How To Heal An Old Injury Of Childhood On Back?

I had a really bad fall (slipped on ice and fell on top of a broken step) when I was 7 years old. At first there was only a small dent/dimple in the middle of my right buttock. Now at the age of 40 the dent has literally moved from the middle to almost the side of my hip like its separating the top and lower part of the muscle. It is ghastly. What can I do about this? I have no initial pain, but when I was pregnant, most of my pain was in my back and buttocks.