Pelvis and hips

Question 1

What projections for femur?

Answer 1

Antero-posterior Femur
Lateral Femur (HBL)

Question 2

How do you do a AP femur

Answer 2

Patient core position:
Patient lying supine on x-ray table with leg extended.

Positioning criteria:
Posterior aspect of femur in contact with image receptor.
Femoral condyles should be equidistant from the image receptor

Centring:
To the middle of the receptor with a VCR.

Collimation:
Collimate to include knee joint and and much femur as possible and lateral soft tissue margins. Knee up PLUS overlapping Hip down projections may be required.

Other info:
100/115cm SID.

Question 3

Lateral femur (HBL)

Answer 3

Patient core position:
Patient lying supine on x-ray table with leg extended.

Positioning criteria:
Patient then turns onto affected side so that Lateral aspect of affected femur is in contact with image receptor, with knee flexed and other limb separated.
Femoral condyles should be superimposed with respect to the IR.

Centring:
To the middle of the IR with a VCR.

Collimation:
Collimate to include from knee to hip joint and lateral soft tissue margins. Knee up PLUS overlapping Hip down projections may be required.

Other info:
100/115cm SID.

Question 4

LMP/ Pregnancy Rule

Answer 4

Women of ‘child-bearing capacity’
When the ‘beam lays in or near the uterus’
Pregnancy status prior to examination
The 28 day rule is normally used.
Could be over-ruled in significant trauma (life-threatening injuries.)

Question 5

Projections for pelvis?

Answer 5

AP Pelvis
AP Both Hips
AP Single Hip

Question 6

What makes up the pelvis girdle?

Answer 6

Innominate bones (2).
Sacrum – part of the vertebral column.
Coccyx – part of the vertebral column.

Question 7

What forms the The Innominate Bone of the pelvis?

Answer 7

Ilium (top bit)
Ischium (lateral)
Pubis (medial)

Question 8

What is the acetabulum?

Answer 8

The acetabulum is a cup-shaped hollow in the pelvis into which the head of the femur (thigh bone) fits to form a ball and socket joint
Made up from all the bones of the pelvis

Question 9

What does ASIS mean and where/what is it?

Answer 9

The anterior superior iliac spine

below the iliac crest

Question 10

What does psis mean and where/what is it?

Answer 10

posterior superior iliac spine

On the posterior side where it joins the spine

Question 11

Where is the iliac crest?

Answer 11

Top round part of the iliac bone

Question 12

What does SIJ?

Answer 12

Sacroiliac Joint

Question 13

What is the Obturator Foramen?

Answer 13

The hole in the pelvis

Question 14

• superior pubic ramus

- inferior pubic ramus

Answer 14

• superior pubic ramus (above the hole)

- inferior pubic ramus (medial low bit of the bone by the hole)

Question 15

What is the Symphysis Pubis?

Answer 15

The middle bit between the pubis, cartilaginous joint in the median plane
on the anterior side of the pelvis

Question 16

Where is the coccyx?

Answer 16

The last bit of the spine

Question 17

How does the appearance differentiate between male and female pelvis?

Answer 17

Female is wider, Smaller & more triangular obturator foramen

Males have a longer sacrum

Question 18

What are the joints of the pelvis?

Answer 18

each other at the Symphysis pubis.
the sacrum at the Sacro-iliac joints (SIJ’s).
The femora at the Hip joints

Question 19

What are the joints of the pelvis?

Answer 19

each other at the Symphysis pubis. (Cartilaginous Symphysis)

the sacrum at the Sacro-iliac joints (SIJ’s). (Synovial plane joint)

The femora at the Hip joints (Synovial ball and socket)

Question 20

What are Clinical indications for femur?

Answer 20

Trauma
? Fracture (?#).

Unexplained pain
? bone lesion

Question 21

How would you take an projection of the femur? Does it fit on the IR?

Answer 21

The joint closest to the pathology should be included on the image if both hip and knee joint cannot be demonstrated. Multiple overlapping projections are usually undertaken.
The routine projections undertaken are an Antero-Posterior and a Lateral.

Question 22

Clinical Indications for pelvis x-ray linked to trauma?

Answer 22

Trauma – 
Fall generally = NOF
High velocity can lead to other pelvic fractures 
Pubic rami
Acetabulum
SIJ disruption
Iliac wing #s

Question 23

Clinical Indications for pelvis x-ray linked for children?

Answer 23

pain in hip / on walking
SUFE-Slipped Upper femoral Epiphysis
DDH-Developmental Dysplasia of the Hip
CDH-Congenital Dislocation of the Hip
Perthes-osteochondritis dessicans
Osteomyelitis.

