Unstable Syndesmotic Injuries Research Articles

Syndesmotic and Deltoid Injuries: Companions or Coincidences

Background: Syndesmotic complex injuries are supposedly associated with injuries to the deltoid ligament (DL) complex. Several syndesmosis classifications take DL injuries into account when rating the stability of the syndesmotic injury. Still, no study has yet assessed the frequency and severity of DL injuries in unstable syndesmotic injuries. The aim of this retrospective cohort study was to assess both the severity of the syndesmotic and DL injury in patients undergoing surgery for an unstable syndesmotic injury. Methods: The integrity of the syndesmotic and DL complex of 37 patients were assessed on MRI by 2 musculoskeletal radiologists. Eligible were adult patients with an acute, isolated, unstable syndesmotic injury (ligamentous or bony avulsions) who underwent surgery. The DL complex was classified as having 3 superficial (TNL/TSL/TCL) and 2 deep (aTTL/pTTL) components. Grade 0 indicated an intact ligament; grade I showed a periligamentous edema; grade II a partial tear presenting as laxity, irregular contour, or partial discontinuity with concomitant hyperintense signaling; grade III a complete tear; or grade IV in case of an avulsion fracture. Frequency and severity of DL injuries were assessed, and possible injury combinations analyzed using an h-cluster analysis and Mann-Whitney U test. Results: Mean severity (grade 0-3) was 2.6 ± 0.8 for the syndesmotic complex and 1.6 ± 1.1 for the DL (superficial 1.5 ± 1.1, deep 1.6 ± 1.1). Seven patients (19%) had no (n = 3; 8%) or minor (grade 1: n = 4; 11%) DL injuries. Overall, 2 different patient clusters and 4 separate ligament clusters were identified. Conclusion: Unstable syndesmotic injuries can occur isolated or with an accompanying DL injury. There appears to be a great heterogeneity between the severity of syndesmotic and deltoid ligament injuries.

A 3-Ligament Syndesmotic Injury Is at Higher Risk for Malreduction Than a 2-Ligament Injury: A CT-Based Analysis.

Syndesmotic malreduction is common and has been associated to an impaired outcome. Various risk factors for DTFJ malreduction have been postulated. The aims of this study were to assess the DTFJ malreduction rate based on (1) the severity of the syndesmotic injury, (2) the anatomy of the tibial incisura, and (3) the fixation device used in patients treated with suture-button systems. This retrospective, radiographic study included all adult patients who were treated for an acute, unilateral, and unstable syndesmotic injury with a suture-button system and postoperative bilateral CT imaging. Included were isolated syndesmotic injuries and fracture cases. The number of syndesmotic ligaments injured, that is, 2-ligament (AiTFL+IOL) and 3-ligament (AiTFL+IOL+PiTFL), was rated for each patient. The quality of DTFJ reduction, as well as the anatomy of the tibial incisura, was rated based on the postoperative, bilateral CT images and the intraoperative DTFJ reduction was recalculated based on the drilling-tunnel deviation. The possible influence on the DTFJ malreduction rate was assessed. A total of 147 patients were included, and 94 and 53 patients had a 2- and 3-ligament syndesmotic injury, respectively. In addition, 113 patients were treated with a single-button system, 26 with a double suture-button system, and 8 with a hybrid fixation (suture-button + screw). Malreduction was significantly higher in 3-ligament compared with 2-ligament injuries, both intraoperatively (51% vs 27%; P = .003) and postoperatively (28% vs 11%; P = .006). The tibial anatomy had no significant influence on the malreduction rates. No significant differences were seen per the different fixation devices used independent of the number of ligaments injured. This study did not find an influence of the incisura's anatomy on the DTFJ malreduction rate. However, we did find that 3-ligament syndesmotic injuries carried a higher risk of intra- and postoperative malreduction compared with 2-ligament injuries.

Fifteen out of 16 elite athletes showed concomitant low-grade cartilage lesions of the ankle with unstable syndesmotic injuries: concerns from a prospective case series

ObjectivesThis study aimed to determine the incidence rate and characterise the location and severity of cartilage lesions in the ankle in elite athletes undergoing suture-button stabilisation for unstable distal syndesmotic...

