Aims. There is a paucity of information on the pre-operative coronal imbalance in patients with degenerative lumbar scoliosis (DLS) and its influence on surgical outcomes. Patients and Methods. A total of 284 DLS patients were recruited into this study, among whom 69 patients were treated surgically and the remaining 215 patients conservatively Patients were classified based on the coronal balance distance (CBD): Type A, CBD < 3 cm; Type B, CBD > 3 cm and C7 Plumb Line (C7PL) shifted to the concave side of the curve; Type C, CBD > 3 cm and C7PL shifted to the convex side. Results. A total of 99 of the 284 (34.8%) patient presented with a pre-operative coronal imbalance (mean CBD: 48.5, standard deviation 18.7 mm). More patients with a Type B malalignment were observed than with a Type C malalignment (62 versus 37). A total of 21 pf the 69 (30.4%) surgically treated patients had a post-operative coronal imbalance, which was found to be more prevalent in Type C patients (p < 0.001). At follow-up, less improvement was observed in terms of Short Form-36 Physical Component Score and visual analogue score for back pain (p = 0.034 and 0.025, respectively) in Type C patients. Conclusion. This study shows that patients with Type C coronal malalignment may be at greater risk of post-operative coronal imbalance following posterior osteotomy. Cite this article: Bone Joint J 2016;98-B:1227–33

Aims. The aim of this study was to compare the clinical and radiological outcomes of patients with early-onset scoliosis (EOS), who had undergone spinal fusion after distraction-based spinal growth modulation using either traditional growing rods (TGRs) or magnetically controlled growing rods (MCGRs). Methods. We undertook a retrospective review of skeletally mature patients who had undergone fusion for an EOS, which had been previously treated using either TGRs or MCGRs. Measured outcomes included sequential coronal T1 to S1 height and major curve (Cobb) angle on plain radiographs and any complications requiring unplanned surgery before final fusion. Results. We reviewed 43 patients (63% female) with a mean age of 6.4 years (SD 2.6) at the index procedure, and 12.2 years (SD 2.2) at final fusion. Their mean follow-up was 8.1 years (SD 3.4). A total of 16 patients were treated with MCGRs and 27 with TGRs. The mean number of distractions was 7.5 in the MCGR group and ten in the TGR group (p = 0.471). The mean interval between distractions was 3.4 months in the MCGR group and 8.6 months in the TGR group (p < 0.001). The mean Cobb angle had improved by 25.1° in the MCGR group and 23.2° in TGR group (p = 0.664) at final follow-up. The mean coronal T1 to S1 height had increased by 16% in the MCGR group and 32.9% in TGR group (p = 0.001), although the mean T1 to S1 height achieved at final follow-up was similar in both. Unplanned operations were needed in 43.8% of the MCGR group and 51.2% of TGR group (p = 0.422). Conclusion. In this retrospective, single-centre review, there were no significant differences in major curve correction or gain in spinal height at fusion. Although the number of planned procedures were fewer in patients with MCGRs, the rates of implant-related complications needing unplanned revision surgery were similar in the two groups. Cite this article: Bone Joint J 2022;104-B(2):257–264

Aims. To compare the rates of sagittal and coronal correction for all-pedicle screw instrumentation and hybrid instrumentation using sublaminar bands in the treatment of thoracic adolescent idiopathic scoliosis (AIS). Methods. We retrospectively reviewed the medical records of 124 patients who had undergone surgery in two centres for the correction of Lenke 1 or 2 AIS. Radiological evaluation was carried out preoperatively, in the early postoperative phase, and at two-year follow-up. Parameters measured included coronal Cobb angles and thoracic kyphosis. Postoperative alignment was compared after matching the cohorts by preoperative coronal Cobb angle, thoracic kyphosis, lumbar lordosis, and pelvic incidence. Results. A total of 179 patients were available for analysis. After matching, 124 patients remained (62 in each cohort). Restoration of thoracic kyphosis was significantly better in the sublaminar band group than in the pedicle screw group (from 23.7° to 27.5° to 34.0° versus 23.9° to 18.7° to 21.5°; all p < 0.001). When the preoperative thoracic kyphosis was less than 20°, sublaminar bands achieved a normal postoperative thoracic kyphosis, whereas pedicle screws did not. In the coronal plane, pedicle screws resulted in a significantly better correction than sublaminar bands at final follow-up (73.0% versus 59.7%; p < 0.001). Conclusion. This is the first study to compare sublaminar bands and pedicle screws for the correction of a thoracic AIS. We have shown that pedicle screws give a good coronal correction which is maintained at two-year follow-up. Conversely, sublaminar bands restore the thoracic kyphosis better while pedicle screws are associated with a flattening of the thoracic spine. In patients with preoperative hypokyphosis, sublaminar bands should be used to restore a proper sagittal profile. Cite this article: Bone Joint J 2020;102-B(3):376–382

