Coxarthrosis

The SARCO-COX study evaluates whether screening for sarcopenia (loss of muscle strength and mass) in adults aged 65 years or older with advanced hip osteoarthritis, followed by a structured postoperative exercise program, improves recovery after total hip replacement surgery compared with standard care. Participants will undergo assessments of muscle strength, muscle mass, physical function, pain, and quality of life before surgery and during follow-up. Blood samples and a small muscle biopsy obtained during the planned surgery will be analyzed to study biomarkers related to muscle health. A total of 150 people are expected to participate in this study. Participants will be divided into three groups: * Group 1: People with sarcopenia who will take part in an exercise programme following surgery. * Group 2: People with sarcopenia who will receive the usual care and follow-up after their surgery. * Group 3: people without sarcopenia who are undergoing surgery and will receive the usual care and follow-up. The study aims to determine whether early identification and targeted rehabilitation of sarcopenia can improve functional outcomes and quality of life after hip replacement.

The study will analyze hip biomechanical parameters using EOS radiographic measurements pre- and post-operatively (3 months) and post-operatively (3 months) CT scans after total hip replacement (THR), neck-preserving THR of the Minihip type or hip resurfacing (HR). Clinical results will be assessed at 3 months and 1 year after surgery. To this end, two types of examination are carried out, both of which are used in current practice: * Pre-operatively: EOS radiography * Post-operatively: EOS radiograph and CT scan Inclusion (m-3; m-1) : * Patient information at pre-operative visit * Non-opposition of patient, family member or legal guardian, if applicable * Questionnaires and clinical examination (standard management) * EOS during anesthetic consultation Follow-up visit (m+3): \- Post-operative follow-up consultation EOS and CT scan (1 week prior to visit) + questionnaire and clinical examination Follow-up visit (m+12): \- Post-operative check-up, questionnaire and clinical examination

The fast track group vs. control group will be compared with regard to hospitalization time and the non-inferiority of the fast track group vs. control group with regard to HOOS will be assessed. The questionnaires will only be collected in the study: Eq-5d-5l, HOOS, self-efficacy, enjoyment of movement, fear of movement, pain catastrophizing.