title: Mechanisms for pumping fluid through cementless acetabular components with holes.
abstract: 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.
authors.affiliation: Hospital for Special Surgery, New York, New York, USA.
authors.forename: William L
authors.initials: WL
authors.lastname: Walter
authors.forename: Jonathan
authors.initials: J
authors.lastname: Clabeaux
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Wright
authors.forename: William
authors.initials: W
authors.lastname: Walsh
authors.forename: William K
authors.initials: WK
authors.lastname: Walter
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Sculco
mesh_terms: 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
chemical_list: D020959:Polyethylene