Pubis
Os pubis
Also known as: pubic bone, pubic tubercle, pubic ramus
The anteroinferior part of the hip bone, consisting of a body and superior and inferior rami. The two pubic bones meet at the pubic symphysis.
Overview
The flattened body lies anteromedially; its medial symphyseal surface joins the opposite pubis via the interpubic disc. Its upper border is the pubic crest, ending laterally at the pubic tubercle — the medial attachment of the inguinal ligament and a key landmark for hernias (inguinal hernias emerge above and medial to it; femoral hernias below and lateral). The superior pubic ramus passes laterally to the acetabulum; on its upper surface runs the sharp pecten pubis (pectineal line), continuous with the arcuate line as part of the pelvic brim and the attachment of the pectineal (Cooper) ligament. The inferior pubic ramus passes down and back to fuse with the ischial ramus.
Muscles attached include rectus abdominis and pyramidalis (crest), pectineus (pecten), adductor longus, adductor brevis and gracilis (body and inferior ramus) and obturator externus (outer surface of the obturator membrane margin).
- Location
Anterior pelvis, either side of the midline above the genitalia.
Parts & subdivisions
- Articulates with the opposite pubis.
- Rectus abdominis; inguinal ligament attaches to the tubercle.
- Part of the pelvic brim; pectineus and pectineal ligament.
- Joins the ischial ramus; adductors and gracilis.
Anatomy
- Articulations
Opposite pubis (pubic symphysis); fused with ilium and ischium.
- Ossification
Primary centre ≈4–5 months fetal; secondary centres including the symphyseal surface, whose changing morphology is used to estimate age at death in forensic anthropology.
Function
- Forms the anterior pelvic ring and the anteroinferior acetabulum
- Acts as a tie-beam resisting spreading of the pelvis
- Attachment for adductor and abdominal muscles
- Protects the bladder
Clinical significance
Pubic ramus fractures
Common osteoporotic fractures in the elderly after a simple fall; groin pain with ability to bear weight, often confused with hip fracture.
Osteitis pubis
Painful inflammation of the symphysis and adjacent bone in athletes (kicking sports) or after pelvic surgery.
Compiled from standard anatomy and physiology references — see the Skeletal System sources. For education only; not medical advice.