Carpalen

Carpalen, or carpal bones, are eight small irregular bones that form the wrist. They are arranged in two horizontal rows: the proximal row consists of the scaphoid, lunate, triquetrum, and pisiform; the distal row consists of the trapezium, trapezoid, capitate, and hamate. The proximal row articulates with the distal radius and with each other, while the distal row articulates with the bases of the metacarpal bones to form the carpo-metacarpal joints. The radiocarpal joint connects the distal radius with the proximal carpal row, and several midcarpal joints lie between the two carpal rows. Collectively, these joints enable a wide range of wrist movements.

Ligaments bind the carpal bones into a stable yet flexible arch and coordinate their motions. On the palmar side, the flexor retinaculum forms the carpal tunnel, through which the median nerve and flexor tendons pass to reach the hand. The carpal bones thus act as a central link between the forearm and hand, providing a stable platform for finger movements while allowing wrist flexion, extension, and deviations.

Clinical relevance includes common injuries such as scaphoid fractures, typically resulting from falls on an outstretched hand; these fractures can threaten blood supply to the bone. Lunate dislocations and other perilunate injuries are also recognized wrist trauma. Carpal tunnel syndrome involves compression of the median nerve within the carpal tunnel and can arise from repetitive use, swelling, or other factors. Variations in carpal bone shape or number occur in a minority of individuals and may affect joint mechanics.