Suture button versus syndesmosis screw fixation in pronation-external rotation ankle fractures: A minimum 6-year follow-up of a randomised controlled trial.

OBJECTIVE: Randomised controlled trials (RCT) with short-term follow-ups have shown that, in treatment of syndesmosis injuries, a suture button device (SB) resulted in better radiographic and functional outcome compared to syndesmosis screw fixation (SS). However, only one RCT has reported long-term results; thus, the syndesmosis malreduction rates for both implants might increase during longer follow-up. The primary objective of this RCT was to evaluate the maintenance of syndesmosis reduction with the SS compared to the SB fixation in patients during a minimum follow-up of 6-years. The secondary objectives were to assess the post-traumatic osteoarthritis (OA) grade and the functional outcome. PATIENTS AND METHODS: At Oulu University Hospital, between January 2010 and December 2011, we enrolled 43 patients with Lauge-Hansen pronation-external rotation type 4/Weber C, ankle fractures with unstable syndesmosis. Patients were randomised to treatment with either a single 3.5-mm tricortical SS (22 patients) or an SB (21 patients). The mean follow-up was 7.1 years (range, 6.2-7.9). Syndesmosis reduction and OA grade was assessed with standing cone-beam computed tomography (CBCT) of both ankles. Malreduction was defined as >2 mm side-to-side difference in the mean width of the syndesmosis. OA was graded according to the Morrey & Wiedeman classification. The Olerud-Molander Ankle Outcome Score (OMAS) and a quality of life questionnaire (RAND 36-Item Health Survey) were used to evaluate functional outcome. RESULTS: Two syndesmoses in the SS group and one in the SB group were malreduced (P = 0.58). Moderate OA after a mean of 7 years post-injury was common. In the SS and SB groups, 9 of 16 and 11 of 13 patients, respectively, had one or more grades serious OA in the injured ankle than in the uninjured ankle (P = 0.11). The mean OMAS was 88 in the SS group and 78 in the SB group (difference between means 7.1, 95% CI: -7.0-21.1, P = 0.32). The RAND-36 results did not differ between groups. CONCLUSION: The SS and SB maintained syndesmosis reduction equally well during follow-up. Our study findings also suggest that both methods result in moderate OA rates and the functional outcome is comparable between these two syndesmosis fixation methods.

A prospective randomised study comparing TightRope and syndesmotic screw fixation for accuracy and maintenance of syndesmotic reduction assessed with bilateral computed tomography.

BACKGROUND: The accuracy and maintenance of syndesmosis reduction are essential when treating ankle fractures with accompanying syndesmosis injuries. The primary aim of this study was to compare syndesmosis screw and TightRope fixation in terms of accuracy and maintenance of syndesmosis reduction using bilateral computed tomography (CT). STUDY DESIGN: Single centre, prospective randomised controlled clinical trial; Level of evidence 1. METHODS: This study (ClinicalTrials.gov, NCT01742650) compared fixation with TightRope(®) (Arthrex, Naples, FL, USA) or with one 3.5-mm tricortical trans-syndesmotic screw in terms of accuracy and maintenance of syndesmosis reduction in Lauge-Hansen pronation external rotation, Weber C-type ankle fractures with associated syndesmosis injury. Twenty-one patients were randomised to TightRope fixation and 22 to syndesmotic screw fixation. Syndesmosis reduction was assessed using bilateral CT intraoperatively or postoperatively, and also at least 2 years after surgery. Functional outcomes and quality of life were assessed using the Olerud-Molander score, a 100-mm Visual Analogue Scale, the Foot and Ankle Outcome Score, and the RAND 36-Item Health Survey. Grade of osteoarthritis was qualified with follow-up cone-beam CT. RESULTS: According to surgeons' assessment from intraoperative CT, screw fixation resulted in syndesmosis malreduction in one case whereas seven syndesmosis were considered malreduced when TightRope was used. However, open exploration and postoperative CT of these seven cases revealed that syndesmosis was well reduced if the ankle was supported at 90˚. Retrospective analysis of the intra- and post-operative CT by a radiologist showed that one patient in each group had incongruent syndesmosis. Follow-up CT identified three patients with malreduced syndesmosis in the syndesmotic screw fixation group, whereas malreduction was seen in one patient in the TightRope group (P = 0.33). Functional scores and the incidence of osteoarthritis showed no significant difference between groups. CONCLUSION: Syndesmotic screw and TightRope had similar postoperative malreduction rates. However, intraoperative CT scanning of ankles with TightRope fixation was misleading due to dynamic nature of the fixation. After at least 2 years of follow-up, malreduction rates may slightly increase when using trans-syndesmotic screw fixation, but reduction was well maintained when fixed with TightRope. Neither the incidence of ankle joint osteoarthritis nor functional outcome significantly differed between the fixation methods.

