Prevalence and Predictors of Adolescent Idiopathic Scoliosis in Adolescent Ballet Dancers

Genetics and pathogenesis of scoliosis

Background

Scoliosis is defined as a lateral spine curvature of at least 10° with vertebral rotation, as seen on a posterior-anterior radiograph, often accompanied by reduced thoracic kyphosis. Scoliosis affects all age groups: idiopathic scoliosis is the most common spinal disorder in children and adolescents, while adult degenerative scoliosis typically affects individuals over fifty. In the United States, approximately 3 million new cases of scoliosis are diagnosed annually, with a predicted increase in part due to global aging. Despite its prevalence, the etiopathogenesis of scoliosis remains unclear.

Methods

This comprehensive review analyzes the literature on the etiopathogenetic evidence for both idiopathic and adult degenerative scoliosis. PubMed and Google Scholar databases were searched for studies on the genetic factors and etiopathogenetic mechanisms of scoliosis development and progression, with the search limited to articles in English.

Results

For idiopathic scoliosis, genetic factors are categorized into three groups: genes associated with susceptibility, disease progression, and both. We identify gene groups related to different biological processes and explore multifaceted pathogenesis of idiopathic scoliosis, including evolutionary adaptations to bipedalism and developmental and homeostatic spinal aberrations. For adult degenerative scoliosis, we segregate genetic and pathogenic evidence into categories of angiogenesis and inflammation, extracellular matrix degradation, neural associations, and hormonal influences. Finally, we compare findings in idiopathic scoliosis and adult degenerative scoliosis, discuss current limitations in scoliosis research, propose a new model for scoliosis etiopathogenesis, and highlight promising areas for future studies.

Conclusions

Scoliosis is a complex, multifaceted disease with largely enigmatic origins and mechanisms of progression, keeping it under continuous scientific scrutiny.

Variability of joint hypermobility in children: a meta-analytic approach to set cut-off scores

Current international consensus of the appropriate Beighton score cut-off to define if a child has generalised joint hypermobile or not is based upon expert opinion. Our aim was to determine the prevalence of Beighton scores of children worldwide to provide a recommendation for establishing the Beighton score cut-off to identify generalised joint hypermobility in children. We used AMED, OVID Medline, Embase and CINAHL to find published articles from inception to April 2024 describing Beighton scores of children up to and including 18 years from the general population. We extracted study demographics including country of publication, total number of participants, summary data about the age and sex of participant, Beighton scores and any cut-off used where authors deemed children hypermobile and how many children were rated at the corresponding Beighton scores. There were 37 articles reporting on the prevalence or incidence of hypermobility at cut-off scores from 28,868 participants. Using the cut-off of ≥ 6 resulted in a prevalence of 6% for studies reporting male data and 13% for studies reporting female data. Limited data reporting availability precluded further sub-analysis at a Beighton score of ≥ 7, age, pubertal status and ethnicity.    Conclusion: The working threshold for identifying generalised joint hypermobility in children should be a Beighton score of 6 or more. Our analysis also suggests a Beighton score of 7 or greater may be appropriate in childhood, particularly for females. What is Known: • The working threshold for identifying generalised joint hypermobility in children previously was set based on expert opinion. What is New: • The threshold to identify hypermobility in children should be at a minimum of ≥ 6 on the Beighton score.

Associations Between Physical Activity and Adolescent Idiopathic Scoliosis: A Systematic Review and Meta-analysis

OBJECTIVE

To investigate the associations between adolescent idiopathic scoliosis (AIS) and physical activity (PA).

DATA SOURCES

MEDLINE, EMBASE, AMED, SPORTDiscus, Cochrane Library, and CINAHL electronic databases were searched from inception to August 2022/plus citation tracking.

STUDY SELECTION

Observational studies of participants with radiographically confirmed AIS with ≥10° lateral spinal curvature (Cobb method) and comparator groups without AIS that measured PA were selected by 2 reviewers.

DATA EXTRACTION

Data were extracted independently and cross-checked by 2 reviewers. Risk of bias was evaluated using Newcastle Ottawa Scales and overall confidence in the evidence using the GRADE approach.

DATA SYNTHESIS

Sixteen studies with 9627 participants (9162, 95% women) were included. A history of vigorous PA significantly reduced the odds of being newly diagnosed with AIS by 24% (odds ratio [OR] 0.76, 95% confidence interval [CI] 0.65-0.89) (high certainty). Moderate PA reduced odds by 13% (moderate certainty) and light PA increased odds by 9% (low certainty), but neither analysis was statistically significant. Ballet or gymnastics (OR 1.47, 95% CI 3.08 (1.90, 5.00) were the only individual sports significantly associated with AIS diagnosis (moderate certainty). Case-control studies of people with and without AIS provided greater evidence that having AIS reduces vigorous PA and sports participation, and less evidence light PA and walking are affected.

