Factors determining pulmonary function in adolescent idiopathic thoracic scoliosis

The Prevalence of Scoliosis after Fontan Circulation Surgery Followed-Up to Adolescence

Introduction

The advancement of surgical techniques and perioperative management for congenital heart disease (CHD) has increased life expectancy. The surgical creation of the Fontan circulation maintains pulmonary blood flow without relying on an effective pump from the abnormal heart, relying on peripheral vascular resistance to maintain effective flow through the lungs. Unfortunately, this delicate mechanism is compromised when scoliosis restricts ventilation, leading to Fontan failure and a poor prognosis for life. This report describes the prevalence of scoliosis with Fontan completion surgery and the role of screening and surgical correction.

Methods

Ninety-six consecutive Japanese patients undergoing Fontan completion surgery for CHD between 2000 and 2017 were identified in our institutional records. The inclusion criterion was at least 7 years of follow-up after Fontan completion surgery, while the exclusion criteria were congenital, syndromic, and neuromuscular scoliosis. Radiographic and clinical parameters, including cardio-thoracic ratio (CTR) for cardiomegaly and cyanosis saturation, were compared between with and without scoliosis.

Results

There were 23 and 40 patients in the scoliosis and no scoliosis groups, respectively. The mean age at the final follow-up was 18.5 and 16.7 years in the scoliosis and no scoliosis groups, respectively (p=0.02). Mean CTR was 43.7% and 39.4% in the scoliosis and no scoliosis groups (p=0.016), and the mean saturation in room air at the final follow-up was 88.8% and 93.2%, respectively (p=0.036). There were no significant differences to clarify the risk factors with multivariate logistic regression analysis.

Conclusions

The prevalence of scoliosis with Fontan completion surgery was 36.5%. Screening for scoliosis is important for children with Fontan circulation surgery as part of their routine follow-up at least until they reach adolescence.

Evidence Level: 4.

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

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

CONCLUSION

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

TRIAL REGISTRATION

 ClinicalTrials.gov ID: NCT05761236.

WHAT IS KNOWN

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

WHAT IS NEW

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

The Role of Muscle Biomarkers in Adolescent Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) is the predominant orthopedic disorder in children, affecting 1-3% of the global population. Research in this field has tried to delineate the genetic factors behind scoliosis and its association with heredity since AIS is considered a polygenic disease and has different genetic and epigenetic factors. The current study conducted a narrative review of the literature, focusing on biomarkers in the pathophysiology of muscle in AIS patients. Articles were collected from Scopus, Pubmed, and Web of Science. The key screening parameters were scoliosis classification, sampling, and the biomarkers evaluated. This review emphasizes potential key mechanisms and molecular regulators in muscle tissue. While there has been limited focus on the proteins contributing to muscle changes in AIS, significant attention has been given to genomic studies of single-nucleotide polymorphisms, particularly in LBX1. Despite these efforts, the exact causes of AIS remain elusive, with several theories suggesting genetic and hormonal factors. This review identified critical protein biomarkers such as Gi-protein alpha subunits, fibrillin-1 and -2, and various differentially expressed proteins, which may be linked to muscle alterations in AIS. This field of research is still limited due to a lack of homogeneity in the distinction of patients by groups and curve severity. Although the pathophysiology of AIS is still unclear, molecular research is important to guide the treatment of AIS before achieving skeletal maturity, thus avoiding serious problems associated with posture changes and low quality of life. In the future, a more comprehensive synergy between orthopedic and molecular research might ameliorate the diagnosis and treatment of AIS patients.

Posterior Spinal Fusion Surgery for Neuromuscular Disease Patients with Severe Scoliosis Whose Cobb Angle Was over 100 Degrees

Background and objectives: Patients with neuromuscular diseases usually have progressive neuromuscular scoliosis (NMS), requiring invasive surgery. Some patients present with severe scoliosis at the time of consultation and are difficult to treat. Posterior spinal fusion (PSF) surgery combined with anterior release and pre- or intraoperative traction would be effective for severe spinal deformities but would be invasive. This study aimed to evaluate the outcomes of PSF-only surgery for patients with severe NMS with a Cobb angle > 100°. Materials and Methods: Thirty NMS patients (13 boys and 17 girls; mean age 13.8 years) who underwent PSF-only surgery for scoliosis with a Cobb angle > 100° were included. We reviewed the lower instrumented vertebra (LIV), duration of surgery, blood loss, perioperative complications, preoperative clinical findings, and radiographic findings, including Cobb angle and pelvic obliquity (PO) in the sitting position pre- and postoperatively. The correction rate and correction loss of the Cobb angle and PO were also calculated. Results: The mean duration of surgery was 338 min, intraoperative blood loss was 1440 mL, preoperative %VC was 34.1%, FEV1.0 (%) was 91.5%, and EF was 66.1%. There were eight cases of perioperative complications. The Cobb angle and PO correction rates were 48.5% and 42.0%, respectively. We divided the patients into two groups: the L5 group, in which the LIV was L5, and the pelvis group, in which the LIV was the pelvis. The duration of surgery and PO correction rate in the pelvis group were significantly higher than those in the L5 group. Conclusions: Patients with severe NMS demonstrated severe preoperative restrictive ventilatory impairments. PSF surgery without anterior release or any intra-/preoperative traction showed satisfactory outcomes, including acceptable scoliosis correction and improved clinical findings, even in patients with extremely severe NMS. Instrumentation and fusion to the pelvis for severe scoliosis in patients with NMS showed good PO correction and low correction loss of Cobb angle and PO, but a longer duration of surgery.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Pulmonary Parameters in Adolescents with Severe Thoracic Idiopathic Scoliosis: Comparison Girls versus Boys

The study compared pulmonary parameters, registered at the preoperative examination, in adolescent boys versus girls, both with severe thoracic idiopathic scoliosis. Thirty consecutive boys and 30 consecutive girls with Lenke 1 or 3 type, in the age range 14−18 years, with a Cobb angle of >50° and Risser sign ≥ 3 were enrolled. Corrected body height was used to calculate pulmonary parameters according to the Global Lung Function (GLI 2012) reference values. Significantly higher values of the calculated predicted pulmonary parameters and the upper and lower limit of normal (ULN and LLN), as well as significantly higher absolute values of forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1), were observed in boys than girls; however, the registered FVC and FEV1, expressed as percentages of the predicted values, tended to be lower in boys. The FEV1 z-score difference between boys and girls may suggest a need for more intensive preoperative pulmonary rehabilitation in boys.

The Influence of Surgical Correction of Idiopathic Scoliosis on the Function of Respiratory Muscles

Background and objective: It is important to introduce respiratory exercises to the therapy of patients after the surgical treatment of adolescent idiopathic scoliosis. Surgical correction is the best way to prevent hypoxia in scoliosis, but whether pulmonary rehabilitation increases the effectiveness of scoliosis surgery has not yet been confirmed. Therefore, the aim of the study was to evaluate the function of respiratory muscles after surgical correction of idiopathic scoliosis. Methods: The study involved 24 patients, aged 13.6 ± 0.6. Maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) were measured using the Mikro RPM. In all patients, before the procedure, 7 days after and 3 months after the procedure, the MIP and MEP were measured. Results: MIP was the lowest 7 days after the procedure; it was 45.28 cmH2O and was statistically significantly lower compared to the measurement before the procedure (p < 0.001) and 3 months after the procedure (p < 0.001). Conclusions: The degree of curvature of the spine before the procedure does not significantly affect initial values of the strength of respiratory muscles. The level of MIP is not dependent on the type of surgery.

Does exercise therapy improve pulmonary function in patients with Adolescent Idiopathic Scoliosis?

INTRODUCTION

Exercise therapy is frequently used for treating patients with Adolescent Idiopathic Scoliosis (AIS) however no previous review has evaluated the effect of exercise therapy on pulmonary function in this population.

OBJECTIVE

To systematically analyze the literature on the effect of exercise therapy on pulmonary function in patients with AIS.

METHODS

A systematic electronic database search (CINAHL, Embase, Medline, Web of Science) was conducted. Manual searches of key reviews and studies were also conducted. Studies that included exercise-based interventions to improve pulmonary function in patients with AIS and reported pre- and post-intervention pulmonary function test scores were included. Test scores were compared using standardized mean difference (SMD) between intervention and control groups in randomized control trials (RCT) and mean ± SD between pre- and post-intervention in prospective intervention studies (PI). Methodological quality was assessed using a modified Downs and Black checklist.

