Peripheral nerves have complex and precise structures that differ from other types of tissues and intrinsic regeneration abilities after injury. Spontaneous recovery is possible for neuropraxia and axonotmesis, while surgical treatment is required for neurotmesis. It remains a challenge to repair nerve gaps, a series of severe neurotmesis. It seems that 3 cm is the upper limit distance for primate peripheral nerves to regenerate spontaneously. Nerve autografts are the gold standard treatment for bridging nerve gaps. In the present review, current biomaterials for repairing gaps after peripheral nerve injury are briefly summarized. Moreover, the microstructure of the peripheral nerve, classifications of peripheral nerve injury, and the Wallerian degeneration are reviewed in the biological view and clinical practice. The failure of nerve regeneration in nerve conduits bridging longer than 3 cm gaps may be contributing to the insufficient vascularization of nerve conduit materials. Future researchers could focus on advanced biomaterials that promoting the angiogenesis of nerve conduits.

BACKGROUND:Superior mesenteric artery (SMA) syndrome is a well-recognized, rare complication of undergoing surgical correction of a spinal deformity. The objective of this study was to summarize the best available evidence on SMA syndrome treatment after scoliosis surgery. To identify differences, special attention was paid to scoliosis pathology, intervention and SMA syndrome presentation. METHODS:A systematic review of the literature was performed on SMA syndrome following scoliosis surgery. The Web of Science, PubMed, Wanfang (Chinese) and EMBASE databases were systematically searched for articles from January 1971 to October 2020. The main subjects discussed are scoliosis pathology, intervention and SMA syndrome presentation. RESULTS:A total of 32 articles with 52 cases were included in our report. The mean age of patients with SMA syndrome following scoliosis surgery was 14.7 ± 2.9 years and the majority (n = 42, 80.8%) were girls. The most frequently reported scoliosis type was adolescent idiopathic scoliosis (n = 34, 65.4%). The mean postoperative days (POD) (interval between the surgical treatment and the onset of symptoms) was 9.6 ± 9.5 days. Different treatment methods were analyzed in 46 patients. We noted a trend toward a higher percentage of patients with POD < 48 hr in the group with surgical treatment than in the conservative treatment group (P = 0.002). CONCLUSION:In summary, in this systematic review, for the first time, we found that the time of onset of postoperative symptoms can be used as an important reference index for surgical intervention. We also believe that recommendations about the treatment of SMA syndrome following scoliosis surgery should include this finding. Given the lack of robust clinical evidence, these findings warrant verification in a prospective multicenter screening trial.

Abstract The aim of the study was to determine if multiple intraspinal anomalies increase the risk of scoliosis correction compared to the normal intraspinal condition or 1 or 2 intraspinal anomalies in congenital scoliosis (CS) and whether correction for multiple intraspinal anomalies need to be performed with preliminary neurosurgical intervention before scoliosis correction. A total of 318 consecutive CS patients who underwent corrective surgery without preliminary neurosurgical intervention at a single institution from 2008 to 2016 were retrospectively reviewed, with a minimum of 2 years of follow-up. The patients were divided into 3 groups according to different intraspinal conditions. In the normal group (N group; n = 196), patients did not have intraspinal anomalies. In the abnormal group (A group; n = 93), patients had 1 or 2 intraspinal anomalies. In the multiple anomaly group (M group; n = 29), patients had 3 or more intraspinal anomalies including syringomyelia, split cord malformation [SCM], tethered cord, low conus, intraspinal mass, Chiari malformation or/and arachnoid cyst. The occurrence of complications as well as perioperative and radiographic data were analyzed. The incidence rate of multiple intraspinal anomalies in CS patients was 9.1% (29/318). No significant difference was observed in the perioperative outcomes or radiographic parameters at the final follow-up. There were no significant differences among the 3 groups in the total, major or neurological complication rates (all P > .05). Two patients (1 in the N group and 1 in the A group) experienced transient neurological complications, whereas no patient experienced permanent neurological deficits during surgery or follow-up. To our knowledge, the current study reported the largest cohort of intraspinal anomalies in patients with CS that has been reported in the literature. The results of our study demonstrated that patients with congenital scoliosis associated with intraspinal anomalies, even multiple intraspinal anomalies that coexist with more complex intraspinal pathologies, may safely and effectively achieve scoliosis correction without preliminary neurological intervention. More complex intraspinal pathologies do not seem to increase the risk of neurosurgical complications during corrective surgery.

