Emergent Care / Stabilization: Immobilization and pain control.

Causes / typical injury mechanism: A greenstick fracture is defined as a partial thickness fracture in which only the periosteum and cortex of the bone are disrupted on one side of the bone. These fractures can occur in the metaphysis and diaphysis of the long bones of the body such as the tibia, fibula, ulna, humerus, radius, and clavicle. Most commonly, greenstick fractures involve the humerus, ulna, or radius after a fall onto outstretched hands (FOOSH). However, they can occur in the setting of a motor vehicle crash, sports injury, or other traumatic mechanism. Most commonly, greenstick fractures result from supination mechanisms and typically result in volar angulation. A smaller portion are pronation injuries with dorsal angulation.

Classic history and presentation: The most common history is the report of a recent fall but can include other mechanisms of trauma that combine bending or twisting forces. Patients will typically report focal pain to the injured extremity. In pediatric patients, nonverbal signs of acute injury can include protecting and refusing to move the injured extremity. A greenstick fracture of one bone is commonly accompanied by a complete fracture of the other (eg, a radial greenstick fracture and complete fracture of the ulna).

Prevalence: Greenstick fractures are most common among pediatric patients younger than 10 years, but they can present in individuals of any age, including adults. The incidence among sexes is reported with variability.

Pathophysiology: This bowing and bending injury occurs most frequently in bones with increased compliance and a thicker, robust periosteum, such as that found in pediatric patients. In children, bone is primarily composed of calcified cartilage compared to the ossified bones of adult individuals.

Related topic: radius and ulna fracture