Top

BMC Musculoskeletal Disorders

Published in:

Open Access 01-12-2021 | Case report

The first magnetically controlled growing rod (MCGR) in the world – lessons learned and how the identified complications helped to develop the implant in the past decade: case report

Authors: Jason Pui Yin Cheung, Kam Yim Sze, Kenneth Man Chee Cheung, Teng Zhang

Published in: BMC Musculoskeletal Disorders | Issue 1/2021

Abstract

Background

The first magnetically controlled growing rod (MCGR) was implanted in 2009. Since then multiple complications have been identified that have helped drive the development of the MCGR and its surgery. The aim of this report is to illustrate how identified complications in the first MCGR helped with developments in the past decade and to report a unique failure mechanism with stud fracture close to the barrel opening.

Case presentation

A 5-year old girl with a scoliosis of 58.5 degrees at T1–9 and 72.8 degrees at T9-L4 had a single MCGR inserted and anchored at T3–4 and L3–4. At postoperative 13 months the MCGR was noted to have lost of distraction between lengthening episodes due to unrestricted turning of the internal magnet. To prevent further loss of distraction, an external magnet was placed outside the skin to prevent the magnet from turning back. The overall balance was suboptimal and after the rod was fully distracted, proximal junctional kyphosis occurred. Subsequently, the MCGR was modified with an internal keeper plate to prevent loss of distraction and a dual set of these rods were implanted when the patient was 9 years old. Extension proximally to C7-T1 was done to manage the proximal junctional kyphosis. Her spinal balance improved and distractions continued. She subsequently developed add-on below and the piston rod was not aligned with the actuator. The lumbar spine was also observed to have autofusion. She subsequently had final fusion surgery performed at the age of 15 from C7-L4 leaving a residual tilt below to avoid fusion to the pelvis. The final extracted rod on the left side indicated the “crooked rod sign” on X-ray and rod dissections revealed a new failure mechanism of stud fracture close to the barrel opening. Body fluids and tissue may infiltrate the rod despite no obvious deformation or fractures resulting in hastened wearing of the threads.

Conclusions

There are various complications associated with MCGRs that are related to rod design and surgical inexperience. Repeated rod stalling is not recommended with potential stud fracture and “crooked rod sign”. Rotor stalling and thread wearing which indicates rod failure still require solutions.

Akbarnia BA, Breakwell LM, Marks DS, McCarthy RE, Thompson AG, Canale SK, et al. Dual growing rod technique followed for three to eleven years until final fusion: the effect of frequency of lengthening. Spine (Phila Pa 1976). 2008;33(9):984–90. https://doi.org/10.1097/BRS.0b013e31816c8b4e.CrossRef

Akbarnia BA, Marks DS, Boachie-Adjei O, Thompson AG, Asher MA. Dual growing rod technique for the treatment of progressive early-onset scoliosis: a multicenter study. Spine (Phila Pa 1976). 2005;30(17 Suppl):S46–57. https://doi.org/10.1097/01.brs.0000175190.08134.73.CrossRef

Winter RB, Moe JH, Lonstein JE. Posterior spinal arthrodesis for congenital scoliosis. An analysis of the cases of two hundred and ninety patients, five to nineteen years old. J Bone Joint Surg Am. 1984;66(8):1188–97. https://doi.org/10.2106/00004623-198466080-00006.CrossRefPubMed

Elsebai HB, Yazici M, Thompson GH, Emans JB, Skaggs DL, Crawford AH, et al. Safety and efficacy of growing rod technique for pediatric congenital spinal deformities. J Pediatr Orthop. 2011;31(1):1–5.CrossRef

Sponseller PD, Thompson GH, Akbarnia BA, Glait SA, Asher MA, Emans JB, et al. Growing rods for infantile scoliosis in Marfan syndrome. Spine (Phila Pa 1976). 2009;34(16):1711–5. https://doi.org/10.1097/BRS.0b013e3181a9ece5.CrossRef