CONCLUSION

Adolescents who participate in more vigorous PA are less likely to be diagnosed with AIS. Ballet and gymnastics are associated with AIS diagnosis, but the direction of this association is uncertain. People with AIS are likely to do less vigorous physical and sporting activity compared with those without AIS, which could negatively affect health and quality of life. Further research is warranted into the inter-relations between PA and AIS, studies need to be of sufficient size, include men, and evaluate vigorous including higher-impact PA compared with moderate or light PA.

Sport improved medium-term results in a prospective cohort of 785 adolescents with idiopathic scoliosis braced full time. SOSORT 2018 award winner

PURPOSE

The association between idiopathic scoliosis (IS) and sports activities remains vague. We aimed to analyse their effect on full-time braced adolescents with IS.

METHODS

We retrospectively recruited all the consecutive patients of a tertiary referral Institute of age ≥ 10 (adolescents), with a juvenile (JIS) or adolescent (AIS) IS diagnosis, Risser 0-2, TLSO brace prescription and self-reported adherence ≥ 20 h per day, and follow-up out-of-brace X-rays 18 months after brace prescription. We divided participants into two groups: SPORT (sport twice or more per week) and CONTROL (sport once per week or less). We calculated odds ratio (OR) to compare the outcome of subjects performing to those not performing sport. We ran a logistic regression with covariate adjustment to assess if sports frequency affected the outcomes.

RESULTS

Out of 33,311 participants assessed for eligibility, 785 satisfied the inclusion criteria (693 females, age 12.7 ± 1.3 and 40 ± 11° Cobb). The SPORT group consisted of 290 participants and the CONTROL group of 495. The SPORT group showed higher odds of improvement (OR = 1.59, 95%CI = 1.17-2.16, p = 0.0018). The odds of improving increased with the frequency of sports activity (OR = 1.20, 95%CI 1.08-1.34).

CONCLUSION

This study shows that sports activities increase the odds of improvement at 18-month follow-up in adolescents with IS treated with a full-time brace. The odds of improvement increase with sports week frequency.

Postural habits and lifestyle factors associated with adolescent idiopathic scoliosis (AIS) in China: results from a big case-control study

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is the most prevalent type of scoliosis affecting children between the ages of 10-16 years. However, risk factors for AIS, particularly the modifiable ones, are still largely unknown. This study aims to investigate the associations of lifestyle and social environment factors with AIS in Chinese schoolchildren.

METHODS

This is a matched case-control study based on survey data collected from school-based scoliosis screening program. We used conditional logistic regression models to describe the relative risk of AIS incidence for each variable in the analyses. To examine the independent effect of each factor on developing AIS, a multivariate conditional logistic regression was conducted and odds ratios (ORs) were adjusted for age and other significant variables.

RESULTS

Overall, 2538 participants from 49 schools were included in this study, comprising 1269 AIS cases and 1269 controls. Mean age of the study population was 13.4 years ± 1.06 (range 10-18). One thousand five hundred and fifty (61.1%) of the study subjects were girls. After adjusting for other significant factors, inappropriate desk heights, either too low (OR = 1.40, 95% CI 1.04-1.90) or too high (OR = 1.61, 95% CI 1.09-2.38), standing with anterior pelvic tilt (OR = 2.73, 95% CI 1.41-5.28), and sleeping on the right side (OR = 1.38, 95% CI 1.00-1.91), remained associated with elevated AIS risks. In contrast, sitting normally and classroom sitting positions change regularly were associated with lower odds of AIS. The adjusted ORs were 0.69 (95% CI 0.50-0.96) for sitting normally, and 0.72 (95% CI 0.53-0.98) for sitting positions change.

CONCLUSIONS

This is the first study to address the associations between desk heights and AIS and showed inappropriate desk heights were related to increased AIS risks. To protect school children from developing AIS, stakeholders are advised to consider introducing height-adjustable desks in the class, changing students' sitting positions in the classroom on a regular basis, and implementing educational programs to help students maintain correct sitting postures.

Prevalence of idiopathic scoliosis in athletes: a systematic review and meta-analysis

Objective

This study aimed to determine the prevalence of idiopathic scoliosis (IS) in child, adolescent and adult athletes of all sports activity levels.

