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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

Unilateral thoracic spinal nerve resection creates early onset thoracic scoliosis in an immature porcine model

PURPOSE

To test whether multiple-level unilateral thoracic spinal nerves (TSN) resection can induce the initial thoracic cage deformity to cause early onset thoracic scoliosis in an immature porcine model; and 2) to create an early onset thoracic scoliosis in a large animal model that can be used to evaluate growth-friendly surgical techniques and instruments in growing spine researches.

METHODS

Seventeen one-month-old pigs were assigned to 3 groups. In group 1 (n = 6), right TSN were resected from T7 to T14 with the contralateral (left) paraspinal muscle exposing and stripping. In group 2 (n = 5), the animals were treated in the same way except the contralateral (left) side was intact. In group 3 (n = 6), bilateral TSN were resected from T7 to T14. All animals were followed up for 17-weeks. Radiographs were measured and analyzed the correlation between the Cobb angle and thoracic cage deformity. A histological examination of the intercostal muscle (ICM) was performed.

RESULTS

In the groups 1 and 2, an average 62 ± 12° and 42 ± 15° right thoracic scoliosis with apical hypokyphosis of a mean - 5.2 ± 16° and - 1.8 ± 9° were created, respectively, during 17-weeks follow up. All curves were located at the operated levels with the convexity toward the TSN resection side. Statistical analysis demonstrated that the thoracic deformities were strongly correlated with the Cobb angle. In group 3, no scoliosis was created in any animal, but an average thoracic lordosis of - 32.3 ± 20.3° was seen. The histological examination showed the ICM denervation on the TSN resection side.

CONCLUSION

Unilateral TSN resection induced the initial thoracic deformity toward the TSN resection side resulting in thoracic hypokyphotic scoliosis in an immature pig model. This early onset thoracic scoliosis model could be used to evaluate the growth-friendly surgical techniques and instruments in future growing spine researches.

Translational and Rotational Postural Aberrations Are Related to Pulmonary Functions and Skill-Related Physical Fitness Components in Collegiate Athletes

This study assessed the relationship between body posture displacements, cardiopulmonary exercise testing (CPET), and skill-related physical fitness tests. One hundred male (60%) and female collegiate athletes (22.2 ± 4 yrs) with normal body mass indexes (BMI up to 24.9) were assessed via the PostureScreen Mobile^® app to quantify postural displacements such as head, thorax, and pelvis rotations and translations. CPET and physical performance tests, including the agility t-test, vertical jump test, stork static balance test (SSBT), and dynamic Y-balance test (YBT), were performed. Spearman correlation (r) and p-values are reported. The postural parameters were found to have moderate-to-high associations with the CPET and agility test, moderate correlations with the vertical jump test and SSBT (head and pelvic postures only), and weak correlations with the YBT. As the postural parameters were more asymmetric, both the CPET and performance skills scores were worse. For example: (1) a medium positive correlation was found between cranio-vertebral angle (CVA) and the vertical jump test (r = 0.54; p-value < 0.001) and SSBT (r = 0.57; p-value < 0.001), while a strong negative correlation was found between CVA and the agility test (r = -0.86; p-value < 0.001). (2) A strong positive correlation was found between CVA and oxygen uptake efficiency slope, load watts VO2 at VT, VO2/kg, and load watts at the respiratory compensation point (RCP) (r = 0.65 and r = 0.71; p < 0.001). Conversely, a significant negative correlation was found between CVA and VE/VO2 at VT (r = -0.61; p < 0.001). Postural rotations and translations of the head, thorax, and pelvis were statistically correlated with the physical performance skills and CPET in the young collegiate athletes. There were moderate-to-high associations with cardiopulmonary functions and the agility tests, moderate correlations with the vertical jump test, and weak correlations with the YBT. Postural alignment may be important for optimal physical performance and optimal cardiopulmonary function. Further research is necessary to elucidate the reasons for these correlations found in our sample of young and healthy athletes.

Paediatric Spinal Deformity Surgery: Complications and Their Management

Surgical correction of paediatric spinal deformity is associated with risks, adverse events, and complications that must be preoperatively discussed with patients and their families to inform treatment decisions, expectations, and long-term outcomes. The incidence of complications varies in relation to the underlying aetiology of spinal deformity and surgical procedure. Intraoperative complications include bleeding, neurological injury, and those related to positioning. Postoperative complications include persistent pain, surgical site infection, venous thromboembolism, pulmonary complications, superior mesenteric artery syndrome, and also pseudarthrosis and implant failure, proximal junctional kyphosis, crankshaft phenomenon, and adding-on deformity, which may necessitate revision surgery. Interventions included in enhanced recovery after surgery protocols may reduce the incidence of complications. Complications must be diagnosed, investigated and managed expeditiously to prevent further deterioration and to ensure optimal outcomes. This review summarises the complications associated with paediatric spinal deformity surgery and their management.

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.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

A Novel Classification of 3D Rib Cage Deformity in Subjects With Adolescent Idiopathic Scoliosis

STUDY DESIGN

This was a multicentric cross-sectional descriptive study.

OBJECTIVE

To analyze patterns of 3D rib cage deformity in subjects with adolescent idiopathic scoliosis (AIS) and their relationship with the spinal deformity.

SUMMARY OF BACKGROUND DATA

Subjects with AIS present with rib cage deformity that can affect respiratory functions. The 3D rib cage deformities in AIS and their relationship to the spinal deformity are still unelucidated.

METHODS

A total of 200 AIS and 71 controls underwent low-dose biplanar x-rays and had their spine and rib cage reconstructed in 3-dimensional (D). Classic spinopelvic parameters were calculated in 3D and: rib cage gibbosity, thickness, width, volume and volumetric spinal penetration index (VSPI). Subjects with AIS were classified as: group I with mild rib cage deformity (n=88), group II with severe rib cage deformity (n=112) subgrouped into IIa (high gibbosity, n=48), IIb (high VSPI, n=48), and IIc (both high gibbosity and VSPI, n=16).

