Spondylolisthesis is a condition in which one vertebra is out of place. The most common form of spondylolisthesis in children is isthmic spondylolisthesis, or pars defect. A birth defect or trauma, like a stress fracture, can cause this to happen.

Symptoms include low back pain, instability of the spinal column, spinal cord compression and muscle spasms in the back of the thighs.

Most children who receive medicine, physical therapy and a doctor's supervision will improve without the need for surgery. In most cases, there is no reason to limit activities during this period. If surgery is recommended, surgeons might remove a part of the vertebrae, realign the spine and fuse it. This relieves pressure on the nerves or spinal cord and helps correct deformities. Surgery is used only for patients whose symptoms worsen or progress.