Posterior interosseous nerve palsy associated with neglected pediatric Monteggia fracture-dislocation: A case report

Introduction: The main goal of the treatment is the anatomical reduction of the ulna fracture and the radial head dislocation in acute and chronic Monteggia cases. Acute pediatric Monteggia lesions are generally treated non-surgically; however, the treatment of chronic Monteggia is challenging. The aim of this article is to share our experiences about treatment of neglected Monteggia lesion. Presentation of case: A 6-year-old girl who underwent a surgery in our clinic for a missed Bado type-III Monteggia fracture-dislocation of the right elbow with concomitant posterior interosseous nerve (PIN) palsy, which resolved spontaneously after the operation. The operation consisted of open reduction of the radial head, transverse ulnar osteotomy and fixation with an intramedullary Kirchner wire, and annular ligament repair without exploring PIN. The patient was seen in routine follow-up periods until the postoperative first year using plain radiographies. At 16th week follow-up, all functions of the PIN were returned. At first-year follow-up, full range of elbow motion was observed; plain radiographies showed radiocapitellar joint congruency, and Mayo Elbow Performance Index was one hundred. Discussion: Treatment planning for chronic, neglected or missed Monteggia fractures is challenging. There is no consensus about the definitive treatment in the literature. Conclusion: We recommend anatomic and stable restoration of radiocapitellar joint by correcting ulna deformity. Radiocapitellar fixation and PIN exploration may not be necessary in all neglected Monteggia lesions