Evaluation of cast wedging in a forearm fracture model

BACKGROUND: In paediatric traumatology fractures are commonly treated with a cast. In this course cast wedging is sometimes performed aiming to reduce the fracture angulation. However, the impact of various factors and measures such as cast material, optimal position of the wedge and wrist position were not assessed in a systematic manner. METHODS: A laser supported model was developed to evaluate the biomechanical processes of cast wedging manoeuvre in a model of a distal diaphyseal forearm fracture. Consecutive measurements were performed to find out the influence of wedge position, cast material and wrist position. FINDINGS: The result of the manoeuvre was revealed to be independent of the cast material (plaster of Paris vs. synthetic cast) used. The optimal position for placing the wedge was shown to be on the concave side of the cast at the level of the fracture. The result of a cast wedging manoeuvre in a dorsally displaced forearm fracture can be optimized with the wrist held in extension. INTERPRETATION: The cast wedging model is not a meticulous copy of the human anatomy but it allows some basic studies on cast wedging technique. The results that can be achieved are similar to the experiences of practical paediatric traumatology. Furthermore the present model may be beneficial for use in education and training programs.