Syndesmotic Ligaments Research Articles

Five-Year Outcomes After Treatment for Acute Instability of the Tibiofibular Syndesmosis Using a Suture-Button Fixation System.

Background:Suture-button repair is a widely accepted surgical treatment for acute and isolated ankle syndesmosis injuries. To our knowledge, midterm results have not previously been reported.Purpose:To evaluate the clinical, qualitative, and quantitative radiological midterm outcomes of suture-button repair after acute isolated ankle syndesmosis injuries.Study Design:Retrospective case series; Level of evidence, 4.Methods:Clinical outcomes were measured using the Foot and Ankle Disability Index (FADI) and the American Orthopaedic Foot and Ankle Society (AOFAS) score. Three-tesla magnetic resonance imaging (MRI) was performed bilaterally at the ankle. Besides morphological sequences for evaluation of the syndesmosis and degenerative changes of the ankle using the Ankle Osteoarthritis Scoring System (AOSS), the MR protocol included a coronal 2-dimensional multislice multiecho sequence for quantitative cartilage T2-weighted mapping. Spearman correlations and paired t tests were used for statistical analysis.Results:This retrospective study included 19 consecutive patients (mean age, 29.7 ± 11.5 years) with acute isolated syndesmosis injuries treated with a suture-button system between January 2006 and June 2014, with a mean follow-up of 5.1 ± 2.6 years. Postoperatively, the median FADI score was 136 (range, 78-136), and the median AOFAS score was 100 (range, 87-100). Seventeen (89.5%) patients reported to have reached their preinjury level of sports activities. MRIs of 16 patients were obtained and all showed intact anterior and posterior syndesmotic ligaments; however, in most patients, the previously injured syndesmotic ligament was thickened compared with the uninjured ankle. Average width of the anterior (P = .81) and posterior (P = .60) syndesmosis was not significantly different between the ipsilateral (3.2 ± 1.2 and 4.4 ± 0.9 mm) and contralateral ankles (3.0 ± 0.6 and 4.2 ± 0.7 mm). The median AOSS score was 1.5 (range, 0-11) for the ipsilateral ankle and 0 (range, 0-6) for the contralateral ankle. T2 values of articular cartilage did not significantly differ between the involved and the uninjured ankle (P = .68). Five patients needed hardware removal due to persistent skin irritation, and 1 patient suffered from reinstability of the ankle resulting in revision surgery 2 years after the index surgery.Conclusion:Suture-button fixation is an excellent treatment for acute and isolated syndesmosis injuries, resulting in stable ankles without early or advanced osteoarthritic changes at midterm follow-up.

Novel anatomical reconstruction of distal tibiofibular ligaments restores syndesmotic biomechanics.

To date, there is a paucity of literature on syndesmotic reconstruction techniques that restore both anatomic stability and physiologic syndesmotic biomechanics. In this cadaveric study, (1) a novel syndesmotic reconstruction surgical technique using autogenous peroneus brevis tendon was described and (2) the biomechanical properties of the reconstruction was investigated. Ten fresh-frozen lower extremities were used in this study. Reconstruction of the anterior and posterior, as well as the interosseous tibiofibular ligaments was performed with a halved peroneus brevis tendon. Biomechanics were assessed using foot external rotation torque and ankle dorsiflexion axial loading tests, which were performed in (a) intact, (b) cut, (c) anatomically reconstructed syndesmotic ligaments, and (d) 3.5mm tricortical syndesmotic screw fixation. Medial-lateral and anterior-posterior displacements of the distal fibula were recorded during foot external rotation and fibular axial displacement was recorded during ankle axial loading. The fibula was displaced posteriorly and proximally with respect to the tibia in all specimens during external rotation and axial loading tests, respectively. Significant differences (p < 0.05) were found in distal fibular displacements between anatomically reconstructed ligaments and screw fixation. Tricortical syndesmotic screw fixation resulted in 59% of posterior fibular displacement when compared to intact ligaments. No significant differences (n.s.) in distal fibular displacement were demonstrated between intact ligaments and anatomically reconstructed ligaments. Anatomical reconstruction of the distal tibiofibular ligaments with the peroneus brevis tendon provides stability and recreates the biomechanical properties of an intact syndesmosis. This new surgical technique may be a viable alternative for the treatment of syndesmotic injuries. V.

Determination of The Most Appropriate Surgical Treatment in Syn-desmotic Injury of Ankle Joint: Application of Taguchi Method

