Tissue response following implantation with the posterior dynamic distraction device (PDDD) in adolescent idiopathic scoliosis (AIS).

PURPOSE: The PDDD is a ratchet-based, unidirectional expandable rod to treat adolescent idiopathic scoliosis (AIS), primarily by correcting scoliotic deformity without full spinal fusion. We hypothesized that the device will be fully tolerated by the host and, if aseptic screw loosening occurs, it will be unrelated to wear particle formation. METHODS: This study comprised tissue samples from seven patients from a prospective study (NCT04296903) to assess the PDDD's safety and benefits, reoperated due to complications. Host response was assessed from histological slides (four levels/implant) in accordance with GLP and ISO10993-6:2016. The elementary chemical composition of wear particles present in tissue sections was quantified by energy dispersive X-ray spectroscopy (EDX). RESULTS: Host reaction was minor, characterized by low levels of diverse inflammatory cells, mild fibrosis, occasional small necrotic foci, neovascularization, hemorrhage, and, rarely, small bone fragments. Twenty-four of 28 tissue sections displayed varying degrees of wear particles (black discoloration), and most sections (17) were scored as 1 (< 25% of the sample). The discoloration observed corresponded to black-appearing, fine granular pigment. EDX analysis confirmed particles were composed of titanium, aluminum, and vanadium. Twenty-six of 28 samples were scored zero for necrosis and 2/28 were scored 1. Eleven samples were scored zero for fibrosis, 12 as 1, and five as 2. No aseptic screw loosening occurred. CONCLUSION: The PDDD induced minimal host reaction with little or no degeneration, inflammation or fibrosis. No changes present could be expected to promote device failure. The PDDD implant for treating AIS is well-tolerated and locally safe.

Automatic assessment of scoliosis surgery outcome on trunk shape using left-right trunk asymmetry.

PURPOSE: To present a novel set of Left-Right Trunk Asymmetry (LRTA) indices and use them to assess the postoperative appearance of the trunk in Adolescent Idiopathic Scoliosis (AIS) patients. METHODS: We hypothesize that LRTA measurements provide complementary information to existing trunk asymmetry indices when documenting the outcome of scoliosis surgery. Forty-nine AIS patients with thoracic curves who underwent posterior spinal fusion were included. All had surface topography scans taken preoperatively and at least 6 months postoperatively. We documented spinal curvature using Radiographic Cobb angles, scoliometer readings and coronal balance. To evaluate Global Trunk Asymmetry (GTA), we used the standard measures of Back Surface Rotation (BSR) and Trunk Lateral Shift (TLS). To measure LRTA, we identified asymmetry areas as regions of significant deviation between the left and right sides of the 3D back surface. New parameters called Deformation Rate (DR) and Maximum Asymmetry (MA) were measured in different regions based on the asymmetry areas. We compared the GTA and LRTA changes with those in spinal curvature before and after surgery. RESULTS: The GTA indices, mainly TLS, showed improvement for more than 75% of patients. There was significant improvement of LRTA in the shoulder blades and waist regions (95% and 80% of patients respectively). CONCLUSION: We report positive outcomes for LRTA in the majority of patients, specifically in the shoulder blades and waist, even when no reduction of BSR is observed. The proposed indices can evaluate local trunk asymmetries and the degree to which they are improved or worsened after scoliosis surgery.

Research progress on the regulation of bone marrow stem cells by noncoding RNAs in adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) is a common spinal deformity in young women, but its pathogenesis remains unclear. The primary pathogenic factors contributing to its development include genetics, abnormal bone metabolism, and endocrine factors. Bone marrow stem cells (BMSCs) play a crucial role in the pathogenesis of AIS by regulating its occurrence and progression. Noncoding RNAs (ncRNAs) are also involved in the pathogenesis of AIS, and their role in regulating BMSCs in patients with AIS requires further evaluation. In this review, we discuss the relevant literature regarding the osteogenic, chondrogenic, and lipogenic differentiation of BMSCs. The corresponding mechanisms of ncRNA-mediated BMSC regulation in patients with AIS, recent advancements in AIS and ncRNA research, and the importance of ncRNA translation profiling and multiomics are highlighted.

BMP6 participates in the pathogenesis of adolescent idiopathic scoliosis by regulating osteopenia.

