Upper Limb Anatomy Flashcards
What veins in the upper limb are considered suitable for cannulation?
Basilic vein
Cephalic vein
Median cubital vein and the median vein of the forearm.
What are the relevant structures in this image?
Radial nerve
Musculocutaneous nerve
Lateral cutaneous nerve
Medial cutaneous nerve
Ulnar nerve
Median nerve (associated with brachial artery)
Label the relevant nerves in this image
Radial nerve
Median nerve
Ulnar nerve
On ultrasound how to differentiate the external and internal carotids
External is medial
Internal is lateral.
Draw the brachial plexus
What does the radial nerve innervate?
All posterior muscle groups in brachiam and antebrachium
All posterior skin sensation
What does the axillary nerve innervate?
Muscles: deltoid and teres minor
Skin: Superolateral arm
What does the median nerve innervate?
Muscles: anterior forearm and radial hand LOAF
Skin : Lateral hand
What does the ulnar nerve innervate?
Flexor carpi ulnaris
Medial 1/2 flexor digitorum profundus
Hand muscles (minus LOAF)
Skin - medial hand (Palmar and dorsal)
Define carpal tunnel syndrome
Compression of the median nerve at the wrist
Most common nerve entrapment.
Typically non-traumatic
What are the typical symptoms of carpal tunnel syndrome?
Pain (burning), tingling, numbness in median nerve area = often at night
Palmar branch and digital branch - - digits 3.5
Weakness of opponents policies, abductor policic brevis + Flexor PB, index and middle lumbricals (thenar eminence atrophy if chronic)
Where are the anchor points of the carpal ligament?
Hook of hamate
Pisiform
Ridge of trapezium
Tubercle of Scaphoid
Roof = flexor retinaculum
What is the pathophysiology of carpal tunnel
Median nerve trapped - creates local nerve ischemia
Overuse syndrome - swelling of tendons and synovium
What are the risk factors for carpal tunnel syndrome?
Females (smaller tunnel)
Genetic (smaller tunnel)
Older age
Pregnancy - resolve with delivery
Heavy manual work and vibrating machinery
Thyroid disease
Trauma
Rheumatoid arthritis
Ganglion cyst
What are the tests for carpal tunnel?
Tinels sign - tap over median nerve at wrist - tingling in 50%
Phalens test - hold flexion for 60second - tingling (70%)
Durkans test - press over carpal tunnel for 30seconds (87%)
What is the diagnosis of carpal tunnel based on?
Clinical diagnosis
May also do nerve conduction tests: confirm, localise, select for surgery, baseline/prognosis, complex/other neuropathies, persistent or recurrent symptoms
What is the first treatment for carpal tunnel syndrome?
Night splints - hold slightly extended/neutral
Activity modification - avoid flexion and extension
What is the second line treatment for carpal tunnel syndrome?
Steroid injection (area NOT nerve) - temporary improvement -> pregnancy or mild
Surgery
What surgery is used for carpal tunnel syndrome?
Cut flexor retinaculum slightly
Relieve pressure and increase size of carpal tunnel
Keep incision to ulnar side of thenar crease (reduces risk to variable palmar branches)
Why are tendon lacerations dangerous?
Slow healing with frequent disability
Difficult to treat
What is the epidemiology of tendon laceration in the hand?
Younger men
Relatively rare
Most commonly little fingers are affected
33% digital nerve also cut
What structures assist in finger flexions?
Tends run through pulleys
Pulleys contrain tendons
Increased mechanism advantage in grip
Pulley/tendon is lubricated so able to glide through
How to test for damage to FDP and FDS?
FDP - ask to bend at distal interphalangeal joint whilst holding proximal straight
FSP - hold other fingers flat - flex middle finger
What is the sign of lacerated tendon on fingers?
Pointing sign - fingers not in line when hand relaxed - one finger (the damaged one points in the wrong direction
What restrictions on movements should be put on after tendon fixation in the fingers?
Flexor tendon damage - limit extension
Extensor tendon damage - limit flexion.
What is the clinical sign wrist drop?
Radial nerve palsy
Unable to extend the wrist
What is claw hand a clinical sign of?
Ulnar nerve palsy
Unable to extend the fingers in the ulnar region (little and fourth) - due to weakened intrinsic muscles compared to extrinsic flexors -> presents with flexion at the PIP
What is hand of benediction a clinical sign of?
Median nerve palsy
Unable to flex the median LOAF
The brachial plexus if formed by the XXXX rami of spinal nerve roots XXXX
Anterior
C5-T1
The cords of the brachial plexus are named relative to their position to the xxxxx
Axillary artery
Which nerves runs over the medial epicondyle of the arm?
Ulnar nerve
What is the relationship between hte brachial artery and the median nerve?
Arises from posterior cord
Initiallt runs lateral to the brachial artery then crosses over anteriorly to run medially through the ACF.
Related to the brachial plecus what is the function of the long thoracic nerve?
Originates from routes C5 to C7
Innervates the serratus anterior muscle
Damage leads to winging of the scapula
What muscles are responsible for shoulder abduction and which nerve supplies these?
Deltoid
Axillary
What is the difference between a nerve rupture and a nerve avulsion?
Avulsion = near root torn awat from spinal cord
Rupture - nerve torn into two
A gymnast presents with a medially rotated arm after injury?
What may cause this? - nerve and muscles
C5,6,7 are injured
Suprascular and axillary nerve
Supraspinatours, infraspinatous and terest minor (the lateral rotators) are not functional.
What is Erbs Palsy?
Also called brachial plexus palsy - injury to C5/C6
Arm weakness resulting from traumatic damage to the brachial plexus e.g during birth or gymnastics
Presents - with waiters tip appearance - internally rotates shoulder, extended elbow, flexed wrist pronated, lack of movement
What abnormality is shown in this image?
What muscles and nerve is responsible for this?
Claw hand
Unopposed extension from extension digotirum on 4th and 5th digits
Due to loss of ulnar nerve damage proximal to elbow = flexor digitorum profundis medially.
What sign is shown in this hand when asked to form a fist?
What muscles and nerves are responsible for this?
Hand of benediction
Median nerve damage
Commonly at carpal tunnel -> unable to flex 1st and 2nd digit
