Metal ion levels post primary unilateral total knee arthroplasty

Amin Masoumiganjgah, Bastiaan Ginsel, Sarah L Whitehouse, Praveen Vijaysegaran, Hugh English, Ross W Crawford


Metal ion release from metal implants through the processes of mechanical wear and corrosion has been one of the main concerns post total joint arthroplasty. However, there have been very few studies to show metal ion exposure post total knee implants.

The aim of this study was to investigate whether blood metal ion levels are raised in patients with well-functioning unilateral primary total knee arthroplasty in the short and the long term after surgery.

Whole blood Chromium and serum Cobalt levels were measured in 22 patients following primary total knee arthroplasty at a minimum of 12 months after surgery and then repeated at a mean of four years. Eleven patients had the cemented triathlon knee system and 11 patients had an uncemented ACS knee system with multilayer coatings.

Cobalt levels in our study are low one year after TKR and stayed within normal limits with no significant rise at four years (p=0.300). Chromium levels raised significantly by four years (p=0.007), but remained within normal range with no evidence of toxic systemic effects. Our data showed no statistically significant difference for cobalt and chromium levels between ACS and Triathlon groups (p=0.62; p=0.54 respectively).

At an average of 50-months post well-functioning total knee arthroplasty, whole blood Chromium levels and serum Cobalt levels are within the normal range. The use of cement is unlikely to influence metal ion release and titanium nitride coating did not influence metal ion release from TKR implants.
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