Syndesmosis Instability Research Articles

What is the frequency of anterior syndesmosis injury in posterior malleolus fracture?

BackgroundPosterior malleolus fractures may be fixed to restore syndesmosis stability. However, these fractures are often accompanied by ruptures of other ligaments that stabilize the syndesmosis. This study investigates the frequency of anterior syndesmosis injury in posterior malleolus fractures and its effect on rotational stability.MethodsSeventy-five consecutive patients who underwent surgery for ankle fractures involving posterior malleolus were prospectively included. Preoperative computed tomography scans in two planes (transverse and sagittal) were used to assess the presence and size of avulsion fractures (LeFort-Wagstaffe and Tillaux-Chaput). Intraoperatively, anterior syndesmosis injuries and rotational stability (determined via the external rotation test) were assessed through direct visualization.ResultsIn 73 patients (97%), a complete injury of the anterior tibiofibular ligament was observed intraoperatively, manifesting as avulsion fractures (8%), ligament injuries (44%), or a combination of both (45%). The mean dimensions of the avulsion fractures were 12.6 mm × 7.5 mm for LeFort-Wagstaffe fractures and 12.4 mm × 7.9 mm for Tillaux-Chaput fractures. Posterior malleolus fractures were stabilized in 57 patients. In 52 of these cases (92%), syndesmosis instability in the direction of external rotation persisted despite fixation of the posterior malleolus.ConclusionsFixation of posterior malleolus fractures is rarely sufficient to fully restore syndesmosis stability. Post-fixation assessment of syndesmosis stability, particularly in external rotation, is essential.

Treatment of Syndesmotic Instability: The Importance of Malleolar Fixation

A significant proportion of syndesmotic injuries often occur simultaneously with malleolar fractures. The existing literature emphasizes that even slight misalignments in the malleolar structures can lead to altered talar motion, ultimately resulting in post-traumatic ankle arthritis. Rotational ankle fractures with syndesmotic injury can manifest with isolated or a combination of lateral, medial, and/or posterior malleolar fractures, and an accurate anatomic restoration of malleolar fractures has been emphasized. One such reason for anatomic reduction is that the fracture fragment may have an important attachment site for ligaments that contributes to the stability of the ankle and syndesmotic joints. While the biomechanical impact of malreduction of the lateral and medial malleolus osteoligamentous complex has been well documented and understood, controversy persists regarding the optimal surgical treatment of posterior malleolar fractures in the context of syndesmosis instability. Advanced imaging and biomechanical studies have shed new light on the role of the posterior malleolus in syndesmosis stability, suggesting that anatomic reduction of the posterior malleolar fragment could decrease the necessity of transfixation of the syndesmosis, lowering the risk of malreduction. As a result, there is growing advocacy for anatomically reducing and fixing the posterior malleolus in ankle fractures with syndesmotic injuries. This review focuses on the critical role of malleolar fixation in the management of syndesmotic injuries. Level of Evidence : Diagnostic Level V—expert opinion. See Instructions for Authors for a complete description of levels of evidence.

