Anterior Inferior Tibiofibular Ligament Research Articles

Ultrasound Assessment of Ankle Syndesmotic Injuries in a Pediatric Population.

To determine sensitivity and specificity for anterior-inferior tibiofibular ligament (AiTFL) integrity and tibiofibular clear-space (TFCS) cut-off points for dynamic evaluation using ultrasound (US) in a pediatric population. Prospective cohort study. Tertiary care university-affiliated pediatric hospital patients between the ages of 12 and 18 sustaining acute ankle trauma with syndesmotic injury. Participants were assigned to the syndesmotic injury protocol that included a standardized MRI and US. Anterior-inferior tibiofibular ligament integrity for static assessment and TFCS measurements for dynamic assessment on US. For dynamic assessment, the distance between the distal tibia and fibula was first measured in neutral position and then in external rotation for each ankle. The US results on AiTFL integrity were compared with MRI, considered as our gold standard. Optimal cut-off points of TFCS values were determined with receiver operating characteristics curve analysis. Twenty-six participants were included. Mean age was 14.8 years (SD = 1.3 years). Sensitivity and specificity for AiTFL integrity were 79% and 100%, respectively (4 false negatives on partial tears). For dynamic assessment, the cut-off points for the differences in tibiofibular distance between the 2 ankles in 1) neutral position (TFCS N I-U ) and 2) external rotation (TFCS ER I-U ) were 0.2 mm (sensitivity = 83% and specificity = 80%) and 0.1 mm (sensitivity = 83% and specificity = 80%), respectively. Static US could be used in a triage context as a diagnostic tool for AiTFL integrity in a pediatric population as it shows good sensitivity and excellent specificity.

Ankle fractures with Chaput fragment: A new classification system with insights into morphology and relation to surgical treatment

BackgroundThe Chaput fragment, a bony avulsion of the anterolateral margin of the distal tibia, is a less commonly discussed fracture pattern in ankle injuries. Its significance in ankle fractures and the optimal fixation technique remains unclear due to limited literature. This study aims to describe the morphology of ankle fractures with Chaput fragment and introduce a new classification system. Materials and methodsWe retrospectively analyzed 33 patients with ankle fractures with associated Chaput fragment treated at our institute over a 3-year period. Data on patient demographics, fracture classification, surgical approach, and fixation method were collected, and a novel classification system for Chaput fragments was proposed. ResultsFour distinct morphological types of Chaput fragment were identified (types 1–4), and three newer variants of trimalleolar fractures were identified (anterior, lateral, and medial variants). Type 1 refers to a small avulsion fragment attached to the anterior-inferior tibiofibular ligament; Type 2 is an anterolateral oblique type; Type 3 refers to an anterolateral fragment with extension into the medial malleolus and Type 4 is a comminuted Chaput fragment. Type 1 Chaput fragment was the most prevalent (60.6%), followed by Type 2 (24.3%), Type 4 (9.1%), and Type 3 (6.1%). The fixation methods ranged from screw fixation, plate fixation, and suture fixation to combinations of these techniques or even indirect stabilization with syndesmotic screws. ConclusionOur new classification system based on morphology includes all possible variants of Chaput fracture. This preliminary data needs to be corroborated by more studies and validated by a larger number of observers

Unveiling Syndesmotic Malreduction: A Proof-of-Concept towards Portable Ultrasound Detection.

To evaluate the utility and diagnostic performance of portable handheld ultrasound for evaluating fibular rotation at the distal tibiofibular articulation after syndesmotic disruption. Four above-the-knee cadaveric specimens were included. Syndesmotic disruption was precipitated by transecting the Anterior Inferior Tibiofibular Ligament, Interosseous Ligament, and Posterior Inferior Tibiofibular Ligament. Thereafter, a proximal fibular osteotomy was performed, and three conditions were modeled at the distal syndesmosis: 1) reduced, 2) 5 degree internal rotation malreduction, and 3) 5 degree external rotation malreduction. Two blinded observers performed separate ultrasonographic examinations for each condition at the level of both the anterior and posterior distal tibiofibular articular surfaces. Syndesmotic gap penetrance, defined as the ability of the P-US to generate signal between the distal fibula and tibia at the level of the incisura, was graded positive if the sonographic waves penetrated between the distal tibiofibular joint and negative if no penetrating waves were detected. The accuracy measures of the anterior and posterior gap penetrance were evaluated individually. Our preliminary results showed that posterior gap penetrance showed good performance when detecting either internal or external rotational malreduction of the fibula with very good specificity (87.5%) and PPV (90.0%). On the other hand, the anterior gap penetrance showed limited performance when detecting either form of rotational malreduction. We introduced a novel sign, the "gap penetrance sign", best measured from the posterior ankle, which can accurately detect syndesmotic malreduction using P-US in a manner that does not require specific quantitative measurements and is readily accessible to early P-US users.

