AIS is present in 3–5% of the general population. Large curves are associated with increased pain and reduced quality of life. However, no information is available on the impact of smaller curves, many of which do not reach secondary care. The objective of this project was to identify whether or not there is any hidden burden of disease associated with smaller spinal curves. The Avon Longitudinal Study of Parents and Children (ALSPAC) is a population-based birth cohort that recruited over 14,000 pregnant women from the Bristol area between 1991–1992 and has followed up their offspring regularly. At aged 15 presence or absence of spinal curvature ≥6degrees was identified using the validated DXA Scoliosis Measure in 5299 participants. At aged 18 a structured pain questionnaire was administered to 4083 participants. Chi-squared was used to investigate any association between presence of a spinal curve at aged 15 and self-reported pain at aged 18 years. Sensitivity analyses were performed by rerunning analyses after excluding those who were told at aged 13 they had a spinal curve (n=27), and using a higher spinal curve cut-off of ≥10degrees. Full data was available for 3184 participants. Of these, 56.8% were female, and 4.2% non-white reflecting the local population. 202 (6.3%) had a spinal curve ≥6degrees and 125 (3.9%) had a curve ≥10degrees. The mean curve size was 12degrees. 140/202 (69.3%) had single curves, and 57.4% of these were to the right. In total 46.3% of the 3184 participants reported aches and pains that lasted for a day or longer in the previous month, consistent with previous literature. 16.3% reported back pain. Those with spinal curves ≥6degrees were 42% more likely to report back pain than those without (OR 1.42, 95%CI 1.00 to 2.02, P=0.047). In addition, those with spinal curves had more days off school, were more likely to avoid activities that caused their pain, were more likely to think that something harmful is happening when they get the pain, and were more afraid of the pain than people without spinal curves (P<0.05). Sensitivity analyses did not change results. We present the first results from a population-based study of the impact of small spinal curves and identify an important hidden burden of disease. Our results highlight that small scoliotic curves that may not present to secondary care are nonetheless associated with increased pain, more days off school and avoidance of activities

Introduction. Forelimb and tail amputations of 3-week-old C57BL/6 mice are known to yield spinal curves similar to adolescent idiopathic scoliosis (AIS). Our previous work showed that tamoxifen produces a significant decrease in severity of these curves. Vertebral osteoporosis was thought to be related to AIS. Interestingly, a histological pilot study has shown that scoliotic mice given tamoxifen were less osteoporotic than were controls. Raloxifene is an oestrogen receptor modulator (SERM) similar to tamoxifen with a more specific effect on bone and is commonly used to treat osteoporosis. We aimed to study and compare the effects of tamoxifen and raloxifene on the rate and magnitude of scoliosis on a C57BL/6 mice model. Methods. 90 female 3-week-old C57BL/6 mice underwent amputations of forelimbs and tails. 78 were available for analysis and were grouped as control (no medications; n=24), TMX group (10 mg tamoxifen/L drinking water; n=30), and RLX group (10 mg raloxifene/L drinking water; n=241). Seven mice from each group (including scoliotic ones) were killed for histological study at week 20 after posteroanterior (PA) scoliosis radiograph examinations. The rest were killed at the end of week 40 after PA radiographs were obtained. Radiographs were assessed for presence and magnitude of spinal curves. Results. Week 20 analysis showed that lower thoracic curve rate (LTr) was higher in RLX group (p=0·029) and thoracolomber rate (TLr) was higher in TMX group (p=0·33) than in the control group. TMX group had higher upper thoracic (UT) curve magnitudes than did the control group (p=0·021). Week analysis showed similar curve rates in all groups. The RLX group had significantly decreased upper (p<0·0001) and lower (p=0·014) thoracic curve magnitudes compared with the control group. The TMX group had significantly lower UT curve magnitudes than did the control group (p=0·014). Conclusions. Raloxifene is shown to be as effective as tamoxifen in decreasing the magnitude of spinal deformities in C57BL/6 mice model. These results suggest that SERMs might be useful to prevent progression of scoliotic curves. Models of higher animals may be warranted

