Frakturen/en

A fracture (Latin fractura, "fracture", from Latin frangere "to break") or a bone fracture is a complete or incomplete interruption of continuity of bone tissue with the formation of two or more fragments with or without displacement. A bone fracture often results in pain and loss of stabilizing function of the bone. The associated verb is to fracture.

Exercises

Fractures

Neighboring structures

Bones

Body regions

Bone Upper ExtremityBone Lower ExtremityBone torso

Organ system

Bones

---

Causes

Fractures are often a result of direct or indirect force acting on the bone, such as accidents, blows, or falls. In addition, pre-existing conditions such as osteoporosis, bone metastases, or a bone tumor can reduce the bone's resistance and be the cause of a fracture. In addition to violence and pre-existing conditions, a fracture can be caused by overload and fatigue; in this context, it is referred to as a fatigue fracture.

Fracture signs

The symptoms of a fracture are called fracture signs. In clinical examination, one divides into sure and uncertain fracture signs. However, the absence of sure fracture signs does not automatically mean that there is no fracture. If a fracture is not visible even in the X-ray, it is called an occult fracture.

Uncertain fracture signs are symptoms that occur with a fracture but can occur without a fracture. They include pain, hematoma, swelling, limited motion, redness, or warmth. Pain is often severe in fractures, even though the bone substance has no pain receptors. Pain is mediated by the nociceptors of the periosteum and endost. In addition, tissue tension due to hemorrhage can be very painful and can be exacerbated by additional muscle activity that seeks to stabilize the fracture.

Sure fracture signs clearly indicate a fracture. This is the case when there is axial misalignment of the bone, visible bone fragments in open fracture or abnormal mobility. Bone gaps (diastases) and step formation in the bone contour are also sure signs. If the fracture site crunches, the fragments rub against each other, this is called crepitation and is another sure sign of fracture.

Diagnosis

In addition to clinical examination, the most important and frequent examination procedure is x-ray imaging. Complicated fractures can additionally be assessed more precisely by CT scans. MRI could also be used if adjacent ligamentous or soft tissue structures are involved. In addition to the actual evaluation of the fracture, exclusion of peripheral nerve and vascular injuries is of high importance. This is done by testing sensation and muscle strength distal to the fracture as well as palpation of peripheral pulses. Vascular and nerve injuries can also be delayed, so these tests must be performed regularly.

Division

Fractures can be classified according to various criteria. Among many other criteria, one classifies according to the following characteristics:

• Course of the fracture line
• Number of bone fragments
• Position of the fragments
• Mechanism of origin
• Localization
• AO classification

Fracture types according to fracture progression

According to the course of the fracture line

The course of the fracture line can vary greatly; a distinction is made between transverse, longitudinal, oblique and spital.

In a transverse fracture the fracture line is transverse to the long axis of the affected bone. It is a complete fracture, often caused by direct application of force to the fixed limb. The opposite of transverse fracture is longitudinal fracture, in which case the fracture line runs along the longitudinal axis of the bone. If the fracture line runs obliquely to the longitudinal axis, it is an oblique fracture. The angles may vary. An oblique fracture often results from an oblique force applied to the limb, similar to the transverse fracture. The fourth subdivision based on the course of the fracture line is the spiral fracture (torsion fracture). Spiral fracture is a bone fracture with a spiral fracture line. It is caused by twisting of the fixed limb.

Fracture types according to fragment number

By the number of bone fragments

Based on the number of fragments, there are different generic terms for fractures. If there is only one fracture gap, it is called a single fragment fracture. Multiple fragment fractures (Multi-segment fractures) are fractures with three to six fragments, here the bone is broken several times. A fracture with exactly three fragments, i.e. two fracture lines is again separately called piece fracture, this is a subtype of the multi-fragment fracture. All fractures with more than six fragments are called comminuted fracture.

