That is not just twisted tibia, I dealt with twisted tibia in 5 chicks last year, none had any open sores like that. There is definitely something else going on there, perhaps a traumatic injury of some kind? Twisted tibia can be a result of an injury or a result of abnormal cartilage growth in the hock caused by growth and weight gain that is too rapid. It also does not look like perosis (slipped tendon) usually those legs are dragging behind the chick not held out in front. I would try to sling the chick as Kathy suggested to get the weight off that leg and use triple antibiotic ointment and I would also think about an oral antibiotic to keep any infection from invading the joint, once the wound is healed you can maybe get a better handle on the underlying issues.