Muscle dysfunction and exercise limitation in adolescent idiopathic scoliosis

Respiratory function and respiratory muscle strength in adolescent idiopathic scoliosis

PURPOSE

It was aimed to analyze the relationship of the respiratory functions, respiratory muscle strength, magnitude of the curvature, angle of trunk rotation (ATR) and brace-wearing duration in patients with adolescent idiopathic scoliosis (AIS).

METHODS

Sixty patients with AIS (43 females), with maximum Cobb angles between 20° and 66° were included in the study. ATR values were measured with a scoliometer. Respiratory function parameters (forced vital capacity [FVC], forced expiratory volume in one second [FEV1], FEV1/FVC ratio, peak expiratory flow [PEF]) and respiratory muscle strengths (maximum inspiratory pressure [MIP] and maximum expiratory pressure [MEP]) were measured by combined spirometry.

RESULTS

There was a negative significant correlation between maximum Cobb angle and ATR with respiratory function parameters except for PEF and FEV1/FVC (r = -0.258-0.441; p = <0.001-0.047). There was a moderate negative correlation between ATR with MIP (cmH2O) (r = -0.377; p = 0.003) and MEP (cmH2O) (r = -0.362; p = 0.005). On the other hand, no correlation was found between brace-wearing duration with respiratory functions, maximum Cobb angle and brace-wearing duration with respiratory muscle results.

CONCLUSION

The results of this study showed that, respiratory functions were normal or mildly affected, and respiratory muscle strengths were weak in AIS. Increased Cobb angle and ATR negatively affected respiratory function; increased ATR was associated with decreased inspiratory and expiratory muscle strength. It is extremely important to carefully evaluate the respiratory system and to know the variables that affect respiratory functions and respiratory muscle strength in achieving optimum recovery in the holistic treatment of individuals with scoliosis.

Associations between paraspinal muscle characteristics and spinal curvature in conservatively treated adolescent idiopathic scoliosis: a systematic review

BACKGROUND CONTEXT

Children with adolescent idiopathic scoliosis (AIS) may show asymmetrical paraspinal muscle characteristics.

PURPOSE

To summarize the evidence regarding: (1) the associations between various paraspinal muscle characteristics and spinal curvature; (2) whether paraspinal muscle properties significantly differed between children with and without AIS; and (3) whether baseline paraspinal muscle characteristics predicted curve progression.

STUDY DESIGN/SETTING

Systematic literature review.

METHODS

Five databases (CINAHL, Academic Search Premier, MEDLINE, Scopus, and PubMed) were searched from inception to May 2022. This protocol was registered in the PROSPERO database of systematic reviews CRD 42020171263. The Critical appraisal skills program, the Appraisal Tool for Cross-Sectional Studies and Quality In Prognosis Studies tool were used to evaluate the risk of bias of the included studies. The strength of evidence of each identified association was determined by the Grading of Recommendations Assessment, Development, and Evaluation System (GRADE).

RESULTS

Of 1,530 identified citations, four cohort, 17 cross-sectional, and 23 case-control studies including 31 with low, nine with moderate and four with high risk of bias were included. Low to very low-strength evidence supported that the convex side of the curve had more type I muscle fibers, higher muscle volume and paraspinal muscle activity, while the concavity had more intramuscular fatty infiltration. Very low-strength evidence substantiated greater side-to-side surface electromyography signals during left trunk bending in prone lying, standing, and standing with perturbation between people with and without AIS. Also, low to very low-strength evidence supported that a larger side-to-side surface electromyography ratio at the lower end vertebra predicted curve progression.

CONCLUSIONS

Our review highlights that paraspinal muscles on the concavity of the curve demonstrate consistent changes (ie, altered muscle-related gene expression, muscle atrophy, increased fatty infiltration, reduced type I fibers, and reduced muscle activity), which may be the cause or consequence.

Association of scoliosis with lower extremity alignments, muscle strengths, and foot characteristics and their alterations in adolescent idiopathic scoliosis

BACKGROUND

The association between changes occurring in the spine and lower body parts is not well understood in adolescent idiopathic scoliosis (AIS).

OBJECTIVES

The first aim of the study was to investigate the association of scoliosis with lower extremity (LE) alignments, foot characteristics, and muscle strengths in adolescents. Secondly, comparisons of the data among AIS with single and double curves and control groups were determined.

METHODS

Thirty-one participants were recruited and classified into 3 groups; AIS with a single curve (n= 7), AIS with double curves (n= 14), and controls (n= 10). Association of the presence of scoliosis with LE alignments (Q and TC angles), LE muscle strengths (hip, knee, and ankle), and foot characteristics (arch indexes) were examined using the point biserial correlation, and the data among three groups were compared using the ANOVA.

RESULTS

Scoliosis was associated with Q angle, arch indexes, and all LE muscle strengths except for hip extensors and ankle plantar flexors strengths. Comparisons among the three groups showed significant increases in LE alignments and foot characteristics in AIS. Almost all LE muscle strengths decreased in AIS, especially for the single curve group.

CONCLUSIONS

Apart from spinal deformity, the AIS has changed in LE alignments, muscle strengths, and foot characteristics. Therapists should consider these associations and alterations for designing proper management.

The effect of Pilates-based exercise applied with hybrid telerehabilitation method in children with adolescent idiopathic scoliosis: A randomized clinical trial

This study aimed to investigate the effect of Pilates-based exercise training applied with hybrid telerehabilitation on Cobb angle, respiratory function, respiratory muscle strength, and functional capacity in patients with adolescent idiopathic scoliosis (AIS). This is an evaluator-blinded, randomized, controlled trial. For the study, 32 patients were randomly allocated into two groups: a hybrid telerehabilitation group (training group), provided with modified Pilates-based exercises with synchronous sessions; and a home-based group (control group), doing the same exercises in their home. The Pilates-based exercise program consists of stretching and strengthening exercises combined with postural corrections and breathing exercises modified according to the curve type and localization of the patients, done every day of the week for 12 weeks. Analyses were made based on the comparison between the angle of trunk rotation, Cobb angle, spirometry, maximal inspiratory (MIP) and expiratory pressures (MEP), and incremental shuttle walk tests done at the beginning and end of the study. The training group showed statistically significant improvements in Cobb angle, PEF%, MIP, and MEP values compared with the control group (p < 0.05).

CONCLUSION

 Pilates-based exercises applied with the hybrid telerehabilitation method can improve Cobb angle and respiratory muscle strength in patients with AIS. The hybrid telerehabilitation method can be used as an alternative to home-based programs, especially in locations and times where there may be limited access to supervised training. Also, the nature of the disease that requires long-term follow-up is another factor where hybrid telerehabilitation may be an advantage.

TRIAL REGISTRATION

 ClinicalTrials.gov ID: NCT05761236.

WHAT IS KNOWN

• Exercise training is one of the main approaches to treating scoliosis.

WHAT IS NEW

• Application of exercises via telerehabilitation method may contribute more to the improvement of scoliosis-related parameters than home-based programs. • Telerehabilitation may be a preferable alternative exercise method in scoliosis, considering the advantages of accessibility and long-term follow-up.

Early Onset Scoliosis and Adolescent Idiopathic Scoliosis: A Review of the Literature and Correlations With Pulmonary Dysfunction

In the management of early onset scoliosis (EOS) and adolescent idiopathic scoliosis (AIS), orthopedic surgeons are tasked with considering the effects that curves and their treatment can have on the respiratory system, possibly the most relevant being pulmonary dysfunction due to thoracic cage changes. The pulmonary impairment that occurs as a result of scoliosis varies widely and requires a multimodal response, including physiologic testing, such as pulmonary function tests (PFTs) and consistent psychosocial monitoring of the patient. This forces healthcare providers to consider all factors affecting the patient's quality of life (QOL) and not just the primary pathology they are treating. One method that could be utilized to ensure a more holistic approach to treatment is the use of patient-reported outcome measures (PROMs) to assess the QOL domains. Thus, this review serves to highlight the importance of addressing and correcting pulmonary dysfunction in the care of children with EOS and AIS in a holistic manner.

