Early Intraprosthetic Dislocation of A Dual Mobility Acetabular Construct

Dislocations represent one of the more common postoperative complications seen after total hip arthroplasty (THA) with estimates ranging from 0.2 to 7% in primary cases and as high as 25% in revision surgeries [1]. In the early 1970s, Giles Bousquet developed a dual mobility (DM) acetabular cup with the goal of reducing dislocation rates. The dual mobility (DM) design consists of two articulations: a large diameter polyethylene articulation with a metal cup and a smaller articulation between a modular femoral head and the polyethylene liner [2]. In a dual mobility (DM) construct, when impingement of the smaller articulation occurs, additional range of motion is available through the articulation of the polyethylene liner within the metal cup. Thus, DM constructs increase the head-neck ratio, and also increase the jump distance; this effectively decreases the dislocation rate of total hip arthroplasty with this construct [3].