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Objective Proximal junctional kyphosis (PJK) is a common sagittal complication of adolescent idiopathic scoliosis (AIS) after corrective surgery, leading to new deformities, pain, and, even, revision surgery. In the present study, we investigated the risk and predictive factors for PJK in patients who had undergone Lenke type 5 AIS correction to identify the parameters relevant to intraoperative guidance. Methods A total of 35 patients with Lenke type 5 AIS who had undergone corrective surgery at our hospital from January 2008 to February 2016 were divided into the PJK (n = 15) and non-PJK (n = 20) groups. Correlation and receiver operating characteristic curve analyses were performed to screen the parameters for significance and calculate the thresholds. A survival analysis was performed to examine the differences between the 2 groups. Results Independent t tests revealed significant differences between the 2 groups in the preoperative pelvic incidence, preoperative pelvic tilt, postoperative proximal junctional angle (PJA), and postoperative thoracic kyphosis (TK). The postoperative PJA, postoperative TK, and other parameters correlated significantly with changes in the PJA at the final follow-up. The receiver operating characteristic curves revealed that the postoperative PJA and postoperative TK effectively predicted for the occurrence of PJK, with a threshold of 9.45° and 25.25°, respectively. The estimated survival times were 14.7 months for a PJA >9.45° and TK >25.25°, 19.2 months for a PJA >9.45°, and 33.9 months for TK >25.25°. Conclusions The results of the present study have shown that the postoperative PJA and postoperative TK can be used to effectively predict for the occurrence of PJK in patients with Lenke type 5 AIS after corrective surgery, with a threshold of 9.45° and 25.25°, respectively.

Background Difficult procedures of severe rigid spinal deformity increase the risk of intraoperative neurological injury. Here, we aimed to investigate the preoperative and intraoperative risk factors for postoperative neurological complications when treating severe rigid spinal deformity. Methods One hundred seventy-seven consecutive patients who underwent severe rigid spinal deformity correction were assigned into 2 groups: the neurological complication (NC, 22 cases) group or non-NC group (155 cases). The baseline demographics, preoperative spinal cord functional classification, radiographic parameters (curve type, curve magnitude, and coronal/sagittal/total deformity angular ratio [C/S/T-DAR]), and surgical variables (correction rate, osteotomy type, location, shortening distance of the osteotomy gap, and anterior column support) were analyzed to determine the risk factors for postoperative neurological complications. Results Fifty-eight patients (32.8%) had intraoperative evoked potentials (EP) events. Twenty-two cases (12.4%) developed postoperative neurological complications. Age and etiology were closely related to postoperative neurological complications. The spinal cord functional classification analysis showed a lower proportion of type A, and a higher proportion of type C in the NC group. The NC group had a larger preoperative scoliosis angle, kyphosis angle, S-DAR, T-DAR, and kyphosis correction rate than the non-NC group. The results showed that the NC group tended to undergo high-grade osteotomy. No significant differences were observed in shortening distance or anterior column support of the osteotomy area between the two groups. Conclusions Postoperative neurological complications were closely related to preoperative age, etiology, severity of deformity, angulation rate, spinal cord function classification, intraoperative osteotomy site, osteotomy type, and kyphosis correction rate. Identification of these risk factors and relative development of surgical techniques will help to minimize neural injuries and manage postoperative neurological complications.

The objective of the study was to compare the efficacy of halo-gravity traction (HGT) with subsequent surgical treatment in adolescent and adult patients with severe scoliosis by evaluating the radiographic outcomes and clinical complications.We performed a retrospective analysis of 51 patients with severe scoliosis who underwent a posterior spinal instrumented fusion with HGT during the perioperative period between March 2010 and June 2017. The patients were divided into 2 groups: adults (age18 years) and adolescents (age 10-18 years). All patients were followed with full posteroanterior and lateral spine radiographs, bending films, neurological complications, and lung function tests for a minimum of 2 years. Deformity correction, pulmonary function testing, and clinical complications were compared between the 2 groups.We identified 29 adults (8 males and 21 females, mean age = 23.7 ± 8.7 years) and 22 adolescents (10 males and 12 females, mean age = 13.0 ± 4.5 years). In the adult group, the mean Cobb angle of the main curve before HGT was 141.7 ± 18.2°, which improved to 126.4 ± 8.6° and 67.5 ± 10.2° after traction and operation, respectively. The kyphotic angle was corrected from 137.1 ± 15.6° before traction to 122.5 ± 11.3° after traction to 67.6 ± 13.8° after operation. The mean functional vital capacity% and forced expiratory volume in one second% were 43.1% and 37.5%, which improved to 46.7% and 41.7% after traction, respectively. In the adolescent group, the mean correction of the main curve improved from 139.3 ± 12.6° before traction to 112.1 ± 8.3° after traction to 59 ± 13.1° after surgical intervention. The kyphotic angle was corrected from 130.7 ± 9.4° before traction to 101.5 ± 12.2° after traction and then to 48.2 ± 10.1° after surgical intervention. Overall, patients in both groups showed significant improvement in their main scoliosis and kyphosis (P0.05), while the correction rate of the main curve and kyphosis was significantly higher in the adolescent group than that in the adult group (P0.05). The functional vital capacity% increased from 44.8% to 55.0% and the forced expiratory volume in one second% increased from 44.0% to 51.0% after using HGT. In terms of surgical outcomes, the incidence of postoperative neurological complications was 27.6% and 18.2% in the 2 groups, respectively.HGT is an effective and safe method to correct spinal deformities and improve lung function, especially in adolescent patients with severe scoliosis. In addition, it can potentially reduce the risk of neurological complications and the level of osteotomy in posterior spinal instrumented fusion surgery.

