Syndesmosis Repair Affects in Vivo Distal Interosseous Tibiofibular Ligament Elongation Under Static Loads and During Dynamic Activities

Radiographic outcomes of flexible and rigid fixation techniques of syndesmotic injuries across various body mass indices: A retrospective analysis

In the setting of ankle trauma, surgical management of syndesmosis injury involves screw fixation and suture button technique. The efficacy of flexible (suture button) versus rigid (screw) fixation in the management of syndesmotic injury has been investigated extensively in current literature. There is sparse data comparing these two techniques across different body mass indices (BMI). In this study, two fellowship-trained foot and ankle surgeons at urban level-1 trauma centers reviewed blinded post-operative ankle radiographs of BMI-stratified patients undergoing syndesmotic fixation. A total of 79 patients were included for analysis based on inclusion and exclusion criteria. There were 42 patients in the screw fixation group and 37 patients in the suture button group. The average follow-up period was 5.5 months. No significant difference was found in the average radiographic measurements when comparing the two fixation types, regardless of BMI parameters. This was consistent when analyzing individual fixation types stratified by BMI, as well as when comparing BMI groups stratified by fixation type. Additionally, the distribution of body mass index was even across both fixation types. Our study demonstrates that both fixation groups achieved comparable anatomic ankle reduction regardless of body mass index. The authors suggest expanding the indication of suture button fixation to include the higher body mass index patients.

In vivo analysis of ankle joint kinematics and ligament deformation of chronic ankle instability patients during level walking

Introduction: Chronic ankle instability (CAI) carries a high risk of progression to talar osteochondral lesions and post-traumatic osteoarthritis. It has been clinically hypothesized the progression is associated with abnormal joint motion and ligament elongation, but there is a lack of scientific evidence. Methods: A total of 12 patients with CAI were assessed during level walking with the use of dynamic biplane radiography (DBR) which can reproduce the in vivo positions of each bone. We evaluated the uninjured and CAI side of the tibiotalar and subtalar joint for three-dimensional kinematics differences. Elongation of the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and posterior talofibular ligament (PTFL) were also calculated bilaterally. Results: For patients with CAI, the dorsiflexion of the tibiotalar joint had reduced (21.73° ± 3.90° to 17.21° ± 4.35°), displacement of the talus increased (2.54 ± 0.64 mm to 3.12 ± 0.55 mm), and the inversion of subtalar joint increased (8.09° ± 2.21° to 11.80° ± 3.41°). Mean ATFL elongation was inversely related to mean dorsiflexion angle (CAI: rho = -0.82, P < 0.001; Control: rho = -0.92, P < 0.001), mean ATFL elongation was related to mean anterior translation (CAI: rho = 0.82, P < 0.001; Control: rho = 0.92, P < 0.001), mean CFL elongation was related to mean dorsiflexion angle (CAI: rho = 0.84, P < 0.001; Control: rho = 0.70, P < 0.001), and mean CFL elongation was inversely related to mean anterior translation (CAI: rho = -0.83, P < 0.001; Control: rho = -0.71, P < 0.001). Furthermore, ATFL elongation was significantly (CAI: rho = -0.82, P < 0.001; Control: rho = -0.78, P < 0.001) inversely correlated with CFL elongation. Discussion: Patients with CAI have significant changes in joint kinematics relative to the contralateral side. Throughout the stance phase of walking, ATFL increases in length during plantarflexion and talar anterior translation whereas the elongation trend of CFL was the opposite. This understanding can inform the development of targeted therapeutic exercises aimed at balancing ligament tension during different phases of gait. The interrelationship between two ligaments is that when one ligament shortens, the other lengthens. The occurrence of CAI didn't change this trend. Surgeons might consider positioning the ankle in a neutral sagittal plane to ensure optimal outcomes during ATFL and CFL repair.

