Abstract
Chronic Monteggia fracture-dislocations in children, defined by presentation beyond four weeks, pose significant surgical challenges. While ulnar osteotomy is central to reconstruction, the optimal technique for ensuring stable radiocapitellar reduction remains a topic of debate. We present the cases of two nine-year-old patients with chronic Bado type I Monteggia lesions. The first patient underwent transverse ulnar osteotomy with annular ligament repair and temporary radiocapitellar fixation but developed recurrent radial head dislocation after K-wire removal. The second patient was treated with a sliding oblique ulnar osteotomy, achieving stable reduction without recurrence and maintaining full elbow motion. These contrasting outcomes underscore the importance of osteotomy configuration. Transverse osteotomies, although simple, offer limited bone contact and controlled correction, which can compromise stability. In contrast, the sliding oblique osteotomy provides increased cortical contact area and intrinsic stability, allowing for precise lengthening and angulation, which is critical in the setting of chronic soft-tissue contracture and joint incongruity. In the surgical management of chronic pediatric Monteggia lesions, the choice of ulnar osteotomy significantly impacts stability. A sliding oblique ulnar osteotomy offers biomechanical advantages over a transverse osteotomy, including greater inherent stability and controlled deformity correction, which may reduce the risk of recurrent dislocation. Surgical planning should prioritize osteotomy geometry to optimize outcomes.