Stress fractures heal on their own

Stress fracture or marching fracture: Fatigue fracture of the bone due to overload

  1. What is the stress fracture (fatigue fracture)?
  2. Symptoms of a stress fracture (fatigue fracture)
  3. Causes of the development of a stress fracture
  4. How does the doctor diagnose a stress fracture?
  5. Conservative treatment of stress fracture
  6. Stress fracture surgery
MRI and X-ray imaging of a stress fracture: CENTER: The MRI (magnetic resonance imaging) image shows a changed bone structure in the area of ​​the calcaneus. The arrows above mark the formation of a mild bone edema in response to an older stress fracture. RIGHT: In the corresponding X-ray image, there is hardly any bone whitening to be seen at this point, which indicates the bone's stress reaction. LEFT: The upper arrows show a clear bone reaction or sclerosis (compression of the bone tissue). © Dr. cutter
The stress fracture is a type of bone fracture that occurs due to repetitive stress. One also speaks of a fatigue fracture or a marching fracture. The overload leads to damage to the bone substance, which the body's own repair processes can no longer compensate for. If, for example, a runner who is significantly increasing his training volume due to an upcoming marathon suddenly experiences pulling pain in the metatarsus, the foot specialist must consider a fatigue fracture. Although the endurance, muscles and circulation of the athlete can cope with the increased training, tendons and bones adapt only slowly. The imaging shows the typical changes in the metatarsus: initially bone edema (water retention) is visible, later the stress reaction can also be seen in the damaged bone substance. Although the foot was not damaged by external force (e.g. accident, injury), a partial or complete bone fracture may exist. In many cases, the treatment of a fatigue fracture is conservative through relief and rest. An operation is only necessary in exceptional cases.

What is a stress fracture and how does it develop?

A stress fracture or a fatigue fracture is a partial or complete fracture of a bone due to overload. Usually an increase in training in connection with repetitive movements (e.g. when running) is the cause of the bone's stress reaction. 2% of all sports injuries are caused by a stress fracture. But too little resilience of the bone due to metabolic damage or in the context of malpositions and relieving postures can promote fatigue fractures.

In the case of a stress fracture, the bone is weakened over a longer period of time so that micro-repairs can no longer compensate for the damage to the bone substance. The lower extremities in particular are affected by such micro-injuries, which the body first repairs. If fine cracks occur again the next time the load is applied, the bone will be damaged again. The balance of bone formation and breakdown is disturbed and at some point the body's own repair system can no longer keep up. Then bone marrow edema (water retention in the bone marrow) develops as a stress reaction, before the bone substance (cancellous bone) and later also the protective bone shell (cortex) are damaged. A stress fracture arises from stress reactions of the bone.

If the fracture occurs in the metatarsal area, it is also called a marching fracture. The term comes from the military, where the symptoms were often observed in soldiers after long marches on foot.

Bone fractures that occur as part of another underlying disease (e.g. osteoporosis or bone tumors) must be differentiated from stress fractures. In this case one speaks of an insufficiency fracture. This also includes incorrect loading due to incorrect positioning of the foot or shin. Elderly people with more pronounced arched feet or flat arched feet or ligament damage are particularly affected, as the bones are overloaded and damaged over many years due to their unphysiological position.

Prevalence - Who Will Get a Stress Fracture?

Most stress fractures occur in active people between the ages of 20 and 30. Sports-induced changes in the bone structure are strongly dependent on the level of performance. Above all, stress fractures in the area of ​​the shin (tibia) or fibula (fibula) on the lower leg and on the heel often occur in running and jumping athletes. In the high performance level, however, the tendency is downward due to the good trainer education. Load peaks are more often observed in amateur athletes or in the lower performance range if the training is increased too quickly. This is often the case when a recreational athlete is preparing for a competition such as a marathon. But even with proper training, fatigue breaks can occur. Overall, women are more likely to develop stress fractures than men. One reason for this prevalence could be the female hormonal balance, since estrogen deficiency in menopause affects the bone metabolism and reduces calcium storage.

Symptoms of the fatigue fracture

At the beginning of the bone damage caused by a stress fracture, sudden pain often occurs in the area of ​​stress. In some cases, an unaccustomed stress took place beforehand, which was the trigger for the pain.

The fatigue fracture can in principle occur in all bones and joints (e.g. knees) of the lower extremity or in the area of ​​the hips and the SI joint (sacroiliac joint). Most commonly, however, the shin (tibia) and foot are affected.

