Spondylolisthesis is a spine condition where one of the bones in your back, known as a vertebra, slips out of its normal position and moves forward over the bone below it. This slippage can put pressure on nearby nerves, leading to discomfort, numbness or weakness, especially in your lower back and legs. It can also cause a sense of instability, or a “catch”, when standing up from a seated or lying position.
Spondylolisthesis can affect people of all ages, but it's most common in adults due to wear and tear on the spine over time. It can happen in younger athletes who participate in sports that put repeated stress on the lower back, such as gymnastics, football or weightlifting.
There are several types of spondylolisthesis, with the two most common being:
- Degenerative spondylolisthesis: This type occurs as part of the natural aging process. Over time, the discs and joints in your spine can wear down, making it easier for a vertebra to slip out of place.
- Isthmic spondylolisthesis: This type develops from a small stress fracture in a part of the vertebra called the pars interarticularis. This tiny crack can weaken the bone’s stability, putting more stress on the disc, which causes it to wear out, allowing the vertebrae to slip forward.
Other, less common forms of spondylolisthesis may be present at birth, result from traumatic injuries, or occur as complications from other spinal conditions.