Radiological landmark of syndesmotic ligament complex by magnetic resonance imaging correlate with fibula free flap harvesting procedure

Preservation of syndesmotic ligaments is crucial for preventing adverse sequelae at the donor site following free fibula osteocutaneous flap harvesting. This study sought to determine the relationship between distal tibiofibular ligaments and the fibular segment to identify radiological landmarks that facilitate safe and precise flap. The distances between the distal tibiofibular ligaments (anterior inferior tibiofibular ligament [AITFL], posterior inferior tibiofibular ligament [PITFL]) and the fibular segment, as well as the lower border of the interosseous membrane, were measured on magnetic resonance imaging (MRI) scans of 296 patients without any perceivable ankle abnormalities. The mean distances (± SD) between the distal end of the fibula and the AITFL, PITFL, and lower interosseous membrane border were 3.0 ± 0.4 cm, 2.6 ± 0.4 cm, and 3.9 ± 0.6 cm, respectively. The distance between the talar dome and the PITFL exhibited a range of 0.0–0.5 cm. Our findings support preserving a distal fibular remnant of at least 4 cm to avoid injury to the syndesmotic ligament throughout fibula osteocutaneous flap harvesting. The talar dome could serve as a useful radiological landmark for identifying the upper border of PITFL during preoperative evaluation, and thus facilitating precise and safe flap procurement.

The Distal Fascicle of the Anterior Inferior Tibiofibular Ligament: A Potential Landmark for Lateral Ankle Ligament Reconstruction.

A reliable landmark and precise distances from the ligament attachments are needed for lateral ankle stabilization surgery. The distal fascicle of the anterior inferior tibiofibular ligament (AITFL) has been used to locate the anterior talofibular ligament (ATFL) or calcaneofibular ligament (CFL) centers on the fibula. However, there is no anatomic study to validate the distal fascicle of the AITFL as a landmark of lateral ankle ligament stabilization, and more importantly, the exact distances from the ATFL or CFL attachments to the distal fascicle of the AITFL are unknown. Sixteen frozen cadaveric specimens (8 paired specimens) with no previous history of ankle injury were used in this study. Whether the distal fascicle of AITFL was present in each specimen was confirmed. Then, the distances from the most distal insertion of the AITFL's distal fascicle to the footprint centers of the ATFL and CFL on the fibula were measured. All measurements were performed by 2 observers, and the intraobserver and interobserver reliabilities were analyzed by intraclass correlation coefficients (ICCs). The distal fascicle of the AITFL was found in all specimens (100%). The mean distance from the most distal insertion of the AITFL's distal fascicle to the footprint centers of the ATFL, CFL, and the intersection center of the 2 ligaments on the fibula was 6.0 to 7.1 mm, 11.5 to 13.2 mm, and 9.0 to 10.0 mm, respectively. Excellent interobserver and intraobserver agreement (all ICCs > 0.9, P < .01) was shown in the anatomic measurements of these distances. In this cadaveric study, we found that the distal fascicle was a constant structure of the AITFL in the lateral ankle. The distances from the most distal insertion of the AITFL's distal fascicle to the ligamentous footprint centers were reliable and may be used to identify the origins of the ATFL and CFL for lateral ankle ligament reconstruction. This anatomic study validates the AITFL's distal fascicle as a potential landmark and, more importantly, determines the range of distances from AITFL's distal fascicle to the attachment centers of lateral ankle ligaments by anatomic measurements. The data may be used to identify the ATFL and CFL for lateral ankle stabilization surgery and become particularly valuable for endoscopic or arthroscopic techniques.

Patterns of Anterior Inferior Tibiofibular Ligament Avulsion Fracture Accompanied by Ankle Fracture

The anterior inferior tibiofibular ligament (AITFL) avulsion fracture accompanying an ankle fracture can compromise ankle stability, necessitating accurate evaluation and a clear understanding of its pathophysiology.. The aim of this study was to investigate the association between AITFL avulsion fracture and Lauge–Hansen, Wagstaffe classification. A retro-prospective study was conducted at a university-affiliated tertiary care medical center. We selected 128 patients who underwent surgery at our institution between January 2013 and July 2017 and analyzed the association between AITFL avulsion fracture and the foot position. According to the modified Wagstaffe classification system, there were 39 cases of type II, followed by 9 cases of type III and 8 cases of type IV. Of the7 pronation-abduction fractures, 3 were AITFL avulsion fracture (43%), while of the 21 pronation-external rotation fractures, 9 were AITFL avulsion fracture (43%). Of the 95 supination-external rotation fractures, there were 56 cases (59%) of AITFL avulsion fractures. Of the pronation fractures, 0% were fibular avulsion fractures and 43% were tibial avulsion fractures. Of the supination fractures, 44% were fibular avulsion fractures and 16% were tibial avulsion fracture. The difference in the ratio of fibular to tibial avulsion fractures between pronation and supination fractures was significant (p < .001). These results suggest that tibial avulsion fractures of type IV in the modified Wagstaffe classification and pronation fractures occur due to collision with the anterolateral corners of the distal bone when the talus externally rotates. Moreover, in cases of pronation fractures, a new type of AITFL avulsion fracture has been observed.