Acute spinal cord injury (ASCI) is a severe traumatic disease of the central nervous system, the underlying mechanism of which is unclear. This study was intended to study the role of EZH2 and miR-146a-5p/HIF-1α in inflammation and glycolysis after ASCI, providing reference and basis for the clinical treatment and prognosis of ASCI injury. We used lipopolysaccharide (LPS) to induce inflammation of microglia, and we constructed the ASCI animal model. qRT-PCR detected the relative expression levels of EZH2, HIF-1α, miR-146a-5p, IL-6, TNF-α, IL-17, PKM2, GLUT1, and HK2 in cells and tissues. Western blot was performed to detect the expression levels of EZH2, HIF-1α, H3K27me3, IL-6, TNF-α, IL-17, PKM2, GLUT1, and HK2. ChIP verified the enrichment of H3K27me3 in the miR-146a-5p promoter region. Bioinformatics predicted the binding sites of HIF-1α and miR-146a-5p, and dual-luciferase reporter assay verified the binding of HIF-1α and miR-146a-5p. ELISA detects the levels of inflammatory factors IL-6, TNF-α, and IL-17 in the cerebrospinal fluid of rats. The GC-TOFMS was used to detect the changes of glycolytic metabolites in the cerebrospinal fluid of rats. EZH2 could mediate inflammation and glycolysis of microglia. EZH2 regulates inflammation and glycolysis through HIF-1α. EZH2 indirectly regulated the HIF-1α expression by mediating miR-146a-5p. EZH2 mediates miR-146a-5p/HIF-1α to alleviate inflammation and glycolysis in ASCI rats. In the present study, our results demonstrated that EZH2 could mediate miR-146a-5p/HIF-1α to alleviate the inflammation and glycolysis after ASCI. Therefore, EZH2/miR-146a-5p/HIF-1α might be a novel potential target for treating ASCI.

BACKGROUND:Osteoarthritis (OA) is a disabling joint disease that causes articular cartilage degeneration. It has been implicated that altered expression of histone deacetylase 2 (HDAC2) is found in patients with OA. However, the specific role of HDAC2 in the development of OA still remains enigmatic. Hence, we sought to characterize the functional relevance of HDAC2 in the development of OA.METHODS:Anterior cruciate ligament surgery was performed to generate the rat model of OA. Luciferase assay was performed to evaluate the relationship between microRNA-503-5p (miR-503-5p) and serum- and glucocorticoid-inducible kinase-1 (SGK1). Functional experiments were conducted to examine the functional significance of miR-503-5p, histone deacetylase 2 (HDAC2), and SGK1 on the progression of OA by determining proliferation, apoptosis, and expression of apoptosis-associated proteins and inflammatory cytokines.RESULTS:HDAC2 could inhibit miR-503-5p expression. SGK1 was the target gene of miR-503-5p. Upregulation of miR-503-5p or silencing of HDAC2 contributed to enhanced proliferation, suppressed apoptosis (reduced expression of Caspase-3 and Bax but elevated expression of Bcl2), and promoted inflammation in chondrocytes of OA rats.CONCLUSION:In conclusion, our study demonstrated that HDAC2 could promote OA through miR-503-5p/SGK1 axis, which might function as a therapeutic target for OA treatment.

BACKGROUND:The aim of this study was to investigate whether C7 slope can be used as a substitute for T1 slope in idiopathic scoliosis.METHODS:From January 2014 to October 2019, 101 patients who received posterior spinal internal fixation and fusion in our hospital were retrospectively analyzed. After analyzing the visibility of vertebral endplates, 46 cases of C7/T1 vertebral endplates were visible, including 14 males and 32 females, aged 9 to 18 years (mean 14.6±2.0 y). The upper C7 slope, lower C7 slope, T1 slope, cervical lordosis and C2 to 7 sagittal vertebral axis were measured before and after operation and at the last follow-up. Pearson correlation coefficient was used to evaluate the correlation strength between upper C7 slope and T1 slope, and lower C7 slope and T1 slope. Through simple linear regression analysis, linear regression equations were generated from the upper and lower C7 slopes to predict T1 slope.RESULTS:According to the 2 researchers' judgment, the visibility rate of the upper C7 endplate was 93.1% before operation, 93.1% after operation, and 91.1% at the last follow-up. The lower C7 endplate's visible rate was 72.3% before operation, 70.3% after operation and 68.3% at the last follow-up. The visible rate of T1 upper endplate was 52.5% before operation, 48.5% after operation and 50.5% at last follow-up. Linear regression analysis showed that the upper C7 slope and T1 slope in idiopathic scoliosis patients, regardless of preoperative (r=0.908, P<0.01), postoperative (r=0.0.886, P<0.01), follow-up (r=0.899, P<0.01), or overall (r=0.895, P<0.01), both have a close correlation; the lower C7 slope and the T1 slope are the same before surgery (r=0.882, P<0.01), after surgery (r=0.940, P<0.01), follow-up (r=0.952, P<0.01), or overall (r=0.929, P<0.01) all have statistical significance.CONCLUSION:When the upper endplate of T1 is not visible on standard radiographs, the upper or lower C7 slope can be used as a reliable alternative measurement parameter for sagittal balance assessment.

