Spondylolisthesis describes where one of the verterbrae moves, or 'slips' forward relative to a neighbouring vertebra. The term is derived from the ancient Greek for 'spine' (spondylo) and 'sliding' (listhesis). It is more common in the lower section (lumbar region) of the spine. Episodes of spondylolisthesis are graded according to severity, with Grade 1 being the mildest form (defined as where less than a quarter of the vertebra has slipped out of place), up to the most severe displacement categorised as Grade 5 (defined as where the entire vertebra has slipped completely out of place). Grade 5 is also known as 'spondyloptosis'. The condition is not uncommon – 2-6 people in every 100 have some degree of spondylolisthesis, with a slightly greater number of men/boys affected than women / girls.
The condition is caused primarily by injury during physical activity, particularly very physical sports including for example soccer / football, weightlifting and gymnastics, where stress fractures in vertebrae are not uncommon. This connection with physical sports may account for the condition affecting males more than females. Although it is connected with these types of sports, spondylolisthesis can also be caused by other injuries or trauma, or simply by 'wear and tear' and / or arthritis developing over a period of time. It is more common in teenagers and adults, although some children are diagnosed with the condition from the age of 7 on. There can also be a hereditary element of the condition, where a joint in the spine has a congenital defect.
Although the condition may not produce any symptoms at all, the following may indicate spondylolisthesis… Back pain that may vary with changes in posture due to excessive movement of one vertebra slipping on another vertebra. Pain in one or both legs, or pain in the buttocks from nerve root compression.
- Weakness / numbness in one or both legs.
- Problems walking.
- Bladder / bowel incontinence (very uncommon).
Tests / Diagnosis
Primary diagnosis is via x-ray which will show if any of the vertebrae are misaligned, or whether there are stress fractures in one or more vertebrae. X rays in different postures while bending forward and bending backwards (Flexion and Extension X rays) may be performed to see the amount of movement across the misaligned spinal level. A CT (computed tomography) scan or MRI (magnetic resonance imaging) scan may also be required to further assess any damage to the area, and for surgical planning.