Melatonin and adolescent idiopathic scoliosis: The present evidence

Lessons from the pandemic era: do we need new strategies to improve conservative treatment adherence in adolescent idiopathic scoliosis? A retrospective analysis

This study aims to examine whether the COVID-19 pandemic affected the adherence to conservative AIS treatment. Adolescent Idiopathic Scoliosis (AIS) is characterized by a lateral curvature of the spine of at least 10 degrees. Compliance rates in conservative treatments are influenced by various factors. From a database of AIS patients, we selected 30 AIS patients who were assessed before, during, and after the COVID-19 pandemic. Data regarding Cobb's angle, brace prescription, prescribed brace wear time, brace wear compliance, and time dedicated to sports activities were collected over a six-year period from January 2018 to December 2023, divided into three 2-year time periods (before, during, and after COVID-19). There was an increased percentage of AIS patients prescribed with a brace during the pandemic. However, no significant differences in Cobb's angle were observed. Additionally, the prescribed wear time showed a significant decrease from the pre-COVID period to the post-COVID period (p-value = 0.03). Wear compliance exhibited a decreasing trend from pre- to during- and post-COVID-19 periods without reaching statistically significant differences, and the time dedicated to sports statistically significantly decreased. These differences were statistically significant when comparing the pre- vs. post- and pre- vs. during-COVID-19 periods (p-values 0.01, 0.04, respectively). Our study highlights changes in AIS conservative treatment during and after the COVID-19 pandemic. The increase in the number of patients prescribed with a brace during the pandemic, although not supported by an increase in Cobb's angle, may be attributed to the concerns about regular monitoring during the reduction of rehabilitation services. The observed decreases in brace compliance and involvement in sport activities, which persisted even in the post-pandemic period, emphasizes the lasting impact of the pandemic on AIS management, necessitating innovative approaches to address these ongoing concerns.

Asymmetric Osteopenia in Adolescent Idiopathic Scoliosis Based on Hounsfield Unit of Computed Tomography

Purpose

To characterize the asymmetrical loss of bone mass and identify the association between scoliosis and osteopenia in patients with adolescent idiopathic scoliosis (AIS).

Methods

Demographic information, Cobb angle, and Hounsfield unit (HU) of the neutral vertebra (NV) and apical vertebra (apex) of the major curve were collected retrospectively in 54 AIS patients. For 84 control subjects, HU values were measured at T12 and L5. Propensity score matching was performed to balance the interference of age and BMI.

Results

In the AIS group, the concave and convex lateral HU of the NV and the convex lateral HU of the apex were negatively correlated with the Cobb angle. The AIS patients had lower bilateral HU. The mean HU and the apex-convex HU were also lower in the AIS group, while the apex-concave HU was slightly higher. After matching, the apex-convex HU of the AIS group remained lower, while the apex-concave HU was higher.

Conclusion

Patients with AIS exhibit osteopenia, particularly on the convex side. The severity of scoliosis was found to be directly proportional to the severity of bone loss and the degree of bilateral osteopenia asymmetry. Appropriate intervention for bone loss may be able to curb the progression of scoliosis.

Association of IL‑6 and MMP‑3 gene polymorphisms with adolescent idiopathic scoliosis: A systematic review and meta‑analysis

The pathogenesis of adolescent idiopathic scoliosis (AIS) remains unclear. It has been found that interleukin-6 (IL-6) rs1800795 locus and matrix metalloproteinase-3 (MMP-3) rs3025058 locus gene polymorphisms may be associated with AIS susceptibility, which has been controversial and needs to be further confirmed by updated meta-analysis. The aim of the present study was to investigate the association of MMP-3 rs3025058 and IL-6 rs1800795 single nucleotide polymorphisms (SNPs) with susceptibility to AIS. All relevant articles that met the criteria were retrieved and included, and the publication dates were limited from January 2005 to December 2023. The allele frequencies and different genotype frequencies of IL-6 rs1800795 and MMP-3 rs3025058 loci in each study were extracted and statistically analyzed by ReviewManager 5.4 software, and the odds ratio (OR) and 95% confidence interval (95% CI) of different genetic models were calculated. The results of the meta-analysis showed that there was no significant association between the gene polymorphism of IL-6 rs1800795 locus and the pathogenesis of AIS. The allele 5A and genotype 5A5A of MMP-3 rs3025058 SNP were associated with AIS susceptibility (5A vs. 6A, OR=1.18; 95% CI, 1.04-1.33; 5A5A vs. 6A6A, OR=1.65; 95% CI, 1.23-2.21; and 5A5A vs. 5A6A + 6A6A, OR=1.54; 95% CI, 1.19-1.99). Results of subgroup analysis revealed that the allele 5A and genotype 5A5A of MMP-3 rs3025058 SNP were associated with AIS susceptibility in the Caucasian population, and the susceptibility of AIS was associated with the genotype 5A5A of MMP-3 rs3025058 SNP in an Asian population. There was no significant association between the gene polymorphism of IL-6 rs1800795 locus and the pathogenesis of AIS, while the allele 5A of MMP-3 rs3025058 locus was associated with the susceptibility to AIS, especially in the Caucasian population.

