From 1980 until 1986 we implanted 211 cementless so-called isoelastic RM Total Hip Replacements. Long-term results will be presented. The principle of ,,Isoelasticity'', the construction of cup and stem are described. A questionaire and a follow up study were designed, which follow strictly the recommendation of SICOT, AAOS and HIP society. The results of both in comparison with the scheme of Merle d'Aubigne shows significant differences. After average 9,1 years 19,3% of the cups and 30,8% of the stems shows radiolucent lines over 2 mm.