A systematic review of studies on the diagnostics and classification system used in surgically treated, acute, isolated, unstable syndesmotic injury: a plea for uniform definition of syndesmotic injuries.

To this day, diagnostic standards and uniform definition for acute, isolated syndesmotic injuries are missing. The aim of the current study was to conduct a systematic review of the classification systems and diagnostics currently applied and to propose a best evidence diagnostic approach. Medline (PubMed), Scopus, Cochrane Central Register of Controlled Trials, and Embase were searched from inception to June 5, 2022, for studies reporting the outcome of surgically treated acute, isolated syndesmotic injuries. First, all classifications used in the eligible studies were identified and illustrated according to the individual syndesmotic structures injured. Second, the indication for surgery and stabilization, based on the diagnostics applied and the time point assessed (pre- or intra-operatively), was analyzed, including the applied cutoff criteria. Ten out of 4190 studies, comprising 317 acute ligamentous syndesmotic injuries, met the inclusion criteria. Seven studies facilitated one of the three different classification systems (Calder, West Point, or Sikka classification). Eight studies based their indication for surgery on a combination of clinical and radiographic examinations and two on radiographs only. The most applied clinical tests were the external rotation stress test and squeeze test. The most common radiologic diagnostics were plain radiographs and MRI. Intraoperatively, instability was verified most commonly using arthroscopy. Current classifications and diagnostics for syndesmotic injuries are heterogeneous, often cannot be attributed to the ligaments injured. An evidence-based diagnostic algorithm based on noninvasive diagnostics and an anatomy-based classification for acute syndesmotic instability is presented.

All-suture fixation of syndesmotic injuries: a case series.

To retrospectively evaluate the clinical outcomes of patients treated for syndesmotic injuries with an all-suture construct technique and compare their patient reported outcome scores with historically published outcomes of syndesmotic injuries fixed with suspensory suture buttons. This was a retrospective case series of patients treated at a Level 1 Trauma Center from May 1, 2018, to June 30, 2022. Ten patients aged 18 and older with unstable syndesmotic injuries treated with all-suture repair. Patients were excluded if they were treated with trans-osseous screws, had previous failed syndesmotic fixation, or suspensory suture button fixation. Patient-reported outcomes including Visual Analog Scale (VAS) pain scores, American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot scores, and complications were recorded. In the patients with 6weeks or more of radiographic follow-up (N = 9), there was no evidence of nonunion, loss of fixation, hardware complication, or whitling of the fibula by the suture. At final follow-up average VAS pain scores were 1.5 out of 10 (range 0-4; SD 1.2), AOFAS ankle and hindfoot scores averaged 89.6 out of 100 (range 86-100; SD 6.1). The pain subscale of the AOFAS score averaged 37.5 out of 40 (range 35-40; SD 2.5). The functional subscale of the AOFAS score averaged 46 out of 50 (range 44-50; SD 3.0). Stiffness was reported in one patient at their follow-up visits, which resolved with continued physical therapy. There were no superficial or deep infections. In conclusion, this case series presents the first clinical outcomes of an all-suture fixation technique for treatment of unstable syndesmotic ankle injuries. Our results suggest that the all-suture fixation technique results in similar patient reported outcomes when compared with historically reported patient reported outcomes of suspensory suture button fixation, and low rates of complication or hardware failure.

