Effect of Surgical Approach on Pulmonary Function in Adolescent Idiopathic Scoliosis Patients: A Systemic Review and Meta-analysis

Surgical Treatment Strategies for Severe and Neglected Spinal Deformities in Children and Adolescents without the Use of Radical Three-Column Osteotomies

Background: Severe spinal deformity manifests as a pronounced deviation from the normal curvature of the spine in the frontal, sagittal, and horizontal planes, where the coronal plane curvature exceeds 90 degrees and may coincide with hyperkyphotic deformity. The most severe deformities exhibit rigidity, with flexibility below 30%. If left untreated or improperly treated, these deformities can result in serious complications associated with progression of the curvature. A combination of surgical techniques is frequently employed to attain optimal outcomes and minimize the risk of complications. The overall medical condition of the patient, their capacity to endure extensive procedures, the expertise of the surgeon, and the resources available all play significant roles in determining the course of management. A systematic and thorough review of the relevant literature was conducted utilizing a variety of electronic databases. The primary objective of this study was to scrutinize the surgical techniques commonly employed in complex spine surgeries for the management of severe scoliosis without resection vertebral body techniques, with higher potential risk of major complications, including permanent neurological deficit. Conclusions: Halo-gravity traction, halo femoral traction, and all techniques for releases of the spine (anterior, posterior, or combine), as well as thoracoplasty, have demonstrated significant effectiveness in managing severe and rigid idiopathic scoliosis. The combination of several of these methods can lead to optimal alignment correction without the need to perform high-risk techniques involving three-column osteotomies. Surgeons must customize the indications based on factors such as available resources, characteristics of the deformity, and the patient's individual profile. Surgical correction of severe scoliosis without vertebral body resection surgeries decreases the potential risks related to neurological and pulmonary complications while providing significant clinical improvement outcomes. The powerful Ponte osteotomy is indicated for severe scoliosis, curves with poor flexibility, for better restoration of hypokyphosis, and decrease of hyperkyphosis. These corrective techniques combined with HGT or temporary internal distraction rods are recommended as viable options for managing individuals with severe rigid spine deformity characteristics. Therefore, they also should be considered and performed by a proficient surgical team. The presence of neuromonitoring is crucial throughout these procedures.

Is the anterior approach still superior to posterior correction in AIS regarding correction, fusion levels and kyphosis when modern posterior systems are used?

PURPOSE

The aim of our study is to compare anterior and posterior corrections of thoracic (Lenke I) and lumbar (Lenke V) curves when modern posterior pedicle screw systems with vertebral derotation techniques are used. Curves that could not be corrected with both systems were excluded.

METHODS

A thoracic group (N = 56) of Lenke I AIS patients (18 anterior and 38 posterior) and a lumbar group (N = 42) of Lenke V patients (14 anterior and 28 posterior) with similar curves < 65° were identified.

RESULTS

Thoracic group The mean postoperative correction (POC) was 68 ± 13.4% in the anterior and 72 ± 10.5% in the posterior group. The postoperative change in thoracic kyphosis was +4° and +5° respectively. The median length of fusion was eight segments in the posterior and seven segments in the anterior groups. In 89% the LIV was EV or shorter in the anterior, and in 71% of the posterior corrections. Lumbar group The mean POC was 75 ± 18.3% (anterior) and 72 ± 8.5% (posterior). The postoperative gain in lumbar lordosis was 0.8° (anterior) and 4° (posterior). The median length of fusion was five segments in both groups and there was no difference in relation of the LIV to the EV.

CONCLUSION

With modern implants and derotation techniques, the posterior approach can achieve similar coronal correction, apical derotation and thoracic kyphosis with similar length of fusion and better lumbar lordosis restoration.

A thoracoscopic anterior approach to the spine for adolescent idiopathic scoliosis does not have a detrimental effect on pulmonary function at 2 years compared to posterior-only surgery

PURPOSE

This study aims to examine pulmonary function outcomes in patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal fusion (PSF) with an anterior thoracoscopic release compared to those undergoing PSF alone.

METHODS

A retrospective review of patients with AIS over a 9-year period at a single institution compared 2 groups: PSF with video-assisted thoracoscopic surgery (PSF/VATS) and patients undergoing a posterior spinal fusion (PSF) alone. Standard radiographs and Forced Expiratory Volume (FEV1) and Forced Vital Capacity (FVC) were obtained preoperatively and at regular follow up periods up to 2-year post-operatively. Within group and between-group comparisons were performed.

