Revised: April 16, 2026
Accepted: May 18, 2026
Published online: June 28, 2026
Processing time: 131 Days and 15.6 Hours
Thoracic scoliosis causes complex three-dimensional deformities of the thoracic cage that can impair lung mechanics and airway geometry, leading to restrictive ventilatory dysfunction. Respiratory impairment differs by etiology, with non-idiopathic scoliosis often showing more severe and persistent deformity. Conventional pulmonary function testing provides global functional assessment but is frequently limited in patients with non-idiopathic scoliosis. Advances in chest computed tomography (CT) allow quantitative evaluation of lung volume and airway morphology, offering an alternative approach to assess respiratory fun
To investigate CT-derived airway morphology and respiratory function in thor
This retrospective observational study included 53 patients ≤ 30 years of age who underwent corrective surgery for thoracic scoliosis and had preoperative and postoperative CT examinations. Patients were classified into idiopathic (n = 25) or non-idiopathic scoliosis (n = 28). Spinal deformity parameters, lung volumes, predicted total lung capacity percentage (TLC%), and airway dimensions were quantified using CT. Group comparisons were performed using the Wilcoxon rank-sum test, correlations were determined using Spearman’s rank correlation, and pre- and postoperative changes were determined using the Wilcoxon signed-rank test.
Patients with non-idiopathic scoliosis had significantly more severe spinal deformities and a lower TLC% compared to patients with idiopathic scoliosis (median TLC%: 39% vs 64%, P < 0.001). The Cobb angle was negatively correlated with TLC% (ρ = -0.52, P = 0.004), lung volumes, and multiple airway parameters in patients with non-idiopathic scoliosis. Surgical correction significantly improved spinal alignment in both groups. CT-derived lung volume parameters did not show significant postoperative changes. In contrast, selective impro
CT-derived analysis showed differences in respiratory impairment between idiopathic and non-idiopathic sco
Core Tip: In thoracic scoliosis, computed tomography (CT)-based analysis demonstrated more pronounced respiratory impairment in non-idiopathic cases, particularly in those with neuromuscular involvement. Associations between spinal deformity and respiratory parameters varied between groups and should be interpreted as exploratory. Although surgical correction improved spinal alignment, CT-derived lung volumes did not show immediate postoperative improvement. However, selective enlargement of the left bronchus suggests a localized effect on airway compression. CT-based evaluation may provide useful complementary information, especially in patients unable to perform reliable pulmonary function testing.
- Citation: Tsuchiya N, Yogi S, Yogi A, Iida G, Yonemoto K, Shimabukuro T, Nishida K, Nishie A. Computed tomography-derived assessment of respiratory impairment in thoracic scoliosis: Comparison between idiopathic and non-idiopathic etiologies. World J Radiol 2026; 18(6): 119975
- URL: https://www.wjgnet.com/1949-8470/full/v18/i6/119975.htm
- DOI: https://dx.doi.org/10.4329/wjr.119975
Thoracic scoliosis produces complex three-dimensional deformities of the thoracic cage that can compromise lung mechanics and airway geometry, ultimately leading to restrictive ventilatory impairment[1]. Although idiopathic scoliosis is often asymptomatic in the early stages, progressive curvature may result in respiratory dysfunction. In contrast, non-idiopathic scoliosis, including congenital, neuromuscular, and syndromic etiologies, frequently involves more severe and persistent thoracic deformity and is therefore more likely to be associated with clinically relevant respiratory compromise[2-6].
Previous studies evaluating respiratory impairment in scoliosis have relied primarily on pulmonary function tests, which provide global functional measures but offer limited insight into the underlying structural mechanisms. Several studies have reported associations between spinal curvature severity and pulmonary function, particularly in idiopathic scoliosis; however, the strength and consistency of these relationships vary across cohorts[7-11]. While surgical correction can improve coronal and axial alignment, the impact on airway morphology and lung volume remains incompletely understood. Moreover, existing imaging studies often focus on isolated parameters or heterogeneous patient populations without clearly distinguishing disease etiology[8,12].
In addition, assessment of respiratory function using conventional pulmonary function tests is often challenging in patients with non-idiopathic scoliosis, particularly patients with cerebral palsy or neuromuscular disorders, due to limited cooperation, cognitive impairment, or respiratory muscle weakness. In these settings, objective imaging-based evaluation may provide complementary and clinically meaningful information that cannot be readily obtained from standard spirometric measurements[13,14].
Recent advances in chest computed tomography (CT) and three-dimensional post-processing enable quantitative assessment of airway diameter and cross-sectional area at standardized anatomic levels, as well as semiautomated whole-lung volumetry[11,15]. These techniques provide an opportunity to directly evaluate the relationships between spinal deformity, airway geometry, and lung volume, and to determine whether such structure-function associations differ between idiopathic and non-idiopathic scoliosis.
The purpose of this study was to investigate CT-derived airway morphology and respiratory function in patients with thoracic scoliosis, with a particular focus on differences between idiopathic and non-idiopathic scoliosis and the correlations between thoracic spinal deformity and respiratory function. As a secondary objective, changes in these parameters before and after corrective surgery were also explored.
The Ethics Committee of Clinical Research of University of the Ryukyus approved this study and waived informed consent. An opt-out notice was provided in accordance with institutional policy and national guidelines.
The study participants were retrospectively selected from patients treated at our institution between January 2019 and December 2024. The picture archiving and communication system was initially used to identify potentially eligible patients, and eligibility was subsequently confirmed through review of electronic medical records.
Inclusion criteria: (1) Age ≤ 30 years; (2) Underwent corrective surgery for thoracic scoliosis; and (3) Pre- and post-operative chest CT images available for analysis.
Exclusion criteria: (1) Fewer than 4 instrumented thoracic vertebral levels; (2) Inadequate CT data, defined as absence of preoperative CT obtained within 6 months before surgery, incomplete coverage of the entire lungs, or slice thickness greater than 1.0 mm; (3) Coexisting thoracic conditions that could affect quantitative analysis, such as pleural effusion or extensive atelectasis; or (4) Failure of automated image analysis by the software.
For longitudinal analysis, postoperative CT examinations performed between 6 months and 12 months after surgery were included to further reduce the potential confounding effects of growth and variability in follow-up duration. Clinical data, including age, gender, height, the indication for corrective surgery, and preoperative pulmonary function test results [percent predicted forced vital capacity (%FVC)], were abstracted from medical records.