Patterns of Anterior Inferior Tibiofibular Ligament Avulsion Fracture Accompanied by Ankle Fracture

Category: Ankle; Trauma Introduction/Purpose: The anterior inferior tibiofibular ligament (AITFL) avulsion fracture accompanying an ankle fracture cause compromising ankle stability, and requires accurate evaluation and clarifies pathophysiology. The aim of this study was to investigate the correlation between AITFL avulsion fracture and Lauge–Hansen, Wagstaffe classification. Methods: 128 patients (70 males and 58 females) operated at the present institution between January 2013 and July 2017 were included. AITFL avulsion fractures occurred in 68 patients. Fracture was diagnosed based on the preoperative simple radiographs obtained of the ankle joint in the anteroposterior, lateral and mortise views. In cases wherein diagnosis was difficult using radiographs alone, CT was additionally used. AITFL avulsion fractures were classified based on the fracture site according to the Wagstaffe classification system. The anteroposterior and horizontal lengths as well as the height of the avulsed bone fragment were measured using CT scans in the coronal, sagittal and axial views. Thereafter, the relationship between the Lauge-Hansen classification of ankle fractures and the characteristics of AITFL fracture was statistically analysed using the Fisher exact test. Results: Type II of the modified Wagstaffe classification system was 39 examples, followed by type III (9 examples) and type IV (8 examples). Out of 7 pronation-abduction fractures, 3 were those of AITFL avulsion fracture, while out of the 21 pronation- external rotation fracture examples, 9 were those of AITFL avulsion fracture. Out of the 95 examples of supination-external rotation fracture, there were 56 examples (59%) of AITFL avulsion fracture. Of the pronation fractures, 0% was a fibular avulsion fracture and 43% were a tibial avulsion fracture. Of the supination fractures, 44% were a fibular avulsion fracture and 16% were a tibial avulsion fracture. The difference in the ratio of fibular and tibial avulsion fractures between the pronation and supination fractures was significant. (p &lt; 0.0001) Conclusion: Some of the AITFL avulsion fractures examined in this study may have been caused by collisions with the talus rather than the traction of the AITFL. Although Wagstaffe fractures accompanied by a supination–external rotation-type fracture results from the traction of the AITFL, a tibial avulsion fracture in a patient with a modified Wagstaffe type 4 fracture and a supination fracture appears to result from a continuous external rotation and repeated collisions of the talus with the anterolateral corner of the distal tibia.

Three-Dimensional Mapping of Chaput Tubercle Fractures: Evaluation of Morphologic Characteristics and Anterior Inferior Tibiofibular Ligament Involvement

Category: Ankle; Trauma Introduction/Purpose: Chaput tubercle fractures, which are thought to represent tibial-sided avulsions of the anterior inferior tibiofibular ligament (AITFL), are prevalent in up to 30% of trimalleolar ankle fractures. The optimal treatment of small Chaput avulsions is debatable; direct fixation with suture anchor devices and indirect (syndesmotic) fixation are considered as viable options, with proponents on both sides. Moreover, recent literature highlights the potential anatomical alterations to the incisura tibialis resulting from malreduction of large Chaput fragments, furthering the case for direct fixation. Hence, we performed a CT- based three-dimensional fracture mapping study to identify the morphological characteristics of these fractures, and to determine whether they consistently involve the AITFL, tibial plafond and incisura tibialis. Methods: This study included adult patients who had an ankle fracture with a Chaput component; the scheme described by Rammelt et al. was used to classify these fractures. CT scans were obtained, and 3D models were generated. The models were superimposed over a statistical shape model of the right tibia which served as a template and fracture lines were marked. The footprints of proximal and main bands of the AITFL and Basset’s ligament were also marked on the template tibia. The tibial template along with the fracture lines was then imported into MATLAB, and an automated script was used to determine the fragment size (length, breadth, and height), fracture surface area, involvement of the tibial plafond, tibial incisura, and the anterior inferior tibiofibular ligament (AITFL) and Basset’s ligament. Fracture maps and heat maps were generated. Agglomerative cluster analysis using Ward’s linkage was used to identify discrete fracture categories. Results: 76 patients, 21 males and 55 females were included in this study. Cluster analysis identified two distinct groups of fractures, each with two unique subgroups. We present this as a modification of the existing classification system. The first group, corresponded to Rammelt Type 1 fractures (sub centimetric extra-articular avulsion fractures, n=47). Of these, 19% (n=9) did not involve the AITFL, which we termed as Type 1a, and 91% (n=48) involved the AITFL, which we termed as Type 1b. The second group consisted of large intra-articular fractures that corresponded to Rammelt Type 2 injuries. Of these 23% (n=6) involved only the incisura, which we termed as Type 2a; 77 % involved both the incisura and the tibial plafond and were termed as Type 2b. Conclusion: We propose a modification of the existing classification of Chaput fractures on the basis of quantitative fracture mapping. This study provides new insights into the morphological characteristics of Chaput fractures. 19% of small Chaput fractures do not involve the AITFL and may not require direct fixation. Conversely, all large-sized fragments involve the incisura and necessitate anatomical reduction to achieve accurate syndesmotic reduction. Our proposed modification can aid in surgical decision-making, particularly in choosing between direct and indirect syndesmotic fixation.