OBJECTIVE:To compare the clinical and radiologic outcomes of patients with different 3-dimensional (3D) hemivertebra morphologies undergoing posterior-only hemivertebra resection and fusion. METHODS:The files of patients with congenital scoliosis (CS) due to single hemivertebra undergoing posterior-only hemivertebra resection and fusion from January 2010 to January 2018 were reviewed. After evaluating the 3D computed tomography images, CS patients were divided into a unison hemivertebra group and a discordant hemivertebra group. Clinical outcomes, radiologic outcomes, and incidence of complications were compared. RESULTS:A total of 42 consecutive patients with CS patients due to a single hemivertebra undergoing posterior-only hemivertebra resection and fusion were included in this study. The Cobb angle of the segmental curve was significantly improved postoperatively and at the last follow-up in both groups (all P < 0.05). At both postoperation and the last follow-up, no significant differences were found in the incidence of complications, Cobb angle of the segmental curve, correction rate of the segmental curve, or other radiologic outcomes between the unison hemivertebra group and discordant hemivertebra group (all P > 0.05). Compared with the unison hemivertebra group, increased operation time (P = 0.006) and intraoperative blood loss (P = 0.037) were found in the discordant hemivertebra group. CONCLUSIONS:For CS patients with unison hemivertebra or discordant hemivertebra, satisfactory radiologic results were obtained by posterior-only hemivertebra resection and fusion. In terms of surgery, the radiologic outcomes of discordant hemivertebra patients were similar to those of unison hemivertebra patients, but discordant hemivertebrae could easily result in longer operation time and more intraoperative blood loss.

Background Cases of obturator nerve impingement (ONI) caused by osteophytes resulting from bone hyperplasia on the sacroiliac articular surface have never been reported. This paper presents such a case in a patient in whom severe lower limb pain was caused by osteophyte compression of the sacroiliac joint on the obturator nerve. Case summary A 65-year-old Asian man presented with severe pain and numbness in his left lower limb, which became aggravated during walking and showed intermittent claudication. The physical examination revealed that the muscle strength of the left lower limb had decreased and that the passive knee flexion test result was positive. Computed tomography (CT) and 3D reconstruction showed a large osteophyte located in the anterior lower part of the left sacroiliac joint. The results of electrophysiological examination showed peripheral neuropathy. A CT-guided obturator nerve block significantly reduced the severity of pain in this patient. According to the above findings, ONI caused by the osteophyte in the sacroiliac joint was diagnosed. This patient underwent an operation to remove the bone spur and symptomatic treatment. After therapy, the patient's pain and numbness were significantly relieved. The last follow-up was performed 6 mo after the operation, and the patient recovered well without other complications, returned to work, and resumed his normal lifestyle. Conclusion Osteophytes of the sacroiliac joint can cause ONI, which leads to symptoms including severe radiative pain in the lower limb in patients. The diagnosis and differentiation of this disease should attract the attention of clinicians. Surgical excision of osteophytes should be considered when conservative treatment is not effective.

The aim of this study was to construct and validate nomograms for predicting lung metastasis and lung metastasis subgroup overall survival in malignant primary osseous neoplasms. Least absolute shrinkage and selection operator, logistic and Cox analyses were used to identify risk factors for lung metastasis in malignant primary osseous neoplasms and prognostic factors for overall survival in the lung metastasis subgroup. Further, nomograms were established and validated. A total of 3184 patients were collected. Variables including age, histology type, American Joint Committee on Cancer T and N stage, other site metastasis, tumor extension and surgery were extracted for the nomograms. The authors found that nomograms could provide an effective approach for clinicians to identify patients with a high risk of lung metastasis in malignant primary osseous neoplasms and perform a personalized overall survival evaluation for the lung metastasis subgroup.