Adolescent idiopathic scoliosis (AIS) is a complex disease characterized by three-dimensional structural deformities of the spine. Its pathogenesis is associated with osteopenia. Bone-marrow-derived mesenchymal stem cells (BMSCs) play an important role in bone metabolism. We detected 1919 differentially expressed mRNAs and 744 differentially expressed lncRNAs in BMSCs from seven patients with AIS and five patients without AIS via high-throughput sequencing. Multiple analyses identified bone morphogenetic protein-6 (BMP6) as a hub gene that regulates the abnormal osteogenic differentiation of BMSCs in AIS. BMP6 expression was found to be decreased in AIS and its knockdown in human BMSCs significantly altered the degree of osteogenic differentiation. Additionally, CAP1-217 has been shown to be a potential upstream regulatory molecule of BMP6. We showed that CAP1-217 knockdown downregulated the expression of BMP6 and the osteogenic differentiation of BMSCs. Simultaneously, knockout of BMP6 in zebrafish embryos significantly increased the deformity rate. The findings of this study suggest that BMP6 is a key gene that regulates the abnormal osteogenic differentiation of BMSCs in AIS via the CAP1-217/BMP6/RUNX2 axis.

Persistent low bone mineral density in adolescent idiopathic scoliosis: A longitudinal study.

BACKGROUND: Since osteopenia has been reported to potentially associated with the progression of scoliosis, bone mineral density (BMD) might have some influences on adolescent idiopathic scoliosis (AIS). However, little is known about longitudinal BMD changes in AIS patients. This study aimed to investigate whether osteopenia in preoperative AIS patients persist at bone maturity, and to evaluate the association between BMD and AIS severity. METHODS: We reviewed 61 AIS patients who underwent surgery when they were Risser grade 4 or below and less than 20 years old (16.6 ± 1.9 years), were followed until they were at least 18 years old and had a Risser grade of 5, and followed at least 2 years after the surgery (mean follow-up 4.9 ± 1.7 years). We evaluated radiographical parameters and proximal femur BMD before surgery and at the final follow-up. A BMD of less than the mean minus 1SD was considered as low BMD. Based on preoperative BMD, 37 patients were assigned to normal BMD (N) group (1.02 ± 0.08 g/cm2) and 24 patients to low BMD (L) group (0.82 ± 0.06 g/cm2). RESULTS: All patients in the N-group had normal BMD at the final follow-up. In the L group, 15 patients (62.5%) had low BMD at the final follow-up (L-L group; preoperative 0.79 ± 0.05 g/cm2 and final follow-up 0.78 ± 0.05 g/cm2). The mean preoperative Cobb angle was significantly larger in the L-L group (67.8 ± 11.2°) than in those with normal BMD at the final follow-up (L-N group, 55.6 ± 11.8°) or the N-N group (50.8 ± 7.6°). Preoperative BMD was significantly negative correlated with the preoperative Cobb angle. The age at surgery and mean preoperative BMI were similar in the L-N and L-L groups. CONCLUSIONS: Of AIS patients with low preoperative BMD, 62.5% still had low BMD after reaching bone maturity, and low BMD was associated with the severity of scoliosis.

Surgeon specialty effect on early outcomes of elective posterior spinal fusion for adolescent idiopathic scoliosis: a propensity-matched analysis of 965 patients.

BACKGROUND AND OBJECTIVE: Comparative effectiveness research plays a vital role in health care delivery. Specialty training is one of these variables; surgeons who are trained in different specialties may have different outcomes performing the same procedure. The objective of this study was to investigate the impact of spine surgeon specialty (neurosurgery vs orthopedic surgery) on early perioperative outcome measures of elective posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). METHODS: This is a retrospective, 1:4 propensity score-matched cohort study. 5520 AIS patients were reviewed from ACS-NSQIP pediatric database. Propensity score matching was utilized. RESULTS: Patients operated on by orthopedic surgeons were more likely to have shorter operation time (263 min vs 285 min), shorter total hospital stay (95 h vs 118 h), lower rate of return to operating room within the same admission (1.2% vs 3.8%), lower discharge rates after postoperative day 4 (23.8% vs 30.9%), and lower unplanned readmission rate (1.6% vs 4.1%), (p < 0.05). On the other hand, patients operated on by neurosurgeons had lower perioperative blood transfusion rate (62.1% vs 69.8%), (p < 0.05). Other outcome measures and mortality rates were not significantly different between the two cohorts. CONCLUSIONS: This retrospective study found significant differences in early perioperative outcomes of patients undergoing PSF for AIS by neurosurgeons and orthopedic surgeons. Further studies are recommended to corroborate this finding which may trigger changes in the educational curriculum for neurosurgery residents.

