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Purpose: Soccer is a popular sport among children and adolescents that exposes to a high risk of injury. Several prevention programs, including the FIFA 11+ Kids program have been developed to decrease this injury rate. The aim of the study was to investigate the knowledge and use of the FIFA 11+ Kids program among soccer coaches of skeletally immature soccer players in a Swiss canton and analyze difficulties of implementing such a prevention program., Materials & Methods: First, an online survey was sent to all soccer coaches involved in Swiss training programs for male players from 7 to 13 years of age. Coaches were identified through existing Swiss coaching networks. A total of 237 coaches completed the survey. Second, the FIFA 11+ Kids program was implemented in three soccer teams (players from 7 to 13 years of age) during 6 months in the same canton. Utilization of FIFA 11+ Kids program and compliance of coaches were recorded by the research staff., Results: Around 84% of the included coaches in the survey were certified. Of those, 59% had been taught injury prevention during their course(s). Only 14% of the included coaches knew one of the FIFA programs (11, 11+, 11+ Kids), of those, about one-third (10 out of 237) used the FIFA 11+ Kids program. After 6 months, none of the soccer coaches applied the entire FIFA 11+ Kids program twice a week. One coach had completely abandoned the program. The main reasons for their disapproval were the time and surveillance needed and the players' lack of motivation. They stated, however, that the exercises were good if used occasionally., Conclusion: Injury prevention should be integrated in every soccer coach education courses. An adaptation of the FIFA 11+ Kids program should be considered, especially for the youngest players., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2023.)

Osteochondritis dissecans of the knee is a disease that typically affects skeletally immature patients. Clinically manifested with knee pain, limping, and joint disfunction, this condition has remained misunderstood and undervalued for a long period. Although being a rare condition, its awareness is of utmost clinical interest because of the possible severe consequences it can bring when misrecognized or inadequately treated. Its etiology remains unclear and is still debated. Many theories have been proposed, including inflammation, local ischemia, subchondral ossification abnormalities, genetic factors, and repetitive mechanical microtrauma, with a likely interplay of the same. This review article aims to deliver and discuss current and up-to-date concepts on epidemiology, etiology, and natural history of this pediatric condition. Level of evidence : level V., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2023.)

Women have made a place for themselves in sport, but there are still inequalities and specific characteristics compared to men. Puberty is marked by hormonal changes that give the female athlete advantages and disadvantages. She then goes through various periods of life that condition her relationship to her body and her performance. Anatomical and hormonal factors influence certain injuries. Proper management of the menstrual cycle can optimize performance. She is more at risk of nutritional deficiencies or energy deficit. Moreover, she suffers more from a negative body image, aggravated by the pressure of the perfect sportswoman! All of these aspects should be considered when taking care of her and following up regularly, in order to avoid long-term consequences., Competing Interests: Les auteurs n’ont déclaré aucun conflit d’intérêts en relation avec cet article.

Objective: To analyze the Winter Youth Olympic Games (YOG) 2020 athletes' understanding and perceptions of harassment and abuse in sport and their knowledge of reporting mechanisms., Design: A cohort study., Setting: The Winter YOG2020 in Lausanne, Switzerland., Participants: Accredited athletes at the YOG2020., Intervention: An athlete safeguarding educational program was delivered at the YOG2020. Participating athletes were encouraged to answer a survey embedded in the safeguarding educational materials during the YOG., Main Outcome Measures: Perception of occurrence of harassment and abuse as well as knowledge of the term "safe sport" and reporting mechanisms., Results: The survey response rate of athletes attending the Safe Sport Booth was 69%. When asked to define Safe Sport, 10% of athletes at the YOG2020 correctly identified a sport environment free from harassment and abuse, 20% identified fair play/antidoping, and 19% safety. When presented with the definition of harassment and abuse, 30.4% expressed surprise, in contrast to 46% in the summer YOG2018. A third (32%) reported that harassment and abuse was either "likely" or "very likely" present in their sport, which was similar to the YOG2018 (34%). The group of athletes not knowing where to go to report harassment and abuse was greater than in the YOG2018 (26% vs 11%). There were no differences in responses between competitive sex (boys' vs girls' events) or type of sport (team vs individual)., Conclusions: Outcomes of this study, such as the development of youth-friendly terminology and emphasizing mechanisms for reporting of harassment and abuse, should inform the development of safeguarding educational materials for youth athletes., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Competing Interests: The authors report no conflicts of interest.

