Percutaneous Transforaminal Endoscopic Surgery (PTES) and mini-incision L5/S1 OLIF with self-lock cage for surgical treatment of L5 spondylolisthesis

Percutaneous Transforaminal Endoscopic Surgery (PTES) and mini-incision L5/S1 OLIF with self-lock cage for surgical treatment of L5 spondylolisthesis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Percutaneous Transforaminal Endoscopic Surgery (PTES) and mini-incision L5/S1 OLIF with self-lock cage for surgical treatment of L5 spondylolisthesis Tianyao Zhou, Tianle Ma, Yutong Gu, Wu Che, Liang Zhang, Yichao Wang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-2218910/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objectives We designed Percutaneous Transforaminal Endoscopic Surgery (PTES) technique under local anesthesia and L5/S1 OLIF (OLIF51) with self-lock cage through mini-incision for the treatment of L5 spondylolisthesis. The purpose of study is to evaluate the feasibility, efficacy and safety of this method. Methods Thirteen cases of L5 spondylolisthesis with nerve root symptoms were included in this study. The patients underwent PTES under local anesthesia in a prone position, and then OLIF51 with self-lock cage and allograft was performed through left abdominal mini-incision and oblique retroperitoneal approach between bilateral iliac vessels with the external oblique, internal oblique and transverse abdominal muscles bluntly separated in turn for L5/S1 in a right oblique position under general anesthesia. Back and leg pain were preoperatively and postoperatively evaluated using VAS, and the clinical outcomes were evaluated with ODI before surgery and at 2-year follow-up. Anterior and posterior intervertebral space height, lumbar lordotic angle, and operative segmental lordotic angle were measured on lumbar spine X-rays preoperatively and postoperatively. The fusion status was assessed according to the Bridwell’s fusion grades. Results The operation duration was 49.1 ± 5.6 minutes for PTES and 73.6 ± 8.2 minutes for OLIF. There was a blood loss of 25(15–45) ml. The incision length was 7.5 ± 1.1 mm for PTES and 46.8 ± 3.8 mm for OLIF. The hospital stay was 5(4–6) days. The follow-up duration was 29(24–37) months. For the clinical evaluation, the VAS of back and leg pain significantly dropped after surgery (p < 0.001) and the ODI significantly decreased from 64.7 ± 7.8% to 12.9 ± 4.3% 2 years after surgery (p < 0.001). Anterior and posterior intervertebral space height, and operative segmental lordotic angle significantly improved after surgery (p < 0.05). Fusion grades based on the Bridwell grading system at 2-year follow-up were grade I in 9 segments (69.2%), grade II in 4 segments (30.8%). No patients had any form of permanent iatrogenic nerve damage and a major complication. No failure of instruments was observed. Conclusions PTES and mini-incision OLIF51 with self-lock cage is a good choice of minimally invasive surgery for L5 spondylolisthesis, which can get direct neurologic decompression and satisfying fusion, and hardly destroy the rectus abdominis and its sheath, paraspinal muscles and bone structures. L5 spondylolisthesis minimally invasive surgery percutaneous transforaminal endoscopic surgery oblique lumbar interbody fusion mini-incision Figures Figure 1 Figure 2 Figure 3 Figure 4 1 Introduction Lumbar spine spondylolisthesis is a common disease and is mostly caused by lumbar degeneration or spondylolysis.[ 1 ] Lumbar interbody fusion is the most commonly used treatment for lumbar spondylolisthesis, including posterior lumbar interbody fusion (PLIF)[ 2 , 3 ], transforaminal lumbar interbody fusion (TLIF)[ 4 , 5 ], anterior lumbar interbody fusion (ALIF)[ 6 , 7 ], oblique lumbar interbody fusion (OLIF)[ 8 – 10 ] and so on. For L5 spondylolisthesis, many studies of PLIF, TLIF and ALIF were reported, but there are few studies of OLIF. Compared with the L2-5 OLIF (OLIF25), the efficacy of indirect neurologic decompression of L5/S1 OLIF (OLIF51) through the approach between bilateral iliac vessels is more unsure, which needs further posterior surgery if neurologic symptoms are not improved. This leads to longer operative time under general anesthesia and more invasiveness. We designed Percutaneous Transforaminal Endoscopic Surgery (PTES) [ 11 , 12 ] under local anesthesia and OLIF51 with self-lock cage for the treatment of L5 spondylolisthesis. The purpose of study is to evaluate the feasibility, efficacy and safety of this technique. 2 Materials And Methods 2.1. Patients This study was approved by the medical ethics committee of Zhongshan Hospital Fudan University, and the reference number is B2022-464R. Informed consent was obtained from all patients and all the surgeons. From Jan 2019 to Feb 2020, 13 cases of L5 spondylolisthesis with nerve root symptoms were included in this study. The patients underwent PTES combined with OLIF51 using self-lock cage through left abdominal oblique retroperitoneal approach in lateral abdominal mini-incision. The inclusion criteria were as follows, 1. Low back pain and unilateral leg pain; 2. Image data of X-ray, MRI and CT showed L5 spondylolisthesis (Meyerding[ 13 ] I° or II°) corresponding to the neurologic findings without other levels of lumbar disc herniation, intervertebral foramen stenosis, lateral recess stenosis or central spinal canal stenosis from L1 to S1 (Fig. 1 ); 3. Preoperative CTA showed the horizontal distance between the right-most border of the left common iliac vessel and the left-most border of the right common iliac vessel at L5/S1 > 25mm; 4. Conservative treatment failed. The exclusionary criteria were the presence of more than 2-level lumbar spondylolisthesis, previous lumbar surgery, spinal infection or tumor, other medical conditions making the patient intolerant to operation, inability to give informed consent, and a likelihood of noncompliance with follow-up. 2.2 Pre- and post-operative imaging All the patients had a preoperative evaluation of CT and MRI imaging to determine L5 spondylolisthesis with disc herniation or lateral recess stenosis. Lateral X-rays were obtained to assess the slip degree of vertebral body according to Meyerding[ 13 ]. Anterior and posterior intervertebral space height (AISH, PISH), lumbar lordosis (LL), and segmental lordotic angle (SLA) were measured on lumbar spine X-rays preoperatively, postoperatively and at 2-year follow-up. AISH and PISH: the perpendicular length from the anterior and posterior lower endplate of L5 to the upper endplate of S1 on the lateral X-ray; LL: the Cobb angle between the upper endplate of L1 and the upper endplate of S1; SLA: the Cobb angle between the superior endplate of L5 and S1 in the surgical segment. A loss of at least 2mm of intervertebral space height is generally considered cage subsidence on X-ray[ 14 ]. The fusion status was assessed according to the Bridwell’s fusion grades on CT[ 15 ]. After the treatment, MRI images were obtained to exclude dural tears or spinal fluid leaks, and reherniation. 2.3. Surgical procedure All the surgeries were undertaken by the same senior surgeon (YT Gu). C-arm was used for intraoperative fluoroscopic imaging. The patient was placed in a prone position with hyperkyphotic bolsters placed under the abdomen on a radiolucent table, especially in the cases of L5/S1 level with high iliac crest. PTES was performed under local anesthesia with conscious sedation. The entrance point of puncture locates at the corner of flat back turning to lateral side at the height of target disc, or cranially or slightly caudally, which is named “Gu’s point”.[ 11 , 12 ] An 18-gauge puncture needle was inserted anteromedially at an angle of about 45° (25°-85°) to horizontal plane, aiming at the vertical line through the intersection of posterior midline and target disc transverse line (Fig. 2 a,b). After the success of puncture (Fig. 2 c,d) and stepwise dilating, press-down enlargement of foramen was performed using a 7.5-mm diameter hand reamer through an 8.8-mm diameter cannula docked at the facet joint[ 11 , 12 ]. When resistance disappeared, the tip of reamer should exceed the medial border of pedicle on posteroanterior view and reach close to the posterior wall of target disc on lateral view. (Fig. 2 e,f) Through a 7.5-mm diameter working cannula, the compressed nerve root, even the contralateral nerve root was freed (Fig. 2 g) after the herniated disc and hypertrophic ligamentum flavum (Fig. 2 h) were removed under endoscope. The stab incision for PTES was about 8 mm. (Fig. 2 i) A transverse line bisecting the disc (L5/S1) was drawn along the metal rod which was placed transversely across the center of the target disc on (a) posteoanterior C-arm view in prone position. (b) Photography showed the surface marking of anatomic disc center identified by the intersection of transverse line (L5/S1) and longitudinal midline, which was the aiming reference point of puncture, and the entrance point of puncture (Gu’s point) located at the corner of flat back turning to lateral side. During puncture, once resistance disappeared, the C-arm view was taken to ensure that the needle reached the target. The tip of puncture needle was in the intracanal area close to the posterior wall of disc on (c) lateral X-ray and near the lateral border of pedicle on (d) posteoanterior X-ray. During press-down enlargement of foramen, when resistance disappeared, the tip of reamer should exceed the medial border of pedicle on (e) posteroanterior C-arm view and reach close to the posterior wall target disc on (f) lateral C-arm view. Under (g) endoscopic view, the compressed nerve root was freed after (h) the hypertrophic ligmentum flavum and herniated disc were removed. (i) The stab incision for PTES was about 8 mm. Then the patients were placed into a right oblique position under controlled general anesthesia with trachea cannula to undergo OLIF51 with self-lock cage. The mini-incision was located inferomedially along the midline between lateral edge of rectus and anterior superior spine of iliac crest at the level of midline between umbilicus and symphysis pubis in left lateral abdomen.