Spondylolisthesis is a pathological condition in which a vertebra slides forward with respect to the lower vertebra. It is a fairly common cause of back pain and affects either younger patients (30-50 years) or adults over 50 years old as a result of degenerative lesions. The most common symptoms include localized pain or even lower extremity pain that limits the patient’s level of activity.
SPONDYLOLISTHESIS TYPES
There are five types of Spondylolisthesis:
- Degenerative
- Isthmic or lytic
- Traumatic
- Dysplastic
- Medical
However, the most common are degenerative and ischemic spondylolisthesis.
- Degenerative Spondylolisthesis
Degenerative Spondylolisthesis is diagnosed when a vertebra slides forward relatively to the lower vertebra. This clinical condition occurs as a result of the normal aging process, in which the bones, joints and ligaments become weak by failing to keep the spine in alignment.
It is observed in patients over 50 years old, most commonly in women (3:1) and is particularly common in people over 65 years old.
Degenerative spondylolisthesis is most commonly found at two specific levels of the spine:
L4-L5 (4th and 5th lumbar vertebra), which is by far the most common localization
L3-L4 (3rd and 4th lumbar vertebra)
It is relatively rare to occur at other levels of the spine, but may involve more vertebrae at two or even three levels. Although it is most commonly found in the lumbar spine, it can also occur at the cervical level and is almost always the result of degenerative lesions of the facet joints.
SYMPTOMS
CAUSES
At each level, the spine consists of an intervertebral disc and two facet joints in addition to its other anatomical structures. The disc generally functions as a shock absorber for the axial loads, while the pair of the facet joints at each level allows motion on the sagittal plane (bending – extension).
Degenerative lesions in the intervertebral structures and intervertebral discs allow for anterior slip (almost always between L4 and L5) despite the integrity of the vertebral bodies (there is no spondylolysis).
DIAGNOSIS
Degenerative spinal degeneration is diagnosed through a process of three steps:
Medical history: This is about getting information on the problem and symptoms that the patient reports, as well as other concomitant health problems that may affect or relate to this pathology.
Physical examination: The patient is thoroughly examined for possible signs of tenderness, pain, range of motion, weakness or neurological symptoms.
Diagnostic tests: In the suspicion of vertebral palsy, after a thorough medical history and physical examination, an X-ray may be performed to confirm the diagnosis and rule out other possible causes of the symptoms. Based on the results of the radiography, further imaging examination with an MRI may be needed.
Unlike isthmic spondylolisthesis, the degree of slippage in degenerative spondylolisthesis is typically not classified in grades, as it is almost always in 1st or 2nd Grade. In cases of degenerative spondylolisthesis, the facet joints are deformed and tend to grow in size (osteophytes) by squeezing the spinal cord and nerve roots causing spinal stenosis.
SYMPTOMS
As the facet joints in the spine degenerate and deform, they compress the spinal cord and nerve roots causing compressive effects and the symptoms of degenerative spondylolisthesis resemble those of the spinal stenosis.
The main symptoms include:
- Backache (lumbar pain) that often extends to the lower extremities. However, many patients with spondylolisthesis report no symptoms, while others report only lower extremity pain.
- Sometimes patients report symptoms of sciatica with pain following the distribution of the sciatic nerve on one or both legs. In addition, they may report feeling their feet tired after prolonged standing or walking (neurogenic lameness).
- In general, patients do not report pain while sitting, because this posture increases the diameter of the vertebra and the spine. In the upright position, the diameter decreases, increasing pressure on the nerve roots and spinal cord.
- Patients usually have tight posterior muscles, stiffness in the waist, and difficulty or pain in over-stretching.
- Pressure on the nerve roots can cause leg weakness, but without severe or permanent damage.
At the level of most of the lumbar spine, nerve roots are involved, not spinal cord as the latter ends in the spinal conus medullaris (L1 vertebra) and continues with the hippuridae (nerve roots exiting below the conus medullaris). When the vertebral stenosis becomes too severe or the patient develops disc herniation as well, he/she may develop cauda equina syndrome with progressive damage to the nerve roots and loss of bladder and bowel control. This is a rare syndrome that requires immediate surgical decompression.
