Table 3.

Results of radiological evaluation of highly cross-linked polyethylene compared with conventional polyethylene

Study	Outcomes
Clavert et al. [4]a	Wear rate	Linear (mm/y)	3D linear (mm/y)	Volume (mm3/y)
		p = 0.002	p = 0.012	p = 0.017
		HXLPE = 0.0239	0.0242	13.741
		CPE = 0.1276	0.1109	60.24
Digas et al. [5]b	Penetration	M/L (mm)	P/D (mm)	A/P (mm)	Total (mm)
		p = 0.3	p < 0.001	p = 0.5	p < 0.001
		HXPEL = −0.019 ± 0.021	0.15 ± 0.030	−0.01 ± 0.026	0.23 ± 0.030
		CPE = −0.05 ± 0.020	0.36 ± 0.046	0.02 ± 0.026	0.41 ± 0.046
Digas et al. [5]b	Penetration	M/L (mm)	P/D (mm)	A/P (mm)	Total (mm)
		p = 0.2	p < 0.001	p = 0.4	p < 0.001
		HXLPE = 0.001 ± 0.0261	0.08 ± 0.020	0.09 ± 0.036	0.20 ± 0.026
		CPE = −0.04 ± 0.015	0.34 ± 0.067	0.03 ± 0.036	0.41 ± 0.056
Engh et al. [7]	Wear rate Osteolysis	Linear 2D (mm/y)	Volume(mm3/y)	Osteolysis	Osteolysis>1cm2
		p < 0.001	p < 0.001	p < 0.001	p = 0.002
		HXLPE = 0.01 ± 0.07	5 ± 22	23(96)	6(96)
		CPE = 0.20 ± 0.13	107 ± 76	52(90)	20(90)
Garcia-Rey et al. [8]	Penetration rate	Linear (mm/y)
		p < 0.001
		HXLPE = 0.006 ± 0.007
		CPE = 0.038 ± 0.013
Glyn-Jones et al. [9]	Wear rate Penetration	Linear wear (mm/y)	Total penetration (mm)
		p = 0.012	p = 0.0184
		HXLPE = 0.03 ± 0.06	0.35 ± 0.14
		CPE = 0.07 ± 0.05	0.45 ± 0.19
Martell et al. [15]	Penetration rate	2D linear (mm/y)	2D volume (mm3/y)	3D linear	3D volume
		p = 0.001	p = 0.049	p = 0.005	p = 0.199
		HXLPE = 0.12 ± 0.05	62.07 ± 34.15	0.14 ± 0.07	62.72 ± 30.48
		CPE = 0.20 ± 0.10	90.89 ± 52.74	0.29 ± 0.17	101.77 ± 62.71
Triclot et al. [23]	Penetration rate	Linear (mm/y)	Volume (mm3/y)
		p = 0.0027	p = 0.0058
		HXLPE = 0.025 ± 0.128	29.24 ± 44.08
		CPE = 0.106 ± 0.109	53.32 ± 48.68

HXLPE highly cross-linked polyethylene, CPE conventional polyethylene, M/L medial(+)/lateral(-), P/D proximal(+)/distal(-), A/P anterior(+)/posterior(-)

^aThe outcomes can not be expressed as mean and standard deviation due to lack of the exact number of participants analysed in the study

^bData from two studies reported in one article