Impacts of Fracture Types on Success Rate of Closed Reduction and Percutaneous Pinning in Pediatric Lateral Condyle Humerus Fractures Displaced >4 mm.

Closed reduction and percutaneous pinning (CRPP) is a promising treatment for pediatric lateral condyle humerus fractures (LCHFs) displaced >4 mm. However, few studies discussed roles of fracture types on success of CRPP in LCHFs. This study aimed to analyze the impacts of types of LCHFs displaced >4 mm on the success rate of CRPP.We retrospectively reviewed 66 consecutive pediatric LCHFs attempted CRPP at our center. Song, Milch, Jakob, and Weiss classification were used to classify LCHFs. The fracture gap ≤2 mm and step of articular surface ≤2 mm were deemed as a successful CRPP. Otherwise, open reduction and internal fixation (ORIF) would be performed. Different fracture types and preoperative displacement were analyzed for their roles on success rate of CRPP in treating LCHFs displaced >4 mm.Fifty patients met the inclusion criteria were finally included in this study. Results showed that Milch type II LCHFs had a higher success rate of CRPP than type I LCHFs (P=0.03, <0.05). Correlation was found between Milch types and success rate of CRPP displaced >4 mm. No difference was found between Song stage 4 and 5 LCHFs displaced >4 mm in success rate of CRPP (P=0.90, >0.05), also no difference was found in pre-operative displacement between CRPP group and ORIF group.Milch classification is more important than Song classification in the success rate of CRPP when treating LCHFs displaced >4 mm. Milch type II LCHFs are recommended to be treated with CRPP, while Milch type I LCHFs are recommended to be treated with ORIF. The current study confirm Song's initial report that closed reduction can be successful and should be attempted for fractures with such displacement rather than going directly to ORIF.Level III.