Chapter 7 Pelvis and Upper FemoraDarv 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?