Comparison of the efficacy of thoracolumbosacral and lumbosacral orthosis for adolescent idiopathic scoliosis in patients with major thoracolumbar or lumbar curves: a prospective controlled study.

Introduction: Thoracolumbosacral orthosis (TLSO) is the most commonly used type of brace for the conservative treatment of adolescent idiopathic scoliosis (AIS). Although lumbosacral orthosis (LSO) is designed to correct single thoracolumbar or lumbar (TL/L) curves, its effectiveness remains underexplored. This novel article aims to compare the effectiveness of LSO with TLSO in treating AIS with main TL/L curves. Methods: This prospective controlled cohort study enrolled patients with AIS with main TL/L curves and minor thoracic curves who were treated with either TLSO or LSO. Demographic and radiographic data were compared between the two groups. Treatment outcomes were also assessed. Risk factors for minor curve progression were identified, and a cut-off value was determined within the LSO group. Results: Overall, 82 patients were recruited, including 44 in the TLSO group and 38 in the LSO group. The initial TL/L curves showed no difference between both groups. However, the baseline thoracic curves were significantly larger in the TLSO group compared to the LSO group (25.98° ± 7.47° vs. 18.71° ± 5.95°, P < 0.001). At the last follow-up, LSO demonstrated similar effectiveness to TLSO in treating TL/L curves but was less effective for thoracic curves. The initial magnitude of thoracic curves was identified as a risk factor for minor curve outcomes in the LSO group. The ROC curve analysis determined a cut-off value of 21° for thoracic curves to predict treatment outcomes. Discussion: In contrast to TLSO, LSO exhibits comparable effectiveness in treating main TL/L curves, making it a viable clinical option; however, it is less effective for thoracic minor curves. The initial magnitude of the minor thoracic curves may guide the selection of the appropriate brace type for patients with AIS with main TL/L curves.

Descending Neurogenic Evoked Potentials Monitoring Is an Effective Alternative in Spinal Deformity Surgery Under Inhaled Anesthesia.

BACKGROUND: To evaluate the reliability of descending neurogenic evoked potentials (DNEP) monitoring in spinal deformity surgery under inhaled anesthesia. METHODS: A total of 180 consecutive patients who underwent spinal deformity surgery in our scoliosis center from July 2014 to August 2016 were reviewed. Intraoperative monitoring including somatosensory evoked potentials (SEP), motor evoked potentials (MEP), and DNEP was conducted routinely throughout operation. Patients were divided into 2 groups according to anesthesia methods: group A (n = 72, inhaled anesthesia, SEP/DNEP) and group B (n = 108, total intravenous anesthesia, SEP/MEP/DNEP). Intraoperative monitoring data were collected and analyzed. RESULTS: Positive alerts were observed in 26 patients (14.5%), of whom 18 (10%) were confirmed as true-positive events in the study population. No false-negative events were recorded. In group A, the sensitivity and specificity of SEP and DNEP were 100% and 93.8% and 100% and 98.5%, respectively. For group B, the sensitivity and specificity of SEP/MEP and DNEP were 100% and 95.9% and 100% and 98%, respectively. CONCLUSIONS: DNEP monitoring seemed to be effective for the detection and prevention of iatrogenic neurologic deficits during spinal deformity surgery. This study indicates that DNEP was an effective alternative in spinal deformity surgery under inhaled anesthesia.

Type 3 bone-disc-bone osteotomy (grade 4+ osteotomy) combined with presurgical halo-pelvic traction: a safe and effective solution to correct severe angular-like kyphoscoliosis.

