Blood supply of femoral Head

Courtesy: Harry Benjamin Laing MRCS, Ortho M8, FRCS(Tr and Orth) Tutorials

There are three sources:

1. Capsular vessels
2. intramedullary vessels
3. contribution from the ligamentum
   teres.

• In the adult the most important source of femoral head blood supply is derived from the capsular vessels.
• These vessels arise from the medial and lateral circumflex femoral arteries, which are in turn branches of the profunda femoris in 79% of cases. In 20% of patients, one or other of these vessels arises from the femoral artery, and in 1% both vessels arise from the femoral artery.
• The medial and lateral femoral circumflex arteries form an extracapsular circular anastomosis(Extracapsular Arterial Ring) at the base of the femoral neck, and the ascending cervical capsular vessels arise from this.
• They penetrate the anterior capsule at the base of the neck at the level of the intertrochanteric line . Within the capsule these are referred to as retinacular vessels.
• There are four main groups (anterior, medial, lateral, and posterior) of which the lateral group is the largest contributor to femoral head blood supply.

The most important retinacular vessels arise from the deep branch of the medial femoral circumflex artery. These vessels supply the main weight-bearing area of the femoral head.

The contributions of the lateral femoral circumflex artery and metaphyseal vessels are much less important by comparison. At the junction of the articular surface of the head with the femoral neck, there is a second ring anastomosis termed the Subsynovial Arterial Ring

BLOOD SUPPLY

Extracapsular arterial ring at the base of the femoral neck

• formed posteriorly by large branch of MFCA
• formed anteriorly by smaller branches of LFCA
• superior and inferior gluteal artery have minor contributions

Sub synovial intraarticular ring

• Ascending cervical branches
• these give rise to retinacular Arteries

Artery of ligamentum teres

• derived from obturator or MFCA
•  inadequate to supply femoral head with displaced fractures;
• forms the medial epiphyseal vessels

Epiphyseal blood supply

• arises primarily from lateral epiphyseal vessels that enter head posterosuperiorly
• vessels from medial epiphyseal artery entering through ligamentum teres;
• epiphyseal arterial branches:
• arise as arteries of subsynovial intraarticular ring

Metaphyseal blood supply

• arises from extracapsular arterial ring
• arise from branches of ascending cervical arteries, subsynovial intra articular ring