Objectives: Doping-related knowledge, beliefs and attitude influence adolescent athletes' susceptibility to prohibited performance-enhancing substances. They might be modified by different cultural backgrounds. This study's aim was to analyse the geographical heterogeneity of doping-related knowledge, beliefs and attitude among adolescent elite athletes., Design: Cross-sectional study., Methods: A questionnaire was distributed to athletes participating in the Winter Youth Olympic Games 2020 in Switzerland. Main outcomes ('subjective and actual knowledge', 'beliefs' and 'attitude') were stratified for athletes' region of origin. Geographical heterogeneity was tested with a two-way analysis of variance, and two multiple regression analyses were conducted to assess independent associations of knowledge, age and athletes' geographical region with doping-related beliefs and attitude., Results: 533 athletes (54% females, mean age: 16.0 ± 1.0 years), completed the questionnaire (response rate: 33%). Actual knowledge was moderate-to-good (9.2 ± 2.9 correct answers out of 13), and scores of attitude and beliefs showed favourable patterns. Considerable geographical heterogeneity was found for knowledge (p < 0.001), beliefs (p = 0.004) and attitude (p < 0.001). Higher subjective knowledge and actual knowledge were favourably associated with attitude (β = -0.096, p = 0.049; β = -0.316, p < 0.001) and beliefs (β = 0.120, p = 0.016; β = 0.212, p < 0.001), independent of age and geographical region., Conclusions: This study demonstrates considerable geographical heterogeneity of doping-related knowledge, beliefs and attitude, which are three essential target factors of doping prevention in adolescent elite athletes. This evidence should encourage medical doctors and other professionals to change their educative anti-doping approach from teaching knowledge about negative consequences into investigating and forming a young athlete's mind-set., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: To describe the injury and illness characteristics among participating athletes during the Lausanne 2020 Youth Olympic Winter Games (YOG 2020), 9-22 January 2020., Methods: The daily number of athlete injuries and illnesses were recorded (1) through the reporting of all National Olympic Committee (NOC) medical teams and (2) in the polyclinic and medical venues by the Lausanne 2020 medical staff., Results: In total, 1783 athletes from 79 NOCs were observed. NOC and Lausanne 2020 medical staff reported 228 injuries and 167 illnesses, equating 11.7 injuries and 8.6 illnesses per 100 athletes over the 14-day period. Injury incidence was highest for snowboard slopestyle (39%), bobsleigh (36%), snowboard big air (29%), ski slopestyle (29%), snowboard cross (24%) and ski cross (21%), and lowest for speed skating, snowboard halfpipe and curling (2%-4%). The highest incidence of illness was recorded for curling (21%), ski mountaineering (15%), snowboard halfpipe (13%), bobsleigh (11%), cross-country skiing (10%) and figure skating (10%). Almost one-third of injuries were expected to result in time loss and 17% of illnesses. Most injuries occurred to the knee (12%) and head (11%), and 64% of illnesses affected the respiratory system. Overall, women suffered more injuries and illness than males., Conclusion: Overall, injury and illness rates were similar compared with recent YOG. While the rate and characteristics of injury and illness varied between sports, consistent patterns across YOG are emerging. If addressed, changes in highlighted areas of risk could have a positive impact on the health and well-being of these young athletes., Competing Interests: Competing interests: TS works as scientific manager in the Medical and Scientific Department of the IOC. LE is head of scientific activities in the Medical and Scientific Department of the IOC, and editor of the British Journal of Sports Medicine and Journal of Bone and Joint Surgery., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Differential diagnosis of soft tissue swelling on exposed body parts in the young athlete is large and mostly includes benign self-limiting conditions, once underlying lesion to the bone, the cartilage, and the ligaments is excluded. Morel-Lavallée lesion represents a rare soft tissue injury requiring prompt intervention to ensure favorable outcome., Cases: A 10-year-old boy presented with 2-week-old swelling of the medial side of the knee without recent traumatic event. Unawareness of Morel-Lavallée lesion in the differential diagnosis led to delayed diagnosis and treatment. A 16-year-old boy came to our pediatric tertiary care center with a similar presentation and history. Timely intervention allowed for favorable outcome and early return to play., Conclusions: Morel-Lavallée lesion is a rare entity in the pediatric population, although underreporting due to unfamiliarity with the diagnosis is highly probable. Raising awareness among professionals in charge of young athletes should allow for better reporting as well as for elaboration of a standardized treatment plan, including rapid intervention and early return to play., Competing Interests: Disclosure: The authors declare no conflict of interest., (Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.)

