Unilateral biportal endoscopic (UBE) surgery is an innovative minimally invasive technique for treating lumbar disc herniation. However, conventional surgical positioning, which combines preoperative surface localization with intraoperative fluoroscopy, has several limitations, including suboptimal accuracy, procedural complexity, and reduced operative efficiency. Additionally, incomplete decompression and over-decompression are common issues in UBE surgery, might leading to disastrous outcomes. However, determining the extent of laminectomy remain a significant challenge. This study explores the use of Kirschner Wire as a localization tool in UBE surgery to enhance localization precision and the the appropriate decompression range. This study included 78 patients diagnosed with lumbar disc herniation (LDH) and radicular pain who underwent UBE discectomy using Kirschner Wires as a localization tool. Another 73 patients with LDH underwent standard UBE discectomy without Kirschner Wires. We compared demographic data, surgical variables, postoperative complications, and health-related quality of life (HRQOL) between the two groups. Incorrect segmental localization occurred in 2 patients in the Kirschner Wire group and 11 patients in the standard UBE discectomy group, indicating a significant difference. The Kirschner Wire group demonstrated shorter total operation time, less time spent identifying the correct segment, fewer instances of radiology exposure, and reduced intraoperative blood loss. Additionally, less paraspinal muscle injury was observed in the Kirschner Wire group. Incomplete decompression was identified in 4 patients in the standard UBE discectomy group, all of whom required revision surgery, whereas no cases of incomplete decompression were observed in the Kirschner Wire group. The incidence of facet injury was higher in the standard UBE discectomy group due to the over-decompression. However, no significant differences were found between the groups in terms of dural tear, root injury, incision infection, and revision surgery. Both groups showed improvements in visual analog scale (VAS) scores for back pain, VAS scores for leg pain, and Oswestry Disability Index (ODI), with a more significant decrease in leg pain VAS scores observed in the Kirschner Wire group. Kirschner Wire is an effective localization tool in UBE discectomy, providing accurate segmental localization and aiding surgeons in determining the extent of laminectomy for decompression, thus reducing the likelihood of incomplete decompression or over-decompression. Additionally, the use of Kirschner Wire can decrease total operation time, radiation exposure, intraoperative blood loss, and paraspinal muscle injury. We recommend Kirschner Wire as localization tools in UBE discectomy to enhance surgical precision and outcomes.

With the emergence of numerous classifications, surgical treatment for adolescent idiopathic scoliosis (AIS) can be guided more effectively. However, surgical decision-making and optimal strategies still lack standardization and personalized customization. Our study aims to devise proper deep learning (DL) models that incorporate key factors influencing surgical outcomes on the coronal plane in AIS patients to facilitate surgical decision-making and predict surgical results for AIS patients. A total of 425 AIS patients who underwent posterior spinal fixation were collected. Variables such as age, gender, preoperative and final follow-up horizontal and vertical coordinate vectors, and screw positioning data were preprocessed by parameterizing image data and transforming various data types into a unified, continuous high-dimensional feature space. Four deep learning models were designed, including Multi-Layer Perceptron model, Encoder-Decoder model, CNN-LSTM Attention model and Deep FM model. For the implementation of deep learning, 70% of the data was adopted for training and 30% for evaluation. The mean square error (MSE), mean absolute error (MAE) and curve fitting between the predicted and corresponding real postoperative spinal coordinates of the test set were adopted to validate and compare the efficacy of the DL models. A total of 425 patients with an average age of 14.60 ± 2.08 years, including 77 males and 348 females, were enrolled in this study. The Lenke type 1 and 5 AIS patients accounted for the majority of the included patients. The results showed that the Multi-Layer Perceptron model achieved the best performance among the four DL models, with a mean square error of 2.77 × 10–5 and an average absolute error of 0.00350 on the validation set. Moreover, the results predicted by the Multi-Layer Perceptron model closely matched the actual coordinate positions on the original postoperative images of patients with Lenke type 1 and AIS patients. Deep learning models can provide alternative and effective decision-making support for AIS patients undergoing surgery. Regarding the learning curve and data volume, the optimal DL models should be adjusted and refined to meet future demands.

