Mechanical test factors affecting short-term rotational stability under combined torsional and compressive loading was assessed in modular press-fit acetabular components with 4 different locking mechanism designs, by measuring the micromotion of the liner-shell interface at either room (20°C) or body temperature (37°C) and with either a high (2943 N) or low (490 N) compressive load. Liner-shell constructs whose short-term stability was statistically significantly affected by temperature exhibited more rotational stability at body temperature than at room temperature. Liner-shell constructs whose short-term stability was statistically significantly affected by the level of compressive load exhibited more rotational stability with high compressive loads than with low loads. Liner-shell constructs with different locking mechanism designs were influenced by temperature and compressive loads differently. It is recommended to consider including these factors in tests of acetabular component locking mechanisms.
Copyright 2008 Elsevier B.V., All rights reserved.
- acetabular component
- liner-shell interface
- locking mechanism
- short-term rotational stability