Ulnar Neuroma-in-Continuity Following Distal Radius Fracture: A Rare Complication Requiring Reconstruction with Nerve Allograft and Dynamic Tendon Transfer

Ulnar nerve injury following distal radius fracture is uncommon and typically presents as transient neuropraxia. We report a case of traumatic ulnar nerve neuroma-in-continuity following open distal radius fracture in a 57-year-old man with associated scapholunate dissociation. Two months after surgical fixation, he developed intrinsic muscle wasting over the left hand and persistent sensory deficits in the ring and little fingers. Nerve conduction study and EMG suggested axonotmesis of the ulnar nerve. Magnetic resonance imaging demonstrated fusiform thickening of ulnar nerve consistent with neuroma-in-continuity. Patient underwent excision of neuroma-in-continuity with nerve allograft reconstruction and dynamic tendon transfer using flexor digitorum superficialis tendon of the middle finger. At 9 months, the patient demonstrated resolution of claw deformity and satisfactory functional recovery. Persistent neurological deficits after distal radius fractures should prompt early investigation and consideration for structural nerve injury.