BackgroundKnowledge about factors affecting functional disability in patients with non-specific chronic low back pain (NSCLBP) is helpful in guiding treatment, but there has been little systematic research on this topic. This study aimed to identify independent factors contributing to functional disability in NSCLBP patients especially the impact of sagittal parameters and body postures in work, learning, and daily life.MethodsSociodemographic data, sagittal parameters, Oswestry Disability Index (ODI), Numeric Rating Scale (NRS), and 36-item Short Form Health Survey (SF-36) of NSCLBP patients were collected. Patients were divided into a low-functional disability group (ODI ≤ 20) and a high-functional disability group (ODI > 20), and the ODI was converted to ranked ODI (RODI) accordingly. Sociodemographic data, sagittal parameters, NRS, and SF-36 were compared by univariate analysis between both groups. A correlation analysis of the aforementioned factors with the RODI was conducted. The sociodemographic data and sagittal parameters related to the RODI were analyzed by logistic regression to select potential RODI-associated factors. The level of significance was set at P < 0.05.ResultsAge, educational background, daily main posture while working or learning (DMPWL), daily standing time while working or learning (DSTTWL), daily sitting time while resting (DSITR), sacral slope–pelvic tilt (SS-PT), spinosacral angle (SSA), NRS, and SF-36 (except mental health, MH) were different between the two groups (P < 0.05). Correlation analysis showed that they were related to the RODI (P < 0.05). The logistic regression analysis indicated that the regression coefficients of a college degree, postgraduate diploma, DSITR, and SSA were (B = −0.197; P = 0.003), (B = −0.211; P = 0.006), (B = −0.139; P = 0.039), and (B = −0.207; P = 0.001), respectively, and the odds ratio (OR) and 95% confidence interval (CI) were 0.489 (0.308; 0.778), 0.299 (0.125; 0.711), 0.875 (0.772; 0.993), and 0.953 (0.925; 0.981), respectively.ConclusionEducational background, DSITR, and SSA are independent factors affecting functional disability in NSCLBP patients. NSCLBP patients with a lower educational background, shorter DSITR, or smaller SSA should be taken into account in clinical practice and therapeutic choices. Extending sitting time for rest and the avoidance of a forward-leaning standing position are beneficial for reducing functional disability in NSCLBP.

BACKGROUND CONTEXT:Sagittal parameters are significantly correlated with health-related quality of life (HRQoL) in adult spinal deformity patients. Their association with HRQoL in patients with nonspecific chronic low back pain (NSCLBP) is unclear. PURPOSE:To analyze the correlation between sagittal parameters and disability in NSCLBP patients. DESIGN:A cross-sectional study. PATIENT SAMPLE:Subjects included 435 patients with NSCLBP divided into low disability and high disability groups. OUTCOME MEASURES:Function was measured using the Oswestry Disability Index (ODI). Pain intensity was measured using the Numeric Rating Scale (NRS) and HRQoL was measured using 36-item Short Form Health Survey (SF-36). METHODS:Sagittal parameters, demographic data, ODI, SF-36 eight-dimensional scores and NRS scores of patients with NSCLBP were collected. Taking ODI=20 as the cut-off value, patients were divided into low disability group (ODI≤20) and high disability group (ODI>20), and ODI were converted to Ranked ODI (RODI) accordingly. Univariate analysis of the correlation among age, gender, body mass index (BMI), sagittal parameters, RODI, SF-36 eight-dimensional scores, NRS scores were then conducted. The variables related to RODI were analyzed by logistic regression to discover their independent influence on RODI. p<.05 was considered to indicate statistical significance. RESULTS:A total of 435 patients with NSCLBP were included. Univariate correlation analysis showed that the correlation coefficients between age, sacral slope-pelvic tilt (SS-PT), spinosacral angle (SSA) and RODI were (r=0.126, p<.01), (r=-0.115, p<.05), (r=-0.116, p<.05), respectively. The logistic regression analysis indicated that the regression coefficients of age and SSA were 0.030 (p=.001), -0.044 (p=.002), respectively, and the odds ratio and 95% confidence interval (CI) were 1.031 (1.012, 1.050), 0.957 (0.930, 0.985). CONCLUSIONS:Age and SSA are independent factors for disability of NSCLBP. SSA can comprehensively reflect the sagittal balance of the spine of patients with NSCLBP. Decreased SSA represents poor sagittal balance, which will increase the disability of NSCLBP.

