Lumbar disc herniation (LDH) is the most common cause of low back pain, the most studied subject in spinal disorders, and the most frequently encountered clinical problem in pain medicine. Since the first description of LDH by Mixter and Barr in 1934, clinical knowledge of LDH has been accumulated for 70 years, and a wealth of experience in diagnosis and treatment has been accumulated. Especially in the last 20 years, the development of neurobiology, spinal surgery, imaging, pain and material science, the application of endoscopic techniques and minimally invasive interventions have given us more options to diagnose and treat LDH. At the same time, it also brings us a lot of confusion, such as how to evaluate traditional therapies? How to objectively view and apply new technologies? How do clinicians choose treatment methods? How to improve the effectiveness of treatment to meet the needs of patients is still a challenge that the medical community must face. At present, we must understand the diagnosis and treatment status of lumbar disc herniation with a scientific attitude in order to strive to improve the diagnosis and treatment of LDH. I. Lumbar disc degeneration is the basic pathogenesis of LDH The lumbar intervertebral disc is one of the earliest organs in the human body to degenerate, starting at about 20 years of age, and is an irreversible process of degenerative change that occurs under the influence of many factors. The degenerated disc has a reduced ability to resist pressure due to the degradation of proteoglycans in the nucleus pulposus and the reduction of polymeric water; the change in collagen composition weakens its ability to buffer pressure and resist tension, and the combined effect of the two decreases the mechanical function of the disc to absorb load and disperse stress. Based on the degeneration of the biochemical composition of the disc, the loss or weakening of biomechanical function leads to a series of changes in the annulus fibrosus, such as fissures, ruptures or even ruptures, which eventually leads to the protrusion of the nucleus pulposus, compression and irritation of the spinal cord and nerve roots, resulting in symptoms and signs of lumbar pain. The International Society for the Study of the Lumbar Spine (ISSLS) and the American Academy of Orthopaedic Surgery (AAOS) classify LDH as degenerative, bulging, herniated (under the posterior longitudinal ligament), prolapsed (behind the posterior longitudinal ligament) and free. The degenerative type is an early change and is not usually confused with the herniated type. The more problematic type is the meaning and treatment of bulging and bulging. Bulging discs are discs that have degenerated to a lower height, with the peripheral annulus fibrosus symmetrically exceeding the normal physiological limits of the vertebral endplate edge, and the discs bulging backwards in the MRI sagittal plane, showing 1,6 to 2,3 mm beyond the periphery of the vertebral body in CT and MRI cross-sections. Often reported as “disc bulge”, such as this imaging report, not combined with the patient’s symptoms, signs and neurological localization, and perform chemical lysis of the nucleus pulposus, intervertebral disc cut suction or electrothermal discoplasty, that can reduce pain, reduce bulging, may go into the wrong area. Theoretically, disc bulge is a physiological degenerative process, and in the absence of other pathological factors, most bulges do not produce symptoms. Most patients with LDH can recover by non-surgical treatment. The pathological typing of LDH has many methods, and the pathological typing is important for judging the prognosis and selecting treatment methods. 1, bulging type (bulging): physiological degeneration, the fiber ring is relaxed but intact, the nucleus pulposus is crinkled, manifested as a uniform fiber ring beyond the edge of the vertebral body end plate. Generally no clinical symptoms, sometimes due to narrowing of the intervertebral space, vertebral joint instability, secondary changes in the joint protrusion, recurrent back pain, rarely radicular symptoms. If combined with developmental spinal stenosis, the spinal stenosis is manifested and spinal decompression should be performed. 2. Protrusion type (protrusion): protrusion is the protrusion of the nucleus pulposus into the annulus fibrosus but the outer layer of the annulus fibrosus is intact, manifesting as a limited protrusion of the intervertebral disc into the spinal canal, which may be asymptomatic, with some patients showing typical neurogenic symptoms and signs. This type can be relieved by conservative methods such as traction, bed rest and lesion injection, but the recurrence rate is high due to the poor healing ability of the ruptured annulus fibrosus. 