Prognostic factors for postoperative complications after K-wire fixation for paediatric forearm fractures: a multivariate analysis

Although osteosynthesis using K-wires is a commonly performed procedure, the outcome is not always preferable. We aimed to identify the prognostic factors for postoperative complications in paediatric patients with both-bone forearm fractures. We reviewed 160 paediatric patients who underwent K-wire osteosynthesis for either distal or diaphyseal forearm fractures. We defined the occurrence rate of postoperative complications as the primary outcome and performed a multivariate logistic regression analysis. Variables such as age, sex, mechanism of injury, presence of an open fracture, ulnar or radial fracture and the associated procedure, the K-wire tip procedure and operation time, the duration from injury to operation and operation to implant removal, and duration of casting were included into the model as possible prognostic factors. The mean follow-up period was 51.2 weeks. The total number of complications was 43 (26.2%). Results of the logistic regression analysis indicated that a shorter duration from surgery to K-wire removal caused a significantly higher rate of postoperative complications [odds ratio (OR), 0.99; 95% confidence interval (CI), 0.97-1.0]. The subgroup analyses revealed that intramedullary K-wire fixation for radial fractures (OR, 1.07 × 10-5; 95% CI, 5.46 × 10-10 to 0.211) and a longer casting duration (OR, 0.84; 95% CI, 0.72-0.99) resulted in fewer postoperative infections. An exposed wire tip in the ulna contributed to more postoperative displacement (OR, 6.87; 95% CI, 1.76-26.9). To decrease the risk of postoperative complications, surgeons should bury the wire tip beneath the skin to facilitate a longer duration of K-wire placement.