In this condition one vertebra slips over the next vertebra. This pathology is common between the 4th and 5th lumbar and 5th and 1st sacral vertebra. The various types of spondylolisthesis are:
- Congenital : there is malformation of the vertebrae resulting in slip. This usually occurs between the 5th lumbar and 1st sacral vertebra. The top of sacrum is rounded and the pars inter-articularis is elongated.
- Lytic : This is the most common type on spondylolisthesis. There is a defect in the pars interarticularis, which is the junction of the pedicle, lamina, transverse process and superior facet. If there is only defect without any slip the condition is called ?Spondylolysis?.
- Degenerative : This commonly occurs in elderly between 4 th and 5 th lumbar vertebra. The facet joints undergo degeneration resulting in subluxation of these joints.
- Traumatic : This occurs following injury due to fractures on both sides of neural arch
- Pathological : This type is seen due to destruction of bone due to underlying pathological process
Patients usually present with back pain with or without leg pain. Sometimes spondylolisthesis can be an incidental finding in patients in x-rays done for other reasons. Symptomatic listhesis needs to be treated with medication, physiotherapy, exercises and local steroid blocks. If there is no response to non-operative treatment surgery is indicated. Spinal fusion is performed with reduction of listhesis. The fusion is performed using pedicular screws inserted into the vertebra from behind. Additional cages may be inserted in between the vertebral discs. Artificial disc replacement is contra-indicated in this condition.