Background Due to the characteristics of neurofibromatosis type I (NF-1) scoliosis, the precise placement of pedicle screws still remains to be a challenge. Triggered screw electromyography (t-EMG) has been proved to exhibit high sensitivity to identify mal-positioned pedicle screws, but no previous study assessed the combination of t-EMG with O-arm-assisted pedicle screw placement in NF-1 scoliosis surgery. Objective To evaluate efficacy and safety for combination of t-EMG with O-arm-assisted pedicle screw placement in NF-1 scoliosis surgery. Materials and methods From March 2018 to April 2020, sixty-five NF-1 scoliosis patients underwent t-EMG and O-arm-assisted pedicle screw fixation were retrospectively reviewed. The channel classification system was applied to classify the pedicle morphology based on pedicle width measurement by preoperative computed tomography scans. The minimal t-EMG threshold for screw path inspection was used as 8 mA, and operative screw redirection was also recorded. All pedicle screws were verified using a second intraoperative O-arm scan. The correlation between demographic and clinical data with amplitude of t-EMG were also analyzed. Results A total of 652 pedicle screws (T10-S1) in 65 patients were analyzed. The incidence of an absent pedicle (channel classification type C or D morphology) was 150 (23%). Overall, abnormal t-EMG threshold was identified in 26 patients with 48 screws (7.4%), while 16 out of the 48 screws were classified as G0, 14 out of the 48 screws were classified as G1, and 18 out of the 48 screws were classified as G2. The screw redirection rate was 2.8% (18/652). It showed that t-EMG stimulation detected 3 unacceptable mal-positioned screws in 2 patients (G2) which were missed by O-arm scan. No screw-related neurological or vascular complications were observed. Conclusions Combination of t-EMG with O-arm-assisted pedicle screw placement was demonstrated to be a safe and effective method in NF-1 scoliosis surgery. The t-EMG could contribute to detecting the rupture of the medial wall which might be missed by O-arm scan. Combination of t-EMG with O-arm could be recommended for routine use of screw insertion in NF-1 scoliosis surgery.

To explore the interventional effect of exercise therapy on idiopathic scoliosis and identify an optimal intervention window, we did a prospective controlled cohort study. The results shows the efficacy of our exercise protocol, and younger patients with a lower Risser grade are most likely to respond., Study Design. A prospective controlled cohort study. Objective. The aim of this study was to explore the interventional effect of exercise therapy on idiopathic scoliosis (IS) and identify an optimal intervention window. Summary of Background Data. Early conservative treatment is helpful for IS. In addition to bracing, current evidence suggests that exercise can play an important role. Methods. We included 99 patients with IS who were treated at the Guangdong Xinmiao Scoliosis Center from August 2013 to September 2017. The inclusion criteria were: new IS diagnosis, Cobb angle 10° to 25°, Risser 0 to 3 grade, only treated with the Xinmiao treatment system (XTS; >3 days/week, >1 h/day), and follow-up >1 year. Patients were divided into three age groups: A

Background Multimodal intraoperative neuromonitoring (IONM) has been proposed as an effective way to reduce permanent neurologic injury during spinal deformity surgery. However, few studies have reported evoked potential changes at different surgical stages of thoracic posterior vertebral column resection (PVCR). Methods A total of 82 cases with severe thoracic deformity (Yang's A type) treated by PVCR in a single institution between January 2010 and March 2015 were reviewed. Multimodal IONM including somatosensory evoked potential, motor evoked potential, and descending neurogenic evoked potential was performed for real-time assessment of spinal cord function during surgery. The risk factors of neuromonitoring events at different surgical stages were documented and analyzed. Results Multimodal IONM was successfully performed in all 82 cases. Thirty-nine neuromonitoring events presented in 27 (32.9%) cases. Neurologic monitoring events were more likely to occur in patients with larger scoliosis and kyphosis, longer osteotomy closure distance, more Halo gravity traction, more screw insertion, and higher PVCR segments. The reasons for monitoring changes included 6 events during screw insertion, 20 during osteotomy, 9 during osteotomy gap closure, and 4 during deformity correction. New postoperative neurologic deficits were observed in 11 (13.4%) cases including 1 incomplete paraplegia, 8 transient cord deficits, and 2 nerve root injuries. Conclusions Multimodal IONM can effectively identify neurologic deficits throughout surgery. Osteotomy and osteotomy gap closure are the surgical stages with the highest neurologic risks during PVCR procedures. It is imperative to improve dexterity since the majority of neuromonitoring events are caused by surgical techniques.

