title: Crack initiation in retrieved cross-linked highly cross-linked ultrahigh-molecular-weight polyethylene acetabular liners: an investigation of 9 cases.
abstract: Nine cross-linked highly cross-linked ultrahigh-molecular weight polyethylene acetabular liners were retrieved at revision surgery. Eight of the liners were fully intact and functional at retrieval. Six cases contained shallow initiated cracks at the root of rim notches; 1 crack had propagated several millimeters. Optical and electron microscopic inspection of the crack surfaces revealed clam shell markings, which are characteristic of fatigue crack initiation. Crack initiation at notches has been identified in reports of catastrophic cross-linked liner failures, with crack initiation sites exhibiting similar morphology and clam shell markings. Thus, we believe that the shallow cracks identified in this case series are precursors to catastrophic rim fracture. The results of this study recommend further investigations to clarify the etiology and prevalence of crack initiation in cross-linked acetabular liners.
authors.affiliation: Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA.
authors.forename: Jevan
authors.initials: J
authors.lastname: Furmanski
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Kraay
authors.forename: Clare M
authors.initials: CM
authors.lastname: Rimnac
mesh_terms: D000077:Acetabulum; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D015331:Cohort Studies; D020878:Device Removal; D019544:Equipment Failure Analysis / Q000379:methods*; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008853:Microscopy; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D011095:Polyethylenes; D011474:Prosthesis Design; D011475:Prosthesis Failure / Q000209:etiology*; D012086:Reoperation
chemical_list: D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene