Management of pediatric distal humerus metaphyseal-diaphyseal junction fracture: A systematic review and meta-analysis.

Purpose: Fractures occurring at the metaphyseal-diaphyseal junction of the distal humerus in children are not commonly documented in the literature. Until this moment, there is no gold standard technique regarding its management and most surgeons treat it as a regular supracondylar humerus fracture by conventional pinning. This systematic review explores the relevant literature to assess the efficacy of different techniques. Methods: This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Our literature search encompassed several online databases, including PUBMED/MEDLINE, Scopus, Web of Science Core Collection, and Google Scholar. Data from articles that met our general inclusion criteria were extracted and categorized into treatment method groupings. Functional and cosmetic outcomes, demographic characteristics, and complications were the main parameters used to analyze the data. Results: Ten retrospective studies met our inclusion criteria with a total of 178 participants of unilateral pediatric distal humerus metaphyseal-diaphyseal junction fractures. Most literature chose closed reduction and percutaneous pinning in seven articles, followed by elastic stable intramedullary nail technique used in three articles, then conservative treatment was chosen in two articles, while only one article used lateral miniplate and assisted K-wire and another article used combined closed reduction and percutaneous pinning and intramedullary K-wire. As regards the operation time; elastic stable intramedullary nails had the shortest time with a mean of 39.7 min (range: 37.5-41.9 min), while closed reduction and percutaneous pinning had the longest time with a mean of 75.47 min (range: 55.9-92.1 min). The shortest healing time was observed in miniplate with a mean of 7.2 weeks, while the most prolonged was in conservative management with a mean of 12 weeks and closed reduction and percutaneous pinning was a mean of 10 weeks. Regarding Flynn's criteria, all participants received excellent and good except in closed reduction and percutaneous pinning; 13 cases were fair and 2 cases were poor. Regarding complications, the most commonly observed complication after metaphyseal-diaphyseal junction fracture was cubitus varus, the highest incidence was in conservative management (33% of cases), followed by closed reduction and percutaneous pinning (10.9% of cases), the least incidence was observed in elastic stable intramedullary nails (3.77% of cases), and none of the cases treated with mini plate developed this complication. Other complications were observed only with closed reduction and percutaneous pinning; 8.5% of cases developed fixation loss, 6.2% of cases had a significantly reduced range of motion, and one case refractured. Conclusion: Pediatric distal humerus metaphyseal-diaphyseal junction fractures should be distinguished from the more prevalent supracondylar humerus fractures, as conventional pinning techniques are associated with a higher incidence of complications and increased both operative and healing times.