Work in the clinical environment led to the identification of the need for an instrument that was capable of continuously monitoring lumbar spinal curves of patients with back pain in order to establish degree of compliance with therapist advice regarding posture and activity during their normal day. Additionally, work by others in the laboratory setting has started to reveal some differences in motion parameters between those with and without back pain. Although there are changes of, in particular, maximum angular velocity associated with pathology of the spine, these changes may be considered the effects of the pathology. By looking at motion parameters taken over longer periods of time, more subtle differences, hopefully more related to possible causes of back pain, may be eventually identified. Factors such as time spent at extremes of range of motion and degree of activity or inactivity may have as great an affect on the production of back pain as vibration and heavy physical load. Unfortunately, even those factors thought most likely to contribute to the onset of back pain have only ever been proven to explain a small percentage of cases. By logging lumbar spinal curves continuously over many hours, profiles of lumbar spinal usage can be calculated thus enabling study of the relationships between posture, activity and pain production. Conventional instrumentation can not be used in the users normal environment either because of bulk or interference from everyday appliances. A small optical fibre goniometer (OFG) and data logger has been developed that is capable of continuously monitoring lumbar sagittal curves. It is robust and suitable for use in normal working environments. For use on the lumbar spine, the instrument’s stiffness was kept to a minimum to make it as comfortable to wear as possible. This has resulted in an instrument that is capable of reproduction of standard curves, in a jig, with a RMS error of 1°. A stiffer instrument would produce smaller errors. Comparative studies against other instruments have been carried out but are not yet published. The instrument takes the form of a small base plate, designed to be glued to the skin over the sacrum, and a flexible rod that is held in place over the lumbar spinous processes by two guide tubes also glued to the skin. The OFG weighs 25g and the datalogger 250g. The OFG and logger can be run safely for over 30 hours at a maximum logging frequency of 50 Hz. The datalogger has a facility for entry of coded information via selector switches which allow the user to put markers on the data train which could be activity of pain behaviour related. Initial trials have been carried out using the instrument to obtain motion profiles of 80 “normal” individuals, 10 males and 10 females from each of 4 age groupings; 20 to 29; 30 to 39; 40 to 49; 50 to 59. Logging duration was normally six hours during their working day. Data was collected at 25Hz. It was established that the instrument was able to produce basic motion parameters that were similar to other instruments. Although, no significant differences in ROM were found with age there were significant differences found between males and females in terms of end range flexion and extension. Additionally, the amplitude of oscillations of spinal curve during walking was found to significantly decrease with age. This may have been indicative of general stiffening of the lumbar spine with age or associated with a possible decrease in walking speed with age. It is envisaged that the instrument will find use in both ergonomic analysis as well as the study of the management of back pain. Use of the instrument to investigate patient compliance with therapist advice is planned and will hopefully help to develop the management of patients with low back trouble. Future development of the instrument is hoped to include incorporation of a sensor to monitor the angle of the base plate, as this will allow better interpretation of the data from the logger post data collection. Additionally information of base plate angle will allow some simple load calculations to be made. Repeatability trials have been carried out using human subjects. Here, the major source of variability was found to be the subjects themselves. Reapplication error was found to be small, compared to subject variability. Comparison with measurements taken using the flexicurve technique and also the Skill System (similar to Isotrak or Fastrak) has been undertaken. Here the two systems were found to follow each other achieving correlation coefficients of 0.99. However, more critical forms of analysis revealed relatively large differences, although these were no greater than others that have compared the inclinometer technique with the flexicurve

