Details

Autor(en) / Beteiligte

• Dahlstrand, Henrik
• Stark, André
• Wick, Marius C
• Anissian, Lucas
• Hailer, Nils P
• Weiss, Rüdiger J

Titel

Comparison of metal ion concentrations and implant survival after total hip arthroplasty with metal-on-metal versus metal-on-polyethylene articulations: A 16-year follow-up of a prospective randomized study

Ist Teil von

• Acta orthopaedica, 2017-09, Vol.88 (5), p.490-495

Ort / Verlag

Taylor & Francis

Erscheinungsjahr

2017

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Background and purpose - Large metal-on-metal (MoM) articulations are associated with metal wear and corrosion, leading to increased metal ion concentrations and unacceptable revision rates. There are few comparative studies of 28-mm MoM articulations with conventional metal-on-polyethylene (MoP) couplings. We present a long-term follow-up of a randomized controlled trial comparing MoM versus MoP 28-mm articulations, focused on metal ions and implant survival. Patients and methods - 85 patients with a mean age of 65 years at surgery were randomized to a MoM (Metasul) or a MoP (Protasul) bearing. After 16 years, 38 patients had died and 4 had undergone revision surgery. 13 patients were unavailable for clinical follow-up, leaving 30 patients (n = 14 MoM and n = 16 MoP) for analysis of metal ion concentrations and clinical outcome. Results - 15-year implant survival was similar in both groups (MoM 96% [95% CI 88-100] versus MoP 97% [95% CI 91-100]). The mean serum cobalt concentration was 4-fold higher in the MoM (1.5 μg/L) compared with the MoP cohort (0.4 μg/L, p < 0.001) and the mean chromium concentration was double in the MoM (2.2 μg/L) compared with the MoP cohort (1.0 μg/L, p = 0.05). Mean creatinine levels were similar in both groups (MoM 93 μmol/L versus MoP 92 μmol/L). Harris hip scores differed only marginally between the MoM and MoP cohorts. Interpretation - This is the longest follow-up of a randomized trial on 28-mm MoM articulations, and although implant survival in the 2 groups was similar, metal ion concentrations remained elevated in the MoM cohort even in the long term.