Spondylolisthesis occurs when a bone from the lower area of the spine, a vertebra, tends to slip out of position which could be confused with a slipped disc, when one of the spinal disc gets ruptured between the vertebrae.
The word spondylolisthesis comes from two parts, spondylo meaning spine and listhesis which mean slippage. Spondylolisthesis is considered a forward or a backward slip of one vertebra, on an adjacent vertebra, one out of the 33 bones of the spinal column.
It usually tends to occur at the base of the spine in the lumbar area which tends to get worse with activity or when standing and one finds relieve on lying down. Causes of spondylolisthesis may include trauma, birth defects, degenerative, tumour and most of the people can be treated conservatively without the need of any surgery.
Those who do not improve with conservative treatment may be required to undergo surgery. Symptoms of this ailment include lower back or leg pain, hamstring tightness, numbness and tingling in the legs. The severity of these symptoms varies from person to person.
Can Be Identified on Plain Radiograph
Spondylolisthesis could also lead to deformity of the spine and narrowing of the spinal canal or compression of the exiting nerve root – foraminal stenosis. Spondylolisthesis in children could occur as a result of birth defect like having thin bones in the spine area or due to some sudden injury.
In the case of adults, it could be due to age related wear of the spine or a degenerative disease such as arthritis. Other possibilities could be bone disease like Paget’s disease of the bone, a fracture due to sustained pressure on the spine as in the case of gymnasts and weight lifters and fracture caused due to sudden injury.
In most of the cases there are no visible signs of spondylolisthesis and people may complain of pain in the back with intermittent pain in the legs. It may also cause muscle spasms or tightness in the hamstrings. Spondylolisthesis can be identified on using plain radiographs where a lateral x-ray from the side portrays if a vertebra has slipped forward on comparing with the adjacent vertebrae and is graded according to the percentage of slip of the vertebra compared with the neighbouring vertebra.
If the person complains of pain, tingling, weakness or numbness in the legs, additional studies may need to be carried out. A CT or MRI scan could help to detect compression of the nerves associated with spondylolisthesis. At times a PET scan could also help in determining if the vertebra at the site of defect is active.
The initial treatment is conservative for spondylolithesis depending on the symptoms. The person should rest and avoid activities which would involve lifting and bending that could reduce the symptoms. Physical therapy could also help to increase the range of motion of the lumbar spine as well as hamstrings to strengthen the core abdominal muscles.
Person experiencing pain numbness with tingling in the legs could benefit from epidural steroid injection and those with isthmic spondylolisthesis could benefit from hyperextension brace which extends the lumbar spine bringing the two parts of the bone at the defect, closer enabling healing. Anti-inflammatory medication could also help in reducing pain by decreasing the inflammation of the nerves and muscles.