Should we repair nonunion of the lateral humeral condyle in children?

Purpose: Patients with nonunion of the lateral humeral condyle often present with pain, instability, progressive cubitus valgus and tardy ulnar nerve palsy. At present repairing of this nonunion is still controversial due to previous reported complications such as stiffness and avascular necrosis (AVN). This study reported the outcomes of treatment in nonunion of the lateral humeral condyle in children.
Methods: We evaluated 17 patients with nonunion of the lateral humeral condyle after repair. Corrective osteotomy was done in patients with valgus deformity of more than 30 degrees and anterior ulnar nerve transposition in patients with ulnar nerve symptoms. Evaluations were performed with the use of radiographic examination, clinical assessment and also evaluated using Mayo Elbow Performance score by interview and physical examination interpreted as excellent (≥ 90 points), good (75-89 points), fair (60-74 points), and poor (<60 points).
Results: Nine patients were male, and eight were female. The mean age at presentation was 6.5 years. The average interval from the injury to the presentation of the symptoms was 31.5 months. The average duration of follow-up was 48.6 months. The range of flexion was 130-145° (average 130°). The Mayo elbow performance score was excellent in 11 patients and good in six patients. Mean Mayo elbow performance score was 94. Osseous union was achieved after the initial operation in 16 patients. One patient had re-operation using local bone graft and healed nicely. Determination of correlation coefficients found good correlation between neglected time and Mayo performance score <89 (-0.741), age of patient was fairly well correlated with Mayo performance score <89 (-0.635) and ROC curve show that neglected lateral condyle fracture in children more than 28 months will reduce the Mayo score.
Conclusion: (1) We support osteosynthesis for children, not only for those who have pain but also for those who are less symptomatic. Good and excellent results by Mayo elbow performance score were found in all patients, and all nonunions were united with good range of motion. (2) Neglecting lateral condyle fracture in children more than 28 months will reduce Mayo performance score to below 89 points. (3) Cases presenting with AVN pre-operatively can still have good results and remodeling potential with congruency of the joint.