Dual Mobility Hip Arthroplasty: Innovative Technological Advances

Abstract

The use of 3D-printed highly porous titanium acetabular cups in total hip arthroplasty (THA) is increasing. The porosity and mechanical properties of such highly porous titanium structures mimic those of natural cancellous bone, possibly allowing biological implant fixation to be improved. Recently, a 3D-printed highly porous Dual Mobility (DM) monobloc construct fully manufactured using Ti6Al4V alloy, with a titanium–niobium nitride (TiNbN) ceramic coating on the articular side to allow articulation against the mobile liner by improving the titanium vs. polyethylene tribological behavior, was introduced in THA. To the best of our knowledge, this is the first highly porous titanium monobloc DM implant on the market. The reasons for using a Ti alloy highly porous DM are multifarious: to prevent any possible adverse reactions due to the corrosion of Cobalt–Chromium–Molybdenum Alloy (CoCrMo) and Stainless Steel (SS) implants and to improve implant primary and secondary stability, particularly in cases of poor bone quality. Finally, with the introduction of an inner TiNbN ceramic coating surface, it was possible to overcome the poor tribological quality of titanium. Another interesting characteristic is this material’s higher implant radiolucency, which might facilitate the radiographic assessment of cup orientation, which can, in turn, facilitate the detection of any intraprosthetic dislocation (IPD) and the measurement of polyethylene wear, which is very important in the study of the durability of THA.