Carpal

Carpal Bones

Latin	Ossa carpi
System	Skeletal system

The carpal bones are a group of eight small bones that form the wrist (or carpus) that connects the hand to the forearm. These bones support and shape the wrist joint, allowing for the complex and flexible movements of the hand.

Structure

The carpal bones are arranged in two rows of four bones each. The proximal row, which articulates with the radius and ulna bones of the forearm, includes the scaphoid bone, lunate bone, triquetral bone, and pisiform bone. The distal row, which articulates with the bases of the five metacarpal bones of the hand, consists of the trapezium bone, trapezoid bone, capitate bone, and hamate bone.

Function

The primary function of the carpal bones is to facilitate effective movements of the hand and wrist. They act as a conduit for the forces exerted from the hand to the forearm. The unique arrangement of the carpal bones allows for the wrist's flexibility and range of motion, including flexion, extension, abduction, and adduction.

Clinical Significance

Injuries to the carpal bones, such as fractures or dislocations, are common due to falls or direct impacts. One of the most common injuries is a fracture of the scaphoid bone, which can lead to complications such as non-union or avascular necrosis due to its blood supply. Conditions such as carpal tunnel syndrome also involve the carpal bones indirectly, as they form part of the boundaries of the carpal tunnel, through which the median nerve passes.

See Also

• Hand anatomy
• Wrist
• Skeletal system
• Bone fracture
• Carpal tunnel syndrome