Background:Ankle injuries are more frequently observed in youth and athletes, and may lead to permanent disabilities if not treated properly. Approximately 10% of ankle injuries are associated with syndesmotic ligament injuries and fixation with screw is frequently applied as surgical treatment. The present study we aimed to determine the most proper model and model parameters by evaluating the minimum equivalent von Mises stress value developed in syndesmotic fixation of the ankle. Methods: By modeling the normal lower extremity in a healthy subject via the finite element analysis (FEA) method, we compared stress developed in a normal standing position in the models of syndesmotic injuries approached by frequently used cortical screws of various lengths and diameters, and by considering the number of screws and localization of fixation. Tibia, fibula, talus, and calcaneus were modeled as a three dimensional (3D) solid model via images of computerized tomography (CT), using the MIMICS program (version 10.01). The obtained 3D model was saved in the MIMICS program in STL (steriolithography) format, and transferred to the Geomagic Studio (version 10) program. Essential corrections were applied to the bones with the aid of the Geomagic program. The model of lower extremity designed was transferred to the Solidworks (version 2014) program in IGES (Initial Graphics Exchange Specification) format, and thus the meniscus and cartilage were modeled. Tensions that developed in the ankle were calculated after forming a mesh pattern via the ANSYS Workbench (version 15.0) software. Results: Sixteen different models obtained were analyzed by the Taguchi method, and the most appropriate models and model parameters were indicated by determining the minimum equivalent von Mises stress value. Conclusion: Screw diameter was determined to be the most important parameter. When 16 different models were considered, a screw diameter of 4.5 mm and three-cortex fixation with two screws parallel to the tibial joint surface were found to produce the most convenient model.DOI: http://dx.doi.org/10.5755/j01.mech.23.1.14024

CAIPIRINHA accelerated SPACE enables 10-min isotropic 3D TSE MRI of the ankle for optimized visualization of curved and oblique ligaments and tendons.

To test the hypothesis that a fourfold CAIPIRINHA accelerated, 10-min, high-resolution, isotropic 3D TSE MRI prototype protocol of the ankle derives equal or better quality than a 20-min 2D TSE standard protocol. Following internal review board approval and informed consent, 3-Tesla MRI of the ankle was obtained in 24 asymptomatic subjects including 10-min 3D CAIPIRINHA SPACE TSE prototype and 20-min 2D TSE standard protocols. Outcome variables included image quality and visibility of anatomical structures using 5-point Likert scales. Non-parametric statistical testing was used. P values ≤0.001 were considered significant. Edge sharpness, contrast resolution, uniformity, noise, fat suppression and magic angle effects were without statistical difference on 2D and 3D TSE images (p > 0.035). Fluid was mildly brighter on intermediate-weighted 2D images (p < 0.001), whereas 3D images had substantially less partial volume, chemical shift and no pulsatile-flow artifacts (p < 0.001). Oblique and curved planar 3D images resulted in mildly-to-substantially improved visualization of joints, spring, bifurcate, syndesmotic, collateral and sinus tarsi ligaments, and tendons (p < 0.001, respectively). 3D TSE MRI with CAIPIRINHA acceleration enables high-spatial resolution oblique and curved planar MRI of the ankle and visualization of ligaments, tendons and joints equally well or better than a more time-consuming anisotropic 2D TSE MRI. • High-resolution 3D TSE MRI improves visualization of ankle structures. • Limitations of current 3D TSE MRI include long scan times. • 3D CAIPIRINHA SPACE allows now a fourfold-accelerated data acquisition. • 3D CAIPIRINHA SPACE enables high-spatial-resolution ankle MRI within 10min. • 10-min 3D CAIPIRINHA SPACE produces equal-or-better quality than 20-min 2D TSE.

Accuracy and Measurement Error of the Medial Clear Space of the Ankle.

Measurement of the medial clear space (MCS) is commonly used to assess deltoid ligament competency and mortise stability when managing ankle fractures. Lacking knowledge of the true anatomic width measured, previous studies have been unable to measure accuracy of measurement. The purpose of this study was to determine MCS measurement error and accuracy and any influencing factors. Using 3 normal transtibial ankle cadaver specimens, deltoid and syndesmotic ligaments were transected and the mortise widened and affixed at a width of 6 mm (specimen 1) and 4 mm (specimen 2). The mortise was left intact in specimen 3. Radiographs were obtained of each cadaver at varying degrees of rotation. Radiographs were randomized, and providers measured the MCS using a standardized technique. Lack of accuracy as well as lack of precision in measurement of the medial clear space compared to a known anatomic value was present for all 3 specimens tested. There were no significant differences in mean delta with regard to level of training for specimens 1 and 2; however, with specimen 3, staff physicians showed increased measurement accuracy compared with trainees. Accuracy and precision of MCS measurements are poor. Provider experience did not appear to influence accuracy and precision of measurements for the displaced mortise. This high degree of measurement error and lack of precision should be considered when deciding treatment options based on MCS measurements.

