title: Analysis of failed Van Straten LPM proximal interphalangeal prostheses.
abstract: The two-piece Van Straten Leuwen Poeschmann Metal (LPM) prosthesis was intended for the proximal interphalangeal joints. However, revision rates of 29% after 19 months were reported, as well as massive osteolysis. Five failed LPM titanium-niobium coated cobalt chromium components were obtained, three distal and two proximal, and subjected to a forensic retrieval analysis. Components were analyzed using a Talysurf contacting profilometer, ZYGO noncontacting profilometer, and environmental-scanning electron microscope. All components were heavily worn. In some regions the titanium-niobium coating had been scratched and penetrated. Elsewhere this coating had been removed where there was minimal scratching, which may have been due to corrosion between the coating and substrate. The osteolysis reported clinically was likely to be linked to the wear debris from the failed titanium-niobium coating and substrate.
authors.affiliation: School of Mechanical and Systems Engineering, Newcastle University, Newcastle upon Tyne, UK. martin.bone2@newcastle.ac.uk
authors.forename: M C
authors.initials: MC
authors.lastname: Bone
authors.forename: J L
authors.initials: JL
authors.lastname: Cunningham
authors.forename: J
authors.initials: J
authors.lastname: Lord
authors.forename: G
authors.initials: G
authors.lastname: Giddins
authors.forename: J
authors.initials: J
authors.lastname: Field
authors.forename: T J
authors.initials: TJ
authors.lastname: Joyce
mesh_terms: D002857:Chromium; D020099:Coated Materials, Biocompatible; D003035:Cobalt; D019544:Equipment Failure Analysis; D005384:Finger Joint / Q000601:surgery*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D009556:Niobium; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013499:Surface Properties; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D009556:Niobium; D002857:Chromium; D003035:Cobalt; D014025:Titanium