RESULTS

Fifteen studies met the inclusion criteria (six RCTs and nine PIs). Results indicated the positive effect of exercise-based therapy on lung volumes (FVC/VC) and FEV₁ in patients with AIS.

CONCLUSION

Exercise therapy has a positive effect on lung volumes in patients with AIS. The quality of many studies was only 'fair,' therefore more suitably powered higher level clinical trials are required.

Evaluation of the Parameters Affecting Respiratory Functions at Adolescent Idiopathic Scoliosis Patients

STUDY DESIGN

This was a retrospective observational study.

OBJECTIVE

The objective of the study was to evaluate the spinal and extraspinal factors responsible for pulmonary dysfunction in adolescent idiopathic scoliosis patients.

SUMMARY OF BACKGROUND DATA

Development of thoracic deformity due to scoliosis results with the restrictive ventilatory pattern and the reduced pulmonary function. To prevent pulmonary function deterioration, it is imperative to understand which factors are causing the restrictive lung disease in adolescent idiopathic scoliosis patients.

MATERIALS AND METHODS

An online database search was conducted in a hospital computerized archive between 2008 and 2018 years. Cobb angle of >30 degrees, Lenke type 1 and 2 patients treated in a single spine unit were included. Coronal and sagittal Cobb angle, bending correction rate for evaluation of flexibility, Risser score, apical vertebra rotation (AVR), and pulmonary function test of patients were obtained.

RESULTS

There was a moderate negative correlation between forced expiratory volume in the first second, forced vital capacity, and AVR. There was no correlation between forced expiratory volume in the first second and forced vital capacity with age, sex, Cobb angle, Risser score, kyphosis, and bending correction rate.

CONCLUSIONS

When considering the results of the current study and the other studies in the literature there is not any strong correlation between the features of scoliotic curvature and respiratory functions. In the current study, 52 (72.22%) of 72 patients with moderate to severe scoliosis had mild to severe respiratory dysfunction. Considering the age-related physiological respiratory loss, to evaluate the necessity of surgical treatment in patients with moderate and severe scoliosis, especially in patients with high AVR, the respiratory functions of the patient should also be evaluated.

LEVEL OF EVIDENCE

Level III.

Spirometry Examination of Adolescents with Thoracic Idiopathic Scoliosis: Is Correction for Height Loss Useful?

Loss of body height is observed in patients with idiopathic scoliosis (IS) due to spine curvatures. The study compared pulmonary parameters obtained from spirometry examination considering the measured versus the corrected body height. One hundred and twenty adolescents with Lenke type 1 or 3 IS who underwent preoperative spirometry examination and radiographic evaluation were enrolled. The mean thoracic Cobb angle was 68° ± 12.6, range 48-102°. The difference between the measured and the corrected body height increased with the greater Cobb angle. Using the corrected body height instead of the measured body height significantly changed the predicted values of pulmonary parameters and influenced the interpretation of the pulmonary testing results.

Rapid Improvement of Severe Pulmonary Hypertension Due to Scoliosis-related Restrictive Ventilatory Disorder

Few reports have highlighted the serial changes in pulmonary hypertension during respiratory management. An 18-year-old girl with severe scoliosis was referred to our hospital for worsening dyspnea on exertion. Based on chest X-ray and transthoracic echocardiography findings showing a tricuspid regurgitation pressure gradient (TRPG) of 64 mmHg, the patient was diagnosed with severe alveolar hypoventilation due to thoracic deformity and severe pulmonary hypertension. Her oxygenation improved rapidly under noninvasive positive pressure ventilation, although partial pressure of carbon dioxide remained >80 Torr. Transthoracic echocardiography on day 7 showed clinically significant and rapid improvement of pulmonary hypertension with a TRPG of 30 mmHg.

Immediate Effects of Sforzesco® Bracing on Respiratory Function in Adolescents with Idiopathic Scoliosis

The thoraco-lumbar bracing is an effective management of adolescent idiopathic scoliosis (AIS). Studies have shown that brace wearing reduces lung volume. Whether or not the Sforzesco brace, frequently used in Italy, affects lung volume has not been investigated. We studied the immediate effect of Sforzesco bracing on lung volumes in 11 AIS patients (10 F, 1 M; aged 13.6 ± 1.6 yrs) mean Cobb angle 26 ± 4.49 degrees. Lung function variables and the perceived respiratory effort were recorded twice, before and 5 min after bracing. The one-way analysis of variance repeated measures, and multiple comparison tests, showed that means of unbraced variables were not significantly different from the corresponding means of predicted values, whereas means under brace were significantly lower (p < 0.05) compared to both predicted and baseline values of respiratory variables. In addition, a significant correlation (p < 0.0001) was found between unbraced and braced values, and linear regression equations were calculated. A significant but clinically unimportant increase in perceived effort was observed under the brace. In conclusion, data indicate that lung function is not impaired in moderate AIS and that wearing the Sforzesco brace causes an immediate, predictable reduction of lung volumes. Data also suggest that the respiratory discomfort during brace wearing could not be due to respiratory function defects.

Morphological patterns of the rib cage and lung in the healthy and adolescent idiopathic scoliosis

The morphology of the rib cage affects both the biomechanics of the upper body's musculoskeletal structure and the respiratory mechanics. This becomes particularly important when evaluating skeletal deformities, as in adolescent idiopathic scoliosis (AIS). The aim of this study was to identify morphological characteristics of the rib cage in relation to the lung in patients with non‐deformed and scoliotic spines. Computed tomography data of 40 patients without any visible spinal abnormalities (healthy group) and 21 patients with AIS were obtained retrospectively. All bony structures as well as the right and left lung were reconstructed using image segmentation. Morphological parameters were calculated based on the distances between characteristic morphological landmarks. These parameters included the rib position, length, and area, the rib cage depth and width, and the rib inclination angle on either side, as well as the spinal height and length. Furthermore, we determined the left and right lung volumes, and the area of contact between the rib cage and lung. Differences between healthy and scoliotic spines were statistically analysed using the t‐test for unpaired data. The rib cage of the AIS group was significantly deformed in the dorso‐ventral and medio‐lateral directions. The anatomical proximity of the lung to the ribs was nearly symmetrical in the healthy group. By contrast, within the AIS group, the lung covered a significantly greater area on the left side of the rib cage at large thoracic deformities. Within the levels T1–T6, no significant difference in the rib length, depth to width relationship, or area was observed between the healthy and AIS groups. Inferior to the lung (T7–T12), these parameters exhibited greater variability. The ratio between the width of the rib cage at T6 and the thoracic spinal height (T1–T12) was significantly increased within the thoracic AIS group (1.1 ± 0.08) compared with the healthy group (1.0 ± 0.05). No statistical differences were found between the lung volumes among all the groups. While the rib cage was frequently strongly deformed in the AIS group, the lung and its surrounding ribs appeared to be normally developed. The observed rib hump in AIS appeared to be formed particularly by a more ventral position of the ribs on the concave side. Furthermore, the rib cage width to spinal height ratio suggested that the spinal height of the thoracic AIS‐spine is reduced. This indicates that the spine would gain its growth‐related height after correcting the spinal deformity. These are the important aspects to consider in the aetiology research and orthopaedic treatment of AIS.

Effect of curve location on the severity index for adolescent idiopathic scoliosis: a longitudinal cohort study

OBJECTIVES

Adolescent idiopathic scoliosis (AIS) is the most common spinal disorder in children. A severity index was recently proposed to identify the stable from the progressive scoliosis at the first standardized biplanar radiographic exam. The aim of this work was to extend the validation of the severity index and to determine if curve location influences its predictive capabilities.

METHODS

AIS patients with Cobb angle between 10° and 25°, Risser 0-2, and no previous treatment were included. They underwent standing biplanar radiography and 3D reconstruction of the spine and pelvis, which allowed to calculate their severity index. Patients were grouped by curve location (thoracic, thoracolumbar, lumbar). Patients were followed up until skeletal maturity (Risser ≥ 3) or brace prescription. Their outcome was compared to the prediction made by the severity index.

RESULTS

In total, 205 AIS patients were included; 82% of them (155/189, 95% confidence interval [74-90%]) were correctly classified by the index, while 16 patients were unclassified. Positive predictive ratio was 78% and negative predictive ratio was 86%. Specificity (78%) was not significantly affected by curve location, while patients with thoracic and lumbar curves showed higher sensitivity (≥ 89%) than those with thoracolumbar curves (74%).