HIGH ANKLE SPRAINS WITH SYNDESMOSIS INSTABILITY: TIME TO MRI MATTERS

IntroductionEarly clinical examination combined with MRI following a high ankle sprain allows accurate diagnosis of syndesmosis instability. However, patients often present late, and for chronic injuries clinical assessment is less reliable. Furthermore, in many centres MRI may be not be readily available. The aims of the current study were to define MRI characteristics associated with syndesmosis instability, and to determine whether MRI patterns differed according to time from injury.MethodsRetrospectively, patients with an unstable ligamentous syndesmosis injury requiring fixation were identified from the logbooks of two fellowship trained foot and ankle surgeons over a five-year period. After exclusion criteria (fibula fracture or absence of an MRI report by a consultant radiologist), 164 patients (mean age 30.7) were available. Associations between MRI characteristics and time to MRI were examined using Pearson's chi-square tests or Fisher's exact tests (significance set at p< 0.05).ResultsOverall, 100% of scans detected a syndesmosis injury if performed acutely (within 6 weeks of injury), falling to 83% if performed after 12 weeks (p=0.001). In the acute group, 93.5% of patients had evidence of at least one of either PITFL injury (78.7%), posterior malleolus bone oedema (60.2%), or a posterior malleolus fracture (15.7%). In 20% of patients with a posterior malleolus bone bruise or fracture, the PITFL was reported as normal. The incidence of posterior malleolus bone bruising and fracture did not significantly differ according to time.ConclusionFor unstable ligamentous syndesmosis injuries, MRI becomes less sensitive over time. Importantly, posterior malleolus bone oedema or fracture may be the only evidence of a posterior injury. Failure to recognise instability may lead to inappropriate management of the patient, long term pain and arthritis. We therefore advocate early MRI as it becomes more difficult to ‘grade’ the injury if delayed.

The role of computed tomography with external rotation and dorsiflexion in decision making for acute isolated non-displaced posterior malleolar fractures Bartoníček and Rammelt type II: a prospective study.

Our objective was to evaluate the syndesmotic and fracture instability using conventional ankle computed tomography (CT) with stress maneuvers. A consecutive sample of 123 individuals with an ankle sprain was assessed for eligibility. In total, 33 patients met the inclusion criteria. All patients underwent a magnetic resonance imaging (MRI) and CT scan with stress maneuvers (CTSM). The patterns of ligament tears f were classified using West Point grades I, IIA, IIB, III. Mann-Whitney test was used to test the differences in the numerical variables between injured and uninjured syndesmoses. The Spearman correlation tested the strength of the association between the tibial joint surface involved in posterior malleolus fracture and syndesmotic instability. In MRI, two patterns of syndesmotic ligament injury predominated. A completely torn anterior inferior tibiofibular (AITFL) and interosseous tibiofibular ligaments (ITFL) and a completely torn AITFL were combined with a partially torn ITFL. In the neutral phase CTSM and during the stress phase the median difference of the narrowest tibiofibular distance between injured and uninjured syndesmoses was 0.2mm (P = 0.057) and 2.3mm (P < 0.0001), respectively. There was no association between the percentage of involvement of the posterior tibial joint surface in the posterior malleolar fracture and syndesmotic instability as measured with CTSM. The conventional computed tomography with external rotation and dorsiflexion represents a reproducible and accurate diagnostic option for detecting syndesmosis instability and fracture instability in acute isolated non-displaced posterior malleolar fractures Bartoníček and Rammelt type II. Prospective study among consecutive patients (Diagnosis); Level of evidence, 2.

Standing on single foot-binding test yields satisfactory results as a novel method for the diagnosis of distal tibiofibular syndesmosis instability: a prospective, cross-sectional diagnostic-accuracy study

BackgroundNon-invasive diagnosis of distal tibiofibular syndesmosis instability (DTSI) was a great challenge to clinicians. We designed a new method, the Standing on single foot-Binding test, and investigated the accuracy of the test in the diagnosis of distal tibiofibular syndesmosis instability in adults with a history of ankle injury.Methods85 participants with ankle injury were subjected to the Standing on single foot-Binding test, MRI and palpation to detect the distal tibiofibular syndesmosis instability (DTSI) and the findings were compared with ankle arthroscopic results. Both participants and arthroscopist were blind to the predicted results of the clinical tests. Sensitivity, specificity, PPV, NPV, LR+, LR − and their 95% CIs were calculated for each of the clinical tests as well as for the positive clinical diagnosis.ResultsThe Standing on single foot-Binding test (SOSF-B test) outperformed MRI and palpation, in terms of sensitivity (87.5%/84.38%), specificity (86.79%/86.79%), PPV (80%/79.41%), NPV (92%/91.2%), LR+ (6.625/6.39), LR- (0.14/0.18) and diagnostic accuracy (87.06/85.88), among others, in the diagnosis of distal tibiofibular syndesmosis instability (DTSI). The diagnostic performance of 20° SOSF-B test was virtually identical to that of 0° SOSF-B test. According to the prevalence (28.7%) of DTSI and LR of four tests, the post-test probability could be used in clinical practice for the prediction of DTSI.ConclusionThis prospective and double-blind diagnostic test showed that the SOSF-B test is clinically feasible for the diagnosis of distal tibiofibular syndesmosis instability (DTSI), and new diagnostic tools for rapid screening of distal tibiofibular syndesmosis instability (DTSI).Level of evidenceII.