RESULTS

Groups IIa and IIb had a higher Cobb angle (33 vs. 54 degrees and 46 degrees, respectively) and torsion index (11 vs. 14 degrees and 13 degrees, respectively) than group I. Group IIb showed more severe hypokyphosis (IIb=21 degrees; IIa=33 degrees; I=36 degrees; control=42 degrees) with a reduced rib cage volume (IIb=4731 cm3; IIa=4985 cm3; I=5257 cm3; control=5254 cm3) and thickness (IIb=135 mm; IIa=148 mm; I=144 mm; control=144 mm). Group IIa showed an increasingly large local gibbosity descending from proximal to distal levels and did not follow the axial rotation of the spine. Group IIc showed characteristics of both groups IIa and IIb.

CONCLUSIONS

This new classification of 3D rib cage deformity in AIS shows that the management of cases with high VSPI (groups IIb and IIc) should focus on restoring as much kyphosis as possible to avoid respiratory repercussions. Treatment indications in groups I and IIa would follow the consensual basic principles reported in the literature regarding bracing and surgery.

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.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pulmonary Implications of Pediatric Spinal Deformities

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

Relationship Between Pulmonary Function and Thoracic Morphology in Adolescent Idiopathic Scoliosis: A New Index, the "Apical Vertebra Deviation Ratio", as a Predictive Factor for Pulmonary Function Impairment

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to investigate the relationship between thoracic morphology (TM) and pulmonary function (PF) in patients with adolescent idiopathic scoliosis (AIS) and the feasibility of the "apical vertebra deviation ratio (AVDR)" as a predictor of PF impairment.

SUMMARY OF BACKGROUND

The PF of AIS is one of the key focuses of clinicians' attention. Early identification of AIS patients who are at risk of developing impaired PF is important for improving patient management.

METHODS

Preoperative PF and radiographic examination data of 108 patients with thoracic AIS were collected. The following TM data were collected: the costophrenic angle distance (CAD), distance between T1 and mean diaphragm height (T1-diaphragm), T1-T12 height, and AVDR. The correlation coefficient between PF and TM measurements was analyzed, and univariable and multivariable linear regressions were used to determine whether the TM measurements could predict PF.

RESULTS

The CAD, T1-diaphragm, and T1-T12 height were significantly positively correlated with forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), vital capacity, and total lung capacity (r = 0.54-0.74, P < 0.01). A linear equation between CAD and pulmonary volume could be established: FVC (L) = -3.46 + CAD (cm) × 0.27 (R2 = 0.54). If T1-T12 height is included, the correlation is further enhanced (R2 = 0.68). There was a significant negative correlation between the AVDR and predicted values of forced vital capacity (FVC%), FEV1%, predicted values of vital capacity, and predicted values of total lung capacity (r = -0.46 to -0.52, P < 0.01). The AVDR could predict the value of each of these variables. One of the linear equations is as follows: FVC% = 110.70-99.73 × AVDR (R2 = 0.272).

CONCLUSION

The two novel, two-dimensional TM measurements, CAD and AVDR, can be used as moderate to strong predictors of PF outcome in statistical terms. An AVDR >0.2 suggests that the patient may suffer from moderate or severe PF damage.Level of Evidence: 4.

Biomechanical Evaluation of Intercostal Muscles in Healthy Children and Adolescent Idiopathic Scoliosis: A Preliminary Study

Spine deformity during adolescent idiopathic scoliosis can induce a rib-cage deformity. This bone deformity can have direct consequences on the chest-wall muscles, including intercostal muscles, leading to respiratory impairments in individuals with severe cases. The aim of this study was to determine whether shear-wave elastography can be used to measure intercostal-muscle shear-wave speed (SWS) in healthy children and those with adolescent idiopathic scoliosis (AIS). Nineteen healthy participants and 16 with AIS took part. SWS measurements were taken by three operators, twice each. Average SWS was 2.3 ± 0.4 m/s, and inter-operator reproducibility was 0.2 m/s. SWS was significantly higher during apnea than in normal breathing (p < 0.01) in both groups. No significant difference was observed between groups in apnea or in normal breathing. Characterization of the intercostal muscles by ultrasound elastography is therefore feasible and reliable for children and adolescents with and without scoliosis.

Prevalence and Key Radiographic Spinal Malalignment Parameters Associated with the Risk of Pulmonary Function Impairment in Patients Treated Surgically to Correct Adult Spinal Deformity

Introduction

There is a significant relationship between pulmonary function and degree of spinal deformity, location of apical vertebrae, and coronal imbalance in patients with childhood spinal deformity. By contrast, the pathophysiology, epidemiology, and influence of deformity on respiratory dysfunction in patients with adult spinal deformity (ASD) remain largely unknown. We sought to clarify and compare the prevalence of pulmonary function impairment in patients with ASD with that in patients with lumbar spinal stenosis (LSS), to determine radiographically which spinal malalignment parameters are associated with a risk of respiratory dysfunction, and to determine the association of respiratory dysfunction with corrective surgery.

Methods

We conducted a prospective study of consecutive patients with a diagnosis of ASD or LSS who underwent spinal surgery. We included data from 122 consecutive patients with ASD and 121 consecutive patients with LSS. Parameters were obtained from full-length lateral radiographs taken with the patients standing and in supine and prone positions. We compared respiratory dysfunction between a group of patients with ASD and LSS and determined correlations between respiratory dysfunction and spinopelvic parameters.

Results

Preoperative % forced vital capacity (FVC) of patients with ASD was significantly lower than that of patients with LSS, and the frequency of restrictive ventilatory impairment was significantly higher in those with ASD (15.7%) than those with LSS (7.4%). Thoracolumbar kyphotic curvature (TK) while the patients were in supine position was significantly greater in the group with restrictive ventilatory impairment, and a significant negative correlation was found between %FVC and TK with the patients in supine position. We found no significant improvement of respiratory dysfunction 1 year after surgery.

Conclusions

Spinal deformity is a potential risk factor for restrictive ventilatory impairment in the elderly. We propose that radiographs obtained when patients are in supine position are valuable for evaluating the flexibility of the TK. Rigid TK might be an etiology of restrictive ventilatory impairment in patients with ASD.