Introduction. In patients with adolescent idiopathic scoliosis (AIS), anomalous extra-spinal left-right skeletal length asymmetries in upper limbs, periapical ribs, and ilia beg the question as to whether these bilateral asymmetries are connected in some way with pathogenesis. The upper arm and iliac length asymmetries correlate significantly with adjacent spinal curve severity respectively in thoracic and lower (thoracolumbar and lumbar) spine. In lower limbs, skeletal length asymmetries and proximo-distal disproportion are unrelated to spinal curve severity. Overall, these observations raise questions about mechanisms that determine skeletal bilateral symmetry of vertebrates in health and disorder, and whether such mechanisms are involved in the cause of this disease. We investigated upper arm length (UAL) asymmetries in two groups of right-handed girls aged 11–18 years, with right thoracic adolescent idiopathic scoliosis (RT-AIS, n=98) from preoperative and screening referrals (mean Cobb angle 45°) and healthy controls (n=240). Methods. Right and left UAL were measured with a Harpenden anthropometer of the Holtain equipment, by one of four observers (RGB, AAC, RKP, FJP). UAL asymmetry was calculated as UAL difference, right minus left, in mm. Repeatability of the measurements was assessed by technical error of the measurement (TEM) and coefficient of reliability (R). Results. In girls with RT-AIS, UAL asymmetry was greater than it was in healthy girls (mean 5·9 mm vs 2·5 mm, ANOVA p<0·001, correcting for age), regressed negatively with age (p<0·001, r= –0·374), and correlated significantly with Cobb angle (r=0·342, p=0·001) and apical vertebral rotation (Perdriolle, r=0·291, p=0·004). In healthy girls, UAL asymmetry was unrelated to age. Plotted against years after estimated menarcheal age, right UAL overgrowth reduced significantly for girls with RT-AIS (r= –0·312, p=0·006, n=76) but not for healthy girls (r=0·000, p=0·985, n=121), which was a significant finding (p=0·052, ANOVA). Conclusions. The abnormal overgrowth of right upper arm length may be secondary, or pathogenetically associated with the RT-AIS trunk deformity. The negative regression of UAL asymmetry may result from (1) older girls having less residual growth and/or (2) a transient, or resolving, asymmetry process common to arm and trunk. We hypothesise that the pathogenetic process of RT-AIS may include two components: a transient bilateral asymmetry process and growth velocity, both of which affect trunk and arm growth. In the spine, these rarely lead to scoliosis resolution because biomechanical, postural, melatonin-signalling, and other factors sustain and aggravate the curve. Four pathomechanisms may induce the asymmetry process in trunk and arms involving (1) neuromuscular function, (2) motor cortex, (3) sympathetic nervous system, and (4) intrinsic time-tallies in growth plates, some of which suggest therapeutic possibilities

This research sought a mathematical model to relate the postero-anterior (PA) and lateral (LAT) views of the spinal curve in scoliosis in an attempt to justify the acquisition of only One X-ray, thereby reducing patient exposure to harmful X-radiation while preserving complete 3D characterization of the spine. Using powerful developments in functional statistics and machine learning, no such relation could be found. Thus, this research sustained the clinical decision to acquire two biplanar X-rays and supported current research in 3D spinal curvature analysis. Scoliosis is monitored through full spinal X-rays, and this serial protocol causes an increased incidence of cancer development. This research sustains the clinical decision at Hôpital Sainte-Justine in Montréal and elsewhere to acquire postero-anterior (PA) and lateral (LAT) X-rays, despite the increased exposure to X-radiation. Indeed, geometrically, these two views are required to reconstruct the spine in 3D. However, under the assumption of strong physiological patterns between the PA and LAT views of the spinal curve, one of these X-rays may be redundant for some or all patients. The purpose of this study was to seek this a priori assumption. To this end, a database consisting of three hundred and sixty-nine spinal reconstructions from distinct patients was used. Two powerful geometric modeling approaches were exploited: functional data analysis and minimum noise fractions. These resulted in five comprehensive, uncorrelated and noise-insensitive features in each plane. Simple linear regression yielded no relation that was statistically significant (p< 0.05) and genereralizable to a set of previously unseen samples. Therefore, nonlinear relational modeling was attempted using support vector regression, a recent advance in machine learning theory. This tool was incapable of identifying a robust regression, suggesting that the PA and LAT views are mathematically independent. Thus, this study highlights the necessity of two biplanar X-rays to evaluate scoliotic deformities and fully characterize spinal shape. Further, this study supports the practical insufficiency observed by clinical staff with respect to current 2D scoliosis classifications that has resulted in current efforts to propose 3D classification schemes

