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Background: The presence of bridging syndesmophytes (BS) in spinal osteotomy region serves traditionally as one critical determinant for selection of osteotomy techniques. While nowadays the proportion of kyphotic ankylosing spondylitis (AS) patients receiving pedicle subtraction osteotomy (PSO) with yet mobile neighboring disc has seen a substantial increase. Literatures investigating the clinical relevance of the presence of BS on kyphosis correction and maintenance following PSO are scarce.Methods: A total of 71 thoracolumbar kyphotic AS patients treated with single-level PSO at our hospital between September 2010 and August 2014 were retrospectively reviewed, 32 of whom were stratified into the BS group (BG). The operative corrections of multiple spino-pelvic sagittal parameters were assessed. Comparison of the contribution of adjacent disc wedging to total correction per PSO segment was made between the BS and non-BS groups (NBG). The correction loss were also evaluated and compared with a minimum 2-year follow-up.Results: A significantly younger age (30.97 ± 8.28 vs. 40.31 ± 8.44 yrs., p < 0.001), smaller pelvic incidence (PI) (43.03 ± 10.60 vs. 49.36 ± 9.75°, p = 0.011), greater wedging index of osteotomized vertebra (1.17 ± 0.16 vs. 1.09 ± 0.08, p = 0.011) and larger local kyphosis (19.59 ± 10.84 vs. 13.56 ± 8.50°, p = 0.013) was observed in NBG preoperatively. Patients in BG and NBG accomplished comparable amount of kyphosis correction per PSO segment (40.22 ± 7.09 vs. 43.85 ± 8.71°, p = 0.062). However, the contribution of adjacent disc wedging to total correction per PSO was significantly larger in NBG [8.10 ± 6.19 (18.5%) vs. 1.09 ± 2.88° (2.7%), p < 0.001]. By ultimate follow-up, the global kyphosis (18.26 ± 10.97 vs. 21.51 ± 10.89°, p < 0.05) and thoracic kyphosis (37.95 ± 11.87 vs. 42.87 ± 11.56°, p < 0.05) deteriorated significantly in the NBG but not BG, so was further pelvic retroversion as represented by increased pelvic tilt (19.46 ± 8.13 vs. 23.44 ± 8.19°, p < 0.05) and decreased sacral slope (23.02 ± 9.12 vs. 18.62 ± 10.10°, p < 0.05). Loss of corrections concerning contribution of adjacent disc wedging was also larger in NBG (1.41 ± 3.27 vs. 0.22 ± 1.49°, p < 0.05).Conclusions: Our study might suggest that the evaluation and treatment methods of kyphotic AS patients needed to be fine-tuned with appropriate subgrouping by the presence of syndesmophytes with bamboo sign as they were potentially distinct groups with different PI, contributor of lordosing capability and prognosis that might require separate analysis. [ABSTRACT FROM AUTHOR]

Purpose: The cartilage oligomeric matrix protein (COMP) was reported to be down-regulated in adolescent idiopathic scoliosis (AIS). The purposes of the study were to evaluate the roles of COMP promoter methylation on the abnormal gene expression and the epigenetic phenotype in AIS.Methods: DNA samples of 50 AIS patients and 50 healthy controls were analyzed. Five CpG sites of COMP gene were amplified and sequenced using the polymerase chain reaction (PCR) and the pyrophosphate sequencing technology, while the COMP gene expression was evaluated using real-time PCR. Comparisons were analyzed with the Chi-square test and independent t test. Pearson coefficients of correlation were used to evaluate the association between gene methylation and clinical phenotypes.Results: The average COMP gene promoter methylation of the AIS and control groups was 12.26 ± 2.36 and 8.76 ± 1.94 (p < 0.0001), and correspondingly the relative expression of COMP gene expression was 0.52 ± 0.12 and 1.16 ± 0.52 (p < 0.001), respectively. The correlation analysis showed significantly negative correlation between methylation level and gene expression (p < 0.0001). The comparison analysis between AIS patients with positive and negative methylation showed significant difference in chronological age (p < 0.001) and Cobb angle of main curve (p = 0.011). The methylation level of the COMP promoters was significantly correlated with Cobb angle of main curve and age (p < 0.0001) among the five CpG sites.Conclusions: AIS patients had significantly high COMP promoter methylation and low gene expression. Positive and high COMP promoter methylation was correlated with young age and high Cobb angle of main curve. Therefore, COMP gene promoter methylation may provide significant prognostic information in predicting the susceptibility and curve progression of AIS. [ABSTRACT FROM AUTHOR]

