Syndesmotic malreduction may decrease fixation stability: a biomechanical study

Center-Center Surgical Technique With Dynamic Syndesmosis Fixation: A Cadaveric Pilot Study

The objective of this cadaveric biomechanical study was to evaluate if the center-center surgical technique is a reliable and repeatable method of achieving proper syndesmotic reduction when using dynamic syndesmotic fixation. Nine fresh frozen above-knee cadaveric lower extremities were used. Computerized tomography (CT) scans were first obtained for each intact specimen as the baseline for comparison. A simulated complete syndesmotic disruption was created by transection of all deltoid and syndesmotic ligaments. Instability of the ankle was confirmed with stress imaging using fluoroscopy. Each unstable specimen was repaired using the center-center surgical technique with dynamic syndesmosis fixation. A series of measurements from the axial CT images of intact and repaired specimens were used to determine the anatomic distal tibiofibular relationships for comparison of changes from intact to postfixation. All radiographic measurements were performed by 4 independent foot and ankle surgeons. The level of inter-rater reliability for all the measurements was found to be "moderate" to "excellent" agreement (ICC value: 0.865-0.983, 95% confidence interval: 0.634-0.996). There was no statistical difference found between rotational alignment of native and postfixation (a/b: p = .843; b-a: p = .125; θ: p = .062). There was a statistical difference detected for lateral alignment at the center of fibularis incisura between native and postfixation (average: -0.6 ± 0.8 mm, range: -2.3 to 1.2 mm, p < .001). There was no statistical difference found for the anteroposterior translation alignment between native and postfixation (d/e: p = .251; f: p = .377). This study demonstrated the use of the center-center surgical technique as a viable and repeatable method for achieving anatomical reduction of the tibiofibular syndesmosis when used with dynamic fixation modalities.

Maisonneuve fracture treated with suture-button system stabilization combined with plate and arthroscopic assistance (SBPAA): Clinical and radiological evaluation in short-medium period

The aim of this study was to estimate the time needed for patients with Maisonneuve fractures to return to routine activities, after treatment with a suture-button system stabilization combined with plate and arthroscopic assistance (SBPAA).

Methods

The study included 13 patients treated at our surgical department from January 2018 to June2022. Specific radiographical follow-up and periodic checks were performed in a short -to-medium term period, to evaluate syndesmosis evolution and tibiofibular overlap with medial clear space (MCS).

Results

Progressive recovery and improvement were observed during follow-up from both radiographic and clinical perspective. Data showed that patients were able to return to full weight-bearing walking around the ninth week and to sport activities in 7.5 months. Long-term complications associated with residual joint stiffness, complex regional pain syndrome, or wound complications were observed in three patients.

Conclusions

Intraoperative arthroscopy represent a valid diagnostic tool to better recognize and evaluate osteochondral lesions in case of syndesmosys. The study demonstrates the importance of intraoperative arthroscopy for recognizing and treating associated osteochondral lesions with proper syndesmosis evaluation. Plate associated to double TightRope represent valid solution to functionally fix and reduce fractures. Additionally, it imitates the normal syndesmosis's anatomy and provides elasticity and robustness, guaranteeing a rapid return to sporting activity. Data and casuistry support these findings.

Comparison of Two Different Methods to Evaluate Ankle Syndesmosis on Lateral Ankle Radiographs

Background Ankle sprains and fractures rank among the most commonly occurring musculoskeletal injuries and hold significant relevance in current medical practice. Accurate information regarding these injuries is crucial for their effective treatment. This study aimed to explore the viability of utilizing ankle lateral radiographs to evaluate syndesmosis in both emergency settings and operating theatres. Methods This randomized retrospective clinical study involved the analysis of 150 ankle lateral radiographs (54 males and 96 females) from patients who presented at our emergency department with suspected ankle injuries. Two authors jointly examined these radiographs and reached a consensus. The anterior tibiofibular (ATF) ratio and anterior-posterior tibiofibular (APTF) ratio were computed. Patients requiring syndesmotic fixation were classified as having experienced a genuine syndesmotic injury. Participants were randomly divided into two equal groups: Group I (normal group) without fractures and Group II (abnormal group) with fractures. Comprehensive patient data, including medical history and clinical examinations, were recorded. Results Gender distribution within the studied population consisted of 54.67% males (n=41) and 45.33% females (n=34) in the abnormal group, while the normal group comprised 37.33% males (n=28) and 62.67% females (n=47). Both APTFR and ATFR methods were found to be inconclusive and unreliable for syndesmosis assessment in ankles. The sensitivity of APTFR stood at 21.33%, with a specificity of 86.67%, a positive predictive value (PPV) of 61.5%, and a negative predictive value (NPV) of 52.4%. Meanwhile, the sensitivity of ATFR was 32%, with a specificity of 80%, a PPV of 61.5%, and an NPV of 54.1%. Conclusions Both techniques demonstrated low sensitivity when ankle fractures were present, indicating their unsuitability for routine clinical diagnosis of syndesmotic disruption via lateral ankle radiographs.

Biomechanical Sequelae of Syndesmosis Injury and Repair

This review characterizes fibula mechanics in the context of syndesmosis injury and repair. Through detailed understanding of fibula kinematics (the study of motion) and kinetics (the study of forces that cause motion), the full complexity of fibula motion can be appreciated. Although the magnitudes of fibula rotation and translation are inherently small, even slight alterations of fibula position or movement can substantially impact force propagation through the ankle and hindfoot joints. Accordingly, implications for clinical care are discussed.

