The symptoms of early osteoarthritis (OA) are quite similar to established knee OA, they differ, particularly in frequency, intensity, and severity. For this reason, in 2023, the International Symposium of intra-articular treatment (ISIAT) technical experts panel (TEP-technical experts panel) published for the first time a questionnaire designed to assess and monitor the follow-up and clinical progression of patients affected by early knee OA. Early management of knee OA is recommended by various guidelines because this approach may alter the course and clinical features of the disease, especially when considering disease-modifying agents that may delay disease progression. Therefore, the assessment of early knee OA with a questionnaire may facilitate the follow-up of OA in the early stages of the disease when treatment is likely to be more effective. This approach will allow to reduce disability and improve patients' quality of life. While creating the Early Osteoarthritis Questionnaire (EOAQ), it was aimed to have a complete, short and easy-to-understand questionnaire and to ensure that the respondents could complete the questionnaire easily and in a short time. The EOAQ consists of 11 questions. The questions were divided into two different groups. While the first two questions were related with clinical characteristics, the other nine questions aimed to investigate the results reported by the patient. For each question, there are three responses depending on the number of episodes: Never, rarely (between one and three episodes) and frequently (more than three episodes) within a 6-month period. Turkish validity and reliability study of the EOAQ has not been conducted yet. For the translation of the questionnaire, the guide recommended by Beaton et al. for the cultural adaptation of questionnaires will be used. According to this guideline the original EOAQ will be translated into Turkish by two experts independently of each other, and then a single Turkish version will be created by two experts working together. This Turkish version will then be translated back into English by an expert who can speak both languages at an advanced level. The experts will then evaluate the translation and adapt the questionnaire accordingly. After the completion of the translated form, 110 patients and 110 control group participants who applied to Istanbul University Istanbul Faculty of Medicine, Department of Physical Medicine and Rehabilitation and met the inclusion criteria will be included. The participants will be informed verbally and in writing about the purpose, duration and method of the study and will be asked to sign an Informed Voluntary Consent Form after their consent is obtained. Participants will fill in the Turkish version of the questionnaire. Along with the questionnaire, knee pain will be questioned with the Numeric Rating Scale (0=no pain, 10=the most severe pain you experience) and disability will be questioned with the WOMAC Questionnaire, whose Turkish validity and reliability study has been conducted. Test-retest method will be applied for reliability analyses; therefore, at least 30 patients among the patients included in the study will complete the questionnaire twice (the second evaluation will be 2 weeks after the first evaluation).