(Fig. 3 a) After the skin and subcutaneous tissues were incised, the external oblique, internal oblique and transverse abdominal muscles were bluntly separated in turn to enter the retroperitoneal space and expose the anterior border of left psoas and bilateral iliac vessels with two narrow long retractors. After fluoroscopic projection for confirming the L5/S1 segment (Fig. 3 b), the intervertebral fibrous annulus was opened anteriorly between bilateral iliac vessels. The intervertebral tissue was removed, and upper and lower cartilage endplates were adequately scraped off, taking care to avoid damaging the bony endplates during the operation. After trial molding (Fig. 3 c), the self-lock cage (Roi-A, Zimmer, USA) of appropriate size was filled with allograft bone and autograft obtained during PTES, and obliquely placed into disc space parallel to the endplate. Then rotate the holder of cage right till parallel to sagittal plane and the fluoroscopic view was taken to confirm good position of cage (Fig. 3 d,e) before two self-lock anchors were inserted from cage into vertebrae (Fig. 3 f,g,h). Finally, the surgical incision (Fig. 3 i) was closed layer by layer with a thin drain tube. (a) Patient was placed into a right oblique position. The L5/S1 intervertebral space was positioned using (b) C-arm view. (c) X-ray view showed the trial molding after discectomy. (d) Lateral and (e) posteoanterior C-arm view checked the position of self-lock cage placed into disc space parallelly to the endplate. (f) The picture was surgical field after two self-lock anchors were inserted from cage into vertebrae. (g) Lateral and (h) posteoanterior C-arm view confirmed good position of internal instruments. (i) The photograph showed the mini-incison for OLIF. Patients could walk with a flexible brace after the drain tube was removed usually 1 or 2 days after surgery when the drainage fluid was less than 20ml/24h. After leaving hospital, patients were encouraged to return to daily life and followed up regularly. 2.4. Clinical follow-up Back and Leg pain were evaluated using the 10-point visual analog scale (VAS) preoperatively, immediately, 1, 2, 3 and 6 months, 1 and 2 years after surgery. The clinical outcomes were evaluated with Oswestry Disability Index (ODI) at 2-year follow-up. During the follow-up, all complications were recorded including iatrogenic nerve damage, vascular injuries, infection, wound healing, thrombosis, or recurrence. 2.5. Statistical analysis All data were analyzed by SPSS version 20.0 Software, and a value of less than 0.05 was considered statistical significance. The one-way ANOVA was used for VAS, anterior intervertebral space height, posterior intervertebral space height, lumbar lordotic angle and operative segmental lordotic angle comparisons at different time points. The ODI score before the treatment and 2 years after surgery are compared by matched samples t-test. 3 Results 13 cases of L5 spondylolisthesis with nerve root symptoms were included in the present study. There were 8 women and 5 men with a mean age of 55(35–71) years. All the patients were successfully treated using the surgical method described. The patients’ characteristics are summarized in Table 1 . Table 1 Summary of the Clinical Data of the Patients Case No. Age (yrs), Sex Meyerding grade Cause of disease Back VAS Score Leg VAS Score Fusion grade Pre-op Post-op 2 years Pre-op Post-op 2 years 1 71, F Ⅱ spondylolysis 8 2 0 7 0 0 I 2 52, F Ⅰ degeneration 10 2 0 8 2 0 I 3 35, M Ⅱ spondylolysis 10 2 1 9 2 0 I 4 60, M Ⅱ spondylolysis 6 0 0 10 3 2 II 5 57, M Ⅰ spondylolysis 6 2 0 10 1 0 I 6 39, F Ⅰ spondylolysis 6 1 0 10 1 0 I 7 68, F Ⅱ spondylolysis 6 1 0 9 1 1 I 8 74, M Ⅰ spondylolysis 9 2 1 8 2 0 II 9 57, F Ⅱ spondylolysis 10 3 1 8 0 0 I 10 37, M Ⅰ spondylolysis 6 1 0 8 1 0 I 11 45, F Ⅱ spondylolysis 7 0 0 9 0 0 II 12 44, F Ⅰ spondylolysis 7 0 0 8 2 0 I 13 55, F Ⅱ spondylolysis 8 2 0 8 1 0 II One-way ANOVA was used to compare the back and leg VAS score. There were significant differences (p < 0.001) among the values of VAS at each time point. The operation duration was 49.1 ± 5.6 minutes for PTES and 73.6 ± 8.2 minutes for OLIF. The frequency of intraoperative fluoroscopy was 5(5–7) times for PTES and 5(4–8) times for OLIF. There was a blood loss of 25(15–45) ml. The incision length was 7.5 ± 1.1 mm for PTES and 46.8 ± 3.8 mm for OLIF. The hospital stay was 5(4–6) days. (Table 2 ) Table 2 The perioperative data PTES OLIF51 Operation duration (min) a 49.1 ± 5.6 73.6 ± 8.2 Frequency of intraoperative fluoroscopy (times) b 5(5–7) 5(4–8) Incision length (mm) a 7.5 ± 1.1 46.8 ± 3.8 Blood loss (ml) b 25(15–45) Hospital stay (days) b 5(4–6) a Exhibited in the format of “Mean ± standard deviation” b Exhibited in the format of “Median (Min-Max)” The follow-up duration was 29(24–37) months. The VAS of back significantly dropped from preoperative 7(6–10), respectively to 2(0–3) immediately after surgery and to 0(0–1) at 2-year follow-up (F = 128.362, P < 0.001). The VAS of leg dropped from preoperative 8(7–10), respectively to 1(0–3) immediately after surgery and to 0(0–2) at 2-year follow-up (F = 222.039, P < 0.001). (Table 1 ) The ODI significantly decreased from 64.7 ± 7.8% to 12.9 ± 4.3% 2 years after surgery (t = 24.060, P < 0.001). (Table 3 ) Table 3 Variations of Each Measured Parameters from the Initial Evaluation to the Last Follow-up ODI Before operation 2 years after operation P value 64.7 ± 7.8% 12.9 ± 4.3% < 0.001 Before operation immediately after operation 2 years after operation P value AISH (mm) 9.7 ± 4.2 16.1 ± 1.0 15.5 ± 1.0 < 0.001 PISH (mm) 2.8 ± 1.4 5.5 ± 2.1 5.1 ± 2.0 0.001 LL (°) 40.4 ± 7.5 44.2 ± 7.6 43.6 ± 7.5 0.397 SLA (°) 12.9 ± 7.2 19.8 ± 6.8 18.0 ± 5.4 0.031 Values are exhibited in the format of “Mean ± standard deviation”. One-way ANOVA was used to compare AISH, PISH, LL and SLA at different time points. T test was used to compare ODI score before surgery and 2 years after surgery. The postoperative radiographs and CT scans demonstrated good position of cage. (Fig. 4 a-c) Postoperative AISH, PISH and SLA were respectively 16.1 ± 1.0mm (F = 24.063, P < 0.001), 5.5 ± 2.1mm (F = 7.881, P < 0.001) and 19.8 ± 6.8° (F = 3.848, P < 0.05), which were significantly higher than those preoperatively. Preoperative and postoperative LL was 40.4 ± 7.5°, 44.2 ± 7.6° respectively, and there was no significant difference (F = 0.948, P = 0.397). No significant changes in AISH, PISH, LL, SLA and no instability at fusion level were observed 2 years after surgery.(Fig. 4 d,e) Fusion grades based on the Bridwell grading system at 2-year follow-up were grade I (Fig. 4 f) in 9 segments (69.2%), grade II in 4 segments (30.8%).(Table 1 ) No subsidence of cages and no failure of instruments were observed. There were no patients with any form of permanent iatrogenic nerve damage and a major complication. 4 Discussion For the treatment of L5 spondylolisthesis, ALIF had some advantages such as hardly any damage of paraspinal muscles and bone structures, less blood loss, faster recovery, bigger cage with possible higher fusion rate because of more touch surface between endplate of vertebra and cage and more graft bone, compared with PLIF or TLIF.[ 10 , 16 – 18 ] Many studies have proved that ALIF can achieve similar or better clinical outcomes as that in PLIF or TLIF.[ 17 , 19 , 20 ] ALIF was performed through abdominal paramedian retroperitoneal approach in supine position, which may damage rectus abdominis or its sheath. In this study, we undertook OLIF51 between bilateral iliac vessels through abdominal oblique retroperitoneal approach in a right oblique position, and the mini-incision was located in left lateral abdomen with the external oblique, internal oblique and transverse abdominal muscles bluntly separated in turn for L5/S1. It can protect the rectus abdominis and its sheath, paraspinal muscles, and the right oblique position allowed the abdominal contents to fall away from the operative field and the left iliac vessels and psoas could be exposed clearly, which can give more guarantee to operative safety. The results showed that there was no injury of blood vessels, ureter and abdominal organs. Different from OLIF through the corridor between the psoas and the great vessels in the segments above L5, particular attention should be paid to OLIF51 resulting from that the level of bifurcation of the great vessels also affects access at L5/S1.