No superiority of cemented metal-on-metal over metal-on-polyethylene THA in a randomized controlled trial at 10-year follow-up.
In a randomized controlled trial, 102 cemented Stanmore 28-mm metal-on-metal total hip arthroplasties (THAs) were compared to 98 metal-on-polyethylene THAs in 195 patients. At a mean follow-up of 10 years, 11 patients (11 hips) were lost to follow-up, 53 patients (55 hips) died, and 6 patients (6 hips) underwent revision. Average age of the surviving patients was 79 years. Harris Hip Scores and Oxford Hip Scores had increased significantly in both groups (P=.000). Ten years postoperatively, mean Harris Hip Score was 86 in the metal-on-metal patients and 87 in the metal-on-polyethylene patients (P=.441); Oxford Hip Scores were 27 and 24, respectively (P=.494). Wear was present in 30 of 52 polyethylene cups. Periprosthetic radiolucencies were seen in 57% of the metal-on-metal patients and in 52% of the metal-on-polyethylene patients (P=.680); they were mainly seen in DeLee & Charnley's zones 1 and 2. Serum cobalt and chromium concentration were higher in the metal-on-metal group (cobalt 1.1, chromium 1.0 vs 0.5 and 0.5 mug/L, respectively; P<.001). Patients with high ion levels (maximum 9.5 and 11 mug/L, respectively) all showed high Harris Hip Scores and few or no periprosthetic radiolucencies, and none were revised. Ten-year survival was 95.5% in the metal-on-metal group (4 revisions) and 96.8% in the metal-on-polyethylene group (2 revisions; P=.402). All revisions were indicated for aseptic loosening. One case of aseptic lymphocytic vasculitis-associated lesions and no pseudotumors were observed. The absence of clinical superiority of the cemented metal-on-metal bearing and the concerns over their biological effects have led us to favor the cemented metal-on-polyethylene THA.
Zijlstra
Wierd P
WP
Department of Orthopedic Surgery, Martini Hospital, PO Box 30033, 9700 RM Groningen, The Netherlands. wpzijlstra@hotmail.com
van Raay
Jos J A M
JJ
Bulstra
Sjoerd K
SK
Deutman
Robert
R
D000368:Aged; D001843:Bone Cements / Q000627:therapeutic use*; D002484:Cementation / Q000706:statistics & numerical data*; D018572:Disease-Free Survival; D019544:Equipment Failure Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D061825:Metal-on-Metal Joint Prostheses / Q000706:statistics & numerical data*; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D015207:Osteoarthritis, Hip / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery*; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control; D016896:Treatment Outcome
D001843:Bone Cements; D020959:Polyethylene