title: Patient-specific hip geometry has greater effect on THA wear than femoral head size.
abstract: In vivo linear penetration in total hip arthroplasty (THA) exhibits similar values for 28mm and 32mm femoral head diameter with considerable variations between and within the studies. It indicates factors other than femoral head diameter influence polyethylene wear. This study is intended to test the effect of patient׳s individual geometry of musculoskeletal system, acetabular cup orientation, and radius of femoral head on wear. Variation in patient׳s musculoskeletal geometry and acetabular cup placement is evaluated in two groups of patients implanted with 28mm and 32mm THA heads. Linear wear rate estimated by mathematical model is 0.165-0.185mm/year and 0.157-0.205mm/year for 28 and 32mm THA heads, respectively. Simulations show little influence femoral head size has on the estimated annual wear rate. Predicted annual linear wear depends mostly on the abduction angle of the acetabular cup and individual geometry of the musculoskeletal system of the hip, with the latter having the greatest affect on variation in linear wear rate.
authors.affiliation: Faculty of Mechanical Engineering, Czech Technical University in Prague, Czechia. Electronic address: matej.daniel@fs.cvut.cz.
authors.forename: Matej
authors.initials: M
authors.lastname: Daniel
authors.affiliation: Laboratory of Clinical Biophysics, Faculty of Health Sciences, University of Ljubljana, Slovenia.
authors.forename: Boris
authors.initials: B
authors.lastname: Rijavec
authors.affiliation: Department of Orthopaedic Surgery, University Medical Centre Ljubljana, Ljubljana, Slovenia.
authors.forename: Drago
authors.initials: D
authors.lastname: Dolinar
authors.affiliation: 1st Faculty of Medicine, Charles University, Prague, Czechia.
authors.forename: David
authors.initials: D
authors.lastname: Pokorný
authors.affiliation: Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Slovenia.
authors.forename: Aleš
authors.initials: A
authors.lastname: Iglič
authors.affiliation: Laboratory of Clinical Biophysics, Faculty of Health Sciences, University of Ljubljana, Slovenia.
authors.forename: Veronika
authors.initials: V
authors.lastname: Kralj-Iglič
mesh_terms: D000077:Acetabulum / Q000033:anatomy & histology* / Q000502:physiology; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D005260:Female; D005270:Femur Head / Q000033:anatomy & histology* / Q000502:physiology; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000502:physiology; D066230:Patient-Specific Modeling; D020959:Polyethylene
chemical_list: D020959:Polyethylene
keywords: Contact pressure; Design; Linear penetration; UHMWPE