[ 8 ] About 28.3% of the population are not suitable for OLIF through the corridor between bilateral iliac vessels at L5/S1 because the entrance is obstructed by the great vessels. [ 21 ] So preoperative CTA is critical to assess the feasibility of operation. The self-lock cage of ALIF was used in OLIF51 in this study and can provide immediate stability and restoration of lumbar anatomy sequence. AISH, PISH, LL and SLA significantly improved after surgery (p < 0.001). Fusion was achieved in all patients at 2-year follow-up and there was no failure of instruments. No subsidence of cage into vertebral body was found, which was related to protection of cortical endplate during preparation of intervertebral space. The results of study showed that anterior and posterior intervertebral space height significantly increased from 9.7 ± 4.2mm and 2.8 ± 1.4mm, respectively to 16.1 ± 1.0mm (P < 0.001) and 5.5 ± 2.1mm (P < 0.001) after surgery. However, the difference of posterior height of L5/S1 space between preoperatively and postoperatively was much less than that of anterior height, which was related with the cage inserted into L5/S1 from the front to back and the posterior disc space could not be distracted enough. This unbalanced distraction of L5/S1 could not tighten the posterior longitudinal ligament, enlarge the cross-sectional area (CSA) of spinal canal and intervertebral foramen and alleviate the pressure on neurologic elements, which made the efficacy of indirect decompression in OLIF51 unsatisfying. Due to the big cage placed into disc space from lateral side to distract anterior and posterior disc space evenly in OLIF25[ 22 – 27 ], the indirect decompression of OLIF25 is better than that of OLIF51. If neurologic symptoms were not improved after OLIF51, further posterior surgery was needed for direct decompression, which sharply reduced the advantages of OLIF because of longer operative time under general anesthesia and more damage. We performed PTES[ 11 , 12 ] under local anesthesia combined with OLIF51 for the treatment of L5 spondylolisthesis. PTES was a transforaminal endoscopic surgical technique with reduced steps, simple orientation and easy puncture, which can significantly decrease the times of fluoroscopy projection and shorten the operation duration[ 11 , 12 ]. The puncture point of PTES is located at the corner of flat back turning to the lateral side, named “Gu’s Point”[ 11 , 12 ], which is determined not depending on X-ray fluoroscopy, distance measurement, age, gender and body size. Gu’s point is more medial than other transforaminal endoscopic techniques and has four advantages: (1) avoid injuring the exiting nerve root; (2) avoid blockage by the high iliac crest for the L5/S1 level; (3) shorten the manipulation path especially in obesity patients; (4) avoid injuring abdominal viscera and great vessels. [ 11 , 12 ] During the procedure of PTES, we performed press-down enlargement of foramen to saw off the ventral bone of the superior articular process so that the working channel can be inserted into the spinal canal even if the puncture angle was 85° to the horizontal plane.[ 11 , 12 ] In addition, the hypertrophic ligamentum flavum and the protruding nucleus pulposus were removed to expand the lateral recess and reduce the pressure of nerve root. The ipsilateral and contralateral nerve roots can be exposed, and the bilateral nerve roots can be decompressed through unilateral approach in a small incision. PTES before OLIF can achieve direct decompression and avoid another entrance into operation room. The reoperation, even PTES, might put more psychological pressure on the patients and the surgeons especially in China where the doctor-patient relationship is sometimes challenging. The results of this study showed that the VAS of leg pain significantly dropped after surgery and ODI was significantly reduced 2 years after surgery, and there was no reoperation for neurologic decompression. PTES technique under local anesthesia was used to achieve direct decompression with hardly greater trauma, more blood loss and longer operative time of general anesthesia added to OLIF. This combination of two minimally invasive surgeries protected the paraspinal muscles and bone structures as much as possible, and there was only 25(15–45) ml of blood loss. The frequency of intraoperative fluoroscopy during the operation was limited, and both the patients and surgeons were protected against the radiation exposure. Compared with general anesthesia, local anesthesia had little influence on physical status. Although it took 49.1 ± 5.6 minutes to perform PTES under local anesthesia the duration of OLIF under general anesthesia was only 73.6 ± 8.2 minutes. The length of incision was small, 7.5 ± 1.1 mm for PTES and 46.8 ± 3.8 mm for OLIF (Fig. 4 g). The natural corridor for OLIF51 and self-lock cage made postoperative drainage fluid little and when less than 20ml/24h the drain tube was removed usually 1 or 2 days after surgery. Patients could leave hospital as soon as possible and the hospital stay was 4(3–5) days. In this study, no patients had any form of permanent iatrogenic nerve damage and a major complication. All these confirmed the safety of combination of two minimally invasive surgeries. 5 Conclusions PTES and mini-incision OLIF51 with self-lock cage is a good choice of minimally invasive surgery for L5 spondylolisthesis, which can get direct neurologic decompression, satisfying fusion, and hardly destroy the rectus abdominis and its sheath, paraspinal muscles and bone structures. Declarations Ethics approval and consent to participate This study was approved by the medical ethics committee of Zhongshan Hospital Fudan University, and the reference number is B2022-464R. All methods were carried out in accordance with relevant guidelines and regulations. Informed consent was obtained from all patients and surgeons. Consent for publication Images are entirely unidentifiable and there are no details on individuals reported within the manuscript. Availability of data and materials The data that support the findings of this study are available from the corresponding author, Yutong Gu, upon reasonable request. Competing interests The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Funding Not applicable. Authors' contributions Study conception and design: Tianyao Zhou and Yutong Gu. Drafting the article: Tianyao Zhou. 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The correlation of intraoperative distraction of intervertebral disc with the postoperative canal and foramen expansion following oblique lumbar interbody fusion. Eur Spine J. 2021;30(1):151–63. Limthongkul W, Tanasansomboon T, Yingsakmongkol W, Tanaviriyachai T, Radcliff K, Singhatanadgige W. Indirect decompression effect to central canal and ligamentum flavum after extreme lateral lumbar interbody fusion and oblique lumbar interbody fusion. Spine (Phila Pa 1976). 2020;45(17):E1077–84. Shimizu T, Fujibayashi S, Otsuki B, Murata K, Matsuda S. Indirect decompression via oblique lateral interbody fusion for severe degenerative lumbar spinal stenosis: a comparative study with direct decompression transforaminal/posterior lumbar interbody fusion. Spine J. 2021;21(6):963–71. Zhao L, Xie T, Wang X, Yang Z, Pu X, Lu Y, Song Y, Zeng J. Comparing the medium-term outcomes of lumbar interbody fusion via transforaminal and oblique approach in treating lumbar degenerative disc diseases . Spine J 2021. Takaoka H, Inage K, Eguchi Y, Shiga Y, Furuya T, Maki S, Aoki Y, Inoue M, Fujiyoshi T, Miyamoto T, Noguchi Y, Nakamura S, Kinoshita T, Kamada T, Takahashi H, Saito J, Norimoto M, Kotani T, Sakuma T, Iijima Y, Ishikawa T, Umimura T, Ohta M, Suzuki-Narita M, Enomoto K, Sato T, Sato M, Suzuki M, Hozumi T, Kim G, Mizuki N, Tsuchiya R, Otagiri T, Mukaihata T, Hishiya T, Ohtori S, Orita S. Comparison between intervertebral oblique lumbar interbody fusion and transforaminal lumbar interbody fusion: a multicenter study. Sci Rep. 2021;11(1):16673. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-2218910","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":155995086,"identity":"b1b05939-adbb-49fd-a100-3d54f177c3ef","order_by":0,"name":"Tianyao Zhou","email":"","orcid":"","institution":"Zhongshan Hospital Fudan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Tianyao","middleName":"","lastName":"Zhou","suffix":""},{"id":155995087,"identity":"ff784161-2b6a-455b-b94a-3f5b783a2178","order_by":1,"name":"Tianle Ma","email":"","orcid":"","institution":"Zhongshan Hospital Fudan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Tianle","middleName":"","lastName":"Ma","suffix":""},{"id":155995088,"identity":"2a2d93f6-d5a8-4df4-8ab3-d20364e7575f","order_by":2,"name":"Yutong Gu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyklEQVRIiWNgGAWjYBACxobz3z//4anhkWdvIFILc+MBMwYemWMyhj0HiNTC3gzSYsNsw3AjgUgtvG0H0h5I5LDxMM58vPEGQ41NNEEtkj0HjhsYnJHhYZdOK7ZgOJaW20BIi+GMgw0SiT1AW2bnmEkwNhwmrMX+/mMGiYP/mHkYbp4hUgtjwzE2yQYeoJYbPERrOcNszMBzjMewB+iXBGL8AtTC+JiBp8Zenv3wxhsfamwIa0EGBhIJpCiHaCFVxygYBaNgFIwMAABYMT5zXkwoMwAAAABJRU5ErkJggg==","orcid":"","institution":"Zhongshan Hospital Fudan University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Yutong","middleName":"","lastName":"Gu","suffix":""},{"id":155995089,"identity":"67fcb237-5381-4454-b608-de9df44e3a35","order_by":3,"name":"Wu Che","email":"","orcid":"","institution":"Zhongshan Hospital Fudan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Wu","middleName":"","lastName":"Che","suffix":""},{"id":155995090,"identity":"d23fb785-5639-4fd5-957e-3c77d6f3fa39","order_by":4,"name":"Liang Zhang","email":"","orcid":"","institution":"Zhongshan Hospital Fudan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Liang","middleName":"","lastName":"Zhang","suffix":""},{"id":155995091,"identity":"86c91168-039f-4b2f-86df-8cc15df3bc45","order_by":5,"name":"Yichao Wang","email":"","orcid":"","institution":"Zhongshan Hospital Fudan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yichao","middleName":"","lastName":"Wang","suffix":""}],"badges":[],"createdAt":"2022-10-30 14:59:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-2218910/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-2218910/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":29922312,"identity":"915d88a9-c224-4cc3-b7c4-18bee3034cfa","added_by":"auto","created_at":"2022-12-05 19:52:11","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":279934,"visible":true,"origin":"","legend":"\u003cp\u003e(a) lateral X-ray, (b,c,d) sagittal CT, (e) axial CT, (f) axial MRI and (g) sagittal MR image showed L5 spondylolisthesis (Meyerding I°) with bilateral spondylolysis and lateral stenosis at L5/S1.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2218910/v1/a101855b29946ae1cb506f68.jpeg"},{"id":29922313,"identity":"827b99aa-6cb1-4405-a4c1-8bbd46051233","added_by":"auto","created_at":"2022-12-05 19:52:12","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":244595,"visible":true,"origin":"","legend":"\u003cp\u003ePTES for direct neurologic decompression in surgical treatment of L5 spondylolisthesis\u003c/p\u003e\n\u003cp\u003eA transverse line bisecting the disc (L5/S1) was drawn along the metal rod which was placed transversely across the center of the target disc on (a) posteoanterior C-arm view in prone position. (b) Photography showed the surface marking of anatomic disc center identified by the intersection of transverse line (L5/S1) and longitudinal midline, which was the aiming reference point of puncture, and the entrance point of puncture (Gu’s point) located at the corner of flat back turning to lateral side. During puncture, once resistance disappeared, the C-arm view was taken to ensure that the needle reached the target. The tip of puncture needle was in the intracanal area close to the posterior wall of disc on (c) lateral X-ray and near the lateral border of pedicle on (d) posteoanterior X-ray. During press-down enlargement of foramen, when resistance disappeared, the tip of reamer should exceed the medial border of pedicle on (e) posteroanterior C-arm view and reach close to the posterior wall target disc on (f) lateral C-arm view. Under (g) endoscopic view, the compressed nerve root was freed after (h) the hypertrophic ligmentum flavum and herniated disc were removed. (i) The stab incision for PTES was about 8 mm.\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2218910/v1/b1100ef1f9e6d9514b70f7a2.jpeg"},{"id":29923323,"identity":"006e47f2-9d57-4966-b8fe-c1067eaa81c5","added_by":"auto","created_at":"2022-12-05 20:00:12","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":250793,"visible":true,"origin":"","legend":"\u003cp\u003eOLIF with self-lock cage through mini-incision for surgical treatment of L5 spondylolisthesis\u003c/p\u003e\n\u003cp\u003e(a) Patient was placed into a right oblique position. The L5/S1 intervertebral space was positioned using (b) C-arm view. (c) X-ray view showed the trial molding after discectomy. (d) Lateral and (e) posteoanterior C-arm view checked the position of self-lock cage placed into disc space parallelly to the endplate. (f) The picture was surgical field after two self-lock anchors were inserted from cage into vertebrae. (g) Lateral and (h) posteoanterior C-arm view confirmed good position of internal instruments. (i) The photograph showed the mini-incison for OLIF.\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2218910/v1/843613fb4065ae5df425fb69.jpeg"},{"id":29923322,"identity":"17f2d387-0acf-4879-b742-9e37c4a09966","added_by":"auto","created_at":"2022-12-05 20:00:12","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":290803,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Posteoanterior and (b) lateral X-ray image, (c) sagittal CT image showed good position of cage immediately after operation. No instability at fusion level was found on (d) hyperflexion and (e) hyperextension lateral X-ray image. Fusion grade at 2-year follow-up was grade I on (f) sagittal CT image. (g) The picture showed the cosmetic incisions for OLIF.\u003c/p\u003e","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2218910/v1/ef28a2f4c22ac4bcdcd2b726.jpeg"},{"id":32106790,"identity":"cf4db1af-0698-4f2b-aaad-dffff3eccd20","added_by":"auto","created_at":"2023-01-27 07:44:36","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":714530,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2218910/v1/9ce7e5d2-f22b-4b90-8873-af44891a7f3f.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Percutaneous Transforaminal Endoscopic Surgery (PTES) and mini-incision L5/S1 OLIF with self-lock cage for surgical treatment of L5 spondylolisthesis","fulltext":[{"header":"1 Introduction","content":"\u003cp\u003eLumbar spine spondylolisthesis is a common disease and is mostly caused by lumbar degeneration or spondylolysis.[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e] Lumbar interbody fusion is the most commonly used treatment for lumbar spondylolisthesis, including posterior lumbar interbody fusion (PLIF)[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], transforaminal lumbar interbody fusion (TLIF)[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], anterior lumbar interbody fusion (ALIF)[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], oblique lumbar interbody fusion (OLIF)[\u003cspan additionalcitationids=\"CR9\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] and so on. For L5 spondylolisthesis, many studies of PLIF, TLIF and ALIF were reported, but there are few studies of OLIF. Compared with the L2-5 OLIF (OLIF25), the efficacy of indirect neurologic decompression of L5/S1 OLIF (OLIF51) through the approach between bilateral iliac vessels is more unsure, which needs further posterior surgery if neurologic symptoms are not improved. This leads to longer operative time under general anesthesia and more invasiveness. We designed Percutaneous Transforaminal Endoscopic Surgery (PTES) [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] under local anesthesia and OLIF51 with self-lock cage for the treatment of L5 spondylolisthesis. The purpose of study is to evaluate the feasibility, efficacy and safety of this technique.\u003c/p\u003e"},{"header":"2 Materials And Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Patients\u003c/h2\u003e \u003cp\u003e This study was approved by the medical ethics committee of Zhongshan Hospital Fudan University, and the reference number is B2022-464R. Informed consent was obtained from all patients and all the surgeons. From Jan 2019 to Feb 2020, 13 cases of L5 spondylolisthesis with nerve root symptoms were included in this study. The patients underwent PTES combined with OLIF51 using self-lock cage through left abdominal oblique retroperitoneal approach in lateral abdominal mini-incision.\u003c/p\u003e \u003cp\u003eThe inclusion criteria were as follows, 1. Low back pain and unilateral leg pain; 2. Image data of X-ray, MRI and CT showed L5 spondylolisthesis (Meyerding[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] I\u0026deg; or II\u0026deg;) corresponding to the neurologic findings without other levels of lumbar disc herniation, intervertebral foramen stenosis, lateral recess stenosis or central spinal canal stenosis from L1 to S1 (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e); 3. Preoperative CTA showed the horizontal distance between the right-most border of the left common iliac vessel and the left-most border of the right common iliac vessel at L5/S1\u0026thinsp;\u0026gt;\u0026thinsp;25mm; 4. Conservative treatment failed.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe exclusionary criteria were the presence of more than 2-level lumbar spondylolisthesis, previous lumbar surgery, spinal infection or tumor, other medical conditions making the patient intolerant to operation, inability to give informed consent, and a likelihood of noncompliance with follow-up.