The use of deep learning enables high diagnostic accuracy in detecting syndesmotic instability on weight-bearing CT scanning.

Delayed diagnosis of syndesmosis instability can lead to significant morbidity and accelerated arthritic change in the ankle joint. Weight-bearing computed tomography (WBCT) has shown promising potential for early and reliable detection of isolated syndesmotic instability using 3D volumetric measurements. While these measurements have been reported to be highly accurate, they are also experience-dependent, time-consuming, and need a particular 3D measurement software tool that leads the clinicians to still show more interest in the conventional diagnostic methods for syndesmotic instability. The purpose of this study was to increase accuracy, accelerate analysis time, and reduce interobserver bias by automating 3D volume assessment of syndesmosis anatomy using WBCT scans. A retrospective study was conducted using previously collected WBCT scans of patients with unilateral syndesmotic instability. One-hundred and forty-four bilateral ankle WBCT scans were evaluated (48 unstable, 96 control). We developed three deep learning models for analyzing WBCT scans to recognize syndesmosis instability. These three models included two state-of-the-art models (Model 1-3D Convolutional Neural Network [CNN], and Model 2-CNN with long short-term memory [LSTM]), and a new model (Model 3-differential CNN LSTM) that we introduced in this study. Model 1 failed to analyze the WBCT scans (F1 score = 0). Model 2 only misclassified two cases (F1 score = 0.80). Model 3 outperformed Model 2 and achieved a nearly perfect performance, misclassifying only one case (F1 score = 0.91) in the control group as unstable while being faster than Model 2. In this study, a deep learning model for 3D WBCT syndesmosis assessment was developed that achieved very high accuracy and accelerated analytics. This deep learning model shows promise for use by clinicians to improve diagnostic accuracy, reduce measurement bias, and save both time and expenditure for the healthcare system. II.

The Role of Computed Tomography with External Rotation and Dorsiflexion in Decision Making for Acute Isolated Posterior Malleolar Fractures Bartoníček and Rammelt Type II: A Cross-Sectional Study

Category: Ankle; Sports Introduction/Purpose: A ligament-centered analysis is currently incorporated in the assessment of joint stability in malleolar fractures. Although several imaging tests are available, in the setting of acute isolated non-displaced posterior malleolar fractures Bartoníček/Rammelt types II and IV diagnosing syndesmotic instability remains challenging. The objective of this multi-center cross- sectional study was to evaluate the syndesmotic and fracture instability using conventional ankle CT with external rotation and dorsiflexion in the setting of acute, isolated non-displaced Bartoníček and Rammelt type II posterior malleolar fractures. Methods: Between March 2018 and September 2022, a consecutive sample of 123 individuals with an ankle sprain were assessed for eligibility. In total, 33 participants met the inclusion criteria. All participants underwent a CT scan (CTSM), comprising a first phase with the ankles in a neutral position, then a stress phase with the ankles in external rotation and dorsiflexion and semiflexed knees. Investigators used the patterns of ligament tear found at MRI and instability at CTSM to classify all participants into West Point grades I, IIA, IIB, or III. Mann-Whitney test was used to test the differences in the numerical variables between injured and uninjured syndesmoses. The Spearman correlation tested the strength of the association between the tibial joint surface involved in posterior malleolus fracture and syndesmotic instability. Results: In MRI reading parameters two patterns of syndesmotic ligament injury predominated. A completely torn AITF and IO ligaments and a completely torn AITF was combined with a partially torn IO. Regarding the deep layer of the deltoid ligament, participants were classified as normal, strained and partially torn. In CT scan reading parameters in the neutral phase, the median difference of 0.2 mm in d measurements between injured and uninjured syndesmoses was not statistically significant (P = 0.057). During the stress phase, the injured and uninjured syndesmoses had distinct behavior, and the 2.3 mm median difference for d measurement was statistically significant (P &lt; 0.0001). Conclusion: The conventional computed tomography with external rotation and dorsiflexion represent a reproducible and accurate diagnostic option for the detection of syndesmosis instability and fracture instability in acute isolated posterior malleolar fractures Bartonícek and Rammelt type II.