CONCLUSIONS

In this multicentric cohort of 205 patients, the severity index was used to predict the risk of progression from mild to moderate scoliosis, with similar results of typical major curve types. This index represents a novel tool to aid the clinician and the patient in the modulation of the follow-up and, for progressive patients, their decision for brace treatment.

KEY POINTS

• The severity index of adolescent idiopathic scoliosis has the potential to detect patients with progressive scoliosis as early as the first exam. • Out of 205 patients, 82% were correctly classified as either stable or progressive by the severity index. • The location of the main curve had small effect on the predictive capability of the index.

The radiographic, pulmonary, and clinical outcomes of patients with severe rigid spinal deformities treated via halo-pelvic traction

Background

The severe rigid deformity patients with pulmonary dysfunction could not tolerate complicated corrective surgery. Preoperative traction are used to reduce the curve magnitude and improve the pulmonary function before surgery, including halo-gravity traction (HGT) and halo-pelvic traction (HPT). The present study aimed to retrospectively compare the radiographic, pulmonary and clinical outcomes of preoperative HGT and HPT in severe rigid spinal deformity with respiratory dysfunction.

Methods

81 cases of severe rigid kyphoscoliosis treated with preoperative traction prior to corrective surgery for spinal deformity between 2016 and 2019 were retrospectively reviewed. Two patient groups were compared, HPT group (N = 30) and HGT group (N = 51). Patient demographics, coronal and sagittal Cobb angles and correction rates, pulmonary function, traction time, osteotomy grade, and postoperative neurological complications were recorded for all cases.

Results

The coronal Cobb angle was corrected from 140.67 ± 2.63 to a mean of 120.17 ± 2.93° in the HGT group, and from 132.32 ± 4.96 to 87.59 ± 3.01° in the HPT group (mean corrections 15.33 ± 1.53 vs. 34.86 ± 3.11 %) (P = 0.001). The mean major sagittal curve decreased from 134.28 ± 3.77 to 113.03 ± 4.57° in the HGT group and from 129.60 ± 8.45 to 65.61 ± 7.86° in the HPT group (P < 0.001); the mean percentage corrections were 16.50 ± 2.13 and 44.09 ± 9.78 % (P < 0.001). A significant difference in the pulmonary function test results was apparent between the two groups; the mean improvements in the FVC% of the HGT and HPT groups were 6.76 ± 1.85 and 15.6 ± 3.47 % (P = 0.024). The HPT group tended to exhibit more FEV% improvement than the HGT group, but the difference was not significant (5.15 ± 2.27 vs. 11.76 ± 2.22 %, P = 0.91).

Conclusions

Patients with severe rigid kyphoscoliosis who underwent preoperative HPT exhibited better radiographic correction of the deformity, and pulmonary function, and required fewer osteotomies compared to the HGT group. Thus, HPT may be useful for severe rigid spinal deformity patients with pulmonary dysfunction.

Management of Rare Causes of Pediatric Chronic Respiratory Failure

The need for long-term noninvasive positive pressure ventilation (NiPPV) in children with chronic respiratory failure is rapidly growing. This article reviews pediatric-specific considerations of NiPPV therapy. Indications for NiPPV therapy can be categorized by the cause of the respiratory failure: (1) upper airway obstruction, (2) musculoskeletal and/or neuromuscular disease, (3) lower respiratory tract diseases, and (4) control of breathing abnormalities. The role of NiPPV therapy in select rare conditions (spinal muscular atrophy, congenital central hypoventilation syndrome, cerebral palsy, scoliosis, and Chiari malformations) is also reviewed.

Comparison of Pulmonary Function After Selective Anterior Versus Posterior Fusion for the Correction of Thoracolumbar and Lumbar Adolescent Idiopathic Scoliosis

STUDY DESIGN

Retrospective multicenter study.

OBJECTIVES

To compare the selective anterior spinal fusion (ASF) versus posterior spinal fusion (PSF) on postoperative pulmonary function testing (PFT) whether thoracotomy with separation of the diaphragm by anterior approach influences the PFT in thoracolumbar and lumbar adolescent idiopathic scoliosis (AIS).

METHODS

A multicenter series of AIS patients who underwent selective spinal fusion were retrospectively reviewed. Seventy-nine female patients were included (mean 15.8 years). There were 35 patients in the ASF group and 44 patients in the PSF group. Patient demographics, radiographic measurements, and PFT data from preoperative to 2-year follow-up were analyzed.

RESULTS

Preoperatively, there were no significant differences in PFTs between the groups. The ASF group patients were more likely to undergo shorter fusions (4.5 instrumented vertebral levels) than those in the PSF group (5.2 levels). At 2-year follow-up, forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV₁) in ASF group were statistically lower than those in PSF group. When comparing preoperative and 2-year changes on each procedure, only %FVC showed significant difference in ASF while FVC, FEV₁, and %FEV₁ did not. Meanwhile, the ASF group showed a significant decrease in FVC at 6 and 12 months compared to preoperative values. In PSF group, there was a decrease at 6 months, returned to preoperative value at 1-year follow-up.

CONCLUSIONS

Pulmonary function after ASF and PSF was similar at 2 years; however, anterior group did not return to the baseline at 6 months and 1 year suggesting anterior approach may affect early postoperative pulmonary function.

Preoperative Pulmonary Function Test Results Are Not Associated With Postoperative Intubation in Children Undergoing Posterior Spinal Fusion for Scoliosis: A Retrospective Observational Study

BACKGROUND

Preoperative pulmonary function tests are routinely obtained in children with scoliosis undergoing posterior spinal fusion despite unclear benefits as a perioperative risk assessment tool and frequent inability of patients to provide acceptable results. The goal of this study was to determine whether preoperative pulmonary function test results are associated with the need for postoperative intubation or intensive care unit admission after posterior spinal fusion.

METHODS

The electronic medical records of patients who underwent posterior spinal fusion at a pediatric tertiary hospital between June 2012 and August 2017 were reviewed. Pulmonary function tests were consistently ordered for all patients, unless the patient was deemed unable to perform the test due to cognitive disability. Cases were categorized as primary or secondary scoliosis.Demographic data, preoperative bilevel positive airway pressure use, Cobb angle, intraoperative allogeneic blood transfusion, and ability to produce acceptable pulmonary function test results were collected for each patient. In patients with satisfactory pulmonary function test results, forced vital capacity and maximum inspiratory pressure were collected. Primary outcomes for analysis were postoperative intubation and intensive care unit admission. Univariable logistic regression models were used to assess the association between each variable of interest and the primary outcomes.

RESULTS

The study sample included 433 patients, 288 with primary scoliosis and 145 with secondary scoliosis. Among patients with primary scoliosis, 90% were able to produce acceptable pulmonary function test results, zero remained intubated postoperatively, and 6 were admitted to the intensive care unit. Among patients with secondary scoliosis, 44% could not attempt pulmonary function tests. Among those who did attempt the test, 30% were unable to produce meaningful results. Forced vital capacity and maximum inspiratory pressure were not found to be associated with postoperative intubation or intensive care unit admission. Weight, Cobb angle, intraoperative blood transfusion, American Society of Anesthesiologists physical status classification, and preoperative bilevel positive airway pressure use were associated with patient outcomes. Among 357 total patients who attempted pulmonary function tests, 37 had high-risk results. Only 1 of these 37 patients remained intubated postoperatively.

CONCLUSIONS

Patients undergoing posterior spinal fusion, especially those with secondary scoliosis, are frequently unable to adequately perform pulmonary function tests. Among patients with interpretable pulmonary function tests, there was no association between results and postoperative intubation or intensive care unit admission. Routine pulmonary function testing for all patients with scoliosis may not be indicated for purposes of risk assessment before posterior spinal fusion. Clinicians should consider a targeted approach and limit pulmonary function tests to patients for whom results may guide preoperative optimization as this may improve outcomes and reduce inefficiencies and costs.

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

QUESTION

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

DESIGN

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

PARTICIPANTS

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

INTERVENTION

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

OUTCOME MEASURES

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION

NCT02413788.

A Comparison of Maximal Voluntary Ventilation and Forced Vital Capacity in Adolescent Idiopathic Scoliosis Patients

STUDY DESIGN

Prospective, single center.

OBJECTIVE

To compare maximal voluntary ventilation (MVV) and forced vital capacity (FVC) testing in the outpatient scoliosis clinic to determine their relative feasibility and sensitivity in assessing pulmonary function in the AIS population.

SUMMARY OF BACKGROUND DATA

Evidence of compromised pulmonary function in patients with severe AIS is well established. The American Thoracic Society (ATS) has established criteria for the reliability and accuracy of pulmonary function tests (PFTs), including MVV and FVC.

