DOXYCYCLINE PENETRATION INTO BONE AND JOINT.

Who can take part

• Age between 18 and 80 years old
• Scheduled for elective surgery for hip replacement due to coxarthrosis
• Signed informed consent
• Patients eligible for French social insurance; Participants able to fully understand the study and who accept its requirements and constraints

Who cannot take part

• Patient with a contraindication to surgical procedure
• Patient who has received antibiotics within one month prior to the procedure
• Patients with contraindications to doxycycline ( hypersensitivity to the active substance or to any of the excipients (particularly as generic formulations are authorized in the study and excipients may therefore differ), hypersensitivity to tetracycline-class antibiotics, co-administration of retinoids, or vitamin A supplementation exceeding 10,000 IU/day, due to the risk of intracranial hypertension and intestinal obstruction)
• history of osteoarticular infection related to hip prosthesis surgery
• Patient with an infection at the time of surgical management
• malabsorption syndrome or conditions likely to impair antibiotic absorption (sleevs, colectomy, gastrointestinal antacids (magnesium, aluminum, or calcium salts, oxides, or hydroxides) and oral iron salts……)
• Malnutrition patient (BMI < 21 kg/m2) or with serum albumin < 30g/L
• Kidney failure with GFR < 60 mL/min/1,73m2
• Women of childbearing age without effective contraception : childbearing age means non menopausal women. Effective contraception includes taking a contraceptive pill or using an Intra Uterine Device
• Patient who did not take Doxycycline as planned in the protocol
• Patient being a relative of the investigator or any member of the team directly involved in the study, including assistant physicians, pharmacists, nurses, and coordinators
• Patients unable to take oral doxycycline
• Pregnant or breastfeeding women
• Patients under guardianship, curatorship, legal protection or conservatorship