1.What is lumbar spondylolisthesis?
Lumbar spondylolisthesis is the partial or complete slippage of the upper vertebrae on the surface of the lower vertebrae due to abnormal intervertebral connections. Simply put, lumbar spine slippage refers to the forward or backward displacement of one vertebral body on another vertebral body. Lumbar spondylolisthesis is generally an anterior slip. Posterior slippage occurs in the lumbar 5 and lumbar 4 vertebrae, accounting for approximately 95% of cases, with 82-90% occurring in the lumbar 5 vertebrae and rare in other lumbar vertebrae. Some traumatic or degenerative slippage can occur simultaneously in multiple segments, even posterior slippage. Zhang Yafeng, Department of Spinal Orthopedics, Wuxi Hospital of Traditional Chinese Medicine
2.How is lumbar spondylolisthesis caused?
Lumbar spondylolisthesis is mainly caused by abnormal bony connection between vertebrae. There are mainly five kinds of abnormal intervertebral bony connection.
(1) Congenital dysplasia: due to a defect in the upper sacral or lumbar 5 vertebral arch, thus lacking sufficient strength to stop the tendency of the vertebral body to move forward and slip forward. It is hereditary, and cases of lumbar vertebral slippage in both parents and children have been reported.
(2) Abnormalities of the isthmus of the articular eminence trigger slippage: abnormalities of the isthmus may include fatigue fractures of the isthmus, acute fractures of the isthmus; and lengthening of the isthmus.
(3) Degenerative changes: wear and tear of the corresponding small joints due to prolonged lumbar instability or increased stress. Degenerative changes, so that it presents a special form, the joint abruptly changed to the level and gradually slipped. Most commonly seen after the age of 50, the incidence of women is three times higher than that of men. Mostly seen in lumbar 4, followed by lumbar 5.
(4) Traumatic: trauma causes fracture of the vertebral arch and isthmus of the small joint, and slippage occurs due to disruption of the continuity of the anterior and posterior structures of the vertebral body.
(5) Pathological fracture: the loss of stability of the vertebral body due to localized lesions involving the upper and lower synapses of the vertebral isthmus, resulting in vertebral body slippage.
In short, in addition to congenital slippage, most scholars now believe that lumbar slippage is mainly caused by trauma and strain. Congenital slippage accounts for 33%, isthmic cleft triggers slippage accounts for 15%, and the most common is degenerative slippage.
3.Clinical symptoms of lumbar spondylolisthesis
Most lumbar spondylolisthesis is asymptomatic. The symptoms and signs of patients are related to the type of slippage, the stability of the lumbar spine, the degree of slippage, age, gender and other factors. Generalized slippage is most often seen to develop after the age of 50, and the incidence increases with age. Patients may have pain in the lumbosacral region, and the soreness and swelling may be dissipated to the back of the thigh or the whole thigh.
When the lumbar spine is less stable, the pain has the following characteristics: pain and stiffness of the lower limbs are realized at rest, which can be slightly relieved after activity, and the pain increases after prolonged standing and squatting activities, and is relieved after rest again. In case of spinal stenosis, there may be pain in the lower limbs, various motor sensory disorders, muscle stiffness, skin tingling, numbness, etc. Sometimes intermittent claudication occurs. When accompanied by disc herniation, the nerve traction sign is positive. The isthmus collapsing slippage is mostly seen under 50 years old may have low back pain and lower extremity pain, which may be aggravated or induced by lumbar hyperextension. Radicular pain may be present in combination with disc herniation.
The physical signs may be increased lumbar convexity and pressure pain of the spinous process at the diseased vertebrae.
4.X-ray performance of lumbar spondylolisthesis
X-ray plain film is very important for the diagnosis of lumbar spondylolisthesis and the formulation of treatment plan. The use of lateral, left and right oblique and power X-ray is necessary. Lateral radiographs can show the degree of slippage, oblique radiographs clearly show the isthmus lesion, and power radiographs, i.e., lumbar hyperextension and flexion radiographs, can determine the degree of lumbar instability.
Tomography and CT have a high diagnostic rate for isthmus lesions, and CT can clarify the presence of spinal stenosis and complications of disc herniation, and spinal canal imaging and nuclear magnetic examination can be used as needed.
5.Diagnosis of lumbar spondylolisthesis
(1) Long-term recurrent lower back pain, pain is aggravated when standing or bending, and alleviated when lying in bed, some patients have sciatica, and a few severe cases have lower limb muscle weakness, muscle atrophy, hyperalgesia, incontinence, etc.
(2) Restriction of lumbar posterior extension activities, anterior enlargement of the lumbar spine, and pressure pain of the spinous process of the affected spine.
(3) According to the above symptoms and signs, if the disease is suspected, lateral and oblique radiographs of the lumbar spine can be taken to clarify the diagnosis, and in some cases, CT and MRI are required to clarify whether the spinal stenosis and intervertebral disc herniation and other complications are combined.
6.Treatment of lumbar spondylolisthesis
(1) Non-surgical treatment: effective for most patients, non-surgical treatment includes bed rest, avoid participating in activities such as lumbar weight-bearing, twisting and bending, lumbar physiotherapy, lumbar brace, waist protection, strengthening lumbar back muscle exercise, local closure, and taking relevant drugs.
(2) Surgery: Surgery can be performed for those whose conservative treatment is ineffective, severe slippage, radiographs confirming the progress of slippage and persistent nerve root compression and spinal stenosis.
There are two types of surgery: one is to reposition and fix the slipped vertebral body with specific instruments through the posterior approach, while performing spinal cord and nerve root decompression and intertransverse process bone graft fusion. The second is to perform intervertebral discectomy and intervertebral bone graft fusion through the anterior approach.
7.Prevention of lumbar spondylolisthesis
(1) Reduce excessive rotation of the lumbar region, squatting and other activities, and reduce excessive weight bearing on the lumbar region. This can reduce the excessive strain and degeneration of the small joints of the lumbar spine, and to some extent avoid the occurrence of degenerative lumbar spondylolisthesis.
(2) reduce body weight, especially to reduce the accumulation of abdominal fat. Excess weight increases the burden and strain of the lumbar spine, especially the accumulation of abdominal fat, which increases the tendency of the lumbar spine to slip forward on the sacrum.
(3) strengthen the functional exercise of the lumbar back muscles. Strong lumbar back muscles can increase the stability of the lumbar spine and antagonize the tendency of the lumbar spine to slip forward. Exercise of the lumbar back muscles can be used in the following two ways. One is the prone position, the two upper limbs in an abducted position, head up, chest up, upper limbs out of bed, while the lower limbs are also straightened and lifted backwards in a swallow-like position. The second is supine position, two knees flexed, feet on the bed, inhalation chest and waist, so that the buttocks leave the bed, exhale recovery.
8, correct grasp of the treatment principles of lumbar spondylolisthesis
Since lumbar spondylolisthesis has its unique pathological anatomical changes and radiological imaging features, it is relatively easy to be diagnosed among the various causes of lumbar pain, and it is supposed to obtain a better treatment effect. However, this is not the case, and some patients’ symptoms do not improve after surgery, and the condition even worsens further. In addition to the operator’s technique and experience, the recognition of different pathological changes of lumbar spondylolisthesis and the choice of indications for different treatment methods are important factors affecting the treatment effect.
(1) Not all lumbar spondylolisthesis require treatment
Some doctors believe that all lumbar isthmic fissures require surgical treatment to prevent further slippage of the lumbar spine, aggravation of symptoms and nerve compression. In fact, some patients with lumbar isthmic spondylolisthesis do not develop symptoms of low back pain until old age, and some patients with even mild spondylolisthesis remain untreated throughout their lives because they have no symptoms of low back pain. Studies have shown that the degree and type of chronic low back pain in patients with acquired lumbar spondylolisthesis is not substantially different from that of normal individuals. Recent studies suggest that the incidence and severity of low back pain in the middle-aged population with mild or moderate lumbar spondylolisthesis diagnosed on radiographs is not different from those without lumbar spondylolisthesis. Therefore, mild lumbar spondylolisthesis is not necessarily the root cause of low back pain, and there is no need for occupational restriction and even less need for surgical treatment for those without low back pain.
(2) Not all lumbar spondylolisthesis with low back pain requires surgery
For patients with lumbar spondylolisthesis who have symptoms of low back pain, first of all, the site and nature of their pain should be clarified, and whether their pain is related to the spondylolisthesis should be judged, because degeneration of the intervertebral disc adjacent to the spondylolisthesis site, small joint lesion or soft tissue injury can lead to low back pain, and symptomatic treatment should be carried out for their causes, or experimental treatment such as braking and physiotherapy should be carried out. If conservative treatment is ineffective or if it is determined that their pain is related to slippage, then surgical treatment should be considered. In addition, the possible drawbacks after lower lumbar fusion should be carefully considered for elderly patients.
(3) Selecting the appropriate surgical procedure according to the severity of the slippage
There are various ways to classify lumbar spine slippage, and the commonly used ones are divided into developmental slippage and acquired slippage, with the latter being more common in clinical practice. Most orthopedic surgeons use the Meyerding scale of 1 to 4 when describing the degree of slippage, but in fact the Newman system may more accurately reflect the condition of lumbar slippage. Because it consists of two parts, the first part is similar to the four-level classification and reflects the horizontal displacement of the posterior inferior angle of the slipped vertebra, and the second part indicates the degree of forward rotation of the anterior inferior angle of the slipped vertebra. It is important to make a comprehensive evaluation of the patient’s age, type of slipped vertebra, degree of slippage, state of the intervertebral disc and spinal canal before surgery, so as to select the appropriate surgical method with a view to achieving the desired result.
(4) Fusion of slipped vertebrae is the ultimate goal of surgical treatment
For patients with lumbar spondylolisthesis, an ideal surgery should include decompression of the compressed neural tissue, repositioning of the slipped vertebral body, and fusion of the slipped vertebral body with the adjacent vertebral body. In patients with sciatica or intermittent claudication, decompression of one or both nerve roots is necessary. However, in patients with mild slippage (<33%), repositioning is generally not necessary, as long as the slipped vertebral body can be fused and the normal physiological anterior convexity of the lumbar spine can be maintained. Instead of putting effort and time into resetting the slipped vertebrae, the operator should concentrate on ensuring the fusion of the slipped vertebrae. There are many kinds of slipped repositioning and fixation devices in the market, and in front of a wide range of new products, we should choose the fixation devices we need according to the actual situation of the patient, rather than blindly pursuing new technologies and ignoring the basic principles of lumbar slipped vertebrae.