Anterior Talofibular Ligament Repair in Combination With Anterior Tibiofibular Ligament Distal Fascicle Transfer for The Treatment of Chronic Lateral Ankle Instability: A Finite Element Analysis

In recent years, anterior tibiofibular ligament-distal fascicle transfers for anterior talofibular ligament augmentation repair have proposed. However, a comprehensive biomechanical study on the anterior tibiofibular ligament-distal fascicle transfer is still lacking. We are established four distinct groups, namely the normal, the anterior talofibular ligament rupture, the anterior talofibular ligament repair, and the anterior talofibular ligament repair + anterior tibiofibular ligament-distal fascicle transfer. We assessed the anterior drawer test and varus stress test of the ankle in each group. Moreover, we employed the model to simulate and compute the total displacement and von-Mises stress of the talus cartilage at varying gait phases, including foot strike, tibia vertical, and toe-off phases. The results of the anterior drawer test and varus stress test revealed that the anterior talofibular ligament repair + anterior tibiofibular ligament-distal fascicle transfer group exhibited greater closeness to the normal group. Regarding von-Mises stress in cartilage, the three gait instants had higher values in the anterior talofibular ligament repair + anterior tibiofibular ligament-distal fascicle transfer group than the other groups. Nevertheless, regarding total displacement, the toe-off phases exhibited higher values in the anterior talofibular ligament repair + anterior tibiofibular ligament-distal fascicle transfer group than the other groups. Using ATiFL-DF transfer to augment ATFL repair is a potential feasible procedure. However, this procedure could potentially compromise the anterior tibiofibular ligament's contribution to the dynamic stability of the ankle. Therefore, we recommend conducting further in-depth research to ensure the suitability and success of this technique in a clinical environment.

Ankle and hindfoot motion of healthy adults during running revealed by dynamic biplane radiography: Side-to-side symmetry, sex-specific differences, and comparison with walking

This study aimed to characterize ankle and hindfoot kinematics of healthy men and women during overground running using biplane radiography, and to compare these data to those previously obtained in the same cohort during overground walking. Participants ran across an elevated platform at a self-selected pace while synchronized biplane radiographs of their ankle and hindfoot were acquired. Motion of the tibia, talus, and calcaneus was tracked using a validated volumetric model-based tracking process. Tibiotalar and subtalar 6DOF kinematics were obtained. Absolute side-to-side differences in ROM and kinematics waveforms were calculated. Side-to-side and sex-specific differences were evaluated at 10 % increments of stance phase with mixed model analysis. Pearson correlation coefficients were used to assess the relationship between stance-phase running and walking kinematics. 20 participants comprised the study cohort (10 men, mean age 30.8 ± 6.3 years, mean BMI 24.1 ± 3.1). Average absolute side-to-side differences in running kinematics waveforms were 5.6°/2.0 mm or less at the tibiotalar joint and 5.2°/3.2 mm or less at the subtalar joint. No differences in running kinematics waveforms between sides or between men and women were detected. Correlations were stronger at the tibiotalar joint (42/66 [64 %] of correlations were p < 0.05), than at the tibiotalar joint (38/66 [58 %] of correlations were p < 0.05). These results provide a normative reference for evaluating native ankle and hindfoot kinematics which may be informative in surgical or rehabilitation contexts. Sex-specific differences in ankle kinematics during overground running are likely not clinically or etiologically significant. Associations seen between walking and running kinematics suggest one could be used to predict the other.

High-Ankle Sprain and Syndesmotic Instability: How Far Have We Come with Diagnosis and Treatment?

Probably one of the most controversial subjects in the orthopedic field is the distal tibiofibular articulation. Even though its most primary knowledge can be a matter of enormous debate, it is in the diagnosis and treatment most of the disagreements reign. Distinguishing between injury and instability remains challenging as well as an optimal clinical decision regarding surgical intervention. The last years presented technology and that was able to bring body to an already well-developed scientifical rationale. In this review article, we aim to demonstrate the current data behind syndesmotic instability in the ligament scenario, whereas using few fracture concepts.