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.

The distal tibiofibular joint effusion may be a reliable index for diagnosing the distal tibiofibular syndesmosis instability in ankle

PurposeTo analyze the accuracy of MRI in diagnosis of distal tibiofibular syndesmosis instability (DTSI) and construct new diagnostic parameters.Materials and methodsThis retrospective study evaluated 212 patients with history of ankle sprains and 3 T MRI and received a final diagnosis of distal tibiofibular syndesmosis instability by ankle arthroscopic surgery from October 2017 and December 2021. We compared the accuracy of syndesmotic injury, qualitative index of distal tibiofibular joint effusion (DTJE), and quantitative index of distal tibiofibular joint effusion (DTJE) in diagnosing distal tibiofibular syndesmosis instability. The criteria for syndesmotic injury were consistent with previous literature, and DTJE was grouped according to the pre-experimental results.ResultsA total of 212 patients (mean age, 35.64 ± 11.79, 74 female and 138 male) were included. Independent predictive MRI features included syndesmotic injury, qualitative index of distal tibiofibular joint effusion, and quantitative index of DTJE including the height, projected area of equal-point method, and projected area of incremental-value method. The quantitative index of DTJE showed a higher area under the receiver operating characteristic curve (0.805/0.803/0.804/0.811/0.817/0.805 > 0.8, P < 0.05; in comparison with all other method). The height measurement method was simpler and easier to operate, that could be gotten only by measuring the DTJE distance of a MRI independent layer, and the cut-off value of the effusion height was 8.00 mm and the Youden index (0.56) was the best.ConclusionsOur research translated a complicated string of MRI multi-dimensional spatial measurements into a simple measuring process, and established the significance of quantifying DTJE in the diagnosis of DTSI. We found that the 8-mm height of DTJE was a more specific indicator for DTSI and could serve as a novel MRI diagnostic cutoff in clinical practice.

A case series comparing ankle motion during functional activities between syndesmotic screw or suture-button fixation methods for distal tibiofibular syndesmosis instability

Distal tibiofibular syndesmosis injuries can be stabilized with syndesmotic screws or suture-buttons. The objective was to compare ankle motion during gait and a step-down task between patients that had syndesmotic screw or suture-button fixation and healthy adults. This case series included two participants who received a syndesmotic screw and two participants that received a suture-button to fixate the distal tibiofibular syndesmosis. Time from surgery was 2 to 5 years. Ankle angles were measured during gait and a step-down task using an optical motion capture system and force plates. Peak angles and angle waveforms were compared to healthy adults (gait n=56, step-down n=14) using descriptive statistics. There was decreased ankle plantarflexion during gait for one participant that had a syndesmotic screw and one participant that had a suture-button compared to healthy adults. During step-down, there was decreased ankle dorsiflexion in three participants (1 suture-button, 2 syndesmotic screw) and decreased ankle eversion for both participants that had syndesmotic screws. There was no clear pattern of which surgical technique resulted in improved ankle motion. Other factors likely played a role in limiting ankle motion such as injury severity. Future studies should further compare ankle motion during functional activities between these surgical techniques in larger samples.