Parents can reliably and accurately detect trunk asymmetry using an inclinometer smartphone app.

PURPOSE: An inclinometer smartphone application has been developed to enable the measurement of the angle of trunk inclination (ATI) to detect trunk surface asymmetry. The objective was to determine the reliability and validity of the smartphone app in the hands of non-professionals. METHODS: Three non-professional observers and one expert surgeon measured maximum ATI twice in a study involving 69 patients seen in the spine clinics to rule out scoliosis or for regular follow-up (10-18 y.o., Cobb [0°-58°]). Observers were parents not familiar with scoliosis screening nor use of an inclinometer. They received training from a 4-minute video. Intra and inter-observer reliability was determined using the generalizability theory and validity was assessed from intraclass correlation coefficients (ICC), agreement with the expert on ATI measurements using Bland-Altman analysis, and correct identification of the threshold for consultation (set to ≥6° ATI). RESULTS: Intra-observer and inter-observer reliability coefficients were excellent ϕ = 0.92. The standard error of measurement was 1.5° (intra-observer, 2 measurements) meaning that a parent may detect a change of 4° between examinations 95% of the time. Comparison of measurements between non-professionals and the expert resulted in ICC varying from 0.82 [0.71-0.88] to 0.84 [0.74-0.90] and agreement on the decision to consult occurred in 83 to 90% of cases. CONCLUSION: The use of a smartphone app resulted in excellent reliability, sufficiently low standard error of measurement (SEM) and good validity in the hands of non-professionals. The device and the instructional video are adequate means to allow detection and regular examination of trunk asymmetries by non-professionals.

Quality of Life Evaluation Using SRS-30 Score for Operated Children and Adolescent Idiopathic Scoliosis.

Background and objective: Adolescent idiopathic scoliosis (A.I.S.) is a disorder with a significant impact on health and self-image. This spinal deformity can affect between 2% and 4% of the adolescent population and may alter one's quality of life. This study aims to assess the patient outcome, satisfaction, and quality of life following surgical treatment using the SRS-30 questionnaire. Materials and Methods: A number of 49 children and adolescent patients diagnosed with idiopathic scoliosis that had surgery were included in this study. They thoroughly completed the SRS-30 questionnaire before and after the surgery, based on which data analysis was carried on. Correlations between the test results and imagistic data (pre- and postoperative Cobb angle, correction rate of Cobb angle, number of instrumented spinal segments, and number of pedicle screws/laminar hooks used in the surgery) were performed. Results: Our results showed that 87.76% of the patients were girls, and the mean age at surgery was 14.83 years. Postoperatively, the Cobb angle improved significantly (p < 0.0001). The questionnaire domain "Satisfaction with management" improved dramatically after surgery, averaging 13.65 points (91% out of the maximum score). The average postoperative test score was 125.1 points. Statistically significant correlations were found between the correction rate and SRS-30 score improvement (p < 0.001), in total as well as per each domain of the survey, respectively. Comparing the questionnaire domains, "Self-image" was positively correlated with "Satisfaction with management" (p < 0.0001). Conclusions: Better correction rate led to higher values of SRS-30 score. Additionally, the younger the age at surgery is, the higher the score. The number of instrumented spinal segments does not alter the quality of life. Overall, the most crucial factor influencing patient satisfaction after surgical treatment is self-image.

Double-sided vertebral body tethering of double adolescent idiopathic scoliosis curves: radiographic outcomes of the first 13 patients with 2 years of follow-up.

