title: Magnetically controlled growing rods for severe spinal curvature in young children: a prospective case series.
abstract: BACKGROUND
  Scoliosis in skeletally immature children is often treated by implantation of a rod to straighten the spine. Rods can be distracted (lengthened) as the spine grows, but patients need many invasive operations under general anaesthesia. Such operations are costly and associated with negative psychosocial outcomes. We assessed the effectiveness and safety of a new magnetically controlled growing rod (MCGR) for non-invasive outpatient distractions.
  
  
  METHODS
  We implanted the MCGR in five patients, two of whom have now reached 24 months' follow-up. Each patient underwent monthly outpatient distractions. We used radiography to measure the magnitude of the spinal curvature, rod distraction length, and spinal length. We assessed clinical outcome by measuring the degree of pain, function, mental health, satisfaction with treatment, and procedure-related complications.
  
  
  RESULTS
  In the two patients with 24 months' follow-up, the mean degree of scoliosis, measured by Cobb angle, was 67° (SD 10°) before implantation and 29° (4°) at 24 months. Length of the instrumented segment of the spine increased by a mean of 1·9 mm (0·4 mm) with each distraction. Mean predicted versus actual rod distraction lengths were 2·3 mm (1·2 mm) versus 1·4 mm (0·7 mm) for patient 1, and 2·0 mm (0·2 mm) and 2·1 mm (0·7 mm) versus 1·9 mm (0·6 mm) and 1·7 mm (0·8 mm) for patient 2's right and left rods, respectively. Throughout follow-up, both patients had no pain, had good functional outcome, and were satisfied with the procedure. No MCGR-related complications were noted.
  
  
  CONCLUSIONS
  The MCGR procedure can be safely and effectively used in outpatient settings, and minimises surgical scarring and psychological distress, improves quality of life, and is more cost-effective than is the traditional growing rod procedure. The technique could be used for non-invasive correction of abnormalities in other disorders.
  
  
  BACKGROUND
  Ellipse Technologies.
authors.affiliation: Department of Orthopaedics and Traumatology, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, China. cheungmc@hku.hk
authors.forename: Kenneth Man-Chee
authors.initials: KM
authors.lastname: Cheung
authors.forename: Jason Pui-Yin
authors.initials: JP
authors.lastname: Cheung
authors.forename: Dino
authors.initials: D
authors.lastname: Samartzis
authors.forename: Kin-Cheung
authors.initials: KC
authors.lastname: Mak
authors.forename: Yat-Wa
authors.initials: YW
authors.lastname: Wong
authors.forename: Wai-Yuen
authors.initials: WY
authors.lastname: Cheung
authors.forename: Behrooz A
authors.initials: BA
authors.lastname: Akbarnia
authors.forename: Keith Dip-Kei
authors.initials: KD
authors.lastname: Luk
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007738:Kyphosis / Q000000981:diagnostic imaging / Q000601:surgery*; D059346:Magnets; D008297:Male; D019637:Orthopedic Procedures / Q000295:instrumentation*; D017060:Patient Satisfaction; D011446:Prospective Studies; D019736:Prostheses and Implants; D011859:Radiography; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013131:Spine / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome