[TA] a thickened band of fused iliac and psoas fascia passing posteriorly from the posterior aspect of the inguinal ligament across the anterior aspect of the femoral nerve to attach to the iliopectineal eminence of the hip bone. The iliopectinal arch thus forms a septum that subdivides the space deep to the inguinal ligament into a lateral muscular lacunae and a medial vascular lacunae. When a psoas minor muscle is present, its tendon of insertion blends with the iliopectineal arch. SYN: arcus iliopectineus [TA], iliopectineal ligament, ligamentum iliopectineale.