Risk factors for fracture redisplacement after reduction and cast immobilization of displaced distal radius fractures in children: a meta-analysis

Purpose Displaced distal radius fractures in children are common and often reduced if necessary and immobilized in cast. Still, fracture redisplacement frequently occurs. This can be prevented by fixation of fracture fragments with K-wires, but until now, there are no clear guidelines for treatment with primary K-wire fixation. This meta-analysis aimed to identify risk factors for redisplacement after reduction and cast immobilization of displaced distal radius fractures in children, and thereby determine which children will benefit most of primary additional K-wire fixation. Methods Eight databases were searched to identify studies and extract data on the incidence of and risk factors for redisplacement of distal radius fractures after initial reduction and cast immobilization in children. Results Twelve studies, including 1256 patients, showed that initial complete displacement (odds ratio [OR] 4.69, 95% confidence interval [CI] 2.98-7.39) and presence of a both-bone fracture (OR 1.95, 95% CI 1.34-2.85) were independent risk factors for redisplacement. Anatomical reduction reduced the redisplacement risk (OR 0.14, 95% CI 0.05-0.40). No significant influence on redisplacement risk could be established for female sex, experience level of the attending surgeon, Cast Index < 0.8, Three-Point Index < 0.8 and patient's age. Conclusions For children with a displaced distal radius fracture, the presence of a both-bone fracture, complete displacement of the distal radius and non-anatomical reduction are risk factors for redisplacement after reduction of their initially displaced distal radius fracture. Children with one or more of these risk factors probably benefit most of reduction combined with primary K-wire fixation.