Congenital scoliosis: etiology and associations

Preliminary study assessing the long-term surgical outcomes of TBX6-associated congenital scoliosis (TACS) patients using the propensity score matching method: exploring the clinical implications of genetic discoveries in congenital scoliosis

BACKGROUND

Compound inheritance of TBX6 accounts for approximately 10% of sporadic congenital scoliosis (CS) cases. Such cases are called TBX6-associated congenital scoliosis (TACS). TACS has been reported to have certain common clinical phenotypes. However, whether the surgical outcomes of TACS patients differ from those of other CS patients remains unclear.

METHODS

We retrospectively searched for patients who were diagnosed with scoliosis. TACS was identified in genetic testing for CS. After propensity score matching, patients with TACS were matched with patients with NTACS according to sex, age, main curvature, classification, deformity location, surgical methods, fusion segment and number of fusions. We evaluated and compared the coronal and sagittal radiographic parameters before surgery, immediately after surgery, and at the final follow-up. Surgical information, including surgical method, fusion segment, blood loss and complications, was also compared and analyzed.

RESULTS

Twenty-eight TACS patients were propensity score matched with 28 NTACS patients among 473 CS patients. The preoperative matching parameters mentioned in the Methods section were similar between the TACS group and the NTACS group. In the TACS group, the correction rate of the cranial compensatory curve (64.9 ± 18.6% vs. 51.2 ± 24.0%, P = 0.014) and the correction rate of the caudal compensatory curve (77.4 ± 12.5% vs. 65.4 ± 22.7%, P = 0.011) were significantly greater than those in the NTACS group, and the loss rate of correction of the cranial compensatory curve in the TACS group (0.6 ± 19.2% vs. 26.7 ± 50.8, P = 0.002) was significantly lower than that in the NTACS group. The total complication rate (7.2% vs. 14.3%) and incidence of adding-on (0 vs. 7.1%) were lower in the TACS group than in the NTACS group. There were no significant differences between the two groups in terms of blood loss, revision rate, other correction parameters, balance parameters or incidence of complications.

CONCLUSIONS

TACS patients had better surgical outcomes than NTACS patients, which means that genetic diagnosis of the TBX6 gene mutation in CS before surgery can help predict better surgical outcomes. The specific genetic mechanism is not yet clear and may be related to the relatively normal development of paravertebral tissues in TACS patients. Further research is needed.

LEVEL OF EVIDENCE

Leve: III.

Musculoskeletal and tendinous details of selected anomalies in the locomotor system of anurans

Previous studies on anuran anomalies predominantly examine isolated cases or focus on external and skeletal features. Our study analyzes a comprehensive sample collected from 1991 to 2017, examining the muscle-tendon system in 24 anuran species across adult, juvenile, and metamorphic stages. This extensive sample size allows us to investigate consistent anomaly patterns across different developmental stages and anuran families, exploring potential common developmental or genetic factors. Our detailed anatomical examination, encompassing musculature, tendons, and skeletal structures, revealed that 21% of the specimens displayed anomalies, a noteworthy finding considering the extensive sample size and duration of the studied sample. Of these anomalies, 17% affected the locomotor system, predominantly in the upper limbs. Key anomalies included, forelimbs and hindlimbs brachydactyly, rotation in forelimbs, partial kyphotic lordosis, and scoliosis. Notably, the digit 4 in the forelimbs and digits 4 and 5 in the hindlimbs were particularly susceptible to teratogenic effects, indicating possible prolonged exposure during development. Our study also uncovered combinations of anomalies and identified a phenotype similar to Poland syndrome. The findings validate the "Logic of Monsters" (LoMo theory) by Alberch, although the name itself may not be deemed appropriate, showing that developmental disruptions in tetrapods are not random but follow distinct sequences and patterns. The name, while unfortunate, accurately reflects the unusual nature of these developmental anomalies. This contributes to the evolving "Evo-Devo-Path" framework, highlighting the study's importance in understanding developmental disruptions in tetrapods.

First Rib Fracture and Absence of Traumatic History in a Patient with Surgically Corrected Scoliosis: A Case Study

This case report is unique due to the rare combination of a history of no trauma and a history of scoliosis correction surgery with instrumentation performed 1 year before presentation. A 23-year-old male patient presented to the emergency department in a stable condition and he looked well. He was able to walk without any limitation, but complained of left upper back pain for 2 days after a sneezing episode. The patient denied history of chest pain, shortness of breath, cough, palpitation, headache, dizziness, nausea, vomiting, and abdominal pain. The chest X-ray showed left first rib fracture, and computed tomography scan of the chest without contrast that was performed to diagnose rib fracture or complications confirmed the diagnosis. This case study concludes that the left first rib fracture is rare in postoperative scoliosis without a history of trauma.

Maternal risk factors for congenital vertebral formation and mixed defects: A population-based case-control study

Background

The etiology and risk factors of congenital vertebral anomalies are mainly unclear in isolated cases. Also, there are no reports on the risk factors for different subgroups of vertebral anomalies. Therefore, we assessed and identified potential maternal risk factors for these anomalies and hypothesized that diabetes, other chronic diseases, smoking, obesity, and medication in early pregnancy would increase the risk of congenital vertebral anomalies.

Methods

All cases with congenital vertebral anomalies were identified in the Finnish Register of Congenital Malformations from 1997 to 2016 for this nationwide register-based case-control study. Five matched controls without vertebral malformations were randomly selected. Analyzed maternal risk factors included maternal age, body mass index, parity, smoking, history of miscarriages, chronic diseases, and prescription drug purchases in early pregnancy.

Results

The register search identified 256 cases with congenital vertebral malformations. After excluding 66 syndromic cases, 190 non-syndromic malformations (74 formation defects, 4 segmentation defects, and 112 mixed anomalies) were included in the study. Maternal smoking was a significant risk factor for formation defects (adjusted odds ratio 2.33, 95% confidence interval 1.21-4.47). Also, pregestational diabetes (adjusted odds ratio 8.53, 95% confidence interval 2.33-31.20) and rheumatoid arthritis (adjusted odds ratio 13.19, 95% confidence interval 1.31-132.95) were associated with mixed vertebral anomalies.

Conclusion

Maternal pregestational diabetes and rheumatoid arthritis were associated with an increased risk of mixed vertebral anomalies. Maternal smoking increases the risk of formation defects and represents an avoidable risk factor for congenital scoliosis.

