Need opinions on planned foot surgery - canine

[smw1]

I have a 1 to 1-1/2 year old rescued Burmese Mt. Dog. At some time in the past, he apparently had an accident where the bottom of the foot was sliced away to where was hanging on by part of the flesh. It was allowed to heal where now the foot is like a shoe where the sole has come unglued and flaps. Dirt, stones, etc. get in the space and it gets rubbed and infected. Any thoughts on the best surgery to correct the problem and bring his foot together again?

smw