title: Variation of the impact duration during the in vitro insertion of acetabular cup implants.
abstract: The acetabular cup (AC) is an implant impacted into a bone cavity and used for hip prosthesis surgery. Initial stability of the AC is an important factor for long term surgical success. The aim of this study is to determine the variations of the impact duration during AC implant insertion. Twenty-two bone samples taken from bovine femurs were prepared ex vivo for the insertion of an acetabular cup implant, following the surgical procedure used in the clinic. For each bone sample, ten impacts were applied using reproducible mass falls (3.5 kg) in order to insert the AC implant. Each impact duration was recorded using a wide bandwidth force sensor. For all bone samples, the impact duration was shown to first decrease as a function of the impact number, then reaching a stationary value equal in average to 4.2±0.7 ms after an average number of 4.1±1.7 impacts. The impact duration may be related to variations of the bone-implant interface contact rigidity because of an increase the amount of bone tissue in contact with the AC implant. Measurements of impact duration have a good potentiality for clinical application to assist the surgeon during the insertion of the AC implant, providing valuable information on the bone-implant interface contact properties.
authors.affiliation: CNRS, Laboratoire Modélisation et Simulation Multi-Échelle, UMR CNRS 8208, 61 avenue du Général de Gaulle, 94010 Créteil Cedex, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Mathieu
authors.forename: Adrien
authors.initials: A
authors.lastname: Michel
authors.forename: Charles-Henri
authors.initials: CH
authors.lastname: Flouzat Lachaniette
authors.forename: Alexandre
authors.initials: A
authors.lastname: Poignard
authors.forename: Philippe
authors.initials: P
authors.lastname: Hernigou
authors.forename: Jérome
authors.initials: J
authors.lastname: Allain
authors.forename: Guillaume
authors.initials: G
authors.lastname: Haïat
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D000818:Animals; D002417:Cattle; D005269:Femur; D006622:Hip Prosthesis; D055595:Mechanical Phenomena; D019919:Prosthesis Implantation / Q000295:instrumentation; D013997:Time Factors
keywords: Acetabular cup implant; Impact; Primary stability