Background: Treatment of severe angular-like kyphoscoliosis is a technically demanding surgical challenge and requires high-risk spinal osteotomy, such as vertebral column resection. Preoperative halo-pelvic traction is commonly used to decrease the curve magnitude. However, few studies have utilized the potent method of bone-disc-bone osteotomy, which could theoretically provide correction up to 60°. This study aimed to evaluate the safety and effectiveness of type 3 bone-disc-bone osteotomy combined with presurgical halo-pelvic traction to correct severe angular-like kyphoscoliosis. Methods: This was a retrospective cohort study. Patients with severe angular-like kyphoscoliosis who underwent presurgical halo-pelvic traction and type 3 bone-disc-bone osteotomy from January 2017 to December 2019 were consecutively reviewed. Patient demographics and clinical data were recorded. The coronal and sagittal Cobb angles were measured preoperation, post-traction, post-operation, and at the final follow-up. Complications were also recorded. Patients' health-related quality of life was evaluated by the Scoliosis Research Society 22 (SRS-22) questionnaire. Paired Student's t test and one-way analysis of variance were used for comparisons among different groups. Results: Thirty patients (18 females and 12 males) with an average age of 20.2 years (range, 13-33 years) were included. The mean preoperative coronal and sagittal Cobb angles were 123.1°±16.4° (range, 90°-155°) and 120.3°±19.9° (range, 90°-156°), respectively. After 2.9±0.7 months (range, 2-4 months) of halo-pelvic traction, the coronal and sagittal Cobb angles decreased significantly to 81.9°±13.2° and 76.0°±12.6°, respectively. Postoperatively, the scoliotic and kyphotic angles further decreased to 42.4°±12.2° and 33.9°±8.8°, respectively. After a mean follow-up of 2.93±1.05 years, the correction rates were maintained at 64.3%±10.6% and 70.5%±6.3%, respectively. Nine patients experienced positive evoked potential events during surgery. Common complications after surgery included transient lower extremity weakness, pneumonia, and pleural effusion. The self-image scores were significantly improved from 2.66±0.27 to 3.36±0.23 compared to preoperation. Conclusions: This study proposes a novel strategy to correct severe angular-like spinal deformities. The combination of presurgical halo-pelvic traction and type 3 bone-disc-bone osteotomy (grade 4+ osteotomy) achieves substantial correction and satisfactory aesthetic outcomes without serious complications.

The asymmetrical ESR1 signaling in muscle progenitor cells determines the progression of adolescent idiopathic scoliosis.

Adolescent Idiopathic Scoliosis (AIS) is a common pediatric skeletal disease highly occurred in females. The pathogenesis of AIS has not been fully elucidated. Here, we reveal that ESR1 (Estrogen Receptor 1) expression declines in muscle stem/progenitor cells at the concave side of AIS patients. Furthermore, ESR1 is required for muscle stem/progenitor cell differentiation and disrupted ESR1 signaling leads to differentiation defects. The imbalance of ESR1 signaling in the para-spinal muscles induces scoliosis in mice, while reactivation of ESR1 signaling at the concave side by an FDA approved drug Raloxifene alleviates the curve progression. This work reveals that the asymmetric inactivation of ESR1 signaling is one of the causes of AIS. Reactivation of ESR1 signaling in para-spinal muscle by Raloxifene at the concave side could be a new strategy to treat AIS.

How to select the lowest instrumented vertebra in NF-1 non-dystrophic scoliosis.

PURPOSE: To investigate lowest instrumented vertebra (LIV) selection strategy for neurofibromatosis type 1 (NF-1) non-dystrophic scoliosis. METHODS: Consecutive eligible subjects with NF-1 non-dystrophic scoliosis were included. All patients were followed up at least for 24 months. Enrolled patients with LIV in stable vertebra were divided into stable vertebra group (SV group), and the other patients with LIV above the stable vertebra were divided into above stable vertebra group (ASV group). Demographic data, operative data, preoperative and postoperative radiographic data, and clinical outcome were collected and analyzed. RESULTS: There were 14 patients in SV group (ten males and four females, mean age 13.9 ± 4.1 years) and 14 patients in ASV group (nine males and five females, mean age 12.9 ± 3.5 years). The mean follow-up period was 31.7 ± 17.4 months for patients in SV group and 33.6 ± 17.4 months for patients in ASV group, respectively. No significant differences were found in demographic data between two groups. The coronal Cobb angle, C7-CSVL, AVT, LIVDA, LIV tilt and SRS-22 questionnaire outcome significantly improved at the final follow-up in both groups. However, significantly higher loss of correction rate and increasement of LIVDA were found in ASV group. Two patients (14.3%) in ASV group but none in SV group suffered adding-on phenomenon. CONCLUSIONS: Although patients in both SV and ASV groups obtained improved therapeutic efficacy at final follow-up, the radiographic and clinical outcome seemed more likely to deteriorate in ASV group after surgery. The stable vertebra should be recommended as LIV for NF-1 non-dystrophic scoliosis.

Intensive bracing management combined with physiotherapeutic scoliosis-specific exercises for adolescent idiopathic scoliosis patients with a major curve ranging from 40-60° who refused surgery: a prospective cohort study.