Sponseller PD, Yazici M, Demetracopoulos C, Emans JB. Evidence basis for management of spine and chest wall deformities in children. Spine (Phila Pa 1976). 2007;32(19 Suppl):S81–90. https://doi.org/10.1097/BRS.0b013e3181453073.CrossRef

Thompson GH, Akbarnia BA, Campbell RM Jr. Growing rod techniques in early-onset scoliosis. J Pediatr Orthop. 2007;27(3):354–61. https://doi.org/10.1097/BPO.0b013e3180333eea.CrossRefPubMed

Thompson GH, Akbarnia BA, Kostial P, Poe-Kochert C, Armstrong DG, Roh J, et al. Comparison of single and dual growing rod techniques followed through definitive surgery: a preliminary study. Spine (Phila Pa 1976). 2005;30(18):2039–44. https://doi.org/10.1097/01.brs.0000179082.92712.89.CrossRef

Akbarnia BA, Emans JB. Complications of growth-sparing surgery in early onset scoliosis. Spine (Phila Pa 1976). 2010;35(25):2193–204. https://doi.org/10.1097/BRS.0b013e3181f070b5.CrossRef

10.

Obid P, Yiu K, Cheung K, Kwan K, Ruf M, Cheung JPY. Magnetically controlled growing rods in early onset scoliosis: radiological results, outcome, and complications in a series of 22 patients. Arch Orthop Trauma Surg. 2020. https://doi.org/10.1007/s00402-020-03518-z.

11.

Cheung JPY, Cheung PWH, Cheung KMC. The effect of magnetically controlled growing rods on three-dimensional changes in deformity correction. Spine Deform. 2020;8(3):537–46. https://doi.org/10.1007/s43390-020-00055-y.CrossRefPubMed

12.

Wick JM, Konze J. A magnetic approach to treating progressive early-onset scoliosis. AORN J. 2012;96(2):163–73. https://doi.org/10.1016/j.aorn.2012.05.008.CrossRefPubMed

13.

Cheung KM, Cheung JP, Samartzis D, Mak KC, Wong YW, Cheung WY, et al. Magnetically controlled growing rods for severe spinal curvature in young children: a prospective case series. Lancet. 2012;379(9830):1967–74. https://doi.org/10.1016/S0140-6736(12)60112-3.CrossRefPubMed

14.

Bess S, Akbarnia BA, Thompson GH, Sponseller PD, Shah SA, El Sebaie H, et al. Complications of growing-rod treatment for early-onset scoliosis: analysis of one hundred and forty patients. J Bone Joint Surg Am. 2010;92(15):2533–43. https://doi.org/10.2106/JBJS.I.01471.CrossRefPubMed

15.

Sankar WN, Skaggs DL, Yazici M, Johnston CE 2nd, Shah SA, Javidan P, et al. Lengthening of dual growing rods and the law of diminishing returns. Spine (Phila Pa 1976). 2011;36(10):806–9. https://doi.org/10.1097/BRS.0b013e318214d78f.CrossRef

16.

Cheung JP, Cahill P, Yaszay B, Akbarnia BA, Cheung KM. Special article: update on the magnetically controlled growing rod: tips and pitfalls. J Orthop Surg (Hong Kong). 2015;23(3):383–90. https://doi.org/10.1177/230949901502300327.CrossRef

17.

Samartzis D, Cheung JP, Rajasekaran S, Kawaguchi Y, Acharya S, Kawakami M, et al. Is lumbar facet joint tropism developmental or secondary to degeneration? An international, large-scale multicenter study by the AOSpine Asia Pacific research collaboration consortium. Scoliosis Spinal Disord. 2016;11:9.CrossRef

18.

Kwan KYH, Cheung JPY, Yiu KKL, Cheung KMC. Ten year follow-up of Jarcho-Levin syndrome with thoracic insufficiency treated by VEPTR and MCGR VEPTR hybrid. Eur Spine J. 2018;27(Suppl 3):287–91. https://doi.org/10.1007/s00586-017-5164-x.CrossRefPubMed

19.

Cheung JP, Samartzis D, Cheung KM. A novel approach to gradual correction of severe spinal deformity in a pediatric patient using the magnetically-controlled growing rod. Spine J. 2014;14(7):e7–13. https://doi.org/10.1016/j.spinee.2014.01.046.CrossRefPubMed

20.