Outcome of bracing vs. surgical treatment in adolescents with idiopathic scoliosis based on device measured daily physical activity: a prospective pilot study

Adolescent idiopathic scoliosis (AIS) can be treated with bracing or surgery, which may affect patient's physical activity (PA). However, there are limited objective assessments of PA in patients with AIS. This study aims to compare the outcome of spinal bracing vs. surgery in patients with AIS based on a device that measured daily PA. In total 24 patients with AIS participated, including 12 patients treated with bracing and 12 with spinal surgery. Daily PA was measured throughout 4 consecutive days using four tri-axial accelerometers and patient-reported functional status was reported using the SRS-22 questionnaire. The participants were assessed both before the treatment and after treatment at a 12-month follow-up. Patients with AIS had no significant change in their PA levels at the 12-month follow-up after surgical correction. On the contrary, patients with AIS following a year-long bracing treatment had significantly reduced time spent active ( P  = 0.04) with an average reduction in walking steps by 2137 steps/day ( P  = 0.005). There was no significant difference in function, pain, self-image and mental health domains following both treatments, as reported by the SRS-22. There was a significant improvement in satisfaction for both treatment groups ( P  ≤ 0.02). Significantly reduced PA and increased sedentary time are reported in patients with AIS following bracing treatment. An objective PA assessment is recommended to track the effect of scoliosis treatment on PA. Patients with AIS should be actively encouraged to achieve and maintain their recommended daily PA levels irrespective of the type of treatment. Level of evidence: Level II.

BMP6 participates in the pathogenesis of adolescent idiopathic scoliosis by regulating osteopenia

Adolescent idiopathic scoliosis (AIS) is a complex disease characterized by three-dimensional structural deformities of the spine. Its pathogenesis is associated with osteopenia. Bone-marrow-derived mesenchymal stem cells (BMSCs) play an important role in bone metabolism. We detected 1919 differentially expressed mRNAs and 744 differentially expressed lncRNAs in BMSCs from seven patients with AIS and five patients without AIS via high-throughput sequencing. Multiple analyses identified bone morphogenetic protein-6 (BMP6) as a hub gene that regulates the abnormal osteogenic differentiation of BMSCs in AIS. BMP6 expression was found to be decreased in AIS and its knockdown in human BMSCs significantly altered the degree of osteogenic differentiation. Additionally, CAP1-217 has been shown to be a potential upstream regulatory molecule of BMP6. We showed that CAP1-217 knockdown downregulated the expression of BMP6 and the osteogenic differentiation of BMSCs. Simultaneously, knockout of BMP6 in zebrafish embryos significantly increased the deformity rate. The findings of this study suggest that BMP6 is a key gene that regulates the abnormal osteogenic differentiation of BMSCs in AIS via the CAP1-217/BMP6/RUNX2 axis.

Reduced volume and altered composition of paraspinal muscles in Marfan syndrome: A retrospective cohort study

Retrospective cohort study. Spinal deformities in patients with Marfan syndrome (MFS) are distinct from those in patients with idiopathic scoliosis (IS). It is more prone to progression and more likely to present with sagittal malalignment than IS. However, the etiology of this characteristic spinal deformity in MFS remains unclear. This study aimed to determine the spinal musculature characteristics in patients with MFS on the hypothesis that the paraspinal muscles of patients with MFS would be qualitatively or quantitatively different from those of patients with IS. Seventeen consecutive patients with MFS aged 25 years or younger undergoing surgery for scoliosis in our hospital were compared with age- and sex-matched patients with IS undergoing surgery for scoliosis. The body size-adjusted relative cross-sectional area (rCSA), fatty infiltration ratio (FI%), and relative functional cross-sectional area (rFCSA) of the psoas muscles (PM) and paravertebral muscles (PVM) at L3/4 and L4/5 were measured using preoperative T2-weighted magnetic resonance imaging. Functional CSA was defined as total CSA minus the fatty infiltration area of each muscle and rFCSA was calculated as the body size-adjusted functional CSA. The rCSA of the PM at L3/4 and L4/5 was significantly smaller in the MFS group than in the IS group (L3/4, P = .021; L4/5, P = .002). The FI% of the PM at L4/5 was significantly higher in the MFS group (P = .044). Consequently, the rFCSA of the PM at L3/4 and L4/5 and the rFCSA of the PVM at L3/4 in the MFS group were significantly smaller than those in the IS group (PM at L3/4, P = .021; PM at L4/5, P = .001; PVM at L3/4, P = .025). Compared with patients with IS, patients with MFS exhibited significantly decreased body-size-adjusted CSA of the PM and reduced body-size-adjusted functional CSA of the PVM and PM. These findings may partially explain the characteristics of distinctive spinal deformities in patients with MFS.

Schroth Physiotherapeutic Scoliosis-Specific Exercise (PSSE) Trials-Systematic Review of Methods and Recommendations for Future Research

The Schroth method is a non-operative treatment for scoliosis and kyphosis, used standalone or as an adjunct to bracing. While supporting evidence for its effectiveness is emerging, methodologic standardization and rigor are equivocal. Thus, we aimed to systematically review methods of published Schroth physiotherapeutic scoliosis-specific exercise (PSSE) trials and provide guidance for future research. We searched six databases for randomized controlled trials (RCT) and non-randomized studies of interventions (NRSIs) investigating the effect of Schroth in children and adults with scoliosis or kyphosis. General characteristics, methodological approaches, treatment protocols, and outcomes reporting were analyzed. Risk of bias (RoB) was assessed using an adapted Cochrane RoB2 tool for RCTs and ROBINS-I for NRSI. Eligible studies (n = 7) were conducted in six countries and included patients with Scheuermann's kyphosis (n = 1) and adolescent idiopathic scoliosis (n = 6). Though all seven studies used the term Schroth to describe their interventions, the Schroth method was used in four of seven studies, of which only one used Schroth classification, three used Schroth therapists, and none prospectively registered the study protocol. Overall, methodological rigor was suboptimal, potentially invalidating evidence synthesis. Authors should follow minimum standards for reporting, including prospectively registering detailed protocols; using appropriate exercise labeling, Schroth classification and certified therapists; naming and describing exercises per classification; and providing therapy dosages, prescription methods, and adherence.

Abolition of sagittal T7-T10 dynamics during forced ventilation in AIS patients with Lenke 1A curves

In healthy subjects, respiratory maximal volumes are highly dependent on the sagittal range of motion of the T7-T10 segment. In AIS, the abolition of T7-T10 dynamics related to the stiffness induced by the apex region in Lenke IA curves could harm ventilation during maximal breathing. The aim of this study was to analyze the dynamics of the thoracic spine during deep breathing in AIS patients and in healthy matched controls. This is a cross-sectional, case-control study. 20 AIS patients (18 girls, Cobb angle, 54.7 ± 7.9°; Risser 1.35 ± 1.2) and 15 healthy volunteers (11 girls) matched in age (12.5 versus 15.8 years mean age) were included. In AIS curves, the apex was located at T8 (14) and T9 (6). Conventional sagittal radiographs of the whole spine were performed at maximal inspiration and exhalation. The ROM of each spinal thoracic functional segment (T1-T7, T7-T10, T10-T12) and the global T1-T12 ROM were measured. In healthy subjects, the mean T1-T12 ROM during forced breathing was 16.7 ± 3.8. AIS patients showed a T1-T12 ROM of 1.1 ± 1.5 (p < 0.05), indicating a sagittal stiffness of the thoracic spine. A wide T7-T10 ROM (15.3 ± 3.0) was found in healthy controls (91.6% of the T1-T12 ROM). AIS patients showed only 0.4 ± 1.4 ROM at T7-T10 (36.4% of the T1-T12 ROM) (p < 0.001). There was a linear relationship between the magnitude of T7-T10 kyphosis in maximal exhalation and both FVC (% of predicted FVC) and FEV1. In conclusion, Lenke 1A AIS patients show a restriction of the thoracic spine motion with an almost complete abolition of T7-T10 ROM, a crucial segment for deep breathing. T7-T10 stiffness could explain the ventilatory limitations found in AIS patients.

Effects of inspiratory muscle training on respiratory muscle strength, respiratory function and functional capacity in adolescents with idiopathic scoliosis : A randomized, controlled trial

BACKGROUND

Adolescent Idiopathic Scoliosis (AIS) may impair respiratory dynamics and affect the performance of inspiratory and expiratory muscles. The benefit of inspiratory muscle training (IMT) is not well investigated in AIS. We aimed to investigate the effects of IMT on respiratory muscle strength, respiratory function and functional capacity in adolescents with mild to moderate AIS.

METHODS

Thirty-six adolescents were randomized into control or IMT groups. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and peak expiratory flow (PEF) were measured by spirometry; respiratory muscle strength by maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP); and functional capacity by 6-min walk test (6MWT) before and after the 8-week-long home-based exercise program. Both groups received conventional exercise program including diaphragmatic breathing exercises, resistive local expansion exercise on the collapsed areas in concave sides of scoliosis, spinal stabilization, strengthening of interscapular muscles and stretching exercises. IMT group also trained with Threshold IMT device for 15 minutes, twice a day for 8 weeks at the intensity of 30% of initial MIP value in addition to conventional exercise program.

