Functional and Radiographic Outcomes after the Removal of Suture-Button Fixation Device in the Treatment of Syndesmosis Diastasis

CATEGORY: Trauma INTRODUCTION/PURPOSE: Suture-button fixation device (TightRope, Arthrex, Naples, Florida) is devised to obviate the need for second operation for removal in the treatment of syndesmosis diastasis, but considerable removal rate has been reported. Nevertheless, functional and radiographic outcomes after suture-button fixation device removal has not yet been well documented. Therefore, the purpose of this study is to investigate the functional and radiographic outcomes of syndesmosis fixation treated with suture-button device before and after device removal. METHODS: The records of 30 patients with syndesmosis injury who underwent suture-button fixation and later device removal between August 2009 and September 2017 were investigated. The mean postoperative time to device removal was 11.9 months (range, 7-19). In plain radiograph, tibiofibula clear space (TFCS), tibiofibula overlap (TFO), and medial clear space (MCS) were measured at three specific follow-up period; immediate postoperative (F1), just before device removal (F2), and at least three months after device removal (F3). For subgroup of 18 patients with CT scans, the Anterior to posterior (A/P) ratio (Normal range: 0.8 -1.2) was measured to investigate malreduction of syndesmosis and they were divided into two groups according to their accuracy of reduction. Additionally, functional outcomes were recorded and compared using American Orthopedic Foot and Ankle (AOFAS) score. Repeated measurement analysis of variance was performed to statistically compare the data and statistical significance was set at P < 0.05. RESULTS: In plain radiographs, TFCS, TFO, MCS at three specific follow-up period showed no significant differences. In CT analysis at immediate postoperative period, 6 cases (30%) revealed malreduction, but 5 of them showed spontaneous reduction at follow- up just before device removal. Malreduced patients (n = 6) had a mean A/P ratio of 1.28 (range, 0.78 -1.52) at F1, 1.08 (range, 0.81- 1.21) at F2, and 1.08 (range, 0.83 -1.22) at F3 (F1, F2: p = 0.021, F1, F3: p = 0.032, F2, F3: p > 0.05). Patients with initial adequate reduction (n = 12) continued to have a reduced syndesmosis during the follow-up period and after the device removal. The AOFAS score did not change significantly before and after removal. CONCLUSION: Our investigation showed that the removal of suture-button device for syndesmosis fixation at average 1-year postoperative time does not bring out reduction loss or functional changes. Thus, removal is advisable for the patients with irritation or discomfort related to device. Furthermore, malreduced syndesmosis after tightrope fixation may have possibility of spontaneous reduction during the follow-up period.