Help for Hemosiderin Staining After Cellulitis?

I fell on concrete & severely injured my knee in 2001. Anterior half of leg just below the knee almost to ankle was soon almost black. 2 days later I developed cellulitis there in about an 8x4" area down the length of the anterior of my shin. To this day, there's a fairly dark stain exactly where the cellulitis was, lightening little, if any. Any hope of improvement or treatment after this long? A similar quarter-size spot after a lumpectomy has gradually mostly faded after 3 yrs.