Slideshow
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Figure 1. Anteroposterior radiograph of the left wrist.
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Figure 2. Lateral radiograph of the left wrist.
An 11-year-old boy presents to the office with pain in his left wrist after he fell during a football game. He describes losing his balance and landing on his left wrist with his arm extended. Following the fall, he experienced immediate pain and states that he has not been able to use his left hand since the fall. Anteroposterior and lateral radiographs of the left wrist are obtained (Figures 1 and 2).
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A metaphyseal fracture of the distal radius is the most common fracture in children and adolescents.1 This type of fracture frequently occurs when a patient falls on an outstretched hand. Most distal radius fractures are displaced dorsally with apex volar angulation. Volar displacement with apex dorsal angulation generally occurs with palmar flexion injuries. Typical fracture patterns in the metaphysis include a buckle fracture (torus), incomplete or greenstick fracture, and bicortical fracture.
Greenstick fractures occur when a force is applied to bone and fractures the convex side or cortex while the bone is bent (plastically deformed) on the concave side but is not fractured. Greenstick fractures are so named because they are similar to bending a green branch off of a tree; the branch typically bends but does not break completely. Angulation of greenstick fractures is influenced by malrotation of the distal radius. Fractures with apex volar angulation result from supinated injuries and can be reduced with pronation. Apex dorsal angulation occurs from a pronation force and can be reduced and casted in varying degrees of supination. Greenstick fractures are more unstable and prone to further displacement than buckle fractures and should be monitored closely with serial radiographs.
The typical degree of acceptable angulation for a distal radius fracture in an 11-year-old patient is approximately 10° to 20° as the remodeling potential is high.2 This patient was treated in a short arm cast for 6 weeks.
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopedics for Physician Assistants.
References
1. Hennrikus WL, Bae DS. Fractures of the distal radius and ulna. In: Waters PM, ed. Rockwood and Wilkin’s Fracture in Children. 9th ed. Philadelphia, PA: Lippincott, Williams, and Wilkins. 2019; 363-373.
2. Noonan KJ, Price CT. Forearm and distal radius fractures in children. J Am Acad Orthop Surg. 1998;6(3):146-156.
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