Spondylolisthesis is the term used to describe when one vertebra slips forward on the one below it. Spondylolisthesis usually occurs towards the base of your spine in the lumbar area. The commonly involved vertebral segment is L5, slipping forward on the first sacral segment (S1). Spondylolisthesis is caused by a defect in a part of the bone called the pars interarticularis. The pars interarticularis is part of the ring of bone at the back of the spine. This ring of bone protects the spinal cord and the nerves which run off it.

When a spondylolisthesis occurs it may cause compression on the spinal nerves which run in the area of the defect. This compression may cause leg pain, tingling and numbness in the legs, or even leg weakness. Severe cases may even cause changes in bladder function. Approximately 5-6% of males and 2-3% of females have a spondylolisthesis. It becomes apparent more often in people who are involved with very physical activities such as weightlifting, gymnastics, or football. Males are more likely than females to develop symptoms from the disorder, primarily due to their engaging in more physical activities. Spondylolisthesis is categorised from Grade 1 to 5, with 5 being the greatest slip.

Types of Spondylolisthesis

Dysplastic (Developmental) Spondylolisthesis

Developmental spondylolisthesis is caused by an anomaly (dysplasia) of the bones of the spine. A child is born with an abnormality of the posterior bones of the spine. Because of the abnormal orientation of the bones, the normal ability of the spine to resist slippage is lost and the vertebral body of L5 slips forward on S1. Usually occurs most commonly in girls, with some familial predisposition, and can be associated with other congenital dysplasia e.g. spina bifida occulta.

Isthmic Spondylolisthesis

Isthmic spondylolisthesis is the most common type seen in children and young adults. Isthmic spondylolisthesis is caused by a defect in a part of the bone called the pars interarticularis. The pars interarticularic is part of the ring of bone at the back of the spine. This ring of bone protects the spinal cord and the nerves which run off it. It occurs when the pars interarticularis which connect the facet joints in the posterior spine are fractured causing a forward slip of the vertebra. The pars serves as a check-rein for movement of the vertebra and when fractured, the vertebra are able to move past each other producing symptoms ranging from mild low back ache to severe neurological deficits (due to compression on spinal nerves).

What is the treatment for Spondylolisthesis?

(1)  Observation

Observation is adequate for the child who has a minimal spondylolisthesis and no symptoms. Regular outpatient clinic appointments with x-rays will enable your doctor to monitor your child’s condition. Symptoms often abate once precipitating activities cease. Treatment may involve restriction of activities causing stress to the lumbar spine (e.g. heavy lifting, gymnastics, and football), physiotherapy, anti-inflammatory and pain reducing medications. Children, or their parents, must discuss their daily activities and hobbies with their orthopaedic surgeon to see if they are all right to continue.

Have your child reassessed immediately by your doctor if he/she develops:

• Changes in bladder control
• Experiences weakness, numbness of the legs or has trouble walking
• Develops pain that radiates down one or both legs.

(2)  Surgery

If your child has neurologic involvement and pain that can not be relieved by conservative measures, your orthopaedic surgeon may recommend surgery. Surgical treatment is designed to stop either the progression of the slip or the abnormal motion which creates pain.

Facts about Spondylolisthesis

• Spondylolisthesis is a Greek term for "slipped vertebral body".
• Spondylolisthesis usually occurs towards the base of your spine in the lumbar area.
• Approximately 5-6% of males and 2-3% of females have a spondylolisthesis.
• In many people, spondylolysis and spondylolisthesis are present, but without any obvious symptoms.
• Isthmic spondylolisthesis is the most common cause of back pain in adolescents; however, most adolescents with spondylolisthesis do not actually experience any symptoms or pain.