What is Cuboid Stress Fractures?
Diagnosing and treating foot conditions can be tricky because the foot is a complicated part of the body. It consists of 26 bones and 33 joints and is divided into three parts: the hindfoot, midfoot, and forefoot. The cuboid bone is located in the midfoot section and finds itself alongside the navicular, three cuneiform bones, as well as placed on the outer edge. This bone connects with the calcaneus at one end and the base of the fourth and fifth toe bones at the other end.
Given the repeated pressure and movements exerted on this area, the foot is often susceptible to overuse injuries, including stress fractures. However, isolated stress fractures in the cuboid bone are quite rare, accounting for less than 1% of cases based on literature review. But it’s still vital to consider if a person continuously experiences pain on the outer side of their foot or ankle, especially when it happens along with other factors such as a history of repetitive activities like running, taking part in triathlons, or jumping activities like ballet.
What Causes Cuboid Stress Fractures?
Stress fractures are a type of damage to the bone often related to high-intensity physical activities such as professional sports, competitive recreational activities, or military training. These injuries usually increase among people who have just altered their training routines.
There are a number of factors that can put someone at risk of getting a stress fracture. These include being involved in high-impact activities like running, jumping, or marching, having less dense bones, being a woman, and not having enough conditioning before starting a strenuous activity. It’s important to mention that female athletes are at a higher risk. Those who don’t have regular periods, have low bone density and follow strict diets tend to have a 30 to 50% higher chance of getting a stress fracture.
With more and more people participating in fitness activities today and our ability to better see these injuries with advanced imaging technology, there are more reported cases of stress fractures now. In fact, they now represent 10% of cases that a typical sports medicine clinic sees.
As for what causes these injuries, we believe it comes down to repeated stress on the bone, whether that be from compressing it or pulling on it. More specifically, in the case of cuboid stress fractures (a type of bone in your foot), this stress can increase if there’s too much weight on one side of the foot because of structural abnormalities or weakening in the soft tissues that help support the foot, such as when the plantar fascia (a band of tissue that runs across the bottom of your foot) weakens or tears.
While a single instance of loading — or putting weight on a bone — does not result in a fracture, when these load stresses add up over time, this can cause the bone to crack, leading to a stress fracture. Before a full-on stress fracture occurs, there’s usually a period of bone stress reaction, which doesn’t involve an actual break in the bone but features changes in the bone that suggest it’s under stress.
Various factors can increase the risk of stress fractures. These include innate factors like gender, age, and race, outside factors like training routine, the kind of shoes you wear, the surface you train on, and the sport you play, biomechanics like the shape of the bone, hormonal factors like irregular periods, using birth control, having a thyroid condition, and dietary factors such as having an eating disorder.
Risk Factors and Frequency for Cuboid Stress Fractures
Stress fractures, or small cracks in the bone caused by overuse, are not uncommon among athletes, but it’s rare for these fractures to occur in a specific bone in the foot called the cuboid. Looking at 196 cases of stress fractures, we found that the majority occurred in the tibial shaft, or the long bone in the leg (44.4%). The foot came in second (15%), then the long bones in the foot called metatarsals (9.7%), and the bones in the back part of the foot tarsals (1%).
In a separate study on soldiers, the majority of the 113 stress fractures looked at were again in the metatarsals, with only one occurring in the cuboid bone. When these cuboid stress fractures are diagnosed, they are most often found in athletes who engage in endurance sports (like marathons, half-marathons, and triathlons). However, they’ve also been reported in other sports that put a lot of stress on the foot like ballet, gymnastics, basketball, and rugby.
- Stress fractures in athletes usually appear in the tibial shaft (44.4%)
- Other common areas include the foot (15%), metatarsals (9.7%), and tarsals (1%).
- A study on soldiers confirmed these types of stress fractures are rare in the cuboid bone.
- When they do occur, cuboid stress fractures are typically found in endurance athletes.
- They’ve been reported in ballet, gymnastics, basketball, and rugby athletes as well due to the high stress these sports put on the foot.
Signs and Symptoms of Cuboid Stress Fractures
If you’re suffering from a stress fracture, you’re likely to experience a slow, gradual increase in pain over weeks or even months. At first, the pain may only show up when you’re up and moving, or bearing weight on the affected foot. As things get worse, you may start to feel pain even when you’re at rest – this is a key sign of a stress fracture.
