Overview

Spondylolysis is a stress-related defect or fracture of the pars interarticularis — a small bony bridge at the back of each vertebra. When the pars fails on both sides of the same vertebra, the vertebra can slip forward over the one below it; that slippage is called spondylolisthesis.

These conditions are a common cause of lower back pain in adolescents and young athletes, particularly in sports with repeated backward bending (extension) and heavy spinal loading.

Typical Pattern

Lower back pain, often central or on one side, that comes on gradually
Worse with leaning back, backbends, landing from jumps, or extension-loaded sport
Stiffness and tight hamstrings are common
Often little pain with simple forward bending
Usually no leg pain early on; leg symptoms can appear if the vertebra slips enough to irritate nerve roots

Why It Develops

The pars interarticularis is a small bridge of bone that takes repeated tension during extension and rotation. In growing athletes with high training loads, repeated loading can progress from bone stress to a stress fracture (spondylolysis).

It is most common in adolescents — seen in sports such as gymnastics, football (especially line play), cricket fast bowling and volleyball — and is rarely found in people who do not load the spine, which is why it is considered a loading-related condition.

How It Is Diagnosed

Spondylolysis is suspected in any young athlete with persistent extension-related low back pain. Diagnosis combines:

The pattern of symptoms and sport history
Imaging — X-rays, MRI, or in some cases CT or SPECT scans — to look for the pars defect and any slip
Measuring the amount of slip (graded as a percentage) when spondylolisthesis is present

Many young athletes heal well; the goal of imaging is to guide treatment and return-to-sport planning.

Treatment

Most low-grade cases are treated without surgery:

Relative rest from the aggravating sport (not full bed rest)
Physiotherapy: core, glute and hamstring strength, trunk control, and gradual reloading
Bracing is used in some cases, particularly during more active healing phases
A graduated return to sport guided by symptoms and healing

Higher-grade slips (generally more than 50%) or slips that progress with nerve symptoms may require a surgical consultation. The large majority of young people with spondylolysis and low-grade spondylolisthesis do well with non-surgical care.

When to Get Assessed

Any adolescent athlete with back pain lasting more than a few weeks, or with pain that worsens with extension, should be assessed rather than assumed to be "growing pains." Urgent assessment is needed if there is new leg weakness or numbness, bladder or bowel changes, or saddle numbness.

References

Cavalier R, Herman MJ, Cheung EV, Pizzutillo PD. "Spondylolysis and spondylolisthesis in children and adolescents: I. Diagnosis, natural history, and nonsurgical management." JAAOS. 2006. https://pubmed.ncbi.nlm.nih.gov/16822889/
POSNA. "Position statement: spondylolysis and spondylolisthesis in children, adolescents and young adults." https://posna.org/POSNA/media/Documents/Position%20Statements/spondystatement2012.pdf
"Treatment of pediatric spondylolysis and spondylolisthesis." 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC11734530/

This information is for education only and is not a medical diagnosis. InjuryAtlas does not replace an assessment by a qualified health professional. If you have severe pain, visible deformity, numbness, loss of function, or symptoms that are getting worse, seek medical care promptly.

Spondylolysis & Spondylolisthesis