Dislocated fracture

According to the position of the fragments

Depending on whether or not the individual bone fragments have been displaced, a distinction is made between dislocated and non-dislocated Fractures. In a dislocated fracture, the fragments are displaced from their original anatomical position. In this case, it is important to return the fracture fragments to their proper position before healing. The dislocation sometimes determines the remaining load-bearing capacity and stability of the fracture.

By mechanism of origin

An avulsion fracture (Alvusion fracture) is a fracture in which a bone fragment, caused by the strong pull on a tendon or ligament anchored in the bone, is torn out of the bone. This fracture is caused by a sudden increase in tension on a tendon or ligament at the bony attachment, because tendons or ligaments have a high tensile strength, especially in younger people.

A shear fracture (chisel fracture) is a bone fracture that occurs at prominent bone segments (e.g., articular processes). It is caused by shear or shearing forces and osteochondral fragments often result. It is also called a chisel fracture because when a joint is compressed, part of the bone is sheared off as if by a chisel blow.

A bending fracture is caused by the limb bending on an edge or by direct impact. Thus, a transverse fracture, oblique fracture, or a lump fracture may occur. In the case of a fragmentary fracture, the broken fragment is called a bending wedge.

Fracture types according to origin

In a burst fracture the bone bursts, which means that there is a centripetal displacement of the fragments. Such fractures occur mainly in the skull and vertebral bodies. This fracture is caused by the action of blunt force and is accompanied by star-shaped fracture lines and often the indentation of fragments. Burst fractures of vertebral bodies are particularly dangerous because bone fragments could shift into the vertebral canal.

A fatigue fracture (stress fracture) is caused by a permanent overload of the bone. It often remains clinically silent for a long time and is only noticeable by a local pressure pain or soft tissue swelling. Even on X-ray, fatigue fractures are often difficult to detect, usually only after a periosteal reaction after a few weeks.

A compression fracture is caused by the compression of a bone in the longitudinal axis. Compression fractures often occur in the spine, for example, when the statics of a vertebral body are weakened. The weakening could occur due to osteoporosis. Another cause of compression fractures is falls from a greater height.

Pathological fractures (Spontaneous fractures) are bone fractures that occur despite normal load and without apparent cause. The reason is then a destruction of the bone substance (osteolysis), which weakens the bone statics. Other causes of destruction can be, for example, tumors, bone metastases, bone cysts or Gaucher's disease.

Greenwood fracture is a type of fracture that occurs only in children and adolescents. Because bone growth is not yet complete, the bone is more elastic and can give way when force is applied. Although the bone buckles, it does not crack. The result is a kink like that of a fresh green twig, hence the name.

According to the localization

If one classifies the fracture according to its localization, there are two variants. If you consider the position on the bone itself, there are three different sections. Fractures on the bone shaft are called shaft fractures' or diaphyseal fractures. In contrast, there are fractures close to the joint, or metaphyseal fractures. Third, there are so-called articular fractures. These are fractures involving the articular surface and luxation fractures. However, this type of classification refers mainly to the long tubular bones.

If one classifies the fractures rather according to the affected body area, there are many different subtypes. These include, for example, the skull fracture, lower leg fracture or femoral neck fracture, and many more.

According to AO classification

The Arbeitsgemeinschaft für Osteosynthesefragen (AO) published a systematic classification of fractures of the long tubular bones in 1958. Today, the AO classification serves as the basis for describing fractures.

A fracture is basically described by four numbers or letters. The first digit stands for the body region (e.g. 3 = femur). The second digit stands for the exact position within this region (e.g. 2 = diaphyseal, on the bone shaft). The third digit is followed by the letter A, B or C, which indicates the complexity of the fracture. The meaning of A-C differs for fractures in the shaft or joint region. The last digit differentiates again according to the severity of the fracture. For example, 32-C3 would be a severe fracture in the mid femur. In children, the AO classification has been adapted so that there are two more letters.

