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This study was performed to prospectively compare the clinical and radiographic outcomes between robot-assisted minimally invasive transforaminal lumbar interbody fusion (RA MIS-TLIF) and fluoroscopy-assisted minimally invasive transforaminal lumbar interbody fusion (FA MIS-TLIF) in patients with degenerative lumbar spinal diseases. One hundred and twenty-three patients with lumbar degenerative diseases (lumbar spinal stenosis with instability and spondylolisthesis [degenerative spondylolisthesis or isthmic spondylolisthesis]) who underwent MIS-TLIF in our hospital were included in this study. Sixty-one patients underwent RA MIS-TLIF (Group A) and 62 patients underwent FA MIS-TLIF (Group B). Group A was further divided into Subgroup AI (46 single-level procedures) and Subgroup AII (15 double-level procedures). Group B was further divided into Subgroup BI (45 single-level procedures) and Subgroup BII (17 double-level procedures). The clinical outcome parameters were the visual analog scale (VAS) score, Oswestry Disability Index (ODI) score, operative time, number of intraoperative fluoroscopies, blood loss, postoperative hospital stay, and postoperative complications. The radiographic change measures were the accuracy of screw placement, facet joint violation (FJV), fusion status, and change in disc height at the proximal adjacent segment at the 2-year follow-up. There were no significant differences in the VAS and ODI scores, blood loss, or postoperative hospital stay between Groups A and B (p0.05). The operative time was longer in Group A than B (p = 0.018). The operative time was longer in Subgroup AI than BI (p = 0.001). However, there was no significant difference between Subgroups AII and BII (p0.05). There was no significant difference in the number of intraoperative fluoroscopies for patients between Groups A and B (p0.05). Although the number of intraoperative fluoroscopies for patients was significantly higher in Subgroup AI than BI (p = 0.019), there was no significant difference between Subgroups AII and BII (p0.05). The number of intraoperative fluoroscopies for the surgeon was significantly lower in Group A than B (p0.001). For surgeons, the difference in the average number of intraoperative fluoroscopies between Subgroups AI and AII was 2.98, but that between Subgroups BI and BII was 10.73. In Group A, three guide pins exhibited drift and one patient developed a lateral wall violation by a pedicle screw. One pedicle screw perforated the anterior wall of the vertebral body and another caused an inner wall violation in Group B. The rate of a perfect screw position (grade A) was higher in Group A than B (p0.001). However, there was no significant difference in the proportion of clinically acceptable screws (grades A and B) between the two groups. The mean FJV grade was significantly higher in Group B than A (p0.001). During at 2-year postoperative follow-up, there was no significant difference in the fusion status between the two groups (p0.05); however, the decrease in disc height at the proximal adjacent segment was significantly less in Group A than B (p0.001). Robot-assisted percutaneous pedicle screw placement is a safer and more accurate alternative to conventional freehand fluoroscopy-assisted percutaneous pedicle screw insertion in MIS-TLIF.

Although Caspar cervical retractor system (CCRS) is commonly utilized in anterior cervical decompression and fixation (ACDF), most urban hospitals still use both traditional S retractor and CCRS in conventional anterior cervical surgeries. Related data to evaluate the effect are required to be reported. The aim of this study is to compare the efficacy between using the traditional cervical S retractor and CCRS in anterior cervical decompression and fixation ACDF.The retrospective study that total 360 patients received ACDF using different retractors (traditional S retractor or CCRS) were enrolled in this study from January 2010 to January 2020. Width change rate of cervical prevertebral soft tissue, throat symptoms, and subjective experiences of the operating surgeons were evaluated by t-test or analysis of variance (ANOVA) respectively.The width change rate of prevertebral soft tissue was significantly higher in the S retractor group than that of the CCRS group both in single segment group (40.9% vs 20.8%, P 0.05) and double segments group (45.8% vs 25.2%; p 0.05). In the three segments group, the width change rate of prevertebral soft tissue was higher in the S retractor group than that of the CCRS group, but with no statistical significance (27.3% vs 23.6%; P 0.05). The incidence rates of dysphagia, dyspnea, and throat discomfort in the traditional S retractor group were significantly higher compared to the CCRS group (P 0.05), while satisfactory rate of surgeon was higher in the CCRS group (P 0.05). However, there was no correlation between anterior soft tissue rate and operative time (P 0.05), as well as the width change rate of anterior soft tissue and the DNRS score (P 0.05).CCRS was superior compared to the traditional S retractor in reducing the postoperative complications and the postoperative fatigue of surgeon. Meanwhile, the width change rate of prevertebral soft tissue was not related to operative time and DNRS score.

Background Hypertrophy of the ligamentum flavum (LF) contributes to the development of spinal stenosis. Smad proteins can mediate the fibrogenesis activity through the transforming growth factor β1 (TGF-β1) pathway, but which Smad protein plays a more important role in the hypertrophy process of LF is unclear. Methods The LF samples were obtained from 50 patients. After the LF cells (LFCs) were cultured, small interfering ribonucleic acid (siRNA) that target human phosphorylated–Smad2, 3, or 4 (p-Smad2,3,4) genes was transfected into LFCs. Next, proteins from cells were extracted and the protein levels of Smad2, Smad3, and Smad4 were detected by Western blot. The messenger ribonucleic acid level of TGF-β1 was measured by real-time polymerase chain reaction (PCR). Furthermore, an enzyme-linked immunosorbent assay was performed to test the impact of Smad2 downstream of the TGF-β1 signaling pathway. Results Degeneration of the LF was characterized by an increase in disorganized elastic fibers and fibrotic transformation by extracellular collagen deposition. The gene expression analysis of fibrotic genes in LFCs showed that knockdown of phosphorylated–Smad2 by siRNA significantly reduced the protein expression level of TGF-β1 compared with other groups. The enzyme-linked immunosorbent assay suggested that the protein expression level of Smad2 can influence the downstream events of TGF-β1 signaling pathway in the LFCs. Conclusions Our findings suggest that Smad2 plays a potential role in the pathologic development of hypertrophy of LF. We also found that Smad2 knockdown by Smad-siRNA can influence the TGF-β1 signaling pathway through decreasing expression of TGF-β1, tumor necrosis factor α, and nuclear factor κb.

