The role of the paravertebral muscles in adolescent idiopathic scoliosis evaluated by temporary paralysis

Effect of sling exercise combined with Schroth therapy on adolescents with mild idiopathic scoliosis: A twelve-week randomized controlled trial

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is the most common structural deformity of the spine during adolescence, which could cause varying degrees of physical and mental damage to patients. Schroth therapy and sling exercise are widely used in the treatment of patients with AIS currently, and have shown the significant therapeutic effect relatively.

OBJECTIVE

To observe the efficacy of sling exercise combined with Schroth therapy on adolescents with mild idiopathic scoliosis (MIS).

METHODS

Sixty patients with AIS were randomly divided into the Schroth+sling group (n= 31) and the Schroth group (n= 29). Patients in both groups received Schroth therapy, and sling exercise was added in the Schroth+sling group. Before and after 12 weeks of treatment, the Cobb angle, angle of trunk rotation (ATR), Scoliosis Research Society-22 (SRS-22) scale score and averaged electromyography (AEMG) of bilateral paraspinal muscles were evaluated.

RESULTS

After the treatment, Cobb angle, ATR in both groups were decreased compared with those before (P< 0.001), and the decrease in the Schroth+sling group was more obvious (P< 0.05). The AEMG of bilateral paraspinal muscles and the total score, posture, mental health of SRS-22 of the two groups improved compared with those before treatment (P< 0.05), and the Schroth+sling group had a significant improvement than the Schroth group (P< 0.05).

CONCLUSION

Schroth therapy improved the degree of scoliosis, torticollis, quality of life, and bilateral paraspinal strength on adolescents with mild idiopathic scoliosis. The effect was more pronounced when the sling exercise was included in the treatment regimens.

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.

Effectiveness of Botulinum Neurotoxin in Treatment of Scoliosis among Children and Adolescents: A Systematic Review and Meta-Analysis

Scoliosis refers to a three-dimensional deviation in the axis of the spine. Muscle imbalance is believed to play a role in scoliosis. Botulinum neurotoxin (BoNT) can reduce muscle overactivity and may have the potential to ameliorate spinal scoliosis. This study investigated the effectiveness of intramuscular BoNT injection in vertebral curve correction and reviewed the possible influencing factors. PubMed, Medline, Cochrane Central Register of Controlled Trials, Web of Science, Airiti Library, and Index of the Taiwan Periodical Literature System databases were searched from inception until 7 September 2022 for eligible studies. The main outcome was the change in Cobb angle after BoNT application. Subgroup analysis was conducted according to differences in study designs, etiology of scoliosis, and methods used for target muscle selection. We enrolled three studies including 31 participants aged between 2 and 18 years. The meta-analysis revealed no significant reduction in the Cobb angle after BoNT injection (standardized mean difference, −0.783, 95% CI, −2.142 to 0.576). Study designs (p = 0.011) and methods used for target muscle selection (p = 0.017) but not etiology of scoliosis (p = 0.997) reached statistical significance between subgroups. In conclusion, the current meta-analysis does not support the application of BoNT in children and adolescents with scoliosis. However, a decisive conclusion could not be made due to high between-study heterogeneity and small sample size. More randomized controlled trials with appropriate target muscle selection and standard outcome measurement should be conducted to examine the efficacy of botulinum neurotoxin in treating scoliosis. INPLASY ID: INPLASY202290031.

Scoliosis and skeletal muscle mass are strongly associated with low back pain-related disability in humans: An evolutionary anthropology point of view

OBJECTIVES

To clarify the potential risk factors and etiology of low back pain (LBP)-related disability, including structural changes of the spine (spinal scoliosis) and body composition components in a population with a high prevalence of LBP.

METHODS

In this cross-sectional study, two self-reported validated questionnaires were used to collect back pain and disability data in an ethnically homogeneous family-based population sample (N = 1078). The scoliosis angle of trunk rotation was measured by a scoliometer on three spinal levels while the patient was bent forward. Body composition parameters, including relative to weight (WT), fat, relative skeletal muscle mass (SMM/WT), and total body water were determined by bioelectrical impedance analysis. Statistical analysis was conducted, accounting for the familial composition of the sample.

