Hjorth MH, et al. - This trial was conducted to evaluate the prevalence of pseudotumors in metal-on-polyethylene (MOP) total hip arthroplasty (THA) in patients with hip articulations. A similar pseudotumor prevalence in MoP THA to metal-on-metal (MoM) hip articulations was noted, which is the most common bearing worldwide. In MoP THA, mixed-or solid pseudotumors were more commonly demonstrated as compared to the MoM hip articulations. Poorer clinical scores and higher metal-ion levels were demonstrated in patients with a mixed or solid pseudotumor as compared to the cases without a pseudotumor or with a cystic pseudotumor.