Authors Martina Tognini, Harry Hothi, Sean Bergiers, Holly Morganti, Johann Henckel, Anna Di Laura, John Skinner, Alister Hart, of The Royal National Orthopaedic Hospital, discuss the use of magnetically controlled growing rods in the surgical treatment of severe early onset scoliosis.
Early Onset Scoliosis (EOS) is a spinal pathology defined as a curvature of the spine ≥10° in the frontal plane with onset before 10 years of age [1]. Among the risks associated with EOS the most severe one is the development Thoracic Insufficiency Syndrome (TIS), defined as the inability of the thorax to support normal respiratory function and lung development in growing children [2], which can lead to increased morbidity and mortality.
Both surgical and non-surgical treatment options have been proposed. Bracing and casting may be effective for less severe curves, yet surgical intervention may be necessary in more acute cases [3]. The most commonly adopted surgical treatment is based on distraction-based constructs, implants correcting the major curve while allowing for spinal growth thanks to extendable rods.
Magnetically Controlled Growing Rods (MCGRs), used in the surgical treatment of severe early onset scoliosis (EOS), are a distraction-based system enabling outpatient distraction procedure, while the alternative system, Traditional Growing Rods (TGRs), require repeated invasive surgeries to perform implant lengthening, with an increased risk of complications and burden to patients and families.
MCGRs are a relatively recent technology, the first prospective patient series rods being published in 2012 [4]. The commercially available MCGR system is the MAGnetic Expansion Control rod, manufactured by NuVasive (Nuvasive Specialised Orthopaedics, San Diego, CA). Since the first use, 7 design iterations have been commercially available, the latest (still implanted) being MAGEC 1.3, 2.0,2.1 and MAGEC X, first used in mid-2017 [5]. The most important design modification introduced with the latest rod design has been the end-cap component development, aimed at enhancing the sealing system between lengthening rod and internal mechanism.
Recently, concerns regarding the risks associated with the use of MCGRs have been raised. The latest design iteration (MAGEC X)