery) which travels with the radial
nerve in the radial nerve groove of the humerus and supplies
structures in the posterior aspect of the upper arm e,g triceps
brachii. The profunda brachii terminates by contributing to an
anastomotic network around the elbwo joint

10. Cont’d
The brachial artery proper descends down the arm
It moves through the cubital fossa underneath the bicipital
aponeurosis, the brachial artery terminates by bifurcating
into the radial and ulnar arteries
Refer to the offline link below for radial and ulnar arteries

11. Clinical relevance
Occlusion or laceration of the brachial artery
The arm has relatively good anastomotic supply. This means
that it is well protected from ischaemia in cases of temporary
or partial occlusion of the brachial artery
However, if the artery is completely occluded or severed, the
resulting ischaemia can cause necrosis of forearm muscles.
Muscle fibres are replaced by scar tissue and shorten
considerably…this can cause a characteristic flexion or
clawlike deformity of the hand, fingers, and wrist called
Volkmann’s ischaemic contracture
Permanent shortening/contracture of the forearm muscles
usually resulting from injury…more common in children

12. Forearm: Radial and
Ulnar arteries
The radial and ulnar arteries are formed by the bifurcation of
the brachial artery within the cubital fossa
The radial artery supplies the posterolateral aspect of the
forearm, it also contributes to anastomotic networks
surrounding the elbow joint and carpal bones
Ulnar artery supplies the anteromedial aspect of the
forearm, it contributes to the anastomotic network
surrounding the elbow joint.

16. COMPILEDBYDR.KWIZERA DENISNGANIZI2019