Historical evolution In the 1950s, Cloward et al. first proposed the concept of trans-lumbar posterior interbody fusion (PLIF), which has significantly improved the fusion rate and clinical outcomes due to the adequate bed of bone graft fusion, abundant blood supply, and good biomechanical environment. However, PLIF surgery also has certain limitations, such as the need for extensive paravertebral muscle stripping on both sides of the lumbar spine during surgery, which leads to a certain degree of postoperative denervation changes in the paravertebral muscles; the need to remove more posterior structures on both sides, such as the laminae and intervertebral tuberosities, which objectively weakens the stability of the lumbar segments; and the technical need for some bilateral nerve root distraction, which increases the chance of nerve root injury.In 1982, Harms et al. proposed the transvertebral foramen approach to lumbar interbody fusion (TLIF). This approach compensates to some extent for the deficiencies of the PLIF procedure. TLIF only weakens the unilateral posterior structures of the lumbar spine and generally does not require intraoperative nerve root distraction, and these technical advantages have led to the rapid promotion of the TLIF technique. Nevertheless, some disadvantages of open lumbar posterior surgery still affect the efficacy of TLIF surgery. In 1997, Foley and Smith proposed the tubular retractor technique, which solved the problem of minimally invasive access to the posterior spine and reduced the strain and stripping of the paravertebral muscles during routine posterior lumbar surgery. 2001, Foley proposed the percutaneous pedicle screw technique, which led to the development of minimally invasive lumbar interbody fusion. 2002, Koo first reported on minimally invasive transforaminal lumbar spine fusion. Koo first reported the minimally invasive posterior transforaminal lumbar interbody fusion (MIS-PLIF) technique, and in 2003, Foley first reported the minimally invasive transforaminal access lumbar interbody fusion (MIS-TLIF) technique. After nearly 10 years of development, MIS-TLIF has been continuously enriched and improved in terms of surgical techniques and indications, and has been accepted by more and more spine surgeons. Indications for surgery 1, lumbar spondylolisthesis (Meyding I / II) 2, discogenic low back pain 3, recurrent disc herniation with low back pain 4, post-discectomy intervertebral space collapse resulting in foraminal stenosis with nerve root compression. 5.Pseudarthrosis formation 6.Posterior lumbar lordosis after laminectomy. 7.Lumbar deformity with coronal/sagittal imbalance. Relative inverse indications 1. Multi-segmental disc involvement (>3 segments). 2. Single-segment disc causing nerve root compression without back pain and segmental instability. 3, Severe osteoporosis. Anesthesia and position Anesthesia: general anesthesia with intubation and static suction compound anesthesia. If available, spinal nerve monitoring can be performed. Position: prone on the standard operating table, applying a four-point Andrew frame, or using a thoracic pad or iliac pad to avoid pressure on the peritoneal cavity, while restoring the normal physiological anterior convexity of the lumbar spine. Adjust the orientation of the surgical bed to facilitate intraoperative C-arm fluoroscopy. For the L4/5 segment, the surgical bed can be parallel to the ground, while for the L5/S1 segment, the surgical bed is at an angle of 20-30 degrees to the ground to clearly display the target vertebral space. Surgical technique 1. Decompression The surgical incision is decided with the aid of C-arm fluoroscopy. Mark the small intervertebral joints on both sides, and in the orthogonal phase, mark the position of the pedicle above and below the operated intervertebral space. Finally, the lateral line of the upper and lower pedicles is marked. The surgical incision is made on this line. The incision is 2-3 cm long and is usually located 2 fingers from the midline. After dissecting the deep fascia, the gap is separated along the Wiltse approach lateral to the paravertebral muscle. A grade-by-grade retraction canal is placed, and after completion of expansion, the bottom of the working channel is placed in the intervertebral small joint complex and the fixation arm is screwed. For unilateral nerve root compression, the incision is chosen on the symptomatic side. The inferior and partial superior articular processes are removed to completely expose the intervertebral foramen and relieve the nerve compression. If the patient has central spinal stenosis or contralateral lateral spinal stenosis, the surgical bed can be tilted to the opposite side and the working channel can be tilted inward to clearly reveal the thickened ligamentum flavum and the hyperplastic bone, and adequate decompression can be achieved with a lamina bite forceps or a high-speed grinding drill with curvature. 