Rationale: In view of patient care, patient characteristics and treatment parameters are registered for all patients visiting the Mobility Clinic of the University Medical Center Utrecht for orthopaedic knee treatment. Patients also fill out questionnaires for function, pain and mobility of the knee, before and after treatment.

Objective: The main objective of this registry is to collect patient characteristics and treatment parameters together with data from the questionnaires in a database. This knee registry can be used for future research questions.

Study design: This is a longitudinal observational registry.

Study population: All patients that visit the Mobility Clinic will be asked to participate in the knee registry. Patients that meet one or more of the following criteria will be excluded: are below the age of 16, not able or willing to sign the broad consent form, not being able to read and understand Dutch language, or receiving medical treatment for their knee elsewhere.

Main study parameters/endpoints: Data will be collected for future research for which the purpose is not known at this time. When new research will be conducted, study parameters will be set. A study application has to be submitted to the institutional ethical review board of the University Medical Center Utrecht. Patients do not need to be asked permission for the use of their data for each study individually. Only when additional information is needed.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The burden for patients to participate in this registry is minimal and consists of time. Any future results may be beneficial for patients. Participation or refusal to participate in the registry has no consequences for their treatment.

Inclusion Criteria:

• Receives orthopaedic knee surgery or conservative knee treatment (advice, physiotherapy, injections etc) at the UMC Utrecht;
• Able to read and understand Dutch language;
• Is able and willing to signs the broad consent form.

Exclusion Criteria:

• Receives no treatment (refusal of surgery or treatment);
• Receives treatment elsewhere.

Patients that visit the Mobility Clinic at the UMC Utrecht for their knee pathology.

New research questions that requires data from the registry need to be discussed and approved by the PI and data manager/coordinator of this registry. The proposal should also be in agreement with the research collaboration and data transfer guidelines and agreements of the UMC Utrecht. Proposals need to be submitted to the institutional ethical review board of the University Medical Center Utrecht. After review, the data selection will be provided to the researcher.

In view of the regulation for clinical trials, the investigators need to save all data for at least 15 years with the goal to be able to go back to patient level. After finishing the project all documents and data are stored at the UMC Utrecht.

The data manager keeps the linking table to personal data.