Background: Short-term studies have demonstrated good surgical outcomes after pedicle subtraction osteotomy (PSO) in ankylosing spondylitis (AS) patients, but there is a paucity of literature focused on middle-term results, especially regarding patterns of loss of correction. The objective of this study is to assess the durability of surgical outcomes and the patterns of loss of correction in thoracolumbar kyphosis secondary to AS following lumbar PSO with over 5-year follow-up.Methods: We performed a retrospective review of 155 consecutive AS patients undergoing lumbar PSO from January 2001 to December 2011. Twenty-four patients were included with an average follow-up of 6.9 years (range, 5-15 years). Radiographical evaluations included global kyphosis (GK), lumbar lordosis (LL), sagittal vertical axis, spinal-sacral angle, kyphosis of proximal non-fused segments (KPNS), angle of fused segments (AFS), osteotomized vertebra angle (OVA), distal intervertebral disc wedging (DIDW) and proximal junctional angle. Meanwhile, clinical outcomes were assessed by the Oswestry disability index (ODI) and Numerical rating scale (NRS).Results: The average correction per PSO segment was 34.9°. Significant improvement in sagittal parameters were found postoperatively, and no obvious deterioration was noticed during the follow-up. Mild loss of correction in GK (2.82°) and LL (3.77°) were observed at the final follow-up (P < 0.05). The KPNS and DIDW increased from 26° and -5.0° postoperatively to 30° and -2.2° at the final follow-up (P < 0.05), respectively. In contrast, no significant diminishment was identified in OVA and AFS (P > 0.05). The ODI and NRS improved significantly from 20.6 and 6.6 preoperatively to 5.9 and 2.3 at the final follow-up (P < 0.05).Conclusions: PSO is an effective procedure for treating AS-related thoracolumbar kyphosis and can maintain sustained surgical outcomes during the middle-term follow-up. The loss of correction was mainly attributable to non-instrumented segments without fully ossified bridging syndesmophyte in the thoracolumbar region instead of instrumented levels. [ABSTRACT FROM AUTHOR]

Study Design: A computed tomography study. Objective: To identify the best scoliotic deformity components that show impact upon the spontaneous postoperative modulation of the deformed anterior chest wall contour in right convex thoracic adolescent idiopathic scoliosis. Summary Of Background Data: Spontaneous postoperative aggravation of the anterior concave costal projection was a common occurrence in adolescent idiopathic scoliosis, yet the risk factors that effectively bridged the gap between what the surgeons did in the interior and how the rib cages reacted on the exterior were still open to debate. Methods: Pre- and postoperative computed tomographic scans of 77 patients with right convex thoracic adolescent idiopathic scoliosis were retrieved and analyzed. According to the postoperative variation of anterior chest wall angle (CWA), the patients were divided into 2 groups with either aggravated or improved CWA. Multiple scoliotic deformity parameters and their surgical correction rates were evaluated, correlated, and then compared between the 2 groups. Moreover, patients with apex located at T9 were isolated and evaluated independently. A logistic regression analysis was used to determine the independent predictors of the spontaneous postoperative modulation of the anterior chest wall contour. Results: The surgical correction rate of Cobb angle (supine), the rotational angle with respect to the sagittal plane (RAsag angle), the rotational angle with respect to the anterior midline of the body (RAml angle), the angle of lateral deviation of the apical vertebrae from the midline (MLdev angle), the posterior hemithorax ratio, the vertebral translation (VT), and the thoracic rotation averaged 64.6%, 19.5%, 30.8%, 39.2%, 15.0%, 41.2%, and 28.7%, respectively. Ratio of aggravated anterior chest wall contour was the highest at the T7 apex group (84.6%) as compared with T8 apex group (47.1%), T9 apex group (19.5%), and T10 apex group (0.0%). The preoperative CWA was significantly lower in the aggravated CWA group when compared with the improved group (2.1 ± 1.8°vs. 6.6 ± 2.4°, P < 0.001). Besides, in the aggravated CWA group, significantly greater surgical correction of VT and lesser correction of RAsag angle were demonstrated when compared with the improved CWA group (VT: 53.0% vs. 34.8%, P = 0.001; RAsag: 2.5% vs. 28.7%, P = 0.000). In the T9 subgroup, remarkably different correction rate of VT and RAsag were similarly observed (VT: 54.9% vs. 35.3%, P = 0.046; RAsag: 4.9% vs. 23.5%, P = 0.034). In terms of other deformity parameters, no significantly different correction rate was consistently detected. In the logistic regression analysis, apex location, CWA, and correction rate of RAsag were demonstrated to be independent factors predictive of the alteration of chest wall contour. Conclusion: In addition to the smaller preoperative CWA and higher apex location, lesser correction of vertebral rotation, if accompanied by great surgical correction of apical VT, could also largely result in a poor postoperative anterior chest wall contour. [ABSTRACT FROM AUTHOR]

