Finger and Hand Anatomy and Positioning

Digits

Each finger and thumb are known as what?

phalanges

Bones of the fingers and toes are known as what?

Phalanx

A singular bone of the finger or toe is known as what?

14

How many bones make up the phalanges?

5

How many bones make up the metacarpals?

8

How many bones make up the carpals?

27

How many bones are in each hand? (add all bones together!)

3 (proximal, middle, distal)

How many phalanges make up each of the 2nd-5th digits?

Thumb (pollex)

Each digit is assigned a number. In anatomical digit numbering, which digit is designated as the 1st?

Pollex

Special name for the thumb?

Pinky

Each digit is assigned a number. In anatomical digit numbering, which digit is designated as the 5th?

Carpals

wrist bones (8 total)

carpometacarpal joint (CMC)

Articulations between carpals and metacarpals

Metacarpals

the five bones that form the palms of the hand

Base of metacarpal

Expanded proximal end that articulates with carpals

body/shaft of metacarpal

Long curved portion

head of metacarpal

Distal round portion

Metacarpophalangeal joint (MCP)

Connects metacarpals to the proximal phalanges

Base of phalanx

Located on the proximal end; articulates with the distal heads of the metacarpals (AKA Metacarpophalangeal joint). (proximal end)

Body/shaft of phalanx

Middle part of the phalanx

head of phalanx

distal end

Proximal phalanges

the phalanges closest to the metacarpals

Proximal interphalangeal joint (PIP)

between proximal and middle phalanges

Middle phalanges

articulate with the proximal and distal phalanges

distal interphalangeal joint (DIP)

joint between middle and distal phalanges

Distal phalanges

the phalanges furthest from the wrist

Interphalangeal joint (IP)

Located between the proximal and distal phalanges

2 (proximal and distal)

How many phalanges make up the thumb?

phalanges

A?

Metacarpals

B?

Carpals

C?

sesamoid bones

D?

1st carpometacarpal joint (CMC)

A?

Body/shaft of phalanx (1st metacarpal)

B?

1st Metacarpophalangeal joint (MCP)

C?

Body/shaft of phalanx (proximal phalanx)

D?

Interphalangeal joint (IP)

E?

Distal phalanx

F?

2nd Metacarpophalangeal joint (MCP)

G?

Body/shaft of phalanx (proximal phalanx)

H?

2nd Proximal interphalangeal joint (PIP)

I?

Body/shaft of phalanx (Middle Phalanx)

J?

2nd Distal interphalangeal joint (DIP)

K?

head of 2nd pharynx (distal Phalanx)

L?

Head of Phalanx

A?

Body/shaft of Phalanx

B?

Base of Phalanx

C?

Scaphoid Fat Stripe

Visualized on PA and oblique projections, Elongated and slightly convex in shape, Located between the radial collateral ligament and adjoining muscle tendons lateral to scaphoid

Pronator Fat Stripe

Visualized on lateral view, Located ¼ of an inch anterior to the radius

dislocation

displacement of a bone from its joint

Bennett fracture (fx)

fracture through base of the first metacarpal bone, extending into the CMC joint with subluxation w/ posterior displacement

Boxer fracture (fx)

Transverse fracture that extends through the metacarpal neck (commonly seen on 5th metacarpal)

Skiers thumb

Sprain or tear of the ulnar collateral ligament (occurs from falling on outstretched arm and hand, thumb bends back toward hand)

Osteoarthritis

degenerative joint disease

rheumatoid arthritis

Chronic systemic disease with inflammatory changes throughout connective tissues

Osteoporosis

A condition in which the body's bones become weak and break easily.

-kVp: low to medium (60-80, typically 55-65 for fingers)

-Grid: No (unless bigger than 10cm or 4in)

-SID: 40in

what are the technical factors needed for a good hand x-ray (kVp, grid, SID)?

long hand=long board (hand perpendicular with IR)

What's the positioning rule for IR/hand positioning?

Correctly exposed images of the upper limbs should reveal soft tissue margins for fat pad visualization and fine trabecular markings of all bones being radiographed (good contrast)

What makes a good hand X-ray?

Yes, it won't take much technique to get through the bone

When X-raying geriatric patients with osteoporosis, should you lower your technical factors?

radiopaque objects, clothing removed placed in gown , long hair, oxygen tubing, and pacemaker leads to avoid reduced detail/scatter

During patient preparation, what must be removed?

1. Limit the number of exposures

2. Collimation

3. shielding (led apron)

4. correct positioning

What 4 things help protect you and the patient against radiation?

BEFORE the examination

When must the anatomical marker be placed?

PA

PA oblique

Lateral "FAN"

What are the routine projections of the hand?

What is the evaluation criteria and procedure for a PA Projection of the Hand X-ray?

