Dual-mobility (DM) bearings in total hip arthroplasty (THA) have secured immense, widespread adoption across both primary and complex revision environments. By pairing a small femoral head within a secondary, freely floating polyethylene liner, these specialized constructs generate a highly protective “large head” effect. This geometry maximizes impingement-free range of motion and expands the clinical jump distance required to minimize dislocation rates, proving especially beneficial in anatomically high-risk cohorts, such as patients with significant spino-pelvic stiffness or a history of prior spinal fusions.
However, as with any advanced technology that complicates basic architecture, the introduction of additional material interfaces can spark severe, unforeseen mechanical failure modes. While historical literature has extensively evaluated intraprosthetic dislocation (IPD) and femoral neck taper corrosion (”trunnionosis”), mechanically assisted crevice corrosion (MACC) at the modular acetabular shell junction has long been dismissed as a purely theoretical concern.
