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OBJECTIVE Achieving solid fusion of the lumbosacral junction continues to be a challenge in long-segment instrumentation to the sacrum. The purpose of this study was to test the condition of adding sacral anchors through an S1 alar screw (S1AS) and multirod construct relative to using S1 pedicle screws (S1PSs) alone with sacroiliac fixation in lumbosacral junction augmentation. METHODS Seven fresh-frozen human lumbar-pelvic spine cadaveric specimens were tested under nondestructive moments (7.5 Nm). The ranges of motion (ROMs) in extension, flexion, left and right lateral bending (LB), and axial rotation (AR) of instrumented segments (L3–S1); the lumbosacral region (L5–S1); and the adjacent segment (L2–3) were measured, and the axial construct stiffness (ACS) was recorded. The testing conditions were 1) intact; 2) bilateral pedicle screw (BPS) fixation at L3–S1 (S1PS alone); 3) BPS and unilateral S2 alar iliac screw (U-S2AIS) fixation; 4) BPS and unilateral S1AS (U-S1AS) fixation; 5) BPS and bilateral S2AIS (B-S2AIS) fixation; and 6) BPS and bilateral S1AS (B-S1AS) fixation. Accessory rods were used in testing conditions 3–6. RESULTS In all directions, the ROMs of L5–S1 and L3–S1 were significantly reduced in B-S1AS and B-S2AIS conditions, compared with intact and S1PS alone. There was no significant difference in reduction of the ROMs of L5–S1 between B-S1ASs and B-S2AISs. Greater decreased ROMs of L3–S1 in extension and AR were detected with B-S2AISs than with B-S1ASs. Both B-S1ASs and B-S2AISs significantly increased the ACS compared with S1PSs alone. The ACS of B-S2AISs was significantly greater than that of B-S1ASs, but with greater increased ROMs of L2–3 in extension. CONCLUSIONS Adding sacral anchors through S1ASs and a multirod construct was as effective as sacropelvic fixation in lumbosacral junction augmentation. The ACS was less than the sacropelvic fixation but with lower ROMs of the adjacent segment. The biomechanical effects of using S1ASs in the control of long-instrumented segments were moderate (better than S1PSs alone but worse than sacropelvic fixation). This strategy is appropriate for patients requiring advanced lumbosacral fixation, and the risk of sacroiliac joint violation can be avoided.

Background: We aimed to propose the apical vertebras distribution modifier to supplement the coronal balance (CB) classification for adult idiopathic scoliosis (AdIS). An algorithm to predict postoperative coronal compensation and avoid postoperative coronal imbalance (CIB) was proposed. Methods: Patients were categorized into CB and CIB groups according to the preoperative coronal balance distance (CBD). The apical vertebras distribution modifier was defined as negative (−) if the centers of the apical vertebras (CoAVs) were on either side of the central sacral vertical line (CSVL) and positive (+) if the CoAVs were on the same side of the CSVL. Results: A total of 80 AdIS patients, with an average age of 25.97 ± 9.20 years, who underwent posterior spinal fusion (PSF) were prospectively recruited. The mean Cobb angle of the main curve was 107.25 ± 21.11 degrees at preoperation. The mean follow-up time was 3.76 ± 1.38 (2–8) years. At postoperation and follow-up, CIB occurred in 7 (70%) and 4 (40%) CB− patients, 23 (50%) and 13 (28.26%) CB+ patients, 6 (60%) and 6 (60%) CIB− patients, and 9 (64.29%) and 10 (71.43%) CIB+ patients. Health-related quality of life (HRQoL) was significantly better in the CIB− group compared with that of the CIB+ group in the dimension of back pain. To avoid postoperative CIB, the correction rate of the main curve (CRMC) should match the compensatory curve for CB−/+ patients; the CRMC should be greater than the compensatory curve for CIB− patients; and the CRMC should be less than the compensatory curve for CIB+ patients, and the inclination of the LIV needs to be reduced. Conclusions: CB+ patients have the least postoperative CIB rate and the best coronal compensatory ability. CIB+ patients are at a high risk of postoperative CIB and have the poorest coronal compensatory capacity in the event of postoperative CIB. The proposed surgical algorithm facilitates the handling of each type of coronal alignment.

