Final answer:
Spiral fractures are characterized by a helical crack resulting from torsional forces. They exhibit pain, swelling, and instability, and healing involves bone resorption and new bone formation. Treatment may require reduction and watchfulness for complications.
Step-by-step explanation:
Spiral fractures are a type of bone fracture that are characterized by a helical crack due to the application of torsion or twisting forces to a long bone. This type of deformation is analogous to other tension, shear, and bulk deformations. Spiral fractures often occur when one part of a limb is immobilized while the other part is forced to rotate. Common characteristics of spiral fractures include a distinctive corkscrew pattern along the length of the bone, severe pain, swelling, and instability of the affected limb.
Healing of spiral fractures typically begins with the formation of a hematoma, progressing through the creation of internal and external calli. Osteoclasts play a crucial role in resorbing dead bone, while osteoblasts are responsible for creating new bone to replace the damaged areas. The healing process is completed as the calli unite, remodeling occurs, and full recovery is achieved. Given their complexity, spiral fractures may require a closed or open reduction for realignment, and they are especially watched for complications such as damage to surrounding nerves or blood vessels due to the nature of the twisting force involved.