Wrist and Forearm

Lateral wrist xray

A true lateral position is evidenced by the following: Ulnar head should be superimposed over distal radius; proximal second through 5th metacarpals all should appear aligned and superimposed

Pisiform

Pea-shaped bone Anterior to the triquetrum Easily palpable

PA Scaphoid-Modified stecher method

Instead of an angle on the tube, elevate the hand on a 20 degree sponge

Which letter corresponds to Lunate(semilunar)?

L

Scaphoid

Largest bone in proximal row Contains a tubercle on the anterior and lateral aspect Palpable near base of thumb Most commonly fractured carpal bone

Which letter corresponds to trapezoid(lesser multangular)?

M

Triquetrum

Roughly pyramidal Articulates anteriorly with the hamate

Wrist Positioning

Routine: -PA -Oblique -Lateral Special -AP -PA Scaphoid w/angle and ulnar deviation -PA Scaphoid w/hand elevated and ulnar deviation "Modified Stecher Method" -PA Projection-Radial deviation -Carpal Canal (tunnel) Tangenital, inferosuperior projection "Gaynor-Hart Method" -Carpal Bridge-Tangenital

What are the routine positions for the wrist?

PA, Oblique, and lateral

PA Scaphoid- with CR angle and ulnar deviation

Scaphoid should be demonstrated clearly without foreshortening, with adjacent carpal interspaces open.

Carpal bones

Scaphoid, Lunate, Triquetrum, Pisiform, Trapezium, Trapezoid, Capitate, Hamate

Trapezoid

Smaller surface anteriorlythan posteriorly

Which letter corresponds to Triquetrum(triangular)?

T

Which letter corresponds to the scaphoid(Navicular)?

s

proximal row of carpals bones

scaphoid, Lunate, Triquetrum, Pisiform

PA Oblique Wrist

-8x10 or 10x12 -40" SID -Align and center wrist to portion of IR being exposed. -From pronated position, rotate wrist laterally 45 degrees -CR to midcarpal area

Which letter corresponds to trapezium(greater multangular)?

G

What special/optional position best demonstrates the carpal interspaces? A. AP B. Carpal Bridge C. Carpal canal D. PA oblique

A. AP

Capitate

Articulates with the base of the 3rd metacarpal Large stand most centrally located carpal

Lunate

Articulates with the radius proximally Crescent shape

Head of Ulna is ?

Distal

PA Oblique wrist w/ sponge

For stability, place a 45 degree sponge under thumb side of hand to support hand and wrist in a 45 degree oblique position

Which letter corresponds to hamate(unciform)?

H

Trapezium

Has a tubercle and groove on anterior surface

Carpal Mneumonic (secondary terms/synonyms)

Never Lower Tillie's Pants Grandma Might Come Home Navicular, Lunate (Semilunar), Triangular, Pisiform, Greater multangular, Lesser multangular, Capitate (Os Magnum), Hamate (Unciform)

If the patient is in severe pain:

No ulnar deviation, NO CR angle, & hand elevated 20 degrees

Which letter corresponds to Pisiform?

P

Head of Radius is ?

Proximal

Radial Deviation/Flexion

The carpals are visible, with adjacent interspaces more open on the medial (ulnar) side of the wrist

Carpal Canal

This projection is performed to R/O abnormal calcification and bony changes in the carpal sulcus that may impinge on the median nerve as with carpal tunnel syndrome.

What carpal bone articulates with the 1st metacarpal?

Trapezium(Greater Multangular)

anatomic snuffbox

Triangular depression located on the posterior surface of the wrist Visible when the thumb is abducted and extended Formed by the tendons of two major muscles of the thumb Overlies the scaphoidbone and radial artery Tenderness in the snuffbox area can indicate a scaphoidfracture

Hamate

Wedge-shaped Hook of hamate located on anterior surface

What is the tube angle for the PA Scaphoid with CR angle and ulnar deviation? a. 10-15 degrees proximally b. 10-15 degrees distally c. 30-45 degrees proximally d. 30 to 45 degrees distally

a. 10-15 degrees proximally

Members of the distal row of carpal bones include: 1. trapezium(greater multangular) 2.scaphoid (navicular) 3.triquetrum(triangular) 4.hamate (unciform) a. 1 and 2 only b. 2 and 3 only c. 1 and 4 only d. 1,2 and 3

c. 1 and 4 only

Proper positioning of the forearm for an AP projection requires that hand to be a. lateral b. flexed c. supinated d. pronated

c. supinated

Which of the following will best demonstrate the carpal scaphoid (Navicular)? a. carpal tunnel b. lateral wrist c. ulnar flexion (deviation) d. radial flexion (deviation)

c. ulnar flexion (deviation)