Aims. Significant correction of an adolescent idiopathic scoliosis in the coronal plane through a posterior approach is associated with hypokyphosis. Factors such as the magnitude of the preoperative coronal curve, the use of hooks, number of levels fused, preoperative kyphosis, screw density, and rod type have all been implicated. Maintaining the normal thoracic kyphosis is important as hypokyphosis is associated with proximal junctional failure (PJF) and early onset degeneration of the spine. The aim of this study was to determine if coronal correction per se was the most relevant factor in generating hypokyphosis. Methods. A total of 95 patients (87% female) with a median age of 14 years were included in our study. Pre- and postoperative radiographs were measured and the operative data including upper instrumented vertebra (UIV), lower instrumented vertebra (LIV), metal density, and thoracic flexibility noted. Further analysis of the post-surgical coronal outcome (group 1 < 60% correction and group 2 ≥ 60%) were studied for their association with the postoperative kyphosis in the sagittal plane using univariate and multivariate logistic regression. Results. Of the 95 patients, 71.6% (68) had a thoracic correction of > 60%. Most (97.8%) had metal density < 80%, while thoracic flexibility > 50% was found in 30.5% (29). Preoperative hypokyphosis (< 20°) was present in 25.3%. A postoperative thoracic hypokyphosis was four times more likely to occur in patients with thoracic correction ≥ 60% (odds ratio (OR) 4.08; p = 0.005), after adjusting for confounding variables. This association was not affected by metal density, thoracic flexibility, LIV, UIV, age, or sex. Conclusion. Our study supports the ‘essential lordosis’ hypothesis of Roaf and Dickson, i.e. with a greater ability to translate the apical vertebra towards the midline, there is a commensurate lengthening of the anterior column due to the vertebral wedging. Cite this article: Bone Joint J 2020;102-B(4):513–518

Aims. To systematically evaluate whether bracing can effectively achieve curve regression in patients with adolescent idiopathic scoliosis (AIS), and to identify any predictors of curve regression after bracing. Methods. Two independent reviewers performed a comprehensive literature search in PubMed, Ovid, Web of Science, Scopus, and Cochrane Library to obtain all published information about the effectiveness of bracing in achieving curve regression in AIS patients. Search terms included “brace treatment” or “bracing,” “idiopathic scoliosis,” and “curve regression” or “curve reduction.” Inclusion criteria were studies recruiting patients with AIS undergoing brace treatment and one of the study outcomes must be curve regression or reduction, defined as > 5° reduction in coronal Cobb angle of a major curve upon bracing completion. Exclusion criteria were studies including non-AIS patients, studies not reporting p-value or confidence interval, animal studies, case reports, case series, and systematic reviews. The GRADE approach to assessing quality of evidence was used to evaluate each publication. Results. After abstract and full-text screening, 205 out of 216 articles were excluded. The 11 included studies all reported occurrence of curve regression among AIS patients who were braced. Regression rate ranged from 16.7% to 100%. We found evidence that bracing is effective in achieving curve regression among compliant AIS patients eligible for bracing, i.e. curves of 25° to 40°. A similar effect was also found in patients with major curve sizes ranging from 40° to 60° when combined with scoliosis-specific exercises. There was also evidence showing that a low apical vertebral body height ratio, in-brace correction, smaller pre-brace Cobb angle, and daily pattern of brace-wear compliance predict curve regression after bracing. Conclusion. Bracing provides a corrective effect on scoliotic curves of AIS patients to achieve curve regression, given there is high compliance rate and the incorporation of exercises. Cite this article: Bone Joint J 2024;106-B(3):286–292