The aim of the present study was to report a clinical survey of hereditary multiple exostoses (HME) in a large Chinese pedigree, and the identification of a novel deletion mutation of exostosin glycosyltransferase 2 (EXT-2) gene. A patient with multiple exostoses with huge cartilage-capped tumors in scapula, knees and ankles received surgery in Department of Orthopedics (Shanghai Changhai Hospital). A total of 20 family members were recruited to the study, with seven members (five male; two female) diagnosed as HME. The family members of the patients with HME were examined, clinical data and peripheral blood samples were collected, and their DNA was sequenced. The incidence of HME in this family pedigree was 35%. Exostoses were most frequently in the tibiae with occurrence in six patients, followed by ribs, femurs, radii, fibulae, scapulae and humeri. DNA sequencing of peripheral blood revealed a novel deletion mutation, c.824-826delGCA, in exon 5 of the EXT-2 gene, which was observed in all the patients with HME, but not in the healthy family members. Several characteristics of HME in the pedigree were observed, such as susceptibility of male gender, decreased average age of onset and height and increased severity of clinical symptoms with generations.

Study design: Retrospective cohort studySummary of Background Data：Restoring the sagittal balance is the significant procedure, which could be evaluated by the relationship of thoracic kyphosis (TK) and lumbar lordosis (LL). Several lumbar lordosis predictive formulas have been proposed. But previous study ignored importance of reciprocal relationship between regional spinal modifications in some ways.Objectives: Realignment of the lumbar lordosis is fundamental in spinal surgery and several formulas have been established to predict the appropriate lumbar lordosis. However, the predictive accuracy of these formulas did not reach their targets. The present study introduced a novel predictive formula for realignment of lumbar lordosis in correction surgery, aiming to predict the individualized ideal lumbar lordosis for different patients.Methods: A total of 311 asymptomatic volunteers were recruited: 220 volunteers for the development of the formula, and the other 91 subjects for validation. General and radiological parameters were evaluated. Correlation analysis between maxLL and other parameters was performed. Multiple regression analysis was conducted to establish the predictive formula using variables related to maxLL. Comparison between predicated maxLL yielded by our formula and other 7 formulas and actual maxLL were conducted to determine the reliability and validity of our predictive formula.Results: MaxLL was correlated with maxTK, SS, PT and PI (all P<0.05). The adjusted multiple regression analysis showed that there were significant associations of maxLL with maxTK and PI (all P<0.001), and the formula was established as follows: maxLL=0.6*maxTK+0.5*PI+3. No significant difference was found between actual maxLL and predicted maxLL yielded by our formula (P=0.408), and our predictive formula has been demonstrated sound reliability and validity. Conclusion: MaxTK and PI were the primary contributors to maxLL, and our novel formula could be safely utilized to predict the ideal lumbar lordosis for patients before surgery.

