The humerus

Question 1

subluxation

Answer 1

defined as an incomplete or partial dislocation of a joint

Question 2

Transthoracic

Answer 2

The term transthoracic refers to a procedure or action that is performed across or through the thoracic cavity, which is the part of the body known as the chest.

Question 3

Frozen shoulder

Answer 3

limited abduction and rotation of the shoulder due to fibrositis

Question 4

Recurrent dislocation.

Answer 4

refers to the repeated dislocation of a joint, typically the shoulder, after an initial dislocation event.

Question 5

Indications for x-ray of the humerus

Answer 5

a. Trauma to rule out the following:
* fracture of the humeral shaft
*Fracture of surgical neck,
* dislocation of the shoulder, subluxation of the acromio-clavicular joint.
b. Pathology such as calcification of tendons, osteoporosis.

Question 6

External rotation of the hand puts the humerus into true AP projection as evidenced
by the following anatomical structures on the image

Answer 6

– humeral epicondyles are equidistant to the image receptor
– interepicondylar line is parallel to the image receptor
– greater tubercle is located laterally in profile
– lesser tubercle anteriorly and medial to the greater tubercle

Question 7

Internal rotation of the hand puts the humerus in a true lateral position where

Answer 7

The greater
tubercle lies anteriorly and medially while lesser tubercle lies medial to proximal humerus.

Question 8

When is neutral rotation of the humerus carried out.

Answer 8

• In traumatic patients where rotation of the part is impossible.

Question 9

Radiation Protection during the examination of the humerus

Answer 9

• Careful technique to avoid repeats
• Collimation of the beam to the required area
• If a trans-thoracic projection is required, great care must be exercised because of the
  radiation dose to the trunk

Question 10

The basic projections for the humerus are:

Answer 10

• AP
• Lateral

Question 11

Antero-posterior projection
Equipment required

Answer 11

• 35 x 43 cm image receptor lengthwise
• 30 x 40 cm for smaller patient
• Erect bucky or chest stand
• Lead protective waist apron

Question 12

Patient positioning in AP of humerus.

Answer 12

• The patient may be supine on the x-ray table or erect facing the x-ray tube with his
  back against the erect bucky or chest stand.
• Place the top edge of the image receptor 3.8 cm above the level of the humeral
  head
• The trunk is rotated towards the affected side to bring the posterior aspect of the
  shoulder, humerus and elbow in contact with the image receptor.
• The affected arm in anatomical position and full extension at the elbow and
  abducted at the shoulder.
• The humeral epicondyles should be equidistant from the image receptor
• The head is turned towards the unaffected side.
• Collimate the beam to include both the shoulder and elbow joints
• Place anatomical marker and apply lead waist apron

Question 13

Centering point of the AP of humerus.

Answer 13

Anterior aspect of humerus midway between shoulder and elbow

Question 14

Direction of central ray in AP of humerus.

Answer 14

Horizontal if patient is erect or vertical if patient is supine 90⁰
to the film

Question 15

Evaluation criteria for AP image of the humerus.

Answer 15

• Evidence of proper collimation
• Elbow and shoulder joints
• Maximal visibility of epicondyles without rotation
• Humeral head and greater tubercle in profile
• Outline of the lesser tubercle located between the humeral head and the greater
  tubercle
• Beam divergence resulting in distortion of the elbow joint
• Similar image brightness and contrast of the proximal and distal humerus
• Soft tissue and bony trabecular detail

Question 16

Lateral projection 2 types.

Answer 16

• Mediolateral
• Lateromedial

Question 17

Lateromedial

Answer 17

• The patient stand facing the x-ray tube and the back side on the image receptor
• Place the top edge of the image receptor 3.8 cm above the level of the humeral head
• Slightly abduct the arm and flex the elbow approximately to 90⁰
• Rotate the body towards the affected side until medial aspect of the humerus is in
  contact with image receptor
• The head is turned towards the unaffected side
• The epicondyles of the humerus must be superimposed

Question 18

Mediolateral

Answer 18

• The patient stand facing the image receptor
• Place the top edge of the image receptor 3.8 cm above the level of the humeral head
• Slightly abduct the arm and flex the elbow approximately to 90⁰
• Rotate body away from affected side until lateral aspect of the humerus is in contact
  with image receptor
• Collimate to include both the shoulder and elbow joints
• The head is turned towards the unaffected side
• The epicondyles of the humerus must be superimposed

Question 19

centering point of lateral projections .

Answer 19

Mediolateral: Medial aspect of humerus midway between shoulder and elbow
Lateromedial: Lateral aspect of humerus midway between shoulder and elbow

Question 19

Evaluation criteria for lateral humerus

Answer 19

• The following should be clearly demonstrated
• Evidence of proper collimation
• Elbow and shoulder joints
• Superimposed epicondyles
• Lesser tubercle in profile on medial aspect
• Greater tubercle superimposed over the humeral head
• Beam divergence resulting into distortion of the elbow joint
• Similar image brightness and contrast of the proximal and distal humerus
• Soft tissue and bony trabecular detail.

Question 20

Supplementary/additional projections for the humerus.

Answer 20

• Antero-posterior projection of Humerus for surgical neck.
  *Transthoracic lateral projection for upper humerus.

Question 21

Antero-posterior projection of Humerus for surgical neck equipment required.

Answer 21

• 18 x 24 cm or 24 x 30 cm image receptor
• Foam pads
• Sandbags
• Lead protective waist apron

Question 22

AP projection of humerus for surgical neck patient position.

Answer 22

• The patient stands or lies supine facing the x-ray tube
• Affected arm slightly abducted and palm of hand in supine
• The patient is rotated towards affected side
• The image receptor is positioned to include the acromion process and proximal
  one third of the humerus

Question 23

Transthoracic lateral projection for upper humerus equipment required.

Answer 23

• 24 x 30 cm image receptor
• Vertical bucky
• Lead protective waist apron

Question 24

Transthoracic lateral projection for upper humerus Equipment required.

Answer 24

• 24 x 30 cm image receptor
• Vertical bucky
• Lead protective waist apron

Question 25

Transthoracic lateral projection for upper humerus patient position.

Answer 25

• Stand or sit the patient in the true lateral position with the affected side in neutral
  rotation in contact with the bucky top.
• Raise the unaffected arm over the patient’s head.
• Immobilise the trunk

Question 26

Evaluation Criteria (Transthoracic Lateral).

Answer 26

• Lateral view of entire humerus and glenohumeral joint should be visualized through
  the thorax without superimposition of the opposite humerus.
  Position.
• Outline of the shaft of the humerus should be clearly visualized anterior to the thoracic
  vertebrae.
• Relationship of the humeral head and the glenoid cavity should be demonstrated.
• Collimation to area of interest.
  Exposure.
• Optimal density (brightness) and contrast demonstrate entire outline of the humerus.
• Overlying ribs and lung markings should appear blurred because of breathing
  technique, but bony outlines of the humerus should appear sharp, indicating no motion
  of the arm during the exposure.