The objective of this observatory is to generate additional real life clinical data in accordance with local regulation (i.e. Post-Market Clinical Follow-up (PMCF) study, a study carried out following the European Conformity (CE) marking of a device and intended to answer specific questions relating to clinical safety or performance (i.e. residual risks) of a device when used in accordance with its approved instructions for use (IFU).

The difficulty of such an observatory is to be able to collect data on the different versions of the devices, on the different possible combinations of implants of an knee arthroplasty. The observatory must also be able to cover devices used in ligament reconstruction surgery.

The observatory will be based on the principle of a "dynamic" cohort during the inclusion period, i.e. with possible inclusions to replace the premature exits.

Technical solutions will be implemented to facilitate data collection from surgeons (electronic Case Report Form (eCRF) and from patients (Electronic Patient Reported Outcome (ePRO) on smartphone/tablet/computer) when feasible.

The data to be collected and the different follow-up times are based on our state-of-the-art, clinical evaluation plans and clinical evaluation reports.

PMCF as part of CE mark renewal, to answer questions related to the safety and clinical performance of the devices, when used according to their approved instructions for use.

This is an European, prospective and retrospective, multicenter, non-comparative study.

Randomization is considered impossible due to surgeon preference, anatomical conditions and other patient factors, and the use of different techniques.

This observatory is non-comparative, due to the absence of a gold standard and the technical, logistical and contractual constraints involved.

This PMCF study (CE-marked MD, any class, used as intended) provide additional non-burdensome and non-invasive procedures.

The Observatory will therefore be based on the principle of a "dynamic" cohort, i.e. with possible exits and inclusions throughout the Observatory period.

The aim of this methodology is to have a sufficient number of patients to be able to carry out descriptive statistical analyses each year, and to be able to calculate the evaluation criteria with the longest possible follow-up of results. Data will be collected before surgery, during surgery and at follow-up visits. Data collection will focus on obtaining short- and long-term data for performance and safety evaluation (up to 20 years for knee arthroplasty prostheses; up to 5 years for knee ligament reconstruction devices). In the case of knee arthroplasty, it is recommended to have performance and safety data at 1, 2, 5 and 10 years of follow-up, as well as safety data at 15 and 20 years if possible. In the case of ligament reconstruction, it is recommended to have performance and safety data at 1 and 2 years, as well as safety data at 5 years. The platform will be able to send automatic notifications to surgeons to remind them of scheduled patient follow-ups, missing data, and encourage them to include new patients if necessary. Self-questionnaires will be completed by patients via a web-based platform, available on computer or smartphone/tablet. Alternatively, patients will complete paper self-questionnaires, which will then be entered into the database by the investigating team.

It will also be possible to arrange for direct telephone contact with patients by an independent structure guaranteeing non-dissemination of nominative data (e.g. CRO). Telephone contact can also be made if the patient is geographically remote or has difficulty travelling. Patient recruitment: Continuous, consecutive, prospective and retrospective (for some implants because few implants have been used for this condition) recruitment to guarantee a minimum number of patients per type of device. Individual written information for each patient will be mandatory. A signed patient consent form will be required in Europe, after sufficient time for reflection.

Inclusion Criteria:

• Any patient undergoing or having undergone implantation of medical devices distributed by FH ORTHO SAS for knee arthroplasty and ligament reconstruction, used in accordance with their approved IFU, in one of the centers participating in the Observatory.
• Patient is at least 18 years old at the time of surgery
• Patient agreeing to participate after having been informed orally and in writing (with written consent if required locally)
• In some countries, such as France, the patient will have to be socially insured to be included in the study.

Exclusion Criteria:

For Arthroplasty:

1. Infection, or latent infection
2. A mental or neuromuscular disorder that might create an unacceptable risk of instability, prosthetic fixation failure, or complications after surgery
3. Insufficient bone stock for proper implant fixation
4. It is the surgeon's responsibility to make sure that the patient does not have any known allergies to one of the compounds of the material listed on the product label.
5. Metabolic diseases that might compromise bone regrowth
6. Drug addiction
7. Incomplete bone growth

For Ligament reconstruction:

1. Infection, or latent infection
2. A mental or neuromuscular disorder that might create an unacceptable risk of instability, prosthetic fixation failure, or complications after surgery
3. Insufficient bone stock
4. Known allergies to one of the compounds of the material listed on the product label.
5. Metabolic diseases that might compromise bone regrowth
6. Uncooperative patient unable to follow recommendations

As the medical devices are used in real life according to their indications, pregnant or breastfeeding women are not excluded from the study, but for safety reasons it is not advisable to include them in the study.

The patient population will be representative of the target population of the medical devices.

The aim is to recruit in the first 3 years in 15-20 sites in France, 487 patients who have benefited from knee arthroplasty or ligament reconstruction of the knee.

Arthroplasty arm: Knee prostheses are intended for patients suffering from functionally serious diseases of the knee causing daily disability that is insufficiently improved by medical treatment (Knee osteoarthrosis, Osteonecrosis of the knee, Inflammatory disease, or Patellofemoral arthritis).

Ligament reconstruction arm: Ligament reconstruction surgery should be considered for patient who have undergone a rupture of the anterior and/or posterior cruciate ligaments requiring partial or total reconstruction.