Aims. It is uncertain whether instrumented spinal fixation in nonambulatory children with neuromuscular scoliosis should finish at L5 or be extended to the pelvis. Pelvic fixation has been shown to be associated with up to 30% complication rates, but is regarded by some as the standard for correction of deformity in these conditions. The incidence of failure when comparing the most caudal level of instrumentation, either L5 or the pelvis, using all-pedicle screw instrumentation has not previously been reported. In this retrospective study, we compared nonambulatory patients undergoing surgery at two centres: one that routinely instrumented to L5 and the other to the pelvis. Methods. In all, 91 nonambulatory patients with neuromuscular scoliosis were included. All underwent surgery using bilateral, segmental, pedicle screw instrumentation. A total of 40 patients underwent fusion to L5 and 51 had their fixation extended to the pelvis. The two groups were assessed for differences in terms of clinical and radiological findings, as well as complications. Results. The main curve (MC) was a mean of 90° (40° to 141°) preoperatively and 46° (15° to 82°) at two-year follow-up in the L5 group, and 82° (33° to 116°) and 19° (1° to 60°) in the pelvic group (p < 0.001 at follow-up). Correction of MC and pelvic obliquity (POB) were statistically greater in the pelvic group (p < 0.001). There was no statistically significant difference in the operating time, blood loss, or complications. Loss of MC correction (> 10°) was more common in patients fixated to the pelvis (23% vs 3%; p = 0.032), while loss of pelvic obliquity correction was more frequent in the L5 group (25% vs 0%; p = 0.007). Risk factors for loss of correction (either POB or MC) included preoperative coronal imbalance (> 50 mm, odds ratio (OR) 11.5, 95%confidence interval (CI) 2.0 to 65; p = 0.006) and postoperative sagittal imbalance (> 25 mm, OR 11.0, 95% CI1.9 to 65; p = 0.008). Conclusion. We found that patients undergoing pelvic fixation had a greater correction of MC and POB. The rate of complications was not different. Preoperative coronal and postoperative sagittal imbalance were associated with increased risks of loss of correction, regardless of extent of fixation. Therefore, we recommend pelvic fixation in all nonambulatory children with neuromuscular scoliosis where coronal or sagittal imbalance are present preoperatively. Cite this article: Bone Joint J 2020;102-B(2):261–267

Aims. The aim of this study was to determine the influence of pelvic parameters on the tendency of patients with adolescent idiopathic scoliosis (AIS) to develop flatback deformity (thoracic hypokyphosis and lumbar hypolordosis) and its effect on quality-of-life outcomes. Patients and Methods. This was a radiological study of 265 patients recruited for Boston bracing between December 2008 and December 2013. Posteroanterior and lateral radiographs were obtained before, immediately after, and two-years after completion of bracing. Measurements of coronal and sagittal Cobb angles, coronal balance, sagittal vertical axis, and pelvic parameters were made. The refined 22-item Scoliosis Research Society (SRS-22r) questionnaire was recorded. Association between independent factors and outcomes of postbracing ≥ 6° kyphotic changes in the thoracic spine and ≥ 6° lordotic changes in the lumbar spine were tested using likelihood ratio chi-squared test and univariable logistic regression. Multivariable logistic regression models were then generated for both outcomes with odds ratios (ORs), and with SRS-22r scores. Results. Reduced T5-12 kyphosis (mean -4.3° (. sd. 8.2); p < 0.001), maximum thoracic kyphosis (mean -4.3° (. sd. 9.3); p < 0.001), and lumbar lordosis (mean -5.6° (. sd. 12.0); p < 0.001) were observed after bracing treatment. Increasing prebrace maximum kyphosis (OR 1.133) and lumbar lordosis (OR 0.92) was associated with postbracing hypokyphotic change. Prebrace sagittal vertical axis (OR 0.975), prebrace sacral slope (OR 1.127), prebrace pelvic tilt (OR 0.940), and change in maximum thoracic kyphosis (OR 0.878) were predictors for lumbar hypolordotic changes. There were no relationships between coronal deformity, thoracic kyphosis, or lumbar lordosis with SRS-22r scores. Conclusion. Brace treatment leads to flatback deformity with thoracic hypokyphosis and lumbar hypolordosis. Changes in the thoracic spine are associated with similar changes in the lumbar spine. Increased sacral slope, reduced pelvic tilt, and pelvic incidence are associated with reduced lordosis in the lumbar spine after bracing. Nevertheless, these sagittal parameter changes do not appear to be associated with worse quality of life. Cite this article: Bone Joint J 2019;101-B:1370–1378