Objective To simulate the process of curve correction with different strategies of pedicle screws placement, and then explore the ideal strategy.Materials and methods:A three-dimensional model was constructed using CT data from a Lenke 1 AIS patient for finite element analysis. Five screw-placement strategies were designed, including collocation of consecutive, interval and alternate screws instrumentation in convex or concave side. The whole surgical procedures of screw-placement strategies were simulated. And their influences in the curve correction as well as the biomechanics of the implants and implant-bone interface were analyzed.Results:The densities of pedicle screws were 100%, 79%, 64%, 57% and 50%, respectively. During curve correction, interval and alternate screws instrumentation demonstrated higher screws stress, while the higher rods and screw-rod interface was observed in consecutive screws instrumentation. When it referred to the interaction force between screws and vertebrae, a lower stress was observed in in consecutive screws instrumentation. After the fixation of rod at convex side, the maximum stress on screws in each strategy was observed in interval screws instrumentation. The higher stress of rods was observed in alternate screws instrumentation in both sides. However, the correction rate of each strategy was similar.Conclusion:There was little distinction on the curve correction rate in different screw-placement strategies. The screw-placement strategy with interval and alternate screws instrumentation has better biomechanics properties than others, except for higher maximum interaction force between screws and vertebrae.

Machine learning (ML), as an advanced domain of artificial intelligence (AI), is progressively changing our view of the world. By implementing its algorithms, our ability to detect previously undiscoverable patterns in data has the potential to revolutionize predictive analytics. Scoliosis, as a relatively specialized branch in the spine field, mainly covers the pediatric, adult and the elderly populations, and its diagnosis and treatment remain difficult. With recent efforts and interdisciplinary cooperation, ML has been widely applied to investigate issues related to scoliosis, and surprisingly augment a surgeon's ability in clinical practice related to scoliosis. Meanwhile, ML models penetrate in every stage of the clinical practice procedure of scoliosis. In this review, we first present a brief description of the application of ML in the clinical practice procedures regarding scoliosis, including screening, diagnosis and classification, surgical decision making, intraoperative manipulation, complication prediction, prognosis prediction and rehabilitation. Meanwhile, the ML models and specific applications adopted are presented. Additionally, current limitations and future directions are briefly discussed regarding its use in the field of scoliosis. We believe that the implementation of ML is a promising revolution to assist surgeons in all aspects of clinical practice related to scoliosis in the near future.

Study design A retrospective study. Background To determine whether radiological parameters such as maximal lumbar lordosis-maximal thoracic kyphosis (maxLL-maxTK), sacral slope-pelvic tilt(SS-PT) and sacral slope/pelvic tilt (SS/PT) could be used as indicators for the diagnosis of degenerative disc disease (DDD) in compensatory sagittal balanced patients. Methods Medical records of sagittal balanced DDD patients and asymptomatic adults within our hospital registry from July 2019 to November 2019 were reviewed. General characteristics and radiological parameters were evaluated between the two groups. Analysis of covariance with age as a covariate was conducted, followed by receiver operating characteristic (ROC) analysis and areas under the curve (AUC) calculation. The max Youden index was calculated to identify the optimal sensitivity specificity pairs. Results A total of 42 DDD patients and 199 asymptomatic adults were included. For those parameters that showed significant differences between the two groups, AUC for SS/PT and SS-PT were the largest, reaching 0.919 and 0.936, respectively. The sensitivity was 0.749, the specificity was 0.952 and the max Youden index was 0.701 when SS/PT = 1.635 was used as threshold. The max Youden index was found for a threshold of SS-PT =8.500, for which the sensitivity increased to 0.854, while the specificity decreased to 0.857. Conclusions Both SS/PT and SS-PT were significantly different between sagittal balanced DDD patients and asymptomatic adults. SS/PT < 1.6 and SS-PT < 8.5 could be used as indicators for the diagnosis of DDD patients with compensatory sagittal balance.

