The symphysis pubis is a fibrocartilaginous joint that connects the left and right superior pubic rami. The symphysis pubis widens during pregnancy as a normal response to child birth. The widening is generally 2 to 3 mm and rarely exceeds more than 1 cm. Progesterone and relaxin are natural hormones that help the strong supporting ligaments stretch as a normal physiologic response to childbirth. Any widening usually regresses after delivery and rarely becomes symptomatic. Symphysis diastasis of greater than 1 cm represents complete disruption of the joint, which is usually symptomatic. Complete disruption may be heard as a popping sound during delivery. A complete disruption causes pain over the symphysis pubis that is made worse with walking.
AP pelvis X-ray is the best study to diagnose symphysis pubis diastasis. A careful physical examination is also necessary to rule out sacroiliac joint (SI) involvement. The SI joint is usually not involved unless the diastasis exceeds 4 cm. Treatment is almost always non-operative. Patients may be weight bearing as tolerated and use a walker for support if needed. Pelvic binders and sleeping in a lateral position can also help with symptoms. Pain usually subsides in 8 weeks but can last as long as 8 months. The diastasis usually reduces over time and becomes asymptomatic. Surgery may be indicated in patients with persistent symptoms and a large diastasis.
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor-in-chief of the Journal of Orthopedics for Physician Assistants (JOPA).
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