METHODS

A total of 91 AIS patients with thoracic curves of 20° or greater were enrolled in the orthopedic clinic. Patients performed PFTs using the CareFusion MicroLoop Spirometer. MVV and FVC values were collected. Results were considered reliable or "passing" when ATS spirometer guidelines were met.

RESULTS

Eighty-seven of the 91 patients (96%) met ATS criteria for the MVV test and 43 of the 91 patients (47%) met criteria for the FVC test. Both MVV (r = -0.41, p < .01) and FVC (r = -0.37, p = .01) were significantly correlated with thoracic Cobb angle. The percentile predicted (%predicted) MVV (r = -0.24, p = .03) and %predicted FVC (r = -0.32, p = .04) were also significantly correlated with thoracic Cobb angle. Of those who passed both tests (42/91 patients), 26% had abnormal MVV results with normal FVC results, and 5% had abnormal FVC results with normal MVV results.

CONCLUSION

MVV and FVC correlated closely with Cobb angle. Twice as many AIS patients could perform an MVV test compared with an FVC test. MVV seems to be a more practical and sensitive PFT than FVC for assessing the pulmonary function of AIS patients in the orthopedic clinic setting.

LEVEL OF EVIDENCE

Level II.

The valuation of concave-side thoracoplasty on the treatment of extremely severe scoliosis with severe pulmonary dysfunction on the base of halo-pelvic traction

Extremely severe scoliosis patients, especially main thoracic Cobb' s angle >150°, often have severe thoracic deformity and pulmonary dysfunction, even the scoliosis is reduced by halo-pelvic traction, the improvement of pulmonary function is not satisfactory, the risk of spinal osteotomy in the next stage is still very high and left with obvious thoracic deformity. How to further improve the pulmonary function and appearance of these patients is a difficult problem to be solved.Twenty extremely severe scoliosis patients with severe pulmonary dysfunction who underwent concave-side thoracoplasty in our hospital from September 2014 to September 2017 were included, data of thoracic volume and pulmonary function were collected before and after operation. The pulmonary function value reported was predicted forced vital capacity (FVC%), T-test was used to analyze the changes of the data by the statistical software SPSS21.0.The 20 patient's averaged Cobb's angle of main thoracic was 163° ± 8° at admission and all of them with severe pulmonary dysfunction before concave-side thracoplasty. After operation, the thoracic volume of patients increased by 500.9 ± 222.9 mL, FVC% increased by 8.9% ± 7.5%. Both the difference has statistical significance (P < .01).Concave-side thoracoplasty based on the halo-pelvic traction cannot only enlarge the volume of the concave thoracic cavity, lighten the compression of lung and further improve the pulmonary function of extremely severe scoliosis, but also can strengthen the correction of scoliosis and spinal rotation. Therefore, it is a safe and effective surgical approach.

Progressive decline in pulmonary function 5 years post-operatively in patients who underwent anterior instrumentation for surgical correction of adolescent idiopathic scoliosis

PURPOSE

To evaluate changes in pulmonary function tests (PFT) at 5 years post-operatively in patients with adolescent idiopathic scoliosis (AIS) and to determine whether these changes are progressive or static after 2 years.

METHODS

AIS surgical patients with pre-operative and 5 year post-operative forced expiratory volume (FEV) and forced vital capacity (FVC) were included. The percentage of patients with pulmonary impairment at 5 years was calculated. Repeated measures ANOVA was used to evaluate changes between pre-operative PFT and 5 years post-operative PFT and to determine whether the changes differed between curve types and approach. A sub-analysis of patients with 2 year data was performed to determine whether PFT changes were static or progressive.

RESULTS

Two hundred and sixty-two patients had undergone pre-operative and 5 year post-operative PFTs. At 5 years, 42% were normal, 41% had mild impairment, and 17% had moderate-severe impairment. Overall, there was a decline in % predicted FVC (p < 0.05); FEV remained stable. There was no difference based on major curve type (p > 0.05). Anterior instrumentation cases declined significantly between pre-operative PFT and 5 years post-operative PFT (FEV: - 10% open, - 6% thoracoscopic; FVC: - 13% open, - 8% thoracoscopic) (p ≤ 0.02). The posterior cases remained stable (2% FEV, p = 0.7; - 0.6% FVC, p = 0.06). A subgroup of 90 patients with 2 year post-operative PFTs demonstrated that changes were progressive between 2 and 5 years post-operatively. The average change in FVC from 2 to 5 years was significantly different between the anterior open (- 9%) and posterior-only (0.7%) groups (p = 0.015).

CONCLUSION

In patients who underwent anterior instrumentation, PFTs declined from the pre-operative to the 5 years post-operative time point. There was a progressive decline of 4-10% beyond 2 years post-operatively. Patients who underwent posterior instrumentation remained stable. These slides can be retrieved under Electronic Supplementary Material.

Correction of Paradoxical Ribcage Motion in Scoliosis by Noninvasive Ventilation

STUDY DESIGN

Observational study of ribcage motion in scoliosis.

OBJECTIVE

To see whether noninvasive ventilation corrected paradoxical inward motion of the ribs during inspiration.

SUMMARY OF BACKGROUND DATA

Paradoxical inward motion of the ribs is observed after rib fractures, low cervical cord injury, and in chronic obstructive pulmonary disease. It is not well recognized in scoliosis and the mechanism in this group has not been studied.

METHODS

Linearized magnetometers were used to measure the diameter of the ribcage. Changes in diameter during tidal breathing were recorded during spontaneous ventilation and noninvasive ventilation in 10 subjects with idiopathic or congenital thoracic scoliosis.

RESULTS

During spontaneous breathing, the median change in ribcage diameter during inspiration was -1.5 (range -2.3 to -0.8) cm. The median change in ribcage diameter during noninvasive ventilation was +0.5 (range -1.1 to +1.2) cm. Noninvasive ventilation improved paradoxical motion in all subjects, completely correcting it in six.

CONCLUSION

Paradoxical inward motion of the ribcage is seen in some subjects with severe scoliosis. This abnormal motion is improved or abolished by noninvasive ventilation. Since noninvasive ventilation takes over the work of breathing from the respiratory muscles, we suggest that inspiratory muscle contraction causes distortion of part of the ribcage in scoliosis, probably because of the abnormal orientation of diaphragmatic muscle fibers.

LEVEL OF EVIDENCE

2.

2016 SOSORT guidelines: orthopaedic and rehabilitation treatment of idiopathic scoliosis during growth

BACKGROUND

The International Scientific Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT) produced its first guidelines in 2005 and renewed them in 2011. Recently published high-quality clinical trials on the effect of conservative treatment approaches (braces and exercises) for idiopathic scoliosis prompted us to update the last guidelines' version. The objective was to align the guidelines with the new scientific evidence to assure faster knowledge transfer into clinical practice of conservative treatment for idiopathic scoliosis (CTIS).

METHODS

Physicians, researchers and allied health practitioners working in the area of CTIS were involved in the development of the 2016 guidelines. Multiple literature reviews reviewing the evidence on CTIS (assessment, bracing, physiotherapy, physiotherapeutic scoliosis-specific exercises (PSSE) and other CTIS) were conducted. Documents, recommendations and practical approach flow charts were developed using a Delphi procedure. The process was completed with the Consensus Session held during the first combined SOSORT/IRSSD Meeting held in Banff, Canada, in May 2016.

RESULTS

The contents of the new 2016 guidelines include the following: background on idiopathic scoliosis, description of CTIS approaches for various populations with flow-charts for clinical practice, as well as literature reviews and recommendations on assessment, bracing, PSSE and other CTIS. The present guidelines include a total of 68 recommendations divided into following topics: bracing (n = 25), PSSE to prevent scoliosis progression during growth (n = 12), PSSE during brace treatment and surgical therapy (n = 6), other conservative treatments (n = 2), respiratory function and exercises (n = 3), general sport activities (n = 6); and assessment (n = 14). According to the agreed strength and level of evidence rating scale, there were 2 recommendations on bracing and 1 recommendation on PSSE that reached level of recommendation "I" and level of evidence "II". Three recommendations reached strength of recommendation A based on the level of evidence I (2 for bracing and one for assessment); 39 recommendations reached strength of recommendation B (20 for bracing, 13 for PSSE, and 6 for assessment).The number of paper for each level of evidence for each treatment is shown in Table 8.

