If you have a torn ACL + meniscus tear, then you should have surgery to address both. If you have an isolated ACL tear and don't participate in activities noted above, then you could try to get by without surgery, but if you experience instability, then should have surgery.
Also, about 30% of ACL tears are eligible for primary ACL repair, where your own ACL is repaired, instead of a traditional reconstruction in which your ACL is replaced with a graft. A handful of surgeons in the U.S. currently perform primary ACL repair.
Vic Goradia, MD
Knee, Shoulder and Sports Medicine Specialist