Washington Redskins survive the loss of rookie QB Robert Griffin III and pull off a last-second comeback, keeping playoff hopes alive with flair. (The Washington Post)

Among the many injuries that can befall the knee of an elite athlete, a “mild” or Grade 1 sprain of the lateral collateral ligament such as the one suffered by Redskins quarterback Robert Griffin III is among the most treatable and least disabling. But at least medically speaking, that does not mean Griffin’s ability to start next Sunday at Cleveland should be considered a given.

“Based on my experience, I wouldn’t be surprised if [the Redskins] protect him and don’t rush him back,” said Neal ElAttrache, an orthopedic surgeon at Kerlan-Jobe Orthopaedic Clinic in Los Angeles, who performed New England Patriots quarterback Tom Brady’s knee surgery in 2009.

“[With] the way he plays — he’s not a stationary quarterback — and the fact he has his whole career ahead of him, I would be surprised if they weren’t very careful with him and let this thing heal up.”

Griffin, 22, was injured in the fourth quarter of the Redskins’ 31-28 overtime victory Sunday over the Baltimore Ravens. Attempting to scramble for a first down over the middle of the field, he was hit in the upper leg as he fell to the ground by Ravens nose tackle Haloti Ngata, a 340-pound, four-time all-pro. The impact buggy-whipped Griffin’s leg in the air, stretching the LCL, one of four stabilizing ligaments in the knee.

An MRI exam given late Sunday night revealed the mild sprain to the LCL. The Redskins are hopeful Griffin can play Sunday in Cleveland, but will know more on Wednesday when the team returns to practice.

The injury to Redskins quarterback Robert Griffin III was a mild, or Grade 1, sprain of the lateral collateral ligament in his right knee.

The Redskins’ immediate fear was that Griffin had re-torn his anterior cruciate ligament (ACL), which he previously tore in 2009 while a sophomore at Baylor, necessitating season-ending surgery.

“Without seeing the MRI myself, I would say in general that if a mild sprain to the LCL is the only damage visible on the MRI, that’s a positive result,” said James C. Dreese, a team physician for the University of Maryland sports teams. “In general, within a couple of weeks you would expect a more minimal injury like that to improve. But in some instances it might be only one week, or in other cases there might be more pain involved and it could take longer.”

Injuries to the LCL, which sits on the outside of the knee, occur far less frequently than those to the ACL, which is often damaged as the foot is firmly planted in the ground. Ironically, one residual effect of Griffin’s 2009 ACL surgery is that it may have prevented further damage to the ligament on Sunday.

“In those first five years after the [ACL] surgery, the ligament is actually stronger,” said Will Carroll, an author of two books on sports injuries who writes as “The Injury Expert” for SI.com.

According to Dreese, the designation Grade 1 means “there is some swelling around the ligament, which means it has gone through some stretching, but the ligament has not been disrupted, with a loss of integrity of the fibers.”

But according to ElAttrache, Griffin’s LCL might not be the biggest issue in the knee. Injuries to the LCL frequently are accompanied by a bone bruise on the medial, or inside, part of the knee. Such bruises are typically difficult to see on an initial MRI scan, because it is hidden by the swelling, but would reveal itself more clearly in two to three days. The Redskins have not said whether Griffin has a bone bruise, in addition to the sprained LCL.

“I wouldn’t be surprised, with that sort of trauma, if he may feel a bit more sore because of the bone bruise,” ElAttrache said. “It may also cause some discomfort that would prevent the knee from functioning immediately. In my experience, those injuries can take several weeks to heal.”

Sprains such as Griffin’s are typically treated with ice packs and compression, but the primary treatment in the first few days after the injury is rest.

“In general, if it’s painful to bear weight or do activity, there is rest involved, or if there’s swelling, you rest until that is resolved,” Dreese said. “Then you increase activity until you’re able to get back to normal. That should take anywhere from a week, to up to three or four weeks.”

Athletes frequently play through sprains — quarterback Brett Favre, then with the Green Bay Packers, played with a mild LCL sprain in 2002 — but that does not come without inherent risks. Ultimately the decision for the Redskins and Griffin on Sunday may come down to how much risk they are willing to take.

“If you haven’t made a full recovery, that certainly places you in jeopardy of having a more significant injury,” Dreese said. “That would certainly be a concern [for the Redskins] this week.”

“Whenever you deal with the lateral side, you really have to be careful and let those heal, if there’s any looseness at all,” ElAttrache said. “The lateral side ligaments are more unforgiving in terms of [being] compromised by how a guy like [Griffin] plays.”