Cobb Angle Of Major Curve Research Articles

Prognostic model development for risk of curve progression in adolescent idiopathic scoliosis: a prospective cohort study of 127 patients.

The study's purpose was to develop and internally validate a prognostic survival model exploring baseline variables for adolescent idiopathic scoliosis curve progression. A longitudinal prognostic cohort analysis was performed on trial data (n = 135) including girls and boys, Cobb angle 25-40°, aged 9-17 years, remaining growth > 1 year, and previously untreated. Prognostic outcome was defined as curve progression of Cobb angle of > 6° prior to skeletal maturity. 34 candidate prognostic variables were tested. Time-to-event was measured with 6-month intervals. Cox proportional hazards regression survival model (CoxPH) was used for model development and validation in comparison with machine learning models (66.6/33.3 train/test data set). The models were adjusted for treatment exposure. The final primary prognostic model included 127 patients, predicting progress with acceptable discriminative ability (concordance = 0.79, 95% confidence interval [CI] 0.72-0.86). Significant prognostic risk factors were Risser stage of 0 (HR 4.6, CI 2.1-10.1, P < 0.001), larger major curve Cobb angle (HRstandardized1.5, CI 1.1-2.0, P = 0.005), and higher score on patient-reported pictorial Spinal Appearance Questionnaire (pSAQ) (HRstandardized 1.4, CI 1.0-1.9, P = 0.04). Treatment exposure, entered as a covariate adjustment, contributed significantly to the final model (HR 3.1, CI 1.5-6.0, P = 0.001). Sensitivity analysis displayed that CoxPH maintained acceptable discriminative ability (AUC 0.79, CI 0.65-0.93) in comparison with machine learning algorithms. The prognostic model (Risser stage, Cobb angle, pSAQ, and menarche) predicted curve progression of > 6° Cobb angle with acceptable discriminative ability. Adding patient report of the pSAQ may be of clinical importance for the prognosis of curve progression.

Initial evaluation of the relationship between maximal axial vertebra rotation and the rotation deformity in adolescent idiopathic scoliosis.

This study evaluated the relationship between maximal axial vertebra rotation (maxAVR) and other clinical and radiological indexes, compared to apical vertebra rotation (AVR) in idiopathic adolescent scoliosis (AIS). Forty consecutive patients of AIS with Cobb angle of major curve > 40° were included. They were scanned by an EOS imaging system and had trunk rotational angle (TRA) measured by scoliometer. The correlation between variables was assessed using Pearson's correlation coefficient and loaded onto a meta-analysis model. There were (34 girls and 6 boys) with an average age of 13.8 ± 1.6years. AVR was maxAVR in only 47.5% (19/40) cases of the major curves and 42.3% (11/26) cases of the minor curves. The correlation between maxAVR and TRA was significantly higher than the correlation between AVR and TRA for the MT curves (p = 0.0001) and TL/L curves (p = 0.0001). On multivariate regression analysis, the magnitude of maxAVR showed a significant correlation with TRA (p = 0.0002), Cobb angle (p = 0.001), and coronal deformity angular ratio (C-DAR) (p = 0.027). The apical vertebra was not the most rotated in most cases. The correlation between maxAVR and TRA was significantly higher than the correlation between AVR and TRA. Moreover, the maxAVR was multivariately related to TRA, Cobb angle, and C-DAR. Level II, diagnostic.

Predictive factors for critical care dependency after posterior spinal fusion for adolescent idiopathic scoliosis

AimsHistorically, patients undergoing surgery for adolescent idiopathic scoliosis (AIS) have been nursed postoperatively in a critical care (CC) setting because of the challenges posed by prone positioning, extensive exposures, prolonged operating times, significant blood loss, major intraoperative fluid shifts, cardiopulmonary complications, and difficulty in postoperative pain management. The primary aim of this paper was to determine whether a scoring system, which uses Cobb angle, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and number of levels to be fused, is a valid method of predicting the need for postoperative critical care in AIS patients who are to undergo scoliosis correction with posterior spinal fusion (PSF).MethodsWe retrospectively reviewed all AIS patients who had undergone PSF between January 2018 and January 2020 in a specialist tertiary spinal referral centre. All patients were assessed preoperatively in an anaesthetic clinic. Postoperative care was defined as ward-based (WB) or critical care (CC), based on the preoperative FEV1, FVC, major curve Cobb angle, and the planned number of instrumented levels.ResultsOverall, 105 patients were enrolled. Their mean age was 15.5 years (11 to 25) with a mean weight of 55 kg (35 to 103). The mean Cobb angle was 68° (38° to 122°). Of these, 38 patients were preoperatively scored to receive postoperative CC. However, only 19% of the cohort (20/105) actually needed CC-level support. Based on these figures, and an average paediatric intensive care unit stay of one day before stepdown to ward-based care, the potential cost-saving on the first postoperative night for this cohort was over £20,000. There was no statistically significant difference between the Total Pathway Score (TPS), the numerical representation of the four factors being assessed, and the actual level of care received (p = 0.052) or the American Society of Anesthesiologists grade (p = 0.187). Binary logistic regression analysis of the TPS variables showed that the preoperative Cobb angle was the only variable which significantly predicted the need for critical care.ConclusionMost patients undergoing posterior fusion surgery for AIS do not need critical care. Of the readily available preoperative measures, the Cobb angle is the only predictor of the need for higher levels of care, and has a threshold value of 74.5°.Cite this article: Bone Joint J 2024;106-B(7):713–719.