CT scanners included Aquilion ONE (320-row scanner, Canon Medical Systems, Otawara, Japan) and Aquilion Precision (160-row scanner, Canon Medical Systems). Preoperative CT was performed within 6 months before surgery. CT scanning was performed during breath-holding at full inspiration with the patient in the supine position. Scanning parameters were as follows: Voltage, 120 kVp; current, automatic exposure control; collimation, 0.5 mm; rotation time, 0.5 second; matrix, 512 × 512; and slice thickness, 1.0 mm. Reconstruction was performed using deep learning reconstruction with the advanced intelligent clear-IQ engine; the reconstruction kernels were Body SHARP for Aquilion ONE and STD for Aquilion Precision (Canon Medical Systems, Tochigi, Japan). We used images reconstructed with a soft tissue algorithm for analysis. For postoperative CT examinations, images reconstructed with a metal artifact reduction algorithm (Single-Energy Metal Artifact Reduction; Canon Medical Systems) were used to minimize artifacts caused by spinal instrumentation and to ensure reliable quantitative assessment of airway geometry and lung volumes[16].
Measurements were performed using Synapse Vincent (version 6.7; Fujifilm Medical Corporation, Tokyo, Japan). Spinal deformity parameters were measured manually using CT images. Measurements were initially performed by a trained medical student and subsequently reviewed and confirmed by a board-certified diagnostic radiologist to ensure accuracy and consistency. CT-derived respiratory parameters were obtained using fully automated segmentation and quantification algorithms implemented in the software (Synapse Vincent). The results of the automated analysis were reviewed and confirmed by a board-certified radiologist. No manual correction was performed, and cases in which automated analysis failed were excluded from the study. This approach was adopted to minimize observer-dependent variability and ensure consistency across measurements. Spinal thoracic deformity parameters were as follows: Cobb angle, apical vertebral translation (AVT), apical vertebral body-rib ratio (AVB-R), and apical vertebral rotation relative to anterior midline (RAml) and the rotation relative to sagittal plane (RAsag; Figure 1). The Cobb angle was measured as the angle between the upper endplate of the most tilted superior vertebra and the lower endplate of the most tilted inferior vertebra of the thoracic curve. AVT was defined as the horizontal distance between the center of the apical vertebra and the plumb line drawn through C7 on the anteroposterior view of spinal CT. AVB-R was defined as the ratio of the right-sided distance to the left-sided distance from the edge of the vertebral body to the ribs. Apical vertebral rotation was defined as the angle of rotation of the vertebral body axis relative to the anterior midline (i.e., the line directed toward the midline of the sternum; RAml) and relative to the vertical plumb line (RAsag)[15]. Spinal thoracic deformity parameters were assessed using the apical vertebra of the thoracic curve as the reference when multiple scoliotic curves were present. The apical vertebral level and the vertebral levels instrumented during scoliosis correction surgery were also recorded.
Respiratory function parameters were as follows: Lung volumes (total, right, left, upper lobe, middle lobe, and lower lobe), predicted total lung capacity percentage (TLC%), maximum/minimum airway diameters, cross-sectional area at four predefined sites (the narrowest tracheal segment, the tracheal bifurcation, and the narrowest segments of the right and left bronchi), and right-to-left bronchial length ratio (Figure 2). Lung and airway were automatically segmented and parameters were calculated by Synapse Vincent. The TLC% was defined as the percentage of measured total lung capacity (TLC) relative to the predicted value (measured TLC/predicted TLC × 100). Predicted TLC was calculated using the Global Lung Function Initiative (GLI) reference equations for static lung volumes based on age, height, gender, and ethnicity[17]. A TLC% value < 80% was considered indicative of reduced lung capacity[18].
The prevalence of tracheal stenosis and reduced lung capacity was summarized using descriptive statistics. Group comparisons (idiopathic scoliosis vs non-idiopathic scoliosis) were performed using the Wilcoxon rank-sum test (Mann-Whitney U test), and categorical variables were compared using the Fisher’s exact test. Pearson correlation analysis was used to evaluate the relationship between CT-derived TLC% and pulmonary function test measurements (%FVC). Spearman’s rank correlation analysis was performed to assess the associations between spinal thoracic deformity parameters and CT-derived respiratory function parameters. A total of 110 correlation analyses were performed to evaluate associations between 5 spinal deformity parameters and 22 CT-derived respiratory variables. Given the exploratory nature of this study, adjustments for multiple comparisons were not performed, and the results were interpreted with caution. Analyses were performed separately for idiopathic and non-idiopathic scoliosis to account for the heterogeneous pathophysiology of scoliosis. In addition, to assess the impact of etiological heterogeneity within the non-idiopathic cohort, an additional exploratory analysis was performed restricted to patients with neuromuscular scoliosis, excluding congenital and syndromic cases. Pre- and post-operative comparisons were performed using the Wilcoxon signed-rank test. Analyses were conducted for the entire cohort and within each group. All data were analyzed using JMP software (version 17.2; SAS Institute Inc.). A P value of < 0.05 was considered statistically significant.
Consecutive patients aged 30 years or younger who underwent corrective surgery for scoliosis and had both preoperative and postoperative CT examinations were selected for this study (n = 162). Exclusions were fewer than four instrumented thoracic vertebral numbers (n = 14), inadequate CT data (n = 82), and analysis failures (n = 13). The reasons for inadequate CT data were as follows: Lack of whole-lung images (n = 74), lack of preoperative images within 6 months (n = 7), and lack of thin-slice images (n = 1). The analysis failures included airway analysis failure (n = 8), left-right lung separation failure (n = 1), and lung segmentation failure (n = 4). The size of the study population was fixed because of the retrospective nature of the study, and a total of 53 patients (19 men and 34 women; median age, 15 years; age range, 11-30 years) were finally included. Based on the underlying etiology, patients were classified as having idiopathic scoliosis (n = 25) or non-idiopathic scoliosis (n = 28). The non-idiopathic scoliosis cohort comprised patients with neuromuscular (n = 20), congenital (n = 4), and syndromic (n = 4) etiologies. The details of the primary disease are summarized in Supple
Baseline characteristics and CT-derived parameters were compared between patients with idiopathic and non-idiopathic scoliosis (Table 1). The idiopathic group had a significantly higher proportion of female patients, whereas the non-idiopathic group was predominantly male. Patients with non-idiopathic scoliosis were significantly shorter than patients with idiopathic scoliosis.
