Background

An increasing number of hip prostheses are inserted without bone cement. Experimental research has shown that hydroxyapatite (HA) coated implants are strongly fixated in the bone, which is believed to reduce the likelihood of prosthetic loosening. However, in recent years, there has been much debate about the role of HA particles in third-body polyethylene (PE) wear and formerly we have shown the revision rate to be high among older-design HA coated cups.