We’ve all heard the news by now. Yankees ace Masahiro Tanaka has a small tear in his Ulnar Collateral Ligament (UCL), and although the dreaded Tommy John Surgery is still a possibility, he’s going to try to rehab the injury first. Tanaka will undergo a platelet-rich plasma injection in his elbow before embarking on a 6-week throwing program. If he doesn’t show signs of improvement during this time, he’ll need to have the ligament surgically repaired, which would likely sideline him until the 2016 season.
Plenty of pitchers have tried to rehab their partially torn UCL’s, only to eventually go under the knife anyway. Luke Hochevar, Dylan Bundy, Chad Billingsley, and Jonny Venters are some recent examples. Meanwhile, its a little harder to find pitchers who successfully pitched through any sort of UCL tear. That list includes Adam Wainwright, Ervin Santana, Danny Duffy, and… well, that’s it. Those are really the only names out there. This might lead you to believe that the rest/rehab method rarely works and that a torn UCL almost always leads to TJ surgery, but that’s not necessarily the case. Pitchers pitch through aches and pains all the time, and we pretty much never hear about it becomes moderately serious. I’d bet that if you took an MRI of every “healthy” pitcher in the majors, at least a few of them would have some sort of damage to their UCL.
Although exact calculus is a bit murky, it’s fair to say that there’s a decent chance Tanaka will need TJ surgery in the coming months, which would put him out of action until the 2016 season. By then, he’d be nearly 20 months post-op, and presumably be back to full strength. But that’s far from a sure thing. From 2003-2012, 58 pitchers with at least 1 fWAR over their prior two seasons had the surgery. Most made full recoveries, but four of them (7%) never made it back to the majors. You could argue that Denny Neagle (2003) was probably nearing the end of his career anyway, but Daniel Hudson, Cory Luebke, and Ryan Madson were in their primes when they went under the knife in early 2012. Two years later, we’re still waiting for them to return. There are also guys like Edinson Volquez and Eric Gagne who did make it back, but were never quite the same pitchers they were brfore their injuries. Sure, 7% is a small probability, but it goes without saying that losing Tanaka forever would be devastating. So if there’s even a small chance that rest coupled with a PRP treatment might do the trick, the Yankees are probably making the right decision.
Now, the benefits of PRP treatments are still largely unproven, but it’s not as though this is some voodo procedure like psychic surgery or ear candling. There’s evidence out there that suggests it might be legit. A 2009 review on scientific literature on the topic concluded that PRP treatments are “a promising, but not proven, treatment option for joint, tendon, ligament, and muscle injuries.” A more recent study found that 30 of 34 subjects with UCL tears “returned to the same level of play without any complaints” following PRP treatment. The study lacked a control, so we don’t know how many would have recovered with just rest and rehab (and no PRP treatment), but even so, there’s reason to believe that PRP treatments can be at least moderately effective.
This is all a long way of saying that it’s hard to know whether or not Tanaka’s PRP/rehab regimen will enable him to eschew Tommy John Surgery, but it’s worth a shot — even if the odds are slim. The rehab process is long and grueling — even if all goes according to plan — and enduring 12-18 months without Tanaka is something the Yankees should try to avoid if at all possible. According to Brian Cashman, Tanaka’s tear is “small,” and three separate doctors recommended that he go the rehab and PRP route. Not only do these doctors know more about this sort of thing than you or I, but they also have access to Tanaka’s MRI. That they all recommended he forgo surgery should tell us something about the mildness of Tanaka’s condition. So if any pitcher has favorable odds of pitching through this kind of structural damage, it’s probably Tanaka. The Yankees are doing all they can to get Tanaka back as soon as possible. Now we’ll just have to wait it out and hope the platelets do their thing.