Moon JK, et al. - The long-term outcomes of cementless primary metal-on-metal total hip arthroplasty (MoM THA) with a 28-mm head and the incidence of osteolysis using computed tomography (CT) were assessed herein. Results suggested that at a mean follow-up of 20 years, MoM THA with a 28-mm head demonstrated a relatively low rate of aseptic implant loosening. At the final follow-up, the mean preoperative the Harris Hip score (HHS) of 50.5 improved to 85.1.