Radiological Outcomes of Magnetically Controlled Growing Rods for the Treatment of Children with Various Etiologies of Early-Onset Scoliosis—A Multicenter Study

Abstract

Background: The management of spinal deformities diagnosed before the age of 10 is critical due to the child’s development, skeletal system, and growth mechanism. Magnetically controlled growing rods (MCGRs) are a surgical treatment option for the growing spine. The aim of this study was to analyze the radiological findings of patients treated with MCGRs for early-onset scoliosis (EOS) of various etiologies. We hypothesized that the MCGRs could provide acceptable long-term radiographic results, such as an increase in the T1–T12 and T1–S1 height and significant overall deformity correction. Methods: We retrospectively reviewed 161 EOS patients with a combined total of 302 MCGRs inserted at five institutions between 2016 and 2022 with a mean follow-up of at least two years. The Cobb angle of the major curve (MC), thoracic kyphosis (TK), lumbar lordosis (LL), and T1–T12 and T1–S1 height measurements were assessed before, after, and during the follow-up. Results: Among the 90 female and 71 male patients, there were 51 neurological, 42 syndromic, 58 idiopathic, and ten congenital scoliosis etiologies. Of the patients, 73 were aged under six years old. The mean follow-up time was 32.8 months. The mean age at placement of the MCGRs was 7 years and that at the last follow-up after fusion surgery was 14.5 years. The mean MC before the initial surgery was 86.2°; following rod implantation, it was 46.9°, and at the last follow-up visit, it was 45.8°. The mean correction rate among the etiology subgroups was from 43% to 50% at follow-up. The mean TK was noted as 47.2° before MCGR implantation, 47.1° after MCGR placement, and 44.5° at the last follow-up visit. The mean T1–T12 height increased by 5.95 mm per year, with a mean T1–S1 height of 10.1 mm per year. Conclusions: MCGR treatment allowed for an average correction of the curvature by 50% during the period of lengthening, while controlling any deformity and growth of the spine, with a significant increase in the T1–T12 and T1–S1 values during the observation period. MCGR treatment in EOS carries a risk of complications. While congenital and syndromic EOS often have short and less flexible curves in those groups of patients, single rods can be as effective and safe. Definitive fusion results in the mean final coronal correction between the start of MCGR treatment and after undergoing PSF of approximately 70%. The mean T1–T12 spinal height increased by 75 mm, while the T1–S1 spinal height gained a mean of 97 mm.

Reply to Tabeling et al. Comment on “Grabala et al. Radiological Outcomes of Magnetically Controlled Growing Rods for the Treatment of Children with Various Etiologies of Early-Onset Scoliosis—A Multicenter Study. J. Clin. Med. 2024, 13, 1529”

“…It is essential to acknowledge that the methodology of MCGR placement that we employ [ 20 , 21 , 22 ] incorporates minimally invasive entry (restricts spontaneous spondylodesis), along with the utilization of larger transpedicular screw dimensions (to mitigate the risk of pull-out and enhance biomechanical characteristics) [ 21 ], which may exert a notable influence on clinical and radiological outcomes and the potential for complications and subsequent interventions [ 13 , 14 ], thereby potentially diminishing the ultimate results for T1–T12, T1–S1, and the definitive rectification of spinal deformity. Imperfections exist in all implants; yet we anticipate that our investigations and findings, as well as those of the authors of the commentary [ 1 , 23 , 24 , 25 ], will contribute to substantial advancements and enhancements in the surgical management of early-onset scoliosis.…”

“…We are immensely gratified by the considerable interest our study has garnered [ 1 ], leading to a multitude of correspondences and official remarks [ 2 ]. The scrutiny of our work and the comprehensive analysis of the research findings will result in a juxtaposition with other studies [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ], thereby enriching the advancement of spinal surgery and enhancing the surgical methodologies employed in treating pediatric patients afflicted with early-onset spinal deformities.…”

“…We express gratitude for the attention paid to segregating patients treated with MCGR from those who have completed the treatment and proceeded to final correction with spondylodesis. It is worth noting that our research was carefully conducted, and the amassed research findings were intended for publication across a series of publications rather than a singular one; however, due to numerous inquiries such as this letter to the editor, the remaining data will be incorporated into the subsequent response [ 1 , 2 ].…”

“…As elucidated by the authors [ 2 ] of the aforementioned study, the calculation for growth in the T1–T12 and T1–S1 segments entailed subtracting the initial postoperative value from the latest postoperative value [ 1 ]. This methodology was consistently applied to ascertain the maintenance of curve correction.…”

Minimally Invasive Controlled Growing Rods for the Surgical Treatment of Early-Onset Scoliosis—A Surgical Technique Video

“…The new generation of SGRs, magnetically controlled growing rods (MCGRs), also shows a high rate of complications, especially in relation to implant complications. According to the manufacturers’ recommendations, MCGR implants should be replaced after 2 years of use [ 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. In 2023, an intermediate product between standard growing rods and magnetically controlled growing rods appeared.…”