Bags such as handbags, shoulder bags, and backpacks are commonly used. However, it is difficult to assess the biomechanical effects of bag-carrying styles on the lumbar spine and paraspinal muscles using traditional methods. This study aimed to evaluate the biomechanical effects of bag-carrying styles on the lumbar spine.We developed a hybrid model that combined a finite element (FE) model of the lumbar spine and musculoskeletal models of three bag-carrying styles. The image data was collected from a 26-years-old, 176 cm and 70 kg volunteer. OpenSim and ABAQUS were used to do the musculoskeletal analysis and finite analysis. Paraspinal muscle force, intervertebral compressive force (ICF), and intervertebral shear force (ISF) on L1 were calculated and loaded into the FE model to assess the stress distribution on the lumbar spine.Different paraspinal muscle activation occurred in the three bag-carrying models. The increase in the ICF generated by all three bags was greater than the bags' weights. The handbag produced greater muscle force, ICF, ISF, and peak stress on the nucleus pulposus than the backpack and shoulder bag of the same weight. Peak stress on the intervertebral discs in the backpack model and the L1-L4 segments of the shoulder bag model increased linearly with bag weight, and increased exponentially with bag weight in the handbag model.Unbalanced bag-carrying styles (shoulder bags and handbags) led to greater muscle force, which generated greater ICF, ISF, and peak stress on the lumbar spine. The backpack produced the least burden on the lumbar spine and paraspinal muscles. Heavy handbags should be used carefully in daily life.

Objective: To analyze the effect of hysterectomy on radiologic lumbar spine degeneration in patients with lumbar disc herniation. Methods: The medical records of 95 female patients aged over 45 years diagnosed with lumbar disc herniation from January 2016 to December 2021 were retrospectively analyzed and grouped according to their hysterectomy status. Thirty-five patients were assigned to the hysterectomy group (HR group) and 60 to the non-hysterectomy group (NHR group). Computerized tomography (CT), magnetic resonance imaging (MRI), and lateral lumbar spine radiographs were used to examine various radiological imaging parameters between the groups. Results: No significant differences in patient characteristics among the groups were found. Functional cross-sectional area and standardized functional cross-sectional area of the psoas and erector spinae muscles at L3-L4, L4-L5, and L5–S1 were significantly lower in the HR group (P

Background To compare preoperative sagittal alignment between patients with multi-segment cervical ossification of the posterior longitudinal ligament (OPLL) and multi-level cervical spondylotic myelopathy (CSM). Methods A total of 198 patients (110 men, 78 women; mean age, 58.8 ± 10.4 years) with severe cervical spondylosis underwent surgical treatment from September 2013 to December 2021. In total, 103 patients were diagnosed with multi-segment cervical OPLL, including continuous type (n = 31), segmental type (n = 31), and mixed type (n = 41). The remaining 95 patients had multi-segment CSM. Several clinical variables were assessed preoperatively, including Japanese Orthopaedic Association (JOA) scores, visual analogue scale (VAS) score, number of hand actions in 10 seconds, hand-grip strength, C2–C7 Cobb angle, C2–C5 Cobb angle, C5–C7 Cobb angle, C2–C7 sagittal vertical axis, C7 slope, T1 slope, K-line, K-line tilt, and range of motion (ROM).Results The JOA scores, number of hand actions in 10 seconds, hand-grip strength, and VAS scores were not significantly different between the two groups (p > 0.05). The C2–C7 and C5–C7 Cobb angles were significantly better in the OPLL group (p < 0.05). The CSM group had a larger ROM (p < 0.001). Within the OPLL group, the ROM was significantly different between the segmental type and continuous type (p < 0.05).Conclusion The sagittal alignment in patients with multi-segment cervical OPLL is good. However, patients with OPLL have greater loss of ROM than those with CSM. Studying the sagittal alignment could provide a theoretical basis for preoperative decision-making.

A magnetic resonance neurography (MRN) study was conducted to assess the neurological safety of endo-transforaminal lumbar intervertebral fusion (endo-TLIF).A total of 56 healthy volunteers (29 men, 27 women; average age, 44 years; age range, 21-60 y) were included in the study. Coronal MRN images were collected from L2/L3 to L5/S1. The working triangle, modified working zone, and safest working zone areas, as well as the vertical and horizontal safe operation diameters, were measured. Linear regression analyses were conducted to explore the correlations between general characteristics (sex, age, height, body mass index) and the measured radiographic indicators.MRN can effectively evaluate the operation zone of endo-TLIF. The safest working zone, modified working zone, and working triangle areas were largest at L4/L5 (92.4±23.4, 136±35.6, and 197±41.7 mm2, respectively) and smallest at L2/L3 (45.5±12.9, 68.1±19.5, and 92.6±24.4 mm2, respectively). The vertical safe operation diameter was large at L4/L5 and L2/L3 (5.34±0.8 and 5.42±0.9 mm, respectively) and smallest at L5/S1 (2.94±0.9 mm). The horizontal safe operation diameter was large at L4/L5 (7.28±1.2 mm) and smaller at L5/S1 and L2/L3 (4.28±1.0 and 4.77±0.8 mm, respectively).L4/L5 has the lowest risk of nerve injury, and it is extra amiable for beginners in endo-TLIF. We recommend that coronal MRN is routinely performed before endo-TLIF to minimize the risk of neurological injury.

