What Is A Pars Defect Of The Spine?

Category: Spine | Author: Stefano Sinicropi | Date: January 30, 2017

Pars Defect of the Spine

A pars defect is a problem that typically develops in the lumbar portion of the spine. It gets its name from the part of the vertebra it affects – the pars interarticularis. When a defect develops in this area of the vertebra, it can lead to separation of the upper, front portion of the bone and the lower, back portion. It is a precursor to spondylolisthesis, another condition we’ve covered on the blog. Today, we’re going to take a closer look at pars defects, and explain how they’re treated.

Pars Defect Problems

To understand the pars defect, we need to undergo a quick anatomy lesson of the spine. Each vertebra has a blocky front portion and a rear portion made up of several knobby parts that project from it. Two of these knobs project downwards, where they form joints with the vertebra below it. The other two knobs project upwards, connecting to the downward pointing knobs on the vertebra above it. These is a small bony bridge that connects these knobs, and that bridge is called the pars interarticularis. There is one pars interarticularis on each side of the vertebra.

Problems can arise in the pars interarticularis for a number of different reasons. A birth defect can lead to a problem with the pars interarticularis on one side of the vertebra, or trauma can cause both of them on a vertebrae to break. Moreover, since the pars interarticularis only heals when it is immobilized in close contact with the fracture ends, it’s difficult to achieve full healing.

Pars Interarticularis and Spondylolisthesis

The overwhelming majority of pars interarticularis defects occur at the lowest lumbar segment above the sacrum bone. When a pars interarticularis defect occurs at this location, the unrestrained vertebra will tend to slip forward, causing the condition spondylolisthesis. Patients with minor or mild cases of spondylolisthesis are more likely to experience regionalized spine pain than the average person, but it isn’t always symptomatic. In severe cases, spinal fusion may be necessary to prevent the vertebra from moving even more out of place or compressing nearby structures.

Advancements in treatment of pars interarticularis defects and spondylolisthesis mean that we can identify problems before any fracture actually occurs. When identified beforehand, pars defects can be prevented with bracing and activity restriction. If the problem is identified after a fracture has occurred, treatment is similar. Patients will often be given a brace to restrict movement, and they will be asked to avoid certain strenuous activities. Bracing can last for 3-4 months while the fracture heals, and once your spine specialist is pleased with your healing, you may begin physical therapy to maintain and strengthen the abdominal and back muscles in the area.

Twin Cities Spine Surgeon

Most people don’t need to undergo surgery for a pars interarticularis defect, but if you do, the aforementioned spinal fusion operation can address the issue. Your surgeon may also recommend a laminectomy in the event that the shifting vertebra is compressing nearby nerves. For more information on the condition, contact Dr. Sinicropi today.

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