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Pre- and post-operative imaging\u003c/h2\u003e \u003cp\u003eAll the patients had a preoperative evaluation of CT and MRI imaging to determine L5 spondylolisthesis with disc herniation or lateral recess stenosis. Lateral X-rays were obtained to assess the slip degree of vertebral body according to Meyerding[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Anterior and posterior intervertebral space height (AISH, PISH), lumbar lordosis (LL), and segmental lordotic angle (SLA) were measured on lumbar spine X-rays preoperatively, postoperatively and at 2-year follow-up. AISH and PISH: the perpendicular length from the anterior and posterior lower endplate of L5 to the upper endplate of S1 on the lateral X-ray; LL: the Cobb angle between the upper endplate of L1 and the upper endplate of S1; SLA: the Cobb angle between the superior endplate of L5 and S1 in the surgical segment. A loss of at least 2mm of intervertebral space height is generally considered cage subsidence on X-ray[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The fusion status was assessed according to the Bridwell\u0026rsquo;s fusion grades on CT[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. After the treatment, MRI images were obtained to exclude dural tears or spinal fluid leaks, and reherniation.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Surgical procedure\u003c/h2\u003e \u003cp\u003eAll the surgeries were undertaken by the same senior surgeon (YT Gu). C-arm was used for intraoperative fluoroscopic imaging. The patient was placed in a prone position with hyperkyphotic bolsters placed under the abdomen on a radiolucent table, especially in the cases of L5/S1 level with high iliac crest. PTES was performed under local anesthesia with conscious sedation. The entrance point of puncture locates at the corner of flat back turning to lateral side at the height of target disc, or cranially or slightly caudally, which is named \u0026ldquo;Gu\u0026rsquo;s point\u0026rdquo;.[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] An 18-gauge puncture needle was inserted anteromedially at an angle of about 45\u0026deg; (25\u0026deg;-85\u0026deg;) to horizontal plane, aiming at the vertical line through the intersection of posterior midline and target disc transverse line (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea,b). After the success of puncture (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec,d) and stepwise dilating, press-down enlargement of foramen was performed using a 7.5-mm diameter hand reamer through an 8.8-mm diameter cannula docked at the facet joint[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. When resistance disappeared, the tip of reamer should exceed the medial border of pedicle on posteroanterior view and reach close to the posterior wall of target disc on lateral view. (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ee,f) Through a 7.5-mm diameter working cannula, the compressed nerve root, even the contralateral nerve root was freed (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eg) after the herniated disc and hypertrophic ligamentum flavum (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eh) were removed under endoscope. The stab incision for PTES was about 8 mm. (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ei)\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eA transverse line bisecting the disc (L5/S1) was drawn along the metal rod which was placed transversely across the center of the target disc on (a) posteoanterior C-arm view in prone position. (b) Photography showed the surface marking of anatomic disc center identified by the intersection of transverse line (L5/S1) and longitudinal midline, which was the aiming reference point of puncture, and the entrance point of puncture (Gu\u0026rsquo;s point) located at the corner of flat back turning to lateral side. During puncture, once resistance disappeared, the C-arm view was taken to ensure that the needle reached the target. The tip of puncture needle was in the intracanal area close to the posterior wall of disc on (c) lateral X-ray and near the lateral border of pedicle on (d) posteoanterior X-ray. During press-down enlargement of foramen, when resistance disappeared, the tip of reamer should exceed the medial border of pedicle on (e) posteroanterior C-arm view and reach close to the posterior wall target disc on (f) lateral C-arm view. Under (g) endoscopic view, the compressed nerve root was freed after (h) the hypertrophic ligmentum flavum and herniated disc were removed. (i) The stab incision for PTES was about 8 mm.\u003c/p\u003e \u003cp\u003eThen the patients were placed into a right oblique position under controlled general anesthesia with trachea cannula to undergo OLIF51 with self-lock cage. The mini-incision was located inferomedially along the midline between lateral edge of rectus and anterior superior spine of iliac crest at the level of midline between umbilicus and symphysis pubis in left lateral abdomen.(Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea) After the skin and subcutaneous tissues were incised, the external oblique, internal oblique and transverse abdominal muscles were bluntly separated in turn to enter the retroperitoneal space and expose the anterior border of left psoas and bilateral iliac vessels with two narrow long retractors. After fluoroscopic projection for confirming the L5/S1 segment (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb), the intervertebral fibrous annulus was opened anteriorly between bilateral iliac vessels. The intervertebral tissue was removed, and upper and lower cartilage endplates were adequately scraped off, taking care to avoid damaging the bony endplates during the operation. After trial molding (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec), the self-lock cage (Roi-A, Zimmer, USA) of appropriate size was filled with allograft bone and autograft obtained during PTES, and obliquely placed into disc space parallel to the endplate. Then rotate the holder of cage right till parallel to sagittal plane and the fluoroscopic view was taken to confirm good position of cage (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed,e) before two self-lock anchors were inserted from cage into vertebrae (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ef,g,h). Finally, the surgical incision (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ei) was closed layer by layer with a thin drain tube.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e(a) Patient was placed into a right oblique position. The L5/S1 intervertebral space was positioned using (b) C-arm view. (c) X-ray view showed the trial molding after discectomy. (d) Lateral and (e) posteoanterior C-arm view checked the position of self-lock cage placed into disc space parallelly to the endplate. (f) The picture was surgical field after two self-lock anchors were inserted from cage into vertebrae. (g) Lateral and (h) posteoanterior C-arm view confirmed good position of internal instruments. (i) The photograph showed the mini-incison for OLIF.\u003c/p\u003e \u003cp\u003ePatients could walk with a flexible brace after the drain tube was removed usually 1 or 2 days after surgery when the drainage fluid was less than 20ml/24h. After leaving hospital, patients were encouraged to return to daily life and followed up regularly.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4. Clinical follow-up\u003c/h2\u003e \u003cp\u003eBack and Leg pain were evaluated using the 10-point visual analog scale (VAS) preoperatively, immediately, 1, 2, 3 and 6 months, 1 and 2 years after surgery. The clinical outcomes were evaluated with Oswestry Disability Index (ODI) at 2-year follow-up. During the follow-up, all complications were recorded including iatrogenic nerve damage, vascular injuries, infection, wound healing, thrombosis, or recurrence.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e2.5. Statistical analysis\u003c/h2\u003e \u003cp\u003eAll data were analyzed by SPSS version 20.0 Software, and a value of less than 0.05 was considered statistical significance. The one-way ANOVA was used for VAS, anterior intervertebral space height, posterior intervertebral space height, lumbar lordotic angle and operative segmental lordotic angle comparisons at different time points. The ODI score before the treatment and 2 years after surgery are compared by matched samples t-test.\u003c/p\u003e \u003c/div\u003e"},{"header":"3 Results","content":"\u003cp\u003e13 cases of L5 spondylolisthesis with nerve root symptoms were included in the present study. There were 8 women and 5 men with a mean age of 55(35\u0026ndash;71) years. All the patients were successfully treated using the surgical method described. The patients\u0026rsquo; characteristics are summarized in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable border=\"1\" id=\"Tab1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eSummary of the Clinical Data of the Patients\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"11\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eCase No.