Design

Systematic review with meta-analysis.

Data sources

Electronic databases (PubMed, Scopus, ProQuest, Sage journals, ScienceDirect, Google Scholar and Springer) were systematically searched up from inception to 28 September 2021.

Eligibility criteria for selecting studies

Observational investigations were included to evaluate the prevalence of IS in athletes (engaged in any type of individual and team sports). Congenital scoliosis, neuromuscular scoliosis, Scheuermann’s kyphosis and de novo scoliosis were not included. The risk of bias was assessed using the tool developed by Hoy et al.

Results

Twenty-two studies were included (N=57 470, range 15–46544, participants), thirteen studies were of high-quality. The estimated prevalence of IS in athletes was 27% (95% CI 20% to 35%, I²=98%), with a 95% prediction interval (1% to 69%). The prevalence of IS was significantly higher in female athletes (35%, 95% CI 27% to 34%, I²=98%). Ballet dancers showed a high IS prevalence (35%, 95% CI 24% to 47%, I²=98%). Recreational athletes showed a higher IS prevalence (33%, 95% CI 24% to 43%, I²=98%) than at competitive-level athletes (0.05%, 95% CI 0.03% to 0.08%, I²=98%), followed by elite (20%, 95% CI 13% to 27%, I²=98%).

Conclusions

The prevalence of IS in athletes was similar or higher to that as seen in other studies of the general population. IS prevalence may have a U-shaped relationship relative to level of competition. Further studies are required to determine which sports have the highest IS prevalence.

Systematic review of the association between isolated musculoskeletal hypermobility and adolescent idiopathic scoliosis

INTRODUCTION

Adolescent idiopathic scoliosis (AIS) affects 1-3% of the population, but its pathogenesis remains unclear. The coexistence of musculoskeletal hypermobility and scoliosis in many inherited syndromes raises the possibility that isolated musculoskeletal hypermobility may contribute to AIS development or progression.

METHODS

We performed a systematic review of the evidence for a relationship between isolated musculoskeletal hypermobility and AIS. A meta-analysis was planned, but if not possible, a narrative evidence synthesis was planned.

RESULTS

Nineteen studies met eligibility criteria for inclusion. One study was excluded due to insufficient quality. Substantial heterogeneity in study design and methodology negated meta-analysis, so a narrative review was performed. Of the 18 studies included, seven suggested a positive association and eight found no association. Three reported the prevalence of musculoskeletal hypermobility in individuals with AIS. Overall, there was no convincing population-based evidence for an association between musculoskeletal hypermobility and AIS, with only two case-control studies by the same authors presenting compelling evidence for an association. Although populations at extremes of hypermobility had a high prevalence of spinal curvature, these studies were at high risk of confounding. Wide variation in methods of measuring musculoskeletal hypermobility and the challenge of assessing AIS in population-based studies hinder study comparison.

CONCLUSIONS

There is a paucity of high-quality evidence examining the association between isolated musculoskeletal hypermobility and AIS. Large-scale prospective studies with adequate adjustment for potential confounding factors could clarify the relationship between musculoskeletal hypermobility and AIS to elucidate its role in the pathogenesis of AIS.

The importance of extrinsic and intrinsic compensatory mechanisms to body posture of competitive athletes a systematic review and meta-analysis

The aim of this systematic review (qualitative analysis) was to identify the variables of changes induced by extrinsic (sport specific training) and intrinsic (individual anatomical predispositions) compensatory mechanisms that impact on the physiological magnitude of spinal curvatures in the sagittal plane and their deviations in the frontal plane. Furthermore, the aim of the quantitative analysis was to verify and objectivize the impact of these variables on athlete’s body posture. A search of electronic database (PubMed, EBSCO, MEDLINE) was conducted to identify all studies on sports training and athlete’s spine and body posture from 2011 to 2021. In the sagittal plane, the pooled proportion accounted for 44.97% (95% CI 31.22–58.72%) for thoracic hyperkyphosis (TH), 4.98% (95% CI 1.60–8.36%) for lumbar hyperlordosis (hyperLL), and 12.35% (95% CI 1.60–8.36%) for lumbar hypolordosis (hypoLL). Furthermore, in the sagittal plane, the pooled mean of thoracic kyphosis angle was 37.59° (95% CI 34.45–40.73%), whereas lumbar lordosis angle was 29.79° (95% CI 26.46–33.12%). Professional athletes tend to have postural disturbances and/or spinal curvature disorders in the sagittal and frontal planes. The meta-analysis indicated which intrinsic and extrinsic components might induce spinal abnormalities.

