Spondylolysis
Many people with spondylolysis are asymptomatic and do not realize they have the condition. It can lead to chronic back pain and loss of flexibility if left untreated. Although adolescents who engage in sports, such as gymnastics, football and weightlifting, are most at risk of this condition, it can also occur in people of all ages without injury or sports participation.
What Is Spondylolysis?
The spine is the body's central support structure that keeps us upright. It comprises a chain of 24 small rectangular-shaped bones, called vertebrae, stacked on top of one another. The vertebrae create a canal that protects the spinal cord and nerve roots. It also makes the natural curves of the back.
Spondylolysis, also called pars fracture or pars defect, is a crack or break in the pars or pars interarticularis of the lumbar vertebrae. The pars interarticularis is a small, thin portion of the vertebra that connects the upper and lower facet joints.
Facet joints are small joints that provide stability and help control the movement of the spine. They work like hinges and run in pairs down the length of the spine on each side.
Spondylolysis may be congenital or acquired. Some children are born with spondylolysis, while adolescents involved in higher-risk sports develop this condition through repetitive stress or injuries to the lower back. These sports include:
- Gymnastics
- Dance
- Football (particularly linemen)
- Rugby
- Wrestling
- Martial arts
- Soccer
- Basketball
- Cheerleading
- Pitching
- Golf
- Tennis
- Volleyball
- Weightlifting
- Butterfly and breaststroke swimming
What Are the Symptoms of Spondylolysis?
People with spondylolysis usually do not know they have it until they experience lower back pain, which generally worsens with exercise or other physical activity, especially those that can strain the lower back or involve a lot of leaning back. When symptoms do occur, the pain may:
- Range from mild to severe in intensity.
- Feel similar to a muscle strain.
- Radiate to the buttocks and back of the thighs.
- Worsen with activity and improve with rest.
Often, patients with spondylolysis will also have some degree of spondylolisthesis. In spondylolisthesis, the stress fracture weakens the bones so much that they cannot maintain their proper position in the spine, causing the vertebrae to slip forward directly to the bone below it. The instability in the spine can cause pain and may also promote the formation of bone spurs or arthritis.
What Are the Causes of Spondylolysis?
Young people are more susceptible to spondylolysis because their bones are still growing. In addition, overuse or overstretching of the lumbar spine can weaken the pars interarticularis, leading to fracture and/or slippage of a vertebra over time.
Genetics can also play a part in developing stress weakness at the location of a spondylolysis. Doctors believe some people are born with thinner vertebral bone than normal, making them more vulnerable to fractures.
How To Diagnose Spondylolysis?
If you have symptoms of spondylolysis, your doctor may ask about your medical history and perform a physical examination of the different areas of your back. You may need to bend backward to hyperextend your spine to check if these movements cause back pain. If you do feel pain, there may be a fracture in your pars interarticularis.
However, other conditions can cause back pain, including a pinched nerve or herniated disc. Your doctor may order the following tests to help rule those out or confirm a diagnosis of spondylolysis:
- Back X-rays – detect fractures in the spine.
- Computed tomography (CT) scans – look for more minor fractures if X-rays are not clear.
- Bone scans – show increased bone activity at the site of the spondylolysis often used in children and young adults.
- Lumbar magnetic resonance imaging (MRI) scans – evaluate leg pain and identify possible areas of stenosis, a condition characterized by the narrowing of the space around the spinal nerves.