CONCLUSION

The 2016 SOSORT guidelines were developed based on the current evidence on CTIS. Over the last 5 years, high-quality evidence has started to emerge, particularly in the areas of efficacy of bracing (one large multicentre trial) and PSSE (three single-centre randomized controlled trials). Several grade A recommendations were presented. Despite the growing high-quality evidence, the heterogeneity of the study protocols limits generalizability of the recommendations. There is a need for standardization of research methods of conservative treatment effectiveness, as recognized by SOSORT and the Scoliosis Research Society (SRS) non-operative management Committee.

Adolescent Idiopathic Scoliosis Thoracic Volume Modeling: The Effect of Surgical Correction

BACKGROUND

Scoliosis has been shown to have detrimental effects on pulmonary function, traditionally measured by pulmonary function tests, which is theorized to be correlated to the distortion of the spine and thorax. The changes in thoracic volume with surgical correction have not been well quantified. This study seeks to define the effect of surgical correction on thoracic volume in patients with adolescent idiopathic scoliosis.

METHODS

Images were obtained from adolescents with idiopathic scoliosis enrolled in a multicenter database (Prospective Pediatric Scoliosis Study). A convenience sample of patients with Lenke type 1 curves with a complete data set meeting specific parameters was used. Blender v2.63a software was used to construct a 3-dimensional (3D) computational model of the spine from 2-dimensional calibrated radiographs. To accomplish this, the 3D thorax model was deformed to match the calibrated radiographs. The thorax volume was then calculated in cubic centimeters using Mimics v15 software.

RESULTS

The results using this computational modeling technique demonstrated that surgical correction resulted in decreased curve measurement as determined by Cobb method, and increased postoperative thoracic volume as expected. Thoracic volume significantly increased by a mean of 567 mm (P<0.001). The percent change in thoracic volume after surgical correction averaged 40% (range, 3% to 87%). The smaller the baseline volume, the greater the change in volume postoperatively (r=-0.86).Evaluation of postoperative data demonstrated that spinal curve measurement as determined by Cobb method was significantly reduced from a mean of 69 degrees (range, 50 to 96 degrees) preoperatively to 27 degrees (range, 13 to 33 degrees) postoperatively (P<0.001).

CONCLUSIONS

This pilot study demonstrates methodologic plausibility for measuring 3D changes in thoracic volumes using 2-dimensional imaging. This is an assessment of the novel modeling technique, to be used in larger future studies to assess clinical significance.

LEVEL OF EVIDENCE

Level 3-retrospective comparison of prospectively collected data.

Maximal Respiratory Muscle Strength and Vital Capacity in Children With Early Onset Scoliosis

STUDY DESIGN

Descriptive cross-sectional study.

OBJECTIVE

To measure respiratory muscle function in children with early onset scoliosis (EOS), determine the frequency of respiratory muscle weakness, and correlate these measures with vital capacity, body mass index, and Cobb angle.

SUMMARY OF BACKGROUND DATA

Progressive restrictive respiratory disease is common among children with moderate to severe EOS. Reduced respiratory muscle strength is associated with the loss of lung function in adolescents and adults with scoliosis. We hypothesized that reduced inspiratory and expiratory respiratory muscle strength also occur in children with EOS and correlate with reduced vital capacity, poor nutritional status, and severity of the spine deformity.

METHODS

We measured maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), forced vital capacity (FVC), body mass index IBMI), and Cobb angle in 49 children with EOS but with no diagnosis of underlying muscle weakness. We measured these indices in 12 children serially over 18 months to see if abnormal respiratory muscle function was sustained.

RESULTS

FVC averaged 51% (SD 21) of predicted norms with 26 subjects having an FVC <50% predicted. The mean MIP was 57% (SD 25) and the mean MEP was 53% (SD 23) of predicted norms. Thirteen (27%) of the group had MIP values >2SD below the age and sex-based norms. BMI ranged between 1% and 99% of age-based norms. Cobb angle averaged 59° (SD27). MIP% and MEP% significantly correlated with FVC% (r =0.37, P = 0.01 and r = 0.52, P < 0.001 respectively)) but not with BMI or Cobb angle. Reduced MIP% and MEP% were sustained over 7 to 41 months.

CONCLUSION

Respiratory muscle weakness is common and persistent in children with EOS and correlates with reductions in vital capacity. Mechanisms for abnormal respiratory function are unclear but must be determined to develop surgical treatment strategies that preserve respiratory muscle function in children with EOS throughout childhood.

LEVEL OF EVIDENCE

2.

How Is Pulmonary Function and Exercise Tolerance Affected in Patients With AIS Who Have Undergone Spinal Fusion?

STUDY DESIGN

Prospectively enrolled AIS patients who underwent spinal fusion, with 2 year follow-up.

OBJECTIVES

To evaluate the cardiovascular fitness and activity level in patients with AIS pre- and post-spinal fusion and to determine if initial curve magnitude or pulmonary function is predictive of exercise capacity.

SUMMARY OF BACKGROUND DATA

Researchers have tried to link pulmonary function testing (PFT) to exercise capacity; the results are mixed. Some report no improvement in PFTs or aerobic activity after surgical correction, and PFT measures were not predictive of exercise capacity. Conflicting results have shown Vo_2max results to fall within normal range in AIS patients while PFTs show minimal impairment.

METHODS

AIS patients underwent PFT and oxygen consumption (VO₂) testing during a submaximal graded exercise test (GXT) pre- and post-spinal fusion. Vo_2max was predicted in those patients who completed the test to 85% of maximal heart rate. Pre- to postoperative changes were assessed and then compared to age-matched control subjects. Correlations between Vo_2max and curve severity, pulmonary function, and activity level were assessed.

RESULTS

Thirty-seven patients participated. Vo_2max was predicted in 23 patients pre- and postoperation. There was a significant reduction in Vo_2max postfusion (39.5 ± 6.5 mL/kg/min vs 42.1 ± 8.1 mL/kg/min, p = .033); however, compared with controls (40.5 ± 6.5 mL/kg/min), all data were within the normal range (p > .05). AIS patients reporting high activity had significantly greater Vo_2max than those reporting low activity both pre and postoperatively, but this difference only met statistical significance preop (p < .05). Curve magnitude and PFT measures were not found to correlate with Vo_2max (p > .05).

CONCLUSIONS

Vo_2max in patients with AIS is within normal range both pre- and postfusion. Pulmonary limitations are accommodated for with a slightly increased breathing rate and a slightly reduced overall workload. Activity level rather than curve severity affects Vo_2max outcomes following fusion in AIS.

Relationship between pulmonary function and degree of spinal deformity, location of apical vertebrae and age among adolescent idiopathic scoliosis patients

INTRODUCTION

This retrospective review aimed to examine the relationship between preoperative pulmonary function and the Cobb angle, location of apical vertebrae and age in adolescent idiopathic scoliosis (AIS). To our knowledge, there have been no detailed analyses of preoperative pulmonary function in relation to these three factors in AIS.

METHODS

A total of 38 patients with thoracic or thoracolumbar scoliosis were included. Curvature of spinal deformity was measured using the Cobb method. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were used to evaluate preoperative pulmonary function. Statistical methods were used to analyse the relationship between preoperative pulmonary function and the factors that may contribute to poor pulmonary function.

RESULTS

The mean age of the patients was 16.68 ± 6.04 years. An inverse relationship was found between the degree of the Cobb angle and FVC as well as FEV1; however, the relationships were not statistically significant (p = 0.057 and p = 0.072, respectively). There was also a trend towards a significant negative correlation between the thoracic curve and FVC (p = 0.014). Patients with larger thoracic curves had lower pulmonary function. A one-year increase in age significantly decreased FVC by 1.092 units (p = 0.044). No significant relationship between age and preoperative FEV1 was found. The median FVC was significantly higher in patients with affected apical vertebrae located at levels L1-L3 than at T6-T8 or T9-T12 (p = 0.006).

CONCLUSION

Lung function impairment was seen in more severe spinal deformities, proximally-located curvature and older patients.

Gait and energy consumption in adolescent idiopathic scoliosis: A literature review

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is a progressive growth disease that affects spinal anatomy, mobility, and left-right trunk symmetry. The disease can modify human gait.

OBJECTIVE

We aimed to review articles describing the measurement of gait parameters and energy consumption in AIS during walking without any intervention.

STUDY DESIGN

Literature review.

METHODS

The search strategy was based on the Population Intervention Comparison Outcome method and included all relevant articles published from 1996 to 2015. Articles were searched in MEDLINE via PubMed, Science Direct, Google Scholar, and ISI Web of Knowledge databases.