A 3-D CT Analysis of Screw and Suture-Button Fixation of the Syndesmosis

Historically, syndesmosis injuries have been repaired with screw fixation; however, some suggest that suture-button constructs may provide a more accurate anatomic and physiologic reduction. The purpose of this study was to compare changes in the volume of the syndesmotic space following screw or suture-button fixation using a preinjury and postoperative 3-D computed tomography (CT) model. The null hypothesis was that no difference would be observed among repair techniques. Twelve pairs of cadaveric specimens were dissected to identify the syndesmotic ligaments. Specimens were imaged with CT prior to the creation of a complete syndesmosis injury and were subsequently repaired using 1 of 3 randomly assigned techniques: (a) one 3.5-mm cortical screw, (b) 1 suture-button, and (c) 2 suture-buttons. Specimens were imaged postoperatively with CT. 3-D models of all scans and tibiofibular joint space volumes were calculated to assess restoration of the native syndesmosis. Analysis of variance and Tukey's method were used to compare least squares mean differences from the intact syndesmosis among repair techniques. For each of the 3 fixation methods, the total postoperative syndesmosis volume was significantly decreased relative to the intact state. The total mean decreases in volume compared with the intact state for the 1-suture-button construct, 2-suture-button construct, and syndesmotic screw were -561 mm3 (95% CI, -878 to -244), -964 mm3 (95% CI, -1281 to -647) and -377 mm3 (95% CI, -694 to -60), respectively. All repairs notably reduced the volume of the syndesmosis beyond the intact state. Fixation with 1 suture-button was not significantly different from screw or 2-suture-button fixation; however, fixation with 2 suture-buttons resulted in significantly decreased volume compared with screw fixation. The results of this study suggest that the 1-suture-button repair technique and the screw fixation repair technique were comparable for reduction of syndesmosis injuries, although both may overcompress the syndesmosis.

Biomechanical Analysis of the Individual Ligament Contributions to Syndesmotic Stability.

Biomechanical data and contributions to ankle joint stability have been previously reported for the individual distal tibiofibular ligaments. These results have not yet been validated based on recent anatomic descriptions or using current biomechanical testing devices. Eight matched-pair, lower leg specimens were tested using a dynamic, biaxial testing machine. The proximal tibiofibular joint and the medial and lateral ankle ligaments were left intact. After fixation, specimens were preconditioned and then biomechanically tested following sequential cutting of the tibiofibular ligaments to assess the individual ligamentous contributions to syndesmotic stability. Matched paired specimens were randomly divided into 1 of 2 cutting sequences: (1) anterior-to-posterior: intact, anterior inferior tibiofibular ligament (AITFL), interosseous tibiofibular ligament (ITFL), deep posterior inferior tibiofibular ligament (PITFL), superficial PITFL, and complete interosseous membrane; (2) posterior-to-anterior: intact, superficial PITFL, deep PITFL, ITFL, AITFL, and complete interosseous membrane. While under a 750-N axial compressive load, the foot was rotated to 15 degrees of external rotation and 10 degrees of internal rotation for each sectioned state. Torque (Nm), rotational position (degrees), and 3-dimensional data were recorded continuously throughout testing. Testing of the intact ankle syndesmosis under simulated physiologic conditions revealed 4.3 degrees of fibular rotation in the axial plane and 3.3 mm of fibular translation in the sagittal plane. Significant increases in fibular sagittal translation and axial rotation were observed after syndesmotic injury, particularly after sectioning of the AITFL and superficial PITFL. Sequential sectioning of the syndesmotic ligaments resulted in significant reductions in resistance to both internal and external rotation. Isolated injuries to the AITFL resulted in the most substantial reduction of resistance to external rotation (average of 24%). However, resistance to internal rotation was not significantly diminished until the majority of the syndesmotic structures had been sectioned. The ligaments of the syndesmosis provide significant contributions to rotary stability of the distal tibiofibular joint within the physiologic range of motion. This study defined normal motion of the syndesmosis and the biomechanical consequences of injury. The degree of instability was increased with each additional injured structure; however, isolated injuries to the AITFL alone may lead to significant external rotary instability.

Metal Artifact Reduction MRI of Total Ankle Arthroplasty

Category: Ankle Arthritis Introduction/Purpose: Total ankle arthroplasty (TAA) is an often successful treatment for end-stage ankle arthritis; however, a subset of patient presents with ankle pain following TAA and concern for early failure. Although radiographs are often diagnostic, patients with normal radiographs and continued pain pose a diagnostic challenge. In those patients, magnetic resonance imaging (MRI) may be helpful to evaluate periprosthetic bone and soft tissues. Traditional high-bandwidth (high-BW) metal artifact reduction sequence (MARS) MRI lessens metal artifacts, but image distortions remain with Cobalt-Chromium implants. Slice- Encoding-Metal-Artifact-Correction (SEMAC) is a recently FDA-approved, advanced MARS technique that promises more powerful metal suppression. Therefore, we prospectively tested the hypothesis that SEMAC MARS MRI facilitates better metal reduction and visibility of periprosthetic structures than does traditional MARS MRI in patients with TAA. Methods: In this IRB-approved study, 20 volunteers [10 females/10 males; age, 59 (41-73) years, 15 (3-24) months post- operatively] with TAA were prospectively enrolled. The research protocol consisted of high-BW and SEMAC MARS MRI using a clinical 1.5 Tesla MRI scanner and a dedicated boot-shaped MRI coil. For each technique, intermediate-weighted and fat- suppressed MR images were obtained in axial, sagittal and coronal orientation. Three observes (2 foot/ankle surgeons and 1 musculoskeletal radiologist) evaluated the high-BW and SEMAC MR images in an independent, random and blinded fashion. Equidistance 5-point Likert scales (1=non-diagnostic, 5=very good) were used to grade image quality as well as the quality of metal suppression and visibility of bone-metal interfaces, tendons, ligaments, bone and joints. Differences between the two MARS techniques were assessed with a Kruskall-Wallis test, and interobserver agreement was graded with Intraclass-Correlation- Coefficient (ICC). Bonferroni-corrected p-values ≤ 0.01 were considered significant. Results: All 20 subjects completed the research protocol. There was good agreement between observers (ICC = 0.79; 95% CI, 0.78-0.80). Image quality of high-BW and SEMAC MR images was similar for tissue contrast, fat suppression, and fluid brightness, whereas image sharpness was one interval higher on high-BW images than on SEMAC images (p &lt; 0.01). Metal reduction of TAA components was significantly better (p &lt; 0.01) on SEMAC images (very good) than on high-BW images (poor-to-adequate). At level of the implants, long flexor and peroneal tendons, deep deltoid, syndesmotic and lateral collateral ligaments, and medial and lateral gutters were significantly better seen (p &lt; 0.01) on SEMAC images (good-to-very good) than on high-BW images (poor-to- adequate). Similar visibility (good-to-very good) was found for the remainder of the tendons, ligaments, bones and joints. Conclusion: Based on the results of our study, we accept the hypothesis that SEMAC MARS MRI outperforms traditional high- BW MARS MRI in the degree of metal artifact reduction as well as visibility of bone implant interfaces and periprosthetic tendons and ligaments at level of the joint line. We believe advanced MARS MRI can be a valuable clinical tool to assess osseous integration and soft tissue lesions in patients following TAA.

