Metal release and excretion from cementless titanium alloy total knee replacements

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Toxicology

Background:

• Total knee arthroplasty (TKA) is a common procedure for knee osteoarthritis.
• Titanium alloys are frequently used in orthopedic implants due to their biocompatibility and strength.
• Wear debris and ion release from implants are potential concerns.

Purpose of the Study:

• To investigate serum and urine concentrations of titanium, aluminum, and vanadium in patients with different types of cementless primary total knee arthroplasty components.
• To assess if metal ion levels correlate with component design, wear, or failure.

Main Methods:

• Serum and urine samples were collected from patients with various TKA component designs (carbon fiber reinforced polyethylene, ultrahigh molecular weight polyethylene, nitrogen ion-implanted surfaces) and from a control group.
• Patients with failed patellar components were also included.
• Concentrations of titanium, aluminum, and vanadium were measured using appropriate analytical techniques.

Main Results:

• Serum titanium concentrations were significantly higher (approximately 50-fold) in patients with failed patellar components and (approximately 10-fold) in those with carbon fiber reinforced polyethylene bearing surfaces compared to control and other implant groups.
• No significant differences in serum or urine concentrations of aluminum or vanadium were observed among any groups.
• Urine analysis showed no significant differences in titanium, aluminum, or vanadium levels across all patient groups.

Conclusions:

• Elevated serum titanium may serve as a biomarker for patellar component failure or accelerated wear in titanium alloy-bearing total knee replacements.
• The toxicological implications of these elevated serum titanium levels remain to be determined.