Effectiveness and safety of a modified (rib ends fixed under transverse process) thoracoplasty for rib hump deformity in adults with severe thoracic scoliosis: A retrospective study

Razor back deformity is one of the most noticeable problems of severe scoliosis. Thoracoplasty has been reported to be a useful approach to correct the rib hump deformity. However, the outcomes of thoracoplasty in patients with severe, rigid, thoracic scoliosis have not yet been evaluated.To evaluate the effectiveness and safety of a modified technique of thoracoplasty (rib ends fixed under transverse process) for rib hump deformity in adults with severe thoracic scoliosis and severe pulmonary dysfunction.Patients with severe thoracic scoliosis and severe pulmonary dysfunction who underwent staged surgical strategy including halo-pelvic traction, spinal osteotomy combined with the modified thoracoplasty were included. To avoid paradoxical breathing result from multiple rib resections and enlarge the capacity of thoracis, the ends after rib resection were fixed under transverse process compared with conventional thoracoplasty. Patients were excluded on the basis of pulmonary diseases and inadequate follow-up. Data on deformity correction and pulmonary complications were reviewed. A t test was performed on the pre- and postoperative data of pulmonary function, height of the rib hump deformity, and total lung area.Eighteen patients (5 men and 13 women) with a major thoracic curve of >130° were included. The mean age of patients was 25.3 ± 3.6 years (range, 19-32 years), with an average length of follow-up of 30.2 months. After application of halo-pelvic traction, the mean major thoracic curve decreased from 168.2° ± 14.28° to 97.3° ± 10.75° and the thoracic kyphosis decreased from 159.4° ± 20.60° to 94.8° ± 9.58°. On average, 6.3 (range, 4-8) ribs were resected. The height of the rib hump decreased from 84.6 ± 13.3 to 15.3 ± 3.4 mm. The average predicted forced vital capacity (FVC%) before surgery was 37.2 ± 13.30%, indicative of severe pulmonary impairment, with a small but non-significant improvement in the FVC% at the final follow-up. The mean total lung area increased from 2583.2 ± 501.36 to 2890.1 ± 537.30 mL at the last follow-up. No severe pulmonary complications occurred.Our modified approach to thoracoplasty procedure is effective and safe in correcting a razor back deformity in patients with severe, rigid, scoliosis, and severe pulmonary dysfunction, without causing any significant change in long-term pulmonary function.

5 Reasons Why Scoliosis X-Rays Are Not Harmful

Radiographic imaging for scoliosis screening, diagnosis, treatment, and management is the gold standard assessment tool. Scoliosis patients receive many repeat radiographs, typically 10-25 and as many as 40-50, equating to a maximum 50 mGy of cumulative exposure. It is argued this amount of radiation exposure is not carcinogenic to scoliosis patients for 5 main reasons: 1. Estimated theoretical cumulative effective doses remain below the carcinogenic dose threshold; 2. Scoliosis patient x-rays are delivered in serial exposures and therefore, mitigate any potential cumulative effect; 3. Linear no-threshold cancer risk estimates from scoliosis patient cohorts are flawed due to faulty science; 4. Standardized incidence/mortality ratios demonstrating increased cancers from aged scoliosis cohorts are confounded by the effects of the disease entity itself making it impossible to claim cause and effect resulting from low-dose radiation exposures from spinal imaging; 5. Children are not more susceptible to radiation damage than adults. Radiophobia concerns from patients, parents, and doctors over repeat imaging for scoliosis treatment and management is not justified; it adds unnecessary anxiety to the patient (and their parents) and interferes with optimal medical management. X-rays taken in the evidence-based management of scoliosis should be taken without hesitation or concern about negligible radiation exposures.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Level IV.

Predicting preoperative pulmonary function in patients with thoracic adolescent idiopathic scoliosis from spinal and thoracic radiographic parameters

PURPOSE

The objective was to analyse the effect of thoracic morphology on pulmonary function in adolescent idiopathic scoliosis (AIS) to predict preoperative lung function.

METHODS

A total of 170 consecutive preoperative patients (average age 15.1 years) with Lenke 1 and 2 AIS underwent pulmonary function testing. Thirteen deformity parameters, including rib hump size, rib asymmetry, spinal intrusion and thoracic/lung dimensions in the sagittal and coronal plane, were measured on whole-spine radiographs. Lung function parameters were expressed as z-scores. Correlation and regression analysis of these parameters with lung function were performed.

RESULTS

Mean thoracic Cobb (MT) was 69.1°, and mean T5-T12 thoracic kyphosis (TK) was 21.8°. MT correlated significantly with FEV₁ and FVC (r_s = - 0.40 and - 0.38). TK correlated weakly with FEV₁ and FEV₁/FVC (r_s = 0.23 and 0.25). FEV₁ and FVC were best predicted by the inverse apical vertebra body-rib ratio (AVBRr^-1, r_s = 0.46 and 0.42), rib hump depth index (RHDi, r_s = - 0.52 and - 0.50) and spinal intrusion ratio (SIr, r_s = - 0.50 and - 0.45). The kyphosis-lordosis index (KLi) correlated with FEV₁/FVC (r_s = 0.29). Multivariate regression analysis of coronal and sagittal Cobb angles produced a model which explained 35% and 30% of the variance in FEV₁ and FVC, whilst a regression model consisting of AVBRr^-1 and SIr was able to predict 54% and 48%.

CONCLUSION

AVBRr^-1, RHDi and SIr measured on posterior-anterior and lateral radiographs provide better estimations of lung function in preoperative AIS patients than Cobb measurements. KLi was an indicator of airway obstruction as measured by FEV₁/FVC.

Flexibility of the thoracic curve and three-dimensional thoracic kyphosis can predict pulmonary function in nonoperatively treated adult patients with adolescent idiopathic scoliosis

BACKGROUND

Although several radiographic predictors for pulmonary function in adolescent patients have been reported, those in adult patients remain unclear. Therefore, we aimed to investigate the associations between spinal deformity and pulmonary function in nonoperatively treated adult patients with adolescent idiopathic scoliosis (AIS).

METHODS

Of 319 patients treated nonoperatively for AIS, 90 (average age, 40.0 ± 6.5 years) underwent both full-length standing radiographs and pulmonary function test. Standard two-dimensional (2-D) radiographic measurements were performed. Three-dimensional thoracic kyphosis (3-D TK) was calculated from 2-D standing radiograph data using a validated formula: 3-D TK (°) = 18.1 + 0.81 × (2-D TK) + 0.54 × (Cobb angle of thoracic curve). 3-D TK was defined as the sum of segmental kyphosis between T5 and T12, which eliminates the overestimation of TK in 2-D measurements due to rotational deformity. Bivariable correlation analysis, followed by a stepwise multiple linear regression analysis, was performed.