A Novel Method for Measurement of Ankle Joint Reaction Force and Response to Syndesmotic Injury

Category: Ankle. Introduction/Purpose: Increasing evidence has suggested that alterations in joint mechanics results in articular pathology. Previous studies demonstrated noninvasive measurements of joint reactive forces (JRF) can be performed reliably without destruction of the peri-articular soft tissue in medium and small size joints of the upper extremity. This study presents a novel, noninvasive measurement of the JRF to investigate the normal and the effects of a syndesmotic injury. The JRF of the tibiotalar joint was also evaluated following anatomic reduction with fixation and malreduction of the syndesmosis. Methods: Eight fresh-frozen human cadaveric lower extremity limbs were obtained disarticulated above the knee. A distraction force was applied across the tibio-talar joint to determine the baseline (normal) ankle force displacement curve. Next, a syndesmotic injury was created by releasing the interosseous syndesmotic ligaments, the transverse tibiofibular ligament and the anterior and posterior tibiofibular ligaments. Prior to sectioning, two drill holes were placed across the joint and tapped to ensure anatomic reduction. JRF were measured using a quadricortical technique with a single or double screw configuration. The syndesmosis was malreduced by anteriorly displacing the fibula 5 mm. After each step, the resultant JRFs were determined using a distraction force across the tibiotalar joint. Results: Force displacement curves obtained from multiple measurements from each specimen with a mean ankle JRF of 31.4 + 2.6 N. Syndesmotic injury resulted in a 35% decrease in tibiotalar JRF (20.3 + 3.0 N, p=0.002). Fixation of the injury using one syndesmotic screw resulted in significant increase in JRF compared to injury JRF (28.7 + 1.4 N, p=0.02). Syndesmotic fixation with 2 screws also demonstrated a trend towards restoration of tibiotalar JRF (28.3 + 2.2 N, p=0.06). There was no statistical difference between fixation of one versus two syndesmotic screws. The JRF for the malreduced syndesmosis was 31.5 + 1.8 N (p=0.03,) resulting in increased forces approaching the baseline JRF. Conclusion: This study demonstrates a non-destructive model by which to measure joint reactive forces (JRF) across the tibiotalar joint and that these forces are diminished as a result of a syndesmotic injury, suggesting joint instability. Surgical stabilization with either 1 or 2 screws creates JRF that are similar to the normal JRF. Even with a malreduced syndesmosis, there appeared to be a JRF similar to baseline tibiotalar joint forces. However malreduction of the syndesmosis may alter the joint dynamics of the ankle in ways that were not measured in this study.

