1. Spondylolisthesis –
Causes and Classifications

2. Spondylolisthesis causes are wide ranging. Vertebral slippage may
result from a congenital defect (that someone was born with), or from
degeneration that accompanies the aging process. Traumatic accidents
or injuries can also cause spondylolisthesis, as can certain diseases.
Because there are so many possible causes of the condition, a
classification system was devised by an orthopedist named Dr. Leon
Wiltse. The classifications include dysplastic spondylolisthesis, isthmic
spondylolisthesis, degenerative spondylolisthesis, traumatic
spondylolisthesis, pathologic spondylolisthesis, and iatrogenic
spondylolisthesis.

3. Exploring the Wiltse
Classification System
The Wiltse classification system for spondylolisthesis causes is as follows:
• Dysplastic spondylolisthesis – congenital defect of the L5 and S1 vertebrae
• Isthmic spondylolisthesis – a stress fracture involving the pars interarticularis
• Degenerative spondylolisthesis – osteoarthritis of the spinal facet joints
• Traumatic spondylolisthesis – a fracture of the vertebral arch
• Pathologic spondylolisthesis – bone diseases like Paget’s disease or
osteosarcoma
• Iatrogenic spondylolisthesis – occurring after a lumbar spine surgery like fusion

4. Isthmic Spondylolisthesis
Isthmic spondylolisthesis is the most common form of the condition because pars
interarticularis fractures can occur for a variety of reasons. Micro-fractures that
lead to complete fractures are particularly prevalent in athletes that frequently
hyper-extend their spines, such as weight lifters, football players, and gymnasts.
Another form of isthmic spondylolisthesis causes the pars bone to increase in
length. This can occur in individuals that have a fractured pars interarticularis, but
instead of completely fracturing, new bone grows between the fractured portions.
The added length can cause a vertebra to slip forward. Finally, traumatic, sudden
forces, such as those experienced in a car accident or fall, can cause pars fractures
and vertebral slippage.

5. Other Components of the
Diagnostic Process
In addition to diagnosing the cause of your spondylolisthesis, whether isthmic or otherwise, your
doctor will also need to determine the severity of your condition. Vertebral slippage is generally
classified as Grade 1, 2, 3, or 4, based on the Meyerding classification
system. Grades 1 and 2 are generally
mild to moderate forms of
spondylolisthesis, while Grades 3 and 4
are moderate to severe. Once the exact
location, severity, and cause of your
condition are determined, your doctor will
prescribe an appropriate treatment regimen.

6. Treatment Options
Unless an instance of spondylolisthesis causes an emergent
need for medical attention, treatments for the condition
typically begin conservatively, or non-surgically. A doctor will
most likely recommend prescription or over-the-counter pain
medication, hot/cold compresses, behavior modification,
bracing, and physical therapy. Surgery generally only becomes
a consideration for severe cases that are drastically reducing
the patient’s quality of life.