In-brace correction (IBC) plays an important role in curve progression of patients with adolescent idiopathic scoliosis (AIS) under brace treatment. We evaluated the coronal deformity angular ratio (C-DAR) as a potential predictor of IBC. Based on our experience, we postulated that a high C-DAR may result in low IBC. This relationship had not been previously studied.To evaluate the relationship of C-DAR and IBC in patients with AIS.A retrospective study.A total of 119 patients with AIS treated with a Gensingen brace in our scoliosis center from July 2015 to October 2017 were included.In-brace correction.Data were collected before and upon brace placement. Correlation analyses between study variables and IBC were performed. A linear regression model was established on the basis of C-DAR.At brace fitting, the average age was 12.62±1.16 (range, 10-15) years and mean major curve Cobb angle was 32.14±4.66° (range, 25-40°). Mean IBC was 59.62%±22.03% (range, 16.2-100%). IBC had significant correlation with C-DAR (r=-0.69; 95% confidence interval, -0.77 to -0.61; p.001). IBC was not significantly correlated with age, sex, height, weight, BMI, menstrual status, or Risser sign. A simple linear regression model established that in-brace correction=115.4-10.7×C-DAR.C-DAR has strong negative correlation with IBC and may estimate the expected IBC. The usage of C-DAR may obviate the need for flexibility radiographs, such as supine or supine lateral bending radiographs.

Background The severe rigid deformity patients with pulmonary dysfunction could not tolerate complicated corrective surgery. Preoperative traction are used to reduce the curve magnitude and improve the pulmonary function before surgery, including halo-gravity traction (HGT) and halo-pelvic traction (HPT). The present study aimed to retrospectively compare the radiographic, pulmonary and clinical outcomes of preoperative HGT and HPT in severe rigid spinal deformity with respiratory dysfunction. Methods 81 cases of severe rigid kyphoscoliosis treated with preoperative traction prior to corrective surgery for spinal deformity between 2016 and 2019 were retrospectively reviewed. Two patient groups were compared, HPT group (N = 30) and HGT group (N = 51). Patient demographics, coronal and sagittal Cobb angles and correction rates, pulmonary function, traction time, osteotomy grade, and postoperative neurological complications were recorded for all cases. Results The coronal Cobb angle was corrected from 140.67 ± 2.63 to a mean of 120.17 ± 2.93° in the HGT group, and from 132.32 ± 4.96 to 87.59 ± 3.01° in the HPT group (mean corrections 15.33 ± 1.53 vs. 34.86 ± 3.11 %) (P = 0.001). The mean major sagittal curve decreased from 134.28 ± 3.77 to 113.03 ± 4.57° in the HGT group and from 129.60 ± 8.45 to 65.61 ± 7.86° in the HPT group (P P P = 0.024). The HPT group tended to exhibit more FEV% improvement than the HGT group, but the difference was not significant (5.15 ± 2.27 vs. 11.76 ± 2.22 %, P = 0.91). Conclusions Patients with severe rigid kyphoscoliosis who underwent preoperative HPT exhibited better radiographic correction of the deformity, and pulmonary function, and required fewer osteotomies compared to the HGT group. Thus, HPT may be useful for severe rigid spinal deformity patients with pulmonary dysfunction.

Study design This was a retrospective analysis. Objective The objective of this study was to assess the intraoperative neuromonitoring auxiliary significance of descending neurogenic-evoked potential (DNEP) for motor-evoked potential (MEP) during severe spinal deformity surgery when MEP-positive event occurs. Summary of background data MEP detection is the most widely applied neurological monitoring technique in spinal deformity surgery. MEP is quite vulnerable to anesthesia, blood pressure, and other intraoperative factors, leading to a high false-positive rate of MEP (3.2%-45.0%), which has greatly interfered with the surgical process. At present, the widely used "presence-or-absence" alarm criteria of MEP is not enough to solve the problem of false positive of MEP. Methods A total of 205 cases undergoing severe spinal deformity correction were retrospectively studied. Overall, 74 MEP-positive cases were classified as 2 subgroups: DNEP (+) and DNEP (-) groups. The MEP recovery, wake-up test, and Frankle grade were used to assess the neurological functions. The perioperative and long-term neurological outcomes were assessed. Results There were significant differences in preoperative scoliosis angle and kyphosis angle between DNEP (-) and DNEP (+) groups. Patients in DNEP (-) group showed more MEP improvement (81.5%), compared with the DNEP (+) group (53.2%). The Wake-up test showed 59.3% motor function deficit cases in DNEP (-) group, which was lower than the 87.2% in DNEP (+) group. More patients in DNEP (-) group had normal nerve function (Frankel level E) than those in DNEP (+) group immediately after surgery, as well as at follow-up. Conclusions MEP-positive cases with intraoperative DNEP (-) showed superior prognosis after severe spinal deformity surgery. Intraoperative DNEP could be regarded as an important quantitative tool to assist MEP to monitor neurological injury and can serve as a temporary substitution monitoring technique after MEP is lost.