Objective To explore the characteristics of compensation of unfused lumbar region post selective thoracic fusion in Lenke 1 and 2 adolescent idiopathic scoliosis Background Preserving lumbar mobility in the compensation is significant in controlling pain and maintaining its functions. The spontaneous correction of the distal unfused lumbar curve after STF has been widely reported, but previous study has not concentrated on the characteristics of compensation of unfused lumbar region post selective thoracic fusion. Method A total of 51 Lenke 1 and2 AIS patients were included, whose lowest instrumented vertebrae was L1 from January 2013 to December 2019. For further analysis, demographic data and coronal radiographic films were collected before surgery, at immediate erect postoperatively and final follow-up. The wedge angles of each unfused distal lumbar segments were measured, and the variations in each disc segment were calculated at the immediate postoperative review and final follow-up. Meanwhile, the unfused lumbar curve was divided into upper and lower parts, and calculated their curve angles and compensations. Results The current study enrolled 41 females (80.4%) and 10 males (19.6%). 36 patients were Lenke type 1, while 15 patients were Lenke type 2. The average main thoracic Cobb angle and thoracolumbar/lumbar Cobb angle were 44.1±7.7°and 24.1±9.3°, preoperatively. At the final follow-up, the disc wedge angle variation of L1/2, L2/3, L3/4, L4/5 and L5/S1 was 3.84±5.96°, 3.09±4.54°, 2.30±4.53°, -0.12±3.89° and -1.36±2.80°, respectively. The compensation of upper and lower coronal lumbar curves at final follow-up were 9.22±10.39° and -1.49±5.14°, respectively. Conclusion When choosing L1 as the lowest instrumented vertebrae, the distal unfused lumbar segments' compensation showed a decreasing trend from the proximal end to the distal end. The adjacent L1/2 and L2/3 discs significantly contributed to this compensation.

Bacground: It is of great significance to optimize the finite element model by spinal flexibility of adolescent idiopathic scoliosis (AIS) patients. The elastic modulus of the intervertebral disc is of critical importance in determining the overall flexibility of the spine. The aim of the present study was to optimize the finite element model of Lenke 1 AIS based on the dynamic flexibility in vivo by matching the optimal elastic modulus of the intervertebral disc. Methods: The Cobb angles under different longitudinal traction loads of one patient with Lenke 1 AIS were dynamically measured by using a spine morphometer with a posture sensor to plot the Cobb angle-longitudinal traction load characteristic curve. A 3D finite element model of the patient was established. The patient’s Cobb angle-longitudinal traction load characteristic curve was used as the dynamic flexibility in vivo to determine the optimal intervertebral disc elastic modulus of the model. Results: The dynamic flexibility curve in vivo of one Lenke 1 AIS patient was successfully obtained, and the patient’s optimal elastic modulus of the intervertebral disc for the finite element model was 5 MPa according to the dynamic flexibility curve in vivo. Conclusions: The use of dynamic flexibility in vivo to optimize the finite element model can provide a new perspective and approach for model optimization, which can reproduce the biomechanical characteristics in vivo of AIS patients.

In order to conduct surface monitoring of the three-dimensional spine morphology of the human body in daily life, a spine morphology measuring method using "single camera, multi-view" to construct stereo vision is proposed. The images of the back of the human body with landmarks of spinous process are captured from multiple angles by moving a single camera, and based on the "Zhang Zhengyou calibration method" and the triangulation principle of binocular stereo vision, the spatial conversion matrices corresponding to each other between all images and the 3D coordinates of the landmarks are calculated. Then the spine evaluation angle used to evaluate the spine morphology is further calculated. The tests' results showed that the spine evaluation angle error of this method is within ±3°, and the correlation between the results and the X-ray film Cobb angles is 0.871. The visual detection algorithm used in this paper is non-radioactive, and because only one camera is used in the measurement process and there is no need to pre-set the camera's shooting pose, the operation is simple. The research results of this article can be used in a mobile phone-based intelligent detection system, which will be suitable for the group survey of scoliosis in communities, schools, families and other occasions, as well as for the long-term follow-up of confirmed patients. This will provide a reference for doctors to diagnose the condition, predict the development trend of the condition, and formulate treatment plans.