RESULTS

There were 110 patients in the study: 12 in the PSF/VATS cohort and 98 in the PSF only cohort. The PSF/VATS group were younger (12.6 vs. 14.6, p = 0.003) and had larger coronal curves (80.8° vs. 60.7°, p = 0.001), and worse preoperative FVC (64.7% vs. 79.6%, p = 0.018) and FEV1 (62.3% vs. 77.6%, p = 0.003). At 2 years, the percent coronal Cobb correction was greater in the PSF/VATS group (67.9% vs. 48.4%, p < 0.001) with greater improvement in thoracic height (32.8 mm vs. 20.7 mm, p = 0.028). While the 2-year PFTs were the same for FEV1% (75.8% vs. 81.8%, p = 0.368) and FVC% (77.3% vs. 83.7%, p = 0.562), there was greater percent improvement over the 2 years in the PSF/VATS cohort: FEV1% (13.5% vs. 4.2%, p = 0.082) and FVC% (12.7% vs. 4.1%, p = 0.112).

CONCLUSION

AIS patients who have a VATS approach in addition to PSF have greater coronal plane correction and improved pulmonary function compared to PSF alone despite more severe spinal deformity and worse baseline pulmonary function.

Abolition of sagittal T7-T10 dynamics during forced ventilation in AIS patients with Lenke 1A curves

In healthy subjects, respiratory maximal volumes are highly dependent on the sagittal range of motion of the T7-T10 segment. In AIS, the abolition of T7-T10 dynamics related to the stiffness induced by the apex region in Lenke IA curves could harm ventilation during maximal breathing. The aim of this study was to analyze the dynamics of the thoracic spine during deep breathing in AIS patients and in healthy matched controls. This is a cross-sectional, case-control study. 20 AIS patients (18 girls, Cobb angle, 54.7 ± 7.9°; Risser 1.35 ± 1.2) and 15 healthy volunteers (11 girls) matched in age (12.5 versus 15.8 years mean age) were included. In AIS curves, the apex was located at T8 (14) and T9 (6). Conventional sagittal radiographs of the whole spine were performed at maximal inspiration and exhalation. The ROM of each spinal thoracic functional segment (T1-T7, T7-T10, T10-T12) and the global T1-T12 ROM were measured. In healthy subjects, the mean T1-T12 ROM during forced breathing was 16.7 ± 3.8. AIS patients showed a T1-T12 ROM of 1.1 ± 1.5 (p < 0.05), indicating a sagittal stiffness of the thoracic spine. A wide T7-T10 ROM (15.3 ± 3.0) was found in healthy controls (91.6% of the T1-T12 ROM). AIS patients showed only 0.4 ± 1.4 ROM at T7-T10 (36.4% of the T1-T12 ROM) (p < 0.001). There was a linear relationship between the magnitude of T7-T10 kyphosis in maximal exhalation and both FVC (% of predicted FVC) and FEV1. In conclusion, Lenke 1A AIS patients show a restriction of the thoracic spine motion with an almost complete abolition of T7-T10 ROM, a crucial segment for deep breathing. T7-T10 stiffness could explain the ventilatory limitations found in AIS patients.

Convex-concave and anterior-posterior spinal length discrepancies in adolescent idiopathic scoliosis with major right thoracic curves versus matched controls

PURPOSE

The apical deformation in adolescent idiopathic scoliosis (AIS) is a combination of rotation, coronal deviation and passive anterior lengthening of the spine. In AIS surgery, posterior-concave lengthening or anterior-convex shortening can be part of the corrective maneuver, as determined by the individual surgeon's technique. The magnitude of convex-concave and anterior-posterior length discrepancies, and how this needs to be modified to restore optimal spinal harmony, remains unknown.

METHODS

CT-scans of 80 pre-operative AIS patients with right convex primary thoracic curves were sex- and age-matched to 80 healthy controls. The spinal length parameters of the main thoracic curves were compared to corresponding levels in controls. Vertebral body endplates and posterior elements were semi-automatically segmented to determine the length of the concave and convex side of the anterior column and along the posterior pedicle screw entry points while taking the 3D-orientation of each individual vertebra into account.

