Test Background High concentrations of cobalt and chromium 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 >134 nmol/L is an indication of excessive wear in a metal-on-metal hip implant. Chromium deficiency has been linked to impaired glucose metabolism; however this test cannot be used to determine chromium deficiency.
Predominantly used for assessing wear of artificial hip joints. High concentrations of chromium are associated with increased wear of artificial hip joints and may contribute to an indication for revision of the procedure. Toxic sources of chromium include dyes, paints, and leather tanning processes.
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:
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
Median whole blood chromium concentrations with well-functioning hips: (median concentration)
Metal-on plastic: Chromium 15 nmol/L
Unilateral metal-on-metal: Chromium 45 nmol/L
Bilateral metal-on-metal: Chromium 45 nmol/L
MHRA Action level of 7ppb is equivalent to 134 nmol/L Cr
Grossly haemolysed plasma or serum samples are unsuitable for this assay.