RESULTS

FEV1, PEF, MIP, MEP and 6MWT distance significantly improved in both groups. IMT group also showed significant improvement in FVC. The increases in FVC, MIP, MEP and 6MWT distance of IMT group were significantly higher compared to control group.

CONCLUSION

IMT is found to be beneficial for patients with AIS for achieving further improvements in respiratory function, respiratory muscle strength and functional capacity compared to conventional exercise program alone.

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.

Patients with Adolescent Idiopathic Scoliosis Have Higher Metabolic Cost during High-Intensity Interval Training

BACKGROUND

Patients with adolescent idiopathic scoliosis (AIS) are found to have a lower level of physical activity, and may have reduced exercise capacity due to spinal deformity. Previous study showed the benefits of high-intensity interval training (HIIT), named E-Fit, which is specifically designed for patients with AIS to improve musculoskeletal health and psychological well-being. To optimize the beneficial effects of training, the current study aimed to investigate the appropriate exercise intensity and metabolic demand in patients with AIS when performing E-Fit.

METHODS

In all, 22 female subjects, 10 diagnosed with AIS and 12 gender-matched healthy controls, aged between 10 and 16 years, were recruited. Subjects were instructed to perform two trials of a seven min E-Fit. Breath-by-breath gas exchange parameters including oxygen consumption (VO₂), heart rate (HR) and the rate of perceived exertion (PRE) were measured during exercise. Demographic data and clinical features of AIS and body composition were obtained. Metabolic demand between AIS and control groups was compared using MANOVA with covariates adjustment.

RESULTS

Patients with AIS had an earlier onset of menarche (p = 0.01), higher visceral adipose tissue (p = 0.04) and percentage body fat (p = 0.03) as compared to controls. Patients with AIS showed a significantly higher adjusted means of VO₂ average in both the first (p = 0.014) and second trials (p = 0.011) of E-Fit. The adjusted mean of the highest measured VO₂ was higher than healthy controls and reached statistical significance in the second trial (p = 0.004). Both the AIS and control group exercised at a similar percentage of VO₂ peak (64.26% vs. 64.60%).

CONCLUSION

Patients with AIS showed higher oxygen consumption during E-Fit than heathy controls, which might indicate a higher metabolic cost. Patients with AIS could carry out exercise at a moderate exercise intensity similar to that of healthy controls, but special considerations in designing an exercise program, such as frequent rest intervals, would be useful to avoid fatigue among patients with AIS.

Is impaired lung function related to spinal deformities in patients with adolescent idiopathic scoliosis? A systematic review and meta-analysis-SOSORT 2019 award paper

PURPOSE

Some teenagers with adolescent idiopathic scoliosis (AIS) display compromised lung function. However, the evidence regarding the relations between pulmonary impairments and various spinal deformity parameters in these patients remains unclear, which affects clinical management. This systematic review and meta-analysis aimed to summarize the associations between various lung function parameters and radiographic features in teenagers with AIS.

METHODS

A search of PubMed, Embase, PEDro, SPORTDiscus, CINAHL, Cochrane Library, and PsycINFO (from inception to March 14, 2022) without language restriction. Original studies reporting the associations between lung function and spinal deformity in patients with AIS were selected. Independent reviewers extracted data and evaluated the methodological quality of the included studies according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pearson correlation and 95% confidence intervals were calculated using random-effects meta-analysis.

RESULTS

Twenty-seven studies involving 3162 participants were included. Limited-quality evidence supported that several spinal parameters were significantly related to lung function parameters (e.g., absolute value and percent of the predicted forced vital capacity (FVC; %FVC), forced expiratory volume in one second (FEV₁; %FEV₁), and total lung capacity (TLC; %TLC)) in AIS patients. Specifically, meta-analyses showed that main thoracic Cobb angles in the coronal plane were significantly and negatively related to FVC (r =  - 0.245), %FVC (r =  - 0.302), FEV₁ (r =  - 0.232), %FEV₁ (r =  - 0.348), FEV₁/FVC ratio (r =  - 0.166), TLC (r =  - 0.302), %TLC (r =  - 0.183), and percent predicted vital capacity (r =  - 0.272) (p < 0.001). Similarly, thoracic apical vertebral rotation was negatively associated with %FVC (r =  - 0.215) and %TLC (r =  - 0.126) (p < 0.05). Conversely, thoracic kyphosis angles were positively related to %FVC (r = 0.180) and %FEV₁ (r = 0.193) (p < 0.05).

CONCLUSION

Larger thoracic Cobb angles, greater apical vertebral rotation angle, or hypokyphosis were significantly associated with greater pulmonary impairments in patients with AIS, although the evidence was limited. From a clinical perspective, the results highlight the importance of minimizing the three-dimensional spinal deformity in preserving lung function in these patients. More research is warranted to confirm these results.

The efficacy of trunk bracing with an instrumented corrective exercise on spinal deformity, pulmonary function, trunk muscle endurance and quality of life in adolescent idiopathic scoliosis: Protocol for a parallel-groups clinical study (Preprint)

BACKGROUND

Adolescent idiopathic scoliosis is a 3D spine distortion with an unidentified etiology. It results in noticeable trunk deformity, decreased muscle strength and endurance at the trunk, changes in chest volume, breathing issues, and ultimately a decline in the quality of life. Trunk bracing and corrective exercises make up most of the treatment of patients with scoliosis when their deformity is between 20° and 45°, and they have not yet attained skeletal maturity. Evidence suggests that spinal deformity in people with scoliosis may result from improper motor control. Automatic response training is an exercise therapy technique that can modify the pattern of trunk muscle control for supporting the spinal column in normal alignment. An apparatus called a cantilever device is required for this type of exercise, which facilitates training at home. In spite of research showing the benefit of braces and therapeutic exercise in adolescents with scoliosis, less emphasis has been given to the impact of home-based training, especially when this intervention is paired with braces.

OBJECTIVE

We aim to compare the efficacy of bracing and a conventional exercise program to a combination treatment that includes trunk bracing and exercises with a cantilever device performed at home on the degree of spine curvature, pulmonary function, trunk muscular endurance, and quality of life.

METHODS

This study was a 2-arms parallel-group clinical study. A total of 16 adolescents with idiopathic scoliosis and single lumbar and thoracolumbar curves of 20°-45° were recruited and randomly assigned into 2 groups. Group A received a combination of trunk bracing and exercise using an instrument known as a "cantilever." Group B (controls) received trunk bracing and a conventional exercise program (without a tool). The study outcomes were the Cobb angle of the scoliotic curve, pulmonary function, the endurance of the trunk muscles, and quality of life. The study outcomes were measured at 2 time points: before the intervention (T1) and 12 weeks following the start of the intervention (T2; at this time, the intervention period has been completed). Multivariate analysis of variance was used to test between- and within-group differences.

RESULTS

Recruitment for this study began in fall 2022 and is expected to be completed by the end of summer 2023.

CONCLUSIONS

We studied the efficacy of a combined trunk bracing program and postural response exercises using a cantilever device in treating adolescent idiopathic scoliosis and compared it with trunk bracing and conventional home exercises. Exercises performed at home using a cantilever device are anticipated to raise the endurance of trunk muscles, which will help reduce trunk deformity, enhance pulmonary function, and improve the quality of life of participants.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials IRCT20220330054371N1; https://www.irct.ir/trial/62811.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/43265.

Pulmonary function in children and adolescents with untreated idiopathic scoliosis: a systematic review with meta-regression analysis

BACKGROUND CONTEXT

One of the controversies in untreated idiopathic scoliosis is the influence of curve size on respiratory function. Whereas scoliosis patients with curves over 90 to 100 degrees are agreed to be at risk for cardiorespiratory failure in later life, the impairment of curves below 90 degrees is generally considered mild. Although various studies showed that pulmonary function is affected in patients with scoliosis, quantification of the relation between curve size and pulmonary function is lacking.

PURPOSE

This systematic review with meta-regression analysis aims to characterize the relation between pulmonary function tests and scoliosis severity in children and adolescents with idiopathic scoliosis.

STUDY DESIGN

Systematic review with meta-regression analysis.

METHODS

Pubmed, Embase, Cochrane, and CINAHL were systematically searched until November 3, 2020, for original articles that reported (1) severity of scoliosis quantified in Cobb angle, and (2) pulmonary function tests in children and adolescents with untreated idiopathic scoliosis. Exclusion criteria were other types of scoliosis, non-original data, post-treatment data, and case reports. All study designs were included, and relevant study details and patient characteristics were extracted. The primary outcome was the effect of Cobb angle on pulmonary function as expressed by the slope coefficient of a linear meta-regression analysis.

