This AM's story which mentioned Matt Wieters being back on the shelf got me thinking about UCLs and how much we all know about that replacement both in the pitcher and in the non-pitcher. I did some reading and this is the distilled version of what I came up with. If an orthopedic surgeon or anyone with greater knowledge of the subject reads this, please weigh in with corrections and embellishments. I'd have used more pictures and links but I wasn't sure about copyright infringement. I did link an image of the elbow's anatomy for those who want to see it and a PDF describing avulsion of the UCL from the humeral head in a 16 year old quarterback (please, no one sue me for copyright infringement. If you must, sue SB Nation, care of Rincewind, if you really need the cash. I have no money). I left off the reference list but can supply one if anyone really wants to read all of that.

What’s an Ulnar Collateral Ligament?

Ligaments are fibrous tissue that connect bone to bone. Often they stabilize joints and keep bones in sockets. They are often, but not always, integral to normal function of the joint. The Ulnar Collateral Ligament (UCL) stretches between the upper arm bone (humerus) to the bigger of the two bones in the forearm (the ulna). The ulna’s the one on the inside of your arm as you look at your palm.

Do I Really Need My UCL?

Most of us, if we didn’t have a UCL, wouldn’t notice it providing we limited our throwing to soft toss. When we tear one no one is in a hurry to replace it since the average person can get by just fine with physiotherapy and a slight alteration in how we manipulate objects.

R.A. Dickey is one of the few people who manages to be a performing MLB pitcher with a compromised UCL (Masahiro Tanaka is another I can think of, but I suspect there’s more of these guys than we realize). Its possible Dickey was born without his. Its equally possible he tore it at a young age and got by just fine without it. However, surgical intervention is pretty common for throwing athletes.

So, What Are Those Interventions?

Ulnar collateral ligaments enjoy two types of surgical treatments:

(1) Repair

(2) Replacement or reconstruction

Option 1 occurs when its an avulsion: the ligament has torn free (often with a chunk of bone) from the humerus. This is a pretty rare occurrence as a diagnosis. By that I mean that the ligament can partially avulse, perhaps causing bone chips, and rest and time will repair it and no one will be the wiser, even after X-ray (non-displaced fractures can be difficult to discern until some weeks after injury when the re-mineralizing bone will glow brighter under X-ray). This is why I never like to hear that a pitcher has "bone chips" in their elbow. I always wonder if that UCL nearly failed catastrophically and the only evidence left of this are bone chips. Even if a player doesn't fail to report the pain he might never be diagnosed by serial X-ray. "One X-ray: no fracture seen" is common and only when the loose bodies hinder the free function of the elbow might you guess at where the problem was. If allowed to rest long enough, that bone will heal, and the avulsion never caught.

That said, the repair of an avulsion is straight forward. Often, if the arm is kept in the correct position, the bone will seat itself back down to where it came from and no surgery is required. Surgical repair may be necessary for complete avulsions, but that's not too common. The issue here is that avulsions can be chronic and not one-off. Missing it may mean big problems later.

Option 2 occurs more commonly with a torn UCL. Then a graft is called for. Not all grafts are the same and human variation comes into the picture here. The most common replacement ligament is a harvested tendon from the patient's forearm. This is a relatively non-important accessory tendon called the "Palmaris Longus Tendon" (PLT) (tendon’s connect muscle to bone) and its about 17cm long on average (you need around 15 to 20cm to do the UCL replacement: length depends on the size of the pitcher’s forearm. At a guess I'd say that Randy Johnson would probably have needed a top of the spectrum length. Nick Punto, much less). When the harvest comes from the patient’s own body it’s known as an "autograft". Once in a while cadaver tendon (an "allograft") is used. That’s pretty rare, though. The PLT is the tendon of choice: you won’t miss it, its strong enough for the job and it requires little reconstruction in order to place it as needed. However, some people don’t have one. They are born without a PLT. Human variation is a bummer sometimes, eh?

So other tendons have to be harvested. These include forearm tendons like the Flexor Carpi Radialis (FCR), a hamstring or achilles tendon (doubt anyone really wants to go with these as an autograft from a pro athlete) or one of the two big toe tendons (you have two, don't be greedy).

Once you have your graft, the fun starts. Holes are drilled out in the ulna and humerus for attachment where the original UCL used to be. Any remnants of the original ligament are kept and used to strengthen the graft. The graft is then spanned across the joint and the ends passed through the holes to form a figure-eight in each insertion site.

They Wanted You To Go To Rehab…

Rehabilitation of the UCL begins with postoperative care. The arm is splinted to give the graft and surgical sites time to heal. Right around 10 days is about right. Gentle range of motion exercises are performed to with the wrist, shoulder and hand. The rest of the body is treated to more vigorous work as the shoulder, chest, and core muscles are worked on to keep strength up. Somewhere in the 10 day post op window a range of motion splint is fitted and the surgical joint is given gentle exercise to promote blood flow and prevent scar from adhering to the inside of the elbow. Rather like we saw Marcus Stroman on his exercise bike mere days after his knee surgery.

As soon as the wounds are healed and there is no evidence of infection or rejection (at the end of 10 days) full joint motion is restored. Then the real painful part of rehab starts. Its an involved and highly individualized process and will stretch anywhere from 8 months to being on a mound throwing from a windup to over 10 months before being allowed to pitch of of a mound. Its a pretty successful surgery with many being able to throw harder than before injury. But, by far, the best rehab is the slow rehab. As much as two months of soft toss and mechanics drills are the gold standard. Matt Harvey got this ultra-slow treatment and it was pretty smart of The Mets to go to all of this trouble with him. But, even with a very conservative program, not everyone is lucky.

But I’m Not A Pitcher. When Can I Come Back?

In general, after around 9 months a pitcher can resume throwing rehab from a wind up once pain free. This is the point at which non-pitchers like Matt Wieters would be scheduled to return to action. The trouble is that not everyone is going to heal the same or at the same rate. Wieters is at 10 months post-op (he was operated on in mid-June of 2014) and clearly is having elbow problems again.

At this point the only option is rest. As much as 2-3 weeks of down time. Then more rehab and throwing mechanics work. We may not see Wieters back for another month. It would be a tragedy if he has to have that surgery revised. Was he rushed back? I don’t think so. But I do think he’d benefit greatly from the Matt Harvey Treatment.