* HSF (Ch. 4) Digit, Hand, and Wrist - 09/15/2025

When is a scaphoid (navicular) view performed?

Only when specifically ordered for suspected scaphoid injury (it is a specialty view)

Where should right/left markers be placed for AP/PA and oblique positions?

lateral side of the extremity

What is required on a PA hand for a digit routine?

An arrow to indicate the affected digit (pen tip with a note is acceptable if an arrow is not available).

What term is more proper than "upper extremity" and why?

Upper limb because it includes the joints

List the divisions of the upper limb.

Hand and wrist, forearm, arm (humerus), and shoulder girdle

How many total bones are found in one adult hand and wrist?

27

How many phalanges are there in one adult hand

14

How many metacarpals are in one adult hand

5

How many carpals in one adult hand

8

How many phalanges are in digits 2-5?

3 (proximal, middle, distal)

How many phalanges are in the thumb?

2 (proximal and distal)

Singular vs plural of the term for finger bones?

(Singular) phalanx, (plural) phalanges

List the three parts of each phalanx and metacarpal.

Head (rounded condyles), body (shaft), and base (square at posterior surface)

What is another name for the tip of a distal phalanx?

Tuft

Describe the appearance of the posterior aspect of hand bones.

Smooth and lack condyles

Describe the anterior aspect of hand bones.

Rounded condyles at the heads

Distal phalanx head shape vs base shape?

Head is rounded with condyles, base is square

How are digits numbered in the hand?

Thumb is always 1, pinky always 5

Which side is the thumb on in anatomical position?

Lateral

Which side is the pinky on in anatomical position?

Medial

What is the palmar surface of the hand?

The anterior surface

What is the dorsal surface of the hand?

The posterior surface

How are metacarpals numbered?

1-5 from thumb to pinky

What bones form the palm of the hand?

5 metacarpals

Metacarpal articulation proximally?

Carpals

Metacarpal articulation distally?

Proximal phalanges

How would you correctly describe pain at the base of the pinky metacarpal?

"Pain at the base of the 5th metacarpal of the right hand"

List the joints of the digits 2-5

DIP (distal interphalangeal) and PIP (proximal interphalangeal)

What is the name of the joint for the thumb?

IP (interphalangeal)

Joint between head of metacarpal and base of proximal phalanx?

MCP (metacarpophalangeal)

Joint between carpals and bases of metacarpals?

CMC (carpometacarpal)

Where is the CR for a PA hand?

3rd MCP joint (base of 3rd proximal phalanx)

Why must the fingers be fully extended for a PA hand?

To keep all joint spaces open because flexion closes the joint space

How should the CR be directed relative to joint spaces?

Parallel to the joint space and perpendicular to the long axes of the bones

What is an alternate mnemonic for carpals lateral to medial, for the proximal row? This would help you to remember the alternative names for each joint.

Some Naughty Lizards Slide Through Tall Cattail Ponds

Name the proximal row of carpals from lateral (thumb) to medial. (P = Lizard)

Scaphoid navicular, lunate semilunar, triquetrum triangular cuneiform, pisiform

What mnemonic helps remember carpals lateral to medial starting distal row? This will help you learn the alternative names to each joint. (Picture it)

Three Great Magicians Taught Little Mice Cool Old Magic, Harnessing Unicorns

Name the distal row of carpals from lateral to medial. (D = Magic)

Trapezium greater multangular, trapezoid lesser multangular, capitate os magnum, hamate unciform

Which carpals form the radiocarpal (wrist) joint?

Scaphoid and lunate with the radius

Which carpal is most commonly fractured and heals poorly?

Scaphoid navicular

Why is scaphoid fracture serious?

Poor blood supply can lead to avascular necrosis

Which carpal is medial to the scaphoid?

Lunate semilunar

The smallest carpal found in the distal row is the?

Trapezoid lesser multangular

Which carpal sits more posterior compared to the pisiform?

Triquetrum triangular cuneiform

Which carpal is the smallest and anterior to the triquetrum?

