Chapter 7 Flashcards
1
Q
The longest and strongest bone of the body is the?
A
femur
2
Q
A small depression located in the center of the femoral head is the
A
fovea capitis
3
Q
The lesser trochanter is located on the ? aspect of the proximal femur.
A
medial
4
Q
It projects ? from the junction between the neck and shaft.
A
posteriorly
5
Q
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 AP projection.
A
15 to 20 degrees internally
6
Q
The terms pelvis and pelvis girdle are not synonymous.
A
true
7
Q
List the four bones that make up the pelvis?
A
right and left hip bones, sacrum, coccyx
8
Q
List the two bones that make up the pelvic girdle?
A
right and left hip bones
9
Q
what other names are used to describe the right and left hip bones?
A
ossa coxae and innominate bones
10
Q
List the three divisions of the hip bones.
A
Illium, Ischium, Pubis
11
Q
All three divisions of the hip bones eventually fuse at the ? at the age of ?
A
Acetabulum, mid teens
12
Q
What are the two important radiographic landmarks found on the ilium?
A
Crest of ilium crest and Anterior superior iliac spine ASIS
13
Q
Which bony landmark is found on the most inferior aspect of the posterior pelvis?
A
Ischial tuberosity
14
Q
What is the name of the joint found between the superior rami of the pubic bones?
A
symphysis pubis
15
Q
The ? of the pelvis is the largest foramen in the skeletal system.
A
obturator foramen
16
Q
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.
A
1 (inch) above and 1 1/2 inches below
17
Q
An imaginary plane that divides the pelvic region into the greater and lesser pelvis is call the
A
pelvic brim
18
Q
List the alternative names for the greater and lesser pelvis.
A
Greater pelvis —false pelvis
Lesser pelvis —-true pelvis
19
Q
List the major functions of the greater pelvis and the lesser pelvis.
A
Greater pelvis —support the lower abdominal organs and the fetus.
lesser pelvis – forms the actual birth canal
20
Q
List the three aspects of the lesser pelvis, which also describe the birth route during the delivery process.
A
A. inlet (superior aperture)
B. Cavity
C. outlet (inferior aperture)
21
Q
Possesses a large tuberosity found at the most inferior aspect of the pelvis.
A
Ischium
22
Q
Ala
A
Ilium
23
Q
Lesser sciatic notch
A
Ischium
24
Q
Posterior superior iliac spine (PSIS)
A
Ilium
25
Possesses a slightly movable joint
Pubis
26
Anterior superior iliac spine (ASIS)
Ilium
27
Forms the anterior, inferior aspect of the lower pelvic girdle
Pubis
28
Articulates with the sacrum to form the SI joints
Ilium
29
in the past, which radiographic examination was performed to measure the fetal head in comparison with the maternal pelvis to predict possible birthing problemss?
cephalopelvimetry
30
What imaging modality has replaced the cephalopelvimetry?
sonography (ulltrasound)
31
Wide, more flared ilia
female
32
Pubic arch angle to 110 degrees
female
33
A heart shaped inlet
Male
34
Narrow ilia that are less flared
Male
35
Pubic arch angle at 75 degree
Male
36
Larger and more round shaped inlet
Female
37
Which two bony landmarks need to be palpated for hip localization?
ASIS
| Symphysis pubis or greater trohanter
38
From the midpoint of the ASIS and the symphysis publis, where would the femoral neck be located?
approximately 2 1/2 inches below the midpoint
39
A second method for locating the femoral head is to palpate the ? and go ? medial to the level of the ? whicch is ? distal to the palpation point.
ASIS
1-2 inches
Symphysis pubis
3-4 inches
40
To achieve a true AP position of the proximal femur, the lower limb must be rotated ? internally.
15 to 20 degrees internally
41
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, or should only be slightly visible on the radiograph.
42
Which physical sign may indicate that a patient has a hip fracture?
The patients foot is rotated externally
43
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
44
Gonadal shielding should be used for all patients of reproductive age, unless ?
it covers anatomic structure of primary interest
45
Should a gonadal shield be used for a hip study of a young male?
yes, shielding places on symphysis publis
46
What is the advantage of of using 90 kv rather than a lower kv range for hip and pelvis studies on younger patients with an analog imaging system?
It reduces patient dose
47
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?
It reduces radiographic contrast
48
Which one of the following conditions is a common clinical indication for performing pelvic and hip examinations on a pediatric (newborn patient)?
Developmental dysplasia of hip (DDH)
49
Geriatric patients are often more prone to hip fractures because of their increased incidence of osteoporosis.
True
50
Which one of the following imaging modalities can be used on a newborn to assess hip joint stability during movement of the lower limbs?
sonography
51
Which one of the following imaging modalities is most sensitive in diagnosing early signs of metastatic carcinoma of the pelvis?
nuclear medicine
52
A degenerative joint disease
Osteoarthritis
53
Most common fracture in older patients because of high incidence of osteoporosis or avascular necrosis
Proximal hip fracture
54
A malignant tumor of the cartilage of hip
Chondrosarcoma
55
A disease producing extensive calcification of the longitudinal ligament of the spinal column
Ankylosing spondylitits
56
A fracture resulting from a severe blow to one side of the pelvis
Pelvic ring fracture
57
Malignancy spread to bone via the circulatory and lymphatic systems or direct invasion
Metastatic Carcinoma
58
Now referred to as developmental dysplasia of the hip.
Congenital dislocation
59
Which of the following devices will improve overall visibility of the proximal hip demonstrated on an axiolateral (inferosuperior) projection?
Compensating filter
60
Which of the following modalties will best demonstrate a possible pelvic ring fracture?
CT
61
Both joints must be included on an AP and lateral projection of the femur even if a fracture of the proximal femur is evident.
true
62
Where is the central ray placed for an AP pelvis projection?
mideay between ASIS and sympysis pubis
63
The central ray for the AP pelvis projection is approximately ? inches inferior to the level of the ASIS.
2 inches
64
Which specific positioning error is present when the left iliac wing is elongated on an AP pelvis radiograph?
Rotation toward left side
65
Which specific positioning error is present when the left obturator foramen is more open than the right ide of an AP pelvis radiograph?
Right rotation
66
Axiolateral, inferosuperior (Danelius-Miller) projection
traumatic
67
Unilateral frog-leg (modified cleaves method)
Not traumatic
68
AP bilateral "frog-leg" (modified cleaves method)
Not traumatic
69
Modified axiolateral (Clements-Nakayama method)
Traumatic
70
AP axial for pelvic "outlet"
Traumatic
71
Which of the following projections is recommended to demonstrate the superoposterior wall of the acetabulum?
PA axial oblique
72
When gonadal shielding is not used, ? (males or females) receive a greater gonadal dose with an AP pelvis projection.
females (because of its location of CR and reproductive organs)
73
How many degrees are the femurs abducted (from the vertical plane) for the bilateral frog-leg projection?
40-45 degrees
74
Where is the central ray placed for a bilateral frog-leg (modified cleaves method) projection?
3 inches below level of ASIS (1 inch above symphysis pubis)
75
Which size of analog cassette should be used for an adult bilateral frog -leg projection?
14*17 inches crosswise
76
Where is the central ray placed for an AP unilateral frog-leg projection?
midfemoral neck
77
Which central ray angle is required for the "outlet" projection (Taylor method) for a female patient?
30 to 45 degrees cephalad
78
Which type of pathology is best demonstrated with the posterior oblique (Judet method)?
Acetabular fractures
79
How much obliquity of the body is required for the posterior oblique projection (judet method)?
45 degrees
80
What type of CR angle is used for a PA axial oblique (Teufel) projection?
12 Cephalad
81
How is the pelvis (body) positioned for a PA axial oblique (Teufel) projection?
PA 35 to 40 degree toward affected side
82
Any orthopedic device or appliance of the hip should be seen in its entirety on an AP hip radiograph.
true
83
The axiolateral (inferosuperior) projection is designed for (traumatic or nontraumatic) situations.
traumatic
84
How is the unaffected leg positioned for the axiolateral hip projection?
It is flexed and elevated to prevent it from being superimposed over the affected hip.
85
Which one of the following factors does not apply to an axiolateral (inferosuperior) projection of the hip on a male patient?
use of gonadal shielding
86
An AP pelvis projection using 90 kV and 8 mAs results in less patient dose than a projection using 80 kV and 12 mAs (for both males and females)
true
87
The unaffected foot during an axiolateral (inferorsuperor) projection can be burned if allowed to rest on the collimater?
true
88
The modified axiolateral required the CR to be angled ? degrees posteriorly from horizontal.
15 to 20
89
Which special projection of the hip demonstrates the anterior and posterior rims of the acetabulum and the ilioischial and iliopubic columns? (include the projection name and the method name.)
posterior oblique projections of acetabulum (judet method)
90
Which central ray angle (if any) is used for the Judet method?
none perpendicullar
91
What is the name of a special projection of the pelvis used to assess trauma to pubic and ischial structures?
AP axial outllet projection (Taylor Method)
92
Axiolateral (inferosuperior)
Danelius-Miller
93
Modified axiolateral
Clements -Nakayama
94
Bilateral or unilateral frog leg
Modified Cleaves
95
PA axial oblique for acetabulum
Teufel
96
AP axia for pelvic "outlet" bones
Taylor
97
Posterior oblique for acetabulum
Judet
98
What is the optimal amount of hip abduction applied for the unilateral "frog-leg" projection to demonstrate the femoral neck without distortion?
