Human Anatomy Vol 1

Articular disc

Ulnar collateral
ligament

Pisiform

Radiocarpal

joint

Radial

collateral

ligament

Midcarpal

joint

Common cavity of other

carpometacarpal joint

First carpometacarpal

joint

Fig. 10.24: Joints in the region of the wrist

from the ulnar collateral ligament between the

styloid process and the triquetral bone. The fibrous

capsule is strengthened by the following ligaments.

On the palmar aspect, there are two palmar carpal

ligaments.

The palmar radiocarpal ligament is a broad band. It

begins above from the anterior margin of the lower

end of the radius and its styloid process, runs

downwards and medially, and is attached below to

the anterior surfaces of the scaphoid, the lunate and

triquetral bones.

The palmar ulnocarpal ligament is a rounded

fasciculus. It begins above from the base of the styloid

process of the ulna and the anterior margin of the

articular disc, runs downwards and laterally, and is

attached to the lunate and triquetral bones.

Both the palmar carpal ligaments are considered

to be intracapsular.

On the dorsal aspect of the joint, there is one dorsal

radiocarpal ligament.It is weaker than the palmar

ligaments. It begins above from the posterior margin

of the lower end of the radius, runs dor,rrnwards and

medially, and is attached below to the dorsal surfaces of

the scaphoid, lunate and triquetral bones (Fig. 10.25).

The radial collateral ligament extends from the tip of

the styloid process of the radius to the lateral side of

the scaphoid bone (Fig. L0.2Q. It is related to the

radial artery.

The ulnar collateral ligament extends from the tip of

the styloid process of the ulna to the triquetral and

pisiform bones.

Both the collateral ligaments are poorly developed.

Dorsal

iniercarpal

ligament

Dorsal

radiocarpal

ligament

Fig. 10.25: Some ligaments of the wrist

Relotions

o Anterior: Long flexor tendons with their synovial

sheaths, and median nerve (see Fig.9.6).

o Posterior: Extensor tendons of the wrist and fingers

with their synovial sheaths (seeFig.9.56).

o Lateral: Radial artery (see Fig.9.70).

BIood Supply

Anterior and posterior carpal arches.

Nerve Supply

Anterior and posterior interosseous nerves.

Movemenls

Moaements: Movements at the radiocarpal joints are

accompanied by movements at the midcarpal joint. The

midcarpal joint is anatomically separate from

radiocarpal joint. The joint between the two rows of

carpal bones does not have smooth joint line because

of multiple small joints. However, it still behaves as a

functional unit in all movements of the wrist joint.

In addition to the congruency and the shape of the

articular surfaces of radius and carpalbones, the length

of the ulna can also affect the amount of motion

available at the wrist joint. In the ulnar negative

variance the distal end of ulna is shorter than the radius

and vice versa in ulnar positive variance. The wrist joint

has the following movements.

L Flexion: It takes place more at the midcarpal than

at the wrist joint. The main flexors are:

i. Flexor carpi radialis.

ii. Flexor carpi ulnaris.

iii. Palmaris longus.

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