A modified partial wedge-shaped metaphyseal ulnar osteotomy for the treatment of ulnar impaction syndrome with reverse oblique sigmoid notch.

We describe a modified metaphyseal ulnar osteotomy to treat ulnar impaction syndrome with a reverse oblique sigmoid notch. Based on a computational analysis of radiographs, a modified wedge metaphyseal ulnar osteotomy was devised with its apex positioned at the ulnar styloid base to avoid impaction between the sigmoid notch and ulnar head. Subsequently, nine patients with ulnar impaction syndrome and a reverse oblique sigmoid notch underwent this operation, combined with arthroscopic exploration and transosseous triangular fibrocartilage complex repair. The mean follow-up was 14 months. All patients achieved bone union within 5 weeks, with no degenerative changes being observed during the follow-up assessments. The final follow-up assessments revealed decreases in ulnar variance and in the scores for Visual Analogue Scale, Quick Disabilities of the Arm, Shoulder and Hand questionnaire and the Patient-Rated Wrist Evaluation. All patients achieved excellent or good grades on the Modified Mayo Wrist Score. This technique is effective in treating the ulnar impaction syndrome with a reverse oblique sigmoid notch.Level of evidence: IV.