Introduction: Vertebral rotation is an important aspect of spinal deformity in scoliosis, associated with ribcage deformity (rib hump). Although both lateral curvature and axial rotation appear to increase together in progressive scoliosis, the mechanisms driving vertebral rotation are not clearly established and it is not known whether lateral curvature precedes rotation, or vice versa. This study investigates the hypothesis that intravertebral (within the bone) rotation in idiopathic scoliosis is caused by growth in the presence of gravity-induced torsions, the twisting moments generated by gravitational forces acting on the scoliotic spine. Methods: The twisting moment Tp acting at an arbitrary point P on a three-dimensional spinal curve is given by Tp=Mp·â, where Mp=r¥F is the total moment due to gravity force F acting at (vector) distance r, and â is the tangent to the spinal curve at P (Figure One). Standing radiographs for five idiopathic scoliosis patients were used to define three-dimensional curves representing the approximate axes of rotation of each spine, running along the anterior edge of the neural canal from T1 to S1. The equilibrium equations above were then solved to calculate gravity-induced torsions exerted by head and torso weight about the spinal axes for each patient. Intravertebral rotations were measured for the same patients using Aaro & Dahlborn’s technique with reformatted computed tomography images in the plane of superior and inferior endplates of each vertebra. The gravity-induced torsion curves were compared with intravertebral rotation measurements to see whether gravity-induced torsion is a likely contributor to intravertebral rotation. Results: Gravity-induced torques as high as 4 Nm act on the spines of idiopathic scoliosis patients due to static body weight in the standing position. Maximum intravertebral rotations (for a single vertebra) were approximately 78. There appears to be general agreement between the measured intravertebral rotations and profiles of gravity-induced torsion along the length of the spine (Figure 2). Rotation measurements confirm the finding of previous authors that maximum intravertebral rotations occur at the ends of a scoliotic curve (with little relative rotation at the apex), and this finding is consistent with the gravity-induced torsion profiles calculated. Conclusion: Gravity-induced torsion is a potential cause of vertebral rotation in idiopathic scoliosis. Since the spine must be curved in three-dimensions (out of plane) to produce such torques, vertebral rotation would be expected to occur subsequent to an initial lateral deviation, suggesting that coronal curvature ‘drives’ axial rotation during scoliosis progression

Background. After surgical correction of thoracic scoliosis, an improvement in the cardio-respiratory adaptation to exercise would be expected because of the correction of the rib cage associated with the spinal deformity. This work intended to evaluate the physiologic responses to incremental exercise in patients undergoing surgical correction of adolescent idiopathic scoliosis (AIS). The hypothesis of this study was that the exercise limitations described in patients with AIS could be related with the physical deconditioning instead of being linked to the severity of the vertebral deformity. Methods. Cross-sectional study of the exercise tolerance in a series of patients with AIS type Lenke 1A, before and 2 years after surgical correction. Twenty patients with AIS and 10 healthy adolescents aged between 12 and 17 years old were evaluated. The average magnitude of the curves was 60.3±12.9 Cobb. Cardio-respiratory function was assessed before surgery and at 2-year follow-up by maximal exercise tolerance test on treadmill following a Bruce standard protocol. Maximal oxygen uptake (VO2), VCO2, expiratory volume (VE), and VE/VO2 ratio were registered. Results. Before surgery, AIS patients showed lower values than healthy controls in all cardio-respiratory parameters. The most important restrictions were the VO2max in ml/kg/min. (30.3±5.4 vs 49.9±7.5), VE (43.2±10.3 vs 82.3±10.7) and VE/CO2 ratio (25.0±3.9 vs 29.6±4.2). Contrary to expectations, two years after surgery most of these parameters decreased but differences with preoperative data were no statistically significant. Besides the great correction of the deformity (coronal plane, 71.5%; axial rotation, 49.3%), the cardio-respiratory tolerance to the exercise was not modified by surgery. Conclusions. Patients with moderate-severe AIS showed a limited tolerance to maximal exercise that does not change 2 years after surgery. This findings suggests that the reduced cardio-pulmonary function during exercise is not strictly associated to the spinal deformity, since great corrections of the spinal curves does not improve functional ventilatory parameters. In addition, the results point out a severe exercise deconditioning in AIS patients. Level of evidence. Level IV