Influence of quality of reduction using radiological criteria on kinematics and kinetics in ankle fractures with unstable syndesmotic injury

BackgroundIn ankle fractures with syndesmotic injury, the anatomic reduction of the ankle mortise is crucial for preventing osteoarthritis. Yet, no studies have analysed the effect of surgical reduction after unstable ankle fractures on patients' active functional outcome. MethodsThe Intraoperative 3D imaging data of patients surgically treated between 2012 and 2019 for ankle fracture with concomitant syndesmotic injury were reviewed. 58 patients were allocated to two groups depending on whether the criteria for radiologically optimal reduction were met (39 patients) or not (19 patients). Criteria for optimal reduction were composed of objectively measured and subjectively rated data. After undertaking the Olerud/Molander ankle score, a gait analysis and several active function tests using 3D motion capture were performed in order to evaluate kinetic and kinematic differences between both groups. FindingsPatients showed deficits of range of motion and balance parameters on the injured ankle, however, there were no significant differences between both groups. InterpretationAlthough, the data did not show that radiological reduction criteria have a statistically significant effect on active functional outcome after a mean follow up time of 5.7 years, tendencies for a better outcome of patients that met the criteria could be seen. It also must be taken into consideration that results are limited by case number and allocation ratio, which made a sub-analysis of the separate reduction criteria unfeasible.

Combining radiographic and CT measurements to rival MRI for the diagnosis of acute isolated syndesmotic injury.

Acute isolated syndesmotic injuries (AISIs) have a high potential to be misdiagnosed or underdiagnosed at initial presentation to the hospital. Although magnetic resonance imaging (MRI) is the gold standard in noninvasive diagnostics, it is not always available immediately and is much more expensive than other imaging modalities. This study identifies improvements in conventional radiography and computed tomography (CT) to diagnose AISI and aims to reduce the number of MRI scans needed to verify the diagnosis. A retrospective case match control study was conducted by searching our trauma database between 2008 and 2022. A study group of patients with AISI (n = 64) and a control group of patients without AISI (n = 76) were formed to generate an equal number of images from both groups (62 radiographs and 22 CT scans). A total of 16 parameters that quantify the distal tibiofibular relation in injured and uninjured ankles were analyzed. For statistical analysis, a two-sided t-test was applied to calculate significant differences (p < 0.05). In a further step, a receiver operating characteristic curve (ROC) was used to determine cut-off values for the most significant parameters. The most significant measurement (p < 0.001) on axial CT scans was the syndesmotic area (SA). The ROC curve revealed an area under the curve (AUC) of 0.94 (95% CI 0.86-1.0) and a cut-off value of 71.68 mm2 that shows a sensitivity and specificity of 95.5% and 81.8%, respectively. This study suggests that radiographic imaging could represent an equally accurate alternative to MRI. These methods might generate the correct diagnosis faster due to their availability and inexpensiveness. By applying our new cut-off values in a clinical setting, the number of underdiagnosed and untreated unstable syndesmotic injuries could be reduced. III, retrospective comparative study.

Needle Arthroscopic Inspection and Treatment of (Osteo)chondral Lesions of the Ankle in Unstable Syndesmotic Injuries Treated With Suture Button Fixation: A Standardized Approach

Both acute and chronic syndesmotic injuries are associated with (osteo)chondral lesions of the ankle in at least 1 out of 5 patients. Having a common denominator of an acute traumatic injury being external rotation and forced dorsiflexion, the injury of a combined unstable syndesmotic injury and a potentially present concomitant (osteo)chondral lesion to the ankle warrants a thorough diagnostic and interventional approach. Furthermore, early diagnosis may prevent further damage to the joint through lifestyle changes and increase the chances of successful conservative or surgical treatment, potentially reducing the progression toward end-stage osteoarthritis. Consequently, technological advances and financial considerations have led to the development of a minimally invasive needle arthroscopic inspection and treatment of concomitant (osteo)chondral injuries of the ankle in the combined treatment of unstable syndesmotic injuries with suture button fixation. The present Technical Note describes this innovative minimally invasive assessment and concomitant treatment technique.

Syndesmotic Suture Button Fixation Results in Higher Tegner Activity Scale Scores When Compared to Screw Fixation: A Multicenter Investigation.

