Intraoperative Arthroscopic Findings of Ulnar Impaction Syndrome

Abstract

Purpose: The purpose of this study was to compare the preoperative magnetic resonance imaging (MRI) findings and intraoperative arthroscopic findings in ulnar impaction syndrome, and to assess the necessity of the arthroscopic evaluation in ulnar shortening osteotomy.Methods: We retrospectively reviewed 46 patients of idiopathic ulnar impaction syndrome, treated by ulnar shortening osteotomy and arthroscopic evaluation, from February 2012 to June 2018. In preoperative MRI and intraoperative arthroscopy, lunate, triquetrum, triangular fibrocartilage complex (TFCC) and lunotriquetral ligament were evaluated.Results: The chance to see the findings of chondromalacia of the lunate and triquetral cartilage in arthroscopy (58% and 2%) was less than the findings of abnormal signal intensity of the lunate and triquetrum in MRI (65% and 22%). The incidence of TFCC lesion in arthroscopy (89%) was almost equal with that of abnormal signal intensity of TFCC in MRI findings (87%). But there were 24 cases (52%) where the prediction of triangular fibrocartilage lesions in MRI was incorrect. In 19 cases (41%), arthroscopic findings were not appropriate with the disease stage of Palmer’s original classification. Conclusion: Although some recent reports say that arthroscopic surgery is not necessary in the treatment of ulnar impaction syndrome, we could confirm the value of arthroscopic evaluation for the identification of ulnocarpal pathologies. We would like to recommend the arthroscopic evaluation of ulnocarpal joint at the same time of the ulnar shortening procedure.