The pain in the affected body region usually occurs together with a complete inability to exercise and sometimes significant swelling. If the patient puts pressure on the area of ​​the bone damage, burning pain can occur that can spread to neighboring regions. The patient therefore often takes a relieving posture.

If the fatigue fracture is the result of overtraining, the pain can begin insidiously and slowly increase. The more you train, the more pronounced the symptoms are and the affected person becomes increasingly unable to perform.

When should you see a doctor?

Depending on the location, various symptoms can indicate the development of a stress fracture at an early stage. If there is an impending calf or shin fracture, pulling pains appear on the inside or outside of the lower leg near the ankle. These occur mainly with high-accelerating movements and under load. If you experience symptoms like this, you should consult a doctor at an early stage in order to counteract progressive bone damage.

The unspecific complaints are initially indistinguishable from periosteum irritation or overloaded tendons. Training is usually still possible at this stage. Continuous pain, which is described as dull or gnawing, can only occur with increasing training load without immobilizing the affected body region. A burden is then no longer possible.

Stress fracture of the tibia (shinbone)

Fatigue fractures on the shinbone (tibia) express themselves very differently. For example, the periosteum or the bone marrow in the bone can be affected by edema (water retention) as a stress reaction. Then unspecific lower leg pain occurs. The actual bone substance (cancellous bone) or the harder outer layer of the bone (cortex) are not always injured. If these structures are affected, the fracture line is usually horizontal. However, longitudinal cracks can also occur along the shin bone. Most stress fractures occur in the lower (distal) area of ​​the tibial shaft. Overall, around 50% of all stress fractures affect the shin.

The fatigue fracture on the foot

In the area of ​​the foot, stress fractures are most common in the metatarsus and the tarsus. The heel (calcaneus) in particular can be affected by a fatigue fracture when exposed to excessive body weight. The stress reactions are usually expressed as bone marrow edema or as visible fracture lines. The heel is then sensitive to pressure and hurts when the foot is moved.

Stress fracture in the knee

In addition to degenerative changes such as osteoarthritis (joint wear), knee pain can also be caused by stress fractures. Usually bone marrow edema occurs first in the knee area due to the overload. Overall, stress fractures of the knee are rare. An MRI can help confirm the diagnosis and differentiate a stress fracture from other diseases of the knee joint. More often, so-called insufficiency fractures, which are caused by other underlying diseases such as osteoporosis, are responsible for bone damage in the knee.

Stress fracture - causes and risk factors

In contrast to a traumatic fracture - for example from a fall - a stress fracture always arises from what is actually accustomed to stress. Repetitive movements that permanently stress the bone are usually responsible for substance damage to the bone. This disrupts the bone metabolism in the damaged area, which changes the relationship between bone breakdown and bone formation. This so-called remodeling is normally responsible for the immediate repair of micro-injuries to the bone. The repetitive movements overload this system and incomplete or complete breaks can occur.

Risk factors for a stress fracture

Not only disease-related changes affect the bone metabolism, but above all also the patient's lifestyle. The following risk factors can be responsible for bone stress reactions:

  • Training mistakes and overtraining
  • abrupt increase in training intensity or scope
  • Improper loading
  • wrong footwear
  • uneven ground
  • incorrect running technique (or other sport-specific causes)
  • Malpositions (e.g. metatarsus adductus deformity)

Most stress fractures are the result of improper or excessive training at high intensity or high volume. But also a changed load distribution, such as a genetically determined or acquired shift of body weight to the outer (lateral) metatarsal bones (metatarsus adductus deformity), can promote a fatigue fracture. At this point, the insufficiency of the first toe beam with load shifting to the second toe beam should also be mentioned. The overloading of the second beam often leads to stress fractures or arthrosis (joint wear) in this area.

Metabolic changes or other underlying diseases can also affect the stability of the bones. One observes bone damage in athletes with menstrual disorders or in people who eat one-sidedly. Electrolyte disturbances or a vitamin D deficiency can also be decisive for poor bone quality. These causes, which can be traced back to other underlying diseases or deficiency symptoms, are referred to as insufficiency fractures. They are to be distinguished from the stress fractures.

Prevent the fatigue fracture

A healthy lifestyle can help prevent stress fractures and damage to the bone substance. Above all, it is important to have a balanced diet with sufficient vitamins and minerals such as calcium. These are just as indispensable for bone health as sunlight, which supports the body in the formation of vitamin D, which is important for the calcium metabolism of the bones.

In addition, athletes should make sure that they maintain a healthy training schedule. Load peaks and abrupt increases in performance can promote fatigue failure. The training should always take place on level ground and with suitable footwear.