Hongtao Ding, Yong Hai, Yuzeng Liu, Li Guan, Aixing Pan, Xinuo Zhang, Bo Han, Yue Li, Peng Yin Department of Spine Surgery, Beijing Chao-Yang Hospital, Capital Medical University of China, Beijing, People’s Republic of ChinaCorrespondence: Yong Hai; Yuzeng Liu, Department of Spine Surgery, Beijing Chao-Yang Hospital, Capital Medical University of China, Beijing, People’s Republic of China, Tel +86 10-85231229 ; +86 13801221889 ; +86 13811552832, Email prof.haiyong@yahoo.com; yong.hai@ccmu.edu.cn; beijingspine2010@163.comStudy Design: This was a prospective randomized controlled trial study.Objective: To elucidate clinical and radiographic outcomes and complications of cortical bone trajectory (CBT)-screw fixation in patients with osteoporosis at 24-month follow-up and to compare the results with those after transforaminal lumbar interbody fusion (TLIF) using traditional pedicle screw (PS) fixation.Methods: We enrolled 124 patients and randomly assigned them to two groups (each group had 62 participants). The primary outcome was fusion rate. Secondary outcomes were VAS, Oswestry Disability Index (ODI), and Japanese Orthopaedic Association (JOA) scores, operation duration, incision length, estimated blood loss, drainage volume, radiological outcomes, and complications.Results: At the 6- and 12-month follow-up points, similar fusion rates were observed based on CT scans in both groups (P=0.583 and 0.583). CBT provided significantly better short-term functional status at 3 months postoperation on ODI and JOA scores (P=0.012 and 0) and similar improvements in pain intensity and functional status at other follow-up points. In addition, CBT resulted in significantly better surgical characteristics. Notably, CBT fixation led to lower incidence of screw loosening (P=0.006).Conclusion: CBT-screw fixation for single-level lumbar fusion in patients with osteoporosis provided improvement in clinical symptoms comparable to that of TLIF using PS fixation. Significantly better lumbar stability was found in the CBT group. We suggest that CBT-screw fixation is a reasonable and superior alternative to PS in TLIF in osteoporosis.Trial Registration Number: ChiCTR1900022658.Date of Registration: April 20, 2019.Keywords: cortical bone-trajectory screw, pedicle screw, lumbar fusion, osteoporosis, randomized controlled trial

Study Design Systematic review and meta-analysis. Objective Compilation of complication outcomes data from the surgical management of severe rigid kyphoscoliosis patients using VCR-based vs non-VCR-based corrective maneuvers is lacking. This meta-analysis aimed to compare complication outcomes between those classified osteotomy approaches. Methods Thorough literature review and meta-analysis were conducted between January 2000 and September 2021. The selection criteria were studies: i) reporting major curve Cobb angle of ≥80° and flexibility of Results Of the 174 patients included, 52.30% (n = 91) and 47.70% (n = 83) were VCR-based and non-VCR-based, respectively. The incidence of dural tears/nerve injuries/significant intraoperative-neuromonitoring changes was significantly higher; [OR = 6.78, CI= (1.75 to 26.17), I2 = 0%, ( P = .006)] in the VCR-based group than the non-VCR-based group. The ‘overall surgical and medical’ complication rate was significantly higher in the VCR-based group, [OR = 1.94, CI= (1.02 to 3.67), I2 = 31%, ( P = .04)]. Conclusion Both VCR-based and non-VCR-based surgical techniques for management of severe rigid scoliosis and kyphoscoliosis patients pose comparable overall surgical complication rates, while a significantly higher perioperative neurological complication incidence was associated with VCR-based technique compared to the non-VCR-based techniques. The VCR-based technique was associated with 6.78 times higher incidence of neurological complications compared to non-VCR-based techniques.

Study design: A retrospective single center study.Objective：To identify risk factors for multiple implant-related complications with growing-rod for early-onset scoliosis.Background: High incidence of implant-related complications in the treatment of early-onset scoliosis with traditional growing rod. The risk factors for multiple implant-related complications (MIRC) have not been adequately studied.Methods: Data of 59 early-onset scoliosis patients who had been underwent growing rod surgery at Beijing Chao-yang Hospital from September 2007 to December 2017 were reviewed. All patients had complete clinical and radiographic data. Patients were divided into groups with or without MIRC. The univariate and multivariate logistic regression analysis were performed to identify the risk factors associated MIRC.Results: The average age of insertion was 8.9 years and mean follow-up was 51.91 months. 234 implantation or expansion surgeries were performed and the average operation interval was 11.4 months. A total of 60 implant-related complications occurred. Ultimately, MIRC developed in 20 (33.9%) of 59 patients. Number of surgery procedure > 3 times , follow-up time ³50 months , preoperative thoracic kyphosis > 50°, postoperative thoracic kyphosis >50°, postoperative lumbar lordosis >50°, postoperative sagittal vertical axial >40mm are potential risk factors for MIRC (P 3 times, postoperative thoracic kyphosis >50°, postoperative lumbar lordosis >50°are independent risk factors for MIFRC (P50°had an 18.647 times higher risk of MIFRC than postoperative thoracic kyphosis angle Conclusions: Traditional growing rod in the setting of EOS has excellent clinical and radiographic outcomes but a high multiple implant-related complications. Number of surgery procedure > 3 times, postoperative thoracic kyphosis >50°, postoperative lumbar lordosis >50° are independent risk factors for MIRC.

