Foot injuries are especially difficult for athletes, and their lifestyle makes them more susceptible to traumatic injuries or continuous stresses on bones and muscles. Often, treatment for these injuries requires either rest or a surgical procedure; both options strain an otherwise rigid training regimen. Now, if an injury was missed, the consequences could be devastating.
A fracture of the navicular bone of the foot is one such insidious injury that often goes undetected for a prolonged period.
In general, the human foot has three sections-- the forefoot where the toes are, the midfoot at the arch, and the hindfoot towards the heel. The little boat-shaped bone in the inner midfoot is called the navicular bone. The bone has several attachments to muscles and other bones to keep the area stable. Like any part of the body, it depends on blood and the vascular highways to carry nutrients. However, the navicular bone, in particular, has fewer blood vessels going into its center.
The midfoot itself doesn't get fractures all that often. Still, navicular fractures represent about a third of all foot stress fractures, especially in younger athletes.
So how does a bone so cushioned between other bones, muscles, and sinews get fractured?
While it is true that some navicular fractures are caused by direct trauma to that area of the foot, these are rare in comparison to stress fractures. Remember that part in the bone's center that gets less blood and nutrients? When a part of the anatomy that is weaker due to the lack of blood vessels gets the brunt of repetitive stresses such as in weight-bearing exercises or marathon training, it can result in a navicular fracture.
Microfractures, specifically. Often, these initial fractures are not seen in plain X-rays or even in a computed tomographic (CT) scan. These hidden fractures result in a cascade of delayed diagnosis and continued bone injury until such a time that the progressive stress causes a fracture line that is visible in the regular X-rays.
Because this is an injury that eludes the usual first-line diagnostics, several researchers have tried to figure out who is more likely to get these fractures. While there have been no sure answers, studies have hinted at those with a condition called pes cavus or a rather foot arch, who wear wide-heeled shoes, [who use improper equipment or technique. In general, exercise training errors and overuse injuries all increase the risk of a fracture. 
To track and field athletes, the most commonly affected by navicular fractures, it may feel like a vague kind of pain along the middle area of the foot especially over the arch. The pain would shoot up when the person is engaged in activities that stress the bone, such as running or jumping. Eventually, the pain becomes progressive--- it will be felt earlier when doing certain activities and well after they've stopped running.
Those who have this injury often delay going to their healthcare practitioner because it's not that bad. They may unconsciously use their forefoot more often in walking or running to alleviate the pain. Some may take about a week's rest from training. Though this may improve the pain, it keeps the athlete blind to the possibility of a growing injury.
And even when they've decided to go to a doctor, the foot itself may not look injured. The joint can move in all directions without pain. The healthcare practitioner will likely not note any deformity, swelling, or signs of bleeding. The foot can feel sensations perfectly well. Its muscles are likely to be as strong as any other uninjured foot.
Should the healthcare practitioner be familiar with this entity, the most sensitive tell is when a specific part of the foot dubbed as the "N spot" is particularly tender when pressed. Pain can happen on its own and persist on its own, like an annoying background noise that you can't shake off. But tenderness is pain that can be induced and replicated in the doctor's office. Sometimes, this can point to a fracture unseen by as many as two-thirds of navicular fracture X-rays.
Once the diagnosis of a navicular fracture is set, the next order of business is the proper treatment. There are three ways to treat a navicular fracture. One way is through surgery, and the other two methods are non-surgical with a non-weight-bearing and a weight-bearing option. Since the people who usually get these fractures are young athletes, there has been greater pressure to use surgical treatments or the weight-bearing option to get them back in the field as soon as possible.
However, a meta-analysis that studied 313 pieces of research on the treatment of navicular fractures came to the opposite conclusion. It turns out that non-weight-bearing immobilization gives statistically similar results to if a patient got surgery. But to get the benefits, it must be a complete cast immobilization for around 6 to 8 weeks, and only then can one gradually put weight on the foot. Otherwise, if the patient doesn't get surgery but permits weight-bearing, the treatment becomes less effective.
A more recent 2015 study found that surgery actually showed inferior outcomes compared to the non-surgical non-weight-bearing treatment. After the surgery, it took significantly longer to return to work, greater persistence of pain, and more were unable to wear their normal shoes.
Surgery is also fraught with complications. In particular, secondary osteoarthritis was seen in as much as 85% of those who underwent surgery compared to 43% in those who did not. Not to mention, it's also the more expensive path!
Also See: A knee scooter for broken foot might be helpful to avoid having the foot touch the ground while moving or traveling. Ask your doctor for options.
Time to heal
The navicular bone fracture healing time is often cited to be around 6 to 8 weeks for most people. If you recall in our treatment, this is the amount of time the foot is usually put into a cast. However, the bone mustn't just heal what was broken-- it must also strengthen itself for continued activity.
Researchers have found that 96% of navicular fractures that have been treated for 6 weeks were able to return to their usual activities at an average of 4.9 months after treatment. This is in comparison with those treated surgically who could return at an average of 5.2 months later.
Navicular fractures are generally rare and thus may be difficult to identify. This can lead to a delay in diagnosis and even improper treatment. Thus, keeping ourselves informed and knowing when to see a professional is the best tool we can have in our pockets.
- Golano P, Fariñas O, Sáenz I. The anatomy of the navicular and periarticular structures. Foot Ankle Clin. 2004;9(1):1-23. doi:10.1016/S1083-7515(03)00155-4
- Gheewala R, Arain A, Rosenbaum AJ. Tarsal Navicular Fractures. [Updated 2021 Jul 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK542221/
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- Torg JS, Moyer J, Gaughan JP, Boden BP. Management of tarsal navicular stress fractures: conservative versus surgical treatment: a meta-analysis. Am J Sports Med. 2010;38(5):1048-1053. doi:10.1177/0363546509355408
- Coulibaly MO, Jones CB, Sietsema DL, Schildhauer TA. Results and complications of operative and non-operative navicular fracture treatment. Injury. 2015;46(8):1669-1677. doi:10.1016/j.injury.2015.04.033