Epigenetic Regulation in Fibrous Dysplasia of Bone: mirDYS Study.

Inclusion Criteria: Control population : * men and women, * 18 years-old and over, * consulting a rheumatologist or an orthopedist for arthrosis * have scheduled surgery for hip or knee replacement surgery or any intervention involving the lower limb or upper limb. Patients with Fibrous dysplasia: * men and women, * 18 years-old and over, * with a diagnosis of fibrous dysplasia previously established by a rheumatologist. Exclusion Criteria: * Refusal to participate in the study * Long- term corticosteroids treatment (\> 3 months) * Treated osteoporosis * Chronic inflammatory rheumatism (rheumatoid arthritis, psoriasic arthritis, spondyloarthropathy) * Collagen disease (osteogenesis imperfecta…) * Paget's disease, benign bone tumors * Uncontrolled hypo/hyper-thyroidism, hypo/hyper-parathryoidism * Severe renal impairment (GFR \< 30 ml/min/1.73m2) * Cancer or bone metastases (current or in the past two years) * Paget disease, benign bone tumor (osteoid osteoma, enchondroma …) * Malabsorptive disease (Celiac disease, Whipple's disease, intestinal bypass, short bowel syndrome) and inflammatory bowel disease * Pregnant women or lactating * Psychiatric disorders * Difficulty in understanding French * Not a beneficiary of french social security * Patients protected by law