X-table Hip Comp Flashcards
What is the longest and strongest bone in the body?
Femur
What ligament attaches to the femoral head?
Ligament capitus
What is the area in between the 2 trochanters called?
Intertrochanteric crest
Angle of the neck to the shaft?
125 degrees +/- 15 degrees depending on width of pelvis and length of legs
Does the angle of the neck to the shaft increase or decrease with a short and wide pelvis?
Less angle for short and wide
More angle for long and narrow
How does the femur sit compared to vertical?
10 degrees medial
How does the angle of the femur change for short and wide vs long and narrow?
Short and wide: more angle
Long and narrow: less angle
How the femur sits from vertical affects what positioning?
CR for lateral knee
How do the head and neck of femur sit?
15-20 anterior
What does the pelvis do?
Served as a base of trunk and forms the connection between the vertebral column and lower limbs
What is the pelvis made up of?
- 2 hip bones
- 1 sacrum
- 1 coccyx
Another name for hip bones?
- ossa coxae
- innominate bones
What portion of the acetabulum does the ilium make up?
Superior 2/5ths
What portion of the acetabulum does the ischium make up?
Inferior and posterior 2/5ths
What portion of the acetabulum does the pubis make up?
Inferior and anterior 1/5th
When doe the ilium, ischium, and pubis fuse?
Middle teens at the acetabulum
Where is the crest of the ilium located?
Between the ASIS and PSIS
What bears the most weight when sitting?
Ischial tuberosities
What is the obturator foramen formed by?
The ramus/body of ischium and by pubis
What is the largest foramen in the human body?
Obturator foramen
Area above the superior symph to superior sacrum (pelvis brim)
Greater, false pelvis
-iliac alae and abdominal muscles = borders
What rest on the floor of the greater/false pelvis?
Lower abdominal organs and fetus
Area below the pelvis brim?
Lesser, true pelvis
What does the true pelvis form?
Birth canal
Parts of the birth canal?
Inlet, midcavity, outlet
What is cephalopelvimetry?
- measurement of the babys head and inlet/outlet of mother’s pelvis
- colcher-sussman ruler
- not used anymore
Male pelvis characteristics?
- narrower, deeper, less flared
- pubic arch is an acute angle
- inlet is narrower, more oval/heart shaped
Female pelvis characteristics?
- wider, shallow, flared
- pubic arch is and obtuse angle
- inlet is larger, more round
Sacroiliac joints?
- joined by SI ligaments
- synovial
- amphiarthrodial
- limited movement
Symphysis pubis (disk thicker in females)
- cartilagenous
- amphiarthrodial
- limited movement
Union of acetabulum?
- cartilaginous
- synarthrodial (in adults)
- no movement
- synchondrosis
Hip joint
- synovial
- diarthrodial
- spheroid/ball and socket
- flexion/extension, abuction/adduction, medial/lateral rotation, circumduction
When is the proximal femur and hip joint in true AP?
15-20 degrees medial rotation
What is the evidence of a hip fracture?
External rotation
Exposure factors?
80-85kVp
AP: 16mAs
Lat: 20mAs
Ankylosing spondylitis?
(Bamboo spine)
- inflammation/fusing of joints
- most often males
- SI joints first, then vertebral column
Avulsion fracture of pelvis?
- use a lower kVP to detect
- adolescent athletes
- tendons/muscles pulling
- AIIS, ASIS, superior corner of symph, iliac crest
Chondrosarcoma?
- malignant tumor of cartilage in pelvis and long bones
- men 45+
Developmental displasia of the hip (congenital dislocation of the hip CDH)
- present at birth
- hip dislocations
Legg-Calve-Perthes disease
- most common aseptic or ischemic necrosis
- typically involve hip
- 5-10yr old boys, limp is first sign
- flattened femoral head
- disruption of blood flow to the head of the femur
Metastatic carcinoma?
- malignancy spreads via circulatory or lymphatic system or direct invasion
- more common than primary malignancy
- bones that contain red bone marrow more common (pelvis, spine, skull, ribs, femora)
Osteoarthritis
Degenerative joint disease
- weightbearing joints (hips, knees etc.)
