title: Serum titanium, niobium, and aluminum levels after instrumented spinal arthrodesis in children.
abstract: METHODS
  A prospective cohort study.
  
  
  OBJECTIVE
  To determine serum titanium, niobium, and aluminum levels in pediatric patients within the first postoperative year after instrumented spinal arthrodesis.
  
  
  BACKGROUND
  Instrumented spinal arthrodesis is a common procedure to correct scoliosis and kyphosis. Titanium-based instrumentation is increasingly favored due to enhanced biomechanical properties, but concerns have arisen regarding metal debris release and the potential for local and systemic complications.
  
  
  METHODS
  The pattern of systemic metal release over time was evaluated by measuring serum titanium, niobium, and aluminum levels preoperatively and 1 week, 1 month, 6 months, and 12 months after instrumented spinal arthrodesis using a titanium alloy. Serum metal levels were measured using high-resolution inductively coupled plasma mass spectrometry.
  
  
  RESULTS
  Thirty-two patients were included in the study group. Mean age at surgery was 14.7 years. Preoperative and postoperative concentrations of serum titanium and niobium were significantly different (P = 0.0001). Median postoperative serum concentrations of titanium and niobium were elevated 2.4- and 5.9-fold above the normal range respectively with 95% and 99% of samples elevated postoperatively. A significant and rapid rise in serum titanium and niobium levels was observed within the first postoperative week, after which elevated serum levels persisted up to 12 months.
  
  
  CONCLUSIONS
  We report abnormally elevated serum titanium and niobium levels in patients with titanium-based spinal instrumentation up to 12 months. The long-term systemic consequences of debris generated by wear and corrosion of spinal instrumentation is unclear but concerning, particularly as these implants inserted into the pediatric population may remain in situ for beyond 6 decades.
authors.affiliation: School of Paedatrics and Reproductive Health, Faculty of Health Sciences, The University of Adelaide, South Australia, Australia. p.cundy@adelaide.edu.au
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Cundy
authors.forename: Georgia
authors.initials: G
authors.lastname: Antoniou
authors.forename: Leanne M
authors.initials: LM
authors.lastname: Sutherland
authors.forename: Brian J C
authors.initials: BJ
authors.lastname: Freeman
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Cundy
mesh_terms: D000293:Adolescent; D000497:Alloys; D000535:Aluminum / Q000097:blood* / Q000493:pharmacokinetics; D002648:Child; D005260:Female; D006801:Humans; D016268:Internal Fixators / Q000009:adverse effects; D007738:Kyphosis / Q000097:blood / Q000601:surgery; D008297:Male; D009556:Niobium / Q000097:blood* / Q000493:pharmacokinetics; D011184:Postoperative Period; D011446:Prospective Studies; D012600:Scoliosis / Q000097:blood / Q000601:surgery; D013123:Spinal Fusion / Q000295:instrumentation*; D014025:Titanium / Q000097:blood* / Q000493:pharmacokinetics
chemical_list: D000497:Alloys; D009556:Niobium; C070282:Ti-6Al-7Nb alloy; D000535:Aluminum; D014025:Titanium