1.What is lumbar spondylolisthesis.
Due to degeneration, trauma or congenital factors such as the lumbar vertebral body and the vertebral arch root or small joint synapse bone continuity interruption, known as lumbar isthmus collapse; vertebral body dislocation resulting in continuity extension, so that the superior vertebral body, the vertebral arch root, transverse process and the upper joint synapse together in the lower vertebral joint above the forward displacement, known as lumbar isthmus collapse combined with lumbar spine slippage. The degenerative factors causing lumbar spondylolisthesis account for more than 60% of the cases. The age of onset is 20-50 years old more often.
2.Etiology.
It is mainly caused by the abnormal intervertebral bony connection. There are mainly 5 kinds of intervertebral bony connection abnormalities.
(1) congenital dysplasia.
(2) abnormalities of the isthmus of the articular eminence triggering slippage.
(3) Degenerative degeneration.
(4) traumatic.
(5) pathological fracture.
3. Clinical manifestations.
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. The incidence of lumbar spondylolisthesis 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 is characterized as follows: pain and stiffness of the lower limbs are realized at rest and 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 occur with combined disc herniation.
Treatment.
Non-surgical treatment.
It is suitable for patients with short history, mild symptoms and no obvious slippage, patients with simple isthmic cleft and patients who are too old and poor in health to tolerate surgery. Non-surgical treatment mainly includes: rest physiotherapy, lumbar back muscle exercise, lumbar girth or brace, symptomatic treatment, etc. After standardized conservative treatment, most patients are able to relieve their symptoms.
Conventional surgical treatment.
1, nerve decompression: decompression is the main means to relieve symptoms. For severe slippage most authors advocate neurological decompression to relieve symptoms.
2, spinal fusion: Although modern surgical techniques can provide early postoperative stability, long-term stability also depends on a strong biological fusion. There are many methods of spinal fusion, which can be divided according to the site of bone grafting: intervertebral fusion, posterior posterolateral fusion, circumferential 360° fusion of the vertebral body, etc.; non-instrumented fixed fusion and instrumented fixed fusion according to whether or not instrumentation is used; and intervertebral fusion according to the surgical approach can be divided into anterior intervertebral fusion (ALIF) and posterior intervertebral fusion (PLIF) and transforaminal intervertebral fusion (TLIF).
3, lumbar spondylolisthesis repositioning: there are more controversies on whether the slipped vertebrae need to be repositioned and whether anatomical repositioning is required during lumbar spondylolisthesis surgery. Some authors believe that reset is not required for <33% of slippage, and that reset should be sought for >33% of slippage. However, most do not advocate the expansion of surgery to force a complete anatomical reset, because the long-term formation of lumbar slippage, its surrounding structure has changed accordingly, with the inherent stress to resist the pull and maintain the slippage, such as forced reset is not only difficult to completely reset, but also will destroy the adapted anatomical relationship, easy to lead to postoperative nerve root tension, nerve pull injury and other complications.
4, internal fixation of the spine.
①Strong fusion internal fixation: The so-called strong fusion internal fixation is an internal fixation system made of metal materials such as titanium alloy with high elastic modulus together with various fusion methods for internal fixation of the spine, with a rigid connection between the internal plant and the vertebral body. Usually strong internal fixation devices are used to correct deformities and stabilize the spine, with a high rate of bone fusion and reduced pseudarthrosis formation.
② Dynamic fusion internal fixation: Dynamic fusion internal fixation can also be called semi-strong internal fixation. This kind of internal fixation system is divided into two kinds, one is made of metal or polymer material with lower elastic modulus; the other is still made of metal material with high elastic modulus, but the device can produce local micro-movement inside. The main purpose is to disperse the load transfer of strong internal fixation with elastic materials or micro-movements, reducing the stress masking effect and the stress concentration in the adjacent segments. The main dynamic fusion fixation systems currently in clinical application are: LK ligament shaping; power screw fixation device; Twinflex dynamic fixation system; CrockYamagishi fixation system.
③ Dynamic non-fusion internal fixation: non-fusion dynamic fixation of the lumbar spine, also known as elastic fixation, is a type of fixation that alters the load transfer and range of motion of the lumbar spine without fusion. It is designed to change the load transmission of the spinal motion segment, prevent the spinal motion in the direction and plane of motion that produces pain, maintain the motion function, prevent the degeneration of the adjacent segment, make the unstable lumbar spine reach its normal state of activity characteristics, and achieve dynamic reconstruction of the lumbar spine sequence. The main dynamic internal fixation systems used for lumbar spondylolisthesis are Grafligament system, Dynesys system, ISOBAR and ISOLOCK system. In recent years, there have been a large number of clinical reports both at home and abroad, and the recent results are satisfactory.
Minimally invasive surgical treatment.
With the development of new technologies in spinal surgery, minimally invasive spinal surgery has made great progress. The representative procedures are: percutaneous lumbar interbody fusion; laparoscopic anterior lumbar spondylolisthesis; endoscopic posterior lumbar spondylolisthesis. These surgeries have been carried out in hospitals at home and abroad, and their recent results are satisfactory, while the long-term results are subject to further follow-up.