title: Long-term follow-up of metal-on-metal total hip replacement.
abstract: Metal-on-metal articulations were reintroduced to reduce polyethylene particle-induced osteolysis. Elevated serum metal levels have been detected at short- and intermediate-term follow-up. There is little knowledge about long-term effects of increased ionic metal generation. Our study was undertaken to provide information about long-term survival, clinical outcome, radiographic appearance, and serum metal concentrations after a minimum 10 years follow-up with a metal-on-metal hip prosthesis: 105 cementless primary total hip prostheses with metal-on-metal articulating surfaces were implanted in 98 patients with a mean age of 56 years. Clinical data, radiographs, and blood samples were obtained at a follow-up visit 10 years after implantation. Serum cobalt and chromium levels were determined with use of atomic absorption spectrometry. General laboratory analyses included a full blood count and kidney function parameters. The Harris score was 92 points and the UCLA score 6 points after 10 years. Small osteolytic lesions and radiolucent lines were found in Gruen's zones 1, 7, 8, and 14. The probability of survival was 98.6%. The median serum cobalt concentration of the 22 patients with their hip replacement as the only source of cobalt was 0.75 microg/L (range, 0.3-50.1 microg/L). No patient was diagnosed with renal insufficiency during the study period. Five patients were diagnosed with a malignancy between surgery and the follow-up. We do not have evidence of an increased rate of primary malignancies nor could we detect renal failure in our study group. Serum metal levels did not differ from short- and intermediate term follow-up values.
authors.affiliation: Department of Orthopaedics, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, and General Hospital Krems, Krems and der Donau, Austria. info@hueft-orthopaede.at
authors.forename: Alexander
authors.initials: A
authors.lastname: Grübl
authors.forename: Martina
authors.initials: M
authors.lastname: Marker
authors.forename: Wolfram
authors.initials: W
authors.lastname: Brodner
authors.forename: Alexander
authors.initials: A
authors.lastname: Giurea
authors.forename: Georg
authors.initials: G
authors.lastname: Heinze
authors.forename: Vanee
authors.initials: V
authors.lastname: Meisinger
authors.forename: Harald
authors.initials: H
authors.lastname: Zehetgruber
authors.forename: Rainer
authors.initials: R
authors.lastname: Kotz
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation*; D001182:Arthroscopy; D002857:Chromium / Q000097:blood; D003035:Cobalt / Q000097:blood; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D010014:Osteolysis / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D017060:Patient Satisfaction; D011183:Postoperative Complications; D011474:Prosthesis Design; D011859:Radiography; D012086:Reoperation; D013054:Spectrophotometry, Atomic
chemical_list: D002857:Chromium; D003035:Cobalt