20 to 30 degrees from vertical
99
The Lauenstein/Hickey method for the unilateral "frog-leg" projection will produce distortion of the femoral neck.
true
100
How is is the IR tilted for the modified axiolateral projection of the hip?
15 degrees from the vertical
101
Gonadal shielding can be used for males for the axiolateral (inferiorsuperior) projection of the hip.
false
102
A very young child comes to the radiology department with a clinical history of DDH. What is the common positioning routine for this condition?
AP pelvis and bilateral "frog-leg" (modified cleaves) projection
103
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 projections?
palpate both ASIS and ensure they are equal distance from the table top. To verify no rotation is still present, ensure that the iliac wings are symmetric, as seen on the radiograph.
104
A physician orders a study for inlet and outlet projections of the pelvis. Which projections could be performed to meet this request?
Axial for pelvic "outlet" (Taylor method) and AP method for pelvic "inlet" projections and possibly the posterior oblique (judet's method) projection to provide another perspective if the inlet and outlet regions of the pelvis.
105
A patient with a possible pelvic ring fracture from a trauma enters the emergency room. 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 determind the presence of a pelvic ring fracture?
Posterior oblique Judet method. CT is often judged to be superior in detecting pelvic ring fractures.
106
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?
AP pelvis and modified axiolateral-clements Nakayama methods
107
A patient with hip pain from a fall enters the emergency room. 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 pelvis and Axiolateral (inferosuperior) left hip. The AP pelvis radiograph should be taken initially w/o leg rotation, the radiograph must be reviewed by the physician and checked for fractures or dislocations before attempting to internally rotate the leg for the axiolateral inferiorsuperior projection.
108
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 prothesis must be seen in its entirely in both projections.
109
A radiograph from a modified axiolatral projection reveals excessive grid lines on the image, which also appears underexposed. What can be done to avoid this problem during the repeat exposure?
Ensure that the central ray is centered to near the midline of the grid cassette and the face of the cassette is perpendicular to the central ray.
110
A radiograph of an AP pelvis reveals that overall the image is underexposed (underpenetrated). The following analog factors were used: 80 kV, 40 inch SID, Buky, and AEC with the center chamber activated. Which one of these factors should be changed to produce increased image density?
When using automatic exposure control (AEC) for an AP pelvis projection the left and right ionization chambers must be activated. The center chamber is over the less dense pelvic cavity, which may lead to an underexposed image.
111
A patient enters the ER with a pelvis injury resulting from a motor vehicle accident. 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?
The PA axial oblique (teufel method) or posterior oblique (judet method) can be taken to demonstrate aspects of the acetabulum more completely.
112
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 to 30 degree central ray cephalad angle, and 40" 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?
A greater central ray angle is required. Female patients require a central ray angle of 30 to 45 degrees.
113
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?
if possible, elevate the patient at least 2 inches by placing sheets or blankets beneath the pelvis.
114
A radiograph of a unilateral frog-leg (modified cleaves) projection produces distortion of the femoral neck. Based on the AP hip projection, the radiologist suspects a nondisplaced fracture of the femoral neck. What can the technologist do to better define this region?
repeat the exposure and only abduct the femur 20 to 30 degrees from vertical. ( it will produce less distortion of the femoral neck)
115
A radiograph of an AP pelvis reveals that the right iliac wing is foreshortened as compared with the left side. Which specific positioning error has been made?
The patient is rotated toward true left-left posterior oblique (LPO)
116
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 error?
Rotate the lower limbs 15 to 20 degrees internally to place the proximal femurs in true AP position. (with general chronic pain, the lower limbs can be rotated safely.
117
List the four bones of the pelvis
right hip
left hip
sacrum
coccyx
118
List the three divisions of the hip bone.
Illium, Ischium, Pubis
119
Innominate bone is another name for :
hip bone
120
What is the largest foramen in the body?
obturator foramen
121
Which of the following landmarks is not a palpable bony landmark?
lesser trochanter
122
What are the two aspects of the ischium?
body and ramus
123
What is the name of the imaginary plane that separates the false from the true pelvis?
pelvic brim
124
lesser trochanter
true pelvis
125
supports the lower abdominal organs
false pelvis
126
formed primarily by the ala of the ilium
false pelvis
127
cavity
true pelvis
128
greater pelvis
false pelvis
129
forms the actual birth canal
true pelvis
130
found below the pelvic brim
true pelvis
131
the pubic arch angel on an average male pelvis is an (acute or obtuse) angel that is (greater than or less than) 90 degress
Acute and less than 90 degrees
132
Heart shaped (oval) inlet
Male
133
Acute pubic arch ( less than 90 degrees)
Male
134
Iliac wings that are more flared
Female
135
Obtuse pubic arch (greater than 90 degrees)
Female
136
Larger and more rounded inlet
Female
137
Iliac wings that are less flared
Male
138
Which one of the following structures is considered to be the most posterior?