3.extrusion type (extrusion): complete rupture of the fibrous ring and posterior longitudinal ligament, the nucleus pulposus protrudes into the spinal canal, and there are obvious symptoms and signs, and extrusion is difficult to heal on its own, the effect of conservative treatment is relatively poor, and most need minimally invasive intervention or surgery. 4, free type (seqestration): the herniated nucleus pulposus is not connected with the corresponding intervertebral disc, and can be free into the upper or lower segments of the spinal canal, intervertebral foramen, etc. Its clinical manifestations are persistent neurogenic symptoms or spinal stenosis symptoms, and a few can appear cauda equina syndrome, and this type often requires surgery. The distinction between LDH and discogenic pain Lower back pain caused by disc lesions can be broadly classified into two categories according to their pathogenesis: discogenic and spinal or neurogenic. The difference lies in whether the pain is confined to the lower back or involves radiating pain to the lower extremities, with the latter indicating nerve root damage, mostly due to disc herniation. Discogenic pain is defined as degeneration of the fibrous annulus forming an internal fissure without superficial rupture, without signs and symptoms of nerve root damage, and is dominated by chronic lumbosacral pain that is aggravated by sitting. The diagnosis depends on MRI showing degenerative manifestations of the intervertebral disc, and T2-weighted images showing a high-signal area posterior to the disc, suggesting a fissure behind the fibrous ring, as the fissure contains fluid from the disc and a local inflammatory response. Discography induces corresponding pain and reveals a disc fissure extending into the outer 1/3 of the annulus fibrosus, usually a marginal tear connected to the nucleus pulposus. At the same time, other adjacent discs may be free of degeneration, and discography without replication of pain is diagnosed as discogenic pain when combined with clinical symptoms and signs. After the diagnosis of this disease, non-surgical treatment is mainly applied, and in recent years, intradiscal electrothermal therapy and ozone nucleolysis therapy are mostly used, the former including radiofrequency intradiscal electrothermal IDET or intradiscal electrothermal annuloplasty IDETA. The puncture catheter of IDETA can be circumferentially curved to reach the posterior annulus fibrosus rupture along the annulus fibrosus tissue and is gradually heated to cause collagen fibers to contract, degenerate, polymerize, and destroy local nerve endings. These new treatment methods have been developed rapidly recently, but the long-term efficacy remains to be observed. (a) Conservative treatment is the basic treatment for LDH. Most patients with LDH can be relieved or cured by conservative therapy, which aims to accelerate the decompression of inflammatory edema in the herniated part of the lumbar disc and the irritated nerve root, thus reducing or relieving the irritation and compression of the nerve root. 1. Conservative therapy is mainly indicated for: (1) young people with the first attack or short duration of the disease; (2) people whose symptoms can be relieved by themselves after rest; (3) people without spinal stenosis on X-ray examination. 2. Specific methods include absolute bed rest, continuous traction, physiotherapy, massage, massage, oral anti-inflammatory and pain-relieving drugs, focal injection therapy, etc. Among them, the role of focal injection therapy is to reduce the inflammatory response of the nerve root, with an efficiency of 76% for the herniated type and only 26% for the bulging type. Generally, the regular conservative treatment for 6-8 weeks has no effect on the consideration of other methods, and it is currently believed that the efficacy of surgery within 2 months of onset is significantly better than that of late surgery. (B) Minimally invasive interventional techniques 1, disc chemolysis (chemonucleolysis) Disc chemolysis is the application of collagenase hydrolysis, resulting in the degradation of the nucleus pulposus or herniated material, through the relief of nerve root irritation and compression to achieve therapeutic purposes. This technique is mainly used for herniated and prolapsed LDH, and numerous basic and clinical studies have shown that disc chemolysis is one of the available treatment options. The current problem in China is that the indications for this treatment should be clarified and the technical operation should be strictly regulated. Due to the lack of formal training of some operators and irregular treatment, various complications and accidents have occurred. Therefore, it is necessary to discuss the safety and operation specification of collagenase chemolysis. According to clinical experience and related research, some experts recognize that the safety of collagenase chemolysis depends on the following factors: (1) correct selection of indications and contraindications; strict operation according to