RESULTS

A total of 126 studies, including 8,723 patients, were retrieved. Meta-regression analysis revealed a statistically significant inverse relation between thoracic Cobb angle and absolute and predicted forced vital capacity in 1 second, forced vital capacity, vital capacity, and total lung capacity. For these outcomes, the slope coefficients showed a decrease of 1% of the predicted pulmonary function per 2.6 to 4.5 degrees of scoliosis. A multivariable meta-regression analysis of potential confounders (age, year of publication, and kyphosis) hardly affected the majority of the outcomes.

CONCLUSION

This meta-regression analysis of summary data (means) from 126 studies showed an inverse relationship between the thoracic Cobb angle and pulmonary function. In contrast to previous conclusions, the decline in pulmonary function appears to be gradual over the full range of Cobb angles between <20 and >120 degrees. These findings strengthen the relevance of minimizing curve progression in children with idiopathic scoliosis.

Effectiveness of Acupuncture for Scoliosis: A Systematic Review

Scoliosis is a 3-dimensional change of the spine, presenting 10° above Cobb angle. Various acupuncture methods are being increasingly performed to correct scoliosis. However, no systematic review has been published. Therefore, we report on the effectiveness of acupuncture on mild scoliosis in this systematic review. We searched various databases for acupuncture treatment for scoliosis published before June 2021. The primary outcome was Cobb angle, and the secondary outcomes were patient-centered scores. Six studies were identified. RCTs that compared combination therapy with acupuncture, and other treatment methods and showed significant improvement in the Cobb angle, and effective rate, but, with low quality evidence. Acupuncture monotherapy resulted in significant improvement in the Cobb angle and had high heterogeneity compared with other treatment methods, but no significant improvement in the effective rate was observed, and the quality of evidence was low. Regardless of the type of scoliosis, acupuncture monotherapy or combination therapy with acupuncture showed significant improvement in the Cobb angle, and the quality of evidence was moderate. No serious adverse events were observed in the 6 studies reviewed. Acupuncture is considered safe, and it is more effective when performed with other conventional treatments.

Influences of Thoracic Spinal Deformity on Exercise Performance and Pulmonary Function: A Prospective Study of 168 Patients with Adolescent Idiopathic Scoliosis

STUDY DESIGN

A prospective study.

OBJECTIVE

The aim of this study was to investigate the factors associated with cardiopulmonary exercise testing (CPET) measurements in patients with adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Patients with AIS display restrictive pulmonary dysfunction on pulmonary function testing (PFT). It remains unknown whether thoracic spinal deformity affects exercise performance.

METHODS

One hundred and sixty-eight patients with AIS from January 2014 to December 2019 were included. They underwent preoperative spinal radiological assessment, PFT, and CPET. The effects of the thoracic curve magnitude, body mass index, physical activity level and history of bracing on pulmonary function and exercise performance were analyzed. The Student t test and two-tailed Pearson test were used in data analysis.

RESULTS

We found significantly reduced forced expiratory volume in 1second (FEV1) in patients with a larger magnitude of the proximal thoracic curve (P < 0.001) and the main thoracic curve (P < 0.001). There was a negative correlation between forced vital capacity (FVC) and the magnitude of the main thoracic curve (P < 0.001) and thoracic hypokyphosis (P < 0.001). In CPET, exercise capacity indicators such as the work rate, peak oxygen intake, and heart rate were not affected by the thoracic curve magnitude. Patients with moderate or severe pulmonary dysfunction had decreased tidal volume (P = 0.01) and ventilatory reserve (P < 0.001), as well as increased respiratory frequency at maximal exercise (P = 0.01). Patients with a moderate or high physical activity level had better exercise capacity, which was reflected by a higher work rate (P = 0.009) and oxygen intake (P < 0.001).

CONCLUSION

There was no significant correlation between radiographic parameters and exercise capacity indicators. When the thoracic curve increased, patients had restrictive ventilatory dysfunction, which led to a tachypneic breathing pattern and reduction of ventilatory reserve during exercise. A physiological change of improved peak oxygen intake was demonstrated in patients with a moderate or high physical activity level.Level of Evidence: 3.

Thoracic Morphology and Bronchial Narrowing Are Related to Pulmonary Function in Adolescent Idiopathic Scoliosis

BACKGROUND

In adolescent idiopathic scoliosis (AIS), lung function impairment is not necessarily related to the coronal spinal deformity. Recently, right-sided bronchial narrowing has been reported in thoracic AIS. The aim of this study was to describe the relation of chest and spinal deformity parameters, bronchial narrowing, and lung volumes with pulmonary function in preoperative AIS.

METHODS

Spinal radiographs, low-dose computed tomographic (CT) scans of the spine including the chest, and pulmonary function tests were retrospectively collected for 85 preoperative patients with thoracic AIS in 2 centers and were compared with 14 matched controls. Three-dimensional lung and airway reconstructions were acquired. Correlation analysis was performed in which radiographic spinal parameters, CT-based thoracic deformity parameters (rib-hump index [RHi], spinal penetration index, endothoracic hump ratio, hemithoracic-width ratio), lung volume asymmetry, and bronchial cross-sectional area were compared with percent-of-predicted spirometry results.

RESULTS

Forty-one patients (48%) had a percent-of-predicted forced expiratory volume in 1 second (FEV1%) or percent-of-predicted forced vital capacity (FVC%) of <65%, and 17 patients (20%) had obstructive lung disease. All thoracic deformity parameters correlated significantly with FEV1% and FVC%; RHi was found to be the best correlate (rs = -0.52 for FEV1% and -0.54 for FVC%). Patients with AIS with impaired pulmonary function had hypokyphosis, a larger rib hump, increased spinal and thoracic rotation, a narrower right hemithorax, and increased intrusion of the spine into the chest. Spinal intrusion correlated with right-sided bronchial narrowing, relative right lung volume loss, and decreased FEV1% and FVC%. Multivariate regression including spinal and thoracic deformity parameters, lung volume asymmetry, and airway parameters could explain 57% of the variance in FEV1% and 54% of the variance in FVC%.

CONCLUSIONS

Chest intrusion by the endothoracic hump is related to right-sided bronchial narrowing and lung function loss in preoperative AIS. The findings support the theory that ventilatory dysfunction in thoracic AIS is not only restrictive but frequently has an obstructive component, especially in patients with hypokyphosis. RHi is the most predictive chest parameter for lung function loss.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Potential Muscle-Related Biomarkers in Predicting Curve Progression to the Surgical Threshold in Adolescent Idiopathic Scoliosis-A Pilot Proteomic Study Comparing Four Non-Progressive vs. Four Progressive Patients vs. A Control Cohort

Previous studies have reported abnormal muscle morphology and functions in patients with adolescent idiopathic scoliosis (AIS). To answer whether such abnormalities could be reflected in their circulation and their clinical implication for predicting curve progression to the surgical threshold, this preliminary study explored the presence of baseline muscle-related proteins and their association with curve progression. Plasma samples were collected at the first clinical visit for AIS, with patients divided into non-progressive or progressive groups (N = four and four) according to their Cobb angle in six-year follow-ups, with age- and sex-matched healthy subjects (N = 50). Then, the samples were subjected to isobaric tags for relative and absolute quantitation (iTRAQ) for global comparison of untargeted protein expression. Seventy-one differentially expressed proteins (DEPs) were found elevated in progressive AIS. Functional analysis showed that 18 of these are expressed in muscles and play an essential role in muscle activities. Among the muscle-related DEPs, α-actin had the highest fold change in progressive/non-progressive groups. This preliminary study firstly suggested higher circulating levels of muscle structural proteins in progressive AIS, indicating the likelihood of structural damage at the microscopic level and its association with progression to the surgical threshold. Further studies with larger sample sizes are warranted to validate these novel candidates for early diagnosis and predicting progression.

Cardiorespiratory function of patients undergoing surgical correction of Scheuermann's hyperkyphosis

The aim of this study was to analyze the impact of surgical correction of the thoracic deformity on the cardiorespiratory function of patients with moderate-severe Scheuermann’s hyperkyphosis (SK). A series of 23 adolescents with SK who underwent surgery through an only posterior approach using all pedicle screw constructs were included in the study. Cardiorespiratory parameters were measured during a maximal exercise tolerance test before and 2 years after surgery. Heart rate, oxygen saturation (SatO2), maximum oxygen uptake (VO2 max), ventilatory capacity at maximal exercise (VEmax), and energy costs were recorded. There were statistically significant differences in the forced vital capacity (FVC) (P < 0.05), total VO₂max (ml/min) (P < 0.01), maximum expired volume (VEmax) per minute (P < 0.01) and cardiovascular efficiency (HR/VO2 ratio) (P < 0.05). None of these changes were clinically relevant. There were no changes in the VO₂max per kg of body mass. The magnitude of the kyphosis correction did not correlate with the change in normalized VO2max or VEmax. In conclusion, patients with moderate-severe SK improve their baseline respiratory limitations and the tolerance to maximum exercise 2 years after surgery. However, the slight cardiorespiratory functional improvements should not necessarily be attributed to the surgery, and could also be caused solely by the residual growth of the lungs and thorax. Furthermore, respiratory functional changes are under thresholds considered as clinically relevant.

