Eagles quarterback Carson Wentz has torn his anterior cruciate ligament and will miss the rest of the Eagles' season.

As fans grapple with news of the knee injury Wentz suffered during Sunday's win over the Rams, many are wondering: How bad is an ACL tear, and how long until he can get back into the game? Read on to find out more about this common injury and how athletes can come back from it.

ACL tears are common

ACL tears are among the most common sports injuries. Eagles fans are no doubt remembering when Donovan McNabb injured his knee back in 2007. More recently, Temple linebacker Chappelle Russell ended his second season in a row with a torn ACL.

It's not just big-time athletes affected by ACL tears. The injury is becoming increasingly common in kids and teens, as well as in older folks trying to keep active.

Recovery prognosis

The good news is that most people with a tear have surgery to reconstruct the ACL and get back to their previous level of activity.

But research shows that later, there is a high incidence of arthritis in patients who tear their ACL, whether or not they have surgery.

Christopher Dodson, a board-certified sports medicine surgeon at Rothman Institute, invited an Inquirer reporter inside the O.R. a couple of years ago to watch an ACL reconstruction. Nearly half of all ACL injuries leave damage to nearby structures; in the case we watched, the patient had a torn meniscus and MCL, neither of which was caught on the original MRI scans.

How to keep your own knees strong

The good news: Unless you find yourself in a situation like Wentz did, with two professional football players attacking you at once, there are techniques you can use to strengthen and protect your knees to prevent ACL tears.