An analysis of thoracic cage deformities and pulmonary function tests in congenital scoliosis

Variation in thoracic inlet measurements and its correlation with pulmonary dysfunction in kyphoscoliotic deformities: a prospective case-control study

BACKGROUND

Pulmonary dysfunction in thoracic kyphoscoliosis has been correlated with chest wall distortion, uneven trunk growth and restrictive pattern. The study aims to analyse the variation in thoracic inlet measurements on pulmonary dysfunction with varying curve magnitude and thoracic cage parameters.

METHODS

In a non-randomised, prospective case-control study, 80 consecutive patients with thoracic kyphoscoliosis were divided into 3 groups based on Cobb angle: Group 1 (31-50), Group 2 (51-80) and Group 3 (> 80). Thoracic inlet measurement was calculated by thoracic inlet index (TI) on MRI at the sternal level. Pulmonary function and thoracic cage parameters [hemi thorax height, rib-apex distance, AP chest diameter at sternal level and transverse thoracic diameter] were documented. TI values were compared with 20 age-matched asymptomatic controls. Multivariate correlation and regression analysis were performed to investigate the correlations.

RESULTS

The mean age of the study cohort was 14.1 ± 4.4 years, including Group 1 (6 patients), Group 2 (55 patients) and Group 3 (19 patients) versus 12.9 ± 2.2 years in controls. The mean TI was 2.8 ± 0.56 in Group 1, 3.7 ± 0.9 in Group 2 and 4.0 ± 1.12 in Group 3 versus 2.6 ± 0.43 in controls. Pulmonary dysfunction was severe with TI > 7.1 (p < 0.001) in Group 3 patients with thoracic hypokyphosis. Multivariate regression for thoracic parameters and TI > 5.6 showed significant correlation of pulmonary dysfunction in Group 2 and 3 curves with apex between T1 and T4, whereas transverse thoracic diameter, rib-apex distance and hemi thorax height were weakly associated.

CONCLUSION

Thoracic inlet index (TI), a neglected pre-operative variable associated with pulmonary dysfunction in thoracic kyphoscoliosis, can be evaluated on MRI without an additional cost and radiation.

LEVEL OF EVIDENCE: 3

Short-term outcomes of an enhanced recovery after surgery pathway for children with congenital scoliosis undergoing posterior spinal fusion: a case-control study of 70 patients

Increasing evidence demonstrates the advantages of an enhanced recovery after surgery (ERAS) protocol; however, few studies have evaluated ERAS in pediatric patients. This study aimed to evaluate the effect of ERAS in pediatric patients with congenital scoliosis. Seventy pediatric patients with congenital scoliosis underwent posterior hemivertebra resection and fusion with pedicle screws and were prospectively randomly assigned to the ERAS group ( n  = 35) and control group ( n  = 35). ERAS management comprised 15 elements including a shortened fasting time, optimized anesthesia protocol, and multimodal analgesia. The control group received traditional perioperative management. Clinical outcome was evaluated by hospital stay, surgery-related indicators, diet, pain scores, laboratory tests, and complications. The surgical outcome showed a similar correction rate in the ERAS group (84.0%) and control group (89.0%; P  = 0.471). The mean fasting time was significantly shorter in the ERAS group than in the control group. Compared with the control group, the ERAS group had significantly shorter mean times to postoperative hospital stay, first anal exhaust and defecation, significantly lower mean pain scores in the first 2 days postoperatively ( P  < 0.05), and a significantly lower mean interleukin-6 concentration on postoperative day 1 ( P  < 0.001). The incidence of complications was similar in the ERAS group and control group ( P  > 0.05). The ERAS protocol is effective and safe for pediatric patients with congenital spinal deformity and may significantly improve the treatment efficacy compared with traditional perioperative management methods. Levels of Evidence: III.

Evaluation of Pulmonary Function After Halo-Pelvic Traction for Severe and Rigid Kyphoscoliosis Utilizing CT with 3D Reconstruction

BACKGROUND

The purpose of the present study was to evaluate changes in pulmonary function, caused by preoperative halo-pelvic traction (HPT) for the treatment of extremely severe and rigid kyphoscoliosis, with use of 3-dimensional computed tomography (3D-CT) reconstruction and pulmonary function tests (PFTs).