PURPOSE: In skeletally immature patients with adolescent idiopathic scoliosis (AIS), vertebral body tethering (VBT) as a fusionless minimally invasive treatment option has been shown to correct the deformity by growth modulation. This prospective cohort study aimed to present the minimum 2 years' results of double-sided VBT applied to double curves of 13 skeletally immature patients with AIS. METHODS: Thirteen skeletally immature patients with AIS and double curves were included. All patients were followed up within a brace for at least 6 weeks. A decision to proceed with surgery was established after the detection of curve progression within the brace (> 40° thoracic, > 35° lumbar) with a minimum curve flexibility of 30%. RESULTS: Patients had an average age of 11.8 years, average follow-up duration of 36.4 months (range 24 to 46), average preoperative main thoracic/thoracolumbar or lumbar curve magnitudes of 48.2°/45.3°. An average of 11.8 levels of tethering was undertaken. Thoracic screws were placed thoracoscopically, while mini-thoracotomy/lumbotomy was added for thoracolumbar levels. Postoperatively, an average first erect thoracic/thoracolumbar major curve magnitudes of 17.3°/14.3° were acquired, while they improved to 9.7°/8.2° at the last follow-up. No neurologic or implant-related complications were acquired. CONCLUSION: Double-sided VBT was detected to provide 80% of thoracic (48.2° to 9.7°) and 82% of thoracolumbar-lumbar curve correction (45.3° to 8.2°) as a result of average two years. As being a growth modulating treatment option, double-sided VBT as applied under strict inclusion criteria was shown to be safe and effective for the correction of double curves in skeletally immature patients with AIS, by yielding a gradual, growth-assisted correction of both curves together with the preservation of coronal-sagittal balance without any major complications.

Minimally invasive surgery versus standard posterior approach for Lenke Type 1-4 adolescent idiopathic scoliosis: a multicenter, retrospective study.

PURPOSE: To compare the safety and efficacy of posterior minimally invasive surgery (MIS) to standard posterior spinal fusion (PSF) surgery for Lenke Type 1-4 adolescent idiopathic scoliosis (AIS). METHODS: This multicenter retrospective study enrolled 112 patients with Lenke Type 1-4 AIS who treated with MIS (n = 64) or PSF (n = 48) between March 2007 and January 2015. Coronal and sagittal parameters were evaluated before surgery, immediately after surgery, and at the last follow-up. Operative time, level of fusion, intraoperative blood loss, blood transfusion, and intraoperative radiation exposure were recorded. 22-item Scoliosis Research Society questionnaire (SRS-22) was applied for assessment of life quality. The accuracy of pedicle screw placement was assessed according to postoperative computed tomography images, and the complications were collected in follow-up period. RESULTS: The baseline characteristics of 2 groups were matched. There was no significant difference between 2 groups in terms of radiographic parameters immediately after surgery and at the last follow-up. The MIS group had significantly longer operative time, more level of fusion, less intraoperative blood loss, and lower blood transfusion rate (p < 0.001). The evaluation of pain using SRS-22 showed significantly lower score in MIS group (p < 0.05). No significant difference was found between 2 groups in terms of accuracy of pedicle screw placement and complications. CONCLUSION: Posterior MIS is a safe and effective alternative to standard open approach for Lenke Type 1-4 AIS patients with curves < 70° and reasonable flexibility. Mid-term results showed MIS had the advantages of less blood loss and pain with more fusion segments.

Computed tomography-based bronchial tree three-dimensional reconstruction and airway resistance evaluation in adolescent idiopathic scoliosis.

PURPOSE: To investigate airway development and airway resistance by computed tomographic three-dimensional (3D) reconstruction of the bronchial tree in patients with adolescent idiopathic scoliosis (AIS). We evaluated factors predicting postoperative respiratory complications to provide timely treatment, prevent complications, and improve operative and anesthetic safety. METHODS: From August 2015 to August 2017, 53 AIS patients with a mean age of 15.4 years (range 10-20 years) were included in this study. Scoliotic parameters on radiographs were analyzed. Airway resistance was obtained by pulmonary function testing. All patients' pulmonary bronchial trees were 3D-reconstructed via chest thin layer computed tomography to explore the correlation between the spinal-thoracic deformity parameters and airway resistance. RESULTS: Correlations between scoliotic parameters and airway development parameters were not statistically significant (P > 0.05). The scoliotic parameters such as Cobb angle, apical vertebral translation, rotation angle to sagittal plane, rotation angle to middle line, and apical vertebral body-rib ratio (AVB-R) were positively correlated with tracheal bifurcation angle (R2: 0.429, 0.374, 0.430, 0.504, and 0.414, respectively; P < 0.05). Cobb angle, rib hump, and apical vertebral body-rib ratio (AVB-R) were positively correlated with left principal bronchus length to right principal bronchus length (PBL-R) (R2: 0.373, 0.503, and 0.377, respectively; P < 0.05). Superficial area of bronchial tree (SABT) and narrow cross section of trachea (NCT) were negatively correlated with plethysmography Pre-Ref resistance ratio (Pre/Ref) (R2: - 0.365 and - 0.452, respectively; P < 0.05). SABT and NCT were negatively correlated with respiratory impedance (Zrs) (R2: - 0.327 and - 0.436, respectively; P < 0.05). CONCLUSIONS: Pulmonary bronchial development in patients with AIS is affected by spinal-thoracic deformity. Comprehensive assessment of preoperative pulmonary function, especially airway resistance, is necessary in patients with AIS whether the thoracic scoliosis is severe or mild-to-moderate. These slides can be retrieved under Electronic Supplementary Material.

