Taking a closer look at the Joel Embiid injury: How bad might it be?

The news of Joel Embiid requiring surgery to fix a fractured navicular bone in his right foot wasn't exactly the Embiid news Bucks fans--and any NBA team fanbase with a shot at Embiid--were hoping to hear as draft night grew closer. This latest curveball now figures to weigh heavily on the decision making process for John Hammond and company, and the risk of taking Embiid at #2 may now be too high for them to want to roll the dice on it, even if Embiid still has the tools to be the best player from this class.

Thankfully there is still a little bit of time left for the teams interested in Embiid to weigh those risks and make as calculated of a guess as they can when it's their time on the clock Thursday. It's certainly not the preferred way to spend the next six days, but there is plenty of information out there on this type of injury. Let's take a closer look at some of that.

So what exactly is a navicular stress fracture?

A navicular stress fracture is usually an incomplete crack of the navicular, a bone in the mid-foot above the arch. We don't know to what degree Embiid suffered this fracture, but this type of injury generally occurs as a result of excessive weight bearing activity, also referred to as an ''overuse injury."

"A muscle (known as the tibialis posterior) attaches to the navicular bone. When this muscle contracts, a pulling force is exerted on the bone. Furthermore, weight bearing activity places compressive force through the navicular. When these forces are excessive or too repetitive and beyond what the bone can withstand, bony damage can gradually occur. This initially results in a bony stress reaction, however, with continued damage may progress to a navicular stress fracture.

A stress fracture of the navicular typically occurs over time with excessive weight bearing activity such as running, sprinting, jumping or dancing. They often occur following a recent increase in activity or change in training conditions (such as surface, footwear or technique changes etc)."

Okay, so these symptoms check out. Embiid maybe isn't use to this type of workout schedule--even if it's less frequent than other draft prospects, it still isn't exactly ''normal" to a guy who just picked up the game a handful of years ago. Also consider that Embiid had been a beach volleyball player before picking up basketball. It may not be likely that the repeated stress of jumping and landing on your bare feet had anything to do with this injury, but it's also not worth ruling out at this point. For all we know, the volleyball could have set the stage for this injury, even if the fracture was a bit delayed.

Is Embiid the first NBA player to have this type of injury?

Certainly not. ESPN's Kevin Pelton detailed the history of players who have suffered from this injury, and the results spread across a wide range of outcomes. Generally, a navicular stress fracture is more concerning for big men--more height and weight leads to more pressure on the foot--but there have been a few instances in which players have returned from the injury with no glaring effects of the injury.

Zydrunas Ilgauskas (played 756 of a possible 902 games)

Ilgauskas offers perhaps the most hopeful outcome for Embiid. Ilgauskas' navicular injury -- which kept him from playing during 1996-97, his rookie season -- was again suffered five games into the 1998-99 season, limited him to 29 games over the next three seasons.

But remarkably, after returning to the court in December 2001, Ilgauskas played at least 78 games each of the following five seasons, moving past his foot issues to become a two-time All-Star. He remained a contributor through his retirement in 2011 at age 36.

Kevin McHale (played 419 of a possible 492 games)

A broken navicular bone was the injury McHale famously played through during the 1987 playoffs, helping the Boston Celtics get to the NBA Finals before losing to the L.A. Lakers. McHale underwent surgery over the summer, which cost him the first month of the 1987-88 season. Thereafter, he played in 64 of 68 games, and missed just four total over the following two seasons. He made the All-Star team four times after the navicular injury before slowing down and retiring at 35.

It's a good sign that it's not entirely doom and gloom with this injury. While both Ilgauskas and McHale had to miss some time, they were both able to return to a solid level of productivity thereafter. In the case of Ilgauskas--who similarly suffered this injury in his rookie year--perhaps by being able to detect the injury before even more stress was placed onto it, the were able to let it fully heal without any mandate for him to perform, allowing him to come back when he was more than healthy. Maybe Embiid will be lucky and had this spotted earlier than usual. Maybe the team that selects him can afford to let him get beyond healthy and there won't be any lingering effects.

Conversely, the injury could continue to show up, no matter how healthy Embiid or team doctors feel that he is. He could then possibly wind up more like these guys.

Bill Walton (played 259 of a possible 738 games)

While playing through pain in the 1978 playoffs, Walton fractured his navicular bone in Game 2 of the Portland Trail Blazers' series with the Seattle SuperSonics -- the last he'd play for the Blazers. After sitting out the entire 1978-79 season, Walton signed with the San Diego Clippers, for whom he'd play just 169 games over six years, missing all of 1980-81 and 1981-82.

Following surgery to reshape his arch, Walton was eventually able to contribute to the 1986 champion Celtics and win the NBA Sixth Man Award. That would prove his last hurrah, as Walton played just 10 games during the following season, his last in the NBA, before being diagnosed with another navicular fracture -- one that, ironically, prompted McHale to play through the same injury.

Yao Ming (played 82 of a possible 246 games)

At 7-foot-6, Yao had already dealt with foot and knee trouble, including a fractured fifth metatarsal bone in his foot, when he was diagnosed with a stress fracture of his navicular bone in February 2008. The Houston Rockets hoped at the time that they'd caught the injury early enough to prevent it from becoming a problem, and Yao returned from surgery to play in the Beijing Olympics and 77 games in 2008-09, when they won their first playoff series since 1997.

During the conference semifinals against the Lakers, however, Yao reinjured the navicular bone. He underwent reconstructive surgery and was ruled out for the entire 2009-10 season before attempting to return the following season. Another stress fracture to his ankle suffered after five games led to Yao's retirement at age 30.

Ugh. I hope this won't be the case. Regardless of if the Bucks select Embiid or not, it just isn't fun to see someone with such immense potential possibly have their career knocked off the tracks by a bum foot.

How likely is it that this injury can be fixed?

Sports Illustrated's Chris Mannix looked into this question today. He spoke with Dr. Kenneth Hunt, Assistant Professor of Orthopedics at Stanford, and the results were encouraging, but not completely alleviating.

"The most common treatment is to make small incisions to place one or two screws across the fracture to stabilize it," Hunt said. "If the fracture is displaced, a bone graft can accelerate healing."
Hunt noted that despite the high profile examples of athletes who have battled recurrences of a navicular fracture, "the healing rates of this fracture are high."

"The majority of these injuries will heal completely," Hunt said. "Getting to it early is a good prognostic sign. In his case, it appears it was treated early and appropriately. In the cases I have seen, the athletes that have recurrent fractures have high arches and stiff feet. They can develop large spurs in the adjacent bones. But again, to the majority of athletes this will heal and not be an issue in the future."

As for recovery time, Hunt said that players generally resume basketball activities in 4-6 months and are ready to play in nine months, though in some cases it can be closer to a year.

Just the possibility that Embiid could miss parts of next season could be enough to drive several teams at the top away, multiple executives told SI.com.

As Mannix also stated in that article, there still are plenty of variables that could swing Embiid's future one way or the other, and that may scare teams like the Bucks off. The good news is that Milwaukee is one of two teams (Cleveland being the other) that have access to Embiid's medical information, so they should lead the pack in terms of doing their due dilligence on this situation. It's not the research they were hoping to be conducting this close to the draft, but at least they'll have as educated of a guess as anyone. We'll just have to wait and see what conclusion they've come to on the 26th.