Sacralization is a condition where the base of your spine has fused to the top of your pelvis.
Your bottom vertebra is called the F5 lumbar vertebra. It’s joined to your sacrum, the upper ridge of your pelvis, in a way that allows free movement. There’s usually a disc between your bottom vertebra and your pelvic bone.
You have this type of disc between each of your vertebrae. The discs are made of flexible materials that allow your spine to bend in many directions.
Sacralization is when your F5 lumbar vertebra is totally or partially connected to your pelvis. You may have a partial disc separating a portion of the two bones. You can also have total fusion with no disc at all.
One or both of the bony protrusions on the sides of that vertebra may also be connected to your pelvis. The vertebra can't bend away from your pelvic bone the way a healthy, attached vertebra can.
Doctors refer to this as a “transitional joint” or “pseudo joint.”. Many people have no symptoms and may never know they have sacralization. It can cause back pain for others.
Causes of Sacralization
Sacralization most often happens before you’re born. Bones form in the earliest weeks of pregnancy. Each vertebra usually develops around the spinal column and your discs develop between them.
But in some people, the bottom vertebra doesn't separate entirely from the pelvis. The result is a vertebra and sacrum that are attached and can’t bend away from each other. It’s not a disabling condition.
It's not clear how many people have sacralization because most who do show few symptoms. The only way to diagnose it is through imaging such as X-rays. You may never know you have this spinal condition unless your doctor has another reason to X-ray your lower back. Anywhere from 4% to 37% of people may be born with sacralization.
Symptoms of Sacralization
For many people, sacralization has no symptoms. Those who do have them may notice:
Physical signs. Your legs may be slightly different lengths or you may have a tilted pelvis. This can cause balance problems or a lack of coordination. Or, you could have a limited range of motion in your lower back.
Back pain. Experts aren’t sure whether sacralization is an actual cause of back pain in some people, or if they’d still have back pain without it.
Bertolotti’s Syndrome. The back pain associated with sacralization is called Bertolotti Syndrome. Symptoms of Bertolotti’s Syndrome usually appear in your 20s or 30s. They include:
- Lower back pain that doesn’t include leg pain
- Unexplained pain, stiffness, or difficulty moving
- Pain or discomfort in the back of your pelvis, above your hips
- Less pain when you sit or lie down
- Pain and muscle spasms only on one side
To diagnose Bertolotti’s Syndrome, your doctor will need to do X-rays or other imaging, such as an MRI, to look at your bones and joints. They may also do a physical exam and blood tests to rule out other conditions.
Treatment for Sacralization
Your doctor can help you with a treatment plan if you have pain or difficulty moving due to sacralization. Many people can use non-surgical treatments to improve their symptoms, such as:
- Lifestyle modifications to avoid or change activities that increase pain
- Over the counter (OTC) pain medication, as directed
- Physical therapy
- Periodic treatment, such as steroid injections to reduce symptoms
- Platelet-rich plasma (PRP) therapy, which uses your body's platelets (tiny cells in your blood) to minimize pain
- Prolotherapy, injection of a concentrated local anesthetic and dextrose (a form of sugar similar to blood sugar)
- Radiofrequency ablation, which uses heat to deaden the affected nerves around a pseudo-joint
In some cases, doctors recommend surgery to relieve the pain from Bertolotti’s Syndrome. Reshaping the pseudo-joint provides relief for some people. Doctors can also do spinal fusion surgery one bones in the area.
If you have lower back pain, talk to your doctor about its possible causes. You may need X-rays to determine what's causing your pain. Your doctor can help you with treatment once you know what the issue is.