Survivorship Comparisons of Ultracongruent, Cruciate-Retaining and Posterior-Stabilized Tibial Inserts Using a Single Knee System Design: Results From the Australian Orthopedic Association National Joint Replacement Registry

Background: Ultracongruent (UC) tibial inserts can increase knee replacement stability, but how survivorship compares to cruciate retaining (CR) or posterior stabilized (PS) inserts is unclear.

Methods: Data from a large joint registry were used to calculate the cumulative percent revision of a single popular knee design used with different inserts. There were 67,523 procedures, of which 12,434 were UC, 21,635 CR, and 33,454 PS. Revision rates and reasons for revision were analyzed.

Results: The cumulative percent revision at 18 years was 8.3% for UC, 9.2% for CR, and 8.9% for PS. There was no difference when UC was compared to CR, but PS had a higher risk of revision. Revision reasons were similar.

Conclusion: Compared to the CR, an UC insert did not increase revision rates and was actually lower than a PS insert. An UC insert does not compromise long-term total knee arthroplasty survivorship in the Genesis II prosthesis.