We have analyzed the arch root morphology, nail placement accuracy, degree of arch deformity, and three-dimensional Cobb angle in patients with NF scoliosis by CT 3D reconstruction. Likewise, we have thoroughly examined arch root morphology, nail placement accuracy, degree of arch deformity, and three-dimensional Cobb angle in patients with idiopathic scoliosis by CT 3D reconstruction. The results of the two groups were statistically analyzed and compared to assess the efficacy and other morphological differences between these groups. For this purpose, 276 patients with scoliosis, including 221 with idiopathic scoliosis and 16 with neurofibromatosis scoliosis, were treated in the hospital, which is from May 2008 to December 2016. The 16 patients with idiopathic scoliosis were matched with patients with neurofibromatosis, and the postoperative CT data were reconstructed in three dimensions, and the measurements included arch morphology, arch transverse diameter, arch-rib joint transverse diameter, three-dimensional coronal Cobb angle, and correction rate. The data of the two groups were statistically analyzed to compare the arch morphology, nail placement accuracy, and treatment effect between patients with NF and patients with AIS. Statistical analysis was performed to compare the differences between NF and AIS patients in terms of morphology, nail placement accuracy, and treatment outcome. The results showed that there were more severely deformed pedicles in NF patients than in idiopathic scoliosis, and the difference between them was statistically significant. Of the 142 screws placed in the NF group, 88 screws were in a good position, and the remaining 54 screws were misplaced.

Objective To compare the safety and accuracy of cortical bone trajectory screw placement between the robot-assisted and fluoroscopy-assisted approaches. Methods This retrospective study was conducted between November 2018 and June 2020, including 81 patients who underwent cortical bone trajectory (CBT) surgery for degenerative lumbar spine disease. CBT was performed by the same team of experienced surgeons. The patients were randomly divided into two groups—the fluoroscopy-assisted group (FA, 44 patients) and the robot-assisted group (RA, 37 patients). Robots for orthopedic surgery were used in the robot-assisted group, whereas conventional fluoroscopy-guided screw placement was used in the fluoroscopy-assisted group. The accuracy of screw placement and rate of superior facet joint violation were assessed using postoperative computed tomography (CT). The time of single screw placement, intraoperative blood loss, and radiation exposure to the surgical team were also recorded. The χ2 test and Student’s t-test were used to analyze the significance of the variables (P Results A total of 376 screws were inserted in 81 patients, including 172 screws in the robot-assisted group and 204 pedicle screws in the fluoroscopy-assisted group. Screw placement accuracy was higher in the RA group (160, 93%) than in the FA group (169, 83%) (P = 0.003). The RA group had a lower violation of the superior facet joint than the FA group. The number of screws reaching grade 0 in the RA group (58, 78%) was more than that in the FA group (56, 64%) (P = 0.041). Screw placement time was longer in the FA group (7.25 ± 0.84 min) than in the RA group (5.58 ± 1.22 min, P P = 0.313). The radiation time of the FA group (0.43 ± 0.07 min) was longer than the RA group (0.37 ± 0.10 min, P = 0.001). Furthermore, the overall learning curve tended to decrease. Conclusions Robot-assisted screw placement improves screw placement accuracy, shortens screw placement time, effectively improves surgical safety and efficiency, and reduces radiation exposure to the surgical team. In addition, the learning curve of robot-assisted screw placement is smooth and easy to operate.