RESULTS

The mixed multiple regression analyses with several LBP-related phenotypes as dependent variables consistently showed significant independent associations with scoliosis and SMM/WT, irrespective of other covariates. The odds ratios (OR)/95% CI for scoliosis ranged between 1.40 (1.19-1.64) and 1.51 (1.27-1.80), and from 0.61(0.51-0.72), to 0.71(0.58-0.87) for SMM/WT, depending on the LBP phenotype. The genetic components of the respective correlations between the LBP-phenotypes and scoliosis or SMM/WT were negligible.

CONCLUSIONS

The associations between LBP-related conditions and postured scoliosis and SMM/WT were consistent and significant and therefore may serve as markers in predicting the development of LBP-related disability. We interpret the origin of these correlations as the evolutionary event due to the imperfect spine anatomy adaptation to a vertical posture resulting from a quick transition to bipedalism from a quadrupedal ancestor.

Adult Scoliosis Following Intrathecal Baclofen Therapy

In this case report, we present an adult case of scoliosis following intrathecal baclofen (ITB) therapy. A 56-year-old female with stroke-induced right spastic hemiparesis for seven years underwent implantation of an ITB pump. Satisfactory spasticity control was achieved using 30 µg/day of baclofen; however, she began to complain of lumbar pain in the postoperative year (POY) 1. Scoliosis, which was not recognized preoperatively, was confirmed in POY 2 (Cobb angle of 19 degrees). It further progressed into a walking disturbance in POY 5 (Cobb angle of 28 degrees). Hence, posterior fusion with decompression was planned. Following the removal of the ITB pump, spasticity management was replaced by Botox injection. However, the progression of scoliosis and neurological conditions stabilized after the removal, and decompression surgery was electively performed in POY 6. Scoliosis remained stable during the two-year follow-up period (Cobb angle of 28 degrees). This case demonstrates the potential risk of ITB-induced scoliosis in an adult patient. Careful preoperative investigations and postoperative follow-up are recommended for patients on ITB therapy.

Assessment of the cross-sectional areas of the psoas major in patients with adolescent idiopathic scoliosis before skeletal maturity

BACKGROUND

The psoas major (PM) can support the lumbar spine and plays an important role in lumbar movement and maintaining lumbar curvature.

PURPOSE

To analyze morphological changes of PM and its relation with the severity of adolescent idiopathic scoliosis (AIS).

MATERIAL AND METHODS

The study was conducted on patients with AIS (age range = 10-18 years) with primary lumbar scoliosis. The cross-sectional area (CSA) of the PM at the L1-L5 levels were measured. The CSA of the PM in patients with AIS was compared with the average CSA of the PM in age-matched controls. The difference in PM at the apical vertebrae level was compared with the Cobb angle to determine the association between PM imbalance and severity of scoliosis.

RESULTS

The CSA of the PM was larger on the concave side than the convex side at the apical vertebrae level and other lumber levels. Patients with a larger Cobb angle had statistically higher PM imbalance at the apical vertebrae level. The CSA of the PM on both the concave and convex sides of patients with AIS were larger than the average CSA of controls aged 16-18 years; however, there was no significant difference between patients with AIS and controls aged 10-15 years.

CONCLUSION

There is a significant PM imbalance in patients with AIS before skeletal maturity, and the imbalance is related to the severity of scoliosis. The morphology of PM changed with the progression of scoliosis.

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.

Functional Electrical Stimulation (FES) and the Effect on Equine Multifidi Asymmetry

Asymmetry of the multifidi has been correlated with scoliosis and back pain in humans and has been investigated as a factor in equine back pain as well. The purpose of this study was to determine if FES would affect the symmetry of equine thoracolumbar multifidi when compared to controls. Twelve horses received 24 FES treatments bilaterally over the thoracolumbar region for 8 weeks. Twelve additional control horses received no FES treatments. Ultrasonographic measurements of the cross-sectional area (CSA) of the multifidi of the treatment horses at seven thoracolumbar levels were compared to determine the change in left and right asymmetry post-FES. The same measurements during the same period were also taken in the control group. All measurements were blinded for evaluation. Statistical significance was assessed utilizing two-sided, matched-pairs t-tests, and Welch's (unequal variances) t-test (alpha = 0.05). Multiple comparisons were accounted for using the Sidak correction. A significant improvement in multifidi asymmetry was observed, post-FES, at all seven thoracolumbar levels, with no evidence of asymmetry improvement in the control group. The difference between mean improvements of the treatment and control groups was statistically significant (P < .001). FES significantly improved the symmetry of equine multifidi, and evidence was provided for the effectiveness of FES at each of seven thoracolumbar levels. The improvement in symmetry appeared to result from increases, decreases, and maintenance of the CSA of the left and right multifidi in various combinations. The FES protocol used in this study has the potential to improve spinal function and assist in reducing back pain in horses.

