Reconstructed animation from four-phase grip MRI of the wrist with ulnar-sided pain.

In order to visualize dynamic variations related to ulnar-sided wrist pain, animation was reconstructed from T2* coronal-sectioned magnetic resonance imaging in each of the four phases of grip motion for nine wrists in patients with ulnar pain. Eight of the nine wrists showed a positive ulnar variance of less than 2 mm. Ulnocarpal impaction and triangular fibrocartilage complex injury were assessed on the basis of animation and arthroscopy, respectively. Animation revealed ulnocarpal impaction in four wrists. In one of the four wrists, the torn portion of the articular disc was impinged between the ulnar head and ulnar proximal side of the lunate. In another wrist, the ulnar head impacted the lunate directly through the defect in the articular disc that had previously been excised. An ulnar shortening osteotomy successfully relieved ulnar wrist pain in all four cases with both ulnocarpal impaction and Palmer's Class II triangular fibrocartilage complex tears. This method demonstrated impairment of the articular disc and longitudinal instability of the distal radioulnar joint simultaneously and should be of value in investigating dynamic pathophysiology causing ulnar wrist pain.