\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eAge (yrs), Sex\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eMeyerding grade\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eCause of disease\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"3\"\u003e\n \u003cp\u003eBack VAS Score\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"3\"\u003e\n \u003cp\u003eLeg VAS Score\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eFusion grade\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePre-op\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePost-op\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2 years\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePre-op\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePost-op\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2 years\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e71, F\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅡ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003espondylolysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e52, F\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅠ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003edegeneration\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35, M\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅡ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003espondylolysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e60, M\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅡ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003espondylolysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eII\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e57, M\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅠ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003espondylolysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e39, F\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅠ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003espondylolysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e68, F\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅡ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003espondylolysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e74, M\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅠ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003espondylolysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eII\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e57, F\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅡ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003espondylolysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e37, M\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅠ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003espondylolysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e45, F\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅡ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003espondylolysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eII\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e44, F\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅠ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003espondylolysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e55, F\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eⅡ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003espondylolysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eII\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eOne-way ANOVA was used to compare the back and leg VAS score. There were significant differences (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) among the values of VAS at each time point.\u003c/p\u003e\n\u003cp\u003eThe operation duration was 49.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.6 minutes for PTES and 73.6\u0026thinsp;\u0026plusmn;\u0026thinsp;8.2 minutes for OLIF. The frequency of intraoperative fluoroscopy was 5(5\u0026ndash;7) times for PTES and 5(4\u0026ndash;8) times for OLIF. There was a blood loss of 25(15\u0026ndash;45) ml. The incision length was 7.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1 mm for PTES and 46.8\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8 mm for OLIF. The hospital stay was 5(4\u0026ndash;6) days. (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e)\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable border=\"1\" id=\"Tab2\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eThe perioperative data\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"3\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePTES\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eOLIF51\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eOperation duration (min)\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003ea\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e49.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e73.6\u0026thinsp;\u0026plusmn;\u0026thinsp;8.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eFrequency of intraoperative fluoroscopy (times)\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003eb\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5(5\u0026ndash;7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5(4\u0026ndash;8)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eIncision length (mm)\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003ea\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e46.8\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eBlood loss (ml)\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003eb\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e25(15\u0026ndash;45)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eHospital stay (days)\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003eb\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e5(4\u0026ndash;6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\"\u003e\u003csup\u003ea\u003c/sup\u003eExhibited in the format of \u0026ldquo;Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation\u0026rdquo;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\"\u003e\u003csup\u003eb\u003c/sup\u003eExhibited in the format of \u0026ldquo;Median (Min-Max)\u0026rdquo;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eThe follow-up duration was 29(24\u0026ndash;37) months. The VAS of back significantly dropped from preoperative 7(6\u0026ndash;10), respectively to 2(0\u0026ndash;3) immediately after surgery and to 0(0\u0026ndash;1) at 2-year follow-up (F\u0026thinsp;=\u0026thinsp;128.362, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The VAS of leg dropped from preoperative 8(7\u0026ndash;10), respectively to 1(0\u0026ndash;3) immediately after surgery and to 0(0\u0026ndash;2) at 2-year follow-up (F\u0026thinsp;=\u0026thinsp;222.039, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). (Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e) The ODI significantly decreased from 64.7\u0026thinsp;\u0026plusmn;\u0026thinsp;7.8% to 12.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3% 2 years after surgery (t\u0026thinsp;=\u0026thinsp;24.060, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). (Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e)\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable border=\"1\" id=\"Tab3\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eVariations of Each Measured Parameters from the Initial Evaluation to the Last Follow-up\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"6\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eODI\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eBefore operation\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e2 years after operation\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e64.7\u0026thinsp;\u0026plusmn;\u0026thinsp;7.8%\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e12.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3%\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBefore operation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eimmediately after operation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 years after operation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAISH (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e16.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePISH (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e5.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.1\u0026thinsp;\u0026plusmn;\u0026thinsp;2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLL (\u0026deg;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e40.4\u0026thinsp;\u0026plusmn;\u0026thinsp;7.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e44.2\u0026thinsp;\u0026plusmn;\u0026thinsp;7.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e43.6\u0026thinsp;\u0026plusmn;\u0026thinsp;7.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.397\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSLA (\u0026deg;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12.9\u0026thinsp;\u0026plusmn;\u0026thinsp;7.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e19.8\u0026thinsp;\u0026plusmn;\u0026thinsp;6.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e18.0\u0026thinsp;\u0026plusmn;\u0026thinsp;5.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.031\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eValues are exhibited in the format of \u0026ldquo;Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation\u0026rdquo;. One-way ANOVA was used to compare AISH, PISH, LL and SLA at different time points. T test was used to compare ODI score before surgery and 2 years after surgery.\u003c/p\u003e\n\u003cp\u003eThe postoperative radiographs and CT scans demonstrated good position of cage. (Fig. \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003ea-c) Postoperative AISH, PISH and SLA were respectively 16.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0mm (F\u0026thinsp;=\u0026thinsp;24.063, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), 5.