When patients leave Barnes-Jewish Hospital in St. Louis after Dr. Robert Thompson, a vascular surgeon, has removed their first rib as part of thoracic outlet decompression surgery, they are given the 4-centimeter piece of bone to take home as a memento, along with detailed instructions on how to care for it. First, soak it in ammonia to remove any residual blood and oil from the bone. Then, use peroxide to whiten it. Finally, apply a coat of Mop & Glo to prevent any oils or dirt from staining the bone. Yes, Mop & Glo -- the stuff used to shine up kitchen floors.

The protocol for a Major League pitcher to return from surgery to correct thoracic outlet syndrome (TOS) is a little less specific -- and a little less proven -- given that fewer than 20 have undergone the procedure. It's three or four days in the hospital, followed by physical therapy three to four weeks later, then light tossing of a baseball at six weeks, more vigorous use of the arm at around eight weeks, and hopefully an all-clear at 12 weeks, with instructions to proceed as tolerated.

Mets ace Matt Harvey will make his first start since undergoing his thoracic outlet surgery eight months ago on Sunday afternoon at 1:05 p.m. ET on MLB.TV against the Cardinals in Port St. Lucie, Fla. His rib, however, is back at his apartment in New York.

Previously, Harvey's first rib was attached behind his first thoracic vertebrae at the base of his neck -- angled down and connected to his sternum just below the collarbone. The first rib is the uppermost of the ribs, much higher than most people generally think ribs are located, and is shown in red on the diagram.



"It's a weird-looking thing, not as big as I thought. It's probably pinkie-sized and it's really thin," said Harvey. "It looks almost like half of a tongue depressor. Makes you wonder why it was causing so many issues."

We all remember Harvey's struggles last May and June. His velocity was down, he couldn't find his release point or his arm slot and he was getting hit harder than he'd ever been hit before. The Dark Knight, so typically stoic, was visibly uncomfortable on the mound. Harvey now admits he was pitching with cold, tingling fingers -- and for several months, no one knew why.

"I knew something wasn't right," Harvey recalls. "I told [pitching coach] Dan [Warthen] and [manager] Terry [Collins] throwing a baseball was one of the easiest things I do. And to go through a process like that, of really not having an idea why it's so difficult to throw, it became pretty tough."

Rangers pitcher Tyson Ross endured a similar ordeal last season. Ross was the Padres' Opening Day starter, then struggled with shoulder and arm injuries all season long before a diagnosis of TOS was finally made.

"It was really a mental grind for me," said Ross. "We checked every box and figured out what it wasn't before we figured out what it was."

According to Thompson, these diagnostic struggles are common and understandable -- especially in pitchers, whose arms are often sore, fatigued, achy or just generally not 100 percent.

"Thoracic outlet syndrome has been quite overlooked, especially in the professional athlete, because something always hurts," said Thompson. "A person with thoracic outlet syndrome might have pain in the shoulder, and might have an MRI that shows mild to moderate changes -- and might even have shoulder surgery for something else, like a rotator cuff or a labrum. Only when that doesn't correct the problem do they look for TOS."

Thompson believes with the growing number of big league pitchers who have had surgery to correct TOS (Phil Hughes, Jaime Garcia , Christopher Young and Chris Carpenter have also undergone the procedure), the condition will be better understood and more quickly diagnosed in the future.

The thoracic outlet lies at the lower part of the neck, beginning just above and behind the collarbone and extending into the upper arm and chest. Thoracic outlet syndrome results when the nerves and blood vessels in this area are compressed.

Neurogenic TOS, in which the brachial plexus nerves that serve the entire arm and hand are compressed, is by far the most common type of TOS. It makes up between 85 and 95 percent of cases -- including Harvey's -- and results in pain, weakness, fatigue and numbness or tingling in the arm or hand, particularly with activities in which the arm is elevated.

"The anatomy of the thoracic outlet is such that the nerve compression occurs more quickly and readily with arm elevation, which tightens the anatomy further," said Thompson. "People who do repetitive-motion tasks with the arm in an elevated position may have a higher frequency of developing symptoms, as those actions enhance and aggravate their symptoms. Pitchers do the most throwing, and the biomechanics of a baseball pitcher are more rigorous on the arm than any other activity I'm aware of."

Those who develop TOS often have a congenital variation in their anatomy that predisposes them to the condition; in other words, there is just less space in the thoracic outlet to begin with. TOS can also be the result of either a repetitive strain or acute injury that results in scarring, tightness and spasm of the scalene muscles, which attach to the first rib. When the scalene muscles are tight, they pull the first rib closer to the collar bone, causing less space in the thoracic outlet and more compression of the structures within.

During TOS surgery, both the rib and the scalene muscles are removed to ensure there will be enough room for the nerves in the thoracic outlet.

The only study of thoracic outlet syndrome in MLB pitchers was done by Thompson with help from the statisticians at PITCHf/x, and it was published in February. All 13 MLB pitchers known to have had the surgery at the time were included in the study. Of them, 10 returned to play in the Majors after the procedure. There were no significant differences pre- and post-op for 15 traditional pitching metrics -- including ERA, WHIP, BB/9 and strikeout-to-walk ratio.

Hughes, who also had his surgery last July, has talked about potentially plating his rib with some sort of precious metal. Harvey recalls a college teammate who had the surgery and kept his rib in his pocket each time he pitched. Royals Minor Leaguer and former first-round Draft pick Kyle Zimmer has his in a little mason jar at his mother's house and won't let her throw it away -- even though he thinks it's gross. Zimmer's teammate, Young, preserved his using Thompson's protocol and plans to put it in a case to display on his office wall, he says, as a symbol of perseverance for his children.

Certainly, Thompson has seen everything done with the removed ribs: earrings, necklaces -- one person even set it with a diamond. Harvey, though, is more concerned about what he's doing on the actual diamond.

"Obviously, it was a very disappointing season for me last year," said Harvey. "[Going from] finally feeling healthy after Tommy John surgery to what happened last year and going through another surgery, there's a process here. I'm just glad that I'm down here healthy and ready to go."