Taper Corrosion and Adverse Local Tissue Reactions in Patients with a Modular Knee Prosthesis

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Pathology

Background:

• Corrosion is observed in modular knee implants but its link to patient outcomes is unclear.
• This study investigated fretting corrosion at modular junctions in Stryker Triathlon TS knee implants.
• Three of 13 retrieved implants showed osteolysis and adverse tissue reactions due to fretting corrosion.

Purpose of the Study:

• To investigate the prevalence and severity of corrosion in modular knee implant components.
• To identify factors influencing corrosion development.
• To correlate corrosion with adverse local tissue reactions and implant failure.

Main Methods:

• Retrieval analysis of 13 Stryker Triathlon TS modular knee implants.
• Examination of modular surfaces for corrosion using scanning electron microscopy and energy-dispersive x-ray spectroscopy.
• Histopathological analysis of tissue samples from patients with adverse local tissue reactions.

Main Results:

• Corrosion was present in 62% of tibial and 75% of femoral components.
• Tibial corrosion was less prevalent but occurred earlier and was more severe.
• Histopathology revealed severe reactions to metal debris, including aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL).

Conclusions:

• Aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) and pseudotumors are reported secondary to modular knee replacement corrosion.
• The threaded taper design and release of cobalt-chromium ions/debris are implicated in adverse reactions, osteolysis, and tissue damage.
• Clinicians must be aware of this complication for earlier recognition and management.