Three-Dimensional Surgical Planning and Patient-Specific Osteotomy Guide in the Management of Chronic Monteggia Fracture: A Case Report.

INTRODUCTION: Chronic Monteggia fracture-dislocations, characterized by persistent radial head dislocation and ulnar malunion, pose significant reconstructive challenges. While three-dimensional (3D) printing has shown promise in upper extremity deformity correction, its application in chronic Monteggia lesions remains limited. CASE REPORT: We report the case of a 24-year-old male presenting with a 1-year history of forearm pain following failed surgical management of a Monteggia fracture. Radiographs revealed a Bado type I chronic Monteggia fracture-dislocation. A personalized 3D-printed osteotomy guide was designed from pre-operative computed tomography data to assist in corrective ulnar osteotomy. The surgical plan included implant removal, corrective osteotomy using a customized surgical guide, bone grafting, and annular ligament reconstruction if unstable radiocapitellar joint after correction. Postoperatively, the patient initially regained functional elbow motion but later developed oligotrophic non-union. Revision surgery with repeat bone grafting resulted in solid union and complete functional recovery. CONCLUSION: This case highlights the potential of 3D-assisted pre-operative planning and patient-specific guides in managing chronic Monteggia deformities. It contributes to the growing evidence supporting personalized surgical technologies in complex upper-limb reconstruction.