Biomechanical Analysis about Syndesmotic Stability for AITFL Augmentation with Fibular Plate

Category: Trauma; Sports Introduction/Purpose: Surgical technique to treatment syndesmosis injury is controversial. Additional suture-tape (ST) augmentation of anterior inferior tibiofibular ligament (AITFL) has been reported to improve syndesmotic stability compared with only suture-button (SB) fixation. ST fixation on the fibula is mainly performed with suture anchors, but suture holes with fibular plates can also be used. However, there is no biomechanical study about syndesmotic injury treated with ST augmentation using fibular plate. The aim of this study is to evaluate the stability of the syndesmosis injury model treated with ST augmentation using fibular plate. Our hypothesis is that ST augmentation using fibular plate can provide equivalent syndesmotic stability compared with ST augmentation using suture anchor. Methods: 8 normal fresh-frozen cadaver legs (4 males and 4 females) were used. The mean age at the time of death was 84.3 (70- 101). The specimens were tested while applied traction and rotational forces to represent dorsiflexion and external rotation of ankle joint. The fibular rotational angle related to the tibia (FRA) and anterior tibiofibular diastasis(aTFD) were measured using the magnetic tracking system while each load was applied. Intact, injured, SB + ST augmentation using suture anchor (anchor model), SB + ST augmentation fixation using fibular plate (plate model) models made, and loaded forces and measured FRA and aTFD with each model. One-way ANOVA was used to evaluate the relationship of the angles or the diastasis among each model. Post-hoc analysis for differences among the models were checked using Dunnett’s test. P value of 0.05 was chosen as the level of significance. Results: With dorsiflexion forces, in the injured model, both FRA and aTFD were significantly increased compared with intact model. In the anchor and plate model, both FRA and aTFD were not significantly different compared with intact model. With external rotation forces, in the injured model, both FRA and aTFD were significantly increased compared with intact model. In the anchor and plate model, both FRA and aTFD were not significantly different compared with intact model. Conclusion: The result of this study presented that ST augmentation using fibular plate provide syndesmotic stability similarly with ST augmentation using suture anchor. This technique was considered to be useful in cases of syndesmosis injury with lateral malleolar fracture. Particularly, it is difficult to use suture anchor for ST fixation to the fibula when there is a comminuted fracture near the AITFL attachment of the fibula. Using plate allows for stable ST fixation to the fibula without worrying about it.

Effect of Distal Tibiofibular Syndesmosis Overcompression on the Biomechanical Properties of the Ankle Bones: An In Vitro Cadaveric Model

Category: Trauma; Ankle Introduction/Purpose: Overtightening of the distal tibiofibular syndesmosis during open reduction and internal fixation (ORIF) of ankle fractures remains a clinical concern, and there are limited data delineating the effect of syndesmosis overcompression on subsequent range of motion of the ankle joint bones. The primary objective of the current study was to determine the effect of syndesmotic overcompression on the relative range of motion (ROM) of the tibia, fibula, and talus, and to determine the syndesmotic fixation construct that most accurately restores native motion. Methods: Ten cadaveric lower limbs were utilized (78.3±13.0 yrs, 4F; 6M). A musculoskeletal simulator at ±7.5 Nm was used to test flexibility in dorsiflexion-plantarflexion, inversion-eversion, and internal-external rotation. After intact testing, syndesmotic probes were used to arthroscopically measure the intact position of the distal tibiofibular syndesmosis. The force needed to compress the syndesmosis just beyond the intact position represented the intact force (100%), and overcompression was defined as 150% of the intact force. The anterior inferior tibiofibular ligament (AITFL), interosseus membrane (IOM), and posterior inferior tibiofibular ligament (PITFL) were then sectioned. Testing was repeated for destabilized, IOM reconstruction at 100% compression and 150% overcompression, IOM reconstruction plus AITFL fixation at 100% compression and 150% overcompression, and AITFL fixation alone. ROM data was reported as a percentage of the intact condition. Repeated measures ANOVA and Bonferroni post hoc test were performed to assess differences between conditions with p&lt; 0.05. Results: Average force needed to compress the syndesmosis was 71.0 ± 22.2 N. There was a significant increase in distal tibiofibular ROM in internal and external rotation for all conditions compared to intact (Figure 1) (p &lt; 0.05). In the axial plane, reconstruction of the IOM membrane did not restore the intact condition and was similar to the destabilized treatment, regardless of compression force. The addition of AITFL fixation significantly reduced distal tibiofibular motion compared to IOM reconstructions alone, but still did not approach the intact condition. Overcompression of the syndesmosis did not significantly affect relative ROM of the ankle bones in any plane (p&gt;0.05). Changes in the proximal tibiofibular ROM were similar in magnitude and direction as the distal tibiofibular ROM for all conditions. Conclusion: In the current study, overcompression of the distal tibiofibular syndesmosis did not restrict relative ROM of the tibia, fibula, or talus. Reconstructing the AITFL in addition to the IOM decreased tibiofibular ROM, particularly in the axial plane. In the clinical setting, surgical reconstruction with dynamic fixation of the distal tibiofibular syndesmosis may result in increased ROM and mechanical stress at the proximal tibiofibular articulation.