Level of evidence

III.

Ovine model of congenital chest wall and spine deformity: From birth to 3 months follow-up

Background

The evolution and treatment of lung alterations related to congenital spine and chest wall deformities (CWD) are poorly understood. Most animal models of CWD created postnatally were not evaluated for respiratory function. The goal of our study was to evaluate the effects of a CWD induced in utero on lung growth and function in an ovine model.

Methods

A CWD was induced in utero at 70-75 days of gestation in 14 ovine fetuses by resection of the 7th and 8th left ribs. Each non-operated twin fetus was taken as control. Respiratory mechanics was studied postnatally in the first week and at 1, 2, and 3 months. Post-mortem respiratory mechanics and lung histomorphometry were also assessed at 3 months.

Results

Eight out of 14 CWD lambs (57%) and 14 control lambs survived the postnatal period. One severe and five mild deformities were induced. At birth, inspiratory capacity (25 vs. 32 mL/kg in controls), and dynamic (1.4 vs. 1.8 mL/cmH2O/kg), and static (2.0 vs. 2.5 mL/cmH2O/kg) respiratory system compliances were decreased in CWD lambs. Apart from a slight decrease in inspiratory capacity at 1 month of life, no other differences were observed in respiratory mechanics measured in vivo thereafter. Postmortem measurements found a significant decrease in lung compliance-for each lung and for both lungs taken together-in CWD lambs. No differences in lung histology were detected at 3 months in CWD animals compared to controls.

Conclusions

Our study is the first to assess the effects of a prenatally induced CWD on lung development and function from birth to 3 months in an ovine model. Our results show no significant differences in lung histomorphometry at 3 months in CWD lambs compared to controls. Resolution at 1 month of the alterations in respiratory mechanics present at birth may be related to the challenge in inducing severe deformities.

Maternal Risk Factors for Congenital Vertebral Anomalies: A Population-Based Study

BACKGROUND

The spectrum of congenital vertebral defects varies from benign lesions to severe, life-threatening conditions. The etiology and maternal risk factors remain mainly unclear in isolated cases. Hence, we aimed to assess and identify potential maternal risk factors for these anomalies. Based on previous studies, we hypothesized that maternal diabetes, smoking, advanced maternal age, obesity, chronic diseases, and medication used during the first trimester of pregnancy might increase the risk of congenital vertebral malformations.

METHODS

We performed a nationwide register-based case-control study. All cases with vertebral anomalies (including live births, stillbirths, and terminations for fetal anomaly) were identified in the Finnish Register of Congenital Malformations from 1997 to 2016. Five matched controls from the same geographic region were randomly selected for each case. Analyzed maternal risk factors included age, body mass index (BMI), parity, smoking, history of miscarriages, chronic diseases, and prescription drugs dispensed during the first trimester of pregnancy.

RESULTS

In total, 256 cases with diagnosed congenital vertebral anomalies were identified. After excluding 66 malformations associated with known syndromes, 190 nonsyndromic malformation cases were included. These were compared with 950 matched controls. Maternal pregestational diabetes was a significant risk factor for congenital vertebral anomalies (adjusted odds ratio [OR], 7.30 [95% confidence interval (CI), 2.53 to 21.09). Also, rheumatoid arthritis (adjusted OR, 22.91 [95% CI, 2.67 to 196.40]), estrogens (adjusted OR, 5.30 [95% CI, 1.57 to 17.8]), and heparins (adjusted OR, 8.94 [95% CI, 1.38 to 57.9]) were associated with elevated risk. In a sensitivity analysis using imputation, maternal smoking was also significantly associated with an elevated risk (adjusted OR, 1.57 [95% CI, 1.05 to 2.34]).

CONCLUSIONS

Maternal pregestational diabetes and rheumatoid arthritis increased the risk of congenital vertebral anomalies. Also, estrogens and heparins, both of which are frequently used in assisted reproductive technologies, were associated with an increased risk. Sensitivity analysis suggested an increased risk of vertebral anomalies with maternal smoking, warranting further studies.

LEVEL OF EVIDENCE

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

WISP2 downregulation inhibits the osteogenic differentiation of BMSCs in congenital scoliosis by regulating Wnt/β-catenin pathway

OBJECTIVES

Bone marrow mesenchymal stem cells (BMSCs) are instrumental in bone development, metabolism, and marrow microenvironment homeostasis. Despite this, the relevant effects and mechanisms of BMSCs on congenital scoliosis (CS) remain undefined. Herein, it becomes our focus to reveal the corresponding effects and mechanisms implicated.

METHODS

BMSCs from CS patients (hereafter referred as CS-BMSCs) and healthy donors (NC-BMSCs) were observed and identified. Differentially expressed genes in BMSCs were analyzed utilizing scRNA-seq and RNA-seq profiles. The multi-differentiation potential of BMSCs following the transfection or infection was evaluated. The expression levels of factors related to osteogenic differentiation and Wnt/β-catenin pathway were further determined as appropriate.

RESULTS

A decreased osteogenic differentiation ability was shown in CS-BMSCs. Both the proportion of LEPR⁺ BMSCs and the expression level of WNT1-inducible-signaling pathway protein 2 (WISP2) were decreased in CS-BMSCs. WISP2 knockdown suppressed the osteogenic differentiation of NC-BMSCs, while WISP2 overexpression facilitated the osteogenesis of CS-BMSCs via acting on the Wnt/β-catenin pathway.

CONCLUSIONS

Our study collectively indicates WISP2 knockdown blocks the osteogenic differentiation of BMSCs in CS by regulating Wnt/β-catenin signaling, thus providing new insights into the aetiology of CS.

Retrospective Analysis of Associated Anomalies in 636 Patients with Operatively Treated Congenital Scoliosis

BACKGROUND

Congenital scoliosis is frequently associated with anomalies in multiple organ systems. However, the prevalence and distribution of associated anomalies remain unclear, and there is a large amount of variation in data among different studies.

METHODS

Six hundred and thirty-six Chinese patients who had undergone scoliosis correction surgery at Peking Union Medical College Hospital from January 2012 to July 2019 were recruited, as a part of the Deciphering disorders Involving Scoliosis and COmorbidities (DISCO) study. The medical data for each subject were collected and analyzed.