RESULTS

The average Cobb angle of the thoracic curve at the time of survey was 49.4° ± 14.6° with flexibility of 37.5% ± 18.2%. Thoracic curve magnitude, flexibility, apical vertebral rotation and translation, and 3-D TK were significantly correlated with percent-predicted forced vital capacity (%FVC) and expiratory volume in 1 s (%FEV1.0). Stepwise multiple regression analysis showed that curve flexibility and 3-D TK were significant, independent predictors of %FVC (R² = 0.358) and %FEV1.0 (R² = 0.335), curve flexibility having a greater impact (standardized coefficient > 0.45) than 3-D TK (<0.32).

CONCLUSIONS

Our results indicate that nonoperatively treated patients with AIS should be recommended to maintain flexibility of the thoracic curve to prevent future pulmonary impairment. Moreover, 3-D TK is another independent predictor of pulmonary function, which suggests that segmental sagittal alignment is a component of deformity correction to focus on.

Rib Cage Measurement Reproducibility Using Biplanar Stereoradiographic 3D Reconstructions in Adolescent Idiopathic Scoliosis

BACKGROUND

A reproducibility study of preoperative rib cage three-dimensional (3D) measurements was conducted for patients with Adolescent Idiopathic Scoliosis (AIS). No prior reliability study has been performed for preoperative 3D reconstructions of the rib cage by using stereoradiography in patients with preoperative AIS. Our objective was to assess the reliability of rib cage 3D reconstructions using biplanar stereoradiography in patients with AIS before surgery.

METHODS

This series includes 21 patients with Lenke 1 or 2 scoliosis (74±20 degrees). All patients underwent low-dose standing biplanar radiographs. Two operators performed reconstructions twice each. Intraoperator repeatability, interoperator reproducibility, and intraclass coefficients (ICC) were calculated and compared between groups.

RESULTS

The average rib cage volume was 4.71 L (SD±0.75 L). Two SD was 0.19 L with a coefficient of variation of 4.1%; ICC was 0.968. The thoracic index was 0.6 (SD±0.1). Two SD was 0.03 with a coefficient of variation of 4.7% and a ICC of 0.820. As for the Spinal Penetration Index (6.4%; SD±2.4), 2SD was 0.9% with a coefficient of variation of 14.3% and a ICC of 0.901. The 3D rib hump 2SD (average 27±8 degrees) was 1.4 degrees. The coefficient of variation and ICC were respectively 5.1% and 0.991.

CONCLUSIONS

Three-dimensional reconstruction of the rib cage using biplanar stereoradiography is a reliable method to estimate preoperative thoracic parameters in patients with AIS.

LEVEL OF EVIDENCE

Level IV-diagnostic study.

Correlation analysis between the pulmonary function test and the radiological parameters of the main right thoracic curve in adolescent idiopathic scoliosis

Background

Scoliosis causes thoracic deformities, and it is necessary to assess these changes in pulmonary function test (PFT). To determine how measurements of spinal and thoracic cage deformities are related to pulmonary function.

Methods

Seventy-two patients with main right thoracic curvature in adolescent idiopathic scoliosis (AIS) underwent a PFT and a radiological parameter evaluation of spinal and thoracic cage deformities. Simple and multiple linear regressions were also used to note whether a combination of variables might better predict PFT values. Means were compared using the two-sample t test or one-way ANOVA with Tukey’s multiple comparison methods.

Results

Forced vital capacity (FVC)% predicted had significantly negative correlations with main thoracic curve Cobb (MT-Cobb) (R² = 0.648, p < 0.001), main thoracic curve-rib hump (MT-RH) (R² = 0.522, p < 0.001), main thoracic curve apical vertebral body-to-rib ratio (MT-AVB-R) (R² = 0.536, p < 0.001), and main thoracic curve apical vertebra translation (MT-AVT) (R² = 0.383, p < 0.001). Multiple regression analysis was performed with FVC% predicted as the dependent variable and MT-Cobb, MT-RH, MT-AVB-R, and MT-AVT as the independent variables. MT-Cobb, MT-RH, MT-AVB-R, and MT-AVT were factors with a significant effect on FVC% predicted (p < 0.001). For 45 patients who had preoperative FVC impairment (FVC% predicted < 80%), their MT-Cobb averaged 76.71°. Twenty-seven patients with normal preoperative FVC (FVC% predicted ≥ 80%) had a smaller mean MT-Cobb of 52.03° (p < 0.001). In other radiological parameters, the impaired FVC group had a MT-AVT of 54.29 mm compared to 38.06 mm for the normal FVC group (p < 0.001). MT-AVB-R averaged 2.92 for the impaired FVC group and 1.78 for the normal FVC group (p < 0.001). MT-RH averaged 28.79 mm for the impaired group and 16.62 mm for the normal group (p < 0.001). Further stratification of preoperative PFT results is divided into three groups. The three groups also showed significant differences in MT-Cobb, MT-RH, MT-AVB-R, and MT-AVT (p < 0.001).

Conclusion

Severe scoliosis leads to an increased degree of thoracic deformity, which increases the risk of lung damage in AIS. Moreover, a more accurate assessment of pulmonary function is achieved through radiological parameters and PFTs.

Do Heavier Patients With Adolescent Idiopathic Scoliosis Have More Preserved Thoracic Kyphosis and Pulmonary Function?

STUDY DESIGN

Retrospective.

OBJECTIVES

We aimed to determine if heavier patients with adolescent idiopathic scoliosis (AIS) had more preserved thoracic kyphosis (TK), and as a result, more preserved pulmonary function.

SUMMARY OF BACKGROUND DATA

Some believe that childhood weight is predictive of adult sagittal plane parameters, with heavier children having greater TK as adults. Generally, thoracic scoliosis is coupled with loss of TK, which is associated with worsening pulmonary function.