| Total (n = 53) | Idiopathic (n = 25) | Non-idiopathic (n = 28) | P value | ||
| Age (year) | 15 (11-30) | 15 (12-30) | 15 (11-26) | > 0.99 | |
| Gender (male) | 19 (35.8) | 2 (10.5) | 17 (89.5) | < 0.001 | |
| Height (cm) | 152 (143, 159) | 157 (154, 162) | 144 (139, 149) | < 0.001 | |
| Cobb angle (°) | 65 (46, 84) | 47 (38, 65) | 82 (59, 99) | < 0.001 | |
| AVT (mm) | 46 (31, 77) | 38 (24, 47) | 75 (43, 92) | < 0.001 | |
| AVB-R | 0.66 (0.35, 0.81) | 0.67 (0.51, 0.78) | 0.61 (0.22, 1.5) | 0.36 | |
| RAml (°) | 38 (26, 59) | 30 (21, 39) | 55 (28, 74) | < 0.001 | |
| RAsag (°) | 20 (12, 38) | 14 (11, 22) | 36 (17, 45) | < 0.001 | |
| TLC% | 54 (37, 68) | 64 (59, 75) | 39 (29, 53) | < 0.001 | |
| Lung volume (mL) | Total | 2307 (1390, 2982) | 2865 (2548, 3421) | 1471 (860, 2178) | < 0.001 |
| Right | 1241 (785, 1582) | 1560 (1376, 1888) | 823 (437, 1145) | < 0.001 | |
| Right upper | 421 (257, 529) | 496 (428, 603) | 262 (168, 381) | < 0.001 | |
| Right middle | 192 (147, 274) | 243 (192, 311) | 155 (104, 210) | < 0.001 | |
| Right lower | 597 (318, 799) | 778 (682, 1002) | 359 (168, 557) | < 0.001 | |
| Left | 1121 (589, 1369) | 1293 (1142, 1542) | 658 (408, 1058) | < 0.001 | |
| Left upper | 564 (315, 726) | 714 (591, 815) | 356 (222, 539) | < 0.001 | |
| Left lower | 504 (259, 648) | 630 (512, 790) | 281 (222, 539) | < 0.001 | |
| Tracheal bifurcation | Min diameter (mm) | 11.9 (10.2, 13.2) | 12.2 (10.9, 13.7) | 11.4 (9.5, 13.1) | 0.15 |
| Max diameter (mm) | 17.4 (15.2, 19.7) | 18.5 (16.9, 19.9) | 15.8 (13.7, 18.5) | 0.01 | |
| Area (mm2) | 178 (139, 211) | 190 (160, 213) | 153 (118, 190) | 0.03 | |
| Narrowest tracheal segment | Min diameter (mm) | 11.9 (9.5, 12.8) | 12.1 (11.8, 13.1) | 9.9 (6.3, 12.4) | 0.001 |
| Max diameter (mm) | 13.8 (12.5, 15.6) | 14.1 (13.4, 15.6) | 13.3 (11.7, 15.5) | 0.18 | |
| Area (mm2) | 136 (93, 164) | 140 (128, 166) | 107 (64, 161) | 0.04 | |
| Narrowest left bronchus | Min diameter (mm) | 5.5 (4.4, 7.1) | 6.3 (5.1, 7.3) | 5.3 (4.1, 6.9) | 0.08 |
| Max diameter (mm) | 7.5 (5.9, 9.9) | 8.6 (6.9, 10.3) | 7.2 (5.3, 8.9) | 0.054 | |
| Area (mm2) | 36 (22, 61) | 45 (30, 64) | 32 (17, 48) | 0.06 | |
| Narrowest right bronchus | Min diameter (mm) | 8.9 (7.2, 10.5) | 9.7 (7.8, 11.0) | 7.9 (7.1, 10.4) | 0.09 |
| Max diameter (mm) | 11.8 (9.2, 14.4) | 13.1 (10.2, 15.3) | 10.9 (8.9, 13.4) | 0.051 | |
| Area (mm2) | 89 (57, 124) | 97 (71, 142) | 78 (56, 111) | 0.04 | |
| Right-to-left bronchial length ratio | 0.84 (0.78, 0.85) | 0.84 (0.80, 0.86) | 0.83 (0.77, 0.85) | 0.36 | |
| Longitudinal analysis cohort (n) | 50 | 24 | 26 | ||
| Number of instrumented thoracic vertebrae | 9 (4-11) | 9 (8, 11) | 9 (8, 10) | 0.41 | |
| Number of instrumented vertebrae | 13 (5-16) | 12 (11, 13) | 14.5 (12, 15) | 0.001 | |
| Follow-up duration (months) | 12 (6-12) | 12 (10-12) | 12 (6-12) | 0.05 | |
Spinal deformity parameters were significantly more severe in non-idiopathic scoliosis than idiopathic scoliosis, including the Cobb angle (Figure 4A), AVT, and RAml (all P < 0.001; Table 1). AVB-R did not differ significantly between groups.
The median TLC% was less than 80% in both groups, indicating reduced lung capacity in idiopathic and non-idiopathic scoliosis. CT-derived respiratory function parameters were significantly lower in the non-idiopathic scoliosis group. The TLC% and total lung volume were markedly lower in non-idiopathic scoliosis than in idiopathic scoliosis (both P < 0.001; Figure 4B), with similar trends observed across all lobar lung volumes (Table 1).
In all patients, the narrowest segments of the trachea and left main bronchus were identified at locations distinct from the bifurcation. In contrast, in some cases, the tracheal bifurcation corresponded to the narrowest segment of the right main bronchus. Airway measurements demonstrated group differences predominantly at the tracheal level: At the tracheal bifurcation and at the narrowest tracheal segment, minimum and maximum diameters and cross-sectional areas were significantly smaller in non-idiopathic scoliosis (Table 1; Figure 4C). In contrast, bronchial parameters showed only limited or borderline differences between groups, and the right-to-left bronchial length ratio did not differ significantly. An additional exploratory analysis restricted to the neuromuscular scoliosis subgroup (n = 20) showed broadly similar overall findings. Between-group differences became more pronounced for several airway parameters, particularly the minimum diameter, maximum diameter, and cross-sectional area of the narrowest segments of the left and right bronchi (Supplementary Table 2).
