With the continuous deepening of clinical crural biomechanics research, people further recognize the importance of crural stability, thus put forward the concept of minimally invasive and make unremitting efforts in minimally invasive treatment of lumbar disc herniation. 1975 Hijikata first reported percutaneous nucleus pulposus removal, some scholars combined it with endoscopic technology to form the lateral approach discectoscope, and 1997 the first generation of posterior discectomy system was developed in the United States. The first generation of posterior discoscopy nucleus pulposus removal system was developed in the United States. Principle of posterior discectomy: Posterior discectomy is an internationally advanced minimally invasive surgical procedure for crural surgery. The system perfectly combines advanced technology and clinical practice, providing patients with a safe and reliable treatment method with little damage and a short course of treatment. It can remove the protruding nucleus pulposus tissue, hypertrophied ligamentum flavum and hyperplastic cohesive articular eminence and other neurological compression factors, so as to obtain a radical curative effect. The system has highly clear observation performance, flexible and stable fixation device and well-designed surgical instruments, which facilitates doctors to carry out treatment smoothly and efficiently. Nowadays, posterior discoscopy can not only treat lumbar disc herniation, but also lumbar spinal stenosis such as lateral saphenous fossa stenosis and central canal stenosis. Posterior discoscopy is a straight tube type medical endoscope with optical fiber light guide, and the mirror body is separated from the light guide beam. This scope is mainly used for the microscopic surveillance of posterior minimally invasive discectomy to better observe the tiny and easily overlooked lesions, to make the surgery more thorough and to reduce the surgical trauma. The working principle is to transmit the light beam to the front end of endoscope objective lens through optical fiber to illuminate the observed object, and then rely on the imaging and magnification of the lens to obtain a clear image, so as to observe the deep tiny lesions. Comparison of current treatments I. Open surgery (major surgery) (I) Method 1. Straight incision in the middle of the crural column about 15–18mm 2. Removal of part of the vertebral plate 3. Removal of the ligamentum flavum 4. Removal of the nucleus pulposus (II) Advantages 1. Good surgical results, intuitive 2. Wide adaptability, able to deal with herniation and stenosis at the same time 3. Low investment in fixed equipment ( (C) Disadvantages 1, trauma is slightly large, there is a certain impact on the lumbar back muscles, some patients have lumbago after surgery 2, postoperative bedtime is a little long 2, percutaneous puncture lateral discectomy (including resectors) (a) Methods 1, puncture under the C-arm; 2, placement of the cannula; 3, fibrous annulus incision, 4, pincer clamping out the nucleus pulposus (B) Advantages Small trauma, less bleeding, fast recovery (C) Disadvantages 1, narrow indications, only resection of discs, the operation can only be performed in a small amount of time, and the operation can only be performed in a small amount of time. (1) Narrow indications, can only remove the intervertebral disc, poor postoperative effect (2) Need other equipment input (C-arm, CT), large investment (3) High incidence of side injuries (e.g., nerve injury, dural damage, low safety factor) (4) Longer training and learning period (3) Nucleotics (a) Method (1) Lateral approach in CT or C-arm guided injection (2) Allergy test (3) Injection (b) Advantages (1) Small trauma, fast recovery (2) Small investment (c) Disadvantages Narrow indications, certain recurrence rate, big side damage. Percutaneous puncture (laser discectomy) (a) method steps with percutaneous puncture, the nucleus pulposus with laser vaporization (b) Advantages Small trauma, quick recovery (c) Disadvantages 1, narrow indications, 2, the need for laser, C-arm support, the cost is high, 3, the laser energy is easy to cause damage to the surrounding tissues, is not easy to control, and even caused by necrosis V. Percutaneous puncture plasma ablation (a) method steps with percutaneous puncture, the nucleus pulposus with a plasma knife. Nucleus pulposus is vaporized and condensed by plasma head (2) Advantages Small trauma, fast recovery (3) Disadvantages 1, narrow indications 2, plasma machine and easy to wear out the head, high cost 6, lateral discectomy (indirect decompression type) (1) Methods 1, lateral puncture 2, placing the trocar, put in the endoscope for observation, 3, the annulus of fibrosis is cut, 4, the nucleus pulposus is clamped out (2) Advantages Small trauma, less bleeding, fast recovery (3) disadvantages 1, price is comparable to the posterior approach, the price is comparable to the posterior approach, the price is comparable to the posterior approach. Points 1, the price is comparable with the posterior 2, the indications are slightly narrow, can not remove the hypertrophic yellow ligament, bone redundancy, etc., can not deal with spinal stenosis 3, there are certain complications 7, posterior discoscopy discectomy (direct removal type) 1, method 1, the crural side of the 1cm, incision length 1, 5cm, 2, drilling holes in the vertebral plate, 3, the removal of hypertrophic yellow ligament, bone redundancy, etc., 4, the removal of the nucleus pulposus, 5, the spinal canal decompression, relaxation of the nerve roots Advantages: small trauma, low bleeding, fast recovery, safety, good efficacy, fast recovery, wide range of indications, able to deal with lumbar disc herniation and spinal stenosis at the same time, mainstream technology recognized by international academics, Disadvantages: high requirements for the operator: need a good foundation in open surgery and a longer learning curve, Posterior discectoscopy is the most advanced technology in the international crural system. Posterior discoscopy is the most advanced minimally invasive surgery concept in the world, which revolutionizes the traditional surgical methods and promotes the development of the technology of the crural surgery, and it is the safest and most effective technological innovation for the invasive crural surgery. Under the supervision of endoscope, the technique directly removes the herniated nucleus pulposus of the intervertebral disc and deals with spinal stenosis with surgical instruments, and the surgical principle, operation process and clinical efficacy are the same as that of open surgery. It is characterized by minimally invasive techniques, with a skin incision of only 1.5cm, without stripping the paraspinal muscles, preserving the supraspinous and interspinous ligaments, most of the superior and inferior articular processes, as well as the unbroken annulus fibrosus and posterior longitudinal ligament, and maintaining the stability of the crista as much as possible, in order to remove the protruding nucleus pulposus tissues, hypertrophied ligamentum flavum, and proliferative and cohesive articular processes and other neurological pressure-causing factors, so as to enable the patients to obtain a radical curative effect. As the operation is performed by specialized orthopedic surgeons, they can better grasp the indications for surgery and treatment effect, and reject the chaotic application of some minimally invasive techniques in the clinic, making the application of minimally invasive techniques more scientific, safer and more secure, which is conducive to the scientific and healthy development of the main stream of minimally invasive techniques of the crestal column, and at the same time, due to the fact that the technique is easy to learn and easy to master, it has become a mature and worthwhile new mainstream technique to be popularized. Compared with some traditional surgical methods, it has the following advantages: wide range of indications for the treatment of lumbar disc herniation and lumbar spinal stenosis; small wounds (about 1.5cm), less tissue damage, less bleeding, and shorter operation time; high safety performance, and the mirror can distinguish the tissues under the mirror clearly, avoiding nerve root injuries; shorter bed rest time and faster recovery after the operation; lower cost of the comprehensive treatment; high acceptance level of the patients; high definition field of vision, facilitating the treatment of lesions that can be easily overlooked; easy to deal with lesions that can be easily overlooked. High-definition vision, easy to deal with the lesions that are easy to ignore; the whole surgical process record, convenient for case discussion and academic exchanges. Posterior discoscopy will be a popular endoscopic system after arthroscopy, cystoscopy and laparoscopy.