Flexible intramedullary nails or Spica casting? A meta-analysis on the treatment of femur fractures in preschool children aged 2–5 years

The objective of this study is to conduct a meta-analysis (1) to evaluate outcomes of flexible intramedullary nails (FIN) versus Spica casting for treating femur shaft fractures in children aged 2–5 years and (2) to investigate the associated complications. The PubMed, Cochrane Library, Embase and Web of Science databases were searched to identify available studies comparing the outcomes of FIN and Spica casting for the treatment of femoral shaft fracture in preschool children. Meta-analysis was conducted with adherence to Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. Eight observational studies involving 4995 patients were included. Two were judged to be of moderate quality, with the remainder being high quality. There were 1573 patients treated by FIN and 3422 by Spica casting. Compared to Spica casting, FIN allowed a quicker return to normal activities (40.49 ± 13.43 vs. 46.97 ± 14.32 days; P < 0.001), had a lower incidence of malunion (0.88 vs. 4.19%; P = 0.01) and unplanned interventions (2.87 vs. 7.53%; P < 0.001), but had slightly longer hospital stay (2.01 ± 1.01 vs. 1.10 ± 0.93 days; P = 0.01) and required a second surgery to remove the nails. Compared with Spica casting, FIN has the advantages of faster returning to normal activities and lower incidence of residual deformities and unplanned reoperation, but a slightly longer time of hospitalization and needs a second surgery to remove the hardware. Existing studies on duration of care and financial burden are insufficient, so further studies are warranted on multicenter and high-level evidence studies. Level of evidence: III.