Diagnosis: How does the foot specialist recognize a stress fracture?

Imaging and clinical examination

The diagnosis of a stress fracture is usually carried out by an experienced orthopedic surgeon or foot specialist. In particular, the physical examination and a detailed anamnesis help the doctor to make a diagnosis. In addition to inquiring about risk factors and underlying diseases, this includes a local palpation examination, which is an essential part of the suspected diagnosis. The orthopedic surgeon examines the condition of muscles, ligaments and tendons in order to rule out overuse complaints and damage to these structures. He also pays attention to swellings, areas of pressure pain or palpable thickening of the bones (callus), which can result from structural changes in the bone.

After this clinical examination, the doctor will arrange an imaging test to assess the situation of the bones, muscles and ligaments. Confirming the diagnosis is not always easy, since bone changes due to stress fractures manifest themselves very variably in the initial stage. X-rays are often not meaningful. Usually, fine interruptions in the bone structure are not visible on X-rays until two to four weeks after the first symptoms appear. Only later can bone condensation, fracture lines or periosteum reactions occur. Therefore, the discrepancy between clinical complaints and the inconspicuous findings must help to make the correct diagnosis in the early stages.

Skeletal scintigraphy offers a possibility for early diagnosis by means of imaging. For the examination, the patient is injected with a radioactive substance that accumulates in particularly metabolically active bone areas, which makes structural disorders visible. However, other bone changes (e.g. bone tumors) can trigger a similar picture, making the diagnosis more difficult.

Therefore, other imaging methods such as digital volume tomography (DVT), computed tomography (CT) or magnetic resonance tomography (MRT) are often used to diagnose a stress fracture.

MRI image of the forefoot with a stress fracture of the 2nd metatarsal bone: In the frontal view in the lower right image, a clear osteoedema of the 2nd metatarsal bone can be seen due to the different display color compared to the neighboring bones. The damaged bone is white, while the remaining bones are shown in gray in the image. The soft tissue reaction around the bone is also clearly visible. A noticeable break in black can be seen on all images. © Dr. cutter

Diagnosis of stress fractures of the SI joint (sacroiliac joint) and other joints

In most cases, fatigue fractures occur in the area of ​​the lower extremities. Above all, the shin and heel are often prone to stress fractures if the load is incorrect. But also in the area of ​​the sacroiliac joint (ISG), which is located between the sacrum and the iliac bone on the hip, there can be load-dependent complaints. However, these express themselves very unspecifically through dull pain during exertion, which is why stress fractures of the SIJ are often recognized late or misdiagnosed. Since digital volume tomography (DVT) can only be performed on the extremities, computed tomography (CT) and SPECT-CT (single Photon Emission Computed Tomography) means of choice at this point.

The most promising way to detect stress fractures in the ankle area is digital volume tomography (DVT). The radiological procedure makes bone and joint changes visible in the early stages by creating sectional images. Stress fractures often develop on the foot in the area of ​​the inner ankle with involvement of the ankle, where they can be detected by digital volume tomography early after the onset of symptoms. In contrast to the MRI image, however, changes to the bone structure are always necessary for the diagnosis by means of DVT in order to be able to reliably diagnose stress fractures. In addition to diagnostics, the imaging process is also used to plan operations.

Stress fracture of the tibia in an athlete (side view): A clear fracture line can be seen in both images, on the left in the X-ray image, on the right in the CT (computer tomography). The metabolic disorder due to malnutrition in the extreme athlete was just as decisive for the delayed bone healing as the insufficient rest. The CT was not done until weeks after the onset of symptoms. The lack of insight on the part of the athlete later led to an operation and the complete abandonment of the sport. © Dr. Thomas Schneider

MRI for early detection of a stress fracture

Patients with a stress fracture experience severe pain and restricted mobility in the early stages. These complaints contradict the changes in the bone visible in the X-ray. Fine interruptions in the bone structure are usually only visible on the X-ray after two to four weeks. During this time, however, the damage to the bone can progress and the symptoms increasingly restrict the patient's everyday life.

Magnetic resonance tomography (MRT) already enables an early and meaningful diagnosis. With the slice image, periosteum reactions and bone marrow edema can be shown, which provide an early indication of a possible stress fracture.MRI also offers an advantage over digital volume tomography, which is also used for early diagnosis, but requires changes in the bone structure in order to be able to detect a fatigue fracture.

Differential diagnostics - which diseases are to be distinguished?