SID: 40inches

Grid: No

kVp: 60-80

CR: center to 3rd metacarpal joint

Patient position: Patient seated sideways at end of table,

Height of table near shoulder height, palmar surface on IR, spread fingers slightly

Evaluation criteria: Entire hand and carpals demonstrated, Center of field at third MCP joint, No rotation of phalanges or metacarpals, Exposure factors

What is the evaluation criteria and procedure for a PA Oblique projection

X-ray?

SID: 40inches

Grid: No

kVp: 60-80

CR: center to 3rd metacarpal joint

Patient position: Patient seated sideways at end of table,

Height of table near shoulder height, Rotate entire hand and wrist laterally 45˚ with digits parallel to IR, spread fingers slightly

Evaluation criteria: Entire hand and carpals demonstrated, Center of field at third MCP joint, Joints open, Adequate separation of phalanges and metacarpals, Exposure factors

What is the evaluation criteria and procedure for a "Fan" Lateral Projection

X-ray?

SID: 40inches

Grid: No

kVp: 60-80

CR: center to 2nd metacarpal joint

Patient position: Patient seated sideways at end of table,

Height of table near shoulder height, Rotate hand and wrist into lateral position with thumb side up, Spread fingers and thumb into a "fan" position

Evaluation criteria: Entire hand and carpals demonstrated, Center of field at second MCP joint, Fingers equally separated Exposure factor

AP

PA Oblique

Lateral

What are the routine projections of the 1st digit?

the 1st metacarpal and trapezium (carpal articulating with 1st metacarpal)

During a thumb x-ray, what must you include?

What is the evaluation criteria and procedure for a AP projection of the 1st digit?

SID: 40inches

Grid: No

kVp: 55-65

CR: center to 1st metacarpal joint

Patient position: Patient seated sideways at end of table,

Height of table near shoulder height, Rotate arm internally to supinate thumb

Evaluation criteria: Entire thumb demonstrated (including first CMC joint), Center field at first MCP joint, No rotation of phalanges, Exposure factors

PA thumb

If the patient can't rotate their arm/hand for an AP projection of the thumb, what projection must be done?

What is the evaluation criteria and procedure for a PA projection of the 1st digit?

SID: 40inches

Grid: No

kVp: 55-65

CR: center to 1st metacarpal joint

Patient position: Place hand in pronation position, Rest thumb on sponge support block that is high enough to keep the thumb from rotating

-PA is not advisable b/c of loss of definition caused by increased OID

What is the evaluation criteria and procedure for a PA Oblique projection 1st digit X-ray?

SID: 40inches

Grid: No

kVp: 55-65

CR: center to 1st metacarpal joint

Patient position: Patient seated sideways at end of table,

Height of table near shoulder height, Abduct thumb slightly with palmar surface of hand in contact with IR to naturally places thumb in 45˚ oblique

Evaluation criteria: Entire thumb demonstrated, Joints partially open as in 45° oblique, Center of field at first MCP joint ,Exposure factors

What is the evaluation criteria and procedure for a Lateral Projection of the 1st Digit?

SID: 40inches

Grid: No

kVp: 55-65

CR: center to 1st metacarpal joint

Patient position: Patient seated sideways at end of table,

Height of table near shoulder height, Start with hand pronated and thumb abducted, Fingers slightly arched

Evaluation criteria: Entire thumb demonstrated, Center of field at first MCP joint, No rotation from lateral evident, Exposure factors

PA

PA Oblique

Lateral

Routine projections for digits 2-5?

What is the evaluation criteria and procedure for a PA Projection digits 2-5

X-ray?

SID: 40inches

Grid: No

kVp: 55-65

CR: center to PIP joint

Patient position: Patient seated sideways at end of table,

Height of table near shoulder height, Pronate hand with fingers extended

Evaluation criteria: Entire finger and minimum ⅓ of MCP demonstrated, Center field at PIP joint, No rotation of phalanges, Exposure factors

What is the evaluation criteria and procedure for a PA Oblique Projection digits 2-5 X-ray?

SID: 40inches

Grid: No

kVp: 55-65

CR: center to PIP Joint

Patient position: Patient seated sideways at end of table,

Height of table near shoulder height, rotate hand laterally 45° for digits 3-5, rotate medially 45° for 2nd digit

Evaluation criteria: Entire phalanx and MCP joint demonstrated, IP and MCP joints open, Center field at PIP, Exposure factors

What is the evaluation criteria and procedure for a Lateral Projection digits 2-5 X-ray?

SID: 40inches

Grid: No

kVp: 55-65

CR: center to PIP Joint

Patient position: Patient seated sideways at end of table,

Height of table near shoulder height,

Lateromedial: 3-5th digits Place hand in lateral position (thumb side up) with finger to be examined fully extended then Flex unaffected fingers Finger is parallel to IR

Mediolateral: 2nd digit Rotate hand medially till thumb side is down and second digit is touching IR then Flex unaffected fingers

Evaluation criteria: Entire phalanx and MCP joint demonstrated, Center field at PIP, True lateral position, Digit parallel to IR, Exposure factors