in Correlation With Activity Level in Three Different Metal-On-Metal Bearings

Christophe A. Pattyn, MD, PhD, Sofie N. Lauwagie,MD, and René C. Verdonk,MD, PhD

The Journal of Arthroplasty Vol. 26 No. 1 2011

Abstract: Seventy consecutive osteoarthritis patients younger than 65 years undergoing a hip arthroplasty were included. Three different metal bearings were used (2 different resurfacing systems and one 28-mm metal bearing) and compared with a ceramic control group. Whole blood cobalt and chromium levels were analyzed preoperatively, at 3 months, 6 months, 1 year, and 2 years. Patients with steep cups (abduction N55°) were excluded. No significant differences in functional scores and activity level were found between either groups. Ion levels were significantly lower with one type of resurfacing. No correlation was found between ion and activity level. In conclusion, although the current second-generation metal bearings may show differences in ion release, more attention should be paid to the correlation between ion release and implant positioning.