Joints

Wrist joint (radiocarpal joint)

The distal radius and the disc form the socket, the proximal carpal row (scaphoid, lunate and triquetrum) the head. Together with the midcarpal joint this produces the full wrist movement; about half of flexion and extension comes from each of the two.

Joint type

Ellipsoid joint (art. ellipsoidea), two degrees of freedom

Latin name

Articulatio radiocarpalis

Movements, axes and normal values

Close-packed position

Full dorsiflexion with radial deviation

Resting (loose-packed) position

Neutral position with slight ulnar deviation

Capsular pattern

Flexion and extension limited to about the same degree

Arthrokinematics

The convex proximal carpal row moves in the concave radius and disc: roll and glide run in opposite directions. During dorsiflexion the carpal row rolls dorsally and glides palmarly.

Stability

Palmar and dorsal radiocarpal ligaments, the collateral ligaments and the intercarpal ligaments, of which the scapholunate is the most important for the mutual rhythm of the carpal bones.

Palpation

Radial and ulnar styloid processes, the anatomical snuffbox containing the scaphoid (tenderness after a fall onto the outstretched hand is a scaphoid fracture until proven otherwise), Lister's tubercle as a landmark on the dorsal radius.

Clinical

Distal radius fracture (Colles); scaphoid fracture with a risk of avascular necrosis; carpal tunnel syndrome, which is not in the joint but under the flexor retinaculum; scapholunate dissociation.

Source

Kapandji, Physiologie articulaire deel 1; Magee, Orthopedic Physical Assessment

Clinical tests

• Phalen test
• Finkelstein test
• Watson test (scaphoid shift)
• Anatomical snuffbox palpation

Conditions

• Scaphoid fracture
• Carpal tunnel syndrome
• Scapholunate dissociation
• De Quervain's tenosynovitis
• Thumb base osteoarthritis