Mechanisms for pumping fluid through cementless acetabular components with holes.
The pumping of fluid and polyethylene wear debris from the joint space to the retroacetabular bone is implicated in the pathogenesis of osteolysis. Three possible mechanisms for this pumping: pressure gradients, diaphragm pumping, and piston pumping were studied in vitro in a laboratory model. The simulated activities of rising from a chair and climbing stairs produced high-pressure gradients and high angles of loading that could pump fluid through the apical hole to the retroacetabular bone. A noncongruent liner acted as a diaphragm pump, producing pressures 6 times higher than that seen with a congruent liner. Pistoning motion of the liner produced pressures 8 times higher than when no pistoning occurs. These pumping mechanisms could be mitigated by the use of acetabular components without holes.
Walter
William L
WL
Hospital for Special Surgery, New York, New York, USA.
Clabeaux
Jonathan
J
Wright
Timothy M
TM
Walsh
William
W
Walter
William K
WK
Sculco
Thomas P
TP
D000077:Acetabulum / Q000601:surgery; D001696:Biomechanical Phenomena; D006621:Hip Joint / Q000503:physiopathology* / Q000601:surgery; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D066298:In Vitro Techniques; D010014:Osteolysis / Q000209:etiology* / Q000517:prevention & control*; D020959:Polyethylene / Q000009:adverse effects; D011312:Pressure; D011474:Prosthesis Design; D013499:Surface Properties; D016138:Walking / Q000502:physiology
D020959:Polyethylene