Neurophysiological, balance and motion evidence in adolescent idiopathic scoliosis: A systematic review

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is a spinal deformity that affects approximately 4% of the world's population. Several hypotheses regarding the etiology of AIS have been investigated. In the last decades, impaired visual-spatial perception, alterations in spatial body orientation and sensory integration deficits have been documented.

OBJECTIVE

We aimed to summarize the neurophysiological, balance, and motion evidence related to AIS published in the last fifteen years, between January 2008 and April 2023. Both observational and interventional studies were considered. Only studies using quantitative assessment methods, such as electroencephalography (EEG), electromyography (EMG), magnetic resonance imaging (MRI), somatosensory evoked potentials, force platform, or motion capture, were included.

METHODS

1250 eligible records identified from online database searching were filtered by duplicate removal, title and abstract screening, and qualitative analysis. 61 articles met the inclusion criteria (i.e., Cobb range 10°-35°, age range 10-18 years) and were summarized.

RESULTS

We found significant evidence of impaired standing balance in individuals with AIS who greatly rely on visual and proprioceptive information to stay upright. EMG studies frequently reported an increased activity on the convex side of the intrinsic spinae muscles. EEG data show increased delta and theta power, higher alpha peak frequencies, and significant suppression in the alpha and beta bands in subjects with AIS during standing tasks. MRI studies report changes in white matter structures, differences in the vestibular system, and abnormal cortical activations over motor-related areas in subjects with AIS. Bracing appears to be an effective treatment for AIS, leading to improvements in static balance and gait. Methodological issues prevent reliable conclusions about the effects of other treatment options.

CONCLUSIONS

This review underscores the importance of quantitative assessment methods to explore the etiology and pathophysiology of AIS. Further research is needed to measure the impact of physical therapy and orthotic treatments on the neurophysiological mechanisms of the disease.

Current biomechanical theories on the etiopathogenesis of idiopathic scoliosis

PURPOSE

There is great controversy about the etiologic origin of adolescent idiopathic scoliosis. Multiple theories have been suggested, including metabolic aspects, endocrine dysfunction, neurological central abnormalities, genetic predisposition and epigenetic factors involved in the development of scoliosis. However, there has always been speculations based on human biomechanical behavior.

METHODS

In this article, we performed a literature review on the biomechanical traits of human posture, and the proposed theories that explain the special characteristics present in idiopathic scoliosis.

RESULTS

The current theory on the etiopathogeneis of AIS suggests that dorsally directed shear loads acting on a preexisting axial plane rotation, in a posteriorly inclined sagittal plane of a growing patient, together with disc maturation, collagen quality at this phase of development and immaturity of proprioception, is the perfect scenario to spark rotational instability and create the three-dimensional deformity that defines idiopathic scoliosis.

CONCLUSION

The unique spinal alignment of human bipedalism, gravity and muscle forces acting straight above the pelvis to preserve an upright balance, and the instability of the soft tissue in a period of growth development, is an appealing cocktail to try to explain the genesis of this condition in humans.

Evaluation of cerebellum volume and trunk oscillation velocity in cases with adolescent idiopathic scoliosis: a preliminary report

PURPOSE

It has been suggested that the cause of the balance disorder seen in adolescent idiopathic scoliosis (AIS) originates from the central nervous system. However, the extent of the balance problem and the dysfunction of which part of the central nervous system has not been investigated in detail. This study aimed to correlate the values obtained by balance analysis and cerebellum volume measurement in female individuals with AIS with healthy individuals.

METHODS

Cerebellum volume was calculated via the cloud-based software " https://volbrain.upv.es " using brain magnetic resonance images of 27 healthy and 26 individuals with AIS. The duration of stay in the test positions, the movement strategy used during this time and the amount of postural sway were analyzed by using a computer-assisted force platform and compared statistically.

RESULTS

Significant differences were found between the AIS and control groups in cerebellum total volume, vermis cerebelli volume (cm3), and trunk oscillation velocity (mm/s) parameters (p < 0.05). Cerebellum and vermis cerebelli volumes were found to be lower and trunk oscillation velocity was found to be greater in patients with AIS.

CONCLUSION

Balance problems in patients with AIS are correlated with decreased cerebellum volume and increased trunk oscillation velocity.

The effect of an exercise intervention on adolescent idiopathic scoliosis: a network meta-analysis

PURPOSE

To explore the effect of exercise intervention on adolescent idiopathic scoliosis (AIS), various exercise forms were compared and the sequence of the possibility of improving the effect of each exercise form was sorted out. We expect that our findings will provide clinicians and patients with more effective treatments and references.

