Joel Embiid's foot injury from a doctor's perspective

Joel Embiid’s foot injury has altered this draft irreparably. Indications are that the Cavaliers were ready to make Embiid the number one overall pick.  But then disaster struck.

Embiid was diagnosed with a stress fracture of the Navicular bone in his foot, which is expected to keep him out 4-6 months, according to reports from ESPN and Chad Ford.  In order to understand more about this injury, we spoke to physical medicine and rehabilitation doctor “AllThatAmar” (obviously a pseudonym to keep his basketball life separate from his work) about what the short and long term affects of a navicular bone stress fracture are. He also runs SLCDunk of SBNation, and you should all go there to check out basketball stuff. Here’s a quick bio:

AllThatAmar is the Managing Editor and apparently also the lead writer for the SB Nation team site SLC Dunk. His Clark Kent job as “that PM&R doc who is always on twitter” allows for him to mix sports writing with sports medicine — where he is equally poor at both. The fact that this part is written in third person by AllThatAmar is evidence of that. Follow him on Twitter @AllThatAmar)


1. First, can you just give us a little background on what the Navicular bone is and where it exactly is in the foot? What bodily functions is it responsible for, and what kind of stress does it take on?

The Navicular bone is the morphological analog of the Scaphoid bone in the hand. What does that mean? Well, it’s a smaller bone that articulates, or is connected to, many other bones in that same area. It’s on the medial part of the foot (inner foot), and acts as a buffer zone for the bones of the ankle and heel with the bones of the toes.

The Navicular’s role in what a foot is supposed to do is to help support the more important bones, and aid in flexibility. It is not as big and strong as the higher impact shock absorber bones in the heel / ankle (talus, calcaneus). And it does not receive the blood flow of the smaller bones that end up forming the toes. Blood flow is important for bone health. So it’s stuck in the middle, if you will, and takes strain from its location as it forms joints with five other foot bones. During normal human operation the bone is perfectly suited for what it does and can do as a part of the system that forms the foot. In situations of strain (physical exertion like a forced march in the Armed forces, or high impact sports with a lot of running, jumping, and changing direction) it is less suited for what humans put it through. As a result, when more forces are applied to a system, the strain has to be accounted for. The toes are filled with muscles and a healthy dose of blood supply. The bigger bones are just stronger and can take more of a beating. The Navicular does not deal with this increased system strain as well as some other bones in the body, and fractures of this bone are actually increasing in prevalence (either through better detection, or more people hurting themselves this way).

I would not characterize most of these stress fractures to be a product of an excessive one time force (acute injury), like what you seen when an athlete breaks a leg or arm or something. This is more like what happens in a kid’s popsicle stick bridge contest, where excessive stress over time weakens the system – and eventually the weakest point gives away (possible acute injury as a product of chronic strain). For the foot the weakest point for high impact athletes appears to be the Navicular bone.

2. What makes a Navicular injury so problematic for an athlete in the short term? When can someone expect to start working out again after this injury, and how long would you expect it to take to get back into game shape?

The problem with a stress fracture to the Navicular is two-fold. The first is just where it is, in the body.

I am going to assume that most of your readers have at one point in their life played SimCity, or some other city building game. The utilities of your city need to be connected to each part of your city for those sections to be connected properly. If you don’t, then some buildings just aren’t connected to the power grid and they will not benefit from all the other things you connected to it. Anatomically the Nav receives poor blood flow, and blood is like the electricity of your body. Because of this problem the bone is unable to heal itself as quickly as possible. You could even simplify it by saying that the vascular structure of the body (the power lines) just does not go to the Navicular enough, complicating that issue of anatomy. Because of where it is, or how it is connected to the body (not just the other foot bones) injury recovery is a dicer thing.

Which brings us to the second part – today the structural problem of the stress fracture seems to be remedied by getting pins inserted to the bone. This is, in my mind, a drastic situation that we do not have many alternatives for. As a corrective procedure this makes sense, if the bone you put pins into is healthy. Bone health is always going to be a question for the Nav though, because of blood flow. The major risk that then happens over time is the risk of Avascular Necrosis, which is as bad as it sounds. For Joel Embiid, I think he can recover from this initial injury in a few months. But this is a kid’s popsicle stick bridge injury, and the weak point is already made weaker by getting the fracture in the first place.

3. What is the long-term impact of this injury? 

This is the issue, because this foot injury is going to be something he will have to accommodate for his entire career. Once your foot gets hurt like this it’s one thing to let it heal, go through physiotherapy, and then go on with your life. But Embiid’s job is going to be one where he has to continually run, jump, change direction, and put his body through strain that the normal human body was not meant to go through. And yes, he’s a professional athlete with a body that is stronger and larger than the vast majority of the human population. That does not make him superman though. He doesn’t have more blood flow to his Navicular than anyone else.