RESULTS

The mean age (and standard deviation) at the time of presentation for scoliosis was 6.4 ± 6.3 years, and the mean Cobb angle of the major curve was 60.8° ± 26.5°. Intraspinal abnormalities were found in 186 (30.3%) of 614 patients, with diastematomyelia being the most common anomaly (59.1%; 110 of 186). The prevalence of intraspinal abnormalities was remarkably higher in patients with failure of segmentation and mixed deformities than in patients with failure of formation (p < 0.001). Patients with intraspinal anomalies showed more severe deformities, including larger Cobb angles of the major curve (p < 0.001). We also demonstrated that cardiac anomalies were associated with remarkably worse pulmonary function, i.e., lower forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF). Additionally, we identified associations among different concomitant malformations. We found that patients with musculoskeletal anomalies of types other than intraspinal and maxillofacial were 9.2 times more likely to have additional maxillofacial anomalies.

CONCLUSIONS

In our cohort, comorbidities associated with congenital scoliosis occurred at a rate of 55%. To our knowledge, our study is the first to show that patients with congenital scoliosis and cardiac anomalies have reduced pulmonary function, as demonstrated by lower FEV1, FVC, and PEF. Moreover, the potential associations among concomitant anomalies revealed the importance of a comprehensive preoperative evaluation scheme.

LEVEL OF EVIDENCE

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

Zebrafish: an important model for understanding scoliosis

Scoliosis is a common spinal deformity that considerably affects the physical and psychological health of patients. Studies have shown that genetic factors play an important role in scoliosis. However, its etiopathogenesis remain unclear, partially because of the genetic heterogeneity of scoliosis and the lack of appropriate model systems. Recently, the development of efficient gene editing methods and high-throughput sequencing technology has made it possible to explore the underlying pathological mechanisms of scoliosis. Owing to their susceptibility for developing scoliosis and high genetic homology with human, zebrafish are increasingly being used as a model for scoliosis in developmental biology, genetics, and clinical medicine. Here, we summarize the recent advances in scoliosis research on zebrafish and discuss the prospects of using zebrafish as a scoliosis model.

The Effect of Traditional Single Growing Rod Technique on the Growth of Unsegmented Levels in Mixed-Type Congenital Scoliosis

STUDY DESIGN

Retrospective case series.

OBJECTIVES

To present outcomes concerning patients with early-onset mixed-type congenital scoliosis (EOMTCS) treated with the traditional single growing rod (TSGR), focusing on the growth of unsegmented levels (USLs).

METHODS

Patients with EOMTCS who underwent TSGR and had a minimum of 4 USLs, 4 distractions, and 3-year follow-up were enrolled. Spine radiographs before and after index surgery and at the latest follow-up were evaluated. The length of the concave and convex side of USLs and thoracic parameters were measured. The absolute value and percentage of growth were calculated.

RESULTS

Fourteen patients (mean age, 7.3 ± 2.8 years) were enrolled. The average follow-up duration was 4.9 ± 1.2 years, during which time 84 distractions and 8 final fusions were performed. The average number of USLs was 6.3 ± 2.2. The total and annual percent growth of concave side of USLs was significantly higher than convex side (32.2 ± 13.3% vs. 23.9 ± 9.5%, p = 0.007; 6.8 ± 2.7%/year vs. 5.1% ± 2.2%/year, p = 0.007, respectively). The concave-to-convex ratio of USLs increased from 58.6 ± 6.4 ± 7.6% at baseline to 68.8 ± 9.3% at the latest follow-up (p < 0.001). The Campbell's space available for lung ratio increased from 74.9 ± 11.1% at baseline to 89.6 ± 7.0% at the latest follow-up (p < 0.001).

CONCLUSIONS

In patients with EOMTCS, unilateral repetitive lengthening with TSGR can accelerate the growth of the concave side of USLs and improve the symmetry of the thorax.

FAM20C plays a critical role in the development of mouse vertebra

BACKGROUND CONTEXT

Family with sequence similarity 20-member C (FAM20C) is a protein kinase that is responsible for the phosphorylation of many secretory proteins; however, its roles in spine or vertebra development have not be studied.

PURPOSE

The aim of this investigation is to analyze the roles of FAM20C in vertebra development.

STUDY DESIGN/SETTING

A mouse study of the Fam20c gene using conditional knockout to assess the effects of its inactivation on vertebra development.

METHODS

By breeding Sox2-Cre mice with Fam20c^flox/flox mice, Sox2-Cre;Fam20c^flox/flox mice (abbreviated as cKO mice) are created. X-ray radiography, resin-casted scanning electron microscopy, Hematoxylin and Eosin staining, safranin O staining, Goldner's Masson trichrome staining, Von Kossa staining, tartrate-resistant alkaline phosphatase staining, immunohistochemistry staining, Western Immunoblotting and real-time PCR were employed to characterize the vertebrae of cKO mice compared to the normal control mice.

RESULTS

Inactivation of Fam20c in mice results in remarkable spine deformity, severe morphology and mineralization defects, altered levels of osteoblast differentiation markers, reduction of activity of the Wnt/β-catenin signaling pathway and reduced level of osteoclastogenesis in the vertebrae.

CONCLUSIONS

FAM20C plays an essential role in vertebral development; it may regulate vertebral formation through the Wnt/β-catenin signaling pathway.

CLINICAL SIGNIFICANCE

Mutations in the human FAM20C gene are associated with Raine syndrome. The findings of this study provide valuable clues for the clinical management of Raine syndrome regarding spine manifestations in patients.

The conservative treatment of congenital scoliosis with hemivertebra: Report of three cases

INTRODUCTION

Scoliosis is the most common type of congenital vertebral disease. This spinal disorder may be due to a failure of formation, segmentation, or a combination thereof. Complete failure of formation causes hemivertebra which can lead to unbalanced growth and deformation. Statistically, 25% of congenital curves do not evolve, 25% progress slightly, while the remaining 50% develop quickly and require treatment. Hemivertebrae can be divided into three types: non-segmented, semi-segmented, and fully-segmented. The fully-segmented types are most likely to progress. Hemivertebra in the thoracolumbar region shows higher rates of progression compared with those in the lumbar area. The treatment may be either conservative or surgical. In general, bracing is not recommended in short and rigid curves, although it may help process secondary curves.