Background. Up to now, an accurate nomogram to predict the lung metastasis probability in Ewing sarcoma (ES) at initial diagnosis is lacking. Our objective was to construct and validate a nomogram for the prediction of lung metastasis in ES patients. Methods. A total of 1157 patients with ES from the Surveillance, Epidemiology, and End Results (SEER) database were retrospectively collected. The predictors of lung metastasis were identified via the least absolute shrinkage and selection operator (LASSO) and multivariate logistic analysis. The discrimination and calibration of the nomogram were validated by receiver operating characteristic (ROC) curve and calibration curve. Decision curve analysis (DCA) was used to evaluate the clinical usefulness and net benefits of the prediction model. Results. Factors including age, tumor size, primary site, tumor extension, and other site metastasis were identified as the ultimate predictors for the nomogram. The calibration curves for the training and validation cohorts both revealed good agreement, and the Hosmer–Lemeshow test identified that the model was well fitted (p > 0.05). In addition, the area under the ROC curve (AUC) values in the training and validation cohorts were 0.732 (95% confidence interval, CI: 0.607–0.808) and 0.741 (95% CI: 0.602–0.856), respectively, indicating good predictive discrimination. The DCA showed that when the predictive metastasis probability was between 1% and 90%, the nomogram could provide clinical usefulness and net benefit. Conclusion. The nomogram constructed and validated by us could provide a convenient and effective tool for clinicians that can improve prediction of the probability of lung metastasis in patients with ES at initial diagnosis.

目的 探讨肋骨畸形(RD)对先天性脊柱侧凸(CS)矫形术后脊柱整体平衡的影响.方法 回顾性分析2009-01—2017-12郑州大学第一附属医院行CS矫形术治疗的86例患儿的临床资料.按是否存在肋骨畸形分为RD组(52例)和NRD组(34例).比较2组患儿的临床资料、术前和术后2周、术后2a时依据全脊椎正侧位X线检查结果,测量、记录、分析影像学参数资料.结果(1)除RD组的术中输血量大于NRD组,差异有统计学意义(P<0.05)外,2组患儿的基线资料和术前影像学参数差异均无统计学意义(P>0.05).(2)术后2周时RD组主弯(MC)的Cobb角大于NRD组,Cobb角减小率(CAD)低于NRD组,差异有统计学意义(P<0.05);2组患者的其他影像学参数差异均无统计学意义(P>0.05).(3)术后2 a时RD组患儿的脊柱矢状位轴(SVA)、CAD小于NRD组,近端交界角(PJA)的变化量(ΔPJA)大于NRD组,差异均有统计学意义(P<0.05);2组患儿的其他影像学参数差异均无统计学意义(P>0.05).(4)术后随访2 a期间,RD组患儿近端交界性后凸(PJK)的发生率高于NRD组,差异有统计学意义(P<0.05).结论 RD对CS术后脊柱整体平衡有负面影响,合并RD患儿的冠状面CAD明显降低,并且矢状面上存在更高的PJK发生率.

目的 分析经皮内镜腰椎间盘切除术(PELD)术后复发的危险因素,构建并验证预测复发概率的列线图(Nomo-gram)图.方法 纳入396例郑州大学第一附属医院2013年1月至2019年10月PELD术后患者.根据术后1 a内手术节段椎间盘是否再次突出将其分为复发组(46例)与未复发组(350例).采用χ2检验对比各变量在复发组与未复发组之间的差异.将差异有统计学意义的变量纳入多因素logistic回归分析,以筛选影响腰椎间盘突出患者PELD术后复发的独立危险因素.基于筛选的相关因素,构建并验证预测患者复发概率的Nomogram图.通过受试者工作特性曲线(ROC)和校准曲线验证Nomogram图的准确度.结果 多因素logistic回归分析显示pfirrmann等级≥Ⅲ级、体质量指数(BMI)≥25 kg·m-2、年龄≥60岁、术后椎间活动度≥10°为PELD术后复发的独立危险因素.ROC曲线下面积为0.898(95％CI:0.817～0.968).同时,校准曲线接近45°走行,表明模型拟合良好.结论 pfirrmann等级≥Ⅲ级、BMI≥25 kg·m-2、年龄≥60岁、术后椎间活动度≥10°是PELD术后复发的独立危险因素.基于这些因素构建的Nomogram图作为一个简单有效的预测工具,可为PELD术后复发概率的预测提供一定的参考作用.