Pisiform

Which carpal articulates with the base of the first metacarpal?

Trapezium greater multangular

Which carpal articulates with the second metacarpal?

Trapezoid lesser multangular

Which carpal articulates with the third metacarpal?

Capitate os magnum

Which carpal articulates with the fourth and fifth metacarpals?

Hamate unciform

What unique feature does the hamate have?

Hamulus or hamular process (hook-like process) on the anterior side

What is an uncommon name for the hamate?

Uniform

Which carpal is the largest of all?

Capitate os magnum

Which carpal looks like a half-moon on lateral wrist?

Lunate semilunar

Which carpal looks like a duck in lateral view?

Scaphoid navicular

What bones form the osseous portion of the wrist joint?

Scaphoid navicular, lunate semilunar, distal radius

Why is the ulna not part of the bony radiocarpal joint?

It only contributes ligaments and soft tissue

Term for bones overlapping on a lateral image?

Superimposition

What is the distal lateral projection of the radius?

Radial styloid process

What is the distal medial projection of the ulna?

Ulnar styloid process

What is located at the proximal end of the radius near the elbow?

Radial head

What is located at the distal end of the ulna near the wrist?

Ulnar head

Where is the ulnar notch?

Radius

What does the ulnar notch articulate with and what does that form?

Ulnar head, distal radio-ulnar joint

Which bone of the forearm extends more distally at the wrist?

Radius

All hand and wrist joints are what functional type?

Diarthrodial freely moveable

What type of joints do the hand and wrist have?

Synovial

Type of movement for interphalangeal (IP

Ginglymus hinge (flexion and extension only)

Type of movement for MCP joints?

Ellipsoid condyloid (flexion, extension, abduction, adduction, and limited circumduction)

Type of movement for 1st CMC joint?

Sellar saddle (flexion, extension, abduction, adduction, circumduction, and opposition)

Type of movement for 2nd-5th CMC joints?

Plane / gliding (minimal movement, bones glide against each other)

Type of movement for intercarpal joints?

Plane / gliding

Type of movement for the radiocarpal joint?

Ellipsoid condyloid (flexion, extension, abduction, adduction, and limited circumduction)

Why is the PA projection preferred for a wrist even though an AP opens intercarpal joints better?

PA is easier for patient positioning

Define radial deviation.

Moving the hand toward radius (opens the medial side of the intercarpal joints)

Define ulnar deviation.

Moving the hand toward ulna (which opens the lateral side of the intercarpal joints and shows the scaphoid best)

Why is ulnar deviation used when imaging the scaphoid?

Scaphoid more visible by opening the lateral intercarpal spaces

What is the fibrocartilaginous disk that cushions the carpals from the radius and ulna and provides smooth joint movement?

Articular disk in wrist

List the four key wrist ligaments.

Ulnar collateral ligament, radial collateral ligament, dorsal radiocarpal ligament, palmar radiocarpal ligament

Function of the dorsal and palmar radiocarpal ligaments?

Prevent extreme hyperflexion and hyperextension of the wrist

Where is the scaphoid fat pad located?

Lateral to the scaphoid

In what views is the scaphoid fat pad seen?

PA and medial oblique wrist

Where is the pronator fat pad located

Anterior to distal radius

In what views is the pronator fat pad seen?

Lateral wrist

What technical factor could hide fat pads on an image?

Using too much mAs can burn out fat pad visibility

When the body is injured what happens to fluid in the joint?

Fluid accumulates which makes fat pads darker (radiolucent)

What view demonstrates the carpal sulcus and visualizes the path of major blood vessels, nerves, pisiform, and hamular process?

Carpal canal (tunnel) view

How do you correctly describe the location of pain for the distal phalanx of the 3rd digit of the right hand?

"Distal phalanx of the 3rd digit of the right hand"

What is the significance of correctly marking the affected digit?

helps radiologist identify precise area of concern (assists with accurate diagnosis)