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OBJECTIVES: The aim of this study was to examine whether asymmetric loading influences macrophage elastase (MMP12) expression in different parts of a rat tail intervertebral disc and growth plate and if MMP12 expression is correlated with the severity of the deformity. METHODS: A wedge deformity between the ninth and tenth tail vertebrae was produced with an Ilizarov-type mini external fixator in 45 female Wistar rats, matched for their age and weight. Three groups were created according to the degree of deformity (10°, 30° and 50°). A total of 30 discs and vertebrae were evaluated immunohistochemically for immunolocalisation of MMP12 expression, and 15 discs were analysed by western blot and zymography in order to detect pro- and active MMP12. RESULTS: No MMP12 expression was detected in the nucleus pulposus. Expression of MMP12 in the annulus progressively increased from group I to groups II and III, mainly at the concave side. Many growth plate chondrocytes expressed MMP12 in the control group, less in group I and rare in groups II and III. Changes in cell phenotype and reduction of cell number were observed, together with disorganisation of matrix microstructure similar to disc degeneration. ProMMP12 was detected at the area of 54 kDa and active MMP12 at 22 kDa. CONCLUSIONS: Expression of MMP12 after application of asymmetric loading in a rat tail increased in the intervertebral disc but decreased in the growth plate and correlated with the degree of the deformity and the side of the wedged disc. Cite this article: Bone Joint Res 2014;3:273-9.

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The present cross sectional study reveals trunk asymmetry (TA) in "normal" Mediterranean juveniles for the first time. The scoliometer readings in both standing and sitting forward bending position (FBP) of 3301 children, (1645 boys, and 1656 girls) aged from 3 to 9 years old were studied. TA was quantified by measuring angle of trunk rotation (ATR) and children were divided in two groups. In group I the ATR was 1 degrees to 6 degrees degrees and in group II> or =7 degrees . 71.25% of boys and 73.27% of girls in standing while 81.13% of boys and 80.74% of girls in sitting FBP, were symmetric (ATR=0 degrees ). The symmetry difference at standing minus sitting FBP for boys and girls was 9.88% and 7.43% respectively. Severe asymmetry (ATR> or =7 degrees ) was found in 1.74% of boys and in 1.75% of girls at the standing and in 1.21% and 1.22% at the sitting FBP respectively. Analysing ATR by age it appears that significant TA changes occur between 8-9 years of age for boys and between 6-7 and 8-9 years for girls. The amount of trunk asymmetry in children is the indicator for referral and further orthopaedic assessment. This report provides, for the first time information about the variability of back morphology in "normal" juveniles which is worth knowing when a child is examined for juvenile scoliosis.

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Wedging of the scoliotic inter-vertebral disc (IVD) was previously reported as a contributory factor for progression of idiopathic scoliotic (IS) curves. The present study introduces a theoretical model of IVD's role in IS pathogenesis and examines if, by reversing IVD wedging with conservative treatment (full- and night-time braces and exercises) or fusionless IS surgery with staples, we can correct the deformity of the immature spine. The proposed model implies the role of the diurnal variation and the asymmetric water distribution in the scoliotic IVD and the subsequent alteration of the mechanical environment of the adjacent vertebral growth plates. Modulation of the IVD by applying corrective forces on the scoliotic curve restores a close-to-normal force application on the vertebral growth plates through the Hueter-Volkmann principle and consequently prevents curve progression. The forces are now transmitted evenly to the growth plate and increase the rate of proliferation of chondrocytes at the corrected pressure side, the concave. Application of appropriately directed forces, ideally opposite to the apex of the deformity, likely leads to optimal correction. The wedging of the elastic IVD in the immature scoliotic spine could be reversed by application of corrective forces on it. Reversal of IVD wedging is thus amended into a "corrective", rather than "progressive", factor of the deformity. Through the proposed model, treatment of progressive IS with braces, exercises and fusionless surgery by anterior stapling could be effective.

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The value of school screening as a research tool for Idiopathic Scoliosis (IS) aetiology has not been recognized adequately in the literature. The aim of the present study is to summarize the contribution of school screening in research of IS aetiology. All the relative publications about research of IS aetiology which originated from our scoliosis school screening program were analyzed. Information is provided about a) the influence of environmental factors in IS prevalence, b) the IS prevalence in girls with visual deficiency, c) the role of melatonin in IS pathogenesis, d) the age at menarche in IS girls and its relation to laterality of the curve, e) the role of the brain in trunk asymmetry and IS pathogenesis, f) the role of the thoracic cage in IS pathogenesis, g) the impact of the lateral spinal profile, h) the role of the intervertebral discs in IS pathogenesis, i) the association of cavus foot with IS and j) anthropometric data in IS patients. The present study provides evidence to support that school screening programs should be continued not only for early detection of IS or for health care purposes, but also as a basis for epidemiological surveys until we learn much more about the aetiology of IS.

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There is skepticism and the worth of school screening for the purposes of health care has been challenged. Numerous reasons are raised by the negativists to abandon these programs, even though the value of school screening is well documented in the literature. The aim of the present study is to update the evidence based recommendations for the improvement of school screening effectiveness, in order to support its continuation. All the relative research papers which originated from our scoliosis school screening program were analyzed. Specific suggestions for a) the organization, b) the optimal age of screening according to the geographical latitude, c) the best examined position, d) the standardization of referrals, e) the follow up of younger referrals with trunk asymmetry and f) the reduction of the financial cost are made. Today there is evidence that the incidence of surgery can significantly be reduced in areas where idiopathic scoliosis can be detected at an early stage through these programs. The introduction of these recommendations to all the existing school screening programs is strongly suggested, to reduce the negative impact they may have on families and on the health system and to improve their effectiveness.

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