1-44

[Previous] [Next]

Section VIII. FRACTURES

1-44. FRACTURES

a. A fracture is defined as a break in the continuity of a bone. Fractures occur when a bone is subjected to more stress than it is able to absorb. Fractures may occur from several specific causes and are categorized as follow.

(1) Direct force. In direct force fracture, a bone is subjected to more stress than it can absorb from an impact with a solid object. For example: a direct blow, as from a baseball bat, or a crushing force, such as some automobile accidents.

 

(2) Twisting. In a twisting (torsion) fracture, an indirect force may cause a break in a bone at a location other than the site of the twisting force. This type of injury is common in skiing accidents.

 

(3) Muscle contraction. In another indirect force fracture, powerful contraction of a muscle may cause the muscles to tear away from the bone, often fracturing or avulsing part of the bone in the process. This type of injury may occur during a grand mal seizure. This type fracture is seen in soldiers in an injury known as "grenade thrower's fracture." The humerus is fractured as a result of the muscular contractions in throwing a hand grenade.

 

(4) Pathological fracture. Bones that have become weakened from age or disease are easily fractured, often from just a slight movement.

 

(5) Fatigue or stress fracture. This type of injury may occur when a bone has been subjected to repeated stress. This phenomenon is commonly associated with sports enthusiasts and soldiers. The repeated stress of sustained running or marching may cause stress fractures of the feet or lower extremities.

b. Sometimes it will be quite obvious that a bone is fractured, but this is not always the case. An X-ray will often be necessary to make the diagnosis of fracture. Specific signs and symptoms will vary according to the

type and location of the fracture. An open fracture with bone protruding from the wound is very obvious. In the case of a closed fracture, however, a fracture will be more difficult to assess. Some signs and symptoms associated with fractures are:

(1) Pain.

 

(2) Deformity (visible or palpable).

 

(3) False motion; abnormal mobility at the fracture site.

 

(4) Discoloration.

 

(5) Edema.

 

(6) Crepitus.

 

(7) Loss of function.

 

(8) Shortening of an extremity.