Upper Extremity: Hand (Part 1)

Question 1

A digit (ray) contains

Answer 1

• Metacarpal
• Proximal phalanx
• Intermediate (Middle) phalanx
• Distal phalanx
• Thumb (pollex) does not have a middle phalanx

Question 2

Joints of the Hand

Answer 2

• Carpometacarpal joints
• Metacarpophalangeal (MCP) joints (“knuckles”)
• Interphalangeal (IP) joints

Question 3

Carpometacarpal Joints

Answer 3

• Between proximal end of metacarpal and distal row of carpals
• 1st carpometacarpal joint is a saddle joint

Question 4

Metacarpophalangeal (MCP) Joints (“Knuckles”)

Answer 4

• Between distal end of metacarpal and proximal phalanges

Question 5

Interphalangeal (IP) Joints

Answer 5

• Proximal (PIP)
• Distal (DIP)
• Thumb only has an interphalangeal joint

Question 6

Middle Finger

Answer 6

• Used as a reference point with finger abduction/adduction

Question 7

Types of Grips

Answer 7

• Power

- Precision

Question 8

Power Grip

Answer 8

• Different types

- Significant force produced

Question 9

Power Grip Relies on

Answer 9

• Finger flexion
• Wrist extension
• Thumb adduction, flexion, opposition

Question 10

Precision Grips

Answer 10

• Different types

- Less force

Question 11

Fascia of the Palm

Answer 11

• Continuous with antebrachial fascia (forearm deep fascia)
• Fascia is thin over thenar and hypothenar regions
• Palmar aponeurosis

Question 12

Palmar Aponeurosis

Answer 12

• Thick, covers central compartment and flexor tendons

- Made up of longitudinal and transverse bands

Question 13

Palmar Aponeurosis Attaches to

Answer 13

• Flexor retinaculum and palmaris longus

- Fibrous sheaths

Question 14

Compartments of the Palm

Answer 14

• Compartments created by bone, deep fascia, and septa extensions

Question 15

Compartments of the Palm Containing Muscle

Answer 15

• Thenar
• Hypothenar
• Central
• Adductor
• Interosseous

Question 16

Spaces of the Compartments of the Arm

Answer 16

• Thenar

- Midpalmar

Question 17

Midpalmar Compartment of the Arm

Answer 17

• Communicates through carpal tunnel into the forearm

Question 18

Fibrous Digital Sheath (Tendon Sheath of the Hand)

Answer 18

• Osseofibrous tunnel
• Surrounds digital synovial sheaths
• Vincula

Question 19

Fibrous Digital Sheath Structure

Answer 19

• Surrounds digital synovial sheaths
• Formed by annular and cruciform ligaments
• Prevents bowstringing

Question 20

Vincula of Fibrous Digital Sheath

Answer 20

• Attaches tendons to bones and neighboring tendons

- Allow for the passage of blood vessels

Question 21

Tendon Sheaths of the Hand

Answer 21

• Fibrous digital sheath
• Ulnar bursa
• Radial bursa

Question 22

Ulnar Bursa

Answer 22

• Communicate with the synovial sheath of the 5th digit

Question 23

Radial Bursa

Answer 23

• Communicates with 1st digital synovial sheath

Question 24

Spread of Infection (Hand to Forearm)

Answer 24

• Midpalmar space > forearm
• 1st digit > wrist/distal forearm
• 5th digit > wrist/distal forearm

Question 25

Clinical Importance of Tendon Sheaths/Infection

Answer 25

- Infection in the synovial sheaths of the hand/digits can spread into the forearm (Space of Parona)

Question 26

Dupuytren's Contracture

Answer 26

- Thickening and shortening of palmar aponeurosis - Most common in ring and little finger - Nodule thickenings progresses to contracture of longitudinal bands

Question 27

Dupuytren's Contracture Cause

Answer 27

- Unknown - Hereditary predisposition - Possible risk factors: smoking, diabetes, manual labor - Microvascular ischemia

Question 28

Dupuytren's Contracture Treatment

Answer 28

- Fasciotomy - Fasciectomy - Collagenase injections (break down collagen)

Question 29

Trigger Finger

Answer 29

- Thickening of a flexor tendon in the distal palm - Restriction of tendon gliding under the fibrous sheath - Palpable nodule that gets “stuck” - Locking of finger into flexion (most common) - “Snaps” into place

Question 30

Trigger Finger Cause

Answer 30

- Unknown - Other disease conditions (diabetes, inflammatory arthritis) - Repetitive, forceful digital flexion

Question 31

Intrinsic Muscles of the Hand

Answer 31

- Thenar muscles - Adductor pollicis - Hypothenar muscles - Lumbricals - Interossei

Question 32

Thenar Muscles

Answer 32

- Abductor pollicis brevis - Flexor pollicis brevis - Opponens pollicis

Question 33

Hypothenar Muscles

Answer 33

- Abductor digiti minimi - Flexor digiti minimi - Opponens digiti minimi

Question 34

Interossei Muscles

Answer 34

- Dorsal | - Palmar

Question 35

Thenar Muscles Proximal Attachments

Answer 35

- Flexor retinaculum | - Carpal bones (trapezium, scaphoid)

Question 36

Thenar Muscles Distal Attachments

Answer 36

- 1st metacarpal (OP) - Base of thumb proximal phalanx - Sesamoid bone ( for APB, FPB)

Question 37

Thenar Muscles Innervation

Answer 37

- Recurrent branch of median nerve | - Deep portion of FPB can be innervated by deep branch of ulnar nerve

Question 38

Thenar Muscles Function

Answer 38

- Name tells you function - APB: abduction of the thumb - FPB flexes CMC and MCP - Opposition involves flexion, abduction and medial rotation at thumb CMC

Question 39

Adductor Pollicis

Answer 39

- 2 heads - Oblique - Transverse

Question 40

Oblique Adductor Pollicis Proximal Attachment

Answer 40

- Capitate | - Base of 2nd and 3rd mets

Question 41

Transverse Adductor Pollicis Proximal Attachment

Answer 41

- Palmar surface of 3rd met

Question 42

Adductor Pollicis (Both Obliqe and Transverse) Distal Attachments

Answer 42

- Medial aspect of proximal phalanx, sesamoid bone

Question 43

Adductor Pollicis (Both) Innervation

Answer 43

- Deep branch of ulnar nerve

Question 44

Adductor Pollicis (Both) Function

Answer 44

- Moves thumb toward hand