Factors influencing the initial micromotion between polyethylene acetabular cups and titanium alloy shells.
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 degrees C) or body temperature (37 degrees C) and with either a high (2,943 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.
Kyle
Richard F
RF
Orthopaedic Biomechanics Laboratory of the Midwest Orthopaedic Research Foundation and Minneapolis Medical Research Foundation, Minnesota, USA.
Riddle
Cheryl D
CD
Kyle
Matthew
M
Rockswold
Sara
S
Bourgeault
Craig
C
D000077:Acetabulum; D019544:Equipment Failure Analysis; D006622:Hip Prosthesis; D006801:Humans; D009038:Motion; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012399:Rotation; D013314:Stress, Mechanical; D013696:Temperature; D014025:Titanium
D020959:Polyethylene; D014025:Titanium