title: A prospective, randomised controlled trial comparing ceramic-on-metal and metal-on-metal bearing surfaces in total hip replacement.
abstract: In a double-blinded randomised controlled trial,   83 patients with primary osteoarthritis of the hip received either   a ceramic-on-metal (CoM) or metal-on-metal (MoM) total hip replacement   (THR). The implants differed only in the bearing surfaces used.   The serum levels of cobalt and chromium and functional outcome scores   were compared pre-operatively and at six and 12 months post-operatively. Data were available for 41 CoM and 36 MoM THRs (four patients   were lost to follow-up, two received incorrect implants). The baseline   characteristics of both cohorts were similar. Femoral head size   measured 36 mm in all but two patients who had 28 mm heads. The   mean serum cobalt and chromium levels increased in both groups,   with no difference noted between groups at six months (cobalt p   = 0.67, chromium p = 0.87) and 12 months (cobalt p = 0.76, chromium   p = 0.76) post-operatively. Similarly, the mean Oxford hip scores,   Western Ontario and McMaster Universities Osteoarthritis index and   University of California, Los Angeles activity scores showed comparable improvement   at 12 months. Our findings indicate that CoM and MoM couplings are associated   with an equivalent increase in serum cobalt and chromium levels,   and comparable functional outcome scores at six and 12-months follow-up.
authors.affiliation: Christchurch Hospital, Department of Orthopaedic Surgery and Musculoskeletal Medicine, University of Otago, Christchurch, P.O. Box 4345, Christchurch, New Zealand. rowanschouten@gmail.com
authors.forename: R
authors.initials: R
authors.lastname: Schouten
authors.forename: A A
authors.initials: AA
authors.lastname: Malone
authors.forename: C
authors.initials: C
authors.lastname: Tiffen
authors.forename: C M
authors.initials: CM
authors.lastname: Frampton
authors.forename: G
authors.initials: G
authors.lastname: Hooper
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D002516:Ceramics / Q000009:adverse effects / Q000627:therapeutic use*; D002857:Chromium / Q000097:blood*; D003035:Cobalt / Q000097:blood*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008670:Metals / Q000009:adverse effects / Q000627:therapeutic use*; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery*; D011446:Prospective Studies; D011474:Prosthesis Design
chemical_list: D008670:Metals; D002857:Chromium; D003035:Cobalt