BACKGROUND: Current guidelines for brace management of adolescent idiopathic scoliosis (AIS) are mostly recommended for curves between 25° to 40°. For AIS patients with curves >40°, surgery is often considered since bracing may be less effective; however, there are still some patients and families who refuse operation. Therefore, further research is necessary to determine optimal bracing management in this group. To date, few protocols for such have been reported in literature. AIM: The aim of this study was to introduce and evaluate the effectiveness of the treatment protocol comprising of intensive bracing management and physiotherapeutic scoliosis-specific exercises (PSSE) in AIS patients with a major curve of 40-60° who refuse surgery. DESIGN: This is a prospective cohort study. SETTING: The study was carried out in an outpatient clinic. POPULATION: 10-18-year-old AIS patients having 40-60°curves and a Risser grade of 0-3, but firmly refusing surgery were eligible. Patients who had a proximal thoracic curve or had undergone any other form of treatment previously were excluded from the study. METHODS: A total of 82 patients were recruited and received the treatment. The primary outcome was defined as "success" when the main curve was below 50° upon reaching skeletal maturity, and "failure" if otherwise. The secondary outcome was defined as improved (>5° reduction), unchanged (≤5° change) or progressed (>5° increase) based on the evolution of the main curve. The per protocol (PP) and intent to treat (ITT) analyses were performed to quantify success rates, while the dropouts were considered as failures. Risk factors associated with bracing failure were identified and a receiver operating characteristic (ROC) curve was used to determine the cut-off value. RESULTS: A total of 77 patients completed the treatment, while 5 dropped out. The average main curve was 47.40±5.93° at baseline and 38.56±11.85° at last follow-up (P<0.001). Our management was successful in 83% and 78% of patients based on the PP and ITT analyses, respectively. When compared with the curve magnitude at baseline, 65% patients improved, 30% remained unchanged, and 5% progressed when using a 5° threshold. Univariate comparison and logistic regression analysis demonstrated that patients with successful outcomes had a significantly smaller baseline curve, larger Risser Stage, and larger in-brace correction (IBC) rate. CONCLUSIONS: For AIS patients with 40-60° curves who refused surgery, our intensive bracing management along with PSSE was practical and effective, achieving success in 78% of patients based on an ITT analysis. A larger baseline curve, smaller Risser Stage, and smaller IBC rate were associated with treatment failure. CLINICAL REHABILITATION IMPACT: Our intensive management provides new insights into improving the effectiveness of bracing in patients with AIS who refuse surgery. This is a promising option for patients with 40-60° curves, since their scoliosis may be treated using a non-surgical technique instead of surgery in the future.

One-stage Spine-shortening Osteotomy Treated Severe Spinal Deformity Associated With Spinal Cord Malformations.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To evaluate the safety and efficacy of spine-shortening using 1-stage 3-column osteotomy for a severe rigid spinal deformity with a spinal cord malformation (SCM). SUMMARY OF BACKGROUND DATA: One-stage spine-shortening osteotomy has been suggested for the treatment of a tethered spinal cord. However, the safety and efficacy of 1-stage spine-shortening osteotomy for the treatment of a severe spinal deformity with an SCM is not known. METHODS: The records of 32 patients with a severe spinal deformity and SCM treated with spine-shortening using 3-column osteotomy from January 2010 to December 2016 were analyzed retrospectively. Intraoperative neurophysiological monitoring was used in all cases. Imaging parameters and neurological complications were analyzed to evaluate clinical safety and efficacy. RESULTS: Spine-shortening using a 3-column osteotomy was conducted successfully in all 32 patients. The mean main coronal curve and maximum kyphotic angle were corrected from 119.8 and 119.1 degrees to 58.6 and 53.9 degrees, respectively, with the corrective rate of 51.4% and 54.3%. The mean correction loss of the major coronal curve and maximum kyphosis was 2.3 and 2.6 degrees, respectively, at a mean follow-up of 73.6 months. Intraoperative monitoring events occurred in 9 patients; of these 9 patients, 3 suffered transient SC injury, and all recovered within 1 year without suffering permanent paralysis. CONCLUSIONS: Spine-shortening using a 3-column osteotomy seems to be safe and efficacious for treating a severe spinal deformity with an SCM. A deep understanding of the method and intensive intraoperative neuromonitoring improved the safety of this challenging and complex surgical procedure.

Efficacy of Halo-Gravity Traction in the Perioperative Treatment of Severe Scoliosis and Kyphosis: A Comparison of Adolescent and Adult Patients.