Patient-specific 3D-printed Brace for Adolescent Idiopathic Scoliosis: A Prospective Cohort Study

To evaluate the efficacy, safety of patient-tailored 3D printed brace in the treatment of adolescent idiopathic scoliosis (AIS), and to compare the health-related quality of life (HRQoL) of patients treated with two different types of brace. From September 2017 to August 2020, 103 AIS patients requiring non-operative management were prospectively recruited in this study. All patients were followed up every 6 months, clinical and radiological examination were assessed at each follow-up time. Full-length anteroposterior X-ray of the spine in the standing position was performed obtained. At the last follow-up, each patient completed a standardized HRQoL questionnaire. Compliance is defined as that the patient insists on wearing the brace for ≥ 23h every day (full-time wearing) and follow-up every 6 months until bone maturity.The rate of major curve Cobb progression was defined that maximum Cobb Angle of major curve greater than 6° compared with that at the initial diagnosis, or aggravated to more than 45° so that orthopedic surgery was recommended during treatment, which was defined as the rate of conversion to surgery. The effects of these two types of braces on the rate of major curve Cobb progression and HRQoL were analyzed by independent sample t-test ad Chi-square test. The thickness was 4 mm for thoracolumbosacral orthosis (TLSO) and 3 mm for 3D-printed brace (3DPB). In addition, compared with the material used in TLSO, the weight (600-800 grams) of the 3DPB materials with the same area is reduced by about 25-30%. 55 patients (49.1%) and 48 patients (33.1%) were respectively included in the 3DPB cohort and the TLSO cohort.The maximum Cobb angle of major curve in the 3DPB cohort was significantly lower than those in the TLSO cohort at 6 months, 12 months and the last follow-up (p < 0.01). The thoracic kyphosis (TK) and lumbar lordosis (LL) of the two cohorts at the last follow-up were lower than those before brace treatment, in addition, there was a significant difference in TK (p = 0.001) and LL (p = 0.004) between the two cohorts at the follow-up. The scores of physical function, pain, self-image, mental health and treatment satisfaction in the Chinese version of SRS-22 in the 3DPB cohort were higher than those in the TLSO cohort (p < 0.01 and p < 0.05, respectively). The scores of the 3DPB cohort were significantly higher than those of the TLSO group in the four dimensions (p = 0.008, 0.013, 0.015, and 0.002, respectively) of the EuroQol-5D health description system except for mobility, and the overall health status of EuroQol-5D was higher for the 3DPB cohort (p < 0.001). At the last follow-up, One patient in the 3DPB cohort and ten patients in the TLSO cohort had major curve Cobb progression of greater than 6°, and the rate of major curve Cobb progression in 3DPB cohort was significantly lower than that in the TLSO cohort (OR 14.2, 95% CI 1.7∼115.8, p < 0.01). One patient in the 3DPB and seven patients in the TLSO cohorts received subsequent surgery or was recommended for surgery, and the rate of conversion to surgery was significantly lower than in the 3DPB cohort (OR 9.2, 95% CI 1.1∼77.9, p < 0.05). Patient-tailored 3D-printed brace is lighter, thinner, and more comfortable than conventional braces in the treatment of AIS. It can substantially improve the HRQoL of patients and can significantly reduce the progression of major curve Cobb progression and rate of conversion of surgery.