METHODS

Twenty-eight patients with severe and rigid scoliosis (Cobb angle, >100°) underwent preoperative HPT and staged posterior spinal fusion. CT, radiographic assessment, and PFT were performed during pre-traction and post-traction visits. The changes in total lung volume were evaluated with use of 3D-CT reconstruction, and the changes in pulmonary function were evaluated with PFTs at each time point. Differences were analyzed with use of 2-tailed paired Student t tests, and correlations were analyzed with use of Spearman rank tests.

RESULTS

None of the patients had pulmonary complications during traction, and all radiographic spinal measurements improved significantly after HPT. The main Cobb angle was corrected from 143.30° ± 20.85° to 62.97° ± 10.83° between the pre-traction and post-traction evaluations. Additionally, the C7-S1 distance was lengthened from 280.48 ± 39.99 to 421.26 ± 32.08 mm between the pre-traction and post-traction evaluations. Furthermore, 3D lung reconstruction demonstrated a notable increase in total lung volume (TLV) (from 1.30 ± 0.25 to 1.83 ± 0.37 L) and maximum lung height (from 176.96 ± 27.44 to 202.31 ± 32.45 mm) between the pre-traction and post-traction evaluations. Moreover, PFTs showed that total lung capacity (TLC) improved between the pre-traction and post-traction evaluations (from 2.06 ± 0.32 to 2.98 ± 0.82 L) and that the changes in T1-T12 distance and maximum lung height were correlated with changes in TLV (p = 0.0288 and p = 0.0007, respectively).

CONCLUSIONS

The application of HPT is a safe and effective method for improving pulmonary function in patients with extremely severe and rigid scoliosis before fusion surgery. The TLV as measured with CT-based reconstruction was greatly increased after HPT, mainly because of the changes in thoracic height.

LEVEL OF EVIDENCE

Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Update on the Diagnosis and Management of Early-onset Scoliosis

PURPOSE OF REVIEW

In this article, we review the most recent advancements in the approaches to EOS diagnosis and assessment, surgical indications and options, and basic science innovation in the space of early-onset scoliosis research.

RECENT FINDINGS

Early-onset scoliosis (EOS) covers a diverse, heterogeneous range of spinal and chest wall deformities that affect children under 10 years old. Recent efforts have sought to examine the validity and reliability of a recently developed classification system to better standardize the presentation of EOS. There has also been focused attention on developing safer, informative, and readily available imaging and clinical assessment tools, from reduced micro-dose radiographs, quantitative dynamic MRIs, and pulmonary function tests. Basic science innovation in EOS has centered on developing large animal models capable of replicating scoliotic deformity to better evaluate corrective technologies. And given the increased variety in approaches to managing EOS in recent years, there exist few clear guidelines around surgical indications across EOS etiologies. Despite this, over the past two decades, there has been a considerable shift in the spinal implant landscape toward growth-friendly instrumentation, particularly the utilization of MCGR implants. With the advent of new biological and basic science treatments and therapies extending survivorship for disease etiologies associated with EOS, the treatment for EOS has steadily evolved in recent years. With this has come a rising volume and variation in management options for EOS, as well as the need for multidisciplinary and creative approaches to treating patients with these complex and heterogeneous disorders.

Postoperative changes in rib cage deviation in adolescent idiopathic scoliosis

BACKGROUND

Scoliosis causes changes in the thorax, but it is unclear what type of changes occur in the thoracic profile after scoliosis surgery.

OBJECTIVE

To investigate changes in rib cage deviation in the postoperative period after adolescent idiopathic scoliosis (AIS) surgery.

METHODS

Forty-four patients with AIS with a main right thoracic curvature underwent posterior surgical fusion (PSF), and radiological parameters of the spine and thorax were evaluated.

RESULTS

The correction rates of main thoracic curve (MT)-Cobb angle at immediate after surgery and postoperative follow-up (2 years) were 64% and 66%, respectively. At these two postoperative time points, the correction rates of height of thoracic vertebrae 1 to 12 (T1T12) were 10% and 12%; the correction rates of Rib-vertebra angle difference (RVAD) were 59% and 52%; the correction rates of Apical rib hump prominence (RH) were 58% and 76%; while the correction rates of Apical vertebral body-rib ratio (AVB-R) were 23% and 25%, respectively. Statistical analysis showed that all these radiological parameters at the two postoperative time points were significantly different from the preoperative values (p< 0.001). There were significant correlations between MT-Cobb angle and T1-T12 height (p< 0.001), RVAD (p< 0.001), RH (p< 0.001), and AVB-R (p< 0.001).