Ischial spines
139
the small depression near the center of the femoral head where a ligament is attached is called the
fovea capitis
140
Which of the following devices should be used for an axiolateral (inferiorsuperior) projection of the hip to equalize density (brightness) of the hip region?
grid
141
Which of the following modalities is used to assess joint stability during movement of the lower limbs on infants?
sonography
142
A geriatric patient with an externally rotated lower limb may have:
fractured proximal femur
143
Which one of the following pathologic indications may result in the early fusion of SI joints?
Ankylosing spondylitis
144
Usually consists of numerous small lytic lesions
Metastatic carcinoma
145
Increased hip joint space and misalignment
DDH
146
Bilateral radiolucent lines across bones and misalignment of SI joints
Pelvic ring fracture
147
Early fusion of SI joints and bamboo spine
Ankylosing spondylitis
148
Epiphyses appear shorter and epiphyseal plate wider.
SCFE
149
Hallmark sign of spurring and narrowing of joint space
Osteoarthritis
150
Which one of the following radiographic signs indicates that the proximal femurs are in position for a true AP projection?
symmetric appearance of iliac wings
151
What is another term for the outlet of the true pelvic.
inferior aperature
152
The typical physical sign for a possible hip fracture is the ? of the involved foot>
external
153
Which one of the following projections or methods is often performed to evaluate a pediatric patient for congenital hip dislocation?
bilateral modified cleaves
154
What type of central ray angle is required when using the AP axial for outlet (Taylor method) for a male patient?
20 to 35 degree cephalad
155
How much is the pelvis and/or thorax rotated for a PA axial oblique (Teufel method) for acetabulum?
35 to 40 degree toward affected side
156
What type of CR angle is required for the PA axial oblique (Teufel method) for acetabulum?
12 degree cephalad
157
The unilateral frog-leg projection (modified cleaves method) is intended for nontraumatic hip situations.
true
158
centering for the AP pelvis projections is 1 inch, superior to the symphysis pubis.
false
159
What type of CR angle is required for the Judet method?
none CR perpendicular
160
Which one of the following methods is used to evaluate the pelvis inlet for possible fracture?
AP Axial projection
161
An initial AP pelvis radiograph reveals possible fractures involving the lower anterior pelvis. The ER physician asks for another projection to better demonstrate this area for the pelvis. The patient is traumatized and must remain in a supine position. Which projection should be taken?
AP Axial outlet projection
162
A radiograph of an axiolateral (inferosuperior) projection of a hip demonstrates a soft tissue density that is visible across the affected hip and acetabulum. This artifacts if obscuring the image of the proximal femur. What is the most likely cause of the artifiact, and how can it be prevented from showing up on the repeat exposure?
leg not sufficiently raised
163
A unilateral frog-leg (modified cleaves) demonstrates foreshortening of the femoral necks. The physician is unsure if there is a defect within the anatomic neck. What can be done to minimize distortion of the neck during a repeat exposure?
less abduction of femur of only 20 to 30 degrees from vertical
164
A radiograph of an AP hip reveals that the lesser trochanter is not visible. Should the technologist repeat the projection?
NO
165
A young patient with a clinical history of SCFE comes to the radiology department. Which projections are most often taken for this condition?
Laterak-mediolateal projection --femur
166
A radiograph produced using the AP Axial (Taylor method) demonstrates that the anterior pelvic bones of a female patient are foreshortened. The following positioning factors were used: supine position, 40 inch SID, andd central ray angled 30 degree caudad and centered 1 to 2 inches distal to symphysis pubis. Which modification should be made during repeat exposure?
Reverse central ray angle
167
A radiograph of an AP projection of the pelvis demonstrates that the left orturator foramen is narrowed and the right one is open. What is the specific positioning error present on this radiograph?
patient rotated left
168
A patient enters the ER with a possible pelvic ring fracture. The AP pelvis projection is inclusive on the extent and location of the fracture. What additional pelvis projection can be taken on this patient to demonstrate possible pelvic fractures?
AP pelvis, PA axial pelvis, AP unilateral, Judet method, Taylor method, Lateral medial, AP bilateral
169
A radiograph of the Teufel method (PA axial oblique) demonstrates distortion of the acetabuluml During positioning, the patient was rotated 35 to 40 degree toward the affected side and CR was angled 20 degrees cephalad. What modifications are needed during the repeat exposure?
should be 12 degrees cephalad
170
femur
the longest and strongest bone in the body.
171
Proximal femur
consists of four essential parts, the head, neck, and greater and lesser trochanters.
172
The head of femur
is rounded and smooth for articulation with the hip bones. It contains a depression, or pit, near its center called the fovea capitilis, wherein a major ligament called the ligament of the head of the femur, or the ligament capitus femoris, is attached to the head of the femur.
173
The neck of femur
is a strong pyramidal process of bone that connects the head with the body or shaft in the region of the trochanters.
