This is a prospective randomised controlled clinical trial and follow-up study comparing primary total hip arthroplasty performed either through a direct anterior approach or a lateral approach. At our hospital(i.e. Emergency County Hospital Cluj-Napoca), the lateral transgluteal approach was standard for more than 40 years. Starting 2008,the minimally invasive anterior approach was gradually implemented with the aim to facilitate early rehabilitation and improve functional results. Reduced blood loss, earlier functional recovery, low dislocation rates and shorter stays in hospital have been attributed to the muscle-sparing properties of the anterior approach.