What is Isthmic Spondylolisthesis?

What is Isthmic Spondylolisthesis? ?


What is Isthmic Spondylolisthesis? Isthmic spondylolisthesis is a type of spinal disorder characterized by the forward displacement of one vertebra over the one below it. This displacement occurs due to a defect or fracture in a small bridge of bone connecting the facet joints at the back of the spine. This defect is called the pars interarticularis, and when it fails to maintain stability, it can lead to slippage of the vertebra.



Several factors can contribute to the development of isthmic spondylolisthesis. One primary cause is a defect in a small bridge of bone known as the pars interarticularis, which connects the facet joints at the back of the spine. This defect, often referred to as a pars defect or pars fracture, can occur due to various reasons:


  1. Repetitive Stress: Activities that involve repetitive hyperextension of the spine, such as gymnastics, weightlifting, or certain sports like football and diving, can place significant strain on the pars interarticularis. Over time, this repeated stress can lead to micro-fractures or weakening of the bone in this area, ultimately resulting in a pars defect.


  1. Genetic Predisposition: Some individuals may have a genetic predisposition to developing isthmic spondylolisthesis. Certain genetic factors may influence the strength and integrity of the pars interarticularis, making some people more susceptible to developing a pars defect than others.


  1. Trauma: A sudden injury or trauma to the spine, such as a fall or a car accident, can also cause a pars fracture. The force generated during such events can result in a direct injury to the pars interarticularis, leading to its fracture or separation.


  1. Degenerative Changes: In some cases, degenerative changes associated with aging can contribute to the development of a pars defect. As the spine undergoes natural wear and tear over the years, the pars interarticularis may weaken, making it more susceptible to injury or fracture.


  1. Congenital Factors: In rare instances, isthmic spondylolisthesis may be present from birth (congenital). Structural abnormalities or malformations in the vertebrae, including abnormalities in the pars interarticularis, can predispose individuals to vertebral slippage later in life.



Symptoms of isthmic spondylolisthesis can vary depending on the severity of the condition. Common symptoms include:

  1. Lower Back Pain: This is the most common symptom and is often aggravated by activities that involve bending or twisting of the spine.
  2. Leg Pain: Pain may radiate into the buttocks or thighs due to compression of the nerves in the lower back.
  3. Tight Hamstrings: Individuals may experience tightness or stiffness in the hamstring muscles.
  4. Changes in Posture: As the condition progresses, there may be visible changes in posture, such as a swayback or exaggerated lordosis.



Diagnosing isthmic spondylolisthesis typically involves a combination of medical history, physical examination, and imaging tests such as X-rays, CT scans, or MRI scans. These tests help to assess the extent of vertebral slippage and identify any associated nerve compression.


Treatment Options

Treatment for isthmic spondylolisthesis depends on the severity of symptoms and the degree of vertebral slippage. Conservative treatments may include:

  1. Rest and Activity Modification: Avoiding activities that exacerbate symptoms and adopting proper body mechanics can help alleviate pain.
  2. Physical Therapy: Targeted exercises can strengthen the muscles supporting the spine and improve flexibility.
  3. Pain Management: Nonsteroidal anti-inflammatory drugs (NSAIDs) or muscle relaxants may be prescribed to manage pain and inflammation.
  4. Bracing: In some cases, wearing a brace may provide additional support to the spine and reduce discomfort.


For severe cases or those that do not respond to conservative measures, surgical intervention may be necessary. Surgical options may include decompression of nerve roots, spinal fusion, or a combination of both.


Dr Sharan has been a pioneer of a less invasive approach to performing surgery on isthmic spondylolisthesis called Awake Spinal Fusion.  By avoiding general anesthesia, using a less invasive approach, along with the integration of pre-operative IV infusions – patients who undergo surgery experience a rapid recovery.  Listen to Kathy’s story here.



Isthmic spondylolisthesis can significantly impact an individual’s quality of life, but with proper diagnosis and management, most people can find relief from their symptoms. It’s essential to work closely with healthcare professionals to develop a treatment plan tailored to your specific needs and circumstances. By understanding the causes, symptoms, and available treatment options, individuals can take proactive steps to manage this condition effectively and improve their overall spinal health.




Stay Up to Date on News and Education