Athletes of pediatric age are growing in number. They are subject to a number of risks, among them sudden cardiac death (SCD). This study aimed to characterize the pediatric athlete population in Switzerland, to evaluate electrocardiographic findings based on the International Criteria for electrocardiography (ECG) Interpretation in Athletes, and to analyze the association between demographic data, sport type, and ECG changes. Retrospective, observational study of pediatric athletes (less than 18 years old) including medical history, physical examination, and a 12-lead resting ECG. The primary focus was on identification of normal, borderline, and abnormal ECG findings. The secondary observation was the relation between ECG and demographic, anthropometric, sport-related, and clinical data. The 891 athletes (mean 14.8 years, 35% girls) practiced 45 different sports on three different levels, representing all types of static and dynamic composition of the Classification of Sports by Mitchell. There were 75.4% of normal ECG findings, among them most commonly early repolarization, sinus bradycardia, and left ventricular hypertrophy; 4.3% had a borderline finding; 2.1% were abnormal and required further investigations, without SCD-related diagnosis. While the normal ECG findings were related to sex, age, and endurance sports, no such observation was found for borderline or abnormal criteria. Our results in an entirely pediatric population of athletes demonstrate that sex, age, and type of sports correlate with normal ECG findings. Abnormal ECG findings in pediatric athletes are rare. The International Criteria for ECG Interpretation in Athletes are appropriate for this age group., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Synovial sarcoma (SyS) is an aggressive mesenchymal malignancy invariably associated with the chromosomal translocation t(X:18; p11:q11), which results in the in-frame fusion of the BAF complex gene SS18 to one of three SSX genes. Fusion of SS18 to SSX generates an aberrant transcriptional regulator, which, in permissive cells, drives tumor development by initiating major chromatin remodeling events that disrupt the balance between BAF-mediated gene activation and polycomb-dependent repression. Here, we developed SyS organoids and performed genome-wide epigenomic profiling of these models and mesenchymal precursors to define SyS-specific chromatin remodeling mechanisms and dependencies. We show that SS18-SSX induces broad BAF domains at its binding sites, which oppose polycomb repressor complex (PRC) 2 activity, while facilitating recruitment of a non-canonical (nc)PRC1 variant. Along with the uncoupling of polycomb complexes, we observed H3K27me3 eviction, H2AK119ub deposition and the establishment of de novo active regulatory elements that drive SyS identity. These alterations are completely reversible upon SS18-SSX depletion and are associated with vulnerability to USP7 loss, a core member of ncPRC1.1. Using the power of primary tumor organoids, our work helps define the mechanisms of epigenetic dysregulation on which SyS cells are dependent., (© 2020 Boulay et al.)

