What is a common complication of untreated fractures?

Untreated fractures can lead to a variety of complications, including infection, muscle atrophy, and joint stiffness.

Infection can occur when the skin is broken due to a fracture, especially in open fractures where there is a break in the skin. The exposure of bone and surrounding tissues increases the risk of bacteria entering the wound, leading to osteomyelitis or other infections.

Muscle atrophy is a natural consequence of immobility. When a fracture is left untreated, the affected limb is not used normally, leading to a decrease in muscle activity and subsequent muscle weakness and atrophy.

Joint stiffness can develop due to prolonged immobilization, which may result from an untreated fracture. The lack of movement can cause the joint capsules and surrounding soft tissues to become stiff and less flexible, leading to decreased range of motion.

Each of these complications illustrates the interconnected nature of musculoskeletal health; thus, untreated fractures carry a risk of all of these issues occurring, making "all of the above" the correct answer.