Hand and Wrist Joints and Ligaments

Question 1

Radiocarpal Joint

Answer 1

Articulation: distal end of radius and articular disc of distal radioulnar joint with proximal row of carpal bones, except pisiform

Type: condyloid type of synovial joint

Movements: flex/ext, add/abd, circumduction

Question 2

Dorsal and Palmer Radiocarpal and Ulnocarpal Ligaments

Answer 2

• Pass from radius and ulna to 2 rows of carpal bones
• Palmar radiocarpal/ulnocarpal ligaments ensure that hand follows forearm during supination
• Dorsal ligaments ensure that hand follows forearm during pronation

Question 3

Carpal Tunnel

Answer 3

• Passageway deep to flexor retinaculum b/w tubercles of scaphoid and trapezium bones on lateral side and pisiform and hook of hamate on medial side
• 9 tendons and 1 nerve pass through carpal tunnel: 4 tendons of flexor digitorum superficialis, 4 from flexor flexor digitorum profundus, flexor pollicus longus tendon, median nerve

Question 4

Intercarpal Joints

Answer 4

Articulation: b/w adjacent carpal bones

Type: plane type of synovial joint

Movement: gliding, which helps to increase overall wrist ROM; midcarpal joint is also involved in wrist flex/abd

Ligaments: anterior/palmer, posterior/dorsal, interosseous (deep w/in joint capsule)

Question 5

Proximal Intercarpal Joints

Answer 5

Articulation between the carpals in the proximal row

Ex: scaphoid-lunate joint

Question 6

Distal Intercarpal Joints

Answer 6

Articulation between the carpals in the distal row

Question 7

Midcarpal Joints

Answer 7

Articulation between carpals in the proximal and distal rows

Question 8

Carpometacarpal Joints

Answer 8

Articulation: b/w distal row of carpals and bases of metacarpals

Joints share same joint capsule except CMC at thumb b/w trapezium and base of 1st metacarpal (has own capsule)

Typle: synovial plane joints, except thumb (synovial saddle joint)

Movement:

• CMC thumb - flex/ext, add/abd, circumduction
• No mvt at CMC joints of digits 2/3
• CMC 4th digit is slightly moveable
• CMC 5th digit is extremely moveable - flex/ext, add/abd, circumlocution

Ligaments: anterior(palmar) and posterior (dorsal) carpometacarpal ligaments, interosseous ligaments (deep)

Question 9

Intermetacarpal Joints

Answer 9

Articulation: articulation b/w metacarpals at their bases

Joints share same joint capsule

Type: synovial plane

Movement: none

Ligaments: anterior and posterior metacarpal ligaments

Question 10

Metacarpophalangeal Joints

Answer 10

Articulation: metacarpal heads and base of proximal phalanges

Type: synovial condyloid

Movements:

• Flex/ext, abd/add, circumduction allowed at digits 2-5 MCP joints
• Flex/ext w/ limited amount of add/abd is allowed for thumb MCP

Question 11

Metacarpophalangeal Joints Ligaments

Answer 11

• Each joint capsule is strengthened by 2 collateral ligaments which pass from the metacarpal heads to the base of the phalanges
• Collateral ligaments fuse on anterior part of joint capsule to form dense fibrocartilaginous plate called the palmar plate or palmar ligament
• Dorsal metacarpophalangeal ligaments help to prevent hyperflexion
• Palmar metacarpophalangeal ligaments help to prevent hyperextension
• MCP joints of digits 2-5 have deep, transverse metacarpal ligaments which help hold the MCP joints together

Question 12

Interphalangeal Joints

Answer 12

Articulation: proximal and distal articulations (heads of the phalanges articulate with the bases of the more distally located phalanges)

Type: synovial hinge

Movement: flex/ext

Ligaments: collateral ligaments, palmar and dorsal ligaments, extensor expansions

Question 13

Extensor Hood

Answer 13

• Extrinsic tendon comes from the extensor digitorum, extensor indicis, and extensor digiti minimi
• Extrinsic tendon is posterior
• Intrinsic tendon comes from palmar and dorsal interossei and lumbricals
• Intrinsic tendon is lateral
• Join together to from central tendon
• Helps to extend at IPs and flex at MCPs