Compound fractures are one of the most devastating injuries, which commonly occur due to motorbike and car accidents or similar high velocity injuries. They are not only difficult to recover from, but are also prone to develop several life-threatening infections and complications. The deformities caused by compound fractures, accompanied with the ugly scarring of the wounds, require treatment by an expert orthopedic and plastic surgeon. Otherwise, the stigma of a compound fracture frequently remains lifelong in the form of a non-healing bone infection.
What is a Compound Fracture?
A bone fracture with an open wound, where the protective barrier of the skin is broken, is called a compound fracture. The wound may either be due to an external injury or a projection of sharp bony edges of fractured bones from the inside. Irrespective of the cause of wound, a break in the continuity of the skin opens the doorway for a host of infectious organisms to enter the interior of a wound. This is the prime reason behind the high rates of wound infection in a person with compound fractures.
Picture 1: Compound Fracture (before and after treatment)
(Source: Wikimedia Commons)
Also in a compound fracture, there is continuous loss of blood due to leaking of blood from the wound. A normal bone fracture also has a certain amount of internal blood loss. But the blood remains confined to a small region, and cannot escape the muscular compartments. There is collection of blood around the broken ends of bones forming a hematoma, which clots (coagulates) and prevents further blood loss. The hematoma is an important component of the healing mechanism after a bone fractures. The relatively deficient hematoma in compound fractures is also a cause of poor healing and associated complications, like delayed union or non union of bones.
Compound Fracture Causes
In general, the velocity of an injury is the main determinant of the severity of a compound fracture. The mildest form of compound fracture, is a punctured wound along with a fracture. Though, the wound is very small in size, even then it is quite sufficient to transfer infectious organisms and also as an outlet for continuous oozing of blood. Hence, it should not be taken lightly. Sometimes, the external wound is quite large with minimal bony injuries. Here, the size of the wound may seem alarming, but the actual injury is quite easy to heal. Therefore, one should not judge a compound fracture injury simply based on external appearance. It is only after a careful evaluation of the injury, which involves clinical as well as radiological assessment, is when one can come to a conclusion about the severity of the injury.
The following causes of compound fractures are listed as per their relative frequencies observed in the ER.
- Road Accidents – car and bike including pedestrians.
- Sports injuries
- Fall from a Height or falling of a heavy object.
- Assault with a weapon or stick.
- Workplace injuries – due to machinery or instruments.
- Penetrating injuries – due to bullet, shrapnel, knife, etc.
The cause of a compound fracture is closely associated with the degree of contamination of the external wound and also the type of infection to specifically be careful about. For example, road accidents are mainly associated with burns and so one has to be careful about pseudomonas infection, sports injuries involving outdoor sports have high chances of contamination with soil bacteria, like tetanus, and so prevention of these specific infections is highly important before they reach bone tissue.
Another important factor in deciding the fate of a compound fracture, is the area of impact. In high velocity injuries, the area of impact is larger, so even if the wound appears small, the impacted soft tissue breaks down due to degenerative changes. Hence, the wound appears to be increasing in size for a few days after injury, when more and more of the actually damaged cells near the wound die and are extruded off during wound dressing. This is in no way a sign of improper treatment and should not raise a doubt regarding the quality of treatment.
Compound Fracture Types
Depending on their severity, compound fractures are graded into 5 types, based on the Gustillo and Anderson classification.
Grade 1: Simple fracture with a puncture wound around 5-10 mm in size.
Grade 2: Simple or complex fracture with >10mm wound size.
Grade 3A: Complex fracture pattern with no soft tissue loss.
Grade 3B: Complex fracture pattern with extensive soft tissue damage.
Grade 3C: Complex fracture pattern with blood vessel injury (requires urgent repair by a vascular surgeon).
Apart from this grading, another important type of compound fractures are secondary compound fractures. These are the bone injuries, where initially after trauma the fracture is well covered by skin, but due to secondary breakdown of the damaged overlying skin and connective tissues, there is formation of a wound over the fracture. This can be due to the delayed impact of the trauma on the overlying structures or destruction of cutaneous blood vessels due to trauma or tightness of the plaster cast used for treatment of the fracture. Blistering of skin over the fracture or rarely infection of the fracture hematoma can also cause secondary wounds at the fracture site and lead to a compound fracture. Thus, improper assessment of the extent of injuries can transform a simple fracture to a compound fracture.
The accurate grading of a compound fracture is highly essential for planning the further management of the injured person. Also a clear account of the injury has to be given by the patient or an observer of the incident to get an idea of the extent and nature of injuries present. If a part of the body gets amputated or cut off from the rest of the body, it should be placed in ice and should be taken along with the patient. Such parts can be resutured (stitched) back to the body only if the delay between injury and treatment is less than 2-3 hours (in ice). This is also applicable to pieces of bone extruded from the open wound of a compound fracture. Bone loss from compound fracture is a major reason for prolonged treatment and can be easily prevented by paying close attention while attending to such injuries at the site of the injury. However, care should be taken to prevent these extruded pieces from contamination and drying by placing them in appropriate fluids, like normal saline with added anti-septic solution. However, no attempt should be made to put the broken piece of bone back in the wound.