I. GENERAL DATA From March 2012 to May 2013, our department applied percutaneous intervertebral foraminoscopy technique to treat 153 patients (168 discs) with lumbar disc herniation, including 21 cases of special types of disc herniation, including 6 cases of recurrent disc herniation (1 case of L3-4, 4 cases of L4-5, and 1 case of L5-S1); and 15 cases of combined degenerative vertebral body slippage in elderly patients ( 16 intervertebral discs) (L3-4 3 cases, L4-5 7 cases, L5-S1 4 cases, L4-5 and L5-S1 1 case), age 49-86 years old, average 43.6 years old, 13 male cases, 8 female cases, patients had varying degrees of radiating pain in the lower limbs and/or lumbosacral pain before surgery. Symptom exacerbation was the shortest for half a month, the longest for 8 months, and the average was 5.6 months. Types of herniation: 11 cases of protruding type (12 intervertebral discs), 7 cases of prolapsed type, 3 cases of free type; 3 cases of intraforaminal type (13.64G), 1 case of extraforaminal type (4.55G), 15 cases of paracentral type (68.18G), 3 cases of central type (13.63G). All the elderly patients in this group had different degrees of underlying diseases, including hypertension, heart disease, chronic bronchitis, emphysema, diabetes mellitus, and old cerebral infarction. Inclusion criteria: (1) Recurrent cases after open surgery (2) Poor or ineffective results after more than 3 months of formal conservative treatment (3) Those with nerve root compression symptoms, positive straight leg raising test and positive strengthening test. (4) Elderly patients with combined degenerative vertebral body slippage, age greater than 60 years old. (5) No manifestation of lumbar instability assessed by imaging and physical examination. Routine preoperative examination: (1) Taking positive lateral and power X-ray film to determine the morphology and size of intervertebral foramina, height of iliac crest, morphology and stability of the spine, and to confirm the site and direction of puncture, (2) Performing lumbar spine CT and MRI to observe the site and type of lumbar intervertebral disc herniation and whether it is accompanied by lumbar spinal canal stenosis and calcification, in order to determine surgical methods, the location and direction of the placement of the working trocars. Surgical methods: (a) Preoperative preparation Detailed communication with the patient before surgery to ensure good cooperation; mobile “G” arm X-ray machine; local anesthesia drugs (0.5% lidocaine injection) and anti-inflammatory painkillers; 10 ml of a 9:1 mixture of Onepac contrast and methylene blue injection; saline 3000 ml of intraoperative continuous perfusion. 3000ml intraoperative continuous perfusion. (B) Surgical method 1, anesthesia and positioning: the patient is lying on the side, the affected side is on the top, the level line of lumbar spinous process and intervertebral space is marked under the orthopantomography of the “G” arm x-ray machine, a lateral line through the lower vertebral body of the posterior upper edge is marked in the lateral position, the intersection of this lateral line with the level line through the intervertebral space is the puncture point, and for the L5-S1 intervertebral discs, the line connecting the highest point of the iliac crest and the line connecting the highest point of the L5 vertebral body and the line connecting the highest point of the L5 intervertebral discs are marked under the orthopantomography of the iliac crest. For the L5-S1 intervertebral disc, the line connecting the highest point of the iliac crest and the horizontal line passing through the upper edge of the L5-S1 intervertebral disc were marked under orthostatic fluoroscopy, and a lateral line passing through the superior articular eminence of the S1 vertebral body to the posterior upper edge of the S1 vertebral body was marked under lateral fluoroscopy. The direction of puncture was the posterior superior margin of the S1 vertebral body. 2.Puncture and intervertebral discography: Routine skin disinfection and laying a towel, with 0.5% lidocaine injection 15-20 ml of layer-by-layer puncture infiltration anesthesia to the articular eminence site, with 18-gauge puncture needle along the direction of the demarcation line puncture to the lower anterior edge of the upper articular eminence of the lower vertebral body, and then with the anterior end of the 15 ° bending of 22-gauge needle through the 18-gauge needle via the foramen ovale insertion of the disc, the disc imaging, can be seen as a result of the distribution of the contrast agent with the The contrast agent can be seen to be distributed in the direction of disc prolapse. 