Test Background High concentrations of cobalt in blood or serum are associated with increased wear of artificial hip joints and may contribute to an indication for revision of the procedure. The MHRA has advised that a concentration of >119 nmol/L is an indication of excessive wear in a metal-on-metal hip implant.
Predominantly used for assessing wear of artificial hip joints. High concentrations of cobalt and in blood or serum are associated with increased wear of artificial hip joints and may contribute to an indication for revision of the procedure.
Sample Required Whole Blood: EDTA Trace element tube (Royal blue cap), EDTA (lavender top) or heparin (green top). Serum: Trace element tube preferred (royal blue top), plain serum (red top) or SST (yellow top). Plasma: Li-Hep tube with or without gel separator
Urine: sterile universal or plain 24hr
Sample Volume 0.5 mL
Stable at 2-8oC.
Sample can be sent by first class post.
Turnaround Time 2 weeks
Expected blood Cobalt concentrations with well-functioning hips: (median concentration)
Metal-on plastic: Cobalt 10 nmol/L
Unilateral metal-on-metal: Cobalt 30 nmol/L
Bilateral metal-on-metal: Cobalt 45 nmol/L
MHRA Action level of 7ppb is equivalent to 119 nmol/L Co.
Grossly haemolysed plasma or serum samples are unsuitable for this assay.