Objective: To compare the long-term clinical and radiographic outcomes of transforaminal endoscopic lumbar discectomy (TELD) versus microdiscectomy (MD). Methods: The data of 154 patients with lumbar disc herniation (LDH) who underwent TELD (n = 89) or MD (n = 65) were retrospectively analyzed. The patients’ clinical outcomes were evaluated using visual analogue scales for leg and low back pain, the Japanese Orthopaedic Association (JOA) score, and the Oswestry Disability Index (ODI). The evolution of radiographic manifestations was observed during follow-up. Potential risk factors for a poor clinical outcome were investigated. Results: During a mean follow-up of 5.5 years (range, 5–7 years), the recurrence rate was 4.49% in the TELD group and 1.54% in the MD group. All scores significantly improved from preoperatively to postoperatively in both groups (p < 0.01). The improvement in the ODI and JOA scores was significantly greater in the TELD than MD group (p < 0.05). Forty-seven patients (52.8%) in the TELD group and 32 (49.2%) in the MD group had Modic changes before surgery, most of which showed no changes at the last follow-up. The degeneration grades of 292 discs (71.0%) were unchanged at the last follow-up, while 86 (20.9%) showed improvement, mostly at the upper adjacent segment. No significant difference was observed in the intervertebral height index or paraspinal muscle-disc ratio. Conclusion Both TELD and MD provide generally satisfactory long-term clinical outcomes for patients with LDH. TELD can be used as a reliable alternative to MD with less surgical trauma. Modic type II changes, decreased preoperative intervertebral height, and a high body mass index are predictors of a poor prognosis.

Objective: To compare the long-term clinical and radiographic outcomes of transforaminal endoscopic lumbar discectomy (TELD) versus microdiscectomy (MD). Methods: The data of 154 patients with lumbar disc herniation (LDH) who underwent TELD (n = 89) or MD (n = 65) were retrospectively analyzed. The patients’ clinical outcomes were evaluated using visual analogue scales for leg and low back pain, the Japanese Orthopaedic Association (JOA) score, and the Oswestry Disability Index (ODI). The evolution of radiographic manifestations was observed during follow-up. Potential risk factors for a poor clinical outcome were investigated. Results: During a mean follow-up of 5.5 years (range, 5–7 years), the recurrence rate was 4.49% in the TELD group and 1.54% in the MD group. All scores significantly improved from preoperatively to postoperatively in both groups (p < 0.01). The improvement in the ODI and JOA scores was significantly greater in the TELD than MD group (p < 0.05). Forty-seven patients (52.8%) in the TELD group and 32 (49.2%) in the MD group had Modic changes before surgery, most of which showed no changes at the last follow-up. The degeneration grades of 292 discs (71.0%) were unchanged at the last follow-up, while 86 (20.9%) showed improvement, mostly at the upper adjacent segment. No significant difference was observed in the intervertebral height index or paraspinal muscle-disc ratio. Conclusion Both TELD and MD provide generally satisfactory long-term clinical outcomes for patients with LDH. TELD can be used as a reliable alternative to MD with less surgical trauma. Modic type II changes, decreased preoperative intervertebral height, and a high body mass index are predictors of a poor prognosis.

Objective: To compare the long-term clinical and radiographic outcomes of transforaminal endoscopic lumbar discectomy (TELD) versus microdiscectomy (MD). Methods: The data of 154 patients with lumbar disc herniation (LDH) who underwent TELD (n = 89) or MD (n = 65) were retrospectively analyzed. The patients’ clinical outcomes were evaluated using visual analogue scales for leg and low back pain, the Japanese Orthopaedic Association (JOA) score, and the Oswestry Disability Index (ODI). The evolution of radiographic manifestations was observed during follow-up. Potential risk factors for a poor clinical outcome were investigated. Results: During a mean follow-up of 5.5 years (range, 5–7 years), the recurrence rate was 4.49% in the TELD group and 1.54% in the MD group. All scores significantly improved from preoperatively to postoperatively in both groups (p < 0.01). The improvement in the ODI and JOA scores was significantly greater in the TELD than MD group (p < 0.05). Forty-seven patients (52.8%) in the TELD group and 32 (49.2%) in the MD group had Modic changes before surgery, most of which showed no changes at the last follow-up. The degeneration grades of 292 discs (71.0%) were unchanged at the last follow-up, while 86 (20.9%) showed improvement, mostly at the upper adjacent segment. No significant difference was observed in the intervertebral height index or paraspinal muscle-disc ratio. Conclusion Both TELD and MD provide generally satisfactory long-term clinical outcomes for patients with LDH. TELD can be used as a reliable alternative to MD with less surgical trauma. Modic type II changes, decreased preoperative intervertebral height, and a high body mass index are predictors of a poor prognosis.

