Spondylolysis and Spondylolithesis

Among child and adolescent athletes, spondylolysis typically represents a fracture of the posterior arch (back part of the spine) in the lower lumbar spine due to overuse and is a relatively common cause of low back pain. Spondylolisthesis involves anterior displacement (forward slippage) of one vertebral body on another due to the presence of these fractures on both side of the posterior arch. Spondylolithesis is less common than spondylolysis.

Spondylolysis can occur on one or both sides (fracture or separation) in the vertebral pars interarticularis, usually in the lower lumbar vertebrae. In young athletes, spondylolysis usually represents a fatigue fracture in the posterior arch of the spine, specifically the bony area of the pars interarticularis (pars) between the zygapophyseal (facet) joints. Although usually an overuse injury, spondylolysis may present following an acute overload. Several observations suggest spondylolysis is primarily a fatigue fracture.

(A) A superior view of a normal lumbar vertebra with cauda equina, nerve roots, intervertebral disc and ligamentum flavum. (B) A superior view demonstrating abnormalities including a thickened ligamentum flavum, a hypertrophied facet and a herniated disc. These pathologic structures cause the canal to narrow and can impinge on the cauda equina and nerve roots. (C) A lateral view of the lumbosacral spine demonstrating spondylolysis and spondylolisthesis. Spondylolysis is a fracture in the pars interarticularis of the vertebra. Spondylolisthesis occurs when this fracture widens and the vertebral body slides forward on the one below it.

Spondylolysis occurs at the fifth lumbar vertebra (L5) approximately 85 to 95 percent of the time, with an L4 locus in 5 to 15 percent of cases.

Multilevel involvement occurs approximately 4 percent of the time, and bilateral involvement occurs in approximately 80 percent of cases. When bilateral defects develop, the vertebral body may slip anteriorly relative to the vertebra below and this is termed spondylolisthesis

Dotted line follows posterior vertebral margins of L5 and the sacrum.

Another type of spondylolitheses occurs not because of a fracture but from ageing changes in the spine. It is found most commonly at the L4-5 level. Arthritis in the spine can destroy the contour of the facet joints and with that the slippage forward. This slippage can often times lead to narrowing or stenosis of the spinal canal.

The prevalence of back pain from early life to adulthood demonstrates a progressive increase from a negligible level below the age of 7 to about 18 percent by the age of 16. However, the incidence is higher in competitive athletes, among whom the incidence of back pain has been reported to be as high as 30 percent. Spondylolysis is the most frequent identifiable source of back pain in the young athlete. In one study comparing adult and adolescent athletes with back pain, spondylolysis was identified in 47 percent of young athletes, while 48 percent of adult back pain was disc-related. In a 45-year prospective study involving 500 subjects, spondylolysis was found in 4.4 percent of first-graders and 6 percent of adults.

 Spondylolysis is most common in athletes who engage in sports involving extreme spinal motion, particularly lumbar extension. These include dancers, gymnasts, figure skaters,  football linemen, wrestlers, and divers.

Dr. Jerry Sobel has extensive knowledge in the diagnosis and treatment of both spondylolysis and spondylolithesis in the adolescent athlete and the adult.