Specialised Orthopaedic Projections

Question 1

What is a carpal tunnel projection and what does it show?

Answer 1

• Axial projection
• Demonstrates medial and lateral prominences and the concavity
• Demonstrates abnormal calcification and bony changes – for carpel tunnel syndrome
• For investigation of hook of hamate, pisiform and trapezium fractures

Question 2

How is a carpal tunnel projection performed?

Answer 2

Multiple views possible
Forearm pronated 
Hand and wrist dorsiflexion
Central Ray approx. 3cm distal 
     to base of third metacarpal 
     (centre of palm)

Question 3

What is a radial head projection and what does it show?

Answer 3

• Demonstrates the radial head in the axial plane.
• Isolation of the radial head using a modified technique.
• For detection of suspected subtle radial head fractures.
• If normal elbow projections come back inconclusive, but the patient’s clinical presentation suggests injury to the radial head.
• FOOSH is the typical cause of radial head injury and may be likely to result in this projection being undertaken.

Question 4

How is a radial head projection performed?

Answer 4

• Positioned as per lateral elbow projection
• Beam is angled 45 degrees towards the long axis of the humerus
• Centred over radial head
• Include skin borders, distal third of humerus and entire radial head

Question 5

What is an acromioclavicular joint projection and what does it show?

Answer 5

AC radiographs are performed for a variety of indications including:
shoulder trauma 
direct blows to the should region
following a fall onto adducted arm
suspected dislocation 
suspected arthritis

Weightbearing and non-weight bearing views compared, as widening ACJ space indicates an injury to the ligament.

Question 6

How is an acromioclavicular joint projection performed?

Answer 6

Patient position
Patient is erect
Midcoronal plane of the patient is parallel to the image receptor
Acromioclavicular joint of the affected side is at the centre of the image receptor
Affected arm is in a neutral position by the patient side

Weight bearing (holding weights) or non-weight bearing

Question 7

What is a Stryker notch projection and what does it show?

Answer 7

Specialised projection of the shoulder.

Helps evaluate articulation of humeral head and the glenoid.

Used to assess hill-sachs lesions (Compression fractures due to frequent dislocations).

Question 8

How is a Stryker notch projection performed?

Answer 8

Patient is erect.

Coronal plane is parallel to image receptor. With the patient’s back to the receptor.

Patient is turned slightly to open up joint space. (30-45°)

Arm is abducted anteriorly and rested on patients head.

Centre at the mid axilla at the level of the Gleno-humeral joint

Question 9

What is a lateral scapula projection and what does it show?

Answer 9

View of the scapula
Also known as a ‘Y-view’
Useful to see coracoid and acromion process in profile
Can see the scapula without any rib superimposition

Used to assess:
suspected dislocations
scapula fractures
degenerative changes

Question 10

How is a lateral scapula projection performed?

Answer 10

Patient erect facing the detector
Patient rotated 45 degrees so the affected shoulder is touching the detector
The hand of affected side is placed on the patient’s abdomen with the arm flexed to 90 degrees
Scapula should be end-on to the detector
Centre over glenohumeral joint, central to the medial scapular border
Collimate to include skin borders laterally and superiorly, and to include whole of scapula

Question 11

What is an intercondylar notch projection and what does it show?

Answer 11

Demonstrates: femorotibial articulation
Theintercondylar areais the rough, central part of the tibial plateau
Theintercondylarfossa of femur (intercondyloid fossa of femur,intercondylar notchof femur) is a deepnotchbetween the rear surfaces of the medial and lateral epicondyle of the femur, two protrusions on the distal end of the femur (thigh bone) that joins the knee.
It varies in shape and size
Female knee – ICN and ACL tend to be smaller
Some studies have shown that patients with a narrow intercondylar notch have a predisposition for ACL tears

Multiple Epiphyseal Dysplasia – A group of disorders of cartilidge and bone developekmtn, primarily affecting the ends of the long bones (epiphysis) arms and legs. Symptoms include; Joint pain, early onset arthritis, short stature (A)

Cyclops lesion – Painful anterior mass that arises as a complication of ACL reconstruction (B)

Haemophilic Arthropathy – A permanent joint disease occurring in haemophilia sufferers as a long term consequence of heamarthrosis (bleeding into joint spaces) (C)

Question 12

How is an intercondylar notch projection performed?