Mental health of patients with adolescent idiopathic scoliosis and their parents in China: a cross-sectional survey.

BACKGROUNDS: Adolescent idiopathic scoliosis (AIS) is an adolescent onset spinal deformity, which can negatively affect the mental health of these patients. But no studies about their parental mental health have been reported so far. In this study, the parental mental health of AIS patients and the associated risk factors were evaluated by a cross-sectional survey. METHODS: 64 AIS patients who underwent conservative or surgical treatments in our hospital from April 2017 to March 2018, and their parents were enrolled in the AIS group. 85 parents of healthy children were enrolled in the control group. Depression and anxiety were separately assessed using the Patient Health Questionnaire (PHQ-9) and the Generalized Anxiety Disorder 7-item scale (GAD-7). Spearman correlation coefficients were first estimated to investigate the relationships among the parental PHQ-9/GAD-7 scores and the patient's PHQ-9/GAD-7 scores in the AIS group. Then, the morbidities of the parental probable major depressive disorder (pMDD, PHQ score ≥ 10) and probable general anxiety disorder (pGAD, GAD-7 score ≥ 10) were compared between the AIS and control groups. Third, the potential risk factors for parental pMDD or pGAD in the AIS group were compared using the chi-squared test or Student's t-test, respectively. Finally, the uneven distributive variates were analyzed using the binary logistic regression model. RESULTS: Both parental depression and anxiety were moderately associated with those of the patients (r = 0.448~0.515, p < 0.01) in the AIS group, respectively. The morbidities of parental pMDD and pGAD in the AIS group were 14.1%, significantly higher than those in the control group (pMDD = 4.7%, p = 0.045; pGAD = 3.5%, p = 0.019). A Cobb angle of the major curve ≥50° (p = 0.034, odds ratio [OR] = 8.264), patients with pMDD (p = 0.018, OR = 17.576), and low education level of the parents (p = 0.026, OR = 0.122) were the risk factors of parental pMDD. Household income < 8000 rmb/month was the risk factor for parental pGAD (p = 0.021). CONCLUSIONS: The morbidities of pMDD and pGAD in parents of AIS patients were higher than those in parents of healthy children. Parental depression and anxiety were closely associated with their children's depression and anxiety. Therefore, the parental mental health of AIS patients should be paid attention to, especially for those parents with risk factors.

Analysis of sensory system aspects of postural stability during quiet standing in adolescent idiopathic scoliosis patients.

BACKGROUND: The aim of this study was to quantitatively analyze quite standing postural stability of adolescent idiopathic scoliosis (AIS) patients in respect to three sensory systems (visual, vestibular, and somatosensory). METHOD: In this study, we analyzed the anterior-posterior center of pressure (CoP) signal using discrete wavelet transform (DWT) between AIS patients (n = 32) and normal controls (n = 25) during quiet standing. RESULT: The energy rate (∆E EYE %) of the CoP signal was significantly higher in the AIS group than that in the control group at levels corresponding to vestibular and somatosensory systems (p < 0.01). CONCLUSIONS: This implies that AIS patients use strategies to compensate for possible head position changes and spinal asymmetry caused by morphological deformations of the spine through vestibular and somatosensory systems. This could be interpreted that such compensation could help them maintain postural stability during quiet standing. The interpretation of CoP signal during quiet standing in AIS patients will improve our understanding of changes in physical exercise ability due to morphological deformity of the spine. This result is useful for evaluating postural stability before and after treatments (spinal fusion, bracing, rehabilitation, and so on).

Accuracy of cannulated pedicle screw versus conventional pedicle screw for extra-pedicular screw placement in dysplastic pedicles without cancellous channel in adolescent idiopathic scoliosis: a computerized tomography (CT) analysis.

