Stress Fracture: Causes, Symptoms, and Treatment of Stress Fractures
A fatigue fracture occurs when the bone reacts to repetitive stress. Fatigue fractures are classified as sports injuries and most commonly occur in the lower extremities. Such a non-traumatic fracture should be diagnosed promptly so that those affected do not delay healing or risk a repeat fracture. In our article, you’ll learn everything about the causes, symptoms, treatment, and prevention of stress fractures.
Stress Fracture: Definition and Cause
A fatigue fracture, also known as a stress fracture or march fracture, is a small crack in an otherwise healthy bone that occurs as a stress reaction to repeated or unusually intense stress. As a result of prolonged mechanical overload, the bone tissue eventually becomes damaged, and the body’s own repair processes can no longer compensate for this damage. Unlike an acute bone fracture, which results from a single strong impact or injury, fatigue fractures develop gradually over time and manifest as bone edema or visible fracture lines. The stability of the bone is generally not as severely compromised by a fatigue fracture as it is by a bone fracture or injury.
Stress fractures frequently occur in the lower extremities, particularly in the bones of the feet and lower legs (in the area of the inner ankle or the front of the shin), as these areas are subjected to constant stress during walking, running, and jumping. Those affected experience particularly severe pain in the forefoot and midfoot. Athletes are therefore more frequently affected by stress fractures, and women are affected slightly more often than men.
Symptoms and Diagnosis
A stress fracture typically presents with localized pain that intensifies with activity and subsides at rest, usually accompanied by swelling, redness, or warmth, as well as tenderness at the affected site. Movement and weight-bearing on the affected bone are usually still possible. However, those affected may have difficulty walking or performing certain activities.
During a medical history interview, a doctor will assess the current symptoms and test range of motion and load-bearing capacity. Imaging techniques may also be used to make a diagnosis. While a pronounced stress fracture is clearly visible on an X-ray, very fine cracks in the bone can often only be detected through an MRI (magnetic resonance imaging) scan. If osteoporosis is suspected as the cause of the fracture, the doctor will order further tests to halt the progression of bone weakness. If you suspect you have a stress fracture, an orthopedic specialist is the right person to consult.
Bones Most Commonly Affected
Certain bones are typically particularly susceptible to stress fractures due to their role in movement and the stress they endure from repeated mechanical forces. These include:
- Metatarsals: The second and third metatarsals are particularly affected, as they bear the most weight during walking and running.
- Tibia: The tibia is particularly prone to stress fractures among runners and athletes.
- Fibula: The fibula can also be affected, particularly during activities that involve repeated jumping or prolonged stress.
- Calcaneus: The calcaneus bears a significant load during many activities and is therefore also susceptible to stress fractures.
- Navicular bone: This bone in the foot is particularly at risk in sports that involve a lot of jumping or sudden changes in direction.
- Femur: This is particularly problematic for long-distance runners.
- Pelvic bones: The pubic bone and ischium, in particular, can be affected by intense physical activities such as long-distance running.
Risk Factors for Stress Fractures
The main causes and risk factors for a stress fracture include overuse—that is, repeated stress and microtrauma without sufficient recovery periods. A sudden increase in activity, such as an excessive increase in training intensity or volume without proper preparation, can also be a cause.
Non-ergonomic running form, foot misalignments, extreme vitamin D deficiency, calcium deficiency, unsuitable footwear, or bone weakness—such as that seen in osteoporosis—can also be cited as risk factors.
Treatment Options
Without treatment, the pain can intensify to the point where it eventually occurs even at rest. The bone’s load-bearing capacity also decreases. Such a fracture should therefore be diagnosed and treated promptly so that it can heal completely. Recovery takes between a few weeks and a few months, regardless of the extent of the fracture. Caution: Putting weight on the affected area too soon carries the risk of a re-fracture and another break from sports.
Treatment options for a stress fracture depend on the severity of the bone damage and the location of the fracture. In most cases, it is sufficient to rest the affected body part so that the bone can regenerate on its own. Regular checkups with a doctor allow the healing process to be monitored. Surgery is only necessary in exceptional cases, such as when conservative measures are ineffective or complications arise. During surgery, the bone is stabilized, thereby promoting healing.
A stress fracture is not, in and of itself, a reason for a sick leave note. However, if your job requires physical exertion, the stress fracture can have significant professional implications, and you may need to stay away from work for an extended period to allow the fracture to heal, resulting in an inability to work and time off due to illness. If your work is physically demanding, consult a doctor to determine how long a sick leave is advisable in order to adequately rest the affected limbs and avoid further damage or delays in healing.