The role of endocrine hormones in the pathogenesis of adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a common spinal deformity characterized by changes in the three-dimensional structure of the spine. It usually initiates during puberty, the peak period of human growth when the secretion of numerous hormones is changing, and it is more common in females than in males. Accumulating evidence shows that the abnormal levels of many hormones including estrogen, melatonin, growth hormone, leptin, adiponectin and ghrelin, may be related to the occurrence and development of AIS. The purpose of this review is to provide a summary and critique of the research published on each hormone over the past 20 years, and to highlight areas for future study. It is hoped that the presentation will help provide a better understanding of the role of endocrine hormones in the pathogenesis of AIS.

The uncoupled anterior and posterior spinal ligament tension (UAPLT) - An improvement to three-dimensional spring model of adolescent idiopathic scoliosis (AIS) pathogenesis

The pathogenesis of Adolescent Idiopathic Scoliosis (AIS) remains unclear. Previous research proposed that ligament laxity is a clinical feature that can be easily overlooked in patients with AIS. We speculated a new hypothesis which is an improvement of our three-dimensional spring model hypothesis of AIS pathogenesis. The tethered string in the spring model stimulates the spinal ligament instead of spinal cord. Spinal overgrowth in the adolescent age leads to higher tension of posterior spinal ligament. And the ligament laxity leads to lower tension of anterior spinal ligament. This uncoupled anterior and posterior spinal ligament tension maybe the key cause of AIS.

Generalized Joint Hypermobility and Injuries: A Prospective Cohort Study of 185 Pre-Professional Contemporary Dancers

Generalized joint hypermobility (GJH) has been mentioned as one of the factors associated with dance injuries, but the findings are inconclusive. This study aims to investigate whether GJH, based on different Beighton score cut-off points, is a potential risk factor for injuries in pre-professional dancers. Four cohorts of first-year pre-professional dancers (N = 185), mean age 19.1 ± 1.3 years, were screened on musculoskeletal functioning at the start of their academic year. The Beighton score was used to measure GJH. During the academic year, the dancers completed monthly questionnaires about their physical and mental health. Based on the Oslo Sports Trauma Research Centre Questionnaire on Health Problems (OSTRC), three injury definitions were used (i.e., all complaints, substantial injury, and time-loss injury). To examine potential risk factors for injuries, univariate and multivariate regression models were applied. The response rate of monthly completed questionnaires was 90%. The overall mean (SD) Beighton score was 2.8. The 1-year injury incidence proportion was 67.6% (n = 125), 43.2% (n = 80), and 54.6% (n = 101) for all complaint injuries, substantial injuries, and time-loss injuries, respectively. The multivariate analyses showed a significant association between a previous long lasting injury in the past year and the three injury definitions (p < 0.05). Pre-professional contemporary dancers are at high risk for injuries and hypermobility. However, these two variables are not associated with each other. Health professionals should take injury history into account when assessing dance students, because this variable is associated with increased injury risk.

Generalized joint hypermobility, scoliosis, patellofemoral pain, and physical abilities in young dancers

Background

Many young girls with generalized joint hypermobility (GJH) choose to participate in dance because their bodies are suited for this activity. Scoliosis tends to occur often in thin girls, who also are more likely to choose dance. Both anomalies (GJH and scoliosis) may be related to reduced abilities such as diminished strength and insufficient postural balance, with increased risk for musculoskeletal conditions. The main objectives of the present study were to determine the prevalence of dancers with GJH, the prevalence of dancers with scoliosis, and the prevalence of dancers with these two anomalies; and, to determine differences in physical abilities and the presence of patellofemoral pain (PFP) between young female dancers with and without such anomalies.

Methods

One hundred thirty-two female dancers, aged 12–14 years, were assessed for anthropometric parameters, GJH, scoliosis, knee muscle strength, postural balance, proprioception ability, and PFP.

Results

GJH was identified in 54 dancers (40.9%) and scoliosis in 38 dancers (28.8%). Significant differences were found in the proportion of dancers with no anomalies (74 dancers, 56.1%) and dancers with both anomalies (34 dancers, 25.8%) (p < .001). Dancers with both anomalies had reduced dynamic postural balance in the anterior direction (p = .023), reduced proprioception ability (p < .001), and weaker knee extensors (p = .036) and flexors (p = .040) compared with dancers with no anomalies. Among dancers with both anomalies, 73.5% suffered bilateral PFP, 17.6% suffered unilateral PFP, and 8.8% had no PFP (p < .001).