PURPOSE: This study aimed at studying the accuracy and safety of extra-pedicular screw insertion for dysplastic pedicles in AIS comparing cannulated screw system versus conventional screw system. METHODS: 104 AIS patients with 1524 pedicle screws were evaluated using CT scan. 302 screws were inserted in dysplastic pedicles using fluoroscopic guidance technique. 155 screws were inserted using a cannulated system (Group 1), whereas 147 screws were inserted using standard screws (Group 2). The pedicle perforations were assessed using a classification by Rao et al.; G0: no violation; G1: <2 mm perforation; G2: 2-4 mm perforation; and G3: >4 mm perforation). For anterior perforations, the pedicle perforations were assessed using a modified grading system (Grade 0: no violation, Grade 1: less than 4 mm perforation; Grade 2: 4 mm to 6 mm perforation; and Grade 3: more than 6 mm perforation). RESULTS: The perforation rate in Group 1 was 4.5% and in Group 2 was 15.6% (p = 0.001). Most of the perforations were anterior perforations (53.3%). The anterior perforation rate in Group 1 was 1.9% compared to 8.8% in Group 2 (p = 0.009). Group 1 has a medial perforation rate of 1.3% compared to Group 2, 6.1% (p = 0.031). The rate of critical pedicle perforation in Group 1 was 2.6% and in Group 2 was 6.8% (p = 0.102). In Group 1, there were no critical medial perforation but there was one G2 lateral perforation, one G2 superior perforation and two G3 anterior perforations. In Group 2, there were three G2 medial perforations, one G2 lateral perforation, one G2 anterior perforation and five G3 anterior perforations. CONCLUSION: Usage of cannulated screw system significantly increases the accuracy of pedicle screw insertion in dysplastic pedicles in AIS.

Estradiol via estrogen receptor beta inhibits chondrogenesis of mouse vertebral growth plate in vitro.

PURPOSE: Abnormal growth of vertebral growth plate (VGP) was considered as one of the etiologic factors in adolescent idiopathic scoliosis (AIS). Previous studies described that estrogen played an important role in the pathogenesis of AIS. The present study was aimed to investigate the effect of estrogen/estrogen receptor axis on mouse VGP chondrocytes in vitro. METHODS: Chondrocytes were isolated from mouse VGP and treated with or without 17ß-estradiol (E2). Cell proliferation was measured by the cell growth rate assay. Gene expression of collagen type II and aggrecan were evaluated by real-time PCR. Expression of the proliferating cell nuclear antigen (PCNA), Sox9, and Smad4 were detected by Western blotting. RESULTS: Estradiol inhibited the proliferation of VGP chondrocytes and the gene expression of collagen type II and aggrecan and downregulated the protein expression of PCNA, Sox9, and Smad4. In addition, the inhibitory effect of estradiol was reversed by ERß small interfering RNA (siRNA) or PHTPP, an ERß antagonist. CONCLUSIONS: Estradiol via estrogen/estrogen receptor ß axis inhibits the proliferation and differentiation of VGP chondrocytes, which might give some new insight into the regulatory mechanism of bone development.

Sagittal alignment of the cervical spine in adolescent idiopathic scoliosis: a comparative study of 42 adolescents with idiopathic scoliosis and 24 normal adolescents.

PURPOSE: Kyphosis of the cervical spine has been reported in patients with adolescent idiopathic scoliosis (AIS). However, few reports have compared sagittal spine alignment of AIS patients with that of the normal population. The purposes of this study were (1) to analyze the characteristics of sagittal alignment, including the cervical spine, in AIS patients with a single thoracic curve (Lenke type 1) compared with the age-matched normal population and (2) to quantify the changes in sagittal alignment of the cervical spine and thoracic kyphosis following posterior spinal fusion. METHODS: In study 1, pre- and postoperative X-ray were measured for the following sagittal plane parameters: lumbar lordosis angle (L1-S1; LL), thoracic kyphosis angle (Th5-12; TK), sacral slope (SS), C7 plumb line (C7PL), cervical lordosis angle (C2-C7 angle; CL), and T1 slope. These measurements were then evaluated with CL and other parameters using spearman rank correlation coefficient between two groups. Comparison was made with the sagittal plane parameters from preoperative 42 AIS (AIS group) with main thoracic curve and 24 normal populations (Control group). In study 2, 38 operative AIS patients had at least 1-year follow-up. These patients (38 AIS patients after the correction surgery) were enrolled. We collected for each patient on pre- and postoperative sagittal plane parameters of X-ray. RESULTS: In study 1, LL and C7PL did not differ significantly between the groups. Although CL was observed in 10 of the 24 patients (41.7 %) in the Control group, the CL was smaller in the AIS group, with 6 of 42 patients (14.3 %). The CL correlated significantly with T1 slope (r = 0.634), C7PL (r = 0.684), and TK (r = 0.311) in the AIS group, and with T1 slope (r = 0.681) and C7PL (r = 0.451) in the Control group. No correlations were observed with respect to the TK. In study 2, the mean CL improved significantly from 7.2° kyphosis preoperatively to 0.1° kyphosis postoperatively. Interestingly, Spearman correlation analysis showed that the postoperative CL correlated significantly with postoperative TK (r = 0.607), postoperative T1 slope (r = 0.701), and postoperative C7PL (r = 0.373). CONCLUSIONS: There were no effects of scoliosis on sagittal spine parameters such as LL and C7PL in AIS patients with a main thoracic curve. Cervical spine alignment was affected by the thoracic deformity in the sagittal plane, as shown by the reduction in the CL after the operation. These findings suggest that TK may be a cause of cervical kyphosis in AIS patients.