Pelvic incidence (PI) is assumed to be fixed, yet studies have reported PI changes after long fusions to the pelvis. In a cohort of ASD patients undergoing surgery with S2-alar-iliac (S2AI) screws, we sought to: (1) report the magnitude of PI changes, and (2) evaluate subsequent pelvic parameter changes. A retrospective case series of ASD patients undergoing surgical correction with S2AI screw placement and sagittal cantilever correction maneuvers was conducted. Patients were categorized based on preoperative PI: High-PI (H-PI) (PI ≥ 60°); Normal-PI (N-PI) (60° > PI > 40°); Low-PI (L-PI) (PI ≤ 40°). PI was measured preoperatively and immediately postoperatively. A significant PI change was established a priori at ≥ 6.0. PI, pelvic tilt (PT), lumbar lordosis (LL), and PI-LL mismatch were analyzed. In 68 patients (82.3% female, ages 22–75 years), the average change in PI was 4.6° ± 3.1, and 25 (36.8%) had a PI change ≥ 6.0° with breakdown as follows: H-PI 12 (66.7%) patients, 9 (25.87%) patients, and 4 (33.3%) patients. Of 25 patients with PI changes, 10 (14.7%) had a PI increase and 15 (22.1%) had a PI decrease. Significant improvements were seen in PT, LL, PI-LL mismatch in all patients with a PI change ≥ 6.0°, in addition to both subgroups with an increase or decrease in PI. PI changes of ≥ 6.0° occurred in 36.8% of patients, and H-PI patients most commonly experienced PI changes. Despite PI alterations, pelvic parameters significantly improved postoperatively. These results may be explained by sacroiliac joint laxity, S2AI screw placement, or aggressive sagittal cantilever techniques.

Study design A morphometric measurement study. Objective To measure the length and angle parameters of the screw paths of pedicle screws (PS), lateral mass screws (LMS), and paravertebral foramen screws (PVFS) of subaxial cervical spine in Chinese population. Summary of background data Aramomi proposed a novel internal fixation technology, named PVFS, as an alternative to LMS and PS for subaxial cervical vertebrae (C3-C7). Methods This study measured the length and medial angles of screw paths on the three-dimensional reconstruction model of cervical computerized tomography data of 50 patients (25 men and 25 women) in our hospital from January 2018 to June 2018. Results In general, the optimum length and medial angle of the PVFS in Chinese population were 10.65 mm and 21.12° at C3; 10.12 mm, 22.62° at C4; 9.82 mm, 23.66° at C5; 9.19 mm, 24.13° at C6; and 9.10 mm, 27.54° at C7. The optimum axial length and medial angle of PS in Chinese population were 30.94 mm, 33.92° at C3; 30.50 mm, 34.95° at C4; 31.92 mm, 33.42° at C5; 30.50 mm, 31.94° at C6; and 29.87 mm, 31.01° at C7. The optimum lengths of LMS paths in Chinese population were C3, 14.84 mm; C4, 15.33 mm; C5, 15.44 mm; C6, 14.74 mm; and C7, 14.06 mm. Conclusion Although the length of PVFS is limited, it still can be used as an effective substitute for LMS and PS. The PVFS does not have the risk of directly injuring the vertebral artery, its safety angle of insertion is larger than that in PS, and it has higher surgical safety.Level of Evidence: 3.

We aimed to investigate the morphologic changes in the intervertebral foramen after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), and analyze the necessity of routinely performing contralateral intervertebral foraminal decompression in degenerative lumbar spondylolisthesis cases with bilateral symptoms.72 single-level degenerative lumbar spndylolisthesis patients with bilateral symptoms were included, all of whom underwent unilateral approach MIS-TLIF. Preoperative and postoperative foraminal height (FH), foraminal width (FW), disc height (DH), distance from existing nerve root to upper edge of lower pedicle (RTP), and contralateral side spinal canal area (CSCA) were measured at surgical and contralateral side. Clinical outcomes were evaluated using the visual analog scale, Oswestry Disability Index, and Japanese Orthopaedic Association score.The preoperative values are comparable between operative and contralateral sides (P.05). The postoperative values for FH on operative and contralateral sides were 16.23±2.48 mm and 16.10±2.42 mm, for FW were 11.36±2.58 mm and 11.31±2.71 mm, for IH were 8.18±1.58 mm and 8.42±1.54 mm, for RTP were 8.58±1.26 mm and 9.14±1.77 mm, and the CSCA of the spinal canal on the contralateral side were 211.59±48.12 mm², respectively. The difference between these was also not statistically significant (P.05). The values increased significantly on the surgical and contralateral side (P.05). The visual analog scale for low-back and leg pain, Japanese Orthopaedic Association, and Oswestry Disability Index improved significantly at 2-year follow-up.Unilateral MIS-TLIF can effectively improve contralateral FH, DH, FW, RTP, and CSCA. It is not necessary to routinely perform contralateral intervertebral foramen decompression in degenerative lumbar spondylolisthesis with bilateral symptoms when symptoms are mild on one side.