RESULTS

The main thoracic curves showed anterior lengthening with a mean anterior-posterior length discrepancy of + 3 ± 6%, compared to a kyphosis of - 6 ± 3% in controls (p < 0.01). In AIS, the convex side was 20 ± 7% longer than concave (0 ± 1% in controls; p < 0.01). The anterior and posterior concavity were 7 and 22 mm shorter, respectively, while the anterior and posterior convexity were 21 and 8 mm longer compared to the controls.

CONCLUSIONS

In thoracic AIS, the concave shortening is more excessive than the convex lengthening. To restore spinal harmony, the posterior concavity should be elongated while allowing for some shortening of the posterior convexity.

Posterior scoliosis correction with thoracoplasty: effect on pulmonary function with a mean follow-up of 4.8 years

PURPOSE

To perform a study to investigate the influence of posterior scoliosis surgery and thoracoplasty on pulmonary function.

METHODS

This was a retrospective observational study of 37 patients with AIS who underwent posterior instrumented surgical correction with thoracoplasty. There was a minimum of 2 years follow-up. Clinical outcomes were measured using the SRS-22 questionnaires. Radiological outcomes were evaluated using standing posteroanterior and lateral radiographs. All patients had pulmonary function tests to evaluate pulmonary volume and flow (forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC)) both before surgery and at the final follow-up.

RESULTS

There were three males and 34 females. The mean age of patients was 14.6 years (range 11-21 years). The mean length of follow was 58 months (range 24-124 months). The average main thoracic Cobb angle in the coronal plane was corrected from 50.0° ± 12.4° preoperatively to 16.6° ± 6.3° postoperatively. The average thoracolumbar Cobb angle in the coronal plane was corrected from 28.2° ± 10.6° preoperatively to 10.1° ± 7.2°. The average thoracic kyphosis angle was corrected from 17.4° ± 11.0° preoperatively to 21.8° ± 10.5°. In terms of the Quality of life Outcomes (QoL), there was a significant increase (p < 0.001) in the mean SRS 22 scores from 3.8 preoperatively to 4.3 postoperatively. A statistically significant increase in the absolute forced expiratory volume in one second (FEV1) from pre-operative values with a p value < 0.001 was seen. There was a statistically significant increase in percentage predicted forced expiratory volume in one second from preoperative values with a p value of 0.008. There was also a statistically significant increase in the absolute forced vital capacity (FVC) from preoperative values with a p value < 0.001. The average percentage predicted forced vital capacity did increase on final follow-up from before surgery, but the increase was not statistically significant.

CONCLUSIONS

We have demonstrated that pulmonary function post-thoracoplasty not only reaches pre-operative levels, but significantly surpasses it with regards to the majority of the pulmonary parameters measured in this study. We also demonstrated satisfactory radiological correction and clinical outcomes.

Is There a Correlation Between Cobb Angle and Pulmonary Function Tests at 2-year Follow-up in Patients With Severe Spinal Deformity Treated by Posterior Vertebral Column Resection?

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim was to evaluate the relationships of Cobb angle and pulmonary function tests (PFTs) changes in severe spinal deformity and underwent posterior vertebral column resection (PVCR).

SUMMARY OF BACKGROUND DATA

No previous study focused on the correlation of deformity correction and PFTs changes in patients with cobb angle >90 degrees.

METHODS

PFTs values [forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and percent-predicted values FVC%, FEV1%] were evaluated preoperative and at 2 years after PVCR. FVC% <80% were defined as restrictive ventilation dysfunction (RVD), the severity of RVD were divided into mild (FEV1% ≥70%), moderate (70% > FEV1% ≥50%) and severe (FEV1% <50%). The relationships among PFTs values improvements and all possible impact factors (mainly correction cobb angle) collected in this study were analyzed. PFTs data were compared among the 3 RVD subgroups (mild vs. moderate vs. severe) and between residual >30 versus <30 degrees.

RESULTS

A total of 53 cases (28 male/25 female, mean ages 18.9 Y) underwent PVCR in one center from 2004 to 2016 were enrolled cobb angle. When 2 years after PVCR, average PFTs values showed significant improvements. PFTs values changes showed no correlation with correction rate and correction angle. The only significant impact factor in this study for FVC, FVC%, FEV1 improvements was preoperative FVC% and the only impact factor for FEV1% improvement was preoperative FEV1%, the relationships were negative. In accordance with the regression analysis, PFTs values improvements among the 3 RVD subgroups from high to low was severe>moderate>mild. However, patients with residual cobb angle <30 degrees had less PFTs values improvements than patients with residual cobb angle >30 degrees.