Deep Learning-Based Prediction Model for the Cobb Angle in Adolescent Idiopathic Scoliosis Patients.

Scoliosis, characterized by spine deformity, is most common in adolescent idiopathic scoliosis (AIS). Manual Cobb angle measurement limitations underscore the need for automated tools. This study employed a vertebral landmark extraction method and Feedforward Neural Network (FNN) to predict scoliosis progression in 79 AIS patients. The novel intervertebral angles matrix format showcased results. The mean absolute error for the intervertebral angle progression was 1.5 degrees, while the Pearson correlation of the predicted Cobb angles was 0.86. The accuracy in classifying Cobb angles (<15°, 15-25°, 25-35°, 35-45°, >45°) was 0.85, with 0.65 sensitivity and 0.91 specificity. The FNN demonstrated superior accuracy, sensitivity, and specificity, aiding in tailored treatments for potential scoliosis progression. Addressing FNNs' over-fitting issue through strategies like "dropout" or regularization could further enhance their performance. This study presents a promising step towards automated scoliosis diagnosis and prognosis.

Is young adult idiopathic scoliosis a distinct clinical entity from adolescent idiopathic scoliosis? a Systematic Review and Meta-analysis comparing pre-operative characteristics and operative outcomes.

PURPOSE: This study aims to conduct a systematic review of the literature comparing pre-operative, intraoperative, and post-operative characteristics between adolescent idiopathic scoliosis (AIS) and young adult idiopathic scoliosis (YAdIS) patients. METHODS: Following PRISMA guidelines, we conducted a search of the PubMed/Medline, EMBASE, and Cochrane Central databases to identify full-text articles in the English-language literature. Our inclusion criteria were studies that compared preoperative, intraoperative, and postoperative characteristics between AIS and YAdIS patients. We performed a meta-analysis reporting mean difference (MD) for continuous variables and Odds ratios (ORs) to assess differences in postoperative complications. RESULTS: Seven studies consisting of 1562 patients were included in the meta-analysis. The AIS group exhibited less intraoperative bleeding and shorter surgical procedures, with a mean difference between groups of 122.3 ml (95% CI 46.2-198.4, p = 0.002) and 28.7 min (95% CI 6.5-50.8, p = 0.01), respectively. Although the preoperative Cobb angle did not differ between groups (p = 0.65), patients with AIS achieved superior postoperative deformity correction, with a mean difference of 7.3% between groups, MD - 7.3 (95% CI - 9.7, - 4.8, p < 0.00001), and lower postoperative Cobb angles of the major curve, MD 4.2 (95% CI 3.1, 5.3, p < 0.00001). YAdIS patients were fused, on average, 0.2 more vertebral levels than AIS patients, MD 0.2 (95% CI 0.01, 0.5, p = 0.04). AIS patients experienced a significantly shorter length of stay after the surgical procedure, with an MD of 0.8 days (95% CI 0.1, 1.6, p = 0.02). No significant difference was found between groups in terms of complications (p = 0.19). CONCLUSIONS: YAdIS should be regarded as a distinct surgical entity, characterized by increased bleeding, longer surgical duration, greater deformity correction challenges, and the need for fusion of additional vertebral levels compared to AIS. Surgeons should be mindful of these differences and discuss them with patients and their families, especially in cases where the correction of the AIS deformity is delayed and there is a high risk of progression after skeletal maturity. Further research is needed to explore alternative surgical techniques and enhance outcomes for YAdIS patients.

