A total hip replacement is one of the most successful and cost-effective surgical procedures in orthopaedics, and involves replacing both the hip ball and socket. Its goal is to provide pain relief, allowing the person to return to a normal lifestyle. JRI Orthopaedics have developed the ACE Acetabular Cup System, which has a H-A.C. coating to promote ossoeintegration of the device within the host bone. To increase the surgeons choice and thus suitability for the patient, there is the option of 3 different socket liners (ceramic, polymer or dual mobility). To ensure maximum safety and performance of medical devices surveillance of the device should be carried out over the devices lifetime. This study is a 10 year surveillance study to assess the clinical, functional and radiological outcomes of the CE-marked ACE Acetabular Cup System. This is done by examining patient outcomes through questionnaires, reviews of X-rays and complications by patients who have received a total hip replacement using the ACE Acetabular Cup System at participating sites.