title: Magnetic controlled growing rods for early-onset scoliosis: a 4-year follow-up.
abstract: BACKGROUND
  There have been no studies with medium-term follow-up of magnetic controlled growing rods (MCGRs).
  
  
  OBJECTIVE
  This study aimed to report our single center experience of a magnetic growing rod system with an average of 4 years' follow-up.
  
  
  METHODS
  A retrospective case series was carried out.
  
  
  METHODS
  The sample comprised patients with early-onset scoliosis treated with magnetic controlled growth rods who were operated in 2011.
  
  
  METHODS
  Cobb angle, spinal growth rate, complications, and revision were the outcome measures.
  
  
  METHODS
  Clinical case notes and radiographs were reviewed.
  
  
  RESULTS
  There were 8 patients (5 dual-rod construct, 3 single-rod construct) who had a minimum of 44 months' follow-up and average of 48 months (44-55 months). Mean age at surgery was 8.2 years (range 3-10). Mean preoperative Cobb angle was 60° (34-94), whereas mean postoperative Cobb angle was 42° (32-63). The average number of extensions was 13.8 (range: 12-20). There were 6 patients (75%) who required 8 revision surgeries: rod problems (N=4), proximal screw pull-out (N=3), and development of proximal junction kyphosis (N=1). All three patients who had single-rod construct underwent revision procedure. Currently, four patients (50%) still have the magnetic rods in situ. The mean duration of MCGR in the patient in the removed group was 39 months (range: 34-46).
  
  
  CONCLUSIONS
  Medium-term results of MCGR are not as promising as previously reported early results. Hence, MCGRs should be used with caution. Single-rod constructs should definitely be avoided. The role of MCGRs in revision cases still remains unknown.
authors: Welsh Centre for Spinal Surgery & Trauma, University Hospital of Wales, Heath Park, Cardiff CF10 2FF, United Kingdom. Electronic address: karhao@gmail.com.
authors: Kar Hao
authors: KH
authors: Teoh
authors: Welsh Centre for Spinal Surgery & Trauma, University Hospital of Wales, Heath Park, Cardiff CF10 2FF, United Kingdom.
authors: Daniel M G
authors: DM
authors: Winson
authors: Welsh Centre for Spinal Surgery & Trauma, University Hospital of Wales, Heath Park, Cardiff CF10 2FF, United Kingdom.
authors: Stuart H
authors: SH
authors: James
authors: Welsh Centre for Spinal Surgery & Trauma, University Hospital of Wales, Heath Park, Cardiff CF10 2FF, United Kingdom.
authors: Alwyn
authors: A
authors: Jones
authors: Welsh Centre for Spinal Surgery & Trauma, University Hospital of Wales, Heath Park, Cardiff CF10 2FF, United Kingdom.
authors: John
authors: J
authors: Howes
authors: Welsh Centre for Spinal Surgery & Trauma, University Hospital of Wales, Heath Park, Cardiff CF10 2FF, United Kingdom.
authors: Paul R
authors: PR
authors: Davies
authors: Welsh Centre for Spinal Surgery & Trauma, University Hospital of Wales, Heath Park, Cardiff CF10 2FF, United Kingdom.
authors: Sashin
authors: S
authors: Ahuja
mesh_terms: D001863:Bone Screws; D002648:Child; D002675:Child, Preschool; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016268:Internal Fixators; D007738:Kyphosis / Q000209:etiology; D059346:Magnets; D008297:Male; D019637:Orthopedic Procedures / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D011183:Postoperative Complications; D012086:Reoperation; D012189:Retrospective Studies; D012600:Scoliosis / Q000503:physiopathology / Q000601:surgery*
keywords: Early-onset scoliosis; MAGnetic Expansion Control system; Magnetic controlled growing rods; Medium-term follow-up; Revision; Survivorship