The ulna osteotomy locking plate II in patients with ulnocarpal impaction syndrome: a retrospective evaluation

Ulnocarpal impaction syndrome is one general cause of ulnar-sided wrist pain. If conservative therapy fails, various surgical procedures and different instruments and implants are available. The aim of this study was to evaluate the results of the ulna osteotomy locking (UOL) plate II from the manufacturer I.T.S. Thirty-five cases (34 patients) with primary or secondary ulnar impaction syndrome treated with the UOL plate II were evaluated retrospectively. Demographic, radiologic and clinical data were collected focusing on the postoperative ulnar variance and the complication rate, especially non-unions and signs of implant failure. Median age was 48 years, with 20 female and 15 male cases. The measured median postoperative ulnar variance was − 0.8 mm (Q1: − 2; Q3: 0). There was no case of a non-union or a postoperative infection. Postoperative complications included one case of secondary dislocation, one case of a neuroma of the dorsal branch of the ulnar nerve and one mild CRPS. A total of six cases wished for an implant removal in the follow-up, of which five complained about local irritation caused by the plate. The UOL plate II has proven to be a reliable option for ulnar shortening osteotomy with a low implant associated complication rate, especially no case of non-union. The occasional need for implant removal should be considered. Due to the retrospective study design, a prospective study comparing the UOL II plate to different plating systems would be desirable.