The purpose of this trial is to evaluate a new method of applying hydroxyapatite coatings on cement-less femoral stems.

60 patients eligible for total hip replacement will be randomized in to two groups, receiving either femoral stems with plasma sprayed hydroxyapatite coating or stems with electrochemically deposited hydroxyapatite. This patients will be followed for at least 5 years. The outcome is evaluated by comparing stability measured by RSA and periprosthetic bone remodeling measured by bone densitometry.

Inclusion Criteria:

• non-inflammatory hip arthritis, life expectancy of at least 10 years and hip anatomy allowing the use of standard implants

Exclusion Criteria:

• infection, revision surgery, severe morbidity and obvious bone loss