blood supplies to bones

Femoral head

groups of arteries

·      4 groups of arteries

Regional anastomoses

Cruciate

·      primary

·      at centre of lesser trochanter

·      formed

·      posteriorly by transverse branch of MCFA

·      anteriorly by transverse branch of LCFA

·      superiorly from descending branch of inferior gluteal a

·      inferiorly from ascending branch of 1st perforator

Trochanteric

·      at greater trochanter

·      formed by

·      ascending branch of inferior

·      descending branch of superior

·      ascending branch of MCFA

·      ascending branch of LCFA

Extracapsular arterial ring

·      at base of femoral neck

·      formed

·      posteriorly by transverse branch of MCFA

·      anteriorly by transverse branch of LCFA

·      MCFA is most important

Ascending cervical arteries

·      branches of extracapsular ring

·      divided into four groups

·      anterior, posterior, medial, lateral

·      MFCA gives rise to posterior, medial and lateral branches

·      LFCA gives rise to anterior branches

·      lateral branches (from MFCA) supplies most of blood to femoral head and neck

·      penetrate capsule at femoral attachment

·      anteriorly at intertrochanteric line

·      posteriorly halfway up femoral neck

·      pass upwards on surface of neck of femur

·      called retinacular arteries

·      form subsynovial intra-articular ring

·      at margin of articular cartilage on neck of femur

·      may be complete or incomplete

·      ring gives rise to branches that enter head of femur

·      called epiphyseal arteries

Artery of ligamentum teres

·      branch of obturator a or MFCA

·      variable supply

·      usually unimportant with small subsynovial circulation

·      may give large artery to supply substantial part of head

·      usually insufficient if other sources interrupted

Age-related changes to epiphyseal supply

·      less than age 4

·      contribution from metaphysis

·      age 4-8 yrs

·      exclusively epiphyseal vessels

·      after than age 8

·      increased contribution from ligamentum teres

Supply
Epiphyseal supply

·      tenuous supply

·      from

·      branches of subsynovial intra-articular ring (lateral epiphyseal arteries)

·      artery of ligamentum teres (medial epiphyseal artery)

·      anastomoses with metaphyseal arteries

Metaphyseal supply

·      excellent supply

·      from

·      branches of extracapsular arterial ring

·      branches of ascending cervical arteries

·      branches of subsynovial intra-articular ring

·      intramedullary branches of superior nutrient artery

·      anastomoses with epiphyseal vessels

Talus

Extraosseous
Posterior tibial artery

Artery of tarsal canal

·      arises from posterior tibial artery 1 cm proximal to division

·      passes anterior to FDL

·      enters tarsal canal

·      only other structure in canal is interosseous talocalcaneal ligament

·      gives off branches that enter talus

·      on medial side

·      inferiorly from tarsal canal

·      continues to tarsal sinus

·      anastomoses with arteries in tarsal sinus

Deltoid branch

·      important branch from artery of tarsal canal

·      lies between leaves of deltoid ligament

·      sends branches that enter through medial surface of body of talus

·      responsible for supply to medial half of body

Anterior tibial artery

Superior neck branches

·      branches from dorsalis pedis

Artery of tarsal sinus

·      formed by anastomosis of

·      branch of dorsalis pedis as it croosses the navicular

·      branch of perforating peroneal artery

·      gives branches that enter lateral side of talus

·      supplies lateral half of body

Peroneal artery

·      unimportant

·      contribute to plexus around posterior talus

·      perforating branch contributes to artery of tarsal sinus

INtraosseous
Head of talus

·      medially

·      branches of dorsalis pedis

·      laterally

·      branches of artery of tarsal sinus

Body of talus

·      laterally

·      from artery of tarsal sinus

·      middle part

·      from branches of anastomosis between artery of tarsal sinus and tarsal canal

·      medially

·      from deltoid artery from artery of tarsal canal

Scaphoid

·      majority of supply from palmar and dorsal branches of radial artery

Palmar scaphoid branch

·      enters distally at tuberosity

·      accounts for 20-30% of supply at distal pole

Dorsal scaphoid branches

·      enter through dorsal ridge in middle 1/3 of bone

·      supply remainder of vascularity