Objective: The aim of this study is to evaluate the incidence of infections in MoM total hip replacement revisions and to propose a therapeutic algorithm that can reduce the onset of this complication. Total hip arthroplasty is one of the most successful procedures performed annually in the world. As the population ages, the number of primary arthroplasty procedures performed each year is rising in conjunction with an increasing revision burden. Metal on Metal (MoM) total hip arthroplasties were reintroduced in over the last fifteen years to meet these needs, larger diameters, improved lubrication, better stability, increased ROM and wear properties of the bearing couple. These advantageous features have led to an exponential diffusion of MoM. Since over last decade, it has become evident that hip replacements with MoM bearing have significantly higher revision rates compared to those with Metal on Polyethylene. The common pathway for this failure mode appears to be increased wear or corrosion with excessive release of metal ions and nanoparticles. Complications such as elevated serum metal ion levels, aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) and pseudotumours have all been well documented, but recent studies suggest increased risk of infection with MoM bearing surfaces.
Patients and methods: We collect data from a cohort of 44 patients who underwent revision of total hip arthroplasty between 2014 and 2017 for the complication of MoM bearing. Studied by radiological images, blood tests, and intraoperative clinical status, part of the population was treated with one stage revision, while the other was treated with a two-stage revision.
Results: Results showed a difference in the occurrence of infections in the two populations.
Conclusions: We consider it appropriate to perform two-stage revision in all case of failure of MoM replacement so as to allow to minimize the likelihood of infection in patients with damaged tissues by ALVAL, pseudotumour, and necrosis that could create an ideal environment for bacterial development.