12.2 Shoulder Surgery

Question 1

a) Which specific nerves must be blocked to achieve effective local anaesthesia for shoulder surgery?
(6 marks)

Answer 1

1. Supraclavicular nerve (C3,4)

(for awake surgery, would either need to
perform superficial cervical plexus block
OR infiltrate around posterior port site).

Skin above clavicle,
shoulder tip and first two
intercostal spaces anteriorly.

2. Upper lateral cutaneous nerve of arm,
   branch of axillary nerve (C5,6).

Skin over deltoid.

3. Medial cutaneous nerve of arm,
   medial cord of brachial plexus (C8, T1).

Skin of medial arm and axilla.

4. Suprascapular nerve (C4–6).
   Acromioclavicular joint,
   capsule, glenohumeral joint.
5. Axillary nerve (C5,6).
   Inferior aspect of capsule
   and glenohumeral joint.
6. Musculocutaneous nerve (C5–7).
   Very variable input.

Question 2

b) What are the possible neurological complications of an interscalene block? (6 marks)

Answer 2

> > Phrenic nerve block or damage.

> > Stellate ganglion block
or damage leading to Horner’s syndrome.

> > Spinal anaesthesia.

> > Epidural anaesthesia.

> > Direct nerve damage of
any of the nerves intended to be blocked,
causing temporary or permanent neuropraxia.

> > Syrinx or cavity formation
in cervical cord due to injection
into it resulting in paraplegia.

Question 3

c) Outline the measures available to reduce all types of neurological damage during shoulder surgery.
(8 marks)

Answer 3

Nerve block:
» Adequate training and
experience of the anaesthetist.

> > Minimise risk of infection and neurotoxicity:
full asepsis, use of 0.5%
chlorhexidine spray, air dried.

> > Minimise risk of neuropraxia:
use of ultrasound, awake patient,
appropriate needle length,
low pressure injection.

> > Avoid nerve blocks altogether.

General anaesthesia:
>> Risk of hypotension causing 
reduced cerebral blood flow especially
if deckchair position: 
ensure adequate filling, appropriate use of
vasopressors and leg elevation,
 avoid excessive depth of anaesthesia.

Positioning:
» Risk of neuropraxias:
careful positioning on table,
padding to avoid peripheral nerve compression
(ulnar and common peroneal at risk in lateral position),

avoid excessive stretch on
brachial plexus in deckchair
or lateral position.

Surgery:

> > Risk of contusion or traction
(rarely laceration) of nerves (axillary nerve

close to inferior shoulder capsule is particularly vulnerable):
minimised by appropriate training,
careful technique.

> > Risk to brachial plexus by arm manipulation: minimise manipulation.