Conclusions

A high prevalence of young girls participating in dance classes had GJH, as the increased joint flexibility probably provides them with some esthetic advantages. The high prevalence of scoliosis found in these young dancers might be attributed to their relatively low body mass, their delayed maturation, and the selection process of dancers. Dancers with both GJH and scoliosis had decreased muscle strength, reduced postural balance, reduced proprioception, with higher risk of PFP. The main clinical implications are the need to reduce the risk of PFP among dancers by developing appropriate strength and stabilizing exercises combined with proprioceptive and postural balance training, to improve the correct alignment of the hyperextended and hypermobile joints, and to improve their supporting muscle strength.

The Beighton Score and Injury in Dancers: A Prospective Cohort Study

CONTEXT

Joint hypermobility has a high prevalence in dancers and may be associated with injury and performance.

OBJECTIVES

To investigate whether total Beighton score can predict injury and to determine the relationship between joint hypermobility and injury, and to report injury demographics.

DESIGN

A prospective cohort injury study.

SETTING

Edge Hill University dance injury clinic.

PARTICIPANTS

Eighty-two dancers (62 females, 20 males).

MAIN OUTCOME MEASURES

Joint hypermobility via the Beighton score ≥4 with lumbar flexion included and removed.

RESULTS

A total of 61 dancers were classified as hypermobile, which was reduced to 50 dancers with lumbar flexion removed. A significant difference existed between pooled total days injured in hypermobile dancers and nonhypermobile dancers with lumbar flexion included (P = .02) and removed (P = .03). No significant differences existed for total Beighton score between injured and noninjured groups with lumbar flexion included (P = .11) and removed (P = .13). Total Beighton score was a weak predictor of total days injured (r2 = .06, P = .51). In total, 47 injuries occurred in 34 dancers, and pooled injury rate was 1.03 injuries/1000 hours. Receiver operating characteristic curve analysis demonstrated an area under the curve of 0.83 for male dancers with lumbar flexion removed, which was considered diagnostic for injury.

CONCLUSIONS

The Beighton score can be utilized to identify dancers who may develop injury. Clinicians should consider the role of lumbar flexion in total Beighton score when identifying those dancers at risk of injury. Different injury thresholds in female and male dancers may aid injury management.

Noncontact sports participation in adolescent idiopathic scoliosis: effects on parent-reported and patient-reported outcomes

Comparing risks against benefits of adolescent idiopathic scoliosis (AIS) patients participating in sports represents a controversial topic in the literature. Previous studies have reported sports participation as a possible risk factor for AIS development, while others describe its functional benefits for AIS athletes. The objective of this study was to determine if sports participation had an impact on pain, function, mental status, and self-perception of deformity in patients and their parents. Patients had full spine radiographs and completed baseline surveys of demographics, socioeconomics, and patient-reported outcomes (PRO): Scoliosis Research Society (SRS)-30, Body Image Disturbance Questionnaire, and Spinal Appearance Questionnaire (SAQ: Children and Parent). Patients were grouped by their participation (sports) or nonparticipation (no-sports) in noncontact sports. Demographics, radiographic parameters, and PRO were compared using parametric/nonparametric tests with means/medians reported. Linear regression models identified significant predictors of PRO. Forty-nine patients were included (sports: n=29, no-sports: n=20). Both groups had comparable age, sex, BMI, bracing status, and history of physical therapy (all P>0.05). Sports and no-sports also had similar coronal deformity (major Cobb: 31.1° vs. 31.5°). Sagittal alignment profiles (pelvic incidence, pelvic incidence minus lumbar lordosis, thoracic kyphosis, and sagittal vertical axis) were similar between groups (all P>0.05). Sports had better SRS-30 (Function, Self-image, and Total) scores, SAQ-Child Expectations, and SAQ-Parent Total Scores (P<0.05). Regression models revealed major Cobb angle (β coefficient: -0.312) and sports participation (β coefficient: 0.422) as significant predictors of SRS-30 Function score (R=0.434, P<0.05). Our data show that for AIS patients with statistically similar bracing status and coronal and sagittal deformities, patients who participated in sports were more likely to have improved functionality, self-image, expectations, and parental perception of deformity. Further investigation is warranted to acquire a comprehensive understanding of the relationship between AIS and patient participation in sports. Maintaining moderate levels of physical activity and participating in safe sports may benefit treatment outcomes. Level of Evidence III - Retrospective Comparative Study.

