L11: Bones, ligaments and joints of the pelvic girdle and thigh Flashcards
Bones in lower limb
femur
tibia and fibula
tarsals
metatarsals
phalanges
lower limb is designed for:
locomotion
- carries heavy load of torso above
- exerts large forces
- resists large forces
- larger muscles than upper limb
movements of the hip
Flexion and Extension
Abduction and Adduction
Internal and External Rotation
Circumduction
knee movements
flexion and extension
ankle movements:
dorsiflexion and plantarflexion
foot movements
inversion and eversion
toes movements
flexion and extension
pelvic girdle consist of :
1x sacrum
2x hip bones
posteriorly, each hip forms a joint with the sacrum [sacroiliac joint]
anteriorly, each hip is joined at the pubic symphysis
hip bone is formed by 3 bones:
Ilium
Ischium
Pubis
what holds the hip bones together in children
a Y-shaped hyaline cartilage named ‘triradiate cartilage’
male vs. female pelvis ; general structure
in males the pelvis is heavy and thick, in females thin and light
hip bone ball and socket joint:
ball - head of femur
socket - acetabulum
male vs female pelvis ; pelvic brim
in females larger and more oval, in males smaller and heart shaped
male vs female pelvis ; pubic arch
in females the angle is bigger than in males
male vs female pelvis ; distance between ischial spines
less in males
sacrum
- distal part of spine
- formed by 5 fused vertebra
- forms sacroiliac joints with left and right iliac bones
- auricular surface of sacrum articulates with auricular surface of iliac bones
femur ; articulation
long bone of the thigh
articulates with acetabulum proximally and tibial plateau distally
Longest + heaviest + possibly strongest bone of the body
Sacroiliac joint
- connects pelvis to spine
- atypical plane synovial joint
- reinforced by ligaments within the joint capsule that pass from sacrum to each ilium
- very sting joint
Hip joint [ Acetabulofemoral Joint]
synovial ball and socket joint - has a fibrous capsule
Head of femur articulates with the acetabulum
What parts of hip joint are covered in cartilage?
Head of femur covered in hyaline cartilage except fovea
Lunate surface of acetabulum covered with hyaline cartilage
fibrous capsule
Lined by synovial membrane
Synovial membrane does not cover cartilage
Name extrascapular ligaments
> Iliofemoral ligament
- y shaped appearance
- limits hip extension
> Pubofemoral ligament
- limits hip abduction and extension
> Ischiofemoral ligament
- limits hip extension with its spiral fibres
Intracapuslar Ligaments
> Ligamentum Teres
- aka Ligamentum capitis
- aka Ligament of head of femur
Ligamentum Teres
Passes from the acetabular fossa to the fovea of the femoral head
*Carries a small branch from the obturator artery
*“Branch of the femoral head”
*Provides arterial supply to head of femur
*Very important during early life
Arterial Supply of the Hip Joint
the femoral neck and head receive most of their blood supply from circumflex branches of the femoral artery
NOT foveolar artery in ligamentum teres
Hip Dislocation
- uncommon
- usually due to a high energy event e.g. road
traffic collisions - A force from anterior, applied along the longitudinal axis of femur, can push it posteriorly out of the acetabulum
- Posterior dislocation of the femur can damage the sciatic nerve, which normally is located just posterior to the proximal femur
Hip Fracture
Hip fracture = fracture of the femoral neck
usually in older patients after a fall
higher risk if patient has osteoporosis
Avascular Necrosis [AVN] of Femoral Head
- Interruption of blood supply due to vessels being severed along fractured femoral neck
- Artery of ligamentum teres does not provide enough supply to femoral head
- Femoral head becomes ischaemic, then necrotic
*AVN of femoral head, just like AVN of scaphoid
total hip replacement:
artificial femoral head
artificial acetabulum
“The Arthritic Hip”
Osteoarthritis
Osteoarthritis in the hip is 2nd most common joint affected by this disease behind thumb CMC joint
Osteoarthritis is a degenerative disease whereby joint cartilage breaks down and bone starts to grind on bone during joint movement
*Stiff and painful, swollen joints
Joint repair : arthroplasty. Hip arthroplasty
