Hello, My father is 77 years old and a diabetic. 2 years ago he had a splinter removed from the side of his foot (just below the small toe) and there is still a hole in his foot that will not heal. It is causing him a great deal of pain to the point where he cannot walk. He had the area checked by Doctors, had x-rays taken, but no one has any answers. The hole is surrounded by calloused skin, but there is no seepage of any kind. You can look right into the hole...it looks black, but we have no idea what it is. Any advice would be sincerely appreciated.