3-D CT Analysis of Screw and Suture-Button Fixation for Syndesmosis Repair

Category: Sports. Introduction/Purpose: Historically, unstable injuries to the distal tibiofibular syndesmosis have been repaired with syndesmotic screws. However, newer repair techniques with inherently flexible implants, including suture-button constructs, may be less susceptible to malreduction and more reliably restore the native anatomy. The purpose of this study was to compare the anatomic accuracy of reduction between a syndesmotic screw and suture-button constructs for syndesmosis repair using a pre- injury and postoperative 3-D model assessment. We hypothesized significant differences would be observed among repair techniques and suture-button constructs would most accurately restore the pre-injury syndesmotic volume. Methods: Twelve matched pairs of cadaveric specimens were dissected to identify the syndesmotic ligaments. Specimens were imaged with CT prior to the creation of a complete syndesmosis injury. The disrupted syndesmosis of each specimen was subsequently reduced using one of three randomly assigned repair techniques: (1) tri-cortical syndesmosis screw (3.5 x 50 mm), (2) one suture-button construct and (3) two suture-button constructs. Specimens were imaged postoperatively with CT. 3-D models of all scans and tibiofibular joint space volumes were created to assess restoration of the native syndesmosis (Figure 1). Volumetric joint space measurements were made starting at the distal aspect of the tibiofibular articulation and extended proximally with four 1 cm sections measured separately. Results: For each of the three fixation methods, the adjusted least squares means for total post-operative volumes of the syndesmosis were significantly decreased relative to the intact state. Total overall decreases in volume compared to the intact state for the one suture-button construct, two suture-button constructs, and syndesmotic screw were -561 mm3, -964 mm3 and - 377 mm3, respectively. Fixation with one suture-button construct was not significantly different from screw or two suture-button fixations. However, the total decrease in volume was significantly greater with the two suture-button repair compared to screw fixation (p &lt; .05). Conclusion: The most important finding of this study was that fixation with one suture-button construct was not significantly different from screw or two suture-button fixations. All repairs significantly reduced the volume of the syndesmosis postoperatively compared to the intact state. Fixation with two suture-buttons resulted in significantly greater decreased volume than screw fixation. The data from the present study suggests that syndesmotic over-compression at time zero, particularly when using multiple suture-button implants, may be another potential factor contributing to malreduction of syndesmosis injuries that deserves further investigation.

Differential Rates of Syndesmotic Fixation in Operatively Treated Ankle Fractures by Subspecialty Training

Category: Trauma Introduction/Purpose: Ankle fractures are a common orthopedic injury in the United States with annual incidence up to 187 per 100,000 persons. Approximately 23% of ankle fractures also involve injury to the syndesmotic ligaments and intraoperative assessment of syndesmotic instability represents a critical aspect of ankle fracture surgery. Recent studies have demonstrated that both Weber B and Weber C distal fibula ankle fractures can have concomitant syndesmotic injury necessitating trans-syndesmotic fixation. Through retrospective review of surgically treated ankle fracture cases, we sought to assess whether there were differences in the rates of intraoperative detection and surgical management of syndesmotic injuries based upon surgeon fellowship training and subspecialty experience. Methods: A multi-center retrospective cohort study of 219 surgically treated ankle fractures over a two year period was performed. Patient selection criteria was based on CPT codes while exclusion criteria included open trauma, pilon fracture, history of prior ankle fracture or pediatric patients. All preoperative radiographs were reviewed for Danis-Weber classification. All post-operative radiographs as well as operative reports were reviewed to confirm surgeon detection of syndesmotic injury and type of trans-syndesmotic fixation utilized. Surgeons were divided into three groups according to fellowship training: foot and ankle (Group 1), trauma (Group 2), and general / other (Group 3). There were 2 foot and ankle fellowship trained orthopedists, 5 trauma fellowship trained orthopedists, and 9 generalists whose fellowships included sports, hand, and spine. Patient demographics and medical risk factors were also recorded in the study. Results: 16.3% of 153 Weber B cases were treated with syndesmotic fixation: 24% of cases in Group 1, 17% of cases in Group 2, and 0% of cases in Group 3 had syndesmotic fixation. Comparing syndesmotic fixation in Groups 1 versus 3 using the Fisher's exact test resulted in p-value of &lt; 0.0655 approaching statistical significance. 71.9% of 64 Weber C cases were treated with syndesmotic fixation: 91% of cases in Group 1, 69% of cases in Group 2, and 50% of cases in Group 3 had syndesmotic fixation. These differences were not statistically significant (p-value of &lt; 0.1919). There were no statistically significant differences in demographics and medical risk factors among patients in the three groups. The study also included 2 Weber A cases. Conclusion: Our data shows an increased association of syndesmotic injury with Weber C compared to Weber B ankle fractures, similar to literature reports. While the data showed no statistically significant difference among the three surgeon groups, higher rates of syndesmotic injuries were intraoperatively detected and surgically treated by foot and ankle as well as trauma fellowship trained surgeons compared with general orthopedists or those with other fellowship background. Accordingly, fellowship training in foot and ankle and heightened experience in this subspecialty may facilitate recognition of syndesmotic injuries accompanying both Weber B and Weber C ankle fractures.

3-D Computed Tomography (CT) Comparison Of The Pre-injury And Post-repair Syndesmosis To Assess Anatomic Reduction