Competitive sports demand numerous sacrifices from young adolescent athletes to reach early performance. This comes at a high price: many injuries, sometimes serious, recurrent fatigue, or undue pressure, bordering on abuse definitions. We present a new concept, which seems quite obvious: health for performance. In the presence of complete biopsychosocial health, adolescent athletes can thrive and meet their athletic, social and academic goals. A conducive sports environment, one which integrates interdisciplinarity with healthcare stakeholders, can allow for a complete harmonious positive development, one which is aligned with Public Health goals. Healthy adolescents may become performing athletes, but they will most definitely contribute positively to their wellbeing, as well as society in general., Competing Interests: Les auteurs n’ont déclaré aucun conflit d’intérêts en relation avec cet article.

Offering an interdisciplinary approach to the athletic adolescent helps to expand the evaluation framework when investigating a medical complaint. It is important to use the opportunity of each consultation to take not only a detailed history of the sporting practice, but also to investigate the social and familial context as well as healthy lifestyle of the young athlete. Considering young athletes within the larger picture of their developmental context of adolescence offers an opportunity to better respect the psychological and physical needs of this life phase. These needs are strongly related to the promotion of a good health among young athletes., Competing Interests: Les auteurs n’ont déclaré aucun conflit d’intérêts en relation avec cet article.

Benefits of physical activity during adolescence have widely been demonstrated. Yet, raising awareness among young athletes and their surrounding about risks associated with too early specialization or energy deficit--with or without eating disorder--is of outmost importance. Such behaviours can affect adolescents' physical or psychological development as well as compromise their athletic career not to mention the potential negative impact on their athletic performance. Primary care practitioners play an important role in early detection and prevention of overuse injuries as well as psychological distress associated with intense physical activity. Such situations need the intervention of an interdisciplinary team in order to prevent long-term complications.

Sport activity is a determinant of health and well-being for adolescents' psychological and physic development. Early detection of traumatic lesions or pathological condition among sportive adolescent in the light of their developmental stage is of outmost importance and is best done by an interdisciplinary team. This clinical management also aims at preventing consequences of inappropriate training. The CHUV has set-up a specific sports medicine outpatient consultation clinic for adolescents in the order to provide the best integrative management of young athletes.

The Wnt pathway is abnormally activated in the majority of colorectal cancers, and significant knowledge has been gained in understanding its role in tumor initiation. However, the mechanisms of metastatic outgrowth in colorectal cancer remain a major challenge. We report that autophagy-dependent metabolic adaptation and survival of metastatic colorectal cancer cells is regulated by the target of oncogenic Wnt signaling, homeobox transcription factor PROX1, expressed by a subpopulation of colon cancer progenitor/stem cells. We identify direct PROX1 target genes and show that repression of a pro-apoptotic member of the BCL2 family, BCL2L15, is important for survival of PROX1(+) cells under metabolic stress. PROX1 inactivation after the establishment of metastases prevented further growth of lesions. Furthermore, autophagy inhibition efficiently targeted metastatic PROX1(+) cells, suggesting a potential therapeutic approach. These data identify PROX1 as a key regulator of the transcriptional network contributing to metastases outgrowth in colorectal cancer., (Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.)

Concussion, a frequent injury in sports, is rarely evoked and often trivialized in children and teenagers. Knowledge of the diverse symptoms and signs to seek for is essential to an appropriate and secure management. The initial treatment relies on cognitive and physical rest followed by a progressive return to school and subsequently sport activities. The aim of this article is to review an injury whose prognosis is generally favourable, but whose rare complications can prove dramatic.

Aim: This study aimed to determine if a new measure of sphericity of the femoral head, the Sphericity Deviation Score (SDS), could be estimated reliably at the stage of healing of Legg-Calvé-Perthes disease (LCPD) and to determine if the SDS at the healing stage reflects the outcome at skeletal maturity., Methods: The SDS was measured with image analysis software on radiographs of 120 children with unilateral LCPD at healing of the disease and at skeletal maturity. The reproducibility of measurement was assessed. SDS values for hips in different Stulberg classes were calculated. On the basis of SDS values at healing of 82 children, a logistic regression model was developed to determine the probability of a good outcome at skeletal maturity. The validity of the model was tested on another 38 children., Results: The SDS values at the stage of healing and at skeletal maturity were comparable. The SDS values were lowest for Stulberg Class I hips and highest for Class IV and V hips. The validated regression model showed a very high probability of a good outcome (Stulberg Class I or II) at skeletal maturity if the SDS at the stage of healing was below 10., Conclusions: A reliable estimate of the outcome of LCPD at skeletal maturity can be made by computing the SDS as soon as the disease heals.