When diagnosing a stress fracture, doctors often inquire about any recent changes in physical activity. They’ll ask if you’ve been running or playing sports longer or more intensely than before, if you’ve switched playing surfaces, and how much recovery time you’re giving yourself between workouts.
It’s also important to answer questions about your eating habits (specifically, how much calcium and vitamin D you get), any medications you take, the type of shoes you wear, and any specialized sports equipment you use. In women, your menstrual history could also be relevant to the diagnosis.
- Gradual increase in pain over weeks or months
- Pain only with weight-bearing and activity initially
- Pain at rest as the injury worsens
- History of increased physical activity
- Changes in playing surfaces or resting time
- Dietary habits, particularly calcium and vitamin D intake
- Medications, footwear and special equipment used
- (For women) Menstrual history
In some instances, stress fractures of the cuboid bone in the foot have been linked with twisting ankle injuries. If you have persistent pain and swelling on the outside of your foot, even after weeks of trying to take care of it yourself, there’s a chance you could have a stress fracture.
During a physical examination, localized tenderness, mild redness and swelling over the outside of the foot, specifically the area of the cuboid bone, could be noted. A particular test called the ‘Nutcracker’ test might bring on pain. In this test, the doctor would hold the heel steady while moving the front of your foot outward, causing compression between your heel and the base of the fourth and fifth toes. These signs provide specific indicators for this type of injury.
Testing for Cuboid Stress Fractures
Typically, early stages of a stress fracture do not show up on regular X-rays. However, X-ray imaging is valuable as a first step to rule out other conditions like tumors, bone infections, or hidden fractures. Regular X-rays initially detect only 15% to 35% of stress fractures, but this sensitivity improves to 30% to 70% over 2 to 3 weeks. This is because the affected bone’s protective covering (the periosteum) reacts to the fracture by developing small patches of new bone, which become more visible over time.
If the diagnosis is unclear, or a stress fracture is suspected, advanced imaging technologies, such as computed tomography (CT scans), MRI (magnetic resonance imaging), or a radionuclide bone scan can be used. The bone scan, which tracks the uptake of a radioactive material by the bones, used to be the preferred method for diagnosing stress fractures in the 1970s.
However, MRI is currently the most popular method for diagnosing stress fractures due to its high specificity and visual clarity. Bone scans are still used in certain situations, for instance, when a patient has metal implants or a pacemaker that doesn’t allow for MRI scans. CT scans can help identify incomplete and complete fractures, but they are not as useful for spotting early signs of stress fractures. As a stress fracture heals, the swelling seen on an MRI is replaced by a hardened outer layer of the bone, which a CT scan captures better.
Ultrasound can also be used as a supplementary tool to physical examination. A recent study indicates that point-of-care ultrasound has a 99% positive predictive value. However, the learning curve involved in operating and interpreting diagnostic bedside ultrasound might limit its usage across various practices.
MRI scans are considered the “gold standard” for diagnosing stress fractures, with a nearly 100% sensitivity. If the pain persists for over two weeks and a stress fracture is suspected, an MRI scan is warranted. It can also be beneficial when there’s uncertainty about the exact diagnosis or if other conditions causing pain in the outer foot need to be ruled out, such as peroneal tendinopathy, painful os peroneum syndrome, or a fracture of the anterior process of the calcaneus or a lateral ankle sprain.
Treatment Options for Cuboid Stress Fractures
A stress reaction or fracture in the cuboid bone (a bone in the foot) can usually be managed by a regular doctor or a specialist like a podiatrist or orthopedic surgeon. This type of injury tends to heal quickly because the cuboid bone has a good blood supply. Treatment often starts with a check-up, ice, and painkillers like NSAIDs or acetaminophen.
Patients are usually advised to follow a step-by-step treatment plan. Initially, they are advised not to put weight on the injured foot for a couple of weeks. Once the pain is gone, they are allowed to bear some weight on the foot. After that, they may use a medical boot or cast for two more weeks. Gradually, they can return to routine activities, starting with walking and low-impact exercises like swimming or cycling. High-level athletes might use a special treadmill. After six weeks of pain-free activity, they might follow a walk-to-run program. Patients may also do strength and motion exercises to regain fitness after the period of rest. Progress through these stages can vary from person to person, but if pain returns, patients should move back a stage and stay there for a week or two.
