Ankylosing spondylitis is a form of inflammatory arthritis. It affects the joints of the spine, in…
What is spondylolisthesis?
Spondylolisthesis is a condition in which a vertebra shifts out of position. It is different from a slipped disc, which is due to a disc between two vertebrae rupturing or becoming damaged. It is estimated that up to 5% of the population have this condition.  It can be caused by a birth defect, a degenerative condition or an injury later in life.
Causes and risk factors
Spondylolisthesis is a displacement of one of your spinal vertebra and can be caused by a number of factors: genetics, fracture, overuse, infection, degeneration or overstretching of the localised muscles and ligaments. The vertebra usually slips forward; a backwards slip is very rare. The actual pain is often due to pressure on nearby nerves, or the overstretching of muscles or ligaments surrounding the vertebra.
Spondylolisthesis in children is often caused by a birth defect that results in weakened or thin bones in their lower spinal column. This structural weakness makes fractures or injury more likely.
In both adults and children, a sudden impact can cause a fracture, which can push a vertebra out of place. In adults, age-related wear and tear can make the spine much more susceptible to fractures. In children, thin bones will be a more likely cause.
Degenerative conditions such as arthritis weaken your spinal vertebrae, making injury more likely.
Strenuous sporting activities that involve super-extension of the spine or heavy impacts, such as gymnastics, cricket or weightlifting, can cause stress fractures in your vertebrae. Stress fractures can cause your vertebrae to shift out of place.
Medical specialists divide spondylolisthesis by types (the cause of the condition and the part of the vertebra that is affected) and by grades (the amount of slippage of the vertebra).
Signs and symptoms
Some cases of spondylolisthesis will not have any symptoms. When symptoms appear, they may include any of the following:
- Lower back pain, which is worse when you are physically active or standing, but improves when you rest;
- Stiffness and tenderness in your lower back;
- Muscle wasting in your buttock muscle;
- Sciatica - pain, numbness or tingling sensations down the back of your leg;
- Tight hamstring muscles that may cause you to 'waddle' when you walk;
- Weakness in your legs;
- Abnormal curvature of the spine, and;
Symptoms by age
Adolescents and younger children tend to have walking and postural abnormalities, while adults tend to have back pain and sciatica.
Methods for diagnosis
In order to diagnose spondylolisthesis, your doctor will want to rule out a number of other causes of lower back pain. Further imaging scans or investigative tests may be suggested if your diagnosis is not obvious.
Your doctor may examine your lower back to look for inflammation and check your spinal curvature. The most common test for spondylolisthesis is the 'straight-leg raise' test: you will be asked to slowly raise one of your legs while lying down. If you have disc herniation in the L5-S1 region, you will experience pain when your leg is raised to around 40 degrees.
Spinal X-rays taken from the front and side will detect any bones that are sitting out of place. Your doctor may also want to take spinal X-rays when you are bending forward or backwards.
Computerised tomography scan (CT scan)
Types of treatment
The type of treatment you undergo will depend on the type of spondylolisthesis you have.
Avoid triggers - if you have an injury or inflammation due to overuse, the best remedy is to avoid that action until you have healed and no longer feel pain.
Many types of back pain will respond well to pain-relief medications such as ibuprofen or paracetamol. Heat packs or icepacks can also be used to provide relief.
A physiotherapist is an expert in how your muscles work and, in particular, how to rehabilitate them after an injury or sprain. They can assess the condition of your muscles, tendons and ligaments, then design exercise programs to strengthen them. Strapping your muscles with special tape may help. Your physiotherapist can teach you exercises and stretching techniques that you can use at home.
Depending on the grade of spondylolisthesis you have, you may be offered a back brace to limit the movement in your spine.
If you have nerve compression and severe pain, your doctor may recommend an injection of local anaesthetic combined with corticosteroid. This works very quickly to reduce symptoms in most cases. However, these injections can only be offered a few times each year, to avoid side effects such as muscle wasting or localised skin discoloration.
Surgery to fuse your vertebrae can help significantly. Since there are always risks associated with any surgical procedure, surgery will only be considered when:
- You have severe pain that does not improve with other treatment;
- You have severe slippage, which is causing extreme pain and pressing on nerves, or;
- You have muscle weakness in both legs.
Complications with spondylolisthesis may occur if you have a severe slippage. This can cause nerve damage and associated lack of function and feeling in your legs, as well as ongoing chronic back pain.
The outlook for the majority of spondylolisthesis cases is good. Regular stretching exercises and avoiding triggers can help relieve symptoms.
There is no absolute way of avoiding injury that may place excessive strain on your spine, such as heavy lifting. Your doctor or physiotherapist can suggest strengthening exercises that can help build up your abdominal core muscles to help protect your lower back.