Multi-segment spine kinematics: Relationship with dance training and low back pain

BACKGROUND

Spine posture, range of motion (ROM) and movement asymmetry can contribute to low back pain (LBP). These variables may have greater impact in populations required to perform repetitive spine movements, such as dancers; however, there is limited evidence to support this.

RESEARCH QUESTION

What is the influence of dance and LBP on spinal kinematics?

METHODS

In this cross-sectional study, multi-segment spinal kinematics were examined in 60 female participants, including dancers (n = 21) and non-dancers (n = 39) with LBP (n = 33) and without LBP (n = 27). A nine-camera motion analysis system sampling at 100 Hz was used to assess standing posture, as well as ROM and movement asymmetry for side bend and trunk rotation tasks. A two-way ANOVA was performed for each of the outcome variables to detect any differences between dancers and non-dancers, or individuals with and without LBP.

RESULTS

Compared to non-dancers, dancers displayed a flatter upper lumbar angle when standing (p < 0.01, ηp² = 0.15), and achieved greater frontal plane ROM for the upper lumbar (p = 0.04, ηp² = 0.08) and lower thoracic (p = 0.02, ηp² = 0.09) segments. There were no differences between dancers and non-dancers for transverse plane ROM (p > 0.05) or movement asymmetry (p > 0.05). There was no main effect for LBP symptoms on any kinematic measures, and no interaction effect for dance group and LBP on spinal kinematics (p > 0.05).

SIGNIFICANCE

Female dancers displayed a flatter spine posture and increased spine ROM compared to non-dancers for a select number of spine segments and movement tasks. However, the overall number of differences was small, and no relationship was observed between LBP and spinal kinematics. This suggests that these simple, static posture, ROM, and asymmetry measures often used in clinical practice can provide only limited generalisable information about the impact of dance or LBP on spinal kinematics.

Adolescent idiopathic scoliosis for the primary care physician: frequently asked questions

PURPOSE OF REVIEW

Provide primary care physicians with the best available evidence to support answers to frequently asked questions by caregivers of patients with adolescent idiopathic scoliosis (AIS).

RECENT FINDINGS

A review of best available evidence shows that schoolbag design and weight are not associated with higher odds of developing AIS. However, patients with AIS are more prone to balance problems with asymmetric backpack carrying and with rising weights. In patients with AIS, the backpack should be worn in a symmetric way and should never exceed 10% of the child's body weight. Although no relationship was found between systematic exercising in general and development of AIS, classical ballet and professional swimming in skeletally immature adolescents were associated to higher odds of having AIS. Since AIS affects adolescent girls mainly, women health issues are of paramount importance in this disease. Except for limited sexual activity and higher need for infertility treatment, patients with AIS perform similar to controls in marriage rates, age at first pregnancy, gestational age, offspring, labor and delivery. Best available evidence shows that adults with AIS diagnosed during adolescence have similar physical activity level compared with controls. In patients with AIS, adults with surgically treated idiopathic scoliosis have slightly lower physical activity level than previously braced and untreated patients.

SUMMARY

Although schoolbag weight isn't associated with higher odds of developing AIS, classical ballet and professional swimming in adolescents are. Except for limited sexual activity, patients with AIS perform similar to controls in remaining women health issues. Adults with AIS diagnosed during adolescence have similar physical activity level compared with controls.

A Novel Mutation of Mitochondrial T14709C Causes Myoclonic Epilepsy with Ragged Red Fibers Syndrome in a Chinese Patient

Background:

Myoclonic epilepsy with ragged red fibers (MERRF) syndrome is characterized by myoclonus, generalized epilepsy, cerebellar ataxia, and ragged red fibers (RRFs) in the muscle. T-to-C transition at nucleotide position 14709 in the mitochondrial tRNA glutamic acid (tRNA^Glu) gene has previously been associated with maternally inherited diabetes and deafness. However, the association between MERRF and mitochondrial T14709C mutation (m.T14709C) has never been reported before.

Methods:

Clinical information of a 17-year-old patient was collected; muscle biopsy and next-generation sequencing (NGS) of whole mitochondrial and neuromuscular disease panel were then conducted. Finally, sanger sequencing was carried out to confirm the mutations.

Results:

The patient presented a typical MERRF phenotype with muscle weakness, epileptic seizure, clonic episodes, cerebellar ataxia, and spinal scoliosis. Muscle biopsy showed RRFs which indicated abnormal mitochondrial functions. NGS of whole mitochondrial gene revealed m.T14709C mutation, confirmed by Sanger sequencing.