174
Greater and lesser trochanters
the greater trochanter is a large prominence that is located superiorly and laterally to the femoral shaft and is a palpable bony landmark. The lesser trochanter is a smaller, blunt, conical eminence that projects medially and posteriorly from the junction of the neck and shaft of femur. The trochanters are joined posteriorly by a thick ridge called the intertrochanteric crest. The body and shaft of the femur is long and almost cylindrical.
175
Angles of femur
The angles of the neck to the shaft on an average adult is approximately 125 degrees, with a variance of +-15 depending on the width of the pelvis and the length of the lower limbs. A taller person would have a femur that is longer and more verticle. the angle would be closer to 140 degrees. For a shorter person the angle would be closer to 110 to 115 degrees. On an average adult in the anatomic position, the longitudinal plane of the femur is about 10 degrees from vertical. The vertical angle is nearer 15 degrees on someone with a wide pelvic and shorter limbs and only about 5 degrees on a long legged person.
Another angle of the neck and head of the femur that is important in radiography is the 15 to 20 degrees anterior angle. of the head and neck in relation to the body of the femur. The head projects somewhat anteriorly or forward a result of this angle. This angle becomes important in radiographic positioning; the femur and leg must be rotated 15 to 20 degrees internally to place the femoral neck parallel to the image receptor for a true AP projection of the proximal femur.
176
Pelvis
means basin, serves as the base of the trunk and forms the connection between the vertebral column and lower limbs. The pelvis consists of four bones--two hips bones (ossa coxae, also called innominate bones), one sacrum and one coccyx.
177
Pelvis versus pelvic girdle
The pelvic girdle consists of only the two hip bones, whereas the term pelvis includes four bones, the right and left hip (innominate) bones, the sacrum, and the coccyx.
178
Hip bone
is composed of three divisions: 1) Ilium 2) Ischium 3) pubis
In a child, these three divisions are separate bones, but they fuse into one bone during the middle teens. The fusion occurs in the area of the acetabulum. The acetabulum is a deep, cupshaped cavity that accepts the head of the femur to form the hip joint.
The ilium, the largest of the three divisions, is located superior to the acetebulum. The Ischium is inferior and posterior to the acetabulum, whereas the pubis is inferior and anterior to the acetabulum.
179
Ilium
is composed of the body and an ala, or wing. The body of the ilium is the more inferior portion near the acetabulum. The ala or wing portion, is the thin and flared superior part of the ilium.
The crest of the ilium is the superior margin of the ala; it extends from the anterior superior iliac spine (ASIS) to the posterior superior iliac spine (PSIS). The iliac crest actually extends between the ASIS and PSIS.
Below the ASIS is a less prominent projection referred to as the anterior inferior iliac spine. Similarly, inferior to the PSIS is the posterior inferior iliac spine.
180
positioning landmarks
The two most important positioning landmarks of these borders and projections are the iliac crest and the ASIS.
181
Ischium
Is the part of the hip bone that lies inferior and posterior to the acetabulum. Each ischium is divided into a body and a ramus. The superior portion of the body of the ischium makes up the posteriorinferior two-fifths of the acetabulum, The lower portion of the body of the ischium (formally called the superior ramus) projects caudally and medially from the acetabulum, ending at the ischial tuberosity. Projecting anteriorly from the ischial tuberosity is the ramus of the ischium.
The obturator foramen is a large opening formed by the ramus and body of each ischium and by the pubis. The obturator foramen is the largest foramen in the human skeletal system.
182
Positioning landmarks
The ischial tuberosities bear most of the weight of the body when when an individual sits.
183
topographic landmarks
the greater trochanter and the superior border of the symphysiis pubis are at around the same level.
184
True and false pelvis
A plane through the brim of the pelvis divides the pelvic area into two cavities. The pelvic brim is defined by the superior portion of the symphysis pubis anteriorly and by the superior, prominent part of the sacrum posteriorly. The general area above or superior to the oblique plane through the pelvic brim is termed the greater, or false, pelvis. The flared portion of the pelvis, which is formed primarily by the alae, or wings, of the ilia, forms the lateral and posterior limits of the false pelvis, whereas the abdominal muscles of the anterior wall define the anterior limits. The lower abdominal organs rest on the floor of the greater pelvis, as does the fetus within a pregnant uterus.
The area inferior to a plane through the pelvic brim is termed the lesser, or true, pelvis. The true pelvis is a cavity that is completely surrounded by bony structures. The size and shape of the true pelvis are of greatest importance during the birth process because the true pelvis is the actual birth canal.
185
True Pelvis
The oblique plane defined by the brim of the pelvis is termed the inlet, or superior aperture, of the true pelvis. The outlet, or inferior aperture, of the true pelvis is defined by the two ischial tuberosities and the tip of the coccyx. The three sides of the triangularly shaped outlet are formed by a line between the ischial tuberosities and a line between each ischial tuberosity and the coccyx. The area between the inlet and outlet of the true pelvis is termed the cavity of the true pelvis. During the birth process, the baby must travel through the inlet, cavity, and outlet of the true pelvis.