METHOD

A thorough search was done on CNKI, Wanfang, WOS, Cochrane library, Embase, PubMed, Scopus and obtained the publication time from the database establishment to May 6, 2023. The relevant contents of the literature that passed the screening criteria were extracted, including relevant information about the sample, first author, intervention measures, intervention time, and outcome indicators. Analysis was performed by Review Manager 5.4 and Stata17.0.

RESULT

The study finally included 12 articles with 538 samples. After comparison, it was found that exercise interventions to reduce Cobb's angle were more effective than conventional therapies and reached a statistically significant difference. Compared with conventional therapy, core strength training, Physiotherapeutic Scoliosis-Specific Exercise (PSSE), yoga, Schroth, and sling reduced the Cobb angle by an average of 3.82 degrees, 3.79 degrees, 4.60 degrees, 3.63 degrees, and 3.30 degrees, respectively. However, the therapeutic effects on AIS did not show statistically significant differences between the exercise interventions. According to the SUCRA value and the cumulative probability, the MeanRank of improving the AIS effect by various sports intervention measures as follows: yoga (2.2), core strength training (2.8), PSSE (2.8), Schroth exercise (3.2), and sling exercise (4.0).

CONCLUSION

Exercise intervention can significantly improve AIS. There was no significant difference in the improvement effect of AIS among different exercise forms. Yoga may have the best effect on AIS improvement.

Daytime administration of melatonin has better protective effects on bone loss in ovariectomized rats

OBJECTIVE

To explore the difference in the protective effects of intraperitoneal injection of exogenous melatonin of daytime or nighttime on bone loss in ovariectomized (OVX) rats.

METHODS

After bilateral ovariectomy and sham surgery, 40 rats were randomly divided into four groups: sham operation group (Sham), ovariectomy (OVX), and daytime melatonin injection group (OVX + DMLT, 9:00, 30 mg/kg/d) and nighttime injection of melatonin (OVX + NMLT, 22:00, 30 mg/kg/d). After 12 weeks of treatment, the rats were sacrificed. The distal femur, blood and femoral marrow cavity contents were saved. The rest of the samples were tested by Micro-CT, histology, biomechanics and molecular biology. Blood was used for bone metabolism marker measurements. CCK-8, ROS, and Cell apoptosis are performed using MC3E3-T1 cells.

RESULTS

Compared with treatment at night, the bone mass of the OVX rats was significantly increased after the daytime administration. All microscopic parameters of trabecular bone increased, only Tb.Sp decreased. Histologically, the bone microarchitecture of the OVX + DMLT was also more dense than the bone microarchitecture of the OVX + LMLT. In the biomechanical experiment, the femur samples of the day treatment group were able to withstand greater loads and deformation. In molecular biology experiments, bone formation-related molecules increased, while bone resorption-related molecules decreased. After treatment with melatonin administration at night, the expression of MT-1β was significantly decreased. In cell experiments, the MC3E3-T1 cells treated with low-dose MLT had higher cell viability and greater efficiency in inhibiting ROS production than the MC3E3-T1 cells treated with high-dose MLT, which in turn more effectively inhibited apoptosis.

CONCLUSION

Daytime administration of melatonin acquires better protective effects on bone loss than night in OVX rats.

Dipeptidyl peptidase-4 is associated with myogenesis in patients with adolescent idiopathic scoliosis possibly via mediation of insulin sensitivity

Background

Abnormal metabolic features have been previously described in adolescent idiopathic scoliosis (AIS) patients. As an important regulator involved in energy metabolism, DPP-4 activity was reported to be remarkably decreased in osteoblasts of AIS patients. To date, there was still a lack of knowledge concerning the role of DPP-4 in the myogenesis of AIS.

Methods

Circulation DPP-4 level was assessed in the serum of 80 AIS girls and 50 healthy controls by ELISA. Myoblasts were purified from muscle specimens of AIS patients and LDH controls, and then treated with metabolic effectors including glucose and insulin. CCK-8 assay was used to assess the cell viability and myotube fusion index was calculated to evaluate myogenesis ability. Gene expressions of downstream signals of DPP-4 were evaluated by RT-qPCR and Western blot respectively.

Results

AIS girls had remarkably down-expressed DPP-4 in both serum level (0.76 fold) and tissue (0.68 fold) level. Treatment with metabolic effectors led to significantly increased DPP-4 expression in the control cells, while there was no increase of DPP-4 in AIS cells. CCK-8 assay showed that the proliferation rate of control cells was significantly increased after being treated. Remarkably higher fusion index was also observed in the treated control cells. By contrast, the fusion index and cell proliferation rate were comparable between the treated and the untreated AIS cells.

Conclusions

Our study suggested a potential role of DPP-4 in abnormal metabolic condition of AIS patients. Compared with control cells, AIS myoblasts presented obviously impaired sensitivity to the treatment of glucose and insulin. Aberrant DPP-4 expression could lead to impaired insulin sensitivity in myoblasts and further influence the cell viability during myogenesis. The molecular mechanism connecting DPP-4 and insulin-related signaling in AIS is worthy of further investigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-02978-w.