CONCLUSIONS

Posterior spinal fusion appears to be effective at correcting scoliosis, and the correction of rib cage deviation also plays an important role.

Estimating pulmonary function after surgery for adolescent idiopathic scoliosis using biplanar radiographs of the chest with 3D reconstruction

AIMS

This study addressed two questions: first, does surgical correction of an idiopathic scoliosis increase the volume of the rib cage, and second, is it possible to evaluate the change in lung function after corrective surgery for adolescent idiopathic scoliosis (AIS) using biplanar radiographs of the ribcage with 3D reconstruction?

METHODS

A total of 45 patients with a thoracic AIS which needed surgical correction and fusion were included in a prospective study. All patients underwent pulmonary function testing (PFT) and low-dose biplanar radiographs both preoperatively and one year after surgery. The following measurements were recorded: forced vital capacity (FVC), slow vital capacity (SVC), and total lung capacity (TLC). Rib cage volume (RCV), maximum rib hump, main thoracic curve Cobb angle (MCCA), medial-lateral and anteroposterior diameter, and T4-T12 kyphosis were calculated from 3D reconstructions of the biplanar radiographs.

RESULTS

All spinal and thoracic measurements improved significantly after surgery (p < 0.001). RCV increased from 4.9 l (SD 1) preoperatively to 5.3 l (SD 0.9) (p < 0.001) while TLC increased from 4.1 l (SD 0.9) preoperatively to 4.3 l (SD 0.8) (p < 0.001). RCV was correlated with all functional indexes before and after correction of the deformity. Improvement in RCV was weakly correlated with correction of the mean thoracic Cobb angle (p = 0.006). The difference in TLC was significantly correlated with changes in RCV (p = 0.041). It was possible to predict postoperative TLC from the postoperative RCV.

CONCLUSION

3D rib cage assessment from biplanar radiographs could be a minimally invasive method of estimating pulmonary function before and after spinal fusion in patients with an AIS. The 3D RCV reflects virtual chest capacity and hence pulmonary function in this group of patients. Cite this article: Bone Joint J 2022;104-B(1):112-119.

Improvement of Pulmonary Function in Arthrogryposis Multiplex Congenita Patients Undergoing Posterior Spinal Fusion Surgery for Concomitant Scoliosis: A Minimum of 3-Year Follow-up

OBJECTIVE

We sought to investigate the long-term outcome of pulmonary function for arthrogryposis multiplex congenita (AMC) patients undergoing posterior spinal fusion (PSF) and to further determine influential factors.

METHODS

Eighteen AMC patients with a minimum of 3-year follow-up after PSF were prospectively collected. All the patients underwent a pulmonary function test before surgery and at the final follow-up. The percentage predicted values of vital capacity (VC%) and forced vital capacity (FVC%) were recorded. The following radiographic parameters were collected including Cobb angle and thoracic kyphosis. The total lung volumes (TLV) were measured on the image of 3-dimensional computed tomography scan by the reconstruction software.

RESULTS

There were 10 males and 8 females with a mean age of 13.8 ± 6.1 years. The mean preoperative VC% and FVC% were 40.5% ± 7.6% and 39.5% ± 4.7%, which were significantly increased to 52.0% ± 7.5% and 51.2% ± 6.8% at the final follow-up (P < 0.001). Besides, there was remarkable improvement in terms of TLV (1.57 ± 0.2 L vs. 2.39 ± 0.6 L, P < 0.001). Remarkable correlations were observed between TLV and pulmonary function tests (r = 0.79, P < 0.001 for VC%; r = 0.78, P < 0.001 for FVC%). Multiple regression analysis showed that 2 variables including Δ thoracic kyphosis and Δ Cobb angle were independently associated with the improvement of pulmonary function.

CONCLUSIONS

The pulmonary function of AMC patients can be well improved through PSF surgery. It was remarkably associated with the correction of curve magnitude and restoration of thoracic kyphosis.

Factors and predictive model associated with perioperative complications after long fusion in the treatment of adult non-degenerative scoliosis

Introduction

Adult non-degenerative scoliosis accounts for 90% of spinal deformities in young adults. However, perioperative complications and related risk factors of long posterior instrumentation and fusion for the treatment of adult non-degenerative scoliosis have not been adequately studied.