These problems affect bigmen more because they are larger, they have a heavier mass, and they usually have to jump the most (tip off, jump balls, going for rebounds on every play, etc). Their bodies also go through the heaviest strain from normal things like running north / south. There is no mystery here, this is just physics. A smaller, lighter player produces less strain on the Navicular bone. So, the types of players who are most prone to getting this injury (and yes, the list of basketball players with navicular stress fractures reads like a list of some of the most injury prone bigmen in recent years: Yao Ming, Zydrunas Ilgauskas, Curtis Borchardt, etc.) are the ones who are at the highest risk of re-injury. There are only so many pins you can put into that bone, and if it’s not getting the blood flow it needs then it’s never going to be healthy enough to accept pins and let them do their job. Eventually the bone becomes weaker and weaker, and can die. This is that Avascular Necrosis issue. You can imagine how much fun it must be for a bone joint (of which the Navicular is kind of a big deal in the foot) to try to work properly after the cell death of one of the bones that touches five other foot bones.

Newer techniques are being developed to remedy this situation, but when I was in medical school this diagnosis led to an easy conclusion – joint replacement. How well would joint replacement look on the medical history of a young 20 year old who has to run and jump and change directions all day? Sadly, Embiid is going to need some progressive, radical new forms of treatment and lots of rest time in between injuries if he wants to keep the Navicular bone he was born with. It is likely that he’s not going to be an 82 game a season player like a John Stockton.

4. Given that a good portion of Embiid’s value comes from his athletic fluidity and footwork, would you expect him to be able to make a full recovery?

Yes and no. When Embiid is cleared to play he should be still way more athletic and mobile compared to the other bigmen he plays against. He’s just not going to be 100% for very long. The effects of having a stress fracture can limit him in the days/weeks before it may take to diagnose the NEXT time he has one. He will be playing with pain. His minutes will be lower than people would wish. Joel will still produce, but the team will have to monitor him so that their high draft pick doesn’t spend more time in a suit than a jersey. Oh, and bones with pins in them are less flexible than non-structurally augmented bones. So that can make them crack or break more as it cannot ‘go with the flow’ and bend at normal levels. So that could result in more stress fractures.

Oh, and stress fractures of the Navicular sometimes happen when there is a rapid change in activity level – like a guy coming off of the disabled list and cleared to run again. Eventually it will be a challenge to balance the time he needs to avoid that popsicle stick bridge collapse from chronic strain and the time the team needs him to be on the floor, because he’s a great young talent.

5. Without knowing the absolute severity of Embiid’s injury, would you draft someone that has a Navicular injury or would you take him off your board? Particularly with Embiid, if you would be willing to draft him, at what pick do you think the reward outweighs the risk?

Back in 2002 the Utah Jazz traded up to pick Curtis Borchardt, who had pins put into his Navicular bone in a pre-draft surgery. He was checked out and labeled good to go. He wasn’t, though. And before the draft I knew he wouldn’t be, and I cried to the heavens when the team decided to get him. I would be a hypocrite right now if I wasn’t worried about Embiid’s injury reduced future.

In the SB Nation mock draft I did pick him #5. So I guess I have more faith in the advances to podiatric medicine than I do in passing on such a talented player. His talent isn’t on trial here, but his body is. Moving away from my obvious concern and support for this kid, and looking at just the facts, I worry about his value to a team over his career. Players like Yao and Big Z had abbreviated careers – maybe not as long as you’d want, but when they were healthy they helped their teams win games. But they had stress fractures in their Navicular during their NBA playing days. Embiid had his first before he even went through summer league. He is a risk, but unlike a guy like Borchardt, is likely to pay some dividends to the team that takes a chance on him.

A Top 3 player is supposed to be a franchise savior, and be expected to play in a lot of games, and play a lot of minutes. Embiid just cannot be penciled in to do this; it would be unfair for the drafting team, and unfair to him to expect that. I do not see many teams passing on him after that. This would be a no-brainer if he was not as skilled and talented as he is. If he was projected to be a bubble first rounder with this injury he would go undrafted. He will be picked in the lottery – there are a few desperate teams out there who need a star, even if he plays 50-60 games a year.

Sam Vecenie

Sam Vecenie is the editor-in-chief of Upside & Motor, as well as an editor at Hardwood Paroxysm. He likes to spend endless hours watching random NCAA game film, and scouring the internet for international basketball. You can find his other work at SBNation's college basketball platform.