Five Duraloc locking ring failures.

We report on 5 cases that underwent revision for locking ring failure in the Duraloc product line (DePuy, Warsaw, Ind). All liner retrievals showed signs of posterior neck/liner impingement and superior edge loading or significant wear. In these cases, we believe superior head migration and neck/liner impingement due to cup anteversion contributed to these locking ring failures. More research is needed to determine the incidence of this complication. Patients with locking ring failures should be closely monitored. Full cup revision, face-changing liners, or cementing liners into well-fixed cups are all options to correct suboptimal cup positioning.