Fracture

What is a bone fracture?

The bones in our body are made of a very hard material. Enclosed by a sensitive layer of periosteum, a stable bony framework is found from the outside to the inside containing fine bony trabeculae, completed by the bone marrow. The human skeleton comprises more than 200 individual bones.

Their function covers everything from maintaining the upright posture of our body and its mobility to protecting the important organs (brain, heart, intestines) and producing blood.

Bones are robust and accustomed to strong forces. Nevertheless, broken bones are not rare. Specialists refer to this as a fracture.

A fracture occurs when a bone breaks into two or more parts which are no longer connected and either retain their original position or have been displaced in relation to each other (dislocation).

What can cause a bone fracture?

The causes of a bone fracture are direct or indirect impact of force on the bone. Accidents, falls or blows often result in a broken bone, while the fracture pattern differs depending on the type.

Bone fractures can occur as a direct result of force, given that the force is very large. However, even smaller strains can produce minute cracks over time and subsequently lead to a complete bone fracture. One common example of this are stress fractures of the foot bones in soldiers who carry heavy backpacks on long marches.

Apart from the heavy load, certain deficiencies can also lead to bone fractures in certain patients, which would not occur in a healthy person. The medical term for this is pathological fracture. They include diseases attacking the bone substance, such as osteoporosis or malignant tumors of bones.

What are the symptoms of bone fractures?

The periosteum covering the bone is full of nerve fibers. This is why a bone fracture produces an intense pain. Similarly, the bone has an extremely rich blood supply, partly due to the fact that blood cells are there. In certain parts, this can lead to massive blood loss during a bone fracture (e.g. pelvic fracture).

The area surrounding the fracture site may be red, warm and swollen. In addition, the range of motion may be reduced or even absent or unnormal in joints or bones.

Many of our body's crucial nerves travel right alongside the bones. While bones are intended to protect nerves, their fracture can lead to nerve damage.

Also other adjacent organs can be damaged by bone fracture fragments and cause symptoms accordingly.

Bone fractures can become problematic if pathogens manage to enter the bone or blood stream via the bone fracture. As a result, inflammation of the bone marrow (osteomyelitis) or blood poisoning (sepsis) may develop which can be difficult to treat.

Compartment syndrome is a complication that particularly affects the legs. Muscle groups of the legs are enclosed by a sturdy fibrous layer that makes up a so-called muscle compartment. Any fracture can lead to bleeding and swelling which is unable to cross the compartment and hence leads to a significant increase in pressure. As a result, the nerves and muscles within the compartment can no longer be supplied and die.

How are bone fractures diagnosed?

Following the patient interview, a comprehensive physical examination is conducted by a specialist in trauma surgery / sports traumatology. At this point, regular investigation of blood flow, motor function and sensitivity to rule out compartment syndrome is extremely important.

Reliable fracture signs include a grinding sound at the fracture site (crepitus - bone rubbing), abnormal mobility and displacement of the fracture fragments. The presence of the latter can be detected by axial malposition, bone fragments penetrating the wound, gaps or levels on palpating the bone.

On imaging, the fracture can then be clearly identified. X-ray, CT, MRI ( particularly in pregnant women) and, in particular cases, sonography and scintigraphy are used.

Orthopedic surgeons or trauma surgeons classify bone fractures into open or closed fractures (soft tissue intact), and also according to the number of fragments, the location of the fracture, and extent (complete or incomplete).

How to treat a bone fracture?

The fracture can be managed either conservatively or surgically.

Conservative treatment is mostly used for closed fractures with a few fragments that are not displaced. In most cases, it is possible to immobilize the affected bone with bandages or a cast.

It is always important to reduce the displaced bone segments to ensure optimal bone healing without the formation of bone scars (callus).

The trauma surgeon will perform the surgery in cases of complicated fractures, instability, joint involvement, and severely displaced fracture pieces. The reduction takes place under visual control. Afterwards the bone fragments are fixed by plates, screws or wires (osteosynthesis).

What is the prognosis and the clinical course of a bone fracture?

Apart from the complications mentioned above, poor fusion of two bone fragments can result in a so-called pseudarthrosis. This forms a kind of joint where there was not supposed to be one.

In any case, the reduction of the bone fragments is important, as only this enables the restoration of a pain-free and physiological movement. For this purpose, the adjacent bones surfaces must be aligned as soon as possible to prevent the defective healing of a bone gap in the form of an excessive bone scar (callus formation).

Early on it is important to begin with mild physiotherapy to prevent muscle atrophy or shortening of the tendons. For larger fractures, follow-up treatment is also recommended.

If you should have further questions about the therapy of bone fractures, please feel free to reach out to your specialist in orthopedics / trauma surgery.

Sources:

• www.herold-innere-medizin.de/pdf/frakturlehre.pdf
• www.gbe-bund.de/gbe10/abrechnung.prc_abr_test_logon
• Winker, Karl-Heinrich (2011): Facharzt Orthopädie Unfallchirurgie. Munich: Urban & Fischer. 
• Grifka, Joachim (2011): Orthopädie und Unfallchirurgie. Für Praxis, Klinik und Facharztprüfung ; mit 155 Tabellen. Berlin [u.a.]: Springer.