The effect of brace treatment on pulmonary functions in adolescent idiopathic scoliosis: An 8-month follow-up study

BACKGROUND

The instant effect of a brace on pulmonary functions of patients with adolescent idiopathic scoliosis (AIS) is known. However, the permanent effects of its regular use are still unclear.

OBJECTIVE

This study aimed to determine whether a brace in patients with AIS had a permanent effect on respiratory functions.

METHODS

Fifteen patients with a mean age of 13.2 ± 1.6 years, and a major Cobb angle of 25.8∘± 7.7∘ participated in this study. Lung volumes and respiratory muscle strength were measured with and without thoracolumbosacral brace, at the end of first month and follow-up period after the patients started using the brace for 23 hours daily.

RESULTS

When the brace was on, the forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), ratio of FEV1/FVC, peak expiratory flow, and forced expiratory flow between 25% and 75% of vital capacity values were found to be lower at both first month and follow-up. After the follow-up, the measurement results did not differ from the results of the first month.

CONCLUSIONS

The brace had a momentary restrictive effect on patients with AIS. However, it did not cause a permanent change in pulmonary functions after the 8-month follow-up.

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.

Feasibility of Rib Kinematics and Intercostal-Space Biomechanical Characterization by Ultrasound in Adolescent Idiopathic Scoliosis

The aim of this work was to determine the feasibility of combined ultrasonography and elastography measurement to characterize the mechanical properties of the intercostal space during breathing. Eighteen asymptomatic participants (ages 13 ± 2 y) and six participants with adolescent idiopathic scoliosis (AIS) were included (Cobb angle 60° ± 12°). Ultrasonographic and elastographic clips were acquired of T8-T9 ribs and the intercostal space. The two adjacent ribs were tracked to infer the breathing cycle. Shear-wave speed (SWS) was measured in the intercostal space at different stages of the breathing cycle. SWS was symmetric in the control group, during both expiration and inspiration. In AIS, the SWS during inspiration was higher in the convex side than in the concave one (p = 0.02). Furthermore, SWS was higher during inspiration than expiration in the control group and in the AIS convex side, but not in the AIS concave side (p > 0.05). This new method combining echography and shear-wave elastography allowed measurement of the mechanical characteristics of the intercostal space at different phases of the breathing cycle and highlighted differences between the AIS and control groups. This approach opens the way to further analyses of the biomechanical characteristics of breathing in severe AIS.

CARDIORESPIRATORY FUNCTION OF PATIENTS WITH ADOLESCENT IDIOPATHIC SCOLIOSIS

ABSTRACT Objective: Adolescent idiopathic scoliosis (AIS) is a spinal deformity that can cause cardiorespiratory dysfunction, contributing to decreases in tolerance for aerobic exercise (TAE) and in functionality. The objective is to assess the TAE and lung capacity of patients who underwent corrective AIS surgery in the pre- (PRE) and postoperative (POST) periods. Methods: Sixty individuals, PRE (n=30, age: 18.5±2.4 years) and POST (n=30, age: 24.5±4.5 years), participated in the study. The forced vital capacity (FVC), the forced expiratory volume in the first second (FEV1) and the FEV1/FVC ratio, as well as the maximum inspiratory and expiratory pressure were verified. The TAE was assessed by the distance travelled in the 6-minute walk test (6MWT), together with blood pressure, heart rate, respiratory rate and peripheral oxygen saturation measured at the beginning and at the end of the test. Results: A mild restrictive pattern in lung function and reduced expiratory muscle strength were observed in both groups, but with no difference between the PRE and POST groups. No difference was found between the PRE (534±67.1 m) and POST (541± 69.5 m) groups for the distance travelled in the 6MWT, though both were below the predicted percentage (82.8±10.0% and 84.8±10.9%, respectively). Hemodynamic and respiratory changes caused by the 6MWT were observed, except for the peripheral oxygen saturation. Conclusion: The results suggest that even after surgical correction, patients with AIS continue to have low TAE. Level of evidence III; Therapeutics Study - Investigation of Treatment Results / Case-control study.

The effectiveness of two different exercise approaches in adolescent idiopathic scoliosis: A single-blind, randomized-controlled trial

OBJECTIVES

The purpose of this study was to compare the efficacy of two different types of exercise methods in patients with adolescent idiopathic scoliosis.

METHODS

In total, 28 subjects with adolescent idiopathic scoliosis with a mild curve magnitude (10°-26°) were randomly divided into two groups: the Schroth group (n = 14) and the core group (n = 14). The patients in the Schroth group were treated with supervised Schroth exercises, and the patients in the core group were treated with supervised core stabilization exercises; both groups performed the exercises for three days per week for a total of 10 weeks, and both were given additional traditional exercises to perform. Assessment included Cobb angle (Radiography), trunk rotation (Adam's test), cosmetic trunk deformity (Walter Reed Visual Assessment Scale), spinal mobility (Spinal Mouse), peripheral muscle strength (Biodex System 4-Pro), and quality of life (Scoliosis Research Society-22 questionnaire).

RESULTS

It was found that patients in the Schroth group showed greater improvement in Cobb angles, thoracic trunk rotation angle, cosmetic trunk deformity, spinal mobility, and quality of life than those in the core group (p<0.05), except for in lumbar trunk rotation angle. Peripheral muscle strength improvement was greater in the core group than in the Schroth group (p<0.05).

CONCLUSION

Schroth exercises are more effective than core stabilization exercises in the correction of scoliosis and related problems in mild adolescent idiopathic scoliosis, and core stabilization exercises are more effective than Schroth exercises in the improvement of peripheral muscle strength.

TRIAL REGISTRATION

NCT04421157.

A QTL for conformation of back and croup influences lateral gait quality in Icelandic horses

BACKGROUND

The back plays a vital role in horse locomotion, where the spine functions as a spring during the stride cycle. A complex interaction between the spine and the muscles of the back contribute to locomotion soundness, gait ability, and performance of riding and racehorses. Conformation is commonly used to select horses for breeding and performance in multiple horse breeds, where the back and croup conformation plays a significant role. The conformation of back and croup plays an important role on riding ability in Icelandic horses. However, the genes behind this trait are still unknown. Therefore, the aim of this study was to identify genomic regions associated with conformation of back and croup in Icelandic horses and to investigate their effects on riding ability. One hundred seventy-seven assessed Icelandic horses were included in the study. A genome-wide association analysis was performed using the 670 K+ Axiom Equine Genotyping Array, and the effects of different haplotypes in the top associated region were estimated for riding ability and additional conformation traits assessed during breeding field tests.

RESULTS

A suggestive quantitative trait loci (QTL) for the score of back and croup was detected on Equus caballus (ECA) 22 (p-value = 2.67 × 10- 7). Haplotype analysis revealed two opposite haplotypes, which resulted in higher and lower scores of the back and croup, respectively (p-value < 0.001). Horses with the favorable haplotype were more inclined to have a well-balanced backline with an uphill conformation and had, on average, higher scores for the lateral gaits tölt (p-value = 0.02) and pace (p-value = 0.004). This genomic region harbors three genes: C20orf85, ANKRD60 and LOC100056167. ANKRD60 is associated with body height in humans. C20orf85 and ANKRD60 are potentially linked to adolescent idiopathic scoliosis in humans.

CONCLUSIONS

Our results show that the detected QTL for conformation of back and croup is of importance for quality of lateral gaits in Icelandic horses. These findings could result in a genetic test to aid in the selection of breeding horses, thus they are of major interest for horse breeders. The results may also offer a gateway to comparative functional genomics by potentially linking both motor laterality and back inclination in horses with scoliosis in humans.

Ultrasonographic measurement of diaphragm thickness in patients with severe thoracic scoliosis

PURPOSE

This study aimed to measure diaphragm thickness using ultrasound in adult patients with severe idiopathic scoliosis.

METHODS

This prospective case-control study included patients with severe idiopathic scoliosis and a healthy control group. The control and patient groups' demographic features, pulmonary function tests, diaphragm thickness, and thickening fraction measured using ultrasonography were compared.