The osteoporosis of the child and the teenager is a pathological reality; its multifactorial pathogenesis often requires a collaborative approach and multidisciplinary. The osteoporosis characterized by a reduction in the bone mineral density is not a uniform pathology; it must be dealt with on all the levels by analyzing the factors of risks, by giving itself the diagnostic means and while insisting on the importance of a preventive approach as well as therapeutic.

The aim of this study was to compare clinical and radiological outcome of lateral condyle fracture of the elbow in children treated with bioabsorbable or metallic material. From January 2008 to December 2009, 16 children with similar fractures and ages were grouped according to the fixation material used. Children were seen at 3, 6, and 12 months and more than 4 years (mean 51.8 months) postoperatively. The clinical results were compared using the Mayo Elbow Performance Score (MEPS). Radiographic studies of the fractured and opposite elbow were assessed at last follow-up control. Twelve children had a sufficient followup and could be included in the study. Seven could be included in the traditional group and 5 in the bioabsorbable group. At 12 months, the MEPS was 100 for every child in both groups. Asymptomatic bony radiolucent visible tracks and heterotopic ossifications were noted in both groups. There were no significant differences in terms of clinical and radiological outcome between the two groups. The use of bioabsorbable pins or screws is a reasonable alternative to the traditional use of metallic materials for the treatment of lateral condyle fracture of the elbow in children.

An increasing number of anterior cruciate ligament injuries are now seen in children and girls seem to be equally affected. Such neglected or untreated lesions could be the cause of early degenerative changes. Recently, many authors support the trend toward early surgical management in skeletally immature patients with complex meniscal tear or recurrent knee instability after proper rehabilitation. Improvement in pediatric knowledge and surgical techniques tend to support a tendency for more surgical treatment in children. The type of management is choosing according to history and physical examination. Magnetic resonance imaging is a useful tool not only for diagnosis but also for surgical treatment planning. We usually recommend anterior cruciate ligament reconstruction in children with knee instability or with further damages to the joint.

Background: Though there is an impression that proximal femoral varus osteotomy (FVO) can result in a valgus deformity at the knee there is no agreement on this issue. This study was undertaken to ascertain whether a FVO predisposes to the development of genu valgum in children with Legg-Calvé-Perthes disease (LCPD)., Methods: One hundred and one children with unilateral LCPD who underwent a FVO during the active stage of the disease and 32 children who were treated non-operatively were followed till skeletal maturity. The FVO was performed with a 20° varus angulation in all the patients and weight-bearing was not permitted till the stage of reconstitution. The alignment of the knee was assessed clinically at skeletal maturity. A subset of 33 operated children also had full length standing radiographs of the limbs. The mechanical axis deviation, femur-tibial angle, lateral distal femoral angle and the medial proximal tibial angle of both limbs were measured on these radiographs., Results: The frequency of clinically appreciable mal-alignment of the knee was not greater on the affected side in patients who had undergone FVO when compared to the unaffected limb and also when compared to the affected limb in non-operated patients. The mechanical axis of the lower limb of operated children was relatively in more valgus than that of normal limbs but they fell within the normal range., Conclusion: This study does not support the impression that a proximal femoral osteotomy for LCPD predisposes to clinically discernable degrees of genu valgum in children who have had 20° of varus angulation at the osteotomy site and who have avoided weight-bearing for a prolonged period following surgery. Further studies are needed to clarify if genu valgum would develop if early post-operative weight-bearing is permitted., Level of Evidence: III.