Aims

The aim of this study was to evaluate the reliability and validity of a patient-specific algorithm which we developed for predicting changes in sagittal pelvic tilt after total hip arthroplasty (THA).

The purpose of this study was to establish the a)feasibility, b) reproducibility of spinal Quantec scans (a non-intrusive surface topography system) and c) the validity of the Quantec Q-angle against Cobb angles from spinal radiographs, in non-ambulant children with cerebral palsy (CP). Eighteen non-ambulant children (aged 5–11 years) with CP had successful clinical, radiological and Quantec assessment of their spine while seated in a supportive seating system. Scoliosis incidence was 72%, Cobb angles ranged from 1–73° (mean 18.2°). Quantec scanning was feasible with appropriate postural support. Mean interobserver differences were 0.5 ± 5.8° (median 1.3°, 5 / 95th percentiles lying at −7.3 / 8.5° respectively). Mean differences between Cobb and Q-angle were 0.02 ± 6.2° (median 1.0°, with 5 / 95th percentiles lying at −8.2 / 7.7° respectively). Surface topography may be used to safely monitor the spine for non-ambulant CP children. Results show similar or improved trends to previous comparisons with idiopathic scoliosis. Ovadia (2007) showed an interobserver mean difference of 6.3 ± 4.9° using an Ortelius800TM system. Thometz (2000) showed mean differences between Cobb and Q-angle ranging from 1.1–12.6 ± 4.9–10.2°. Further research is needed for the user group described in this study with larger spinal curves. Ethics approval: Ethics approval granted by Leeds (West) Research Ethics Committee. COREC number: 08/H1307/22. Interest Statement: None

Introduction. Calmodulin probably has a regulatory role in muscle contraction and its antagonism may decrease the magnitude and progression of scoliosis. A separate study has shown that tamoxifen (TMX), a known antagonist, is effective in altering the natural history in an avian model; however, whether the same effect is conceivable in mammals is unknown. We aimed to analyse whether the natural course of scoliosis in mice may be altered by the administration of TMX. Methods. 60 female, 3-week-old, C57BL/6 mice underwent amputations of forelimbs and tails. 57 mice were assigned to three groups: control group, no medications; TMX group, 10 mg TMX/L drinking water; and combined group, 10 mg TMX plus 10 mg trifluoperazine (TFP)/L drinking water. PA scoliosis radiographs were taken at 20 and 40 weeks and evaluated for presence and magnitude of spinal curves. Results. Four mice were lost to follow-up in the TMX group. Overall scoliosis rate was significantly lower in the TMX group (33%) than in the control (90%) and combined (68%) groups (p=0·001) at week 40. Similarly, upper thoracic scoliosis rate was lower in the TMX group (27%) than in control (74%) and combined (47%) groups (p=0·01). The thoracic scoliosis rate was also lower in the TMX group (7%) group than in control (63%) and combined (26%) groups (p=0·001). Combined drug group had lower thoracic and lumbar Cobb angles (17·50° [□}3·45]) than did the control group (29·40° [□}5·98]; p=0·031). Furthermore, double curve incidence at week 40 was lower in TMX group (12%) than in control (74%) and combined (47%) groups (p=0·001). Triple curve incidence was lower in combined (0%) and TMX (6%) groups than in the control group (15%), but this result was not significant (p=0·167). Conclusions. TMX effectively decreased the incidence and magnitude of the scoliotic curves in C57BL/6 mice scoliosis model. This is a novel finding, and could be very important in opening a pathway for the conservative treatment of idiopathic scoliosis by oral drugs