Diagnosis of subtle syndesmotic instability using conventional CT-imaging and axial force in different foot positions

BackgroundCurrently, there is no available method that can objectively and reliably detect subtle instability of the distal tibiofibular joint. The purpose of this study is to diagnose, using computerized axial tomography and an adjustable simulated loading device, subtle instability of the tibiofibular syndesmosis. MethodsFifteen healthy individuals and 15 patients with clinical suspicion of subtle instability of the tibiofibular syndesmosis (total 60 ankles) were studied using an adjustable simulated loading device (ASLD). This device allows to perform bilateral ankle CT scans in two forced foot and ankle positions (30° of plantar flexion, 15° of inversion, 20° of internal rotation and 15° of dorsal flexion, 15° of eversion, 30° of external rotation). Axial load was applied simultaneously in a controlled manner (70% body weight). Measurements on the axial image of computed tomography were: syndesmotic area (SA), fibular rotation (FR), position of the fibula in the sagittal plane (FPS), depth of the incisura (ID), anterior direct difference (ADD), middle direct difference (MDD) and posterior direct difference (PDD). ResultsStatistically significant differences were observed in the variable syndesmotic area between healthy (mean=−0.14, SD=4.33) and diseased (mean=16.82, SD=12.3)(p < 0.001). No statistically significant differences were found in the variables ADD, MDD, PDD, ID, FPS and FR. ConclusionsMeasurement of syndesmotic area employing axial force and forced foot positions using the ASLD may be useful for the diagnosis of subtle tibiofibular syndesmosis instability.

Salvage of Chronic Syndesmosis Instability: A Retrospective Review With Mid-Term Follow-Up

Malreduced syndesmotic injuries lead to poor outcomes. No consensus exists regarding preferred surgical treatment. This study aims to assess clinical and radiographic outcomes in patients undergoing distal tibiofibular arthrodesis or stabilization. Retrospective review identified patients undergoing distal tibiofibular arthrodesis or stabilization between 2003 and 2019. Surgical factors, revision surgeries, and American Orthopedic Foot and Ankle Score ankle-hindfoot scores were collected. Radiographs were independently evaluated by 4 surgeons. Seventy patients were included. Mean American Orthopedic Foot and Ankle Score scores (n = 33) improved from 48 ± 16 preoperatively to 85 ± 14 (p < .001) at a median follow-up of 31.1 months. Mean Kellgren scores (n = 47) increased from 2.1 ± 1 to 2.5 ± 1 (p < .001) and the mean medial clear space decreased from 3.2 mm ± 0.8 mm to 2.8 mm ± 0.8 mm (p <.001) with no differences between the arthrodesis and stabilization groups. Zero patients progressed to arthroplasty or fusion. Patients demonstrated significant functional improvement after distal tibiofibular arthrodesis and stabilization. Progression of arthritis, while statistically significant, was not clinically significant.

Associations of overweight, obesity and osteoporosis with ankle fractures

BackgroundStudies exploring risk factors for ankle fractures in adults are scarce, and with diverging conclusions. This study aims to investigate whether overweight, obesity and osteoporosis may be identified as risk factors for ankle fractures and ankle fracture subgroups according to the Danis-Weber (D-W) classification.Methods108 patients ≥40 years with fracture of the lateral malleolus were included. Controls were 199 persons without a previous fracture history. Bone mineral density of the hips and spine was measured by dual-energy x-ray absorptiometry, and history of previous fracture, comorbidities, medication, physical activity, smoking habits, body mass index and nutritional factors were registered.ResultsHigher body mass index with increments of 5 gave an adjusted odds ratio (OR) of 1.30 (95% confidence interval (CI) 1.03–1.64) for ankle fracture, and an adjusted OR of 1.96 (CI 0.99–4.41) for sustaining a D-W type B or C fracture compared to type A. Compared to patients with normal bone mineral density, the odds of ankle fracture in patients with osteoporosis was 1.53, but the 95% CI was wide (0.79–2.98). Patients with osteoporosis had reduced odds of sustaining a D-W fracture type B or C compared to type A (OR 0.18, CI 0.03–0.83).ConclusionsOverweight increased the odds of ankle fractures and the odds of sustaining an ankle fracture with possible syndesmosis disruption and instability (D-W fracture type B or C) compared to the stable and more distal fibula fracture (D-W type A). Osteoporosis did not significantly increase the odds of ankle fractures, thus suffering an ankle fracture does not automatically warrant further osteoporosis assessment.