BACKGROUND:Postmenopausal osteoporosis results from estrogen withdrawal and is characterized mainly by bone resorption. Shikonin is a bioactive constitute of Chinese traditional herb which plays a role in antimicrobial and antitumor activities. The study was designed to investigate the role of shikonin on postmenopausal osteoporosis and explore its underlying mechanisms.METHODS:Immunofluorescence staining was performed to evaluate the effects of shikonin on actin ring formation. The expression levels of the nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathway were determined by Western blot analysis. To determine whether shikonin influences the receptor activator of nuclear factor-κB ligand (RANKL)-induced association between receptor activator of NF-κB (RANK) and tumor necrosis factor receptor associated factor 6 (TRAF6), immunofluorescence staining and immunoprecipitation experiments were performed. During our validation model, histomorphometric examination and micro-computed tomography (CT) were conducted to assess the morphology of osteoporosis.RESULTS:Shikonin prevented bone loss by inhibiting osteoclastogenesis in vitro and improving bone loss in ovariectomized mice in vivo. At the molecular level, Western blot analysis indicated that shikonin inhibited the phosphorylation of inhibitor of NF-κB (IκB), P50, P65, extracellular regulated protein kinases (ERK), c-Jun N-terminal kinase (JNK), and P38. Interaction of TRAF6 and RANK was prevented, and downstream MAPK and NF-κB signaling pathways were downregulated.CONCLUSION:Osteoclastic bone resorption was reduced in the presence of shikonin in vitro and in vivo. Shikonin is a promising candidate for treatment of postmenopausal osteoporosis.

Background: Very few studies have focused on the complication of rod fracture after posterior long construct fusion in adults with spinal deformity. Therefore, this retrospective study aimed to investigate the incidence and risk factors of this complication. Methods: The study reviewed 213 adult patients with spinal deformity treated by long construct fusion between January 2009 and January 2017. Ten patients (4.6%) with rod fracture were included in the case study group. For each case of rod fracture, we selected two age-matched and gender-matched controls. Independent two-sample t test and Chi-square test were used to compare the differences between variables. Binary logistic regression analysis was performed to identify independent risk factors of rod fracture. Results: Statistically significant differences were observed between the groups, in terms of additional bone grafts volume (P = 0.015), osteotomy (P = 0.017), skipped screw in sagittal apex region (P = 0.012), TK change (P = 0.023), and preoperative TLK (P = 0.036). However, there were no differences in terms of age (P = 0.933), follow-up time (P = 0.513), gender distribution (P = 0.650), fusion segments (P = 0.085), the number of screws (P = 0.131), density of screws (P = 0.088), preoperative MC (P = 0.120), postoperative MC (P = 0.430), MC change (P = 0.126), preoperative TK (P = 0.590), postoperative TLK (P = 0.074), TLK change (P = 0.064), preoperative LL (P = 0.084), postoperative LL (P = 0.065), and LL change (P = 0.914). Binary logistic regression analysis revealed that osteotomy (P = 0.023) and skipped screw strategy in sagittal apex region (P = 0.046) were the primary factors included in the equation [ Odds Ratio (OR) = 11.669 and 7.659, respectively]. Conclusion: In our study, the prevalence of rod fracture in adult patients with spinal deformity after long construct fusion was 4.6%; osteotomy was the main risk factor of rod fracture these patients. The skipped screws in sagittal apex region could increase the risk of rod fracture because the stress on the rods failed to be distributed to different segments. (c) 2018 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

The assessment of the spinal shape is of great help in the treatment of spinal deformity diseases. So a novel three-dimensional shape reconstruction method for human spinal deformity is proposed in this paper. By measuring the posture and arc length information of the human spine surface, the coordinates of each sample point can be calculated using the recursive algorithm, and then the reconstructed spinal shape can be obtained according to the coordinates of these spatial points. Besides, the Cobb angle, which is an important basis for the diagnosis of spinal disease in the medical field, can also be obtained. To verify the feasibility and accuracy of this method, some experiments are made in a spinal model and three subjects. The maximum relative error of the deviation distance between the curve obtained by the reconstruction method and the actual curve is less than 5 percent by analyzing the experimental results and the error of the Cobb angle is within 4 degree, which is less than the maximum permission errors (MPE, less than 5 degree) in the medical field and the reliability of the instrument is greater than 0.8. Compared with the existing methods, this method has many advantages, such as high precision, convenient for measuring, less time-consuming and low in cost, which make it have wide application prospects in daily monitoring and measurement for spinal deformity patients.

