9. Surgical and functional anatomy of the hand

Question 1

What’s the first thing you see when you remove the skin on the palm of the hand?

Answer 1

palmar fascia

Question 2

palmar fascia

Answer 2

Tough layer anchoring skin to skeleton

Extension of forearm fascia

Tightened by palmaris longus (apes)

Dupuytren’s disease

Question 3

Dupuytren’s disease

Answer 3

Thickening of fascia
Contracture

Genetic (biggest risk factor)
Smoking
Alcohol
Diabetes/epilepsy

Question 4

Flexor tendons

Answer 4

Superficial/deep
superficial tend to function individually and deep function together

Single/mass action & nerve supply

Flexor sheath
Lumbrical muscles (unique)

Traumatic rupture
Trigger fingers

Question 5

Trigger fingers

Answer 5

Catching of tendons at A1 pulley
Degenerate nodule
Thickening of sheath

Overuse
Degeneration
Change of direction of tendon

Treatment: steroid injection to get rid of inflammation so that it doesn’t catch so much. Surgical: cut A1 pulley open to make hole bigger so tendon nodule can slip through, but can cause problems further up

Question 6

Nerve problems

Answer 6

Median & ulnar nerves
Digital nerves to each finger/thumb
Dermatomes

Injury
Compression neuropathies

Question 7

Testing dermatomes of hand

Answer 7

median nerve tip of index finger
ulnar nerve tip of little finger
radial nerve tip of 1st webbed space

Question 8

Carpal tunnel

Answer 8

Median nerve compression at wrist
Osseous/ligamentous tunnel

Tendons
Nerves

Nerve function. 3 of thenar muscles & sensory symptoms in the radial half of the hand.

Question 9

Thenar muscles

Answer 9

Abductor brevis
Opponens
Flexor brevis
Adductor (ulnar)

Fine control
Species advantage

Question 10

Carpal tunnel signs

Answer 10

Thenar wasting

Loss of abduction

Loss of opposition

Question 11

Carpal tunnel syndrome

Answer 11

Ulnar nerve compression at elbow
Fascial compression @ 3 sites

Nerve only

Nerve function. Forearm & hand muscles, sensory symptoms ulna half of hand.

Treatment: surgical only to decompress the nerve. Do not inject steroids because ulnar tunnel v small and you can inject it straight into nerve

Question 12

Muscles

Answer 12

Flexor digiti quinti
Abductor
(opponens)

Interossei

FCU, FDP (m/r/l)

Question 13

Interosseous muscles

Answer 13

Palmar/dorsal
Insertion to proximal phalanx
Adduction/abduction
palmar is adduction and dorsal is abduction (PAD and DAB)

Insertion to extensor hood
Interphalangeal extension

Ulnar nerve

Question 14

ulnar nerve signs

Answer 14

Wasted hypothenar web spaces

Paradoxical wasting thenar

Forearm wasting

Clawing of digits

Question 15

extensor tendons

Answer 15

Extend MCP joints of fingers
Thumb tendons
Wrist tendons
Retinaculum

12 in all
Some multistranded (APL/EDC/EDQ)

Question 16

de Quervain’s disease

Answer 16

Triggering and pain of thumb extensors

Degeneration
Overuse
Ciprofloxacin
Anastrazole

Treatments: splint but not well tolerated, steroids, surgery on extensor retinicularim

Question 17

Ruptures

Answer 17

Lacerations
Fracture

Synovitis
Arthritis

No triggering

Question 18

Digital extensor hood

Answer 18

Long extensors
Interossei
Lumbrical

Finely balanced

Complex multibundle flat tendon

Question 19

Osteology

Answer 19

3 phalanges in fingers
2 phalanges in thumb
5 metacarpals
2 sesamoids in thumb
8 carpal bones

Question 20

bone problems

Answer 20

Radial fracture
Scaphoid fracture

1st CMC osteoarthritis

Rheumatoid arthritis

Treatment: splint, steroids, surgery