186
Birth Canal
During a routine delivery, the baby's head first travels though the pelvic inlet, then to the midcavity, and finally through the outlet before it exits in a forward direction.
187
Cephalopevimetry
an examination performed on a pregnant woman, whereby specific type of metal ruler was placed next to the pelvic for AP and lateral projections.
188
male versus female pelvis
the female pelvis is wider, with the ilia more flared and more shallow from front to back. The male pelvis is narrower, deeper, and less flared.
The second difference is the angle of the pubic arch, formed by the inferior rami of the pubis just inferior to the symphysis pubis. In the female, the angle is usually obtuse or greater than 90 degrees, whereas the male, the pubic arch usually forms an acute angle of less than 90 degrees.
The third difference is the shape of the inlet or superior aperture. The inlet in the female is usually larger and more round, whereas in the male, it is usually narrower and more oval or heartshaped.
189
Joints
Sacroiliac joints--joints between the sacrum and each ilium
symphysis pubis--structure between the right and left pubic bones
Union of acetabulum--temporary growth joint of each acetabulum that solidifies in the midteen years.
Hip Joints---joints between the head of the femur and the acetabulum of the pelvis.
190
Sacroilliac joints
wide flat joints located on each side obliquely between the sacrum and each ilium.
191
Symphysis pubis
is the articulation of the right and left pubic bones located in the midline of the anterior pelvis. The most superior anterior aspect of this joint is palpable.
192
Union of Acetabulum
Three divisions of each hip bone are separate bones in a child but come together in the acetabulum by fusing during the middle teens to become completely indistinguishable in an adult.
193
Hip joint
is classified as a synovial type, which is characterized by a large fibrous capsule that contains synovial fluid. It is freely movable, or diarthrodial, joint and is the truest example of a spheroid (ball an socket) movement type.
The head of the femur forms more than half a sphere as it fits into the relatively deep, cup-shaped acetabulum. This connection makes the hip joint inherently strong as it supports the weight of the body while still permitting a high degree of mobility. The articular capsule surrounding this joint is strong and dense, with the thickest part being superior, as would be expected because it is in line with the weight bearing function of the hip joints. A series of strong bands of ligaments surround the articular capsule and joint in general, making this joint very strong and stable.
Movements of the hip joint include flexion and extension, abduction and adductiion, medial (internal) and lateral (external) rotation, and circumduction.
194
Location of Head and Neck
A long standing tradition method used to locate the femoral head and neck is first to determine the midpoint line between the ASIS and the symphysis pubis. The neck is approximately 2.5 inches, and the head 1.5 inches distal and at right angles to the midpoint of this line.
the greater trochanters are also located on the same horizontal line as the symphysis pubis.
the level of the symphysis pubis is between 3 to 4 inches medial and 3 to 4 inches distal to the ASIS.
195
Appearance of Proximal Femur in anatomic Position
The proximal head and neck of the femur project approximately 15 to 20 degrees anteriorly or forward with respect to the rest of the femur and the lower leg. Thus, when the leg is in the true anatomic position, as for a true AP leg, the proximal femur actually is rotated posteriorly 15 to 20 degrees. Therefore, the femoral neck appears shortened and the lesser trochanter is visible when the leg and ankle are in true anatomic postion.
196
Internal Rotation of Leg
By internally rotating the entire leg lower limb, the proximal femur and hip joint are positioned in a true AP projection. The neck of the femur is now parallel to the imagine surace and will not appear foreshortened.
the lesser trochanter is key in determining the correct leg and foot position (on a radiograph image). If the entire leg is rotated internally a full 15 to 20 degrees, the outline of the lesser trochanter generally is not visible at all or is only slightly visible. If the leg is straight AP, or when it is externally rotated, the lesser trochanter is visible.
197
Evidence of Hip Fracture
The femoral neck is a common fracture site for an older patient who has fallen.The typical sign for such a fracture is the external rotation of the involved foot, where the lesser trochanater is clearly visualized in profile.
198
Summary: Effect of Lower Limb Rotation
1. Anatomic Position
Long Axes of feet vertical
Femoral necks partially foreshortened
Lesser trochanters partially visible
2. 15 to 20 degrees medial rotation (desired position to visualize pelvis and hips)
Long Axes of feet and lower limbs roated internally 15 to 20 degree
Femoral heads and necks in profile
True AP projection of proximal femora
Lesser trochanters not visible or only slightly visible on some patients
3. External Rotation
Long Axes of feet and lower limbs equally rotated laterally in a normal relaxed position
Femoral necks greatly foreshortened
Lesser trochanters visible in profile internally
4. Typical rotation with hip fracture
Long axis of left foot externally rotated (on side of hip fracture)
Unaffected right foot and limb in neutral position
Lesser trochanter on externally rotated (left) limb more visible; neck area foreshortened.
