Comparative study of lateral condyle fracture with or without posteromedial elbow dislocation in children

The purpose of this study was to compare the surgical findings and clinical outcomes of the lateral condylar fractures of the humerus with or without posteromedial elbow dislocation in children. Between January 2013 and June 2016, a total of 21 Milch type II humeral condylar fractures were treated with open reduction and internal fixation. The average follow-up was 2.8 years (range, 1 to 4 years). There were 8 patients in group A with posteromedial elbow dislocation and 13 patients in group B without dislocation. The surgical findings, bone union time, the recovery of function, and the time needed to regain full range of elbow movement were all compared. The complications encountered during operation and follow-up were documented. Surgical findings showed that all the fracture lines in group A extended to the lower medial part of the trochlea. The fracture lines in group B only involved the lateral and middle part of the trochlea. There were no significant differences in bone union time between the two groups. The time needed to regain full range of elbow movement after operation in group A (21 +/- 4.0 weeks) was significantly longer in group B (17.85 +/- 2.51 weeks; P < 0.05). There were no significant differences in MEPS, the flexion-extension arc, and the total range of flexion and extension between the two groups (P < 0.05).There was no difference in complications between the two groups (P < 0.05). The fracture lines in Milch type II fractures of lateral humeral condyle with concomitant posteromedial elbow dislocation extend to the lower medial part of the trochlea. The soft tissue injuries are more badly so that longer time needed to regain full range of elbow movement. Initial recognition of this rare injury is essential to regain satisfactory functional outcomes.