Pelvis
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The femur is the longest and strongest bone in the body.
The proximal femur consists of four essentials:
Head - is rounded and smooth for articulation with the hip bones. It contains a depression, or pit, near its center called the fovea vanities.
Neck - is a strong pyramidal process of bone that connects the head with the body or shaft in the region of the trochanters.
Greater Trochanters - a large prominence located superiorly and laterally to the femoral shaft and is palpable.
Lesser Trochanters - smaller, blunt, conceal eminence that projects medially and posteriorly from the junction of the neck and shaft of the femur.
The trochanters are joined posteriorly by a thick ridge called the intertrochanteric.
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The complete pelvis 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 hip bones also called innominate bones.
One scrum
One coccyx
Each hip bones also called is composed of three divisions:
Ilium - located superior to the acetabulum.
Ischium - is inferior and posterior to the acetabulum.
Pubis - is inferior and anterior to the acetabulum.
The fusion occurs in the area of the acetabulum.
The ilium is composed of a body and an ala, or wing.
The body of the ilium is two-fifths of the acetabulum.
The two important positioning landmarks of these borers and projections are the iliac crest and ASIS.
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The superior portion of the body of the ischium makes up the posteroinferior two-fifths of the acetabulum.
The landmarks include ischial tuberosities.
The pubic bone of the pubis is anterior and inferior to the acetabulum and includes the anteroinferior one-fifth of the acetabulum.
The obturator foreman is a large opening formed by the ramus and body of each ischium and by the pubis.
It is the largest foramen in the human skeletal system.
All land marks are: iliac crest, ASIS, greater trochanter, symphysis pubis, and ischial tuberosity.
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A plane through the brim of the pelvis divided the pelvis area into two cavities. The pelvic brim is defined bu 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 area inferior to a plane through the pelvic brim is termed the lesser, or true, pelvis.
The true pelvis forms the actual birth canal.
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.
Differences between Female and Male
Female:
Gynecoid
Platypelloid
Wider
Ilia more flared
Shallow
Round or oval inlet
80-85 degrees pubic arch
Less protrusion of ischial spines
Male:
Android
Anthropoid
Narrow
Less flared Ilia
Deeper
Heart-shaped inlet
50-60 degrees pubic arch
More protrusion of ischial spines
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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 - joint between the head of the femur and the acetabulum of the pelvis.
Sacroiliac joint is a special type of synovial joint that permits little movement.
The reason for this classification is that the joint surfaces are irregularly shaped and the interconnecting bones are snugly fitted because they serve a weight-bearing function.
The symphysis pubis is classified as a cartilaginous joint of the symphysis subtype in that only limited movement is possible (amphiathrodial).
Thick pad that is capable of being compressed or partially displaced, thereby allowing limited movement of these bones, as in the case of pelvic trauma or during the childbirth process in females.
Classified as a cartilaginous-type joint of the synchondrosis subtype, which is immovable, or synarthrodial.
The hip joints between is classified as a synovial type.
It is freely moveable, or diarthrodial, joint and is the truest example of a ball and socket (spheroidal).
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A long-standing traditional method used to locate the femoral head and neck is first to determine the midpoint of a line between the ASIS and the symphysis pubis.
Head 1 ½ inches distal and at right angles to the midpoint of this line.
If the entire leg is rotated internally a full 15 to 20 degrees, the outline of the lesser trochanter is not generally visible at all or is only slightly visible on some patients.
The typical physical sign for such a fracture is the external rotation of the involved foot.
WARNING: if evidence of a hip fracture is present, a pelvis radiograph should be taken “as is” without attempting to rotate the leg internally.
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No sheilding
To reduce total radiation does to the patient, a higher kVp range of 80 to 90 may be used for hip and pelvic examinations.
A mummy wrap helps prevent the upper limbs from interfering with the anatomy of interest on a challenging patient.
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Patients who have undergone hip replacement surgery should not be placed in the modified Cleaves position for any postsrugergical procedures.
Read alternative modalities
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Ankylosing spondylitis - fusion of the sacroiliac joints. Working up the vertebral column and creating a radiographic characteristics known as bamboo spine.
Avulsion fractures of the pelvis - Fractures cause extreme pain and are difficult to diagnose if not imaged properly. Occur in adolescent athletes who experience sudden, forceful, or unbalanced contraction of the tendinous and muscular attachments, such as might occur while running hurdles.
Chrondrosarcoma - a malignant tumor of the cartilage
Developmental dysplasia of the hip (DDH) - These hip dislocations are caused by condition present at birth and may require frequent hip radiographs.
Femoroacetabulum impingements (FAI) - Defect of the femoral head and/or acetabulum. There are three forms.
Leg-Calve-Perthes disease - the most common type of aspecting of ischemic necrosis. A limp is usually the first clinical sign: radiographs demonstrate a flattened femoral head that later can appear fragmented.
Metastatic carcinoma - the malignancy spreads to the bone via the circulatory system or lymphatic system, or by direct invasion.
