Diagnosis
Since a fatigue fracture is not associated with a clear fracture event, diagnosis is usually made late.Diagnostic measures for the detection of a fatigue fracture are, on the one hand, the clinical examination of the foot for certain fracture signs (fracture signs) such as axial malpositioning of the bone, bone crackling (crepitation), abnormal mobility or visible bone fragments, as well as for uncertain fracture signs such as pain, swelling, bruising (hematoma), warming and restricted mobility. On the other hand, imaging procedures such as X-ray, MRI, CT or skeletal scintigraphy (examination of the metabolic activity of the bone using radioactively labeled substances) are useful; MRI and scintigraphy are best suited to visualize the small fracture lines and the loss of bone mass. Frequently, an incipient fatigue fracture is not visible in conventional X-rays.
Frequently, a fatigue fracture is not diagnosed by magnetic resonance imaging, since the patient’s symptoms described and the X-ray examination often lead to the diagnosis of a fatigue fracture with less effort as well. However, MRI is the best way to detect very fine so-called hairline fractures of the bone, which would otherwise have been overlooked in a standard X-ray examination. More than 50 percent of fatigue fractures are not yet visible on X-ray in the early stages, but can already be diagnosed by MRI. The advantage of MRI compared to X-ray examination or computed tomography is that the patient is not exposed to harmful radiation. In contrast to the other two methods, however, an MRI examination also takes longer.
Symptoms
Since the fatigue fracture usually develops insidiously over a longer period of time, it causes other complaints than an acute fracture. Patients complain of pain in the area of the broken (fractured) foot bone, initially under stress and later also at rest. Frequently, the fatigue fracture is also not associated with a sudden loss of function of the foot due to a violent impact, as is the case with an acute fracture. However, as in the case of a sudden fracture, overheating, swelling and reddening of the foot at the fracture site can also occur. Because the symptoms appear very untypical for the patient, a rheumatological illness is often assumed at first.
