The Impact of Suture Button Removal in Syndesmosis Fixation

Abstract

The suture button (SB) device was introduced to negate the need for routine hardware removal in the treatment of syndesmosis injuries. However, a considerable SB removal rate has been reported, and the impact of removal is unknown. This study aimed to evaluate the radiographic and clinical outcomes after removal of SB for syndesmosis fixation. A total of 36 patients who underwent removal surgery after syndesmosis fixation using SB were identified. The mean postoperative time to removal was 12.2 months. On a plain radiograph, tibiofibular clear space (TFCS) was measured and compared at three follow-up time points. In patients with computed tomography (CT) imaging (n = 18), the anterior-to-posterior (A/P) ratio was measured to evaluate changes in quality of reduction. Additionally, clinical outcomes were assessed. There were no significant differences in TFCS between the three follow-up periods. None of the patients exhibited recurrent diastasis after SB removal. Although CT analysis demonstrated malreduction in six patients (33.3%), five of six patients had a subsequent spontaneous reduction of the syndesmosis. Clinically, all patients described the resolution of symptoms related to painful hardware at the final follow-up. Our results demonstrate that SB removal at one year following syndesmosis fixation leads to improved clinical symptoms without negatively impacting the quality of syndesmosis reduction.

Keywords: ankle fracture; diastasis; removal; suture button; syndesmosis; syndesmosis injury; tibiofibular joint.

Figure 1

Anteroposterior measurement ratio (A/P ratio) was calculated by measuring the distance from the central point of the incisura to the most anterior (a) and posterior (b) edge of the fibula. The central point of the incisura was measured by calculating half the distance between the anterior and posterior margins of the incisura.

Figure 2

Preoperative, intraoperative, and postoperative images of a patient with syndesmosis injury concurrent with a lateral malleolar fracture: (A) ankle anteroposterior (AP) view reveals mild widening tibiofibular space (arrow) and medial clear space (asterisk); (B) ankle mortise view shows a fracture line along the fibula; (C) intraoperative image demonstrating overt widening of the tibiofibular space (arrowheads), indicating a syndesmosis injury (positive hook test); (D–F) ankle AP views show maintenance of reduction throughout the follow-up period ((D), immediate postoperative; (E), just before hardware removal; (F), three months after hardware removal).

Figure 3

Sequential change of syndesmosis reduction in computed tomography: (A) anteriorly malreduced syndesmosis in immediate postoperative (T1) image. (A/P ratio = 1.5); (B) spontaneous reduction of malreduced syndesmosis a year after initial fixation (T2, just before hardware removal). Note centered fibular in relation to incisura compared to (A) (A/P ratio = 1.2); (C) there was no difference in syndesmosis reduction status three months after suture button removal (T3) (A/P ratio = 1.2). Abbreviations: A/P ratio, anteroposterior measurement ratio.

Figure 4

Anteroposterior (A/P) ratio of the syndesmosis in the initially malreduced and adequately reduced group during the study period. In the initially malreduced group, the A/P ratio changed from the immediate postoperative period (T1) to just before suture button removal (T2) with statistical significance (p < 0.05), and there were no changes after suture button removal (T3). There were no changes in the adequately reduced group during the study period. *, p < 0.05; ns, not significant.

Figure 5

Functional outcomes before (T2) and after hardware removal (T3). Mean and standard deviation of AOFAS at T2 (94.3 ± 5.8) and T3 (95.9 ± 5.0); ankle dorsiflexion at T2 (24.3 ± 3.8 degrees) and T3 (25.7 ± 3.5 degrees); ankle plantarflexion at T2 (35.7 ± 2.7 degrees) and T3 (36.2 ± 1.8 degrees).

Figure 6

Sequential axial images of computed tomography showing cortical lysis of the fibula following suture button (SB) fixation: (A) immediate postoperative image showing intact fibular cortex facing the oblong button of the SB; (B) a year after initial fixation, medial translation of the oblong button is noticed (asterisk) with a mild widening of the tibiofibular space; (C) after SB removal, definite cortical lysis of the fibula is observed (white arrowhead).