Background Single-stage spine-shortening osteotomy without treating spinal cord malformations may have potential advantages for the treatment of severe congenital scoliosis (CS) with type I split spinal cord malformation (SSCM); however, the study of this technique was limited. Objective To evaluate the safety and efficacy of a single-stage spine-shortening osteotomy in the treatment of severe CS associated with type I SSCM. Methods A retrospective study was designed to compare 2 case series including 12 severe CS patients with type I SSCM and 26 patients with type A cord function (without spinal cord malformations, evoked potential abnormalities, and neurological dysfunctions preoperatively) treated with a single-stage spine-shortening posterior vertebral column resection (PVCR). Patient demographic, clinical, operative, and radiographic data were obtained and compared between groups. Results The surgical procedure was successfully performed in both groups, and the patients were observed for an average of 44.9 mo (range 25-78 mo) after the initial surgery. The radiographic parameters, intraoperative data, and new neurological deficits showed no difference, while deformity angular ratio (SSCM group: control group = 16.6 ± 3.6: 20.1 ± 3.9, P = .01) and corrective rate (SSCM group: control group = 50%: 58%, P = .046) of the main curve were statistically different between groups. All of the new neurological deficits were recovered within 1 yr. Conclusion The single-stage spine-shortening PVCR with moderate correction could be applied to the treatment of CS associated with type I SSCM. This strategy can achieve safe spinal deformity correction while obviate the neurological complications brought by the detethering procedures, which merits further clinical investigation.

Background Context Posterior three-column spinal osteotomies were shown to be effective to treat severe and stiff kyphoscoliosis. Translations at the site of osteotomy after deformity correction were commonly seen intraoperatively, which might cause potential neurologic deficits. However, this phenomenon was not thoroughly discussed in the current literature. Purpose This study aimed to evaluate the three-dimensional (3D) translations at the three-column osteotomy site and their effects on neurologic outcome in the surgical correction of severe and stiff kyphoscoliosis. Study Design/Setting A retrospective study was carried out. Patient Sample Sixty-nine patients treated by posterior three-column spinal osteotomy for severe kyphoscoliosis of idiopathic, congenital, neuromuscular, neurofibromatosis, and tuberculosis origin were included. Outcome Measures General, coronal, and sagittal translations were graded three-dimensionally according to the theory of Meyerding. Methods The charts of 69 clinical patients with severe and stiff kyphoscoliosis treated by posterior three-column osteotomy from January 2013 to June 2015 were reviewed. There were 35 male patients with an average age of 21.5 years and 34 female patients with an average age of 22.5 years. The etiologies of these spinal deformities were idiopathic, congenital, neuromuscular, neurofibromatosis, and tuberculosis. According to our classification system of spinal cord neurologic function, there were 41 type A, 13 type B, and 15 type C cases. The 3D spine models were reconstructed from thin-sliced computed tomography (CT) scan, and the 3D translations at the three-column osteotomy site were graded and analyzed. Results The incidences of general translation (GT), frontal translation (FT), and sagittal translation (ST) were 62.3%, 52.2%, and 26.1%. The incidence of evoked potential (EP) change in cases with GT/FT being or more than grade II (GT, 42.9%; FT, 50.0%) was significantly higher than that with GT/FT being less than grade II (GT, 16.7%; FT, 18.2%), whereas the incidence of EP change in cases with ST being or more than grade I (33.3%) was significantly higher than that with ST being less than grade I (9.8%). No linear correlations were found between spine shortening distance, deformity correction rate, and the degree of translation. Conclusions The 3D translations are common in posterior three-column spinal osteotomies regardless of anterior strut graft placement. The increase of translation will increase neurologic risks, with GT or FT less than grade II and ST less than grade I being relatively safe.

Objective To assess the clinical and radiographic outcomes of posterior vertebral column resection (PVCR) without anterior support in treatment of Yang type A severe rigid thoracic kyphoscoliosis. Methods The records of 27 Yang type A severe thoracic kyphoscoliosis patients treated with PVCR without anterior support from January 2010 to September 2013 were analyzed retrospectively. Intraoperative multimodal neurophysiological monitoring was conducted in all patients. The 6 modes were somatosensory evoked potential, motor evoked potential, descending neurogenic evoked potential, spinal cord evoked potential, and electromyography (both triggered and free run). Radiographic parameters and complications were used to evaluate the clinical outcomes. Results PVCR without anterior support was conducted successfully in all 27 patients. Intraoperative monitoring events occurred in 3 patients (3/27); of these, 1 patient (1/27) showed postoperative spinal cord injury, but completely recovered within 9 months after the operation (Frankel level E). The number and osteotomy space of vertebrae resection were mean 1.33 levels and 3.7 cm, respectively. All cases achieved good coronal and sagittal curve correction. No implant related complications occurred until the latest follow-up. The average follow-up was 40.1 months (range, 24–59 months). Conclusions In this study, we found that posterior vertebral column resection (PVCR) without any anterior support with a mean 3.7 cm shortening of the spinal column is safe, if close and unyielding contact of end plates can be obtained. A comprehensive understanding of the technique and intensive intraoperative neuromonitoring is mandatory to perform these challenging and complex spine deformity correction procedures safely.