In idiopathic scoliosis, lung volumes showed moderate correlations with rotational deformity parameters. Total lung volume correlated negatively with RAml and RAsag (ρ = -0.42 and -0.40, respectively; P < 0.05 for both), and similar correlations were observed for right lung volume (Table 2). No significant correlation was observed between Cobb angle and TLC%. Several airway parameters at the narrowest tracheal segment were associated with spinal deformity indices: Minimum tracheal diameter correlated negatively with AVT and positively with AVB-R, while cross-sectional area correlated positively with AVB-R and negatively with RAml (Table 2). The right-to-left bronchial length ratio showed moderate correlations with the Cobb angle and AVT.
| Cobb angle | AVT | AVB-R | RAml | RAsag | |||||||
| ρ | P value | ρ | P value | ρ | P value | ρ | P value | ρ | P value | ||
| TLC% | 0.069 | 0.74 | -0.28 | 0.16 | 0.24 | 0.24 | -0.37 | 0.06 | -0.32 | 0.11 | |
| Lung volume | Total | 0.12 | 0.54 | -0.21 | 0.30 | 0.22 | 0.28 | -0.42 | 0.03 | -0.40 | 0.04 |
| Right | 0.11 | 0.60 | -0.30 | 0.13 | 0.34 | 0.09 | -0.53 | 0.005 | -0.57 | 0.002 | |
| Right upper | 0.21 | 0.30 | -0.18 | 0.38 | 0.18 | 0.38 | -0.39 | 0.04 | -0.48 | 0.01 | |
| Right middle | 0.006 | 0.97 | -0.25 | 0.21 | 0.35 | 0.07 | -0.35 | 0.07 | -0.28 | 0.16 | |
| Right lower | 0.12 | 0.56 | -0.30 | 0.13 | 0.35 | 0.08 | -0.54 | 0.004 | -0.59 | 0.001 | |
| Left | 0.10 | 0.61 | -0.08 | 0.69 | 0.053 | 0.80 | -0.28 | 0.17 | -0.20 | 0.31 | |
| Left upper | 0.24 | 0.22 | -0.12 | 0.55 | 0.11 | 0.59 | -0.30 | 0.14 | -0.33 | 0.09 | |
| Left lower | -0.088 | 0.67 | -0.15 | 0.46 | 0.16 | 0.42 | -0.31 | 0.13 | -0.16 | 0.42 | |
| Tracheal bifurcation | Min diameter | 0.29 | 0.15 | -0.23 | 0.91 | 0.19 | 0.34 | -0.22 | 0.28 | -0.29 | 0.15 |
| Max diameter | -0.15 | 0.46 | -0.25 | 0.22 | 0.24 | 0.23 | -0.23 | 0.26 | -0.15 | 0.45 | |
| Area | 0.042 | 0.84 | -0.15 | 0.47 | 0.31 | 0.12 | -0.31 | 0.12 | -0.26 | 0.20 | |
| Narrowest tracheal segment | Min diameter | -0.21 | 0.30 | -0.42 | 0.03 | 0.56 | 0.003 | -0.56 | 0.003 | -0.45 | 0.02 |
| Max diameter | 0.063 | 0.76 | -0.13 | 0.52 | 0.35 | 0.08 | -0.37 | 0.06 | -0.36 | 0.07 | |
| Area | -0.11 | 0.57 | -0.28 | 0.17 | 0.47 | 0.01 | -0.51 | 0.008 | -0.43 | 0.03 | |
| Narrowest left bronchus | Min diameter | -0.065 | 0.75 | -0.13 | 0.53 | 0.22 | 0.27 | -0.24 | 0.24 | -0.15 | 0.47 |
| Max diameter | -0.15 | 0.44 | -0.23 | 0.25 | 0.31 | 0.12 | -0.36 | 0.07 | -0.22 | 0.27 | |
| Area | -0.091 | 0.66 | -0.18 | 0.37 | 0.27 | 0.18 | -0.30 | 0.13 | -0.19 | 0.34 | |
| Narrowest right bronchus | Min diameter | 0.053 | 0.77 | -0.097 | 0.64 | 0.14 | 0.49 | -0.10 | 0.62 | 0.008 | 0.96 |
| Max diameter | 0.066 | 0.75 | -0.11 | 0.57 | 0.24 | 0.23 | -0.21 | 0.31 | -0.13 | 0.50 | |
| Area | 0.011 | 0.95 | -0.22 | 0.28 | 0.30 | 0.13 | -0.28 | 0.16 | -0.17 | 0.39 | |
| Right-to-left bronchial length ratio | 0.40 | 0.043 | 0.42 | 0.03 | -0.40 | 0.04 | 0.28 | 0.16 | 0.11 | 0.59 | |
In non-idiopathic scoliosis, a structure-function relationship was observed. The Cobb angle showed significant negative correlations with the TLC% (ρ = -0.52, P = 0.004) and total lung volume (ρ = -0.55, P = 0.002), with similar correlations observed for right and left lung volumes (Table 3). The Cobb angle was also correlated negatively with multiple airway parameters, including tracheal bifurcation diameter and cross-sectional area, as well as several bronchial measurements (Table 3).
