Gascoyne T, et al. - Identification of aseptic loosening of several hydroxyapatite (HA)-coated femoral stems from a single manufacturer at mid-term follow-up, despite prior radiographic appearance of osseointegration, led researchers to determine the possible causes and associated risk factors for stem loosening via performing radiographic review and implant retrieval analysis. They identified 46 retrieved hip stems (Corail, DePuy-Synthes) and grouped them by bearing type: metal-on-metal (MoM), metal-on-polyethylene, and ceramic-on-ceramic. Thirty-seven percent of examined cases displayed aseptic loosening. As per observation, risk of mid-term loosening of previously osseointegrated HA-coated femoral stems was high when paired with a MoM bearing. It seems that the loosening mechanism is progressive in nature and is related to the MoM bearing, possibly interacting with the HA coating. In case of early recognition of such loosening, rapid revision may allow for retention of the femoral stem.