 In younger patients, acetabulum components are most often implanted without the use of cement. A direct ingrowth of bone to the implant is crucial to the attainment of good results in those cases where cement is not employed. A new implant material tantalum has shown better properties than the implant material which is in use today titanium. The advantages of tantalum implants are greater porosity, reduced stiffness and a higher friction coefficient than with titanium implants. 