| Cobb angle | AVT | AVB-R | RAml | RAsag | |||||||
| ρ | P value | ρ | P value | ρ | P value | ρ | P value | ρ | P value | ||
| TLC% | -0.52 | 0.004 | -0.42 | 0.02 | 0.52 | 0.004 | -0.50 | 0.005 | -0.50 | 0.005 | |
| Lung volume | Total | -0.55 | 0.002 | -0.43 | 0.02 | 0.50 | 0.005 | -0.52 | 0.003 | -0.48 | 0.008 |
| Right | -0.48 | 0.009 | -0.37 | 0.04 | 0.48 | 0.008 | -0.46 | 0.01 | -0.45 | 0.01 | |
| Right upper | -0.50 | 0.005 | -0.35 | 0.06 | 0.53 | 0.003 | -0.43 | 0.02 | -0.44 | 0.01 | |
| Right middle | -0.26 | 0.17 | -0.30 | 0.11 | 0.40 | 0.03 | -0.41 | 0.02 | -0.45 | 0.01 | |
| Right lower | -0.42 | 0.02 | -0.30 | 0.11 | 0.39 | 0.03 | -0.38 | 0.04 | -0.36 | 0.06 | |
| Left | -0.62 | < 0.001 | -0.45 | 0.01 | 0.48 | 0.008 | -0.54 | 0.002 | -0.48 | 0.009 | |
| Left upper | -0.56 | 0.001 | -0.48 | 0.009 | 0.50 | 0.006 | -0.54 | 0.002 | -0.47 | 0.01 | |
| Left lower | -0.62 | < 0.001 | -0.44 | 0.01 | 0.38 | 0.04 | -0.55 | 0.002 | -0.50 | 0.006 | |
| Tracheal bifurcation | Min diameter | -0.41 | 0.02 | -0.35 | 0.06 | 0.23 | 0.23 | -0.27 | 0.16 | -0.21 | 0.26 |
| Max diameter | -0.53 | 0.003 | -0.36 | 0.05 | 0.38 | 0.04 | -0.42 | 0.02 | -0.30 | 0.11 | |
| Area | -0.52 | 0.004 | -0.38 | 0.04 | 0.31 | 0.09 | -0.36 | 0.054 | -0.25 | 0.19 | |
| The narrowest tracheal segment | Min diameter | -0.29 | 0.12 | -0.40 | 0.03 | 0.32 | 0.09 | -0.38 | 0.04 | -0.30 | 0.11 |
| Max diameter | -0.32 | 0.09 | -0.37 | 0.04 | 0.37 | 0.048 | -0.36 | 0.06 | -0.24 | 0.20 | |
| Area | -0.33 | 0.08 | -0.39 | 0.03 | 0.45 | 0.01 | -0.41 | 0.02 | -0.32 | 0.08 | |
| The narrowest left bronchus | Min diameter | -0.39 | 0.03 | -0.40 | 0.03 | 0.24 | 0.21 | -0.37 | 0.049 | -0.33 | 0.07 |
| Max diameter | -0.36 | 0.054 | -0.36 | 0.06 | 0.24 | 0.21 | -0.31 | 0.10 | -0.27 | 0.15 | |
| Area | -0.37 | 0.050 | -0.38 | 0.04 | 0.18 | 0.33 | -0.35 | 0.06 | -0.33 | 0.08 | |
| The narrowest right bronchus | Min diameter | -0.42 | 0.02 | -0.38 | 0.04 | 0.078 | 0.69 | -0.31 | 0.10 | -0.28 | 0.13 |
| Max diameter | -0.41 | 0.02 | -0.35 | 0.06 | 0.051 | 0.79 | -0.31 | 0.10 | -0.23 | 0.22 | |
| Area | -0.42 | 0.02 | -0.38 | 0.04 | 0.073 | 0.70 | -0.32 | 0.09 | -0.25 | 0.18 | |
| Right-to-left bronchial length ratio | 0.27 | 0.15 | 0.26 | 0.17 | -0.29 | 0.12 | 0.43 | 0.02 | 0.47 | 0.01 | |
Heatmap of Spearman’s rank correlations between spinal thoracic deformity parameters and CT-derived respiratory function parameters is shown in Figure 5. The correlation results for the entire cohort are provided in Supplementary Table 3 for reference.
An additional exploratory analysis restricted to the neuromuscular scoliosis subgroup (n = 20) demonstrated sig
Postoperative CT were available in 50 of 53 patients, including 24 with idiopathic scoliosis and 26 with non-idiopathic scoliosis. Following scoliosis correction surgery, the Cobb angle and AVT improved significantly in the overall cohort and in both etiologic groups (all P < 0.001; Table 4). RAml also improved significantly in the overall cohort and in idiopathic scoliosis, whereas no significant change was observed in non-idiopathic scoliosis. AVB-R improved significantly only in idiopathic scoliosis, while RAsag did not show significant postoperative change.
| Entire | Idiopathic | Non-idiopathic | ||||||||
| Pre-operative | Post-operative | P value | Pre-operative | Post-operative | P value | Pre-operative | Post-operative | P value | ||
| Cobb angle (°) | 64 (46, 84) | 28 (17, 50) | < 0.001 | 47 (38, 65) | 18 (16, 26) | < 0.001 | 82 (56, 96) | 47 (34, 63) | < 0.001 | |
| AVT (mm) | 46 (32, 76) | 16 (9, 46) | < 0.001 | 38 (27, 47) | 10 (7, 16) | < 0.001 | 75 (45, 93) | 45 (33, 70) | < 0.001 | |
| AVB-R | 0.67 (0.36, 0.81) | 0.73 (0.50, 0.83) | 0.06 | 0.68 (0.51, 0.75) | 0.74 (0.63, 0.80) | 0.002 | 0.66 (0.24, 1.76) | 0.57 (0.36, 1.34) | 0.99 | |
| RAml (°) | 39 (26, 59) | 27 (20, 50) | < 0.001 | 32 (22, 39) | 22 (17, 27) | < 0.001 | 55 (28, 72) | 48 (34, 67) | 0.09 | |
| RAsag (°) | 21 (13, 38) | 19 (13, 39) | 0.95 | 15 (11, 23) | 14 (10, 18) | 0.05 | 36 (16, 45) | 38 (20, 48) | 0.07 | |
| TLC% | 54 (40, 68) | 56 (41, 70) | 0.80 | 64 (59, 75) | 67 (55, 75) | 0.93 | 41 (30, 54) | 44 (33, 56) | 0.58 | |
| Lung volume (mL) | Total | 2354 (1478, 2974) | 2380 (1577, 3077) | 0.85 | 2845 (2545, 3318) | 2802 (2471, 3381) | 0.94 | 1500 (880, 2190) | 1741 (966, 2299) | 0.71 |
| Right | 1269 (837, 1572) | 1231 (918, 1653) | 0.98 | 1534 (1375, 1828) | 1499 (1300, 1752) | 0.67 | 862 (463, 1156) | 960 (533, 1170) | 0.58 | |