Osteoarthritis - This condition is known as a degenerative joint disease (DJD), with degeneration of joint cartilage and adjacent bone causing pain and stiffness.
Pelvis ring fractures - a severe blow or trauma to one side of the pelvis may result in a fracture opposite from the site of primary trauma. This type of trauma is referred to as a contrecoup injury.
Proximal femur (hip) fractures - these fractures are most common in older adult or geriatric patients with osteoporosis or avascular necrosis.
Slipped capital femoral epiphysis (SCFE) - This condition usually occurs in 10-16 year olds during rapid growth. The epiphysis appears shorter and the epiphyseal plate wider, with small margins.
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AP PROJECTION: FEMUR-MID AND DISTAL
Knee joint space wil not appear fully open because of divergent x-ray beam.
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LATERAL-MEDIOLATER OR LATEROMEDIAL PROJECITONS: FEMUR- MID AND DISTAL
Place patient in the lateral recumbent position, or supine for trauma patient.
Recumbent
Do not attempt this position if patient has severe trauma
Flex knee approximately 45 degrees with patient on affected side, and align femur to midline of table or IR.
Trauma lateromedial
Place support under affected leg and knee and support and ankle in true AP position.
Place IR on edge against medial aspect of thigh to include knee, with horizontal x-ray bea, directed from lateral side.
CR perpendicular to femur and directed to midpoint of IR
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Lateral-mediolateral projection: femur - mid and proximal
Do not attempt this position for patients with possible fracture of the hip or proximal femur. Refer to trauma hip routine in this chapter.
Flex affected knee 45 degrees
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Lab #1 - AP PELVIS PROJECTION: PELVIS
Ensure that pelvis is not rotated; distance from tabletop to each ASIS should be equal
Separate legs and feet, then internally rotate long axes of feet and entire lower limb 15 to 20 degrees.
Lesser trochanters should not be visible at all; for many patients, only the tips are visible
No rotation is evidenced by symmetric appearance of the iliac alar, or wings, foreshortened or closed obturator foramina.
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AP AXIAL OUTLET PROJECTION: PELVIS
Bilateral view of the bilateral pubis and ischium to allow assessment of pelvic trauma for fractures and displacement.
Angle CR cephalad 20 to 35 degrees for males and 30 to 45 degrees for females.
Direct CR to a midline point 1 to 2 inches distal to the symphysis pubis or greater trochanters.
KNOW THAT AP AXIAL OUTLET IS ALSO TAYLOR METHOD
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AP AXIAL INLET PROJECTION
Angle CR cauded 40 degrees
Direct CR to a midline point at level of ASIS
A axial projection that demonstrates the pelvic ring or inlet
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POSTERIOR OBLIQUE PROJECTION: PRLVIS-ACETABULUM
JUDET METHOD
When centered to the downside acetabulum, the anterior rim of the acetabulum and posterior column are demonstrated.
When centered to the upside acetabulum, the posterior rim of the acetabulum and anterior column are demonstrated.
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With patient semiphone, provide pillow for head andposition for affected side down. Position can be performed erect.
Place patient in anterior oblique, with both pelvis and thorax 35 to 40 degrees from tabletop or wall Bucky. Support with wedge sponge.
Center IR longitudinally to CR at level of femoral head.
Angle CR 12 degrees cephalad.
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AP UNILATERAL PROJECTION: HIP AND PROXIMAL FEMUR
rotate affected leg internally 15 to 20 degrees
CR angle is perpendicular to the femoral neck.
Any existing orthopedic appliance should be visible in it’s entirety.
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AXIOLATERAL PROJECTION - TRAUMA: HIP AND PROXIMAL FEMUR
DANELUS-MILLER METHOD
common projection for trauma, surgery, and post surgery patients.
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AP BILATERAL PROJECTION-HIPS
MODIFIED CLEAVES METHOD
Developmental dysplasia of hip (DDH), also known as congenital hip dislocation.
Abduct both femoral 40 to 45 degrees from vertical
Less abduction of femoral of only 20 to 30 degrees from vertical plane provides for the least foreshortening of femoral head and neck region, but this placement foreshortens the entire proximal femoral, which may not be desirable.
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LAB #2- MEDIOLATERAL PROJECTION-HIP AND PROXIMAL FEMUR
MODIFIED CLEAVES METHOD
NONTRAUMA hip
Flex knee and hip on affected side, as shown, with sole of foot against inside of opposite leg near knee if possible.
Abduct femur 45 degrees from vertical for general proximal femur region.
The optimum femur abduction for demonstration of the femoral neck with minimal distortion is 20 to 30 degrees from vertical on most patients. (If you want femoral neck)
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MODIFIED AXIOLATERAL PROJECTION-POSSIBLE TRAUMA:HIP AND PROXIMAL FEMUR
CLEMENTS-NAKAYAMA METHOD
when the patient had limited movement in both lower limbs
Tilt IR about 15 degrees from vertical
Angle CR 15 to 20 degrees from horizontal
Femoral head and neck should be seen in profile.
ONLY IF PATIENT CANT MOVE EITHER HIP