Suture buttons and metal screws have been used and compared in biomechanical, radiographic, and clinical outcome studies for syndesmotic injuries, with neither implant demonstrating clear superiority. The aim of this study was to compare clinical outcomes of both implants. Patients who underwent syndesmosis fixation at 2 separate academic centers from 2010 through 2017 were compared. Thirty-one patients treated with a suture button and 21 patients treated with screws were included. Patients in each group were matched by age, sex, and Orthopaedic Trauma Association fracture classification. Tegner Activity Scale (TAS), Foot and Ankle Ability Measure (FAAM), patient satisfaction score, surgical failure, and reoperation rates were compared. Patients who underwent suture button fixation had significantly higher TAS scores than those who underwent screw fixation (p < 0.001). There was no significant difference in FAAM ADL scores between cohorts (p = 0.08). Symptomatic hardware removal rates were similar (3.2% suture button cohort vs 9.0% in screw cohort). One patient (4.5%) underwent revision surgery secondary to syndesmotic malreduction after screw fixation, for a reoperation rate of 13.5%. Patients with unstable syndesmotic injuries treated with suture button fixation had higher mean TAS scores compared to patients treated with screws. Foot and Ankle Ability Measure and ADL scores in these cohorts were similar.Level of Evidence: Level 3 Retrospective Matched Case-Cohort.

Ankle Sprains in Athletes: Current Epidemiological, Clinical and Imaging Trends.

Ankle injuries are frequent sports injuries. Despite optimizing treatment strategies during recent years, the percentage of chronification following an ankle sprain remains high. The purpose of this review article is, to highlight current epidemiological, clinical and novel advanced cross-sectional imaging trends that may help to evaluate ankle sprain injuries. Systematic PubMed literature research. Identification and review of studies (i) analyzing and describing ankle sprain and (ii) focusing on advanced cross-sectional imaging techniques at the ankle. The ankle is one of the most frequently injured body parts in sports. During the COVID-19 pandemic, there was a change in sporting behavior and sports injuries. Ankle sprains account for about 16-40% of the sports-related injuries. Novel cross-sectional imaging techniques, including Compressed Sensing MRI, 3D MRI, ankle MRI with traction or plantarflexion-supination, quantitative MRI, CT-like MRI, CT arthrography, weight-bearing cone beam CT, dual-energy CT, photon-counting CT, and projection-based metal artifact reduction CT may be introduced for detection and evaluation of specific pathologies after ankle injury. While simple ankle sprains are generally treated conservatively, unstable syndesmotic injuries may undergo stabilization using suture-button-fixation. Minced cartilage implantation is a novel cartilage repair technique for osteochondral defects at the ankle. Applications and advantages of different cross-sectional imaging techniques at the ankle are highlighted. In a personalized approach, optimal imaging techniques may be chosen that best detect and delineate structural ankle injuries in athletes.

NOVEL DYNAMIC STABILIZATION SYSTEM PROVIDES BETTER AP TRANSLATION AND AXIAL TIBIOFIBULAR JOINT STABILITY

The quest for optimal treatment of acute distal tibiofibular syndesmotic disruptions is still in progress. Using suture-button repair devices is one of the dynamic stabilization options, however, they may not be always appropriate for stabilization of length-unstable syndesmotic injuries. Recently, a novel screw-suture repair system was developed to address such issues. The aim of this study was to investigate the performance of the novel screw-suture repair system in comparison to a suture-button stabilization of unstable syndesmotic injuries.Eight pairs of human cadaveric lower legs were CT scanned under 700 N single-leg axial loading in five foot positions – neutral, 15° external/internal rotation and 20° dorsi-/plantarflexion – in 3 different states: (1) pre-injured (intact); (2) injured, characterized by complete syndesmosis and deltoid ligaments cuts simulating pronation-eversion injury types III and IV as well as supination-eversion injury type IV according to Lauge-Hansen; (3) reconstructed, using a screw-suture (FIBULINK, Group 1) or a suture-button (TightRope, Group 2) implants for syndesmotic stabilization, placed 20 mm proximal to the tibia plafond. Following, all specimens were: (1) biomechanically tested over 5000 cycles under combined 1400 N axial and ±15° torsional loading; (2) rescanned. Clear space (diastasis), anterior tibiofibular distance, talar dome angle and fibular shortening were measured radiologically from CT scans. Anteroposterior (AP), axial, mediolateral and torsional movements at the distal tibiofibular joint level were evaluated biomechanically via motion tracking.In each group clear space increased significantly after injury (p ≤ 0.004) and became significantly smaller in reconstructed compared with both pre-injured and injured states (p ≤ 0.041). In addition, after reconstruction it was significantly smaller in Group 1 compared to Group 2 (p &lt; 0.001). AP and axial movements were significantly smaller in Group 1 compared with Group 2 (p &lt; 0.001). No further significant differences were identified/detected between the groups (p ≥ 0.113).Although both implant systems demonstrate ability for stabilization of unstable syndesmotic injuries, the screw-suture reconstruction provides better anteroposterior translation and axial stability of the tibiofibular joint and maintains it over time under dynamic loading. Therefore, it could be considered as a valid option for treatment of syndesmotic disruptions.

