The bones of the spine – the 'vertebrae' – are 'stacked' one on top of the other. When a vertebra slips forward relative to the vertebrae above and below, this is referred to as spondylolisthesis.
It tends to occur more frequently in the lumbar section of the spine (the lower back region) than elsewhere.
The degree of sponsdylolisthesis is measured using a scale of 1 to 5, where 1 is a minor slippage (defined as less than 25% of the vertebra) and 5 is a major slippage (where the entire vertebra has slipped).
Spondylolisthesis is perhaps more common that you might think – up to 6% of the population has the condition to some degree. Males are slightly more prone to spondylolisthesis than females.
The primary cause of spondylolisthesis is some form of injury (trauma), often occurring in contact sports and very physically demanding sports. This can be either a single accident, or as a result of the creation of microfractures due to joint hyperextension, common in weightlifters and gymnasts. Other sports where this condition is a higher risk include football and soccer.
These are also sports where the risk of bone fractures in vertebrae ('spondylolysis') are higher than in other sports.
Causes other than injury include…
- Age-related degeneration.
- Congenital bone defects (i.e. inherited).
It is rare for children to be diagnosed with condition, although it does happen. It is more common from the age of 13 and into adulthood.
In some cases, spondylolisthesis causes no symptoms at all. Where symptoms do occur, they are likely to include…
- Pain in the legs (sometimes only one leg, but sometimes both).
- Back pain.
- Pain in the buttocks.
- Muscle weakness or numbing in one or both legs.
- Difficulty walking.
- Urinary / faecal incontinence (rare).
Any pain is generally made worse when bending over or twisting.
Tests / Diagnosis
The main diagnostic technique used for spondylolisthesis is x-ray, which will immediately show any presence of the condition. Other scans, such as CT and MRI scans may be recommended to determine if there is any further tissue damage.