MAINTENANCE TREATMENT
There are a wide range of non-surgical therapies that can help with the pain caused by degenerative spinal degeneration:
Modification of Activities and NSAIDs
Patients can change some of their usual activities to spend more time sitting and less time upright or walking. This activity modification includes:
A short rest period (e.g. one to two days of rest – bedding)
Avoid standing up or walking long distances
Avoid strenuous exercises
Avoid activities that require over-extension
If these changes drastically reduce the pain and other symptoms of the patient, then this will be an acceptable way of managing the problem for a fairly long time. Extra options, such as cold or hot pads and painkillers or anti-inflammatory drugs (NSAIDs) can alleviate pain after intense activity.
For patients who want to be more active, a stationary bike can be an option as seating is easily tolerated. Physiotherapy and swimming can also help to train the patient without too much stress.
Many patients benefit from controlled, step-by-step exercise as part of a physiotherapy program to maintain spine movement, which relieves pain and enables functionality in daily activities.
Epidural Injection with Corticosteroids
For patients with severe pain, especially in the lower extremities, epidural injections with corticosteroids may be a reasona
ble treatment option. Injections are effective in helping to control pain with a success rate of up to 50%. If the injection helps the patient it can be repeated up to three times a year. The length of time that the beneficial effect of the injection may last varies from one week to one year.
Surgical treatment
Degenerative spondylolisthesis rarely requires surgery, and most patients can successfully control their symptoms with the above methods. Surgery can be recommended in cases where pain drastically reduces the functionality of the patient in their daily activities, while causing progressive neurological deterioration.
The purpose of surgery is to align and stabilize these vertebrae and reduce pressure on the nerve roots.
The procedure usually consists of two parts:
- Decompression (also called laminectomy).
- Spinal Fusion with special materials
Laminectomy alone increases the instability and it is estimated that 60% of patients will need supplementary spinal fusion. A randomized study comparing spinal fusion with and without materials (screws and rods) concluded that the results with materials were much better.
Laminectomy and Spinal Fusion
Lumbar laminectomy differs from micro-discectomy in that the incision and detachment of the tissues is greater.
- Initially, and after the level has been precisely determined, an incision of about 8-10 cm is performed. The incision and detachment of the erector spinae on both sides on multiple levels follows.
- After approaching the vertebrae, part of the vertebral lamina bilaterally is carefully removed (laminectomy), allowing nerve roots to be exposed, as well as part of the hypertrophic ligamenta flava.
- Finally, a very small piece of facet joints is cut to offer the nerve roots more space.
Postoperatively, patients are hospitalized for one to three days, and the mobility that a patient regains depends on their preoperative condition and age.
During surgery, special screws and rods are placed after laminectomy and decompression of the spine.
This is quite a major operation and hospital stay typically ranges from one to four days. Patients return to their daily activities after three months.
Success Rates and Risks – Complications
Success rates after laminectomy and spinal fusion for the treatment of degenerative spondylolisthesis exceeds 90% with improved patient mobility and significant reduction in pain levels. However, there are some complications and risks, as with any surgery. Some of these include: pseudoarticulation, material failure, persistent pain, infection, bleeding or rupture of the meninges as well as possible damage to the nerve roots. Most of these complications are rare and in some cases the risk increases. In particular, smoking, obesity, osteoporosis, diabetes mellitus, rheumatoid arthritis, and multi-level laminectomy increase complication rates.
Since degenerative spondylolisthesis is a disease affecting patients over 60-65 years of age, surgery involves all of the aforementioned risks, although the risk is directly related to the general health of the patient and not to their age.
-
ISTHMIC OR LYTIC SPONDYLOLISTHESIS
In isthmic spondylolisthesis, the vertebral body slides forward relatively to the lower vertebra due to a minor fracture in a particular bone fragment of the spine, the pars interarticularis. This fracture appears to be caused by continued charging at this site and tends to be more frequent at ages 5 to 7 years, although most symptoms appear as the patient grows older, in adolescence.
