A spiral fracture, also known as a torsion fracture, is a type of complete bone fracture that occurs when a long bone is broken by a twisting force or impact. The fracture line looks like a corkscrew, and the resulting broken bone usually has jagged edges, which can complicate the healing process. Spiral fractures can be either displaced or stable, depending on whether the parts of the bone at the break line up correctly or not.

Spiral fractures usually affect long bones in the body, such as the femur, tibia, and fibula in the legs, or the humerus, ulna, and radius in the arms. They can be caused by falls, accidents, sports injuries, or any impact that twists the bones with great force. For example, a spiral fracture of the tibia can occur in young children when they fall short on an extended leg while jumping, which is known as "toddlers fracture".

The most common and obvious symptom of a spiral fracture is pain in the injured area, which can be dull, heavy, or agonizing, depending on the severity of the injury. Other symptoms may include bone stiffness, restricted range of motion, swelling, redness, and tenderness. In the case of an open fracture, where there is a break in the skin, jagged bones and bone fragments may be visible, in addition to bleeding.

Treatment for spiral fractures can depend on the severity of the breakage, but may include surgery, rest, and physical therapy. Because of the way in which a spiral fracture occurs, the healing process can be complicated, and detached bone fragments may make treatment even more difficult. Recovery time can vary depending on which bones are fractured and what caused the breaks, but most people need a few months to recover from a spiral fracture.