3.Inserting the working trocar: Remove the 22-gauge puncture needle, insert the guide wire along the 18-gauge puncture needle, and make an incision of about 7mm in length with the guide wire as the center, and then insert the first-level guide rods with a diameter of 2mm along the guide wires (straight guide rods and curved guide rods can be used as appropriate), and then again fluoroscopy is used to determine the position of the positive and lateral guide rods. A 3.5, 4.5, and 5.5 mm dilatation catheter was inserted step by step to enlarge the surgical access, the 3.5 and 4.5 dilatation catheters were removed, and a 0.5% lidocaine needle was withdrawn and pushed into the superior articular eminence by 2-3 mm, and then a 3-mm diameter ring drill was inserted along the 2-mm-diameter first-level guide rod to remove part of the bone from the lateral margin of the superior articular eminence. The ring drill was seen to be located in the line of the medial margin of the upper and lower pedicles on orthopantomography, and the ring drill was located in the posterior-superior margin of the lower vertebral body on lateral view. After removing the ring drill, a 3.5 mm dilatation catheter was inserted along the one-level guide rod, and a 5 mm diameter ring drill was inserted to remove the bone, and the position was determined to be accurate in the orthogonal position. 4.5 mm and 5.5 mm dilatation catheters, and 6.5 mm and 7.5 mm ring drills were inserted to remove the bone from the lateral margin of the superior articular process to enlarge the intervertebral foramen, and a 7.5 mm diameter beveled working sleeve was inserted to expand the intervertebral foramen, with the opening direction facing toward the disc. The 7.5mm diameter beveled working trocar is then inserted with the opening direction toward the intervertebral disc. 4. Insert the intervertebral foramenoscope and remove the intervertebral disc tissue: The intervertebral foramenoscope is inserted through the working trocar, and through the central working channel of the 3.7mm endoscope, the nucleus pulposus forceps and nucleus pulposus scissors of different types and angles are used to remove the protruding, prolapsed and free intervertebral disc tissues, and the nerve roots are probed and loosened, and the bipolar radiofrequency microscope is used to stop the hemorrhage and ablate the fibrous annulus to form a crumple and the nerve compression can be seen to be lifted and then the operation is finished. (C) Postoperative treatment Routinely place the drainage tube, remove the working trocar and fix it, and pull it out on the next day. Check whether the patient’s straight leg raising test has improved, the degree of pain relief in the lower limbs, and get out of bed with a waist cuff the next day. At the same time, apply dehydration, nutritive nerve drugs, and avoid heavy labor and strenuous exercise for 3 months after surgery. (D) Efficacy evaluation criteria Patients’ visual analog pain score (VAS) for low back pain was divided into 0-10 points according to the degree of pain, with 0 points representing no pain and 10 points representing the worst pain. Macnab criteria: excellent: low back and leg pain disappeared, lower limb sensory-motor normal, no limitation of activities; good: occasional slight low back and leg pain but does not affect work and life; OK: low back and leg pain reduced compared with the preoperative period, and occasional use of painkillers; poor: no improvement of the symptoms after the operation, or even aggravation, and long-term use of painkillers is required. (E) Statistical processing SPSS11.5 software was used to analyze the data statistically, and the measurement data were expressed as mean ± standard deviation (±SD), and the data before and after surgery were subjected to paired t-test, with P<0.05 indicating that the difference was statistically significant. Results All 21 patients received regular outpatient and telephone follow-up for 1-13 months, with an average of 5.6 months. All the postoperative symptoms were satisfactorily improved or disappeared. There were no intraoperative complications such as dural tear and vascular nerve injury, no transient nociceptive hypersensitivity and burning neuralgia in the lower limbs, and no infections; 3 cases showed weakness in the lower limbs after the operation, with muscle strength of IIICIV grade, normal sensation, which didn't affect standing and walking, and recovered to normal in 2-3 weeks. The average operation time of this group was 50min(30-80min), and the average hospitalization time was 6d(4-8d). The lower limb innervation area was scored using the VAS score, which was 8.9±2.3 points preoperatively, 2.1±1.6 points 3 days postoperatively, and 1.6±1.4 points at the final follow-up. The results were statistically