Immediate vs Gradual Brace Weaning Protocols in Adolescent Idiopathic Scoliosis

Lack of evidence and consensus for brace weaning protocol in adolescent idiopathic scoliosis (AIS) results in clinicians prescribing gradual weaning in the hope of avoiding curve deterioration after weaning. However, gradual weaning contributes to prolonged brace wear, which can affect spinal stiffness and health-related quality of life (HRQoL). To determine whether gradual weaning results in better curve magnitude and truncal balance maintenance after brace weaning vs immediate brace removal for patients with AIS. This was an open-labeled randomized clinical trial commenced in April 2017 with 24-month follow-up completed in January 2023. Outcome assessors were masked to weaning protocol assigned. The study took place at a territory-wide tertiary scoliosis clinic serving the largest number of referrals in the local population. Patients with AIS ready to wean off of brace wear were eligible (402 were screened; 33 were excluded [15 for <18 hours/day of brace-wear compliance before weaning, 11 were treated with Milwaukee brace, and 7 declined to participate]; and 369 were included), and those who were treated with a custom molded thoracolumbosacral orthosis and had reached skeletal maturity were consecutively recruited. Patients were randomized to gradual weaning protocol (n = 176) with an additional 6 months of nighttime wear before completely stopping or immediate weaning protocol (n = 193) with immediate brace removal at recruitment. Changes in major curve Cobb angle and truncal balance from the time of weaning to 6-month, 12-month, and 24-month follow-up. HRQoL was also assessed using the refined Scoliosis Research Society 22-item and EuroQol 5-dimension questionnaires. A total of 369 patients (mean [SD] age, 14.9 [1.1] years; 304 [83.4%] girls) were randomized with 284 (77.0%) completing 24-month longitudinal follow-up. Immediate and gradual weaning groups had no significant differences in change of major Cobb angle at postweaning 6-month (difference, -0.6°; 95% CI, -1.4 to 0.2; P = .17), 12-month (difference, -0.3°; 95% CI, -1.2 to 0.6; P = .47), and 24-month (difference, -0.3°; 95% CI, -1.2 to 0.7; P = .60) follow-up. The number of curve progression, nonprogression, and rebound cases were comparable (χ22 = 2.123; P = .35). Postweaning changes in truncal balance and HRQoL demonstrated no significant differences between groups. Gradual weaning did not demonstrate superiority to immediate weaning with predefined criteria of Cobb angle and truncal balance maintenance and HRQoL after brace weaning. Gradual and immediate weaning achieved very similar maintenance of brace outcomes in AIS. We therefore recommend the consideration of immediate brace weaning, which aims to benefit patients with earlier time for increased exercises and activity level. ClinicalTrials.gov Identifier: NCT03329716.

Evaluation of In-Brace Coronal and Sagittal Plane Measurements Between CAD/Chêneau-Style and Traditionally Fabricated Wilmington Braces in Adolescent Idiopathic Scoliosis

ABSTRACT Introduction Traditional thoracolumbosacral orthosis fabrication involves truncal casting (traditionally fabricated [TF] Wilmington brace [WB]), whereas the newer Chêneau-style brace (computer-aided design [CAD]) involves three-dimensional truncal scanning technology. We sought to evaluate how these two brace styles affect the position of the spine in the coronal and sagittal plane. Materials and Methods Inclusion criteria included adolescent idiopathic scoliosis treated with WB or CAD Chêneau-style brace, major curve Cobb angle 20°–45°, age 10–15 years, Risser 0–3, and radiographs (prebrace and in-brace posteroanterior and lateral). Analysis included 28 CAD Chêneau-style braces and 56 WB patients. Results There was no difference between groups regarding age, sex, body mass index, major curve location, major curve degree, sagittal plane curvature, and pelvic parameters. In-brace analysis demonstrated decreased sagittal plane curvatures and increased T1 pelvic angle in both groups; both had significantly reduced major curve correction. Coronal plane major curve correction ratio of the two groups was similar (P = 0.236). In the CAD Chêneau-style brace group, the thoracolumbar junction became more kyphotic (P = 0.03). In the WB group, both coronal balance and thoracic trunk shift were leftward (P = 0.001). Both groups had a significant increase in T1 pelvic angle, but this increase was higher in the CAD Chêneau-style brace group (P = 0.045). Conclusions Both braces exert a flattening effect on the spine and positive global sagittal balance. Coronal plane major curve correction was similar for both groups. Coronal plane trunk shift and C7 coronal balance were significantly changed leftward after WB application. Kyphotic thoracolumbar transition and forward tilt of the spine (T1 pelvic angle) were significantly greater in CAD Chêneau-style brace than WB. Clinical Relevance A Chêneau-style brace fabricated with CAD/computer-aided manufacturing technology can produce a brace comparable to one fabricated by traditional methods using cast molding.

Factors that influence in-brace derotation effects in patients with adolescent idiopathic scoliosis: a study based on EOS imaging system

ObjectiveTo investigate the effects of bracing on apical vertebral derotation and explore the factors that influence in-brace derotation effects in adolescent idiopathic scoliosis (AIS) patients.Summary of background dataFor patients with AIS, vertebral rotation causes cosmetic appearance abnormalities and acts as an indicator for curve progression. However, there have been few studies investigating the precise derotation effects of bracing for apical vertebra. The application of EOS imaging system enables quantitative evaluation of vertebral rotation in the axial plane in a standing position.MethodsThere were 82 eligible patients enrolled in current study, who underwent EOS imaging evaluation before and immediately after bracing. The clinical demographic data (age, gender, Risser sign and menstrual status) were recorded. The correlation analyses between derotation effects and key parameters (age, pre-brace Cobb angle, thoracic kyphosis, lumbar lordosis, vertebral rotation, pelvis axial rotation and apical vertebral level) were performed. The in-brace derotation effects stratified by gender, Risser sign, apical vertebral level, menarche status, coronal balance and sagittal balance were also analyzed.ResultsThe rotation of apical vertebra was decreased from 8.8 ± 6.0 degrees before bracing to 3.8 ± 3.3 degrees immediately after bracing (p < 0.001), and the derotation rate was 49.2 ± 38.3%. The derotation degrees in brace was significantly correlated with major curve Cobb angle (r = 0.240, p = 0.030), minor curve Cobb angle (r = 0.256, p = 0.020) and total curve Cobb angle (r = 0.266, p = 0.016). Both the pre-brace apical vertebral rotation and apical vertebral level were significantly correlated with derotation effects in brace (p < 0.001). Patients with thoracic major curve showed worse derotation effects than those with lumbar major curve (p < 0.001). In addition, patients with coronal balance showed better in-brace derotation effects than those with coronal decompensation (p = 0.005).ConclusionsA satisfactory apical vertebral derotation rate (approximately 50%) could be obtained immediately after bracing in AIS patients. Pre-brace Cobb angle of curve, pre-brace apical vertebral rotation, apical vertebral level and coronal balance exhibited close associations with in-brace derotation effects of apical vertebra.

