- Distal ends of radius and ulna radial notch. It does not articulate with the carpus;
- Carpus prevented from doing so by articular disc. Head at its
- Metacarpus lower end. Styloid process projects from medial
- Phalanges border of head, lateral to it lies tendon of ECU.
Joints
Articular disc
- Wrist joint
- Distal radioulnar joint - Traingular fibrocartilage
- Joints of the hand - Apex attached to lateral side of base of styloid
Muscles and fasciae process of ulna
Blood vessels: Arteries & veins - Base attached to lower border of ulnar notch
Nerves of radius
- Shuts off inferior radio ulnar joint from wrist
joint
- Strongly unites radius and ulna
TFCC = Triangular Fibro Cartilage Complex
Articulates with:
- Scaphoid and lunate bones at wrist
- Ulna at distal radioulnar joint
Features include:
- Styloid process projects distally from lateral
margin
- Ulnar notch on medial side articulates with
round head of ulna
- Inferior articular surface articulates with
scaphoid & lunate bones of the carpus
- Dorsal tubercle on posterior aspect of distal
end-grooved on its medial side by tendon of
EPL
Left ant.
Left post.
, It is approximately the size and shape of a medium
sized cashew nut. Articulates with the radius, lunate,
trapezoid, trapezium and capitate. Tubercle (X) gives
attachment to flexor retinaculum. Over 80% of the
bone is covered in articular cartilage.
Proximal row:
Scaphoid = Some
Lunate = Lunatics
Triquetrum = Try
Pisiform = Positions
Distal row:
(greater multiangular)
Trapezium = That
Trapezoid = They
Capitate = Can’t
Hamate = Handle X
Carpus is concave anteriorly.
All bones are cartilaginous at birth and ossification
starts in the 1st year and completed by the 12th year. Identified by the crest and groove which mark its
rough anterior surface (X). The groove, which lies on
Flexor retinaculum attached:
the medial side of the crest, lodges the tendon of the
Medially: to pisiform bone and hook of hamate FCR, and its margins give attachment to the two layers
Laterally: to tubercle of scaphoid and trapezium of the flexor retinaculum.
Forms carpal tunnel.
A triangular deepening on the radial, dorsal aspect of
the hand. The name originates from the use of this
surface for placing and then sniffing powdered
tobacco, or “snuff”.
Medial (ulnar) border
- Tendon of the extensor pollicis longus
Lateral (radial) border
- APL & EPB
Proximal (upper) border
- Styloid process of radius
Floor:
- Trapezium
- Scaphoid
Situated on the radial side of the wrist; it forms the
radial border of the carpal tunnel. Is the largest bone
of the proximal row of wrist bones, its long axis is
from above downward, lateralward and forward.
, Fracture of the scaphoid can cause damage to the
median nerve and to the superficial branch of the
radial nerve but it is not a common cause for median
nerved compression in carpal tunnel syndrome.
5 metacarpals, each has a base, shaft & head.
1st metacarpal (thumb)
- Shortest and most mobile
- More anterior than the others
- Extensor surface directed laterally not
backward.
Bases of metacarpals articulate with distal row of
carpus. 2-5 metacarpals also articulate with each
other. (2-5) shaft of each bone is slightly concave
forward and triangular in transverse section.
Readily distinguishable by its wedge shape and a 3 surfaces:
hook-like process (hamulus) projecting from its
palmar surface. This gives attachment to the flexor - Posterior
retinaculum. Lies within the distal row of carpal bones - Lateral
and articulates with the metacarpals of the little and - Medial
ring finger. Articulations
Base
1. With the trapezium
2. With the trapezium, trapezoid, capitate and
3rd metacarpal
3. With the capitate and 2nd and 4th metacarpals
4. With the capitate, hamate, 3rd and 5th
metacarpals
5. With the hamate and 4th metacarpal.
Heads articulate with proximal phalanges
Fractured scaphoid
Fracture of the scaphoid bone is common in young
adults. Unless treated effectively, the fragments will
not unite and permanent weakness and pain of wrist
will result. This can lead to the subsequent
development of osteoarthritis.