Jim Harbaugh: Tank Carradine had mass of scar tissue removed this offseason

San Francisco 49ers head coach Jim Harbaugh met with the national media on Thursday, taking questions for 10 minutes during the NFL Combine. He got several Jonathan Martin questions, but naturally swatted them away for the most part. The most notable piece of information to come from the press conference was news on Tank Carradine. Coach Harbaugh said that Tank had a procedure earlier this offseason to remove a mass of scar tissue from his knee.

Tank's recovery has been a tough one to figure out. There were reports that his recovery was rushed for the draft. He started the season on the NFI list, was activated briefly, and then we saw him end up on injured reserve the rest of the way. There was no word on the shut-down, but this tells us something. Coach Harbaugh said prior to the procedure he could not get full extension on his knee, but since then he was looking like a different man.

The build-up of scar tissue is something called arthrofibrosis. I'll talk to socalisteph about getting some more detail on this, but she had a few comments, and there is some other content out there discussing it.

On Tank: Abnormal accumulation of scar tissue in the knee is called arthrofibrosis. Once it develops, it's hard to get your motion back.

— So Cali Steph (@SoCaliSteph) February 20, 2014

There's an interesting medical article that discusses this very issue. They talked about people getting arthrolysis to restore mobility, and basically confirm this is something from which a person can recover, but it's a complication. Their conclusion is fairly general, but is still worth noting:

If a complication occurs in spite of all these precautions, the decision to proceed to surgery should be made early before all the anatomical structures of the knee stiffen. The later surgery is being done, the less predictable the result will be.

I don't know enough to determine whether this qualifies as an early or late procedure, but I have to think this is later given the stiffening of the joint Coach Harbaugh mentioned.

It's a setback to the overall process, but it remains to be seen exactly where he stands in the big picture. The 49ers return to the practice field for their offseason workout program as soon as April 21. The first phase consists of two weeks of strength, conditioning and rehab work. After that we start seeing individual positional work. We'll get a basic idea of things through the first phase, but for Tank, what he is involved in during Phase 2 will tell us a whole lot more. Additionally, how the team approaches the defensive line in May's draft might tell us a little something as well.