Upper Extremities

All joints of the upper limbs are what?

Synovial and freely moveable

A poorly positioned lateromedial hand demonstrates the distal radius posterior to the ulna and the shortest of the 2-5 metacarpals situated anterior to the other metacarpals. What is the positioning error?

The hand is too externally (laterally) rotated

A lateral radiograph of the 3rd digit demonstrates a concave anterior surface of the phalanges and a flat posterior surface of the phalanges. The fingernail is demonstrated in profile. What is the positioning error?

There is no positioning error

Distal carpal bones

Trapezium, trapezoid, capitate, hamate

What positions are used to demonstrate the hand in lateral projection?

Ulnar surface on IR, hand extended; radial surface on IR, hand extended; ulnar surface on IR, fingers in a fan lateral

Alternative name for hamate

Unciform

What is the wrist formed by?

8 carpals

A PA wrist projection with slight external rotation demonstrates:

A closed radioulnar articulation and open carpal interspaces on the lateral side of the wrist

A PA wrist with accurate positioning demonstrates:

An open radioulnar articulation, the radial styloid in profile, the long axis of the 3rd metacarpal aligned with the mid-forearm, and open 2-5 metacarpal (MC) joint spaces

If a lateral wrist projection is internally rotated where will the radius be in relation to the ulna?

Anterior

If a lateral wrist is rotated externally where will the pisiform be in relation to the scaphoid?

Anterior (looks like it is below the scaphoid on an image)

A fracture of the metacarpal neck is known as a ___________ fracture

Boxer's

What must the patient do in order for the trapezium to be demonstrates without superimposition of the second metacarpal on a lateral wrist projection?

Depress the first metacarpal (the thumb must be in the same plane as the second metacarpal)

(T/F) To obtain a PA oblique projection of the second digit, the hand should be rotated laterally (externally) from a PA position.

False

Where should the scaphoid and pisiform be positioned on an accurate lateral projection of the wrist?

The pisiform should be in the middle of the scaphoid

An external oblique wrist projection demonstrates an obscured trapeziotrapezoidal joint space and excessive trapezoid and capitate superimposition. How do you fix this positioning for an optimal projection?

Internally rotate the wrist

What projections demonstrates the distal radius and ulna completely superimposing?

Lateral wrist projection

Alternative name for trapezoid

Lesser multangular

Alternative name for capitate

Os magnum

What projection will demonstrate the scaphoid free from superimposition?

PA axial with ulnar deviation (Stecher method)

How many phalanges are there in the thumb?

2

For a PA projection of the second digit, where is the central ray is directed to?

PIP joint

Proximal interphalangeal joint

PIP joint

Which bones articulate with the head of metacarpal bones?

Proximal phalanges

Which side of the arm is positioned against the IR for a lateral projection of the second digit?

Radial

From PA, how much is the digit rotated for a PA oblique radiograph?

45 degrees

From a pronated hand position, how much obliquity is required for a PA oblique projection?

45 degrees

What is the first bone located in the proximal row and lateral side of the wrist?

Scaphoid

What is the first bone located on the proximal row and lateral side of the wrist?

Scaphoid

Alternative name for lunate

Semilunar

What is the patient position most commonly used to perform a radiograph of a finger?

Sitting at the end of the table

How many phalanges are there in the hand?

14

What is the central ray angle for a PA axial projection with ulnar deviation (Stecher method)?

20 degrees

From a pronated hand position. how much obliquity is required for a lateral projection?

90 degrees

For a lateral projection of the hand, where is the central ray is directed to?

Second MCP joint

Interphalangeal joint

IP joint

Where is the central ray for a PA/AP projection of the wrist?

Midcarpal area

Alternative name for scaphoid

Navicular

How are the metacarpals identified?

Numbered 1 through 5 from lateral (thumb side) to medial (little finger side)

Proximal carpal bones

Scaphoid, lunate, triquetrum, pisiform

What is the palm of the hand formed by?

5 metacarpals

What projection best demonstrates the carpal interspaces?

AP

The 3rd metacarpal of the hand articulates with what carpal bone?

Capitate

Which group of bones articulate with the base of metacarpal bones?

Carpals

What type of upper limb joints are formed in part by the bases of the metacarpals?

Carpometacarpal

A fracture of the distal radius with posterior displacement is known as a _____________ fracture

Colle's

Alternative name for triquetrium

Cuneiform

Distal interphalangeal joint

DIP joint

What must be demonstrated on all projections of the thumb?

Distal/proximal phalanges, MCP and CMC joints and the trapezium

A PA oblique radiograph shows the midaspect of the 4-5 metacarpals are partially superimposed. What is the positioning error?

Excessive lateral rotation

When positioning an AP thumb projection, how should the hand be placed?

Extreme internal rotation

What is the digit at the lateral (thumb) side of the hand called?

First digit

Which movements do interphalangeal joints allow?

Flexion and extension

Alternative name for trapezium

Greater multangular

What is the most distal portion of each metacarpal?

Head

What part of the metacarpal bone forms part of each metacarpophalangeal joint?

Head

For lateral projections of the 1-3 metacarpals what surface should rest on the IR?

Lateral surface

Metacarpophalangeal joint

MCP joint

Which projection of the thumb produces the greatest object-to-image-receptor distance (OID)?

PA projection

A PA projection of the hand reveals the distal radius, ulna and carpal bones were cut off. What should be done to correct this?

Repeat the PA projection to include all of the carpals and 1 inch of the distal radius and ulna (distal phalanges through 1 inch of the distal radius and ulna)

What happens when the digits are flexed excessively positioning for a PA wrist projection?

The base of the metacarpals superimposes over the carpals closing the CMC joints

Alternative name for pisiform

There isn't one

Why should the hand be slightly arched for a PA projection of the wrist?

To reduce the OID of the carpal bones

(T/F) A properly positioned PA hand radiograph will demonstrate equal concavity on both sides of the phalanges and metacarpals of digits 2-5.

True

(T/F) When the hand is pronated the thumb is placed in a oblique position.

True

What angle is used for a PA/AP projection of the wrist?

0 degrees

What angle is used for a lateral projection of the wrist?

0 degrees

The central ray should be directed at what joint for radiographs of the 1st digit?

MCP joint

For lateral projections of the 4-5 metacarpals what surface should rest on the IR?

Medial surface

What are the two saddle joints in the body?

Patella and thumb

What position would best demonstrate the interphalangeal joints?

Positions where the digits are parallel to the IR

If a lateral wrist projection is externally rotated where will the radius be in relation to the ulna?

Posterior

If a lateral wrist is rotated internally where will the pisiform be in relation to the scaphoid?

Posterior (sticking out)

How is the hand positioned for a PA oblique projection of the first digit?

Pronated