Espiral AtlasIntercarpal and midcarpal joints
articulationes intercarpales et articulatio mediocarpalis
Study entry
Classification
Plane synovial joints: between the bones of each row, the midcarpal (between the two rows) and that of the pisiform.
Surfaces
Neighboring surfaces of the carpal bones; in the midcarpal, the proximal row with the distal one.
Capsule
The intercarpal and carpometacarpal joints (except that of the thumb) form a continuous joint cavity; the radiocarpal one is separate. Anterior, posterior and interosseous ligaments unite the bones.
Movements
Small glides, which add to those of the radiocarpal joint. Flexion and extension begin at the midcarpal joint; most of the flexion and adduction occurs at the radiocarpal joint, and extension and abduction involve the midcarpal more.
Blood supply
Dorsal and palmar carpal arches.
Innervation
Anterior interosseous branch of the median and dorsal and deep branches of the ulnar.
Clinical
Knowing which cavities communicate matters for the spread of infections and for arthroscopy.
Source: cap. 3, «Articulaciones del miembro superior: articulaciones intercarpianas»
Clinical correlation
Fractures and dislocations of the carpus; dislocation of the lunate
Anterior dislocation of the lunate is rare but serious: it comes from a fall on the wrist in extension. The lunate is pushed from the floor of the carpal tunnel toward the palmar surface and may compress the median nerve (carpal tunnel syndrome). Because it is poorly vascularized, it may become necrotic, and is sometimes removed. In severe osteoarthritis of the carpus, the bones may need to be fused (arthrodesis). In a child, fracture-separation of the distal epiphysis of the radius is common: the lateral radiograph shows the epiphysis displaced backward; put back in place, growth is usually normal.
Related clinical cases
- Fractures and dislocations of the carpus; dislocation of the lunate