Conclusion:

We present a sporadic patient with typical MERRF presentation carrying the mutation of m.T14709C, which expanded the spectrum of m.T14709C.

Differences in lower limb biomechanics between ballet dancers and non-dancers during functional landing tasks

OBJECTIVES

To determine the differences in the lower limb landing biomechanics of adolescent ballet dancers compared to non-dancers when performing a hop and a stop jump task.

DESIGN

Cross-sectional.

SETTING

Laboratory.

PARTICIPANTS

Thirteen adolescent female ballet dancers (11.8 ± 1.1 years) and 17 non-dancers (10.9 ± 0.8 years) performed hop and stop jump tasks.

MAIN OUTCOME MEASURES

Vertical ground reaction force, and three-dimensional ankle, knee and hip joint angles and moments during the landing phase.

RESULTS

Dancers displayed greater sagittal plane joint excursions during the hop and stop jump at the ankle (mean difference = 22.0°, P < 0.001, 14.8°, P < 0.001 respectively), knee (mean difference = 18.1°, P = 0.001, 9.8°, P = 0.002 respectively) and hip (stop jump task; mean difference = 8.3°, P = 0.008). Dancers displayed a larger hip extensor moment compared to non-dancers (P < 0.001) during the stop jump task only. Dancers also took longer to reach peak vGRF and jumped three times higher than non-dancers (P < 0.001) during the stop jump task. No difference in peak vGRF between groups was displayed for either task.

CONCLUSIONS

Adolescent dancers demonstrate a transfer of landing technique to non-ballet specific tasks, reflective of the greater jump height and sagittal plane joint excursions. This landing strategy may be associated with the low rate of non-contact ACL injuries in female dancers.

Risk factors for musculoskeletal injury in elite pre-professional modern dancers: A prospective cohort prognostic study

OBJECTIVES

To examine risk factors for injury in pre-professional modern dancers.

DESIGN

With prospectively designed screening and injury surveillance, we evaluated four risk factors as categorical predictors of injury: i) hypermobility; ii) dance technique motor-control; iii) muscle tightness; iv) previous injury. Screening and injury data of 180 students enrolled in a university modern dance program were reviewed over 4-yrs of training. Dancers were divided into 3-groups based on predictor scores. Dance exposure was based on hours of technique classes/wk. Negative binomial log-linear analyses were conducted with the four predictors, p < 0.05.

RESULTS

Dancers with low and high Beighton scores were 1.43 and 1.22 times more likely to sustain injury than dancers with mid-range scores (p ≤ 0.03). Dancers with better technique (low or medium scores) were 0.86 and 0.63 times less likely to sustain injury (p = 0.013 and p < 0.001) compared to those with poor technique. Dancers with one or 2-4 tight muscles were 2.7 and 4.0 times more likely to sustain injury (p ≤ 0.046). Dancers who sustained 2-4 injuries in the previous year were 1.38 times more likely to sustain subsequent injury (p < 0.001).

CONCLUSIONS

This contributes new information on the value of preseason screening. Dancers with these risk factors may benefit from prevention programs.

Ultrasonography and clinical examination of knee injuries in pre- and post- menarche dancers

This study aimed at evaluating whether the prevalence of knee injuries and morphological features are different among pre-and-post menarche dancers; Sixty-seven pre-and-post menarche dancers were screened for anthropometric parameters; knee laxity; patella femoral pain syndrome (PFPS), pathologies and anatomical structure of the knees. Both groups showed a high and similar prevalence of PFPS. The post-menarche dancers produced a significantly higher rate of Tanner stages 3-4 (p = .010), greater weight (p < .001) higher BMI (p = .003); and, higher prevalence of MCL pathology, pes planus, and scoliosis compared with pre-menarche dancers (p < .05). The pre-menarche dancers started dance practice earlier (p = .008); and, showed significantly higher prevalence of lateral laxity, patellar laxity, positive Lachman test and positive Drawer test compared with post-menarche dancers (p < .05). Interactions (menarche yes/no by PFPS no/one leg/both legs) were found for BMI (p = .044; η² = .187), trochlear cartilage thickness (p = .020; η² = 0.121) and tip of patella - trochlear groove distance (p = .024; η² = .150). Pre-and-post-menarche female dancers demonstrated similar prevalence of knee injuries, with different body morphology.

