Tendon of obturator externus

The tendon of the obturator externus represents the posterior and lateral continuation of the muscle’s converging fibres.

The tendon passes posterior to the neck of the femur and beneath the hip joint capsule. It crosses the posterior aspect of the femoral neck, lying anterior to the tendon of the obturator internus and superior to the quadratus femoris.

Along its course, the tendon is separated from the capsule of the hip joint by a small bursa that reduces friction during hip movements.

Insertion

The tendon inserts into the trochanteric fossa of the femur, located on the medial surface of the greater trochanter.

Relations

• Anteriorly: Capsule of the hip joint and femoral neck

• Posteriorly: Obturator internus tendon and gemelli muscles

• Inferiorly: Quadratus femoris

Actions

• Acts as the lateral (or external ) rotator of the thigh.

• Contributes to joint stabilization by pulling the head of the femur medially into the acetabulum.