Ankle and syndesmosis instability: consensus and controversies.

Ankle sprains are mainly benign lesions, but if not well addressed can evolve into permanent disability. A non-treated lateral, syndesmotic or medial ankle instability can evolve into ankle osteoarthritis. For this reason, diagnosis and treatment of these entities is of extreme importance.In general, acute instabilities undergo conservative treatment, while chronic instabilities are better addressed with surgical treatment. It is important to identify which acute instabilities are better treated with early surgical treatment.Syndesmosis injuries are frequently overlooked and represent a cause for persistent pain in ankle sprains. Unstable syndesmotic lesions are always managed by surgery.Non-treated deltoid ligament ruptures can evolve into a progressive valgus deformity of the hindfoot, due to its links with the spring ligament complex. This concept would give new importance to the diagnosis and treatment of acute medial ligament lesions.Multi-ligament lesions are usually unstable and are better treated with early surgery. A high suspicion rate is required, especially for combined syndesmotic and medial lesions or lateral and medial lesions.Ankle arthroscopy is a powerful tool for both diagnostic and treatment purposes. It is becoming mandatory in the management of ankle instabilities and multiple arthroscopic lateral/syndesmotic/medial repair techniques are emerging.Cite this article: EFORT Open Rev 2021;6:420-431. DOI: 10.1302/2058-5241.6.210017

Clinical outcomes of isolated acute instability of the syndesmosis treated with arthroscopy and percutaneous suture-button fixation

To present the short- to midterm clinical outcomes of a series of patients with isolated acute syndesmosis instability treated with arthroscopy and percutaneous suture-button fixation. A review of 17 patients treated through the arthroscopic approach. The mean age of the patients was 27.8years and the mean follow-up was 31.5months. Clinical and functional evaluations were based on the VAS, AOFAS ankle-hindfoot score and time of return to preinjury level of activities. Imaging analysis was performed with stress radiographs, MRI and CT scan with stress. The average VAS was 0.5 and the mean AOFAS score was 95.5. Out of the 17 patients, 15 were able to return to their preinjury level of activities. The mean time of return to activities was 5.06months. Arthroscopic approach and percutaneous suture-button fixation provided satisfactory clinical and functional results for selected patients with ASI at short- to midterm follow-up. Level IV, retrospective case series.

Screw versus suture button in treatment of syndesmosis instability: Comparison using weightbearing CT scan

BackgroundThe superiority of screw or suture button fixation for syndesmotic instability remains debatable. Our aim is to compare radiographic outcomes of screw and suture button fixation of syndesmotic instability using weight bearing CT scan (WBCT). MethodsTwenty patients with fixation of unilateral syndesmotic instability were recruited and divided among two groups (screw = 10, suture button = 10). All patients had WBCT of both ankles ≥12 months postoperatively. ResultsIn suture button group, injured side measurements were significantly different from normal side for syndesmotic area (P = 0.003), fibular rotation (P = 0.004), anterior difference (P = 0.025) and direct anterior difference (P = 0.035). In screw group, syndesmotic area was the only significantly different measurement (P = 0.006). ConclusionWhile both screw and suture button didn’t completely restore the syndesmotic area as compared to the contralateral uninjured ankle, external malrotation of the fibula was uniquely associated with suture button fixation. Level of EvidenceIII Retrospective Cohort Study

