The spine is made up of a column of connected bones called vertebrae. The pars interarticularis is an area on the vertebrae that joins together the upper and lower joints in the spine. If the pars “breaks” or fractures, the condition is called spondylolysis and most commonly occurs in the lowermost part of the spine. Spondylolysis may result in lumbar pain, but there may be no symptoms at all. Spondylolisthesis refers to slipping of one of the vertebrae and typically results from either a spondylolysis injury or as a result of “wear and tear” arthritis pushing the vertebra.
Young athletes, such as gymnasts, football players, or wrestlers, can develop a stress fracture in this region as a result of repetitive stress and loading of the spine. Because of the constant and repetitive forces the low back experiences, this fracture may not completely heal. In about 5% of the population, there is a developmental deficiency which ultimately results in a break in the junction between the front and back of one of the lower vertebrae of the lumbar spine.
What are the symptoms?
Spondylolysis or acute fracture of the pars in the young (adolescent) patients typically present with low back pain. Patients will often describe the pain that is reproduced by leaning backward and extending the lumbar spine.
Spondylolisthesis itself may not cause any symptoms for years (if ever) after the slippage has occurred. Often, it can be the resulting sequelae, not the actual spondylolisthesis, that leads to symptoms. The most common consequences of spondylolisthesis include spinal stenosis, disc degeneration, facet (spinal) joint arthritis, and formation of facet cysts. The resultant spinal stenosis can arise from mechanical pressure placed upon the nerves either in the central canal of the lumbar spine or as the nerves exit within the neural foramen. Patients who experience symptoms from nerve involvement may describe both low back and buttock pain as well as radiating symptoms such as numbness, tingling, pain, or weakness affecting the lower limb(s).
How is it diagnosed?
Studies have shown that 5-10% of patients seeing a spine specialist for low back pain will have either a spondylolysis or spondylolisthesis. However, because spondylolisthesis is not always painful, the presence of a fracture (spondylolysis) and slip (spondylolisthesis) on the x-ray image does not mean that this is the source of your symptoms. For this reason, it is essential that your treating physician properly evaluate your symptoms and personally interpret your radiographic studies to ensure that your spinal condition is properly diagnosed and that appropriate treatment is prescribed.
Your doctor will begin by taking a history and performing a detailed physical examination. X-rays are often ordered when a spondylolysis or spondylolisthesis is suspected. Sometimes, additional tests may be needed to clarify the diagnosis. A computed tomography (CT) scan can best and more clearly show a fracture or defect in the bone. An MRI scan may be ordered to demonstrate an acute fracture or stress reaction in the bone while also clearly revealing the soft tissue structures, including the intervertebral discs and spinal nerves, which might also be contributing to the overall pain syndrome. Bone scans such as a SPECT scan are also utilized and often considered a “gold standard” for revealing an acute fracture or spondylolysis.
What treatments are available? If your doctor determines that a spondylolysis or spondylolisthesis is causing your pain, care typically commences with a comprehensive non-surgical treatment approach. Younger patients with asymptomatic spondylolysis are typically removed from sport to allow for fracture healing and are often fitted for a custom brace in an effort to prevent further stresses and loading to the injured vertebrae. With time, and as the pain subsides, activity is progressed, and patients are introduced to a spine and sport-specific rehabilitation program. Similarly, in cases of symptomatic spondylolisthesis, initial treatments might include a short period of relative rest, anti-inflammatory medications to control pain, bracing for stabilization, physical therapy, and ultimately a customized exercise regimen designed to improve both strength and flexibility. Only when such treatment approaches fail are further interventions, including injection therapy and surgery, considered.
Medications used to control pain are called analgesics. Most pain can be treated with non-prescription medications such as aspirin, acetaminophen, naproxen, or ibuprofen. If you have severe persistent pain, you may be prescribed stronger analgesics for a short period of time. Sometimes, your doctor may prescribe muscle relaxants to help with pain control, particularly during evening hours. As with any medication, the goal in prescribing is to maximize benefits realized through as low a dosage as possible, while minimizing adverse side effects (such as constipation and drowsiness).
An important part of your treatment plan is exercise therapy that is specially designed to reduce your back or leg symptoms. Patients with an acute fracture or spondylolysis are not immediately introduced to therapy but rather are first rested or braced to allow for bone and fracture healing. Patients with spondylolisthesis and spinal stenosis will then often benefit from a “flexion biased” spine stabilization and rehabilitation approach. Learning and continuing a home exercise and stretching program after more formal physical therapy is completed are essential aspects of treatment.
Our doctors have identified a group of therapists throughout the region who have specialized training in treating patients with spinal conditions. We can assist you in locating these therapists so that you receive the best spine care available.
Both our experience and the scientific literature have shown that non-surgical treatments for spondylolysis and spondylolisthesis are a safe and often effective approach for these conditions. The physicians of Long Island Spine Rehabilitation Medicine, experts in the field of non-surgical spinal care, are uniquely trained to evaluate and treat patients presenting with the full spectrum of symptoms arising from lumbar spondylolysis, spondylolisthesis, and spinal stenosis.
Selective spinal injections performed with fluoroscopic guidance may be recommended if you have severe leg or back pain arising as a result of the spondylolysis or spondylolisthesis. These are targeted injections of a corticosteroid/local anesthetic mixture into the epidural space immediately surrounding the inflamed and compressed spinal nerve or into a spinal facet joint. In cases in which the primary pain generator is less certain, selective spinal injections can be utilized in a diagnostic fashion in an effort to anesthetize and confirm to true source of pain. These injections are performed in a target and diagnosis specific fashion and are offered to aggressively control the acute inflammatory phase of injury and as a component of a comprehensive rehabilitation program. Long term outcome studies evaluating such interventions often describe moderate and lasting relief from symptoms in symptomatic stenosis patients who choose a non-surgical treatment approach even when previous therapies have failed.
What About Surgery?
Surgery is typically reserved for that small percentage of patients whose pain cannot be relieved by non-surgical treatment methods and whose quality of life is notably compromised by ongoing leg symptoms. Surgery is also indicated for patients with pronounced or progressive neurological deficits, such as weakness or numbness in the lower limbs or for patients with cauda equina syndrome (a rare neurological deterioration which includes loss of bladder or bowel control).
As spinal stenosis results in a narrowing of the bony canal, the goal of the surgery is to open up (decompress) the canal to increase the space around the nerves. This decompressive procedure is known as a laminectomy. Surgery, when necessary, will very often relieve the leg pain associated with stenosis and, less reliably, pain complaints localized to the lumbar region.
In those cases in which a spondylolisthesis is evident or if excessive motion (instability) is observed, fusion surgery may be concurrently recommended. A fusion is performed along with decompression to provide stability to the surgical segment. A fusion is performed by placing bone graft, bone substitute, and/or instrumentation between the vertebrae being fused. Fortunately, the success rate of fusion surgery for relief of symptoms resulting spondylolisthesis approaches 75%.