OBJECTIVE

To assess the effectiveness of bracing in congenital scoliosis due to hemivertebra.

CASES PRESENTATION

Searching in our database, we found three cases of patients with congenital scoliosis due to fully-segmented hemivertebra. The first of them was 6 years old at the time of diagnosis with a fully-segmented hemivertebra in L5, determining an L1-L5 (S1) lumbar curve. The second one was 10 years old at the time of diagnosis with a fully-segmented hemivertebra in L2 and a T11-L4 (L5 sacralized) thoracolumbar curve. The last one was 3 years old at the time of diagnosis with a fully-segmented hemivertebra in L3 (in six lumbar bodies), determining a thoracolumbar curve T12-L4.

RESULTS

We utilized a Milwaukee brace for the first patient, a Boston brace for the second patient, and a Progressive Action Short Brace (PASB) for the third patient. At the beginning of the treatment, the Cobb angles measured 23°, 53°, and 25°, respectively. During treatment, the Cobb angles measured 22°, 35°, and 15°, respectively. At the end of treatment, the Cobb angles measured 18°, 45°, and 12°, respectively. At long-term follow-up, the curves measured 20°, 45°, and 12° Cobb angles, respectively.

CONCLUSIONS

Comparing our cases with those found in the literature we can confirm the ability of conservative treatment to change the natural history of congenital lumbar scoliosis due to failure of formation. From our experience, in all cases of CS with hemivertebra, before considering a surgical approach, conservative treatment should be implemented as early as possible without waiting for the progressive deformation of the adjacent normal vertebrae.

Cross-sectional analysis and trend of vertebral and associated anomalies in Chinese congenital scoliosis population: a retrospective study of one thousand, two hundred and eighty nine surgical cases from 2010 to 2019

PURPOSE

The objective of this article is to report associated anomaly incidences of a large CS cohort and analyze interrelationships among vertebral anomaly types and associated abnormalities.

METHODS

We retrospectively searched and extracted medical records of 1289 CS inpatients surgically treated in our institute from January 2010 to December 2019. All patients have taken spine X-ray, CT, MRI, echocardiogram, urogenital ultrasound, and systemic physical examination. We analyzed information on demographics, CS types, and associated anomalies.

RESULTS

CS type was found to be 49.1% for failure of formation (FF), 19.5% for failure of segmentation (FS), and 31.4% for mixed defects (MD). Intraspinal defects were found in 29.4% patients (16.0% for FF, 45.4% for FS, 40.5% for MD), cardiac in 13.7% (12.3% for FF, 14.3% for FS, 15.6% for MD), genitourinary in 5.8% (4.1% for FF, 6.0% for FS, 8.4% for MD), gastrointestinal in 3.6% (4.7% for FF, 1.6% for FS, 3.0% for MD), and musculoskeletal in 16.4% (10.3% for FF, 19.9% for FS, 23.7% for MD). The intraspinal and musculoskeletal defect incidences were significantly higher in patients with failure of segmentation and mixed defects. We also observed a decreasing trend for intraspinal and musculoskeletal defect incidences as well as a tendency for more failure of formation and less failure of segmentation from 2010 to 2019.

CONCLUSIONS

The intraspinal and musculoskeletal defect incidences were higher in patients with failure of segmentation and mixed defects. Strong interrelationships were found between intraspinal and musculoskeletal defects and among cardiovascular, genitourinary, and gastrointestinal defects. From 2010 to 2019, the proportion of patients with failure of formation increased significantly, causing a decrease in the intraspinal and musculoskeletal defect incidences over time. Female sex, failure of segmentation, and mixed defects could be considered risk factors for more associated anomalies in CS individuals, which would help surgeons in medical management and prenatal consultation.

Prevalence of congenital scoliosis in infants based on chest-abdomen X-ray films detected in the emergency department

PURPOSE

To investigate the prevalence of congenital scoliosis (CS) in infants based on chest-abdomen radiographs.

METHODS

A retrospective review was conducted on infants in the emergency department (ED) of a tertiary children's hospital between February 2008 and September 2019. Patients who had undergone chest-abdomen X-rays were included. All films from the enrolled patients were screened for CS. Their demographic characteristics, type, and location of the vertebral and rib anomalies, and concomitant defects of other systems were analyzed.

RESULTS

In total, 50,426 infants were enrolled; 89 (1.8‰) were diagnosed with CS, including 56 males and 33 females. There was no gender difference in CS prevalence. The visiting age of the CS patients (70 ± 98days) was significantly younger than that of the non-CS group (P < 0.05), with CS patients mainly visiting for digestive (53.9%) and respiratory symptoms (41.6%). Sixty-eight (76.4%) CS patients had main thoracic (T6-T11) vertebral malformations. Rib anomalies were documented in 27 (30.3%) patients, of which 14 had complex rib anomalies. Forty (44.9%) patients had concomitant defects of other organs, of which eight patients had two systemic abnormalities mixed. The most common extraspinal defects were imperforate anus (21, 23.6%) and congenital cardiac defects (17, 19.1%).

CONCLUSION

The prevalence of CS in infants based on chest-abdomen X-rays in the ED was 1.8‰. Both the vertebral and rib anomalies mainly affected the main thoracic region. The spine deformities in infants with concomitant defects of other organs could be identified earlier because of early-onset symptoms, which also bring out a selection bias in our analysis.

Cost-effectiveness analysis of using the TBX6-associated congenital scoliosis risk score (TACScore) in genetic diagnosis of congenital scoliosis

Background

We previously reported a novel clinically distinguishable subtype of congenital scoliosis (CS), namely, TBX6-associated congenital scoliosis (TACS). We further developed the TBX6-associated CS risk score (TACScore), a multivariate phenotype-based model to predict TACS according to the patient’s clinical manifestations. In this study, we aimed to evaluate whether using the TACScore as a screening method prior to performing whole-exome sequencing (WES) is more cost-effective than using WES as the first-line genetic test for CS.

Methods

We retrospectively collected the molecular data of 416 CS patients in the Deciphering disorders Involving Scoliosis and COmorbidities (DISCO) study. A decision tree was constructed to estimate the cost and the diagnostic time required for the two alternative strategies (TACScore versus WES). Bootstrapping simulations and sensitivity analyses were performed to examine the distributions and robustness of the estimates. The economic evaluation considered both the health care payer and the personal budget perspectives.

