Extensor Tendon Rupture in Ulnar Impingement Syndrome: A Case Report

Ulnar impingement syndrome is caused by a shortened ulna impinging on the distal radius and causing a painful, disabling pseudoarthrosis. Vaughan-Jackson syndrome is characterized by a disruption of the digital extensor tendons, beginning on the ulnar side with the extensor digiti minimi (EDM) and extensor digitorum communis (EDC) tendon of the small finger. While ulnar impingement and Vaughan-Jackson syndrome are not uncommon, it is rare to observe the two conditions occurring simultaneously. We report a unique case of ulnar impingement syndrome presenting with Vaughan-Jackson syndrome, revealing that the degenerative changes from ulnar impingement syndrome can cause attrition rupture of the EDM and EDC tendon of the little finger. This entails increased clinical significance of ulnar impingement, because in addition to its potential to cause debilitating pain, there is also consequence of functional deficits if extensor tendon rupture were to occur due to progressive degenerative changes. The surgical management of distal radioulnar joint (DRUJ) arthritis arising from ulnar impingement may include various intra-operative techniques to prevent post-operative extensor tendon rupture.