In a room full of orthopaedic surgeons, you can’t throw a cat without hitting a few docs who have torn their ACL’s and never had them reconstructed. Why? Because a lot of orthopaedists don’t regularly participate in sports that involve rapid direction change, cutting, jumping, landing or pivoting; and if you don’t do those things, the likelihood that you’ll experience knee instability is low.
There are a great number of elite level swimmers, runners, cyclists, weight lifters, triathletes and even a number of recreational tennis players, skiers, etc who do not choose to have their ACLs reconstructed (see "Do I need to have ACL surgery?"). We call these athletes “ACL-copers”.
Things get more murky when we look at the aging athlete (40+) who regularly participates in organized cutting/pivoting sports – these people are regularly challenging their knee stability, and in my practice, I treat ‘em just like they’re 20-years old.
Also, the nature of a person’s vocation or specific athletic activities may make one graft more suitable than another. A person who runs long distances or who kneels or squats or crawls regularly (e.g. a firefighter, carpenter, plumber or avid yoga participant or marathon runner) may have an increased risk of tendinitis or pain with bone-patellar tendon-bone (BTB) reconstruction compared to hamstring autograft (HS).