A "ruptured" ACL? Does that mean it tore apart? ....or is it "stretched"? I too just injured my ACL (tore it apart, injured my PCL and my MCL in addition to dislocating my knee
). Anyway, as a human, they say that they usually let a stretched ACL alone and usually only do surgery on a "torn" one. What do the x-rays show? I know you will do what is best for your baby. Get a second opinion and MAKE SURE of what the damages are before making any decision. I wish you both the very best.