Muscular Contribution to Adolescent Idiopathic Scoliosis from the Perspective of Stem Cell-Based Regenerative Medicine

Adolescent idiopathic scoliosis (AIS) is a relatively frequent disease within a range 0.5%-5.0% of population, with higher frequency in females. While a resultant spinal deformity is usually medically benign condition, it produces far going psychosocial consequences, which warrant attention. The etiology of AIS is unknown and current therapeutic approaches are symptomatic only, and frequently inconvenient or invasive. Muscular contribution to AIS is widely recognized, although it did not translate to clinical routine as yet. Muscle asymmetry has been documented by pathological examinations as well as systemic muscle disorders frequently leading to scoliosis. It has been also reported numerous genetic, metabolic and radiological alterations in patients with AIS, which are linked to muscular and neuromuscular aspects. Therefore, muscles might be considered an attractive and still insufficiently exploited therapeutic target for AIS. Stem cell-based regenerative medicine is rapidly gaining momentum based on the tremendous progress in understanding of developmental biology. It comes also with a toolbox of various stem cells such as satellite cells or mesenchymal stem cells, which could be transplanted; also, the knowledge acquired in research on regenerative medicine can be applied to manipulation of endogenous stem cells to obtain desired therapeutic goals. Importantly, paravertebral muscles are located relatively superficially; therefore, they can be an easy target for minimally invasive approaches to treatment of AIS. It comes in pair with a fast progress in image guidance, which allows for precise delivery of therapeutic agents, including stem cells to various organs such as brain, muscles, and others. Summing up, it seems that there is a link between AIS, muscles, and stem cells, which might be worth of further investigations with a long-term goal of setting foundations for eventual bench-to-bedside translation.

Exploring the Pathological Role of Collagen in Paravertebral Muscle in the Progression of Idiopathic Scoliosis

BACKGROUND

Paravertebral muscle (PVM) is considered as a contributing factor of idiopathic scoliosis (IS); collagen is crucial for maintaining the mechanical properties of PVM, but only a few researches have described this field. In this study, we observed the muscle stiffness of PVM and the curvature of the spine by adjusting the content of collagen in PVM of rats and explored the role of collagen in the progression of IS.

METHODS

32 female Sprague Dawley rats were randomly divided into four groups: neutralizing antibody (NA) group (group 1), normal control group (group 2), IS group (group 3), and IS with NA group (group 4). TGF-β1 NA was injected into PVM in group 1 and group 4, while Normal saline in group 2 and group 3. The Cobb angle and muscle stiffness were measured before and after injection; the rats were sacrificed at one week after injection, and performed histological, Western Blot, and qRT-PCR examinations.

RESULTS

X-rays showed that scoliosis occurred in group 1 and relieved in group 4. The stiffness of PVM was decreased significantly on the convex side in group 1, while on the concave side in group 4. The expression of TGF-β1 and COL1 on the concave side in IS rats (group 3) was significantly increased than that in normal rats (group 2), the concentration of COL1 and COL3 in group 3 was significantly higher than that in group 2, and the addition of TGF-β1 NA significantly downregulated COL1 and COL3 in group 1 and group 4. The concentration of COL1 in convex PVM was negatively related to Cobb angle in group 1 and group 2, and in concave PVM was positively related to Cobb angle in group 3 and group 4. However, no significant correlation was found between COL3 and Cobb angle in group 3 and group 4.

CONCLUSIONS

Asymmetric biomechanical characteristics of PVM was an important etiological factor of IS, which was directly correlated with collagen, it could be adjusted by local intramuscular injecting of TGF-β1 NA, and finally had an effect on the shape of the spine.