Recurrent Knee effusion

Patient: Over the past 2 years, I have had my right knee (surgically repaired in 2003, broken femur, 4 screws) swell up suddenly and acutely with blood being drawn out twice as well as numerous other occasions with mild swelling causing joint immobilization and pain. The most recent happening in august of this year, with all the cardinal signs of swelling as well as a tightness of hamstrings. The most puzzling thing is that this occurred while sitting in a chair. I am a very active person playing soccer, weightlifting as well as working outdoors. My question to you is what could be causing these bizarre episodes??

Doctor: Given your past medical history of multiple injuries in your knee, the several episodes of swelling might be due to Dege enerative Menisci tears that often manifest with recurrent effusions due to synovitis. The menisci are C-shaped wedges of fibro cartilage located between the tibia and femur, and very close related to knee ligaments and attached also to the joint capsule. They are susceptible to get injured with leg rotation movements or rotational forces applied to them, and the lesion produced can be partial or complete tear. Meniscus injuries are common in active people as you, who are involved in sporting (soccer, football)or other physical activities. Locking or buckling is a common symptom after a meniscus lesion develops. Locking usually occurs at 20-45° of joint extension. If a torn fragment has been trapped within the joint, extension may feel limited against a rubbery resistance. Joint inflammation, effusion (synovitis) or capsular involvement also maybe present. A more reliable indicator of meniscus lesion is a click or snaps after the joint unlocks, it can be or not associated with pain. Many menisci tears heal spontaneously, also, can be treated with casting depending of the severity of the tear. With time the symptoms tend to improve. If this is not the case and you keep having the swelling episodes I strongly recommend a re-evaluation of your knee  by a Orthopedic surgeon or sports medicine especialist