BETTER ANTEROPOSTERIOR TRANSLATION AND AXIAL TIBIOFIBULAR JOINT STABILITY PROVIDED BY NOVEL DYNAMIC SCREW-SUTURE STABILIZATION SYSTEM FOR SYNDESMOTIC REPAIR

The quest for optimal treatment of acute distal tibiofibular syndesmotic disruptions is still in full progress. Using suture-button repair devices is one of the dynamic stabilization options, however, they may not be always appropriate for stabilization of length-unstable syndesmotic injuries. Recently, a novel screw-suture repair system was developed to address such issues. The aim of this study was to investigate the performance of the novel screw-suture repair system in comparison to a suture-button stabilization of unstable syndesmotic injuries.Eight pairs of human cadaveric lower legs were CT scanned under 700 N single-leg axial loading in five foot positions – neutral, 15° external/internal rotation and 20° dorsi-/plantarflexion – in 3 different states: (1) pre-injured (intact); (2) injured, characterized by complete syndesmosis and deltoid ligaments cuts simulating pronation-eversion injury types III and IV, and supination-eversion injury type IV according to Lauge-Hansen; (3) reconstructed, using a screw-suture (FIBULINK, Group 1) or a suture-button (TightRope, Group 2) implants for syndesmotic stabilization, placed 20 mm proximal to the tibia plafond/joint surface. Following, all specimens were: (1) biomechanically tested over 5000 cycles under combined 1400 N axial and ±15° torsional loading; (2) rescanned. Clear space (diastasis), anterior tibiofibular distance, talar dome angle and fibular shortening were measured radiologically from CT scans. Anteroposterior, axial, mediolateral and torsional movements at the distal tibiofibular joint level were evaluated biomechanically via motion tracking.In each group clear space increased significantly after injury (p ≤ 0.004) and became significantly smaller in reconstructed compared with both pre-injured and injured states (p ≤ 0.041). In addition, after reconstruction it was significantly smaller in Group 1 compared to Group 2 (p &lt; 0.001). Anteroposterior and axial movements were significantly smaller in Group 1 compared with Group 2 (p &lt; 0.001). No further significant differences were detected between the groups (p ≥ 0.113).ConclusionsAlthough both implant systems demonstrate ability for stabilization of unstable syndesmotic injuries, the screw-suture reconstruction provides better anteroposterior translation and axial stability of the tibiofibular joint and maintains it over time under dynamic loading. Therefore, it could be considered as a valid option for treatment of syndesmotic disruptions.

Imaging Threshold for Assessment of the Correct Reduction in the Treatment of Unstable Syndesmotic Injuries - A Retrospective Analysis of 57 CT Scans.

