The word spondylolisthesis comes from the Greek words spondylos, which means “spine” or “vertebra,” and listhesis, which means “to slip or slide.” A spondylolisthesis happens when one of the spine’s vertebrae (bones) slips forward over the vertebra beneath it. Spondylolisthesis occurs most often in the lumbar spine (low back).
Symptoms of Spondylolisthesis
Most patients with spondylolisthesis have no symptoms. When symptoms do occur, they may include the following:
Pain in the low back, thighs, and/or legs — especially after exercise — that radiates into the buttocks Muscle spasms Leg pain or weakness Tight hamstring muscles Irregular gait (walking pattern)
Types of Spondylolisthesis
Isthmic spondylolisthesis (51%) is the most common type. It occurs as the result of spondylolysis, a condition that leads to small stress fractures (breaks) in the part of the spinal bone called the pars interarticularis. Most cases actually develop before age 9 and are asymptomatic (no pain).
- Degenerative spondylolisthesis (25%) is the second most common form of the disorder. From age and activity, degenerative changes occur to the spinal structures, especially the discs. When the discs and joints of the spine wear down, they are less able to resist movement by the vertebrae.
- Traumatic spondylolisthesis (<3%) in which an injury leads to a spinal fracture or slippage.
- Pathological spondylolisthesis (<3%) results when the spine is weakened by disease — such as osteoporosis, an infection, or tumor.
- Dysplastic (Congenital) spondylolisthesis (21%) results from abnormal bone formation in utero (womb). In this case, the abnormal arrangement of the vertebrae puts the vertebrae at greater risk for slipping.
- Post-surgical spondylolisthesis
- Grading of Spondylolisthesis
Most spine physicians use the Meyerding Grading System to classify slips. This is a relatively easy system to understand. Slips are graded on the basis of the percentage that one vertebral body has slipped forward over the vertebral body below.
Grade I: 1-24% of the vertebral body has slipped forward over the body below
Grade II: 25-49% slip
Grade III: 50-74% slip
Grade IV: 75%-99% slip
Grade V: If the body completely slips off the body below it is classified as a Grade V slip, known as spondyloptosis.
Generally, Grade I and Grade II slips do not require surgical treatment and are treated non-operatively. Grade III and Grade IV slips may require surgery if the spine is unstable and pain is unrelenting.
Diagnosis
Imaging is necessary to diagnose spondylolisthesis. Simple x-rays of the low back are usually adequate to show a vertebra out of place. However, computed tomography (CT) or magnetic resonance imaging (MRI) provides detailed images and may be needed to more clearly see the spinal structures involved.
Spondylolisthesis is a common finding on imaging studies and its presence does not necessarily mean that you need surgery. A simple x-ray can be performed to determine if the effected levels are stable.
Treatment
Nonsurgical Treatment. Nonsurgical treatment for mild spondylolisthesis is successful in about 75% of cases. Nonsurgical treatment may combine the following:
Relative rest: The patient may be advised to temporarily avoid aggressive activities such as sports.
Anti-inflammatory medication or analgesic medication
A brace or back support may be prescribed to help stabilize the lower back and reduce pain.
Injections: Spondylolisthesis pain may originate in different places. Nerve impingement causes pain to radiate (travel) down the legs. Nerve impingement can be caused by a degenerated disc possibly damaged during vertebral slip, or from facet joint stress also attributable to the spondylolisthesis.
Pain caused by stress on the facet joints can be helped with medial branch block injections, and pain from the pressure on the nerves may be helped from intermittent epidural steroid injections. Patients that respond to lumbar medial branch blocks may benefit from a radiofrequency procedure for longer term pain relief.
Surgery. Surgery may be necessary if the vertebra continues to slip or if pain is not relieved with nonoperative treatment and interferes with daily activities. Surgery is successful in relieving symptoms in 85-90% of people with severe symptomatic spondylolisthesis.
Laminectomy and fusion. The most common surgical procedure used to treat spondylolisthesis is called a laminectomy and fusion. In this procedure, the compressed spinal canal is widened by removing or trimming the laminae (roof) of the vertebrae. This is done to create more space for the nerves and relieve pressure on the spinal cord. The surgeon may also need to remove all or part of the vertebral disc (discectomy) and then also fuse vertebrae together. If fusion is done, various devices (like screws or interbody cages) may be implanted to enhance fusion and to support the unstable spine.
To Learn More
If you have been diagnosed with spondylolisthesis, or are interested in learning how about treatment options to manage your pain, please contact our pain management experts at the California Spine and Pain Institute. We would be happy to make an appointment for a consultation and provide additional information about other treatment options.
