Predictors of ideal outcomes after reconstructive surgery for chronic Monteggia fracture in children

Background: We aimed to analyze surgical outcomes of reconstructive surgery for chronic Monteggia fracture, which is one of the most challenging problems for orthopaedic surgeons. Methods: Twenty-eight patients were followed during 55.6 ± 32.0 months after open reduction of the radial head combined with ulnar osteotomy and annular ligament reconstruction. The mean interval from trauma was 15.1 ± 19.6 months, and the mean age at the surgery was 9.1 ± 3.5 years. In addition to the chronological age, elbow maturity was assessed using the Sauvegrain score. Surgical outcomes were primarily evaluated using the Kim's score. In addition, we newly defined more successful criteria for the ideal surgical outcomes, equivalent to preinjury status. Results: There were 19 excellent, 3 good, 4 fair, and 2 poor outcomes based on the Kim's scoring system. Among the 19 patients with excellent outcomes, 14 met our criteria for the ideal outcomes. The age (p < 0.001) and the Sauvegrain score (p < 0.001) were lower, and the interval (p = 0.004) was shorter in 14 patients with ideal outcomes. There were 9 patients with preoperative deformation of the radial head, and all of them showed non-ideal outcomes. In regression analyses, lower Sauvegrain score (p = 0.004) and shorter interval (p = 0.012) were associated with higher postoperative Kim's score, and lower Sauvegrain score (p = 0.031) was related to the achievement of the ideal outcomes. With the Sauvegrain score of >21.5, all patients had postoperative re-dislocation or osteoarthritic changes regardless of the interval. With the Sauvegrain score of <21.5 and an interval of ≤7 months, the ideal outcomes were achieved in 85.7%, and no patients had postoperative re-dislocation or osteoarthritic changes. Conclusion: Over the skeletal ages of 14 years in boys and 11.5 years in girls, reconstructive surgery must be cautiously indicated. Under these skeletal ages with an interval of ≤7 months and undeformed radial head, it appears to be ideal. Study design: Level III, Retrospective comparative study.