Results

From the health care payer perspective, the strategy of using the TACScore as the primary screening method resulted in an average cost of $1074.2 (95%CI: $1044.8 to $1103.5) and an average diagnostic duration of 38.7d (95%CI: 37.8d to 39.6d) to obtain a molecular diagnosis for each patient. In contrast, the corresponding values were $1169.6 (95%CI: $1166.9 to $1172.2) and 41.4d (95%CI: 41.1d to 41.7d) taking WES as the first-line test (P < 0.001). From the personal budget perspective, patients who were predicted to be positive by the TACScore received a result with an average cost of $715.1 (95%CI: $594.5 to $835.7) and an average diagnostic duration of 30.4d (95%CI: 26.3d to 34.6d). Comparatively, the strategy of WES as the first-line test was estimated to have significantly longer diagnostic time with an average of 44.0d (95%CI: 43.2d to 44.9d), and more expensive with an average of $1193.4 (95%CI: $1185.5 to $1201.3) (P < 0.001). In 100% of the bootstrapping simulations, the TACScore strategy was significantly less costly and more time-saving than WES. The sensitivity analyses revealed that the TACScore strategy remained cost-effective even when the cost per WES decreased to $8.8.

Conclusions

This retrospective study provides clinicians with economic evidence to integrate the TACScore into clinical practice. The TACScore can be considered a cost-effective tool when it serves as a screening test prior to performing WES.

An Overview of the Current State of Pediatric Scoliosis Management

Historically pediatric scoliosis represents a condition deeply rooted within the origins of orthopedic surgery. Today only a few subspecialized surgeons treat pediatric scoliosis patients. In severe cases surgery can hold progression of and correct pathologic spinal curvature. The goal of this article is to provide an overview of the current state of pediatric scoliosis management. It aims to increase the attention of general physicians and orthopedic surgeons to a niched but rather frequently encountered pediatric pathology to facilitate early recognition and diagnosis. A thorough research of literature was conducted to summarize the different scoliosis types, their etiology and presentation. Classification, normal human growth phases and curve progression risk have been further elaborated. Finally, current treatment options with their benefits, shortcomings and complications were laid out and discussed. Among the etiological groups a focus was put on idiopathic scoliosis, in particular adolescent idiopathic scoliosis as the most frequently encountered subtype.

Melatonin protected against the detrimental effects of microRNA-363 in a rat model of vitamin A-associated congenital spinal deformities: Involvement of Notch signaling

Congenital spinal deformities are a result of defective somitogenesis and are associated with vitamin A deficiency (VAD). However, the molecular mechanisms of VAD-associated congenital spinal deformities remain largely unknown. Increasing number of studies suggested that microRNAs and melatonin played important roles in the development of congenital spinal deformities. In this study, we showed that the whole-embryo expression of miR-363 was upregulated in VAD rats. Furthermore, we demonstrated that miR-363 inhibited the proliferation and neuronal differentiation of primary cultured NSCs, accompanied by downregulation of Notch1. To this end, melatonin suppressed miR-363 expression and rescued the effects of miR-363 on NSC proliferation and neuronal differentiation together with restoration of Notch signaling. The present study provided new insights into the mechanism of VAD-associated spinal deformities and the therapeutic effect of melatonin that may lead to novel understanding of the molecular mechanisms of congenital spinal deformities.

New tomographic contribution to characterizing mesosaurid congenital scoliosis

The presence of a pathology in the vertebral column of the early Permian mesosaurid specimen ZPAL R VII/1, being one of the oldest amniotic occurrences of congenital scoliosis caused by a hemivertebra, was recently recognized. Here we provide CT data to further characterize the phenomenon. The affected hemivertebra is wedged (incarcerated) between the preceding and succeeding vertebrae. The neural canal is misshapen but continuous and the number of dorsal ribs on each side of the specimen corresponds with the number of the vertebrae, documenting its congenital (homeobox-related) derivation.

Impaired Annulus Fibrosus Development and Vertebral Fusion Cause Severe Scoliosis in Mice with Deficiency of c-Jun NH2-Terminal Kinases 1 and 2

Mitogen-activated protein kinases, including c-Jun NH2-terminal kinase (JNK), play an important role in the development and function of a large variety of tissues. The skeletal phenotype of JNK1 and JNK2 double-knockout (dKO) mice (JNK1^fl/flCol2-Cre/JNK2^-/-) and control genotypes were analyzed at different embryonic and postnatal stages. JNK1/2 dKO mice displayed a severe scoliotic phenotype beginning during development that was grossly apparent around weaning age. Alcian blue staining at embryonic day 17.5 showed abnormal fusion of the posterior spinal elements. In adult mice, fusion of vertebral bodies and of spinous and transverse processes was noted by micro-computed tomography, Alcian blue/Alizarin red staining, and histology. The long bones developed normally, and histologic sections of growth plate and articular cartilage revealed no significant abnormalities. Histologic sections of the vertebral column at embryonic days 15.5 and 17.5 revealed an abnormal organization of the annulus fibrosus in the dKOs, with chondrocyte-like cells and fusion of dorsal processes. Spinal sections in 10-week-old dKO mice showed replacement of intervertebral disk structures (annulus fibrosus and nucleus pulposus) by cartilage and bone tissues, with cells staining for markers of hypertrophic chondrocytes, including collagen X and runt-related transcription factor 2. These findings demonstrate a requirement for both JNK1 and JNK2 in the normal development of the axial skeleton. Loss of JNK signaling results in abnormal endochondral bone formation and subsequent severe scoliosis.

Postoperative pulmonary complications following posterior spinal instrumentation and fusion for congenital scoliosis

Background

Congenital scoliosis (CS) may lead to more serious pulmonary complications compared with idiopathic scoliosis after spinal fusion surgery. However, little has been reported about postoperative pulmonary complication events in patients with CS after spinal fusion surgery.

Objective

To investigate the incidence of and predictive factors of postoperative pulmonary complications following posterior spinal instrumentation and fusion surgery for the treatment of CS.

Methods

We retrospectively reviewed the records of 174 patients with CS (128 females and 46 males, mean age 16.4 years) treated with posterior spinal instrumentation and fusion surgery between January 2012 and April 2017. We extracted demographic, medical history, and clinical data, and investigated the major predictive factors for postoperative pulmonary complications by logistic regression and receiver-operating characteristic curves analyses.