different (p0.01) when comparing the preoperative and postoperative periods. Referring to Macnab efficacy assessment criteria, 15 cases were excellent, 6 cases were good, 1 case was possible, 0 cases were poor, and the excellent rate was 95.45G. IV.DISCUSSION 1.Characteristics of percutaneous foraminoscopy technology for lumbar disc herniation: The percutaneous foraminoscopy technology for the treatment of lumbar disc herniation has been continuously developed on the basis of percutaneous discectomy and suction, which is carried out in the paracentral opening of the spinous process at the midline of the spine at a distance of 10-14cm under local anesthesia, via lumbar spine Under local anesthesia, the percutaneous puncture is performed at 10-14cm from the midline of the spinous process, through the lumbar spine, expanding the puncture channel step by step without pulling the dural sac and nerves, and then the 7.5mm working trocar is inserted into the anterior lateral space of the epidural cavity through the intervertebral foramen to take out the protruding, detached and free intervertebral disc tissues under the endoscopic visualization and to lift the compression on the nerve root and the dural sac. The procedure is performed under local anesthesia without damaging the posterior tissues of the lumbar spine or the important osteoarticular ligamentous structures of the lumbar spine. In addition, there is no obvious interference with the nerve tissue in the spinal canal, which will not lead to obvious bleeding and adhesion in the spinal canal. The surgery has the advantages of small trauma, low cost, low bleeding and fast recovery, so it is favored by both doctors and patients. 2, the choice of surgical indications: percutaneous intervertebral foraminoscopy technology to treat lumbar disc herniation is through the enlarged intervertebral foramen directly into the epidural cavity of the anterolateral space, can be removed under the direct vision of endoscopy or removal of huge protruding, free, dislodged intervertebral disc tissues and neural root canal enlargement, and ultimately achieve the real meaning of the nucleus pulposus removal and nerve root decompression and loosening, so as to relieve the symptoms. The indications are: giant herniated, prolapsed and free intervertebral disc herniation. However, with the deepening of people's understanding of the disease and the improvement of surgical techniques, the indications for surgery are also expanding. However, the selection of specific indications should be based on the original indications, and different cases should be selected according to the operating skills of the surgeon and the different conditions of the patients to establish an individualized plan, so as to achieve the best therapeutic effect with minimal trauma. Tessys and Yess techniques are used to avoid risks and adopt "targeting" techniques to reach the lesion area, so as to successfully and safely complete the removal of the compressed intervertebral disc tissues and decompression and release of the nerves. 3. Characteristics of two special types of disc herniation: (1) Recurrent lumbar disc herniation refers to the situation where the symptoms are relieved for at least 6 months after lumbar discectomy, and then the disc tissue of the same or opposite side of the same segment protrudes again and compresses the nerve root. Postoperative recurrence is the main cause of disc surgery failure, with a recurrence rate of 5% to 11%. Traditional treatment is still based on the classic posterior laminectomy and decompression nucleus pulposus removal; however, due to the local anatomical changes caused by the initial surgery and the varying degrees of fibrous scar adhesion inside and outside of the spinal canal, lumbar disc revision surgery is not only associated with a high level of surgical complications, such as dura mater tear and nerve root injury, as well as spinal instability caused by small joints breaking through, but also with a high level of surgical difficulty. The risk of nerve root and cauda equina injury is extremely high. In order to increase the safety rate and reduce the difficulty of surgery, adequate anatomical exposure, extensive soft tissue dissection, and access from the unoperated intervertebral space of the neighboring segments are the most common surgical approaches for lumbar disc revision. Expanded decompression often results in further destabilization of the spine, requiring concomitant intervertebral bone grafting plus internal fixation and fusion, with long operative time, excessive bleeding, high risk, and many complications, which have been learned from many lessons. Although minimally invasive lumbar disc revision with METRx has been