Effect of Fibula Shortening on Medial Clear Space and Lateral Translation of the Talus: An Anatomical Cadaveric Study

Category: Ankle; Trauma Introduction/Purpose: Fibular shortening with an medial and syndesmotic ligament instability causes lateral translation of the talus. We hypothesise that the interaction of the anterior inferior tibiofibular ligament (AITFL) tubercle of the fibular with the anterior tibial incisura would precipitate lateral translation due to the size differential. Methods: Twelve cadaveric ankle specimens were dissected, removing all soft tissue except for ligaments. They were fixed onto a bespoke jig allowing tibial fixation and free movement of the talus and fibula. The fibula was progressively shortened in 5mm increments until complete ankle dislocation, measuring the medial clear space with each increment. Results: The larger AITFL tubercle interaction with the smaller tibial incisura caused a significant increase in lateral translation of the talus. This occurred in most ankles between 5-10mm of fibular shortening. The medial clear space widened following 5mm of shortening in 5 specimens (mean: 2.07, s.d: 2.53). All 12 specimens experienced widening by 10mm fibular shortening (Mean: 7.21mm, s.d: 2.21) and reached complete dislocation by 35mm fibular shortening. Conclusion: This study shows, that with fibular shortening, the interaction between the distal fibular AITFL tubercle and the anterior tibial incisura precipitates a lateral translation of the talus in an ankle fracture model where the medial and syndesmotic ligaments have been transected and the lateral ligaments remain intact. The interaction occurred between 5 and 10mm of fibular shortening. Beyond this point there was a near linear correlation between fibular shortening and medial clear space widening

Anterolateral Ankle Impingement due to Bassett’s Ligament

Category: Arthroscopy; Ankle Introduction/Purpose: The Bassett’s ligament, an accessory band of the anterior inferior tibiofibular ligament (AITFL), is known to be a normal ligamentous structure present in 21-92% of cases. The Bassett’s ligament is also known as a structure that causes anterolateral impingement of the ankle joint after an ankle sprain. However, not much is known about the cause or prognosis of anterolateral impingement by Bassett's ligament. In this study, the symptoms, characteristics, and postoperative results of impingement by Bassett's ligament were reported. Methods: From November 2017 to August 2021, 12 patients who underwent surgical treatment for pain in the anterolateral aspect of the ankle joint, which did not improve with conservative treatment, were enrolled. There were 5 males and 7 females, and the average age was 34.4 years (21-76). The symptoms complained of by the patients and accompanying injuries were analyzed. And the arthroscopic findings and postoperative results were analyzed. Results: All patients had a history of ankle sprain before symptoms. All patients complained of pain and tenderness in the anterolateral aspect of the ankle joint, and the pain improved after injection of lidocaine. And 3 patients (25%) complained of snapping during ankle ROM. Ankle instability was present in 10 patients (83.3%), and OLT was present in 2 patients (16.7%). Arthroscopic findings showed that the Bassett’s ligament impinged with the anterolateral aspect of the talar dome during ROM in all cases. And synovitis was found around the Bassett ligament in all cases, fraying of the Bassett ligament in 5 cases (41.7%), and fraying of the cartilage of the dome of the talus in 4 cases (33.3%). Anterolateral ankle pain disappeared in all patients after surgery. Conclusion: Impingement between the talar dome and the Bassett’s ligament should be considered as one of the causes of anterolateral ankle pain, especially in patients with ankle sprains.

Effect of Plate and Screw Fixation on Stability of Weber B/Supination-External Rotation Fractures with Partial Deltoid Ligament Injury (SER4a): Robotic-Based Joint Testing

Category: Trauma; Ankle Introduction/Purpose: Fibular fractures with signs of concomitant deltoid ligament injury have been operated on with plate and screw fixation of the fibula for decades. More recently, clinical studies have suggested that some fibular fractures have only partial deltoid ligament injury and that the deep posterior tibiotalar ligament may be intact (SER4a), allowing for nonoperative treatment. The purpose was to determine whether fibula fracture fixation using plate and screws improves stability and restores normal joint kinematics in such fractures. It was hypothesised that fixation of the fibula fracture does not add significantly to the stability of SER4a models or restore normal joint kinematics. Methods: Fifteen cadaveric foot and ankle specimens underwent biomechanical testing using a six-degrees-of-freedom force- movement robotic arm in three states: intact joint, SER4a model (anterior inferior tibiofibular ligament sectioned + oblique trans syndesmotic fibular osteotomy + superficial layer of deltoid ligament sectioned + deep anterior tibiotalar ligament sectioned) and SER4a model + plate and screw fixation of the fibula. Joint stability was measured in lateral translation, valgus, and talar internal- and external rotation in three talocrural joint positions: 20° plantarflexion, neutral, and 10° dorsiflexion. Fluoroscopy was used to measure isolated talar lateralisation and talar tilt. The foot was rigidly fixed to a custom pedestal, while the tibia was rigidly fixed to the robot arm through a load cell. Talar lateral translation at neutral ankle position was the primary outcome. Results: Fixation of the fibular fracture reduced lateral translation by 0.16 millimetres (P = .101) at neutral ankle position (See Figure 1). In general, the tests for lateral translation and valgus showed no differences between the SER4a models and the SER4a models with fibular fracture fixation. As for talar internal rotation, the fixation only slightly increased stability. But, when the talus was externally rotated, the fixation provided stability. Although the fixation improved stability during rotations, it did not fully restore the native ankle kinematics. Conclusion: The results suggest that plate and screw fixation of the fibular fracture does not significantly reduce instability or restore intact joint stability in SER4a models. These results support the nonoperative treatment of these fractures, as suggested by previous clinical studies.

