My son fell from the bike, dragged for an about 10ft, his left know has that ligament torn (his bottom sides of knee pain). Xray shows now sign of fractures. what is the treatment. We have given him antibiotic medicine and pain killers, swelling controlling tablets. it is 7 days gone, still pain persists. What is the treatment and and how long this will take. He is only 21 years oold