Lec 12 Intrinsic Hand and Wrist

Question 1

Short Muscles

Answer 1

Lumbricals
Palmar Interossei
Dorsal Interossei

Question 2

Lumbricals

Answer 2

MA: Flex MCP, Extended PIP of 2-5 digit

PA: 1&2 lateral FDP tendons as UNIpennate, 3&4 medial FDP tendons as BIpennate

DA: radial side of extensor expansion of digits 2-5

N: 1&2 Median N C8 T1
3&4 Ulnar N C8 T1

Question 3

Palmar interossei

Answer 3

MA: Adduct digits 2, 4, 5, assists with MCP flexion and PIP extension

PA: anterior surface of digits 2, 4, 5,

DA: extension expansion, base of proximal phalanges 2, 4, 5

N: Ulnar N (deep branch) C8 T1

Question 4

DAB

Answer 4

MA: abduct digits 2-4, assist with MCP flexion and PIP extension

PA: adjacent sides of two metacarpals (as bipennate)

DA: extensor expansion and base of proximal phalanges of digits 2-4

N: Ulnar (deep branch) C8 T1

Question 5

Thenar Muscles

Answer 5

flexor pollicis brevis
abductor pollicis brevis
opponens pollicis

Question 6

What bone is listers tubercle on?

Answer 6

Radius

Pulley for EPL

Question 7

What muscles attach to the hook of hamate and pisiform?

Answer 7

Flexor Carpi Ulnaris attaches distally to pisiform and hook of hamate

Abductor Digiti Minimi originates at pisiform

Flexor Digiti Minimi originates at hook of hamate

Opponens Digit Minimi originates at hook of hamate

Question 8

What muscles attach to the scaphoid?

Answer 8

Abductor Pollicis Brevis,
Flexor Pollicis Brevis,
Opponens Pollicis (Thenar) all originate on scaphoid tubercle (and trapezium tubercle)

Question 9

How many metacarpals and phalanges are there on one hand?

Answer 9

Metacarpals - 5
Phalanges - 14

Question 10

List the palmar arches - where are they and what do they help with?

Answer 10

Distal transverse arch - across metacarpals

Proximal transverse arch - across top of metacarpals

Longitudinal arch - runs from the wrist to the tips of the fingers, following the natural curve of the hand

help with grasp

Question 11

Figure 3.91 Book

Question 12

Thumb extension - muscles and joints

Answer 12

EPL - CMC, MCP and IP joints

EPB - CMC and MCP joints

APL - CMC joint

Question 13

Thumb Flexion - joints and muscles

Answer 13

FBL - “flexes phalanges” CMC, MCP, IP joints

FPB - CMC and MCP joints

Question 14

Thumb abduction - joints and muscles

Answer 14

APL - CMC joint

APB - CMC and MCP joints

Question 15

Thumb adduction - joints and muscles

Answer 15

Adductor Pollicis

Question 16

Thumb opposition

Answer 16

Opponens Pollicis

FPB and APB assist

Question 17

What is the common joint in the thumb for osteoarthritis?

Answer 17

CMC

(trapezium and 1st metacarpal)

Question 18

Where is no mans zone?

Answer 18

zone II, contains MCP and PIP and the split of FDS which makes it a hard place for surgery because its hard to put back together the split tendon

Question 19

How are flexor tendon injuries classified?

Answer 19

by zones - 5 distinct zones

Question 20

Describe the digital pulley system

Answer 20

There are 5 Annular ligaments that run on palmar side of fingers, A1-A5 that stabilize the flexor tendons (FDS and FDP)

A2 - base of proximal phalanx
A4 - middle phalanx

Cruciate ligaments run diagonally in between the annular ligaments, 4 per finger, allowing for movement of tendons

Question 21

What does the digital pulley system prevent?

Answer 21

Bowstringing = when flexor tendons move away from the digits during flexion

bowstringing decreases finger flexion and weakens grasps

Question 22

Be able to identify the sagittal band, lateral band, central slip and terminal tendon of the extensor hood

Question 23

What is trigger finger

Answer 23

real name is stenosing tenosynovitis

inflammation of the A1 ligament that causes finger to get locked in flexed position

Question 24

What is the floor of the snuffbox?

Answer 24

Arterial artery

Question 25

Know where to locate the deep palmar branch and superficial palmar arch

What is the parent structure?

Answer 25

deep palmar branch - lower arch on metacarpals (closer to wrist). parent structure is radial artery

superficial palmar arch is the arch farther from the wrist AND on top! parents structure is ulnar artery

Question 26

Where are the digital branches

Answer 26

arteries at distal phalanx of digits, parent structure is the deep and superficial palmar arches

Question 27

Mallet finger deformity

Answer 27

Ruptured long extensor tendon (ED or EI)

DIP flexion position

avulsion - tendon is pulled away from the bone

Question 28

Boxers fracture

Answer 28

neck of the 5th metacarpal (right before the knuckles)

Question 29

Gamekeepers thumb

Answer 29

(Skiers thumb)

Tear in the ulnar collateral ligament of the thumb which connect thumb to hand (MCP)

know where this is! think adductor muscles location BUT on dorsal side

Question 30

List the intrinsic hand muscles (categories)

Answer 30

Thenar muscles
hypothenar
adductor compartment
short muscles

Question 31

Which short muscles of the hand or bipennate and which are unipennate?

Answer 31

1&2 lumbricals are unipennate
3&4 lumbricals are bipennate

PAD is unipennate
DAB is bipennate

Question 32

What goes through carpal tunnel? What structure creates carpal tunnel?

Answer 32

Transverse carpal ligament (flexor reticulum)

tendons of FDP and FDS
Flexor carpi radialis
Flexor pollicis longus

MEDIAN NERVE

Question 33

What is and what goes through Guyons canal?

Answer 33

ulnar artery and vein

pisiform and hook of hamate

Question 34

function of palmer aponeurosis

Answer 34

protects neurovascualr structures

Question 35

function of synovial sheaths

Answer 35

lubricate tendons

reduce friction during movement

Question 36

Dupuytrens Contracture

Answer 36

abnormal thickening of palmar aponeurosis

contracture of 4th and 5th digits

this one you CANT force straight whereas trigger finger you can