Background context Macrophages play important roles in the progression of intervertebral disc herniation and radiculopathy. Purpose To better understand the roles of macrophages in this process, we developed a new mouse model that mimics human radiculopathy. Study Design/Setting A preclinical randomized animal study. Methods Three types of surgeries were performed in randomly assigned Balb/c mice. These were spinal nerve exposure, traditional anterior disc puncture, and lateral disc puncture with nerve exposure (n=16/group). For the nerve exposure group, the left L5 spinal nerve was exposed without disc injury. For the traditional anterior puncture, L5/6 disc was punctured by an anterior approach as previously established. For lateral puncture with nerve exposure, the left L5 spinal nerve was exposed by removing the psoas major muscle fibers, and the L5/6 disc was punctured laterally on the left side with a 30G needle, allowing the nucleus to protrude toward the L5 spinal nerve. Mechanical hyperalgesia (pain sensitivity) of hind paws was assessed with electronic von Frey assay on alternative day for up to 2 weeks. MRI, histology, and immunostaining were performed to confirm disc herniation and inflammation. Results Ipsilateral pain in the lateral puncture with nerve exposure group was significantly greater than the other groups. Pro-inflammatory cytokines IL-1β and IL-6 were markedly elevated at the hernia sites of both puncture groups and the spinal nerve of lateral puncture with never exposure group on postoperative day 7. Heterogeneous populations of macrophages were detected in the infiltration tissue of this mouse model and in tissue from patients undergone discectomy. Conclusions We have established a new mouse model that mimics human radiculopathy and demonstrates that a mixed phenotype of macrophages contribute to the pathogenesis of acute discogenic radiculopathy. Clinical significance This study provides a clinically relevant in vivo animal model to elucidate complex interactions of disc herniation and radicular pain, which may present opportunities for the development of macrophage-anchored therapeutics to manage radiculopathy.

We sought to assess the elasticity change of the paravertebral fascia and muscle in adolescent idiopathic scoliosis patients with Lenke Type 1, 2, or 3 curves after posterior selective fusion surgery.The shear wave elasticity imaging system was used to assess the elasticity of the thoracic paravertebral muscles and fascia both on the concave and convex sides. Three regions of interest, including the apex, upper end, and lower end of the main curve, were tested.Ten female patients, with an average age of 16.6 ± 2.7 years old, were included. The average post-operation follow-up period was 9.0 ± 2.4 months. The Cobb angle was significantly corrected from 63.6 ± 12.0° to 10.7 ± 5.4° (p 0.05). The length of the trunk increased from 40.4 ± 2.5 cm to 46.0 ± 2.8 cm (p 0.05). The elasticity of deep fascia didn't show a significant change post-operation (p 0.05). The elasticity of the paravertebral muscle on the concave side had a significant increase at the final follow-up (p 0.05). The elasticity of the paravertebral muscle on the convex side also increased at the upper end (p 0.05). The elasticity asymmetry of the deep fascia decreased, but the elasticity asymmetry of the paravertebral muscle increased at the upper end of the curve (p 0.05).The paravertebral muscle on the concave side is stiffer after surgery. Elastic asymmetry of paravertebral muscle increased and elastic asymmetry of the deep fascia decreased at the upper end of the curvature. Further study is needed to elucidate the mechanism by which the paravertebral soft tissue responds after surgery.

Background Whether to preserve L5-S1 with no pre-existing pathology in the fusion for patients with adult degenerative scoliosis (ADS) remains controversial. This study is to determine the predictors of L5-S1 diseases for the distal fusion to L5 in the long instrumented fusion for ADS. Methods A total of 159 patients with ADS who had undergone long floating fusion were evaluated with a minimum 2 year follow-up between 2014 to 2018. The patient- and surgical-related risk factors for each individual were identified by using univariate testing. All patients were divided into groups with and without L5-S1 diseases. Univariate testing was used to identify the potential risk factors. Independent risk factors of L5-S1 diseases were identified using multivariate logistic regression. Results BMD of the patients with L5-S1 diseases were much higher than that without L5-S1 diseases (P = 0.003). Postoperative sacral slope in L5-S1 diseases group was much higher than that without L5-S1 diseases group (P = 0.000). Patient-related independent risk factors for the development of L5-S1 diseases included gender (OR = 0.41, P = 0.016) and BMD (OR = 0.42, P = 0.000). Surgical-related independent risk factors for the development of L5-S1 diseases included fusion level (OR = 2.64, P = 0.033) and postoperative sacral slope (OR = 1.43, P = 0.000).ConclusionsGender and BMD were the most common patient-related independent risk factors, Fusion levels and postoperative sacral slope were the most common surgical-related independent risk factors. Prevention of these risk factors can reduce the incidence of L5-S1 diseases in patients with long floating fusion.

