The knee joint is where the thighbone (femur) and the shinbone (tibia) come together. A smaller bone called the fibula, on the outside of the lower leg, is also related to the knee joint. The kneecap (patella) is in front of the end of the thigh bone.

The bones are connected by several strong ligaments and cushioned by two pieces of cartilage called menisci (plural of meniscus).