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Reader Beware! Medical mumbo-jumbo to follow.

By this point you're probably all aware that everyone's favorite miracle call-up is going in for what's being called "minor arthroscopic surgery" to repair a chondral defect in his right elbow. It's being treated as no big deal by the local media, and Lowe is expected to be healthy and ready to pitch by next spring. Just a little winter tune-up, right?

Well, it's not really that simple. Now, before going any further I should make it clear that I don't have any special knowlege of Lowe's particular condition, and that all I have to go off is what's been reported in the paper. I can't speak to the presentation or severity of the injury, so I'm forced to generalize and make some assumptions. Please understand that as you read on. This post deals with what's most likely going on in Lowe's elbow, but I can't make any guarantees.

A "chondral defect" refers to a hole or divot in the cartilage of, in Lowe's case, the elbow. Given that one of the primary purposes of cartilage is to allow for the smooth movement of neighboring bones (not to mention the absorption of pressure), it's easy to see why this poses a problem. A healthy elbow is built in just such a way that, when perfectly intact, everything works fine, but make one little change that alters the structural balance and things can go south in a hurry. Having a little hole in your cartilage, then, somewhat changes the way the joint functions and can place additional stress on the primary and secondary stabilizers, which are the ligaments. That's bad. So not only does a chondral defect cause mild pain, but it also threatens to escalate into a much more severe condition down the road for throwing athletes who already put a ton of stress on their elbows.

So why not just let the cartilage heal itself, like you would for any other tissue? As it turns out, cartilage doesn't really regenerate itself, at least not very quickly, so you need a surgeon to go in and stimulate regrowth by poking little holes in the bone around the defect. That sounds bad, but because cartilage doesn't contain any blood vessels, you need to promote nearby bleeding to encourage regeneration. This is actually a very simple procedure that can be done arthroscopically, and it's exactly how Dr. Yocum is planning to go about making Mark Lowe all better. Lowe's surgery is being reported as "minor" because the operation itself is exactly that. Bleeding will stimulate regeneration of tissue to fill in the divot, and before too long the hole will be gone.

Here's the problem, though: the regenerated tissue - known as "fibrocartilage" - is structurally and biomechanically inferior to the articular cartilage it's replacing. It has a more haphazard arrangement, it's weaker, and it's prone to degradation over time. It does serve as a decent plug, but it's more of a short-term solution that you hope lasts a while than an effective perdurable treatment. It's all right for the general public, but for a pitcher or a quarterback, you'd really like to have something better that can guarantee you a higher long-term success rate.

Unfortunately, because articular cartilage cannot be regenerated at this time (there's your "holy grail" of orthopaedic surgery), the alternative solutions are more radical. One idea would be to transplant nonessential tissue (plus a small piece of bone) from somewhere else in the joint into the defect, thereby directly replacing articular cartilage with articular cartilage. You'd still be left with a hole, but it would be in a location of considerably lesser importance, so it wouldn't be an issue. However, this process can't guarantee that the replacement plug grows in properly, so you can end up with a warped and textured surface instead of a smooth one, and that just causes all kinds of other problems. To the best of my knowledge, this kind of operation is still fairly uncommon in human patients, although it does show promise.

Another potential solution is something called "autologous chondrocyte implantation" (ACI). In this procedure, a small biopsy of nonessential articular cartilage is taken from the patient and sent to a lab where it's cultured to a greater amount, at which point it's injected back into the patient to fill the defect. This is generally considered to be an effective treatment, but because it's a long-term process (both growing the cells in a lab and healing the area after injection), it's usually done when other surgical procedures have come up short, and it's not really an option for someone like Lowe who doesn't have that much time on his hands.

And so we're left with Yocum having to poke holes around Lowe's damaged cartilage, a procedure known as "microfracture." We're left with this knowing that it's far more likely to be a short-term treatment than a permanent solution, but because the alternative routes are more radical and would take longer to get Lowe back into a competitive state, there's not much of a choice. To the best of anyone's knowledge, the transplant/implant operations have never been used on a professional baseball player. This isn't the Mariners' risk-averse nature coming into play, as I thought initially; it's the inherent conservatism of Major League Baseball, and its tendency to focus on immediate gains rather than more distant achievements. Players need to get healthy as quickly as possible, so teams look for the fastest treatments, even if they may not necessarily have the upside of more long-term solutions. Lowe could have an ACI done, but who wants to wait that long? Not the Mariners, and certainly not Mark Lowe, whose livelihood depends on his durability and how many innings he can throw every year.

What it comes down to is that, while Lowe's surgery is indeed a minor procedure that should stop the pain and allow him to throw, there's a very real chance that it only serves to delay a bigger problem, rather than prevent it. Should the regenerated fibrocartilage degrade, Lowe's going to be looking at a more significant operation, quite possibly a ligament replacement. Steve Karsay had work done on damaged cartilage in his elbow and had to undergo Tommy-John surgery a year later. It's not a guarantee by any means - who knows, Lowe might never had his elbow flare up on him again in his life - but it's a distinct possibility. The Mariners are just hoping that this operation puts off any recurrences until it's far enough in the future that Lowe's playing for someone else.

I don't mean to scare anyone, and obviously I'm hoping that Lowe's chondral defect is as minor as they come, and we never have to talk about it again. Because I haven't spoken with anyone who's seen the MRIs, I can't claim to know exactly what's going on in his elbow, or even how it happened, be it from a singular trauma or pressure over time. All I can do is fill you in on what could come out of this if his defect is a "normal" one, since the local media obviously has no interest in doing so themselves. Ideally Mark Lowe comes out of this whole episode fine and ready to dominate seventh and eighth innings for the next several years, but if he doesn't, I think we have a pretty good idea why.