Dual Mobility in Total Hip Arthroplasty

Is there a rationale to use a dual mobility poly insert for failed Birmingham metal-on-metal hip replacements? A retrieval analysis

“…Dual mobility implants combine two articulations [9]: one between the femoral head and the polyethylene liner (primary articulation), and a second between the convex surface of the polyethylene liner and the acetabular component (secondary articulation). The large diameter of the secondary articulation increases the jump-distance and therefore enhances the stability of the hip and increases its safe range of motion [10].…”

Catastrophic failure of a dual mobility bearing in a revision total hip arthroplasty

“…It has also been suggested that a DM construct increases wear as well [9]. The question this report poses is does the combination of both synergistically increase wear?…”

Serum Metal Ion Levels Following Total Hip Arthroplasty With Modular Dual Mobility Components

“…It is believed that this enhanced stability is due to greater range of motion (ROM) before neck to socket impingement and increased joint jump distance associated with use of larger femoral head [5]. Dual mobility components, recently introduced in the US, effectively increase head size and reduce the incidence of THA instability [6][7][8][9][10][11][12]. Increased head size, coupled with the potential for motion at two articulating surfaces leads to increased ROM prior to impingement and likely explains the low incidence of reported instability when this device is used [7,9,11].…”

“…There are several potential advantages associated with this device, including use of a larger articulating bearing and increased impingement-free ROM due to dual articulations. Several investigators have reported near elimination of THA instability when using dual mobility technology[6][7][8][9][10][11][12]. One report demonstrated a 0% incidence of instability if THA was performed with a 36 mm or larger femoral head.…”