OBJECTIVE: 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. METHODS: 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 (age >18 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. RESULTS: 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 (P < 0.05), while the correction rate of the main curve and kyphosis was significantly higher in the adolescent group than that in the adult group (P < 0.05). 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. CONCLUSIONS: 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.

Intraoperative Neuromonitoring Auxiliary Significance of DNEP for MEP-positive Event During Severe Spinal Deformity Surgery.

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.

How to select the lowest instrumented vertebra in Lenke 5/6 adolescent idiopathic scoliosis patients with derotation technique.

PURPOSE: To introduce and evaluate our lowest instrumented vertebra (LIV) selection criteria for Lenke type 5/6 adolescent idiopathic scoliosis (AIS) patients with de-rotation technique. METHODS: There were 53 eligible Lenke 5/6 AIS patients with minimum 2-year follow-up enrolled in current study. The LIV selection criteria were: (1) the first vertebra touching the central sacral vertical line (CSVL) or the most cephalad vertebra which can return to stable zone under lateral bending position; (2) vertebral rotation no more than grade II by Nash-Moe rotation evaluation; (3) the lowest instrumented vertebra disc angle (LIVDA) could be reversed on lateral bending position. Demographic data, operation data and radiographic data were obtained and analyzed. RESULTS: Both clinical evaluation and radiographic data showed satisfactory outcome. The thoracolumbar/lumbar curve was improved from 53.4 ± 11.0° preoperatively to 6.9 ± 2.6° at the final follow-up. Two patients (3.8%) with adding on and two patients (3.8%) with coronal decompensation were identified at the final follow-up. LIV translation, LIV tilt and LIV disc angle were gradually improved after operation. The preoperative LIV tilt was positively correlated with Cobb angle (p = 0.010) and AVT (p = 0.030) at the final follow-up, and preoperative LIVDA was positively correlated with Cobb angle (p = 0.033) at the final follow-up. CONCLUSION: In Lenke 5/6 scoliosis, the current LIV selection criteria with de-rotation technique contribute to satisfactory correction rate of 87.1% and minimal alignment complications of 7.6%. LIV could be spontaneously and progressively improved after operation. Preoperative LIV tilt and LIVDA could predict postoperative correction and coronal balance.

Efficacy and safety for combination of t-EMG with O-arm assisted pedicle screw placement in neurofibromatosis type I scoliosis 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.

Quantitative determining of pre-operative osteotomy plan for severe spinal deformity: an analysis of 131 consecutive Yang's A type cases from single center.

PURPOSE: This study aimed to quantify osteotomy protocol for severe spinal deformity correction based on pre-operative demographic, clinical and radiologic parameters. METHODS: A total of 131 Yang's A type severe spinal deformity patients were included. All patients received one of following osteotomies: Ponte/2 (Ponte osteotomy/Grade 2 osteotomy, n = 30), PSO/3 (pedicle subtraction osteotomy/Grade 3 osteotomy, n = 19), BDBO/4 (bone-disc-bone osteotomy/Grade 4 osteotomy, n = 26), SVCR/5 (single-level vertebral column resection/Grade 5 osteotomy, n = 38) and MVCR/6 (multilevel vertebral column resection/Grade 6 osteotomy, n = 18). Demographic, clinical and radiologic characteristics were compared among groups. RESULTS: Tukey's test identified 6 significant variables between paired groups: age for MVCR/6 versus Ponte/2 + PSO/3 + BDBO/4 + SVCR/5 groups; bending Cobb angle for Ponte/2 versus MVCR/6; sagittal deformity angular ratio (S-DAR) for Ponte/2 + PSO/3 versus BDBO/3 + SVCR/5 versus MVCR/6; pre-operative scoliosis for Ponte/2 versus SVCR/5; total-DAR (T-DAR) and pre-operative kyphosis for Ponte/2 + PSO/3 versus BDBO/4 + SVCR/5 + MVCR/6. Receiver Operating Characteristic (ROC) analysis showed the Area under the Curve (AUC) for the 6 variables ranged from 0.69 to 0.839. Multivariate k-means clustering analysis showed that Ponte/2 + PSO/3, BDBO/4 + SVCR/5, and MVCR/6 were three comparatively significant clusters, which could be discriminated by pre-operative kyphosis, T-DAR, age and S-DAR. CONCLUSION: This study showed that osteotomy plan of severe spinal deformity could be determined as follows: Firstly, Ponte/2 + PSO/3 and BDBO/4 + SVCR/5 + MVCR/6 groups can be divided by either T-DAR (cutoff = 28) or the Cobb angle of pre-operative maximum kyphosis (cutoff = 100). Secondly, Ponte/2 + PSO/3 group could be further dichotomized into Ponte/2 and PSO/3 by age (cutoff = 18). Finally, BDBO/4 + SVCR/5 + MVCR/6 group could be divided into BDBO/4 + SVCR/5 and MVCR/6 groups by S-DAR (cutoff = 20).