Introduction: Scoliosis was found to develop in mice with neurotrophin 3 (NTF3) deficiency. Increased expression of NTF3 mRNA was detected in the paravertebral muscle in adolescent idiopathic scoliosis (AIS). Moreover, linkage study has defined a novel AIS locus on chromosome 12p and NTF3 gene located in this interval. Objectives: To investigate whether the NTF3 gene polymorphisms was associated with the susceptibility or curve progression of AIS. Materials and Methods: 362 AIS patients including 29 males (mean age 15.30 years) and 377 age-matched healthy controls including 37 males (mean age 15.86 years) were recruited. Cobb angle, risser sign some other clinical indexes were recorded. Two SNPs were selected through the HapMap database and genotyped by PCR-RFLP. Case control association study and case only association study were performed. Results: The genotype and allele frequency distribution were similar between AIS and normal control. The AIS patients with AA genotype of promoter polymorphism of NTF-3 gene (rs11063714) showed significantly lower maximum Cobb angle than the patients with AG or GG genotypes. Conclusion: The NTF3 gene polymorphism is not associated with the occurrence of AIS, but the promoter polymorphism (rs11063714) was found to be associated with the curve severity. These findings indicated that NTF3 gene might be a disease-modifying gene of AIS. Significance: Our study first reported the association between NTF3 gene polymorphism and the curve severity of AIS. Further study is required to elucidate the role of NTF3 gene in the abnormal NTF3 expression in the paravertebral muscle from AIS. [ABSTRACT FROM AUTHOR]

Introduction: Bracing is the most commonly used non-operative treatment for adolescent idiopathic scoliosis (AIS). However, it may lead to thoracic kyphosis (TK) reduction. The elastic belt (EB) has been used as brace in some AIS patients. The effect of EB on sagittal profile has not been reported. Objective: To evaluate the effect of brace and EB on the sagittal profile of AIS patients. Method: 21 patients treated with Milwaukee brace and 16 patients with Boston brace were included. Standing lateral X-ray films were obtained in three conditions: without treatment, with brace and with EB. The following parameters were measured: (1) T5-T12 TK, (2)T2-T12 TK, (3) L1-S1 lumber lordosis (LL), (4) sacral slope, (5) pelvic tilt, (6) pelvic incidence. All parameters were analyzed using paired-t test between 3 conditions. Results: The T5-T12 TK and T2-T12 TK were significantly different between 3 conditions. The TK was reduced by brace and more by EB. In Milwaukee brace subjects, L1-S1 lordosis was similar when wear EB or no treatment but significantly smaller when wear brace. No significant differences were found in pelvic parameters between the 3 conditions in both groups. Conclusion: The TK and LL were reduced by brace .The EB show more reduction effect on the TK but no effect on LL. Significance: Thoracic hypokyphosis has been thought as a risk factor of curve progression and harm to pulmonary function in AIS patients. Significant reduction effect on thoracic kyphosis should be considered when using EB as brace for AIS. [ABSTRACT FROM AUTHOR]

Introduction: Bjurei's equation has been used for height correction in scoliosis patients for decades. A significant controversy on the accuracy of height correction, however, was found in patients with severe scoliosis. Objectives: To investigate the effectiveness of Bjurei's equation in height correction in scoliosis patients with large Cobb angle. Methods: 77 patients with adolescent idiopathic scoliosis (AIS) (male 11, female 66) underwent correction surgery were recruited. Standing height (SH) and arm span were measured before and after operation. Pre- and post-operative posteroanterior radiograms of standing whole spine were taken and Cobb angle of main curve was measured. SH was corrected by either arm span (SHa) or Bjurei's equation (SHb). The pre-operative SHb was compared with SHa and postoperative SHb by Students t test. The association between the pre- and postoperative SHb difference (▵SHb) and Cobb angle was plotted. Results : The SHa was similar as SH in all subjects but significantly lower than the pre-operative SHb. Similar pre- and post-operative SHb was found in patients with Cobb angle<60°. In patients with Cobb angle >60°, however, the difference (▵SHb) increased with the increase of Cobb angle (figure 1). Conclusion : The SHa calculated by arm span equation selected may not show the real SH of AIS subjects. Bjurei's equation is suitable for height loss correction in scoliosis patients when the Cobb angle is no more than 60°. Significance: This study provides more information for the application of Bjurei's equation. [ABSTRACT FROM AUTHOR]