A navicular stress fracture is a common overuse injury in active athletes. We see this injury in runners, basketballers, track and field athletes, and soccer players. In many cases, the diagnosis is late. So, how do you diagnose and treat a navicular bone stress fracture?

Why does a navicular stress fracture occur? 

 

navicular stress fracture

 

There are several reasons why the navicular bone is susceptible to bone stress.

First, the bone is positioned in the mid-foot. This means high forces are applied to the bone during a foot strike. Second, the blood supply to the central portion of the bone is poor, which means that healing is lacking. Finally, as the pain is mild in the early stages, most people push on with activity leading to a greater chance of bone stress progression into a fracture.

Risk fractures for a navicular stress fracture include abnormal foot biomechanics such as high arches or flat feet, a sudden increase in training volume or intensity and relative energy deficiency syndrome (RED-S).

Symptoms 

Usually, pain is vague and not specific to any one point. Athletes often point to the ankle, mid-foot, or inside arch of the foot. Generally, pain is worse with training and improves with rest. Athletes usually keep training as the pain is not as bad as other stress fractures. As a result, this leads to a delay in diagnosis.

We suspect a navicular stress fracture if there is tenderness in the body of the navicular bone. In 80% of cases, people are tender at the ‘N’ spot. Sometimes, there is stiffness in the ankle and mild focal swelling in the mid-foot.

Usually, X-rays do not detect navicular stress fractures. Often, we need an MRI scan to see swelling and a break in the navicular bone. A CT scan is helpful to define the fracture a bit more, including whether it has the potential to heal or needs surgery. Sclerosis at the fracture sites signifies poor healing potential. Also, repeat CT can be used to monitor healing.

Treatment of a navicular stress fracture

boot for calcaneal stress fracture

We treat most cases without surgery. However, treating this fracture right the first time is essential as healing is poor.

We recommend a cast or walking boot with crutches for six weeks. Then, transitioning from a walking boot to a shoe should take 2-4 weeks. This should be followed by six weeks of gradually returning to running and sport. At this time, it is essential to do intensive therapy to return movement and strength to the ankle and calf. Balance exercises are crucial. Also, proper shoes and orthotics can help reduce the load on the navicular.

Navicular stress fracture surgery

Sometimes, pain may not settle or can return if people do too much. We often term this process non-union. In these cases, we recommend surgical fixation to help with healing. Usually, we do surgery with a screw to fix the fracture, followed by non-weight bearing in a boot for at least six weeks. Surgery is also recommended if there is a complete fracture at diagnosis.

Other frequently asked questions about navicular stress fracture:

What are other causes of pain near the navicular bone? 

Other possible causes of mid-foot pain include tibialis posterior tendonitis, mid-foot arthritis, accessory navicular syndrome, deltoid ligament injury and tarsal coalition. 

What other treatments help bone healing with a navicular stress fracture? 

Eoxogen or low pulsed ultrasound has shown potential in healing complex stress fractures. It needs to be used every day for at least two months. Also, high-dose Vit D supplementation may help accelerate healing in people with low Vit D levels.

Final word from Sportdoctorlondon about a navicular stress fracture

Consider a navicualr stress fracture in a runner or athlete with medial ankle or mid-foot pain. Early diagnosis means a better outlook and quicker recovery.

Other related conditions:

Dr Masci is a specialist sports doctor in London. 

He specialises in muscle, tendon and joint injuries.