What is spinal cord tethering?
Spinal cord tethering happens when the spinal cord gets stuck to the bones or tissues around it. Normally, the spinal cord hangs loosely inside the spine and can move when you bend, stretch, or grow. When the cord is tethered, it cannot move. It gets pulled tight, which can hurt the nerves and reduce blood flow. Over time, this can damage the spinal cord.
Tethering can happen before birth or later in life. It usually affects the lower part of the spine. Many people with Spina Bifida can have tethering, but it is rare in Spina Bifida Occulta. In children, the spinal cord stretches as they grow. In adults, bending and moving can stretch it. If a tethered cord is not treated, it can cause long‑lasting problems.
What is tethered cord syndrome?
Tethered cord syndrome is when a person has several signs or symptoms caused by a tethered spinal cord. A doctor may notice some signs, and the patient may feel others.
Common signs and symptoms include:
- Back pain that gets worse with activity and better with rest
- Leg pain
- Tingling or numbness in the legs
- Weak muscles
- Trouble walking
- Muscle spasms
- Changes in leg or foot shape
- Curved spine (scoliosis)
- Bowel or bladder problems
- Changes in feeling or sensation
How does tethering happen in myelomeningocele?
Early in pregnancy, a baby’s spinal cord reaches all the way down to the tailbone. As the baby grows, the bones of the spine grow faster than the spinal cord, so the cord appears to move upward.
In babies with Spina Bifida, the spinal cord is attached to the skin and cannot move up normally. Even after surgery at birth to close the opening, the spinal cord stays low and scars into place. As the child grows, the spinal cord gets stretched, which can damage it and affect movement, bladder function, or bone growth.
How does tethering happen in milder forms of Spina Bifida?
In milder forms of Spina Bifida, tethering often shows up later, sometimes in adulthood. It may get worse with physical activity, injury, or pregnancy. It can also be caused by narrowing of the spine or extra bone growth.
Symptoms may appear slowly over time. These can include:
- Back pain that gets worse with activity
- Leg pain
- Weakness or trouble walking
- Muscle tightness
- Leg or foot deformities
- Scoliosis
- Bowel or bladder changes
How is a tethered cord diagnosed?
If a child with Spina Bifida and a shunt shows new problems, doctors first check the shunt, because shunt problems can look like tethering. This is usually done with a CT or MRI scan of the brain.
After the shunt is checked, or if the child does not have a shunt, doctors do an MRI of the spine. Almost all children with Spina Bifida show some tethering on MRI, so surgery is only done if symptoms are getting worse.
Doctors may also use:
- Spine X‑rays or CT scans
- Muscle strength tests
- Walking (gait) studies
- Bladder tests (urodynamics)
These help show changes over time and guide treatment.
When is surgery done?
A neurosurgeon decides on surgery after reviewing symptoms and test results. Even though MRI often shows tethering, surgery is only done when the child is getting worse, such as more pain, weaker muscles, trouble walking, or bladder/bowel changes.
When standard untethering of the spinal cord cannot be done—because of heavy scar tissue, past surgeries, or a high risk of harming important nerve structures—vertebrectomy with spinal fusion can serve as an alternative surgical option. This procedure helps relieve pressure and reduce tension on the spinal cord. During the surgery, doctors remove selected vertebral segments and then stabilize the spine. This shortens the spinal column, which indirectly reduces the pulling force on the tethered cord. Studies show that this approach can slow worsening neurological problems, lessen pain, and help prevent further decline in certain patients, especially when traditional untethering is too risky.
What happens after surgery?
Most patients stay in the hospital for 2–5 days. Many return to normal activities in a few weeks. Some surgeons ask patients to lie flat for a couple of days to prevent spinal fluid leaks.
Pain is usually not very strong because the area may already be numb. Muscle or bladder improvement depends on how long the problem existed before surgery. Untethering mainly stops things from getting worse, it cannot fix all past damage.
Are there treatments other than surgery?
Medicines, rest, or physical therapy may help with pain for a short time, but surgery is the only treatment that can fix the tethering itself.
What are the risks of surgery?
Untethering is usually safe, but risks include:
- Infection
- Bleeding
- Damage to the spinal cord, which could worsen muscle or bladder/bowel function
These problems happen in only about one to two percent of cases.
Can tethering happen again?
Most children need only one surgery, but about 10–20% may need another as they grow. This is most common between ages 7–12. Adults can also have retethering from scar tissue or injury, but it is less common.
Can tethering be prevented?
Many methods have been tried, but only surgery has been shown to work long‑term. With careful checkups, doctors can find tethering early and treat it before serious damage happens.
Reviewed in April 2021 by Pamela Wilson, MD
This information does not constitute medical advice for any individual. As specific cases may vary from the general information presented here, SBA advises readers to consult a qualified medical or other professional on an individual basis.
