Spondylolisthesis is a Greek term meaning slipping of the spine. It is the abnormal forward movement of one vertebra over the vertebra below. Most often, this forward slip of the vertebra occurs in the lumbar area of the spine. This slippage and herniation of the disc causes pressure on the nerve roots associated with the affected vertebrae, causing pain and dysfunction.

There are various types of spondylolisthesis.

Type 1 – Congenital spondylolisthesis:

An individual is born with the abnormality of the posterior bony arch of the spine, which causes the slippage. This is usually seen at the L5-S1 level and often associated with abnormality of the facet joints. Patients usually present with back pain during the adolescent growth spurt. CT and MRI scans are required to diagnose the dysplasia (abnormal bone formation).

Type 2 – Isthmic spondylolisthesis:

Isthmic spondylolisthesis is caused by a defect in a part of the bone called the pars interarticularis. The pars bone connects the upper joint of one vertebra to the lower joint. The defect is usually caused by a stress fracture in individuals with a hereditary predisposition (some minor abnormality or weakness of the pars at birth). In certain individuals a defect may exist without any forward slip, referred to as spondylolysis. This too can be painful.

Type 3 – Degenerative spondylolisthesis

Degenerative spondylolisthesis is a forward slippage secondary to arthritis of the spine. Spinal stenosis is usually associated with this process. This is due to a long standing degenerative disc leading to weak facet joints in the back of the spine. This is usually seen at L4-L5 level.

Non surgical treatment is always tried initially in the form of physiotherapy and life style modifications. But for a patient with a high grade spondylolisthesis or a child showing high dysplastic spondylolisthesis surgery is the first option of treatment. The surgery is done to decompress the neural element and to realign and maintain the vertebral column to near normal biomechanics.

Case - 1

14 year old girl presented with severe back pain and hamstring spasm. X-rays and MRI images show spondyloptosis. Postoperative image shows reduction to Grade I.