Expert on Jay Cutler’s sprain: ‘You do not want this injury’

John Fox says, often, that he’s not a doctor.

John Fernandez is. And the hand, wrist and elbow orthopedic surgeon at Rush University Medical Center said Wednesday that Jay Cutler has an injury that can be particularly pernicious for quarterbacks.

The thumb ligament can be as important for quarterbacks as the elbow ligament is for a pitcher.

“This is the ‘Tommy John’ of the football quarterback, basically,” the surgeon said.

The Bears quarterback, of course, doesn’t need surgery, coach John Fox said. His right thumb remained in a cast Wednesday, when Cutler attended practice but did not participate.

“You do not want this injury,” said Fernandez, who does not treat Cutler. “For one, it puts you out. Two, it’s very unpredictable in terms of how it’s going to recover.”

The Bears provided little clarity Wednesday. Fox said only that Cutler has “iced it” and that it “probably helped the swelling.” Asked if Cutler will miss two-to-three weeks, Fox wouldn’t answer, saying reports of timelines “tend not to be true anyway.”

Sources told the Sun-Times that Cutler first injured his thumb in Week 1. Fox wouldn’t admit as much, saying his quarterback took every regular snap during practice last week.

The issue is not only when Cutler returns, but how effective he will be.

Thumb ligaments are “super, super important” for quarterbacks, Fernandez said, because they help them to throw with accuracy, velocity and spin, and allow them to grip the football securely.

In that sense, they are as useful as the elbow ligament that a baseball pitcher relies on — and that is replaced in Tommy John surgery. They even share the same name: ulnar collateral ligament, shorthand for a ligament that’s on the underside of the arm that stands to the side of a joint.

“Virtually any other position on the team, you can function very well with this kind of injury, including a wide receiver or a tight end,” Fernandez said. “But the ulnar collateral ligament is critical for the quarterback.”

Fernandez compared the thumb’s UCL to a leather belt, a passive restraint that attaches bones together. There are three kinds of thumb sprains, ranging from first degree, a stretched ligament, to third, a tear with no function.

Fernandez suspects Cutler had a second-degree sprain, in which some of the collagen fibers are torn; anything worse, he said, and Cutler likely would have required surgery that would have kept him out two months, if not the rest of the season.

Grade 2 sprains are typically treated with two-to-six weeks of rest, Fernandez said, depending on severity. Casting the thumb helps immobilize it during common activities — turning a key, holding a pen, opening a bottle — so that collagen fibers can heal back together again and repair the ligament.

Doctors can treat the injury with platelet-rich plasma, in which someone’s own blood is spun through a centrifuge to isolate “growth factors,” which are then injected back into the body.

“It’s like hiring more people on a project so the project gets done more quickly,” Fernandez said.

Comparing Cutler’s current injury to his 2011 right thumb fracture — and subsequent surgery — is more linear than it sounds, too, because ligament damage often comes with a break.

An acute thumb sprain is called a “skier’s thumb,” while the chronic version is called “gamekeeper’s thumb.”

Either way, it’s bad news for quarterbacks.

“The big question is, once he goes back in there — even if he doesn’t fall on it, which is obviously the greatest risk to the ligament — just gripping the ball,” Fernandez said. “Unless he’s completely pain-free and that ligament is super-stiff, it’s going to significantly decrease his ability to grip with strength.

“So it’s going to affect his ability to throw, throw accurately, throw with velocity.”