Study Design: Retrospective case-control study. Objective: We aimed to evaluate the value of 3-dimensional printing (3DP) spine model in the surgical treatment of severe spinal deformity since the prosperous development of 3DP technology. Methods: Severe scoliosis or hyper-kyphosis patients underwent posterior fixation and fusion surgery using the 3DP spine models were reviewed (3DP group). Spinal deformity surgeries operated by free-hand screw implantation during the same period were selected as the control group after propensity score matching (PSM). The correction rate, pedicle screw accuracy, and complications were analyzed. Class A and B screws were defined as accurate according to Gertzbein and Robbins criteria. Results: 35 patients were enrolled in the 3DP group and 35 matched cases were included in the control group. The perioperative baseline data and deformity correction rate were similar between both groups ( P > .05). However, the operation time and blood loss were significantly less in the 3DP group (296.14 ± 66.18 min vs. 329.43 ± 67.16 min, 711.43 ± 552.28 mL vs. 1322.29 ± 828.23 mL, P < .05). More three-column osteotomies (Grade 3-6) were performed in the 3DP group (30/35, 85.7% vs. 21/35, 60.0%. P = .016). The screw placement accuracy was significantly higher in the 3DP group (422/582, 72.51% vs. 397/575, 69.04%. P = .024). The screw misplacement related complication rate was significantly higher in the free-hand group (6/35 vs. 1/35, P = .046). Conclusions: The study provided solid evidence that 3DP spine models can enhance surgeons’ confidence in performing higher grade osteotomies and improve the safety and efficiency in severe spine deformity correction surgery. 3D printing technology has a good prospect in spinal deformity surgery.

Objective. We aimed to evaluate the value of 3-dimensional printing (3DP) spine model in the surgical treatment of severe spinal deformity since the prosperous development of 3DP technology.Materials and Methods. Severe scoliosis or hyper-kyphosis patients underwent posterior fixation and fusion surgery using the 3DP spine models were reviewed (3DP group). Spinal deformity surgeries operated by free-hand screw implantation during the same period were selected as the control group after propensity score matching (PSM). The correction rate, pedicle screw accuracy, and complications were analyzed. Class A and B screws were defined as accurate according to Gertzbein and Robbins criteria.Results. 35 patients were enrolled in the 3DP group and 35 matched cases were included in the control group. The perioperative baseline data and deformity correction rate were similar between both groups (P>0.05). However, the operation time and blood loss were significantly less in the 3DP group (296.14±66.18 min vs. 329.43±67.16 min, 711.43±552.28 mL vs. 1322.29±828.23 mL, PConclusion. The study provided solid evidence that 3DP spine models can enhance surgeons' confidence in performing higher grade osteotomies and improve the safety and efficiency in severe spine deformity correction surgery. 3D printing technology has a good prospect in spinal deformity surgery.

Background The objective of the study was to evaluate our innovative percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF) for the treatment of lumbar degenerative diseases. Methods Two fresh-frozen human cadavers with soft tissues were donated for the experiment. Both cadavers had no history of previous spine surgery. The PE-TLIF surgery was performed on 3 levels (L4-5 of the first one, and L3-4, L4-5 of the second one) in October 2015. The PE-TLIF technique mainly included the following aspects: primary guide pins and a specially designed superior articular process (SAP) guide insertion, working channel setup, endoscopic decompression and fusion, and pedicle screw implantation and fixation. Under the surveillance of C-arm fluoroscope, four primary guide pins were inserted. The inferior primary guide in the hypothetically symptomatic side was confirmed as the first guide pin. At the end of the first guide pin, the specially designed SAP guide was installed. The secondary guide pin was inserted in the SAP via self-designed SAP guide. Under the protection cannula, part of the superior articular process was removed by oriented SAP resection device, so the working channel was smoothly put through the Kambin’s triangle. The endoscope was inserted close to the exiting nerve root. Rotation of the working channel kept the nerve root out of it. Results Three levels of PE-TLIF were successfully performed in two cadavers. Self-designed SAP guide made the secondary guide pin inserting the SAP accurately. Decompression was adequate and the traversing nerve root was relieved. Three aimed intervertebral levels are implanted with two 7-mm-high PEEK cages and one expandable cage. The expandable cage could be adjusted from 8 mm to 13 mm. Surgical incisions included four 15 mm incisions for percutaneous screw fixation and one 12 mm incision for working channel. There was no nerve injury during the operations. Conclusions Our present results showed that the novel minimally invasive surgery PE-TLIF was feasible for the treatment of lumbar degenerative diseases.