Objectives:Historically, unstable injuries to the distal tibiofibular syndesmosis have been repaired with syndesmotic screws. However, newer repair techniques with inherently flexible implants, including suture-button constructs, may be less susceptible to malreduction and more reliably restore the native anatomy. The purpose of this study was to compare the anatomic accuracy of reduction between a syndesmotic screw and suture-button constructs for syndesmosis repair using a pre-injury and postoperative 3-D model assessment. We hypothesized significant differences would be observed among repair techniques and suture-button constructs would most accurately restore the pre-injury syndesmotic volume.Methods:Twelve matched pairs of cadaveric specimens were dissected to identify the syndesmotic ligaments. Specimens were imaged with CT prior to the creation of a complete syndesmosis injury. The disrupted syndesmosis of each specimen was subsequently reduced using one of three randomly assigned repair techniques: (1) tri-cortical syndesmosis screw (3.5 x 50 mm), (2) one suture-button construct and (3) two suture-button constructs. Specimens were imaged postoperatively with CT. 3-D models of all scans and tibiofibular joint space volumes were created to assess restoration of the native syndesmosis (Figure 1). Volumetric joint space measurements were made starting at the distal aspect of the tibiofibular articulation and extended proximally with four 1 cm sections measured separately.Results:For each of the three fixation methods, the adjusted least squares means for total post-operative volumes of the syndesmosis were significantly decreased relative to the intact state. Total overall decreases in volume compared to the intact state for the one suture-button construct, two suture-button constructs, and syndesmotic screw were -561mm3, -964mm3, and -377mm3, respectively. Fixation with one suture-button construct was not significantly different from screw or two suture-button fixations. However, the total decrease in volume was significantly greater with the two suture-button repair compared to screw fixation (p < .05).Conclusion:The most important finding of this study was that fixation with one suture-button construct was not significantly different from screw or two suture-button fixations. All repairs significantly reduced the volume of the syndesmosis postoperatively compared to the intact state. Fixation with two suture-buttons resulted in significantly greater decreased volume than screw fixation. The data from the present study suggests that syndesmotic over-compression at time zero, particularly when using multiple suture-button implants, may be another potential factor contributing to malreduction of syndesmosis injuries that deserves further investigation.

Arthroscopically Assisted Open Reduction–Internal Fixation of Ankle Fractures: Significance of the Arthroscopic Ankle Drive-through Sign

Standalone open reduction–internal fixation (ORIF) of unstable ankle fractures is the current standard of care. Intraoperative stress radiographs are useful for assessing the extent of ligamentous disruption, but arthroscopic visualization has been shown to be more accurate. Concomitant arthroscopy at the time of ankle fracture ORIF is useful for accurately diagnosing and managing syndesmotic and deltoid ligament injuries. The arthroscopic ankle drive-through sign is characterized by the ability to pass a 2.9-mm shaver (Smith & Nephew, Andover, MA) easily through the medial ankle gutter during arthroscopy, which is not usually possible with both an intact deltoid ligament and syndesmosis. This arthroscopic maneuver indicates instability after ankle reduction and fixation and is predictive of the need for further stabilization. Furthermore, when this sign remains positive after fracture fixation, it may guide the surgeon to further evaluate the adequacy of fixation for the possible need for further fixation of the syndesmosis or deltoid. We present the case of an ankle fracture managed with arthroscopy-assisted ORIF and describe the clinical utility of the arthroscopic ankle drive-through sign.

Plantar talar head contusions and osteochondral fractures: associated findings on ankle MRI and proposed mechanism of injury

To evaluate the significance of plantar talar head injury (PTHI) in predicting osseous and soft tissue injuries on ankle MRI. The IRB approved this HIPAA-compliant retrospective study. The study group consisted of 41 ankle MRIs with PTHI that occurred at our institution over a 5 ½ year period. Eighty MRIs with bone injuries in other locations matched for age, time interval since injury, and gender formed a control group. Injuries to the following structures were recorded: medial malleolus, lateral malleolus/distal fibula, posterior malleolus, talus, calcaneus, navicular, cuboid, lateral, medial and syndesmotic ligaments, spring ligament complex, and extensor digitorum brevis (EDB) muscle. Twenty separate logistic regressions determined which injuries PTHI predicted, using the Holm procedure to control for family-wise alpha at 0.05. PTHI strongly predicted the occurrence of injuries involving the anterior process of the calcaneus [24% of cases, odds ratio (OR) 12.66], plantar components of the spring ligament (27%, OR 9.43), calcaneal origin of the EDB and attachment of the dorsolateral calcaneocuboid ligament (22%, OR 7.22), cuboid (51%, OR 6.58), EDB (27%, OR 5.49), anteromedial talus (66%, OR 4.78), and posteromedial talus (49%, OR 4.48). PTHI strongly predicted lack of occurrence of syndesmotic ligament injury (OR 19.6). The PTHI group had a high incidence of lateral ligamentous injury (78%), but not significantly different from the control group (53%). PTHI is strongly associated with injury involving the transverse tarsal joint complex. We hypothesize it results from talo-cuboid and/or talo-calcaneal impaction from a supination injury of the foot and ankle.

