Aims. This systematic review aims to identify 3D predictors derived from biplanar reconstruction, and to describe current methods for improving curve prediction in patients with mild adolescent idiopathic scoliosis. Methods. A comprehensive search was conducted by three independent investigators on MEDLINE, PubMed, Web of Science, and Cochrane Library. Search terms included “adolescent idiopathic scoliosis”,“3D”, and “progression”. The inclusion and exclusion criteria were carefully defined to include clinical studies. Risk of bias was assessed with the Quality in Prognostic Studies tool (QUIPS) and Appraisal tool for Cross-Sectional Studies (AXIS), and level of evidence for each predictor was rated with the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. In all, 915 publications were identified, with 377 articles subjected to full-text screening; overall, 31 articles were included. Results. Torsion index (TI) and apical vertebral rotation (AVR) were identified as accurate predictors of curve progression in early visits. Initial TI > 3.7° and AVR > 5.8° were predictive of curve progression. Thoracic hypokyphosis was inconsistently observed in progressive curves with weak evidence. While sagittal wedging was observed in mild curves, there is insufficient evidence for its correlation with curve progression. In curves with initial Cobb angle < 25°, Cobb angle was a poor predictor for future curve progression. Prediction accuracy was improved by incorporating serial reconstructions in stepwise layers. However, a lack of post-hoc analysis was identified in studies involving geometrical models. Conclusion. For patients with mild curves, TI and AVR were identified as predictors of curve progression, with TI > 3.7° and AVR > 5.8° found to be important thresholds. Cobb angle acts as a poor predictor in mild curves, and more investigations are required to assess thoracic kyphosis and wedging as predictors. Cumulative reconstruction of radiographs improves prediction accuracy. Comprehensive analysis between progressive and non-progressive curves is recommended to extract meaningful thresholds for clinical prognostication. Cite this article: Bone Jt Open 2024;5(3):243–251

Adolescent idiopathic scoliosis is a three-dimensional deformity of the spine, affecting 1–3% of the population. Most cases are treated conservatively. Curves exceeding 45° in the thoracic spine and 40° in the lumbar spine may require correction and fusion surgery, to limit the progression of the curve and prevent restrictive pulmonary insufficiency (curves above 70°). When fusion is required, it may be performed either by posterior or anterior approaches. Posterior is useful for thoracic (Lenke I) curves, notably to correct the thoracic hypokyphosis frequently observed in AIS. Anterior approaches by thoraco-lombotomies allow an effective correction of thoraco-lumbar and lumbar curves (Lenke V and VI), with fewer levels fused than with posterior approaches. However, the approach requires diaphragm splitting and one may be concerned about the long-term pulmonary consequences. The literature provides conflicting insight regarding the consequences of the approach in anterior scoliosis correction, the interpretation of the results being difficult knowing that the correction of the scoliosis itself may improve pulmonary function. This is a retrospective observational study done at a Tertiary Institution. The HRQOL scores have been collected as a prospective cohort. Clinical and radiographic data was collected from patients charts and analysed by two senior surgeons. A cohort of 64 patients were operated in the given time period. 50 patients met the inclusion criteria. No major complications were reported. The Union rate was 100% and no post operative complications were noted. Pre and post SRS scores improved in all patients. The Anterior approach for Lenke V AIS gives great surgical exposure and allows for excellent correction of Cobb angle with minimal risk to the patient

