Gonna dip my toe into this pool.... Just short background before - my wife is a physiotherapist that specializes in sports injuries and works in the Olympic clinic (ie - the main hub for rehab and research for elite Olympic sport athletes). She is also doing a PT certificate with the International Olympic Committee and, funny enough, just finished a module on ACL and knee injuries.
1. Once there is an ACL tear, the chances of a retear are high. High does not mean it will happen, but there knee is not the same, obviously. The surgically repaired is not stronger or less likely to re-tear.
2. Also important to remember, when shaving a graft from the athletes hamstring or patella tendon, you need to rehab both - the knee and the muscle/tendon that was surgically cut to provide the graft. And of course, as in an surgery, there is always a risk of added issues. For example, I know of an elite Judoka that had her ACLR surgery about 2 months ago, and now had to reopen the knee because of blood cluttering that hindered full range motion,
3. The current school of thought around ACLR (rapture) rehab is to do a conservative rehab, ie - not an operation, but let the ligament heal. There is a new procedure in Australia where the knee is kept at an ideal 90 degree angle to allow the ligament to attach, and the rehab is actually to rebuild strength and full range of motion. However, North America (and the USA in particular) is very pro operation and there was even a case of a volleyball player who had a scholarship to Div1 college, and arrived there post conservative rehab with full strength and range of motion. However, the insurance (college) would only cover her if she did the operation and she was sort of forced into doing it to maintain the scholarship.
4. While there are several empirically proven programs in sports to reduce the risk of ACLR like FIFA11 (soccer) or Boksmart (Rugby), they actually are not proven to reduce risk in basketball.
5. The length of rehab required is the same, by the way, and research has proven that the chances of successful rehab are higher the more time is given for rehab. ie an early return, specifically earlier than 9 months, would significantly hinder the chance to avoid a re-tear. Anything shorter than 9 months is not recommended (and in fact, 8 months and 4 months are similar, meaning that returning at either point has the same impact, whereas 9 months is the minimum recommended for a FULL return to play and contact).
6. Not empirically proven but is my personal opinion - ACLR is just . In all sports!
If you're very interested in learning about ACLR, I would recommend the
British Journal of Sports Medicine (BJSM), or following
Mick Hughes, an Australian physiotherapist that shares great stuff on ACLR (and more).