Expert Consensus for Early Onset Scoliosis Surgery

Diagnostic and therapeutic strategies in early onset scoliosis: A current concept review

Substantial advances in the treatment of early onset scoliosis (EOS) over the past two to three decades have resulted in significant improvements in health-related quality of life of affected children. In addition to classifications that address the marked heterogeneity of this patient population, increasing understanding of the natural history of the disease, and new implants and treatment techniques have resulted in innovations unlike any other area of pediatric orthopedics. The growing understanding of the interaction between spinal and thoracic growth, as well as dependent lung maturation, has had a lasting impact on the treatment strategy of this potentially life-threatening disease. The previous treatment approach with early corrective fusion gave way to a growth-friendly concept. Despite the steady development of new growth-friendly surgical treatment options, whose efficacy still needs to be validated, as well as a revival of conservative growth control with serial casts and/or braces, the psychosocial burden of the long lasting and complication-prone treatments remains high. As a consequence, EOS still represents one of the greatest pediatric orthopedic challenges.

Radiographic and clinical outcomes after definitive spine fusion for skeletally immature patients with idiopathic scoliosis

PURPOSE

To assess the intermediate-term radiographic and clinical outcomes of skeletally immature idiopathic scoliosis (IS) patients that underwent definitive fusion (DF).

METHODS

A retrospective review of patients with IS who were Risser 0 with open tri-radiate cartilages at the time of DF with minimum 5-year follow-up. Outcomes included Scoliosis Research Society (SRS)-30 scores, major Cobb angle, pulmonary function tests (PFTs), and unplanned returns to the operating room (UPROR). Adding-on was defined as progression of the major Cobb angle > 5° or tilt of the lowest instrumented vertebra > 5°.

RESULTS

Thirty-two patients (78% female, mean age 12.2 ± 1.3 years old, mean preoperative major Cobb 64.8° ± 15.9) were included. Of these patients, 20 (62.5%) experienced adding-on and 6 (18.8%) required a revision surgery to correct their progressive spinal deformity. Adding-on was associated with lower 5-year postoperative SRS scores for appearance (3.7 ± 0.7 vs 4.4 ± 0.3, p = 0.0126), mental health (4.2 ± 0.6 vs 4.6 ± 0.3, p = 0.0464), satisfaction with treatment (4.0 ± 0.8 vs 4.7 ± 0.4, p = 0.0140), and total score (4.0 ± 0.4 vs 4.4 ± 0.2, p = 0.0035). The results of the PFTs did not differ between groups. Patients experienced an average of 0.53 UPROR/patient.

CONCLUSION

DF in skeletally immature patients results in a high rate of adding-on, which adversely affects Health-Related Quality of Life. However, reoperation rates, both planned and unplanned, remain lower when compared to patients undergoing growth-friendly treatment.

Update on the Diagnosis and Management of Early-onset Scoliosis

PURPOSE OF REVIEW

In this article, we review the most recent advancements in the approaches to EOS diagnosis and assessment, surgical indications and options, and basic science innovation in the space of early-onset scoliosis research.

RECENT FINDINGS

Early-onset scoliosis (EOS) covers a diverse, heterogeneous range of spinal and chest wall deformities that affect children under 10 years old. Recent efforts have sought to examine the validity and reliability of a recently developed classification system to better standardize the presentation of EOS. There has also been focused attention on developing safer, informative, and readily available imaging and clinical assessment tools, from reduced micro-dose radiographs, quantitative dynamic MRIs, and pulmonary function tests. Basic science innovation in EOS has centered on developing large animal models capable of replicating scoliotic deformity to better evaluate corrective technologies. And given the increased variety in approaches to managing EOS in recent years, there exist few clear guidelines around surgical indications across EOS etiologies. Despite this, over the past two decades, there has been a considerable shift in the spinal implant landscape toward growth-friendly instrumentation, particularly the utilization of MCGR implants. With the advent of new biological and basic science treatments and therapies extending survivorship for disease etiologies associated with EOS, the treatment for EOS has steadily evolved in recent years. With this has come a rising volume and variation in management options for EOS, as well as the need for multidisciplinary and creative approaches to treating patients with these complex and heterogeneous disorders.

Automated Clustering Technique (ACT) for Early Onset Scoliosis: A preliminary report

PURPOSE

While the C-EOS system helps organize and classify Early Onset Scoliosis (EOS) pathology, it is not data-driven and does not help achieve consensus for surgical treatment. The current study aims to create an automated method to cluster EOS patients based on pre-operative clinical indices.