successfully reported, it is still very difficult to perform the procedure due to the need to enter through the original incision, and there are certain challenges and limitations. The intervertebral foraminal technique with lateral foraminal access bypasses the scar tissue formed posteriorly by the initial procedure and reduces the risk of dural sac tear and nerve injury. The working channel is obtained through a reaming drill, which allows direct removal of herniated discs and other compressed nerve tissue without disturbing the scar tissue, achieving decompression under direct vision. Intraoperative observation of nerve pulsation consistent with heartbeat is a sign of adequate nerve decompression. In this group, 6 cases of recurrent lumbar disc herniation were treated by intervertebral foramenoscopy technology and achieved satisfactory results without complications. As there are still few cases, further practice and summarization are needed, but it has very obvious advantages compared with posterior open surgery and posterior laminectomy. (2) Elderly patients with degenerative vertebral body slippage: the symptoms of lumbar disc herniation in the elderly are atypical, the disease course is long, recurrent, often secondary to different degrees of lumbar spinal stenosis, and most of them are combined with basic diseases, so that the open surgery is poorly tolerated or becomes a contraindication to give up the surgical treatment, so the elderly are subjected to the torture of the disease for a long period of time, which is very painful. Vertebral body slippage is often regarded as a manifestation of spinal instability and requires repositioning and fixation. The traditional approach is posterior approach laminectomy and decompression of the spinal canal, which is not only traumatic, bleeding and slow recovery, but also affects the stability of the lumbar spine. Elderly patients with combined degenerative vertebral body slippage, most of them show symptoms of nerve root compression, with a longer course of the disease, lumbar symptoms are no longer obvious, and the initial manifestation of slippage instability has been stabilized on its own, and the therapeutic purpose can be achieved by decompression and release of the nerve root. If open surgery through the posterior road, lumbar spine stability will be further damaged, need intervertebral fusion and transpedicular screw internal fixation, the surgery is more traumatic, often make both doctors and patients are afraid of the risk of giving up the surgery, and can not be treated. In recent years, with the deepening of the understanding of its pathological mechanisms and the advancement of technology, the concept of "precision spine surgery" has been put forward, and smaller invasive decompression surgeries have become a trend. Therefore, for older patients who cannot tolerate surgery; for those who cannot accept open surgery for underlying diseases; for those who have no obvious unstable degenerative slips after clinical evaluation, intervertebral foraminoscopy can achieve the purpose of decompression and release of compressed nerve roots under direct vision without destroying the stability of the spine, with less trauma, less bleeding, fewer complications, quicker recovery, less pain, less cost, safe and effective, which can be tolerated by the majority of patients. It can be tolerated by most patients. All 15 patients in this group achieved satisfactory results. Therefore, intervertebral foramenoscopy is an effective treatment method for elderly patients with degenerative vertebral body slippage. However, it should be noted that in degenerative vertebral body slippage, the intervertebral height is lost, the upper and lower diameter of the nerve root canal becomes smaller; the growth of the bony cribriforms at the edge of the upper and lower vertebral endplates, and the growth of the upper and lower synchondrosis, hypertrophy, cohesion, and slippage lead to a narrowing of the anterior and posterior diameter of the nerve root canal and its medial opening area, as well as a displacement of the dural sac and the nerve root. Therefore, it is important to avoid compression of the nerve root during the surgical operation, ask the patient's response at any time, and use a ring drill to enlarge the intervertebral foraminal approach to achieve decompression to improve the symptoms if necessary. In conclusion, percutaneous intervertebral foraminoscopy is an effective method for treating elderly patients with recurrent disc herniation and degenerative vertebral body slippage, with the advantages of less trauma, less bleeding, fewer complications, safety and reliability, and no damage to spinal stability, which can be reasonably adopted.