The side distribution of single spinal curves in our school screening referrals for 1988–99 (n=218) suggests that the mechanism(s) determining curve laterality for the upper spine differs from those for the lower spine. We address here the laterality of right thoracic AIS. In the search to understand the aetiology of AIS some workers focus on mechanisms initiated in embryonic life including a disturbance of bilateral symmetry. The normal external bilateral symmetry of the body, highly conserved in vertebrates, results from a default process involving mesodermal somites. The normal internal asymmetry of the heart, major blood vessels, lungs and gut with its glands is also highly conserved among vertebrates. There is recent evidence that vertebrates retain an archaic asymmetric visceral organization in thoracic and abdominal organs (Cooke). In early embryonic life the visceral asymmetry develops from the breaking of the initial bilateral symmetry by a binary asymmetry switch producing asymmetric gene expression around the embryonic node and/or in the lateral plate mesoderm. In the mouse this switch occurs during gastrulation by cilia driving a leftward flow of fluid and morphogen(s) at the embryonic node (nodal flow) favouring precursors of heart, great vessels and viscera on the left. Based on the non-random laterality of thoracic AIS curves, we suggest that the binary asymmetry switch – through genetic/environmental factors extending to involve anomalously left-sided mesodermal precursors of vertebrae, ribs and/or muscles (positively or negatively), explains the distribution of right/left thoracic AIS. Some support for this hypothesis is the prevalence of scoliosis curve laterality associated with situs inversus

Aims: To obtain data on the bone mineral density state in a group of patients with neuroþbromatosis-1 spinal curves, to search for possible accompanying changes in the bone mineral turnover and to determine whether the genotypes at three known polymorphic loci are associated with a decreased bone mineral density in scoliotic patients with neuroþbromatosis. Methods: As part of the preoperative evaluation, dual X-ray absorptiometry was used to assess the bone mineral density of the lumbar spine in 12 patients with neuroþbromatosis- 1, supplemented by laboratory blood/urine investigations. In the pilot study, genetic polymorphisms were tested in the VDR gene, the COL1A1 gene and the OER gene by standard PCR technique. Results: A signiþcant decrease in bone mineral density of lumbar spine was measured. An inverse relation was suggested between the severity of scoliosis and the lumbar spine Z-scores. A three-fold prevalence of the homozygous polymorphism (CC) over the heterozygous form (Cc) of the COL1A1 gene was observed in the nonscoliotic NF1 patients as compared to the patients with scoliosis, presenting with an almost equal distribution in this genotype. Conclusions: The bony tissue abnormality observed intraoperatively in neuroþbromatosis-1 patients may be described as a diminution of the axial bone mineral density. The increased prevalence of the CC genotype of the COL1A1 gene in nonscoliotic NF patients appears to have a possible protective role against spinal deformities in NF1 patients. The evaluation of bone mineral density in the course of the preoperative planning is proposed in neuroþbromatosis-1

