title: In vitro wear testing of the PyroCarbon proximal interphalangeal joint replacement: Five million cycles of flexion and extension.
abstract: Clinical results of the PyroCarbon proximal interphalangeal joint replacement are inconsistent with various complications reported. To address this, in vitro testing was conducted using finger joint simulators. Two PyroCarbon proximal interphalangeal prostheses were tested in a lubricant of dilute bovine serum to 5 × 10(6) cycles of flexion-extension (90°-30°) with dynamic forces of 10 N applied. At intervals of 3000 cycles testing ceased and a static load of 100 N was applied to simulate gripping. In addition, two 'control' prostheses were immersed alongside the test prostheses to account for lubricant absorption. Wear and roughness averages (Ra) were measured every 1 × 10(6) cycles. Minimal wear for all of the components was measured with a negligible increase in Ra for most of the components. One condyle of one component increased in Ra over the 5 × 10(6) cycles with a value above the recommended 50 nm. Unidirectional marks were visible on the condyle from micrographs, consistent with an abrasive wear mode.
authors.affiliation: School of Mechanical and Systems Engineering, Newcastle University, Newcastle upon Tyne, UK andrew.naylor@newcastle.ac.uk.
authors.forename: Andrew
authors.initials: A
authors.lastname: Naylor
authors.affiliation: School of Mechanical and Systems Engineering, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Martin C
authors.initials: MC
authors.lastname: Bone
authors.affiliation: School of Engineering and Computing Sciences, Durham University, Durham, UK.
authors.forename: Anthony
authors.initials: A
authors.lastname: Unsworth
authors.affiliation: Upper Limb Research Unit, Wrightington Hospital, Lancashire, UK.
authors.forename: Sumedh C
authors.initials: SC
authors.lastname: Talwalkar
authors.affiliation: Upper Limb Research Unit, Wrightington Hospital, Lancashire, UK.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Trail
authors.affiliation: School of Mechanical and Systems Engineering, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Joyce
mesh_terms: D000818:Animals; D002244:Carbon / Q000737:chemistry*; D002417:Cattle; D007595:Joint Prosthesis; D054327:Lubricants; D008422:Materials Testing / Q000379:methods*; D008954:Models, Biological; D011474:Prosthesis Design; D044967:Serum
chemical_list: D054327:Lubricants; C009139:pyrolytic carbon; D002244:Carbon
keywords: Wear analysis/testing; biomechanical testing/analysis; joint simulators; orthopaedic tribology; surfaces