METHODS

A total of 142 patients with AIS and a structural main thoracic curve were analyzed. We excluded patients with structural proximal thoracic curves (Lenke 2 and 4). Standing preoperative radiographs, pulmonary function tests, and preoperative body mass indices (BMIs) were reviewed. The main thoracic Cobb angle, T2-T12 TK, percentage predicted forced vital capacity (FVC) and BMI were recorded. Spearman correlation was determined. Linear regression analysis used FVC as the primary outcome and BMI, TK, and Cobb angle as the independent variables. BMI categories were overweight/obese (BMI ≥25) and normal (BMI <25). Wilcoxon rank-sum tests were performed to detect a difference in TK and BMI between the 2 groups. The Cobb angles between the two groups were analyzed by t tests.

RESULTS

Demonstrated correlations included BMI and FVC (0.37, p ≤.01), FVC and TK (0.26, p <.01), BMI and TK (0.23, p = .01), and FVC and Cobb angle (-0.23, p = .01). Linear regression revealed that Cobb angle (p ≤.01), TK (p <.01), and BMI (p <.01) remained statistically significant predictors of FVC. Wilcoxon rank-sum tests revealed a statistically significant difference between TK (p = .03) and FVC (p <.01) in the overweight/obese group and the normal group, with the overweight/obese group having greater values for both TK and FVC. The Cobb angles between the overweight/obese and normal group were not significantly different (p = .72).

CONCLUSIONS

Heavier AIS patients have greater values of TK and percentage predicted FVC.

LEVEL OF EVIDENCE

Level III.

Thoracic cage volume and dimension assessment by optoelectronic molding in normal children and adolescents during growth

PURPOSE

The thoracic spine, the chondral and osseous ribs, and the sternum together make up the thoracic cage. These elements are strictly correlated, although their growth is not synchronous. The purpose of this study is to provide a comprehensive data set of thoracic dimensions and non-invasive volumetric assessment in a large cohort of males and females from early childhood to young adult age.

METHODS

In all, 622 healthy individuals (406 girls, 216 boys) aged 6-18 years were consecutively enrolled between 2006 and 2016. All had to be healthy with no history of spinal deformity, or any lung, cardiovascular, systemic or neuromuscular disease. The optical ORTEN system for trunk surface data acquisition was used to calculate thoracic cage volume (V) and perimeter (Pe), anterior-posterior depth (AP) and transverse diameter (TD), AP/TD ratio, sternal length (St), and T1-T12 distance (Tle) in all patients.

RESULTS

The overall average age was 11.1 ± 2.5 years (4-18) for girls and 11.0 ± 3.1 years (4-18) for boys. Average growth parameters were: standing height 146.2 ± 14.6 cm (103-172) for girls and 146.4 ± 20.0 cm (94-192) for boys, sitting height 75.4 ± 8.6 cm (61-91) for girls and 75.5 ± 10.3 cm (60-99) for boys, weight 37.6 ± 10.4 kg (16-65) for girls and 38.3 ± 14.3 kg (13.7-104) for boys, BMI 16.7 ± 3.7 (18.5-26) for girls and 17.0 ± 3.3 (18.7-34.3) for boys. At age 6-8 years: V was 52.5% of its final size in girls and 44.9% in boys; Pe was 80.2% its final length in girls and 76.8% in boys; St reached 68% of its final size in girls and 66.9% in boys; Tle reached 73.3% of its final length in girls and 71.2% in boys. At skeletal maturity, thoracic cage volume in boys was 19.4% greater than in girls (p < 0.05). AP/TD ratio remained < 1 in all age groups and did not differ between genders (p > 0.05).

CONCLUSION

Growth of the thoracic cage is shown to be a gradual process that is more linear than previously reported. Only small increases in annual growth rates were observed during the pubertal growth spurt. The most important events characterizing thoracic cage development occurred during the first few years of postnatal growth. The circular cross-section of the very young child's thorax reached adult-like proportions together with its ovoid shape before age 6 years.

Ventilation/perfusion SPECT/CT in patients with severe and rigid scoliosis: An evaluation by relationship to spinal deformity and lung function

OBJECTIVE

Structural changes of the spine and chest wall associated with SRS result in poor cardiopulmonary function. Comprehensive assessment of pulmonary function is extremely important for patients with SRS before a correction operation. We explore the changes of distribution of lung ventilation and perfusion function in patients with SRS using SPECT/CT and describe the relation between these changes with Cobb angle and FVC%.

PATIENTS AND METHODS

From March 2015 to August 2016, 16 consecutive SRS patients with a mean age of 20.1 years(range 11-36 years) were included in the study. Scoliotic parameters on radiographs were analyzed. FVC% were obtained by spirometry test. Lungs ventilation/perfusion single photon emission computed tomography scans was performed preoperatively in all patients to explore pulmonary ventilation and perfusion function changes. These changes were measured as the deviation form the normal perfusion and ventilation function distribution in right and left lung and correlated with the Cobb angle of main curve and FVC%.

RESULTS

The regional lung ventilation and perfusion function defects were not found in all SRS patients. Ventilation function deviation was a mean 5.7%(range, -3.6% to 10.1%), significantly less than perfusion function deviation of 8.2%(range, -0.3% to 22.2%) (P = 0.015, t = -2.732). Lung ventilation and/or perfusion function deviation did not correlated with Cobb angle and FVC%, respectively. There was significant correlation between lungs ventilation and perfusion function deviation(P = 0.001, r = 0.753).

CONCLUSION

The ventilation and perfusion function distribution were favourable in convex and concave side lung of SRS. Deformity bring about greater lungs perfusion function changes than ventilation function. The measurement of lung ventilation and perfusion function changes may represents an additional functional feature to assess pulmonary function of SRS more comprehensively.

Prediction of respiratory function in patients with severe scoliosis on the basis of the novel individualized spino-pelvic index

OBJECTIVE

Our study aimed to evaluate the pulmonary function of patients with severe scoliosis after correcting standing height with spino-pelvic index (SPI).

METHODS

Inclusion criteria: (1) with a coronal Cobb angle of more than 90°; (2) diagnosed as congenital (CS) or idiopathic scoliosis (IS); (3) aged between ten and 20 years; (4) with pulmonary function test (PFT) at the primary consultation. Patients with previous surgical intervention, with angular kyphosis, and with neuromuscular disease were excluded. Length of spine (LOS), height of spine (HOS), and height of pelvis (HOP) were measured on coronal films. SPI was defined as the ratio between LOS and HOP. The corrected body height was calculated: corrected body height = body height + (SPI × HOP - HOS). The PFTs included the following parameters: VC_max, FVC, FVC% predicted, FEV1, FEV1% predicted, PEF, and MVV. PFT results were recalculated using the corrected body height.

RESULTS

Thirty patients were diagnosed as IS and 27 as CS with average Cobb angles of 99.88° ± 11.83 and 98.06° ± 14.27, respectively. Significant differences were observed in VC_max and FVC between IS and CS patients (P < 0.05). All the corrected PFT parameters were significantly lower than the original PFT parameters (P < 0.05).

CONCLUSION

For the first time, this study proposed a method to predict pulmonary function of patients with severe scoliosis using SPI, as an age-independent parameter in normal adolescents. After body height correction, pulmonary function of patients with severe scoliosis was found to be significantly decreased, indicating that pulmonary function impairment was underestimated in patients with severe scoliosis when evaluating pulmonary function with arm span.

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.

Three-dimensional True Spine Length: A Novel Technique for Assessing the Outcomes of Scoliosis Surgery

BACKGROUND

Current assessment of spine growth for patients undergoing growth friendly surgical treatment for early-onset scoliosis (EOS) is the use of serial, 1-dimensional standard-of-care coronal vertical spine height (SoCVH) measurements. Any growth of the spine out of the coronal plane is missed by the SoCVH, which may underestimate the actual growth of the spine. This study set to validate the novel 3-dimensional true spine length (3DTSL) radiographic measurement technique for measuring growth of EOS patients.

METHODS

3DTSL measurement accuracy, reliability, and repeatability was assessed using 10 physical model configurations. In addition, interrater and intrarater reliabilities (IRRs) were assessed using interclass coefficient (ICC) analyses of 23 retrospective EOS patient clinical radiographs. 3DTSL measurements were compared with SoCVH measurements.

RESULTS

The model assessment showed excellent accuracy with a mean error of 1.2 mm (SD=0.9; range, 0.0 to 3.0) and mean ICC of 0.999.IRR ICCs of the clinical radiographs averaged 0.952 for the 3DTSL and 0.975 for the vertical height whereas IRRs averaged 0.944 and 0.965, respectively (all P<0.001).Mean clinical 3DTSL curve lengths were 193.9 mm (SD=30.0; range, 142.8 to 276.8), whereas the SoCVH averaged 156.1 mm (SD=29.7; range, 74.7 to 207.3). The mean difference between the matched 3DTSL and SoCVH measurements was 37.8 mm (SD=21.4; range, 1.3 to 95.4) and was statistically significant (P<0.0001). On average, the 3DTSL of the measured spines was 124.2% of the measured SoCVH, with a progressive difference as the Cobb or kyphosis angles increased.

CONCLUSIONS

The novel 3DTSL measurement is accurate, repeatable, and complements the current growth assessments for EOS treatments.

LEVEL OF EVIDENCE

Level II-diagnostic study-development of a diagnostic criteria on basis of consecutive patients, with gold standard.

Long-term Pulmonary Function After Open Anterior Thoracolumbar Surgery in Thoracolumbar/Lumbar Idiopathic Adolescent Scoliosis

STUDY DESIGN

A prospectively updated, long-term case series analysis.

OBJECTIVE

The aim of this study was to report the effect of thoracolumbar anterior open surgery performed during adolescence on adult pulmonary function.

SUMMARY OF BACKGROUND DATA

There seems to be subclinical impairment of pulmonary function in the mid-term (2-5 years) in patients who underwent thoracotomy or thoraco-phreno-laparotomy after adolescent idiopathic scoliosis (AIS) surgery. However, long-term results when patients reach adulthood are lacking.

METHODS

Prospective data of pulmonary function tests (PFTs) on adult patients who underwent anterior open surgery during adolescence due to main thoracolumbar/lumbar curves were collected. Forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and the Tiffeneau index (TI: FEV1/FVC) with a 12-year minimum follow-up were recorded. These figures were compared with reference (predicted) values and preoperative data.

RESULTS

Twenty-four patients were included. All patients had undergone a thoraco-phreno-laparotomy. None of the patients had pulmonary disease. Mean age was 15.83 years at the time of surgery and the mean follow-up was 18.26 years (12-29 years).Long-term results of the 24 operated patients (mean ± SD: FVC = 3.3 ± 0.39; FEV1 = 2.6 ± 0.38; TI = 80.3 ± 5.7) showed a similar FVC and slightly worse FEV1 than reference values (FVC = 3.4 ± 0.48; FEV1 = 3.03 ± 0.42; TI = 82.4 ± 1.3), (P = 0.21; P = 0.02; P = 0.3, respectively). Nevertheless, the values were within the normal percent-predicted range for FVC (93.5% ± 11.2) and FEV1 (91.4% ± 12.8). In 14 patients, long-term figures (median ± IQR): FVC = 3.2 ± 0.6; FEV1 = 2.54 ± 0.42; TI = 81.5 ± 11.2) were compared with preoperative values (median ± IQR: FVC = 2.9 ± 0.8; FEV1 = 2.47 ± 0.93; TI = 84.8 ± 34.2), (P = 0.08, P = 0.92, P = 0.026, respectively). Only the TI showed significant differences due to disproportionate improvement of FVC and FEV1 during the follow-up years.

CONCLUSION

Thoracolumbar/lumbar AIS patients who underwent a thoraco-phreno-laparotomy during adolescence showed, in the long-term (18 years follow-up), a similar FVC compared with the reference values that was slightly superior than the values before surgery. Despite the lower FEV1 than the reference values and taking into consideration our limitations, the percent-predicted values were within the normal range, indicating no major pulmonary impairment in the long run.

LEVEL OF EVIDENCE

4.

Three-dimensional and volumetric thoracic growth in children with moderate idiopathic scoliosis compared with normal

We aimed to measure thoracic dimensions and volume in relation to growth and verify the influence of scoliosis on thoracic growth. A reference group of 294 healthy volunteers was compared with a group of 557 patients with idiopathic scoliosis ranging in age from 3 to 25 years. The optical ORTEN system for trunk surface data acquisition was used to calculate thoracic volume, perimeter, anterior-posterior and transversal diameters, T1-T12 length, and sternal length. There was no significant difference in thoracic dimensions and volume between scoliosis and reference groups in either girls or boys. Thoracic volume correlated with weight and with sitting height. The transversal diameter represented ∼30%, the anterior-posterior diameter 20%, and the thoracic perimeter 100% of sitting height. Mild and moderate scoliosis does not affect thoracic diameters and volume at any stage of growth. Relationships between thoracic parameters and sitting height are valuable indicators in clinical practice. They do not differ between normal individuals and scoliotic patients with moderate trunk asymmetry.