RESULTS

End-expirium values were similar between the two groups (p = 0.902). However, end of inspirium, change level, and diaphragm thickening fraction were significantly lower in the scoliosis group (p < 0.001 for all). Cobb degree values were inversely correlated with forced expiratory volume in 1 s (%) (r =  - 0.909, p < 0.001), forced vital capacity (%) (r =  - 0.887, p < 0.001), and end-inspirium thickness (r =  - 0.673 and p < 0.001) values. Furthermore, diaphragm thickness at the end of inspirium was positively correlated with forced expiratory volume in 1 s (%) (r = 0.636, p = 0.001) and forced vital capacity (%) (r = 0.646, p = 0.001) values. No significant correlation was found between diaphragm thickening fraction and forced expiratory volume in 1 s or forced vital capacity.

CONCLUSION

Ultrasound can provide valuable information about diaphragm morphology and quantify diaphragm contraction.

Histone methyltransferase MLL4 controls myofiber identity and muscle performance through MEF2 interaction

Skeletal muscle depends on the precise orchestration of contractile and metabolic gene expression programs to direct fiber-type specification and to ensure muscle performance. Exactly how such fiber type-specific patterns of gene expression are established and maintained remains unclear, however. Here, we demonstrate that histone monomethyl transferase MLL4 (KMT2D), an enhancer regulator enriched in slow myofibers, plays a critical role in controlling muscle fiber identity as well as muscle performance. Skeletal muscle-specific ablation of MLL4 in mice resulted in downregulation of the slow oxidative myofiber gene program, decreased numbers of type I myofibers, and diminished mitochondrial respiration, which caused reductions in muscle fatty acid utilization and endurance capacity during exercise. Genome-wide ChIP-Seq and mRNA-Seq analyses revealed that MLL4 directly binds to enhancers and functions as a coactivator of the myocyte enhancer factor 2 (MEF2) to activate transcription of slow oxidative myofiber genes. Importantly, we also found that the MLL4 regulatory circuit is associated with muscle fiber-type remodeling in humans. Thus, our results uncover a pivotal role for MLL4 in specifying structural and metabolic identities of myofibers that govern muscle performance. These findings provide therapeutic opportunities for enhancing muscle fitness to combat a variety of metabolic and muscular diseases.

Biomechanical Evaluation of Intercostal Muscles in Healthy Children and Adolescent Idiopathic Scoliosis: A Preliminary Study

Spine deformity during adolescent idiopathic scoliosis can induce a rib-cage deformity. This bone deformity can have direct consequences on the chest-wall muscles, including intercostal muscles, leading to respiratory impairments in individuals with severe cases. The aim of this study was to determine whether shear-wave elastography can be used to measure intercostal-muscle shear-wave speed (SWS) in healthy children and those with adolescent idiopathic scoliosis (AIS). Nineteen healthy participants and 16 with AIS took part. SWS measurements were taken by three operators, twice each. Average SWS was 2.3 ± 0.4 m/s, and inter-operator reproducibility was 0.2 m/s. SWS was significantly higher during apnea than in normal breathing (p < 0.01) in both groups. No significant difference was observed between groups in apnea or in normal breathing. Characterization of the intercostal muscles by ultrasound elastography is therefore feasible and reliable for children and adolescents with and without scoliosis.

Mapping of Back Muscle Stiffness along Spine during Standing and Lying in Young Adults: A Pilot Study on Spinal Stiffness Quantification with Ultrasound Imaging

Muscle stiffness in the spinal region is essential for maintaining spinal function, and might be related to multiple spinal musculoskeletal disorders. However, information on the distribution of muscle stiffness along the spine in different postures in large subject samples has been lacking, which merits further investigation. This study introduced a new protocol of measuring bilateral back muscle stiffness along the thoracic and lumbar spine (at T3, T7, T11, L1 & L4 levels) with both ultrasound shear-wave elastography (SWE) and tissue ultrasound palpation system (TUPS) in the lying and standing postures of 64 healthy adults. Good inter-/intra-reliability existed in the SWE and TUPS back muscle stiffness measurements (ICC ≥ 0.731, p < 0.05). Back muscle stiffness at the L4 level was found to be the largest in the thoracic and lumbar regions (p < 0.05). The back muscle stiffness of males was significantly larger than that of females in both lying and standing postures (p < 0.03). SWE stiffness was found to be significantly larger in standing posture than lying among subjects (p < 0.001). It is reliable to apply SWE and TUPS to measure back muscle stiffness. The reported data on healthy young adults in this study may also serve as normative reference data for future studies on patients with scoliosis, low back pain, etc.

Stress distribution changes in growth plates of a trunk with adolescent idiopathic scoliosis following unilateral muscle paralysis: A hybrid musculoskeletal and finite element model

This study aimed to investigate changes occurred in the stress distribution in the growth plates (GPs) of a trunk with adolescent idiopathic scoliosis (AIS) following unilateral muscle paralysis. We hypothesized that weakening the appropriately chosen muscles on the concave side can decelerate AIS deformity progression. Muscle forces and reaction loads were estimated by an optimization-driven musculoskeletal (MS) model of adolescents with a normal- and an AIS trunk, and then applied on the finite element model of GPs of L1 through L4. Different set patterns of 95% reduction in the strength of the concave-side longissimus thoracis pars thoracic (LGPT), multifidus lumborum (MFL), and LGPT + MFL muscles were performed in the MS models. Results of this study showed that weakening of the concave-side MFL and LGPT muscles rendered a 35% correction in the symptomatic axial rotation of the AIS spine, and a reduction of about 25% in the compressive von Mises stress on the concave side of GPs, respectively, which can decelerate the deformity progression. It was observed that unilateral muscle weakening caused a compensatory activation of the rest of muscles to retain the spine stability. The intradiscal pressures and ratio between the rotations toward either side of the scoliotic spine, found here, matched well with some recent in-vivo investigations. One of the applications of the stability-based MS model of AIS spine with unilaterally weakened muscles presented in this study is to optimize the performance of the currently used braces. To fortify the presented therapeutic approach, experiments should be done on scoliotic animals.

Accelerometer based assessment of daily physical activity and sedentary time in adolescents with idiopathic scoliosis

BACKGROUND

Studies have shown a positive correlation between higher physical activity (PA) and health benefits. However, device-based assessment of PA and sedentary time (ST) in people with adolescent idiopathic scoliosis (AIS) has not been deeply investigated.

OBJECTIVE

Analysis and comparison of weekend and weekdays PA and ST using multiple accelerometers in people with AIS with different curvature severity compared to healthy controls.

METHODS

24 participants with AIS divided into 2 groups of 12 with Cobb angles < 40° and > 40°, along with 12 age and BMI matched healthy controls. Daily PA and ST during four consecutive days were measured using four tri-axial accelerometers. Clinical functional assessment was performed using the scoliosis research society (SRS-22) questionnaire.

RESULTS

The combined weekend and weekdays average daily step count was found to be 22% and 29% lower in the AIS groups with Cobb angle < 40° and > 40°, respectively, compared to the controls. The average ST was also reported to be 5% and 7% higher in the AIS groups with Cobb angle < 40° and > 40°, respectively, compared to the controls. The reported differences were significant in the AIS group with higher Cobb angle (p≤0.05). No significant differences in PA or ST were reported between the AIS groups based on curvature severity.

CONCLUSIONS

Decreased PA and increased ST observed in patients with AIS may have long term health implications and may play a role in the disease process. The device-based assessment of PA to understand potential benefits in clinical practice is recommended.

Annual Observation of Changes in the Angle of Trunk Rotation. Trunk Asymmetry Predictors. A Study from a Scoliosis Screening in School Adolescents

Adolescent forms of idiopathic scoliosis are commonly encountered deformities of the thoracic and lumbar spine. They affect a significant number of adolescents, yet their cause is still unknown. The presented research is a cross-sectional analysis of 3933 volunteers (2131 girls and 1802 boys). The participants were primary school students aged 9 to 13 years old. This study determined a relationship between predictors such as: body mass, body height and body mass index (BMI) (independent variables) and angle of trunk rotation (ATR) value (dependent variable). Moreover, a stepwise multiple regression with backward selection was conducted to determine to what extent the dependent variable is explained by body mass, body height and BMI. In the group of 11,12,13-year-old girls, the analyzed results of multiple stepwise regression were statistically significant. Among the all studied predictors, it has been shown that body mass in the 11-year-old girls and body height in 12- and 13-year-old girls are major correlates of a 1-year ATR increase in proximal and main thoracic spine levels.