Methods

We evaluated clinical and radiographical results from 146 patients with adult non-degenerative scoliosis who underwent long posterior instrumentation and fusion. Preoperative clinical data, intraoperative variables, and perioperative radiographic parameters were collected to analyze the risk factors for perioperative complications. Potential and independent risk factors for perioperative complications were evaluated by univariate analysis and logistic regression analysis.

Results

One hundred forty-six adult non-degenerative scoliosis patients were included in our study. There were 23 perioperative complications for 21 (14.4%) patients, eight of which were cardiopulmonary complications, two of which were infection, six of which were neurological complications, three of which were gastrointestinal complications, and four of which were incision-related complication. The independent risk factors for development of total perioperative complications included change in Cobb angle (odds ratio [OR] = 1.085, 95% CI = 1.035 ~ 1.137, P = 0.001) and spinal osteotomy (OR = 3.565, 95% CI = 1.039 ~ 12.236, P = 0.043). The independent risk factor for minor perioperative complications is change in Cobb angle (OR = 1.092, 95% CI = 1.023 ~ 1.165, P = 0.008). The independent risk factors for major perioperative complications are spinal osteotomy (OR = 4.475, 95% CI = 1.960 ~ 20.861, P = 0.036) and change in Cobb angle (OR = 1.106, 95% CI = 1.035 ~ 1.182, P = 0.003).

Conclusions

Our study indicate that change in Cobb angle and spinal osteotomy are independent risk factors for total perioperative complications after long-segment posterior instrumentation and fusion in adult non-degenerative scoliosis patients. Change in Cobb angle is an independent risk factor for minor perioperative complications. Change in Cobb angle and spinal osteotomy are independent risk factors for major perioperative complications.

Three-dimensional reconstruction image by biplanar stereoradiography reflects pulmonary functional states inadolescent idiopathic scoliosis

This study investigated whether the rib cage parameters estimated based on reconstructed three-dimensional (3D) images with biplanar stereoradiography reflect pulmonary functional states in adolescent idiopathic scoliosis (AIS) patients. A total of 67 Lenke type 1 or 2 AIS patients (59 females and 8 males, mean age 14.4 years) were enrolled. All patients underwent preoperative pulmonary functional tests (PFT) and biplanar stereoradiography. Vital capacity (VC) and forced vital capacity (FVC) pulmonary functional data were collected. Rib-cage parameters (maximum thickness, maximum width, thoracic index (TI), rib hump (RH), rib-cage volume (RCV), spinal penetration index (SPI), endothoracic hump ratio (EHR), vertebra-sternum angle (VSA), rib vertebral angle difference (RVAD), and vertebral lateral decentering (VLD)) were quantified from 3D images. Patients were divided into two groups: restrictive lung disorder (RLD) (%FVC < 80%) and non-RLD (%FVC ≥ 80%). The maximum width and RCV were significantly correlated with VC (p < 0.0001), and FVC (p < 0.0001). RH, EHR, and VSA were negatively correlated with %FVC (p < 0.01). TI, SPI, and RVAD were not correlated with any pulmonary parameters. The maximum widths of RLD patients were significantly shorter than those of the non-RLD patients (218.3 mm vs. 229.7 mm, p < 0.01). The RCV of RLD patients was significantly smaller than that of the non-RLD patients (3.94 L vs. 4.49 L, p < 0.0001). The maximum width and RCV measured by 3D images with biplanar stereoradiography reflected pulmonary functional variables in patients with AIS.

Growing-rod implantation improves nutrition status of early-onset scoliosis patients: a case series study of minimum 3-year follow-up

BACKGROUND

Early onset scoliosis (EOS) may cause malnutrition in affected patients. Growing-rod treatment has been an effective protocol for treating EOS. The objective of this study is to demonstrate whether growing-rod treatment improves nutritional status of EOS patients.

METHODS

Fifty-two EOS patients who had dual growing-rod surgery was enrolled. The minimum follow-up was 3-years. Their body weights were normalized based on the data of two National Population Census of China. Z-scores were used to indicate the standard deviation from the median body weight-for-age.

