What is the Role of Scoliosis Surgery in Adolescents and Adults with Myelomeningocele? A Systematic Review
Authors: Bradko Viachaslau , Castillo Heidi , Fremion Ellen , Conklin Michael , Dahl Benny , Castillo Jonathan 
Published: December 2021

Abstract

Background
Life expectancy of individuals with spina bifida has continued to improve over the past several decades. However, little is known about the longitudinal course of scoliosis in individuals with myelomeningocele (MMC), a spina bifida subtype, across their lifespan. Specifically, it is not known whether management during or after the transition years from adolescence to adulthood is associated with comorbidities in adulthood nor if these individuals benefit from scoliosis treatment later in life.

Questions/purposes
In this systematic review, we asked: (1) Is the risk of secondary impairments (such as bladder or bowel incontinence, decreased ambulation, and skin pressure injuries) higher among adolescents and adults with MMC and scoliosis than among those with MMC without scoliosis? (2) Is there evidence that surgical management of scoliosis is associated with improved functional outcomes in adolescents and adults with MMC? (3) Is surgical management of scoliosis associated with improved quality of life in adolescents and adults with MMC?

Methods
We performed a systematic review of articles in Medline and Embase from 2000 until February 5, 2021. Search terms such as “spinal dysraphism,” “spina bifida,” “meningomyelocele,” and “scoliosis” were applied in diverse combinations. A total of 1429 publications were identified, and 13 were eligible for inclusion. We included original studies reporting on scoliosis among individuals older than 15 years with MMC. When available, we extracted the prevalence of MMC and scoliosis, studied population age, percentage of patients experiencing complications, functional outcomes, and overall physical function. We excluded non-English articles and those with fewer than 10 individuals with scoliosis and MMC. We used the Preferred Reporting Items for Systematic Reviews and Meta-analyses, and registered the review before data collection (PROSPERO: CRD42021236357). We conducted a quality assessment using the Methodologic Index for Nonrandomized Studies (MINORS) tool. In 13 included studies, there were 556 individuals with MMC and scoliosis. Most were retrospective case series, although a minority were retrospective/comparative studies. The mean MINORS score was 12.3 ± 1.65 (a MINORS score over 12 generally is considered good reporting quality, scores below 12 are considered at high risk of bias).

Results
In general, studies found that individuals with MMC and scoliosis were more likely to have secondary impairments such as bladder/bowel incontinence, decreased ambulation, and pressure injuries than were patients with MMC without scoliosis. These secondary impairments were associated with hydrocephalus and high-level MMC lesions. However, when one study evaluated mortality, the results showed that although most deceased individuals who had spina bifida had scoliosis, no association was found between the age of death and scoliosis. Among the studies evaluating functional outcomes, none supported strong functional improvement in individuals with MMC after surgery for scoliosis. No correlation between the Cobb angle and sitting balance was noted; however, the degree of pelvic obliquity and the level of motor dysfunction showed a strong correlation with scoliosis severity. There was no change in sitting pressure distributions after spinal surgery. The lesion level and scoliosis degree independently contributed to the degree of lung function impairment. Although studies reported success in correcting coronal deformity and stopping curve progression, they found no clear benefit of surgery on health-related quality of life and long-term outcomes. These studies demonstrated that the level of neurologic function, severity of hydrocephalus, and brainstem dysfunction are greater determinants of quality of life than spinal deformity.

Conclusion
This systematic review found that adolescents and adults with MMC and scoliosis are more likely to have secondary impairments than their peers with MMC only. The best-available evidence does not support strong functional improvement or health-related quality of life enhancement after scoliosis surgery in adolescents and adults with MMC. The level of neurologic dysfunction, hydrocephalus, and brainstem dysfunction are greater determinants of quality of life. Future prospective studies should be designed to answer which individuals with MMC and scoliosis would benefit from spinal surgery. Our findings suggest that the very modest apparent benefits of surgery should cause surgeons to approach surgical recommendations in this patient population with great caution, and surgeons should counsel patients and their families that the risk of complications is high and the benefits may be small.

Level of Evidence
Level IV, therapeutic study.