The Common Vein
Copyright 2010
Definition
The pubis of the musculoskeletal system is characterized by its two rami that held maintain the structure anteriorly of the pelvis and allow for weight transfer to the limbs during standing and to the ischium when sitting.
It is part of the pelvis, making up the anterior part of the acetabulum, and articulates with its counterpart of the other side to make the pubic symphysis. It consists of bone tissue once mature.
Its unique structural features include a flattened body, pubic crest, pubic tubercle, pectin pubis and two rami (superior and inferior).
The body of the pubis articulates with the contralateral pubis at the pubic symphysis.
The pubic crest is the site of abdominal muscle attachment at the anterior-superior border of the pubic symphysis.
The pubic tubercle is a projection that is a palpable landmark for the inguinal region serving as an attachment for the inguinal ligament.
The pectin pubis is the obliquely running ridge on the lateral part of the superior pelvic ramus.
The two rami are the superior and inferior pubic rami. These rami help to maintain the posture of the pelvis.
Along with the ramus of the ischium, the inferior ramus forms a bar of bone known as the ischiopubic ramus.
The pubis undergoes primary ossification starting and appearing at age 6 months and undergoing fusion at age 15. The pubis fuses with the ilium and ischium at the triradiate cartilage at the acetabular dome to form the innominate bone at maturity around age 15 to form the bony acetabulum. The two innominate bones and the sacrum make up the pelvis. The pubis bone as well as all other bones, muscles, and ligaments of the body are derived of mesodermal origin in embryo.
The function of the pubis is to support and protect the internal organs, allow for muscle attachments, help form the pubic symphysis joint, and make up part of the acetabulum or the hip socket. The ilium, ischium, and pubis provide vital protection to veins, arteries, and nerves in the pelvis. Fractures to the pelvis can injury the vascular, neurologic, gastrointestinal, and genitourinary system.
Common diseases include fractures and pubic symphysis separation.
During pregnancy, the pubic symphysis can separate due to relaxation of the pelvic ligaments from the hormone relaxin. The hormone relaxin assists in the passing of the fetus through the pelvic canal, however can also cause discomfort.
Commonly used diagnostic procedures include clinical history, physical exam, x-ray, MRI, bone scan, and CT scan.
It is usually treated with internal or external surgical fixation or non-operative approaches for fractures.
References
Elstrom J, Virkus W, Pankovich (eds), Handbook of Fractures (3rd edition), McGraw Hill, New York, NY, 2006.
Koval K, Zuckerman J (eds), Handbook of Fractures (3rd edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.
Lieberman J (ed), AAOS Comprehensive Orthopaedic Review, American Academy of Orthopaedic Surgeons, 2008.
Moore K, Dalley A (eds), Clinically Oriented Anatomy (5th edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.