Development and assessment of a digital X-ray software tool to determine vertebral rotation in adolescent idiopathic scoliosis

BACKGROUND CONTEXT

The amount of vertebral rotation in the axial plane is of key importance in the prognosis and treatment of adolescent idiopathic scoliosis (AIS). Current methods to determine vertebral rotation are either designed for use in analogue plain radiographs and not useful in digital images, or lack measurement precision and are therefore less suitable for the follow-up of rotation in AIS patients.

PURPOSE

This study aimed to develop a digital X-ray software tool with high measurement precision to determine vertebral rotation in AIS, and to assess its (concurrent) validity and reliability.

STUDY DESIGN/SETTING

In this study a combination of basic science and reliability methodology applied in both laboratory and clinical settings was used.

METHODS

Software was developed using the algorithm of the Perdriolle torsion meter for analogue AP plain radiographs of the spine. Software was then assessed for (1) concurrent validity and (2) intra- and interobserver reliability. Plain radiographs of both human cadaver vertebrae and outpatient AIS patients were used. Concurrent validity was measured by two independent observers, both experienced in the assessment of plain radiographs. Reliability-measurements were performed by three independent spine surgeons.

RESULTS

Pearson correlation of the software compared with the analogue Perdriolle torsion meter for mid-thoracic vertebrae was 0.98, for low-thoracic vertebrae 0.97 and for lumbar vertebrae 0.97. Measurement exactness of the software was within 5° in 62% of cases and within 10° in 97% of cases. Intraclass correlation coefficient (ICC) for inter-observer reliability was 0.92 (0.91-0.95), ICC for intra-observer reliability was 0.96 (0.94-0.97).

CONCLUSIONS

We developed a digital X-ray software tool to determine vertebral rotation in AIS with a substantial concurrent validity and reliability, which may be useful for the follow-up of vertebral rotation in AIS patients.

Untreated Thoracic Curve in Adult Idiopathic Scoliosis: What Are Patients' Concerns?

STUDY DESIGN

Retrospective two-cohort comparative analysis of data collected prospectively.

OBJECTIVES

To analyze a cohort of patients with untreated thoracic curves of an adult multicenter deformity database [European spine study group (ESSG)], describe patient characteristics and concerns, and establish the rate and motivations for surgical intervention.

SUMMARY OF BACKGROUND DATA

Idiopathic thoracic curves have a significant clinical and socioeconomic impact during adolescence. However, little attention has been given to adult thoracic scoliosis. The complaints of patients that have reached adulthood with an untreated thoracic curve are still not well studied.

METHODS

The database of 1,142 prospective consecutive adult patients with deformity was searched to identify patients with untreated thoracic idiopathic curves: Schwab Type T curves, and Schwab Type D with thoracolumbar/lumbar (TL/L) curves <40° and a difference between main thoracic (MT) and the TL/L ≥15°. Demographic data, different radiologic preoperative parameters, and health-related quality of life questionnaires were assessed.

RESULTS

Forty-two patients met inclusion criteria, showing the following characteristics: age, 30.9 ± 12.5 years; thoracic Cobb, 55.6 ± 10.8°; lumbar Cobb, 28.1 ± 7.3°; sagittal vertical axis, 2.9 ± 19.3 cm; Core Outcome Measures Index (COMI), 4 ± 2.5; Oswestry Disability Index (ODI), 20.4 ± 17.4; Scoliosis Research Society-22 questionnaire (SRS-22) subtotal, 3.6 ± 0.7; 36-Item Short Form Health Survey (SF-36) mental health, 46.1 ± 10.1; SF-36 physical health, 47.3 ± 11.1. Only 13 of these patients underwent surgery. Compared with nonoperated patients, they were younger (24.3 ± 7.3 vs. 33.8 ± 13.4 years; p = .009), had larger MT curves (58.7° ± 9.6 vs. 50.6° ± 8.3; p = .012), and had worse SRS-22 self-image scores (2.9 ± 0.8 vs. 3.5 ± 0.8; p = .042). No patients older than 50 years underwent surgery, despite having worse SRS-22 function (3.0 ± 0.9 vs. 4.1 ± 0.9, p = .032) and worse ODI scores (42.4 ± 19.9 vs. 18.7 ± 18.0, p = .026).

CONCLUSIONS

Very few adult deformity patients sought treatment because of untreated thoracic scoliotic curve. The probability of undergoing surgery was low (13/42), and it was associated with youth, curve magnitude, and poor self-image. The rate of surgical treatment of the thoracic curve appears to diminish with age, despite its being associated with poorer function and greater disability in the older patient.

Complications and Radiographic Outcomes of Posterior Spinal Fusion and Observation in Patients Who Have Undergone Distraction-Based Treatment for Early Onset Scoliosis

STUDY DESIGN

Retrospective, multicenter.

OBJECTIVES

To compare surgical and radiographic outcomes of early-onset scoliosis (EOS) patients who had stopped lengthening for ≥2 years without additional surgery to those who had posterior spinal fusion (PSF) at the end of lengthening.

SUMMARY OF BACKGROUND DATA

Because of the risk of significant complications with PSF in patients with EOS, "watchful waiting" at the end of lengthening has been suggested as a viable alternative.

METHODS

Retrospective review of the Children's Spine Study Group (CSSG) database identified all patients with the diagnosis of EOS who had distraction-based treatment, who were ≥2 years from their last distraction, and who had complete records. Radiographic measures were obtained by a single unbiased trained observer. Treatment outcomes including curve correction, height and length gain, as well as complications were recorded.

RESULTS

The 37 patients (21 females and 16 males) had a mean age of 7.2 years; 12 were in the observation (OBS) and 25 in the PSF group. The PSF group had a slightly greater coronal Cobb angle and maximal kyphosis at the end of distraction. Although there was some correction of the coronal Cobb angle and maximal kyphosis following PSF, the differences between the two groups were not statistically significant at final follow-up. At final follow-up, the OBS group obtained 88% of T1-T12 height and 90% of T1-L1 length of that obtained by the PSF group. Twenty-six complications occurred in 15 patients, all in the PSF group.