Welborn MC, Krajbich JI, D'Amato C. Use of magnetic spinal growth rods (MCGR) with and without preoperative halo-gravity traction (HGT) for the treatment of severe early-onset scoliosis (EOS). J Pediatr Orthop. 2019;39(4):e293–e7. https://doi.org/10.1097/BPO.0000000000001282.CrossRefPubMed

21.

Charroin C, Abelin-Genevois K, Cunin V, Berthiller J, Constant H, Kohler R, et al. Direct costs associated with the management of progressive early onset scoliosis: estimations based on gold standard technique or with magnetically controlled growing rods. Orthop Traumatol Surg Res. 2014;100(5):469–74. https://doi.org/10.1016/j.otsr.2014.05.006.CrossRefPubMed

22.

Wong CKH, Cheung JPY, Cheung PWH, Lam CLK, Cheung KMC. Traditional growing rod versus magnetically controlled growing rod for treatment of early onset scoliosis: cost analysis from implantation till skeletal maturity. J Orthop Surg (Hong Kong). 2017;25(2):2309499017705022.CrossRef

23.

Kwan KYH, Alanay A, Yazici M, Demirkiran G, Helenius I, Nnadi C, et al. Unplanned reoperations in magnetically controlled growing rod surgery for early onset scoliosis with a minimum of two-year follow-up. Spine (Phila Pa 1976). 2017;42(24):E1410–E4. https://doi.org/10.1097/BRS.0000000000002297.CrossRef

24.

Jones CS, Stokes OM, Patel SB, Clarke AJ, Hutton M. Actuator pin fracture in magnetically controlled growing rods: two cases. Spine J. 2016;16(4):e287–91. https://doi.org/10.1016/j.spinee.2015.12.020.CrossRefPubMed

25.

Cobanoglu M, Shah SA, Gabos P, Rogers K, Yorgova P, Neiss G, et al. Comparison of intended lengthening of magnetically controlled growing rods: ultrasound versus X-ray. J Pediatr Orthop. 2019;39(2):e141–e6. https://doi.org/10.1097/BPO.0000000000001072.CrossRefPubMed

26.

Gilday SE, Schwartz MS, Bylski-Austrow DI, Glos DL, Schultz L, O'Hara S, et al. Observed length increases of magnetically controlled growing rods are lower than programmed. J Pediatr Orthop. 2018;38(3):e133–e7. https://doi.org/10.1097/BPO.0000000000001119.CrossRefPubMed

27.

Cheung JPY, Yiu KKL, Samartzis D, Kwan K, Tan BB, Cheung KMC. Rod lengthening with the magnetically controlled growing rod: factors influencing rod slippage and reduced gains during distractions. Spine (Phila Pa 1976). 2018;43(7):E399–405. https://doi.org/10.1097/BRS.0000000000002358.CrossRef

28.

Poon S, Spencer HT, Fayssoux RS, Sever R, Cho RH. Maximal force generated by magnetically controlled growing rods decreases with rod lengthening. Spine Deform. 2018;6(6):787–90. https://doi.org/10.1016/j.jspd.2018.03.009.CrossRefPubMed

29.

Teoh KH, von Ruhland C, Evans SL, James SH, Jones A, Howes J, et al. Metallosis following implantation of magnetically controlled growing rods in the treatment of scoliosis: a case series. Bone Joint J. 2016;98-B(12):1662–7. https://doi.org/10.1302/0301-620X.98B12.38061.CrossRefPubMed

30.

Wang Y, Hansen ES, Hoy K, Wu C, Bunger CE. Distal adding-on phenomenon in Lenke 1A scoliosis: risk factor identification and treatment strategy comparison. Spine (Phila Pa 1976). 2011;36(14):1113–22. https://doi.org/10.1097/BRS.0b013e3181f51e95.CrossRef

31.