Thoracoplasty has been described as primarily a cosmetic resection of the rib hump. The purpose of our study was to investigate whether removal of a normal spine stabilizer affected the correction of the spine, particularly in the sagittal plane. Thirty-eight adolescent idiopathic scoliosis patients who underwent thoracoplasty were compared with eighteen controls in terms of maintenance of correction and patient satisfaction using the SRS questionnaire. Thoracoplasty had no effect on curve correction in the coronal plane. It did show a significant effect on sagittal plane correction of the thoracic hypokyphosis without any significant detractors in terms of patient outcome. To investigate whether thoracoplasty affected spinal correction. We also compared patient outcomes thoracoplasty patients and controls, as well as long-term curve maintenance. Thoracoplasty did increase the correction of thoracic hypokyphosis, without any significant detractors in terms of patient outcome. Current understanding of the scoliotic curve as a three dimensional helix has led to increased recognition of the importance of sagittal contour and balancing the spine’s reciprocal curves to avoid problems such as flat back syndrome. Correction of the scoliotic curve intraoperatively may require the removal of spine stabilizers such as the disc and annulus, posterior facet and capsule, and thoracic cage stabilizers such as the ribs. Thirty-eight patients who had either concave para-median or convex Steel mid-rib thoracoplasty were reviewed and compared to eighteen controls. Prospective patient outcomes using the Scoliosis Research Society instrument with an average of > one year follow-up were available for thirty patients. Degree of curve settle and maintenance of correction was measured on follow-up radiographs. Thoracoplasty had no effect on curve correction in the coronal plane. It did show a significant effect on sagittal plane correction of thoracic hypokyphosis. The paramedian group showed a mean increase of tweleve degrees, the Steel group 8.7 degrees, and, the control group 3.1 degrees. No significant difference between pain, satisfaction, function, and self-image was found. Long-term radiographic follow-up (average three years) showed a mean coronal curve settle of 4.6 degrees (thoracoplasty) versus 3.1 degrees (non-thoracoplasty), and an accompanying improvement in sagittal plane correction of 4.2 and 3.0 degrees, respectively

Pedicle screw constructs (PSC) in scoliosis are a recently established and widely accepted method of managing scoliotic curves posteriorly. There is a perceived improved coronal and rotational correction when compared to other posterior only constructs. With continued use of this method, the authors and deformity surgeons in general have become aware of persistent thoracic hypokyphosis. This review of 3 years of scoliosis cases using PSC looks at four different implant strategies utilised to manage this problem and our current practice. These strategies were:. All titanium 5.5 mm rod diameter (Expedium, Depuy spine). All titanium 5.5 mm rod diameter with periapical washers (Expedium, Depuy spine). All titanium 6.0 mm rod diameter (Pangea, Synthes). Titanium pedicle screws with 5.5 mm diameter cobalt chrome rods (Expedium Depuy spine). We have reviewed our outcomes with these strategies with respect to thoracic hypokyphosis. Strategy 1 had the highest rate of hypokyphosis on postoperative radiographs. Strategy 4 seems to have the best correction of coronal and sagittal plane abnormality post operatively. As a consequence, our current practice is the use of titanium pedicle screws and 5.5 mm diameter cobalt chrome rods when managing scoliosis with a pedicle screw construct

Aim:. To evaluate the effect of a stiffer rod in normalising thoracic hypokyphosis in adolescent idiopathic scoliosis (AIS). Methods:. A retrospective review of AIS cases performed at our institution was carried out. In order to reduce variability, the analysis included only Lenke 1 cases which had all pedicle screw constructs, with similar constructs and implant density. Cases that underwent anterior release were excluded. All cases had the same implant (Expedium 5.5, Depuy-Synthes, Raynham, USA). The rod material differed in that some cases had 5.5 titanium, whilst others had 5.5 cobalt chrome. The preoperative and postoperative sagittal Cobb angle was measured. Results:. 35 patients met the inclusion criteria. 15 had titanium rods and 20 had cobalt chrome rods. The mean fulcrum correction index was similar between groups. The preoperative coronal and sagittal Cobb was similar between the two groups. There was no statistically significant difference in the postoperative sagittal Cobb between the two groups (ANOVA one way test). Discussion:. Despite the theoretical advantage of a stiffer construct improving the sagittal profile in AIS, this study identified no such benefit despite closely matching the two groups. All pedicle screw constructs do not seem to improve the sagittal profile despite the use of a stiffer rod. Conflict of interest:. Depuy-Synthes fund a fellow in this unit. Conflict Of Interest Statement: No conflict of interest