- most common arthritis
- osteophytes
Pelvic ring fracture
-severe blow/trauma to one side of the pelvis may result in a fracture site away from primary trauma site
Hip fractures
-most common in geriatrics with osteoporosis or avascular necrosis
Slipped capital femoral epiphysis (SCFE)
- 10-16yr old during rapid growth
- minor trauma can precipitate its development
- epiphysis appears shorter and epiphyseal plate wider with smaller margins
Intertrochanteric fracture
-between greater and lesser trochanter
AP bilateral frog leg pelvis is also known as?
Modified cleaves
When should you not perform a modified cleaves (pelvis)?
Do not attempt on patient with destructive hip disease or potential hip fracture/dislocation
How much do you abduct legs for modified cleaves?
40-45 degrees
What does 20-30 degree abduction do for a modified cleaves?
- least amount of femoral neck foreshortening
- but foreshortening of entire proximal femora
What happens to the greater trochanter as abduction increases?
Greater trochanter moves superior towards femoral head (at 45 deg abduction it is between the lesser trochanter and femoral head which is what we want)
Ap axial outlet projection also known as?
Taylor method
What is seen on the AP axial outlet projection?
Pubis and ischium
Angling for AP outlet projection?
Males: 20-35 degrees cephalad
Females: 30-45 degrees cephalad
CR 1-2” below symph
Ap axial inlet pelvis-what is seen?
-for posterior displacement or inward/outward rotation of anterior pelvis
Angle for AP axial inlet projection?
40 degrees causes
CR at ASIS
Posterior oblique pelvis-acetabulum-also known as?
Judet view
What is seen on the judet view?
Acetabular fracture?
How much do we oblique for the judet view? What rims are seen when?
45 degrees
Downside: anterior rim/iliac wing
Upside: posterior rim/obturator foramen
Pa axial oblique-acetabulum- also known as? What is it for?
Teufel method
- acetabular fracture (superior rim)
- affected side down
- 35-40 degree anterior oblique
- 1” above greater trochanter, 2” lateral to MSP
- concave fovea capitus, open obturator foramen
Another name for the axiolateral inferosuperior trauma hip? When is it used?
Danelius-miller method
-when the leg cant be moved
What is the difference between the modified cleaves and the lauenstein hickey method?
Lauenstein foreshortens the neck, but demonstrates the head and acetabulum well (pt rotated on side to bring femur down onto table)
Modified axiolateral -possible trauma-Celements/Nakayama method
- when inferosuperior cant be obtained
- IR tilted 15 degrees and placed 2” below tabletop
- CR 15-20 degrees posterior (down, pt is on back), centered to femoral neck on the upside
- lateral oblique views of the acetabulum, femoral head, and neck
Fat planes in the pelvis and their locations?
- Obturator internus: within the pelvis inlet next to the medial brim
- Iliopsoas: medial to lesser trochanter
- Pericapsular: superior to femoral neck
- Gluteal: superior to the pericapsular fat plane
What do the fat planes demonstrate, if visualized?
Aids in the detection of intra-articular and peri-articular disease
On a lateral, as the leg is abducted, what happens to the greater trochanter?
The greater trochanter moved towards the femoral head as the abduction increases
AP: as the distal femur is elevated, what happens to the greater trochanter?
As elevation increases, the greater trochanter moved medially
How to find the femoral neck and head?
Femoral head: CR 1.5” distal to the line connected ASIS and symph
Femoral neck: CR 2.5” distal
OR
CR 1-2” medial and 3-4” distal to ASIS
Axiolateral inferosuperior (X-table) hip: what happen if the IR is not parallel to the femoral neck? Angle to large or too small?
Foreshortening
Too large angle: greater trochanter proximal to lesser, over femoral neck
Too small angle: greater trochanter distal to lesser trochanter
X-table hip: what happens if leg is in external rotation?
- greater trochanter posterior
- lesser trochanter superimposing femoral neck
X-table hips special considerations for obese patients?
-IR higher than crests to get acetabulum and femoral head on x ray
AP Pelvis: when will the lesser trochanters be in profile?
Legs externally rotated so feet are at 45 degrees (femoral epicondyles 60-65 degrees), femoral neck demonstrated on end