RESULTS

The median follow-up time was 6 years. Preoperatively, the prevalence of malnutrition (Z < - 2) was 21.2%, and reduced to 9.6% at the end of the follow-up. Preoperatively, the average Z-score was - 0.94, and it increased to - 0.65 at the latest follow-up (p < 0.05). Patients with preoperative Z-score below - 1 had more significant increase of Z-scores (- 2.15 vs - 1.26, p < 0.001). A significant negative correlation between the change of Z-score and the preoperative Z-score (correlation coefficient - 0.65, p < 0.001).

CONCLUSIONS

The growing rod surgery and lengthening procedures significantly improves the nutrition status of EOS patients. The body weight gains are more significant in patients with lower body weights.

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.

Pulmonary Implications of Pediatric Spinal Deformities

"Pediatric spinal deformities may be associated with pulmonary complications in a patient's lifetime. A review of the diagnosis of spinal abnormalities includes classifications of scoliosis and kyphosis, correlating physical examination findings and radiographic interpretation. The natural history of untreated spine deformities is reviewed along with the associated altered pulmonary compromise. Treatment options for children affected by spinal deformities are discussed, including the relative indications, the efficacy, pros and cons of different treatment options, along with the evidence to support these. This overview of spine deformities includes research outcomes to support the care of these pediatric patients."

Vertical Expandable Rib-based Distraction Device for Correction of Congenital Scoliosis in Children of 3 Years of Age or Younger: A Preliminary Report

BACKGROUND

This study was designed to evaluate the treatment outcome of very young children with congenital scoliosis aged 3 years or under after surgery with a vertical expandable prosthetic titanium rib (VEPTR)-based distraction device.

METHODS

A retrospective study of 13 children undergoing implantation of a vertical expandable rib-based distraction device. From September 2007 to June 2018, 13 children (7 male and 6 female patients) with congenital scoliosis were followed after treatment with a VEPTR. The outcome parameters were complications, thoracic height, kyphosis, lordosis, and coronal major scoliosis curve. In addition, the American Society of Anaesthesiologists (ASA) score, assisted ventilation rating, and hemoglobin and body mass index were analyzed. Data were examined separately by 2 investigators.

RESULTS

The mean age at initial surgical treatment was 24.4±10.6 months, follow-up was 91.5±23.1 months. The mean number of surgical procedures per patient was 14±3.9 (total 182 operations). Apart from planned operations every 6 months, 5 unplanned operations (2.7%) were performed. The major scoliosis curve improved significantly from 55.2±21.9 degrees to 40.5±18.7 degrees, thoracic spine height T1-T12 significantly from 111±12 mm to 137±23 mm, T1-S1 height significantly from 211±13 mm to 252±36 mm and space available for the lung from 80.9%±11.3% to 84.4%±8.8% (preoperatively and at 5-y follow-up, respectively). Kyphosis increased significantly from 30±21.4 degrees to 42.6±23.5 degrees and lordosis from 32.4±20.9 degrees to 37.6±10.4 degrees. Hemoglobin levels were virtually unchanged. Weight increased from 10.6±2.8 kg to 20.2±5.0 kg at final follow-up, but body mass index decreased from 16.6±3.7 kg/m² to 15.7±2.9 kg/m².

CONCLUSIONS

The expandable rib-based distraction device is an effective method to treat severe congenital scoliosis in very young children. It can control the deformity and promotes spinal and thoracic growth.

LEVEL OF EVIDENCE

Level IV.

Genome-Wide Analysis of circular RNAs and validation of hsa_circ_0006719 as a potential novel diagnostic biomarker in congenital scoliosis patients

Congenital scoliosis (CS) is a form of spinal curvature resulting from anomalous development of vertebrae. Recent studies demonstrated that circRNAs could serve as potential biomarkers of disease diagnosis. Genome‐wide circRNAs expression in seven CS patients and three healthy controls was initially detected. Bioinformatics analysis was conducted to explore the potential pathological pathway of CS. Quantitative PCR (qPCR) was performed to validate the selected circRNAs in the replication cohort with 32 CS patients and 30 healthy controls. Logistic regression controlling for gender was conducted to compare the expression difference. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value. Twenty‐two differentially expressed circRNAs were filtered from genome‐wide circRNA sequencing. Seven circRNAs were validated by qPCR. Only hsa_circ_0006719 was confirmed to have a higher expression level in the CS group than the healthy control group (P = 0.036). Receiver operating characteristic curve also suggested that hsa_circ_0006719 had significant diagnostic value for CS (AUC = 0.739, P = 0.001). We described the first study of circRNAs in CS and validated hsa_circ_0006719 as a potential novel diagnostic biomarker of CS.