Aim: Osteoarthritis (OA) is the most common joint disorder and a leading cause of disability. While early proactive management is crucial in alleviating symptoms in OA patients, currently available therapeutic approaches are yet to achieve an ideal level of efficacy. The path to the development of a potent treatment begins with the thorough understanding of the pathophysiology of OA. The present study aims to explore the mechanism by which SGK1 is involved in OA progression. Methods: Firstly, the potential target gene of SGK1 was screened and SGK1 expression was determined in OA through bioinformatics analysis. Mouse OA model was then established and chondrocytes were extracted, after which inflammation was induced with lipopolysaccharide (LPS). Following LPS treatment, the chondrocytes were transfected with synthesized plasmids to explore the impact of SGK1, CREB1, and ABCA1 on apoptosis, proliferation and inflammation in OA. ChIP-PCR and dual-luciferase reporter gene assay were conducted to determine the binding relation between SGK1 and CREB1 as well as between CREB1 and ABCA1. Results: OA mice presented with high expression of SGK1. Interestingly, we found that SGK1 inhibited CREB1 expression in chondrocytes, thereby inducing inflammation and suppressing chondrocyte proliferation. CREB1 was found to have a positive correlation with ABCA1 expression, while down-regulation of CREB1 resulted in the inhibition of cell proliferation and aggravated inflammation, which could be reversed by overexpressed ABCA1. Conclusion: Taken altogether, silencing of SGK1 alleviated OA through epigenetic regulation of CREB1 and ABCA1 expression. These findings may provide novel insight into SGK1-based strategy for OA treatment.

OBJECTIVE: To investigate the risk factors and to construct a nomogram for the prediction of postoperative neck tilt (PNT) in patients with Lenke I and II adolescent idiopathic scoliosis (AIS). METHODS: A total of 95 patients with Lenke I and II AIS who underwent posterior segmental spinal instrumentation and fusion between the years 2010 and 2018 (with an average 2-year follow-up) at a single institution were retrospectively investigated. The full spine X-rays of patients were measured preoperatively, postoperatively, and at the final follow-up. Variables were compared between the PNT group (n = 33) and the non-PNT group (n = 62), and univariate and multivariate logistic regressions were performed to identify the independent predictors for the occurrence of PNT. The discrimination and calibration of the nomogram were validated by the receiver operating characteristic curve and calibration curve. RESULTS: Variables including the preoperative neck tilt, postoperative upper instrumented vertebrae imbalance, postoperative T1 tilt, and decreasing values in the main thoracic curve (Delta MTC) minus decreasing values in the proximal thoracic curve (Delta PTC) (Delta MTC - Delta PTC) were identified as the predictors for the nomogram. The area under the receiver operating characteristic curve was 0.900 (95% confidence interval, 0.857-0.932). Meanwhile, the calibration curve revealed good agreement, and the Hosmer and Lemeshow test determined that the model was well fitted. CONCLUSIONS: Preoperative neck tilt, postoperative upper instrumented vertebrae imbalance, postoperative T1 tilt, and Delta MTC-Delta PTC are predictors for the nomogram. The nomogram can provide surgeons with a simple and effective tool to predict the occurrence and development of patients with PNT in Lenke I and II AIS.

STUDY DESIGN:Retrospective analysis.OBJECTIVE:The aim of this study was to develop and validate a nomogram for the prediction of lung metastasis in patients with malignant primary spinal tumors.SUMMARY OF BACKGROUND DATA:In patients with malignant primary spinal tumors, lung metastasis is usually found by computed tomography (CT) and is considered to be an essential factor affecting the prognosis and survival.METHODS:We retrospectively collected 580 malignant primary osseous spinal neoplasms patients from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2015. The least absolute shrinkage and selection operator (LASSO) and multivariate logistic analysis were used to identify independent factors. These prognostic factors were included in the nomograms. The nomograms were validated based on its calibration, discrimination, and clinical utility. The overall survival of the patients was analyzed using the Kaplan-Meier method and the survival differences were tested by the log-rank test.RESULTS:We randomly divided all these patients (n = 580) into a training cohort (n = 408) and a validation cohort (n = 172). The results showed that the risk of lung metastasis was independently influenced by histologic type, use of surgery, clinical T stage, clinical N stage, and tumor extension (all P < 0.05). The nomogram consisted of five clinical features and provided good calibration and discrimination in the training and validation cohort, with an area under the curve of 0.858 and 0.811, respectively. Decision curve analysis showed that the nomogram was clinically useful. The Kaplan-Meier curves showed a significant difference between the higher and lower risk of lung metastasis groups (P < 0.001).CONCLUSION:Nomograms were developed to predict the risk of lung metastasis in patients with malignant primary spinal tumors. The nomogram showed favorable discrimination and calibration values, which may help optimize treatment decision-making for patients.LEVEL OF EVIDENCE:4.

