1. Forearm, Wrist and Hand Anatomy
Alastair Stephens
Dan Waite

2. Label the carpal bones of the wrist.
Scaphoid Lunate Triquetral Pisiform Hamate Capitate Trapezoid Trapezium
What can a fracture of the scaphoid result in? H C Td Tm T
The blood flow can be disrupted as it runs distal to proximal and this can lead to avascular necrosis. S P L

3. What are the boundaries of the cubital fossa?
Inter-epicondylar line
Superior border
Aponeurosis of biceps
Covers roof of fossa and protects the median nerve
Brachioradialis
Lateral border
Pronator teres
Medial border

4. What are the boundaries of the anatomical snuffbox?
What can be palpated in the anatomical snuffbox?
EPL
Radial artery
Radial styloid process
Scaphoid
Trapezium
Base of 1st metacarpal
Cephalic vein passes over snuffbox
EPB & AP

5. What is the carpal tunnel formed by?
The retinaculum attaches to pisiform, hook of hamate, scaphoid tubercle and trapezium tubercle
Passes ~2cm distal to distal wrist crease HH TT
What passes through the carpal tunnel? P ST
Flexor digitorum superficialis (x4)
Flexor digitorum profundus (x4)
Flexor pollicis longus
Median nerve

6. What are the sensory distributions of the hand
What are the sensory distributions of the hand? Where do you test for each nerve?
Ulnar
Median
Radial
Ulnar nerve on the 5th digit
Median nerve on the 2nd digit
Radial nerve over the first dorsal interosseous * * *

7. What is the innervation to these compartments?
Anterior Forearm
Posterior Forearm
Hand
Everything is radial nerve
Everything is median nerve
Except:
Flexor carpi ulnaris (ulnar)
Flexor carpi profundus to digits 4 and 5 (ulnar)
Everything is ulnar nerve
Except:
Thenar muscles (median)
Lumbrical to digits 2 and 3 (median)
Ulnar nerve
Radial nerve
Median nerve

8. What movements occur at the radio-ulnar joints?
Proximal radio-ulnar joint
Nursemaid’s elbow
Pronation: Median Nerve
Pronator teres and pronator quadratus
Supination: Musculocutaneous Nerve and Radial Nerve
Biceps and Supinator
Radial tuberosity
Avulsion fracture by biceps
Distal radio-ulnar joint

9. What is Froment’s sign? What is Allen’s test?
Allen’s test determines if there are any vascular anomalies between the radial and ulnar arteries prior to any vascular procedures.
The radial and ulnar arteries are compressed and ulnar released, noting if the whole hand becomes perfused again.
Ulnar nerve damage leads to adductor pollicis brevis paralysis, leading to excess thumb flexion whilst pinching.

10. What’s the difference between Ulnar Claw and Hand of Benediction?
Name
Nerve damaged
Typical presentation
Digits affected
Muscle Involved
Ulnar Claw
Ulnar nerve lesion at the wrist
At rest
Digits 4 and 5
The lumbricals to digits 4 and 5 are paralysed. This leads to a loss of flexion at the MCP joint and a loss of extension at the IP joints. This results in the hyperextension of the MCP joints by the unopposed extensor digitorum, and the flexion of the IP joints by the unopposed flexor digitorum profundus and superficialis.
Hand of Benediction
Median nerve lesion at the wrist or elbow
Attempting to make a fist
Digits 2 and 3
The lumbricals and flexor digitorum profundus tendons to digits 2 and 3 are paralysed. This leads to a loss of flexion at the MCP joint and the DIP joints. If the patient is asked to make a fist, they will be able to flex digit 4 and 5 but not digits 2 and 3.

11. Right Lung Apex Tumour (pancoast tumour)
Steve, 72, comes to his GP complaining that he’s unable to move all of the digits on his right hand except his thumb. During the consultation, the GP notices Steve has a hoarse voice and a droopy right eyelid. What is the likely diagnosis, and explain why?
Right Lung Apex Tumour (pancoast tumour)
Klumpke’s Palsy
Compression of the C8-T1 nerve roots leads to paralysis and wasting of the small muscles of the hand (claw hand deformity)
Right recurrent laryngeal nerve compression
Recurs at the right lung apex
Horner’s Syndrome
Compression of the cervical sympathetic chain

12. Thank you.
Any questions?