gluteal region and posterior thigh Flashcards
what are the lower limbs designed for?
stability and bearing weight and to aid in locomotion
what provides a clear line of demarcation between the trunk and lower extremity anteriorly?
inguinal ligament
what divides the trunk and lower extremity posteriorly?
it is a transitional zone= the gluteal region
what does the gluteal region include?
rounded buttocks and the less prominent lateral hip
what bounds the gluteal region?
superiorly- iliac crest
medially- intergluteal cleft
inferiorly- gluteal fold
what is the pelvic girdle (“os coxae”) formed by?
two hip bones laterally and anteriorly and the sacrum psoteriorly
what are the 3 fused bones that form the os coxa?
ilium, ischium, pubis
what is the name of the cartilage found intervening in children before ossification?
triradiate cartilage
which bone of the acetabulum is the only weight bearing part?
the ilium
what is the longest and heaviest bone in the body that transmits weight from the hip bone to the tibia?
femur
how is the femur oriented and why?
obliquely to put the knees more adjacent and inferior to the trunk
what are the prominent features of the femur?
the head, neck, greater trochanter, lesser trochanter, large condyles at distal ends
what is the angle of inclination?
126º
important because frees the lateral surface of the femur for attachment of the knee extenders
what is the angle of torsion?
allows for rotary movements of the femoral head to convert into flexion and extension, abd/add and rotational movements
describe the anterior sacroiliac joint
auricular surfaces of the sacrum and ilium have irregular surfaces which interlock. the joint is unique among synovial joints since its mobility is very little
what is the name of the thin anterior fibers of the sacroiliac capsule?
anterior sacroiliac ligaments
what is the name of the posterior fibers of the sacroiliac capsule and what are they a continuation of?
posterior sacroiliac ligaments continuation of deeper interosseous ligaments
what are the posterior sacroiliac ligaments?
surround the posterior sacroiliac joint, external continuations of deeper interosseous ligaments that are very strong fibers connecting the tuberosities of the sacrum and ilium. their orientation pulls the ilia inward when body weight drives the scrum downward
what do the iliolumbar ligaments do?
strengthen the lumbrosacral joints by spanning from the TPs of L4-5 to the ilium
where does the sacrotuberous ligament run?
from the posterior ilium and the lateral sacrum and cocyx to the ischial tuberosity
where does the sacrospinous ligament run?
from the lateral sacrum and coccyx to the ischial spine
what do both the sacrotuberous and sacrospinous ligaments resist?
the anterior/inferior rotation of the sacrum from body weight
what is the greater sciatic foramen an opening for?
structures entering or leaving the pelvis
what is the lesser sciatic foramen an opening for?
structures entering or leaving the perineum
describe the femoral head
it articulates with the acetabulum to form the hip joint
it is about 2/3 of a sphere covered with articular cartilage, except for a central area, the fovea, which provides the attachment site fo the ligament of the femoral head
what part of the femoral head is exposed and articulates with the joint capsule?
the anterior part
what is the labrum?
a lip of cartilage extending off the rim of the acetabulum that deepens the socket and adds about 10% more surface area to the acetabulum
what is the transverse acetabular ligament?
the inferior continuation of the labrum that spans the acteabular notch
what is the deepest most central part of the acetabulum?
acetabular fossa
what are the movements at the hip joint?
flexion-extension, adduction-abduction, medial-lateral rotation, and circumduction
describe dislocation at the hip joint
common congenital problem, especially in girls. later in life, anterior trauma with the femur in the flexed, adducted and medially rotated position. the femoral head dislocates posteriorly where the capsule is deficient, the affected limb appears to be shortened and medially rotated
describe surgical hip replacement
osteoarthritis is common and often the hip is replaced with a metal prosthesis taking the place of the femoral head and neck- it is cemented into the medullary canal and a plastic socket replaces acetabulum
where does the capsule attach?
from the acetabular rim and transverse acetabular ligament proximally, but only to the intertrochanteric line anteriorly (Posteriorly there is NO attachment to the femur)
what ligaments support the joint? which one is the main?