Results

A total of 26 (14.9%) patients developed postoperative pulmonary complications, consisting of pleural effusion (10.9%), pneumonia (6.9%), pneumothorax (1.1%), atelectasis (2.3%), hypoxemia (6.3%), and respiratory failure (1.1%). Logistic regression analysis revealed that the predictive factors for postoperative pulmonary complications were age > 18.1 years (P = 0.039), a Cobb angle of > 77° (P = 0.011), operation time of > 430 min (P = 0.032), and blood transfusion volume > 1500 ml (P = 0.015).

Conclusions

Postoperative pulmonary complications are among the main complications following posterior spinal instrumentation and fusion surgery in patients with CS. Such patients aged >18.1 years, with Cobb angles > 77°, operation times > 430 min, and/or blood transfusion volume of > 1500 ml may be more likely to develop postoperative pulmonary complications.

Functional and In Silico Assessment of GDF3 Gene Variants in a Chinese Congenital Scoliosis Population

Background

The present study aimed to evaluate the pathogenicity of 5 GDF3 gene variations using functional and in silico assessment approaches in a Chinese congenital scoliosis population.

Material/Methods

We selected 13 patients carrying 5 variants from a congenital scoliosis cohort. The PCR products of samples were verified by Sanger sequencing. The data and sequence alignment were analyzed using Chromas and ClustalW. SIFT and PolyPhen-2 were used to predict the functional effects of each missense and amino acid substitutions. SWISS-MODEL server and Swiss-PdbViewer were used to analyze conformational changes of GDF3 structure. DUET, UCSF Chimera, and Ligplot software were used to further explore the protein stability, side chains, and hydrophobic interaction changes, respectively. Luciferase reporter gene and Western blot assays were used to perform functional assessments for every variant from the molecular level.

Results

Of the 13 patients, the S212L variant reoccurred in 9 patients. The rest of the patients carried 1 missense mutation each. The variants of R84L and R84C were predicted as probably damaging loci. S212L, N215S, A251T were predicted as benign loci. In functional assays, R84L, S212L, and A251T display inhibitory effects on functional assays. N251S mutation showed a negative effect in protein expression assays but not in luciferase reporter gene assays. The variant of R84C displayed no negative effects on 2 functional assays.

Conclusions

Our results suggest that the 4 of the 5 variants in GDF3 gene contribute different pathogenicity in congenital scoliosis, which may provide molecular evidence for clinical genetic testing.

Abnormalities associated with congenital scoliosis in high-altitude geographic regions

PURPOSE

To assess the different characteristics of congenital scoliosis between low-altitude geographic regions and high-altitude geographic regions in Chinese population and discuss the role of hypoxia on those differences.

METHODS

A total of 120 patients with congenital scoliosis who underwent surgical treatment in our Hospital between January 2009 and October 2017 were identified. Complete data were reviewed, including medical records, X-ray, CT, and MRI pre-operatively. According to the patient's birthplace, they were divided into low-altitude geographic regions (low group) and high-altitude geographic regions (high group). Characteristics of vertebral deformities, rib deformities, and intra-spinal malformations in two groups were analyzed.

RESULTS

A total of 397 segments of vertebral deformities were involved in the two groups, of which 136 were involved in high group and 261 in low group. The average segments involved were 4.5 and 2.9, respectively, in two groups. 63.3% patients in high group have rib deformities, which is significantly higher than that of low group (41.1%); and the proportion of patients with complex rib deformities in high group was also higher than that in low group (57.9% VS 24.3%). The incidence of CS associated with intra-spinal malformations in low group was 38.9%, which was similar to those reported previously; however, the incidence of that in high group was 63%, significantly higher than previous reports.

CONCLUSION

Our results suggested that CS patients in high-altitude geographic regions might tend to have higher proportion and more severe of rib deformities, and also be more likely to accompany with intra-spinal malformations. So we supposed that hypoxia not only aggravated the proportion and severity of rib deformities, but also affected the development of spinal cord in humans.

Revision surgery after pregnancy in a patient with congenital kyphoscoliosis: A case report

RATIONALE

Rod breakage during pregnancy and delivery has never been described in a patient who has undergone surgery for congenital scoliosis (CS). Here, we present an unusual but significant case of revision surgery.

PATIENT CONCERNS

A 29-year-old woman presented with low back pain during pregnancy after posterior osteotomy, correction and fusion at T9 to L5 for CS. Radiographs during follow-up, 4 months after the patient gave birth, demonstrated rod breakage.

DIAGNOSES

Rod breakage after orthopaedic surgery of congenital kyphoscoliosis INTERVENTIONS:: The patient was taken into the operating room for replacement of the broken rods, recovery of sagittal balance, bone graft fusion, and improvement of stability by cross-connection. The patient recovered fully by the 3-month postoperative follow-up.

OUTCOMES

In follow-up, the instruments were in good condition, the orthopedic effect was not lost, and low back pain relief was observed.

LESSONS

We opine that the rod breakage during pregnancy resulted from weight gain and a lack of an anterior approach to the supportive bone graft. Therefore, female patients with spinal surgery should visit the hospital for advice before pregnancy.

Osteoporotic Vertebral Fractures as Part of Systemic Disease

Our understanding of the genetic control of skeletogenesis and bone remodeling is expanding, and normally, bone resorption and bone formation are well balanced through regulation by hormones, growth factors, and cytokines. Osteoporosis is considered a systemic disease characterized by low bone mass and microarchitectural deterioration of bone tissue. Consequent increased bone fragility results in higher fracture risk. The most common osteoporotic fractures are located in the spine, and they form a significant health issue. A large variety of systemic diseases are associated with risk of osteoporotic vertebral fractures, illustrating its multifactorial etiology. Prevalences of these conditions vary from common to extremely rare, and incidence peaks differ according to etiology. This review appreciates different aspects of osteoporotic vertebral fractures as part of systemic disease, including genetic, immunologic, inflammatory, metabolic, and endocrine pathways. It seems impossible to be all-comprehensive on this topic; nevertheless, we hope to provide a reasonably thorough overview. Plenty remains to be elucidated in this field, identifying even more associated diseases and further exposing pathophysiological mechanisms underlying osteoporotic vertebral fractures.

