Serum Titanium Following Total Ankle Arthroplasty

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Toxicology

Background:

• Circulating metal levels post-total ankle arthroplasty (TAA) are largely uncharacterized.
• The influence of implant modularity on metal ion release in TAA is not well understood.

Purpose of the Study:

• To quantify serum metal levels (cobalt, chromium, titanium) in patients after primary TAA.
• To investigate the impact of tibial component design (modular vs. nonmodular) on these metal levels.

Main Methods:

• A cross-sectional study involving 10 patients with nonmodular tibial implants, 10 with modular tibial implants, and 21 controls.
• Serum samples were analyzed for cobalt, chromium, and titanium using inductively coupled plasma mass spectrometry at least 12 months post-TAA.
• Comparison of metal levels between TAA groups and controls, and between modular and nonmodular tibial implant groups.

Main Results:

• Serum titanium levels were significantly elevated in both nonmodular (0.619 µg/L) and modular (0.993 µg/L) TAA groups compared to controls (0.150 µg/L).
• Modular tibial implants showed higher serum titanium levels than nonmodular tibial implants (P=.003).
• Serum cobalt and chromium levels did not differ significantly between groups; no associations were found between metal levels and clinical or radiographic outcomes.

Conclusions:

• This study provides initial evidence that TAA is associated with elevated serum titanium levels.
• Modular tibial components in TAA may lead to increased titanium release compared to nonmodular designs.
• Further research is needed to explore the mechanisms behind increased titanium release from modular TAA components.