CONCLUSIONS

Two years after PVCR, PFTs values were significantly improved. There is no linear correlation between cobb angle change and PFTs values improvements. Lower preoperative FVC% and FEV1% indicate more PFTs values improvements at 2 years post-PVCR.

LEVEL OF EVIDENCE

Level III.

Association between intra-operative hemodynamic changes and corrective procedures during posterior spinal fusion in adolescent patients with scoliosis: A case-control study

Previous reports indicated that a decrease in intra-operative cardiac output and mean arterial pressure occurs due to thoracic cage deformities when patients with scoliosis are placed in the prone position. The aims of this study were to investigate the occurrence of hypotension during posterior spinal fusion in adolescent patients with scoliosis, and the association between hypotension, surgical procedures, changes of thoracic cage morphology.This retrospective, single-center, case-control study included 106 patients who underwent surgeries for spinal deformity at our institute between June 2014 and March 2020. The inclusion criteria were: age ≤19 years at the time of surgery, lowest instrumented vertebra over L5, posterior spinal fusion as the first surgery for scoliosis, and no severe cardiac or pulmonary disease pre-operatively. Finally, 49 patients met the criteria, and were divided to 3 groups as follows: thoracic constructive curve using a 6.0-mm cobalt-chromium alloy circular rod (T-C group; n = 28); thoracolumbar/lumbar constructive curve using a 6.0-mm cobalt-chromium alloy circular rod (L-C group; n = 8); and thoracic constructive curve using a 5.5-mm cobalt-chromium alloy beam-like rod (T-B group; n = 13). The beam-like rod is characteristic as the rod is mounted to screw heads without cantilever force. Intra-operative changes in circulation associated with corrective procedures, perioperative data, and sagittal depth and sternum deviation of thoracic cage were compared between the 3 groups.The T-C group had a higher rate of hypotension alarm than did the other groups (7 vs 0 vs 0; P = .047). Corrective procedures included rodding 4 times, rod rotation maneuver once, and direct vertebral rotation twice. Blood pressure was increased by pausing the correction procedures, increasing infusion, and administering vasopressors. The T-C and T-B groups had greater sternum deviation parameters than the L-C group, both before and after surgery. All parameters associated with sagittal depth and sternum deviation decreased significantly after surgery in the T-C and the T-B groups.In corrective surgery for constructive thoracic scoliosis, the corrective procedures requiring the application of compression force in the forward direction should be closely monitored in view of their possible influence on circulatory conditions.

Does pulmonary function improve after surgical correction of adult idiopathic scoliosis?

PURPOSE

The aim was to investigate pulmonary function after surgical correction of adult idiopathic scoliosis.

METHODS

This study included 146 adult scoliosis patients aged 20-50 years (main curve in thoracic spine). Respiratory function was assessed as predicted forced vital capacity (%FVC) and the ratio of forced expiratory volume in 1 s / FVC (%FEV₁) preoperatively and 2 years postoperatively and classified as a normal function (≥ 80%), mild impairment (≥ 65% and < 80%), and moderate impairment (< 65%).

RESULTS

Preoperative %FVC and %FEV₁ were 85.3% and 85.4%, which were 81.5% and 87.5% at 2 years post-surgery. The preoperative %FVC was mild and moderate in 39 (26.7%) and 12 patients (11.6%), respectively. The %FVC significantly improved (+ 6.2% ± 11.4%, P < 0.001) postoperatively for moderate severity but significantly decreased postoperatively (- 6.4% ± 9.4%, P < 0.001) for normal function. The preoperative %FEV₁ was mild and moderate in 27 (18.5%) and 0 patients, respectively. The %FEV1 significantly improved postoperatively (6.3% ± 5.3%, P < 0.001) for mild severity but did not significantly change for normal severity. Twenty-three (15.8%) and 41 (28.1%) patients showed improved ⊿%FVC and ⊿% FEV₁ > 5%. Logistic regression analysis showed that preoperative %FVC and %FEV₁ severities were independent factors affecting postoperative recovery of %FVC (OR 0.95) and %FEV₁ (OR 0.85).

