title: Multiple loading conditions analysis can improve the association between finite element bone strength estimates and proximal femur fractures: a preliminary study in elderly women.
abstract: This is a preliminary case-control study on osteopenic/osteoporotic elderly women, testing the association of proximal femur fracture with minimum femoral strength, as derived from finite element (FE) analysis in multiple loading conditions. Fracture cases (n=22) in acute conditions were enrolled among low-trauma fractures admitted in various hospitals in the Emilia Romagna Region, Italy. Women with no history of low-trauma fractures were enrolled as controls (n=33). Patients were imaged with DXA to obtain aBMD, and with a bilateral full femur CT scan. FE-strength was derived in stance and fall configurations: (i) as the minimum strength among those obtained for multiple loading conditions spanning a domain of plausible force directions, and (ii) as the strength associated to the most commonly used single loading conditions. The association of FE-strength and aBMD with fractures was tested with logistic regression models, deriving odds ratios (ORs) and area under the receiver operating characteristic curve (AUC). FE-strength from multiple loading conditions better classified fracture cases from controls (OR per SD change=9.6, 95% CI=3.0-31.3, AUC=0.87 in stance; OR=9.5, 95% CI=2.9-31.2, AUC=0.88 in fall) compared to aBMD (OR=3.6, 95% CI=1.6-8.2, AUC=0.79 for total femur aBMD), while FE-strength results from the most commonly used single loading conditions were similar to aBMD. Only FE-strength from multiple loading conditions remained significant in age- and aBMD-adjusted models (OR=10.5, 95% CI=1.8-61.3, AUC=0.95). In summary, we highlighted the importance of considering different loading conditions to identify bone weakness, and confirmed that femoral FE-strength estimates may add value to aBMD predictions in elderly osteopenic/osteoporotic women.
authors.affiliation: Laboratorio di Bioingegneria Computazionale, Istituto Ortopedico Rizzoli, Italy; Dipartimento di Ingegneria Civile, Università di Roma Tor Vergata, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Falcinelli
authors.affiliation: Laboratorio di Bioingegneria Computazionale, Istituto Ortopedico Rizzoli, Italy. Electronic address: schileo@tecno.ior.it.
authors.forename: Enrico
authors.initials: E
authors.lastname: Schileo
authors.affiliation: Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Balistreri
authors.affiliation: Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Baruffaldi
authors.affiliation: Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Bordini
authors.affiliation: Department of Mechanical Engineering, University of Sheffield, UK; Insigneo Institute for In Silico Medicine, University of Sheffield, UK.
authors.forename: Marco
authors.initials: M
authors.lastname: Viceconti
authors.affiliation: Radiologia diagnostica ed interventistica, Istituto Ortopedico Rizzoli, Italy.
authors.forename: Ugo
authors.initials: U
authors.lastname: Albisinni
authors.affiliation: Clinica Ortopedica, Università di Parma, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Ceccarelli
authors.affiliation: Ortopedia Programmata, Ospedale di Faenza, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Milandri
authors.affiliation: Ortopedia-Traumatologia e Chirurgia protesica e dei reimpianti d'anca e di ginocchio, Istituto Ortopedico Rizzoli, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Toni
authors.affiliation: Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Italy.
authors.forename: Fulvia
authors.initials: F
authors.lastname: Taddei
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena / Q000502:physiology; D015992:Body Mass Index; D016022:Case-Control Studies; D005260:Female; D005264:Femoral Fractures / Q000378:metabolism* / Q000503:physiopathology; D005269:Femur / Q000378:metabolism* / Q000502:physiology; D020342:Finite Element Analysis; D006801:Humans; D008875:Middle Aged; D058866:Osteoporotic Fractures / Q000378:metabolism
keywords: Biomechanics; Bone strength; Case–control study; Finite-element analysis; Osteoporosis; Proximal femur fracture