An incongruence of the distal tibiofibular joint (TFJ) after treatment of upper ankle joint injury represents a prearthrotic deformity and must be corrected. The objectives of this study were to analyze postoperative CT scans after surgical treatment of unstable syndesmotic injuries, and to determine the prevalence of syndesmotic malreduction and its contributing factors. The specific parameters of three-dimensional imaging for objective detection of malreduction should be identified as a helpful intraoperative imaging threshold. Postoperative CT scans of 57 patients were analyzed by identifying cases requiring correction. Factors that influenced the reduction result (patient age, sex, fracture type and surgeon qualifications) were evaluated. The following CT measurements were determined: anterior (AD) and posterior tibiofibular distance (PD), TFJ width, anteroposterior fibular translation (APT), length and rotation of the fibula, position of the malleoli to the talar joint surface. A confidence interval of 95% was assumed (significance level p < 0.05). A very high proportion of the cases required revision (38.5%). Age (p=0.199), sex (p=0.752), body mass (p=0.722), and fracture type (p=0.266) had no significant influence on the reduction result. The risk of requiring correction was slightly lower for well-experienced trauma surgeons. The measurements revealed the following thresholds: AD: ø 3.2 mm (±2.2), PD: ø 5.1 mm (±2.2), TFJ: ø 3.4 mm (±1.4), APT: ø 7.9 mm (±3.5), and rotation: ø 10.7° (±6.8). The fibula was too long in 4 cases (7%) and too short in 8 cases (14%). There was a malleolar incongruence in 5 cases (8.7%). The analysis revealed a significant correlation between the ratio of the anterior and posterior tibiofibular distances and a need for correction. The ratio between the anterior and posterior tibiofibular distances in the axial sectional image is an aid for intraoperative assessment of the correct reduction in the TFJ.

Value of Intraoperative 3D Imaging on the Quality of Reduction of the Distal Tibiofibular Joint When Using a Suture-Button System.

The quality of reduction of the distal tibiofibular joint (DTFJ) has a major impact on the outcome. Novel suture-button systems as well as intraoperative 3D imaging can be applied to increase the quality of DTFJ reduction intraoperatively. The individual effect of either remains unknown. The aim of this study was to investigate the value of intraoperative 3D imaging on the quality of reduction of the DTFJ when using a suture-button system. Retrospective, radiographic study including adult patients who underwent surgical stabilization of the syndesmosis with a suture-button system for acute, unilateral, unstable syndesmotic injuries with postoperative bilateral CT imaging. The use of an intraoperative 3D scan was the individual surgeon's choice. Assessed was whether the intraoperative 3D imaging had an influence on the postoperative quality of DTFJ reduction and revision rates. These findings were put in perspective to the correction potential of the suture-button system. A total of 147 patients were included; 76 of these received an intraoperative 3D imaging. Neither the rate of formal malreduction (17% vs 17%) nor the postoperative revision rate (4% vs 3%) differed significantly between patients with or without intraoperative 3D imaging. Intraoperative 3D imaging revealed a false-negative rate of 14%. The intrinsic correction potential of the suture-button system reduced the number of formally malreduced DTFJs in both groups by 51%. The additional value of intraoperative 3D imaging to assess the quality of DTFJ reduction in our series did not improve syndesmotic reduction when using a flexible suture-button system. Level III, retrospective comparative cohort study.

Does the Level of Syndesmotic Screw Insertion Affect Clinical Outcome after Ankle Fractures with Syndesmotic Instability?

Ankle fractures are often combined with syndesmotic instability, requiring reduction and stabilization. However, the optimal level for syndesmotic screw positioning remains unclear. This study aims to evaluate the effect of different syndesmotic screw insertion levels on postoperative clinical outcomes and determine whether an optimal level exists. This retrospective study included data from 43 adult patients with acute closed ankle fractures combined with intraoperative evidence of unstable syndesmotic injuries who underwent open reduction internal fixation from January 1, 2017 to March 1, 2018 according to the inclusion and exclusion criteria. All 43 patients were divided into three groups based on the syndesmotic screw placement level: trans-syndesmotic group: screw level of 2-3cm; inferior-syndesmotic group: screw level <2cm; and supra-syndesmotic group: screw level >3cm. Clinical outcomes were measured at the final follow-up, including the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, Olerud-Molander Ankle Score (OMAS), short-form 36-item questionnaire (SF-36), visual analogue scale (VAS) score and restrictions in ankle range of motion (ROM). The relationships between screw placement level and clinical outcomes were analyzed with the Kruskal-Wallis H-test and Spearman correlation analysis. The median follow-up duration was 15months (range, 10-22months). No patients developed fracture nonunion or malunion or experienced hardware failure. The outcome scoring systems showed an overall score for the entire group of 94.91 points for the AOFAS ankle-hindfoot score, 83.14 for the OMAS, 96.65 for the SF-36, 1.77 for the VAS, 9.14° for the restrictions in dorsiflexion, and 1.30° for the restrictions in plantarflexion. There were no significant differences among three groups in clinical outcomes (P > 0.05). Neither the AOFAS score nor OMAS had significant correlations with screw insertion level (P=0.825 and P=0.585, respectively). No postoperative arthritis or widening of the tibiofibular space was observed at the final follow-up. Different syndesmotic screw placement levels appear not to affect the clinical outcomes of ankle fractures with syndesmotic instability. No optimal level was observed in this study. Our findings suggest other clinically acceptable options apart from syndesmotic screw placement 2-3cm above the ankle.