CONCLUSION

Pulmonary function improved in patients with preoperative pulmonary impairment of < 65% in %FVC and < 80% in %FEV₁, and the real improvement was limited to patients with severe preoperative impairment.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Incidence rate of congenital scoliosis estimated from a nationwide health insurance database

To investigate the epidemiology of congenital scoliosis (CS) and treatment trends. An age-matched, nationwide, population-based study was conducted using the National Health Insurance and Health Insurance Review and Assessment databases from 2010 to 2015. Data regarding the diagnosis and treatment of scoliosis were extracted using International Classifications of Diseases, 10th revision codes. The age-matched normal population was determined from the Korean Statistical Information Service database. We analyzed the incidence rate of CS according to age and sex, as well as the proportion of surgically treated patients. A total of 1664 patients (aged 0-19 years) were diagnosed with CS. The overall average incidence rate of CS over the 5-year period was 3.08 per 100,000 persons, with the highest and second highest rates at 0 years and 12-16 years of age, respectively. The incidence rate stratified by age ranged from 1.5 to 20.1 per 100,000 persons among the age-matched normal population, with peaks at 0 years of age and the second growth spurt in adolescence (12-16 years for males; 10-14 years for females). Anterior surgery was rarely performed; posterior surgery was performed in 92 patients (5.5% of all patients), with the highest prevalence (56.5%) in patients diagnosed at 10-14 years of age. The overall average incidence rate of CS over a 5-year period was 3.08 per 100,000 persons. Only 5.5% of patients underwent surgery within 5 years after the initial diagnosis.

The effects of thoracoplasty on immediate post-operative recovery in adolescent idiopathic scoliosis

PURPOSE

The purpose of this study was to evaluate differences in pain, opiate utilization and oxygen (O₂) consumption during the immediate post-operative course for patients undergoing posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) with and without thoracoplasty.

METHODS

Patients aged 10-21 years old that had undergone PSF for AIS were identified from 1/1/16-8/1/18. A cohort of patients that did not have a thoracoplasty group was used as a control group. A standardized pain protocol (rapid response pathway) was implemented on all patients. A retrospective chart review was performed. Pre-operative, operative and post-operative data and SRS scores were analyzed.

RESULTS

Forty-six patients (38 girls, 8 boys) were included, 23 in each group. The average age was 15.2 years (range 12.0-19.3) and BMI was 20.9 (range 13.1-37.6). Differences in visual analog scores, post-operative oxygen and narcotic consumption were not statistically significant on any POD. Total opiate utilization was 146.06 morphine milligram equivalents (MME) in the control group and 149.41 MME in the thoracoplasty group (p = 0.78). One-year SRS self-image scores were higher in the thoracoplasty group (4.24 vs 3.96) (p = 0.007). There was no difference in length of hospitalization (3.6 vs 3.5 days), levels fused (12.9 vs 12.9) or blood loss (334.1 vs 413.5 mL). There was one pleural effusion and no instances of intercostal neuralgia or pneumothorax in the thoracoplasty group.

CONCLUSION

There is no increase in immediate post-operative pain, narcotic use or oxygen consumption when a thoracoplasty is performed with a PSF for AIS. Improved SRS self-image scores were seen after thoracoplasty.

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.

Pulmonary Function Improves in Patients with Adolescent Idiopathic Scoliosis who Undergo Posterior Spinal Fusion Regardless of Thoracoplasty: A Mid-Term Follow-Up

Introduction

The purpose of the present study was to determine, in a mid-term follow-up 5 years or more after surgery, the forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and expiratory flow in patients with adolescent idiopathic scoliosis (AIS) who underwent posterior spinal fusion (PSF) with or without thoracoplasty.

Methods

The subjects were 134 patients with AIS who underwent PSF between 2004 and 2013. Forty-five patients agreed to participate in the study. We divided the patients into two groups as follows: 24 patients who underwent PSF with thoracoplasty from 2004 to 2010 in the TP group and 21 patients who underwent PSF without thoracoplasty from 2011 to 2013 in the non-TP group. We evaluated whole spine X-ray imaging and pulmonary function tests (PFTs) in these patients. PFTs measured FVC, FEV1, peak expiratory flow (PEF), maximum expiratory flow at 50% FVC (V50), maximum expiratory flow at 25% FVC (V25), and the ratio of V50 to V25 (V50/V25).

