hip and pelvis Flashcards
what is the pelvic girdle
- connects bones of the lower limb to axial skeleton
- consists of 2 pelvic bones
- pelvic bones unite anteriorly at the pubic symphasis
- pelvic bones untie posterior ally at sacroiliac joints
- pelvic bones, pubic symphysis, coccyx, sacrum form the bony pelvis
- provides strong support for spine and pelvic/ lower abdominal contents
what are the bones of the pelvic girdle
ilium (a + p )
ischium (p)
pubis (a)
what is the ilium
- winged like portion (ala)
- inferior body (anterior)
- has crest at top
- has 4 spines (ASIS and AIIS) and (PSIS and PIIS)
- has greater sciatic notch next to PIIS
what is the ischium
- on posterior side
- prominent ischial spine (a)
- lesser sciatic notch right underneath (a)
- has inferior ramus (flat bony bar that extends from bottom of bone with the inferior pubis ramus)
- the superior body forms the floor of the acetabulum
- has ischial tuberosity (p)
- spine and tuberosity form that sciatic notches
what is the pubis
- superior and inferior ramus
- superior ramus forms part of acetabulum
- inferior mets with inferior ramus of the ischium
- body articulates with other pubis bone at pubic symphysis
- pubic symphysis where hip bones meet anteriorly
what is obturator foramen
hole in the middle of ilium, ischium and pubis
what is the iliac fossa
smooth concave surface of ilium
- iliacus muscle originates here
- bordered by iliac crest, anterior border and medial border (p)
what do iliac spines do
attachment point for many muscles
what do the sciatic notches do
allow for nerves, blood vessels and tendons to pass through into the thigh and gluteal regions
what does the ischial spine do
provide attachment point for sacrospinous ligaments
what is the acetabulum
- deep fossa that forms at the meeting points of the ilium, ischium and pubis
- head of femur articulates here
- acetabular notch allow for blood vessel, nerve and ligament attachments
- together the femoral head and acetabulum form the hip joint
what is the true pelvis
- known as lesser pelvis
- contains the rectum, bladder and reproductive organs
- inferior to pelvic brim
- encloses pelvic brim (anatomical limit between the true and false)
what is the false pelvis
- located superior to pelvic brim (line formed by sacrum, iliac vessels and colon)
- upper part of pelvis that forms lower part of abdominal cavity
- bounded by ilium on either side of
differences between male and female pelvis
F:
- larger and wider than male
- rounder pelvic inlet
- sacrum is shorter, wider and more curved
- iliac crest lower
- pubic arch wider (thumb and index)
M:
- deeper, narrower false pelvis
- sacrum is longer, narrower and straighter
- iliac crest is higher
- pubis arch is V-shaped (index and middle angle
joints of pelvic girdle
- pubic symphysis: cartilage that connects 2 pelvic bones and useful in childbirth
- sacroiliac joint: link pelvis to lower spine and support weight of upper body when standing
- hip joint: ball and socket and coating of articular cartilage on femoral head and acetabulum to alleviate friction
what are the ligaments of the pelvis (anterior)
-pubofemoral ligament: connect pubis to femur and prevent over extension
-anterior sacroiliac ligament: connect sacrum and ilium
- superior pubic ligament: support pubic symphysis
- obturator membrane: provide attachment point for muscles and closes the foramen
- inguinal ligament: runs from ASIS to pubic tubercle
what are the posterior ligaments of the pelvis
- sacrotuberous ligament: connect sacrum and coccyx to ischial tuberosity
- greater sciatic foramen: formed by sacrotuberous and sacrospinous ligaments ad allow opening for nerves, blood vessels and muscles to pass from pelvis to lower limb
- lesser sciatic foramen: small opening allowing for passage of nerves blood vessels and muscles to pass from pelvis to gluteal region and perineum
- sacrospinous ligament: connect sacrum and coccyx to ischium spine and stabilises sacroiliac joint
extracapsular ligaments of pelvis
- pubofemoral ligament: attach pubis to femur and prevent overabduction and overextension
- ischiofemoral ligament: attach ischium to femur but wraps around p -> a and tucks into the iliofemoral ligament and prevent overextension
- iliofemoral ligament: (y shaped), attach ilium to femur and prevent overextension
intracapuslar ligaments of the pelvis
- zona orbicularis: encircles the neck of the femur and stabilises hip
- transverse acetabular ligament: stabilises the hip joint and deepens the socket
- ligament of femoral head: hidden within joint capsule and connects femoral head to acetabulum
why is the hip joint stable
- bony and lateral anatomy of the acetabulum and femoral head