CONCLUSIONS

Observation may be a viable alternative to PSF after distraction-based treatment in a subset of patients with EOS. PSF was found to provide no significant curve correction or gains in spine height and length compared to observation and carries a significant risk of complications.

LEVEL OF EVIDENCE

Level III, therapeutic.

Cardiopulmonary Exercise Testing in Patients with Idiopathic Scoliosis

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

Goal-Directed Fluid Therapy Based on Stroke Volume Variation in Patients Undergoing Major Spine Surgery in the Prone Position: A Cohort Study

STUDY DESIGN

A retrospective observational study.

OBJECTIVE

The aim of this study was to test whether a goal-directed fluid therapy (GDFT) protocol, based on stroke volume variation (SVV), applied in major spine surgery performed in the prone position, would be effective in reducing peri-operative red blood cells transfusions.

SUMMARY OF BACKGROUND DATA

Recent literature shows that optimizing perioperative fluid therapy is associated with lower complication rates and faster recovery.

METHODS

Data from 23 patients who underwent posterior spine arthrodesis surgery and whose intraoperative fluid administration were managed with the GDFT protocol were retrospectively collected and compared with data from 23 matched controls who underwent the same surgical procedure in the same timeframe, and who received a liberal intraoperative fluid therapy.

RESULTS

Patients in the GDFT group received less units of transfused red blood cells (primary endpoint) in the intra (0 vs. 2.0, P = 0.0 4) and postoperative period (2.0 vs. 4.0, P = 0.003). They also received a lower amount of intraoperative crystalloids, had fewer blood losses, and lower intraoperative peak lactate. In the postoperative period, patients in the GDFT group had fewer pulmonary complications and blood losses from surgical drains, needed less blood product transfusions, had a shorter intensive care unit stay, and a faster return of bowel function. We found no difference in the total length of stay among the two groups.

CONCLUSION

Our study shows that application of a GDFT based on SVV in major spine surgery is feasible and can lead to reduced blood losses and transfusions, better postoperative respiratory performance, shorter ICU stay, and faster return of bowel function.

LEVEL OF EVIDENCE

3.

Sagittal Spine Length Measurement: A Novel Technique to Assess Growth of the Spine

STUDY DESIGN

The accuracy and repeatability of a novel sagittal spine length (SSL) radiographic measurement was examined using photographic and radiographic imaging.

OBJECTIVES

To validate the new SSL technique for measuring growth in early-onset scoliosis (EOS) patients.

SUMMARY OF BACKGROUND DATA

Current assessment of patient growth undergoing growth-friendly surgical treatment for EOS is the use of serial vertical spine height measurements (VH) on coronal radiographs. Spine-based distraction implants are able to control the coronal plane deformity of scoliosis, but exhibit a "law of diminishing returns" in the impact of each follow-up lengthening surgery. As these treatments are kyphogenic, we hypothesize that the increase in kyphosis is, in fact, growth out of plane, not captured by standard spine height measurements.

METHODS

Measurement accuracy was assessed using 6 spine model alignments and clinical radiographs of 23 retrospective EOS patients. Inter- and intrarater reliabilities were assessed using interclass coefficient (ICC) analyses. The discrepancy between the VH and SSL was also investigated.

RESULTS

The model assessment showed excellent accuracy, with a 1.54 mm (SD: 1.07, range: 0.03-3.14, p = .226) mean error and mean ICCs of 0.999. As the kyphosis increased, a progressive difference between the phantom VH and SSL was observed. Interrater reliability ICCs of the clinical radiographs averaged 0.981 and 0.804, whereas intrarater reliabilities averaged 0.966 and 0.826, for the coronal and sagittal radiographs, respectively. Mean clinical SSLs were 177.5 mm (SD: 28.5, range: 114.3-250.3), whereas the VH averaged 161.6 mm (SD: 31.8, range: 58.5-243.0), resulting in a 16.0-mm (SD: 16.7, range: 0.3-90.3, p < .0001) difference between the two measurements with a progressive difference as the kyphosis increased.

CONCLUSIONS

The novel SSL measurement is accurate, repeatable, and complements the current growth assessments for EOS treatments. Until sagittal spine lengths are taken into consideration, the "law of diminishing returns" should be interpreted with caution.

LEVEL OF EVIDENCE

Level II - Prospective Comparative Study.

Associations of LBX1 gene and adolescent idiopathic scoliosis susceptibility: a meta-analysis based on 34,626 subjects

Background

The results of studies investigating the association between the ladybird homeobox 1 (LBX1) gene polymorphisms and the risk of adolescent idiopathic scoliosis (AIS) are not all the same. As such, we performed a meta-analysis to estimate the association between LBX1 gene polymorphisms and AIS susceptibility.

Methods

Relevant studies published before 15 November 2015 were identified by searching PubMed, EMBASE, ISI web of knowledge, EBSCO, CNKI and CBM. The strength of relationship was assessed by using odds ratios (ORs) and 95 % confidence interval (CI).

Results

A total number of eight case-control studies including 10,088 cases and 24,538 controls were identified. The results showed that T allele of rs111090870 increased AIS susceptibility in Asians (T vs. C, OR = 1.22, 95 % CI: 1.16–1.29, P < 0.001), Caucasians (T vs. C, OR = 1.17, 95 % CI: 1.14–1.21, P < 0.001) and in female (T vs. C, OR = 1.21, 95 % CI: 1.17–1.25, P < 0.001). The G allele of rs678741 decreased AIS risk in female (G vs. A, OR = 0.83, 95 % CI: 0.81–0.85, P < 0.001), and the G allele of the rs625039 increased AIS susceptibility in Asians (G vs. A, OR = 1.14, 95 % CI: 1.11–1.17, P < 0.001).

Conclusions

Our meta-analysis provides evidence that rs111090870, rs678741 and rs625039 polymorphisms near LBX1 gene are associated with AIS susceptibility in some populations. However, our findings are based on only a limited number of studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1139-z) contains supplementary material, which is available to authorized users.

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

PURPOSE

Study of patients with adolescent idiopathic scoliosis.

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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