Hand

Question 1

8 carpal bones of the hand

Answer 1

see attached image

Question 2

Sensory distribution of nerves on hand

Answer 2

see attached image

Question 3

Which intrinsic muscles of hand does radial nerve innervate?

Answer 3

Trick question- none. All intrinsic muscles of hand innervated by either median or ulnar nerve

Question 4

Which intrinsic muscles of hand does ulnar nerve innervate?

Answer 4

Opponens pollicis, 3rd and 4th lumbricals, hypothenar group (opponens digiti minimi, flexor digiti minimi, abductor digiti minimi), palmaris brevis

Question 5

Which intrinsic muscles of hand does the median nerve innervate?

Answer 5

All others. Includes rest of thenar group (abductor and adductor pollicis brevis, flexor pollicis brevis), palmar/dorsal interossei, 1st and 2nd lumbricals

Question 6

Which hand tendon repairs can usu fixed in ER?

Answer 6

Extensor tendon lacs. Flexor tendons are more difficult to repair.

Question 7

Extrinsic muscles of the hand innervation

Answer 7

Extensor muscles: radian nerve. All the rest are median, with exception of flexor carpi ulnaris (ulnar), and medial flexor digitorum profundis (ulnar)

Question 8

Flexor tendon zones of the hand

Answer 8

Zones I and II: 1-3 weeks for repair. Zones III-V: immediate repair warranted. see attached image

Question 9

Extensor tendon zones of the hand

Answer 9

see attached image

Question 10

What is the “safe” position for hand splinting prior to hand surgery?

Answer 10

see attached image

Question 11

Felon

Answer 11

Infection of pulp space of any of the distal phalanges, caused by minor trauma over finger pad. Complications: cellulitis, flexor tendon sheath infection, osteomyelitis. Tx: I&D (NOT over flexor crease of DIP). Abx: 1st gen cephalosprin for staph

Question 12

Paronychia

Answer 12

Infection of the lateral nail fold, caused by nail biting, manicures. Tx: if non-fluctuant, 7 days abx, warm soaking. If fluctuant, I&D, usu don’t need abx unless cellulitis present.

Question 13

Tenosynovitis

Answer 13

Surgical emergency! Infection of flexor tendon and sheath due to penetrating trauma/dirty wound (e.g. dog bite). Infection can spread along sheath and involve other digits. Organisms: polymicrobial, Staph, Gonorrhea. Tx: Immobilize and elevate hand, IV abx, consult hand surgery stat.

Question 14

Gamekeeper’s thumb (aka skier’s thumb)

Answer 14

Avulsion of ulnar collateral ligament of first MCP joint due to forced abduction of thumb -> inability to pinch. Tx: thumb spica cast 3-6 wks for partial, surgery for complete tear.

Question 15

Carpal tunnel syndrome causes

Answer 15

Tumor (lipoma, fibroma), ganglion cyst, tenosynovitis (2/2 RA, trauma), edema (pregnancy, thyroid dz, amyloid), gout, trauma to carpal bones

Question 16

Ganglion cyst

Answer 16

Synovial cyst caused by leakage of synovial fluid from joint into surrounding tissue. Most commonly on radial wrist. Dx: xray should show no changes since it is soft tissue deal. Tx: reassurance, aspiration if severe pain, surgery if median nerve compression or really ugly.

Question 17

Mallet finger

Answer 17

Rupture of extensor tendon at insertion into distal phalanx -> inability to extend DIP. Splint for 6-8 weeks, surgery may be needed for those injuries not splinted early.

Question 18

Trigger finger

Answer 18

Stenosis of tendon sheath flexor digitorum leading to nodule formation within the sheath -> snapping or clicking when flexing and extending the digit. Tx: splint MP joint in extension, steroid injection, surgical release if these fail.

Question 19

High pressure injection injuries

Answer 19

For example from grease gun, spray gun. Can appear harmless puncture at first but progresses to more severe pain, swelling, tissue necrosis in 24 hrs. Tx: IV abx, I&D by surgery team, amputation may be necessary.

Question 20

Scaphoid fracture

Answer 20

Snuffbox tenderness. May not show up on radiographs for 2 weeks so if xray negative, immobilize in thumb spica cast and reimage in a few weeks

Question 21

Colles’ fracture

Answer 21

Distal radius fracture, fall on outstretched hand. Tx: short arm cast 4-6 weeks unless complexity requires surgery

Question 22

What is a thumb spica cast anyway?

Answer 22

see attached image