iliofemoral ligament, pubofemoral ligament, ischiofemoral ligament
the main is the iliofemoral
where does the iliofemoral ligament span?
from the AIIS and acetabular rim to the intertochanteric line
what does the iliofemoral ligament prevent?
hyperextension of the hip by “screwing” the femoral head into the acetabulum
where does the pubofemoral ligament span?
from obturator crest of pubic bone to blending with capsule and iliofemoral ligament
what does the pubofemoral ligament prevent?
hyperabduction of the hip, but also tightens during extension
where does the ischiofemoral ligament span?
it is posterior from the ischial part of the acetabular rim to the neck of the femur, medial to the greater trochanter
what does the ischiofemoral ligament check rein?
hyperextension
what is the main blood supply to the hip?
the medial circumflex femoral artery
what does the medial circumflex artery arise from?
the deep femoral artery near the neck of the femur
where does the artery to the femoral head travel through?
the ligament to the head of the femur
describe hip fracture/femoral neck fracture
especially common in older individuals with osteoporosis, healing can be difficult if medial circumflex femoral artery (branches) is damaged. avascular necrosis is a consequence
what muscles make up the superficial gluteal layer?
glute med, max and min, and tensor fascia lata
what is common with all the superficial gluteal muscles?
all have proximal attachments to the ala and margins of the ilium and mainly extend, abduct and medially rotate the thigh
what muscles make up the deep gluteal layer?
piriformis, obturator internus, superior gemellus, inferior gemellus, and quadratus femoris
what is common with all the deep gluteal layer muscles?
they are much smaller and have distal attachments on or near the intertrochanteric crest of the femur, these muscles laterally rotates the thigh but also stabilize the hip joint by steadying the femoral head in the acetabulum along with the ligaments
what do the clunial nerves supply?
the skin of the buttocks, the superior and middle clunial nerves are posterior rami coming from upper lumbar and sacral levels
what are the deep gluteal nerves and what do they all arise from?
superior gluteal, inferior gluteal, nerve to quadratus femoris, posterior cutaneous nerve of the thigh, pudendal, nerve to obturator internus
arise from the sacral plexus (L4-S3) passing through the greater sciatic foramen and all but superior gluteal nerve emerge inferior to the piriformis muscle
describe a superior gluteal nerve injury
loss of function of gluteus medius and minimus, the gait is affected- individual leans toward supported side to allow foot to clear the ground while coming forward for next step. when standing on one foot, gluteus medius are weak in pulling the ipsilateral hemiplevis downward the pelvis then drops on the unsupported side (pos trendelenbrug)
describe intragluteal injections
gluteal muscles have great bulk for absorption of medications, the superolateral quadrant is safe for such injections
where does the superior gluteal artery emerge from?
the sciatic foramen superior to piriformis m to supply the gluteal muscles. it has anastomoses to the medial circumflex femoral arteries
where does the inferior gluteal artery emerge from?
the greater sciatic foramen inferior to the piriformis muscle. also participates in anastomoses around the hip with the circumflex femoral arteries. artery to sciatic nerve emerges off
where does the internal pudendal artery emerge from?
out through the greater sciatic foramen and back into the pelvis through the lesser sciatic foramen to supply perineal skin, external genitalia and perineal muscles (travels with pudendal nerve)
what does the deep artery of the thigh (profunda femoris) give branches to?
to the posterior thigh called “perforating branches” that penetrate the aponeurotic aspect of the adductor magnus muscle
what 3 common features do the hamstring muscles share?
- proximal attachment to ischial tuberosity
- act on 2 joints (extend thigh at hip, flex leg at knee)
- innervated by the tibial division of sciatic nerve
describe a “pulled” hamstring
common in quick-start sports. the hamstrings may be strained or possibly avulse from the ischial tuberosity in severe cases. “warming up/stretching” is important to protect against such injuries which are sudden and very painful. hematoma may accompany injuries
where does the sciatic nerve emerge?
from the pelvis inferior to the piriformis m through the greater sciatic foramen
which part of the sciatic nerve innervates the gluteal region?
neither
what is innervated by the sciatic nerve inferior to the knee?
everything except one exception by the saphenous nerve
