Stress fracture of the pars interarticularis

Introduction

A child's spine is made up of 33 small bones that link together. These bones are called vertebrae.

As your child grows into an adult, some vertebrae will fuse together, reducing the number to 24.

The vertebrae are connected with very thin pieces of bone on both sides. These are called the pars interarticularis.

Stress fracture of the pars interarticularis is a condition where there is a break or fracture in the pars interarticularis on one or both sides. This type of fracture usually happens in the lower part of the spine, called the lumbar region, which goes from the lower back to the bottom. 

This condition is also known as:

• a pars defect
• spondylolysis.

A stress fracture in the pars interarticularis can develop after repeated, ongoing strain, like in sports or physical activity. Activities that cause these fractures usually involve bending, stretching, or twisting the lower back. 

Activities can include:

• cricket
• gymnastics
• diving
• soccer
• weight lifting
• tennis.

Some children are born with weakness in their spine, which means they can develop the condition even if they do not do sports or physical activity.

Children and teenagers are generally more at risk for stress fractures in the pars-articularis because their bones are still growing. They are also more likely to play sports and do physical activity regularly.

Symptoms of a stress fracture in the pars interarticularis generally include pain:

• in one or both sides of the lower back
• that spreads to the bottom
• that gets worse with bending backwards, standing for long periods and running
• that slowly gets worse over time rather than starting suddenly.

See your local doctor or physiotherapist as soon as possible if your child starts to develop pain or discomfort during sports and activities, even if it is mild.

Your child’s local doctor or physiotherapist will do a physical check if they think there may be a stress fracture in the pars interarticularis. They might ask your child to bend or twist gently to see where and how severe the pain is.

If they think there is a stress fracture, your child’s doctor will order scans to make a diagnosis.

Scans can include:

• x-rays to see any fractures in the spine
• a bone scan to check for any abnormal areas in the bones
• CT scans to check how severe the fracture is and whether it can heal well.

Treatment for a stress fracture in the pars interarticularis will depend on how severe the fracture is and whether the doctor thinks it can heal well.

Your child’s doctor may recommend:

• taking a break from sports and activities for 6-12 weeks to let the bones heal
• using a back brace to prevent any movement that will cause pain or make the fracture worse
• seeing a physiotherapist to strengthen the muscles and improve posture
• checking your child’s movement and pain when they go through growth spurts.

Speak to your child’s doctor about medications to help with pain or swelling.

With good rest and treatment, the fracture can heal, and your child’s pain should slowly go away.