Appropriate pelvic obliquity measurement method in Lenke type 5C adolescent idiopathic scoliosis: a preliminary study.

Background: Although pelvic obliquity (PO) is a risk factor for postoperative coronal decompensation in corrective surgery in adolescent idiopathic scoliosis (AIS), especially Lenke 5C, methods of measuring PO are controversial. This study aimed to establish an appropriate measurement method using multiplanar reconstructed computed tomography (MPR-CT) images instead of standing posteroanterior (PA) whole-spine radiographs to evaluate PO in patients with Lenke 5C AIS. Methods: This study was a retrospective cross-sectional study. Twenty-five patients who underwent corrective surgery for AIS in Osaka University Hospital from August 2014 to February 2023 were included. Cobb angle, L5 tilt, C7 plumb line to center sacral vertebral line (C7PL-CSVL), and leg length discrepancy (LLD) were measured on standing PA whole-spine radiographs preoperatively. Sacral obliquity (SO), the slope of the upper endplate of S1, and iliac obliquity (IO), the tilt of the line connecting the iliac crests, were measured on standing PA whole-spine radiographs and MPR-CT (SO/IO-X-ray, SO/IO-CT, respectively). S1 angle and S2 angle were measured on CT. Results: The mean age of the patients was 18.7±3.9 years and all of them were females. SO-X-ray and SO-CT were larger than IO-X-ray and IO-CT, respectively. SO-X-ray was highly correlated with SO-CT (r=0.838, P<0.001). L5 tilt had higher correlation with SO-CT (r=0.884, P<0.001) than with SO-X-ray (r=0.726, P=0.001) and IO-CT (r=0.550, P=0.22). L5 tilt was correlated poorly with IO-X-ray (r=0.104, P=0.69). The S1 angle was 4.5±3.5° meanwhile the S2 angle was 1.2±2.1°, the sacral deformity was mainly due to the S1 vertebral wedging. Conclusions: Given the asymmetric sacral morphology, SO is more appropriate pelvic parameter than IO to represent the sacral tilt of Lenke 5C AIS, especially when measured using CT images to overcome the poor visibility on PA whole-spine radiographs.

Pre-contoured patient-specific rods result in superior immediate sagittal plane alignment than surgeon contoured rods in adolescent idiopathic scoliosis.

Background: Adolescent idiopathic scoliosis (AIS) surgery typically involves posterior spinal fusion (PSF) using rods contoured by the surgeon, which may be time-consuming and may not reliably restore optimal sagittal alignment. However, pre-contoured patient-specific rods may more optimally restore sagittal spinal alignment. This study evaluates the radiographic outcomes of AIS patients who underwent PSF utilizing surgeon contoured vs. pre-contoured rods. Methods: This is a retrospective cohort study of AIS patients who underwent PSF with either surgeon contoured or pre-contoured rods. Demographics, Lenke classification, fused levels, osteotomies, estimated blood loss (EBL), and surgical time were also obtained via chart review. Coronal curve magnitude, T5-T12 thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), PI-LL mismatch, and T1 pelvic angle (TPA) were obtained pre-operatively, postoperatively and at last follow up. Outcome measures included rate of achievement of postoperative radiographic alignment goals (TK between 20 and 40 degrees, PI-LL mismatch within 10 degrees, and TPA <14 degrees). Predicted post-operative sagittal alignment was also compared with observed measurements. Student's and paired t-tests were performed to determine significant mean differences for continuous variables, and chi-square for categorical variables. Results: No differences were found in demographics, Lenke classification, preop radiographic measurements, fused levels, osteotomies, EBL, and surgical time in the surgeon contoured cohort (n=36; average follow up 11.3 months) and pre-contoured cohort (n=22; average follow up 9.7 months). At last follow up, 95.5% of patients with pre-contoured rods vs. 61.1% of patients with surgeon contoured rods (P=0.004) met TK goal. During assessment of first standing postoperative X-ray, 72.7% of patients with pre-contoured rods vs. 33.3% of patients with surgeon contoured rods met PI-LL mismatch goal (P=0.004). Other radiographic measurements were similar. Artificial intelligence (AI) predicted and observed differences for the pre-contoured group were 3.7 for TK (P=0.005), -7.6 for PI-LL mismatch (P=0.002), and -2.6 for TPA (P=0.11). Conclusions: AI and pre-contoured rods help achieve global sagittal balance with high accuracy and improved kyphosis restoration and PI-LL mismatch than surgeon contoured rods in AIS patients.