specifications; (3) awareness of the risk of inadvertent introduction of collagenase into the subarachnoid space and preventive measures. (1) Indications: (1) chronic LDH with clear clinical diagnosis and ineffective conservative treatment; (2) acute and subacute LDH; (3) herniated and prolapsed LDH; (4) LDH with central calcification of the protrusion but no surrounding calcification; (5) combined with mild bony spinal stenosis without nerve entrapment and cauda equina syndrome. (2) Contraindications: (1) combined bony spinal stenosis with nerve entrapment and cauda equina syndrome; (2) severe bilateral lateral saphenous stenosis or lesion with ipsilateral lateral saphenous stenosis; (3) severe calcification of the protrusion; (4) significant apprehension in patients with a history of severe drug allergy; (5) severe metabolic diseases such as cirrhosis, active tuberculosis, severe diabetes mellitus; (6) pregnant women and children under 14 years of age. (3) Recognize the risk of inadvertent introduction of collagenase into the subarachnoid space and preventive measures: ① Animal experiments showed that collagenase injection into the subarachnoid space of rats led to spinal cord hemorrhage and necrosis, and all rats developed hind limb paralysis. It is suggested that collagenase accidentally injected into the subarachnoid space can cause spinal cord injury. ②Clinical observation revealed that anterior epidural space puncture placement of sacral fissure could cause delayed spinal anesthesia, with an incidence of 1,22%. ③ collagenase chemical lysis when the local anesthetic test dose observation time should be extended to 20 minutes, 20 minutes after no signs of spinal anesthesia before the injection of collagenase, this method is called delayed spinal anesthesia test. It is an effective measure to prevent the inadvertent introduction of collagenase into the subarachnoid space by promoting this method through clinical observation of large samples. 2. percutaneous lumbar discectomy (PLD) The mechanism of PLD is to reduce disc pressure by removing disc tissue, thereby reducing or eliminating the tension mechanism of nerve root damage. Clinical reports of randomized controlled studies have an excellent rate of less than 70%, with only 10-15% of indications. Patients requiring surgery are suitable for this technique, but the operation is blind and the postoperative recurrence rate is high. The efficacy and reliability are inferior to those of chemolysis and endoscopic disc removal, and this technique is not used alone. 3, percutaneous laser disc decompression (PLDD) operation is similar to PLD, which uses laser to generate heat energy to vaporize disc tissue, dry and dehydrate it, reduce the tension and pressure of nucleus pulposus tissue on nerve roots, and relieve radicular symptoms. Most authors report significantly lower efficacy than chemolysis. This procedure is also a non-directly invasive procedure, and its safety, efficacy, and cost-effectiveness ratio need to be further observed. Endoscopic discectomy (MED) (1) There are three types of endoscopes according to the access: (1) posterior-lateral transvertebral foramen approach discectomy. (2) Anterior laparoscopy. (3) Posterior intervertebral discoscopy: i.e., standard interlaminar disc approach. (2) MED is suitable for single-segment paracentral herniation and prolapse, and allows simultaneous decompression of the spinal canal such as lateral fossa enlargement. Due to good monitoring of the imaging system, it avoids blindness, precise positioning, appropriate amount of resection and effective decompression, little trauma, fast recovery, good spinal stability, and high recent excellent rate. However, due to the limitation of exposure, high technical requirements, difficulty, difficulty of complete surgery, and long-term efficacy to be further observed. (3) Selection of surgical methods 1. Indications for surgery LDH is diagnosed by symptoms, signs, imaging and neurological localization, and is not relieved by regular conservative treatment for 6 to 8 weeks. 2. Contraindications to surgery Patients with severe cardiopulmonary, hepatic and renal diseases, infectious lesions, severe neurasthenia and psychiatric disorders. 3. Choice of surgical method (1) Open decompression: low back pain with unilateral lower limb pain, accumulating one gap. (2) Hemilaminectomy: patients with low back pain accompanied by unilateral limb pain and accumulated two interstitial spaces or patients with original diagnosis of protrusion of a certain interstitial space and intraoperative discovery of pathological changes in that interstitial space insufficient to explain preoperative symptoms and the need to explore the adjacent interstitial space. (3) Total laminectomy: ① Giant central lumbar disc herniation with symptoms of acute cauda equina injury. (2) For recurrence after nucleus pulposus removal that is ineffective with conservative treatment and requires a second operation. ③For those with extreme posterolateral type or combined with spinal stenosis. Partial resection of the articular process or resection of the articular process to achieve complete decompression of the spinal canal and nerve root canal is the fundamental guarantee of satisfactory results. Clinical data and a large number of cases follow-up excellent rate of 80-90%, 15 years after surgery, the excellent rate is still in 75-80%. 