Mysteriously Swollen Knee

Question:

Three days into a five-day hike, your knee blows up to the size of a softball—no fall, no trauma. Why, and what can you do to help the knee?

Submitted by – Edward, Tallahassee, FL

Answer:

The swollen joint indicates that fluid has collected there. This usually happens due to trauma (either big or small), infection, or arthritic inflammation. The first of these, trauma fluid, could be composed of either blood from a big acute injury (like a fracture or ligament rupture) or synovial fluid from smaller irritations. The increase in synovial fluid is similar to a blister that gets bigger due to constant irritation as the body tries to protect itself.

If you have no known injury, my guess is that you probably have some degeneration that is getting irritated on the hike. Could be early/late arthritis, chronic meniscal injury, or an instability. It sounds like it reoccurs and then goes away after the overuse, so I am ruling out rheumatoid/gout/other arthritis and infection.

I would recommend trying to protect the knee—use ski poles; well-cushioned insoles; maybe newer, cushioned boots instead of, say, old leather. Do not carry extra weight in the pack or anywhere on yourself (one pound equals 7 pounds on the knee going up and down hills).

Conditioning exercises (such as leg extensions) help the legs work more efficiently with hiking and might make them more ready to accept the work put on them. Ice, compression, and ibuprofen may help reduce the size of the swelling, but does not reduce the actual irritation or micro-trauma, whichever is the cause. So, if none of this helps, find a local doctor. —Buck