RESULTS

We selected 33 studies investigating the effect of scoliosis deformity on gait parameters and energy expenditure during walking. Most of the studies concluded no significant differences in walking speed, cadence and step width in scoliosis patients and normal participants. However, patients showed decreased hip and pelvic motion, excessive energy cost of walking, stepping pattern asymmetry and ground reaction force asymmetry.

CONCLUSION

We lack consistent evidence of the effect of scoliosis on temporal spatial and kinematic parameters in AIS patients as compared with normal people. However, further research is needed to assess the effect of scoliosis on gait and energy consumption.

Relationship between Lung Volume and Pulmonary Function in Patients With Adolescent Idiopathic Scoliosis: Computed Tomographic-based 3-Dimensional Volumetric Reconstruction of Lung Parenchyma

STUDY DESIGN

Retrospective.

OBJECTIVES

We determined values for the volume of right lung (Vr), left lung (Vl), total lung volume (Vt), and left/right lung volume ratio (Vl/Vr), allowing comparison between those data measured and those of age-matched controls. To find whether lung volume correlates with preoperative pulmonary function.

SUMMARY OF BACKGROUND DATA

To our knowledge, no study on relationship between computed tomographic (CT) scans determined lung volume and pulmonary function test (PFT) in scoliosis have been published.

METHODS

All examinations with PFT (31 cases) were identified. Three-dimensional volumetric reconstruction of lung parenchyma was performed on existing preoperative CT scans for 26 idiopathic scoliosis patients. Vl, Vr, Vt, Vl/Vr, and absolute value of right volume minus left volume (|Vr-Vl|) were calculated and correlated with PFTs. To determine if significant difference of preoperative lung volume exists between idiopathic scoliosis patients and controls. Linear regression models, using 3-dimensional lung volume parameters as predictors for vital capacity (VC), forced vital capacity (FVC), and total lung capacity (TLC), were created.

RESULTS

Vt was positively correlated with VC, FVC, forced expiratory volume in 1 second (FEV1), TLC, predicted value for FVC (FVC%), predicted value for FEV1 (FEV1%), predicted value for TLC (TLC%), and predicted value for maximal ventilator volume (MVV%) (P<0.05); |Vr-Vl| was not correlated with ventilation parameters (P>0.05); Diffusion parameters were not correlated with CT-reconstructed lung volume parameters (P>0.05); male and female adolescent idiopathic scoliosis patients had less Vt, Vr, and Vl compared with those of age-matched controls (P<0.05).

CONCLUSIONS

Vt was positively correlated with VC, FVC, FEV1, TLC, FVC%, FEV1%, TLC%, and MVV%. Vt, Vr, and Vl of adolescent idiopathic scoliosis patients were less than those of age-matched controls.

Adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is the most common form of structural spinal deformities that have a radiological lateral Cobb angle - a measure of spinal curvature - of ≥10(°). AIS affects between 1% and 4% of adolescents in the early stages of puberty and is more common in young women than in young men. The condition occurs in otherwise healthy individuals and currently has no recognizable cause. In the past few decades, considerable progress has been made towards understanding the clinical patterns and the three-dimensional pathoanatomy of AIS. Advances in biomechanics and technology and their clinical application, supported by limited evidence-based research, have led to improvements in the safety and outcomes of surgical and non-surgical treatments. However, the definite aetiology and aetiopathogenetic mechanisms that underlie AIS are still unclear. Thus, at present, both the prevention of AIS and the treatment of its direct underlying cause are not possible.

Three-dimensional computed tomography for assessing lung morphology in adolescent idiopathic scoliosis following posterior spinal fusion surgery

OBJECTIVE

To evaluate the changes in lung morphology in subjects with adolescent idiopathic scoliosis (AIS) following posterior spinal fusion surgery.

METHODS

From April 2009 to August 2013, 30 AIS patients (nine males and 21 females) were enrolled in this study. All scans were obtained with the patient in the supine position and the breath held in deep inspiration and performed both before and after surgery. Syngo software was used to manage the computed tomography scan imaging and to calculate the lung volume, lung height and pulmonary cross-sectional area in the apical vertebral plane.

RESULTS

Left lung, right lung and total lung volumes and convex to concave lung volume ratio did not change significantly after corrective surgery. There was a statistically significant improvement in left lung and right lung heights after posterior spinal fusion surgery. However, the pulmonary cross-sectional area in the apical vertebrae plane was smaller postoperatively than preoperatively.

CONCLUSIONS

This study showed that lung height in AIS patients increased significantly immediately postoperatively whereas lung volume did not change significantly. Thoracic symmetry was improved postoperatively in these patients.

Scoliosis and chest cage deformity measures predicting impairments in pulmonary function: a cross-sectional study of 492 patients with scoliosis to improve the early identification of patients at risk

STUDY DESIGN

This study examines the correlations between pulmonary function tests (PFTs) and radiographical measures of spinal deformities in patients with scoliosis.

OBJECTIVE

To define the parameters that enable more accurate predictions of restricted pulmonary function (PF) in patients with scoliosis.

SUMMARY OF BACKGROUND DATA

The early identification of patients with scoliosis who are at risk of developing severe curve progression and restricted PF is critical to improving patient care.

METHODS

A total of 492 patients with a thoracic/thoracolumbar curve (TC) and preoperative PFTs as well as radiographical analysis of the TC and thoracic kyphosis (TK) were assessed. The forced vital capacity (FVC) was expressed as a percentage of the predicted value (FVC%). According to guidelines for the severity of pulmonary impairments, classifications were used: no impairment (FVC > 80%), mild (65 < FVC ≤ 80%), moderate (50 < FVC ≤ 65), and severe impairment (FVC ≤ 50%). Main radiographical parameters were included and statistical analyses were used to identify radiographical predictors and to develop prediction models.

RESULTS

The average age was 17 years, 94% of the patients had adolescent idiopathic scoliosis, 20% had lordoscoliosis (TK <10°). The average FVC% was 75% ± 17%, their average TC was 57° ± 21°, and TK was 26° ± 25°. A total of 38% had no impairment, 37% exhibited mild impairment, 15% had moderate impairments, and 10% were severely impaired. Spinal deformities identified by radiographical analysis (TC, TC-flexibility, apical vertebral rotation, TK, and rib hump) significantly influenced FVC% (P < 0.01). TK logistic regression analysis revealed that 2 factors are predictive for an FVC 50% or less: increased scoliosis with a low TK less than 0° (odds ratio = 7.3) or a high TK more than 60° (odds ratio = 20). A model for predicting FVC values more than 50% was established and shown to achieve a correct classification rate of 94%.

CONCLUSION

Patients with increasing coronal and sagittal plane deformities with a high thoracic scoliosis apex are at the highest risk for reduced FVC%. The models developed provided improved estimations of actual PF based on the magnitude of the radiographical deformity.

Functional aerobic exercise capacity limitation in adolescent idiopathic scoliosis

BACKGROUND CONTEXT

Exercise limitation has been described in patients with adolescent idiopathic scoliosis (AIS); however, whether the walking performance is impaired in these patients should be elucidated.

PURPOSE

Thus, we aimed to evaluate the physiologic responses to the incremental shuttle walk test (ISWT) in patients with AIS.

STUDY DESIGN/SETTING

Cross-sectional study.

PATIENT SAMPLE

Twenty-nine patients with AIS and 20 healthy adolescents aged between 11 and 18 years old.

OUTCOME MEASURES

Oxygen uptake (VO₂), incremental shuttle walk distance (ISWD), ΔVO₂/Δwalking velocity, ΔHR/ΔVO₂, ΔVE/ΔVCO₂, and linearized Δtidal volume (VT)/ΔlnVE, forced expiratory volume in the first second of expiration (FEV1), and forced vital capacity (FVC).

METHODS

We performed two ISWTs, and the data used were acquired in the second test. We also evaluated the lung function and respiratory muscle strength through spirometry test and manovacuometry, respectively. All authors confirm that there are no conflicts of interest. To compare the means or medians of variables between patients and healthy subjects, we used the unpaired t test or Mann-Whitney U test, respectively. The correlations were assessed by Pearson or Spearman coefficients according to the distribution of the studied variables. The probability of alpha error was set at 5% for all analyses.

RESULTS

Adolescent idiopathic scoliosis patients showed significant lower values of ISWD, VO₂, and ventilation at the end of the ISWT, as well as lower FEV₁ and FVC; they also presented significantly shallower slope of ΔVT/ΔlnVE, whereas VO₂ related significantly with ISWD (r=0.80), FVC (r=0.78), FEV₁ (r=0.73), and ΔVT/ΔlnVE (r=0.58).

