Reliability and validity of the evaluation of pain in patients with total knee replacement.

Ninety-two knees in 46 patients were evaluated with regard to pain: in 51 of these knees, implantation of a hinged endoprosthesis had been performed. The reliability and validity of 2 pain evaluation methods were assessed: the knee-pain questionnaire method (standard version including 10 questions and modified version including 14 questions) and the visual analogue scale method (standard version without numbering and 0-10 scale). The visual analogue scale--standard version and 0-10 scale--turned out to be more reliable than the questionnaires. The 0-10 scale was the most valid when compared to the patients' own opinions regarding pain.