Ulnar impingement syndrome after Darrach procedure: treatment by advancement lengthening osteotomy of the ulna.

The Darrach procedure was the standard treatment for painful disorders of the radioulnar joint for several decades. However, recent articles have described unsatisfactory results after this procedure including dorso-palmar instability of the ulna, clicking upon rotation of the forearm, ulnar translocation of the carpus, and a painful ulnar impingement syndrome. Management of these problems following an ulnar shortening procedure requires restoration of ulnar length to provide stability to the triangular fibrocartilage complex and ulnar sling mechanism. Also, recurrent impingement must be prevented. A technique of ulnar lengthening by advancement step osteotomy in conjunction with a "matched" resection of the advanced ulna is presented. Three case reports illustrate its use.