Background Screw-rod constructs have been widely used to correct spinal deformities, but the effects of different screw-rod systems on anti-rotational torque have not been determined. This study aimed to analyze the biomechanical effect of different rod-screw constructs on anti-rotational torque. Methods Three conventional spinal screw-rod systems (Legacy, RF-F-10 and USSII) were used to test the anti-rotational torque in the material test machine. ANOVA was performed to evaluate the anti-rotational capacity of different pedicle screws-rod constructs. Results The anti-rotational torque of Legacy group, RF-F-10 group and USSII group were 12.3 ± 1.9 Nm, 6.8 ± 0.4 Nm, and 3.9 ± 0.8 Nm, with a P value lower than 0.05. This results indicated that the Legacy screws-rod construct could provide a highest anti-rotation capacity, which is 68% and 210% greater than RF-F-10 screw-rod construct and USSII screw-rod respectively. Conclusions The anti-rotational torque may be mainly affected by screw cap and groove design. Our result showed the anti-rotational torque are: Legacy system > RF-F-10 system > USSII system, suggesting that appropriate rod-screw constructs selection in surgery may be vital for anti-rotational torque improvement and preventing derotation correction loss.

Study design A retrospective review of data collected prospectively. Objective The study aimed to assess the possible effects of idiopathic scoliosis on left ventricular (LV) myocardial performance in children and adolescent patients. Summary of background data Spine anomaly may impair cardiorespiratory function. It has been confirmed that respiratory function decreased in patients with scoliosis. However, limited study of the effect of scoliosis on heart function has been published, and no assessment of myocardial deformation of these patients has been reported to our knowledge. Methods Forty-one patients with a median age of 16 years and a median Cobb's angle of 75 degrees were studied. LV myocardial deformation was evaluated using 2-dimensional speckle-tracking echocardiography. The results were compared with those of 33 controls. The correlations between Cobb's angle and echocardiographic parameters in patients were also explored. Results Compared with controls, patients had significantly lower global LV longitudinal systolic strain in all 3 views (4 chamber, 2 chamber, and 3 chamber views), lower global radial and circumferential strains in mitral valve (MV) level and papillary muscle (PM) level; reduced LV longitudinal early diastolic strain rate (SRe) in all 3 longitudinal views and reduced radial SRe in MV level and reduced circumferential SRe in apical (AP) level; decreased LV longitudinal late diastolic strain rate in 4-chamber view and decreased radial ones in all 3 short-axis levels. Among patients, Cobb's angle correlated negatively with LV global radial strain of MV level (r=-0.37, P=0.02), global circumferential strain of MV level (r=-0.35, P=0.03), and global circumferential strain of PM level (r=-0.49, P=0.001), whereas positively with LV longitudinal SRa of 4-chamber view (r=0.46, P=0.003), longitudinal SRa of 2-chamber view (r=0.49, P=0.001), and circumferential SRa of AP level (r=0.35, P=0.02). Conclusions LV mechanics are impaired in patients with idiopathic scoliosis, which correlate with the severity of scoliosis. Our findings suggest the need and provide a mechanical basis for further studies in these patients.

The aim of the present study was to evaluate the different expression levels of thyroid hormone responsive (THRSP; Spot14)/S14 related, Mig12 (S14R) during bone marrow mesenchymal stem cell (BM-MSC) adipogenesis in adolescent idiopathic scoliosis (AIS) patients. MSCs were retrospectively isolated from AIS patients and controls, and adipogenic differentiation was induced. Total RNA was extracted for Affymetrix 3′-IVT expression profiling microarrays and compared with the results from healthy controls. The results were confirmed by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) validation and the protein expression levels of Spot14 and its paralogous gene S14R by western blotting and immunohistochemistry. A total of 300 significantly altered mRNAs were detected (111 upregulated and 189 downregulated) and confirmed by RT-qPCR. The mRNA expression levels of seven genes, including Spot14, were altered by >2-fold in AIS patients. Spot14/S14R was selected for further investigation. The results of the western blotting demonstrated that mRNA and protein expression levels of Spot14/S14R were significantly higher in AIS patients than the controls (P