Aims. To report the outcome of spinal deformity correction through anterior spinal fusion in wheelchair-bound patients with myelomeningocele. Methods. We reviewed 12 consecutive patients (7M:5F; mean age 12.4 years (9.2 to 16.8)) including demographic details, spinopelvic parameters, surgical correction, and perioperative data. We assessed the impact of surgery on patient outcomes using the Spina Bifida Spine Questionnaire and a qualitative questionnaire. Results. The mean follow-up was 5.4 years (2 to 14.9). Nine patients had kyphoscoliosis, two lordoscoliosis, and one kyphosis. All patients had a thoracolumbar deformity. Mean scoliosis corrected from 89.6° (47° to 151°) to 46.5° (17° to 85°; p < 0.001). Mean kyphosis corrected from 79.5° (40° to 135°) to 49° (36° to 65°; p < 0.001). Mean pelvic obliquity corrected from 19.5° (8° to 46°) to 9.8° (0° to 20°; p < 0.001). Coronal and sagittal balance restored to normal. Complication rate was 58.3% (seven patients) with no neurological deficits, implant failure, or revision surgery. The degree of preoperative spinal deformity, especially kyphosis and lordosis, correlated with increased blood loss and prolonged hospital/intensive care unit stay. The patients reported improvement in function, physical appearance, and pain after surgery. The parents reported decrease in need for everyday care. Conclusion. Anterior spinal fusion achieved satisfactory deformity correction with high perioperative complication rates, but no long-term sequelae among children with high level myelomeningocele. This resulted in physical and functional improvement and high reported satisfaction. Cite this article: Bone Joint J 2021;103-B(6):1133–1141

Aims. To report the surgical outcome of patients with severe Scheuermann’s kyphosis treated using a consistent technique and perioperative management. Methods. We reviewed 88 consecutive patients with a severe Scheuermann's kyphosis who had undergone posterior spinal fusion with closing wedge osteotomies and hybrid instrumentation. There were 55 males and 33 females with a mean age of 15.9 years (12.0 to 24.7) at the time of surgery. We recorded their demographics, spinopelvic parameters, surgical correction, and perioperative data, and assessed the impact of surgical complications on outcome using the Scoliosis Research Society (SRS)-22 questionnaire. Results. The mean follow-up was 8.4 years (2 to 14.9). There were 85 patients (96.6%) with a thoracic deformity. Posterior spinal fusion with closing-wedge osteotomies and hybrid instrumentation was used in 86 patients; two patients underwent combined anterior and posterior spinal fusion. The mean kyphosis was corrected from 94.5° to 47.5° (p < 0.001). Coronal and sagittal balance returned to normal. The rate of complications was 12.5%: there were no neurological deficits, implant failure, or revision surgery. SRS-22 scores improved from a mean 3.6 (1.3 to 4.1) to 4.6 (4.2 to 5.0) at two years (p < 0.001) with a high rate of patient satisfaction. Non-smokers and patients with lower preoperative SRS-22 scores showed greater improvement in their quality of life. Sagittal pelvic balance did not change after correction of the kyphosis and correlated with lumbar lordosis but not with thoracic or thoracolumbar kyphosis. Conclusion. Posterior spinal fusion using hybrid instrumentation, closing-wedge osteotomies, and iliac bone grafting achieves satisfactory correction of a severe kyphosis resulting in improvements in physical and mental health and a high degree of patient-reported satisfaction. Cite this article: Bone Joint J 2021;103-B(1):148–156

Aims. Spinal fusion remains the gold standard in the treatment of idiopathic scoliosis. However, anterior vertebral body tethering (AVBT) is gaining widespread interest, despite the limited data on its efficacy. The aim of our study was to determine the clinical efficacy of AVBT in skeletally immature patients with idiopathic scoliosis. Methods. All consecutive skeletally immature patients with idiopathic scoliosis treated with AVBT enrolled in a longitudinal, multicentre, prospective database between 2013 and 2016 were analyzed. All patients were treated by one of two surgeons working at two independent centres. Data were collected prospectively in a multicentre database and supplemented retrospectively where necessary. Patients with a minimum follow-up of two years were included in the analysis. Clinical success was set a priori as a major coronal Cobb angle of < 35° at the most recent follow-up. Results. A total of 57 patients were included in the study. Their mean age was 12.7 years (SD 1.5; 8.2 to 16.7), with 95% being female. The mean preoperative Sanders score and Risser grade was 3.3 (SD 1.2), and 0.05 (0 to 3), respectively. The majority were thoracic tethers (96.5%) and the mean follow-up was 40.4 months (SD 9.3). The mean preoperative major curve of 51° (SD 10.9°; 31° to 81°) was significantly improved to a mean of 24.6° (SD 11.8°; 0° to 57°) at the first postoperative visit (45.6% (SD 17.6%; 7% to 107%); p < 0.001)) with further significant correction to a mean of 16.3° (SD 12.8°; -12 to 55; p < 0.001) at one year and a significant correction to a mean of 23° (SD 15.4°; -18° to 57°) at the final follow-up (42.9% (-16% to 147%); p < 0.001). Clinical success was achieved in 44 patients (77%). Most patients reached skeletal maturity, with a mean Risser score of 4.3 (SD 1.02), at final follow-up. The complication rate was 28.1% with a 15.8% rate of unplanned revision procedures. Conclusion. AVBT is associated with satisfactory correction of deformity and an acceptable complication rate when used in skeletally immature patients with idiopathic scoliosis. Improved patient selection and better implant technology may improve the 15.8% rate of revision surgery in these patients. Further scrutiny of the true effectiveness and long-term risks of this technique remains critical. Cite this article: Bone Joint J 2020;102-B(12):1703–1708