Combined aerobic and resistance training improves respiratory and exercise outcomes more than aerobic training in adolescents with idiopathic scoliosis: a randomised trial

QUESTION

In adolescents with idiopathic scoliosis, does combined aerobic and resistance training improve respiratory function, perceived exertion and functional exercise capacity more than aerobic training only?

DESIGN

Randomised controlled trial with concealed allocation, blinded assessors and intention-to-treat analysis.

PARTICIPANTS

Forty adolescents with idiopathic scoliosis and formal indication for surgical correction (spinal curvature ≥ 45 deg).

INTERVENTION

Both groups undertook three 60-minute training sessions per week for 12 weeks. The experimental group performed combined aerobic and resistance training and the control group performed only aerobic training.

OUTCOME MEASURES

At baseline and upon completion of treatment, participants completed: a 6-minute walk test with Borg scale (0 to 10) rating of exertion, spirometry, maximal respiratory pressures and peak expiratory flow measurement.

RESULTS

After 12 weeks of training, the experimental group improved more than the control group on the 6-minute walk test (MD 22 m, 95% CI 4 to 40), with lower perceived exertion at the end of the test (MD -1.2, 95% CI -1.9 to -0.4). The experimental group also improved more than the control group on several respiratory measures, including: FEV₁ (MD 270 ml, 95% CI 30 to 510), maximal inspiratory pressure (MD 4 cmH₂O, 95% CI 1 to 8) and peak expiratory flow (MD 33 l/minute, 95% CI 7 to 58).

CONCLUSION

In adolescents with idiopathic scoliosis, combined aerobic and resistance training improves functional exercise capacity and several respiratory outcomes more than a similar training regimen with aerobic training only. It is unclear whether the magnitude of the benefits is large enough to be worthwhile.

TRIAL REGISTRATION

NCT02413788.

Impact of Thoracic Cage Dimension and Geometry on Cardiopulmonary Function in Patients With Congenital Scoliosis: A Prospective Study

STUDY DESIGN

A prospective study of cardiopulmonary function in patients with congenital scoliosis (CS).

OBJECTIVE

To investigate the relationship of thoracic cage deformity and exercise tolerance in CS patients.

SUMMARY OF BACKGROUND DATA

Congenital thoracic scoliosis and chest deformity lead to restrictive pulmonary dysfunction and in some severe cases cause cardiopulmonary failure. However, it is still unknown the relationship between thoracic deformity and exercise performance.

METHODS

Patients with congenital thoracic spinal deformity were included and had radiological assessment of thoracic cage, pulmonary function testing, and cardiopulmonary exercise testing. Thoracic dimension including height, width, and depth were measured and geometry parameters were calculated. Two-tailed Pearson and Spearman correlation test and linear regression analysis were performed to investigate correlation of radiographic parameters, pulmonary function, and physical capacity.

RESULTS

Sixty patients (41 females and 19 males) were included, with an average age of 18.9 years. Patients with smaller thoracic height (P < 0.001) and width (P < 0.01) and larger depth (P < 0.05) had significantly worse static pulmonary function. In exercise testing, these patients showed significant tendency of ventilation insufficiency, including lower minute ventilation (P < 0.05), faster breathing frequency (P < 0.05), and smaller tidal volume (P < 0.01). Thoracic depth was negatively correlated to exercise capacity, reflected by work rate (P < 0.001), peak oxygen intake (P < 0.001), and heart rate (P = 0.043). Patients with abnormal thoracic geometry, especially a lower ratio of height to depth and a lower ratio of width to depth, have significantly worse static pulmonary function and exercise capacity (all P < 0.05).

CONCLUSION

Decreasing thoracic height and width results in restrictive pulmonary dysfunction. Distortion and asymmetry of the thoracic cage are associated with abnormal breathing pattern and reduction of exercise capacity.

LEVEL OF EVIDENCE

3.

Magnetic Resonance Imaging-Based Morphological Change of Paraspinal Muscles in Girls With Adolescent Idiopathic Scoliosis

STUDY DESIGN

A cross-sectional study.

OBJECTIVE

To investigate and compare any morphological differences in paraspinal muscles (PSM) between adolescent idiopathic scoliosis (AIS) patients (with severe or non-severe curves) and healthy controls.

SUMMARY OF BACKGROUND DATA

Several studies have reported abnormalities in biochemical, electromyographic activity, and histological changes of PSM in AIS. However, these studies only had qualitative data and without comparison with controls. Changes of muscle mass and mean density at the lumbar region have been described for scoliotic spines. All these findings suggested that imbalance of PSM in AIS could be a contributing factor to the development of severe scoliotic curve.

METHODS

T2-weighted MR images with multi-planar reconstruction were acquired in 41 Chinese AIS girls with a primary right-sided thoracic curve and 23 age-matched controls. In AIS, measurements of PSM were taken on both concavity and convexity of scoliosis starting from two vertebrae above and two below the apex. Morphological assessments of the multifidus (MF) and erector spinae (ES) muscles on both sides were made including signal intensity (SI) and fat deposition using manual tracing and thresholding technique, respectively. Same parameters were measured in controls at matched vertebrae. One-way analysis of variance (ANOVA) and Pearson correlation tests were used for statistical analysis.

RESULTS

Abnormalities were found at concavity of muscles between AIS and controls. Significantly higher SI and fatty components was observed in AIS at MF muscles on concavity than controls (P-value <0.001). Additionally, SI at MF muscles was significantly correlated with Cobb angle.

CONCLUSION

Increased SI and fatty components are asymmetrically present in PSM at apex in AIS. Our results showed higher intensity in PSM at concavity in AIS when compared with controls. There was a significant linear correlation between abnormal muscle signal and scoliotic curve. Above features are suggestive of altered muscle composition in concave PSM, possibly due to prolonged compression and reduced muscle activity of PSM caused by the spinal deformity.

LEVEL OF EVIDENCE

4.

Association between physical activity and scoliosis: a prospective cohort study

BACKGROUND

Little is understood about the causes of adolescent onset idiopathic scoliosis (AIS). No prospective studies assessing the association between physical activity and idiopathic adolescent scoliosis have been carried out. We aimed to carry out the first prospective population-based study of this association.

METHODS

The Avon Longitudinal Study of Parents and Children (ALSPAC) collected self-reported measures of physical ability/activity at ages 18 months and 10 years. Objective measures of physical activity were collected by accelerometry at age 11 years. scoliosis was identified using the dxa scoliosis Method at age 15 years. Participants with scoliosis at age 10 years were excluded.

RESULTS

Of 4640 participants at age 15 years who had DXA scans, 267 (5.8%) had scoliosis. At age 18 months, those infants who were able to stand up without being supported were 66% less likely to have developed scoliosis by age 15 (P = 0.030) compared with infants who could not. Those children whose mothers reported they did most vigorous physical activity at age 10 years were 53% less likely to develop scoliosis (P = 0.027). Those children who did more objectively measured moderate/vigorous physical activity at age 11 were 30% less likely to have developed scoliosis (P < 0.001). Results were not affected by adjustment for age, gender, lean mass, fat mass or back pain.

CONCLUSIONS

We report reduced physical ability and activity as early as age 18 months in those who go on to develop scoliosis by age 15 years. Further research is justified to examine the mechanisms underlying this association.

Cardiopulmonary Function in Patients with Congenital Scoliosis: An Observational Study

BACKGROUND

Patients with congenital scoliosis often have restrictive pulmonary dysfunction on static pulmonary function testing (PFT). Although frequently asymptomatic during daily activities, these patients are generally assumed to have reduced exercise capacity. The aim of this study was to use dynamic cardiopulmonary exercise testing (CPET) to investigate exercise capacity and its association with spinal deformity in patients with congenital scoliosis.

METHODS

Sixty patients with congenital scoliosis who underwent preoperative spinal radiography, PFT, and CPET were included from January 2014 to November 2017. The impact of thoracic spinal deformity and rib anomalies on pulmonary function and physical capacity was investigated.

RESULTS

A significant deterioration in pulmonary function with increases in the severity of the major thoracic curve was demonstrated by the forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and total lung capacity (all p < 0.001). The ratio of FEV1 to FVC was similar regardless of thoracic curve severity. A smaller tidal volume during exercise testing reflected restrictive dysfunction in the patients with the most severe curves. CPET also revealed a significant trend of faster breathing by patients with a severe thoracic curve (p < 0.001). Exercise capacity indicators such as work rate (p = 0.019), heart rate (p = 0.015), and oxygen saturation (p = 0.006) were significantly reduced only in patients with a thoracic curve of >100°. Pulmonary dysfunction was the major contributor to exercise intolerance. Compared with mild pulmonary dysfunction, moderate and severe dysfunction was associated with an abnormal breathing pattern and lower work rate (p = 0.032) and peak oxygen intake (p = 0.042), indicating worse exercise tolerance.

