Objective:To compare the clinical efficacy of percutaneous endoscopic interlaminar discectomy (PEID) and posterior small incision microdiscectomy (MD) in the treatment of recurrent lumbar disc herniation.Methods:A retrospective analysis was conducted on the data of 132 patients who underwent revision surgery for recurrent lumbar disc herniation at the same segment at Qilu Hospital of Shandong University between July 2012 and August 2022. The patients were treated with either PEID or MD. The PEID group consisted of 90 patients, including 51 males and 39 females, with a mean age of 42.7±11.3 years and a mean body mass index (BMI) of 23.7±3.4 kg/m 2. The surgical segments were L 4-5 in 38 cases and L 5S 1 in 52 cases. The primary surgeries included open discectomy in 7 cases, laminectomy with bone graft in 3 cases, MD in 35 cases, and PEID in 45 cases. The MD group consisted of 42 patients, including 30 males and 12 females, with a mean age of 41.2±12.6 years and a mean BMI of 24.3±4.7 kg/m 2. The surgical segments were L 4-5 in 19 cases and L 5S 1 in 23 cases. The primary surgeries included open discectomy in 2 cases, laminectomy with bone graft in 1 case, MD in 17 cases, and PEID in 22 cases. The visual analogue scale (VAS) scores for low back pain and leg pain, Oswestry disability index (ODI), immediate postoperative VAS score for surgical wound pain, intraoperative blood loss, surgical wound length, operation duration, length of hospital stay, and various complications before and after surgery were compared between the PEID and MD groups. Results:The operation duration in the PEID group was 81.7±11.3 min, that in the MD group was 85.2±9.5 min, but the difference was not statistically significant ( t=1.740, P=0.081). The intraoperative blood loss in the PEID group was 4.4±2.9 ml, the surgical wound length was 0.9±0.2 cm, and the length of hospital stay was 3.1±1.3 d, all significantly less than those in the MD group (26.6±10.3 ml, 3.4±1.1 cm, and 8.7±1.6 d, respectively), with statistically significant differences ( P<0.05). Both groups were followed up, with a mean follow-up duration of 24.4±5.5 months in the PEID group and 24.5±4.9 months in the MD group, and there was no statistically significant difference between the two groups ( t=0.101, P=0.920). Both the PEID and MD groups showed significant improvements in postoperative VAS scores for leg pain, VAS scores for low back pain, and ODI compared with preoperative values ( P<0.05). Additionally, the VAS score for surgical wound pain on the first postoperative day in the PEID group was 1.2±0.4, which was lower than that in the MD group (2.9±0.6), with a statistically significant difference ( t=19.261, P<0.001). The incidence rates of muscle weakness, postoperative sensory abnormalities, and dural tears in the PEID group were 12%(11/90), 27%(24/90), and 6%(5/90), respectively, significantly lower than those in the MD group [31%(13/42), 40%(17/42), and 33%(14/42), respectively], with statistically significant differences ( P<0.05). However, there were no statistically significant differences between the two groups in the incidence rates of recurrence, residual nucleus pulposus, spinal cord-like hypertension syndrome, subcutaneous wound infection, or intervertebral space infection ( P>0.05). No patients in either group developed retroperitoneal hematoma postoperatively. Conclusion:For patients with recurrent lumbar disc herniation after primary posterior surgery, PEID demonstrates equally excellent clinical efficacy compared with MD, with smaller surgical trauma and a lower incidence of complications.

Objective:To compare the clinical efficacy of percutaneous endoscopic interlaminar discectomy (PEID) and posterior small incision microdiscectomy (MD) in the treatment of recurrent lumbar disc herniation.Methods:A retrospective analysis was conducted on the data of 132 patients who underwent revision surgery for recurrent lumbar disc herniation at the same segment at Qilu Hospital of Shandong University between July 2012 and August 2022. The patients were treated with either PEID or MD. The PEID group consisted of 90 patients, including 51 males and 39 females, with a mean age of 42.7±11.3 years and a mean body mass index (BMI) of 23.7±3.4 kg/m 2. The surgical segments were L 4-5 in 38 cases and L 5S 1 in 52 cases. The primary surgeries included open discectomy in 7 cases, laminectomy with bone graft in 3 cases, MD in 35 cases, and PEID in 45 cases. The MD group consisted of 42 patients, including 30 males and 12 females, with a mean age of 41.2±12.6 years and a mean BMI of 24.3±4.7 kg/m 2. The surgical segments were L 4-5 in 19 cases and L 5S 1 in 23 cases. The primary surgeries included open discectomy in 2 cases, laminectomy with bone graft in 1 case, MD in 17 cases, and PEID in 22 cases. The visual analogue scale (VAS) scores for low back pain and leg pain, Oswestry disability index (ODI), immediate postoperative VAS score for surgical wound pain, intraoperative blood loss, surgical wound length, operation duration, length of hospital stay, and various complications before and after surgery were compared between the PEID and MD groups. Results:The operation duration in the PEID group was 81.7±11.3 min, that in the MD group was 85.2±9.5 min, but the difference was not statistically significant ( t=1.740, P=0.081). The intraoperative blood loss in the PEID group was 4.4±2.9 ml, the surgical wound length was 0.9±0.2 cm, and the length of hospital stay was 3.1±1.3 d, all significantly less than those in the MD group (26.6±10.3 ml, 3.4±1.1 cm, and 8.7±1.6 d, respectively), with statistically significant differences ( P<0.05). Both groups were followed up, with a mean follow-up duration of 24.4±5.5 months in the PEID group and 24.5±4.9 months in the MD group, and there was no statistically significant difference between the two groups ( t=0.101, P=0.920). Both the PEID and MD groups showed significant improvements in postoperative VAS scores for leg pain, VAS scores for low back pain, and ODI compared with preoperative values ( P<0.05). Additionally, the VAS score for surgical wound pain on the first postoperative day in the PEID group was 1.2±0.4, which was lower than that in the MD group (2.9±0.6), with a statistically significant difference ( t=19.261, P<0.001). The incidence rates of muscle weakness, postoperative sensory abnormalities, and dural tears in the PEID group were 12%(11/90), 27%(24/90), and 6%(5/90), respectively, significantly lower than those in the MD group [31%(13/42), 40%(17/42), and 33%(14/42), respectively], with statistically significant differences ( P<0.05). However, there were no statistically significant differences between the two groups in the incidence rates of recurrence, residual nucleus pulposus, spinal cord-like hypertension syndrome, subcutaneous wound infection, or intervertebral space infection ( P>0.05). No patients in either group developed retroperitoneal hematoma postoperatively. Conclusion:For patients with recurrent lumbar disc herniation after primary posterior surgery, PEID demonstrates equally excellent clinical efficacy compared with MD, with smaller surgical trauma and a lower incidence of complications.

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.

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.