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

STUDY DESIGN

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

OBJECTIVE

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

SUMMARY OF BACKGROUND DATA

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

3.

Cardiopulmonary Function in Patients with Congenital Scoliosis: An Observational Study

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

Risk factors for postoperative pulmonary complications in the treatment of non-degenerative scoliosis by posterior instrumentation and fusion

PURPOSE

The aim of this study was to evaluate the prevalence and risk factors for postoperative pulmonary complications (PPC) after posterior instrumentation and fusion (PIF) in patients with non-degenerative scoliosis.

METHODS

We retrospectively evaluated 703 patients (224 males, 479 females) diagnosed with non-degenerative scoliosis who underwent PIF in our center from January 2010 to January 2018. Preoperative, perioperative, demographic data, surgical methods and radiographic parameters were extracted and analyzed to identify risk factors for PPC.

RESULTS

The mean age of the patients was 20.8 ± 9.0 years with the following diagnoses: congenital scoliosis (287/703, 40.8%), idiopathic scoliosis (281/703, 40.0%), neuromuscular scoliosis (103/703, 14.7%) and syndromic scoliosis (32/703, 4.5%). PPC manifested in 82 patients (11.7%) including pleural effusion (39/82, 47.6%), pneumonia (33/82, 40.2%), pneumothorax (3/82, 3.7%), respiratory failure (3/82, 3.7%), hemothorax (2/82, 2.4%), pulmonary edema (1/82, 1.2%) and pulmonary embolism (1/82, 1.2%). Multifactorial regression analysis confirmed that revision surgery [odds ratio (OR) = 2.320, P = 0.030], preoperative respiratory disease (OR = 14.286, P < 0.001), preoperative Cobb angle of main curve > 75° (OR = 1.701, P = 0.046) and thoracoplasty (OR = 4.098 P < 0.001) were risk factors for PPC after PIF in patients with non-degenerative scoliosis.

CONCLUSIONS

A prevalence of 11.7% PPC was observed after PIF. Risk factors were preoperative Cobb angle of main curve > 75°, preoperative respiratory disease, revision surgery and thoracoplasty. Surgeons should recognize and pay attention to these risk factors and take appropriate preventive measures to prevent severe pulmonary complications. These slides can be retrieved under Electronic Supplementary Material.

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.

Analysis of patterning in the occurrence of skeletal lesions used as indicators of vitamin D deficiency in subadult and adult skeletal remains

Paleopathological investigations of conditions linked to vitamin D deficiency have increased in the last twenty years, and a suite of skeletal lesions has been established to aid in the diagnosis of vitamin D deficiency disease in subadults and adults. This paper analyzes the occurrence of these lesions in a large skeletal series comprising 3541 Roman period individuals (1st-6th century AD). Sixteen lesions reported in rickets in subadults, and 13 associated with residual rickets and osteomalacia in adults, were analyzed. Among subadults, there were clear associations among post-cranial lesions. Porotic cranial changes were associated with each other, but not with post-cranial lesions. A range of conditions could have produced the cranial lesions. There was a general paucity of correlations between indicators found in adults, and the difficulty in recording bending deformities was clear. Pseudofractures appear to provide a useful means of investigating osteomalacia in adults. In general, a simple algorithmic approach using presence or absence of lesions is unlikely to provide an adequate means of diagnosing vitamin D deficiency in paleopathology. Knowledge and consideration of the underlying physiological mechanisms involved in lesion formation, combined with individual judgement, will be required to differentially diagnose cases.

Referral for Adolescent Idiopathic Scoliosis by Pediatric Primary Care Providers

This study sought to examine primary care physician opinions regarding referral practices for patients with adolescent idiopathic scoliosis (AIS) and to determine if curve severity at the time of referral is correlated with insurance status. A survey was distributed to pediatric primary care providers to determine referral practices. A chart review of patients referred to a pediatric spine specialist for AIS was performed. A total of 59.3% of respondents stated their referral threshold for AIS patients was <20°. The mean curve size in privately insured patients was 27° (range 6°-68°), whereas the mean curve size in the publicly insured group was 27.6° (range = 6°-58°; P = .9). Large disparities among referral practices exist among pediatric primary care providers, although insurance status did not seem to affect curve size at the time of referral. Encouraging education initiatives for pediatric primary care providers may encourage appropriate referral for AIS.

