title: Metal neck and liner impingement in ceramic bearing total hip arthroplasty.
abstract: Although impingement between the neck of the metallic stem and the ceramic liner has been suspected to be the cause of ceramic liner failure in ceramic-on-ceramic total hip arthroplasty (THA), no report has directly demonstrated microscopic damage on ceramic liner. We performed 18 reoperations on 18 patients who had undergone third generation ceramic-on-ceramic THA. Considering impingement, 16 patients, who were reoperated more than 1 year after previous ceramic bearing THA, were evaluated. Retrieved alumina liners, showing evidence of impingement, were examined by means of visual inspection and scanning electron microscopy (SEM). Four of the 16 hips showed neck notching and black stained liners, evidence of metallic neck to ceramic impingement. Impinged alumina bearings had been implanted for an average of 62.5 months (range: 35-99 months) before reoperation. SEM of the black stained area demonstrated disruptive wear and loss of surface integrity. Furthermore, one liner had multiple microcracks, and its cross-sectional SEM analysis revealed one microcrack propagating into the deep portion of the ceramic liner. Our observations suggest that metal neck-to-ceramic impingement in ceramic-on-ceramic THA can cause microcrack formation in ceramic liner.
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Young-Kyun
authors.initials: YK
authors.lastname: Lee
authors.forename: Jeong Joon
authors.initials: JJ
authors.lastname: Yoo
authors.forename: Kyung-Hoi
authors.initials: KH
authors.lastname: Koo
authors.forename: Kang Sup
authors.initials: KS
authors.lastname: Yoon
authors.forename: Hee Joong
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D002516:Ceramics; D005260:Female; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D011475:Prosthesis Failure / Q000209:etiology*; D012086:Reoperation; D055815:Young Adult