Os Coxa Bone; Anterior View Markings
Ilium Bone Markings.
a. Iliac Crest or Crest of Ilium (Crista iliaca) is the curved upper ridge of the ilium. The latissimus dorsi, quadratus lumborum, erector spine, iliacus, tensor fasciae latae, and abdominal muscles attach along the surface of this ridge.
b. Iliac Fossa (Fossa iliaca) is a broad depression located along the anteromedial surface, inferior to the iliac crest. It is an attachment point for the iliacus muscle.
c. Anterior Superior Iliac Spine (Spina iliaca anterior superior) is a anterior projection from the iliac crest that serves as an attachment point for the sartorius muscle and inguinal ligament.
d. Anterior Inferior Iliac Spine (Spina iliaca anterior inferior) is a projection below the anterior superior iliac spine that is as an attachment point for the rectus femoris muscle.
Pubic Bone Markings.
e. Symphysis pubis or pubic symphysis (Symphysis pubica; symphysis pubis) is the cartilaginous joint between the two pubic bones.
f. Body of pubis (Corpus ossis pubis) is the flatten, medial end of the pubis that lies adjacent to the symphysis.
g. Inferior Pubic Ramus (Ramus inferior ossis pubis) is a thin, flat, downward extension that runs diagonally from the medial pubis to the ischial ramus. The adductor brevis, adductor magnus, and gracilis muscles attach along the surface of this ramus.
h. Superior Pubic Ramus (Ramus superior ossis pubis) is a band of bone that runs along the superior aspect of the pubis. The surface of this ramus is an attachment site for the pectineus muscle.
i. Pubic crest (Crista pubica) is a short, superiomedial ridge that runs extends horizontally from the symphysis to the pubic tubercle. It is an attachment point for the abdominal muscles.
j. Pubic tubercle (Tuberculum pubicum) is a projection from the lateral end of the pubic crest and serves as an attachment point for the inguinal ligament.
Ischium Bone Markings.
k. Ramus of Ischium (Ramus ossis ischii) is a thin, flat, anterior extension of the ischium that joins with the inferior ramus of the pubic bone. The adductor magnus muscle attaches along its surface.
Interdivisional Bone Markings.
l. Obturator foramen (Foramen obturatum; foramen obturatorium) is a large opening enclosed by the pubic and ischial rami. Most of the foramen is covered by a ligamentous membrane (obturator membrane), which helps decrease the weight of the os coax. The obturator vessels and nerves pass through a large canal located in the upper portion of the membrane.
m. Acetabulum (Acetabulum) is a large, rounded depression on the external (lateral) surface of the os coxa. It is formed by portions of the ilium, ischium, and pubic bones and accepts the head of the femur to form the hip joint.