Inclusion Criteria:  Patient aged 18 years or older, having been informed of the research Patient who has had a total hip replacement implanted for at least six months as a first-line treatment Patient who has been regularly monitored since the operation and for whom all clinical and radiological data are available during follow-up visits  Exclusion Criteria:  Patient undergoing revision surgery Patient who has indicated his opposition to the use of his medical data Patient under legal protection, guardianship or curators