OBJECTIVE To assess the role of foraminoplasty during percutaneous endoscopic transforaminal discectomy (PETD) and compared the 2-year clinical results of patients underwent PETD w/o foraminoplasty. METHODS A total of 412 patients, who underwent PETD at L3-S1 by the same surgical group, were enrolled in this study. The MRI was used to determine the height (H1) and width (W1) of the intervertebral foramen of L3-S1, the distance between the exiting nerve root and the upper edge of the lower vertebral pedicle (H2), and the distance (W2) between the point with 3 mm to the ventral side of the intervertebral space and superior articular process. The intervertebral foramen widths in the flexion (W3) and extension positions (W4) were also measured. A VAS of low back pain (LBP) and leg pain, ODI and JOA scores of LBP were used to assess the clinical results. RESULTS Intraoperative verification showed that 347 cases (group A) did not need foraminoplasty, while the other 65 patients (group B) needed foraminoplasty, including 31 at L4-5 and 34 at L5-S1. The H1 and H2 of L3-S1 were reduced gradually without significant difference between two groups. The W1, W2, W3 and W4 were higher in group A (p 0.05). The VAS score of LBP was better in group A (p

BackgroundWe aimed to analyze the clinical results of Schwab grade 4 osteotomy combined with percutaneous pedicle screws (PPS) fixation for treatment of post-traumatic thoracolumbar kyphosis (PTK).MethodsThirty four patients with PTK (group A) were included in our study. The average age was 54.9 ± 3.3 years. All patients had severe back pain with 8.6 ± 1.3 VAS scores. The affected level was T12 in 16 patients and L1 in 18 patients. The average preoperative regional kyphosis angle (RKA) was 30.7 ± 6.00. Three patients had neurological dysfunction with ASIA grade D. All patients underwent Schwab grade 4 osteotomy combined with PPS fixation. The control group (Group B) were 26 PTK patients treated with Schwab grade 4 osteotomy and open pedicle screws fixation in our institution.ResultsOperation time in groups A and B was 280 ± 50 min and 210 ± 30 min, respectively (P P P > 0.05). CT showed that the misplacement rate in groups A and B was 5.5 and 6.6% (P > 0.05). The average follow-up in groups A and B was 25.2 ± 7.6 months and 30.6 ± 2.7 months. No fracture and other complications were observed in both groups. Solid bone fusion was showed in all cases at 6 months follow-up. In groups A and B, all patients with preoperative neurological dysfunction recovered to ASIA grade E at the last follow-up. The VAS score of back pain improved significantly from 8.6 ± 1.3 to 1.6 ± 1.0 at the last follow-up in group A (P ConclusionSchwab grade 4 osteotomy combined with percutaneous pedicle screws fixation is a minimally invasive, safe and effective method for PTK treatment.

Background Percutaneous vertebroplasty is the most common treatment for osteoporotic vertebral compression fracture. However, the morbidity of vertebroplasty-related complications, such as cement leakage, remains high. We tested a new technique of unilateral pulsed jet lavage and investigated its effect on the intravertebral pressure and bone cement distribution. Methods Thirty lumbar vertebrae (L1-L5) from six cadaver spines were randomly allocated into two groups (with and without irrigation). Prior to vertebroplasty, pulsed jet lavage was performed through one side of the pedicle by using a novel cannula with two concentric conduits to remove the fat and bone marrow of the vertebral bodies in the group with irrigation. The control group was not irrigated. Then, standardized vertebroplasty was performed in the vertebral bodies in both groups. Changes in the intravertebral pressure during injection were recorded. Computed tomography (CT) was performed to observe the cement distribution and extravasations, and the cement mass volume (CMV) was calculated. Results During cement injection, the average maximum intravertebral pressure of the unirrigated group was higher than that of the irrigated group (4.92 kPa versus 2.22 kPa, P < 0.05). CT scans showed a more homogeneous cement distribution with less CMV (3832 mm3 vs. 4344 mm3, P < 0.05) and less leakage rate (6.7% vs. 46.7%, P < 0.05) in the irrigated group than in the control group. Conclusions Unilateral pulsed jet lavage can reduce intravertebral pressure and lower the incidence of cement leakage during vertebroplasty. An enhanced bone cement distribution can also be achieved through this lavage system.

Objective To investigate the incidence of superior facet joint violation (FJV) during percutaneous pedicle screw placement in minimally invasive transforaminal lumbar interbody fusion, and assess the possible risk factors for FJV. Methods An analysis of 91 patients with lumbar degenerative diseases treated with percutaneous pedicle screw placement via minimally invasive transforaminal lumbar interbody fusion from 2012 to 2018 was performed. Superior FJV was evaluated and graded by 3-dimensional lumbar computed tomography reconstruction. Analysis of possible risk factors included general condition of patients, anatomical characteristics of facet joint (FJ; axial, sagittal, and coronal diameters of FJ, facet angle, lumbar lordosis angle, lumbar lordosis index, and depth of lamina), and surgical factors (pedicle screw angle, screw-superior FJ distance, cranial angle, proximal rod length, and rod contouring). Results The overall violation rate of superior FJ was 34.07% (62/182), and high-grade violation rate was 16.06% (27/182). The logistic regression analysis revealed that body mass index ≥30 kg/m2 and pedicle screw placement at L5 were independent risk factors of FJV. Anatomical factors showed that the incidence of FJV was significantly increased when axial, sagittal, and coronal diameters of FJ were all ≥12 mm or FA was ≥40°. Surgical factors showed that the FJV group had a smaller pedicle screw angle and screw-superior FJ distance compared with the non-FJV group (P Conclusions Body mass index ≥30 kg/m2 and pedicle screw placement at L5 were independent risk factors of superior FJV. FJV was more likely to occur in hypertrophic FJ (axial, sagittal, and coronal diameters ≥12 mm) or coronal orientation (FA ≥40°).

