[Study on stability of elastic fixation with TightRope button-loop titanium plate in the reconstruction of the lower...

To compare clinical efficacy of TightRope button-loop titanium plate elastic fixation and hollow tension screw fixation in treating ankle fractures with accompanying tibiofibular syndesmosis injury.

A retrospective analysis was conducted on 42 patients with ankle fractures accompanied by syndesmosis injury who were admitted from January 2020 to January 2023. The patients were divided into TightRope group and cannulated screw group based on fixation methods. There were 19 patients in TightRope group, including 8 males and 11 females;aged from 34 to 67 years old with an average of (45.63±8.75) years old;body mass index (BMI) ranged from 20.1 to 26.7 kg·m^-2 with an average of (23.36±1.88) kg·m^-2;the course of disease ranged from 1 to 6 days with an average of(2.42±1.58) days;9 patients on the left side and 10 patients on the right side;4 patients with pronation abduction type, 12 patients with pronation eversion type, and 3 patients with supination eversion type according to Lauge-Hansen classification;elastic fixation was performed using TightRope button band titanium plates. There were 23 patients in cannulated screw group, including 15 males and 8 females;aged from 32 to 56 years old with an average of (43.22±6.82) years old;BMI ranged from 19.6 to 28.6 kg·m-2 with an average of(24.18±1.96) kg·m^-2;the course of disease ranged from 1 to 5 days with an average of (2.61±1.03) days;10 patients on the left side and 13 patients on the right side;4 patients with pronation abduction type, 14 patients with pronation eversion type, and 5 patients with supination eversion type according to Lauge-Hansen classification;hollow pull force screws were used for fixation. American Orthopaedic Foot and Ankle Society(AOFAS) ankle-hindfoot scores, the distance between the lower tibia and fibula, the length of the lower tibia-fibula overlap, AOFAS-AH grade, total gait score, the partial and complete weight-bearing time, and complications between two groups before operation and 3, 6, and 12 months after operation were compared.

Both groups were followed up after operation, the follow-up period for TightRope group ranged from 12 to 16 months with an average of (13.68±1.11) months, while that for cannulated screw group ranged from 12 to 16 months with an average of (13.83±0.98) months. At 3 months after operation, pain and total score of TightRope group on AOFAS ankle-hindfoot scale were (37.37±4.52) and (91.16±7.79) points respectively, which were higher than those of hollow screw group (30.87±6.68) and (83.78±13.06) points, and the differences were statistically significant (P<0.05). There were no statistically significant difference in scores of the other items and total score of AOFAS ankle-hindfoot between two groups before operation and 3, 6, and 12 months after operation (P>0.05). The scores for each item and total score between two groups at 3, 6, and 12 months after operation were all higher than those before operation, and the differences were statistically significant (P<0.05). There was no statistically significant difference in excellent rate of AOFAS ankle-hindfoot between two groups at 12 months after operation (P>0.05). There were no statistically significant difference in distance between the lower tibia and fibula, the length of the lower tibia-fibula overlap between two groups at preoperative stage and at 3, 6, and 12 months after operation(P>0.05). The distance and overlap length of the lower tibiofibular interval at 3, 6, and 12 months after operation between two groups were significantly improved compared to those before operation, and the differences were statistically significant(P<0.05). Postoperative gait score of TightRope group at 12 months was (90.47±2.27) points, which was higher than that of cannulated screw group (88.78±2.35) points, and the difference was statistically significant (P<0.05). The duration of partial weight-bearing in TightRope group was (4.05±0.91) weeks, which was shorter than that in cannulated screw group (5.09±1.47) weeks, and the difference was statistically significant (P<0.05). There was no statistically significant difference in duration of complete weight-bearing between two groups (P>0.05). After operation, the gap between the tibia and fibula was normal between groups, and the fracture alignment was good. There was no infection or poor fracture healing. In cannulated screw group, 2 patients had screw fractures after partial weight-bearing and the screws were removed through surgery.

TightRope button-loop titanium plate with elastic fixation could maintain the stability of distal tibiofibular syndesmosis while promoting the early recovery of ankle joint function, reducing postoperative complications and the need for the secondary surgeries. However, its long-term efficacy still requires further research and verification.