title: Range of Movement for Impingement and Dislocation Avoidance in Total Hip Replacement Predicted by Finite Element Model.
abstract: Dislocation is a serious complication in total hip replacement (THR). An inadequate range of movement (ROM) can lead to impingement of the prosthesis neck on the acetabular cup; furthermore, the initiation of subluxation and dislocation may occur. The objective of this study was to generate a parametric three-dimensional finite element (FE) model capable of predicting the dislocation stability for various positions of the prosthetic head, neck, and cup under various activities. Three femoral head sizes (28, 32, and 36 mm) were simulated. Nine acetabular placement positions (abduction angles of 25°, 40° and 60° combined with anteversion angles of 0°, 15° and 25°) were analyzed. The ROM and maximum resisting moment (RM) until dislocation were evaluated based on the stress distribution in the acetabulum component. The analysis allowed for the definition of a "safe zone" of movement for impingement and dislocation avoidance in THR: an abduction angle of 40°-60° and anteversion angle of 15°-25°. It is especially critical that the anteversion angle does not fall to 10°-15°. The sequence of the RM is a valid parameter for describing dislocation stability in FE studies.
authors.affiliation: Department of Orthopaedic Surgery, University Hospital Lozano Blesa, San Juan Bosco, 15, 50009 Saragossa, Spain.|C/El Greco, 150, Urbanización Virgen de la Columna, 50730 El Burgo de Ebro, Saragossa, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Ezquerra
authors.affiliation: Aragón Institute of Engineering Research (I3A), University of Zaragoza, Maria de Luna s/n, Campus Río Ebro, Edificio "Agustín de Betancourt", 50018 Saragossa, Spain.
authors.forename: María Paz
authors.initials: MP
authors.lastname: Quilez
authors.affiliation: Aragón Institute of Engineering Research (I3A), University of Zaragoza, Maria de Luna s/n, Campus Río Ebro, Edificio "Agustín de Betancourt", 50018 Saragossa, Spain.
authors.forename: María Ángeles
authors.initials: MÁ
authors.lastname: Pérez
authors.affiliation: Department of Orthopaedic Surgery, University Hospital Lozano Blesa, San Juan Bosco, 15, 50009 Saragossa, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Albareda
authors.affiliation: Department of Orthopaedic Surgery, University Hospital Lozano Blesa, San Juan Bosco, 15, 50009 Saragossa, Spain.
authors.forename: Belén
authors.initials: B
authors.lastname: Seral
keywords: Dislocation; Finite element analysis; Impingement; Resisting moment; Safe zone