Wrist & Hand Anatomy

Question 1

Anatomical Snuff Box

Borders, floor, artery

Answer 1

• Lateral border = abductor pollicis longus and extensor pollicis brevis (DeQ’s SynD)
• Medial border = extensor pollicis longus
• Floor = scaphoid
• Radial artery

Question 2

Dorsal Tunnels

Answer 2

• Tunnel 1 – ABPL & EPB (site of tenosynovitis (De Quervain’s))
• Tunnel 2 – ECRB &ECRL
• Tunnel 3 – EPL
• Tunnel 4 – Extensor digitorum and extensor indicis
• Tunnel 5 – Extensor Digiti minimi (palpable in indentation just lateral to ulnar styloid process)
• Tunnel 6 – Extensor Carpi Ulnaris tendon (palpable with extension and ulnar deviation)

1-4 on radius, 5-6 on ulna

Question 2

Carpal Tunnel

Borders and contents

Answer 2

Carpal Tunnel
Covered by Flexor retinaculum

Ulnar border
Pisiform and Hook of hamate

Radial border
Scaphoid tubercle and tubercle of trapezium

Contains
Median nerve, FDS, FDP, FPL

Question 3

Guyon’s Canal

Location and contents

Answer 3

Pisiform to Hook of hamate - covered by pisohamate lig
Contains - Ulnar nerve

Question 4

Radiocarpal Closed Pack

Answer 4

Full extension

Question 5

Radiocarpal arthrokinematics

Answer 5

Carpals = convex
Radius = concave

Question 6

Distal radioulnar arthrokinematics

Answer 6

Head of ulna = convex
Ulnar notch of radius = concave

Question 7

Midcarpal Joints

Answer 7

Compound articulation between the proximal row and distal row of carpal bones (except the pisiform)

There is greater ROM at the midcarpal joints than intercarpal joints

Question 8

Midcarpal Joints

Resting position, closed pack, capsular pattern

Answer 8

Resting position = neutral or slight flexion with ulnar deviation

Closed packed = extension with ulnar deviation

Capsular pattern = flexion=extension

Question 9

CMC Jts Resting position

Answer 9

1. Thumb- midway bt/ abduction and adduction, and midway bt/ flex-ext
2. Fingers- midway bt/ flex-ext

Question 10

CMC Closed pack

Answer 10

1. Thumb- full opposition
2. Fingers- full flx

Question 11

CMC capsular pattern

Answer 11

1. Thumb- ABD then EXT
   Fingers- equal in all directions

Question 12

Metacarpophalangeal Joints D1

Answer 12

Synovial hinge Joint; uniaxial: FLX/EXT
2 sesamoid bones at palmar surface of joint, attached to volar plate: act as attachment site for D1 MCP med and lat collateral ligament otherwise, similar to MCP 2-5

Question 13

MCP D2-5

Answer 13

Condyloid joints; 2* of freedom: FLX/EXT, ABD/ADD
They have collateral ligaments (taut during flex, lax during ext.)
They also have palmar ligaments and deep transverse metacarpal ligaments

Question 14

MCP Joints Resting, Closed Pack, Capsular Pattern

Answer 14

Resting position = slight flexion
Closed packed = thumb- full opposition; fingers 2-5- full flexion
Capsular pattern = flex > ext

Question 15

The triangular fibrocartilage complex

Answer 15

(TFCC) is a cartilage structure located on the ulnar side of the wrist that, cushions and supports the small carpal bones in the wrist. The TFCC keeps the forearm bones (radius and ulna) stable when the hand grasps or the forearm rotates.