Objective: To compare the long-term clinical and radiographic outcomes of transforaminal endoscopic lumbar discectomy (TELD) versus microdiscectomy (MD). Methods: The data of 154 patients with lumbar disc herniation (LDH) who underwent TELD (n = 89) or MD (n = 65) were retrospectively analyzed. The patients’ clinical outcomes were evaluated using visual analogue scales for leg and low back pain, the Japanese Orthopaedic Association (JOA) score, and the Oswestry Disability Index (ODI). The evolution of radiographic manifestations was observed during follow-up. Potential risk factors for a poor clinical outcome were investigated. Results: During a mean follow-up of 5.5 years (range, 5–7 years), the recurrence rate was 4.49% in the TELD group and 1.54% in the MD group. All scores significantly improved from preoperatively to postoperatively in both groups (p < 0.01). The improvement in the ODI and JOA scores was significantly greater in the TELD than MD group (p < 0.05). Forty-seven patients (52.8%) in the TELD group and 32 (49.2%) in the MD group had Modic changes before surgery, most of which showed no changes at the last follow-up. The degeneration grades of 292 discs (71.0%) were unchanged at the last follow-up, while 86 (20.9%) showed improvement, mostly at the upper adjacent segment. No significant difference was observed in the intervertebral height index or paraspinal muscle-disc ratio. Conclusion Both TELD and MD provide generally satisfactory long-term clinical outcomes for patients with LDH. TELD can be used as a reliable alternative to MD with less surgical trauma. Modic type II changes, decreased preoperative intervertebral height, and a high body mass index are predictors of a poor prognosis.

Objective: To compare the long-term clinical and radiographic outcomes of transforaminal endoscopic lumbar discectomy (TELD) versus microdiscectomy (MD). Methods: The data of 154 patients with lumbar disc herniation (LDH) who underwent TELD (n = 89) or MD (n = 65) were retrospectively analyzed. The patients’ clinical outcomes were evaluated using visual analogue scales for leg and low back pain, the Japanese Orthopaedic Association (JOA) score, and the Oswestry Disability Index (ODI). The evolution of radiographic manifestations was observed during follow-up. Potential risk factors for a poor clinical outcome were investigated. Results: During a mean follow-up of 5.5 years (range, 5–7 years), the recurrence rate was 4.49% in the TELD group and 1.54% in the MD group. All scores significantly improved from preoperatively to postoperatively in both groups (p < 0.01). The improvement in the ODI and JOA scores was significantly greater in the TELD than MD group (p < 0.05). Forty-seven patients (52.8%) in the TELD group and 32 (49.2%) in the MD group had Modic changes before surgery, most of which showed no changes at the last follow-up. The degeneration grades of 292 discs (71.0%) were unchanged at the last follow-up, while 86 (20.9%) showed improvement, mostly at the upper adjacent segment. No significant difference was observed in the intervertebral height index or paraspinal muscle-disc ratio. Conclusion Both TELD and MD provide generally satisfactory long-term clinical outcomes for patients with LDH. TELD can be used as a reliable alternative to MD with less surgical trauma. Modic type II changes, decreased preoperative intervertebral height, and a high body mass index are predictors of a poor prognosis.

