Distal Radioulnar Joint Volar Instability After Ligament Reconstruction Failure Treated with Sigmoid Notch Osteotomy

Because osseous abnormalities result in distal radioulnar joint instability, a sigmoid notch osteotomy is used to restore stability. This article describes a case of distal radioulnar joint volar instability treated with sigmoid notch osteotomy of the volar rim. A 22-year-old man presented with a 9-month history of right wrist pain with volar instability after a fall, which was treated conservatively. He reported a history of remote trauma when he was 7 years old but had been asymptomatic since then. Four months later, he underwent anatomical distal radioulnar joint ligament reconstruction at another hospital after a diagnosis of distal radioulnar joint instability, but the instability had persisted. Computed tomography revealed dynamic volar subluxation of the ulnar head with hypoplasia and a flattened volar lip of the sigmoid notch. Therefore, a sigmoid notch osteotomy of the volar rim was performed. Postoperatively, an above-elbow cast was applied with forearm pronation for 6 weeks. Six months later, the patient had regained 60 degrees of supination and 70 degrees of pronation. He reported minor pain and no instability. Computed tomography scan at 6 months postoperatively revealed union of the osteotomy site and confirmed the maintenance of reduction. The patient returned to work.