X-ray of a Child's Hand and Wrist
All information for this imageModule Name: hand_wrist
Module Title: X-ray of a Child's Hand and Wrist
Image Info: X-ray; source - Wuarchive.
Created by: Lynn Bry
InformationKey points: phalanx | metacarpal | capitate | hamate | lunate | pisiform | scaphoid | trapezoid | trapezium | triquetral | radius | ulna |
Introduction: This X-ray has been taken of a child's hand and wrist. Note the epiphyseal gaps, particularly evident at the ends of the radius and the ulna. Also note the gaps between the carpal bones of the wrist. In an adult, the average space is no more than 2mm.
The carpal bones can be divided into two rows, proximal - from left to right in the image: pisiform, triquetral, lunate, and scaphoid; and distal (closest to the fingers..) - hamate, capitate, trapezoid, and trapezium. The wrist consists of two primary joints - the radiocarpal joint, and intercarpal joints. None of the carpal bones articulate directly with the ulna of the forearm.
The convex alignment of the bones forms a channel anteriorly - the carpal tunnel. Many nerves, tendons and other important structres pass thorugh this tunnel to reach the hand. Compression can lead to carpal tunnel syndrome.
Annotationscapitate: The capitate is the largest of the carpal bones. It resides in the distal row of carpal bones. The bone articulates with scaphoid and lunate bones of the proximal row, and primarily with the third metacarpal bone.
distal_phalanx: Distal-most bones of the fingers and thumb.
hamate: The hamate is the outer-most bone of the distal row of carpal bones. It articulates with the 4th and 5th metacarpals distally (ring and index finger..), and with the lunate and triquetral bones in the proximal row of the wrist. A 'hook' on the outside of the hamate bone forms one border of the carpal tunnel. Many important nerves and tendons to the hand travel through this channel. Anything which constricts the canal can lead to carpal tunnel syndrome, an often painful condition of the hands and wrist.
lunate: The lunate is one of three bones in the proximal row which articulates with the radius of the forearm.
metacarpal: The metacarpal bones of the finger and thumb articulate with the distal row of carpal bones. The epiphyses at either end of the metacarpal bones can be clearly seen. A cartilagenous epiphyseal plate lies between each epiphyses, and the underlying diaphyses of the bone. Growth occurs at these plates.
middle_phalanx: Middle bone of the fingers. The thumb has no middle phalanx.
phalanx: The phalanges are the bones of the fingers.
pisiform: The pisiform is the outer-most bone of the proximal row of carpal bones. It sits atop the anterior surface of triquetral bone and has little involvement in transmitting weight from the forearm to the hand.
proximal_phalanx: Proximal is defined as the phalanx closest to the body.
radius: One of the two bones of the forearm - it lies on the side of the thumb. Note the epiphysis at the top of the bone. A cartilagenous epiphyseal plate lies in the slight gap between the radial epiphysis, and underlying diaphysis. The bone elongates at these plates during growth.
The radiocarpal joint consists of the radius and its articulation with three carpal bones - the scaphoid, lunate and triquetral bones.
scaphoid: The scaphoid is one of three carpal bones which articulate with the radius. It also articulates with the trapezium to help move the thumb.
trapezium: The trapezium articulates primarily with the metacarpal of the thumb, and also with the scaphoid bone. It lies in the distal row of carpal bones. The tubercle of the trapezium form part of the border of the carpal tunnel, a groove over the anterior of the wrist and hand thorugh which nerves and many tendons travel into the palmar surface.
trapezoid: The trapezoid bone articulates with the second metacarpal bone (index finger).
triquetral: The triquetral bone resides on the proximal row of carpal bones. It articulates with a cartilagenous disc between the wrist and the radius and ulna of the forearm.
ulna: One of the two bones of the forearm - it lies on the side of the 5th finger. Note the epiphysis at the top of the bone. A cartilagenous epiphyseal plate lies in the slight gap between the ulnar epiphysis and underlying diaphysis. The bone elongates at these plates during growth.
The ulna does not directly articulate with any of the carpal bones.
Click on the image again to pull up specific information.
Created with Annotation 1.0