The Valid Diagnostic Parameters in Bilateral CT Scan to Predict Unstable Syndesmotic Injury with Ankle Fracture

Preoperative CT parameters to predict tibiofibular syndesmosis injury associated with ankle fracture: a propensity score-matched analysis

BACKGROUND

Untreated ankle fractures with concomitant tibiofibular syndesmosis injury often lead to postoperative pain and early traumatic arthritis. CT has advantages in the preoperative diagnosis of combined ankle injuries. However, a few studies have investigated the best preoperative CT parameters to predict tibiofibular syndesmosis injuries associated with ankle fractures. This study aimed to identify and evaluate the optimal preoperative CT parameters for predicting tibiofibular syndesmosis injuries associated with ankle fractures.

METHODS

We retrospectively analyzed 129 patients who underwent preoperative CT of an ankle fracture treated between January 2016 and April 2022 at a tertiary A hospital. All patients underwent open reduction and internal fixation and intraoperative stability testing. Based on the Cotton test, the patients were divided into the stable group (n = 83, 64.3%) and unstable group (n = 46, 35.7%). After 1:1 propensity score matching, the general conditions, anterior tibiofibular distance (TFD), posterior TFD, maximum TFD, tibiofibular syndesmosis area, sagittal fracture angle, Angle-A, and Angle-B were compared between the stable and unstable groups.

RESULTS

The propensity score-matched cohort comprised 82 patients. There were no significant differences between the stable and unstable groups in sex, age, affected side, operation interval, injury mechanism, Lauge-Hansen classification, sagittal fracture angle, and Angle-A (all P > 0.05). Compared with the stable group, the unstable group had a significantly greater aTFD, pTFD, maxTFD, and area (all P < 0.05). PTFD, maxTFD, and area were positively correlated with joint instability. Angle-B was smaller in the unstable group (57.13°) than the stable group (65.56°). ROC analysis showed that Area (AUC 0.711) and maxTFD (AUC 0.707) had the highest diagnostic efficacy.

CONCLUSION

MaxTFD and Area were the best predictive parameters; a larger Area was associated with a higher likelihood of instability of the tibiofibular syndesmosis after ankle fracture fixation.

Classifications of posterior malleolar fractures: a systematic literature review

INTRODUCTION

Complex ankle fractures frequently involve the posterior malleolus. Many classifications describing posterior malleolar fractures (PMF) exist. The aim of this study was to provide a systematic literature review to outline existing PMF classifications and estimate their accuracy.

METHODS

The databases PubMed and Scopus were searched without time limits. Only specific PMF classifications were included; general ankle and/or pilon fracture classifications were excluded. Selection and data extraction was performed by three independent observers. The systematic literature search was performed according to the current criteria of Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA). The methodological quality of the included studies was quantified using the modified Coleman score.

RESULTS

A total of 110 studies with a total of 12.614 patients were included. Four main classifications were identified: Those describing the size of the posterior malleolar fracture (n = 66), Haraguchi (n = 44), Bartoníček/Rammelt (n = 21) and Mason (n = 12). The quality of the studies was moderate to good with a median Coleman-score of 43.5 (14-79) and a weighted median Coleman-score of 42.5 points. All classifications achieved a substantial to perfect score regarding the inter- and intraobserver reliability, with Mason scoring the lowest in comparison.

CONCLUSIONS

None of the reviewed PMF classifications has been able to establish itself decisively in the literature. Most of the classifications are insufficient in terms of a derivable treatment algorithm or a prognosis with regard to outcome. However, as the Bartoníček/Rammelt classification has the greatest potential due to its treatment algorithm, its reliability in combination with consistent predictive values, its usage in clinical practice and research appears advisable.

A 10-Year Follow-Up of Ankle Syndesmotic Injuries: Prospective Comparison of Knotless Suture-Button Fixation and Syndesmotic Screw Fixation

Background: Acute syndesmosis injury (ASI) is an indication for surgical stabilization if instability is confirmed. In recent years, fixation using the knotless suture-button (SB) device has become increasingly established as an alternative to set screw fixation (SF). This study directly compared the clinical long-term results after prospective randomized inclusion. Materials and Methods: Between 2011 and 2012, 62 patients with ASI were enrolled in a prospective, randomized, and monocentric study. Forty-one patients were available for a 10-year follow-up ((31 males and 10 females), including 21 treated with SB (mean age 44.4 years), and 20 with SF (mean age 47.2 years)). In addition to comparing the demographic data and syndesmosis injury etiology, follow-up assessed the Olerud−Molander Ankle Score (OMAS) and FADI-Score (Foot and Ankle Disability Index Score) with subscales for activities of daily living (ADL) and sports activity. Results: The mean OMAS was 95.98 points (SB: 98.81, SF: 93.00), the mean FADI ADL was 97.58 points (SB: 99.22, SF: 95.86), and the mean FADI Sport was 94.14 points (SB: 97.03, SF: 91.10). None of the measurements differed significantly between the groups (p > 0.05). No clinical suspicion of chronic instability remained in any of the patients, regardless of treatment. Conclusions: The short-term results showed that athletes in particular benefit from SB fixation due to their significantly faster return to sports activities. However, the available long-term results confirm a very good outcome in the clinical scores for both approaches. Chronic syndesmotic insufficiency was not suspected in any of the patients. Level of evidence: I, randomized controlled trial.

Intraoperative chertsey test, is it a reliable alternative to computed tomography scan for diagnosing syndesmotic injuries of the ankle?

Background:

The present study aims to evaluate the diagnostic exactitude of the intraoperative Chertsey test in tibiofibular syndesmotic injuries in patients with malleolar fractures, in comparison with a computed tomography (CT) scan.

Materials and Methods:

In this study, patients with malleolar fractures operated between 2018 and 2020 were examined. Thirty-nine patients were enrolled in the study. A three-dimensional preoperative CT scan was obtained. The opposite unfractured ankle was also scanned and considered as the control group. The Chertsey test was performed during the operation to assess the syndesmosis injury. Then, patients were partitioned into two distinct groups, considering the condition of their ankle, namely the Chertsey positive (unstable syndesmosis) group and the Chertsey negative (stable syndesmosis) group.

Results:

The outcomes of the present survey illustrated that the Chertsey test was positive in 16 patients (41.03%) and negative in 23 patients (59.07%). The median of all CT scan parameters (anterior tibiofibular distances (TFD), middle TFD, posterior TFD, and maximal TFD and volume) before surgery in the group of patients with a positive Chertsey test was significantly higher, measured against the unfractured control group (P < 0.001 for all parameters). Furthermore, a comparison of CT scan parameters and syndesmosis space volume before surgery between the two groups of patients with positive and negative Chertsey test results showed that the measurement of parameters in Chertsey-positive patients was significantly higher than the Chertsey-negative patients (P < 0.001).

Conclusion:

Chertsey test could be used to diagnose syndesmosis injuries in patients with malleolar fractures due to its high importance in the outcome of patients.

The Syndesmosis, Part I: Anatomy, Injury Mechanism, Classification, and Diagnosis

Ankle fractures are common injuries to the lower extremity with approximately 20% sustaining a concomitant injury to the syndesmosis. Although the deltoid ligament is not formally included in the syndesmotic complex, it plays an important role in the mortise stability. Therefore, its integrity should be always evaluated when syndesmotic injury is suspected. Given the anatomic variability of the syndesmosis between individuals, bilateral ankle imaging is recommended, especially in cases of subtle instability. Diagnostic tests that allow dynamic assessment of the distal tibiofibular joint in the 3 planes are the most reliable in determining the presence of syndesmotic injury.