Lumbar spinal stenosis is a condition in which abnormalities in the bony and fibrous structures of the lumbar spinal canal occur due to certain factors, resulting in narrowing of the canal in one or more places and the development of clinical symptoms by compression of the dura and nerve roots. This disease is one of the common causes of lumbar pain and has a tendency to increase in incidence clinically due to increased awareness of it in recent years. There are many methods of measuring the lumbar spinal canal, and the measurement data varies somewhat among schools. It is generally accepted that a sagittal diameter of less than 12 mm of the two diameters of the spinal canal can be considered as stenosis. Some scholars believe that due to individual differences, it is more clinically meaningful to calculate the spinal index than to simply measure the two diameters of the spinal canal. With the development of medical imaging, the understanding will become more perfect. Etiology and classification] (a) Congenital (developmental or idiopathic) lumbar spinal stenosis. (2) Acquired (secondary) lumbar spinal stenosis 1. degenerative degeneration and posterior bulging of the intervertebral disc, osteophytes at the posterior edge of the vertebral body and arch, small joint hypertrophy and coalescence, epidural vascular abnormalities and fatty inflammatory edema, etc. 2. Injurious After lumbar fracture dislocation, the displaced bone and new bone can cause spinal stenosis. This type is not discussed in this paper. 3. Medical origin Bone scabs formed after posterior spinal fusion, adhesions and scar formation after laminectomy or injection therapy for lumbar disc herniation. 4. spinal slippage congenital or acquired discontinuity of the spinal isthmus, secondary to spinal slippage. (C) Mixed lumbar spinal stenosis The coexistence of the above-mentioned congenital and acquired factors is more common in clinical practice. 【Clinical manifestations】 Long-term recurrent lower back, sacral and hip pain, unilateral or bilateral, may radiate to the lower extremities. When the upper lumbar spinal nerve is damaged, the pain radiates to the groin and anterolateral thigh; when the lower lumbar spinal nerve is damaged, the pain radiates to the posterior thigh, posterior lateral calf and foot. Neurovascular ischemia may cause intermittent claudication. Some patients may have dyspareunia, male sexual dysfunction, and abnormal perineal sensation. On examination, there is pressure pain next to the spinous process of the lower lumbar spine, and when the lumbar region is extended posteriorly, the pain increases due to the reduction of the effective space in the spinal canal, which restricts lumbar extension. Straight leg raise test may be positive. Abnormal sensation in the lateral calf and dorsalis pedis. Weakness of the anterior tibial, extensor, and toe extensor muscles. The knee tendon reflex and Achilles tendon reflex are abnormal. There are also a few patients without obvious signs. Diagnosis】 Clinical manifestations are the basic basis for diagnosis, and the following auxiliary examinations can be done for accurate diagnosis. Lumbar spine x-ray frontal and lateral radiographs, and if necessary, additional oblique and hyperextension and hyperflexion radiographs. Scoliosis, reduced or absent lumbar anterior lordosis, narrowing of the intervertebral space, osteophytes, fracture dislocation, spondylolisthesis and other changes can be seen on the film, and the sagittal and transverse diameters of the lumbar spinal canal can be measured. Vertebral canal imaging can reveal changes such as obstruction, filling defects in small joints and intervertebral discs, and interruption of nerve root sheaths in different conditions. In addition, electromyography, ultrasound, CT, and MRI can be helpful in diagnosis. Treatment】 (a) Non-surgical treatment Most patients can have their symptoms relieved after non-surgical treatment. In some patients, the symptoms can be relieved by self-reconstruction of lumbar thrust segment stability as the age increases gradually. See the overview of this section for non-surgical treatment methods. (II) Surgical treatment Indications: ①Patients with severe neurological dysfunction, especially cauda equina dysfunction. (ii) Those who have long-term non-surgical treatment that is ineffective and have severe symptoms. (iii) Most mixed spinal stenosis. Surgery is required to release the compression of the dura and nerve roots. The operation includes laminectomy, excision of the hypertrophic ligamentum flavum, partial excision of the superior articular eminence, enlargement of the nerve root canal and release of nerve adhesions. The criteria for complete decompression are restoration of dural pulsation and nerve root glide of 1 cm or more. In cases with preoperative intervertebral joint instability, bilateral laminectomy and synovectomy, and complete decompression before the age of 40, a spinal fusion should be performed at the same time as the above mentioned operations.