Ventral screw osteosynthesis is a common surgical method for treating fractures of the odontoid peg, but there is still no consensus about the number and diameter of the screws to be used. The purpose of this study was to develop a more accurate measurement technique for the morphometry of the odontoid peg (dens axis) and to provide a recommendation for ventral screw osteosynthesis. Images of the cervical spine of 44 Caucasian patients, taken with a 64-line CT scanner, were evaluated using the measuring software MIMICS. All measurements were performed by two independent observers. Intraclass correlation coefficients were used to measure inter-rater variability. The mean length of the odontoid peg was 39.76 mm (. sd. 2.68). The mean screw entry angle α was 59.45° (. sd. 3.45). The mean angle between the screw and the ventral border of C2 was 13.18° (. sd. 2.70), the maximum possible mean converging angle of two screws was 20.35° (. sd. 3.24). The measurements were obtained at the level of 66% of the total odontoid peg length and showed mean values of 8.36 mm (. sd. 0.84) for the inner diameter in the sagittal plane and 7.35 mm (. sd. 0.97) in the coronal plane. The mean outer diameter of the odontoid peg was 12.88 mm (. sd. 0.91) in the sagittal plane and 11.77 mm (. sd. 1.09) in the coronal plane. The results measured at the level of 90% of the total odontoid peg length were a mean of 6.12 mm (. sd. 1.14) for the sagittal inner diameter and 5.50 mm (. sd. 1.05) for the coronal inner diameter. The mean outer diameter of the odontoid peg was 11.10 mm (. sd.  1.0) in the sagittal plane and 10.00 mm (. sd. 1.07) in the coronal plane. In order to calculate the necessary screw length using 3.5 mm cannulated screws, 1.5 mm should be added to the measured odontoid peg length when anatomical reduction seems possible. The cross-section of the odontoid peg is not circular but slightly elliptical, with a 10% greater diameter in the sagittal plane. In the majority of cases (70.5%) the odontoid peg offers enough room for two 3.5 mm cannulated cortical screws. Cite this article: Bone Joint J 2013;95-B:536–42

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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.

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The aim of this study was to reassess the rate of neurological, psoas-related, and abdominal complications associated with L4-L5 lateral lumbar interbody fusion (LLIF) undertaken using a standardized preoperative assessment and surgical technique.

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Only a few studies have investigated the long-term health-related quality of life (HRQoL) in patients with an idiopathic scoliosis. The aim of this study was to investigate the overall HRQoL and employment status of patients with an idiopathic scoliosis 40 years after diagnosis, to compare it with that of the normal population, and to identify possible predictors for a better long-term HRQoL.

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The prevalence of scoliosis is not known in patients with idiopathic short stature, and the impact of treatment with recombinant human growth hormone on those with scoliosis remains controversial. We investigated the prevalence of scoliosis radiologically in children with idiopathic short stature, and the impact of treatment with growth hormone in a cross-sectional and retrospective cohort study.

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To determine whether side-bending films in scoliosis are assessed for adequacy in clinical practice; and to introduce a novel method for doing so.

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The aim of this study was to compare outcomes after growth-friendly treatment for early-onset scoliosis (EOS) between patients with skeletal dysplasias versus those with other syndromes.

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To determine the major risk factors for unplanned reoperations (UROs) following corrective surgery for adult spinal deformity (ASD) and their interactions, using machine learning-based prediction algorithms and game theory.