BACKGROUND Paraspinal muscle (PSM) has been suggested to have a role in adolescent idiopathic scoliosis (AIS). Few studies have investigated the fiber type-specific changes of PSM in detail. MATERIAL AND METHODS Bilateral multifidus muscles were harvested from the apical vertebra level (T7-T10) of 12 AIS patients and 6 control individuals. Immunohistological staining was performed to evaluate the muscle fiber type composition, fiber type-specific cross-sectional area (CSA), myonuclei density, and the total and activated satellite cell (SC) density. The correlations between these characteristics and curve initiation/severity were analyzed. RESULTS In comparison with the PSM in convexity and the control group, PSM in concavity showed a significant reduction of CSA (concavity, 2601.1±574.1 μm²; convexity, 3732.1±545.1 μm²; control, 3426.5±248.4 μm²), myonuclei density (concavity, 2.0±0.3 myonuclei/fiber; convexity, 2.5±0.4 myonuclei/fiber; control, 2.2±0.2 myonuclei/fiber), and activated SC density (concavity, 0.7±0.4 cells/100 fibers; convexity, 1.5±0.7 cells/100 fibers; control, 1.2±0.3 cells/100 fibers) for fiber type I. The Cobb angle was positively correlated with the bilateral ratio of CSA (convexity/concavity) for both fiber types. The apical vertebral translation was positively correlated with bilateral difference of myonuclei density (type I), total SC density (types I and II), and activated SC density (type I). CONCLUSIONS The fiber type-specific pathological changes on the concave side seemed to be more severe. Some fiber type-specific characteristics (CSA, myonuclei density, total/activated SC density) were closely associated with curve severity. More attention should be paid to PSM physiotherapy treatment on the concave side.

Background Three-column osteotomies were developed to treat severe spinal deformities but result in high neurologic complications and require further risk stratification. The present study investigated whether the combination of spinal cord function classification (SCFC) and deformity angular ratio (DAR) could further stratify the neurologic risks in the surgical correction of severe and stiff kyphoscoliosis. Methods The patients with kyphoscoliosis who had undergone posterior 3-column osteotomies at the spinal cord level were reviewed. Using our SCFC system, the preoperative neurologic function (type A, B, or C) was classified. The sagittal DAR (S-DAR), coronal, and total DARs were calculated. Intraoperative monitoring events and new neurologic deficits (NNDs) postoperatively were documented and analyzed using the SCFC and DAR or both combined. Results The NND rates increased significantly from type A to C (P = 0.000) and increased exponentially with an increase in S-DAR in types B and C but not type A. They also increased exponentially with aggravation of the SCFC in the medium and high but not low S-DAR group. All NNDs had recovered at 3 months for type A and most had recovered at 6 months for type B or C. Conclusions The NNDs in type A SCFC usually experienced better recovery even with high S-DARs. Type B SCFC with an S-DAR >20° and type C SCFC with any S-DAR resulted in significantly greater intra- and postoperative neurologic risks. The combination of SCFC and S-DAR can further stratify the intra- and postoperative neurologic risks with these procedures.

BACKGROUND The use of posterior vertebral column resection (PVCR) has extended the treatment of severe spinal deformity. However, the practice guidelines for anterior column support in patients treated by PVCR remain ill defined. The objective of the present study was to compare the clinical and radiographic outcomes of severe thoracic spinal deformity treated by PVCR with and without anterior column support (ACS). METHODS We performed a prospective study of 57 patients with severe thoracic deformity (classified as Yang's A type) treated by PVCR with or without anterior column support from January 2010 to April 2015. The patient characteristics, radiographic parameters, intraoperative data, and complications were analyzed to clarify these 2 clinical series. RESULTS The sex, age, diagnosis, curve magnitude, and curve type were similar between the PVCR with ACS group (n = 21) and non-ACS group (n = 36) preoperatively. Evaluation of the radiographic parameters, intraoperative data, and complications found no statistically significant intergroup differences, except for the osteotomy distance (non-ACS group, 4.0 cm; ACS group, 5.3 cm; P < 0.001) and shortening distance of the osteotomy gap (non-ACS group, 4.0 cm; ACS group, 3.5 cm; P = 0.005). CONCLUSIONS The results of the present study have shown that PVCR without ACS seems to be a safe and effective technique for Yang's A type severe thoracic spinal deformity correction compared with PVCR with ACS. PVCR without ACS requires a relatively smaller osteotomy range and could potentially decrease the risk of implant failure due to bone to bone fusion.

