Anatomy of the Fingers, Hand, and Wrist
Metacarpals
A group of five bones in the hand that compose the palm
Trapezium, trapezoid, capitate, and hamate
Carpal bones of the distal row of carpals from the first digit to the fifth digit
Scaphoid, lunate, triquetrum, and pisiform
Carpal bones of the most proximal row of carpals from the first digit to the fifth digit
Hamate
Carpal in the distal row that articulates with both the 4th and the 5th metacarpal
Trapezium, trapezoid, and capitate
Carpals in the distal row that each articulate with one metacarpal starting with the first digit
Hamulus
Hook-like process that projections off the anterior or palmar surface of the hamate
Distal interphalangeal joint (DIP)
Joint between the distal phalanx and the medial phalanx of digits 2-5
Proximal interphalangeal joint (PIP)
Joint between the medial phalanx and the proximal phalanx of digits 2-5
Carpometacarpal joint
Joint in the hand between the metacarpals and carpals
Metacarpophalangeal joint
Joint in the hand between the proximal phalanges and the metacarpals of digits 1-5
5
Number of digits on each hand. They are labeled accordingly with the thumb being 1
Ulnar deviation
Position for wrist x-rays that is used to evaluate the scaphoid. the hand is tilted toward the ulna
Radial deviation
Position for wrist x-rays that is used to view the medial aspect of the carpals. The hand is tilted toward the radius
Less than 40 inches
SID for ulnar or radial deviation because magnification is desired
Phalanges
The bones that compose the fingers or digits of the hand. They extend from the tip of the finger to the base
Carpal sulcus
The carpal tunnel or canal that is the concave anterior or palmar aspect of the carpals through which blood vessels and nerves pass
Scaphoid
The most common carpal bone to be injured
Head, body (shaft), and base
The three parts of each metacarpal
Proximal, middle, and distal phalanges
The three phalanges that compose fingers 2,3, 4, and 5 (not the thumb)
Tuft
The tips of the distal phalanges
19
The total number of bones in one hand
27
The total number of bones in the hand and wrist of one upper extremity
14
Total number of phalanges within the digits of one hand
5-10 degrees toward the elbow
Angle of the x-ray tube that must be used for ulnar and radial deviation
5
Number of metacarpal bones in the palm of one hand
Interphalangeal joints
The joints between the distal and medial phalanges and the medial and proximal phalanges on digits 2-5 or the single joint between the distal and proximal phalanges of the 1st digit
8
The number of carpal bones in one hand
Proximal and distal phalanges
The two phalanges that compose the 1st finger (the thumb)