Positioning instructions for the lateral projection of the forearm include: 1. humerus and forearm form a 90 degree angle 2. CR to be directed to mid forearm area 3. hand to be lateral a. 1 only b. 2 and 3 only c. 3 only d. 1,2 and 3

d. 1,2 and 3

What carpal bone lies between the lunate and the pisiform? a. trapezium (greater multangular) b. scaphoid (navicular) c. capitate (Os magnum) d. triquetrum (triangular)

d. Triquetrum (triangular)

What position is demonstrated in the following photograph? a. carpal bridge b. ulnar flexion with tube angle c. radial flexion d. modified stetcher method

d. modified stetcher method

distal row of carpal bones

trapezium, trapezoid, capitate, hamate

Lateral Forearm- Lateromedial Projection

-11x14 or 14x17 -40" SID -Elbow bent 90 degrees -Drop the shoulder to place entire upper limb on same horizontal plane -Rotation hand and wrist into true lateral position -CR to midforearm -Must get both joints on radiograph (minimum of 1 to 11/2 inches of both joints)

AP Projection: Forearm

-11x14 or 14x17 -40" SID -Fully extend hand and arm palm up -Instruct patient to lean laterally as necessary to place entire wrist, forearm and elbow in as near a true frontal position as possible -CR to midforearm -Must get both joints on radiograph (minimum of 1 to 11/2 inches of both joints)

PA Scaphoid with CR angle and ulnar deviation

-Position for a PA wrist and w/o moving the arm gently evert the hand toward the ulnar sides as far as the patient can tolerate with lifting or rotating distal forearm. -Angle CR 10-15 degrees proximally along the long axis of the forearm (towards elbow) -CR to scaphoid -8x10 or 10x12 -40" SID

PA Projection- Radial Deviation

-Position for a PA wrist and w/o moving the arm gently invert the hand toward the radial side as far as the patient can tolerate with lifting or rotating distal forearm -No CR angle -CR to midcarpal area -8x10 or 10x12 -40" SID

Lateral Wrist- Lateromedial Projection

-8x10 or 10x112 -40" SID -Align and center wrist to portion of IR being exposed -Flex elbow 90 degrees and place the wrist and hand in thumb-up lateral position -CR to midcarpal area

PA Wrist

-8x10 or 10x12 -40" SID -With hand pronated, arch hand slightly to place the carpals in close contact with IR -CR to midcarpal area

Carpal Bridge

-8x10 to 10x12 -Have patient stand or sit at the end of the table and then lean over and place dorsal surface of hand, palm upward, on cassette -Angle the 45 degrees to the large axis of the forearm -CR to a midpoint of the distal forearm about 4 cm (11/2 inches) proximal to the wrist -Demonstrates calcification or other pathology of the dorsal aspect of carpal bones

Forearm Positioning

-AP -Lateral

Carpal Canal (Tunnel)

-Also called Gaynor-hart method or tangential inferosuperior projection -Ask patient to hyperextend wrist to place the metacarpals and fingers as near vertical as possible w/o lifting the wrist off the IR -CR 25 to 30 degrees to the long axis of the hand -Direct CR to a point 2 to 3 cm (1 inch) distal to the base of the third metacarpal

Alternative AP Wrist

-Best demonstrates the intercarpal spaces (keep hand arched) -Carpal interspaces are more parallel to the divergent rays in this position

What are the structures best shown for the position performed below? A. Open up carpal interspaces and visualize the carpals on the lateral aspect of the wrist B. Open up carpal interspaces and visualize the carpals on the medial aspect of the wrist. C. To correct the foreshortening of the scaphoid (navicular) D. To check for carpal tunnel syndrome

B. Open up carpal interspaces and visualize the carpals on the medial aspect of the wrist.

Which letter corresponds to capitate (Os Magnum)?

C

Which of the following statement is NOT true? A. The radial notch is on the ulna B. The neck of the radius lies directly distal to it's head C. The olecranon process is proximal to the head of the ulna D. The neck of the ulna lies directly proximal to it's head

D. The neck of the ulna lies directly proximal to it's head

What projection is demonstrated in the photograph? A. AP B. PA oblique C. Mediolateral D. Lateromedial

D.Lateromedial