Some additional oral medications have been explored, such as bisphosphonates, birth control pills, and vitamin D supplements. However, studies have not definitively shown that they can prevent or treat stress fractures. Examining vitamin D levels in athletes with stress injuries, especially women, can be useful. One study found that a daily vitamin D and calcium supplement reduced stress fracture rates. Clinicians should consider checking vitamin D levels for patients with stress fractures, especially if the injury is in an unusual location or is not healing as expected.
Calorie restriction, which can lead to low body mass, is common in athletes like gymnasts, dancers, and track-and-field competitors. These athletes should be evaluated and treated if needed, as not having enough nutrients can increase the risk of stress fractures and delay healing.
Bone stimulators, which use either electromagnetic energy or pulsed ultrasound to promote healing, have gained attention recently. Unfortunately, the evidence is not clear that they improve healing. Similarly, shock-wave therapy has been shown to stimulate the growth of bone and blood vessels, providing a possible treatment option for stress fractures. Studies have shown it can be as effective as surgery for treating non-healing fractures.
What else can Cuboid Stress Fractures be?
There are several conditions similar to a cuboid stress fracture, a condition where overuse of the foot could potentially cause a small crack in the cuboid bone. One of them is peroneus brevis tendonitis, which is inflammation of a tendon in the foot. Another is Os Peroneum, an extra round bone found in the foot that can get inflamed from repetitive activities. These conditions can be differentiated from cuboid stress fracture by specific characteristic symptoms and tests. For example, Os Peroneum can often be diagnosed if the additional bone is visible on a X-ray and if the patient feels pain in a specific area of the foot.
Subluxed cuboid syndrome is another condition to consider that can cause pain on the outer side of the foot. It is often present in about 7% of patients who have suffered a specific type of ankle injury. Relief from this condition often involves manual manipulation techniques.
Tarsometatarsal osteoarthritis, a form of arthritis in the foot, can also mimic the pain caused by the cuboid stress fracture. This condition usually follows a pattern of morning pain, followed by a pain-free period, then increasing aches as the day goes on. While physical exams alone may not be able to differentiate between this type of arthritis and a cuboid stress fracture, X-rays often show typical signs of arthritis such as a narrowing joint space, bone spurs, and cysts forming under the cartilage of the joint.
What to expect with Cuboid Stress Fractures
Cuboid stress fractures, which are fractures in a particular foot bone, typically heal quickly and carry a good prognosis due to the bone’s strong blood supply. They are categorized as “low-risk” stress fractures and usually heal with non-surgical treatment.
In a study series involving six fractures in foot bones, known as tarsal bones, it was reported that division 1 collegiate athletes were generally able to return to athletic activities after an average of 12.1 weeks.
Possible Complications When Diagnosed with Cuboid Stress Fractures
Stress fractures can sometimes have complications. Even though this condition is typically seen as low-risk, some complications can include:
- Bone not healing properly, which could require surgery
- The affected area becoming weaker
- Issues related to wearing a cast such as skin damage
- Excessive new bone growth which can lead to chronic pain in the fractured area
If a person with a stress fracture develops these complications, it will be important for them to be referred to an orthopedist, podiatrist, or sports medicine specialist for further treatment.
Preventing Cuboid Stress Fractures
The importance of medical attention for athletes experiencing any unusual discomfort or symptoms must be stressed upon by their coaches. It’s essential to educate athletes about various health aspects as well. In our practice of sports medicine within the military, we spend considerable time discussing the importance of choosing the right footwear, appropriate training surfaces, and correct techniques of running, racing, and walking.
Healthcare professionals should also insist on athletes using shoes specifically designed for running or walking, rather than general sports shoes. These professionals need to have knowledge about the right running shoes for different types of feet (normal arch, high arch, flat arch).
Moreover, athletes should be motivated to gradually increase their workout time, speed, and distance. They should also be encouraged to cross-train with activities such as cycling, swimming, and using the elliptical trainer. Lastly, advice on a proper diet is crucial – it’s important that they consume enough calories, vitamins, and minerals with a special focus on calcium and vitamin D.