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1mm (F\u0026thinsp;=\u0026thinsp;7.881, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and 19.8\u0026thinsp;\u0026plusmn;\u0026thinsp;6.8\u0026deg; (F\u0026thinsp;=\u0026thinsp;3.848, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), which were significantly higher than those preoperatively. Preoperative and postoperative LL was 40.4\u0026thinsp;\u0026plusmn;\u0026thinsp;7.5\u0026deg;, 44.2\u0026thinsp;\u0026plusmn;\u0026thinsp;7.6\u0026deg; respectively, and there was no significant difference (F\u0026thinsp;=\u0026thinsp;0.948, P\u0026thinsp;=\u0026thinsp;0.397). No significant changes in AISH, PISH, LL, SLA and no instability at fusion level were observed 2 years after surgery.(Fig. \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003ed,e) Fusion grades based on the Bridwell grading system at 2-year follow-up were grade I (Fig. \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003ef) in 9 segments (69.2%), grade II in 4 segments (30.8%).(Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e) No subsidence of cages and no failure of instruments were observed. There were no patients with any form of permanent iatrogenic nerve damage and a major complication.\u003c/p\u003e"},{"header":"4 Discussion","content":"\u003cp\u003eFor the treatment of L5 spondylolisthesis, ALIF had some advantages such as hardly any damage of paraspinal muscles and bone structures, less blood loss, faster recovery, bigger cage with possible higher fusion rate because of more touch surface between endplate of vertebra and cage and more graft bone, compared with PLIF or TLIF.[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan additionalcitationids=\"CR17\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e] Many studies have proved that ALIF can achieve similar or better clinical outcomes as that in PLIF or TLIF.[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] ALIF was performed through abdominal paramedian retroperitoneal approach in supine position, which may damage rectus abdominis or its sheath. In this study, we undertook OLIF51 between bilateral iliac vessels through abdominal oblique retroperitoneal approach in a right oblique position, and the mini-incision was located in left lateral abdomen with the external oblique, internal oblique and transverse abdominal muscles bluntly separated in turn for L5/S1. It can protect the rectus abdominis and its sheath, paraspinal muscles, and the right oblique position allowed the abdominal contents to fall away from the operative field and the left iliac vessels and psoas could be exposed clearly, which can give more guarantee to operative safety. The results showed that there was no injury of blood vessels, ureter and abdominal organs. Different from OLIF through the corridor between the psoas and the great vessels in the segments above L5, particular attention should be paid to OLIF51 resulting from that the level of bifurcation of the great vessels also affects access at L5/S1.[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] About 28.3% of the population are not suitable for OLIF through the corridor between bilateral iliac vessels at L5/S1 because the entrance is obstructed by the great vessels. [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] So preoperative CTA is critical to assess the feasibility of operation.\u003c/p\u003e \u003cp\u003eThe self-lock cage of ALIF was used in OLIF51 in this study and can provide immediate stability and restoration of lumbar anatomy sequence. AISH, PISH, LL and SLA significantly improved after surgery (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Fusion was achieved in all patients at 2-year follow-up and there was no failure of instruments. No subsidence of cage into vertebral body was found, which was related to protection of cortical endplate during preparation of intervertebral space. The results of study showed that anterior and posterior intervertebral space height significantly increased from 9.7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.2mm and 2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4mm, respectively to 16.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0mm (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and 5.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1mm (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) after surgery. However, the difference of posterior height of L5/S1 space between preoperatively and postoperatively was much less than that of anterior height, which was related with the cage inserted into L5/S1 from the front to back and the posterior disc space could not be distracted enough. This unbalanced distraction of L5/S1 could not tighten the posterior longitudinal ligament, enlarge the cross-sectional area (CSA) of spinal canal and intervertebral foramen and alleviate the pressure on neurologic elements, which made the efficacy of indirect decompression in OLIF51 unsatisfying. Due to the big cage placed into disc space from lateral side to distract anterior and posterior disc space evenly in OLIF25[\u003cspan additionalcitationids=\"CR23 CR24 CR25 CR26\" citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], the indirect decompression of OLIF25 is better than that of OLIF51.\u003c/p\u003e \u003cp\u003eIf neurologic symptoms were not improved after OLIF51, further posterior surgery was needed for direct decompression, which sharply reduced the advantages of OLIF because of longer operative time under general anesthesia and more damage. We performed PTES[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] under local anesthesia combined with OLIF51 for the treatment of L5 spondylolisthesis. PTES was a transforaminal endoscopic surgical technique with reduced steps, simple orientation and easy puncture, which can significantly decrease the times of fluoroscopy projection and shorten the operation duration[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The puncture point of PTES is located at the corner of flat back turning to the lateral side, named \u0026ldquo;Gu\u0026rsquo;s Point\u0026rdquo;[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], which is determined not depending on X-ray fluoroscopy, distance measurement, age, gender and body size. Gu\u0026rsquo;s point is more medial than other transforaminal endoscopic techniques and has four advantages: (1) avoid injuring the exiting nerve root; (2) avoid blockage by the high iliac crest for the L5/S1 level; (3) shorten the manipulation path especially in obesity patients; (4) avoid injuring abdominal viscera and great vessels. [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] During the procedure of PTES, we performed press-down enlargement of foramen to saw off the ventral bone of the superior articular process so that the working channel can be inserted into the spinal canal even if the puncture angle was 85\u0026deg; to the horizontal plane.[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] In addition, the hypertrophic ligamentum flavum and the protruding nucleus pulposus were removed to expand the lateral recess and reduce the pressure of nerve root. The ipsilateral and contralateral nerve roots can be exposed, and the bilateral nerve roots can be decompressed through unilateral approach in a small incision. PTES before OLIF can achieve direct decompression and avoid another entrance into operation room. The reoperation, even PTES, might put more psychological pressure on the patients and the surgeons especially in China where the doctor-patient relationship is sometimes challenging. The results of this study showed that the VAS of leg pain significantly dropped after surgery and ODI was significantly reduced 2 years after surgery, and there was no reoperation for neurologic decompression.\u003c/p\u003e \u003cp\u003ePTES technique under local anesthesia was used to achieve direct decompression with hardly greater trauma, more blood loss and longer operative time of general anesthesia added to OLIF. This combination of two minimally invasive surgeries protected the paraspinal muscles and bone structures as much as possible, and there was only 25(15\u0026ndash;45) ml of blood loss. The frequency of intraoperative fluoroscopy during the operation was limited, and both the patients and surgeons were protected against the radiation exposure. Compared with general anesthesia, local anesthesia had little influence on physical status. Although it took 49.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.6 minutes to perform PTES under local anesthesia the duration of OLIF under general anesthesia was only 73.6\u0026thinsp;\u0026plusmn;\u0026thinsp;8.2 minutes. The length of incision was small, 7.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1 mm for PTES and 46.8\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8 mm for OLIF (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eg). The natural corridor for OLIF51 and self-lock cage made postoperative drainage fluid little and when less than 20ml/24h the drain tube was removed usually 1 or 2 days after surgery. Patients could leave hospital as soon as possible and the hospital stay was 4(3\u0026ndash;5) days. In this study, no patients had any form of permanent iatrogenic nerve damage and a major complication. All these confirmed the safety of combination of two minimally invasive surgeries.