Objective:To simulate the placement of percutaneous cortical bone trajectory (CBT) screws on reconstructed CT images and three-dimensional lumbar model and to measure the morphometric parameters for guiding the placement of percutaneous CBT screws.Methods:The CT images of 100 adult patients with lumbar spine diseases were studied. The CT images were reconstructed using Mimics software. Taking the projection point on the lamina at the junction of the inner and lower edge of the smallest coronal section of lumbar pedicle as the entry point, the cephalad angle, lateral angle, maximum screw length, maximum screw diameter, distance between trajectory and spinous process were measured. At the same time, the relationship between the trajectory and spinous process was observed by using the reconstructed three-dimensional image.Results:The lateral angle of the trajectory from L 1 to L 5 were 9.3° (8.9°, 9.8°), 9.6° (8.9°, 9.8°), 10.4° (9.5°, 11.3°), 11.81°±1.24° and 13.6° (12.5°, 14.5°), respectively. The cephalad angle from L 1 to L 5 were 26.6° (26.0°, 27.0°), 26.2° (25.7°, 26.5°), 26.9° (26.5°, 27.4°), 25.94°±0.92° and 24.3° (22.7°, 25.4°), respectively. Significant statistic differences were found among all levels in the cephalad angles and lateral angles. The mean diameters of the trajectory from L 1 to L 5 were 5.65±0.49 mm, 6.38±0.60 mm, 6.91±0.67 mm, 7.42±0.76 mm and 8.33 (7.59, 9.01) mm, respectively. Except L 1 and L 5, there were significant differences among all levels in the maximum screw diameters. The mean length of the trajectory from L 1 to L 5 were 36.4 (35.4, 37.0) mm, 36.7 (35.8, 37.3) mm, 37.6 (37.1, 38.1) mm, 37.8 (37.3, 38.1) mm and 36.2 (35.2, 36.9) mm, respectively, and there were also significant differences among all levels. The ration in superior endplate for each segment were 41.08% (34.36%, 45.60%), 37.94% (32.97%, 43.63%), 40.18% (34.56%, 44.49%), 38.61% (34.80%, 46.24%) and 40.9% (35.32%, 46.02%), respectively and statistical differences were significant between L 1 and L 2 and L 2 and L 5. The mean distance between the trajectory and the spinous process from L 1 to L 5 were 7.27±1.23 mm, 7.19 (5.97, 8.28) mm, 7.32 (6.01, 8.28) mm, 7.31±1.36 mm and 7.45 (6.32, 8.23) mm, respectively. In the sagittal CT image, the tip of the trajectory located near the posterior two-fifths of the superior end plate, and the extended line of the trajectory located at the inferior edge of spinous process. In the three-dimensional reconstruction model, no obstruction was found between the simulated screws and the spinous process. Conclusion:Lumbar CBT screw can be implanted percutaneously, and spinous process will not hinder the implantation process. Spinous process and upper endplate can be used as a sign to guide the percutaneous CBT screw implantation. Digital analog screw placement can offer a useful reference for the clinical application of percutaneous cortical bone trajectory screw.

The study showed a case of missed diagnosis of Leriche syndrome. Patients with intermittent claudication were diagnosed as lumbar spinal stenosis by local hospital with lumbar MRI. When conservative treatment was ineffective, the patients were treated in our spine clinic. However, the lumbar MRI showed no significant stenosis, and arteriovenous ultrasound also showed no abnormality. Vascular surgeons believed that patient’s symptoms had little correlation with vascular lesions. After careful reading of lumbar spine MRI, we found that the signal intensity of abdominal aorta increased unevenly below L₂ vertebral level. CTA examination of abdominal aorta revealed sclerosis of abdominal aorta and common iliac artery, stenosis and occlusion of abdominal aorta and common iliac artery lumen below the level of renal artery orifice. The patient was finally diagnosed as Leriche syndrome.

