What is a compound fracture?
The term fracture refers to a break in a bone. Depending on the characteristics of the break, a fracture can be classified into different types. A compound fracture refers to a fractured bone that is also accompanied by damage to the overlying tissues and skin. This results in an open wound. The break in the overlying skin could be caused by either an external injury or the sharp ends of the broken bones inside.
Regardless of the cause of the open wound, a compound fracture is prone to getting infected by the microbes in the environment and causing serious complications.Another important feature of a compound fracture is leakage of blood from the open wound. This leads to considerable loss of blood. A simple fracture of the bone without any overlying wound is also accompanied by blood loss.
However, the loss of blood in a simple fracture is relatively less when compared to the loss of blood in a compound fracture. This is because the loss of blood in a simple fracture occurs in a small area that is delimited by tissue compartments. The leaked blood does not flow out of these tissue compartments. Blood leakage in fractures results in the formation of blood clots, which prevent further blood loss by sealing the injured area.
Compound fractures display poor or delayed healing because of less blood clot formation at the site of injury. In addition, several life-threatening infections and other complications may also occur in cases of compound fractures. Bone infections and physical deformities due to compound fractures may persist throughout life. The management of compound fractures is also a difficult endeavor.
Due to the involvement of multiple tissues, several specialist surgeons may be required to treat a compound fracture. A patient’s general condition also determines the type of surgical procedures can be implemented.
Types of Compound Fractures
Compound fractures are usually classified into the following five grades, depending on their severity.
Grade 1 fracture
A grade I fracture is a simple fracture that has an overlying puncture wound of about 5-10mm.
Grade 2 fracture
Grade 2 fractures can be simple or complex fractures that are accompanied by overlying wounds of more than 10mm in size.
Grade 3A fracture
Grade 3A fractures are complex fractures that are not accompanied by any damage to the soft tissues.
Grade 3B fracture
Grade 3B fractures are complex fractures that are accompanied by extensive damage to the soft tissues.
Grade 3C fracture
Grade 3C fractures are complex fractures that are accompanied by injury to the blood vessels. Grade 3C fractures require immediate vascular surgery.
The above classification system is based on the Gustillo and Anderson classification. An accurate grading of the fracture is essential for deciding the proper course of treatment and avoiding complications.
Secondary Compound Fracture
A secondary compound fracture is another important type of compound fracture in which the skin overlying the fractured bone is intact to begin with. There is a secondary breakdown of the ovelrying skin and connective tissue due to destruction of cutaneous blood vessles or delayed impact of the trauma.
The plaster cast used to treat the fracture may contribute to the development of secondary compound fracture by causing trauma to the cutaneous blood vessels. Secondary wounds could also result from blistering of the skin and infection of the fracture hematoma.
Causes of Compound Fractures
The main cause of a compound fracture is a forceful injury that causes damage to the skin, connective tissues, and bone. The following are some situations in which forceful injuries can lead to compound fractures:
Vehicle collissions and other types road accidents are the most common cause of compound fractures.
High velocity collisions in contact sports are also a common cause of compound fractures.
Read more on traumatic brain injury.
Falls from a high platform or falling of a heavy object on the body can also result in compound fractures.
Physical assault with a stick or weapon can also cause compound fractures.
Injuries in the workplace caused by heavy machinery leads to some cases of compound fracture.
Penetrating injuries caused by objects such as knife, sharpnel, and bullets can also cause compound fractures in some cases.
Signs and Symptoms
The signs and symptoms of compound fractures emanate from the broken bones as well as the overlying open wound. Pain and bleeding are common features of a compound fracture. It is important to be aware of the signs and symptoms of compound fractures because some of the signs and symptoms may signal a life-threatening complication that requires emergency medical attention.
- Stretch pain: A serious complication of compound fracture is compartment syndrome, which is characterized by tenderness, contraction and curling up of the fingers or toes. Trying to stretch the contracted parts of the limbs causes significant pain. Compartment syndrome is a limb-threatening emergency that requires immediate medical intervention. Fibrosis of muscles that may result from this condition can persist throughout life.
- Pale pulse: Injury to the blood vessels can cause a weak pulse in the extremities of the limbs. Lack of sufficient blood supply to the extremities may result in tissue death within a couple of hours.
- Foul odor: Infection of the open wounds in the case of compound fractures can cause a life-threatening condition known as gas gangrene. This condition is characterized by an offensive foul odor from the wounds. The foul odor may be likened to the odor of rotting fish. Limb amputation is the only way to protect the patient from the rapid spread of gas gangrene. Antiserum against gas gangrene bacteria should be given in the early stages of fracture management in order to prevent the occurrence of this lethal infection.
Treatment of Compound Fractures
Treatment of compound fractures requires a comprehensive assessement of the extent of the injury and the status of the patient. A variety of tests and involvement of various medical specialists is typically required.
The wounds are washed and antiseptics are given.
External bone fixators (uni-planar, bi-planar, and ring fixators) are used to temporarily fix the fractured bones and allow the wound to heal. Temporary fixation aids tissue repair and prevents futher injury to blood vessels, soft tissues, and nerves. Permanent fixation of fractured bones is done only after the open wound heals.
Complications of Compound Fractures
Delayed complications of compound fractures include chronic osteomyelitis, delayed wound healing, and nonhealing fracture. Chronic osteomyelitis refers to an infection of the bone that can persist for many months and years. Oral antibiotics are not able to treat this condition. Eventually, the infected bone tissue needs to be replaced with bone grafts. Delayed wound healing also delays permanent fixation of the fracture.