| Right upper | 421 (263, 528) | 418 (255, 536) | 0.99 | 490 (427, 600) | 489 (34, 575) | 1.00 | 276 (183, 388) | 274 (174, 401) | 0.91 | |
| Right middle | 193 (149, 275) | 205 (142, 274) | 0.93 | 257 (191, 316) | 235 (190, 312) | 0.81 | 157 (106, 223) | 165 (101, 229) | 0.80 | |
| Right lower | 624 (370, 797) | 632 (411, 830) | 0.98 | 778 (671, 992) | 786 (652, 933) | 0.70 | 413 (171, 563) | 469 (230, 576) | 0.53 | |
| Left | 1122 (671, 1362) | 1131 (674, 1435) | 0.83 | 1285 (1132, 1525) | 1297 (1157, 1617) | 0.74 | 701 (407, 1098) | 726 (440, 1105) | 0.84 | |
| Left upper | 568 (365, 726) | 585 (368, 750) | 0.83 | 709 (587, 795) | 718 (604, 798) | 0.77 | 381 (228, 549) | 373 (251, 495) | 0.83 | |
| Left lower | 512 (267, 644) | 560 (285, 686) | 0.59 | 602 (508, 769) | 628 (533, 783) | 0.53 | 324 (158, 531) | 365 (84, 610) | 0.77 | |
| Tracheal bifurcation | Min diameter | 11.8 (10.3, 13.2) | 11.9 (10.8, 13.5) | 0.56 | 12.1 (10.8, 13.7) | 12.3 (10.9, 13.9) | 0.51 | 11.4 (9.7, 13.1) | 11.7 (10.6, 12.5) | 0.89 |
| Max diameter | 17.5 (15.4, 19.7) | 17.2 (15.2, 20.0) | 0.84 | 18.3 (16.8, 19.9) | 17.6 (16.2, 19.9) | 0.63 | 16.1 (13.9, 18.8) | 16.3 (14.1, 19.7) | 0.67 | |
| Area | 180 (140, 213) | 175 (140, 213) | 0.65 | 189 (159, 214) | 194 (160, 221) | 0.87 | 153 (125, 196) | 162 (123, 213) | 0.71 | |
| Narrowest tracheal segment | Min diameter | 11.8 (9.4, 12.8) | 11.4 (9.2, 12.8) | 0.88 | 12.2 (11.8, 13.0) | 12.0 (11.8, 13.0) | 0.85 | 9.7 (6.0, 12.2) | 10.6 (7.9, 12.0) | 0.52 |
| Max diameter | 13.8 (12.4, 15.7) | 14.0 (12.9, 15.9) | 0.68 | 14.1 (13.4, 15.7) | 14.0 (13.2, 16.2) | 0.98 | 13.3 (11.6, 15.9) | 14.1 (11.9, 15.8) | 0.64 | |
| Area | 136 (94, 160) | 139 (105, 166) | 0.69 | 149 (128, 165) | 141 (125, 173) | 0.95 | 107 (67, 160) | 125 (86, 156) | 0.56 | |
| Narrowest left bronchus | Min diameter | 5.5 (4.5, 7.3) | 6.8 (5.2, 8.2) | 0.001 | 6.5 (5.1, 7.4) | 7.0 (5.5, 8.6) | 0.06 | 5.3 (4.2, 7.1) | 6.3 (4.7, 7.8) | 0.006 |
| Max diameter | 7.5 (5.9, 9.9) | 9.3 (6.9, 11.3) | < 0.001 | 8.8 (6.9, 10.4) | 10.0 (7.4, 11.4) | 0.02 | 7.3 (5.5, 9.1) | 8.6 (6.2, 11.3) | 0.003 | |
| Area | 35 (22, 61) | 55 (31, 79) | < 0.001 | 47 (31, 65) | 59 (35, 81) | 0.02 | 33 (19, 52) | 47 (26, 78) | 0.003 | |
| Narrowest right bronchus | Min diameter | 8.9 (7.3, 10.5) | 7.8 (6.2, 10.1) | 0.16 | 9.8 (7.6, 11.0) | 8.5 (7.0, 10.0) | 0.20 | 8.0 (7.2, 10.2) | 7.0 (5.3, 10.2) | 0.35 |
| Max diameter | 11.7 (9.1, 14.4) | 11.4 (8.6, 13.7) | 0.50 | 12.8 (9.8, 15.4) | 11.6 (10.0, 13.9) | 0.35 | 10.9 (8.9, 13.4) | 9.4 (7.9, 13.1) | 0.67 | |
| Area | 88 (58, 123) | 77 (48, 110) | 0.32 | 97 (67, 143) | 83 (60, 110) | 0.28 | 78 (55, 106) | 56 (34, 111) | 0.60 | |
| Right-to-left bronchial length ratio | 0.84 (0.79, 0.86) | 0.81 (0.79, 0.86) | 0.42 | 0.84 (0.80, 0.86) | 0.82 (0.80, 0.86) | 0.43 | 0.83 (0.77, 0.86) | 0.81 (0.77, 0.86) | 0.68 | |
Regarding CT-derived respiratory parameters, TLC% and lung volume measurements showed no significant postoperative changes in the overall cohort or within either etiologic group (Table 4). Most tracheal and bronchial parameters also remained unchanged after surgery. In contrast, parameters of the narrowest left bronchus showed significant postoperative improvement. In the overall cohort, the minimum diameter, maximum diameter, and cross-sectional area increased significantly after surgery (all P ≤ 0.001). In idiopathic scoliosis, the maximum diameter and cross-sectional area increased significantly, whereas in non-idiopathic scoliosis, the minimum diameter, maximum diameter, and cross-sectional area all increased significantly.
This study provides three principal findings. First, patients with non-idiopathic scoliosis demonstrated more severe spinal deformities and more pronounced impairment in CT-derived respiratory function compared to patients with idiopathic scoliosis. Second, the patterns of association between spinal deformity and respiratory parameters differed between groups, although these findings should be interpreted as exploratory. Third, although scoliosis correction surgery significantly improved spinal alignment, CT-derived lung volume parameters did not improve in the early postoperative period. However, selective changes in left bronchial dimensions suggest a localized effect on airway compression, while overall respiratory function appears preserved rather than immediately improved.