Augmented stress weightbearing CT for evaluation of subtle tibiofibular syndesmotic injuries in the elite athlete.

We aim to present a novel imaging technique utilizing weight-bearing CT with syndesmotic stress to identify subtle, unstable syndesmotic injuries. We illustrate this with a case presentation of such an injury in an elite athlete that ultimately required operative fixation. In order to perform an augmented stress weightbearing CT, the patient is in the standing position, feet facing forward, and with weight distributed equally. The patient is then coached to internally rotate the shin and knee. This places an external rotational moment on the TFS due to the planted foot and ankle. The augmented stress images undergo 3D reconstruction and post-processing to render coronal and sagittal images. These are subsequently compared to standard, conventional weightbearing CT images performed without the external rotation stress. We illustrate this technique by presenting a case in which a 21-year-old collegiate athlete sustained a Grade II syndesmotic injury, diagnosed by MRI and clinical exam without evidence of instability by standard weightbearing CT or weightbearing radiographs. After undergoing the augmented stress weightbearing CT, the instability was noted. This prompted subsequent operative fixation and ultimately return to sport. We propose this technique for diagnosing unrecognized, subtle dynamically unstable syndesmosis injuries where clinical suspicion persists despite negative imaging, particularly in the elite athlete.

Letter to the Editor: Can Weightbearing Cone-beam CT Reliably Differentiate Between Stable and Unstable Syndesmotic Ankle Injuries? A Systematic Review and Meta-analysis.

Baumbach, Sebastian Felix MD1; Hamberger, Maximilian Anselm2; Polzer, Hans MD1; Schepers, Tim MD, PhD3 Author Information

Novel Dynamic Screw-Suture Stabilization System for Syndesmotic Repair Provides Better Anteroposterior Translation and Axial Tibiofibular Joint Stability: A Human Cadaveric Study

Category: Ankle; Basic Sciences/Biologics; Trauma Introduction/Purpose: The quest for optimal treatment of acute distal tibiofibular syndesmotic disruptions is still in full progress. Using suture-button repair devices is one of the dynamic stabilization options, however, they may not be always appropriate for stabilization of length-unstable syndesmotic injuries. Recently, a novel screw-suture repair system was developed to address such issues. The aim of this study was to investigate its performance in comparison to a suture-button stabilization of unstable syndesmotic injuries. Methods: Eight pairs of human cadaveric lower legs were CT scanned under 700 N single-leg axial loading in five foot positions - neutral, 15° external/internal rotation and 20° dorsi-/plantarflexion - in 3 different states: (1) pre-injured (intact); (2) injured, characterized by complete syndesmosis and deltoid ligaments cuts simulating pronation-eversion injury types III and IV as well as supination-eversion injury type IV according to Lauge-Hansen; (3) reconstructed, using a screw-suture (FIBULINK, Group 1) or a suture-button (TightRope, Group 2) implants for syndesmotic stabilization, placed 20 mm proximal to the tibia plafond/joint surface. Following, all specimens were: (1) biomechanically tested over 5000 cycles under combined 1400 N axial and +-15° torsional loading; (2) rescanned. Clear space (diastasis), anterior tibiofibular distance, talar dome angle and fibular shortening were measured radiologically from CT scans. Anteroposterior, axial, mediolateral and torsional movements at the distal tibiofibular joint level were evaluated biomechanically via motion tracking. Results: In each group clear space increased significantly after injury (p &lt;= 0.004) and became significantly smaller in reconstructed compared with both pre-injured and injured states (p &lt;= 0.041). In addition, after reconstruction it was significantly smaller in Group 1 compared to Group 2 (p &lt; 0.001). Anteroposterior (AP) and axial movements were significantly smaller in Group 1 compared with Group 2 (p &lt; 0.001, Figure). No further significant differences were identified/detected between the groups (p &gt;= 0.113). Conclusion: Although both implant systems demonstrate ability for stabilization of unstable syndesmotic injuries, the screw- suture reconstruction provides better anteroposterior translation and axial stability of the tibiofibular joint and maintains it over time under dynamic loading. Therefore, it could be considered as a valid option for treatment of syndesmotic disruptions.