目的 分析后路全椎弓根螺钉系统治疗脊柱侧凸术后并发症的情况,旨在减少和预防术后并发症的发生.方法 分析106例行后路全椎弓根螺钉系统治疗的脊柱侧凸患者术后并发症情况,对先天性和特发性脊柱侧凸患者以及不同性别患者的并发症进行比较,并提出预防和补救措施.结果 患者均获得随访,时间2.5～6.5年.13例患者术后发生并发症,11例(15.9％)为先天性脊柱侧凸患者,2例(5.4％)为特发性脊柱侧凸患者,差异无统计意义(P>0.05).69例先天性脊柱侧凸患者术后并发症发生情况:切口渗液5例,切口感染2例,脑脊液漏1例,脊髓神经损伤2例,断棒1例;37例特发性脊柱侧凸患者术后发生切口渗液2例.不同性别脊柱侧凸患者术后并发症发生率比较差异无统计意义(P>0.05).结论 脊柱侧凸矫形术后并发症发生率较高,但积极的预防与处理会获得良好的预后.

Background: There are several risk factors for proximal junctional kyphosis (PJK) in adolescent idiopathic scoliosis (AIS) surgery. Decreased rod contouring angle (RCA) has been proposed as a risk factor for PJK, but the role of difference between proximal junctional angle (PJA) and RCA (PJA-RCA) has not been fully investigated. The aim of this study was to assess the role of PJA-RCA for the development of postoperative PJK in AIS. Methods: We performed a retrospective analysis of 96 AIS patients who underwent posterior segmental spinal instrumentation and fusion between the years 2012 and 2018 (minimum 1.5-year and average 2-year follow-up) at a single institution. Each patient was measured on preoperative, postoperative and final follow-up long-cassette standing radiographs. The PJA-RCA was regarded as a new definition that reflects the match degree between proximal rod contouring and vertebra curvature, and radiographic parameters were compared between PJK and non-PJK group. Results : Among the 96 patients with a mean age of 14.00 years (± 0.82), the overall incidence of PJK was 22%. PJK group showed a significantly greater preoperative SVA (P = 0.032) and larger correction of SVA (P = 0.007) than non-PJK group. At the last follow-up, PJK patients had significantly greater LL (P = 0.046). Patients in the PJK group had significantly greater preoperative PJA-RCA than the non-PJK group (4.07±3.30 vs. 1.42±4.28, P = 0.024). However, RCA was not significantly different between two groups (3.88 ± 4.34 vs. 2.86 ± 3.36, P = 0.405). In addition, Pearson correlation coefficient showed a significant correlation between the change of SVA and the last follow-up PJA (r = -0.208, P = 0.042). Preoperative PJA-RCA and postoperative PJA-RCA demonstrated similar results which showed a strong correlation with the last follow-up PJA (r = 0.528 and r = 0.532 respectively, P < 0.000). Conclusions: As a new reflex of improper rod contouring, large PJA-RCA is a risk factor for PJK in AIS, and PJK might be a compensation mechanism rather than complication when spine is shifted and overcorrected. Keywords: adolescent idiopathic scoliosis, proximal junctional kyphosis, proximal junctional angle, rod contouring angle.