In the present cohort, the idiopathic group had a higher proportion of female patients, which is consistent with the known epidemiology of idiopathic scoliosis[8]. Non-idiopathic scoliosis demonstrated not only reduced respiratory parameters but also more severe spinal deformities. These findings likely reflect both the magnitude of thoracic deformity and disease-specific factors[2]. One possible explanation lies in the differing natural histories of these conditions. Idiopathic scoliosis typically stabilizes after skeletal maturity, allowing partial adaptation of the thoracic cage and respiratory muscles to structural distortion. In contrast, non-idiopathic scoliosis—including congenital, neuromuscular, and syndromic etiologies—is often associated with prolonged disease duration, impaired thoracic growth, and reduced chest wall compliance[5,11,19]. In particular, the substantial proportion of patients with neuromuscular scoliosis in the present cohort suggests that respiratory muscle weakness may further contribute to impaired ventilation in addition to structural thoracic restriction. These combined factors may account for the more pronounced respiratory impairment observed in non-idiopathic scoliosis.
Correlation analyses suggested differing patterns of association between spinal deformity and respiratory parameters. In non-idiopathic scoliosis, increasing coronal deformity tended to be associated with reduced lung capacity and smaller airway dimensions. In idiopathic scoliosis, respiratory parameters showed associations with rotational deformity indices, whereas correlations with the Cobb angle were not consistently suggested. However, given the exploratory nature of the analyses and the multiple statistical comparisons performed, these findings should be interpreted with caution. In addition, when the analysis was restricted to the neuromuscular subgroup, some correlations became less prominent, suggesting that the observed differences between etiologic groups may be influenced in part by cohort composition. Importantly, this interpretation remains consistent with previous reports showing variable and cohort-dependent associations between the Cobb angle and pulmonary function in idiopathic scoliosis[3,11].
Airway narrowing was observed across the cohort; however, its clinical relevance may differ by etiology. In non-idiopathic scoliosis, airway dimensions tended to be more closely associated with deformity severity, suggesting a potential contribution of airway compression to respiratory dysfunction. CT-derived quantitative assessment may therefore provide complementary information, particularly in patients with limited ability to perform reliable pulmonary function testing[13-15]. Although CT involves radiation exposure, the present analysis was performed using clinically indicated preoperative CT examinations obtained for spinal evaluation. Therefore, no additional radiation exposure was required for the assessment of respiratory function. This approach may provide additional functional information with
Although scoliosis correction surgery significantly improved spinal alignment, CT-derived lung volume parameters did not show significant improvement in the early postoperative period. Previous studies have reported conflicting results regarding postoperative improvement in respiratory function[4,20,21]. Importantly, the principal objective of scoliosis correction surgery is to prevent progression of spinal deformity and to maintain functional alignment, particularly in the sitting position, and not solely to improve respiratory function. From this perspective, the absence of postoperative deterioration in CT-derived respiratory parameters may be interpreted as preservation of respiratory function rather than lack of surgical benefit.
Postoperative changes in airway parameters were predominantly observed in the left bronchus. Given that the left main bronchus is longer and more anatomically constrained than the right main bronchus, the left main bronchus may be more affected by thoracic deformity and spinal alignment. This anatomic consideration may partly account for the side-specific postoperative changes observed in this study.
Longer-term follow-up is required to determine whether surgical correction contributes to sustained preservation or delayed improvement of respiratory function. Thoracic deformity is associated with an increased risk of respiratory complications, including atelectasis and pneumonia; therefore, surgical outcomes should be assessed not only for functional improvement but also for potential reductions in respiratory morbidity[1].
This study had several limitations. This study was a single-center, retrospective study with a relatively small sample size, which may limit the generalizability of the findings. In addition, because Okinawa is a geographically isolated region with limited medical access, corrective surgery for non-idiopathic scoliosis may be performed later than in other regions, potentially resulting in a higher proportion of severe cases and introducing selection bias. The limited sample size may also have reduced the statistical power to detect significant differences or associations, particularly in the subgroup analyses. Because multiple statistical tests were performed, there was an increased risk of type I error. There
CT-derived assessment demonstrated differences in respiratory impairment between idiopathic and non-idiopathic scoliosis, with more pronounced impairment in non-idiopathic cases. Associations between spinal deformity and re
The authors thank Koume Matsushita, Sorano Zokura, Mana Kinjo, and the radiology technologists and spine surgery teams for their cooperation.
| 1. | Koumbourlis AC. Scoliosis and the respiratory system. Paediatr Respir Rev. 2006;7:152-160. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 115] [Cited by in RCA: 160] [Article Influence: 8.0] [Reference Citation Analysis (0)] |
| 2. | Inal-Ince D, Savci S, Arikan H, Saglam M, Vardar-Yagli N, Bosnak-Guclu M, Dogru D. Effects of scoliosis on respiratory muscle strength in patients with neuromuscular disorders. Spine J. 2009;9:981-986. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 34] [Cited by in RCA: 35] [Article Influence: 2.1] [Reference Citation Analysis (0)] |
| 3. | Kan MMP, Negrini S, Di Felice F, Cheung JPY, Donzelli S, Zaina F, Samartzis D, Cheung ETC, Wong AYL. Is impaired lung function related to spinal deformities in patients with adolescent idiopathic scoliosis? A systematic review and meta-analysis-SOSORT 2019 award paper. Eur Spine J. 2023;32:118-139. [RCA] [PubMed] [DOI] [Full Text] [Cited by in RCA: 29] [Reference Citation Analysis (0)] |