Akbarnia BA, Mundis GM Jr, Salari P, Yaszay B, Pawelek JB. Innovation in growing rod technique: a study of safety and efficacy of a magnetically controlled growing rod in a porcine model. Spine (Phila Pa 1976). 2012;37(13):1109–14. https://doi.org/10.1097/BRS.0b013e318240ff67.CrossRef

32.

Cheung JPY, Cheung KM. Current status of the magnetically controlled growing rod in treatment of early-onset scoliosis: what we know after a decade of experience. J Orthop Surg (Hong Kong). 2019;27(3):2309499019886945.CrossRef

33.

Joyce TJ, Smith SL, Kandemir G, Rushton PRP, Fender D, Bowey AJ, et al. The NuVasive MAGEC rod urgent field safety notice concerning locking pin fracture: how does data from an independent explant center compare? Spine (Phila Pa 1976). 2020;45(13):872–6. https://doi.org/10.1097/BRS.0000000000003439.CrossRef

34.

Dahl B, Dragsted C, Ohrt-Nissen S, Andersen T, Gehrchen M. Use of a distraction-to-stall lengthening procedure in magnetically controlled growing rods: a single-center cohort study. J Orthop Surg (Hong Kong). 2018;26(2):2309499018779833.CrossRef

35.

Cheung JPY, Zhang T, Bow C, Kwan K, Sze KY, Cheung KMC. The crooked rod sign: a new radiological sign to detect deformed threads in the distraction mechanism of magnetically controlled growing rods and a mode of distraction failure. Spine (Phila Pa 1976). 2020;45(6):E346–E51. https://doi.org/10.1097/BRS.0000000000003268.CrossRef

36.

Joyce TJ, Smith SL, Rushton PRP, Bowey AJ, Gibson MJ. Analysis of explanted magnetically controlled growing rods from seven UK spinal centers. Spine (Phila Pa 1976). 2018;43(1):E16–22. https://doi.org/10.1097/BRS.0000000000002221.CrossRef

37.

Cheung JPY, Yiu K, Kwan K, Cheung KMC. Mean 6-year follow-up of magnetically controlled growing rod patients with early onset scoliosis: a glimpse of what happens to graduates. Neurosurgery. 2019;84(5):1112–23. https://doi.org/10.1093/neuros/nyy270.CrossRefPubMed

38.

Zhang T, Sze KY, Peng ZW, Cheung KMC, Lui YF, Wong YW, et al. Systematic investigation of metallosis associated with magnetically controlled growing rod implantation for early-onset scoliosis. Bone Joint J. 2020;102-B(10):1375–83. https://doi.org/10.1302/0301-620X.102B10.BJJ-2020-0842.R1.CrossRefPubMed

Title: The first magnetically controlled growing rod (MCGR) in the world – lessons learned and how the identified complications helped to develop the implant in the past decade: case report
Authors: Jason Pui Yin Cheung
Kam Yim Sze
Kenneth Man Chee Cheung
Teng Zhang
Publication date: 01-12-2021
Publisher: BioMed Central
Published in: BMC Musculoskeletal Disorders / Issue 1/2021
Electronic ISSN: 1471-2474
DOI: https://doi.org/10.1186/s12891-021-04181-0

At a glance: The STEP trials

Springer Medicine

The first magnetically controlled growing rod (MCGR) in the world – lessons learned and how the identified complications helped to develop the implant in the past decade: case report

Abstract

Background

Case presentation

Conclusions

At a glance: The STEP trials

Springer Medicine

Abstract

Background

Case presentation

Conclusions

Please log in to get access to this content

Other articles of this Issue 1/2021

Periarticular analgesic injection containing a corticosteroid after total hip arthroplasty may prevent deep venous thrombosis: a retrospective comparative cohort study

Parasitosis of the vertebral canal mimicking lumbar intervertebral disc herniation: a case report

Characteristics of hip impingement syndrome in patients with multiple hereditary exostoses

Characterization of hyaluronan-coated extracellular vesicles in synovial fluid of patients with osteoarthritis and rheumatoid arthritis

Identification of factors related to behaviors associated with musculoskeletal pain among elementary students

Role of psychosocial factors on the effect of physical activity on physical function in patients after lumbar spine surgery