Background: Large sample sizes are needed if discrete outcome measures are used to perform outcome studies, whereas more practicable sample sizes are sufficient if continuous outcome measures are used. Recognizing the need to devise reliable continuous outcome measures for assessing the outcomes of treatment of Legg-Calvé-Perthes disease, we evaluated a method of quantifying the shape and size of the femoral head and the femoral-acetabular relationship from computer images of anteroposterior and lateral radiographs with the help of image-analysis software., Methods: Radiographs of 121 skeletally mature individuals with healed Legg-Calvé-Perthes disease were analyzed, and the sphericity deviation score, femoral head enlargement, femoral neck growth inhibition, and composite femoral congruency arc were calculated., Results: Each of these measurements was reproducible, with distinctly different values for hips in each of the Stulberg classes. Measures of sphericity and congruence (the sphericity deviation score and the composite femoral congruency arc) could very clearly discriminate between spherical and aspherical hips, and there was a strong correlation between these two measurements., Conclusions: The study shows that it is possible to have reliable quantitative measures of the outcome of Legg-Calvé-Perthes disease at skeletal maturity.

Purpose: We encountered problems with the Curtis and Fisher technique of quadricepsplasty for congenital quadriceps contracture, including wound dehiscence, insufficient lengthening of the quadriceps and instability of the knee. We modified the operative technique to address these three problems. We undertook this study to evaluate the results of the modified technique of quadricepsplasty to determine if we succeeded in overcoming these limitations of the original technique., Methods: Twenty children (33 knees) underwent the modified Curtis and Fisher quadricepsplasty through a lateral incision; a long tongue of the rectus femoris was raised and the vasti mobilised without dividing the lateral retinaculae till the collateral ligaments. The children were followed up for a mean period of 63 months and evaluated. The healing of the wound, active and passive range of motion (ROM) of the knee, the stability of the knee, quadriceps power and knee function were assessed., Results: Primary wound healing occurred in 32 of 33 knees. Adequate lengthening of the quadriceps sufficient to facilitate knee flexion to 90° was possible. Considerable improvement in the ROM was noted. In non-syndromic congenital dislocation of the knee (CDK), the quadriceps power was Grade 5, but minor degrees of extensor lag was noted. In a proportion of patients, minor degrees of joint instability was present. The majority of children were community walkers. The overall results were better in non-syndromic CDK than in children with arthrogryposis, but differences of some variables were not significant., Conclusion: The modifications to the original Curtis and Fisher technique overcame the specific problems they were expected to avoid.

Purpose: The study was undertaken to: (1) describe the characteristic radiological features and problems of management of the loss of one condyle of the femur or tibia following septic arthritis of the knee in infancy and (2) test a hypothesis of the cause of the loss of a single condyle., Methods: Radiographs of eight children with the loss of one condyle of the femur or the tibia following septic arthritis in infancy were reviewed. The course and outcome in two of these children who underwent reconstructive operations were studied. The knees of 35 stillborn foetuses were dissected to determine if the presence of synovial septae could account for the isolated loss of one condyle following infection., Results: All eight cases showed characteristic features of loss of half the epiphysis, the underlying physis and part of the adjacent metaphysis; the other condyle was totally spared. The two children who underwent elaborate reconstructive procedures had poor outcomes at skeletal maturity, despite a series of additional operations. The foetal cadaveric study showed that complete infrapatellar synovial septae are present in some foetuses approaching 40 weeks of gestation., Conclusions: The pattern of loss of a femoral or tibial condyle following septic arthritis is consistent with total preservation of the other condyle. The outcome of surgical reconstruction of the missing condyle is poor. The presence of a complete synovial septum could result in the localisation of infection to one half of the joint, with the destruction of one condyle.

