Pelvic landmarks
1-Sacral promontory –
Sacral promontory is the anterior projecting margin of the first sacral vertebra (S1). It forms the posterior boundary of the pelvic brim and is an important landmark used in measuring pelvic diameters, especially the conjugate diameters in obstetrics.
2-Alae or wing of the Sacrum –
The ala or wings of sacrum is located on either side of the first sacral vertebra, lateral to the sacral promontory, forming the upper lateral part of the sacrum .
3-Sacroiliac joints
Sacroiliac joint is the joint between the sacrum and ilium . There are two sacroiliac joint present in each side of the pelvis
4-Iliopectineal lines
Iliopectineal line is a ridge on the inner surface of the hip bone formed by the arcuate line of the ilium and the pectineal line of the pubis. It forms the lateral boundary of the pelvic brim .
5-Iliopectineal eminence
The iliopectineal eminence is a bony prominence at the junction of the ilium and pubis, formed by the meeting of the arcuate line and pectineal line.
6-Superior Ramus of the pubic bone
The superior ramus of the pubic bone is the upper branch of the pubis extending from the body of the pubis to the ilium. It forms part of the pelvic brim and contributes to the structure of the pelvis.
7-Upper inner border of the pubic bone .
It is a sharp ridge on the superior ramus of the pubic bone, on its inner side.
8-Upper inner border of the symphysis pubis
upper margin of the pubic symphysis on its inner (pelvic) side