Incidence of ceramic liner malseating in trident ^® acetabular shell

The low wear rates associated with ceramic hip articulations have made them a popular bearing for younger patients. Although few complications have been observed, one report revealed several instances of incomplete seating of the ceramic liner in the metallic shell. We performed a cohort study of consecutive THAs using a ceramic-ceramic bearing. Radiographic analysis showed 50 (7.2%) of the group of 694 hips had evidence of incomplete seating of the liner in the metallic shell. Although we observed no adverse effects at 6 to 12 weeks, we encourage surgeons to carefully assess liner placement in the metal shell at the time of surgery to avoid this unintended consequence and to assess placement at the time of followup so patients can be properly followed when incomplete seating is identified. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.