Answer 12

AP
No grid or filter neded.
Usual exposure around 60kVp and 8mAs.
SID 100cm
Patient is positioned supine on the x-ray table with a cyushion for their head.
Flex knee 40/45 degrees.
Place IR under the knee and raise it to support it in place and reduce the OID.
Centre the IR and the central ray to the midknee joint.
Ensure no rotation of the knee.
Angle the central ray 40 degrees to match the lower leg.
Collimate to the knee joint

PA
Prone on table.
Flex knee 40-45 degrees and support with pad.
Centre IR and central ray to to midpopliteal crease.
Angle central ray 40-45degree

Question 13

What is a Rosenberg projection and what does it show?

Answer 13

Radiographic view to demonstrate joint space narrowing due to cartilage degeneration
Performed PA Weight Bearing
Used for early detection of OA
Most sensitive view for Tibio-Femoral arthritis
Distal Femur to Proximal Tibia and Fibula
Demonstrates bilateral Tibio-Femoral joint spaces under the effect of gravity (weight bearing)

Question 14

How is a Rosenberg projection performed?

Answer 14

Performed bilaterally
Horizontal Central Ray perpendicular to the IR
Directed to mid-point of the knee joint at the level of the patella apices
Collimate to include the distal 1/3 of femur and proximal 1/3 of Tib/Fib

Patient is standing
Facing the IR (PA)
If the tube doesn’t go low enough, patient can stand on a step
Feet positioned straight ahead, with even weight distribution across both feet
Patient can hold stability handle
Flex knees at 45° with patella’s touching IR
Maximum stress in the knee joint is between 35 ° - 60 °
(Gonad shielding can be used for this projection)

Ensure no rotation of bilateral knees
Evident in symmetrical appearance of femoral and tibial condyles
Intercondylar fossa should be open
Trabecular marking of all bones should appear clear and sharp
Indicates no movement during exposure

Question 15

What is a skyline patella projection and what does it show?

Answer 15

An inferior-superior projection of the patella.

It is one of many different methods to obtain an axial projection of the patella.

This projection is best suited to patients able to maintain a semi-recumbent position on the examination table

Helpful to assess knee pain due to suspected patellofemoral compartment osteoarthritis

Common reason for assessing the patello-femoral joint space, investigating the presence of patella subluxation and in evaluating other inflammatory and degenerative conditions

Question 16

How is a skyline patella projection performed?

Answer 16

The patient is semi-recumbent on the table holding a detector superior of the patella in the landscape orientation
Patient’s feet should be very close to the tube side of the bed
The knee is bent close to 30°
Often a pillow or cushion should be placed behind the patient to assist them in maintaining this position

Inferior-superior axial projection
Centring point: the central ray will be angled 30° from horizontal beam, shooting inferior-superior towards the patella. This will require the tube to lay below the level of the examination table; hence the patient should be as close to this end of the table as possible.
Collimation:
laterally to include the skin margins of the knee
inferior to include the femoropatellar joint space
superior to include medial skin margin

Question 17

What is a Judet projection and what does it show?

Answer 17

A view consisting of two oblique radiographic projections centred on the hip in question
Image consisting of two oblique radiographic projections centred on the hip in question, tilted 45 degrees medially or laterally from a true anteroposterior direction.

Iliac oblique 
--assessment of theposterior column
--anterior wall of the acetabulum
Obturator oblique view
--demonstrates theanterior columnof the pelvis 
--posterior wall of theacetabulum

Performed to investigate:
Suspicion of an acetabular fracture
posterior hip dislocation

Question 18

How is a Judet projection performed?

Answer 18

Iliac Oblique:

• patient is supine
• theunaffectedside is rotated roughly 45°anterior, generally aided with a 45° sponge
• Patient is central on the table so no risk of over rolling
• • 5cm distal and 5 cm medial of the ASIS closest to the image receptor

Obturator Oblique:

• patient is supine
• theaffectedside is rotated roughly 45° anterior, generally aided with a 45° sponge
• Patient is central on the table and no risk of over rolling
• • 5 cm distal and 5 cm medial of the ASIS that is rolled up anterior to the image receptor

Collimate:
superior to the level of the ASIS
inferior to the proximal femur
laterally to the skin margins
medially to thepubic symphysis