Pubic Bone: Structure, Function & Diseases

The pubic bone is one of the bones of the body and, together with the ilium and ilium, forms the pelvis. Together with the other pelvic bones, it also forms the acetabulum. In women, it lies lower than in men.

What is the pubic bone?

The pubic bone (called Os pubis in Latin) refers to a bone of the pelvis. In addition to the pubic bone, it is also composed of the ilium and the ilium. The Os pubis is located on both sides of the pelvis and comes together at the front at the pubic symphysis. It is also a part of the hip joint – which it forms with the two pelvic bones – and it is the origin of some muscles that are part of the pelvic floor structure. The pubic bone is lower in women than in men.

Anatomy and structure

The pubic bone forms the anterior part of the acetabulum (called the hip joint), which together with the head of the thigh (caput femoris) forms the hip joint. The anterior edge of the pubic bone is also titled the pecten ossis pubis (pubic ridge). On the other hand, the so-called midline, which denotes the junction of the two pubic bones, is often called the symphysis. The os pubis is found on both sides of the pelvis and comes together at the front via a fibrocartilaginous junction (pubic symphysis). Because this joint is made of fibrocartilage, the two pubic bones are minimally displaceable with respect to each other. Two pubic rami are attached to the pubic bones. These are medically referred to as the ramus superior (the upper branch) and ramus inferior (the lower branch) of the os pubis. These two branches provide the connections to the adjoining bones and are thus a part of the hip joint. Towards the front and upwards, on the other hand, the upper branch is connected to the ilium (called os ilium), while the lower branch (medically called ramus inferior ossis pubis) is connected to the ischium (Latin: os ischii). Unlike the fibrocartilaginous connections of the two pubic bones, these junctions are bony and immobile. At the transition to the midline, the pubic crest is characterized by a small hump called the tuberculum pubicum. This serves as the attachment point of the inguinal ligament. The pubic ridge ends laterally in another hump (eminentia iliopubica). This hump forms the boundary with the ilium. However, the pubic bone also borders the anterior arch of the foramen obturatorum (a large opening in the pelvis). This hole is closed by two skeletal muscles from the group of deeper hip muscles (Musculus obturator externus and Musculus obturator internus). Only a minimal canal known as the canalis obturatorius remains open. A nerve of the lumbar plexus (the obturator nerve) and a vital vein and artery of the thigh and pelvic region pass through this canal – medically, these are named the obturator vein and artery. However, the pubococcygeus muscle, the transversus perinei profundus muscle (a muscle of the pelvic floor), and the puborectalis muscle, which, like the pubococcygeus muscle, is also an important part of the pelvic floor musculature, also originate at the pubic bone.

Function and tasks

Since it is an important part of the entire pelvis and also the hip joint, the pubic bone takes on a major role in the support function of the body. The pelvis is known to be important for the ability to walk upright, but breathing and proper posture are also seriously influenced by the pelvis. For this reason, the pubic bone also affects these things. But there is another reason that the formation and health of the pubic bone can have both negative and positive effects on the body’s support function and musculoskeletal system. This is because the pubic bone is built over the ilium and ischium. Thus, it is attached to the spine as part of the pelvic ring.

Diseases and ailments

There are not many known diseases that are directly related to the pubic bone. However, that doesn’t mean that the pubic bone can’t still be affected by a variety of bone, tendon and muscle diseases. On the other hand, the pubic bone is often plagued by overuse, as it is often under a great deal of strain due to its large role in supporting the body. When the pelvis is overloaded, inflammation can form in the pubic bone as a result. This usually manifests itself as severe pain that begins in the pubic area and quickly spreads to the groin and lower abdominal muscles.Such inflammation occurs quite frequently in athletes such as footballers, which is why this condition is also colloquially titled soccer disease. Inflammation of the os pubis is also not infrequently diagnosed during pregnancy due to the high stress on the pelvis. The reason for this is the baby, which exerts increasing pressure on the pelvic area due to its constantly growing size. This stretches the bone, which in turn can lead to inflammation, but also slight cracks in the surrounding pelvic bones – the pubic bone is very often affected by this. Most of the time, however, this type of injury or inflammation heals within a few weeks with the right amount of rest and proper medical treatment. During this time, however, those affected should not lift too heavy and avoid spreading their legs too wide.