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and percutaneous endoscopic TLIF (PE-TILF) have been widely used in spine surgery. The use of a robot-guided technique provided several advantages; however, few studies have investigated the clinical outcomes of robot-assisted PE-TLIF (PE RA-TLIF).The aim of this prospective cohort study was to compare the clinical outcomes of PE RA-TLIF with MIS-TLIF for the treatment of lumbar 4-5 (L4-5) spondylolisthesis.Prospective cohort study.Qilu Hospital of Shandong University.Fifty-eight cases diagnosed with L4-5 spinal stenosis with instability and Meyerding grade I spondylolisthesis (degenerative spondylolisthesis or isthmic spondylolisthesis) were included in this study. Twenty-six patients (group A) were treated with PE RA-TLIF, and the others (group B) underwent MIS-TLIF. The surgical procedures for PE RA-TLIF included the percutaneous implantation of pedicle screws (PS) under robot guidance, percutaneous fully endoscopic transforaminal decompression, and interbody fusion. The Japanese Orthopedic Association (JOA) score, the visual analog scale (VAS) for low back pain (LBP), the VAS for leg pain/numbness, and the Oswestry disability index (ODI) were used as follow-up clinical outcomes, and the lumbar interbody fusion rate was evaluated by CT. All statistical analyses were performed with SPSS 22.0, and the results were presented as mean ± standard deviation (SD).There were 4 cases of spinal stenosis with instability, 17 cases of degenerative spondylolisthesis, and 5 cases of isthmic spondylolisthesis in group A. For group B, there were 6 cases of spinal stenosis with instability, 19 cases of degenerative spondylolisthesis, and 7 cases of isthmic spondylolisthesis. The preoperative scores for the JOA, ODI, VAS for LBP, and VAS for leg pain were not statistically comparable between the 2 groups (P0.05). The incision length for decompression and interbody fusion, estimated blood loss (EBL), and 1-day and 3-day incision pain were significantly higher in group B than in group A (P0.05). The mean operative time was longer in group A than in group B (P0.05). The operation time of the first 10 cases (251 ± 24 min) was much longer than that of the last 16 cases (200 ± 17 min) in group A. The misplacement rate of percutaneous pedicle screw placement was higher in group B (P0.05). No infections of incisions and interbody or nerve root or dural injuries were found in either group A or B. No differences were found between the 2 groups in the JOA scores, ODI, leg pain VAS score, or lumbar interbody fusion rate at the 2-year follow-up. The VAS for back pain was better in group A than in group B (P0.05).The PE RA -TLIF procedure is technically challenging and has a steep learning curve, and the study was not strictly randomized.PE RA-TLIF is a safe and effective procedure that can significantly improve the accuracy of pedicle screw placement, reduce surgical trauma, and facilitate rapid postoperative recovery. However, this technique has a steep and long learning curve and requires long-term follow-ups.

Study Design Retrospective. Objectives To report and compare the application of robotic-assisted navigation with an O-arm or three-dimensional (3D) C-arm-assisted pedicle screw insertion in scoliosis surgery, and compare with free-hand technique. Methods One hundred and forty-four scoliosis patients were included in this study. Ninety-two patients underwent robotic-assisted pedicle screw insertion (Group A), and 52 patients underwent freehand fluoroscopy-guided pedicle screw insertion (Group B). Group A was further divided into Subgroup AI (n = 48; robotic-assisted navigation with an O-arm) and Subgroup AII (n = 44; robotic-assisted navigation with a 3D C-arm). The evaluated clinical outcomes were operation time, blood loss, radiation exposure, postoperative hospital stay, and postoperative complications. The clinical outcomes, coronal and sagittal scoliosis parameters and the accuracy of the pedicle screw placement were assessed. Results There were no significant differences in blood loss and postoperative hospital stay between Groups A and B ( P = .406, P = .138, respectively). Radiation exposure for patients in Group A (Subgroups AI or AII) was higher than that in Group B ( P < .005), and Subgroup AI had higher patient radiation exposure compared with Subgroup AII ( P < .005). The operation time in Subgroup AII was significantly longer than that in Subgroup AI and Group B ( P = .016, P = .032, respectively). The proportion of clinically acceptable screws was higher in Group A (Subgroups AI or AII) compared with Group B ( P < .005). Conclusions Robotic-assisted navigation with an O-arm or 3D C-arm effectively increased the accuracy and safety in scoliosis surgery. Compared with robotic-assisted navigation with a 3D C-arm, robotic-assisted navigation with an O-arm was more efficient intraoperatively.

