Background and purpose. The use of trabecular metal (TM) cups for primary

total hip arthroplasty (THA) increases. Some recent data suggests that the use

of TM in primary THA might be associated with an increased risk of revision.

We compared implant survival of Continuum acetabular cups with other

commonly used uncemented cups. Patients and methods. Data on 11,390

primary THAs with the Continuum cup and 30,372 THAs with other uncemented

cups (reference group) was collected from the Finnish Arthroplasty Register.

Kaplan–Meier survival estimates were calculated; the endpoint was revision for

any reason, for infection, or for dislocation. Revision risks were assessed with

adjusted Cox multiple regression models. A subgroup analysis on the use of

neutral or elevated liners in the Continuum group was made.

Results. The 7-year survivorship of the Continuum group was 94.6% (95% CI

94.0-95.2) versus 95.6% (CI 95.3-95.8) in the reference group for revision for

any reason. The risk for revision was higher in the Continuum group than in

the reference group both for revision for any reason (HR 1.3 (CI 1.2–1.5) and for

revision for dislocation ((HR 1.9 (CI 1.5–2.3). There was no difference in the rates

of revision because of infection (HR 0.99, (CI 0.78-1.3)). Use of a neutral liner

increased the risk for revision due to dislocation in comparison with the use of

an elevated rim liner in the Continuum group (HR 1.7 (CI 1.2-2.5)).

Interpretation. THA with Continuum cups is associated with an increased risk of

revision compared to other uncemented cups, mainly due to revisions because

of dislocation. Our results support the use of elevated liner when Continuum

cups are used for primary THA.