Unexpected Metal Ion Elevation and Adverse Tissue Reactions in Trident II Dual Mobility Constructs With Ceramic Heads

Dual mobility (DM) constructs reduce dislocation risk in total hip arthroplasty. The Trident II system accepts a cobalt-chromium liner to create a DM bearing. However, dissimilar metal at the cup-liner interface raises concerns for corrosion. This case series describes six cementless primary Trident II DM total hip arthroplasty patients who experienced gradual onset of hip pain with low-grade inflammatory symptoms and elevated serum cobalt. All patients underwent revision surgery for metallic debris reaction. Preoperative magnetic resonance imaging revealed local tissue reaction, and intraoperative findings confirmed corrosion at the cup-liner interface. Surviellance through serum metal ion testing and magnetic resonance imaging may prevent soft tissue damage and facilitate timely revision. As DM systems evolve, further investigation is warranted to evaluate safety.