zona orbicularis

Introduction

Annular ligament on the neck of the femur formed by circular fibers of the articular capsule of the hip joint

Circular fibers of the zona orbicularis are most abundant at the inferior & posterior part of the articular capsule where they wrap the femoral neck.

Anteriorly, they blend with the deep surface of the iliofemoral ligament & attach to the anterior inferior iliac spine.

Function

• hold the femoral head in the acetabulum
  • tightens the articular capsule of the hip when iliopsoas muscle contracts

More general terms

• ligament

Additional terms

• femur
• hip joint
• orbicularis muscle