Aims. Magnetically controlled growing rod (MCGR) systems use non-invasive spinal lengthening for the surgical treatment of early-onset scoliosis (EOS). The primary aim of this study was to evaluate the performance of these devices in the prevention of progression of the deformity. A secondary aim was to record the rate of complications. Patients and Methods. An observational study of 31 consecutive children with EOS, of whom 15 were male, who were treated between December 2011 and October 2017 was undertaken. Their mean age was 7.7 years (2 to 14). The mean follow-up was 47 months (24 to 69). Distractions were completed using the tailgating technique. The primary outcome measure was correction of the radiographic deformity. Secondary outcomes were growth, functional outcomes and complication rates. Results. The mean Cobb angle was 54° (14° to 91°) preoperatively and 37° (11° to 69°) at the latest follow-up (p < 0.001). The mean thoracic kyphosis (TK) was 45° (10° to 89°) preoperatively and 42° (9° to 84°) at the latest follow-up. The mean T1–S1 height increased from 287 mm (209 to 378) to 338 mm (240 to 427) (p < 0.001) and the mean sagittal balance reduced from 68 mm (-76 to 1470) preoperatively to 18 mm (-32 to 166) at the latest follow-up. The mean coronal balance was 3 mm (-336 to 64) preoperatively and 8 mm (-144 to 64) at the latest follow-up. The mean increase in weight and sitting and standing height at the latest follow-up was 45%, 10% and 15%, respectively. The mean Activity Scale for Kids (ASKp) scores increased in all domains, with only personal care and standing skills being significant at the latest follow-up (p = 0.02, p = 0.03). The improvements in Cobb angle, TK and T1-S1 heights were not related to gender, the aetiology of the EOS, or whether the procedure was primary or conversion from a conventional growing rod system. A total of 21 children developed 23 complications at a rate of 0.23 per patient per year. Seven developed MCGR-specific complications. Complications developed at a mean of 38 months (3 to 67) after the initial surgery and required 22 further procedures. Children who developed a complication were more likely to be younger, have syndromic EOS, and have a single-rod construct (6.9 versus 9.3 years, p = 0.034). Conclusion. The progression of EOS can be controlled using MCGRs allowing growth and improved function. Younger and syndromic children are more likely to develop complications following surgery. Cite this article: Bone Joint J 2018;100-B:1187–1200

Aims. We present the results of correcting a double or triple curve adolescent idiopathic scoliosis using a convex segmental pedicle screw technique. Patients and Methods. We reviewed 191 patients with a mean age at surgery of 15 years (11 to 23.3). Pedicle screws were placed at the convexity of each curve. Concave screws were inserted at one or two cephalad levels and two caudal levels. The mean operating time was 183 minutes (132 to 276) and the mean blood loss 0.22% of the total blood volume (0.08% to 0.4%). Multimodal monitoring remained stable throughout the operation. The mean hospital stay was 6.8 days (5 to 15). Results. The mean post-operative follow-up was 5.8 years (2.5 to 9.5). There were no neurological complications, deep wound infection, obvious nonunion or need for revision surgery. Upper thoracic scoliosis was corrected by a mean 68.2% (38% to 48%, p < 0.001). Main thoracic scoliosis was corrected by a mean 71% (43.5% to 8.9%, p < 0.001). Lumbar scoliosis was corrected by a mean 72.3% (41% to 90%, p < 0.001). No patient lost more than 3° of correction at follow-up. The thoracic kyphosis improved by 13.1° (-21° to 49°, p < 0.001); the lumbar lordosis remained unchanged (p = 0.58). Coronal imbalance was corrected by a mean 98% (0% to 100%, p < 0.001). Sagittal imbalance was corrected by a mean 96% (20% to 100%, p < 0.001). The Scoliosis Research Society Outcomes Questionnaire score improved from a mean 3.6 to 4.6 (2.4 to 4, p < 0.001); patient satisfaction was a mean 4.9 (4.8 to 5). . Conclusions. This technique carries low neurological and vascular risks because the screws are placed in the pedicles of the convex side of the curve, away from the spinal cord, cauda equina and the aorta. A low implant density (pedicle screw density 1.2, when a density of 2 represents placement of pedicle screws bilaterally at every instrumented segment) achieved satisfactory correction of the scoliosis, an improved thoracic kyphosis and normal global sagittal balance. Both patient satisfaction and functional outcomes were excellent. Cite this article: Bone Joint J 2017;99-B:1080–7