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Bontrager Chapter 7- Femur and Pelvic Girdle

Terms in this set (131)

The largest and strongest bone of the body is the
femur
A small depression located in the center of the femoral head is the
fovea capitis
The lesser trochanter is located on the ___ aspect of the proximal femur.
It projects ___ from the junction between the neck and shaft
medial
posteriorly
Because of the alignment between the femoral head and pelvis, the lower limb must be rotated ___* internally to place the femoral neck parallel to the plane of the image receptor to achieve a true anteroposterior (AP) projection.
15-20*
True/False: The terms pelvis and pelvic girdle are not synonymous.
True
List four bones that make up the pevlis
Right and left hip bones, sacrum, coccyx
List two bones that make up the pelvic girdle
List two additional terms used for these bones
Right and left hip bones
Ossa Coxae, innominate bones
List three divisions of the hip bones
ilium, ischium, pubis
All three divisions of the hip bone eventually fuse at the ___ at the age of___.
acetabulum, midteens
What are the two important radiographic landmarks found on the ilium?
crest of ilium (iliac crest), anterior superior iliac spine (ASIS)
Which bony landmark is found on the most inferior aspect of the posterior pelvis?
Ischial tuberosity
What is the name of the joint found between the superior rami of the pubic bones?
Symphysis pubis
The ___ of the pelvis is the largest foramen in the skeletal system
Obturator foramen
The upper margin of the greater trochanter is approximately ___ above the level of the superior border of the symphysis pubis, and the ischial tuberosity is about ___ below.
1 in (2.5 cm); 1.5-2 in (4-5 cm)
An imaginary plane that divides the pelvic region into the greater and lesser pelvis is called the
Pelvic Brim
List the alternate terms for the greater and lesser pelvis
Greater pelvis: false pelvis
Lesser pelvis: true pelvis
List the major function of the greater pelvis and the lesser pelvis
Greater pelvis: supports lower abdomen organs and fetus
Lesser pelvis: forms actual birth canal
List the three aspects of the lesser pelvis, which also describes the birth route during the delivery process.
a. inlet
b. cavity
c. outlet
Ala
Posterior superior iliac spine (PSIS)
Anterior superior iliac spine (ASIS)
Articulates with the sacrum to form the SI joint
Ilium
Possesses a large tuberosity found at the most inferior aspect of the pelvis
Lesser sciatic notch
Ischium
Possesses a slightly movable joint
Forms the anterior, inferior aspect of the lower pelvic girdle
Pubis
In the past, which radiographic examination was performed to measure the fetal head in comparison with the maternal pelvis to predict possible birthing problems?
What imaging modality has replaced the procedure?
Cephalopelvimetry; Sonography (ultrasound)
Wide, more flared ilia
Pubic arch angle of 110*
Larger and more round-shaped inlet
Female pelvis
A heart-shaped inlet
Narrow ilia that are less flared
Pubic arch angle 75*
Male pelvis
Which two bony landmarks need to be palpated for hip localization?
1. ASIS
2. Symphysis pubis
From the midpoint of the imaginary line created by the two landmarks (ASIS & Symphysis pubis), where would the femoral neck be located?
approximately 2.5 in (6-7cm) below midpoint of line
Another method for locating the femoral head is to palpate the ____ and go ____inches medial at the level of the ____, which is ____inches distal to the original palpation point
ASIS; 1-2in;
Symphysis pubis; 3-4in
To achieve a true AP position of the proximal femur, the lower limb must be rotated ___ internally.
15-20*
Which structures on an AP pelvis or hip radiograph indicate whether the proximal head and neck are in position for a true AP projection?
Lesser trochanter should not be visible
Which physical sign MAY indicate that a patient has a hip fracture?
Patients foot rotated externally
Which projection should be taken first and reviewed by a radiologist before attempting to rotate the hip into a lateral position (if trauma is suspected)?
AP pelvis
Gonadal shielding should be used for all patients of reproductive age, unless ___?
It covers anatomic structures of primary interest
Should a gonadal shield be used for a hip study on a young female?
If yes, describe how it should be placed on the patient.
Yes; at ASIS, bottom of the shield placed at inferior margin of symphysis pubis.
Should a gonadal shield be used for a hip study on a young male?
If yes, describe how it should be placed on the patient.
Yes; top of shield placed inferior margin of symphysis pubis
What is the advantage of using 90 kV rather than a lower kV range for hip and pelvis studies on younger patients with an analog imaging system?