Outcome of the surgical treatment of adolescent idiopathic scoliosis using the Scoliosis Research Society outcome questionnaire

Background Adolescent idiopathic scoliosis (AIS) is a structural deformity of the spine. Posterior deformity correction represents the gold standard of the surgical treatment of AIS. The fixation technique was shifted from hybrid fixation to the all pedicle screw construct, which could produce superior deformity correction. Patient-oriented outcome questionnaires have become an important measure of the success of surgical correction. This study was conducted to assess the outcome of all pedicle screw constructs in treating AIS using the Scoliosis Research Society (SRS)-24 outcome questionnaire. Patients and methods Seventy-nine AIS patients were included with a minimum 2-year follow-up. Clinical and radiographic measurements were evaluated at preoperative, postoperative, and final follow-up periods. Complications and results of the SRS-24 questionnaire were analyzed. Sex, Lenke classification, levels of the lowest instrumented vertebra, curve magnitude, and percentage of curve correction were correlated with the SRS-24 questionnaire results. Results There were 59 females and 20 males. The mean age of the patients was 14.2 ± 2.5 years. According to Lenke classification, the majority of the curves were type 1 (57 patients), followed by type 5 (11 patients), type 2 (six patients), type 3 (three patients), type 6 (two patients), and no type 4. The mean preoperative major curve Cobb angle was 59.3 ± 9.045° and the mean postoperative Cobb angle was 5.82 ± 5.932°. The average score for SRS-24 was 4.17. The mean preoperative pain score was 3.29, which improved to 4.30 after at least 2 years of follow-up (P˂0.005). Statistically significant improvement was seen in the general self-image, function from back condition, and level of activity. After surgery, the mean score for self-image was 4.19, and for function was 3.55. The postoperative function was the lowest, while the postoperative satisfaction score was the best of all domains, with a mean score of 4.55. About 90% of patients were satisfied with the results of their surgical correction. Magnitude of curve and amount of correction did not significantly alter the SRS scores. Conclusion All pedicle screw construct is an efficient and safe method in AIS correction. The surgical treatment in our AIS patients has resulted in a perceived benefit in all domains of SRS-24 questionnaire.

Effectiveness of Facetectomy in Correction of Adolescent Idiopathic Scoliosis.

Surgical correction of adolescent idiopathic scoliosis (AIS) using the facetectomy technique with the utilization of segmental pedicle screws aims to achieve correction of coronal and sagittal imbalances and preserve normal neurological function. In this study, we aimed to certify the effectiveness of the facetectomy technique in the correction of AIS by analyzing technique outcomes. This is a retrospective, single-center study. From January 2018 to March 2022, a total of 51 patients with AIS who underwent inferior facetectomy with segmental pedicle screw constructs at the Royal Rehabilitation Center were reviewed. Radiological parameters including the major curve Cobb angle, and global coronal balance were evaluated preoperatively, postoperatively, and at the final follow-up. Surgical parameters and complications were also reported. The mean major curve Cobb angle was 59.5 ± 4.9° preoperatively, 13.6 ± 2.7° postoperatively, and 14.5 ± 2.6° at the final follow-up, with correction rates of 77.2% and 75.7%, respectively. The mean global coronal balance was 2.7 ± 1.1 cm preoperatively, 1.7 ± 0.73 cm postoperatively, and 1.4 ± 0.55 cm at the final follow-up. Two cases of pleural injuries were reported intraoperatively. Postoperatively, two cases experienced superficial wound infections, one experienced pulmonary embolism, and one patient had revision surgery due to the loosening of a single screw. None of these complications lasted long. When combined with posterior segmental pedicle screw constructs, inferior facetectomy can provide an effective rate of correction in a reasonably safe manner.

