Hip bone portion. The inferior pubic ramus is thin and flat. It passes laterally and downward from the medial end of the superior ramus. It becomes narrower as it descends and joins with the inferior ramus of the ischium below the obturator foramen. The hip bone is ossified from eight centers: three primary, one each for the ilium, ischium, and pubis, and five secondary, one each for the iliac crest, the anterior inferior spine (said to occur more frequently in the male than in the female), the tuberosity of the ischium, the pubic symphysis (more frequent in the female than in the
Hip bone sacroiliac joint. Each hip bone is connected to the corresponding femur (thigh bone) (forming the primary connection between the bones of the lower limb and the axial skeleton) through the large ball and socket joint of the hip. The hip bone is formed by three parts: ilium, ischium, and pubis. At birth, these three components are separated by hyaline cartilage. They join each other in a Y-shaped portion of cartilage in the acetabulum. By the end of puberty the three regions will have fused together, and by the age of 25 they will have ossified. The two hip bones join