Reduces patient dose
What is the disadvantage of using 90 kV for hip and pelvis studies, especially on older patients with some bone mass loss with an analog imaging system?
reduces radiographic contrast
Which one of the following conditions is a common clinical indication for performing pelvic and hip examinations on a pediatric (newborn) patient?
a. osteoporosis
b. Developmental dysplasia of hip (DDH)
c. Ankylosing spondylitis
d. Osteoarthritis
b. Developmental dysplasia of hip (DDH)
Geriatric patients are often more prone to hip fractures because of their increased incidence of osteoporosis. (True/False)
True
Which one of the following imaging modalities can be used on a newborn to assess hip joint stability during movement of the lower limbs?
a. Sonography
b. Computer tomography
c. Magnetic resonance imaging
d. Nuclear medicine
a. sonography
Which one of the following imaging modalities is most sensitive in diagnosing early signs of metastatic carcinome of the pelvis?
a. Sonography
b. Computer tomography
c. Magnetic resonance imaging
d. Nuclear medicine
d. Nuclear medicine
A degenerative joint disease
Osteoarthritis
Most common fracture in older patients because of high incidence of osteoporosis or avascular necrosis
Proximal hip fracture
A malignant tumor of the cartilage of hip
Chondrosarcoma
A disease producing extensive calcification of the longitudinal ligament of the spinal column
Ankylosing spondylitis
A fracture resulting from a severe blow to one side of the pelvis
Pelvic ring fracture
Malignancy spread to bone via the circulatory and lymphatic systems or direct invasion
Metastatic carcinoma
Now referred to as developmental dysplasia of the hip
Congenital dislocation
Which of the following devices will improve overall visibility of the proximal hip demonstrated on an axiolateral (inferosuperior) projection?
a. small focal spot
b. 6:1 grid
c. compensating filter
d. shadow shield
c. compensating filter
Which one of the following modalities will best demonstrate a possible pelvic right fracture?
a. CT
b. Nuclear medicine
c. MRI
d. sonography
a. CT
Both joints most be included on an AP and lateral projection of the femur even if a fracture of the proximal femur is evident. (True/false)
True
Where is the central ray placed for an AP pelvis projection?
midway between ASIS & symphysis pubis
The central ray for the AP pelvis projection is approximately ___ inch(es) (cm) inferior to the level of the ASIS.
2in, 5cm
Which specific positioning error is present when the left iliac wing is elongated on an AP pelvis radiograph?
rotated toward the left side
Which specific positioning error is present when the left obturator foramen is more open than the right side on an AP pelvis radiograph?
right rotation
Axiolateral, inferosuperior (Danelius-Miller) projection
Modified axiolateral (Clements-Nakayama)
AP axial for pelvic "outlet"
Traumatic injuries
Unilateral frog-leg (modified Cleaves)
AP bilateral frog-leg (modified Cleaves)
Nontraumatic injuries
Which of the following projections is recommended to demonstrate the superoposterior wall of the acetabulum?
a. AP axial "inlet"
b. PA axial oblique
c. Axiolateral inferosuperior
d. Modified axiolateral
b. PA axial oblique
When gonadal shielding is not used, ___(males/females) receive a greater gonadal dose with an AP pelvis projection.
Females
How many degrees are the femurs abducted (from the vertical plane) for the bilateral frog-leg projection?
40-45*
Where is the central ray placed frog-leg (modified Cleaves method) projection?
3" below level of ASIS
Which size of analog cassette should be used for an adult bilateral frog-leg projection?
14x17in (35x43cm)
Where is the central ray placed for an AP unilateral frog-leg projection?
Midfemoral neck
Which central ray angle is required for the "outlet" projection (Taylor method) for a female patient?
a. 15-25* caudad
b. 30-45* cephalad
c. 20-35* cephalad
d. None (central ray is perpendicular)
b. 30-45* cephalad
Which type of pathology is best demonstrated with the posterior oblique (Judet method)?
a. Acetabular fractures
b. Anterior pelvic bone fractures
c. Proximal femur fractures
d. Femoral neck fractures
a. Acetabular fractures
How much obliquity of the body is required for the posterior oblique projection (Judet method)?
a. None (CR perpendicular)
b. 20*
c. 30*
d. 45*
d. 45*
What type of CR angle is used for a PA axial oblique (Teufel) projection?
a. 15* cephalad
b. 15-20* cephalad
c. 5* caudad
d. 12* cephalad
d. 12* cephalad
How is the pelvis (body) positioned for a PA axial oblique (Teufel) projection?
a. PA with 45* rotated away from affected side
b. Prone or erect PA- no rotation
c. PA 35-40* toward affected side
d. AP with 40* away from affected side
c. PA 35-40* toward affected side
True/False
Any orthopedic device or appliance of the hip should be seen in its entirety on an AP hip radiograph.
