pelvis and femur Flashcards
what are the 4 bones of the pelvis
- sacrum
- illium
- ischium
- pubis
what are the 4 joints of the pelivs
- sacroilliac joint
- pubic symphysis
- sacrococcygeal joint
- hip joint
what type of joint is the sacroiliac, pubic symphysis, sacrococcygeal and hip joint
- sacroiliac = syndical plane
- pubic = fibrocartilaginous
- sacrococcygeal = fibrocartilaginous
- hip = ball and socket
what do you can the bones of the pelvis before and after fusion?
- hemi-pelvis (pre) (left and right pelvis)
- innominate bones (after joining of illium, ischium and pubis)
what are the 4 prominent bony landmarks of the illium bone
- anterior superior/inferior iliac spine
- posterior superior/inferor illac spine
what 2 parts does the ischium consist of
- body
- ischial ramus
how does the ischium join to the pubis
ischial ramus joins with inferior ramus of pubis
what 3 parts make up the pubis
- body
- inferior/superior ramus
what is formed due to the joining of the ischial ramus and pubis inferior ramus
obturator foramen
what do you call the cartilage that joins the pubis, ischium and illium
triradiate cartilage
what is the usual width of the pubic symphysis cartilaginous joint?
3-5mm
what forms the pelvic ring
- the 2 innominate bones (left and right hemi-pelvis) and pelvis spine (sacrum and coccyx)
what are the 5 bony landmarks of the pelvis
- iliac crest
- ASIS
- PSIS
- pubic symphysis
- ischial tuberosity
what 5 areas of the pelvis can you get an avulsion fracture
- iliac crest
- ASIS
- AIIS
- ischial tuberosity
- body of pubis/inferior pubi ramus
what 2 parts of the femur can you get an avulsion fracture
greater and lesser trochanter
what is the longest, strongest and heaviest bone in the body
femur
when doing a pelvic xray, when would it not be suitable to rotate the feet medially for better view of the femoral neck?
if there is trauma or other pathology suspected
what should be seen on a gold standard AP pelvis xray
- coccyx and symohysis are in straight line and positioned in the middle line of image
- both sides of iliac wings and obturator foramen are symmetrical
- distance between the superior border of pubic symphysis and tip of coccyx is between 1 and 3 cm
how can you tell if someones feet is over rotated, adequately rotated or under rotated from a pelvic xray
- no rotation/ external rotation = shortening of femoral neck
- adequate internal rotation = lesser and greater trochanter seen, femoral neck is also visble
- over internal rotation = cannot see lesser trochanter
during HBL pelvis, how must you place the IR to get a good image of the femoral neck
you must angle the lower border of the detector away from the body until it is parallel with the femoral neck
what is a grid used for
- placed between patient and xray film to reduce scattered radiation reaching the detector and thus improve image contrast
when/why would grids be useful
- as scattered radiation is increased in thicker patients and at larger field sizes, grids are useful in such scenarios to improve image contrast
find a diagram and label all the parts of the pelvis and femur
the angle formed at the convergence of the inferior pubic rami has what anatomical name
pubic arch
