A simplified technique to determine the presence of a suprapatella knee effusion and aspirate fluid.
Stay away from the various vessels and tendons in the ankle. Is the reddness just cellulitis or is it deeper in the joint?
Sounds scary, but really simple. Don't pretend to know if there is a swelling. Look and tap if needed. Also a nice technique when you want to reduce the pain from arthritis (by placing steroids).