The lowest point of fibula (LPF) could be used as a reliable bony landmark for arthroscopic anchor placement of lateral ankle ligaments ----compared with open Broström procedure

BackgroundArthroscopic technique procedures was wide accepted for the treatment of chronic ankle instability (CAI). But little acknowledge was involved to the bony landmarks and anatomic features of different bundles of lateral ligaments under arthroscopic view.MethodsSixty patients with acute or chronic lateral ankle ligaments injury (LAI) were collected prospectively, and divided randomly into two groups. In arthroscopic group, the bone tunnels were made on the LPF arthroscopically. And in open group, the bone tunnels were made on the Fibular obscure tubercle (FOT) in open procedure. The inferior bundle of ATFL and Arcuate fibre was also identified reference to the LPF and labeled by a PDS II suture penetration. Following that, The distances of the bone tunnels to the different bony markers were measured and compare between two groups. The penetrating locations of PDS II on the inferior bundle of ATFL and Arcuate fibre were also confirmed intraoperatively. And the safe angle of anchor implantation on the axial view was measured on postoperative CT scan.ResultsThe distances of bone tunnel to the fibular tip, the fibular insertion of anterior-inferior tibiofibular ligament (AITFL), and the FOT in arthroscopic and open locating groups were 4.9 ± 2.2 and 6.3 ± 2.2 mm, 13.5 ± 2.7 and 12.4 ± 1.1 mm, 5.8 ± 2.2 and 5.6 ± 1.0 mm, respectively. The distances of bone tunnels to the FOT and fibular tip on 3d-CT view was 4.4 ± 1.5 and 4.6 ± 0.9 mm, 14.4 ± 3.2 and 13.2 ± 1.8 mm in arthroscopic and open group, and there were no significant differences between two groups. The safe angle of arthroscopic anchor placement on the axial plan was ranged from 24.9 ± 6.3o to 58.1 ± 8.0o. The PDS II sutures penetrating on the inferior bundles of ATFL and the arciform fibres were also comfirmed successfully by open visualizaion.The average distance of penetration point to the horizontal line cross the fibular tip was 2.3 ± 2.7 mm (ranged from − 3.1 to 6.0 mm), and to the vertical line cross the FOT was 2.7 ± 2.7 mm (ranged from − 2.5 to 7.5 mm).ConclusionTake the lowest point of fibula under arthroscopy (LPF) as a bony reference, we could identify the iATFL under arthroscopic visualization. By this way, we could place the suture anchors properly to the fibular footprint and suture the iATFL fibres successfully.

Are Lateral Ankle Ligament Banding Patterns and Band Thickness Symmetrical Between Contralateral Uninjured Limbs?

Objective: The aim of this study was to determine whether the number and thickness of ligament bands of lateral ankle ligaments are symmetrical between contralateral uninjured ankles of the same healthy person, using sonography. Materials and Methods: The ligaments investigated include the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and the anterior inferior tibiofibular ligament (AITFL). The influence of age, sex, height, weight, body mass index, and hours of physical exercise on uninjured ankle ligament band thickness was also explored. The lateral ankle ligaments of both limbs of 27 physically active adults (18–50 years of age) were sonographically imaged in short and long-axis planes to determine the number of bands and measure each band thickness. The ligament banding and ankle ligament band thickness was compared between contralateral uninjured limbs. Results: Bilateral symmetry of the number of ATFL, CFL, and AITFL bands was consistently identified between right and left uninjured limbs using short-axis sonographic imaging. No significant difference ( P &gt; .05) in ankle ligament band thickness (acquired from long-axis images of ligament bands) between uninjured contralateral limbs was identified. Conclusion: The current sonographic practice of comparison of ankle ligament morphology and thickness between uninjured and injured limbs of the same person following an acute ankle injury to aid diagnosis of injury would appear justified.

Evaluating the Efficacy of Tension Band Wiring Fixation for Chaput Tubercle Fractures.

Chaput tubercle fractures, located at the attachment site of the anterior inferior tibiofibular ligament (AITFL) on the distal tibia, have the potential to destabilize the syndesmosis joint. This study aims to assess the effectiveness of tension band wiring (TBW) as a surgical intervention for managing Chaput fractures and the consequent syndesmosis instability. A retrospective review of patient charts was undertaken for those who had undergone ankle fracture surgery from April 2019 through May 2022. The surgical procedure involved direct fixation of the Chaput fractures using the TBW method. Radiological assessments were performed using postoperative simple radiographs and computed tomography (CT) scans, while clinical outcomes were evaluated using the Olerud-Molander Ankle Score (OMAS) and the visual analog scale (VAS). The study included 21 patients. The average OMAS improved significantly, rising from 5.95 preoperatively to 83.57 postoperatively. Similarly, the average VAS score dropped from 7.95 before the surgery to 0.19 thereafter. Minor wound complications were reported by three patients, and one case of superficial infection was resolved with antibiotic therapy. Our findings suggest that the TBW technique is an effective surgical approach for treating Chaput fractures and associated syndesmosis instability. It provides reliable fixation strength and leads to improved long-term functional outcomes. Further research is needed to compare the TBW technique with alternative methods and optimize the treatment strategies for these complex ankle fractures.

