Egypt's second faith is Coptic Christianity. Copts are heirs of an ancient Christian rite. Coptic Christianity was the predominant religion in Egypt until the 10th century when a lot of Christians diverted to Islam. Christianity itself was brought in Egypt by St. Mark in the middle of the first century AD.
Other possible causes of swelling behind the knee include abscesses (infections); tumors of the skin, soft tissue, or bones; bleeding; deep venous thrombosis (blood clot in the deep veins of the legs); or deformity of the joint after a fracture of any of the bones of your knee joint.
Dislocated kneecap: The kneecap slides out of position, causing knee pain and swelling. IT (iliotibial) band syndrome: The iliotibial (IT) band is a piece of tough tissue that runs from your hip down to the outer part of your knee. When you overdo activity, it can become inflamed over time. That causes pain on the outer side of the knee and is common in runners when going downhill. Loose cartilage: Sometimes, a knee injury can break loose cartilage. These pieces can get stuck in the joint, which causes pain and swelling.