STUDY DESIGN This was a retrospective observational study. OBJECTIVE We aimed to characterize the feasibility of assessing the accuracy of cortical bone trajectory (CBT) screw placement in midline lumbar interbody fusion using a traditional pedicle screw insertion accuracy evaluation system based on computed tomography (CT). SUMMARY OF BACKGROUND DATA Since Santoni and colleagues proposed CBT as an alternative approach for the treatment of lumbar degenerative disease, CBT has been biomechanically and clinically investigated in detail. The reported misplacement rate was 0%-12.5%. Therefore, these cortical screws may result in severe complications, such as nerve root, vascular, and spinal cord injuries. However, to the best of our knowledge, the accuracy of the current assessment system of cortical bone screw placement has not been described clearly. MATERIALS AND METHODS Overall, 342 cortical screws of 69 consecutive patients with lumbar degenerative disease who underwent midline lumbar interbody fusion surgery in one surgeon's initial phase were examined retrospectively. A comprehensive and detailed pedicle screw accuracy classification and grading system was introduced in our study, including 5 types of misplacement: (1) medial and (2) lateral cortical bone perforation (MCP and LCP) of the corresponding pedicle, (3) anterior cortical bone perforation of the vertebral body, (4) endplate perforation, and (5) foraminal perforation (FP). The degree of interobserver and intraobserver agreement with regard to the screw positions based on CT were used as indicators of the reliability of the modified classification system. All patients were retrospectively assessed for screw placement-related complications throughout the entire treatment course to evaluate the relationship between the procedure adequacy and neurological symptoms. RESULTS The interobserver and intraobserver agreements were substantial-to-almost perfect (κ=0.78 and 0.88, respectively) in distinguishing the acceptable-placed pedicle screws from those with partial or complete cortical perforation. In the MCP and LCP-the most common types of misplacement-the interobserver agreement was substantial (κ=0.70 and 0.76, respectively), and the intraobserver agreement was almost perfect (κ=0.85 and 0.89, respectively). In total, there are 7 (2.05%) MCP and 65 (19.01%) LCP screws. The screw placement-related complication rate is significantly higher in the MCP and FP groups than that in the LCP group. CONCLUSIONS Our study demonstrated that using a pedicle screw classification and grading system based on CT to assess the accuracy of CBT screw placement is feasible and practical. MCP and FP screws are more likely to cause neurological deficits with statistical significance, especially grade 2 MCP. We recommend inexperienced surgeons choose a lateral trajectory rather than a medial one if they cannot ensure accurate screw insertion. LEVEL OF EVIDENCE Level III.

Study design Retrospective comparative study. Objective To compare the efficacy and safety of one-stage posterior multiple-level asymmetrical Ponte osteotomies (MAPOs) and single-level posterior vertebral column resection (VCR) for severe and rigid adult idiopathic scoliosis (ADIS). Summary of background data The surgical treatment of severe and rigid ADIS is a demanding and difficult challenge due to its complicated characteristics. Spine surgeons have often pursued advanced correction techniques such as VCR for such patients, which reported to present excellent correction outcomes. But this attractive procedure brought the greatest risk to both surgeons and patients. Methods A total of 48 patients who underwent MAPO or VCR and fusion surgery with minimum 2-year follow-up between February 2009 and November 2015 were enrolled. Twenty-six patients were included in MAPO group and 12 patients in VCR group with an average age of 26.65 ± 8.40 and 27.92 ± 7.50 years, respectively. The average follow-up was 30.24 ± 10.55 months. The surgical details and complications were recorded. The radiological parameters and clinical outcome including Oswestry Disability Index and Scoliosis Research Society-22 questionnaire scores were collected and analyzed. Results The main curve in MAPO and VCR group were corrected from an average of 98.52° ± 16.50° to 44.11° ± 17.72° and 108.91° ± 16.56° to 56.49° ± 18.82° with no significant difference. The postoperative coronal and sagittal parameters of the two groups were all improved and it showed no significant differences between the two groups. The mean operative time and blood loss of VCR group were significantly greater than those of MAPO group. All the clinical scores were significantly improved at final follow-up, with no significant difference. The incidence of complications in MAPO group was 3.85%, which was significantly lower than that of VCR group. Conclusion The surgical procedure of multiple asymmetrical Ponte osteotomy is a safe, easy-to-operate, and effective technique that can correct scoliosis and restore the sagittal alignment. It can gain similar correction outcome to VCR, offering the advantages of reduced operation time, blood loss, and greatly reduced the complication. Level of evidence 3.

