English to Portuguese Medical Medical (general)

http://rheumatology.oxfordjournals.org/content/48/11/1442.sh...
The study consisted of two visits. At Visit 1, a plain radiograph of the ‘index joint’ was obtained. The ‘index joint’ was defined as a joint that has had the most acute attacks of gout historically. The index joint plain radiograph had to be free of erosive damage in order for the subject to qualify for Visit 2.


https://www.nice.org.uk/guidance/cg177/chapter/2-research-re...
or example, altered use because of pain in one joint often leads to increased mechanical stress and pain at other sites, and having chronic pain at one site can influence the experience of pain elsewhere in the body. However, almost all trials of treatments for osteoarthritis focus on a single joint, and if a participant has bilateral symptoms or additional symptoms at a different joint site only one 'index' joint (the most painful) is assessed.