“Flexible nature of fixation” in syndesmotic stabilization of the inferior tibiofibular joint affects the radiological reduction outcome

Purpose

Fibular mobility after suture button stabilization (SBS) of inferior tibiofibular joint (syndesmosis) injuries has been described. This effect is called the “flexible nature of fixation (FNF).” In this study, we aimed to quantify FNF in syndesmotic stabilization.

Methods

Postoperative bilateral computed tomography (CT) of ankle fractures with syndesmosis stabilization by SBS or syndesmotic screw (SYS) was retrospectively analyzed. The transverse offset (TO) and vertical offset (VO) were defined by evaluating the drill channels. The reduction outcome was evaluated by the side-to-side difference between the clear space and the anterior tibiofibular distance (antTFD). The calculated anterior tibiofibular distance (cal-antTFD) was calculated by subtracting the TO from the validated antTFD. Subsequently, a reevaluation of the reduction outcomes after SYS or SBS stabilization was performed using cal-antTFD.

Results

Sixty patients (44 with SBS and 16 with SYS stabilization) were analyzed. The intra-rater and inter-rater reliabilities for TO and VO were excellent (α > 0.92). SYS stabilization showed lower mean TO (− 0.02 mm; SD 0.14) and VO (0.11 mm; SD, 0.29 mm) than SBS stabilization (TO 1.16 mm, SD 1.4 mm; VO 0.2 mm, SD 0.8 mm; p = 0.001). The rate of malreduction according to cal-antTFD was higher than that of antFTD (p = 0.033).

Conclusion

The presented method, which evaluates the position of the tibial to the fibular drill channel, allowed the quantification of the “FNF.” The often described difference in the dynamic stabilization of SBS compared to the rigid stabilization by SYS could be objectified. Considering cal-antTFD illustrates that FNF potentially reduces the rate of malreduction in SBS stabilization.

Intraoperative Assessment of Reduction of the Ankle Syndesmosis

PURPOSE OF REVIEW

Postoperative malreduction of the ankle syndesmosis is common, poorly defined, and its assessment is controversial. In the absence of a gold standard method to evaluate the ankle syndesmosis, a variety of techniques have been described. As the knowledgebase expands, data illustrating caveats for such techniques has become available. The purpose of this review is to highlight literature-sourced technical pearls and their related caveats for the intraoperative assessment of the ankle syndesmosis.

RECENT FINDINGS

Although numerical criteria are commonly used to assess syndesmotic reduction, anatomical variation in the healthy population frequently exceeds proposed cutoffs. Patient-specific uninjured anatomy can be defined by comparing to the uninjured contralateral ankle; however, side-to-side variation is present for many anatomical relationships. Advanced imaging (e.g., lateral radiographs, 3-dimensional radiography) can influence intraoperative surgeon decision-making and improve syndesmosis reduction, but minute improvements in syndesmosis reduction may not outweigh increased operating time and costs. Intraoperative imaging is an adjunct, not a replacement for direct visualization or palpation when reducing the syndesmosis. Arthroscopy may benefit younger patients with high physical demands by improving identification of intra-articular pathology absent on MRI. Although anatomical reduction is important to restore pre-injury biomechanics, it is unclear whether differences in reduction quality influence patient-reported outcomes. In the absence of a gold standard, awareness of the options for intraoperative assessment of the syndesmosis and their respective accuracy and limitations reported herein could enhance surgeons' ability to intraoperatively reduce the syndesmosis with the tools currently available.

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.

Evidence-Based Surgical Treatment Algorithm for Unstable Syndesmotic Injuries

Background: Surgical treatment of unstable syndesmotic injuries is not trivial, and there are no generally accepted treatment guidelines. The most common controversies regarding surgical treatment are related to screw fixation versus dynamic fixation, the use of reduction clamps, open versus closed reduction, and the role of the posterior malleolus and of the anterior inferior tibiofibular ligament (AITFL). Our aim was to draw important conclusions from the pertinent literature concerning surgical treatment of unstable syndesmotic injuries, to transform these conclusions into surgical principles supported by the literature, and finally to fuse these principles into an evidence-based surgical treatment algorithm. Methods: PubMed, Embase, Google Scholar, The Cochrane Database of Systematic Reviews, and the reference lists of systematic reviews of relevant studies dealing with the surgical treatment of unstable syndesmotic injuries were searched independently by two reviewers using specific terms and limits. Surgical principles supported by the literature were fused into an evidence-based surgical treatment algorithm. Results: A total of 171 articles were included for further considerations. Among them, 47 articles concerned syndesmotic screw fixation and 41 flexible dynamic fixations of the syndesmosis. Twenty-five studies compared screw fixation with dynamic fixations, and seven out of these comparisons were randomized controlled trials. Nineteen articles addressed the posterior malleolus, 14 the role of the AITFL, and eight the use of reduction clamps. Anatomic reduction is crucial to prevent posttraumatic osteoarthritis. Therefore, flexible dynamic stabilization techniques should be preferred whenever possible. An unstable AITFL should be repaired and augmented, as it represents an important stabilizer of external rotation of the distal fibula. Conclusions: The current literature provides sufficient arguments for the development of an evidence-based surgical treatment algorithm for unstable syndesmotic injuries.