True
The axiolateral (inferosuperior) projection id designed for ___(traumatic or nontraumatic) situations.
traumatic
How is the unaffected leg positioned for the axiolateral hip projection?
flexed and elevated to prevent from being superimposed over affected hip
Which one of the following factors for NOT apply to an axiolateral (inferosuperior) projection of the hip on a male patient?
a. IR parallel to femoral neck
b. 80 to 90 kV
c. Use gonadal shielding
d. Use stationary grid
c. Use gonadal shielding
True/ False
An AP pelvis projection using 90 kV and 8 mAs results in less patient dose that a projection using 80 kV and 12 mAs (for both males and females)
True
True/ False
The unaffected foot during an axiolateral (inferosuperior) projection can be burned if allowed to rest on the collimator
True
The modified axiolateral requires the CR to be angled ___*posteriorly from horizontal.
15-20*
Which special projection of the hip demonstrated the anterior and posterior rims of the acetabulum and the ilioischial and iliopubic columns? (include projection and method name)
Which CR is used for this projection?
Posterior oblique of acetabulum (Judet method)
0* perpendicular
What is the name of a special projection of the pelvis used to assess trauma to pubic and ischial structures? (include projection and method name)
AP axial outlet projection; Taylor method
Axiolateral (inferosuperior)
Danelius- Miller
Modified axiolateral
Clements-Nakayama
Bilateral or unilateral frog-leg
Modified Cleaves
PA axial oblique for acetabulum
Teufel
AP axial for pelvic outlet bones
Taylor
Posterior oblique for acetabulum
Judet
What is the optimal amount of hip abduction applied for the unilateral "frog-leg" projection to demonstrate the femoral neck without distortion?
a. 45* from vertical
b. 90* from vertical
c. 10* from vertical
d. 20-30* from vertical
d. 20-30* from vertical
True/False
The Lauenstein/Hickey method for the unilateral "frog-leg" projection will produce distortion of the femoral neck.
True
How much is the IR tilted for the modified axiolateral projection of the hip?
15* from vertical
True/False
Gonadal shielding can be used for males for the axiolateral (inferosuperior) projection of the hip.
False
A radiograph of an AP pelvis projection reveals that the lesser trochanters are readily demonstrated on the medial side of the proximal femurs. The patient is ambulatory but has a history of early osteoarthritis in both hips. Which positioning modification needs to be made to prevent this positioning?
rotate lower limbs 15-20* internally to place proximal femurs in true AP
A radiograph of an AP pelvis reveals that the right iliac wing is forshortened as compared with the left side. Which specific positioning error has been made?
rotation to the left. Left posterior oblique (LPO)
A radiograph of a unilateral frog-leg (modified Cleaves) projection distortion of the femoral neck. Based on the AP hip projection, the radiologist suspects a non displaced fracture of the femoral neck. What can the technologist do to better define this region?
repeat the exposure and only abduct the femur 20-30* from vertical.
A radiograph of an axiolateral (inferosuperior) projection reveals that the posterior aspect of the acetabulum and femoral head were cut off of the bottom of the image. The ER physician requests that the position be repeated. What can be done to avoid this problem on the repeat exposure?
elevate the patient at least 2in by placing sheets or blankets beneath the pelvis
A radiograph of an AP axial projection for anterior pelvic bones reveals that the pubic and ischial bones are not elongated sufficiently. The following analog factors were used for this study: 86 kV, 7 mAs, bucky, 20-30* CR cephalad angle, and 40in SID. The female patient was placed in a supine position on the table. What must be changed to improve the quality of the image during the repeat exposure?
Greater CR angle is required. Female patients require a CR angle of 30-45*
A patient enters the ER with a pelvis injury resulting from a MVA. The initial AP pelvis projection demonstrates a possible defect or fracture of the left acetabulum. No other fractures are detected and the patient is able to move comfortably. What additional projections can be taken to demonstrate a possible acetabular fracture?
PA axial oblique (Teufel) or posterior oblique (Judet).
A radiograph of an AP pelvis reveals that overall the image is underexposed (underpenetrated). The following analog factors were used: 80 kV, 40in SID, Bucky, and AEC with the center chamber activated. Which one of the these factors should be changed to produce increased image density?
AEC- Right and left chambers must be activated. Center chamber over less dense pelvic cavity. (under exposed image)
A radiograph from a modified axiolateral projection reveals excessive grid lines on the image, which also appears underexposed. What can be dome to avoid this problem during the repeat exposure?
Ensure the CR is centered near the midline of the grid cassette and the face of the cassette is perpendicular to the CR
A portable AP and lateral hip study is ordered for a patient who is in recovery following hip replacement surgery. The radiograph of the AP hip reveals that the upper portion of the acetabular prosthesis is slightly cut off but is included on the lateral projection. Should the technologist repeat the AP projection?
Yes! Any orthopedic appliance or prosthetic must be seen in its entirety in both projections
A patient with hip pain from a fall enters the ER. The physician orders a left hip study. When moved to the radiographic table, the patient complains loudly about the pain in the left hip. Which positioning routine should be used for this patient?