Objective:To investigate and compare the biomechanical strength of paravertebral foramen screws (PVFS), lateral mass screws (LMS) and pedicle screws (PS).Methods:A total of 30 human cervical spine vertebrae (C 3-C 6) were harvested from 8 fresh-frozen cadaver specimens whose mean age was 45.3±11.2 years at death. The vertebrae were randomly divided into three groups for specific screws. For each vertebra, one side was randomly chosen for direct pullout strength test (speed 5 mm/s), and the other side for fatigue test (displacement ±1.0 mm, frequency 1 Hz, 500 cycles) and residual pullout strength test. 4.5 mm × 12 mm screws were used for PVFS, 3.5 mm × 14 mm screws for LMS, and 3.5 mm × 24 mm screws for PS. Results:The direct pullout strength was 327.10±17.07 N for PVFS, 305.71 ± 11.63 N for LMS, and 635.67 ± 22.82 N for PS. The residual pullout strength was 265.62 ±18.19 N for PVFS, 192.80 ±17.10 N for LMS, and 494.89 ±41.79 N for PS. The residual pullout strength of PVFS, LMS and PS respectively, compared with the direct pullout strength, decreased by 18.8%, 36.93% and 22.15% ( tPVFS=7.795 , tLMS=17.267 , tPS=9.349 , P<0.001). The direct pullout strength of PS was higher than that of PVFS and LMS( t=34.245, t=40.741, P< 0.001), as well as PVFS was slightly higher than LMS ( t=3.275, P=0.004). The residual pullout strength of PS was the highest, PVFS was the second, and LMS was the smallest ( F=314.619, P<0.001). For the fatigue test, the load at the first cycle and the first time when the set position was reached of PVFS were higher than those of LMS ( t=3.625, P=0.002; t=5.388, P<0.001) and PS ( t=2.575, P=0.019; t=2.680, P=0.015), but there was no difference between those of LMS and PS ( t=0.609 , P=0.550; t=1.953 , P=0.067). The load at the last cycle of PVFS and PS was higher than that of LMS ( t=5.341 , P<0.001 ; t=3.439 , P=0.003), while there was no difference between PVFS and PS ( t=1.606, P=0.126). Conclusion:The direct pullout strength of PVFS was slightly higher than that of LMS, and the residual pullout strength was significantly higher than LMS. The property of fatigue resistance of PVFS was similar to PS and obviously better than LMS. In summary, PVFS can be used as an effective substitute for LMS and PS.

Objective:To measure and compare the length and angle parameters of the screw paths of paravertebral foramen screws (PVFS), pedicle screws (PS) and lateral mass screws (LMS) of subaxial cervical spine.Methods:This study included the cervical computerized tomography (CT) scans of 50 healthy volunteers (25 males and 25 females) in our hospitalfrom January 2018 to June 2018. The average age of the volunteers was 56.00±15.90 years (range, 29-89 years). After three-dimensional reconstruction of CT data, the screw starting points, length of screw paths,optimal medial angles, maximum medial angles and minimum medial angles of PVFS, PS and LMS (Magerl technique) on C 3-C 7 segments were designed and measured on the reconstructed 3D model, and the pedicle widths at various segments of cervical vertebrae were measured. All parameters were measured twice in an interval of two weeks by one orthopaedic surgeons with experience in spine surgery, and the average values of the two measurements were used. Results:In general, the optimum length and medial angle of the PVFS in Chinese population were 10.65 mm and 21.12° at C 3; 10.12 mm, 22.62° at C 4; 9.82 mm, 23.66° at C 5; 9.19 mm, 24.13° at C 6; and 9.10 mm, 27.54° at C 7. The C 3 segment had the longest general optimal length, and the C 7 segment had the shortest general optimal length of PVFS ( F=19.287, P<0.001). However, there was no significant difference in optimal length of PVFS between C 6 and C 7 vertebrae ( P=0.674). The C 7 vertebra had the largest general medial angle, meanwhile the C 3 vertebra had the smallest general medial angle ( F=19.752, P<0.001). The optimum lengths of screw path of PVFS in males at the segments of C 4, C 6 and C 7 vertebrae were longer than those in females (C 4t=2.912, C 6t=3.884, C 7t=5.468, P<0.05), and the optimal medial angle at C 4, C 6 and C 7 segments were smaller than those in females (C 4t=3.560, C 6t=4.370, C 7t=4.738, P<0.05). The optimum length and medial angle of PS in Chinese population were 30.94 mm, 33.92° at C 3; 30.50 mm, 34.95° at C 4; 31.92 mm, 33.42° at C 5; 30.50 mm, 31.94° at C 6; and 29.87 mm, 31.01° at C 7. The general pedicle widths were 5.35 mm at C 3; 5.56 mm at C 4; 5.99 mm at C 5; 6.34 mm at C 6; and 6.86 mm at C 7. The optimum lengths of LMS paths in Chinese population were C 3, 14.84 mm; C 4, 15.33 mm; C 5, 15.44 mm; C 6, 14.74 mm; and C 7, 14.06 mm. In Chinese population, the optimal length of PVFS was 9.10-10.65 mm, and the optimal medial angle was 21.12°-27.54°. The general optimal length of PVFS path were shorter than those of LMS and PS at C 3-C 7 segments ( P<0.05), and the general optimal medial angles were smaller than those of PS at C 3-C 7 segments ( P<0.05). Conclusion:Because of the length of screw path of PVFS is limited, it does not have the risk of direct vertebral artery injury. The insert angle of PVFS is steeper and safer than that of PS. In summary, cervical PVFS can be used as an effective supplement to PS and LMS.

