title: Feasibility of detecting orthopaedic screw overtightening using acoustic emission.
abstract: A preliminary study of acoustic emission during orthopaedic screw fixation was performed using polyurethane foam as the bone-simulating material. Three sets of screws, a dynamic hip screw, a small fragment screw and a large fragment screw, were investigated, monitoring acoustic-emission activity during the screw tightening. In some specimens, screws were deliberately overtightened in order to investigate the feasibility of detecting the stripping torque in advance. One set of data was supported by load cell measurements to directly measure the axial load through the screw. Data showed that acoustic emission can give good indications of impending screw stripping; such indications are not available to the surgeon at the current state of the art using traditional torque measuring devices, and current practice relies on the surgeon's experience alone. The results suggest that acoustic emission may have the potential to prevent screw overtightening and bone tissue damage, eliminating one of the commonest sources of human error in such scenarios.
authors.affiliation: 1 Cardiff School of Engineering, Cardiff University, Cardiff, UK.
authors.forename: Rhys
authors.initials: R
authors.lastname: Pullin
authors.affiliation: 2 Orthopedic Department, Ringerike Sykehus, Hønefoss, Norway.
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Wright
authors.affiliation: 1 Cardiff School of Engineering, Cardiff University, Cardiff, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Kapur
authors.affiliation: 1 Cardiff School of Engineering, Cardiff University, Cardiff, UK.
authors.forename: John P
authors.initials: JP
authors.lastname: McCrory
authors.affiliation: 1 Cardiff School of Engineering, Cardiff University, Cardiff, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Pearson
authors.affiliation: 1 Cardiff School of Engineering, Cardiff University, Cardiff, UK.
authors.forename: Sam L
authors.initials: SL
authors.lastname: Evans
authors.affiliation: 1 Cardiff School of Engineering, Cardiff University, Cardiff, UK.
authors.forename: Davide
authors.initials: D
authors.lastname: Crivelli
mesh_terms: D000162:Acoustics; D001696:Biomechanical Phenomena; D001863:Bone Screws / Q000009:adverse effects; D001842:Bone and Bones / Q000293:injuries / Q000601:surgery; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D006801:Humans; D016571:Neural Networks, Computer; D019637:Orthopedic Procedures / Q000009:adverse effects / Q000379:methods; D019415:Torque
keywords: Acoustic emission; biomedical devices; medical signal processing; orthopaedic procedures; orthopaedic screws