Microfracture to old injury

Hi, I'm about a month away from having a MF on my right medial femoral condyle area, the result of an old ACL injury. I'm 40 and in good shape. I tore my ACL almost 20 years ago playing soccer in college. After one failed ACL repair back in '92, I had it successfully repaired in '97 by a well known OS at Mass General. Although my knee overall is "good" and structurally strong, I'm hoping the MF technique will alleviate pain I have after skiing, softball, running, hiking, etc. My athletics have subsided considerable over the last few years as the pain afterward was not worth it. Does anyway have some success stories regarding repairing and old defect? I'm hoping to get some quality of life in regards to athletics, coaching kids, etc. Thanks in advance.