Table 1: Summary of Significant Clinical Studies Confirming a Wear Rate Decrease with 1st Generation HXLPE in the Mid-Term Follow-Up

Study	Design and Follow-up	HXLPE	HEAD	Follow-Up	Mean Wear Rate mm/yr (After Bedding-In)	Wear Rate Decrease
Dorr et al. JBJS A 2005	Prospective, cohorts37 hips/37	Durasul95 kGy, remelted	28 mm CrCo	5 years	0.029 vs 0.065	45%
D’Antonio et al. CORR 2005	Retrospective, comparative56 hips/53	Crossfire105 KGy, annealed	28 mm CrCo	Mean 5 yr (min 4)	0.036 vs 0.131	72%
Engh et al. J Arthr 2006	Prospective, randomized 208 hips	Marathon50 kGy, remelted	28 mm CrCo	5.7 yr(4.1-7.2)	0.01 vs 0.19	95%
Olyslaegers et al. J Arthr 2008	Case-control with historical60 hips/20	Longevity100 KGy, remelted	28 mm CrCo	XLPE 5.06 yr (52-69 mo),Std PE 5.1 yr (55-79)	0.05 vs 0.101	50%
García-Rey et al. J BJS-B 2008	Prospective, randomized45 hips/45	Durasul95 kGy, remelted	28 mm CrCo	66.3 mo(60-92)	0.006 vs 0.038	84.3%
Geerdink et al. CORR 2009	Randomized, double blind17 hips/23	Duration30 KGy,annealed	28 mm CrCo	Mean 8yr(7-9)	0.088 vs 0.142	38%