Table 2.

Cemented total hip arthroplasty with 5 different articulations showing total head penetration from postoperatively to 2-, 5-, and 10-year follow-up for each study group. Also includes “bedding-in,” annual wear rate, and head penetration from 1-year to 10-year follow-up. Values are mean with 95% confidence intervals, the results from the linear mixed model

Factor	Steel/CPE a	CoCr/CPE b	OxZr/CPE b	CoCr/XLPE b	OxZr/XLPE b
Total head penetration, mm c
2 years	0.13 (0.03–0.23)	0.34 (0.27–0.42)	0.36 (0.28–0.44)	0.09 (0.02 to 0.16)	0.08 (–0.00 to 0.16)
5 years	0.26 (0.13–0.39)	0.85 (0.75–0.95)	1.00 (0.89–1.11)	0.12 (0.02 to 0.22)	0.10 (–0.02 to 0.21)
10 years	0.42 (0.25–0.58)	1.47 (1.33–1.61)	1.81 (1.66–1.96)	0.12 (–0.01 to 0.25)	0.13 (–0.02 to 0.27)
Bedding-in, mm d	0.09 (0.05–0.13)	0.16 (0.13–0.20)	0.19 (0.15–0.23)	0.06 (0.03 to 0.09)	0.06 (0.02 to 0.09)
Total wear from 1 year, mm e	0.34 (0.12–0.56)	1.35 (1.16–1.55)	1.68 (1.44–1.92)	0.08 (–0.11 to 0.26)	0.06 (–0.14 to 0.26)
Annual wear rate in mm f	0.04 (0.01–0.06)	0.15 (0.12–0.17)	0.18 (0.15–0.21)	0.007 (–0.015 to 0.03)	0.007 (–0.017 to 0.03)

For abbreviations, see Figure 1.

^aCharnley/Ogee.

^bSpectron EF/Reflection

^cTotal head penetration from postoperatively until the given year.

^dHead penetration from postoperatively to 1-year follow-up.

^eWear from 1- to 10-year follow-up, thus excluding bedding-in.

^fWear rate, calculated as annual wear rate from 1-year to 10-year follow-up.