A pars defect is so named due to its anatomical location on the pars interarticularis of the vertebrae. The pars interarticularis is a thin piece of bone that connects the upper and lower parts of the posterior vertebrae. This part of the bone is weaker relative to the other parts of the vertebrae. A stress fracture or defect in the pars interarticularis can occur unilaterally or bilaterally.

This injury is most common in the lumbar or lower spine but can occur in the thoracic or cervical spine (mid back or neck) as well. One risk of a pars defect is that it can cause slipping of the vertebrae anteriorly. This condition is called spondylolisthesis. 6-8% of the general population will be affected by a pars defect. Symptoms of this condition usually arise before age twenty meaning children and adolescents are most often affected.

HOW DOES A PARS DEFECT DEVELOP?

Pars defects are most often found in young athletes. Considered a stress fracture of the vertebrae, pars defects typically overuse injuries and develop in response to repeated mechanical stress on the spine rather than due to a single traumatic event like a fall or car accident. Repeated extension (back bending) for example, could cause a pars defect in some individuals. Due to the mechanism of injury, athletes are at the highest risk for developing a pars defect as they repeatedly load the spine.

Sports that might increase the risk of developing a pars defect include:

• Gymnastics
• Football
• Swimming
• Diving
• Weight lifting
• Wrestling

SYMPTOMS OF A PARS DEFECT

The majority of cases of pars defects are actually asymptomatic and are usually an incidental finding on imaging. In these cases, treatment is usually not warranted. Symptomatic pars defects often present with the following symptoms:

• Acute or gradual onset of low back pain
• Pain that is usually worse with activity and better with rest
• Rotation and side bending can worsen symptoms when the pars defect is in the lower back
• Pain that is usually localized to the area of injury, radiating symptoms are less common

DIAGNOSIS OF A PARS DEFECT

The symptoms of a pars defect can mimic those of other back conditions and back injuries. Proper diagnosis is important to allow for the correct treatment. Clinical tests performed in a physical therapy or doctor’s office are not specific enough to definitively diagnose this condition. Imaging tools such as CT scan, MRI or SPECT scan are usually needed.

If you decide to work with a physical therapist to help correct your Pars Defect issues, your entire treatment plan could consist of around 8-20+ different physical therapy sessions that will each last 60-90 minutes. Once you complete your customized physical therapy treatment plan, you will be able to continue to do the prescribed stretches and exercises utilized during your PT sessions yet in the comfort of your own home.

PHYSICAL THERAPY FOR A PARS DEFECT

Conservative management is the first line of treatment for symptomatic pars defects. Conservative management includes physical therapy, bracing to minimize motion at the healing bone, anti-inflammatories and avoiding the aggravating activity. In cases where conservative management fails or there is significant instability, severe pain or neurologic symptoms, surgery may be recommended to repair and stabilize the bone. Physical therapy goals for pars defects treated conservatively include:

• Guidance on rest and activity modification to reduce movement and stress across the injured vertebra
• Pain reduction
• Promotion of blood flow to the healing bone through gentle exercises like isometrics
• Minimize loss of fitness and muscle performance in unaffected areas of the body
• Address underlying causes of the injury such as hyper or hypomobility, motor control or strength impairments
• Optimize movement patterns to decrease risk of re-injury and facilitate return to sport
• Facilitating returns of global strength and muscle performance to support return to activities

Physical therapy goals for pars defect following surgical management include:

Guidance on avoiding bending, lifting and twisting as outlined by your post-surgical instructions
• Pain reduction
• Promotion of blood flow to the healing bone through gentle exercises like isometrics
• Minimize loss of fitness and muscle performance in unaffected areas of the body
• Address underlying causes of the injury such as hyper or hypomobility, motor control or strength impairments
• Optimize movement patterns to decrease risk of re-injury and facilitate return to sport
• Facilitating returns of global strength and muscle performance to support return to activities

SCHEDULE AN INITIAL EVALUATION FOR PARS DEFECTS TODAY

Managing a pars defect correctly can help you or your child return to the activities they love to do more safely. Physical therapy is an excellent option for managing this condition and our team of PTs is ready to help. If you or your child have been diagnosed with a pars defect or are noticing uncomfortable symptoms in the spine, call us today to learn more about our services and schedule an evaluation with one of our physical therapists.

Resources:
Debnath UK. Lumbar spondylolysis-Current concepts review. Journal of Clinical Orthopaedics and Trauma. 2021 Oct 1;21:101535.