Clinical Outcome of Magnetically Controlled Growing Rod in Early-onset Scoliosis: A Systematic Review

Safety and efficacy of growth-friendly instrumentation for early-onset scoliosis in patients with spinal muscular atrophy type 1 in the disease-modifying treatment era

Purpose

To evaluate the safety of growth-friendly instrumentation for early-onset scoliosis (EOS) in patients with spinal muscular atrophy (SMA) type 1 who received disease-modifying treatment (DMT) and analyze short-term efficacy.

Methods

Retrospective search was conducted between 2017 and 2023. Patients with genetically confirmed SMA type 1 who were surgically treated for spinal deformity and receiving DMTs (nusinersen, risdiplam, or onasemnogene abeparvovec) were included. SMA types 2 and 3 and patients who do not receive DMTs were excluded. Clinical and radiographic data were collected at preoperative, postoperative, and latest follow-up visits.

Results

Twenty-eight patients (mean follow-up: 16 months (range 2-41)) were included. The mean age at surgery was 60 months (range 29-96). Fifteen were treated with dual magnetically controlled growing rods (MCGR), four with unilateral MCGR and a contralateral guided growth system, three with Vertical Expandable Prosthetic Titanium Rib (VEPTR®) implants, five with self-distracting systems, and one with traditional dual growing rods. The mean amount of correction was 57% (44°± 17) for scoliosis and 83% (13°± 11) for pelvic obliquity. The mean T1-12 height gain during surgery was 31 mm (±16 mm), while the mean T1 S1 height gain was 51 mm (±24 mm), and instrumented growth was observed during follow-up. Five patients (18%) developed six serious adverse events: three surgical site infections, two anchor failures, and one rod fracture, and all required unplanned reoperations. No neurologic complication, difficulty during nusinersen injections, or respiratory decline was recorded.

Conclusion

We report that spinal deformity in this population can be safely treated with growth-friendly instrumentation, with similar complication rates when compared with SMA type 2.

Beyond the gut: spectrum of magnetic surgery devices

Since the 1970s, magnetic force has been used to augment modern surgical techniques with the aims of minimizing surgical trauma and optimizing minimally-invasive systems. The majority of current clinical applications for magnetic surgery are largely centered around gastrointestinal uses-such as gastrointestinal or bilioenteric anastomosis creation, stricturoplasty, sphincter augmentation, and the guidance of nasoenteric feeding tubes. However, as the field of magnetic surgery continues to advance, the development and clinical implementation of magnetic devices has expanded to treat a variety of non-gastrointestinal disorders including musculoskeletal (pectus excavatum, scoliosis), respiratory (obstructive sleep apnea), cardiovascular (coronary artery stenosis, end-stage renal disease), and genitourinary (stricture, nephrolithiasis) conditions. The purpose of this review is to discuss the current state of innovative magnetic surgical devices under clinical investigation or commercially available for the treatment of non-gastrointestinal disorders.

The Evolving Use of Magnets in Surgery: Biomedical Considerations and a Review of Their Current Applications

The novel use of magnetic force to optimize modern surgical techniques originated in the 1970s. Since then, magnets have been utilized as an adjunct or alternative to a wide array of existing surgical procedures, ranging from gastrointestinal to vascular surgery. As the use of magnets in surgery continues to grow, the body of knowledge on magnetic surgical devices from preclinical development to clinical implementation has expanded significantly; however, the current magnetic surgical devices can be organized based on their core function: serving as a guidance system, creating a new connection, recreating a physiologic function, or utilization of an internal–external paired magnet system. The purpose of this article is to discuss the biomedical considerations during magnetic device development and review the current surgical applications of magnetic devices.

Optimizing Expansion Clinic for Patients With Magnetic Controlled Growth Rods

In 2017, members of the Pediatric Spine Study Group reported that 80% of new growth-friendly implants inserted were magnetically controlled growing rods (MCGRs). MCGRs are usually expanded more often than every 6 months, as was general practice with traditional growth rods. The growing volume of expansion visits is managed variably at different centers. Although there is existing research comparing MCGRs with traditional systems for efficacy and complications, there is limited literature regarding how expansion clinics are managed. This article reviews current practices such as scheduling, expansion verification, billing, and other key parameters for running expansion clinics.

Is there an indication for surgery in patients with spinal deformities? - A critical appraisal

Background

High-quality evidence exists to support physiotherapy and brace treatment for scoliosis and other spinal deformities. However, according to previous systematic reviews, it seems that no evidence exists for surgery. Nevertheless, the number of research articles focussing on spinal surgery highly exceeds the number of articles focussing on conservative treatment.

Objective

The purpose of this study is to conduct an updated search for systematic reviews providing high-quality evidence for spinal surgery in patients with spinal deformities.

Method

A narrative review including PubMed and the Cochrane database was conducted on April 12, 2020, with the following search terms: (1) spinal deformities, surgery, systematic review and outcome; (2) kyphosis, surgery, systematic review and outcome; (3) Scheuermann's disease, surgery, systematic review and outcome, and (4) scoliosis, surgery, systematic review and outcome.

Results

No reviews containing prospective controlled or randomised controlled studies were found providing evidence for surgery.

Conclusions

A general indication for spine surgery just based on the Cobb angle is not given. In view of the long-term unknown variables and the possible long-term complications of such treatment, a surgical indication for patients with spinal deformities must be reviewed on an individual basis and considered carefully. A current systematic review appears necessary in order to be able to draw final conclusions on the indication for surgery in patients with spinal deformities.

Clinical implications

In view of the increasing number of surgeons with an affiliation to industry, the indication for surgery needs to be given by independent conservative specialists for spinal deformities in order to provide an objective recommendation.