Results

The main thoracic curves were 53.6 ± 10.1° before surgery, 19.8 ± 7.6° 1 week after surgery, 22.3 ± 8.3° 2 years after surgery, and 23.3 ± 7.6° at the most recent observation. Compared with preoperative values, FVC, FEV1, and % FEV1 were improved significantly at the most recent observation. No significant difference was observed between % FVC before surgery and at the most recent observation. Compared with preoperative values, PEF, V50, and V25 were improved significantly at the most recent observation. V50/V25 did not change significantly. The changes in PFT values in the TP group and the non-TP group were compared. No significant differences were observed in FVC, % FVC, FEV1, % FEV1, PEF, V50, or V25.

Conclusions

Regardless of whether thoracoplasty was performed or not, FVC, FEV1, and expiratory flow were improved 5 years or later after PSF.

Clinical Issues for Pediatric Pulmonologists Managing Children With Thoracic Insufficiency Syndrome

Thoracic insufficiency Syndrome (TIS) is a recently coined phrase to describe children with spine and chest wall deformities, inherited and acquired, who have respiratory impairment, and are skeletally immature. This population has both restrictive and less often obstructive lung disease due to changes in spine and rib configuration which reduce lung volume, stiffen the chest wall, and reduce respiratory muscle strength. Although the population is heterogeneous with regard to age of onset, etiology, severity of deformity, and rate of progression of the deformity, there are common issues that arise which can be addressed by pediatric pulmonologists. These are illustrated in this review by using Early Onset Scoliosis as a common form of TIS. The pulmonary issues pertaining to TIS require collaboration with multi-disciplinary teams, particularly spine surgeons, in order to make decisions about non-surgical and surgical strategies, timing of surgery and medical supportive care over time. Pulmonary input about respiratory function should be used in conjunction with structural features of each deformity in order to determine the impact of the deformity and the response to various treatment options. In those patients with residual lung function impairment as young adults, pediatric pulmonologists must also ensure successful transition to adult care.

Effectiveness and safety of surgical interventions for treating adolescent idiopathic scoliosis: a Bayesian meta-analysis

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is the most common form of spinal deformity in children and adolescents which presents as complex three-dimensional (3D) deformity of the spine and rib cage. This study aimed to estimate the effectiveness and safety of surgical interventions for AIS using Bayesian meta-analysis.

METHODS

The PubMed, EMBASE, and Cochrane Controlled Register of Trials were searched through Oct 1, 2019, without language restrictions. Relevant studies evaluating combined effectiveness and safety of surgical interventions for AIS were included according to eligibility criteria. The primary outcome measures included pulmonary function (change of absolute forced vital capacity and forced expiratory volume in 1 second from pre-operation to post-operation) and incidence of complications. The secondary outcome measure was change of Cobb angle from pre-operation to post-operation. Data was pooled using a random effects model in pairwise meta-analysis. Bayesian meta-analysis combined direct and indirect evidence using a Bayesian framework.

RESULTS

Twenty-eight case-controlled studies with totally 1970 participants were included. This Bayesian meta-analysis combining direct and indirect evidences indicated that posterior fusion with instrumentation without thoracoplasty (PSF) had the highest probability to achieve better pulmonary function and lower complication rate; video assisted anterior fusion with instrumentation without thoracoplasty (VAT) had the highest probability to obtain better Cobb angle correction based on analysis of rank probability.

CONCLUSION

This Bayesian meta-analysis demonstrated that PSF had the highest probability to achieve better post-surgical pulmonary function and lower complication rate, which gives a practical recommendation of PSF as a primary surgical treatment for AIS. The results also support statistics that current surgeries adopted more PSF but less open anterior approach surgery and thoracoplasty. More research work is required to address the effectiveness and safety of VAT for treating AIS more convincingly.

Posterior Correction Techniques for Adolescent Idiopathic Scoliosis

Adolescent idiopathic scoliosis represents a complex, three-dimensional deformity of the spine. Posterior spinal fusion is commonly performed in severe cases to avoid the long-term adverse sequelae associated with progressive spinal deformity. The goals of spinal fusion include halting the progression of deformity, optimizing spinal balance, and minimizing complications. Recent advances in short-segment spinal fixation have allowed for improved three-dimensional deformity correction. Preoperative planning and assessment of spinal flexibility is essential for successful deformity correction and optimization of long-term outcomes. Judicious use of releases and/or spinal osteotomies may allow for increased mobility of the spine but are associated with increased surgical time, blood loss, and risk of complications. Appreciation of implant design and material properties is critical for safe application of correction techniques. Although multiple reduction techniques have been described, no single technique is optimal for every patient.