It is estimated that 5-7% of the population have fracture in this small piece of bone (spondylolysis) and/or spondylolisthesis but they are asymptomatic. It is also estimated that 80% of people with vertebral palsy will never develop symptoms, and if they do, they will not need surgery.
CAUSES
The pars interarticularis is that part of the bone that connects the upper and lower articular fascia of the same vertebra.
It is a thin piece of bone with poor blood supply, which makes it prone to fractures. The most likely is the fracture to be present without the vertebrae sliding forward (simple spondylolysis).
When this small piece is fractured it usually does not cause pain or other symptoms. The main cause is not injury but minor injuries after ongoing stress.
The isthmic spondylolisthesis occurs more frequently at the L5-S1 level of the spine, the lower level of the lumbar spine. It can also occur at L4-L5 or L3-L4 levels but the most common cause at these levels is injury. It is not a congenital condition since it has never been found in the fetal or infant spine. Slipping of the body is more likely to occur during adolescence, and after adulthood is considered to be rare.
At the level of L5-S1 there is no risk of high instability because the lumbosacral and iliolumbar ligaments stabilize the L5 vertebrae on the sacral bone.
SPONDYLOLISTHESIS CLASSIFICATION
The severity of spondylolisthesis is measured on the lateral (profile) radiographs of the lumb
ar spine and it is graded from 1 to 4. The spondylolisthesis is measured by the percentage of the upper vertebrae sliding relatively to the lower one.
1st Grade: 0-25% slide
2nd Grade: 26-50% slide
3rd Grade: 51-75% slide
4th Grade: 76-100% slide
Although very rare, vertebral collapse can occur, in which the vertebral body of the L5 slides towards the pelvis. Fortunately, most spondylolistheses are classified as Grade 1 or 2 and in case symptoms appear, they can be treated without surgery.
SYMPTOMS
As with degenerative spondylolisthesis, symptomatic isthmic spondylolisthesis can have some symptoms:
- In general, patients do not report pain while sitting, because this posture increases the diameter of the vertebra and the spine. In the upright position, the diameter decreases, increasing pressure on the nerve roots and spinal cord.
- Patients usually have tight posterior muscles, stiffness in the waist, and difficulty or pain in over-stretching.
- Pressure on the nerve roots can cause leg weakness, but without severe or permanent damage.
- Backache (lumbar pain) that often extends to the lower extremities. However, many patients with spondylolisthesis report no symptoms, while others report only lower extremity pain.
- Sometimes patients report symptoms of sciatica with pain following the distribution of the sciatic nerve on one or both legs. In addition, they may report feeling their feet tired after prolonged standing or walking (neurogenic lameness).
At the level of most of the lumbar spine, nerve roots are involved, not spinal cord as the latter ends in the spinal conus medullaris (L1 vertebra) and continues with the hippuridae (nerve roots exiting below the conus medullaris). When the vertebral stenosis becomes too severe or the patient develops disc herniation as well, he/she may develop cauda equina syndrome with progressive damage to the nerve roots and loss of bladder and bowel control. This is a rare syndrome that requires immediate surgical decompression.
Additional symptoms for the 2nd, 3rd and 4th Grade Spondylolisthesis:
In addition to the above symptoms, patients with 2nd, 3rd and 4th degree spondylolisthesis exhibit a macroscopically recognizable deformity of their spine, especially if the spondylolisthesis is accompanied by large angulation. Specifically: The patient will be presented with a shorter torso with a protruding abdomen
- They will also have significant lordosis and increased pelvic tilt.
- Finally, he/she will have tight posterior lumbar muscles that lead patients to a strange gait
Rarely, patients may also exhibit symptoms of cauda equina syndrome with progressive numbness or weakness in the legs and inability to control the bladder and bowel. In this case, the patient should seek immediate medical attention.
TREATMENT
The principles of treatment are the same as those of degenerative spondylolisthesis. Especially for adolescents with symptoms, conservative non-steroidal anti-inflammatory drugs (NSAIDs), rest and physiotherapy are sufficient for the vast majority of patients, while surgical treatment includes the options mentioned above.
