A knee contusion is a bruised knee, according to the American Society of Orthopaedic Surgeons. "Contusion" is medical jargon for a bruise. Contusions are one of the most common injuries. They are caused when either direct or repeated blows to an area damage muscle and connective tissue without breaking the skin.
Symptoms of a contusion include pain and tenderness, a feeling of tightness, and blue or purple discoloration in the injured area states EMedicineHealth. A fresh bruise may initially appear red before turning to the deep purple-blue discoloration normally seen with bruising. As the body heals, the bruised area turns yellow-green before returning to its normal color.
Treatment for a knee contusion involves following the RICE protocol, according to WebMD. RICE stands for Rest, Ice, Compression and Elevation. The patient should stay off the injured knee, using crutches to avoid weight bearing. Ice should be applied 10 to 20 minutes at a time, several times a day. When icing, the patient should protect the skin from frostbite with a thin towel or pillowcase. The knee should be bandaged with an ACE wrap to provide support. Elevating the knee above heart level minimizes swelling. An over-the-counter nonsteroidal anti-inflammatory drugs such as ibuprofen or naproxen can reduce inflammation and relieve pain.