Chapter 7



Chapter 7

Pelvis and Upper Femora

Darv Nomann R.T. (R)

Pelvis

Consists of four bones

Right and left innominate, or hip, bones

Sacrum

Coccyx

Serves as the base for the trunk and a girdle for lower limb attachment

Pelvic Girdle

Composed of only the two hip bone

Each bone has three parts

Ilium

Ischium

Pubis

Pelvic Girdle

These three bones come together to form the acetabulum

The cup-shaped socket that articulates with the head of the femur

Pubis

Consists of

Body

Superior ramus

Inferior ramus

Body forms about one fifth of anterior acetabulum

Obturator foramen

Formed by junction of ischial ramus and pubis inferior ramus

Hip Bone

Hip Bone

Proximal Femur

Head

Neck

Greater trochanter

Lesser trochanter

Joints of the Pelvis

Sacroiliac (SI) joints

Articulation between the right and left ilia and the sacrum

Irregular, gliding type

Hip joints

Articulation of the head of the femurs with the acetabula

Synovial, ball-and-socket type

Joints of the Pelvis

Pubic symphysis

Junction of right and left pubic bones in the midline

Cartilaginous, slightly moveable joint

Gender Differences in Pelvic Anatomy

Males

Heavier, narrower, deeper

Angle at pubic symphysis is acute

Females

Wider, shallower, lighter

Angle at symphysis is obtuse

Localizing Anatomy

Bony landmarks

Iliac crest

ASIS

Pubic symphysis

Greater trochanter

Ischial tuberosity

Tip of coccyx

Localizing Anatomy

Highest point of greater trochanter lies in same horizontal plane as the midpoint of the hip joint and coccyx

Most prominent point of greater trochanter is in same horizontal plane as the pubic symphysis

Hip Joint Localization

Palpate ASIS and superior margin of pubic symphysis

Draw a line connecting the two

Midpoint directly above acetabular cavity center dome

Draw a line at right angle to midpoint of the above line

Line parallels femoral neck

Femoral head = 1.5˝ (3.8 cm) distal

Femoral neck = 2.5˝ (6.4 cm) distal

Hip Joint Localization

General Procedural Guidelines

Pelvis and Upper Femora, Femoral Necks, and Hip

General Procedural Guidelines

Patient preparation

General patient position

IR size

SID

ID markers

Radiation protection

Patient instructions

Patient Preparation

Remove artifacts from anatomy of interest

Undergarments (elastic = artifact)

Clothing

Provide gown

General Patient Position

Ambulatory patients

Supine on x-ray table

Nonambulatory patients

Use proper transfer techniques to table

If transfer is not possible, use grid IR

IR Size

Textbook gives guidelines

Grid IR needed for examinations taken with patient in bed or on stretcher

SID

SID is standardized as a part of procedural protocol

When SID is not specified under a projection, Merrill’s Atlas recommends 48˝ (122 cm)

ID Markers

Right or left side markers must be included

Other required ID markers must be in the blocker or elsewhere on the final image

Radiation Protection

Shield male patients

Refer to guidelines on p. 344, Volume 1

Shielding females will obscure anatomy of interest on some examinations

Other radiation protection measures

Close collimation

Optimum technique factors

Patient Instructions

Explain positions and breathing instructions

Respirations are suspended for exposure

Radiographic Procedures

Essential Projections of the Pelvis and Upper Femora, Femoral Necks, Hip, and Acetabulum

Essential Projections: Pelvis

AP

AP Pelvis and Upper Femora

Patient position – supine

Part position

MSP of body centered to midline

Equal ASIS to table distance on both sides

Medially rotate feet and lower limbs

15 to 20 degrees

Places femoral necks parallel with IR

Do not rotate if trauma or other pathology suspected

AP Pelvis and Upper Femora

Upper border of IR 1˝ to 1.5˝ inches

(2.5 to 3.8 cm) above crests

CR

Perpendicular to IR

Collimated field

Size of IR

Essential Projections: Femoral Necks

AP Oblique (modified Cleaves)

Note: This method is contraindicated if fracture or pathology is suspected.

