Serum Titanium Levels Remain Elevated 6 Years and Beyond From Spinal Instrumentation in Children

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Pediatric Health

Background:

• Pediatric spinal implants can release circulating metal ions into the body.
• Previous studies indicated elevated chromium, cobalt, nickel, and persistent titanium serum levels post-surgery.

Purpose of the Study:

• To continue a prospective study on children undergoing spinal deformity surgery.
• To analyze long-term (beyond 6 years) circulating metal ion levels, including titanium, chromium, cobalt, and nickel.

Main Methods:

• Prospective study involving 34 participants returning for testing over 6 years post-surgery.
• High-resolution inductively coupled plasma mass spectrometry used for metal ion analysis.
• Linear mixed effects models applied to analyze serum levels over time, adjusting for baseline measurements.

Main Results:

• Median titanium levels at 6 years were 2.40 times higher than pre-surgery levels, though decreased from 2-year levels.
• Median chromium levels increased significantly from 2 years but were not significantly different from baseline at 6 years.
• Cobalt levels remained elevated compared to baseline but decreased from 2-year levels; nickel levels showed no significant change.

Conclusions:

• Titanium levels persist significantly above baseline beyond 6 years after pediatric spinal instrumentation.
• The long-term health implications of metal ion deposition in organs and potential effects on offspring are unknown.
• Observed increases in chromium levels in "all titanium" constructs suggest potential metallurgical irregularities.