Clinical outcome of distal tibiofibular arthrodesis with plate fixation for the treatment of chronic frank syndesmosis instability

BackgroundNumerous treatment strategies have been reported for the treatment of chronic frank distal tibiofibular syndesmosis instability, including several small case series treated by syndesmosis arthrodesis. The aim of this study is to report the treatment of this condition using a specially contoured plate and the associated clinical outcomes. MethodsOver a period of 8 years, patients presented in our institution with chronic frank distal tibiofibular syndesmosis instability were eligible to participate. All patients were managed with plating and screw fixation. The average follow-up period was 58 months (range, 12-99). Clinical outcome was evaluated using the American Orthopaedic Foot & Ankle Society ankle-hindfoot score. ResultsIn total, 8 patients met the inclusion criteria and formed the basis of this study. All patients could tolerate full weightbearing 3 months after surgery. The mean Visual Analog Scale pain score and the American Orthopaedic Foot & Ankle Society ankle-hindfoot score were significantly improved at the last follow-up (P<0.05). All patients were satisfied with the result and 7 patients returned to sports. 4 patients had mild limitation of ankle range of motion compared with the unaffected side. ConclusionSyndesmosis arthrodesis was a feasible method for the treatment of chronic frank syndesmosis instability according to our findings. Syndesmosis arthrodesis with plate and screw stabilization is another viable option to be considered into the surgeon's armamentarium. Larger scale studies are desirable to provide further evidence of this method of treatment.

What is the Effect of Lateral Ankle Ligament Injury on Syndesmotic Stability? Arthroscopic evaluation

Category:Ankle; Arthroscopy; Sports; TraumaIntroduction/Purpose:Numerous studies have shown a high incidence of associated lateral ankle and syndesmotic ligamentous injuries. It is unclear, however, if there is a direct contribution of the lateral ligaments towards stabilizing the syndesmosis. Using arthroscopy, we assessed to what extent lateral ankle ligaments contribute to syndesmotic stability in the coronal and sagittal plane. Our hypothesis was that lateral ankle ligament injury has effect on syndesmosis instability.Methods:Sixteen fresh frozen above-knee amputated cadaveric specimens were divided into two groups that underwent arthroscopic evaluation for syndesmotic stability. In both the groups, the assessment was done with all syndesmotic and ankle ligaments intact and later with sequential transection of the anterior talofibular ligament (ATFL), the calcaneofibular ligament (CFL), the posterior talofibular ligament (PTFL), anterior inferior tibiofibular ligament (AITFL), the interosseous ligament (IOL) and the posterior inferior tibiofibular ligament (PITFL). In all scenarios, coronal and sagittal loading conditions were considered under 100N of direct force to fibula. The measurements of the distal tibiofibular coronal plane space at the anterior and posterior third of syndesmosis were performed using arthroscopic probes with increment of 0.2mm diameter. Further the sagittal translation were measured by arthroscopic scaled probe. Dunnett test was used to compare the findings of each ligamentous transection state to the intact state. A p-value < 0.05 was considered significantly defferent.Results:Compared with the intact ligamentous state, there was no difference in coronal and sagittal stability when the lateral ankle ligaments (ATFL, CFL, PTFL) and AITFL were transected (Table1 and 2, Group1). However, after subsequent transection of the IOL, or after transection of the lateral ankle ligaments (ATFL, CFL or and PTFL) alongside the AITFL and IOL, both coronal space and sagittal translation increased as compared with the intact state (p-values p<0.001 respectively) (Table1 and 2, Group2).Conclusion:Our findings suggest that lateral ankle ligaments do not directly contribute to syndesmotic stability in the coronal and sagittal plane. In concomitant acute syndesmotic and lateral ligament injury, surgeons should pay attention to whether there is combined IOL injury to determine the fixation of syndesmosis.

Diagnosis of tibiofibular syndesmosis instability in Weber type B malleolar fractures.