To evaluate the efficacy and safety of posterior multiple-level asymmetrical Ponte osteotomies for rigid adult idiopathic scoliosis.A retrospective study was conducted for adult patients with rigid idiopathic scoliosis (flexibility of main curve25%) who underwent one-stage multiple-level asymmetrical Ponte osteotomies with a minimum of 2-year follow-up between February 2009 and November 2015. The demographic data and surgical issues were collected, and the improvement of clinical function scores and radiologic parameters were obtained after surgery and during the follow-up to assess deformity correction, spinal balance, and clinical outcome.A total of 49 patients were included (10 male and 39 female) in this study, with an average age of 26.53 years old. The average follow-up was 28.37 ± 6.98 months. All the cases presented a significant improvement of the main curve and focal kyphosis from 85.62 ± 19.80° to 36.19 ± 16.74° and 53.98 ± 26.80° to 30.88 ± 18.69°, with a mean correction rate of 57.73% and 41.23%. The postoperative coronal and sagittal parameters were all significantly improved, except coronal balance. The mean operative time and blood loss were 267.86 ± 54.49 minutes and 838.78 ± 538.93 mL. All the clinical function scores of patients were significantly improved at the final follow-up. Only one patient had a complication related to surgical incision, with no neurologic complications occurring.The surgical procedure of multiple-level asymmetrical Ponte osteotomy is a safe and effective technique, with reduced operation time, blood loss, and complications, and may offer an appropriate option to address the problems of rigid adult idiopathic scoliosis.

Aims: To measure the anatomical structure of lumbar spine by computed tomography (CT) scan, and explore the posterior edge of abdominal organs on the lateral lumbar X-ray in lateral puncture, in order to provide an anatomical basis for spinal microendoscopy to avoid abdominal organ injury. Methods: A total of 50 patients with abdominal enhanced CT scan in our hospital were included. The spine from L1 to S1 were divided into 16 axial levels (containing the superior level of vertebral body, middle part of vertebral body, and inferior level of vertebral body) to make out safety zone, critical puncture point and critical angle in accordance with the anatomical position of posterior renal fascia and parietal peritoneum on the lateral lumbar X-ray. Results: From L1 to S1, the projection of the lowest point of the posterior renal fascia and parietal peritoneum and the projection of the critical puncture point turns from the dorsal side of the posterior vertebral body to the ventral side. And the two projection points are in the same position on the middle level of L4 vertebral body, which is on the posterior margin of L4 vertebral body. The critical puncture angle is also gradually reduced, and is approximate 0° at the middle level of L4. There is no statistically significant difference between left and right side of the body. Conclusion: The safety zone, critical puncture point and critical angle of L1-S1 were determined in accordance with the projection of the lowest point of the posterior renal fascia and parietal peritoneum, which provided an anatomical guidance for avoiding the injury of posterior renal fascia or abdominal organs during operation.

We sought to assess the biomechanical properties of the paravertebral muscles in adolescent idiopathic scoliosis patients with Lenke Type 1, 2, or 3 (Lenke 1-3) curves.The MyotonPro® and shear wave elasticity imaging system were used to assess the biomechanical features of the thoracic paravertebral muscles on concave and convex side in adolescent idiopathic scoliosis patients with Lenke 1-3 curves. The Cobb angle of the main curve was measured using the anteroposterior whole spine radiograph in the standing position.A total of 40 adolescent idiopathic scoliosis patients with a mean Cobb angle of 66.49° (SD 32.8°) were included in this study. Muscle tone, stiffness and Deborah number on the concave side was significantly greater than that on the convex side. Relaxation time was significantly longer on the convex side than on the concave side. No statistically significant difference in muscle elasticity was observed between the concave side and the convex side (P 0.05). Pearson correlation analysis demonstrated that stiffness on the concave side was moderately positively correlated with the Cobb angle (P 0.05, r = 0.582); the Deborah number on both sides and the relaxation time on the concave side showed a moderate negative correlation with the Cobb angle (P 0.05, r = -0.632; r = -0.432; r = -0.611).Concave paravertebral muscle tone and stiffness were greater than those on convex side in adolescent idiopathic scoliosis patients. The asymmetric biomechanical characteristics of paravertebral muscles are closely related to the severity of scoliosis.

