Syndesmotic Widening Research Articles

Do Syndesmotic Injury Patterns Influence Functional and Radiological Outcomes in Complex Ankle Fractures? A Retrospective Cohort Study

Category: Ankle; Trauma Introduction/Purpose: Syndesmosis injury can be of a varying magnitude; little information exists about the influence of degree of initial syndesmotic injury/instability on functional outcomes in ankle fractures, nor is there any correlation of this with follow up radiological parameters. Aims and Objectives: To identify and define morphological patterns of syndesmotic injury in ankle fractures according to a zone based evaluation, and correlate initial degree of instability with mid-term functional and radiological outcomes using validated scores Design: Retrospective cohort study, to review a prospective question. Methods: 40 complex ankle fractures out of 120 ankle fractures in our ankle registry met the inclusion criteria ie significant documented syndesmosis involvement needing stabilization, with all initial clinical and radiological records available. The patients were followed up between January 2020 to July 2021. Injury characteristics, fracture morphology of posterior malleolus, medial malleolus and fibula were noted and classified by validated classification systems based on x-rays and CT scan. The syndesmosis was analyzed on axial CT scan; it was divided into 3 zones, A,B,C from anterior to posterior, and degree of displacement and morphology was noted. Immediate post-operative radiographs were evaluated for fracture and syndesmosis reduction. The patients were evaluated at final follow up with both ankle specific scores (Olerud Molander score, Ankle-Hindfoot scale, Manchester-Oxford Foot questionnaire) and quality of life score (SF-12). Ankle Osteoarthritis grade was used to evaluate radiological outcomes. Results: Mean follow-up was 19 months. 22(55%) patients had syndesmotic widening on plain radiographs; however in pre- operative CT scan evaluation 40(100%) patients had syndesmotic injury based on the Zone evaluation of the syndesmosis. 22 patients had Zone A injury (widening, AITFL, Chaput, Wagstaff). 22 patients had widening of Zone B. Zone C was involved in 30 patients (PM fracture,PITFL involvement). At final follow up; the mean OMAS was 83.38±16.35, mean Ankle-Hindfoot scale= 88±9.98, mean Mox-FQ score=27.15±13.35 & mean SF-12 were (MCS=56.59±8.24, PCS=51.18±8.48). There was no significant difference in outcome scores based on fracture types, Posterior malleolus morphology, or based on zones of syndesmosis injury. Syndesmosis malreduction contributed to significantly poorer outcomes (SF-12, OMAS, MoxFQ) Conclusion: Despite a zonal classification of syndesmotic injury on CT and more clarity of injury patterns, we could not corelate the site and extent of syndesmotic injury with final functional and radiological outcomes. The one factor that has significant influence is initial accurate reduction of both the malleolar fractures and syndesmosis injury. In this the CT based axial classification may play a role.

Should all Small Shell Posterior Malleolar Fractures be Considered for Fixation? Results from a 3D Fracture Mapping Study

Category: Ankle; Trauma Introduction/Purpose: Approximately 10-15% of posterior malleolar fractures (PMFs) are "small shell," extra-articular fragments. Current classification systems present difficulties to perform a uniform typification of PMFs and contain no consensus on whether they should be fixed. Anatomical studies have identified two distinct components of the posterior inferior tibiofibular ligament (PITFL); the superficial band is thought to be more important than its deep counterpart in imparting syndesmotic stability. However, the involvement of one or both bands of the PITFL by small shell PMFs has not been evaluated so far. Hence, we conducted this study to perform 3D mapping of small shell PMFs and to determine whether surgeons should fix these routinely. Methods: Ankle fracture patients with a ‘small shell’ PMF (Haraguchi 3/Mason 1/Bartoníček 1 or 2) were included. Demographics, radiological features, treatment, and outcomes were recorded. 3D models of the fractured tibiae were generated from CT scans and superimposed on a statistical shape model of the right tibia, which served as a template. Fracture lines along with footprints of superficial and deep PITFL were marked on the template. 3D fracture heat maps were generated. Size of the fracture fragments and involvement of the superficial and deep PITFL footprints were quantified using a custom MATLAB script (Figure 1). Sparing of the footprint was defined as an overlap of < 1% between the fracture line and the footprint areas. Odds ratios (OR) with 95% confidence intervals (CI) were determined to determine which variables correlated with sparing of the PITFL footprint; P-values of < 0.05 were considered significant. Results: Thirty-nine patients were included. The superficial PITFL footprint was spared in 15 (38%), deep PITFL in 10 (26%), and both in 4 cases (10%). Males and Weber C fractures had a higher likelihood of sparing the superficial and deep PITFL footprints, respectively (P = 0.04). Supination external rotation (SER) patterns were less likely to demonstrate syndesmotic widening if either PITFL footprint was spared. Direct fixation of the PMF was done in 1 case; syndesmotic fixation in 25 cases and in 14 cases, no syndesmotic fixation was done. Of these, 11 were SER injuries where stability was achieved after fixation of medial and lateral malleoli. In 1 SER and pronation external rotation (PER) injury case, the syndesmosis was stable after fixation of a large Chaput fragment. Conclusion: This study demonstrated that 48% of small shell PMFs spare either the superficial or deep footprint of the PITFL; in 10% both PITFL footprints were spared. Hence, 58 % of small-shell PMFs may not benefit from direct fixation. Additionally, SER injuries with small shell PMFs that spare either PITFL footprint may not demonstrate radiographic instability and may not need direct or indirect fixation after addressing other components of the ankle fracture. However, given the fact that syndesmotic stability is not dictated by the PITFL alone, it remains prudent to stress the syndesmosis per-operatively to determine if syndesmotic fixation is needed.