\u003c/p\u003e"},{"header":"5 Conclusions","content":"\u003cp\u003ePTES and mini-incision OLIF51 with self-lock cage is a good choice of minimally invasive surgery for L5 spondylolisthesis, which can get direct neurologic decompression, satisfying fusion, and hardly destroy the rectus abdominis and its sheath, paraspinal muscles and bone structures.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the medical ethics committee of Zhongshan Hospital Fudan University, and the reference number is B2022-464R. All methods were carried out in accordance with relevant guidelines and regulations. Informed consent was obtained from all patients and surgeons.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eImages are entirely unidentifiable and there are no details on individuals reported within the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data that support the findings of this study are available from the corresponding author, Yutong Gu, upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStudy conception and design: Tianyao Zhou and Yutong Gu. Drafting the article: Tianyao Zhou. Data collection: Wu Che and Liang Zhang. Analysis and interpretation of data: Tianle Ma. Revising it critically for important intellectual content: Yutong Gu. Supervision: Yichao Wang. All authors reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eKoreckij TD, Fischgrund JS. Degenerative spondylolisthesis. J Spinal Disord Tech. 2015;28(7):236\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFenton-White HA. Trailblazing: the historical development of the posterior lumbar interbody fusion (PLIF). 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J Orthop Surg Res. 2017;12(1):25.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang H, Zhou TY, Gu YT, Yan ZQ. Evaluation of efficacy and safety of percutaneous transforaminal endoscopic surgery (PTES) for surgical treatment of calcified lumbar disc herniation: a retrospective cohort study of 101 patients. BMC Musculoskelet Disord. 2021;22(1):65.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKoslosky E, Gendelberg D. Classification in brief: The Meyerding classification system of spondylolisthesis. Clin Orthop Relat Res. 2020;478(5):1125\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKanas M, Leite MS, Ueta RHS, Curto DD, Martins DE, Wajchenberg M, Puertas EB. Comparison of Farfan modified and Frobin methods to evaluate the intervertebral disc height. Coluna/Columna. 2014;13(1):31\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBridwell KH, Lenke LG, McEnery KW, Baldus C, Blanke K. 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Front Surg. 2022;9:829469.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLightsey HMt, Pisano AJ, Striano BM, Crawford AM, Xiong GX, Hershman S, Schoenfeld AJ, Simpson AK: \u003cb\u003eALIF versus TLIF for L5\u003c/b\u003e-\u003cb\u003eS1 isthmic spondylolisthesis\u003c/b\u003e: \u003cb\u003eALIF demonstrates superior segmental and regional rdiographic outcomes and clinical improvements across more patient\u003c/b\u003e-\u003cb\u003ereported outcome measures domains\u003c/b\u003e. \u003cem\u003eSpine (Phila Pa\u003c/em\u003e 1976) 2022.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBuell TJ, Shaffrey CI, Bess S, Kim HJ, Klineberg EO, Lafage V, Lafage R, Protopsaltis TS, Passias PG, Mundis GM, Eastlack RK, Deviren V, Kelly MP, Daniels AH, Gum JL, Soroceanu A, Hamilton DK, Gupta MC, Burton DC, Hostin RA, Kebaish KM, Hart RA, Schwab FJ, Ames CP, Smith JS. 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Indirect decompression effect to central canal and ligamentum flavum after extreme lateral lumbar interbody fusion and oblique lumbar interbody fusion. Spine (Phila Pa 1976). 2020;45(17):E1077\u0026ndash;84.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShimizu T, Fujibayashi S, Otsuki B, Murata K, Matsuda S. Indirect decompression via oblique lateral interbody fusion for severe degenerative lumbar spinal stenosis: a comparative study with direct decompression transforaminal/posterior lumbar interbody fusion. Spine J. 2021;21(6):963\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao L, Xie T, Wang X, Yang Z, Pu X, Lu Y, Song Y, Zeng J. \u003cb\u003eComparing the medium-term outcomes of lumbar interbody fusion via transforaminal and oblique approach in treating lumbar degenerative disc diseases\u003c/b\u003e. Spine J 2021.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTakaoka H, Inage K, Eguchi Y, Shiga Y, Furuya T, Maki S, Aoki Y, Inoue M, Fujiyoshi T, Miyamoto T, Noguchi Y, Nakamura S, Kinoshita T, Kamada T, Takahashi H, Saito J, Norimoto M, Kotani T, Sakuma T, Iijima Y, Ishikawa T, Umimura T, Ohta M, Suzuki-Narita M, Enomoto K, Sato T, Sato M, Suzuki M, Hozumi T, Kim G, Mizuki N, Tsuchiya R, Otagiri T, Mukaihata T, Hishiya T, Ohtori S, Orita S. Comparison between intervertebral oblique lumbar interbody fusion and transforaminal lumbar interbody fusion: a multicenter study. Sci Rep. 2021;11(1):16673.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"L5 spondylolisthesis, minimally invasive surgery, percutaneous transforaminal endoscopic surgery, oblique lumbar interbody fusion, mini-incision","lastPublishedDoi":"10.21203/rs.3.rs-2218910/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-2218910/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjectives\u003c/h2\u003e \u003cp\u003eWe designed Percutaneous Transforaminal Endoscopic Surgery (PTES) technique under local anesthesia and L5/S1 OLIF (OLIF51) with self-lock cage through mini-incision for the treatment of L5 spondylolisthesis. The purpose of study is to evaluate the feasibility, efficacy and safety of this method.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThirteen cases of L5 spondylolisthesis with nerve root symptoms were included in this study. The patients underwent PTES under local anesthesia in a prone position, and then OLIF51 with self-lock cage and allograft was performed through left abdominal mini-incision and oblique retroperitoneal approach between bilateral iliac vessels with the external oblique, internal oblique and transverse abdominal muscles bluntly separated in turn for L5/S1 in a right oblique position under general anesthesia. Back and leg pain were preoperatively and postoperatively evaluated using VAS, and the clinical outcomes were evaluated with ODI before surgery and at 2-year follow-up. Anterior and posterior intervertebral space height, lumbar lordotic angle, and operative segmental lordotic angle were measured on lumbar spine X-rays preoperatively and postoperatively. The fusion status was assessed according to the Bridwell\u0026rsquo;s fusion grades.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe operation duration was 49.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.6 minutes for PTES and 73.6\u0026thinsp;\u0026plusmn;\u0026thinsp;8.2 minutes for OLIF. There was a blood loss of 25(15\u0026ndash;45) ml. The incision length was 7.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1 mm for PTES and 46.8\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8 mm for OLIF. The hospital stay was 5(4\u0026ndash;6) days. The follow-up duration was 29(24\u0026ndash;37) months. For the clinical evaluation, the VAS of back and leg pain significantly dropped after surgery (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and the ODI significantly decreased from 64.7\u0026thinsp;\u0026plusmn;\u0026thinsp;7.8% to 12.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3% 2 years after surgery (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Anterior and posterior intervertebral space height, and operative segmental lordotic angle significantly improved after surgery (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Fusion grades based on the Bridwell grading system at 2-year follow-up were grade I in 9 segments (69.2%), grade II in 4 segments (30.8%). No patients had any form of permanent iatrogenic nerve damage and a major complication. No failure of instruments was observed.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003ePTES and mini-incision OLIF51 with self-lock cage is a good choice of minimally invasive surgery for L5 spondylolisthesis, which can get direct neurologic decompression and satisfying fusion, and hardly destroy the rectus abdominis and its sheath, paraspinal muscles and bone structures.\u003c/p\u003e","manuscriptTitle":"Percutaneous Transforaminal Endoscopic Surgery (PTES) and mini-incision L5/S1 OLIF with self-lock cage for surgical treatment of L5 spondylolisthesis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-12-05 19:52:07","doi":"10.21203/rs.3.rs-2218910/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a81b43bc-412e-4390-a902-34bb79b3c47e","owner":[],"postedDate":"December 5th, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2023-02-20T00:14:19+00:00","versionOfRecord":[],"versionCreatedAt":"2022-12-05 19:52:07","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-2218910","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-2218910","identity":"rs-2218910","version":["v1"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}