METHODS

A total of 1114 EOS patients were used for the study, with the following distribution by etiology: congenital (240), idiopathic (217), neuromuscular (417), syndromic (240). Pre-operative clinical indices used for clustering were age, major curve (Cobb) angle, kyphosis, number of levels involved in a major curve (Cobb angle) and kyphosis along with deformity index (defined as the ratio of major Cobb angle and kyphosis). Fuzzy C-means clustering was performed for each etiology individually, with one-way ANOVA performed to assess statistical significance (p < 0.05).

RESULTS

The automated clustering method resulted in three clusters per etiology as the optimal number based on the highest average membership values. Statistical analyses showed that the clusters were significantly different for all the clinical indices within and between etiologies. Link to the ACT-EOS web application: https://biomed.drexel.edu/labs/obl/toolkits/act-eos-application .

CONCLUSION

An automated method to cluster EOS patients based on pre-operative clinical indices was developed identifying three unique, data-driven subgroups for each C-EOS etiology category. Adoption of such an automated clustering framework can help improve the standardization of clinical decision-making for EOS.

Diseases and comorbidities associated with early-onset scoliosis: a retrospective multicenter analysis

PURPOSE

To determine the frequencies of various diseases associated with all types of early-onset scoliosis, both idiopathic and nonidiopathic.

METHODS

Retrospective collection of patients within a 21-year interval. Children under 10 years old presenting with scoliosis were included. Medical records were used to collect: identifier, date of birth, sex, diagnosis, follow-up, curve pattern, comorbidities, initial and final cobb angle. Different patient variables were tabulated with associated comorbidities for comparison.

RESULTS

The cohort contained 469 patients, with 227(48.4%) males and 242(51.6%) females. Total comorbidities equaled 1051, where 190 were unique. Only 124(26.4%) patients had an isolated diagnosis of early-onset scoliosis, 79(16.8%) had a single comorbidity, and 266(56.7%) had multiple comorbidities. "Global developmental delay" was most commonly observed, 198(42.2%) times. The central nervous system was involved more often than other organ systems, seen in 394(54.4%) instances. Males had more comorbidities than females. Idiopathic patients had the least number of comorbidities, while neuromuscular patients had the most. Idiopathic types had more musculoskeletal conditions, while congenital types had more cardiovascular diseases. Curve sides did not affect distributions. Cases which progressed had more comorbidities, especially in the respiratory, digestive, and cardiovascular systems. Diseases that could affect either extremity or side, were more likely to be bilateral.

CONCLUSIONS

Early-onset scoliosis patients may present with complex comorbidities in multiple organ systems. The most commonly observed disease entities were: global developmental delay, developmental dysplasia of the hip, and epilepsy. Clinicians should be aware of the common associations, in order to screen for and begin appropriate investigations, referrals, and treatments in affected cases.

LEVEL OF EVIDENCE

Level III.

Early-onset scoliosis: a narrative review

Early-onset scoliosis (EOS) is defined as any spinal deformity that is present before 10 years old, regardless of etiology.

Deformity must be evaluated based on the intercorrelation between the lungs, spine, and thorax.

Curvatures of early-onset have increased risk of progression, cardiorespiratory problems, and increased morbidity and mortality.

Progression of the deformity may produce thoracic insufficiency syndrome, where a distorted thorax is unable to support normal respiratory function or lung growth.

Management and treatment of EOS should pursue a holistic approach in which the psychological impact and quality of life of the patient are also taken into consideration.

Growth-friendly surgical techniques have not met the initial expectations of correcting scoliotic deformity, promoting thoracic growth, and improving pulmonary function.

Elongation-Derotation-Flexion Casting Treatment of Early-Onset Progressive Scoliosis in Skeletal Dysplasia

BACKGROUND

Early-onset scoliosis in children with skeletal dysplasia is progressive, contributing to cardiopulmonary restrictive disease. Serial elongation-derotation-flexion (EDF) casting, used in other etiologies of scoliosis to delay curve progression, may be beneficial in maximizing spine growth. Our hypothesis is serial EDF casting can be safely used as a temporary alternative to surgery, delaying progression and preserving growth, to treat scoliosis in skeletal dysplasia.

METHODS

All patients with skeletal dysplasia treated at a single institution with serial EDF casting for scoliosis were reviewed retrospectively. Radiographic parameters: Cobb angle of major and minor curves, curve location, thoracic height, thoracolumbar height, space available for lung, and rib vertebra angle difference were measured before casting (C1), in first casting (C2), in last casting (C3), and out of last casting (C4). Peak inspiratory pressure (PIP) values were monitored and recorded during the casting application.