A weakening of the bone does not always have to be due to an overload. Certain diseases also lead to demineralization of the bone and thus promote stress fractures. First and foremost, osteoporosis and vitamin D metabolic disorders should be mentioned, which result in a gradual breakdown of the bone substance. Chronic bone inflammation, compartment syndromes (substance damage due to increased tissue pressure) or osteoarthritis (joint wear) as well as bone tumors and metastases also damage the bones. People with diabetes mellitus are also at increased risk of bone damage. A disease that mainly affects the elderly is Paget's disease, which is associated with increased bone loss. In children and adolescents, fibrous dysplasia can also trigger a fracture. Similar to bone tumors, the disease leads to malgrowth of the bone tissue, as a result of which the bone develops a fibrous substance and loses its hardness.

Conservative therapy for stress fracture

Conservative therapy through rest should always be the first choice for treating a fatigue fracture. All stresses that cause pain are to be avoided. The immobilization depends on the location and severity of the stress fracture. If there is a stress fracture in the area of ​​a joint surface or if a joint is involved, the corresponding part of the body should always be relieved and completely immobilized, otherwise there is a risk of bone fragments slipping off. The relief can be provided by crutches or - depending on the location of the stress fracture - by special relief shoes or load-redistributing shoe insoles with support for the arch of the foot. Complete immobilization in a plaster cast is not necessary. In some cases partial loads - e.g. B. in the water or while cycling - to allow the patient a light exercise.

Metabolically effective treatment options for fatigue fractures

Heat treatments can help to stimulate the metabolism in damaged bones. For the application, however, the pain situation is decisive, as the heat also increases the blood circulation in the affected body part, which can trigger pain. If possible, the patient should refrain from using non-steroidal painkillers (e.g. ibuprofen), since the pain is an essential warning signal during stress. In some cases, ultrasound, acupuncture or phonophoresis (the use of sound waves) can help treat stress fractures, but there is no reliable evidence of its effectiveness.

X-ray at the beginning of the symptoms (left) and after three months (right): A visible bone reaction has occurred due to permanent overloading of the shin (tibia). In the right picture you can clearly see the callus formation, a thickening of the bone as a stress reaction. It does not develop until weeks after the first symptoms appear, often as a sign of the healing of a substance damage. In some cases, such callus formation may be the only indication of an overuse response. © Dr Thomas Schneider

Stress fracture surgery

Surgical therapy for stress fractures is an absolute exception. In most cases, conservative treatment and immobilization are sufficient to restore the patient's ability to exercise. An operation is only necessary in special cases.

Indications for an operation:

  • impaired bone healing (> 6 months)
  • Formation of a callus (bone thickening)
  • Development of bone fragments
  • Bone instability with complete fractures

Operations are useful when the bone cannot heal on its own and there is delayed spontaneous healing. This can be the case, for example, with a fracture in the middle area of ​​the tibia. In order to stimulate the bone to heal, it is drilled in a surgical procedure.

Another complication that can occur in the context of a fatigue fracture is the so-called callus, a thickening of the bone as a reaction to the damage to the substance. This must be removed in one operation. Complete fractures that result in bone instability or fractures of the inner ankle with involvement of the joint surface must also be treated by correcting the position. If there are bone fragments, there is a risk of slipping. In this case an osteosynthesis is necessary. The surgeon assembles the bone fragments so that they can grow together in a corrected position after the operation.

The aim of the operation for a stress fracture is always to achieve the healing of the bone in a physiological position and thus the bone's load-bearing capacity. After the bone has stabilized, the patient can be mobilized at an early stage.

How long does it take for a fatigue fracture to heal?

The most important measure to treat a stress fracture is to immobilize the affected limb. After conservative treatment as well as surgery, it takes about 6 months to restore fitness to exercise. Complicated tibial fractures (broken tibia) require a slightly longer healing time of around 10 months. If the inner ankle is affected, healing can be completed within 4 to 6 months. Stress fractures of the forefoot usually heal even faster, often within 6 to 8 weeks. Consistent, early treatment and relief is urgently needed here. If the load is resumed too early or too quickly, recurrences (renewed fractures) are to be feared. Before the patient starts exercising again, an imaging procedure should be performed to secure the bony structure.

Complications after stress fracture

Complicated courses of a stress fracture occur above all if the patient does not adhere to the necessary rest period and stresses too early. Complications often occur in the area of ​​the inner ankle or on the anterior shin. If there is a complete fracture, it can happen that the bone does not heal properly and a pseudarthrosis develops. This is a sham joint that occurs in an area of ​​the bone that is not normally articulated. Pseudarthrosis is usually associated with pain and functional restrictions.