CONCLUSIONS

Congenital scoliosis leads to restrictive pulmonary dysfunction, which reduces the tidal volume and forces patients to accelerate respiratory rates during exercise. Patients with a thoracic curve of >100° are unable to compensate and have significantly reduced exercise capacity.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Center of pressure progression patterns during level walking in adolescents with idiopathic scoliosis

The purpose of this study was to determine whether functional walking performance measured with Timed Up-and-Go (TUG) and center of pressure (CoP) progression pattern is different across adolescents with various curve severity of idiopathic scoliosis (IS). The CoP coordinates during a stance phase for self-paced level walking between adolescent with three different severities of IS (mild IS, moderate IS, and severe IS) and age-matched normal subjects were measured with foot pressure measurement. The average data of three trials were compared among groups with repeated measure analysis of variance. Results showed that the TUG was different between normal and AIS subjects, indicating use of TUG as a marker of functional walking performance in AIS is plausible but studies with larger sample size is needed before using TUG to identify AIS with different scoliosis severity. The results also showed that the CoP displacement, velocity and acceleration during a stance phase was different across groups, and with the most prominent deviations found in the moderate IS group. The medial-lateral shifting of the CoP trajectory at mid-foot regions in all IS groups deviated the most. A tendency of asymmetry in CoP progression pattern between feet in IS groups was also found. The deviation of the spine alignment in frontal plane could change the CoP progression patterns during level walking, suggesting the risk of the locomotors subjecting to abnormal loading during daily walking. Education and conservative interventions might be needed for preservation of medical outcome and prevention of back pain and/or musculoskeletal consequences later in the lives of AIS with and without surgical correction.

FUNCTIONAL CAPACITY IN ADOLESCENT IDIOPATHIC SCOLIOSIS DURING THE POSTOPERATIVE PERIOD

ABSTRACT Introduction: Patients with Adolescent Idiopathic Scoliosis (AIS) show reduced exercise capacity during the Incremental Shuttle Walk Test (ISWT). However, we not know how patients behave in the late postoperative (LPO) period. Objective: The aim of this study was to evaluate the ISWT distance (ISWTD) and physiological responses during ISWT in AIS patients during the LPO period. Methods: We included 22 patients with AIS in the LPO period (SG) and 21 adolescents in the Control Group (CG). We assessed pulmonary function (FVC and FEV1). During ISWT, a gas analyzer was used to assess peak oxygen (VO2) and submaximal relations: Oxygen Uptake Efficiency Slope (OUES) and the breathing pattern (ΔVT/ΔlnVE). Results: Significantly lower values were observed in SG: VO2 (22 ± 5 vs. 27 ± 4), ISWTD (567 ± 94 vs.604 ± 86), FVC (2.70 ± 0.47 vs. 3.33 ± 0.52) and FEV1 (2.41 ± 0.46 vs. 2.84 ± 0.52). There were significant correlations between ISWTD and VO2/Kg (r = 0.80); between OUES and ΔVT/ΔlnVE (r = 0.65); and between the main thoracic curve with VO2/Kg (r= −0.61). Conclusion: AIS patients in the LPO period have significantly reduced exercise capacity associated with reduced lung function, residual spinal curve and cardiovascular deconditioning. Level of Evidence III; Prognostic Studies - Investigation of the effect of characteristic of a patient on the outcome of the disease.

Asymmetric expression of H19 and ADIPOQ in concave/convex paravertebral muscles is associated with severe adolescent idiopathic scoliosis

Background

Adolescent idiopathic scoliosis (AIS) is the most common paediatric spinal deformity. The etiology and pathology of AIS remain unexplained, and have been reported to involve a combination of genetic and epigenetic factors. Since paravertebral muscle imbalance plays an important role in the onset and progression of scoliosis, we aimed to investigate transcriptomic differences by RNA-seq and identify significantly differentially expressed transcripts in two sides of paravertebral muscle in AIS.

Methods

RNA-seq was performed on 5 pairs of paravertebral muscle from 5 AIS patients. Significantly differentially expressed transcripts were validated by quantitative reverse polymerase chain reaction. Gene expression difference was correlated to clinical characteristics.

Results

We demonstrated that ADIPOQ mRNA and H19 is significantly differentially expressed between two sides of paravertebral muscle, relatively specific in the context of AIS. Relatively low H19 and high ADIPOQ mRNA expression levels in concave-sided muscle are associated with larger spinal curve and earlier age at initiation. We identified miR-675-5p encoded by H19 as a mechanistic regulator of ADIPOQ expression in AIS. We demonstrated that significantly reduced CCCTC-binding factor (CCTF) occupancy in the imprinting control region (ICR) of the H19 gene in the concave-sided muscle contributes to down-regulated H19 expression.

Conclusions

RNA-seq revealed transcriptomic differences between two sides of paravertebral muscle in AIS patients. Our findings imply that transcriptomic differences caused by epigenetic factors in affected individuals may account for the structural and functional imbalance of paravertebral muscle, which can expand our etiologic understanding of this disease.

Electronic supplementary material

The online version of this article (10.1186/s10020-018-0049-y) contains supplementary material, which is available to authorized users.

Impact of Scoliosis Severity on Functional Capacity in Patients With Adolescent Idiopathic Scoliosis

PURPOSE

The aim of this study is to evaluate the walked distance and physiological responses during incremental shuttle walk test in patients with different degrees of adolescent idiopathic scoliosis (AIS).

METHODS

We evaluated 20 healthy teenagers and 46 patients with AIS; they were divided into 2 groups: AIS > 45° and AIS < 45°. The volunteers performed an incremental shuttle walk test, and the following physiological responses were quantified: oxygen consumption, tidal volume, ventilation, and the incremental shuttle walked distance. Respiratory muscle strength was quantified, pulmonary function test was performed, and the forced vital capacity and expiratory volume in the first second were obtained.

RESULTS

Patients with AIS > 45° presented significant reduced incremental shuttle walked distance compared with the AIS < 45° and control group [447 (85), 487 (95), and 603 (85), respectively]. Patients with AIS also showed reduced forced vital capacity (P = .001) and expiratory volume in the first second (P = .005) compared with control group. Moderate correlations between forced vital capacity (r = -.506) and tidal volume (r = -.476) with scoliosis angles were found.

CONCLUSIONS

The incremental shuttle walk test was capable of identifying reduced functional capacity in patients with different degrees of AIS. Moreover, the severity of spinal curvature may exert influence on ventilatory and metabolic variables.

Effect of idiopathic thoracic scoliosis on the tracheobronchial tree

Introduction

High prevalence of obstructive lung disease has been reported in patients undergoing surgical correction of thoracic scoliosis. Airway narrowing due to spine morphology is analysed as a contributing factor.

Methods

Preoperative surgical planning CTs of 34 patients with right-sided thoracic scoliosis (age: 17.6±9.0) were retrospectively analysed and compared with 15 non-scoliotic controls (age: 16.3±5.1). Three-dimensional models of spine and airway lumen were reconstructed. Based on thoracic sagittal profile, patients were divided into hypokyphosis (HypoS: <10°), normal kyphosis (NormS: ≥10° and <40°) and hyperkyphosis (HyperS: ≥40°) groups. Lumen area of bronchi, bifurcation angles and minimum spine–airway distance were measured. Pulmonary function tests were correlated to scoliosis, kyphosis and lumen area.

Results

Loss of kyphosis led to proximity between bronchus intermedius (BI) and spine. HypoS (NormS) had lumen area reductions in the right main bronchus of 29% (19%), BI of 45% (23%), right middle lobar bronchus of 46% (32%) and right lower lobe bronchus (RLL7) of 66% (37%), respectively (P<0.05). The lower right superior segmental bronchus was reduced across all scoliotic groups (P<0.05). Airways were displaced caudal by 0.65±0.45 vertebra in patients with scoliosis. Loss of kyphosis correlated negatively with forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC), FVC/(FVC predicted) and FEV₁/(FEV₁ predicted) (P<0.01). Lumen area of trachea, right upper lobar bronchus, BI and RLL7 correlated negatively with FEV₁/FVC. BI and RLL7 narrowing were strong predictors of FVC and FEV₁ loss (P<0.001).

Conclusions

Right-sided main stem airways are narrowed in HypoS and NormS. Loss of kyphosis leads to narrowing of BI and its trifurcation. FEV₁/FVC correlated negatively with airway narrowing, implying an obstructive element to lung function impairment in patients with scoliosis and hypokyphosis.