Table 2.

Patients’ data

Study groups	Group A 28-mm ceramic on CPE	Group B 28-mm ceramic on XLPE	Group C 28-mm oxidized zirconium on XLPE	Group D 28-mm oxidized zirconium on XLPE
Number of hips available	45	46	48	49
Clinical rating scores	Preoperative	Preoperative	Preoperative	Preoperative
	Postoperative	Postoperative	Postoperative	Postoperative
HHS (mean; range)	45 (28–60)	48 (30–57)	51 (26–64)	46 (25–55)
	92 (62–100)	91 (58–100)	94 (65–100)	90 (55–100)
Oxford Hip Score	17 ± 8	17 ± 8	18 ± 8	18 ± 8
	37 ± 8	38 ± 8	38 ± 8	38 ± 8
Linear wear (mean ± SD) (μm)	Cup inclination
	40°–50°	40°–50°	40°–50°	40°–50°
	> 50°	> 50°	> 50°	> 50°
2 years	1051 ± 260	985 ± 210	733 ± 174	700 ± 168
	1068 ± 478	1010 ± 380	831 ± 198	828 ± 174
5 years	1478 ± 180	2356 ± 285	635 ± 155	650 ± 164
	1723 ± 433	2489 ± 410	844 ± 190	891 ± 201
10 years	1700 ± 305	2750 ± 345	700 ± 162	695 ± 162
	2322 ± 485	3111 ± 399	880 ± 210	899 ± 188
Linear wear rate (μm/year)
2 years	522 ± 140	475 ± 120	348 ± 087	341 ± 85
	530 ± 231	495 ± 285	403 ± 101	406 ± 97
5 years	260 ± 58	382 ± 78	122 ± 38	124 ± 34
	341 ± 82	470 ± 277	163 ± 45	177 ± 52
10 years	158 ± 52	243 ± 64	68 ± 22	65 ± 23
	210 ± 64	299 ± 287	85 ± 37	82 ± 41
Volumetric wear (mm3)
2 years	53.6 ± 11.5	72.3 ± 12.8	34.2 ± 5.9	31.1 ± 6.5
5 years	79.1 ± 12.4	142.0 ± 22.3	31.0 ± 5.5	32.0 ± 5.8
10 years	89.5 ± 13.1	162.5 ± 25.3	35.6 ± 6.4	35.4 ± 5.0
Volumetric wear rate (mm3/year)
2 years	40.5 ± 11.5	37.9 ± 9.0	19.1 ± 4.5	24.4 ± 6.7
5 years	30.6 ± 8.5	36.6 ± 8.8	20.6 ± 5.5	20.5 ± 6.1
10 years	38.0 ± 8.0	48.0 ± 10.1	21.5 ± 5.4	21.0 ± 6.4

CPE = conventional polyethylene; XLPE = crosslinked polyethylene; HHS = Harris hip score.