AP pelvic and axiolateral (inferiosuperior) left hip.
A patient has just been moved to his hospital room after a bilateral hip replacement surgery. The surgeon has ordered a postoperative hip routine for both hips. Which specific positioning routine should be used? (The patient can be brought to radiology department.)
AP pelvis and modified axiolateral
Clements-Nakayama method
A patient with a possible pelvic ring fracture from a trauma enters the ER. THe AP pelvis projection, which was taken to determine whether the right acetabulum is fractured, is inconclusive. Which other radiographic projection can be taken to better visualize the acetabulum? What other imaging modality can be used to determine the presence of a pelvic ring fracture?
Posterior oblique (Judet). CT often judged to be superior in detecting pelvic ring fractures.
A physician orders a study for inlet and outlet projections of the pelvis. Which projections could be performed to meet this request?
AP axial for pelvis "outlet" and AP axial for pelvic "inlet" and possible posterior oblique
A technologist notices that his AP pelvis projections often demonstrate a moderate degree of rotation. What positioning technique can the technologist perform to eliminate (or at least minimize) rotation on his AP pelvis projection?
Palpate ASIS and ensure they are equal distance from table top. Verify no rotation. Ensure the iliac wings are symmetric.
A very young child comes to the radiology department witha clinical history of DDH. What is the most common positioning routine for this condition?
AP pelvis and bilateral frog-leg (modified Cleaves) projection
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The depression or pit located at the center of the femoral head is the:
Fovea capitis
Which of the bones of the pelvic girdle is the largest?
Ilium
Which of the following bony landmarks is located posterior to the acetabulum?
Ischial tuberosity
The "false pelvis" forms the birth canal in females. (true/false)
False
The pelvic arch of the male pelvis forms an acute angle (<90*). (true/false)
True
What is the joint mobility of the symphysis pubis?
Amphiarthrodial
Which bony landmark should NOT be visible on a correctly positioned AP pelvis (nontrauma)?
Lesser trochanter
Where is the CR centered for an AP pelvis projection?
Midway between ASIS and symphysis pubis
To minimize distortion of the femoral neck for an AP bilateral frog-leg projection, the lower limbs should be abducted:
20-30*
What type of CR angle is required for the AP axial "outlet" projection for a male patient?
20-35*
How much is the affected side rotated for the PA axial oblique projection (Teufel method)?
35-40*
How is the cassette aligned for an axiolateral (Danelius-Miller method) projection?
Parallel to femoral neck
Which of the following projections is best suited for the patient with limited movement of both lower limbs to demonstrate a lateral perspective of the proximal femur?
Clements-Nakayama method
Which position/s will best demonstrates signs of developmental dysplasia?
Bilateral frog
Which projections will best demonstrate the ilioischial column and iliopubic column of the pelvis?
AP obliques (Judet)
LPO and RPO 45* AP obliques
What situation is the Clements-Nakayama method utilized for?
hip fractures (bilateral) or limited hip movement
lateral/proximal hip trauma
Which projection provides the greatest amount of gonadal dose for a male?
axiolateral, inferosuperior shoot through
Why must the lower limb be rotated 15-20* internally for AP hip projections?
lesser trochanter not in profile and places femoral neck parallel to the IR
How should the student radiographer rotate the lower limbs so that the lesser trochanters are not visualized on an AP pelvis image?
15-20* medial rotation of leg
What specific positioning error caused an AP image of the pelvis to demonstrate that the left iliac wing is forshortened as compared to the right wing?
rotation to the right, RPO
What specific positioning error caused an AP image of the pelvis to demonstrate that the right obturator foramen is more open or elongated as compared with the left?
rotation onto the left hip
What causes a soft tissue artifact on an image of an axiolateral projection of the hip?
tissue from unaffected leg
What positioning erroe will cause grid lines on an image?
CR and IR not perpendicular
Describe the projection which the student radiographer should perform first on any type of pelvis/hip trauma.
AP pelvis
Your patient presents with chronic pain of the left hip. What projections should the student radiographer proceed with?
pelvis and frog-leg (Cleaves)
Your lateral projection of a hip prosthetic device reveals that the proximal end is cut, but was demonstrated on the AP image. Is this acceptable?
No! the entire prosthetic much be visible on both AP and Lateral projections
What will cause the obturator foramina to appear forshortened on the Taylor projection?
not enough cephalad CR angulation
20-25* males
30-45* females
Describe how the student radiographer should perform a hip series on a cognitively impaired patient who presents with extreme hip pain.
axiolateral
Which additional projection can be performed to demonstrate a possible pelvic ring fracture?
AP axial
40* caudad angle
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