Navicular stress fractures are one of the most common types of stress fracture affecting athletes who do sports that involve sprinting, changing direction quickly, and jumping. It also affects long distance runners. It is classed as a high-risk stress fracture because it often takes a very long time to heal, or it requires surgery. Remember, if you need more help with an injury, you're welcome to consult one of our physios online via video call.
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What is the navicular?
The navicular is a small bone on the inner part of your mid-foot (see picture below). A navicular stress fracture is an overuse injury that develops when you work the bone too hard and it doesn’t get enough time to recover between training sessions.
The middle third of the navicular has a very poor blood supply. It is thought that this makes it harder for that part of the bone to recover and repair after sport or exercise, which predisposes it to stress injuries.
Causes of navicular stress fractures
Training errors (a sudden increase in training intensity and/or not enough recovery time between training/sport sessions) are the main causes of this injury. Other factors, like a vitamin D deficiency or not taking in enough calories, may also play a role. Excessive pronation or restricted ankle dorsiflexion (tilting your foot upwards towards your knee) may also predispose you to this injury.
Symptoms of navicular stress fractures
A navicular stress fracture typically causes a poorly localised ache in the mid-foot that radiates along the top, inner part.
The pain is usually mild at first and without a clear cause and then gradually becomes more intense.
Initially, it’s only painful while you train or play your sport, and it feels better soon after. However, if you ignore it and continue to train and/or do sport in spite of the pain, it may also start to ache when you’re walking, standing, or even just sitting.
It may hurt when you press on the navicular bone, but not always.
Diagnosis
Your physio or doctor will use your clinical history (how your pain started and how it behaves) plus their physical examination to make a diagnosis. If it hurts when you press on the navicular bone, it’s very likely that you have a navicular stress fracture.
An X-ray may be useful to rule out other conditions like tarsal coalition, but it’s not very good at picking up navicular stress fractures as such. MRI scans are best for diagnosing navicular stress injuries.
There are other common conditions with similar symptoms that should be excluded before you can be sure that your pain is caused by a navicular stress fracture. Some of the main ones include tibialis anterior tendinopathy, tibialis posterior tendinopathy, and a sprain of the mid-foot.
Treatment of navicular stress fractures
If your scan showed a bone stress reaction (irritated bone but no fracture) or a nondisplaced navicular stress fracture (i.e. no part of the bone has moved), then you’ll very likely be able to recover if you follow a conservative treatment approach (see below).
If you have a displaced fracture (i.e. the fractured ends of the bone are out of alignment with each other), you will likely require surgery.
Conservative treatment usually consists of:
1. Six to eight weeks of immobilization in an orthopaedic boot and absolutely NO weightbearing. This is crucial; the research clearly shows that you have to take the load off your foot 100% for at least six weeks if you want the conservative treatment to succeed. You can maintain and improve your cardiovascular fitness through non-weightbearing activities such as swimming.
2. Once the boot is removed, it’s important to ensure that you get full range of motion back in your ankle and foot joints, which will be stiff due to their time in the boot. This can be done with exercises but also hands-on mobilisation of the joints by a physiotherapist.
3. You should also ensure that you strengthen all the muscles that control your foot and ankle. Start with lightweight exercises in straight lines, but gradually progress to more complex movements that simulate the forces created by your sport and with heavier weight.
4. Proprioception exercises (e.g. balancing exercises) are important to rebuild your foot and ankle’s position sense, i.e. how well your brain can control it when you’re not looking at it.
5. Your foot muscles and bones will need some time to get used to carrying your weight again. This is why it’s important not to rush into sport but rather to increase your time on your feet and the level of impact gradually. First get used to normal amounts of walking, then add in run-walk sessions, then continuous running, and finally, transition into more explosive, multi-directional, or high intensity runs. This process can take three months or longer.
6. Making sure that your vitamin D levels are optimal and your diet contains all the nutrients you need can also help your healing.
Expected recovery time
It usually takes about 12 weeks (after the boot is removed) to regain your full strength, control, and mobility and to make a safe return to full sport. So, this means a total rehab time of around five months. This may sound like a long time, but your body needs time to repair and regain it’s full strength. Also, the navicular bone’s poor blood supply doesn’t help.
Surgery for navicular stress fractures
Surgery most often entails fixing the fracture with one or more screws and sometimes a bone graft.
There’s currently a bit of an argument between medical professionals about in which cases and how soon surgery should be considered for navicular stress fractures.
Some argue that it should be the treatment of choice for elite athletes or patients with high physical demands, as this will help speed up return to sport and prevent recurrence. But the evidence is pretty contradictory, and there’s currently not enough high-quality research to support or refute this view.
Others argue that it is better to allow the body to heal itself and to avoid the possible complications (both short and long term) of surgery, and that surgery should only be considered if conservative treatment (as outlined above) has failed.
How we can help
Need more help with your injury? You’re welcome to consult one of the team at SIP online via video call for an assessment of your injury and a tailored treatment plan.
We're all UK Chartered Physiotherapists with Master’s Degrees related to Sports & Exercise Medicine. But at Sports Injury Physio we don't just value qualifications; all of us also have a wealth of experience working with athletes across a broad variety of sports, ranging from recreationally active people to professional athletes. You can meet the team here.
About the Author
Maryke Louw is a chartered physiotherapist with more than 15 years' experience and a Master’s Degree in Sports Injury Management. Follow her on LinkedIn and ResearchGate.