Isaacs J, Frankenhoff J
A Master Skills Publication; Ed. Greenberg J, 2013; Chapter 13, Pages 137-148, 2013
Ulnar impaction syndrome (UIS), also known as ulnar abutment syndrome, is a painful degenerative process affecting the ulnar side of the wrist presumably in response to chronic ulnar-carpal overload. Initially recognized as sequela of radial shortening following malunited wrist fractures, eventually the role of atraumatic etiologies was recognized, as well. Though a higher incidence of UIS is noted in patients with a positive ulnar variance, the exact role of this anatomic variation in the development of ulnar-sided wrist pain is not completely understood. Regardless, both biomechanical and clinical data strongly supports the effectiveness of surgically “unloading” the ulnar side of the wrist in the treatment of this disorder. While this can be achieved through either a pen or arthroscopic resection of several millimeters of the distal ulnar articular surface and ulnar head, extraarticular ulnar shortening is the most commonly reported surgical treatment strategy. Through there is little agreement as to the best way to technically perform the ulna-shortening osteotomy, the adherence to well-established principle will improve the likelikehood of achieving a favorable outcome.