Background Few studies have examined long-term outcomes for patients after arthroscopic treatment for intraarticular hip conditions, and none have done so beyond 10 years postarthroscopy. Examining outcomes beyond 10 years is necessary to determine factors that contribute to conversion to THA in patients undergoing hip arthroscopy for labrochondral damage. Questions/purposes (1) What is hip survivorship free from THA in patients who underwent arthroscopic labral débridement, with or without chondroplasty at least 15 years before? (2) What factors are associated with conversion to THA after arthroscopic labral débridement, with or without chondroplasty? (3) Can these data be used to estimate the risk of conversion to THA based on patientand hip-related factors? Methods Between 1989 and 2000, one surgeon performed 552 arthroscopic hip procedures for symptomatic labral tears, with or without associated articular cartilage damage. Of these, the hip status was known in 404 hips (73%) at a minimum of 15 years after the index procedure, with 20 of those patients having died during the followup period. During the study period, patients were offered hip arthroscopy for labral tears with mechanical symptoms, with or without underlying articular cartilage damage. Patient age, sex, acetabular and femoral head Outerbridge grade at surgery, and presence of labral tear were recorded. We One of the authors certifies that he (JCM), or a member of his or her immediate family, has received or may receive payments or benefits, during the study period, in an amount of less than USD 10,000 from Stryker (Kalamazoo, MI, USA); has received or may receive payments or benefits, during the study period, in an amount of less than USD 10,000 from Innomed (Savannah, GA, USA); has received or may receive payments or benefits, during the study period, in an amount of less than USD 10,000 from Arthrex (Naples, FL, USA), outside the submitted work. Clinical Orthopaedics and Related Research® neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDA approval status, of any drug or device before clinical use. Each author certifies that his or her institution has approved the reporting of these cases, and that all investigations were conducted in conformity with ethical principles of research. Our institutionally-approved database does not require patients to sign a consent form to document surgical and clinical data.