Procedure for Recurring Opening of Leg Scar?

I have an old scar on my lower outer leg about 12 inches long. A few years ago, the scar opened up in small area and grew to be a hold about the size of a quarter and about 2 inches deep. After extensive compression wraps, prisma, and 2 aplegraft procedures, the wound healed. All was good; then I went swimming one day and noticed after drying off, some white stuff on the towel. I looked at the scar and noticed it had opened again. I am a diabetic and keeping my sugars under control. Is there any procedure out there that will cover the scar completely so that this will stop recurring?