2016 SOSORT guidelines: orthopaedic and rehabilitation treatment of idiopathic scoliosis during growth

BACKGROUND

The International Scientific Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT) produced its first guidelines in 2005 and renewed them in 2011. Recently published high-quality clinical trials on the effect of conservative treatment approaches (braces and exercises) for idiopathic scoliosis prompted us to update the last guidelines' version. The objective was to align the guidelines with the new scientific evidence to assure faster knowledge transfer into clinical practice of conservative treatment for idiopathic scoliosis (CTIS).

METHODS

Physicians, researchers and allied health practitioners working in the area of CTIS were involved in the development of the 2016 guidelines. Multiple literature reviews reviewing the evidence on CTIS (assessment, bracing, physiotherapy, physiotherapeutic scoliosis-specific exercises (PSSE) and other CTIS) were conducted. Documents, recommendations and practical approach flow charts were developed using a Delphi procedure. The process was completed with the Consensus Session held during the first combined SOSORT/IRSSD Meeting held in Banff, Canada, in May 2016.

RESULTS

The contents of the new 2016 guidelines include the following: background on idiopathic scoliosis, description of CTIS approaches for various populations with flow-charts for clinical practice, as well as literature reviews and recommendations on assessment, bracing, PSSE and other CTIS. The present guidelines include a total of 68 recommendations divided into following topics: bracing (n = 25), PSSE to prevent scoliosis progression during growth (n = 12), PSSE during brace treatment and surgical therapy (n = 6), other conservative treatments (n = 2), respiratory function and exercises (n = 3), general sport activities (n = 6); and assessment (n = 14). According to the agreed strength and level of evidence rating scale, there were 2 recommendations on bracing and 1 recommendation on PSSE that reached level of recommendation "I" and level of evidence "II". Three recommendations reached strength of recommendation A based on the level of evidence I (2 for bracing and one for assessment); 39 recommendations reached strength of recommendation B (20 for bracing, 13 for PSSE, and 6 for assessment).The number of paper for each level of evidence for each treatment is shown in Table 8.

CONCLUSION

The 2016 SOSORT guidelines were developed based on the current evidence on CTIS. Over the last 5 years, high-quality evidence has started to emerge, particularly in the areas of efficacy of bracing (one large multicentre trial) and PSSE (three single-centre randomized controlled trials). Several grade A recommendations were presented. Despite the growing high-quality evidence, the heterogeneity of the study protocols limits generalizability of the recommendations. There is a need for standardization of research methods of conservative treatment effectiveness, as recognized by SOSORT and the Scoliosis Research Society (SRS) non-operative management Committee.

Etiological Theories of Adolescent Idiopathic Scoliosis: Past and Present

Adolescent idiopathic scoliosis is one of the most common spinal deformities, yet its cause is unknown. Various theories look to biomechanical, neuromuscular, genetic, and environmental origins, yet our understanding of scoliosis etiology is still limited. Determining the cause of a disease is crucial to developing the most effective treatment. Associations made with scoliosis do not necessarily point to causality, and it is difficult to determine whether said associations are primary (playing a role in development) or secondary (develop as a result of scoliosis). Scoliosis is a complex condition with highly variable expression, even among family members, and likely has many causes. These causes could be similar among homogenous groups of AIS patients, or they could be individual. Here, we review the most prevalent theories of scoliosis etiology and recent trends in research.

Scoliosis in mitochondrial myopathy: case report and review of the literature

The mitochondrial myopathies include a diverse group of disorders characterized by morphological abnormalities of muscle mitochondria. Little is reported about spinal deformity associated with this syndrome.This study presents a case of scoliosis occurring in the setting of mitochondrial myopathies and explores the possible mechanisms between the 2 diseases.A previously unreported scoliosis in mitochondrial myopathies is described. The patient was a 16-year-old Chinese adolescent boy undergoing a posterior correction at thoracic 2-lumbar 3 (T2-L3) levels using the Moss-SI spinal system. At 48-month follow-up, the patient was clinically pain free and well balanced. Plain radiographs showed solid spine fusion with no loss of deformity correction. After evaluating 60 mitochondrial myopathies, patients referred to Peking Union Medical College Hospital from February 2009 to May 2013, the prevalence of scoliosis among patients with mitochondrial myopathies was 5% (3/60), much higher than that among general population (2%).The scoliosis in mitochondrial myopathies is usually extensive and progressively aggravated and the correction of the associated spinal deformities is generally difficult. Therefore, the exact role of mitochondrial myopathy in the development of scoliosis requires further study for a better understanding of the disease, as well as adequate and effective patient care.