Stems cells have been used to cure ACL, so I'm sure it would work. Problem is, stem cell research is banned in the U.S., so you would have to find a doctor outside of the country for 10's of thousands of dollars.
Not to mention! The research of using stem cells to cure your injury my not be developed yet.
While most of the stem cell news of recent years has focused on laboratory work, many people are not aware that they have the potential to improve stem cell circulation in their own bodies. No, not through surgery or from an injection, but simply through supplements to their diet. Stem cell nutrition, though it has been the subject of numerous successful scientific studies, has yet to catch on in a big way with the general public. This is likely due to misinformation, a lack of understanding, and aversion to anything having to do with stem cells due to the controversy surrounding the abortion issue.