By Dr. Rick Morris
You’ve come back from your doctor and he said you’ve got a cyst in your back--a Synovial Cyst. He said the best treatments (rest, ice, anti-inflammatories and stretching) were all the things you’d done. Now he’s recommending spinal injections, which were riskier and at best only a temporary fix, and eventually surgery.
You went right home and started some serious synovial cyst research. None of the options suggested by your doctor seemed optimal, and the pain was so bad you could barely stand, walk, work—everything! You only felt o.k. when you were off your feet. This wasn’t a life!
Let’s Start With The Basics…What Is A Synovial Cyst?
A synovial cyst is a fluid filled sac (like a blister) that forms from the excessive rubbing together of two vertebrae against one another. The point where they "rub" is called a facet.
This is an MRI of the lower back showing a synovial cyst bulging into the spinal canal. The friction of the facets create a cyst, similar to the blister that forms when your foot rubs against a badly fitting shoe.
Although they can occur anywhere in the spine, they’re most commonly seen between L4 and L5.
This is an MRI showing a cross section of the lumbar spine with a synovial cyst coming from the facets and bulging into the spinal canal. Since this canal holds the spinal cord and spinal nerves, it's apparent why it can cause severe low back and leg pain.
Why Did MY Back Form This Cyst?
Excessive or abnormal movement in the facets can cause a synovial cyst. These are the most common causes:
- Scoliosis: An abnormal side-to-side curvature of the spine.
- Spondylolisthesis: The forward slippage of one vertebra over another.
- Leg length Inequality: Uneven leg lengths create an unlevel pelvis and often a scoliosis. Prior back surgery: 4. Discectomies, laminectomies and fusions cause excessive movement at or above the surgical site.
- Hyperelastic or unstable joints: About 5% of us are born with hyperelastic ligaments and have excessive joint movement. Prior injuries or damage to your discs or ligaments can create unstable joints as well.
- Abnormally shaped facets (called Tropism) can cause abnormal movement of the vertebrae.
How Do I Know If I Have A Synovial Cyst?
A synovial cyst can only be diagnosed by MRI as shown in the pictures above. As you have seen, it often takes up space in the spinal canal or intervertebral foramen (a hole between the vertebrae where the spinal nerves leave the spine) and squeezes the spinal cord or spinal nerves.
Standing is often more painful than sitting while bringing ones knees to their chest may be relieving (as it opens the narrowed canal). As we've said, it usually causes low back and leg pain, but rarely starts before the age of 45.
You may notice these symptoms are similar to those seen in Spinal Stenosis; This isn't just a coincidence since the synovial cyst actually causes spinal stenosis by narrowing the spinal canal or intervertebral foramen. In fact, it’s not unusual for a patient to come in knowing they have Spinal Stenosis without ever it's caused by a synovial cyst.
All Right, I Have A Synovial Cyst: What Do I Do About It?
There are a few treatment options, let’s go through them:
- Epidural Injections: A cortisone injection given to the facets to bring down the swelling. They can even possibly “pop” the cyst while they are there with the needle. Of course, this injection carries a small risk of serious nerve damage, spinal infection, bowel or bladder dysfunction and even death. The precise risk is not known, but is considered small. The skill of the doctor performing the injection is paramount, so if you’re considering having one performed, get a referral from our office—we know the best. Unfortunately, its benefit is usually temporary as the cyst often reforms since the cause of the facet irritation (scoliosis, joint laxity, etc…) is never properly addressed.
- Surgery: Cysts can be removed surgically. Unfortunately, scar tissue can develop making the problem worse and the faulty spinal mechanics that led to the facet irritation in the first place are not addressed. Often more invasive surgical procedures are needed such as a facetotomy, laminectomy and fusion to access the cyst or to “stabilize” the spinal segments. Unfortunately, these surgeries carry greater risks and should only be performed if all other methods have failed.
- Physical Medicine: Heel lifts, corrective exercises, postural modifications, spinal alignment and non-surgical spinal decompression (to decompress the facets and strengthen the discs) is a very effective long term treatment, but requires doctors that are quite skilled and comprehensive in their approaches. In fact, our office successfully treats this problem frequently and our patients have long-term benefit without ever requiring surgery. But, they must continue the exercises given to them, even after the pain is gone, to maintain facet stability.
Synovial Cysts are a cause of spinal and foraminal stenosis(narrowing of the spinal canals) that cause low back and leg pain. It’s diagnosed only by MRI and treated by a precise physical medicine approach designed for this problem. Surgery should only be used as a last resort as they have potentially serious adverse effects.
Our office specializes and successfully treats this condition daily while rarely requiring surgery. If you’ve been told you have a synovial cyst, please see us before undergoing injections or surgery.