Repeated cobalt and chromium ion measurements in patients with large-diameter head metal-on-metal ReCap-M2A-Magnum total hip replacement

Figures & data

Figure 1. Flow chart of the study.

Table 1. Comparison of demographic variables between the control group (= overall unilateral ReCap Magnum THR group, n = 1,047) and the study group (n = 319)

	Study group	Control group	p-value
Female patients (%)	59	55	0.2
Age (SD)	64 (9)	65 (10)	0.2
Median femoral head
diameter (SD), mm	49 (4)	49 (4)	0.4
Mean acetabular inclination (SD)	43 (7)	43 (8)	1

Table 2. Differences in WB CO and CR levels (ppb)

	Initial	Control	p-value
WB Co, n = 319
median	1.4 (0.4–63)	1.1 (0.2–68)
geometric mean	1.5	1.2	< 0.001
WB Cr, n = 317
median	1.6 (0.6–13)	1.1 (0.3–19)
geometric mean	1.7	1.2	< 0.001

Figure 5. Spaghetti plots for individual Co and Cr values at initial and control measurements. Values are naturally log-transformed.