Introduction: Dual-Mobility Total Hip Arthroplasty: A Durable Game Changer or the Next Cause for Concern?

The utilization of dual mobility (DM) articulations in total hip arthroplasty (THA) is increasing. The appeal of DM implants rests in their ability to increase the effective ball head size for a given THA construct compared to conventional bearings, thereby reducing the risk of postoperative instability. Although the concept of DM articulation in THA is not new, and early clinical experience dates back to the 1970s, its widespread use is a relative recent phenomenon. Furthermore, unlike our European counterparts who routinely use monoblock DM acetabular components in THA, the most common DM implants used in North America and worldwide are of a modular nature in which a metallic liner is coupled to a multibearing acetabular component and thus, creating a metal-on-metal interface.

Over the years, all of us have seen trends emerge and adopted with enthusiasm only then to see them later abandoned because of unforeseen complications. The use of metal-on-metal articulations in THA was also supposed to solve the problems of both wear and dislocation and at one point, utilization of these implants exceeded 30% of THAs performed in the United States. In hindsight, probably a significant number of patients were unnecessarily exposed to the risks of metallosis and adverse local tissue reactions. Therefore, the purpose of this symposium is to (1) review the evidence for the indications for DM implants in both primary and revision THA; (2) present basic science data on the risk of corrosion in modular DM implants; and (3) highlight the possible ongoing questions and concerns with DM implants. Our goal is to provide a balanced critical review of this technology and define its place in the hip surgeon’s armamentarium today.