The Impact of 3D Foot Alignment on Detection of Distal Tibiofibular Syndesmotic Widening after Injury using Comparative Contralateral Distance Mapping

Category: Ankle; Trauma Introduction/ Purpose: Previous studies identified a link between increased hindfoot valgus and distal tibiofibular syndesmosis (DTFS) widening in patients with flatfoot deformity using foot-ankle offset (FAO). However, it is not known what the impact of 3D foot alignment is on the DTFS in the presence of a known syndesmotic injury, particularly in varus. Weight-bearing Computed Tomography (WBCT) has emerged as a highly precise tool for diagnosing deformities of the foot and ankle. Under weight-bearing, it is possible to precisely detect deviations in DTFS stability. The objective of this cadaveric study was to determine the relationship between hindfoot alignment, measured by FAO, and DTFS widening in specimens with complete DTFS ligamentous injury. We hypothesized that DTFS widening would be significantly greater in specimens with increased hindfoot valgus. Methods: Two WBCT scans of the foot and ankle were obtained for each of 17 matched pairs (34 legs) of through-knee cadaveric specimens in a radiolucent frame under 80lbs of load to simulate double legged stance, a baseline scan with intact syndesmotic ligaments and a second after surgical ligament sectioning. All syndesmotic ligaments were released through a direct lateral approach to the distal fibula. Models of the bones were created from scans using Disior Bonelogic. Distance mapping was used to evaluate DTFS widening over the entire DTFS interface, as well as the anterior/posterior sections, in the first 1cm, 3cm, and 5cm from the joint after injury. Post-injury distance maps were compared to the contralateral baseline normal scan as a control. FAO was measured post-injury and compared to the difference in DFTS widening between the injured leg and its contralateral, healthy control. Linear regression and Spearman’s correlations were used to evaluate relationships. Results: Significant correlations between hindfoot alignment and DTFS widening were identified at every level in the syndesmosis. The Spearman’s rho values for the entire DTFS interface at 1cm, 3cm, and 5cm were 0.393 (p = 0.0316), 0.458 (p = 0.0101), and 0.369 (p = 0.0446), respectively. Anterior Spearman’s rho values at 1cm and 3cm were 0.453 (p = 0.0119) and 0.420 (p = 0.0209), respectively. Inter-observer variability of the FAO measurements showed no statistical difference (p = 0.4248). Extremely varus FAO measurements (FAO < -10%) showed negligible changes in syndesmotic opening. Linear regression also demonstrates a positive trend. The R2 values for the entire interface at 1cm, 3cm, and 5cm were 0.127, 0.213, and 0.158. Anterior R2 values at 1cm and 1cm were 0.133 and 0.1583. Conclusion: In this cadaveric study, we confirmed our hypothesis showing that valgus FAO was correlated with syndesmosis opening from an uninjured to an injured site. These data are in accord with prior findings relating FAO and DTFS opening in flatfeet and additionally demonstrate a stronger positive trend in the presence of known injury with smaller changes in tibiofibular distances after injury for extreme varus alignments. This study provides important context to the clinically relevant comparison of contralateral feet. The trend in our data allows for predictable results for the degree of injury in patients with valgus foot alignment.

