Articulating Surfaces

Question 1

Radiocarpal joint

Answer 1

> Distal Radius
- concave with 2 fossa
triangular fibrocartilaginous complex
- biconcave
*Carpals collectively form convex articular surface
Scaphoid
- convex surface that articulates with radius
Lunate
- mainly articulate with tfcc but some with radius
triquetrum
- articulates entirely with tfcc

Question 2

Midcarpal joint

Answer 2

> Between proximal and distal row of carpals
First row = concave
Second row = convex
- Scaphoid to trapezium/trapezoid/capitate
- lunate to capitate and hamate
- triquetrum to hamate

Question 3

Intercarpal joints (first row)

Answer 3

Between adjacent carpal articular surface all covered in fibrocartilage
Scaphoid
- medial facets for capitate (midcarpal - mc) and lunate
- distal facets for trapezium (mc) and trapezoid (mc)
Lunate
- laterally with scaphoid
- medially with triquetral
- distally with hamate and capitate (mc)
Triquetrum
- laterally with lunate
- hamate distally (mc)
- oval facet on palmar surface for pisiform
Pisiform
- flat dorsal surface articulates with triquetrum

Question 4

Intercarpal joints (2nd row)

Answer 4

Trapezium
- proximally with scaphoid (mc)
- medially with trapezoid
Trapezoid
- proximally with scaphoid (mc)
- medially with capitate
- laterally with  trapezium
Capitate
- proximally with scaphoid (mc) and lunate (mc)
- medially with hamate
- laterally with trapezoid
Hamate
- proximally with lunate (mc) and triquetrum (mc)
- laterally with capitate

Question 5

Carpometacarpal joints

Answer 5

1st:
- trapezium (convex one way and concave the other)
- base of 1st metacarpal (opposite to trapezium)
- both covered in hyaline cartilage
Other (2-5) - (all covered in hyaline cartilage)
2nd = trapezium/trapezoid/capitate to 2nd Metacarpal
3rd = Capitate to 3rd metacarpal
4th = capitate/hamate to 4th metacarpal
5th = hamate to 5th metacarpal

• Intermetacarpal joints - between adjacent metacarpals

Question 6

Metacarpophalangeal joints

Answer 6

Convex metacarpal head to concave proximal phalanx base

> covered in hyaline cartilage

Question 7

Interphalangeal joints

Answer 7

Thumb
- convex proximal phalanx to convex distal phalanx
Others
PIP - proximal to middle phalanx
DIP - Middle to distal phalanx