The study is a non-controlled retro- and prospective multi center patient registry study.

Subjects will be given a study ID number assigned at first brace fitting after consenting to partake. Participants will be asked to fill in a questionnaire either in electronic or paper version at first fitting. Additional follow up questionnaires will be implemented at 4 weeks, 6 months and 1 year post initial brace fitting. After that period patients will be contacted every year, until brace termination/ knee surgery or death.

This is a noninterventional registry study pertaining to knee OA braces. There are no comparative devices or treatments. Subjects are expected to follow the recommendations of the brace subscriber and other health care professionals at any time independent of their continuation within the registry.

Subjects will be enrolled at the clinic where their brace was prescribed or at the site where the brace was fitted.

There is no formal end date for this data registry. A revisit to this protocol may be motivated after 5 years, to assess if longer follow up is required.

For individual participants follow up will continue with annual questionnaires as long as the brace is in use. The questionnaires will be administered either through mail with a paper version, or through a link to an electronical version (ePRO). There is also a possibility of administrating the questionnaires as a phone guided interview, if that is a mean that serves the patient or clinics better. The planned follow-ups are at 4 weeks, 6 months, 1 year from brace prescription and then annually as long as participants are disposed as "ongoing" in the registry.

The questionnaires contains question about pain, function, medication, general brace use and quality of life question.

Inclusion Criteria:

• Patients that are prescribed knee brace for symptomatic treatment of knee OA from partaking clinics
• Older than 18 years

Exclusion Criteria:

• Younger than 18 years
• Not willing or able to sign informed consent, or not cognitive impairments preventing understanding of the questionnaires.

Subjects are patients that have been prescribed knee braces for treatment of knee OA. The brace prescription is independent of the registry, i.e. no one is prescribed a brace because of the registry or for the purpose of this data collection per se