Fractures occur when bones break due to energy applied to them in excess of what these can sustain. There could be different types of fractures depending on the site and severity of the injury, type of force that acted on bone and involvement of surrounding tissues.
There are multiple ways to list the types of fractures. The classification of fractures not only helps to suggest the severity and mechanics of injury that occurred but also helps to formulate the most suitable treatment.
There are many types of fracture classifications and often more than one for a given region of fracture.
In this article, we would stick to the basic definition of fracture and general classification of fractures that could be applied across all the regions.
Types of Fractures based on Breaking Pattern
Different types of fractures which are based on breaking pattern are
A fracture in which the break is across the bone, at a right angle to the long axis of the bone. The following figure would illustrate.
In this fracture, instead of the break being at the right angle, it goes in an oblique direction to the long axis of the bone. The fracture is confined to one plane. In other words, the bone has broken at an angle.
The following x-ray shows an oblique fracture
This fracture is easily confused with the oblique fracture. Instead of a straight break as in oblique fracture that is only in one plane, the break, in this case, traverses both the planes. To understand this you need to imagine a three-dimensional view of the bone.
If you take a stick and slice it at an angle so that it is divided into two, it is similar to the oblique fracture. But if you twist and break that stick it would result in a broken pattern that would start from one point, move obliquely in on direction, reach the other end and then continue on another side of the stick in a spiral fashion to meet the original point.
The diagram above would give you a rough idea of what I am trying to say. Compare it with the oblique fracture diagram and you would be able to appreciate the difference.
If the injury results in multiple breaks in the bone, they are visible as different fragments. These kinds of fractures are called comminuted fractures.
It is a type of comminuted fracture only.
The bone is fractured at two distinct levels. The reduction of this fracture is difficult and nonunion common as seen in the following x-ray. Segmental fracture is defined as a comminuted fracture where one fragment retains the complete cortex of the bone.
This is a fracture in which the ends are driven into each other. Cancellous bone is typically involved, and union often occurs rapidly. A torus fracture or buckle fracture is a pediatric impaction fracture in which the cortex of long bone buckles, with no loss of cortices.
This is a fracture of the cancellous bone caused by a localized force that breaks and depresses one segment below the level of the surrounding bone. These are generally intra-articular fractures and commonly seen in the knee.
Types of Breaks Based on Displacement of Fragments
Depending on the displacement of fragments, the fracture can be displaced or undisplaced.
If bone fragments stay together maintaining structural alignment of the bone, it is called an undisplaced fracture. A hairline fracture is an example of an undisplaced fracture.
But the fragment of the bone may move from their original position resulting in separation of the fragments. Such a fracture is called a displaced fracture.
Butterfly fragment is a popular term for a wedge-shaped fragment of the bone split from the main fragments,
The following x-ray would show a butterfly fragment
Incomplete and Complete Fractures
These terms indicate the completeness of a fracture
An incomplete fracture is one where the fracture has not involved the bony cortex on all sides. torus fractures and greenstick fractures are examples of incomplete fractures.
Incomplete fractures are often seen in pediatric injuries.
A fracture is complete if there is a complete break of cortex on all sides. Depending on the severity of the injury, the fracture may or may not be displaced.
Stable and Unstable Fractures
Rather than the initial displacement, unstable fractures are those fractures that tend to displace after reduction. This stability after reduction is important as it guides the treatment that should be given and the implant that must be chosen.
These fractures do not tend to displace after the reduction of the fracture.
Based on Soft Tissue Damage
Complicated fractures are those in which there is significant soft tissue damage to major nearby structures (nerves, vessels, ligaments, and muscles).
There is minimal soft tissue damage.
Here, I must mention that there is always an amount of trauma to the surrounding soft tissue whenever a fracture occurs. The bone cannot break in isolation. The energy is dissipated to the soft tissue as well.
But the fracture becomes complicated only when there is significant trauma to the soft tissue that may alter the course of the treatment or prognosis of the injury.
Types of Fractures based on Articular Involvement
These terms are typically used for fractures that occur near the joints.
Intraarticular fractures are those in which the fracture line extends into the joint space. Extraarticular fractures are those in which the fracture line does not enter the joint space.
Presence of wounds that communicate with a fracture.
A fracture that communicates with the external wound is called an open fracture. The fracture thus is closed no more but is open with the external environment.
In some injuries like pelvic injuries, if an internal visceral would is present that communicates with the fracture, the fracture is also an open fracture [open from within].
A closed fracture is one in which the skin or other soft tissue envelope overlying the fracture site is intact.
Examples of open fractures are – When a bone fragment from within breaks out through the skin or when some outside force penetrates both the skin and bone.
Open fractures are surgical emergencies, and most require operative treatment.
[Read more on Open Fractures]
Fractures Caused by Insufficient Trauma
Most of the fractures are caused by significant trauma. However, there are types of fractures are caused by insignificant trauma. There may be several reasons for this.
Fractures resulting from trivial trauma because the bone is weak, are called insufficient fractures.
Osteoporosis, an age-related loss of bone mineral and microarchitectural change in the bone. As bone weakens, a trivial trauma can result in fractures. A simple fall in old age may result in fractures of the hip region whereas the same injury in young persons will just result in soft tissue injury.
Such fractures that occur in the osteoporotic skeleton are popularly also called osteoporotic fractures.
Pathological fractures occur when a bone is weakened by a disease such as infection, malignancy or lack of nutrition. Spontaneous fractures occur when the bone is so weakened that fracture may occur even by forces of daily use e.g., lifting of hand or simple movements of walking. This generally occurs when the disease is quite advanced.
Stress fractures are a special type of fractures which occur with repetitive exposure of the normal bone to the forces to which it is not accustomed to. An example of this would be sudden jogging for long distances without training.
A point to note is that bone is otherwise normal in these cases i.e. not weakened by any pathology.
Fractures are also known by the persons who first described them. These fractures are called eponymous fractures. Though not scientific but it is a common practice to call fractures by these names.
There is a long list of eponymous fractures and these have been discussed in a separate article. Few commonly used fracture eponyms are –
- Barton fracture: Intra-articular distal end radius fracture
- Cotton fracture: Trimalleolar fracture of ankle
- Pott’s fracture: Bimalleolar fracture of ankle
- Jones fracture: Fracture of base of the fifth metatarsal
- Monteggia fracture: Ulna fracture with radial head dislocation
- Galeazzi fracture: radius fracture with lower radioulnar joint disruption
You can read more about eponymous fractures