Revision Ankle Syndesmosis Fixation: Functional Outcome after TightRope® Fixation

ABSTRACT Introduction Syndesmotic injuries present a challenge to orthopedic surgeons. Malreduction of the syndesmosis has been reported to cause instability and secondary osteoarthritis and is correlated with poor subjective and objective outcomes. There are very few studies that report the outcome after revision fixation of these injuries. Previous studies have reported varying techniques for revision syndesmosis reconstruction, including screw fixation and tendon transfers. We present the results of the use of the TightRope® suture for revision syndesmosis fixation. This implant has the advantage of maintaining physiological motion whilst allowing for healing of syndesmotic ligaments and prevents the need for further surgery to remove screws in already scarred soft tissues. Materials and methods We retrospectively analyzed 124 patients who required syndesmotic stabilization from January 2000 until December 2009. Eight of these 124 patients required surgical revision of their failed syndesmosis fixation, each of which was stabilized with the TightRope® Suture. All eight patients were followed up and their outcomes assessed. Seven of the eight patients in our study had technically sound initial fixation of the syndesmosis. Four of the eight patients had syndesmotic separation after screw removal 10 weeks after primary fixation. Results In our study, 6 of the 8 patients had good or satisfactory outcomes based on American Orthopedic Foot and Ankle Society (AOFAS) scores. In spite of accurate revision fixation of the syndesmosis, two patients required further surgery. One patient had conversion to an ankle fusion because of persistent syndesmotic widening and ongoing pain after revision surgery. Another patient required syndesmotic arthrodesis as a result of persistent pain. Conclusion TightRope® suture fixation is a good method of syndesmosis stabilization in patients requiring revision surgery. Randomized studies would be required to compare the effectiveness of this method of fixation with screw fixation. How to cite this article Rajagopalan S, Moonot P, Sangar A, Taylor H. Revision Ankle Syndesmosis Fixation: Functional Outcome after TightRope® Fixation. J Foot Ankle Surg (Asia- Pacific) 2016;3(1):23-27.

Diaphyseal tibiofibular synostosis in professional athletes: Report of 2 cases

Anterior leg pain is common in professional athletes and tibiofibular synostosis is reported to be a rare cause of anterior compartment pain or ankle pain related to sports activities. The management and appropriate treatment of this condition in professional athletes is controversial and the literature on the topic is sparse. Distal synostosis is usually related to ankle sprain and syndesmotic ligament injury, and proximal synostosis has been linked to leg length discrepancy and exostosis. Mid-shaft synostosis is even less common than proximal and distal forms. We present the treatment of mid-shaft tibiofibular synostosis in 2 cases of professional athletes (soccer and basketball player), along with a review of the literature. When diaphyseal synostosis is diagnosed, first-line conservative treatment, including ultrasound-guided steroid injection is recommended. However, if it does not respond to conservative management, surgical resection may be indicated to relieve symptoms.

Radiographic identification of the primary structures of the ankle syndesmosis.

The purpose of this study was to quantitatively describe the locations of the syndesmotic ligaments and the tibiofibular articulating cartilage surfaces on standard radiographic views using reproducible radiographic landmarks and reference axes. Twelve non-paired ankles were dissected to identify the anterior-inferior tibiofibular ligament (AITFL), posterior-inferior tibiofibular ligament (PITFL), interosseous tibiofibular ligament (ITFL), and the cartilage surfaces of the syndesmosis. Structures were marked with 2-mm radiopaque spheres prior to obtaining lateral and mortise radiographs. Measurements were performed by two independent raters to assess intra- and interobserver reliability via intraclass correlation coefficients (ICCs). Measurements demonstrated excellent agreement between observers and across trials (all ICCs≥0.960). On the lateral view, the AITFL tibial origin was 9.6±1.5mm superior and posterior to the anterior tibial plafond. Its fibular insertion was 4.4±1.7mm superior and posterior to the anterior fibular tubercle. The centre of the tibial cartilage facet of the tibiofibular contact zone was 8.4±2.1mm posterior and superior to the anterior plafond. The proximal and distal aspects of the ITFL tibial attachment were 45.9±7.9 and 12.4±3.4mm proximal to the central plafond, respectively. The superficial and deep PITFL coursed anterior and distally from the posterior tibia to fibula. On the mortise view, the AITFL tibial attachment centre was 5.6±2.4mm lateral and superior to the lateral extent of the plafond (4.3mm lateral, 3.3mm superior), and its fibular insertion was 21.2±2.1mm superior and medial to the inferior tip of the lateral malleolus. Quantitative radiographic guidelines describing the locations of the primary syndesmotic structures demonstrated excellent reliability and reproducibility. Defined guidelines provide additional clinically relevant information regarding the radiographic anatomy of the syndesmosis and may assist with preoperative planning, augment intraoperative navigation, and provide additional means for objective postoperative assessment.