RESULTS

Eleven patients met the inclusion criteria (mean 9.7 castings). The mean duration of EDF serial casting was 35 months. The mean major Cobb angles were 54 degrees° (C1), 30 degrees (C2), 37 degrees (C3), and 49 degrees (C4) with no statistically significant differences. The mean minor Cobb angles were 35 degrees (C1), 25 degrees (C2), 33 degrees (C3), and 51 degrees (C4) with no statistically significant differences. The mean thoracic heights were 130 mm (C1), 155 mm (C2), 173 mm (C3), and 160 mm (C4). The 19-mm mean difference between C2 and C3 represents spinal growth. The PIP-1, PIP-2, and PIP-3 mean values were 15, 27, and 18 cmH2O, respectively. Changes in PIP-1 and PIP-2 and PIP-2 and PIP-3 were statistically significant.

CONCLUSION

Serial EDF casting can delay surgical scoliosis correction in children younger than 7 years with a diagnosis of skeletal dysplasia. Our study showed that serial casting controls progression of the major curve and allows longitudinal growth of the spine with possible expansion of lung volume for nearly 3 years. During cast application, PIP increased with molding and traction, and improved until windowing and trimming of the cast.

LEVEL OF EVIDENCE

Level IV-retrospective study.

When Is a Growth-friendly Strategy Warranted? A Matched Comparison of Growing Rods Versus Primary Posterior Spinal Fusion in Juveniles With Early-onset Scoliosis

BACKGROUND

In 7 to 11-year-old juveniles with severe early-onset scoliosis (EOS) the optimal surgical option remains uncertain. This study compares growing rods (GRs) followed by definitive posterior spinal fusion (PSF) versus primary PSF in this population. We hypothesized that the thoracic height afforded by GRs would be offset by increased rigidity, more complications, and more operations.

METHODS

This retrospective comparative study included EOS patients aged 7.0 to 11.9 years at index surgery treated with GR→PSF or primary PSF during 2013 to 2020. Primary outcomes were thoracic height gain (ΔT1-12H), major curve, complications, and total operations. Primary PSFs were matched with replacement 1-to-n to GR→PSFs by age at index, etiology, and major curve.

RESULTS

Twenty-eight GR→PSFs met criteria: 19 magnetically controlled GRs and 9 traditional GRs. Three magnetically controlled GRs were definitively explanted without PSF due to complications. The remaining 25 GR→PSFs were matched to 17 primary PSFs with 100% etiology match, mean Δ major curve 1 degree, and mean Δ age at index 0.5 years (PSFs older). Median ΔT1-12H pre-GR to post-PSF was 4.7 cm with median deformity correction of 37%. Median ΔT1-12H among primary PSFs was 1.9 cm with median deformity correction of 62%. GR→PSFs had mean 1.8 complications and 3.4 operations. Primary PSFs had mean 0.5 complications and 1.3 operations. Matched analysis showed adjusted mean differences of 2.3 cm greater ΔT1-12H among GR→PSFs than their matched primary PSFs, with 25% less overall coronal deformity correction, 1.2 additional complications, and 2.2 additional operations per patient.

CONCLUSIONS

In juveniles aged 7 to 11 with EOS, on average GRs afford 2 cm of thoracic height over primary PSF at the cost of poorer deformity correction and additional complications and operations. Primary PSF affords an average of 2 cm of thoracic height gain; if an additional 2 cm will be impactful then GRs should be considered. However, in most juveniles the height gained may not warrant the iatrogenic stiffness, complications, and additional operations. Surgeons and families should weigh these benefits and harms when choosing a treatment plan.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

[Scoliosis in spinal muscular atrophy]

5q-spinal muscular atrophy (5q-SMA) is an autosomal recessive neuromuscular disorder caused by a biallelic mutation of the survival of motor neuron 1 SMN1 gene. The resulting lack of SMN protein causes a progressive degeneration of anterior motor neurons and muscular atrophy, which leads to a progressive scoliosis in two-thirds of affected cases. Depending on the disease subtype and severity, affected patients can subsequently develop respiratory insufficiency, leading to a fatal outcome. Ground-breaking research on this devastating disorder has led to the approval of novel therapies that may alter the clinical course of this disease in the future. Here we present a summary of these new therapies, current operative strategies for 5q-SMA associated scoliosis and provide an outlook for possible implications for the future.