Osteology of the Lower Limb

INNOMINATE (HIP BONE)

  • Tubercle of iliac spine is 5cm posterior to ASIS
    • It is most lateral part of pelvis
    • Intertubercular line is at level of L5 vertebrae
  • Most superior part of pelvis is 7.5 cm behind the tubercle
    • Supracristae plane passes through the spine of L4
  • ASIS
    • Inguinal ligament
    • Sartorius
  • AIIS
    • Straight head of rectus femoris
    • Iliofemoral ligament
  • PSIS
    • Sacrotuberous ligament
    • Dimple at level of S2
  • PIIS
  • Pubic symphysis
    • Secondary cartilaginous joint

Ossification

  • Cartilaginous
  • Primary centres 3
    • Ilium 2nd month gestation
    • Ischium 3rd month
    • Pubis 4th month
  • At birth
    • Acetabulum is wholly carilage
  • 7 years ischial & pubic rami fuse
  • Secondary centres
    • Acetabular cartilage 8 years complete 18years
    • Periphery of pelvis fused 25 years

FEMUR

  • 2nd bone to ossify (clavicle is 1st)
  • Primary
    • Shaft 7th week
  • Secondary
    • Lower end 9th month i.e. at birth fuses 20 years
      • Medicolegal evidence of maturity
    • Head during 1st year after birth 18 years
    • Great troch 4th year 18 years
    • Lesser troch 12-14 years 18 years

PATELLA

  • Primary
    • Several centres 3-6 years quickly
      • One centre may not fuse & form a bipartite patella

TIBIA

  • Primary
    • Shaft 8th week fetal
  • Secondary
    • Upper immediately after birth 20 years
    • Tuberosity 10 years
    • Lower during 1st year 18 years

FIBULA

  • Primary
    • Shaft 8th week
  • Secondary
    • Upper 4th year 20 years
    • Lower 2nd year 18 years

FOOT

  • Tarsus
    • 7 bones
    • proximal row
      • talus, calcaneus
    • distal row
      • medial to lateral
      • navicular
      • medial, intermediate, lateral cuneiforms, cuboid

OSSIFICATION OF FOOT BONES

  • Primary
    • Calcaneus 3rd month fetal birth
    • Talus 6th month fetal birth
    • Cuboid 9th month fetal
    • Navicular during first 4 years
    • Cuneiforms during first 4 years
  • Secondary centres
    • Calcaneus
      • Posterior surface
    • Talus
      • Lateral tubercle
    • 5th metatarsal
      • tubercle
    • navicular
      • tuberosity