The multisystem deformities features of Klippel-Feil syndrome patients combined with congenital scoliosis

Objective: To summarize the characteristics of multisystem deformities in patients with Klippel-Feil syndrome (KFS) combined with congenital scoliosis (CS). Methods: Within the framework of the "Deciphering Disorders Involving Scoliosis and Comorbidities (DISCO)" research collaboration, a retrospective analysis was conducted on patients diagnosed with KFS and CS at Peking Union Medical College Hospital between April 2005 and August 2022. Patient data, including imaging examinations and medical records, were collected to summarize the spinal and associated deformities. Results: A total of 82 KFS patients with concurrent CS were included, comprising 42 males and 40 females. The average age was (12.8±8.9) years. Among the KFS patients, there were 31 cases of Type Ⅰ, 12 cases of Type Ⅱ, and 39 cases of Type Ⅲ. The most common location for the major curve of scoliosis was the mid-thoracic segment (42 cases, 51.2%). Hemivertebrae deformities were most frequently observed in the upper thoracic segment (31 cases, 60.8%). There were no statistically significant differences in age, gender, major curve Cobb angle, or region of hemivertebrae occurrence among the different types of KFS (all P>0.05). Apart from spinal vertebral deformities, intraspinal deformities had the highest comorbidity rate (33 cases, 40.2%). The subjects were divided into two groups based on the presence or absence of intraspinal deformity (absence as group G0, presence as group G1), there was a statistically significant difference in the main Cobb angle [M(Q1, Q3)] between the two groups, which was 45.0° (27.5°, 62.0°) and 60.0° (37.5°, 83.5°), respectively (P=0.044). Additionally, a portion of the patients had concurrent cardiovascular system abnormalities (13 cases, 15.9%), craniofacial-ocular-auricular abnormalities (8 cases, 9.8%), genitourinary system abnormalities (7 cases, 8.5%), and gastrointestinal abnormalities (2 cases, 2.4%). Conclusions: Patients with KFS combined with CS commonly present with a major curve of spinal deformity in the mid-thoracic segment and often have comorbidities involving multiple systems. When combined with intraspinal anomalies, the major curve exhibits a greater degree of curvature.

Sequential Correction versus Conventional Correction for Severe and Rigid Kyphoscoliosis: A Retrospective Case Control Study.

Conventional correction techniques were challenging and of high risk of neurological complications for the correction of severe and rigid kyphoscoliosis. A new technical note we developed and named as sequential correction, was used to treat severe and rigid kyphoscoliosis. The present study was to compare the clinical outcomes of sequential correction versus conventional correction for the treatment of severe and rigid kyphoscoliosis. This is a respectively case-control study. Between January 2014 and December 2019, 36 adults underwent the surgical correction of severe and rigid kyphoscoliosis and were included in the present study. Among them, 20 adults underwent conventional correction, 16 adults underwent sequential correction. Major curve Cobb angle, kyphotic angle, coronal imbalance, and sagittal vertical axis were compared between two groups. The patient-reported health-related quality of life outcomes, including the Oswestry disability index score, and SRS-22 questionnaire, were recorded. Independent samples t-test, Mann-Whitney U test, and Wilcoxon signed-rank test, were used to compare the differences between two groups according to the results of normal distribution test. In conventional correction group, the mean major curve Cobb angle was 122.50° preoperatively, 40.35° immediately after surgery, and 43.95° at final follow-up postoperatively; the mean kyphotic angle was 97.45° preoperatively, 34.45° immediately after surgery, and 38.30° at final follow-up postoperatively. In the sequential correction group, the mean major angle was 134.44° preoperatively, 44.56° immediately after surgery, and 46.25° at final follow-up postoperatively; the mean kyphotic angle was 112.31° preoperatively, 39.00° immediately after surgery, and 40.38° at final follow-up postoperatively. The mean major curve Cobb angle and kyphotic angle of both groups were improved significantly, while there were no significant differences between two groups (p > 0.001). Improved self-reported quality of life scores were achieved postoperatively and at final follow-up postoperatively, and there were no significant differences between the two groups. The total complication rate of the patients underwent conventional correction was 55%, and the total complication rate of the patients underwent sequential correction was 43.75%. The complication rate of the two groups showed no significant difference. Sequential correction is an excellent and safe treatment for severe and rigid kyphoscoliosis in adults, with similar clinical outcomes with conventional correction. The total complication rate of the patients who underwent sequential correction was slightly lower than conventional correction.