AP Oblique Femoral Necks (Modified Cleaves)

Patient position

Supine

Part position for bilateral

No rotation of pelvis

ASIS equal distance from table top

Flex hips and knees

Draw feet up as much as possible

Abduct thighs equally and maximally

Place soles of feet together for support

AP Oblique Femoral Necks (Modified Cleaves)

Center IR 1˝ (2.5 cm) above pubic symphysis

CR

Perpendicular to MSP at level 1˝ (2.5 cm) above pubic symphysis

Collimated field

Size of IR

AP Oblique Femoral Necks (Modified Cleaves)

Part position for unilateral

Center ASIS of affected side to midline of grid

Flex affected hip and knee

Draw foot up to opposite knee as much as possible

Abduct thigh about 45 degrees laterally

CR

Perpendicular to femoral neck

Essential Projections: Hip

AP

Lateral (mediolateral) (Lauenstein; Hickey)

Axiolateral (Danelius-Miller)

AP Hip

Patient position

Supine

Part position

No rotation of pelvis

ASIS to table top distance equal on both sides

Medially rotate lower limb and foot about

15 to 20 degrees

Places femoral necks parallel to IR

AP Hip

CR

Perpendicular to femoral neck

Use localization technique described previously

Adjustment may be necessary if orthopedic device is present

Collimated field

Size of IR

Axiolateral Hip (Danelius-Miller)

Patient position

Supine

Axiolateral Hip (Danelius-Miller)

Part position

Elevate pelvis for thin patients

Flex knee and hip of unaffected limb to place thigh vertical

Rest unaffected leg and foot on a support

No rotation of pelvis

Rotate affected limb 15 to 20 degrees medially

Axiolateral Hip (Danelius-Miller)

IR

Vertical with upper border in crease above iliac crest

Angle lower border away from body until parallel with femoral neck

Support IR in position

Axiolateral Hip (Danelius-Miller)

CR

Horizontal and perpendicular to long axis of femoral neck

Lesson 2

Image Critique of the

Pelvis, Femoral Necks, Hip, and Acetabulum

Image Evaluation

Essential Projections

Pelvis, Femoral Necks and Hip

AP Pelvis and Upper Femora

Entire pelvis and proximal femora

Lesser trochanters, if seen, demonstrated on medial border of femora

Femoral necks without superimposition

Greater trochanters in profile

Both ilia equidistant to edge of image

AP Pelvis and Upper Femora

Both greater trochanters equidistant to edge of image

Lower vertebral column in center of image

Symmetric obturator foramina

AP Pelvis and Upper Femora

Ischial spines equally demonstrate

Sacrum and coccyx aligned with pubic symphysis

Projection? Anatomy?

AP Oblique Femoral Necks

(Modified Cleaves)

No rotation of pelvis

Symmetric structures

Acetabulum, femoral head and neck clearly demonstrated

Lesser trochanter on medial side of femur

AP Oblique Femoral Necks

(Modified Cleaves)

Greater trochanter does not superimpose femoral neck

Femoral axes at equal angles from hips

Projection? Anatomy?

AP Hip

Femoral head penetrated and seen through acetabulum

Parts of ilium and pubic bones included

Any orthopedic device in its entirety

Hip joint

AP Hip

Greater trochanter in profile

Entire long axis of femoral neck without foreshortening

Proximal one third of femur

Lesser trochanter, if seen, is minimally demonstrated on medial side of femur

Projection? Anatomy?

Lateral Hip (Lauenstein)

Hip joint in center

Hip joint, acetabulum, and femoral head clearly demonstrated

Femoral neck overlapped by greater trochanter

Projection? Anatomy?

Lateral Hip (Hickey)

Hip joint in center

Hip joint, acetabulum, and femoral head clearly demonstrated

Femoral neck free of superimposition

Projection? Anatomy?

Axiolateral Hip (Danelius-Miller)

Femoral neck without overlap from greater trochanter

Small amount of lesser trochanter on posterior surface

Small amount of greater trochanter on anterior and posterior surfaces of proximal femur

Soft tissue shadow of unaffected thigh not seen in anatomy of interest

Axiolateral Hip (Danelius-Miller)

Hip joint with acetabulum

Any orthopedic appliance in its entirety

Ischial tuberosity below femoral head

Projection? Anatomy?

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