目的 探讨青少年特发性脊柱侧凸患者双下肢不等长(LLD)与脊柱侧凸的关系,并分析矫形手术后LLD的改善情况及影响LLD改善的危险因素.方法 回顾性分析2010年1月至2013年1月在海军军医大学(第二军医大学)长海医院骨科脊柱外科就诊的85例青少年特发性脊柱侧凸患者的病例资料.根据患者术前及术后2年的影像学资料测量分析站立位X线片双侧股骨头高度差(HD-bFH)及矫形术后该参数的变化.根据患者术前HD-bFH,将患者分为非LLD组(HD-bFH＜5 mm)和LLD组(HD-bFH≥5 mm),比较两组患者的一般特征和影像学参数的差异,并分析HD-bFH变化与其他参数的相关性.结果 85例患者术前HD-bFH为(0.80±5.57) mm,术后2年患者HD-bFH为(-0.49±4.93)mm,术后与术前相比差异有统计学意义(P=0.022).主胸弯型(Lenke Ⅰ、Ⅱ、Ⅲ型,n=50)和胸腰弯/腰弯型(LenkeV和Ⅵ型,n=33)患者术前HD-bFH差异无统计学意义[(0.52±5.86) mm vs (1.53±5.12) mm,P=0.427].85例患者中,31例(36.5％)发生LLD.非LLD(n=54)与LLD(n=31)患者的一般特征和影像学参数差异无统计学意义(P＞0.05).术后HD-bFH的变化与Risser征(rs=-0.512,P=0.020)及腰弯矫形程度(r=-0.605,P=0.018)相关.结论 本研究中青少年特发性脊柱侧凸患者LLD的发生率为36.5％.双下肢长度差异的改变与矫形手术密切相关,腰弯矫形程度和Risser征是其危险因素.

Postoperative shoulder imbalance (PSI) is a common complication of adolescent idiopathic scoliosis (AIS). However, results regarding risk factors for PSI are contradictory. This study was performed to explore the risk factors associated with PSI in AIS and determine whether PSI could be predicted. Medical records of AIS patients receiving correction surgery from January 2012 to January 2015 were reviewed. Anteroposterior films were evaluated before and after the surgery and at the 2-year follow-up. Patients were divided into two groups according to whether PSI was observed at 2-year follow-up. Risk factors for PSI were analyzed, and a PSI index was proposed and verified. A total of 114 AIS patients (PSI/non-PSI: 60/54) were included. The univariate analysis showed that PTC (proximal thoracic curve), preoperative PTC-to-MTC (main thoracic curve) ratio, preoperative bending Cobb angle of PTC, preoperative bending Cobb angle of the lumbar curve, postoperative PTC, postoperative AVT (apical vertebral translation) of PTC, AVT of PTC at follow-up, and adding-on angle were significantly different between two groups. Adjusted logistic regression analysis showed that postoperative AVT of PTC and adding-on angle were the primary contributors to PSI in patients with AIS. The PSI index was defined as 1.2 × postoperative AVT of PTC + 1.1 × adding-on angle. According to the receiver operating characteristic curve, the cutoff point for the PSI index in predicting the development of PSI was 15. The positive and negative predictive values were 80% and 87%, respectively. To prevent PSI, we recommend sufficient correction of AVT of PTC and prevention of adding-on. These slides can be retrieved under Electronic Supplementary Material.