| 4. | Upadhyay SS, Day GA, Saji MJ, Leong JC. Restrictive pattern of pulmonary functions in idiopathic and congenital scoliosis following spinal fusion. Eur Spine J. 1993;2:22-28. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 5] [Cited by in RCA: 6] [Article Influence: 0.2] [Reference Citation Analysis (0)] |
| 5. | Muirhead A, Conner AN. The assessment of lung function in children with scoliosis. J Bone Joint Surg Br. 1985;67:699-702. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 81] [Cited by in RCA: 71] [Article Influence: 1.7] [Reference Citation Analysis (3)] |
| 6. | Vitale MG, Matsumoto H, Bye MR, Gomez JA, Booker WA, Hyman JE, Roye DP Jr. A retrospective cohort study of pulmonary function, radiographic measures, and quality of life in children with congenital scoliosis: an evaluation of patient outcomes after early spinal fusion. Spine (Phila Pa 1976). 2008;33:1242-1249. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 140] [Cited by in RCA: 143] [Article Influence: 7.9] [Reference Citation Analysis (0)] |
| 7. | Kang GR, Suh SW, Lee IO. Preoperative predictors of postoperative pulmonary complications in neuromuscular scoliosis. J Orthop Sci. 2011;16:139-147. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 31] [Cited by in RCA: 41] [Article Influence: 2.7] [Reference Citation Analysis (0)] |
| 8. | Weinstein SL, Dolan LA, Spratt KF, Peterson KK, Spoonamore MJ, Ponseti IV. Health and function of patients with untreated idiopathic scoliosis: a 50-year natural history study. JAMA. 2003;289:559-567. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 467] [Cited by in RCA: 494] [Article Influence: 21.5] [Reference Citation Analysis (0)] |
| 9. | Martínez-Llorens J, Ramírez M, Colomina MJ, Bagó J, Molina A, Cáceres E, Gea J. Muscle dysfunction and exercise limitation in adolescent idiopathic scoliosis. Eur Respir J. 2010;36:393-400. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 69] [Cited by in RCA: 88] [Article Influence: 5.2] [Reference Citation Analysis (0)] |
| 10. | Johari J, Sharifudin MA, Ab Rahman A, Omar AS, Abdullah AT, Nor S, Lam WC, Yusof MI. Relationship between pulmonary function and degree of spinal deformity, location of apical vertebrae and age among adolescent idiopathic scoliosis patients. Singapore Med J. 2016;57:33-38. [RCA] [PubMed] [DOI] [Full Text] [Full Text (PDF)] [Cited by in Crossref: 66] [Cited by in RCA: 48] [Article Influence: 4.8] [Reference Citation Analysis (0)] |
| 11. | Kempen DHR, Heemskerk JL, Kaçmaz G, Altena MC, Reesink HJ, Vanhommerig JW, Willigenburg NW. Pulmonary function in children and adolescents with untreated idiopathic scoliosis: a systematic review with meta-regression analysis. Spine J. 2022;22:1178-1190. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 4] [Cited by in RCA: 35] [Article Influence: 8.8] [Reference Citation Analysis (0)] |
| 12. | Qiabi M, Chagnon K, Beaupré A, Hercun J, Rakovich G. Scoliosis and bronchial obstruction. Can Respir J. 2015;22:206-208. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 8] [Cited by in RCA: 15] [Article Influence: 1.4] [Reference Citation Analysis (0)] |
| 13. | Daghighi A, Tropp H. Computed tomography lung volume estimation and its relation to lung capacities and spine deformation. J Spine Surg. 2019;5:132-141. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 5] [Cited by in RCA: 5] [Article Influence: 0.7] [Reference Citation Analysis (0)] |
| 14. | Chun EM, Suh SW, Modi HN, Kang EY, Hong SJ, Song HR. The change in ratio of convex and concave lung volume in adolescent idiopathic scoliosis: a 3D CT scan based cross sectional study of effect of severity of curve on convex and concave lung volumes in 99 cases. Eur Spine J. 2008;17:224-229. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 19] [Cited by in RCA: 21] [Article Influence: 1.1] [Reference Citation Analysis (0)] |
| 15. | Wang J, Zhou B, Yang X, Zhou C, Ling T, Hu B, Song Y, Liu L. Computed tomography-based bronchial tree three-dimensional reconstruction and airway resistance evaluation in adolescent idiopathic scoliosis. Eur Spine J. 2020;29:1981-1992. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 2] [Cited by in RCA: 5] [Article Influence: 0.8] [Reference Citation Analysis (0)] |
| 16. | Katsura M, Sato J, Akahane M, Kunimatsu A, Abe O. Current and Novel Techniques for Metal Artifact Reduction at CT: Practical Guide for Radiologists. Radiographics. 2018;38:450-461. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 286] [Cited by in RCA: 227] [Article Influence: 28.4] [Reference Citation Analysis (1)] |
| 17. | Hall GL, Filipow N, Ruppel G, Okitika T, Thompson B, Kirkby J, Steenbruggen I, Cooper BG, Stanojevic S; contributing GLI Network members. Official ERS technical standard: Global Lung Function Initiative reference values for static lung volumes in individuals of European ancestry. Eur Respir J. 2021;57:2000289. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 44] [Cited by in RCA: 289] [Article Influence: 57.8] [Reference Citation Analysis (0)] |
| 18. | Pellegrino R, Viegi G, Brusasco V, Crapo RO, Burgos F, Casaburi R, Coates A, van der Grinten CP, Gustafsson P, Hankinson J, Jensen R, Johnson DC, MacIntyre N, McKay R, Miller MR, Navajas D, Pedersen OF, Wanger J. Interpretative strategies for lung function tests. Eur Respir J. 2005;26:948-968. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 4572] [Cited by in RCA: 3897] [Article Influence: 185.6] [Reference Citation Analysis (0)] |
| 19. | Xue X, Shen J, Zhang J, Zhao H, Li S, Wang Y, Liang J, Weng X, Qiu G. An analysis of thoracic cage deformities and pulmonary function tests in congenital scoliosis. Eur Spine J. 2015;24:1415-1421. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 22] [Cited by in RCA: 28] [Article Influence: 2.3] [Reference Citation Analysis (0)] |
| 20. | Lee DK, Chun EM, Suh SW, Yang JH, Shim SS. Evaluation of postoperative change in lung volume in adolescent idiopathic scoliosis: Measured by computed tomography. Indian J Orthop. 2014;48:360-365. [RCA] [PubMed] [DOI] [Full Text] [Full Text (PDF)] [Cited by in Crossref: 11] [Cited by in RCA: 15] [Article Influence: 1.3] [Reference Citation Analysis (0)] |
| 21. | Zhang H. Evaluation of improved lung and airway morphology using CT 3D reconstruction after severe scoliosis correction: a retrospective cohort study. J Orthop Surg Res. 2026;21:161. [RCA] [PubMed] [DOI] [Full Text] [Full Text (PDF)] [Reference Citation Analysis (0)] |
| 22. | Stanojevic S, Kaminsky DA, Miller MR, Thompson B, Aliverti A, Barjaktarevic I, Cooper BG, Culver B, Derom E, Hall GL, Hallstrand TS, Leuppi JD, MacIntyre N, McCormack M, Rosenfeld M, Swenson ER. ERS/ATS technical standard on interpretive strategies for routine lung function tests. Eur Respir J. 2022;60:2101499. [RCA] [PubMed] [DOI] [Full Text] [Cited by in Crossref: 1283] [Cited by in RCA: 1019] [Article Influence: 254.8] [Reference Citation Analysis (0)] |