Sequential correction of severe and rigid kyphoscoliosis: a new technical note and preliminary results

ObjectiveThe present study is to evaluate the clinical outcomes of the sequential correction of severe and rigid kyphoscoliosis.MethodsBetween January 2014 and December 2020, 27 adults with severe and rigid kyphoscoliosis underwent sequential correction combined with posterior grade 4 or grade 5 spinal osteotomy. Radiological parameters, including the major curve Cobb angle, kyphotic angle, coronal imbalance, and sagittal vertical axis (SVA), were compared. Patient self-reported health-related quality of life (HRQOL) scores were used to evaluate clinical outcomes.ResultsThe mean major curve Cobb angle improved from 134.30 ± 13.24° to 44.48 ± 9.34° immediately after surgery and to 46.11 ± 8.94° at the final follow-up. The mean kyphotic angle improved from 112.15 ± 20.28° to 38.63 ± 15.00° immediately after surgery and to 39.85 ± 14.92° at the final follow-up. The mean preoperative major curve Cobb angle of grade 5 spinal osteotomy group was higher than that of grade 4 spinal osteotomy group. Coronal imbalance and SVA slightly improved. The patient self-reported HRQOL scores improved postoperatively and at the final follow-up. Activity, appearance and total scores of the SRS-22 of the grade 5 spinal osteotomy group at the final follow-up were significantly better than those of the grade 4 spinal osteotomy group.ConclusionsSequential correction combined with posterior grade 4 or grade 5 spinal osteotomies is an excellent and safe treatment for severe and rigid kyphoscoliosis in adults. Sequential correction combined with posterior grade 5 spinal osteotomies can be used to correct severe and rigid kyphoscoliosis with higher major curve Cobb angle.

Directed Versus non-directed Standing Postures in Adolescent Idiopathic Scoliosis: Its Impact on Curve Magnitude, Alignment and Clinical Decision Making.

Prospective study. To investigate the difference in major curve Cobb angle and alignment between directed and non-directed positioning for adolescent idiopathic scoliosis (AIS) and to evaluate implications on treatment decision-making. Proper positioning of patients with spinal deformities is important for assessing usual functional posture in standing, so management strategies can be customized accordingly. Whether postural variability affects coronal and sagittal radiological parameters and the impact of posture on management decisions remain unknown. Patients with AIS presenting for initial consultation at the tertiary scoliosis clinic were recruited. They were asked to stand in two positions: passive, non-directed position; and directed position by the radiographer. Radiological assessment included major and minor Cobb angle, coronal balance, spinopelvic parameters, sagittal balance and alignment. Cobb angle difference >5⁰ between directed and non-directed positioning was considered clinically impactful. Patients with or without such difference were compared. Over- or under-estimation of the major curve (at 25⁰ or 40⁰) by non-directed positioning were examined due to relevance to bracing and surgical indications. This study included 198 patients, with 22.2% experiencing Cobb angle difference (>5⁰) between positioning. The major curve Cobb angle was smaller in non-directed than directed positioning (median difference: -6.0⁰, upper and lower quartile: -7.8, 5.8), especially for curves ≥30⁰. Patients with a Cobb angle difference had changes in shoulder balance (P=0.007) when assuming a directed position. Non-directed positioning had 14.3% of major Cobb 25⁰ underestimated and 8.8% overestimated, whereas 11.1% of curves >40⁰ were underestimated. Strict adherence to a standardized radiographic protocol is mandatory for reproducing spine radiographs reliable for curve assessment, as a non-directed position demonstrates smaller Cobb angles. Postural variation may lead to over-, or under-estimation, of the curve size relevant for both bracing and surgical decision-making. II.

Vertebral body tethering in adolescent idiopathic scoliosis with more than 2years of follow-up- systematic review and meta-analysis.

Whilst spinal fusion remains the gold standard in the treatment of adolescent idiopathic scoliosis (AIS), anterior vertebral body tethering (AVBT) is gaining momentum with relatively few studies on its efficacy thus far. To conduct a systematic review reporting on the early results of AVBT for patients undergoing surgery for AIS. We aimed to systematically evaluate the relevant literature pertaining to the efficacy of AVBT with respect to degree of correction of the major curve Cobb angle, complications and revision rates. Systematic review. Of a total of 259 articles, 9 studies met the inclusion criteria and were analysed. Overall, 196 patients of (mean age 12.08years) underwent an AVBT procedure for correction of AIS with a mean follow-up of 34months. Degree of Cobb angle correction, complications and revision rates were used as outcome measures. A systematic review of the literature on AVBT was performed for studies published between Jan 1999-March 2021 applying the PRISMA guidelines. Isolated case reports were excluded. Overall, 196 patients of (mean age 12.08years) underwent an AVBT procedure for correction of AIS with a mean follow-up of 34months. There was a significant correction of the main thoracic curve of scoliosis (mean preoperative Cobb angle 48.5°, post-operative Cobb angle at final follow-up of 20.1°, P = 0.01). Overcorrection and mechanical complications were seen in 14.3% and 27.5% of cases, respectively. Pulmonary complications including atelectasis and pleural effusion were seen in 9.7% of patients. Tether revision was performed in 7.85%, and revision to a spinal fusion in 7.88%. This systematic review incorporated 9 studies of AVBT and 196 patients with AIS. The complication and revision to spinal fusion rates were 27.5% and 7.88%, respectively. The current literature on AVBT is restricted largely to retrospective studies with non-randomised data. We would recommend a prospective, multi-centre trial of AVBT with strict inclusion criteria and standardised outcome measures.

