MAGNETICALLY CONTROLLED GROWING RODS FOR THE TREATMENT OF EOS: EXPERIENCE FROM A SINGLE CENTER AND XPS SURFACE ANALYSIS OF THE RODS
Abstract
The treatment of early-onset scoliosis (EOS) remains one of the biggest challenges in paediatric orthopaedics. Magnetically controlled growing rods (MCGRs) have increased in popularity compared to traditional growing rods (TGRs), providing curve correction, spinal growth and a reduction of the associated surgical trauma. Between May 2015 and July 2022, 24 patients with EOS were treated with an MCGR system using a standardized implantation procedure. An ultrasonography- or radiography-controlled distraction of 3 mm every 3 months was performed. Whole spine radiographs were taken pre-operatively, post-operatively, and in six month interval. The Cobb angle, T1-S1 height, and growth were measured. All the patients had a dual-rod construct implantation. The mean age of the surgical patients was 8 years (6–11), and the mean follow up was 39 months (2–84). The etiology of the EOS was syndromic in six patients, congenital in two, idiopathic in three and neuromuscular in 12. One patient had a conversion from TGR, and one patient had a concomitant resection of hemivertebra. The mean preoperative Cobb angle was 69° (30–108°), postoperative was 38° (16–66°), and 38° (9–69°) at final follow-up. The mean pre-operative T1–S1 length was 289 mm, increasing to 326 mm post-operatively, and 353 mm at the final follow-up. The mean spinal growth was 64 mm (26–110 mm). Two retrieved rods were examined using X-ray photoelectron spectroscopy (XPS). A surface analytical technique to determine the surface chemistry after exposure of the rods in the body. The MCGR system represents a safe and less invasive option for the treatment of EOS.
References
2. S. Yang, L. M. Andras, G. J. Redding, D. L. Skags, Early-Onset Scoliosis: A Review of History, Current Treatment, and Future Directions, Pediatrics, 137 (2016), doi: 10.1542/peds.2015-0709
3. B. A. Hickey, C. Towriss, G. Baxter, S.Yasso, S. James, A. Jones, J. Howes, P. Davies, S. Ahuja, Early Experience of MAGEC Magnetic Growing Rods in the Treatment of Early Onset Scoliosis, Eur. Spine J., 23 (2014) S1, 61–65, doi:10.1007/s00586-013-3163-0
4. Dimeglio, F. Canavese, The Growing Spine: How Spinal Deformities Influence Normal Spine and Thoracic Cage Growth, Eur. Spine J., 21 (2012) 1, 64–70, doi:10.1007/s00586-011-1983-3
5. C. C. Hasler, Early-onset Scoliosis: Contemporary Decision-Making and Treatment Options, J. of Pediatr. Orthop., 38 (2018), S13–S20, doi:10.1097/bpo.0000000000001184
6. M. Jenks, J. Craig, J. Higgins, I. Willits, T. Barata, H. Wood, C. Kimpton, A. Sims, The MAGEC System for Spinal Lengthening in Children with Scoliosis: A NICE Medical Technology Guidance. Appl. Health Econ. Health Policy, 12 (2014) 6, 587–599, doi: 10.1007/s40258-014-0127-4
7. U. Metkar, S. Kurra, D. Quinzi, S. Albanese, W. F. Lavelle, Magnetically Controlled Growing Rods for Scoliosis Surgery, Expert Rev. Med. Devices, (2017), 1743-4440 doi: 10.1080/17434440.2016.1274230
8. W. Thompson, C. Thakar, D. J. Rolton, J. Wilson MacDonald, C. Nnadi, The Use of Magnetically-Controlled Growing Rods to Treat Children with Early-Onset Scoliosis, Bone Joint J., 98-B (2016), 1240–47, doi:10.1302/0301-620X.98B9.37545
9. P. R. P. Rushton, I. Siddique, R. Crawford, N. Birch, M. J. Gibson, M. J. Hutton, Magnetically Controlled Growing Rods in the Treatment of Early-Onset Scoliosis: A Note of Caution, Bone Joint J., 99-B (2017), 708–13, doi: 10.1302/0301-620X.99B6.BJJ-2016-1102.R2
10. The MAGEC System for Spinal Lengthening in Children with Scoliosis, Medical Technologies Guidance, https://www.nice.org.uk/guidance/mtg18/chapter/2-The-technology, 15.2.2020
11. J.R. Cobb, The Problem of the Primary Curve, J. Bone Joint Surg. Am., 42-A (1960), 1413–1425
12. N. Figueiredo, S. F. Kananeh, H. H. Siqueira, R. C. Figueiredo, M. W. Al Sebai, The Use of Magnetically Controlled Growing Rod Device for Pediatric Scoliosis, Neurosciences (Riyadh), 21 (2016) 1, 17–25, doi:10.17712/nsj.2016.1.20150266
13. P. Hosseini, J. Pawelek, G. M. Mundis, B. Yaszay, J. Ferguson, I. Helenius, K. Cheung, G. Demirkiran, A. Alanay, A. Senkoylu, H. Elsebaie, B. A. Akbarnia, Magnetically Controlled Growing Rods for Early-Onset Scoliosis: A Multicenter Study of 23 Cases with Minimum 2 Years Follow-Up. Spine, 41 (2016) 18, 1456–1462. doi:10.1097/brs.0000000000001561
14. B. Akbarnia, K. Cheung, K. Kwan, D. Samartzis, A. Alanay, J. Ferguson, C. Thakar, P. Panteliadis, C. Nnadi, I. Helenius, M. Yazici, G. H. Demirkiran, Effects of Frequency of Distraction in Magnetically Controlled Growing Rod (MCGR) Lengthening on Outcomes and Complications, Spine J., 16 (2016) 4, S56, doi.org/10.1016/j.spinee.2016.01.057
15. C. Thakar, D. C. Kieser, M. Mardare, S. Haleem, J. Fairbank, C. Nnadi, Systematic Review of the Complications Associated with Magnetically Controlled Growing Rods for The Treatment of Early Onset Scoliosis. Eur. Spine J., 27 (2018) 9, 2062–2071, doi:10.1007/s00586-018-5590-4
16. B. A. Akbarnia, K. Cheung, H. Noordeen, H. Elsebaie, M. Yazici, Z. Dannawi, N. Kabirian, Next Generation of Growth-Sparing Techniques: Preliminary Clinical Results of a Magnetically Controlled Growing Rod in 14 Patients with Early-Onset Scoliosis, Spine, 38 (2013) 8, 665–670, doi:10.1097/brs.0b013e3182773560
17. C. Yilgor, A. Efendiyev, F. Akbiyik, G. Demirkiran, A. Senkoylu, A. Alanay, M. Yazici, Metal Ion Release during Growth-Friendly Instrumentation for Early-Onset Scoliosis: A Preliminary Study, Spine Deformity, 6 (2018) 1, 48–53, doi: 10.1016/j.jspd.2017.06.005
18. S. Poon, H. T. Spencer, R. S. Fayssoux, R. Sever, R. H. Cho, Maximal Force Generated by Magnetically Controlled Growing Rods Decreases with Rod Lengthening, Spine Deform., 6 (2018) 6, 787–790, doi:10.1016/j.jspd.2018.03.009
19. J. F. Moulder, W. F. Stickle, P. E. Sobol, K. D. Bomben, “Handbook of X-Ray Photoelectron Spectroscopy”, Physical Electronics Inc., Eden Prairie, Minnesota, USA, 1995.