Comparison the treatment of anterior inferior tibiofibular ligament anatomical repair and syndesmosis screw fixation for syndesmotic injuries in ankle fracture

BackgroundThe fixation method of syndesmotic injuries in ankle fractures remains controversial. The goal of the study was to compare radiographic and clinical outcomes between anterior inferior tibiofibular ligament (AITFL) anatomical repair with syndesmosis screw fixation in syndesmotic injuries.MethodsWe analyzed 62 patients who were treated with AITFL anatomical repair or syndesmosis screw fixation for syndesmotic injuries in an advanced teaching hospital between March 2016 and March 2019. Fixation was performed with AITFL anatomical repair in 30 patients (AAR group) and syndesmosis screw in 32 patients (SS group). Radiographic evaluations were the differences in mean anterior and posterior (A difference and P difference) tibiofibular distance between injured and uninjured ankle computed tomography (CT) scan at 6 months postoperatively. Clinical evaluation of patients was done using the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle Hindfoot Score, the Olerud-Molander Ankle (OMA) score and visual analogue scale (VAS) score at 1, 3, 6 months and 1, 2 years postoperatively.ResultsThe A difference and P difference on CT was no differences (1.6 ± 0.8 mm, 1.3 ± 0.7 mm vs. 1.5 ± 0.7 mm, 1.2 ± 0.7 mm) between the two groups (All of P > 0.05). The AAR group had higher mean AOFAS score (65.6 ± 5.9, 82.3 ± 4.2, 87.6 ± 5.6 vs. 61.8 ± 5.2, 79.1 ± 4.0, 83.8 ± 4.9; P = 0.008, 0.003, 0.007) and higher mean OMA score (45.7 ± 8.7, 79.2 ± 6.5, 84.1 ± 5.3 vs. 40.4 ± 7.3, 74.8 ± 6.3, 80.3 ± 5.8; P = 0.012, 0.009, 0.010)) at 1, 3 and 6 months postoperatively. The AAR group had lower mean VAS scores (2.6 ± 1.2, 1.7 ± 0.7 vs. 3.4 ± 1.2, 2.2 ± 1.1; P = 0.018, 0.038) at 1 and 3 months postoperatively.ConclusionsThe results of this study suggest that the AITFL anatomical repair technique could effectively improve ankle function during daily activity. Therefore, AITFL anatomical repair technique is expected to become a better fixation method for syndesmotic injuries.

Effect of Posterior Malleolar Fixation on Syndesmotic Stability

Background: Transsyndesmotic fixation with suture buttons (SBs), posterior malleolar fixation with screws, and anterior inferior tibiofibular ligament (AITFL) augmentation using suture tape (ST) have all been suggested as potential treatments in the setting of a posterior malleolar fracture (PMF). However, there is no consensus on the optimal treatment for PMFs. Purpose: To determine which combination of (1) transsyndesmotic SBs, (2) posterior malleolar screws, and (3) AITFL augmentation using ST best restored native tibiofibular and ankle joint kinematics after 25% and 50% PMF. Study Design: Controlled laboratory study. Methods: Twenty cadaveric lower-leg specimens were divided into 2 groups (25% or 50% PMF) and underwent biomechanical testing using a 6 degrees of freedom robotic arm in 7 states: intact, syndesmosis injury with PMF, transsyndesmotic SBs, transsyndesmotic SBs + AITFL augmentation, transsyndesmotic SBs + AITFL augmentation + posterior malleolar screws, posterior malleolar screws + AITFL augmentation, and posterior malleolar screws. Four biomechanical tests were performed at neutral and 30° of plantarflexion: external rotation, internal rotation, posterior drawer, and lateral drawer. The position of the tibia, fibula, and talus were recorded using a 5-camera motion capture system. Results: With external rotation, posterior malleolar screws with AITFL augmentation resulted in best stability of the fibula and ankle joint. With internal rotation, all repairs that included posterior malleolar screws stabilized the fibula and ankle joint. Posterior and lateral drawer resulted in only small differences between the intact and injured states. No differences were found in the efficacy of treatments between 25% and 50% PMFs. Conclusion: Posterior malleolar screws resulted in higher syndesmotic stability when compared with transsyndesmotic SBs. AITFL augmentation provided additional external rotational stability when combined with posterior malleolar screws. Transsyndesmotic SBs did not provide any additional stability and tended to translate the fibula medially. Clinical Relevance: Posterior malleolar fixation with AITFL augmentation using ST may be the preferred surgical method when treating patients with acute ankle injury involving an unstable syndesmosis and a PMF ≥25%.