Anterior instrumented fusion for adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity of the spine consisting of a lateral curvature, apical vertebral rotation, and an impairment of the sagittal profile. Surgical options include anterior and posterior approaches. Anterior instrumented fusion is suitable in Lenke type 1 and 5 curves. It supplies excellent results in coronal plane correction and is superior in the restoration of the sagittal profile and apical derotation. Fusion is shorter compared to posterior correction, and the complication rate is low. Pulmonary function is impaired postoperatively but recovers within a few years.

Does Posterior Scoliosis Correction Improve Respiratory Function in Adolescent Idiopathic Scoliosis? A Systematic Review and Meta-analysis

STUDY DESIGN

A systematic review and meta-analysis.

OBJECTIVES

Pulmonary dysfunction is often advocated among the indications for surgical correction of adolescent idiopathic scoliosis (AIS). Previous studies have discussed the effect of scoliosis correction on respiratory function without reaching a definitive conclusion: Some showed that the respiratory function can improve after scoliosis surgery without defining the precise role of anterior, posterior, and combined approaches on this improvement; furthermore, the majority of these studies did not take normal growth into account. As a result, the role of surgery remains to be clarified. The object of the present study was to synthesize the current knowledge regarding changes in respiratory function after posterior corrective surgery for AIS.

METHODS

A comprehensive systematic search was performed to identify all relevant studies in the following electronic databases: MEDLINE, EMBASE, CINAHL (EBSCO). We focused on the studies (1) that discussed posterior fusion surgery for AIS without thoracoplasty, (2) that discussed comparisons of pre- and postoperative percent-predicted values of forced vital capacity (%FVC) or forced expiratory volume (%FEV), and (3) with minimum 2-year follow-up. Forest plots were depicted and Z value was calculated as a test for overall effect.

RESULTS

Ten studies (6 prospective and 4 retrospective studies) met our inclusion criteria. The overall effect showed that there was no significant difference in %FVC or %FEV between pre- and postoperative measurements (very low evidence).

CONCLUSIONS

Posterior correction surgery for mild to moderate AIS patients showed no significant improvement of postoperative respiratory function measured by relative, percent-predicted values at minimum 2-year follow-up.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Dual Sequential Short Anterior Correction in Double Major Adolescent Idiopathic Scoliosis

STUDY DESIGN

retrospective comparative study.

INTRODUCTION

The standard surgical technique for double major adolescent idiopathic scoliosis (AIS) has been the fusion of both thoracic and thoracolumbar/lumbar curves from the posterior approach. Although short anterior correction is established in AIS with single thoracic or thoracolumbar/lumbar curves, anterior correction in double major curves has not yet been described. The purpose of this study is to compare this novel technique with standard posterior pedicle screw instrumentation in double major AIS.

METHODS

19 consecutive patients with a double major AIS were treated surgically either with pedicle screw instrumentation and posterior fusion (n = 11) or dual anterior short instrumentation and fusion (n = 8) of both curves. The mean follow-up was 5.6 ± 3 years (2-10 years). Clinical and radiologic results, results of pulmonary function, and Scoliosis Research Society (SRS) questionnaire are analyzed and compared.

RESULTS

The length of fusion was 7.6 ± 0.7 vertebrae with the anterior technique and 12 ± 1 vertebrae with the posterior technique (p < .001). Cobb angle correction was 78% and 53% in thoracic curves, and 80% and 59% in lumbar curves with posterior and anterior technique respectively (p < .05). The preoperative pulmonary function remained unchanged to the last follow-up in both groups. The scores of SRS-24 questionnaire were similar preoperatively and at the last follow-up in both groups.

CONCLUSION

This novel technique of dual sequential short anterior correction is an alternative to the standard posterior long fusions in the double major AIS. A significantly less amount of mobile segments needs to be fused leaving the thoracolumbar junction mobile and saving at least one lumbar mobile segment distally.

LEVEL OF EVIDENCE

Level III.

Current concepts in the surgical management of adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a complex 3D deformity of the spine. Its prevalence is between 2% and 3% in the general population, with almost 10% of patients requiring some form of treatment and up to 0.1% undergoing surgery. The cosmetic aspect of the deformity is the biggest concern to the patient and is often accompanied by psychosocial distress. In addition, severe curves can cause cardiopulmonary distress. With proven benefits from surgery, the aims of treatment are to improve the cosmetic and functional outcomes. Obtaining correction in the coronal plane is not the only important endpoint anymore. With better understanding of spinal biomechanics and the long-term effects of multiplanar imbalance, we now know that sagittal balance is equally, if not more, important. Better correction of deformities has also been facilitated by an improvement in the design of implants and a better understanding of metallurgy. Understanding the unique character of each deformity is important. In addition, using the most appropriate implant and applying all the principles of correction in a bespoke manner is important to achieve optimum correction.