Radiographic Identification of the Syndesmotic Structures of the Ankle

Objectives:Syndesmotic ligament sprains may result in significant time lost from sport and can lead to chronic pain and instability. While syndesmotic anatomy has been well-defined, quantitative radiographic guidelines for identifying the anatomic ligament attachment sites and tibiofibular cartilage surfaces have not been adequately defined. The purpose was to define quantitative radiographic guidelines for identifying the origins and insertions of the syndesmotic ligaments and tibiofibular articulating cartilage surfaces with respect to radiographic landmarks and standard reference lines.Methods:Twelve non-paired fresh-frozen ankles were dissected to identify the attachments of the anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), interosseous tibiofibular ligament (ITFL), and the cartilage surfaces of the tibiofibular articulation. The center of each structure was marked with a 2 mm radiopaque sphere at the level of the cortex. Standard lateral and mortise radiographs were obtained using a fluoroscopy c-arm and calibrated using a 25.4 mm diameter radiopaque sphere positioned in the field of view. Using a picture archiving and communications system, measurements were performed twice by two independent raters to calculate intra- and inter-rater reliability via intraclass correlation coefficients (ICCs).Results:Measurements demonstrated excellent agreement between raters and across trials (All inter- and intra-rater ICCs ≥ 0.960) for all structures and radiographic views. On the lateral view, the AITFL tibial origin was 9.6 ± 1.5 mm superior and posterior to the anterior tibial plafond (Table 1). Its fibular insertion was 4.4 ± 1.7 mm superior and posterior to the anterior fibular tubercle. The superficial PITFL originated 7.4 ± 1.6 mm superior to the posterior plafond and inserted 22.0 ± 2.3 mm superior and posterior to the lateral malleolus. The corresponding measurements for the deep PITFL were 3.2 ± 1.5 mm superior and 15.4 ± 3.4 mm superior and posterior, respectively. The proximal and distal edges of the ITFL tibial origin were 45.9 ± 7.9 mm and 12.4 ± 3.4 mm proximal to the central aspect of the plafond respectively. The center of the tibiofibular contact area was 8.4 ± 2.1 mm posterior and superior to the anterior plafond. On the mortise view, the AITFL tibial attachment was 5.6 ± 2.4 mm medial and superior to the lateral extent of the plafond and its fibular insertion was 21.2 ± 2.2 mm superior and medial to the lateral malleolus. The corresponding superficial PITFL measurements were 2.7 ± 1.7 mm and 21.5 ± 3.2 mm respectively. The ITFL distal tibial margin was 11.1 ± 3.5 mm proximal to the tibial plafond.Conclusion:Radiographic measurements demonstrated excellent agreement among reviewers and across trials suggesting clinical reproducibility and surgical utility of the defined parameters. Regardless of the type of surgical treatment, these parameters will assist with preoperative planning, augment intraoperative navigation, and provide additional means for objective post-operative assessment of hardware and tunnel placement. Furthermore, radiographic landmarks may be of particular use in revision or arthroscopic assisted cases where surgical landmarks may be obscured or not readily visible.

Arthroscopic Evaluation of Syndesmotic Instability in a Cadaveric Model.

Ankle fractures are among the most common lower extremity injuries. Proper care requires evaluation for syndesmotic ligament disruption. Ankle arthroscopy has been proposed as an intraoperative tool that can evaluate stability. Our focus was to evaluate the amount of displacement produced in the coronal, sagittal, and transverse planes visualized through ankle arthroscopy in a cadaveric model. Seven below-knee specimens were mounted in a traction tower. Four groups were evaluated: no ligamentous disruption; anterior inferior tibiofibular ligament and interosseous ligament disruption; above plus anterior talofibular ligament and calcaneofibular ligament disruption; and posterior inferior tibiofibular ligament and transverse ligament disruption. Force was applied and measured using a digital scale. The amount of displacement of the fibula in relation to the center of the incisura was measured under arthroscopic evaluation using a calibrated probe. An intact syndesmosis and lateral ankle ligaments provided multiplanar stability. In group 2, syndesmosis diastasis was appreciated in the transverse-external rotation plane with as little as 6 lb of force. In group 3, a greater amount of displacement was appreciated with less force. Multiplane instability was visible in every specimen with as little as 2 lb of force. Group 4 specimens were completely disrupted and so grossly unstable that testing was impossible. Ankle arthroscopy has the potential to evaluate even partial disruption of the syndesmotic ligament complex. Instability in the sagittal and transverse planes was encountered early in the spectrum of disruption. Traditional evaluation methods have poor sensitivity for instability in these planes. Arthroscopic evaluation of subtle displacement in multiple planes may assist the surgeon in understanding the extent of the syndesmotic injury. Further studies are necessary to determine to what extent instability requires fixation as well as the role for arthroscopy in assessing anatomic reduction of the syndesmosis after fixation is performed.

Rare Ankle Fracture Pattern: Bosworth Fracture can Lead to Post-Traumatic Arthritis if Unrecognized Early

This article describes a case report of a Bosworth fracture-dislocation with review of the current literature (Table 1) and makes recommendations as to the timing of surgical fixation to help avoid future complications such as post-traumatic arthritis. A Bosworth fracture-dislocation is a rare type of ankle fracture where the proximal portion of the fibula fracture is dislocated posterior to the incisura fibularis [1,24,5]. In most instances the distal syndesmotic ligaments are disrupted allowing for this fracture variant [5]. This type of ankle fracture is challenging to reduce if not irreducible because of the posterolateral osseous portion of the tibia preventing close reduction of the fibula [6,7]. Our case shows how this type of fracture can be close reduced. With disruption of the syndesmotic ligaments the proximal portion of the distal fibula was unstable which then allowed it to re-dislocate posterior behind the tibia after being close reduced. If this type of fracture-dislocation is not identified it can be detrimental to the function and prognosis of the patient [2,8]. Up to this point literature has not described whether this rare variant should be treated differently than typical ankle fractures as to the timing of surgical fixation.