Rehabilitation and Recovery
During the acute phase, it is important to completely relieve pressure on the affected bone and, if necessary, immobilize it with a cast or brace. Using crutches can help take the weight off the affected limb. Pain relievers such as acetaminophen or ibuprofen can help manage the pain. However, they should be used sparingly, as they can interfere with bone healing.
After about six weeks, when the pain has gradually subsided and healing has begun, you can start to slowly and gradually increase the load—ideally under the guidance of a physical therapist or exercise therapist. Passive and active movement exercises help maintain mobility and prevent muscle atrophy. However, you should be pain-free when performing these exercises.
About 12 to 24 weeks after the injury, you can resume strength training to strengthen the surrounding muscles and improve the stability of the affected limb.
About half a year after the fracture, you can resume your usual exercise routine. However, make sure to keep the intensity and duration low at first. The return to full activity should be gradual. Through this carefully tailored rehabilitation and recovery process, you can support the complete healing of a stress fracture and thus prevent future injuries.
Prevention of Stress Fractures
Whether you’ve already suffered a stress fracture or want to prevent one, here are a few measures that can help:
- Gradually increase your training intensity: Be sure to increase the intensity, duration, and frequency of your workouts gradually to give your bones time to adapt. As a rule of thumb, increase your training volume by no more than 10 percent per week.
- Adequate recovery: Schedule regular rest days to give your body the time it needs to recover.
- Varying activities: Avoid repetitive strain and ensure variety in the sports you practice to engage different muscle groups and avoid one-sided training.
- Improve your running form: To identify and correct form mistakes, you can seek help through a professional analysis, for example at a running store.
- Proper Footwear: Wear shoes that fit well and are suited to your running style. Rotate your shoes regularly to ensure your feet have adequate support and protection. Use orthopedic insoles if needed.
- Choose the right surface: Train on soft, cushioned surfaces instead of hard surfaces like asphalt to reduce the impact on your bones.
- Warm-up: Before each training session, you should warm up thoroughly to prepare your muscles and tendons for the upcoming exertion.
- Strengthening exercises: Incorporate exercises to strengthen your leg and foot muscles into your workout to reduce the strain on your bones. Calf raises, leg presses, and exercises with resistance bands have proven to be particularly effective. You’ll find the best exercises for healthy feet here.
- Vitamin D and Calcium: Athletes, in particular, should make sure to meet their vitamin D and calcium needs to prevent stress fractures.
Complications and Long-Term Effects
Even though a stress fracture heals without complications on its own, complications and resulting problems can arise in some cases.
Complications include:
1. Failure to heal (pseudoarthrosis):
- If the fracture does not heal properly, pseudarthrosis may develop, resulting in the formation of a false joint. This leads to chronic pain and instability.
2. Delayed healing:
- The healing process may take longer than expected—resulting in persistent pain and limited function.
3. Re-fractures:
- Refractures may occur, especially if the original fracture has not fully healed or if the bone continues to be subjected to excessive stress.
4. Muscle atrophy and weakness:
- Prolonged immobilization and limited movement can lead to muscle atrophy and weakness, which prolongs rehabilitation.
The following long-term effects may occur:
1. Chronic pain:
- Even after complete healing, those affected may experience persistent pain, especially during physical activity or when the weather changes.
2. Altered biomechanics:
- Due to changes in gait or movement patterns intended to protect the affected area, other joints and muscles may become overloaded, which can lead to secondary problems.
3. Reduced bone density:
- In individuals with underlying risk factors such as osteoporosis, a stress fracture may be a sign of reduced bone density, which increases the risk of further fractures.
4. Activity limitations:
- Affected individuals may also experience long-term limitations in their ability to engage in certain activities or sports.
5. Osteoarthritis:
- If joints are affected or there are repeated injuries, osteoarthritis may develop over time.
Summary
- A stress fracture is a small crack in the bone caused by repeated or unusually intense stress.
- Unlike fractures caused by injuries or impact, a stress fracture develops gradually.
- It frequently occurs in the lower extremities, particularly in the feet and lower legs.
- Typical symptoms include localized pain that worsens with activity and subsides at rest, often accompanied by swelling, redness, and tenderness.
- To make a diagnosis, the doctor relies on the patient’s medical history, a physical examination, and imaging techniques such as X-rays and MRI
- Preventive measures include gradually increasing training intensity, adequate rest, varying activities, improving running technique, wearing proper footwear, training on soft surfaces, warming up and stretching, strength-building exercises, and ensuring an adequate intake of vitamin D and calcium, especially for athletes.
- Treatment for a stress fracture includes rest and, if necessary, immobilization of the affected body part. Surgery is rarely necessary.
