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

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.

Pulmonary function in children and adolescents with untreated idiopathic scoliosis: a systematic review with meta-regression analysis

BACKGROUND CONTEXT

One of the controversies in untreated idiopathic scoliosis is the influence of curve size on respiratory function. Whereas scoliosis patients with curves over 90 to 100 degrees are agreed to be at risk for cardiorespiratory failure in later life, the impairment of curves below 90 degrees is generally considered mild. Although various studies showed that pulmonary function is affected in patients with scoliosis, quantification of the relation between curve size and pulmonary function is lacking.

PURPOSE

This systematic review with meta-regression analysis aims to characterize the relation between pulmonary function tests and scoliosis severity in children and adolescents with idiopathic scoliosis.

STUDY DESIGN

Systematic review with meta-regression analysis.

METHODS

Pubmed, Embase, Cochrane, and CINAHL were systematically searched until November 3, 2020, for original articles that reported (1) severity of scoliosis quantified in Cobb angle, and (2) pulmonary function tests in children and adolescents with untreated idiopathic scoliosis. Exclusion criteria were other types of scoliosis, non-original data, post-treatment data, and case reports. All study designs were included, and relevant study details and patient characteristics were extracted. The primary outcome was the effect of Cobb angle on pulmonary function as expressed by the slope coefficient of a linear meta-regression analysis.

RESULTS

A total of 126 studies, including 8,723 patients, were retrieved. Meta-regression analysis revealed a statistically significant inverse relation between thoracic Cobb angle and absolute and predicted forced vital capacity in 1 second, forced vital capacity, vital capacity, and total lung capacity. For these outcomes, the slope coefficients showed a decrease of 1% of the predicted pulmonary function per 2.6 to 4.5 degrees of scoliosis. A multivariable meta-regression analysis of potential confounders (age, year of publication, and kyphosis) hardly affected the majority of the outcomes.

CONCLUSION

This meta-regression analysis of summary data (means) from 126 studies showed an inverse relationship between the thoracic Cobb angle and pulmonary function. In contrast to previous conclusions, the decline in pulmonary function appears to be gradual over the full range of Cobb angles between <20 and >120 degrees. These findings strengthen the relevance of minimizing curve progression in children with idiopathic scoliosis.

Anterior versus posterior spinal fusion for Lenke type 5 adolescent idiopathic scoliosis: a systematic review and meta-analysis of comparative studies

PURPOSE

To review and compare clinical and radiologic outcomes between anterior spinal fusion (ASF) and posterior spinal fusion (PSF) for the treatment of Lenke type 5 adolescent idiopathic scoliosis (AIS).

METHODS

A systematic review was performed according to Preferred reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. All level I-III evidence studies investigating the clinical and radiologic outcomes of ASF and PSF for the treatment of Lenke type 5 AIS were included.

RESULTS

Nine studies (285 ASF patients, 298 PSF patients) were included. ASF was associated with a significantly lower number of levels fused compared with PSF (p < 0.01) with similar immediate and long-term coronal deformity correction (p = 0.16; p = 0.12, respectively). PSF achieved a better correction of thoracic hypokyphosis in one study and lumbar hypolordosis in three studies. PSF was associated with a significant shorter length of stay (LOS) compared with ASF (p < 0.01). One long-term study demonstrated a significantly higher rate of proximal junctional kyphosis (PJK) with PSF compared with ASF. There were no significant differences in major complication or re-operation rates.

CONCLUSION

For the treatment of Lenke type 5 AIS, there is moderate evidence to suggest that ASF requires a lower number of instrumented levels to achieve similar immediate and long-term coronal deformity correction compared with PSF. There is some evidence to suggest that PSF may achieve better thoracic and lumbar sagittal deformity correction compared with ASF. There is some evidence to suggest a higher incidence of PJK at long-term follow-up with PSF compared with ASF. ASF is associated with a longer post-operative LOS compared with PSF.

Is there a variance in complication types associated with ALIF approaches? A systematic review

Purpose

Anterior lumbar interbody fusion (ALIF) is a well-established alternative to posterior-based interbody fusion techniques, with approach variations, such as retroperitoneal, transperitoneal, open, and laparoscopic well described. Variable rates of complications for each approach have been enumerated in the literature. The purpose of this study was to elucidate the comparative rates of complications across approach type.

Methods

A systematic review of search databases PubMed, Google Scholar, and OVID Medline was made to identify studies related to complication-associated ALIF. PRISMA guidelines were utilised for this review. Meta-analysis was used to compare intraoperative and postoperative complications with ALIF for each approach.

Results

A total of 4575 studies were identified, with 5728 patients across 31 studies included for review following application of inclusion and exclusion criteria. Meta-analysis demonstrated the transperitoneal approach resulted in higher rates of retrograde ejaculation (RE) (p < 0.001; CI = 0.05–0.21) and overall rates of complications (p = 0.05; CI = 0.00–0.23). Rates of RE were higher at the L5/S1 intervertebral level. Rates of vessel injury were not significantly higher in either approach method (p = 0.89; CI =  − 0.04–0.07). Rates of visceral injury did not appear to be related to approach method. Laparoscopic approaches resulted in shorter inpatient stays (p = 0.01).

Conclusion

Despite the transperitoneal approach being comparatively underpowered, its use appears to result in a significantly higher rate of intraoperative and postoperative complications, although confounders including use of bone morphogenetic protein (BMP) and spinal level should be considered. Laparoscopic approaches resulted in shorter hospital stays; however, its steep learning curve and longer operative time have deterred surgeons from its widespread adaptation.

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.