Blood Supply of the Femoral Head

Regional Anastomoses

Trochanteric Anastomosis

  • Centred on the trochanteric fossa
  • Comprised of
    • Descending branch of the superior gluteal artery
    • Ascending branch LFCA anteriorly
    • Ascending branch MFCA posteriorly
    • Ascending branch inferior gluteal artery

Cruciate Anastomosis

  • Centred on the lesser trochanter
  • Comprised of
    • Descending branch of the inferior gluteal artery
    • Transverse branch of the LFCA
    • Transverse branch of the MFCA
    • Ascending branch of the first perforator

Extracapsular arterial ring

  • Found at the base of the neck & described by Crock
  • Tends to be incomplete
  • Consists of the
    • Ascending branch of the LFCA anteriorly
    • Ascending branch of the MFCA posteriorly
  • MFCA
    • most important contributor to the Lateral Epiphyseal Artery (Trueta & Sevitt 1953)
    • Arises from the profunda femoris
    • Passes posteriorly between
      • Psoas & Pectineus
      • Obturator externus & Adductor brevis
      • Quadratus femoris & Adductor magnus
    • Divides on anterior aspect of Quadratus femoris into ascending & transverse branch
    • Pass laterally on upper & lower border of Quadratus femoris

Ascending Cervical Vessels

  • Arise from the extracapsular ring
  • Comprised of four retinacular vessels
    • Anterior
    • Posterior
    • Medial
    • Lateral
  • These vessels enter the neck at the attachment of the capsule (anterior at the intertrochanteric line & posteriorly at the intertrochanteric crest) & run up the neck
  • lateral vessels provide the greatest volume of the femoral head
  • LFCA gives rise to the anterior vessels & the MFCA gives rise to the rest

Subsynovial Ring (of Chung)

  • Forms from the retinacular vessels as ring on the surface of neck at margin of the articular cartilage
  • Epiphyseal arteries enter the head from here
    • Lateral Epiphyseal most important
  • Classified as complete & incomplete (Hunter 1743)
  • Greater number incomplete in males – ? greater incidence in males
  • When incomplete the defect was called anterior, posterior or combined

Artery of Ligamentum Teres

  • Branch of the Obturator Artery usually but occasionally the MFCA
  • Importance is uncertain but probably supplies the head in children more consistently than adults
  • Usually insufficient if other vessels divided

Age related changes in blood supply to Epiphysis

  • Age < 4
    • Receives blood from the metaphyseal vessels
  • Age 4-8
    • Blood from separate epiphyseal vessels as the physis is barrier to blood flow
  • Age > 8
    • The ligamentum teres has increasing significance in supply (20%)
    • Trueta suggested that did not supply until 3-4 years

Supply

  • Epiphyseal
    • Arises from the subsynovial ring as the Lateral Epiphyseal Artery
    • Artery of Ligamentum Teres (Medial Epiphyseal Artery)
    • These anastomose with the Metaphyseal arteries
    • Tenuous supply
  • Metaphyseal
    • Excellent supply
    • From the
      • Branches of the extracapsular arterial ring
      • Ascending cervical branches
      • Subsynovial ring
      • Intramedullary branches of the superior nutrient artery
      • Anastomosis with the epiphyseal artery