Study design A retrospective case series. Objective We sought to evaluate the prevalence and risk factors of proximal junctional kyphosis (PJK) after growing-rod surgery in patients with early onset scoliosis (EOS). Summary of background data Growing-rod surgery is the primary treatment in patients with progressive EOS when conservative treatment fails. PJK is one of the most commonly reported postoperative complications. Materials and methods We retrospectively evaluated 50 patients (24 boys and 26 girls) diagnosed with EOS who underwent growing-rod surgery. Preoperative and follow-up demographic data, surgical strategies, and radiographic parameters were recorded and analyzed to identify PJK risk factors. Results The mean age of patients at the time of the initial surgery was 8.6±2.5 years. Mean follow-up was 33.5±10.8 months, and mean number of lengthening surgeries were 2.14±1.52. Twenty-eight of the surgical procedures were single growing-rod surgeries, of which 22 were dual growing-rod surgeries. The upper instrumented vertebrae (UIV) ranged from C6-T6, and the lower instrumented vertebrae ranged from L1-S1. Ultimately, PJK developed in 14 (28%) of 50 patients. Taller patients, UIV distal to T2, and greater postoperative upper thoracic scoliosis (UTS) were suspected potential risk factors of PJK during the univariate analysis (P 50 degrees (hazard ratio=1.049; P=0.046) were the independent risk factors of PJK during growing-rod treatment in patients with EOS. Conclusions The prevalence of PJK was 28% during growing-rod treatment in EOS. The independent risk factors for PJK were UIV distal to T2 and postoperative UTS >50 degrees. It is important for spine surgeons to recognize these risk factors when planning surgeries, and counseling patients and families about this possible complication. Level of evidence Level III.

Objective To explore the clinical and spinopelvic features in patients with lumbar spondylolisthesis and degenerative lumbar scoliosis (LSDLS) and those with standalone lumbar spondylolisthesis (SALS). Patients and Methods We retrospectively analyzed 130 patients with lumbar spondylolisthesis seen between 05/2013 and 12/2016 in our hospital. Propensity score matching was used to reduce an age distribution imbalance between the two groups. Clinical and spinopelvic parameters were compared by independent samples t test and chi-square test. Nonlinear binary logistic regression analysis was used to analyze the independent factors. Results There was no significant difference between groups for body mass index, level of intercrest line, level of spondylolisthesis, grade of spondylolisthesis, sagittal translation, segmental angulation, thoracic kyphosis, or sagittal vertical axis. The LSDLS group had significantly lower lumbar lordosis (LL) than the SALS group. The LSDLS group showed significantly greater pelvic tilt (PT) and ratio of PT to SS (sacral slope) (PT/SS), and lower SS. The pelvic incidence (PI) was not significantly different. The LSDLS group showed stronger significant differences in PT/SS compared to the SALS group. With each 0.1 increase in PT/SS, the risk of LSDLS increased 1.465 times. Conclusions Patients with spondylolysis are less prone to development of DLS. Lower LL and SS, and higher PT are associated with the occurrence of LSDLS. Increased PT/SS may play an important role in the pathogenesis of LSDLS.

To report the surgical experience of selective hemivertebrae resection for a case of congenital scoliosis with multiple hemivertebrae deformities. A 14-year-old male presented with progressive rib hump, tilted torso and spine deformity was admitted in our department. No abnormalities were detected in neurological examination and the comprehensive imaging study demonstrated congenital scoliosis of multiple hemivertebrae in T5, T10, L1 and L3. Treatment of the patient commenced with a 10-day skin traction therapy prior to the surgery. Selective resection of hemivertebrae in T5 and L1 was performed with segmental fusion from T3 to L2. After surgical procedure, the patient achieved a good coronal and sagittal balance along with a good correction of the curve. 18-month postoperative follow-up showed no evidence of significant loss of correction. No device-related complication such as implant loosening or failure or neurologic complication occurred during the follow-up. Besides, patient’s shoulder balance was further improved and coronal balance was maintained in a normal range. Many factors have to be considered in the clinical decision-making of congenital scoliosis with multiple hemivertebrae deformities patients. Much emphasis in this regard is laid on the type and location of the hemivertebrae as well as the patient’s age. Selective hemivertebrae resection may be more suitable for such patients.

IntroductionAdjacent segment degeneration (ASDeg) or adjacent segment disease (ASDis) is a matter of concern after lumbar fusion. Whether the motion-preservation procedures could reduce the prevale...