Aim: This study tested quantitatively whether calculated loading asymmetry of a spine with scoliosis, together with measured bone growth sensitivity to altered compression could explain the observed rate of scoliosis progression during adolescent growth. Scoliosis is thought to progress during growth because angular deformity produces asymmetrical spinal loading, generating asymmetrical growth, etc. in a ‘vicious cycle’. Materials and Methods: The magnitude of asymmetrical spinal loading was estimated for a spine with scoliosis, assuming physiologically plausible muscle activation strategies. In animal studies of vertebral and tibial growth plates of three different species, the growth plate response to sustained compression was measured and correlated with histological measures of chondrocytic proliferation and hypertrophic enlargement. These data were expressed in a linear formulation of growth G as a function of compressive stress, thus:. G = Gm(1-β(_-_m)); where β=1.68 MPa-1 was the empirically determined constant. (The subscript m signifies the ‘baseline’ growth and physiological stress). The vertebral and discal contributions to human adolescent spinal growth velocity were measured from stereo-radiographs of 208 patients of with scoliosis. The estimates of level-specific spinal loading asymmetry, together with the relationship expressing growth sensitivity to load were included in an analysis that was used to estimate the resulting asymmetrical vertebral growth, and its contribution to the progression of a scoliosis curvature. The initial geometry represented a lumbar scoliosis of 26° Cobb, averaged and scaled from measurements of fifteen patients’ radiographs. Spinal growth during each of the adolescent years was estimated from growth curves obtained from cross-sectional logistic-correlation of the radiographically determined spinal and vertebral heights versus age. Results: The analyses of mechanically modulated growth of the spine with an initial 26° Cobb scoliosis predicted curve progression for the majority of eleven loading conditions (effort magnitude and direction) that were analysed. The averaged final lumbar spinal curve magnitude was 34° Cobb at age 16 years when the efforts producing the spinal loading were at 50% of maximum effort, and it was 42° Cobb when the efforts were at 75% of maximum. Conclusions: An analysis that included analytically determined spinal load asymmetry and empirically determined growth sensitivity to load predicted that a substantial component of scoliosis progression during growth is biomechanically mediated. Clinical Relevance: The rationale for conservative management of scoliosis during skeletal growth assumes a biomechanical mode of deformity progression (Hueter-Volkmann principle). The present study provides a quantitative basis for this previously qualitative hypothesis. The findings suggest that an important difference between progressive and non-progressive scoliosis might lie in the differing muscle activation strategies adopted by individuals, leading to the possibility of improved prognosis and conservative interventions, as well as treatments employing early minimally invasive localised growth modulation or arrest

Introduction: Until now, the non-surgical therapeutic approach for idiopathic scoliosis (IS) was based on rigid brace using three points pressure and distraction technique. For the first time we wanted to use a dynamic approach for the treatment of IS. For this goal we have developed a Dynamic Correction Brace (DCB) or SpineCor to use the forces of the dynamic spine to optimise the reduction of spinal curves and permit neuromuscular integration during the period of correction. Methods and results: The effectiveness of the treatment depends on the reducibility of the curve with the brace. The goal of this study is to quantify the reducibility of scoliosis curves through a study of the variation of Cobb angle, during and after treatment. Between 1993 and 1999, 113 adolescents with classic indications of idiopathic scoliosis were treated by the same orthopaedist with the DCB. The mean age at the beginning of the treatment is 12.9 years old. The potential reducibility (PR) of the curves was estimated by the percentage of reduction of the initial Cobb’s angle corresponding to the maximum correction obtained during the course of treatment and after the treatment for the patient at maturity. Fifty patients have completed their treatment and are at maturity. From this cohort of patients treated by the DCB, 73.4% had a reduction of 5° or more than their principal Cobb angle; 22.8% were stable, but non-reducible, with a change of less than 5°; and 3.8% conserved an evolutive potential, with an increase in the Cobb angle of 5° or more. A significant difference was evident for PR between the group presenting an initial Cobb angle < 30° and those presenting an initial Cobb angle > 30° (p< 0.05). 65.8 per cent of the patients presented with an initial Cobb angle < 30° for a mean PR of 40.6% and were categorised according to the following: a) 26% of the patients had a PR ≤20%; b) 41% obtained a PR between 20% and 50%; and c) 33% had a PR > 50%. The other patients (34.2%) with an initial Cobb > 30° and a mean PR 22% were also categorised: 39% had a PR ≤20%; b) 48% had a PR between 20% and 50% and c) 13% > 50%. For patients who have completed their treatment 85% have a correction or are stabilised, 15% are worse or needed surgery during the treatment. For these patients, 53% have a correction of < 20%, 31% have a correction between 20 and 50%, and 16% have a correction of > 50%. Conclusion: The reducibility of the curve during the treatment is very informative concerning the prognosis treatment. The effectiveness of a DCB is comparable to effectiveness of other rigid braces for which the results have been published