STUDY DESIGN Retrospective analysis. OBJECTIVE To evaluate whether radiologic parameters affect spine surgeon's osteotomy choice in patients with severe and stiff thoracic kyphoscoliosis. SUMMARY OF BACKGROUND DATA Three-column osteotomies were developed to address severe and stiff kyphoscoliosis. Current choice on osteotomies is based on the morphology of kyphosis, global balance, and locations of the main curvature; however, quantitative basis for decision making is still lacking. METHODS Sixty patients with severe and stiff thoracic kyphoscoliosis who underwent three-column osteotomy in the thoracic spine were classified into four groups according to the grade of osteotomy. The radiologic parameters including maximum scoliosis, maximum kyphosis, deformity angular ratio (DAR; maximum Cobb angle divided by number of vertebrae involved), apical vertebral translation, coronal balance, and sagittal balance were measured and compared. Correlation analysis between the radiologic parameters and the osteotomy grades was conducted. Perioperative and long-term complications were reviewed. RESULTS The overall scoliosis was corrected from a mean preoperative Cobb angle of 129.1° (range, 90-174°) to 56.4° (range, 14-100°), and overall kyphosis was corrected from 124.3° (range, 64-180°) to 54.3° (range, 11-95°). As the osteotomy grades increased, the mean preoperative maximum kyphosis increased from 104.5° to 151.8° and the mean sagittal DAR (S-DAR) increased from 16.4 to 24.9. Statistically significant between-group differences were found for preoperative maximum kyphosis (P = 0.001), S-DAR (P = 0.045), and total DAR (P = 0.033). Significant correlations were observed between the preoperative maximum kyphosis and the osteotomy grade (r = 0.454, P

STUDY DESIGN Retrospective study. OBJECTIVES This study is to measure and analyze the changes of three-dimensional (3D) distances of spinal column and spinal canal at the three-column osteotomy sites and address their clinical and neurologic significance. SUMMARY OF BACKGROUND DATA Three-column osteotomies were developed to treat severe and stiff spine deformities with insufficient understanding on the safe limit of spine shortening and the relationship between the shortening distance of the spinal column and that of the spinal canal. METHODS Records of 52 continuous patients with severe and stiff scoliosis treated with three-column spine osteotomies at our institution from July 2013 to June 2015 were reviewed. The preoperative spinal cord function classification were type A in 31 cases, type B in 10 cases, and type C in 11 cases. The types of osteotomies carried out were extended pedicle subtraction osteotomy in nine patients and posterior vertebral column resection in 43 patients. Multimodality neuromonitoring strategies were adopted intraoperatively. 3D pre- and postoperative spine models were reconstructed from the computed tomography (CT) scans. The distances of convex and concave spinal column and the spinal canal shortening were measured and analyzed. RESULTS The spinal column shortening distance (SCSD) measured on the 3D models (27.8 mm) were statistically shorter than those measured intraoperatively (32.8 mm) (P

Introduction This prospective study was to investigate the successful rate of intraoperative motor evoked potentials (MEP) monitoring for children (0.05). As well, no difference in MEP successful rates was observed in two groups with different anesthetic techniques. No wake-up test and no post-operative neurological deficits occurred in this series of patients. Conclusion Low dose anesthesia by either TIVA with propofol or sevoflurane-based mixture anesthesia protocol can help the intraoperative spinal cord monitoring to successfully elicit MEP and perform reliable monitoring for patients below 12 years of age. © 2011 Springer-Verlag., published_or_final_version

Spinal cord function classification systems are not useful for guiding surgery in patients with severe spinal deformities. The aim of this study is to propose a classification system for determining a surgical strategy that minimizes the risk of neurological dysfunction in patients with severe spinal deformities. The records of 89 patients with severe spinal deformities treated with vertebral column reconstruction from 2008 to 2013 were retrospectively analyzed. Based on neurophysiological monitoring, magnetic resonance imaging, and neurological symptoms patients were categorized into three groups: group A, normal spinal cord, normal evoked potentials and no neurological symptoms; group B, spinal cord abnormalities and/or abnormal evoked potentials but no neurological symptoms; group C, neurological symptoms with or without spinal cord abnormalities/abnormal evoked potentials. Outcomes and complications were compared between the groups. A total of 89 patients (51 male, 38 female) were included with 47 (52.8 %), 16 (18.0 %), and 26 (29.2 %) patients in groups A, B and C, respectively, and a mean follow-up 34.5 months. There were no differences in age, gender, average preoperative scoliosis, and kyphosis among three groups, but there were differences with respect to the causes of severe spinal deformity and the corrective rate of scoliosis and kyphosis. Changes in intraoperative evoked potentials were different in these three types according to this new classification, and the recovery rates of changes in the three groups were 71.1, 50.0, and 14.1 %, respectively. Postoperative spinal cord injury was positively related to intraoperative changes of evoked potentials. The classification system may be useful for guiding surgical decisions in patients with severe spinal deformities to minimize the risk of neurological complications.

Objectives: This study sought to evaluate left ventricular, right ventricular, and left atrial mechanics and their interactions in patients with congenital scoliosis without clinical heart failure.Methods: A total of 23 patients with a median age of 14 years and a median Cobb’s angle of 61° were studied. Ventricular and atrial myocardial deformation was measured using speckle tracking echocardiography. The results of the patients were compared with 22 controls.Results: Compared with controls, the patients had a significantly greater annular a velocity (p=0.04) and lower e/a ratio (p=0.03); the left ventricular deformation significantly decreased in radial global (p=0.04) and segmental systolic strain and early diastolic strain rate (p=0.03); the left atrial deformation showed a significantly lower positive strain (p=0.02), greater negative strain (p=0.01), and active contractile strain rate (p=0.01). For the patients, the Cobb’s angle was negatively correlated with the left ventricular global radial systolic strain (r=−0.65, p=0.001), left atrial positive strain (r=−0.68, pConclusions:Impaired left ventricular and altered left atrial mechanics occur relatively early in patients with congenital scoliosis, and are correlated with the severity of their scoliosis. Our findings provide evidence of preclinical heart dysfunction in patients with this disorder.