Genetics of Osteoporotic Vertebral Fractures

Our understanding of the genetic control of skeletogenesis and bone remodeling is increasing, and in addition to various nongenetic risk factors, a positive family history confers an increased risk of fracture. Vertebral fractures are the most common osteoporotic fractures and they are often a first manifestation of osteoporosis. This review presents the current state of knowledge on the genetic basis of osteoporotic vertebral fractures and, additionally, of structural vertebral deformities resembling osteoporotic vertebral fractures but which may have their own genetic basis. We conclude that, apart from tentative screening for rare monogenic forms of osteoporosis in very unusual case presentations, not enough is currently known to encourage routine genetic screening in regular osteoporotic vertebral fracture cases.

Environmental aspects of congenital scoliosis

Growing evidence has proved that many aspects of our lifestyle and the environment contribute to the development of congenital disease. Congenital spinal deformities are due to anomalous development of the vertebrae including failure of formation and segmentation during embryogenesis. The causes of congenital scoliosis have not been fully identified. A variety of factors are implicated in the development of vertebral abnormalities. Previous studies have demonstrated that both genetics and environmental factors are implicated in the development of vertebral abnormalities. However, no specific cause for congenital scoliosis has been identified. In our review, we focus on the environmental factors for the development of congenital scoliosis. Various maternal exposures during pregnancy including hypoxia, alcohol use, vitamin deficiency, valproic acid, boric acid, and hyperthermia have been observed to be associated with the occurrence of congenital scoliosis. This review describes the major environmental contributors of congenital scoliosis with an emphasis on treatment aspects associated with environmental disposition in congenital scoliosis.

Key role for the transcriptional factor, osterix, in spine development

BACKGROUND CONTEXT

Osterix (Osx) is an important transcriptional factor for bone formation; however, its role in spine development has not been determined.

PURPOSE

The goal of the present study is to observe the role of Osx in spine development.

STUDY DESIGN/SETTING

Deletion and overexpression of Osx were achieved in Osx knockout and transgenic mice, respectively, to determine the effect of Osx on spine development.

METHODS

With 2.3-kb type I collagen as a promoter, Osx were deleted in mice, and overexpression of Osx was obtained in Osx transgenic mice. Video, X-ray radiology, histology, tartrate-resistant acid phosphatase staining, Safranin O staining, and immunohistochemistry were used to assess the effect of Osx deletion and overexpression on spine development. This study was supported by National Science Foundation of China (81271935) and Foundation of State Key Laboratory of Trauma, Burns and combined injury (SKLZZ SKLZZ201124). No potential conflict of interest to disclose.

RESULTS

Overexpression of Osx did not have an obvious effect on spine development, whereas deletion of Osx led to severe spine deformities that included wedged vertebrae, spinal stenosis, and congenital scoliosis. Also, Osx deactivation resulted in shortened vertebrae and excessive bone volume in the vertebrae. TRAP staining showed that activity of osteoclasts decreased in Osx-null mice, and examination with TdT-mediated dUTP nick end labeling revealed that the apoptosis rate at the growth plate decreased significantly in Osx-null mice. Excessive formation of bone was positive for Safranin O staining.

CONCLUSIONS

Osx plays an important role in spine development, and its deactivation leads to severe spine deformities.

Scoliosis-Associated Cervical Spine Pathologies

STUDY DESIGN

A total of 126 scoliosis patients admitted to the hospital were screened for concomitant cervical pathologies.

OBJECTIVES

To investigate the prevalence of cervical spine pathologies and the clinical relevance of magnetic resonance imaging (MRI) in the evaluation of patients with neuromuscular, congenital, syndromic, and idiopathic scoliosis.

BACKGROUND SUMMARY

With the development of MRI, upper neural axis abnormalities such as syringomyelia and Chiari malformation are increasingly being found in patients with scoliosis, but no report in the literature describes other pathologies in the cervical area seen concomitant with different scoliosis types.

METHODS

A total of 126 consecutive patients who were classified as having neuromuscular, congenital, syndromic, and idiopathic scoliosis were retrospectively evaluated. Data regarding cervical neural axis abnormalities obtained from the MRI studies were analyzed and classified into each type of scoliosis group.

RESULTS

A total of 126 patients with scoliosis were evaluated for hindbrain and cervical spine anomalies. Patients were divided into 4 groups regarding the type of scoliosis. The cervical spine of all patients was evaluated with MRI and other radiologic methods when needed. The most frequently seen pathology was syringomyelia. Other pathologies found included congenital vertebral anomalies, Chiari malformation, arachnoid cyst, atlanto-axial dissociation, split cord, posterior vertebral fusion, vertebral hypoplasia, neurenteric cyst, myelomalacia, dermoid cyst, and decrease in craniovertebral angle. Cervical pathologies were most frequently seen in neuromuscular scoliosis, followed by congenital and syndromic groups.

CONCLUSIONS

Cervical spinal pathologies vary according to the type of scoliosis. The number of cervical spinal pathologies diagnosed in idiopathic scoliosis patients was least compared with neuromuscular and syndromic groups. The most common pathology was syringomyelia, followed by congenital vertebral anomalies and cerebral tonsillar hernia. Preoperative MRI scan provides vital information regarding cervical spinal pathologies encountered in scoliosis patients.

Vertebral column resection for complex congenital kyphoscoliosis and type I split spinal cord malformation

INTRODUCTION

Congenital progressive kyphoscoliosis associated with split spinal cord malformation (SSCM) is a very rare disease.

METHODS AND RESULTS

Here, we present the case of a 23-year-old woman who was found kyphoscoliosis when she was 10 years old and developed rapidly. Thereafter, no management was proposed before her consultation at our center. On examination, numbness was found in the right low limbs, kyphoscoliosis was detected in thoracolumbar, the trunk deviated to the right on standing view and curvature of the thoracolumbar spine was left-sided, the left rib hump was severe and there was little muscle tissue felt under the right side paravertebral area, the pelvis was oblique with the right side higher than the left side, the right arcus costarum was 5 cm below the right iliac crest. One-stage corrective surgery was determined, at first, halo-wheelchair traction gradually with increased traction weights out of hospital for a month; then, after a reasonable correction achieved without any neurological deficits. The one-stage operation was taken through single posterior segmental pedicle screw instrumented fusion with VCR between T12 and L1. Post-operative recovery was uneventful and there were no complications, she was discharged 10 days post operation. At 2 years follow-up, the patient's outcome is excellent with balance and correction of the deformity.