Are torso asymmetry and torso displacements in a computer brace model associated with initial in-brace correction in adolescent idiopathic scoliosis?

BackgroundLack of initial in-brace correction is strongly predictive for brace treatment failure in adolescent idiopathic scoliosis (AIS) patients. Computer-aided design (CAD) technology could be useful in quantifying the trunk in 3D and brace characteristics in order to further investigate the effect of brace modifications on initial in-brace correction and subsequently long-term brace treatment success. The purpose of this pilot study was to identify parameters obtained from 3D surface scans which influence the initial in-brace correction (IBC) in a Boston brace in patients with AIS.MethodsTwenty-fiveAIS patients receiving a CAD-based Boston brace were included in this pilot study consisting of 11 patients with Lenke classification type 1 and 14 with type 5 curves. The degree of torso asymmetry and segmental peak positive and negative torso displacements were analyzed with the use of patients’ 3D surface scans and brace models for potential correlations with IBC.ResultsThe mean IBC of the major curve on AP view was 15.9% (SD = 9.1%) for the Lenke type 1 curves, and 20.1% (SD = 13.9%) for the type 5 curves. The degree of torso asymmetry was weakly correlated with patient’s pre-brace major curve Cobb angle and negligible correlated with major curve IBC. Mostly weak or negligible correlations were observed between IBC and the twelve segmental peak displacements for both Lenke type 1 and 5 curves.ConclusionBased on the results of this pilot study, the degree of torso asymmetry and segmental peak torso displacements in the brace model alone are not clearly associated with IBC.

Can the proximal humeral ossification system (PHOS) effectively guide brace weaning in patients with adolescent idiopathic scoliosis?

PurposeThe proximal humeral epiphyses can be conveniently viewed in routine spine radiographs. This study aimed to investigate whether the proximal humeral epiphyseal ossification system (PHOS) can be used to determine the timing of brace weaning in adolescent idiopathic scoliosis (AIS), as assessed by the rate of curve progression after brace weaning.MethodsA total of 107 patients with AIS who had weaned brace-wear at Risser Stage ≥ 4, no bodily growth and post-menarche ≥ 2 years between 7/2014 and 2/2016 were studied. Increase in major curve Cobb angle > 5° between weaning and 2-year follow-up was considered curve progression. Skeletal maturity was assessed using the PHOS, distal radius and ulna (DRU) classification, Risser and Sanders staging. Curve progression rate per maturity grading at weaning was examined.ResultsAfter brace-wear weaning, 12.1% of the patients experienced curve progression. Curve progression rate for weaning at PHOS Stage 5 was 0% for curves < 40°, and 20.0% for curves ≥ 40°. No curve progression occurred when weaning at PHOS Stage 5 with radius grade of 10 for curves ≥ 40°. Factors associated with curve progression were: Months post-menarche (p = 0.021), weaning Cobb angle (p = 0.002), curves < 40° versus ≥ 40° (p = 0.009), radius (p = 0.006) and ulna (p = 0.025) grades, and Sanders stages (p = 0.025), but not PHOS stages (p = 0.454).ConclusionPHOS can be a useful maturity indicator for brace-wear weaning in AIS, with PHOS Stage 5 having no post-weaning curve progression in curves < 40°. For large curves ≥ 40°, PHOS Stage 5 is also effective in indicating the timing of weaning together with radius grade ≥ 10.

Comparison of Overall Complication Rates in VCR-Based vs Non-VCR-Based Corrective Techniques in Severe Rigid Kyphoscoliosis Patients: A Systematic Review and Meta-Analysis.

Systematic review and meta-analysis. Compilation of complication outcomes data from the surgical management of severe rigid kyphoscoliosis patients using VCR-based vs non-VCR-based corrective maneuvers is lacking. This meta-analysis aimed to compare complication outcomes between those classified osteotomy approaches. Thorough literature review and meta-analysis were conducted between January 2000 and September 2021. The selection criteria were studies: i) reporting major curve Cobb angle of ≥80° and flexibility of <25% or 30%; ii) comparing VCR or ≥ Type V Schwab osteotomy defined as VCR-based vs [non-VCR-based] techniques, (any osteotomy or technique other than VCR); iii) published in English with ≥10 patients; iv) reporting complication rates; and v) having minimum of 2-year follow-up. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Significance level was set at (P < .05). Of the 174 patients included, 52.30% (n = 91) and 47.70% (n = 83) were VCR-based and non-VCR-based, respectively. The incidence of dural tears/nerve injuries/significant intraoperative-neuromonitoring changes was significantly higher; [OR = 6.78, CI= (1.75 to 26.17), I2 = 0%, (P = .006)] in the VCR-based group than the non-VCR-based group. The 'overall surgical and medical' complication rate was significantly higher in the VCR-based group, [OR = 1.94, CI= (1.02 to 3.67), I2 = 31%, (P = .04)]. Both VCR-based and non-VCR-based surgical techniques for management of severe rigid scoliosis and kyphoscoliosis patients pose comparable overall surgical complication rates, while a significantly higher perioperative neurological complication incidence was associated with VCR-based technique compared to the non-VCR-based techniques. The VCR-based technique was associated with 6.78 times higher incidence of neurological complications compared to non-VCR-based techniques.

