Spondylolisthesis describes abnormal alignment of the bones (vertebral bodies) in your spine. In the healthy state, these bones line up on top of each other perfectly, held together by strong joints and ligaments. But if these joints and ligaments become weak or damaged, the vertebral bodies “slip” out of alignment. When a vertebral body slips forward (anterior) relative to the one below, the result is anterolisthesis. When the vertebral body slips backward (posterior), the result is posterolisthesis.
Because spondylolisthesis results from weak joints and ligaments in the spine, these joints (e.g. interverbal discs, facet joints) can become quite painful, causing neck or low back pain depending on the location of spondylolisthesis.
In addition, abnormal alignment between the vertebral bodies can cause narrowing (spinal stenosis) of the passages in the spine that nerves travel through. The resulting pinched nerves can create pain, numbness, tingling, or even weakness (radiculopathy) wherever these nerves travel in the body, even far away from the area of spondylolisthesis.
Fortunately, most patients with spondylolisthesis can become symptom free by engaging in certain core strengthening and skeletal stabilization exercises. A physical therapist specializing in the spine can show you how these are done..As core muscles become stronger, they help reinforce weak joints and ligaments, restoring natural alignment. Corticosteroid injections can provide short-term relief of severe pain. Rarely, surgery is necessary because spondylolisthesis is too advanced or unstable.
Most people with spondylolisthesis are symptom-free, and never know that they have the condition. However, some people may develop mild to severe symptoms.
At the cervical level, symptoms may include pain in the neck and shoulder blades, headache, and pain into the arms and hands. In more severe case, you may have weakness in the arms and hands, trouble holding onto objects, or trouble with balance.
At the lumbar level, you may experience low back pain and tenderness, along with decreased range of motion and flexibility. Leg symptoms include stiffness, tight hamstring and buttock muscles, or pain shooting down the leg (radiculopathy). In more advanced cases, a patient may experience gait abnormalities such as limping or waddling, and difficulty controlling bladder or bowel.
There are many causes of spondylolisthesis. In all cases, there is weakening of the joints and ligaments that hold vertebral bodies together and in proper alignment.
- Degenerative wear and tear (spine arthritis) is the most common cause of spondylolisthesis. As joints age, they become weaker, and ligaments can fray. As a result, these ligaments cannot hold vertebral bodies together properly. Degenerative spondylolisthesis occurs most commonly at the lumbar spine (L4-5).
- Congenital weakening of joints and ligaments can cause early-onset spondylolisthesis. In these cases, an individual may have been born without certain structural elements (e.g. pars “stress fracture” defect) in the spine, leading to accelerated wear and tear on the remaining structural elements. This occurs most commonly at the L5-S1 level where the lumbar and sacrum come together.
- Traumatic spondylolisthesis can result from an injury to a joint or ligament that does not heal, leading to misaligned vertebral bodies.
- Pathological spondylolisthesis can occur when joints and ligaments are weakened by infection or tumors.
- Post-surgical spondylolisthesis refers to slippage that results from surgery (e.g. laminectomy) that has damaged joints and ligaments.
Additional risk factors include family history of back problems, injury or trauma to the neck or low back, straining the neck or low back, smoking, sports, or exercises that apply large forces to the spine such as football or weightlifting.
A history and physical examination, that includes a detailed neurological evaluation, will be performed by your physician. The physical examination includes observation of your gait, posture, range of motion, curvature and alignment, palpation of spine and surrounding muscles and soft tissues. Reflexes, motor strength, and sensation will be assessed during the neurological exam.
During the examination, your physician may find:
- Limited range of motion
- Tight Hamstring muscles
- Positive straight leg raise test
- Paraspinal muscle spasm or tenderness
- Abnormal gaits, waddling gait, or limping
- Tenderness of the spinous process above the slipped vertebra
- Abnormal neurologic signs: numbness, tingling, muscle weakness, or decreased reflexes, depending on the degree of slippage and nerve-root impingement
- X-rays of the spine, with the patient standing up, allows for an accurate assessment and diagnosis of spondylolisthesis. X-rays are also obtained with the patient bending forward (flexion) and bending backward (extension) to measure the degree of instability of the involved vertebrae.
- Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) scan may need to be obtained to identify the location of nerve compression associated with spondylolisthesis.
The degree of slippage is determined by a radiologist or a doctor upon reviewing x-rays. A grading system is used based on the position of one vertebral body relative to the one below it. Slippage is graded I through IV:
- Grade I: 1% to 25% slippage
- Grade II: 26% to 50% slippage
- Grade III: 51% to 75% slippage
- Grade IV: 76% to 100% slippage
Most people with mild cases of spondylolisthesis respond well to conservative treatment. Conservative treatments include activity restriction for acute pain flare ups, medications to reduce inflammation, and bracing to temporarily support the spine. Physical therapy for core strengthening and stretching can prevent recurrences of pain, reduce pressure on the spine, and maintain or improve range of motion. Alignment can also be improved by muscle strengthening.
- Medication: Over the counter medications such as Advil or Tylenol may be used to treat your pain if symptoms are mild or moderate. Oral corticosteroids many also be prescribed to reduce inflammation.
- Physical therapy: Exercises, manual (i.e. massage) therapy and modalities (e.g. heat, ice, electric stimulation) can be used to decompress the site of compression and treat the swelling and pain in order to promote tissue healing and reduce pain. Education can be provided to modify activities to avoid strain to the effected nerve.
- Injections: Corticosteroids may be injected directly to the area of inflammation to reduce swelling closer to the nerve root. A physician may perform an image guided injection near the nerve root thought to be the source of the patient’s pain or a direct injection into the affected joint. While corticosteroids do not fix spinal stenosis, they do help decrease the inflammation that so often causes crippling pain. After this pain has been reduced, the patient can function normally and engage in curative exercise therapy.
For a small minority of patients, symptoms do not improve with conservative care. Usually, this is because their spondylolisthesis is too severe, has resulted in nerve damage, or is extremely unstable. These patients may require surgery. Approximately 85% to 90% of patients with severe spondylolisthesis experience symptomatic relief after surgery.
- Laminectomy: A portion of the vertebrae known as the lamina, along with overgrown joints and ligaments, are removed to give the compressed nerves more space to travel through the spinal column. This procedure, which can be performed with minimally invasive techniques, can provide almost instantaneous relief of severe nerve pain caused by spondylolisthesis.
- Spinal Fusion: In addition to decompressing the nerves with laminectomy, spinal fusion entails restoring normal alignment between the vertebral bodies, and stabilizing abnormal movement between bones. Spinal fusion is required only in cases of very unstable spondylolisthesis. Even though it involves more extensive surgery than simple laminectomy, it can be performed with minimally invasive techniques that allow patients to rapidly return to normal activities.
Spondylolisthesis is an abnormal alignment of the bones (vertebral bodies) in your spine. In the healthy state, these bones line up on top of each other perfectly. Most people with spondylolisthesis are symptom-free, and never know that they have the condition. Symptoms at the cervical spine (neck) may include pain in the neck and shoulder blades, headache, etc. while symptoms at the lumbar spine (low back) may include tenderness, decreased range of motion and flexibility, to stiffness and pain shooting down the leg.
Most patients with symptomatic spondylolisthesis can be managed and respond well to conservative treatments. For severe cases, surgical procedures such as decompressive laminectomy and/or spinal fusion may be performed. Careful evaluation by an experienced spine doctor is necessary to determine which treatments are appropriate.
If you notice increasing neck or low back pain, numbness, tingling, or weakness radiating into the arms or legs, you should seek the advice of an experienced professional. You do not have to live in pain.