CONCLUSIONS

Adolescent idiopathic scoliosis correlated to walking limitation and was associated to reduced pulmonary function and worse breathing pattern during exercise. Our results suggest that walking-based aerobic exercises should be encouraged in these patients.

Evaluation of postoperative change in lung volume in adolescent idiopathic scoliosis: Measured by computed tomography

BACKGROUND

Change in total lung volume after surgical correction in adolescent idiopathic scoliosis (AIS), measured by computed tomography (CT), has not been studied previously. The primary objective of this study was to measure the change in lung volume between pre and postoperative AIS using low-dose CT and secondary objective was to investigate its relationship to postoperative pulmonary complications.

MATERIALS AND METHODS

55 AIS patients underwent surgery for correction and fusion using a posterior only approach and pedicle screws. Pre and postoperative lung volumes were measured using a 3-dimensional (3D) whole spine CT (low dose protocol: Tube current, 60 mA; tube voltage 120 kV). Postoperative low dose CT was undertaken at 4 weeks after operation to evaluate the acute changes of postoperative lung volumes and pulmonary complications. The software that was used recognizes the "air density shade" of the lung and the volume of every section of the lung. The software then automatically calculates total lung volume by summation of all section volumes. The relationships between postoperative pulmonary complications and changes in lung volume on low dose CT as well as preoperative forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were calculated using logistic regression analysis.

RESULTS

There was a decrease of 12% ± 23.2% in total lung volume postoperatively on 3D low dose CT (P < 0.001). Thirteen patients had increased lung volume while 42 had decreased lung volume postoperatively. Pulmonary complications were treated without severe sequale. Lung volume increased by 19.65% ± 19.84% in 13 patients and decreased by 21.85% ± 13.32% in 42 patients (P = 0.647). Lung volume was increased in patients whose preoperative lung volume, FEV1 and FVC were lower than in patients whose values were higher (r = -0.273, -0.291 and - 0.348; P = 0.044, 0.045 and 0.015, respectively). Postoperative lung volume was also increased when intraoperative fluid administration was larger and operative time was longer (r = 0.354, 0.417 and P = 0.008, 0.002, respectively). There was a statistically significant negative correlation in the change of lung volume in female patients when compared with male patients (r = -0.294, P = 0.03).

CONCLUSION

Patients with AIS who have preoperative reduced lung volumes or lung functions can achieve further increased lung volume after surgical correction. Pulmonary complications during perioperative period were mostly treated with proper management without severe sequale. Therefore, although surgery for AIS is considered to be a high risk procedure, we can recommend to correct spine deformity in patients with severe AIS in order to improve lung function and long term prognosis.

Should postoperative pulmonary function be a criterion that affects upper instrumented vertebra selection in adolescent idiopathic scoliosis surgery?

STUDY DESIGN

A multicenter, prospective evaluation of pulmonary function testing (PFT) and radiographical measures in patients surgically treated for adolescent idiopathic scoliosis (AIS).

OBJECTIVE

The objective of this study was to evaluate pulmonary function to determine whether a more proximal upper instrumented vertebra (UIV) negatively impacts pulmonary function in patients surgically treated for AIS.

SUMMARY OF BACKGROUND DATA

There seems to be increasing concern that a more proximal extent of posterior thoracic spinal instrumentation and fusion reduces postoperative pulmonary function. However, there are few reports that analyze the relation between the selection of UIV and pulmonary function in AIS.

METHODS

PFT and radiographical examination of 154 patients with major thoracic AIS (Lenke type 1-4) undergoing posterior thoracic spinal instrumentation and fusion without thoracoplasty were completed prospectively. Patients were divided into groups based on UIV (T1-T3 vs. T4-T5) and Lenke curve type (2 and 4 vs. 1 and 3) and analyzed respectively. Demographic, radiographical measurements, and PFT data from preoperative and 2-year time points were analyzed.

RESULTS

Patients with a structural upper thoracic curve (Lenke 2 and 4) had significantly lower preoperative PFT values than those without a structural upper thoracic curve (Lenke 1 and 3). Lenke 2 and 4 patients were also more likely to be fused proximally (82%, T1-T3) than those in the Lenke 1 and 3 groups (42%, T1-T3, P< 0.05). Preoperatively, those with UIV from T1 to T3 tended to have lower PFT values than those with UIV from T4-T5; however, only percent total lung capacity was statistically different (P< 0.05). Both UIV groups showed significant increases in all absolute values (forced vital capacity, forced expiratory volume in 1s, total lung capacity) at 2-year follow-up (P< 0.05) as expected with growth, and the percent predicted values (% forced vital capacity, % forced expiratory volume in 1s, % total lung capacity) remained stable.

CONCLUSION

Although patients with UIV: T1-T3 showed slightly lower PFT values than UIV: T4-T5, the presence of a double thoracic curve was the primary cause of PFT reduction in these patients. Including the upper thoracic spine in the fusion had no significant effect on pulmonary function 2 years after surgical correction of AIS.

LEVEL OF EVIDENCE

3.

Multicenter Comparison of the Factors Important in Restoring Thoracic Kyphosis During Posterior Instrumentation for Adolescent Idiopathic Scoliosis

STUDY DESIGN

Multicenter review, prospectively collected data.

OBJECTIVES

To determine factors predictive of postoperative correction of hypokyphosis when segmental posterior pedicle screw implants were used in treating thoracic adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Correcting hypokyphosis, which is common in patients with thoracic AIS, may be important in preventing junctional kyphosis, maintaining lumbar lordosis, and improving pulmonary function.

METHODS

A multicenter, prospective database was reviewed for Lenke type 1-4 AIS patients with preoperative kyphosis of 5° to 20°, treated with posterior pedicle screws and 5.5-mm rods. Surgeons with a minimum of 20 patients identified were included. Patients were divided into 2 groups postoperatively based on first erect X-rays: those remaining hypokyphotic (HK) (T5-T12 less than 20° or an increase less than 5° in T5-T12 kyphosis) and those restored to normal kyphosis (NK) (T5-T12 greater than 20° with 5° or more increase). Regression analysis was done on 5 preoperative factors thought to influence the postoperative kyphosis: preoperative kyphosis, surgeon, rod material (standard, high-strength, and ultra-high-strength steel; titanium; and cobalt chromium), implant density, and use or no use of a posterior release (Ponte osteotomies).

RESULTS

Of 280 patients included, 222 remained hypokyphotic and 53 achieved normal kyphosis. There were no differences in preoperative kyphosis (13.4° ± 5°, HK group vs. 14.5° ± 4°, NK group) and age (14.7, HK group vs. 14.6, NK group) between patients brought to greater than 20° (NK) and those who remained less than 20° (HK). Of the factors evaluated, the surgeon who performed the operation was the only significant predictor of restoration of normal kyphosis. Comparison of surgeons showed that the rate of normalizing kyphosis ranged from 6% to 42% (p = .001). There was no difference in the degree of preoperative kyphosis among surgeons.

CONCLUSIONS

Restoration of thoracic kyphosis remains a challenge in posteriorly treated thoracic AIS patients. The surgeon was the only significant predictor of restoring normal kyphosis, which emphasizes the importance of intraoperative techniques.

Neurogenic respiratory failure

It is uncommon for the lungs to be primarily involved in neurological conditions but severe respiratory problems can arise indirectly. These are usually the result of disorders of central ventilatory control, respiratory muscle weakness, or bulbar involvement. The effects of those disorders can be predicted by an understanding of the nervous control mechanisms and mechanical factors that determine effective ventilation. Awareness of these potential complications, and the increased availability of more advanced diagnostic and monitoring techniques in everyday clinical practice, has resulted in the introduction of specific treatments to try to reduce consequent morbidity and mortality.

Posterior correction of thoracic adolescent idiopathic scoliosis with pedicle screw instrumentation: results of 48 patients with minimal 10-year follow-up

PURPOSE

Since early 1990s pedicle screws in thoracic spine have been used in posterior correction of adolescent idiopathic scoliosis (AIS). Long-term results are scarce. We report clinical, radiological and pulmonary function results of 48 consecutive patients with 10-year minimal follow-up.