Study Design: Retrospective. Objectives: To present rarely reported complex fractures of the upper cervical spine (C1-C2) and discuss the clinical results of the posterior temporary C1-2 pedicle screws fixation for C1-C2 stabilization. Methods: A total of 19 patients were included in the study (18 males and 1 female). Their age ranged from 23 to 66 years (mean age of 39.6 years). The patients were diagnosed with complex fractures of the atlas and the axis of the upper cervical spine and underwent posterior temporary C1-2 pedicle screws fixation. The patients underwent a serial postoperative clinical examination at approximately 3, 6, 9 months, and annually thereafter. The neck disability index (NDI) and the range of neck rotary motion were used to evaluate the postoperative clinical efficacy of the patients. Results: The average operation time and blood loss were 110 ± 25 min and 50 ± 12 ml, respectively. The mean follow-up was 38 ± 11 months (range 22 to 60 months). The neck rotary motion before removal, immediately after removal, and the last follow-up were 68.7 ± 7.1°, 115.1 ± 11.7°, and 149.3 ± 8.9° ( P < 0.01). The NDI scores before and after the operation were 42.7 ± 4.3, 11.1 ± 4.0 ( P < 0.01), and the NDI score 2 days after the internal fixation was removed was 7.3 ± 2.9, which was better than immediately after the operation ( P < 0.01), and 2 years after the internal fixation was removed. The NDI score was 2.0 ± 0.8, which was significantly better than 2 days after the internal fixation was taken out ( P < 0.001). Conclusions: Posterior temporary screw fixation is a good alternative surgical treatment for unstable C1-C2 complex fractures.

BACKGROUND Atlantoaxial dislocation (AAD) is a rare and potentially life-threatening condition. Various underlying mechanisms of injury are described in the literature. Here, the authors report an unusual nontraumatic injury mechanism of AAD in a 12-year-old patient. OBSERVATIONS A 12-year-old boy presented with intolerable neck pain and numbness in both upper limbs. The patient’s symptoms had started 2 months after the initiation of online classes during the coronavirus disease 2019 pandemic without a history of trauma. He used a computer for personal study and online classes for prolonged hours with no respite. On physical and radiological evaluation, he was diagnosed with AAD. Before surgery, skull traction was applied to reduce the dislocation and posterior C1 lateral mass screw and C2 pedicle screw fixation was performed. An optimal clinical outcome was achieved with no postoperative complications. A preoperative visual analog scale score of 8.0 was reduced to 0 postoperatively. LESSONS A prolonged fixed neck posture is an unusual underlying cause of AAD. Posterior C1 lateral mass and C2 pedicle screw fixation results in an optimal clinical outcome.

Study design Prospective study. Objective The aim of this study was to prospectively assess the clinical outcomes of modified MIS-TLIF for the treatment of single-segment lumbar spondylolisthesis. Summary of background data MIS-TLIF is a safe and effective procedure in the treatment of lumbar degenerative disease. To avoid durotomy and nerve root injury, we modified the surgical order of MIS-TLIF such that the interbody fusion procedure was performed before the decompression procedure. Methods One hundred thirty-nine patients with single-segment lumbar spondylolisthesis were separated into two groups. 67 patients underwent modified MIS-TLIF (group A). In group B, 72 patients underwent routine MIS-TLIF. The Japanese Orthopaedic Association (JOA) score and the visual analogue scale (VAS) scores for lower back pain (LBP) and leg pain were assessed during the postoperative follow-up, and the lumbar interbody fusion rate was evaluated by CT scanning. Results The mean operative time, incision length, average blood loss and incision pain level were not significantly different (P > 0.05) between the two groups. No nerve root or dural injuries were observed in group A. In group B, there were 2 cases of dural injury and 3 cases of nerve root injury. One patient experienced temporary numbness and weakness on dorsiflexion of the foot, which recovered in three months. No differences were identified between the two groups when postoperative JOA scores, back pain, leg pain VAS scores or the lumbar interbody fusion rate. Conclusion Both methods are effective in the treatment of lumbar degenerative disease. Modified MIS-TLIF is a safe and effective procedure that can significantly reduce the occurrence of injury to the dura and nerve root during decompression and the interbody fusion procedure.Level of Evidence: 3.

Study Design: Retrospective. Objectives: To study the violation rate of 3 different types of facet joint violation (FJV) grading systems (Babu, Shah, and Park), and to evaluate the accuracy, reliability, and association with clinical outcomes of the above 3 grading systems. Methods: 152 patients of lumbar spinal stenosis treated with percutaneous pedicle screw placement were enrolled in our study. FJV was evaluated on 3-dimensional lumbar CT reconstruction. Three types of grading systems were used to evaluate FJV: Babu’s system (grading by the severity of violation), Shah’s system (grading by side of violation), and modified Park’s system (grading by different components to cause violation). The violation rate and observer consistency of the 3 grading systems were analyzed. Clinical outcomes were evaluated by visual analog score (VAS), Oswestry disability index (ODI) score. Results: Kappa coefficients of interobserver consistency on Babu, Shah, and Park grading systems were 0.726,0.849,0.692, respectively. The violation rate of Babu, Shah, and Park grading systems were comparable, which were 34.54%, 32.57%, 33.55%, respectively. In all 3 grading systems, the postoperative VAS low-back pain and ODI scores in non-FJV groups were lower than those in FJV groups ( P < .05), and there were no significant differences between 2 groups in VAS leg pain( P >.05). Conclusions: Babu, Shah and modified Park grading system are reliable grading systems, and it reported comparable violation rate. The self-reported clinical outcomes of patients with FJV were worse at 2-year follow-up. For clinical application, it is recommended to use 2 or even 3 different grading systems together to evaluate the FJV.