The radiographic, pulmonary, and clinical outcomes of patients with severe rigid spinal deformities treated via halo-pelvic traction.

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 < 0.001); the mean percentage corrections were 16.50 ± 2.13 and 44.09 ± 9.78 % (P < 0.001). A significant difference in the pulmonary function test results was apparent between the two groups; the mean improvements in the FVC% of the HGT and HPT groups were 6.76 ± 1.85 and 15.6 ± 3.47 % (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.

Risk and Predictive Factors for Proximal Junctional Kyphosis in Patients Treated by Lenke Type 5 Adolescent Idiopathic Scoliosis Correction.

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.

Risk factors for neurological complications in severe and rigid spinal deformity correction of 177 cases.

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.

A Retrospective Study of Surgical Correction for Spinal Deformity with and without Osteotomy to Compare Outcome Using Intraoperative Neurophysiological Monitoring with Evoked Potentials.

BACKGROUND This study aimed to evaluate the effects of different combined evoked potentials monitoring modes for non-osteotomy and osteotomy surgery of spinal deformity, and to select individualized modes for various surgeries. MATERIAL AND METHODS We retrospectively reviewed a total of 188 consecutive cases undergoing spinal deformity correction. All patients were classified into 2 cohorts: non-osteotomy (Group A) and osteotomy (Group B). According to intraoperative evoked potential monitoring mode, Group A was divided into 2 sub-groups: A1 [spinal somatosensory evoked potential (SSEP)/motor evoked potential (MEP), n=67)] and A2 [SSEP/MEP/descending neurogenic evoked potential (DNEP), n=52]. Group B was classified as B1 (SSEP/MEP, n=27) and B2 (SSEP/MEP/DNEP, n=42). The demographics, surgical parameters, and evoked potential events of different combined monitoring modes were analyzed within each group. RESULTS The baselines of SSEP/MEP/DNEP in all cases were elicited successfully. Three cases with evoked potential (EP) events (2 with MEP changes and 1 with SSEP/MEP change) were noted in Group A1 and 1 with SSEP change in Group A2, with no neurological complications. Thirteen cases in Group B1 were positive for MEP intraoperatively, including 16 EP events (13 with MEP change and 3 with both SSEP+MEP changes), with no neural complications. In Group B2, 15 cases had 21 EP events, including 12 with MEP change and 2 with SSEP+MEP changes, with no complications. Postoperative neurological complications were observed in 5 of the 7 cases with SS4EP/DNEP changes. CONCLUSIONS Intraoperative simultaneous SSEP/MEP can effectively reflect neurological function in non-osteotomy spinal surgery patients. Simultaneous SSEP/MEP/DNEP can effectively avoid the unnecessary interference by false-positive results of MEP during osteotomy.

Fiber Type-Specific Morphological and Cellular Changes of Paraspinal Muscles in Patients with Severe Adolescent Idiopathic Scoliosis.

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.

Development and validation of deep learning algorithms for scoliosis screening using back images.

Adolescent idiopathic scoliosis is the most common spinal disorder in adolescents with a prevalence of 0.5-5.2% worldwide. The traditional methods for scoliosis screening are easily accessible but require unnecessary referrals and radiography exposure due to their low positive predictive values. The application of deep learning algorithms has the potential to reduce unnecessary referrals and costs in scoliosis screening. Here, we developed and validated deep learning algorithms for automated scoliosis screening using unclothed back images. The accuracies of the algorithms were superior to those of human specialists in detecting scoliosis, detecting cases with a curve ≥20°, and severity grading for both binary classifications and the four-class classification. Our approach can be potentially applied in routine scoliosis screening and periodic follow-ups of pretreatment cases without radiation exposure.

Multimodality Intraoperative Neuromonitoring in Severe Thoracic Deformity Posterior Vertebral Column Resection Correction.

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.

Surgical Outcome Comparison of Posterior Vertebral Column Resection with or without Anterior Column Support in Treatment of Yang's Type A Severe Thoracic Spinal Deformity.

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.