Syndesmosis Instability

The syndesmosis is one of important stabilizer of the ankle joint and consists of a complex ligamentous structure: the anterior inferior tibiofibular ligament; the interosseous ligament; the posterior inferior tibiofibular and the transverse ligaments. The posterior syndesmosis plays the most important role providing 40–45% of the resistance to diastasis, while the AITFL provides around 35%. Major injuries of two of the syndesmosis components represent a loss of more than 50% of resistance to diastasis and may result in instability. Syndesmosis injury or a high ankle sprain, is a frequent athletic trauma accounting for 1% to 18% of all ankle sprains, 17 to 84% of all sport injuries, and 10% of all ankle fractures. Most of the mechanism injury is external rotation injury. A radiographic study suggested that about 20.3% of ankle sprains were combined with a syndesmosis injury. Without proper treatment, the chronic syndesmosis injury remains symptomatic for more than 6 months after the initial trauma, with persistent pain, functional disability, and early-stage ankle arthritis. Normally, syndesmosis widens 1 mm during normal gait. Widening of syndesmosis more than 1 mm can reduce tibiotalar contact surface about 42%. The degenerative changes can occur if the lateral talar shift more than 2 mm. Clinical tests for syndesmosis injuries are external rotation stress test, Cotton test, dorsiflexion-compression test, squeeze test, crossed-leg test, fibular translation and AITFL palpation. Standard radiographs are part of ankle trauma evaluation, especially for fracture exclusion, applying the Ottawa criteria. Computerized tomography (CT) scan is a useful tool to assess tibiofibular diastasis, fibular rotation and joint asymmetry, but shows low sensitivity. MRI is showing very high sensitivity and specificity in identification of syndesmotic injuries. For stable lesion can be treated with conservative means, including non weight bearing or protected weight bearing with a cast or walking boot and a rehabilitation protocol. An unstable lesion requires a surgical procedure to avoid long-term disability and chronic instability. Ankle arthroscopy remains essential for diagnosis and treatment. With accessory tools that measure the syndesmosis gap (e.g. 3.5 mm shaver canula or a metallic tools). Passage of a 3 mm spherical probe during external rotation indicates very high likelihood of rupture of both the AITFL and the IOL. Also, concomitant intra-articular pathologies (osteochondral lesions, other ligamentous rupture or loose bodies) can be presented, with 19% needs to be addressed, reinforcing the role of arthroscopy not only for diagnosis but also for treatment. It is also an excellent tool to evaluate anatomic reduction and residual diastasis.

Role of Syndesmotic Ligaments in Lateral Ankle Instability

Category: Ankle; Sports; Trauma Introduction/Purpose: Despite the success of surgical intervention, about 13-35% of patients continue to have ankle symptoms after surgery for lateral ankle instability which could be due to presence of undetected and thus untreated injury to other ankle ligaments.Concomitant lateral ankle ligament and syndesmotic ligamentous injuries are common. It is unknown, however, whether syndesmotic ligaments directly contribute to lateral ankle stability. Therefore, the aim of this study was to fluoroscopically evaluate whether the syndesmotic ligaments contributes to lateral ankle stability. Methods: Twenty-four above-knee cadaveric specimens were divided into three groups that underwent fluoroscopic evaluation for lateral ankle stability. In all the groups, the assessment was first done with all syndesmotic and ankle ligaments intact. Thereafter, Group 1 underwent sequential transection of the lateral ankle ligaments: (1) anterior talofibular ligament (ATFL), (2)calcaneofibular ligament(CFL), and (3)posterior talofibular ligament (PTFL). Group 2 underwent sequential transection of the lateral ankle ligaments followed by the syndesmotic ligaments: (1) ATFL, (2) CFL, (3) PTFL, (4) anterior inferior tibiofibular ligament(AITFL), (5)interosseous ligament(IOL), and (6)posterior inferior tibiofibular ligament (PITFL). Group 3 alternating and sequential transection of the syndesmotic and lateral ankle ligaments: (1) AITFL, (2) ATFL, (3) CFL, (4) IOL, (5) PTFL, and (6) PITFL. In all scenarios, three loading conditions were considered:(1)An anterior drawer test at 50N and 80N of direct force, (2) talar tilt under 1.7Nm torque, and (2) lateral clear space (LCS) under 1.7Nm torque. Wilcoxon rank-sum test was used to compare the findings of each ligamentous transection state to the intact state. Results: The lateral ankle remained stable after transection of all syndesmotic ligaments (AITFL, IOL, PITFL). However, after additional transection of the ATFL, the lateral ankle became unstable in varus and anterior drawer testing conditions (p-values ranging from 0.036-0.012). Lateral ankle instability was also observed after transection of the ATFL and AITFL (p-values ranging from 0.036-0.012). Subsequent transection of the CFL worsened the lateral ankle instability. Conclusion: Our findings suggest that syndesmotic injuries can destabilize otherwise stable lateral ankle sprains. When treating lateral ankle instability, clinician should maintain a lower threshold for operative intervention for syndesmotic stabilization if there are any residual symptoms over the AITFL.