Table 1.

Head penetration and osteolysis by liner type

Variable	Osteolysis present			Osteolysis absent			All conventional	All HXLPE
	Total	Conventional	HXLPE	Total	Conventional	HXLPE
N	13	12	1	85	38	47	50	48
Head penetration (mm/year)	0.17 ± 0.12*	0.157 ± 0.11	0.07	0.07 ± 0.08*	0.142 ± 0.09‡	0.03 ± 0.04‡	0.15 ± 0.09†	0.03 ± 0.04†

* p = 0.03; ^‡p < 0.001; ^†p < 0.0001; HXLPE = highly crosslinked polyethylene.