Bones, Joints and Movement - L0 9

9. Identify the major joint and associated ligaments in the wrist region. Explain what kind of movements occur at the joints and other pertinent information.

Movement Videos

The radiocarpal (wrist) joint involves the articulation of the distal end of radius and proximal row of carpals (excluding the pisiform), and is a synovial, condyloid joint. In regards to surface anatomy, this joint is located approximately at the level of the proximal wrist crease. It is important to note that the ulna does not form a direct articulation at the wrist joint. The actions of the radiocarpal joint are very closely aligned with those created at the distal radio-ulnar and intercarpal joints.

Accessory structures of radiocarpal (wrist joint):

• Ligaments:

  • Palmar & dorsal radiocarpal ligaments limit wrist extension & flexion, respectively

    • Ulnar collateral ligament of wrist joint: spans between the ulnar styloid process and triquetrum

    • Radial collateral ligament of wrist joint: spans between the radial styloid process and scaphoid

• Clinical significance:

  • FOOSH (Falling On an Out-Stretched Hand)

    • Fracture of distal radius: can be caused by direct injury or FOOSH; most common fracture of upper extremity

      • Colles' fracture: specific fracture of distal radius

        • Complete (and often comminuted), transverse fracture of distal radius, which will displace in a dorsal direction causing a "dinner fork deformity" (posterior angulation)

    • Fracture of scaphoid: can be caused by direct injury or FOOSH; most commonly fractured carpal bone

      • Often misdiagnosed early because of difficulty of detection in early radiographs; necrosis and bone resorption in the area due to poor blood supply are common and easily detected in imaging completed ~10 days after injury

There are multiple joints in the hand including:

• Carpometacarpal (CMC) joints: between distal row of carpals and metacarpals

• Metacarpophalangeal (MP or MCP) joints: between metacarpals and proximal phalanges; 'knuckles'

• Proximal interphalangeal (PIP) joints: between proximal and intermediate (middle) phalanges

• Distal interphalangeal (DIP) joints: between intermediate and distal phalanges