OBJECTIVE: To perform a meta-analysis exploring the correlation between cervical lordosis (CL) and sagittal spine alignment in patients with adolescent idiopathic scoliosis (AIS) after surgery for determining a surgical strategy. METHODS: We searched 3 electronic databases for studies discussing the correlation between CL and spine sagittal alignment in patients with AIS. Studies reported from the inception of the database to June 2019 were retrieved without any language restrictions. Summary correlation coefficient (r) values were extracted from each study, and 95% confidence intervals (CIs) were calculated. In addition, we conducted subgroup analyses in different curve type subgroups with at least 2 studies. RESULTS: Ten relevant studies involving 539 patients were evaluated in this meta-analysis. The Pearson correlation (r) for CL and the T1 slope was -0.69; (95% CI, -0.79 to -0.54). The fixed-effects summary correlation between CL and thoracic kyphosis in patients was moderate (r = -0.40; 95% CI, -0.48 to -0.31). In addition, the fixed-effects summary correlations between CL and lumbar lordosis (r = 0.19; 95% CI, 0.07-0.30), pelvic incidence (r = -0.08; 95% CI, -0.20 to 0.04), pelvic tilt (r = -0.06; 95% CI, -0.18 to 0.06), and sacral slope (r = -0.06; 95% CI, -0.18 to 0.06) in patients were weak. CONCLUSIONS: There is a strong negative correlation between CL and the T1 slope in patients with AIS. Given the lack of robust clinical evidence, these findings warrant verification by large prospective registries and randomized trials with long follow-up periods.

OBJECTIVE:This is the first systematic review and meta-analysis on the overall incidence of intraspinal abnormalities in patients with congenital scoliosis (CS) and potential influencing factors.METHODS:We searched three large electronic databases (PubMed, EMBASE, and Cochrane Library) for potentially relevant studies. The quality of the included studies was assessed independently by two authors using the Methodological Index for Non-Randomized Studies (MINORS) criteria. Data on the number of CS patients, number of CS patients with intraspinal abnormalities, sex of the patients, and CS types were extracted from the included studies. R software was used to pool and analyze all the extracted data.RESULTS:This meta-analysis included 10 articles, and 671 of 1863 CS patients undergoing magnetic resonance imaging (MRI) examinations were identified to have intraspinal abnormalities. The overall incidence of intraspinal abnormalities in the patients with CS was 37% (95% CI, 29-45%). Diastematomyelia was the most common intraspinal abnormality and was detected in 45.60% of the patients with intraspinal abnormalities (306/671). The remaining intraspinal abnormalities included syringomyelia (273/671, 40.69%), tethered cord (190/671, 28.32%), low conus (58/671, 8.64%), intraspinal mass (39/671, 5.81%), Chiari malformation (32/671, 4.77%), fatty filum (27/671, 4.02%), spina bifida (occulta excluded) (17/671, 2.53%), tumor (17/671, 2.53%), cyst (12/671, 1.79%), syringomyelus (4/671, 0.60%), dural ectasia (1/671, 0.15%), and undiagnosed cord MRI hyperintensity (1/671, 0.15%). The patient's sex and CS type were not factors that affected the incidence of intraspinal abnormalities in CS patients (all P > 0.05).CONCLUSIONS:This meta-analysis revealed that the overall incidence of intraspinal abnormalities detected by MRI in CS patients was 37%. Diastematomyelia was the most common intraspinal abnormality. The patient's sex and CS type were not factors that affected the incidence of intraspinal abnormalities in CS patients.

OBJECTIVE: To compare the pedicle morphology of nondystrophic scoliosis secondary to neurofibromatosis type 1 (ND-NF1) scoliosis secondary to neurofibromatosis type 1 (NF1-S) and adolescent idiopathic scoliosis (AIS) using computed tomography (CT) in a consistent classification system. METHODS: The transverse pedicle widths of cancellous and cortical channels were measured using preoperative spinal CT images (T1-L5) and then classified as having type A-E pedicles; type B, C, D, and E pedicles were regarded as abnormal. A subset of these patients, a postoperative CT was performed to evaluate the accuracy of pedicle screw placement. According to the perforation of the medial or lateral pedicle walls by the pedicle screw, the placement of screw was classified by a grade ranging from 0 to 3, and grades 2 and 3 were regarded as misplacement. RESULTS: In total, 3230 pedicles were measured and classified, and the incidence rate of abnormal pedicles in the ND-NF1 group was significantly greater than that of the AIS group (65.9% vs. 61.4%, P = 0.03). The misplacement rate in the ND-NF1 group was significantly greater than that in the AIS group (12.2% vs. 7.4%; P = 0.01), and in terms of the corresponding 1100 pedicles, the incidence rate of abnormal pedicles in the ND-NF1 group was higher than that in the AIS group (71.7% vs. 64.9%; P = 0.02). CONCLUSIONS: The incidence rate of abnormal pedicles in patients with ND-NF1 is significantly greater than that of patients with AIS, and it may the reason for the higher misplacement rate of pedicle screws in patients with ND-NF1.