the purpose of this study is to develop and validate a new PRO measurement tool for the knee joint, the so-called Munich Knee Questionnaire (MKQ), allowing for a qualitative self-assessment of the Knee Injury and Osteoarthritis Outcome Score (KOOS), the International Knee Documentation Committee (IKDC), the Lysholm Knee Score, the Western Ontario Meniscal Evaluation Tool (WOMET) and the Tegner Score.

A systematic review of the literature was performed to identify valid and commonly used instruments regarding follow-up examinations in the field of knee surgery. PubMed.gov was searched for knee-specific terms (knee, surgery, joint, lower extremity) combined with psychometric (follow-up, validity, reliability, responsiveness) and instrument-specific terms (self-reported, patient-based, measurement tool, outcome measure, questionnaire). Hence, the KOOS, IKDC, Lysholm, WOMET and Tegner Score were identified as frequent used and valid measurement tools in the evaluation of knee joint function. After analysing each single question of these questionnaires for coincidences regarding measurement of specific knee function, the identified items were condensed to one single question for each specific item. Typical functional abilities (flexion/extension) were depicted as photographs. Thus, one single questionnaire with a total of 33 questions divided in five subscales (Symptoms, Pain, Work and Activities of daily life, Sports and Recreational activities, Physical function and knee related Quality of Life), was created.

Inclusion Criteria:

• all patients presenting with knee pain

Exclusion Criteria:

• no exclusion

all patients with knee pain