Question 24

Clinical indications for pelvis linked to pain in hip but not trauma?

Answer 24

Pain in hip ?
Osteoarthritis (OA),
Avascular Necrosis
or loose prosthesis.

Question 25

What does SOJ mean and what is it?

Answer 25

Sacroiliac joint, | Where the sacrum and the iliac bone meet

Question 26

What do you do for Patient Preparation?

Answer 26

``` Explanation of procedure. Informed consent Change into a gown. Safety checks. LMP check ```

Question 27

What projections are there for the pelvis?

Answer 27

AP Pelvis AP Both Hips AP Single Hip Lateral Turned Horizontal Beam “Frog” leg lateral (Lauenstein) AP SIJ PA SIJ

Question 28

Whats the patient position for AP pelvis and both hips?

Answer 28

Patient supine on table. Criteria: Median Sagittal Plane (MSP) perpendicular to the table and co-incident with central long axis of the table. ASIS’s equidistant from table top. Lower limbs slightly internally rotated (so heels are slightly apart but big toes touching together) brings necks of femora parallel to the IR & greater + lesser trochanters into profile.

Question 29

What's the centering point for AP pelvis? and collimation?

Answer 29

Over the midline, 5cm above the upper border of the symphysis pubis with a vertical central ray (whole Pelvis). Collimate to include the superior border of Iliac crests and as much as the femora as you can.

Question 30

What's the centering point for AP hips? and collimation?

Answer 30

Over Symphysis pubis. In the Midline Collimate to include inferior ileum, acetabulum & upper 1/3rd of Femora (or entirety of prosthesis).

Question 31

What SID and cassette and AED would you pick for Pelvis, Hip x-ray?

Answer 31

35 x 43cm regular cassette placed landscape in the table bucky, 100cms FFD. 100/115 SID AED- for pelvis any one (or pick all 3) For hip depends on metal work, one of the sides that doesnt have metal work.

Question 32

Centering for an AP single hip

Answer 32

Imagine a line between ASIS and the upper border of symphysis pubis (use R&L as appropriate!) From the mid-point of this line imagine another line at 90° to this (this is called a perpendicular bi-sector) Centre 2.5cm distally along this line (Lateral and Inferior).

Question 33

Collimation for AP single hip?

Answer 33

Hip Joint. Whole of prosthesis (if present). Whole of the Symphysis Pubis.

Question 34

Turned Lateral single Hip. | Patient positioning

Answer 34

From the supine position on table. Criteria: Rotate patient onto affected side (raise unaffected side) so that the Median Sagittal Plane (MSP) is at 45’. Use a large pad to support the patient in this position. Knee on Affected side is flexed and externally rotated until lateral aspect is in contact with table (cf lateral knee). VCR at standard SID Centre as for an AP single hip.

Question 35

Patient position Frog Laterals of both Hip Joints?

Answer 35

Patient supine. Criteria: Median Sagittal Plane (MSP) perpendicular to the table. Plantar aspect of feet touching. Both Knees flexed and externally rotated by upto 60°(or symmetrical).

Question 36

Patient positioning for HBL hip

Answer 36

Patient supine (as for AP pelvis) Criteria: Median Sagittal Plane (MSP) perpendicular to the table. Do not move the affected leg. Unaffected Hip & Knee flexed & supported out of the way of horizontal superimposition.

Question 37

Horizontal Beam Lateral Hip image receptor?

Answer 37

Imaging Receptor: Within grid (stationary box grid or sometimes erect bucky is used with DR). Supported parallel to the NOF (450 to long axis of patient) Upper border in contact with Iliac Crest of affected side.

Question 38

Centering for HBL hip?

Answer 38

Centring: Midway between the anterior and posterior skin margins Directed through the hip joint of the affected limb. Horizontal central ray (HCR) Perpendicular to IR (to avoid grid cut off) Standard SID

Question 39

Collimation for HBL hip?

Answer 39

Collimate to include: Acetabulum. Proximal 1/3rd of Femur. Ischial Tuberosity.

Question 40

Clinical indications for SLJ?

Answer 40

Clinical indications Trauma Pain / Degenerative change/ Inflammation. Pre / Post Surgery

Question 41

How to do AP SIJ?

Answer 41

Patient Supine MSP perpendicular to central long axis of the Table ASIS’s equidistant to Table Table detector VCR with10-200 Cranial Angle. Centred along MSP at a level midway between ASIS and Symphysis pubis

Question 42

How to do PA SIJ?

Answer 42

Patient Prone MSP perpendicular to central long axis of the Table PSIS’s equidistant to Table Table detector VCR with10-200 Caudal Angle. Centred along MSP at a level midway between the PSIS’s