4.Efficacy assessment A small number of people still have residual low back pain and worsening symptoms after LDH treatment with standard surgery. These manifestations are often attributed to pathological changes such as narrowing of the intervertebral space after discectomy, secondary lumbar instability, and spinal stenosis. The pain of many of these patients has been resolved by methods such as segmental fusion, including posterior intertransverse fusion; interbody fusion and the interbody fusion device technique (BAK, Cage) developed in the 1990s, and it is now generally accepted that the fusion rate is positively correlated with the clinical satisfaction rate. It has also been observed through a group of patients combined with internal fixation followed by posterior posterolateral fusion that despite a fusion rate of 89%, the clinical satisfaction rate was only 60%. Therefore, some authors believe that a solid fusion does not necessarily predict a satisfactory clinical outcome and that there may be other reasons for residual symptoms after conventional disc surgery. (iv) Reconstruction techniques The accelerated degeneration of adjacent segments after lumbar fusion and the formation of pseudoarthrosis in the fused segment leading to intractable postoperative low back pain have raised concerns. Allogeneic disc transplantation, artificial disc replacement, attempts at artificial nucleus pulposus technology and experimental studies on gene therapy for delaying and reversing disc degeneration aimed at rebuilding the physiological function of the disc are new topics in the treatment of disc diseases. 1. Allogeneic disc transplantation is currently difficult to be clinically applied because it is prone to early degeneration and displacement. Artificial nucleus pulposus prosthesis replacement is suitable for a small number of patients with LDH and discogenic lower back pain with intact annulus fibrosus and intervertebral space height ≥5 mm, and the clinical effect is symptom relief and satisfactory restoration of intervertebral space height. Its shortcomings are prosthesis displacement and postoperative lumbar and leg pain residual, materials and processes to be further studied. 2. Artificial total disc replacement The indications that can be considered at present are mainly discogenic pain, post-lumbar discectomy failure syndrome, and LDH in general should be regarded as a contraindication, because most LDH have good long-term results by conventional decompression and/or fusion. The choice of indication for any technique is the primary issue, because if there are very few cases with this technique or if there are other simpler, safer, and more effective methods available, then the widespread use of this technique is questionable. Until the material problem is solved, no artificial disc design and technology can replace conventional decompression fusion, and blind clinical application can be too costly for patients. 3, gene therapy Some people hope that gene therapy strategies to achieve the purpose of delaying or reversing disc degeneration, growth factors and disc degeneration, regeneration of the relationship between one of the hot spots, animal testing through transgenic methods to regulate the expression of a certain growth factor to promote the regeneration of the intervertebral disc extracellular matrix has shown initial results, I believe that in the future there is hope to apply to humans, to delay the purpose of disc degeneration. In conclusion, it is the inescapable responsibility of our clinicians to explore, innovate and experiment with therapeutic methods, and it is correct to require any innovation to be less costly, safer and more effective than existing methods. At present, in addition to conventional open surgery, minimally invasive interventional techniques have been an important means of treating LDH, especially for those with more severe symptoms, with better results than conservative treatment. For spine surgery how to prevent postoperative failure syndrome (FBSS) has always been a challenge to the operator, practice has proved that strict mastery of the indications for surgery and careful performance of the first surgery is the key to prevent postoperative FBSS, because the second surgery can only improve in 50% of cases, while 20% worsen. Therefore, the correct diagnosis and reasonable treatment of LDH is the key to achieve satisfactory results.