199
Exposure Factors and patient dose
To reduce total radiation dose to the patient, a higher kV range of 80 to 85 Kv may be used for hip and pelvic examinations. This higher kV technique, with lower mAs, results in a lower radiation dose to the patient. Higher kV, however, decreases contrast (analog imaging only) and may not be advisable.
200
Pediatric Applications
Pelvic and hip radiographic examinations are not performed often on children, except on newborns with developmental dysplasia of the hip (DDH)
201
Injured leg
It is critical that the injured limb not be moved if the leg is externally rotated. An AP projection of both hips for comparison should be taken first, without movement of the affected limb, to check for fractures. This step may be followed by an inferiorsuperior (Danelius-Miller) projection of the affected hip.
Patients who have undergone hip replacement surgery should not be placed in the frog-leg position for any post surgical procedure. An inferosuperior lateral is indicated in addition to the AP projection.
202
Compensating filter
The use of a compensating filter for axiolateral projections of the hip will allow better penetration of the femoral head while preventing overpenetration of the femoral neck and shaft region.
203
CT
is helpful for studying the relationship of the femoral head to the acetabulum before hip surgery or for performing a postreduction study of a development hip dislocation.
Fractures of the pelvic ring missed on conventional radiographic projections, especially those involving the ischial and pubic rami, often are demonstrated during CT scan.
204
Sonography (ultrasound)
useful for evaluating newborns for hip dislocation and for assessing joint stability during movement of the lower limbs.
205
Nuclear medicine
useful in providing early evidence of certain bony pathologic processes, such as occult fractures, bone infections, metastatic carcinoma, or other metastatic or primary malignancies.
206
Ankylosing sponylitis
for effect is fusion of the SI joints. The diseases causes extensive calcification of the anterior longitudinal ligament of the spinal column.It is progressive and works up the spinal column creating a radiographic characteristic known as bamboo spine. Males are most often affected.
207
Avulsion fractures of the pelvis
difficult to diagnose, usually affects athletes who experience sudden. forceful, or unbalanced contraction of the tendinous and muscular attachment.
208
Chondrosarcoma
a malignant tumor of the cartilage, it usually occurs in the pelvis.
209
Developmental dysplasia of the hip (DDH)
dislocations caused at birth.
210
Metastatic carcinoma
The malignancy spreads to the bone via the circulatory system.
211
Osteoarthritis
degenerative joint disease
212
Pelvic ring fracture
because of the closed ring structure of the pelvis, a severe blow or trauma to one side of the pelvis may result in a fracture site away from the site of the primary trauma, thus requiring clear radiographic visualization of the entire pelvis.
213
Proximal femur (hip) fractures
Common in older adults with osteoporosis
214
slipped capital femoral epipysis
occurs in 10-16 year olds during rapid growth
215
Non trauma Pelvis
mid and distal femur --AP and Lateral
Routine proximal femur and hip lateral ---AP bilateral frog-leg or unilateral frog leg
AP---AP unilatral hip
216
Trauma
Routine---lateromedial of mid and distal femur
Routine lateral ---of proximal femur and hip
Axiolateral inferosuperior (Danelius Miller method)
Modified axiolateral hip (clements-nakayama method)
Special pelvis
AP axial outlet projection (Taylor method)
AP axial inlet projection
Posterior oblique acetabulum (Teufel method)
217
Lateral-midiolateral Projection: Femur-mid-and proximal
SID 40 inches
KV 80-85
Flex knee to about 45 degrees
Have patient roll back about 15 degrees to prevent superimposition of proximal femur and hip joint
Proximal one-half to two-thirds of the proximal femur and hip joint should be shown.
superimposition of greater and lesser trochanters by the femur exists with only a small part of the trochanters visible on medial side. Most of the greater trochantr should be superimposed by the neck of the femur.
Perpendicular to IR
218
AP Pelvis Projection (Bilateral Hips): Pelvis
ensure that pelvis is not rotated; distance from table top to each ASIS should be equal
Separate legs and feet, then internally rotate long axes of feet and lower limbs 15 to 20 degrees
CR is perpendicular, directed midway between level of ASIS and the symphysis pubis. This is approximately 2 inches inferior to level of ASIS.
No rotation is evidenced by symmetric appearance of the iliac alae, or wings, the ischial spines, and two obturator foramina. A foreshortened or closed obturator foramen indicates rotation in the direction. ( a closed or narrowed right obturator foramen compared with the left indicates rotation toward the right)
The right and left Ischial spines should appear equal in size. Correct centering evidenced by demonstration of entire pelvis and superior femora without foreshortening in collimated field.
