A 6-year-old boy is brought to the emergency department due to an injury to his left arm. About an hour ago, he was jumping on the bed when he bounced off and landed on his outstretched left hand. He cried and has not wanted to use the arm since then. The patient has no chronic medical conditions. Examination shows mild edema of the left distal forearm with intact sensation and pulses distally. Palpation of the forearm produces sharp pain. The patient refuses to move the wrist. Radiograph is shown in the image below:
Show Explanatory Sources
The forearm is immobilized. This patient is at greatest risk for developing which of the following long-term complications?
Show Explanatory Sources
Distal forearm fractures are common in children and typically occur after a fall onto an outstretched hand. Patients have pain, swelling, and limited range of motion of the wrist.
Because the periosteum surrounding the bone is thick and strong in children, the fracture may involve only one side of the bony cortex rather than extending through the width of the bone. This is known as a greenstick fracture, as seen on this patient's x-ray. The opposite side appears to have a deformation or bend without a break in the cortex.
Prompt reduction (if displaced) and immobilization of the forearm is required for greenstick fractures because they are considered unstable due to the potential for refracture or further displacement if improperly treated. Repeat x-rays should be performed prior to cast removal to confirm bony union. Once the fracture is fully healed, no long-term complications are expected.
(Choice A) A fracture that interrupts blood supply to the bone can lead to avascular necrosis. This condition is most commonly seen with femoral neck fractures and is unlikely to occur with a greenstick fracture.
(Choice B) Chronic osteomyelitis is a potential complication of an open fracture in which disruption of the skin can introduce bacteria to the injured bone. This patient has no loss of skin integrity, making infection unlikely.
(Choice C) Growth arrest caused by a fracture involving the growth plate (physis) can lead to limb length discrepancy. In contrast, this child has a diaphyseal fracture.
(Choice D) Long-term limited range of wrist supination and pronation is a complication of malunion after a severely displaced radial fracture. This patient's fracture is only mildly angulated, and malunion is not typically seen with greenstick fractures.
Educational objective:
Greenstick fractures of the forearm are common in children due to relatively strong periosteum, which limits the fracture line from extending through the width of the bone. Treatment is immobilization to prevent refracture, and no long-term complications are expected.