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.
Other conditions that cause knee pain include: 1  Bursitis. 2  A bursa is a sac of fluid that resides below the skin overlying your joints. 3  Overuse, a fall, or repeated bending and kneeling can irritate the bursa overlying the knee cap (patella), causing pain and swelling. The iliotibial band is a piece of tough tissue that runs from your hip down to the outer part of your knee. 2  If it's irritated by overuse or other problems, it can become inflamed and cause pain on the outer side of the knee.