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)