CONCLUSION

Based on the Grand Round case and relevant literature, we discuss the different options for the treatment of congenital kyphoscoliosis associated with type I SSCM. In the patient whose kyphoscoliosis is severe and rigid, we recommend an initial release followed by halo-wheelchair traction gradually to correct the deformity, once optimal correction acquires during the traction, the posterior instrumented fusion with VCR upper the bony spur could be done safely without the resection of bony spur.

Characterization of two ENU-induced mutations affecting mouse skeletal morphology

Using the N-ethyl-N-nitrosourea (ENU) mutagenesis screen, we have identified two skeletal morphology mutants, Skm1 and Skm2. Positional cloning and candidate gene sequencing localized the causative point mutations within the genes coding for natriuretic peptide receptor C (NPR-C) and filamin b (FLNB), respectively. Mice that carry a mutation in Npr3 exhibit a skeletal overgrowth phenotype, resulting in an elongated body and kyphosis. Skm2 mice, carrying a mutation in Flnb, present with scoliosis and lordosis. These mutant mice will serve as useful models for the study of vertebral malformations.

Non-fusion and growing instrumentation in the correction of congenital spinal deformity associated with split spinal cord malformation: an early follow-up outcome

STUDY DESIGN

A retrospective case review.

INTRODUCTION

To evaluate the safety and efficacy of the non-fusion technique in achieving and maintaining the proper correction for congenital spinal deformity (CSD) and allowing normal spinal growth in patients with split spinal cord malformation (SSCM).

MATERIALS AND METHODS

Seven patients who had CSD and SSCM were adopted, with a mean age of 8 years. All the patients in this study received Halo-gravity traction (HGT) prior to expansion of the spine and instrumentation with vertical expandable titanium prosthetic rib, growing rod or their hybrid. Five of them underwent opening wedge thoracoplasty simultaneously. And the two patients with type I SSCM underwent bony spur excision in the initial surgery before corrective manipulation. Then all the patients received a lengthened operation every six months. Changes of their major curve and length of T1-S1 spine were measured, and complications, neurological status were recorded. All the patients were followed up with an average of 32.6 months.

RESULTS

Their mean major curve improved from 90.1° to 58.6° with a correction rate of 34.9 %. The T1-S1 length increased from 26.3 to 34.7 cm at final follow-up. Especially, one of the type I SSCM patients whose neurological deterioration was found preoperatively was significantly improved.

CONCLUSION

Preoperative Halo-gravity traction followed by non-fusion and growing instrumentation may be effective and safe for young children of CSD associated with SSCM. But it is an ongoing study and additional large multicenter studies are necessary to further assess the safety and efficacy of non-fusion and growing instrumentation.

Vitamin A deficiency induces congenital spinal deformities in rats

Most cases of congenital spinal deformities were sporadic and without strong evidence of heritability. The etiology of congenital spinal deformities is still elusive and assumed to be multi-factorial. The current study seeks to elucidate the effect of maternal vitamin A deficiency and the production of congenital spinal deformities in the offsping. Thirty two female rats were randomized into two groups: control group, which was fed a normal diet; vitamin A deficient group, which were given vitamin A-deficient diet from at least 2 weeks before mating till delivery. Three random neonatal rats from each group were killed the next day of parturition. Female rats were fed an AIN-93G diet sufficient in vitamin A to feed the rest of neonates for two weeks until euthanasia. Serum levels of vitamin A were assessed in the adult and filial rats. Anteroposterior (AP) spine radiographs were obtained at week 2 after delivery to evaluate the presence of the skeletal abnormalities especially of spinal deformities. Liver and vertebral body expression of retinaldehyde dehydrogenase (RALDHs) and RARs mRNA was assessed by reverse transcription-real time PCR. VAD neonates displayed many skeletal malformations in the cervical, thoracic, the pelvic and sacral and limbs regions. The incidence of congenital scoliosis was 13.79% (8/58) in the filial rats of vitamin A deficiency group and 0% in the control group. Furthermore, vitamin A deficiency negatively regulate the liver and verterbral body mRNA levels of RALDH1, RALDH2, RALDH3, RAR-α, RAR-β and RAR-γ. Vitamin A deficiency in pregnancy may induce congenital spinal deformities in the postnatal rats. The decreases of RALDHs and RARs mRNA expression induced by vitamin A deprivation suggest that vertebral birth defects may be caused by a defect in RA signaling pathway during somitogenesis.

Surgical and conservative treatment of patients with congenital scoliosis: α search for long-term results

Background

In view of the limited data available on the conservative treatment of patients with congenital scoliosis (CS), early surgery is suggested in mild cases with formation failures. Patients with segmentation failures will not benefit from conservative treatment. The purpose of this review is to identify the mid- or long-term results of spinal fusion surgery in patients with congenital scoliosis.

Methods

Retrospective and prospective studies were included, reporting on the outcome of surgery in patients with congenital scoliosis. Studies concerning a small numbers of cases treated conservatively were included too. We analyzed mid-term (5 to 7 years) and long-term results (7 years or more), both as regards the maintenance of the correction of scoliosis and the safety of instrumentation, the early and late complications of surgery and their effect on quality of life.

Results

A small number of studies of surgically treated patients were found, contained follow-up periods of 4-6 years that in the most cases, skeletal maturity was not yet reached, and few with follow-up of 36-44 years. The results of bracing in children with congenital scoliosis, mainly in cases with failure of formation, were also studied.

Discussion

Spinal surgery in patients with congenital scoliosis is regarded in short as a safe procedure and should be performed. On the other hand, early and late complications are also described, concerning not only intraoperative and immediate postoperative problems, but also the safety and efficacy of the spinal instrumentation and the possibility of developing neurological disorders and the long-term effect these may have on both lung function and the quality of life of children.

Conclusions

Few cases indicate the long-term results of surgical techniques, in the natural progression of scoliosis. Similarly, few cases have been reported on the influence of conservative treatment.

In conclusion, patients with segmentation failures should be treated surgically early, according to the rate of deformity formation and certainly before the pubertal growth spurt to try to avoid cor- pulmonale, even though there is lack of evidence for that in the long-term. Furthermore, in patients with formation failures, further investigation is needed to document where a conservative approach would be necessary.