Syndesmotic Suture Button Fixation Results in Higher Tegner Activity Scale Scores When Compared to Screw Fixation: A Multicenter Investigation

Category: Ankle Introduction/Purpose: Injuries of the syndesmosis may occur in isolation or association with rotational ankle fractures. The use of suture button 'tight-ropes' versus metal screws for fixation across the syndesmosis has become a highly debated topic. Previous authors have compared subjective, functional, and radiographic outcomes between the two fixation methods with good outcomes reported. The primary aim of this study is to compare clinical outcomes of syndesmotic suture button fixation versus syndesmotic screw fixation for operative management of syndesmotic injuries. A secondary aim is to determine failure rates of both fixation techniques requiring revision syndesmosis surgery. We hypothesize that there will be no difference in subjective outcomes or activity scores when comparing screw versus suture button. This study is to improve patient care and outcomes. Methods: In this multi-center, retrospective cohort study, we identified patients with syndesmotic injuries who underwent surgical treatment at two separate academic referral centers from 2010 through 2017. All patients were diagnosed by attending orthopaedic surgeons at the participating study sites, and where their syndesmotic injuries were treated with either suture-button fixation or metal screw fixation based on surgeon preference. Patients were matched by age, gender, and OTA fracture classification. The primary subjective outcome measure was the Tegner activity level, and the secondary subjective outcomes measures were the Foot and Ankle Ability Measure (FAAM) activities of daily living (ADL) subscale, FAAM sport subscale, and patient satisfaction score. The primary objective outcomes included failure and reoperation rate. Results: 41 patients treated with a suture button (71% male, mean age 39.7 years) and 21 patients treated with metal screws (67% male, mean age 43.7 years) were included in the study. Patient demographics were similar between groups. There was no significant difference in FAAM ADL scores between patients based on surgical procedure for the treatment of a syndesmosis injury (suture button versus metal screw fixation), t (50) = 1.373 (p =0.176). There was a significant difference in Tegner activity scale scores, with patients who underwent suture button fixation reporting significantly higher Tegner activity level scores on average than those who underwent syndesmosis repair with screw fixation (U = 141, p =0.002) (Figure 1). Conclusion: In this multi-center study, we report higher mean Tegner activity scale scores in patients treated with suture button fixation when compared to patients treated with metal screws for unstable syndesmotic injuries. Patients in both treatment cohorts reported similar FAAM ADL scores. The authors believe that both syndesmotic fixation techniques are acceptable in the treatment of syndesmosis of injuries, but recommend consideration given to suture button fixation in patients with higher activity levels.

CORR Insights®: Can Weightbearing Cone-beam CT Reliably Differentiate Between Stable and Unstable Syndesmotic Ankle Injuries? A Systematic Review and Meta-Analysis.

CORR Insights®: Can Weightbearing Cone-beam CT Reliably Differentiate Between Stable and Unstable Syndesmotic Ankle Injuries? A Systematic Review and Meta-Analysis.