Prosthetic Joint Infection (PJI) of a Total Hip Replacement (THR) is a disastrous complication of an otherwise extremely successful surgical procedure. It is associated with a burdensome treatment for the patient, significant challenges for the medical team and high costs for society. As more joint replacements are being performed each year, due to an ageing population and lower thresholds for surgery, the number of PJIs is on the rise. Many of these patients will be referred to University Hospitals Leuven as the physicians have extensive experience with this particular pathology and can offer a multidisciplinary and patient-tailored treatment. Many controversies exist in the field of PJI treatment, both with regard to the surgical aspects as well as the antibiotic treatment. Setting up randomized controlled trials to answer these questions has been proven to be very difficult due to large variations in patients, implants, germs, soft and hard tissues, antibiotic resistance patterns, and so on. Also, surgery for PJIs is usually non-elective / semi-urgent and therefore time to include patients into different trials is limited. Therefore the investigators will prospectively collect data on patients with PJI treated at University Hospitals Leuven, starting 01/01/2022, in order to have knowledge of own results and inform patients about chances of success prior to treatment; perform internal audits and quality checks; answer questions in the field of PJI treatment not suitable for RCTs.

Prosthetic Joint Infection (PJI) of a Total Hip Replacement (THR) is a disastrous complication of an otherwise extremely successful surgical procedure. It is associated with a burdensome treatment for the patient, significant challenges for the medical team and high costs for society. As more joint replacements are being performed each year, due to an ageing population and lower thresholds for surgery, the number of PJIs is on the rise. Many of these patients will be referred to University Hospitals Leuven as the physicians have extensive experience with this particular pathology and can offer a multidisciplinary and patient-tailored treatment.

Many controversies exist in the field of PJI treatment, both with regard to the surgical aspects as well as the antibiotic treatment. Setting up randomized controlled trials to answer these questions has been proven to be very difficult due to large variations in patients, implants, germs, soft and hard tissues, antibiotic resistance patterns, and so on. Also, surgery for PJIs is usually non-elective / semi-urgent and therefore time to include patients into different trials is limited.

Nevertheless, prospectively collecting data on patients with PJI who are not involved in RCTs can already be helpful. It would allow the investigators to provide the patients with percentages of success of certain interventions based on historical results. At the moment the investigators have to rely on results reported by other groups, who might use different techniques or a facing a different germ spectrum.

Furthermore, prospectively collecting data on this cohort of patients, would make it possible for the investigators to do internal audits for quality control. Being able to perform simple checks, for example is every patient discussed in the multi-disciplinary team meeting, or is the hospital switching to targeted antibiotics soon enough, would already add to the quality of the service and could lead to adjustments in the protocols.

Also, certain scientific questions, which do not lend themselves to RCTs, such as the rate of success of treatment of PJI caused by rare germs (e.g. fungi) or in a specific population (e.g. octogenarians, transplant patients), could be answered by maintaining a prospective database

Inclusion Criteria:

• 18 years or older
• patients diagnosed with PJI of the hip based on EBJIS 2021 criteria

Exclusion Criteria:

• Patients unable to provide written informed consent
• Patients who prefer treatment outside of University Hospitals Leuven
• Patients with infections of the native hip joint
• Patients with fracture-related infections (FRI)
• Patients with uncertain diagnosis of PJI according to the 2021 EBJIS criteria
• Patient younger than 18 years

Every adult patient (> 18 years), regardless of sex or age, with a PJI of the hip, as based on the EBJIS 2021 criteria, is eligible for inclusion on this study. This would therefore also include women of childbearing age, although this would be extremely rare.