Scaphoid, Forearm and Elbow

Question 1

When working with angles what must you check?

Answer 1

The SID

Question 2

What is the scaphoid?

Answer 2

• the largest carpal in the proximal row
• anterior and lateral tubercles
• palpable near the base of the thumb
• “anatomical snuffbox”

Question 3

What is the carpal canal?

Answer 3

• bony passageway for the median nerve and flexor tendons to pass through
• goes through the carpals and the flexor retinaculum
• compression of the median nerve causes carpal tunnel syndrome

Question 4

What is the elbow?

Answer 4

• articulation of the humerus with the radius and ulna
• distal humerus has two condyles (trochlea and capitulum)
• epicondyles are the medial and lateral protuberances above
• distal humerus has 2 fossae (olecranon and coronoid)
• 2 fat pads seen on the lateral projection

Question 5

Scaphoid - PA Projection

Answer 5

position - hand prone in ulnar deviation
CR - perpendicular to IR
CP - scaphoid
collimation - base of 1st metacarpal to ulnar head

Question 6

Scaphoid - PA Axial Projection

Answer 6

Position - hand prone in ulnar deviation
CR - 20 degrees proximally
CP - Scaphoid
collimation - base of 1st metacarpal to ulnar head

Question 7

Scaphoid - Alternate PA Axial Projection

Answer 7

Position - hand prone in ulnar deviation - hand elevated on a 20 degree sponge
CR - perpendicular to IR
CP - Scaphoid
collimation - base of 1st metacarpal to ulnar head

Question 8

Scaphoid - PA and PA Axial Evaluation Criteria

Answer 8

• distal radius and ulna to proximal half of meta carpals
• scaphoid and adjacent joint spaces open
• axial method should show scaphoid freer from superimposition
• no rotation
• ulnar deviation
• see boney trabeculae and soft tissue

Question 9

What is the scaphoid series?

Answer 9

Rafert-Long method
4 images
PA and PA axial with angles of 10, 20 and 30

Question 10

Tangential carpal canal projection

Answer 10

• hyperextend wrist
• slight radial rotation (flattens carpal canal)
  CR - 25-30 proximally
  CP - Palm of the hand, include all of the canal
• styloids to centre of IR

Question 11

Tangential carpal canal evaluation criteria

Answer 11

• carpals are in an arch
• pisiform separate and in profile
• hook of hamate
• common athletic injuries can be diagnosed with this projection: hook of hamate, pisiform and trapezium

Question 12

Forearm - AP Projection

Answer 12

3 major joints must be on the same plane (wrist, elbow and shoulder)
- arm supinated, ensure elbow and wrist are true AP - epicondyles equidistant
CR - perpendicular
CP - middle of forearm
collimate 5cm or 2in past each joint

Question 13

Forearm - AP Evaluation Criteria

Answer 13

• entire forearm and both end joints
• slight superimposition of proximal radius/ulna
• no elongation/foreshadowing of humeral epicondyles
• partially open wrist and elbow joints
• open radioulnar space

Question 14

Forearm - lateral projection

Answer 14

3 joints on same plane, arm bent 90, wrist and lateral in true lateral best you can
CR - perpendicular
CP - middle of forearm
Collimate 5cm or 2in past each joint

Question 15

Forearm - lateral evaluation criteria

Answer 15

• entire forearm and both end joints
• superimposition of distal radius/ulna
• superimposition of radial head and coronoid process
• superimposed humeral epicondyles
• radial tuberosity facing anteriorly

Question 16

What projections do you start hanging in anatomical position?

Answer 16

elbow

Question 17

Elbow - AP projection

Answer 17

3 joints on same plane
hand supinated, epicondyles equidistant to IR
CR - Perpendicular
CP - middle of elbow
collimate 8cm or 3in on either side of joint

Question 18

Elbow - AP Evaluation Criteria

Answer 18

• radial head, neck and tuberosity slightly superimposed with proximal ulna
• open humeroradial joint
• no rotation

Question 19

Elbow - Lateral Projection

Answer 19

3 joints on same plane
elbow flexed 90, thumb up, superimpose epicondyles - may need sponge under wrist
CR - perpendicular to IR
CP - elbow
collimate 8cm or 3in on either side of the joint

Question 20

Elbow - Lateral Evaluation Criteria

Answer 20

true lateral position
- superimposed humeral epicondyles
- radial tuberosity facing anteriorly
- tip of coronoid process should cover 2/3 of radial head
- olecranon process in profile

Question 21

If the coronoid process is too high in relation to the radial head, then…..