219
AP Bilateral Frog-leg projection: Pelvis
| "Modified Cleaves"
equal distance of ASIS
flex both knees 90 degrees
abduct both femora 40-45 degrees from vertical
Ensure that both femora are abducted the same amount and that pelvis is not rotated.
IR directed 3 inches below level of ASIS (1 inch above symphysis pubis)
Suspend respiration
Less abduction of femora of only 20 to 30 degrees from vertical provides for the least foreshortening of femoral necks, but this placement foreshortens the entire proximal femora, which may not be desirable.
femoral heads, necks, acetabulum, and trochanteri areas are visible on one radiograph
No rotation is evidenced by symmetric appearance of the pelvic bones, especially the ala of the ilium, two obturator foramina, and ischial spines, if visible. The femoral heads and necks and greater and lesser trochanters should appear equal in size if both thighs were abducted equally. The lesser trochantrs should appear equal in size, as projected beyond the lower or medial margin of the femora. Most of the area of the greater trochanters appears superimposed over the femoral necks, which appear foreshortened.
Non trauma hip
DDH
220
AP Axial Outlet Projection (for anterior-inferior pelvic bones) Pelvis
Taylor Method
Angle CR Cephalad 20 to 30 degrees for males and 30 to 45 degrees for females (these different angles are caused by differences in the shape of male and female pelvis)
Direct CR to a midline point 1 to 2 inches distal to the superior border of the syphysis pubis or greater trochanter
Suspend respiration
bilateral view of the bilateral pubis and ischium to allow assessment of pelvic, trauma for fractures and displacement
221
AP Axial Inlet projection : Pelvis
Assessment of pelvic trauma for posterior displacement or inward or outward rotation of the anterior pelvis
Angle CR 40 degrees caudad
Direct IR to midline point at level of ASIS
Suspend respiration during exposure
demonstrates pelvic ring or inlet (superior aperture) in its entirety
Superimposed anterior and posterior portions of the pelvic ring
222
Posterior Oblique Pelvis--Acetabulum (Judet method)
When anatomy of interest is downside, direct CR and centered 2 inches distal and 2 inches medial to downside ASIS
When anatomy of interest is upside, direct perpendicular and centered to 2 inches directly distal to upside ASIS
Suspend respiration
When centered to the downside acetabulum, the anterior rim of the acetabulum and the posterior (ilioischial) column are demonstrated. The iliac wing also is well visualize.
When centered to the upside acetabulum, the posterior rim of the actabulum and the anterior (iliopubic) column are demonstrated. The obturator foramen also is visualized.
The obturator foramen should be open, if rotated correctly, for the upside oblique, and should appear closed on the downside oblique.
223
PA Axial Oblique Projection--Acetabulum
| Teufel Method
When anatomy of interest is downside, direct the CR perpendicular and centered to 1 inch superior to the level of the greater trochanter, approximately 2 inches lateral to midsagittal plane.
Angle CR 12 degrees cephalad
Suspend respiration for the exposure
Centered to the downside acetabulum, the superoposterior wall of the acetabulum is demonstrated.
224
AP unilateral Hip Projection: Hip and Proximal Femur
Rotate affected leg internally 15 to 20 degrees
CR is perpendicular to IR, directed to 1 to 2 inches distal to midfemoral neck. Femoral neck can be located about 1 to 2 inches medial and 3 to 4 inches distal to ASIS.
Suspend respiration
The proximal one-third of the femur should be visualized, along with the acetabulum and adjacent parts of the pubis, ischium, and ilium.
The lesser trochanter should not project beyond the medial border of the femur, with some patients only its very tip is seen with sufficient internal rotation of leg.
Postoperative or Follow up Exam to demonstrate the acetabulum, femoral head, neck and greater trochanter.
225
Axiolateral inferosuperior projection: hip and proximal femur-TRAUMA (Danelius-Miller Method)
Common projection for trauma
Lateral view for fracture or dislocation assessment in trauma hip situations
Place IR in crease above iliac crest and adjust so that it is parallel to femoral neck and perpendicular to CR
Internally rotate affected leg 15 to 20 degrees unless possible fracture
CR i perpendicular to femoral neck
Suspend respiration during exposure
226
Unilateral Frog-Leg projection--Mediolateral: Hip and Proximal Femur (Modified Cleaves Method)
NonTrauma hip
abduct femur 45 degree from vertical
CR is perpendicular directed to midfemoral neck
Suspend respiration during respiration
The optimum femur abduction for demonstration of the femoral neck without any foreshortening is 20 to 30 degrees from vertical on most patients. This results in significant foreshortening of the proximal femur region.
227
Modified Axiolateral-Possible Trauma Projection: Hip and Proximal Femur
(clements-nakayama method
Angle CR mediolaterally as needed so that it is perpendicular to and centered to femoral neck, it should be angled posteriorly 15 to 20 degrees from horizontal.
Suspend respiration during exposure
