wrist

The wrist is a complex synovial joint formed by articulations of the radius, the articular disc of the distal radioulnar joint and the carpal bones.

Gross anatomy

Articulations

The wrist is made up of three joint articulations :

Movements

Movements at the condyloid radiocarpal joint of the wrist include :

  • flexion
    • primary: flexor carpi radialis and flexor carpi ulnaris
    • secondary: palmaris longus, abductor pollicis longus, flexor digitorum superficialis and flexor digitorum profundus
  • extension
  • adduction (ulnar deviation)
    • simultaneous contraction of flexor and extensor carpi ulnaris
  • abduction (radial deviation)
  • circumduction
    • the sequential occurrence of the above four movements produces circumduction

A greater proportion of the total range (60) of wrist extension occurs at the radiocarpal joint . In contrast, a greater proportion of the total range (80) of wrist flexion occurs at the midcarpal joint, which is also the primary joint involved in wrist adduction and abduction .

Ligaments

The wrist joint has intrinsic and extrinsic stabilizing structures .

Intrinsic

Extrinsic

​Associated structures
Joint capsule

A two-layered synovial capsule envelops the radiocarpal joint, attaching proximally to the radius and ulna, and distally to the carpal bones. The joint capsule thickens to form palmar, dorsal and collateral ligaments .

Fat pads

Arterial supply

Arterial supply of the wrist is via the palmar and dorsal carpal arches .

  • palmar carpal arch
  • dorsal carpal arch
    • supplied by palmar carpal branches of the radial and ulnar arteries
    • reinforced by the anterior interosseous artery, alongside penetrating deep branches of the deep palmar arch

Innervation

Innervation of the wrist is via the anterior interosseous nerve (arising from the median nerve), posterior interosseous nerve (arising from the radial nerve), and the deep and dorsal branches of the ulnar nerve .

Variant anatomy

Ossification

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