Ulnar Impaction Syndrome Secondary to Chronic Monteggia Fracture: A Case Report.

BACKGROUND: Report on surgical management of ulnar impaction syndrome secondary to chronic Monteggia fractures are limited, and optimal techniques and outcomes remain unclear. Herein, we report a case in which preoperative stress evaluation followed by diaphyseal-level ulnar-shortening osteotomy led to favorable clinical outcomes.

CASE DESCRIPTION: A 54-year-old woman with a childhood forearm injury presented with ulnar-sided wrist pain. Imaging revealed ulnar impaction syndrome with foveal triangular fibrocartilage complex (TFCC) injury. An asymptomatic anterior radial head dislocation, consistent with a chronic Monteggia fracture, was also identified. Conservative management was unsuccessful; thus, she underwent diaphyseal-level ulnar-shortening osteotomy and TFCC reconstruction. The dislocated radial head remained stable under longitudinal stress, justifying the ostomy alone without radial head intervention. Postoperatively, distal radioulnar joint instability resolved immediately. At 18 months, the radial head had not migrated proximally, and the patient was pain-free.

CLINICAL RELEVANCE: Ulnar-shortening osteotomy for ulnar impaction syndrome secondary to chronic Monteggia fracture raises concerns about proximal radial head migration through the interosseous membrane. However, our findings indicate that when the dislocated radial head remains stable under longitudinal stress, diaphyseal ulnar-shortening osteotomy may be an effective treatment option.