No, Neymar Can't Come Back This World Cup. That Could Paralyze Him.

To the surprise of very many, when Neymar went down in the 86th minute against Colombia on Friday, the 22-year-old striker wasn't faking. After being kneed in the back by Colombia's Juan Zúñiga, Neymar was carried off the field and taken directly to a hospital, where doctors soon discovered that he'd suffered a fractured vertebrae in the lumbar region of his spine, a situation that can potentially be a medical emergency.

"Unfortunately, he's not going to be able to play," Brazil's team doctor, Rodrigo Lasmar said, several hours after the injury. "It's not serious in the sense that it doesn't need surgery, but he'll need to immobilize it to recover."

Teams are understandably cagey about revealing information about the health of their players—U.S. coach Jürgen Klinsmann was apparently bluffing when he said that striker Jozy Altidore was ready for last week's game against Belgium—but the news about Neymar was swift and unequivocal. His World Cup was over.

That hasn't stopped a little hope trafficking from slipping through. Unsubstantiated reports claim Neymar might be able to play in the World Cup final if he's willing to get doped up on painkillers before the game. Let's take a look at why that's not only implausible, but potentially very dangerous; attempting to play a competitive soccer game so soon after the injury that Neymar suffered wouldn't simply cause a number of complications—it could leave the Brazillian star paralyzed.

It's useful to begin with a brief primer on the basics of spinal anatomy. The human vertebral column consists of 33 vertebrae, which span the length of the spine, from neck to butt. Starting from the top, there are seven cervical vertebrae of the neck (C1 to C7); twelve thoracic vertebrae of the chest and abdomen (T1 to T12); and five lumbar vertebrae of the lower back (L1 to L5). These 24 vertebrae have joints that allow movement from side-to-side and from front-to-back. (They're the reason you can touch your toes or swing a golf club). Further down, in the tailbone, are the remaining nine vertebrae in the sacrum and coccyx, which are fused together. They can't move, and really just serve as protection for the bottom of the spinal cord.

Neymar reportedly fractured the 3rd lumbar vertebrae in his lower back, a condition that can potentially destabilize the spine. When someone suffers a vertebral fracture, the most important thing to assess is the stability of the spine. An unstable spine can compromise the spinal cord, which can potentially lead to paralysis. In fact, the manner in which FIFA's doctors removed Neymar from the field—he was carried off on an unrestrained stretcher—could have, in the very worst case, caused paralysis from the jarring motion. Ideally, you'd see players' spines restrained — and their neck stabilized if the injury is higher up — anytime someone needs to be carried off due to a possible spine injury.

When he arrived at the hospital, it's unlikely that anyone knew the extent of Neymar's injury or whether he'd need surgery. The first thing a doctor will look for is evidence of nerve damage and will poke and prod at patients to determine if their nerves are working properly. Doctors encountering acute, excruciating back pain also check for something called saddle anesthesia, which is numbness in the groin similar to what a city slicker would get from riding a horse. This can herald a medical emergency, one in which the spinal fracture is causing impingement of blood vessels or nerve tissue, and can require immediate neurosurgery to fix. The other thing doctors look for is bowel or bladder dysfunction. If a patient can't hold onto his pee or poop, it could also be an emergency that requires surgery. Then we assess leg strength, coordination, and reflexes.

The first reflex I check for in a patient with agonizing back pain is the cutaneous abdominal reflex—which involves stroking the bellybutton—to see if the abdominal muscles appropriately contract. Then I take out my reflex hammer and tap on the knees, to see if the patellar reflex is intact. Lastly, I check for something called the anal wink, by stroking the skin in and around the anus to make sure the anal sphincter is contracting properly. If it doesn't contract (or wink), the pudendal nerve may be compromised, which can also constitute a medical emergency necessitating neurosurgery. Neymar undoubtedly received an anal probe when he arrived at the hospital on Friday.

This may seem like overkill, but it's not. The part of the body that Neymar injured is a hub of neurologic activity but the nerves that travel near his fractured vertebrae may be difficult to identify just by talking with him about what hurts. If a patient with severe back pain does have neurologic impairment, the next step is to obtain imaging, usually in the form of a CAT scan or MRI. When Brazil's team doctor announced that Neymar would not need surgery, it's because the history and physical revealed no neurologic defects and because the imaging showed no evidence of spinal cord compression or major neurologic injury. All good news, and it bodes well for his recovery.

So what's next?

The centerpiece of Neymar's rehabilitation will involve physical therapy, which for a lumbar fracture like his typically lasts several months (an elite athlete can often shorten that time substantially; we'll know much more about his timetable for recovery in the coming weeks). The goal for rehabilitation will be to strengthen his core abdominal muscles to stabilize his lower back and to improve the range of motion in his hips so that pain-free movement can occur above and below the site of injury.

Depending on how rehab goes, you may also see him wearing a stabilization belt or a Boston Overlap Brace, which provides support for the muscles and bones of the lower back. (About eighty percent of users find it helpful). While this is going on, he'll likely be receiving a slew of pain relievers—things like Tylenol and ibuprofen—or even stronger medications like OxyContin if the pain becomes unbearable.

For the next few days, however, Neymar will be asked to stay off his feet and get as much rest as possible. Many patients with lumbar fractures are instructed to lie in bed for the majority of the day, which may be difficult for a guy accustomed to being so active. (That's what Brazil's team doctor was referring to when he said that Neymar will "need to immobilize it to recover.") The good news is that young, healthy soccer players who suffer this type of injury usually make a full recovery. Neymar isn't ruined, at least. Brazil's team doctors expect Neymar to return to play in about 40 or 45 days, just in time for the start of his club season in La Liga.

The idea that he might return to play in time for the World Cup final is sheer lunacy. If his spine isn't fully healed, or if he's dealing with an unstable fracture, he could suffer another injury—one far more devastating—that could leave him paralyzed.


Matt McCarthy is an assistant professor of medicine at Weill Cornell Medical College in Manhattan. You can follow him on Twitter here.