Slip Sliding Away: Spondylolisthesis

By: Thomas J. Perlewitz, MD

If you’re feeling pain and instability in your spinal column, you may have spondylolisthesis – the forward or backward slippage of a vertebra onto the one below it. Most common in the lower back, it can occur anywhere in the spinal column and is a common cause of low back and nerve-related pain.

Five types of spondylolisthesis exist. We explore two below.

Isthmic Spondylolisthesis

Isthmic spondylolisthesis is caused by stress fractures at the lower, posterior portion of the spine, where facet joints are connected by a thin area of bone. “When the back of the vertebra detaches from the front portion, the spine slips forward at this level causing progressive deterioration and collapse of the disc space, and narrowing of opening where the spinal nerve exits the spine canal,” says Thomas Perlewitz, MD, Spine Specialist and Orthopedic Surgeon.

The vertebra most commonly affected is L5-S1, and the most common nerve, L5. The vertebra loosens, forcing the spine to bear abnormal and excessive motion through the damaged level. This results in back pain commonly related to the degeneration of the disc. With time, “sciatica” (nerve pain) may occur in one or both legs.

“It is estimated that six to seven percent of the general population has this condition,” says Dr. Perlewitz. “Recent CT scan studies estimate the prevalence as high as 11 to 12 percent.”

  • Men are three times more likely than women to be impacted.
  • Isthmic spondylolisthesis starts young. Up to four percent of those with this condition have it by first grade. The remaining 96 percent have it by age 18.
  • Gymnasts, football linemen, wrestlers, volleyball players, and weight lifters are frequently impacted, as their activities involve extensions or repetitive stress on the spine.
  • Pediatric athletes who report significant and persistent lower back pain also have a high prevalence of this condition.

Degenerative Spondylolisthesis

Degenerative spondylolisthesis results from the progressive degeneration of the facet joints and/or the discs in the spine.

“This is an age-related ‘wear and tear’ problem,” says Dr. Perlewitz. “Just as people develop knee joint and hip joint arthritis with time, the cartilage of the paired joints can wear out, resulting in abnormal motion and instability.”

In this case, the spine’s posterior arch remains intact and drags the nerve sack forward, potentially “pinching” at the disc space below. Patients often develop nerve pain in the buttocks and both legs. Back pain arises from the instability and abnormal motion at the impacted facets.

Symptoms include heaviness and fatigue in the legs and a decrease in the ability to walk distances. “Sitting down and resting, as well as adopting a forward list or lean with walking often improves or resolves these symptoms,” says Dr. Perlewitz.

  • The prevalence of degenerative spondylolisthesis increases with age. It’s most common amongpeople 60 to 69 years old, with up to 41 percentof this population affected.
  • Women are three times more likely than men toacquire this condition.

Initial treatments may include physical therapy, activity modification, anti-inflammatories (NSAIDs), and an emphasis on core strengthening, body mechanics, and posture.

“Interventional spine procedures and injections are the next level of care,” says Dr. Perlewitz. “Surgical decompression of compressed nerve tissue and stabilization of the unstable segment through spinal fusion is the last resort for those who fail nonoperative treatment modalities.”</p