Postoperative neck tilt (PNT) is a phenomenon in adolescent idiopathic scoliosis (AIS) patients which is distinct form shoulder imbalance. There were scarce studies performed to explore the risk factors for PNT in Lenke 1 and 2 AIS patients, and whether it can be predicted after surgery remains unknown. The objective of this study is to explore the prevalence and risk factors for PNT, and introduce an index for prediction of PNT in Lenke 1 and 2 AIS patients after correction surgery. Medical records of Lenke 1 and 2 AIS patients who received correction surgery were reviewed from February 2013 to February 2015. Posteroanterior films were evaluated before surgery and at 2 years’ follow-up. Patients were divided into two groups according to whether PNT occurred at the 2 years’ follow-up. Risk factors of PNT were analyzed, and PNT Index was proposed and verified. One hundred two Lenke 1 and 2 AIS patients were recruited in this study. The prevalence of PNT after correction was 40.2%. According to the postoperative CAT (Cervical Axis Tilt), patients were divided into two group: PNT group (CAT≧5°, n = 41) and non-PNT group (CAT< 5°, n = 61). Postoperative T1 tilt, preoperative proximal thoracic curve (PTC), postoperative PTC and postoperative coronal balance (CB) were significantly different between two groups. Logistic regression showed that postoperative PTC and postoperative CB were the primary risk factors for PNT, which could be predicted by the regression equation: PNT Index = 1.1 x postoperative PTC (degrees) - 0.9 x postoperative CB (millimeters). On the basis of ROC curve, if PNT Index was more than 10, the occurrence rate of PNT was 86%. On the contrary, the rate of no PNT phenomenon was 80%. Postoperative PTC and postoperative CB were the important factors for PNT in Lenke 1 and 2 AIS patients. Sufficient correction of PTC and moderate correction of CB should be recommended when operating on Lenke1 and 2 AIS patients.

Immediate postoperative coronal imbalance (IPCIB) is a common reason for worse postoperative appearance in adolescent idiopathic scoliosis (AIS) patients and rarely improves on its own at follow-up, thereby greatly influencing the patients’ health-related quality of life. However, no studies have been performed to detect the primary risk factors for IPCIB and it remains unclear whether the condition can be predicted preoperatively. The purpose of this study is to detect the primary risk factors for IPCIB in Lenke 5 and Lenke 6 AIS patients and to explore whether IPCIB can be predicted preoperatively. Medical records of Lenke 5 and Lenke 6 AIS patients who underwent correction surgery in our hospital from June 2017 to October 2018 were analyzed. Anteroposterior films were evaluated before and after surgery. Patients were divided into two groups, i.e., occurrence and non-occurrence of IPCIB. The risk factors for IPCIB were analyzed, and an IPCIB index was proposed and verified. Thirty-seven Lenke 5/Lenke 6 AIS patients with IPCIB and 48 patients without IPCIB were recruited. Univariate analysis showed that there were significant differences between the two groups in the number of unfused vertebrae, preoperative thoracic Cobb angle, preoperative lumbar Cobb angle, preoperative translation of lumbar apex, preoperative coronal balance, preoperative L5 tilt, preoperative bending L5 tilt, postoperative translation of thoracic apex, postoperative lumbar Cobb angle, postoperative translation of lumbar apex, postoperative radiographic shoulder height, and postoperative L5 tilt. Logistic regression analysis showed that the preoperative bending L5 tilt, postoperative translation of the thoracic apex, and postoperative lumbar Cobb angle were the primary risk factors for IPCIB. The IPCIB index was defined as 1.3 * preoperative bending L5 tilt + 1.5 * postoperative translation of thoracic apex − 0.8 * postoperative lumbar Cobb angle. The receiver operating characteristics curve indicated that the occurrence rate of IPCIB was 88% and the non-occurrence rate was 90% when the IPCIB index was greater than 16. The preoperative bending L5 tilt, postoperative translation of the thoracic apex, and the postoperative lumbar Cobb angle were the primary risk factors for IPCIB in Lenke 5 and Lenke 6 AIS patients. The IPCIB index can be used to predict the occurrence of IPCIB with high accuracy. Our results indicate that the thoracic curve should be adequately corrected during surgery; however, moderate correction of the lumbar curve is recommended. These slides can be retrieved under Electronic Supplementary Material.

Proximal junctional kyphosis (PJK) is a devastating complication for adult spinal deformity (ASD) after correction surgery. However, there is no consensus on the risk factors of PJK, and whether it can be predicted remains unknown. The aim of this study is to detect the primary risk factors for PJK in ASD, and introduce a novel index for prediction of PJK.