Persistently Raised Serum Titanium Levels After Spinal Instrumentation in Children

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Pediatric medicine

Background:

• Metal-on-metal hip replacements can cause elevated metal ion levels.
• Pediatric spinal implants are known to release metal ions like titanium, chromium, cobalt, and nickel.

Purpose of the Study:

• To determine if circulating metal ion levels are maintained up to two years post-spinal deformity surgery.
• To compare different spinal implant systems and rod materials.

Main Methods:

• Prospective study of 56 children undergoing spinal deformity surgery.
• Repeated measurement of circulating titanium, cobalt, chromium, and nickel using inductively coupled plasma mass spectrometry.
• Analysis using linear mixed-effects models to account for repeated measures.

Main Results:

• Titanium levels peaked at 30 days and remained significantly elevated (5.14x baseline) at two years.
• Cobalt levels peaked at 30 days, declined but remained elevated (1.74x baseline) at two years.
• Chromium and nickel levels returned to baseline by six months and remained so at two years. Implant systems showed similar results.

Conclusions:

• Persistent and rising titanium levels in pediatric patients are concerning.
• Titanium's ability to cross the placental barrier and accumulate in organs suggests potential risks for fetal development.
• Further research is needed to assess the long-term implications of elevated titanium in this population.