thumb|Scaphoid of the right hand on X-ray (labeled S)
The scaphoid bone is one of the carpal bones of the wrist. It is situated between the hand and forearm on the thumb side of the wrist (also called the lateral or radial side). It forms the radial border of the carpal tunnel. The scaphoid bone is the largest bone of the proximal row of wrist bones, its long axis being from above downward, lateralward, and forward. It is approximately the size and shape of a medium cashew nut.
Structure
The scaphoid is situated between the proximal and distal rows of carpal bones. It is located on the radial side of the wrist, It articulates with the radius, lunate, trapezoid, trapezium, and capitate. Over 80% of the bone is covered in articular cartilage. The lateral surface is narrow and gives attachment to the radial collateral ligament. The medial surface has two facets, a flattened semi-lunar facet articulating with the lunate bone, and an inferior concave facet, articulating alongside the lunate with the head of the capitate bone. The scaphoid is also involved in movement of the wrist. Delays may compromise healing. Failure of the fracture to heal ("non-union") will lead to post-traumatic osteoarthritis of the carpus. The name refers to the shape of the bone, supposedly reminiscent of a boat. In older literature about human anatomy, the scaphoid is referred to as the navicular bone of the hand (this time from the Latin navis for boat); there is also a bone in a similar position in the foot, which is called the navicular. The modern term for the bone in the hand is scaphoid; in human anatomy the term navicular is reserved for the bone in the foot.
Additional images
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File:Scaphoid bone (left hand) - animation01.gif|Scaphoid bone of the left hand (shown in red). Animation.
File:Scaphoid bone (left hand) - animation02.gif|Scaphoid bone of the left hand. Close up. Animation.
Image:Scaphoid bone1.jpg|Scaphoid bone.
File:Gray219 - Scaphoid bone.png|Scaphoid shown in yellow. Left hand. Palmar surface.
File:Gray220 - Scaphoid bone.png|Scaphoid shown in yellow. Left hand. Dorsal surface.
File:Ospoignet - Scaphoid bone.png|Cross section of wrist (thumb on left). Scaphoid (labelled as "Navicular") shown in red.
File:Dissection of the human hand - 01 - scaphoid bone.png|Wrist joint. Deep dissection. Posterior view.
File:Slide1dsds - Scaphoid bone.png|Scaphoid forms the radial (thumb-side) border of the carpal tunnel. Wrist joint. Deep dissection. Anterior (palmar) view.
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