Second to Fifth CMC Joints

• Joint Classification:

  • Synovial plane joints
• Axis of movement:

  • Complex (very little movement available)
• Articular Surfaces:

  • 2nd CMC: 2nd MC with trapezoid and little capitate and trapezium

  • 3rd CMC: 3rd MC with capitate

  • 4th CMC: 4th MC with hamate and little capitate

  • 5th CMC: 5th MC with hamate
• Joint Capsule:

  • Shared fibrous capsule across all four CMC joints and lined with synovial membrane
• Ligaments:

  Dorsal carpometacarpal ligaments (thickening in capsule on dorsal aspect)

  • Fibres running from distal row of carpal bones to bases of MC’s

  Role of all ligaments : Reinforce capsule and stabilise joint
• Ligaments:

  Palmar carpometacarpal ligament (thickening in capsule on palmar aspect)

  • Fibres running from distal row of carpal bones to bases of MC’s
• Ligaments:

  Interosseous ligaments of CMC

  • Short ligaments from capitate and hamate to 3rd or 4th MC
• Movements:

  • Minimal: allow for small gliding movements only