title: Ex vivo estimation of cementless acetabular cup stability using an impact hammer.
abstract: Obtaining primary stability of acetabular cup (AC) implants is one of the main objectives of press-fit procedures used for cementless hip arthroplasty. The aim of this study is to investigate whether the AC implant primary stability can be evaluated using the signals obtained with an impact hammer. A hammer equipped with a force sensor was used to impact the AC implant in 20 bovine bone samples. For each sample, different stability conditions were obtained by changing the cavity diameter. For each configuration, the inserted AC implant was impacted four times with a maximum force comprised between 2500 and 4500 N. An indicator I was determined based on the partial impulse estimation and the pull-out force was measured. The implant stability and the value of the indicator I reached a maximum value for an interference fit equal to 1 mm for 18 out of 20 samples. When pooling all samples and all configurations, the implant stability and I were significantly correlated (R(2) = 0.83). The AC implant primary stability can be assessed through the analysis of the impact force signals obtained using an impact hammer. Based on these ex vivo results, a medical device could be developed to provide a decision support system to the orthopedic surgeons.
authors.affiliation: CNRS, Laboratoire de Modélisation et de Simulation Multi-Echelle, UMR CNRS 8208,61 Avenue du Général de Gaulle, Créteil 94010, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Michel
authors.affiliation: Service de Chirurgie Orthopédique et Traumatologique, Hôpital Henri Mondor AP-HP, CHU Paris 12, Université Paris-Est, 51 avenue du Maréchal de Lattre de Tassigny, Créteil 94000, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Bosc
authors.affiliation: Service de Chirurgie Ostéo-articulaire et carcinologique, Clinique Arago, 54, boulevard Saint-Jacques, 75014 Paris, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sailhan
authors.affiliation: CNRS, Laboratoire de Modélisation et de Simulation Multi-Echelle, UMR CNRS 8208,61 Avenue du Général de Gaulle, Créteil 94010, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Vayron
authors.affiliation: CNRS, Laboratoire de Modélisation et de Simulation Multi-Echelle, UMR CNRS 8208,61 Avenue du Général de Gaulle, Créteil 94010, France; Ecole de Technologie Superieure, Department of Mechanical Engineering, 1100 Rue Notre-Dame Ouest, Montréal, QC H3C 1K3, Canada. Electronic address: guillaume.haiat@univ-paris-est.fr.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Haiat
mesh_terms: D000077:Acetabulum; D000818:Animals; D002417:Cattle; D006622:Hip Prosthesis; D008422:Materials Testing; D055595:Mechanical Phenomena
keywords: Acetabular cup implant; Bone; Hip prosthesis; Vibration analysis; impact