Preliminary Results of Total Hip Arthroplasty in Subjects at Risk for Dislocation Using a Novel Modular Cementless Dual-Mobility Cup. A Single-Center Prospective Study

Abstract

Nowadays total hip arthroplasty (THA) is widely considered the operation of the century in orthopedic and traumatological fields. Despite this fact, instability and dislocation after THA are a common reason for revision surgery. The purpose of this prospective study is to evaluate the preliminary clinical and radiological results of a novel dual mobility cup. We evaluated 32 consecutive cases of patients who underwent THA using a novel dual mobility cup—with holes in the cup, a modular metallic inlay and a crosslinked polyethylene. All of them were considered at risk of instability of the implant due to primary or concomitant diagnosis. The preoperative Harris hip score was 54.7 on average. At a minimum 2 years follow-up, the mean HHS raised up to a mean value of 88.4; this improvement was statistically significant (p < 0.0001). None of the patients enrolled in this study sustained a postoperative dislocation at a mean follow-up of 39.6 months. Furthermore, no patients sustained modular liner dissociation or an intraprosthetic dislocation. As such, survivorship free from dislocation was 100% at both 2 and 5 years. This study demonstrates that the modular dual mobility (DM) socket provides dual articulation, larger jump distance, and greater range of motion before impingement, which significantly reduce the rate of dislocation.

Analysis of contact pressure in a 3D model of dual-mobility hip joint prosthesis under a gait cycle

“…The dual-mobility hip joint prosthesis model was used to reduce wear of the implant compared to a singlemobility hip joint prosthesis that has been proven in both mechanical 39 and medical 40 perspectives. According to Jamari et al 29 , contact pressure has a linear correlation with wear on implant bearings; therefore, contact pressure studies can indicate the intensity of wear on implant bearings.…”

Dual Mobility Hip Arthroplasty: Innovative Technological Advances

“…These modular DM devices have a standard titanium metal-backed shell, which allows an inner metal liner to couple the outer titanium surface with the polyethylene liner. The use of modular prostheses has currently demonstrated satisfactory results, while also adding a series of new complications [15][16][17][18]. As with all monoblock DM devices, it lacks the additional screw fixation options available for other conventional metal-backed acetabular shells.…”