- thick fibrous capsule around the joint which hold synovial fluid to alleviate friction
what is the hip joint made of
- femoral head
- joint capsule which surrounds the joint (synovial) therefore holds synovial fluid
- femoral head ligament attaches head 2 acetabulum
- fibrosis-elastic fat pad alleviate friction
- ischiofemoral ligament wraps around to front of femur
major arteries of the pelvic girdle
- abdominal aorta: originate from diaphragm and provide blood to pelvis, abdomen and legs
- common iliac artery: originates in lower back and supplies blood to legs, pelvis and reproductive organs
- internal iliac artery: originate in pelvis where it descends from CIA and supplies pelvis/organs, reproductive organs ad medial part of thigh
- external iliac artery: largest branch of CIA and forms main blood supply to lower extremity
- femoral artery: supply blood to entire lower leg (anterior)
major veins of the pelvis
- inferior vena cava: carry blood from lower body to the heart (one of largest veins in the body)
- common iliac vein: formed when external and internal veins join and eventually create inferior vena cava
- external iliac vein: runs from back of inguinal ligament and ends near the sacroiliac joint
- internal iliac vein: carry blood from buttocks, external genitals, inner thigh and perineum
- femoral vein: deep vein in thigh and continues from popliteal vein of the knees
order of blood vessels
- external iliac ARTERY
- internal iliac ARTERY
- internal iliac VEIN
- external iliac VEIN
course of the blood vessels
Internal iliac artery descends into the true pelvis to supply the pelvic organs,
and its branches exit through the obturator canal, and greater sciatic foramen
External iliac artery runs along the pelvic brim,
passes under the inguinal ligament
where it continues as the femoral artery
Pelvic veins merge into the common iliac veins
and exit the pelvis to form the inferior vena cava
nervous supply of the pelvis
- formed by lumbar plexus (formed by lumbar spinal nerves and responsible for providing elevation to the lower abdomen, pelvis and lower limbs
- provide innervation to buttocks, genitals and lower limbs
- also formed by sacral plexus (formed by sacrum nerves)
key nerves in pelvis
L - femoral nerve: largest nerve in lumbar plexus (L2 to L4)/ motor and sensory processing in lower limbs = controls the major hip flexor muscles and knee extension muscles
saphenous nerve (branch): originate from L3 and L4 nerve roots/ emerges below the knee/ provide sensation to lower knee, calf, ankle and foot arch
L - obturator nerve: L2 to L4/ peripheral nerve that runs thru the groin/ provide motor and sensory innervation to thigh, hip and knee
S - sciatic nerve: L4 to S3/ largest nerve in body/ provide motor innervation to posterior compartment of thigh
S - pudendal nerve: S2 to S4/ mixed nerve that provides motor and sensory innervation to pelvic region
major muscles of the pelvic girdle
- iliacus and psoas major merge to form iliapsoas muscle that inserts into lesser trochanter of femur
- iliacus origin on ilium crest and psoas major origin on spine
- inserts on anterior side of femur
- piriformis located on the posterior wall of the lesser pelvis and posterior to the hip joint
- passes through the greater sciatic notch, and inserts on the superior aspect of the greater trochanter
- stabilises joint and help with lower body movement
- gluteus medius is a hip abductor/ origin on ilium crest and insert on greater trochanter
- gluteus maximus is a hip extensor/ origin on sacrum and part of ilium and insert on anterior side of femur
major muscles for hip flexion and extension
A: rectus femoris is a hip flexor/ origin on ilium and inserts into patella via quad tendon
A: sartorius is hip flexor/ origin on ASIS and insert on superior medial aspect of tibial shaft
P: gluteus maximus is a hip extensor/ origin on sacrum and part of ilium and insert on anterior side of femur
these 3 are part of the hamstring muscle group
P: semitendonous hamstring is located between bicep femoris and semimembranous
P: semimembranous hamstring is located deep in semitendonous and its the most medial muscle
P: biceps femoris is located closest to the outside of the body and the function includes hip extension
major muscles for hip abduction and abduction
adductor group:
- adductor brevis= origin at anterior surface of pubic body and inferior pubic ramus surface and insets into upper third of femur
= adducts thigh at hip joint
- adductor longus= origin at anterior aspect of pubic body and inser on middle third of femur
- adductor magnus= origin at pubis and ischium and insert on adductor tubercle on medial femoral condyle
-gluteus minimus= origin from gluteal surface of ilium and insert on greater trochanter
-gluteus medius