ObjectiveThis study was performed to analyze the clinical value of X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) examinations for the diagnosis of distal tibiofibular syndesmosis injuries in Weber type B ankle fractures with reference to the ankle arthroscopic findings.MethodsThis retrospective clinical study involved 52 patients with type B ankle fractures from August 2014 to January 2018. We analyzed the patients’ preoperative imaging data and judged the stability of the distal tibiofibular syndesmosis using X-ray, CT, and MRI examinations. We also evaluated the syndesmosis stability with arthroscopy both statically and dynamically.ResultsWith the arthroscopic findings as the standard, the sensitivity of X-ray for diagnosing syndesmosis instability was 52.8%, the specificity was 100%, and the diagnostic efficiency was 67.3%. The sensitivity of CT for diagnosing syndesmosis instability was 77.8%, the specificity was 100%, and the diagnostic efficiency was 84.6%. The sensitivity of MRI for diagnosing syndesmosis instability was 100%, the specificity was 81.3%, and the diagnostic efficiency was 94.2%.ConclusionThis study suggests that an arthroscopic examination may be recommended when the X-ray or CT features are different from the MRI findings while diagnosing tibiofibular syndesmosis instability in Weber type B malleolar fractures.

Screw Versus Suture Button in Treatment of Syndesmosis Instability: Clinical and Radiographic Outcomes Using PROMIS and Weight Bearing CT Scan

Category:Trauma; Ankle; SportsIntroduction/Purpose:Traumatic injuries to the distal tibiofibular syndesmosis are relatively common and can be associated with ankle fractures or occur as purely ligamentous injuries. Unstable syndesmotic injuries require surgical repair, generally performed using either screw or suture button fixation. The superiority of either fixation method remains a subject of ongoing debate. The aim of this study is to compare both clinical and radiographic outcomes of screw and suture button fixation of syndesmosis instability using Patient-Reported Outcomes Measurement Information System (PROMIS) and weight bearing CT scan (WBCT).Methods:Medical records were reviewed to identify patients who had a unilateral syndesmotic injury requiring surgical stabilization and who were at least one year out from injury. Exclusion criteria included patients less than 18 years old, ipsilateral pilon fracture, history of contralateral ankle or pilon fracture or syndesmosis injury, BMI >40, and any neurological impairment. Twenty eligible patients were recruited to complete PROMIS questionnaires and undergo bilateral WBCT scan of both ankles, divided into two groups. In the first group (n=10) the patients had undergone screw fixation of the syndesmosis, while in the second group (n=10) the syndesmosis was fixed using a suture button construct. All patients completed PROMIS questionnaires for pain intensity, pain interference, physical function and depression. Radiographic assessment was performed using axial images of WBCT scan of both the injured ankle and the contralateral normal side at a level one cm proximal to the tibial plafond (Figure 1).Results:At an average follow up of three years, none of the recruited patients required a revision surgery. There was no significant difference between the two groups in terms of the four PROMIS questionnaires (P values ranged from 0.17 to 0.43). In the suture button group, the measurements of the injured side were significantly different from the normal side for the syndesmotic area (P=0.003), fibular rotation (P=0.004), anterior difference (P=0.025) and direct anterior difference (P=0.035).Other measurements of posterior difference, middle difference, direct posterior difference and fibular translation were not significantly different (P values ranged from 0.36 to 0.99). In the screw fixation group, the syndesmotic area was the only significantly different measurement in the injured side as compared to the normal side (P=0.006).Conclusion:Screw and suture button fixation for syndesmotic instability have similar clinical outcomes at average three years follow up as measured by PROMIS scores. Both screw and suture button did not entirely restore the syndesmotic area as compared to the contralateral normal ankle, suggesting some residual diastasis on weight bearing CT. In addition, as compared to screw fixation, the suture button did not seem to restore the normal fibular rotation, with residual external rotation of the fibula noted. Longer clinical follow up is necessary to understand the clinical implication of such malreduction.