Knowing that "sick" articular cartilage can lead to arthritis, Paine added, "Arthritis can end your career just as quickly as instability in your knee."
Reestablishing range of motion is a key early component of rehab because it prevents the buildup of scar tissue and, again, protects the cartilage. The infection and resulting slow start of rehab place Brady at risk of developing more scar tissue.
"The infection alone increases the ability of scar tissue to form," said Diane English, a team physician for Boston College athletics. "That's the biggest fear. If you get an infected knee, it can just turn to a wad of scar because infection builds up all sort of adhesions and things like that.
"One of the things about infection is you want to rest the knee and let the antibiotics work and not have swelling. There are no options. You really just have to wait for the infection to clear up, then start on the physical therapy. That's why it's delayed and that's why there's such a question of a time frame for someone like him."
A month after surgery, patients often can do the leg presses, lunges, calf raises, stationary bicycling, and stair stepping. Functional activities generally begin at the eight- to 10-week mark with running. Jumping follows at 10-14 weeks. Cutting comes last, at 12-16 weeks. Around the six-month mark, athletes can return to full participation in sports.
But even then, there remains work to be done.
"When the other guys get to hang it up and take a shower and go home, you're going to be on the bike," said Paulos. "You're going to do leg presses. You're going to maintain your muscle strength and the lifting program, the progressive resistive exercise program, the whole time you're staying sports-active.
"If you don't, you'll find that that leg will stay slightly smaller than the normal leg. When you don't use it, it will get weaker at twice the rate of a normal leg. So you have to have a maintenance program designed to keep those muscles comparable to the other leg."
In the short and long term, Brady has both time and constant medical attention (if needed) working in his favor.
"If someone wanted to bet me today if Brady makes it back, I would not bet against him, no way," said Kevin Wilk, who as associate clinical director of Birmingham, Ala.,-based Champion Sports Medicine works closely with Dr. James Andrews and who has helped more than 500 NFL players recover from ACL surgery. "He'll make it back because he's a smart guy, a pro athlete with the best of medical care.
"They're not going to let him fail. They're going to do everything humanly possible. Unless something goes really weird, something that was a 1 in 2 million shot, he's going to make it back and back at the same level."
Shira Springer can be reached at springer@globe.com