Hounsfield unit for assessing asymmetrical loss of vertebral bone mineral density and its correlation with curve severity in adolescent idiopathic scoliosis.

BackgroundLow bone mass concomitantly occurs in patients with adolescent idiopathic scoliosis (AIS) and can persist until skeletal maturity. The purpose of this study was to assess the asymmetrical loss of vertebral bone mineral density (vBMD) and its correlation with curve severity in patients with AIS using Hounsfield unit (HU) values measured from computed tomography scans.MethodsA total of 93 AIS patients were retrospectively recruited. The HU values of the vertebral body (VB-HU) and pedicle screw trajectory (PST-HU) were measured from four vertebrae above (Apex − 4) to four below (Apex + 4) the apical vertebra (Apex) of the major curve. The VB-HU and PST-HU at the upper end vertebra, Apex, and lower end vertebra within the concave and convex sides of the major and minor curves and stable vertebrae were obtained.ResultsA significant correlation was found between the Cobb angle and VB-HU at the periapical levels of the major curve. VB-HU and PST-HU at periapical levels were significantly greater within the concavity than the convexity of both major and minor curves. The asymmetric ratios of VB-HU and PST-HU were significantly correlated with the major curve Cobb angle, peaked at the apex, and gradually diminished from the apex to the end vertebrae. The asymmetrical loss of vBMD aggravated with the progression of curve severity, presenting as VB-HU, significantly decreased within the convexity and insignificantly decreased within the concavity of the major curve.ConclusionThe asymmetrical loss of vBMD was associated with the progression of curve severity in AIS. For patients with severe AIS, the distraction of the pedicle screws at the concave side should be a priority in correcting the major curve, and supplemental anchors and larger-sized screws should be placed within the convex side around the apex of the major curve to reduce the risk of screw loosening after surgery.

Health-Related Quality of Life Assessment in Idiopathic Early-Onset Scoliosis Treated by Serial Mehta Casting.

This was a retrospective clinical study of patients with idiopathic early-onset scoliosis (IEOS) treated by serial Mehta derotational cast in a single facility. A standardized casting protocol was used for patients aged ≤5 years with IEOS (curve ≥20°). Patients' demographics, clinical and radiological outcomes, and major curve Cobb angle were recorded, and health-related quality of life (HRQoL) using the 24-item early-onset scoliosis questionnaire (EOSQ-24) was assessed. A total of 15 patients with IEOS were managed by serial Mehta cast between October 2014 and September 2018 with a mean follow-up period of 42.33 ± 6.37 (range 32-55) months. The mean precast curve was 56.8° ± 12.01°, and the mean final postcast curve was 26.4° ± 19.12° (P = 0.0008). The EOSQ-24 was inversely proportional to the magnitude of the residual curve. There were 2 cases with superficial skin irritation and a single case with repeated vomiting after casting. IEOS can be managed effectively by serial Mehta cast, which is proved not only by the clinical and radiological outcome but also by the improvement of the quality of life of the patients and their families as measured by the EOSQ-24.

When Will You Succeed Casting Patients With Early-onset Scoliosis? Prospective Evaluation of Predictive Radiographic Parameters.

In a recent retrospective study, in cast correction of the major curve correlated with final curve size in patients with early-onset scoliosis treated with casting. We therefore sought to perform a prospective study with controlled methodology to determine if there are parameters associated with reduction of coronal deformity. A prospective, observational study was conducted between 2014 and 2019 at selected sites willing to comply with a standard radiographic and follow-up protocol. Radiographic data was collected at time points of precast, in traction, initial in-cast, and at minimum 1 year follow-up. Multivariate linear regression models were utilized to control for potential confounders using a stepwise procedure. Twenty-nine patients met inclusion criteria. On multivariate analysis, traction major curve (P=0.043) and initial in-cast (P=0.011) major curve Cobb angles were independently associated with final out of cast major curve Cobb angle. The only factor that was independently associated with failure to cure (<15-degree major curve) was traction major curve Cobb angle (P=0.046). A threshold traction major curve Cobb angle of 20 degrees was found to have good accuracy with 81% sensitivity and 73% specificity (receiver operator curve area: 0.869, P<0.001). A traction major curve Cobb angle over 20 degrees would accurately predict failure of casting treatment to cure scoliosis in 79% of cases. A threshold in-cast major curve Cobb angle of 21 degrees was found to have slightly less accuracy than traction with 69% sensitivity, 82% specificity, and 74% accuracy (receiver operator curve area: 0.830, P=0.004). Radiographic measurements in traction and initially in the cast are predictive of curve size at follow-up for children with early-onset scoliosis treated with casting. The standardization and utility of traction films should be further explored. Level II.