METHODS

Forty-eight consecutive patients (42 females, 6 males) with 41 Lenke 1 (lumbar modifier A = 19, B = 8, C = 14), 7 Lenke 2 (lumbar modifier A = 2, B = 4, C = 1) were operated for AIS from posterior with pedicle screw alone instrumentation. Risser stage at the time of operation was 0-3 in 24, more than 3 in 24 patients. Mean age was 15.3 years. The data were prospectively collected preoperatively, at 6 weeks, 2 years and 10 years postoperatively. Cobb angle, sagittal and coronal balance, distal adjacent disc angle and lowest fused vertebral tilt were documented at all time-points. Choice of fusion levels is described. Not every vertebra was instrumented with pedicle screws. The implant density was average one pedicle screw per vertebra or 50 %. Derotation and translation of apical vertebrae on the concave side were performed for correction. The overall outcome and the outcome of different curve types were analyzed statistically.

RESULTS

Lowest instrumented vertebra (LIV) was distal end vertebra in two-thirds of the patients and was one below distal end vertebra in one-third of the patients. The main thoracic curve correction was 63 %, from 58° ± 12° preoperative to 21° ± 9° at 6 weeks. The Cobb angle was 23° ± 10° at 2 years and 26° ± 10° at 10 years. The apical vertebral rotation improved 35 %, the non-instrumented lumbar curves improved 47 %, the distal adjacent disc angle decreased from 6° ± 3° preoperatively to -2° ± 4° postoperatively and the last instrumented vertebral tilt decreased from 23° ± 8° preoperatively to 5° ± 5° postoperatively. All these parameters remained stable up to 10-year follow-up. The scoliosis correction was not associated with any change in the preoperative thoracic kyphosis and lumbar lordosis. The % FVC remained unchanged with 74 ± 21 % preoperatively to 74 ± 11 % at 2 years and 75 ± 10 % at 10 years. The SRS-24 score was 93 ± 18 points at 2 years and 95 ± 22 points at 10 years. There were no neurological complications, no pedicle screw-related complications.

CONCLUSION

Posterior correction of thoracic AIS with pedicle screw instrumentation is safe and produces a long-term stable correction and high patient satisfaction. An implant density of 50 % is sufficient to achieve these results. LIV can be the distal end vertebra or one below the distal end vertebra depending on the position of the distal end vertebra to the centre sacral line. The preoperative pulmonary function does not change on long term.

Pulmonary function in children with idiopathic scoliosis

Idiopathic scoliosis, a common disorder of lateral displacement and rotation of vertebral bodies during periods of rapid somatic growth, has many effects on respiratory function. Scoliosis results in a restrictive lung disease with a multifactorial decrease in lung volumes, displaces the intrathoracic organs, impedes on the movement of ribs and affects the mechanics of the respiratory muscles. Scoliosis decreases the chest wall as well as the lung compliance and results in increased work of breathing at rest, during exercise and sleep. Pulmonary hypertension and respiratory failure may develop in severe disease. In this review the epidemiological and anatomical aspects of idiopathic scoliosis are noted, the pathophysiology and effects of idiopathic scoliosis on respiratory function are described, the pulmonary function testing including lung volumes, respiratory flow rates and airway resistance, chest wall movements, regional ventilation and perfusion, blood gases, response to exercise and sleep studies are presented. Preoperative pulmonary function testing required, as well as the effects of various surgical approaches on respiratory function are also discussed.

The impact of halo-gravity traction on curve rigidity and pulmonary function in the treatment of severe and rigid scoliosis and kyphoscoliosis: a clinical study and narrative review of the literature

INTRODUCTION

The treatment of rigid and severe scoliosis and kyphoscoliosis is a surgical challenge. Presurgical halo-gravity traction (HGT) achieves an increase in curve flexibility, a reduction in neurologic risks through gradual traction on a chronically tethered cord and an improvement in preoperative pulmonary function. However, little is known with respect to the ideal indications for HGT, its appropriate duration, or its efficacy in the treatment of rigid deformities.

MATERIALS AND METHODS

To investigate the use of HGT in severe deformities, we performed a retrospective review of 45 patients who had severe and rigid scoliosis or kyphoscoliosis. The analysis focused on the impact of HGT on curve flexibility, pulmonary function tests (PFTs), complications and surgical outcomes in a single spine centre.

RESULTS

PFTs were used to assess the predicted forced vital capacity (FVC%). The mean age of the sample was 24±14 years. 39 patients had rigid kyphoscoliosis, and 6 had scoliosis. The mean apical rotation was 3.6°±1.4°, according to the Nash and Moe grading system. The curve apices were mainly in the thoracic spine. HGT was used preoperatively in all the patients. The mean preoperative scoliosis was 106.1°±34.5°, and the mean kyphosis was 90.7°±29.7°. The instrumentation used included hybrids and pedicle screw-based constructs. In 18 patients (40%), a posterior concave thoracoplasty was performed. Preoperative PFT data were obtained for all the patients, and 24 patients had ≥3 assessments during the HGT. The difference between the first and the final PFTs during the HGT averaged 7.0±8.2% (p<.001). Concerning the evolution of pulmonary function, 30 patients had complete data sets, with the final PFT performed, on average, 24 months after the index surgery. The mean preoperative FVC% in these patients was 47.2±18%, and the FVC% at follow-up was 44.5±17% (a difference that did not reach statistical significance). The preoperative FVC% was highly predictive of the follow-up FVC% and the response during HGT. The mean flexibility of the scoliosis curve during HGT was only 14.8±11.4%, which was not significantly different from the flexibility measures achieved on bending radiographs or Cotrel traction radiographs. In rigid curves, the Cobb angle difference between the first and final radiographs during HGT was only 8°±9° for scoliosis and 7°±12° for kyphosis. Concerning surgical outcomes, 13 patients (28.9%) experienced minor and 15 (33.3%) experienced major complications. No permanent neurologic deficits or deaths occurred. Additional surgery was indicated in 12 patients (26.7%), including 7 rib-hump resections. At the final evaluation, 69% of the patients had improved coronal balance, and at a mean follow-up of 33±23.3 months, 39 patients (86.7%) were either satisfied or very satisfied with the overall outcome.

CONCLUSION

The improvement of pulmonary function and the restoration of sagittal and coronal balance are the main goals in the treatment of severe and rigid scoliosis and kyphoscoliosis. A review of the literature showed that HGT is a useful tool for selected patients. Preoperative HGT is indicated in severe curves with moderate to severe pulmonary compromise. HGT should not be expected to significantly improve severe curves without a prior anterior and/or posterior release. The data presented in this study can be used in future studies to compare the surgical and pulmonary outcomes of severe and rigid deformities.

Added value of percutaneous vertebroplasty: effects on respiratory function

OBJECTIVE

The objective of our study was to investigate the effects of percutaneous vertebroplasty on respiratory function in patients with compression fractures caused by osteoporosis.

SUBJECTS AND METHODS

Ninety-eight patients (87 women, 11 men; mean age, 74 years; age range, 60-90 years) with compression fractures of 75 thoracic (Th7-Th12) and 89 lumbar (L1-L5) vertebrae were enrolled in this study. Percentage vital capacity (VC%), percentage forced vital capacity (FVC%), and percentage forced expiratory volume in 1 second (%FEV1) were measured using a spirometer before, 1 day after, and 1 month after percutaneous vertebroplasty. The Wilcoxon signed rank test was used to evaluate whether any significant differences in VC%, FVC%, or %FEV1 values existed between before, 1 day after, and 1 month after percutaneous vertebroplasty.

RESULTS

The VC% and FVC% values had improved significantly by 1 month after percutaneous vertebroplasty compared with before percutaneous vertebroplasty (p<0.01). No significant difference was noted between values before and 1 day after percutaneous vertebroplasty. Likewise, no significant difference was identified in %FEV1 before percutaneous vertebroplasty and either 1 day or 1 month after percutaneous vertebroplasty. The mean degree of improvement in VC% values after percutaneous vertebroplasty for patients with one vertebra treated, which we refer to as the "single-vertebroplasty" group, and for patients with two or more vertebrae treated, or "multiple-vertebroplasty" group, was 1.1%±7% (SD) and 6.3%±8%, respectively, representing a significant difference between groups (p=0.01). The mean VC% values before and 1 month after percutaneous vertebroplasty differed significantly (p=0.02) in the thoracic group and overlapping group.

CONCLUSION

Percutaneous vertebroplasty improves restrictive ventilatory impairment, but this improvement requires approximately 1 month to occur. Greater improvement in restrictive ventilatory dysfunction was observed in patients who underwent multiple vertebroplasty procedures than those who underwent a single procedure and in patients who underwent treatment of thoracic vertebrae than those who underwent treatment of other vertebrae.