Table 2.

Whole-blood concentrations of chromium and cobalt ions

		Chromium, ppb					Cobalt, ppb
Case no.	Initial value	7 days	30 days	180 days	Final value	Initial value	7 days	30 days	180 days	Final value	Observation (days postop.)
Low metal ion cases
1	0.78	na	na	na	0.26	0.53	na	na	na	0.47	3
2	1.7	3.0	1.8	na	1.0	1.4	1.3	1.1	na	0.9	35
3	3	3.3	1.7	1.4	1.4	1.4	1.7	1.1	1.2	1.2	183
4	2.9	1	na	na	1	3.8	0.9	na	na	0.9	7
High metal ion cases
5	1.9	2.5	2.4	1.4	0.4	8.8	6.9	6.5	3.7	0.3	363
6	1.5	1.0	na	na	1.0	7.7	6.0	na	na	6.0	7
7	3.1	3.1	2.6	na	0.5	8.9	10.9	9.2	na	1.7	135
8	6.6	5.8	7.7	4.9	4.7	11	7.5	10	5.6	5	196
9	21.3	4.3	6.1	na	5	24	22.1	14	na	5	77
10	13.8	6.7	6.1	2.4	0.7	33	15.4	14	2.1	2.1	340
11	23	19.5	10.8	7.1	6.3	42	32	19	8.4	8.2	224
12	41.9	40	28.8	na	24.3	70	41.9	37	na	7.2	165
13	36.0	23	16.8	18.8	16.1	71	14	11	4.3	3.0	270
14	37.5	na	na	na	32.1	102	na	na	na	89	3
15	53	30	9.2	na	7.8	141	55	38	na	11.9	85
16	101.3	79.5	53	54.1	36.3	156	99.4	61	5	1.2	322
Mean (high ion cases)
	28	20	14	15	11	56	28	22	4	12	182
95% CI	13–44	6.2–33	5.1–24	0.0–30	4.3–18	27.8–85	12.3–44	11.6–32	3.3–6.4	–1.6 to 25	114–250

Reported at the time of revision (initial value), at 7, 30, and 180 days after revision, and at the final blood draw (last observation). Data for fixed time points have been interpolated from the nearest available measurements.