I'm not an orthopedist. I'm not a doctor. I don't know much about the human knee at all. But, since the Clippers first showed interest in Chris Paul the question of his injury history, particularly the condition of his right knee keeps coming up. There's been a lot of rumor and innuendo that hinted that Paul's knees were progressively degrading, similar to what happened to Brandon Roy. Could this be true? Did the Clippers just trade the house for a player who might be forced into retirement in just a few short years?

Chris Paul, like most players doesn't like to talk about his injuries, which was pretty evident in an Clippers otherwise pleasant introduction of Paul last week. Paul handled every question with grace and aplomb until one reporter asked him about the health and condition of his knee. He glared at the reporter and said (something like), "You wanna play? Let's go. I'm ready to play."

So, what's the truth about Chris Paul's knees?

How many surgeries has Chris Paul had on his knees? - Paul has had one knee surgery, in February 2010, on his right knee. Apparently the lateral meniscus (the one most basketball players tend to damage) was torn. The surgeon, renowned orthopedist James Anderson was unable to repair the cartilage, and instead chose to remove it. Paul's left knee is fine and has never known a surgeon's knife.

Human knees have two C-shaped pads of cartilage at the bottom of the joint between the large bones of the leg. They lubricate the ends of the femur and tibia and act as "shock absorbers". (Zach Lowe published a solid article about NBA players and their menisci here.) Damage to the meniscus is fairly common among basketball players. The preferred method of repair is generally to sew the tear together or clip the damaged tissue away and leave as much cartilage in place as possible.

(The Clipper's own Eric Bledsoe tore one of his menisci this past fall. His knee was repaired by the same James Andrews. I've been unable to determine whether the meniscus was removed, repaired, or cut away. Like I said, teams and players don't like to talk about it.)

Why did they remove the meniscus rather than cut away or repair the tear in Paul's knee? - Hard to know. We don't have access to the medical reports. What I've read indicates that Anderson thought the meniscus was irreparable so he removed it. One pretty scary issue has arisen... that the team or the player might have made a decision to remove the cartilage rather than repair it because the rehab is generally much shorter in the case of removal rather than repair. Did Paul or the team decide to take the quick, more dangerous exit ramp? Bill Simmons brought that up issue here. But I've found no information that the decision was anything other than an operating room choice made by Paul's surgical team... and, understandably, I suppose, they're not talking.

Is Paul's knee progressively deteriorating? Pro athletes, basketball players in particular put a great deal of pressure on their knees. Lowe's article conjects that few heavily experienced NBA players have not suffered some knee damage in the course of their playing careers. Chris Paul has had one of the two menisci removed from his right knee removing some of the cushioning. Different athletes respond differently to meniscus surgery, but most recover very well. Removing the lateral meniscus reduces stability in the knee. But proper rehabilitation and conditioning can go a long way to insuring Paul's knee stays healthy.

Eventually, and this is my opinion, it seems likely Paul will suffer some form of osteoarthritis... when that might happen, or if it might happen during his playing career... is unknown.

Is Paul's knee injury similar to Brandon Roy's? Yes and no. Brandon Roy's knees have been operated on six times, the first time in high school and all four of his menisci have been completely removed. Paul is missing one meniscus in his right knee.

Is Paul's knee in somekind of "bone on bone" state? We hear a lot about this, but the phrase "bone on bone" is misleading. This link is a detailed post written by an orhopedic surgeon for BlazersEdge. The term "bone on bone" is a graphic depiction of roughly what's going on with Brandon Roy's knees but the medically correct term is "osteoarthritis", which doesn't sound nearly as scary as bone-on-bone. Are Chris Paul's large leg bones rubbing together in the absence of cartilage? Apparently not, but there's no cartilage in there keeping them apart either.

Is Chris Paul is a candidate for micro-fracture surgery? Maybe. Here's an article from Basketball Prospectus written by Will Carroll about micro-fracture surgery. MFS is still somewhat a radical and relatively new technology, where surgeons put tiny holes and fissures into the bones of the knee that help blood reach parts of the knee that don't normally see a lot of replenishing blood flow... aiding the growth of protective cartilage. But the cartilage isn't the same kind of cartilage that forms the meniscus. In the case of Brandon Roy, he flew to Los Angeles to visit Dr. Neal El Attrache (the guy who repaired Blake Griffin's knee two years ago). El Attrache sent Roy home, saying the micro-surgery wasn't necessary... because it wouldn't do any good. The menisci couldn't grow back because there's nothing left to grow back. Micro-fracture surgery is generally considered a court of last resort for players with severely injured knees. It's worked for some players (Amare' Stoudemire, Jason Kidd) not so much for others (Chris Webber, Anfernee Hardaway). There's a list of players who've had the surgery, in the Basketball Prospectus article that's pretty interesting.

What about a meniscus transplant? Good question. This may be an option, someday. Marshall Faulk had cadaver cartilage inserted into his knee, but only after his playing days were over. No active professional athlete has had a meniscus transplant.

What about miracle German knee technology, the thing Kobe Bryant had done this summer? This is interesting stuff, but it's very new and there's varying opinions about its effectiveness. The idea is that you draw a bunch of blood from the body, centrifuge out the platelets and concoct an oxygen-rich concentrate and inject it back into the area you want to help, in this case the knee. The concentrate is supposed to reinvigorate and strengthen the joint. Does it work? People disagree as to its effectiveness... common sense would indicate that it wouldn't encourage a missing meniscus into healing. But parts of the knee are blood starved and it might encourage regrowth.

So, should we be worried about Chris Paul's health, specifically the condition of his right knee? It's understandable if unfortunate that Paul, his doctors, and his former team have released so little information about his injuries. We know he was out for 37 games in 2010 after the injury, apparently tried to come back too soon, then wore a large and unwieldy knee brace for part of last year. Speculation grew that there was no cartilage remaining in the joint or that he would need further surgery. Neither of these rumors were true. And Paul stopped wearing the brace in games mid-season last year, took the Hornets to the playoffs, and seemed to have all or most of his old skills back.

But historically, Paul doesn't miss many games. In the four seasons before the injury he missed a total of 24. Last year he played 80 games (missing two because he suffered a concussion). And there's another thing about Chris Paul that's important to remember. While he's lightning fast, he's a player who relies on his brain as much as his body. Like Steve Nash or Jason Kidd (or Larry Bird or Magic Johnson) his greatest asset has little to do with physical prowess. Though his scoring numbers have fallen since his injury, his court-awareness and leadership haven't flagged a bit. He even somehow managed to drag a David West-less Hornets team into the playoffs just last year. He might not be quite as quick as he once was, might not be cut as explosively, but his skills are still extraordinary, and his greatest asset, his brain, has absolutely nothing to do with his right knee.