Answer 21

humerus is too elevated
- shoulder too high
- elbow too low

Question 22

If coronoid process is between radial head and condyles, then…..

Answer 22

hand is too low

Question 23

If radial head is between coronoid process and condyles, then…..

Answer 23

hand is too high

Question 24

When is the posterior elbow fat pad visible in a lateral projection?

Answer 24

usually only if there is an injury or the elbow is too extended, injury can also cause raised anterior fat pad

Question 25

Elbow - Medial AP Oblique Projection

Answer 25

Arm extended, hand pronated, epicondyles at 45 angle CR - perpendicular to IR CP - middle of elbow collimate to 8cm or 3" on either side of joint

Question 26

Elbow - Medial AP Oblique Evaluation Criteria

Answer 26

- coronoid process in profile - trochlea - elongated medial epicondyle - ulna superimposed by the radial head and neck - olecranon within the olecranon fossa

Question 27

Elbow - Lateral AP Oblique Projection

Answer 27

Arm extended, hand supinated, rotate externally until epicondyles at 45 angle CR - perpendicular CP - middle of elbow collimate to 8cm or 3" on either side of joint

Question 28

Elbow - Lateral AP Oblique Evaluation Criteria

Answer 28

- radial head, neck and tuberosity free of ulna - elongated lateral epicondyle - capitulum

Question 29

What do you do if the patient is unable to full extend their arm?

Answer 29

no issues with the lateral projection Requires 2 different AP projections - humerus parallel o IR - forearm paralle to IR

Question 30

Elbow - Partial Flexion Distal Humerus and Proximal Forearm Projection

Answer 30

supinate hand if possible CR - perpendicular to IR CP - middle of elbow Distal humerus: seat patient so entire humerus is on same plane Proximal forearm: patient may need to stand to get forearm parallel to IR

Question 31

Elbow - Partial Flexion Distal Humerus and Proximal Forearm Evaluation Criteria

Answer 31

- area of interest should be free of distortion (area parallel to IR) - are not of interest will be foreshortened

Question 32

What is acute flexion?

Answer 32

when patient presents elbow fully flexed and unable to straighten it at all - can do lateral 2 projections to make AP - Distal humerus parallel to IR - proximal forearm - distal humerus still parallel to IR - CR at proximal angle

Question 33

Elbow - Acute Flexion Distal Humerus Projection

Answer 33

humerus parallel to IR CR - perpendicular to IR CP - 5cm or 2" superior to olecranon

Question 34

Elbow - Acute Flexion Distal Humerus Evaluation Criteria

Answer 34

- no rotation - humerus and forearm superimposed - olecranon process and distal humerus without distortion

Question 35

Elbow - Acute Flexion Proximal Forearm Projection

Answer 35

humerus parallel to IR CR - perpendicular to forearm CP - 5cm or 2" superior to olecranon REMEMBER SID

Question 36

Elbow - Acute Flexion Proximal Forearm Evaluation Criteria

Answer 36

- no rotation - proximal radius and ulna with minimal distortion - joint space is more open than on distal humerus image

Question 37

Elbow - Radial Head Series Projection

Answer 37

4 views - shows the entire circumference of the radial head free of superimposition - positioning set up same as for the lateral elbow 1. hand supinated as much as possible 2. hand in lateral position 3. hand pronated 4. hand internally rotated

Question 38

Elbow - Radial Head Series Evaluation Criteria

Answer 38

- radial head partially superimposed by coronoid, but seen in all 4 images - elbow flexed 90 - radial tuberosity anterior for first 2, posterior for latter 2

Question 39

What is the Coyle Method?

Answer 39

Axiolateral elbow Same position as lateral elbow but hand pronated CR - 45 towards shoulder CP - mid elbow collimate 8cm or 3" on either side of joint

Question 40

What are the advantages of the Coyle Method?

Answer 40

- radial head, neck and tuberosity mostly free of superimposition - open joint between radius and capitulum - elongated epicondyles