 [ Symptoms ] i have pain on the backside & sides of knee if twisted bad pain is there anything i can do other than knee brace [ Disease ] common no can it happen yes if the person who sutured you did not use absorbable sutures supposed to dissolve in a few weeks to a month or s0 and used cotton or regular suture material this can occur sometimes fibers from clothing can be trapped under the skin if your wound was not carefully irrigated why it took ten years i can not say since i have no way of seeing this string like substance to be sure of its nature or confirming that it is old suture material