Cardiopulmonary Exercise Testing in Patients with Idiopathic Scoliosis

BACKGROUND

Scoliosis causes impairment of the respiratory and cardiovascular systems. Traditional pulmonary function tests only examine patients under static conditions. The aim of our study was to investigate the correlation between radiographic parameters and dynamic cardiopulmonary capacity in patients with idiopathic scoliosis.

METHODS

Forty patients with idiopathic scoliosis were included in this prospective study from January 2014 to February 2016. The patients underwent full radiographic assessment of deformity, pulmonary function testing, and cardiopulmonary bicycle ergometer testing. The impact of the severity of thoracic curvature and kyphosis on pulmonary function and physical capacity was investigated.

RESULTS

Thirty-three female patients with a mean age of 15.5 years (range, 11 to 35 years) and coronal thoracic curvature of 49.4° (range, 24° to 76°) and 7 male subjects with a mean age of 15.9 years (range, 13 to 18 years) and coronal thoracic curvature of 47.1°(range, 22° to 80°) were included. No correlation was found between coronal thoracic curvature and pulmonary function test results in the female patients. Female patients with a thoracic curve of ≥60° had lower blood oxygen saturation at maximal exercise in the cardiopulmonary exercise test (p = 0.032). Female patients with a thoracic curve of ≥50° had a higher respiratory rate (p = 0.041) and ventilation volume per minute (p = 0.046) and lower breathing reserve at maximal exercise (p = 0.038). Thoracic kyphosis in female patients was positively correlated with pulmonary function, as shown by the forced expiratory volume in 1 second (r = 0.456, p = 0.01), forced vital capacity (r = 0.366, p = 0.043), vital capacity (r = 0.525, p = 0.006), and total lung capacity (r = 0.388, p = 0.031), as well as with tidal volume (r = 0.401, p = 0.025) in cardiopulmonary exercise testing. Female patients who engaged in regular exercise had better peak oxygen intake normalized by body weight (p < 0.001), peak oxygen intake normalized by the predicted value (p = 0.003), maximum heart rate (p = 0.020), and heart rate reserve (p = 0.014).

CONCLUSIONS

Overall exercise tolerance was not correlated with the magnitude of the thoracic curve and kyphosis. Some parameters of ventilatory function and pulmonary gas exchange worsened as thoracic curvature increased or kyphosis decreased. Exercise capacity was better in patients who engaged in regular aerobic exercise, and physical activity is recommended for patients with idiopathic scoliosis.

LEVEL OF EVIDENCE

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

Correlation between severity of adolescent idiopathic scoliosis and pulmonary artery systolic pressure: a study of 338 patients

PURPOSE

Study of patients with adolescent idiopathic scoliosis.

OBJECTIVE

To examine the correlation between pulmonary arterial pressure and coronal Cobb angle of idiopathic scoliosis.

METHODS

A total of 338 patients (82.8 % female) with idiopathic scoliosis (average age 15.6 years; range 14-20 years) were included. Preoperatively, the coronal Cobb angle of curvature and the apex location and direction were determined from radiographic records. Tricuspid regurgitation velocity (TRV) and inferior vena cava diameter were also measured using Doppler echocardiography. Pulmonary arterial systolic pressure (sPAP) was calculated from the TRV according to the modified Bernoulli equation and correlations between sPAP and the features of scoliosis were identified by statistical analysis.

RESULTS

Among the 338 patients, there were 305 thoracic curves, 276 (90.5 %) of which were right curves, and 265 thoracolumbar/lumbar curves. sPAP varied from 5.0 to 37.6 mmHg. Pulmonary hypertension could not be excluded in the case of one patient. A mild correlation (Spearman test, correlation coefficient = 0.187, P = 0.001) between sPAP and coronal Cobb angle of the main thoracic (MT) curves was identified. Correlations between sPAP and the degree of other curves were not significant. Patients with sPAP >20 mmHg also had larger thoracic curve angles (mean MT 42.16° vs. 52.45°; U test, P = 0.002). There were no differences in sPAP levels between patients with right and left thoracic curves.

CONCLUSIONS

A mild positive correlation was identified between sPAP and the coronal Cobb angle of the MT curves. There was no relationship between sPAP and the direction of the curvature.