It was last looked at last year and x-rayed, but not problematic enough for an operation. Everyone in the profession who I trust advises building up the muscles around the spine through exercise. I'm not qualified in anyway but if the problem is lower back then lay on your back on the floor with your knees bent and your feet flat on the floor about a foot and a half apart. Whatever is comfy really. Because we don't usually use the muscles around the base of our spines you will have to find them first. You can do this by pushing your lower back into the floor. If you are using your stomach muscles to do this you're doing it wrong. The muscles you are trying to get going are further round the back.

The following extract is from espine.com

"Spondylolisthesis is defined as the movement of adjacent vertebra relative to each other.

Although spondylolisthesis can be caused by many pathologic entities, degenerative spondylolisthesis is by far the most common. With aging, discs lose water content and ultimately height. As the vertebra on either side of the disc come closer to each other through the loss of disc height, the upper vertebra slides forward on the subadjacent vertebra producing spondylolisthesis. High stresses and motion produce degeneration of the disc and for this reason the most susceptible levels of the lumbar spine, L4-L5, followed by L3-L4 and L5-S1 are the vertebral segments most commonly involved.

Spondylolisthesis is also associated with deterioration of the facet joints connecting the two vertebra. As the facet joints become arthritic due to this deterioration, they enlarge in an attempt to confer stability. As the two rings of the vertebral segments which make up the spinal canal, slide past each other, the canal narrows in size . The combination of canal narrowing and enlargement of the facet joints, produces the characteristic nerve compression problems found in degenerative spondylolisthesis. The nerves are compressed in two major areas at the site of a degenerative sponlylothisis. It is believed that a reduction in nerve blood flow accounts for the symptoms produced from spinal canal narrowing (Spinal stenosis).

Extracted from A Patients Guide to Low Back Pain

Symptoms

Spondylolysis and Spondylolisthesis are important because they can be a cause of low back pain.  Just because you have one of these conditions, does not mean that you will necessarily ever have problems with your back, but you are at a higher risk of developing chronic low back pain than the normal population.  These conditions can cause typical mechanical back pain symptoms, or they can cause compressive (or neurogenic) type symptoms - or both. The mechanical symptoms occur primarily because the spinal segment affected by the spondylolysis is unstable resulting in segmental instability.  The compressive symptoms can arise because the nerves at the segment involved are pinched.  There is usually a lump of tissue in the area of the spondylolysis - probably where the fracture tried to heal itself.   This lump of tissue may press on the nerve roots as they leave the spine.  The forward slip of the vertebra also makes the spinal canal smaller, leaving less room for the nerve roots.

There is usually pain across the small of the back and into the buttocks.  If there are compressive symptoms, there may be pain down the leg to the foot, numbness in the foot and possibly weakness in trying to raise the foot.

Diagnosis

The diagnosis of Spondylolysis and Spondylolisthesis is dependent on seeing the abnormality on either X-rays, CAT scan or MRI scan.  In most cases it is easily seen on regular X-rays of the low back.  The symptoms are really no different from other causes of low back pain.  On the other hand, just because you have a Spondylolysis or Spondylolisthesis on your X-ray doesn't mean your symptoms are from the defect.  You may still have a herniated disk or some other condition that is causing your pain, so your doctor will carefully look for other causes of your pain.

Treatment

Treatment for Spondylolysis and Spondylolisthesis is not really much different than for other causes of mechanical and/or compressive back pain.  In most cases, surgery will not be necessary.  The mechanical symptoms that are a result of the segmental instability can be reduced by strengthening the back muscles.  A physical therapist will probably be recommended to help you with a series of exercises designed to help stabilize the spine by strengthening the back and abdominal muscles.  Medications may be used for short periods of time to control pain, ease muscle spasm, and help regain a normal sleep pattern if you are having trouble sleeping.  Short periods of bed rest may help with acute painful episodes.  A back brace, or corset, may reduce pain.

Surgery is necessary only if all of the above treatments fail to keep your pain at a tolerable level.  Surgical treatment for Spondylolysis and Spondylolisthesis must address both the mechanical symptoms and the compressive symptoms if they are present.   This usually means that the nerves that exit the spine must be freed of all pressure and irritation. This is usually done by performing a complete laminectomy. Laminectomy means remove the lamina.  Removing the lamina allows more room for the nerves, and enables the surgeon to remove lump of tissue surrounding the spondylolysis defect that is irritating the nerves.  This allows more room for the nerves of the spine and reduces the irritation and inflammation on the nerves.

Once the nerves are freed, a spinal fusion is usually performed to control the segmental instability.