Other classifications

Furthermore, one divides into complete (complete) and incomplete (incomplete)' Fractures. In a complete fracture, the cortical bone is completely severed. In an incomplete fracture, on the other hand, there is still a connection between the ends of the fracture.

Depending on the joint involvement in the fracture, there are intraarticular and extraarticular' Fractures. Intraarticular means involving a joint and extraarticular means outside the joint.

Frakturen können offen oder geschlossen sein, wobei offene Brüche meist komplizierter sind. Bei geschlossenen Frakturen ist der Weichteilmantel um die Fraktur noch intakt, während bei offenen Frakturen die Weichteile durchtrennt sind und der Knochen frei liegt. Hier besteht eine hohe Infektionsgefahr. Das Ausmaß der Weichteilverletzung kann nach Tscherne und Oestern klassifiziert werden, sodass es auch hier nochmals Unterteilungen nach dem Schweregrad gibt.

Treatment

Initial treatment consists mainly of immobilization and fixation of the affected body region. The affected area should be moved as little as possible to avoid additional pain. The actual treatment then follows in the hospital after diagnosis.

Roughly, the treatment procedures are divided into conservative and surgical treatment. Conservative procedures include immobilization with a cast, but also closed reduction with subsequent casting. In closed reduction, external pushing and pulling is used to remove the misalignment of the bone. This is not surgery, but can still take place under general anesthesia. The surgical form of treatment, on the other hand, is open reduction. The bone fragments are straightened in surgery and then joined together by devices such as screws, wires, nails or plates. The materials are often removed after healing is successful, but not necessarily. This procedure is called osteosynthesis (from Greek "ostheos" = "bone" and "synthesis" = "composition"). Osteosynthesis is mainly necessary for more complicated fractures, for example, multiple fragments, an open fracture, or fractures that extend into the joint. Clear surgical indications are arterial occlusions, nerve injuries or compartment syndrome. Typical osteosynthesis procedures are explained below.

Screw osteosynthesis

The individual fragments are reconnected by a screw and thus fixed. The screws can be made of different materials, typical are for example titanium or steel. In large bones such as the femur, screws are often not sufficient and additional plates are used for reinforcement.

Plate osteosynthesis

In plate osteosynthesis, the fracture is stabilized using a metal plate. There are different plate shapes that are used depending on the type of fracture. These include, for example, support plates, angle plates, compression plates, or neutralization plates. The metal is usually removed completely after 12-18 months.

Tension chord osteosynthesis

When multiple fragments are pulled apart by tensile forces, a tension chord osteosynthesis can help to intercept the tensile forces and convert them into compressive forces. Tension chord osteosynthesis is used for relatively small fragments subjected to strong tensile forces. Wire slings are predominantly used.

Incarrow nailing

Intramedullary nailing can be used for shaft fractures of a large long bone, such as the femur, tibia, or humerus. For this purpose, an intramedullary nail is driven into the medullary cavity of the bone; this is called intramedullary splinting. This method has the advantage that the fracture does not have to be opened and the incision is relatively small. Additional locking may be performed at one or both ends.

External fixators

The fixator is attached to the bone with Schanz screws, which are connected to a force carrier by so-called clamps. The screws protrude outward through the skin, allowing the force carrier to remain outside the soft tissues. This procedure is used, for example, in open fractures or in the primary treatment of patients with polytrauma.

Complications

A fracture can be associated with numerous complications, including compartment syndrome, infection, necrosis, high blood loss with shock, or injury to neighboring structures such as organs, nerves, blood vessels, or joints. Furthermore, a bridging callus may be formed or pseudoarthrosis may occur if a false joint is created by failure to fuse. In addition, there is a risk of fat embolism or complex regional pain syndrome (CRPS).

Free exploration

Look at the models of the bones with fracture in 3D and explore this freely. Afterwards you can check your learned knowledge through the exercises.

---

ÜBUNGSAUFGABEN

WEITERE ARTIKEL

Bones

Femur

---