Purpose of the study: The long-term results after surgical treatment of idiopathic scoliosis depends not only on the correction in the coronal plane but also the restoration of good sagittal balance and thus satisfactory sagittal curvatures. Recent publications have shown moderate correction of the thoracic hypokyphosis of idiopathic scoliosis with instrumentations using hooks and pedicular screws. We report results in the coronal and sagittal play with a reduction technique by simultaneous translation on two rods (ST2R). Material and method: The radiographic parameters were measured preoperatively, at 6 weeks, at 1 year, and at last follow-up (range 2 – 7.4 years) in a consecutive series of 72 patients treated with posterior instrumentation and reduction using the ST2R system. The same operator performed all procedures using stable anchors (pedicle screws or self-stabilizing clamps). Screws and clamps had a threaded polyaxial extension which was linked to the rod by a connector. The deformity was reduced by progressively tightening the two rods alternatively using the nuts on the threaded extensions. This manoeuvre enabled the vertebrae to migrate progressively toward the rods, producing an anteroposterior translation. Results: In the coronal plane, the mean main curvature was reduced from 54 to 17 and was maintained (70%) without loss of angle at last follow-up. There was not difference between the 56 patients with thoracic scoliosis (Lenke 1–4) and the 16 patients with thoracolumbar or lumbar scoliosis (Lenke 5 and 6). In the sagittal plane, for the patients with preoperative hypokyphosis (32 patients < 20), the mean kyphosis was significantly improved from 9 to 30 and remained stable at last follow-up (31) with a mean gain of 21 (p< 0.001). One patient still had hypokyphosis (18) at last follow-up. For patients with normal kyphosis preoperatively (> 20), the mean gain was 7. Conclusion: In this consecutive series of 72 adolescents with idiopathic scoliosis, reduction by simultaneous translation on two rods was a simple and effect method which restored normal thoracic kyphosis

Purpose of the study: Prolongation of the phyisiological sagittal rectitude of the thoracolumbar junction (T11-T1) is often observed in thoracic, double major and lumbar idiopathic scoliosis. The purpose of this study was to check the potential relationship between vertebral rotation, type of curvature in the frontal plane, and the observation of sagittal rectitude exceeding four vertebrae. Material and methods: The preoperative radiographs of 54 patients (48 female, 6 male, mean age 21 years) with idiopathic scoliosis were analysed with Spineview. The type of curvature: thoracic, double major or lumbar (Lenke 1, 3 or 5) and the Cobb angles were noted. The levels included in the zone of sagittal rectitude, the thoracic kyphosis, the lumbar lordosis, the sacral slope, the pelvic incidence and version, the T1 to T9 tilts were noted on the lateral view. Vertebral rotation was analysed for all thoracic and lumbar vertebrae using the method described by Perdriolle, Nash and Moe on the anteroposterior radiographs. The axial rotation was measured on the scanner. Results: Curvatures ranged from 36 to 104° (mean 59°). Fifty-two patients had a flat or concave back. Mean T1 tilt was 3°; it was 6° at T9. The pelvic incidence was 49°, the sacral slope 40°, the pelvic version 9°. The detailed analysis demonstrated zones of inferior thoracic hypokyphosis, and superior lumbar hypolordosis resulting in sagittal rectitude (5–7 vertebrae). The maximal vertebral rotation was situated at the superior part of the hypokyphosis or the inferior part of the hypolordosis. Three configurations were identified: 27 thoracic curvatures (Lenke 1) with cranial prolongation of the sagittal rectitude (T8-L1) and maximal rotation at T7-T8; 21 double major curvatures (Lenke 3 with cranial and caudal prolongation (T9-L2 and maximal rotation at T8-T9 and L2-L3 respectively; and 6 lumbar curvatures (Lenke 5) with caudal prolongation (T12-L4) and maximal rotation at L1-L2. Conclusion: Thoracolumbar sagittal rectitude can be prolonged with three geometric configurations related to the type of thoracic, double major and lumbar curvatures. This zone of rectitude indicates the level of the maximal vertebral rotation at is superior or inferior extremity. It also reflects the zones of segmental hyperkyphosis and hypolordosis that need to be corrected during the surgical treatment of the scoliosis