To report the clinical use of uniplanar cannulated pedicle screws for the correction of Lenke type 1 adolescent idiopathic scoliosis (AIS), and to evalute its safety and clinical outcomes.A total of 68 patients with Lenke type 1 AIS were retrospective analyzed, among which 38 patients were treated with uniplanar cannulated screws at the concave side of periapical levels and multiaxial screws at the other levels (group A). The remaining 30 patients were treated with all multiaxial screws (group B). The preoperative and postoperative radiographic parameters, axial vertebral rotation, and the safety of the pedicle screws were evaluated.Preoperative data were comparable between the 2 groups. The postoperative proximal thoracic curve, main thoracic curve, thoracolumbar/lumbar curve, and apical vertebral rotation were significantly improved in both groups (P0.05). The coronal correction rates in group A and B were 83% and 81.9% (P = 0.723). The derotation rates in group A and B were 60.8% and 43.2% (P0.05). The rotation classification in the group A was also better than group B. The misplacement rate in group A and B was 7.9% and 11.8% (P0.05), and the total misplacement rate on the concave side (11.4%) was higher than that of convex side (8.4%). On the concave side, the misplacement rate in group A and B was 9.7% and 12.3%. On the convex side, the misplacement rate in group A and B was 5.9% and 11.1% (P0.05).Collectively, uniplanar cannulated pedicle screws could effectively increase the accuracy of pedicle screws and facilitate the derotation of the apical vertebra compared with the multiaxial pedicle screws.

Background In the present study, we reported the clinical use of uniplanar cannulated pedicle screws for the correction of Lenke type 1 adolescent Idiopathic scoliosis (AIS), and its safety and clinical outcomes were also evaluated. Methods 68 patients with Lenke type 1 AIS were included, among which 38 patients were treated with uniplanar cannulated screws at the concave side of periapical levels and multiaxial screws at the other levels (group A). Moreover, the remaining 30 patients were treated with all multiaxial screws (group B). The preoperative and postoperative radiographic parameters of the Lenke type 1 AIS, axial vertebral rotation, and the safety of the pedicle screws were evaluated by X-rays and computed tomography (CT). Results Preoperative data was comparable between two groups. The postoperative proximal thoracic (PT) curve, main thoracic (MT) curve, thoracolumbar/lumbar (TL/L) curve, and apical vertebral rotation were significantly improved compared with the preoperative data. The coronal correction rates in group A and B were 83% and 81.9%, respectively (P > 0.05). The derotation rates in group A and B were 60.8% and 43.2%, respectively (P

OBJECTIVEThis study aimed to evaluate the clinical outcomes of percutaneous endoscopic transforaminal discectomy (PETD), microendoscopic discectomy (MED), and microdiscectomy (MD) for treatment of symptomatic lumbar disc herniation (LDH).METHODSOne hundred ninety-two patients with symptomatic LDH at L3–4 and L4–5 were included in this study. The mean (± SD) age of patients was 34.2 ± 2.6 years (range 18–62 years). The patients were divided into groups as follows: group A was treated with PETD and included 60 patients (31 men and 29 women) with a mean age of 36.2 years; group B was treated with MED and included 63 patients (32 men and 31 women) with a mean age of 33.1 years; and group C was treated with MD and included 69 patients (36 men and 33 women) with a mean age of 34.0 years. The Japanese Orthopaedic Association (JOA) scale for low-back pain (LBP), Oswestry Disability Index (ODI), creatine phosphokinase activity 3 days after surgery, and visual analog scale (VAS) scores for LBP and leg pain were used for evaluation of clinical results.RESULTSThere were no significant differences in mean preoperative JOA score, ODI score, and VAS scores for LBP and leg pain among groups A, B, and C. Incision length, duration of the operation, blood loss, creatine phosphokinase, length of hospital stay, and postoperative incision pain according to the VAS were best in the PETD group (p < 0.05). The number of seconds of intraoperative fluoroscopy was highest in the PETD group (p < 0.05), whereas there was no difference between the MED and MD groups. Three cases from the MED group and 2 cases from the MD group had an intraoperative durotomy. No CSF leakage was observed after surgery. One case from the MED group and 3 cases from the MD group had incision infections. There were no neurological deficits related to the surgeries in any of the groups. Fifty-five (91.6%), 59 (93.7%), and 62 patients (89.9%) had at least 2 years of follow-up in groups A, B, and C, respectively. At the last follow-up, JOA scores, VAS scores of LBP and leg pain, and ODI scores were significantly better than preoperative correlates in all groups. There were no differences among the 3 groups in JOA scores, JOA recovery rate, ODI scores, and VAS scores for leg pain. The VAS score for LBP was best in the PETD group (p < 0.05). No lumbar instability was observed in any group. Three cases (5.5%) in the PETD group had recurrent LDH, and 2 recurrent cases (3.4%) were confirmed in the MED group.CONCLUSIONSPETD, MED, and MD were all reliable techniques for the treatment of symptomatic LDH. With a restricted indication, PETD can result in rapid recovery and better clinical results after at least 2 years of follow-up.