Neuroblastoma (NB) is a neural crest-derived childhood tumor characterized by a remarkable phenotypic diversity, ranging from spontaneous regression to fatal metastatic disease. Although the cancer stem cell (CSC) model provides a trail to characterize the cells responsible for tumor onset, the NB tumor-initiating cell (TIC) has not been identified. In this study, the relevance of the CSC model in NB was investigated by taking advantage of typical functional stem cell characteristics. A predictive association was established between self-renewal, as assessed by serial sphere formation, and clinical aggressiveness in primary tumors. Moreover, cell subsets gradually selected during serial sphere culture harbored increased in vivo tumorigenicity, only highlighted in an orthotopic microenvironment. A microarray time course analysis of serial spheres passages from metastatic cells allowed us to specifically "profile" the NB stem cell-like phenotype and to identify CD133, ABC transporter, and WNT and NOTCH genes as spheres markers. On the basis of combined sphere markers expression, at least two distinct tumorigenic cell subpopulations were identified, also shown to preexist in primary NB. However, sphere markers-mediated cell sorting of parental tumor failed to recapitulate the TIC phenotype in the orthotopic model, highlighting the complexity of the CSC model. Our data support the NB stem-like cells as a dynamic and heterogeneous cell population strongly dependent on microenvironmental signals and add novel candidate genes as potential therapeutic targets in the control of high-risk NB.

The physical-activity and sporting at the child and the teenager is probably, in these years 2000, in full change. In a paradoxical way, extremely sporting children or teenagers are living beside extremely sedentary school-boys, neglecting the majority of the physical-activities and preferring a home-lifestyle. In the evaluation of overload sporting lesion of at teenager, it is thus imperative to take into account not only the individual characteristics of the child: its sex, its age, its stage of growth, its psychology, the presence or not of preexistent pathologies or anatomical disorders. It is naturally necessary to wonder about the training methods of the activity, but it appears fundamental to me to evaluate the child from a sensitivo-motor point of view and this can be carried out by assessments physio-therapeutic or aptitude tests carried out by doctors of the sport.

Purpose: Totally implanted vascular (TIVA) ports are used in children for repeated blood samples or intravenous treatments. We have recently published a prospective evaluation of surgical incidents and early complications associated with these devices. This work is the final part of the same study, assessing late complications over a follow-up of 2 yrs., Methods: From January 2006 to January 2008, children older than 1 yr of age with a diagnosis of solid or blood cell malignancy were included. Insertion technique and care of the device were standardized. Every manipulation was prospectively recorded by specialized nurses. Obstruction was documented clinically. When bacteremia was suspected, routine central and peripheral blood cultures were drawn., Results: Forty-five consecutive patients were enrolled in the study. Mean age at the time of the procedure was 8.5 yrs. There was no catheter-related infection within the first 4 weeks post-surgery. No device had to be removed because of infection or obstruction during follow-up. Frequent accesses to the port (=3 per day over a 10-day period) were associated with an 8-fold risk of infection., Conclusion: Insertion and use of TIVA devices were frequently associated with complications. No device had to be removed because of infection or obstruction over the follow-up period, although no prophylactic antibiotic agent was used. Restrictive use of antibiotics may prevent opportunistic infection. Frequent access to the device was significantly associated with line infection (odds ratio=8.43). No risk factor was identified for obstruction which occurred at a rate of 5.3 per 10,000 accesses.

Epiphyseal fractures of the distal humerus and their treatment are common, source of many complications that may be immediate but also delayed. If the families accept the possibility of trauma to their child as part of his leisure activities or sports at times intense, they are much more intolerant if their child does not return after injury and repair, optimal function and physical performance unchanged. This intolerance, faced with the trauma but not its consequences, requires us to be particularly careful in the information given to the patient but also in monitoring the first few weeks. The treatment of epiphyseal fractures remains difficult and must be performed by trained teams, aware of the subtleties of pathology. It is essential to organize close monitoring and critical to be able to correct errors or secondary displacement in the first 15 days.