STUDY DESIGN Report of a new technique. OBJECTIVE We describe a new technique of double-curve synchronous derotation with convex correction for double-major adolescent idiopathic scoliosis (AIS) and is highlighted through illustrative cases. SUMMARY OF BACKGROUND DATA Rotational deformity is a significant component of scoliosis, which causes a secondary rib hump, and adversely affects patients' psychological and social well-being, and long-term functional results. For AIS, direct vertebral rotation is confirmed as a better and effective method for apical rotational correction and rib hump improvement than rod rotation technique, avoiding the need for an adjuvant thoracoplasty. However, this technique is mainly applied to Lenke I type thoracic curves with derotation of the main curve. There are no reports applying this technique in double-major scoliosis. OPERATIVE TECHNIQUE With the patient lying prone, a standard posterior incision exposure and segmental screws placement was performed, 2 vertebral column manipulator devices were installed on the apical region of both curves, then both curves were synchronously derotated and following convex correction at both the curves, the concave rods were secured in situ. RESULTS There were 11 double-curve cases divided into 3 groups: double-curve derotation group (A group, 3 cases), single-curve derotation group (B group, 4 cases), and rod derotation group (C group, 4 cases); all cases had minimum 2-year follow-up. Three illustrative cases corrected by double-curve synchronous derotation with convex correction are presented with better apical rotational and correction in thoracic and lumbar curves than single-curve derotation and rod derotation cases. The mean apical derotational corrective rates were 95.3%, 46.7%, and 38.8% in the lumbar curve, 66%, -35.1%, and -38.9% in thoracic curve. The 3-dimensional correction was maintained at a minimum 2-year follow-up. CONCLUSIONS Double-curve synchronous derotation with convex correction is a safe and effective technique for rotational and coronal correction in AIS with double curves, which can avoid apical rotation aggravation in minor curve induced by major curve derotaion.

Background Although it is speculated that scoliosis may induce cardiac dysfunction, there is no report about evaluation of cardiac function, especially right cardiac function in patients with scoliosis. Therefore, we evaluated right ventricular function in idiopathic scoliotic patients with mild to severe curves and compared them with healthy children and adolescents matched in age, then explored relationship between scoliosis and right ventricular function. Methods Thirty-seven patients diagnosed with idiopathic scoliosis with a mean age of 16y/o (range, 8-25y/o) and an average spine curve of 77.5°Cobb (range, 30-157°) were studied by echocardiography. TAD was obtained using M-mode echocardiography. Similar examination was performed in a control group of 17 healthy individuals in matched-age. According to the different curve degree, all patients were divided into 3 groups (mild, moderate and severe). Comparison was done among the groups and the relationship between TAD and spine curve of Cobb was analyzed. Results Patients with severe scoliosis showed depressed TAD. There was good correlation between TAD and spine curve of Cobb. Conclusions Patients with severe scoliosis showed a significant lower right ventricular systolic function.

Longer spinal fusions have been shown to result in improved deformity correction; however, loss of normal flexibility in the fusion area should not be ignored. Current consensus was to achieve a shorter fusion in primary surgery, with the goal of preserving as much of the distal motion segment as possible. However, the correlation between the length of fusion and functional outcome remains controversial. To the best of our knowledge, a previous study has demonstrated the function outcomes and the differences in HRQoL with specific fusion levels. In this cross-sectional study, 172 patients (mean age, 17.8 y) with idiopathic scoliosis treated by spinal fusion (mean time since surgery, 29.7 mo) were included to measure lumbar spine mobility and quality of life using validated outcome instruments in the study population. Patients were assigned to 5 groups according to the lower instrumented vertebra (LIV) level: group A (fusion above L2) 26 patients; group B (fusion to L2) 21 patients; group C (fusion to L3) 46 patients; group D (fusion to L4) 53 patients; and group E (fusion to L5) 26 patients. At each follow-up, patients were asked to complete the Scoliosis Research Society 22 (SRS-22) Questionnaire. Lumbar mobility was assessed using a dual digital inclinometer. Average spinal range of motion (ROM) was 41.4 degrees (SD, 20.7), forward flexion was 29.2 degrees (SD, 15.0), and backward extension was 12.2 degrees (SD, 9.5). The total spinal range of motion and forward flexion dropped noticeably as the LIV got more distal. Statistically significant between-group differences (1-way ANOVA) were found for ROM (P