Introduction Chicken studies implicate pinealectomy within a week of hatching as a cause of scoliosis. The nature of the scoliosis has been demonstrated to be similar to that of human idiopathic scoliosis. Scoliosis was not induced following pinealectomy in Rhesus monkeys (primate model). No human studies have been reported. The aim of this study is to determine if idiopathic scoliosis is associated with treatment for pineal lesions (presumably resulting in pinealectomy) in a human paediatric population. Methods A medical records search was performed in five Australian States for pineal lesions. Identified patients underwent clinical or radiological evaluation for scoliosis. Pathology varied from germ cell tumour, germinoma, pineoblastoma, teratoma to a pineal cyst and an epidermoid cyst. Treatment ranged from biopsy/ extirpation to radiotherapy/chemotherapy. Results Of 48 identified patients, thirteen are deceased. No scoliosis was present in the last imaging of the deceased. The mean age at presentation was 9.7 years (range 1–18 years). Ten are female. Two males have idiopathic scoliosis (4.2%). One has a 12° right upper thoracic curve (with 32° kyphosis) and the other has a 60° right thoracolumbar curve, requiring a two-stage arthrodesis. Discussion Although the incidence of idiopathic scoliosis in this cohort is greater than expected from Caucasian population studies (2–3%), it is not typical idiopathic-type, which has a female preponderance of larger deformities. New-born chicken studies demonstrate an incidence of between 50 and 100% scoliosis in the three months following pinealectomy. Chickens of both sexes are involved. Fundamental differences exist between chicken and human/primate models including the age at pinealectomy and the anatomical site of the pineal gland. Chickens have a naturally lordotic thoracic spinal curvature whilst humans/primates have a naturally kyphotic thoracic spine. Adolescents with idiopathic scoliosis have either thoracic hypokyphosis or a thoracic lordosis. Contrary to current beliefs, no causal link can be established between pineal lesions and the development of idiopathic scoliosis in a paediatric population

Background: context: In Adolescent Idiopathic Scoliosis (AIS), the correction of thoracic hypokyphosis with hooks instrumentation and also with pedicle screws system is moderate. Purpose: To compare radiographic results between two instrumentations with thoracic screws using two different. Methods: of reduction: cantilever reduction (CR group– MOSS-MIAMI system) versus simultaneous translation on two rods (ST group – PASSMED system). Study design: Retrospective comparative analysis of two consecutive cohorts of patients treated by the same surgeon at a single hospital. Patient sample: Forty-two adolescent idiopathic thoracic scoliosis (Lenke type 1, 2 and 3) underwent a posterior spinal fusion and instrumentation: 20 patients in CR group and 22 patients in the ST group. The minimum follow-up was two years (Mean follow-up: 71 months and 47 months). Outcomes measures: Thoracic sagittal kyphosis between T4 and T12 and Cobb angle measurements of major and minor curves evaluated preoperatively, postoperatively and the final visit, by an independent observer. Methods: In CR group, we have used polyaxial pedicle screws and one or two monoaxial thoracic hooks. In ST group, we have used polyaxial pedicle screws and poly-axial claws which provide same stability than screws. Three groups of preoperative kyphosis were generated: 11 patients with severe hypokyphosis (T4–T12 < 10°) (5 in CR group and 6 in ST group); 11 patients with mild hypokyphosis (between 10 and 20°) (respectively 4° vs 7°) and 20 with normokyphosis (> 20°) (respectively 11 vs 9). Results: At the final follow-up, for patients with a severe preoperative hypokyphosis, the mean gain was 14 degrees in the CR group (8° preop to 22° postop) and 25° in the ST group (6° preop to 31 postop) (p< 0.05). For patients xith mild hypokyphosis, te mean gains were respectively 7 degrees (16° preop to 23° postop) and 18° (16° preop to 34° postop) (p< 0.05). After surgery, 3 patients of CR group had hypokyphosis alors que all patients had normal kyphosis (> 20°) in the ST group. In the coronal plane, the mean correction of scoliosis are similar in the two groups (75% vs 69% p=NS). Discussion and Conclusion: In posterior instrumentation for AIS, simultaneous reduction on two rods provides a better correction of the thoracic kyphosis than the cantilever reduction in patient with preoperative hypokyphosis. This surgical technique seems to restore thoracic normal kyphosis

Aims

High-grade dysplastic spondylolisthesis is a disabling disorder for which many different operative techniques have been described. The aim of this study is to evaluate Scoliosis Research Society 22-item (SRS-22r) scores, global balance, and regional spino-pelvic alignment from two to 25 years after surgery for high-grade dysplastic spondylolisthesis using an all-posterior partial reduction, transfixation technique.