To evaluate the efficacy of the in situ late osteosynthesis for slightly displaced fractures of the lateral humeral condyle.

From 2000 to 2004, 12 patients (8 boys and 4 girls) were managed with in situ late osteosynthesis for fractures of the lateral humeral condyle. The average age at the time of operation was 6 years 1 month (1 year 7 months~9 years 1 month), and the mean amount of fragment displacement was 3.3 mm (2.0~4.5 mm). The operative procedure included curettage and in situ fixation of the fragment.

Bony union was achieved in all cases after avg. 48 months (33~73 months) follow-up assessment. According to the score system of Dhillon et al, 7 patients had excellent, 3 had good, 2 had fair results. None of the patients developed avascular necrosis or premature closure of the epiphysis.

We suggest that in situ fixation is an effective method for the late treatment of slightly displaced fracture of the lateral humeral condyle.