Cancer stem cells (CSCs) display plasticity and self-renewal properties reminiscent of normal tissue stem cells, but the events responsible for their emergence remain obscure. We recently identified CSCs in Ewing sarcoma family tumors (ESFTs) and showed that they retain mesenchymal stem cell (MSC) plasticity. In the present study, we addressed the mechanisms that underlie ESFT CSC development. We show that the EWS-FLI-1 fusion gene, associated with 85%-90% of ESFTs and believed to initiate their pathogenesis, induces expression of the embryonic stem cell (ESC) genes OCT4, SOX2, and NANOG in human pediatric MSCs (hpMSCs) but not in their adult counterparts. Moreover, under appropriate culture conditions, hpMSCs expressing EWS-FLI-1 generate a cell subpopulation displaying ESFT CSC features in vitro. We further demonstrate that induction of the ESFT CSC phenotype is the result of the combined effect of EWS-FLI-1 on its target gene expression and repression of microRNA-145 (miRNA145) promoter activity. Finally, we provide evidence that EWS-FLI-1 and miRNA-145 function in a mutually repressive feedback loop and identify their common target gene, SOX2, in addition to miRNA145 itself, as key players in ESFT cell differentiation and tumorigenicity. Our observations provide insight for the first time into the mechanisms whereby a single oncogene can reprogram primary cells to display a CSC phenotype.

Cancer stem cells that display tumor-initiating properties have recently been identified in several distinct types of malignancies, holding promise for more effective therapeutic strategies. However, evidence of such cells in sarcomas, which include some of the most aggressive and therapy-resistant tumors, has not been shown to date. Here, we identify and characterize cancer stem cells in Ewing's sarcoma family tumors (ESFT), a highly aggressive pediatric malignancy believed to be of mesenchymal stem cell (MSC) origin. Using magnetic bead cell separation of primary ESFT, we have isolated a subpopulation of CD133+ tumor cells that display the capacity to initiate and sustain tumor growth through serial transplantation in nonobese diabetic/severe combined immunodeficiency mice, re-establishing at each in vivo passage the parental tumor phenotype and hierarchical cell organization. Consistent with the plasticity of MSCs, in vitro differentiation assays showed that the CD133+ cell population retained the ability to differentiate along adipogenic, osteogenic, and chondrogenic lineages. Quantitative real-time PCR analysis of genes implicated in stem cell maintenance revealed that CD133+ ESFT cells express significantly higher levels of OCT4 and NANOG than their CD133- counterparts. Taken together, our observations provide the first identification of ESFT cancer stem cells and demonstration of their MSC properties, a critical step towards a better biological understanding and rational therapeutic targeting of these tumors.

Background: Totally implanted vascular access devices are frequently used in children for repeated blood samples or intravenous treatments. This prospective study aims at identifying the risk factors associated with infections, obstructions and surgical complications of these devices in pediatric patients., Methods: From January 2006 to January 2008, all children older than one year of age with a diagnosis of solid or blood cell malignancy were included in the study. Insertion was performed by the surgeon according to a standardized protocol after landmark-guided puncture of the subclavian or internal jugular vein by a senior anesthesiologist. Dressing and post-operative care were standardized. Every manipulation was prospectively recorded by specialized dedicated nurses, and all patients were screened for complications one month post-surgery., Results: 45 consecutive patients 1 to 16 years old were enrolled in the study. Mean age at the time of procedure was 8.5 years (range 1.3-15.6; SD +/- 4.88). There were 12 peroperative adverse events in 45 procedures (27%), detailed as follows: 3 pneumothoraces (7%), 3 hematomas (7%), 6 arterial punctures (13%). Among these events, intervention was necessary for two pneumothorax and one arterial puncture. There was no air embolism. At one month, we recorded 5 post-operative complications (11%): 2 thrombotic obstructions, one unsightly scar, and one scapular pain of unknown etiology. One patient needed repositioning of the catheter. There was no catheter-related infection., Conclusion: Prospective recording of TIVA insertion in children reveals a significant number of early incidents and complications, mainly associated with the percutaneous puncture technique. We found no infection in this series. Results of a longer follow-up in the same population are pending.