2, intervertebral space preparation and intervertebral fusion Under the working channel, intervertebral spacers are placed step by step to remove the cartilage endplate and most of the fibrous ring and nucleus pulposus, and to reveal the bony endplate. After completion of the intervertebral space preparation, the intervertebral bone graft fusion operation was performed. Autologous three-sided cortical iliac bone is the ideal material for bone grafting, but at the same time it brings additional surgical trauma and causes complications in the bone extraction area. As an alternative, a commonly used option is to apply an intervertebral fusion device (Cage) with built-in autologous cancellous bone, which can achieve a high fusion rate and clinical efficacy. Foreign scholars have used intervertebral fusion devices combined with recombinant bone morphogenetic protein-2 (rBMP2), etc., and have obtained good results in clinical follow-up. The materials of fusion devices have also seen some improvements and innovations. From the initial titanium metal, polyetheretherketone with elastic modulus closer to bone tissue, to the degradable polymorphic material PL-DLA, etc. On the basis of intervertebral fusion, it can also be combined with posterior posterolateral bone graft fusion to achieve 360 degree fusion. 3. Percutaneous pedicle screw instrumentation The entry point for the pedicle screw is selected with the aid of C-arm fluoroscopy. Usually the entry point is located at the intersection of the line between the root of the transverse process and the base of the superior articular process. Compared with open posterior lumbar surgery, the pedicle screw entry point can be more outward to obtain a greater inward angle and to increase the screw’s resistance to extraction. After deciding on the entry point, the arch puncture is performed with a Jamshidi needle, and the direction of entry is corrected by fluoroscopy in the ortho-lateral position. The ideal direction and depth of entry is such that the tip of the Jamishdi needle approaches the medial edge of the arch projection in the ortho-lateral phase, and the tip is entering the vertebral body in the lateral phase. After confirming the above direction and depth, the arch root guide pin is placed and the tapping of the arch root is performed with a hollow wire tapping. Attention should be paid to the position of the guide pin, both to prevent the withdrawal of the guide pin during operation and to pay more attention to the process of tapping with the guide pin, which may cause damage to internal organs and large blood vessels if it penetrates the front of the vertebral body. After completing the tapping, screw in the appropriate length of pedicle screw. Repeat these steps to place the remaining pedicle screws. Depending on the specific procedure of the different brands of pedicle fixation systems, the fixation rods are placed, segmental compression is performed, anterior lumbar convexity is restored, and final fixation is completed. Some authors advocate placing the contralateral pedicle screws and bracing the intervertebral space for temporary fixation before performing ipsilateral decompression and intervertebral fusion. The incision is closed layer by layer and no drainage tube is usually necessary. Postoperative management The patient is removed from the floor for the first day after surgery and discharged from the hospital within three days for recuperation. Clinical outcomes In general, the outcomes of MIS-TLIF are comparable to those of conventional TLIF surgery, but with significant advantages in terms of surgery-related trauma, intraoperative bleeding, length of hospital stay, and recovery time. Of course, MIS-TLIF also has a steep learning curve, radiation exposure, and other related features that deserve attention. Peng et al. compared the two-year follow-up results of MIS-TLIF and conventional TLIF surgery, and the clinical outcomes were similar, but MIS-TLIF had less pain in the early postoperative period, shorter hospital stay, early recovery, and fewer complications. dhall retrospectively compared the clinical follow-up results of MIS-TLIF and open TLIF, and the clinical outcomes were similar, but the open group had more intraoperative bleeding and longer hospital stay. Selznick reported that MIS-TLIF could be used successfully in patients undergoing lumbar revision without increased nerve injury or intraoperative bleeding, but with an increased incidence of dural tears. The authors noted that MIS-TLIF for lumbar revision patients is challenging and should be performed by an experienced surgeon. Follow-up of 131 consecutive MIS-TLIF cases at our institution showed that the clinical outcomes of MIS-TLIF were not inferior to those of open TLIF surgery; however, MIS-TLIF had significant advantages in terms of intraoperative bleeding, length of stay, intraoperative complications, and the relative costs of surgery and treatment. We have also made useful exploration and accumulated some experience in applying MIS-TLIF technology to treat lumbar isthmic slippage and lumbar discogenic low back pain, as well as computer navigation technology-assisted MIS-TLIF surgery. Conclusion As a special technique, it has its own rules. First, the learning curve is steep. Compared with traditional TLIF surgery, the operation time is longer; for less experienced surgeons, inadequate decompression, dural tears, nerve misinjury and pedicle screw dislocation are also common complications. Second, radiographic exposure. intraoperative positioning and internal fixation of MIS-TLIF, both of which depend on imaging assistance, result in long x-ray exposure for the surgeon and patient; however, as Voyadzis points out, mastery of any new technique requires time, patience, and tenacity on the part of the surgeon. We believe that training and learning in minimally invasive spine-specific techniques should be enhanced and the feasibility of combining computer navigation technology with minimally invasive spine surgery techniques should be explored to improve surgical accuracy and reduce surgical procedure risks.