Background Recently, the excellent outcomes of temporary fixation of C1-2 without fusion in the treatment of odontoid fracture had been reported. It is still unclear if this technique could achieve the equivalent outcomes as the golden standard technique of anterior screw fixation. The objective of this study is to compare the clinical outcome of two treatments of fresh type II odontoid fracture: anterior cannulated screws fixation (ACSF) versus posterior instrumentation of C1-2 without fusion (PIWF). Methods This is a retrospective study. This series included 28 males and 8 females, and the mean age was 41.5 years (range, 22 to 70 years). Eleven patients were treated with ACSF, and 25 patients with PIWF. For PIWF, the implants were removed after fracture union was confirmed at 0.75~1.5 years later. All patients underwent preoperative and serial postoperative clinical examinations at approximately 3 months, 6 months, and annually thereafter. The neck disability index (NDI) was used to assess the neck discomfort caused by the operation. The range of rotary motion was evaluated at each visit. All fractures were reassessed postoperatively with serial X-films and CT scans of the cervical spine at each follow-up visit, to evaluate screw position, fracture alignment, and fusion status. Results All patients achieved immediate spinal stabilization after surgery, and none experienced neurologic deterioration. The follow-up periods ranged from 24 to 60 months. The average range of neck rotation was dramatically lost in PIWF after fixation (46° and 89° respectively in ACSF and PIWF), and recovered to 83° after the implant was removed. The NDI in PIWF was statistically higher than that in ACSF (5 and 13% respectively in ACSF and PIWF) after the first operation and decreased to 8% 1 year after the secondary operation. The fusion rates were 90.9 and 96% respectively in ACSF and PIWF. Both groups had a case of fracture non-union. Conclusions For fresh type II odontoid fractures, high rate of fracture union can be achieved by both ACSF and PIWF. For most fresh type II odontoid fractures, anterior screw fixation was the best option for its simplicity and preservation of normal atlanto-axial rotary function. Posterior instrumentation without fusion could preserve most of the atlanto-axial rotary function and lead to moderate neck discomfort and is also a good alternative if anterior screw fixation is contraindicated.

The aims were to use magnetic resonance imaging (MRI) to compare the efficacy of fat-suppressed proton-density turbo-spin-echo (FS-PD-TSE) images and T1-weighted (T1WIs) and T2-weighted images (T2WIs) in identifying cartilaginous endplate failure (CEF), and to propose a modified Rajasekaran classification based on the FS-PD-TSE sequence. Thirty-one lumbar disc herniation (LDH) cases were enrolled. Totally, 155 discs and 310 endplates were evaluated by MRI with T1W, T2W, and FS-PD-TSE sequences. Disc degeneration (DD), LDH grades, and the total endplate score (TEPS) of CEF were evaluated. Chi-square, Spearman rank correlation analysis, and multiclass logistic regression were used to compared the sensitivity in diagnosing CEF. A modified Rajasekaran classification based on FS-PD-TSE sequence was established to diagnose CEF. The multiclass logistic regression model was used to analyse the relationship between modified Rajasekaran classification and DD and LDH. There were 117 (75.5%) segments with CEF in T1WIs, 115 (74.2%) in T2WIs, and 127 (81.9%) in FS-PD-TSE, respectively. Chi-square test showed FS-PD-TSE images were more sensitive than T1WIs and T2WIs (P

OBJECT Lumbar spondylolysis and isthmic spondylolisthesis occur most commonly at only one spinal level. The authors report on 13 cases of lumbar spondylolysis with spondylolisthesis at multiple levels. METHODS During July 2007–March 2012, multiple-level spondylolysis associated with spondylolisthesis was diagnosed in 13 patients (10 male, 3 female) at Qilu Hospital of Shandong University. The mean patient age was 43.5 ± 14.6 years. The duration of low-back pain was 11.7 ± 5.1 months. Spondylolysis occurred at L-2 in 2 patients, L-3 in 4 patients, L-4 in all patients, and L-5 in 5 patients. Spondylolysis occurred at 3 spinal levels in 3 patients and at 2 levels in 10 patients. All patients had spondylolisthesis at 1 or 2 levels. Japanese Orthopaedic Association and visual analog scale scores were used to evaluate preoperative and postoperative neurological function and low-back pain. All patients underwent pedicle screw fixation and interbody fusion or direct pars interarticularis repair. RESULTS Both low-back pain scores improved significantly after surgery (p < 0.05). Postoperative radiographs or CT scans showed satisfactory interbody fusion or pars interarticularis healing. No breakage, dislodging, or loosening of the pedicle screw hardware was observed for any patient. CONCLUSIONS Multiple-level lumbar spondylolysis and spondylolisthesis occurred more often in men. Most multiplelevel lumbar spondylolysis occurred at 2 spinal levels and was associated with sports, trauma, or heavy labor. Multiplelevel lumbar spondylolysis occurred mostly at L3–5; associated spondylolisthesis usually occurred at L-4 and L-5, mostly at L-4. The treatment principle was the same as that for single-level spondylolisthesis.

Objective: To evaluate the clinical results of combined expansive open-door laminoplasty by splitting of spinous processes and selective anterior cervical decompression and fusion in treatment of multilevel severe cervical spondylotic myelopathy (CSM). Methods: Twenty-eight patients (16 men and 12 women) underwent one-stage combined expansive open-door laminoplasty and selective anterior decompression and fusion for severe CSM; the average patient age was 51.3 years (range, 32–63 years). Clinical results were assessed by Japanese Orthopaedic Association (JOA) scores, number of finger grip and releases (G and R) in ten seconds, hand-grip strength, visual analog scale (VAS) of axial pain, and C2-C7 angle. Results: There was no worsening of neurological symptoms due to cord injury, cerebrospinal fluid leakage, or wound infection. All cases completed one-year follow-up. The JOA scores, number of G and R in ten seconds, and hand-grip strength were all significantly improved (P < 0.05). Satisfactory decompression was shown by MRI or CT to have been achieved in all cases. The C2-C7 angle did not differ significantly from that found pre-operatively. The axial neck pain score was 2.0 ± 0.1 on VAS. Conclusion: Combined expansive open-door laminoplasty by splitting of spinous processes and selective anterior decompression and fusion achieves complete spinal canal decompression with minimal morbidity; this strategy is effective in improving the surgical outcomes of CSM in one-year follow-up.