In this article, we review the current concepts in AIS surgery.

Cite this article: Bone Joint J 2018;100-B:415–24.

Pulmonary function and thoracic deformities in adolescent idiopathic scoliosis 27 years or longer after spinal fusion with Harrington instrument

BACKGROUND

The aim of this study was to conduct an investigation into spinal fusion with Harrington instrument (HI) in patients with adolescent idiopathic scoliosis (AIS) and to survey pulmonary function and thoracic deformity outcomes many years after surgery.

METHODS

Subjects comprised 194 patients diagnosed with AIS and treated with spinal fusion using HI between 1968 and 1987. Patients who gave their informed consent were subjected to a complete standing spine X-ray, chest CT, and pulmonary function tests. Eighteen patients were eligible for inclusion. Mean age at the time of follow-up was 49.9 years and the mean duration of follow-up was 35.3 years. CT axial image was used at the apex of the main thoracic curve. Apical vertebral rotation was determined from RA sag measured by the method of Aaro et al. Thoracic cage deformities were measured as follows: Rib hump index (RHi) according to the method of Aaro et al. and posterior hemithoracic symmetry ratio (PHSr) according to the method of Campbell et al.

RESULTS

Pulmonary function tests revealed mean forced vital capacity (FVC) of 2.28 (range: 1.00-3.04) L and mean %FVC of 83.5% (range: 35.6%-117.8%). Restrictive ventilation disorder with %FVC <80% was seen in 5 patients (27.7%). %FVC had strong negative correlations with RA sag (r = -0.798), RHi (r = -0.820, p < 0.001), PHSr (r = -0.705), and proximal thoracic curve (r = -0.721). Main thoracic curve (r = -0.674) and apical vertebral rotation of thoracic curve (r = -0.685) showed moderate negative correlations. Multiple regression analysis revealed RHi was a most significant factor on %FVC.

CONCLUSIONS

In AIS patients examined 27 years or longer after surgery, restrictive ventilation defects were observed in 27.7%. Factors aggravating %FVC were large rib humps and large vertebral rotations. Three-dimensional correction of the spine and thoracic cage deformities is vital in order to avoid pulmonary function impairment many years after surgery.

Rapidly increasing incidence in scoliosis surgery over 14 years in a nationwide sample

PURPOSE

Severe scoliosis is primarily managed with surgery. This cohort study describes the incidence of surgically treated scoliosis among Swedish youth and young adults, stratified by age, sex, scoliosis type, and surgical approach and identifies changes in incidence rate and hospital length of stay (LOS), infections requiring re-surgery and mortality within 90 days.

METHODS

Swedish youth, 0-21 years, (n = 3062) with a diagnostic code for scoliosis and spine surgery between 2000 and 2013 were selected from the National Patient Register. Incidence was computed by comparing individuals with surgically treated scoliosis to the total at risk population. Linear regression models and Spearman correlation coefficients analyzed trends over time.

RESULTS

Overall annual incidence per 100,000 individuals was 9.1 (5.9 males/12.5 females). Annual incidence increased over 14 years from 5.1 to 9.8; an average 4.6% per year (p < 0.001). Adolescent idiopathic scoliosis was most common (4.5 per 100,000; n = 1516) followed by neuromuscular 2.7 (n = 913) and congenital 0.7 (n = 236). Average LOS decreased among scoliosis types except infantile and neuromuscular scoliosis. Posterior fusion was the most common surgical approach (75%) followed by anterior (18%) and anteroposterior fusion (7%). Posterior fusions significantly increased with a resultant decrease in anterior and anteroposterior fusion over time. Individuals with neuromuscular scoliosis exhibited the highest mortality (n = 12; 1.3%) and (n = 59; 6%) of individuals with neuromuscular scoliosis and (n = 12; 15%) with scoliosis related to MMC required revision surgery due to post-op infection.

CONCLUSIONS

Surgical management of scoliosis is increasing with a concurrent decrease in hospital LOS. Surgical management of neuromuscular scoliosis is associated with high 90-day post-operative infections and mortality rate.

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.