hello, i m facing a problem in my knee .what happen is while travelling, or standing on uneven surface like wedge or playing something my knee cap goes sideway that is onthe left for right knee after which it causes severe pain and instant blood clot happen around knee which make it immovable for 1 month and i need to get a plaster for a month. It is rather an old problem as it has happened three times before at age of 15, then one year later, then after 2 year and now after three year, it is causing the same fear as i m getting the sensation of happening again. It has not happened yet may be because i m not doing any physical work like playing or running. Could you suggest me wy is it happening and whats the remedy. Also, this happens to my mother , sister and brother but in their caseit is not that serious and it remain painful for them for a 3-4 days. Thanks.