03-07: The Wrist

Question 1

Joints of the wrist - Radiocarpal joint

Answer 1

• Proximally: Distal end of the radius articulates with distal end of the ulnar disk
• Distally: Scaphoid, lunate and triquetrum
• Condyloid joint (Biaxial)

Question 2

Joint motions of Radiocarpal joint

Answer 2

• Vex on Cave
• Flexion: Posterior roll, anterior glide
• Extension: Anterior roll, posterior glide
• Radial Deviation: Medial Glide, Lateral Roll
• Ulnar Deviation: Medial roll, Lateral glide

Question 3

Joints of the wrist - Midcarpal joint

Answer 3

• Nonaxial: Plane or gliding joint
• Also known as intercarpal joint
• Occurs between the two rows of carpal bones

Question 4

Flexion Retinaculum

Answer 4

Ligament that surrounds wrist; keeps tendons from bowing

Question 5

Tranverse Carpal Ligament

Answer 5

• Deep to Flexor Retinaculum
• 4 “high points” pillars form canopy: Lateral - Scaphoid, Trapezium, Medial - Pisiform, Hook of hamate
• High points form tunnel - “Carpal Tunnel” (base of palm at the crease)

Question 6

Attachment sites for Common Flexor and Extensor Tendons

Answer 6

Medial Epicondyle of Humerus (Flexor)
Lateral Epicondyle of Humerus (Extensor)
- Muscles that act on wrist have origins proximal to elbows

Question 7

Attachment site for Extensor Carpi Radialis Longus (ECRL)

Answer 7

Lateral Supracondylar Ridge of Humerus

- Muscles that act on wrist have origins proximal to elbows

Question 8

Radial Collateral Ligament

Answer 8

To be entered

Question 9

Ulnar Collateral Ligament

Answer 9

To be entered

Question 10

Pisohamate Ligament

Answer 10

To be entered

Question 11

PIsometacarpal Ligament

Answer 11

To be entered

Question 12

Tunnel of Gyon

Answer 12

Formed by Pisohamate and Pisometacarpal ligaments - Forms floor of carpal tunnel - Median nerve passes through tunnel

Question 13

Palmar Fascia (Aponeurosis)

Answer 13

• Thick triangular fascia on the superficial palmar surface of the hand
• Protects palmar structures and muscle attachment

Question 14

Triangular Fibrocartilagenous Complex (TFCC)

Answer 14

• Also known as Ulnar Triquestral Meniscus Joint
• Fibrous Cartilage
• Important for supination
• Area of injury when torn

Question 15

Flexor Carpi Radialis (FCR)

Answer 15

O: Medial Epicondyle of Humerus (Common Flexor Tendon)
I: Base of the 2nd-3rd metacarpal
A: Wrist flexion, Radial Deviation
N: Median Nerve (C6, C7)

Question 16

Flexor Carpi Ulnaris (FCU)

Answer 16

O: Medial Epicondyle of Humerus (Common Flexor Tendon), Posterior Ulna
I: Pisiform and Base of the 5th metacarpal
A: Wrist flexion, Ulnar Deviation
N: Ulnar Nerve

Question 17

Palmaris Longus (PL)

Answer 17

O: Medial Epicondyle of Humerus (Common Flexor Tendon)
I: Palmar Fascia
A: Wrist flexion
N: Median Nerve

• One or both of these muscles may be missing and may be used in tendon transportation (Tommy Johns surgery)

Question 18

Extensor Carpi Radialis Longus (ECRL)

Answer 18

O: Lateral Epicondyle of Humerus (Common Extensor Tendon)
I: Base of the dorsal aspect of the 2nd Metacarpal
A: Wrist Extension, Radial Deviation
N: Radial Nerve

Question 19

Extensor Carpi Radialis Brevis (ECRB)

Answer 19

O: Lateral Epicondyle of Humerus (Common Extensor Tendon)
I: Base of the dorsal aspect of the 3rd Metacarpal
A: Wrist Extension
N: Radial Nerve

Question 20

Extensor Carpi Ulnaris (ECU)

Answer 20

O: Lateral Epicondyle of Humerus (Common Extensor Tendon)
I: Base of the dorsal aspect of the 5th Metacarpal
A: Wrist extension, Ulnar Deviation
N: Radial Nerve

Question 21

Wrist Drop

Answer 21

Radial nerve is damaged - cannot extend wrist

Question 22

Thenar Eminence

Answer 22

• Ennervated by Median Nerve