Effect of syndesmosis injury in SER IV (Weber B)-type ankle fractures on function and incidence of osteoarthritis.

BACKGROUND: Syndesmosis fixation of Lauge-Hansen SER IV, Weber B ankle fractures is controversial. This study compared a matched pair of SER IV patients with stress proven syndesmotic injuries with the same number without stress proven syndesmotic injury in terms of functional, pain, and radiologic result. METHODS: The study was based on a RCT-study comparing syndesmotic transfixation to no fixation in SER IV (Weber B)-type ankle fractures. Twenty-four patients with a syndesmosis injury found on the intraoperative 7.5 Nm standardized external rotation test were compared to 24 patients with a stable syndesmosis. The pairs were matched by fracture morphology, sex, and age. The primary outcome measure was ankle function as assessed by the Olerud-Molander score. Weight-bearing plain radiographs and 3T MRI of the injured ankle were used to assess ankle joint congruity and osteoarthritis, according to Kellgren-Lawrence classification and cartilage defects. RESULTS: The Olerud-Molander score was 86 in syndesmosis injury patients and 90 in patients with normal syndesmosis (P = .28). The incidence of ankle joint osteoarthritis on plain radiographs was not significantly different between the groups (Grade I 5% vs 21%; Grade II 86% vs 75%; Grade III 9% vs 4%; P = .34). MRI scans showed TC joint cartilage defects in 54% of the patients: 12 (56%) in the syndesmosis injury group vs 13 (54%) in the group without syndesmosis injury (P > .9). CONCLUSION: After 4 to 6 years of follow-up, clinical and radiologic outcome were not different in patients with syndesmosis injury compared to patients with stable syndesmosis in SER IV (Weber B)-type ankle fractures. LEVEL OF EVIDENCE: Prognostic Level II, comparative study.

Syndesmotic fixation in supination-external rotation ankle fractures: a prospective randomized study.

BACKGROUND: This study compared mid-term functional and radiologic results of syndesmotic transfixation with no fixation in supination external rotation (SER) ankle fractures with intraoperatively confirmed syndesmosis disruption. Our hypothesis was that early-stage good functional results would remain and unfixed syndesmosis disruption in SER IV ankle fractures would not lead to an increased incidence of osteoarthritis. METHODS: A prospective study of 140 operatively treated patients with Lauge-Hansen SER IV (Weber B) ankle fractures was performed. After bony fixation, the 7.5-Nm standardized external rotation stress test for both ankles was performed under fluoroscopy. A positive stress examination was defined as a difference of more than 2 mm side-to-side in the tibiotalar or tibiofibular clear spaces on mortise radiographs. The patients were randomized to either syndesmotic screw fixation (13 patients) or no syndesmotic fixation (11 patients). After a minimum of 4 years of follow-up (mean, 58 months), ankle function and pain (Olerud-Molander, a 100-mm visual analogue scale [VAS] for ankle function and pain) and quality of life (RAND-36) of all 24 patients were assessed. Ankle joint congruity and osteoarthritis were assessed using mortise and lateral projection plain weight-bearing radiographs and magnetic resonance imaging (MRI; 3T) scans. RESULTS: Improvement in Olerud-Molander score, VAS, and RAND-36 showed no significant difference between groups during the follow-up. In the syndesmotic transfixation group, improvements in all functional parameters and pain measurements were not significant, whereas in the group without syndesmotic fixation, the Olerud-Molander score improved from 84 to 93 (P = .007) and the pain (VAS) score improved from 11 to 4 (P = .038) from 1 year to last follow-up. X-ray or MRI imaging showed no difference between groups at the last follow-up visit. CONCLUSION: With the numbers available, no significant difference in functional outcome or radiologic findings could be detected between syndesmosis transfixation and no-fixation patients with SER IV ankle fracture after a minimum of 4 years of follow-up. LEVEL OF EVIDENCE: Level II, prospective comparative study.