Objective: To compare the incidence of adjacent segment degeneration (ASDeg) and clinical outcomes of minimally invasive versus traditional transforaminal lumbar interbody fusion (TLIF) in the treatment of L _4,5 single-segment lumbar spinal stenosis (LSS) and explore the risk factors of ASDeg. Methods: All of 115 patients with LSS who were treated by the same group of doctors from 2009 to 2013, with a minimum follow-up of 5 years. Thirty-eight patients underwent minimally invasive trans-foraminal lumbar interbody fusion (MIS-TLIF) and 77 patients underwent traditional TLIF. Standing radiographs at the preopera-tive period and the final follow-up were assessed. Radiological parameters included lumbar lordosis (LL), fused segment angle (FSA), disc height (DH) and range of motion (ROM). Babu classification was used to identify facet joint violation (FJV) in patients at 5-year follow-up. Clinical outcomes were assessed according to visual analog scale (VAS) score, Japanese Orthopaedic Associa-tion (JOA) score and Oswestry Disability Index (ODI). Student's t-test, Chi-square test, and non-parametric test were used as the main statistical methods. Results: The mean age of MIS-TLIF group was 58.2±8.8 years, and that of TLIF group was 54.7±11.2 years, and there was no significant difference between the two groups. The mean follow-up time was 64.5±3.8 months in the MIS-TLIF group and 63.9±3.3 months in the TLIF group, and there was no significant difference between the two groups. There were 17 cases of degenerative spondylolisthesis in MIS-TLIF group (44.7%) and 35 cases of degenerative spondylolisthesis in TLIF group (45.5%), and there was no significant difference between the two groups. There was no significant difference in DH and ROM of L_3,4, L_4,5, L₅S₁ between the two groups before operation. There was no significant difference in VAS, JOA and ODI scores between the two groups before operation. The VAS, JOA and ODI scores were significantly improved at the last follow-up compared with those before operation. After 5-year follow-up, 56 cases (48.7%) had ASDeg. The incidence of ASDeg was 31.6% in MIS-TLIF group and 57.1% in TLIF group, and there was statistical differences between the two groups (χ²=6.656, P <0.01). Among them, 32 cases only had upper segment ASDeg (6 cases in MIS-TLIF group, 26 cases in TLIF group), 19 cases only had lower segment ASDeg (6 cases in MIS-TLIF group, 13 cases in TLIF group), and 5 cases had both upper and lower ASDeg (5 cases in the TLIF group). The DH of adjacent segments decreased after operation, but the loss of DH in MIS-TLIF group was smaller than that in TLIF group, including L_3,4 segments (-4.9%±6.4% vs-8.7%±7.2%, t=-2.761, P <0.01), L5S1 segment (-4.7%±9.8% vs-10.5%±11.7%, t=-2.623, P <0.01). The ROM of adjacent segments increased in both groups, but the increase of ROM in MIS-TLIF group was smaller than that in TLIF group, including L _3,4 segments (1.1°±1.8° vs 2.3°±2.5°, t=-3.122, P <0.01), L₅S₁ segment (0.9°± 1.9 ° vs 1.8°±1.9 °, t=-2.353, P <0.01). The incidence of FJV was 54.2% in patients with ASDeg in MIS-TLIF group and 47.7% in patients with ASDeg in TLIF group. Chi-square analysis showed that FJV was related to ASDeg in both groups (χ²=3.869, P < 0.05). Conclusion Both of the two surgical methods have good clinical effects on L _4,5 single-segment LSS. The incidence of AS-Deg after MIS-TLIF is lower than that of TLIF. FJV is a risk factor for ASDeg.