Sacral Insufficiency Fracture

What it is

This is a stress fracture of the sacrum — the triangular bone at the base of the spine — that occurs in bone weakened by osteoporosis. Unlike a fracture from a fall or accident, it often happens with little or no injury, sometimes from the ordinary load of standing and walking. It is most common in older women with thinning bones, and is also seen after pelvic radiation or long-term steroid use.

What it feels like

The usual picture is low back, buttock, hip, or groin pain that comes on without a clear injury, is worse with standing and walking, and eases with rest. Because there is no dramatic event behind it, it is easily mistaken for arthritis or a pinched nerve, and the diagnosis is sometimes delayed.

How we diagnose it

These fractures often do not show on a plain X-ray, so a normal X-ray does not rule one out. An MRI (or sometimes a CT or bone scan) shows it clearly. The key clue is new, unexplained low back or pelvic pain in someone whose bones are at risk — which is reason enough to look closely.

How we treat it

Most sacral insufficiency fractures heal without surgery. Treatment focuses on:

• Staying as active as your pain allows, with help managing it in the meantime
• Treating the underlying osteoporosis — bone-strengthening medication, vitamin D and calcium, and fall prevention
• A minimally invasive cement procedure (sacroplasty) for pain that will not settle

Surgery is rarely needed. Healing usually takes several weeks to a few months. I treat the bone health just as seriously as the fracture itself — because that is what protects you from the next one.

The science — for the curious

A sacral insufficiency fracture is frequently the first clear sign that osteoporosis has become significant. That makes it both a problem to heal and an opportunity: finding and treating the weak bone now is the single best way to prevent the next fracture, which in osteoporosis often follows the first. Strengthening the bone is not a side note to recovery — it is a central part of it.

Learn more

OrthoInfo — Osteoporosis and Spinal Fractures: orthoinfo.aaos.org

OrthoInfo — Fractures of the Thoracic and Lumbar Spine: orthoinfo.aaos.org

This handout is general education about a common condition and does not replace the personalized advice we discuss in clinic. If anything here does not match what we talked about, what we talked about wins — please ask me.