Pubic symphysis diastasis is a disruption of the pubic bones in front of the body. It is a known complication of pregnancy and vaginal childbirth. The entire pelvis is formed by the sacrum (wedge-shaped bone at the base of the spine), the coccyx (tailbone at the bottom of the sacrum), and the hip bones. The upper (socket) portion of the hip is made up of the ilium (pelvic crest), ischium (bones you sit on), and pubis (birth canal ring).
Separation of the symphysis pubis is referred to as symphyseal diastasis. The pubis symphysis is in front of the body where the two pelvic bones come together. A disruption of the connective tissue between the two pelvic bones at the symphysis pubic can cause pelvic instability. Disruption can be defined as translation (movement of the pubis on one side up or down), widening (separation), or impaction (narrowing or overlapping of the space between the two bones).
Experts propose that normal motion in this area is up to 0.5 mm in men and up to 1.5 mm in women who aren’t pregnant. Pregnant women (or women who have had multiple births) may have up to a 3.0 mm shift. Anything beyond these guidelines may be a sign of change in alignment and considered a positive response for pelvic instability.
If X-ray tests confirm the presence of symphyseal diastasis, there are several ways to approach its treatment. Patients with mild diaphysis who don’t have any symptoms may not need treatment. In cases, of mild-to-moderate separation, careful monitoring may be all that’s required. The condition may improve over time with rest. The physician may recommend that the patient remain non weight-bearing for up to four weeks.
Sometimes a pelvic binder is recommended. Special cloth or canvas binders have been designed for use during pregnancy to help prevent the diaphysis from occurring. A pelvic binder can also be used after pregnancy to help restore a more normal anatomical position.
But for the person with pain and/or instability, conservative care may not be enough. Surgery may be needed when painful instability does not respond to nonoperative measures. Internal fixation using wires, screws, or a plate and screws may be possible. For more complicated or involved injuries, an external pelvic fixator frame with fixation pins may be used.
Reduction of the symphyseal widening with the internal or external fixation is usually done with fluoroscopic guidance. A fluoroscope is a special type of real-time X-ray that allows the surgeon to see while inserting the necessary hardware.
Anytime a woman presents with pelvic pain after childbirth, a medical evaluation is advised. Damage to any part of the pelvic ring usually means there’s disruption to another portion of the ring. It’s easy to underestimate the extent of pelvic injury after birth and delivery. Early treatment may be needed to help prevent further damage.