Effect of Arthroscopically Confirmed Syndesmotic Widening on Outcome Following Isolated Broström Operation for Chronic Lateral Ankle Instability.

Tibiofibular syndesmosis (TFS) widening sometimes is not evident on radiography but can be found under arthroscopy in chronic lateral ankle instability (CLAI). This study aimed to evaluate the effect of TFS widening severity on clinical outcomes and return to activities after isolated Broström operation in CLAI patients and to propose an indication for its surgical intervention. A total of 118 CLAI patients undergoing diagnostic ankle arthroscopy and open Broström-Gould operation were included. Based on the middle width of TFS measured under arthroscopy, patients were divided into the TFS-2 group (≤2 mm, n = 44), the TFS-3 group (2-4 mm, n = 42), and the TFS-4 group (≥4 mm, n = 32). The time to return to recreational sport and work, Tegner activity score, and proportion of returning to preinjury sports at the final follow-up were evaluated and compared. Other subjective evaluations included the American Orthopaedic Foot & Ankle Society score, visual analog scale, and Karlsson-Peterson score. Among the 3 groups, the TFS-4 group demonstrated the longest mean time to return to work and recreational sports, with the lowest proportion returning to preinjury sports. The TFS-4 group showed a significantly higher rate of sprain recurrence (12.5%) than the other 2 groups (P =.021). All the other subjective scores significantly improved after the operation without differences among the 3 groups. Concomitant severe syndesmotic widening adversely affects the return to activities after Broström operation in CLAI cases. The CLAI patients with a middle TFS width ≥4 mm were associated with delayed return to work and sports, a lower proportion of returning to preinjury sports, and more sprain recurrence, which might require further surgical intervention for syndesmosis in addition to Broström surgery. Level III, retrospective cohort study.

Ankle syndesmotic instability assessment using a three-dimensional distance mapping algorithm: a cadaveric pilot WBCT study

Objective: This cadaveric pilot study was to develop a weight bearing computed tomography (WBCT) three-dimensional (3D) distance mapping algorithm that would allow for detection of syndesmotic instability. Methods: Pilot study, two cadaveric specimens. Syndesmotic instability was induced by release of all syndesmotic ligaments through a conventional lateral ankle approach. WBCT imaging under simulated weight bearing was acquired before and after syndesmotic destabilization. Syndesmotic incisura and ankle gutter distances were assessed using a 3D distance mapping WBCT algorithm. Results: We found increases in the overall mean syndesmotic distances in the injured syndesmosis when compared to pre-injury state, and color coded distance maps allowed easy interpretation of the syndesmotic widening following ligament sectioning and destabilization of the syndesmotic joint. Conclusion: The WBCT 3D distance mapping algorithm has the potential to allow detection of mild syndesmotic instability with a relatively ease of interpretation by using color-coded distance maps. Level of Evidence V; Cadaveric Study.

Three-Dimensional Distance Maps of Ankle and Syndesmotic Joints from Weightbearing CT in Progressive Collapsing Foot Deformity: A Retrospective Case-Control Study

Category:AnkleIntroduction/Purpose:Recently, weightbearing computed tomography (WBCT) has been utilized to provide more comprehensive and accurate assessment of complex foot and ankle deformities, notably to diagnose and stage Progressive Collapsing Foot Deformity (PCFD). The 3D data provided by WBCT has enabled the developed of novel tools like distance mapping (DM), coverage mapping (CM), and volume measurements. Over the past year, novel DM and CM have shown promise in providing sensitive automated measures of peritalar subluxation, a major component of PCFD. However, the early effects of PCFD on the tibiotalar joint have not yet been quantified. This study sought to use DM and CM to objectively characterize the effects of PCFD on the tibiotalar and tibiofibular joints. We hypothesized that changes seen in early PCFD will be identified.Methods:IRB approval for retrospective review of patient data from 2014-2020 was obtained to identify patients with clinical and radiographic diagnoses of PCFD. The first consecutive 20 patients with symptomatic flexible PCFD and high-resolution weightbearing CT examination without arthritis that had not undergone prior surgery were selected and compared with 20 controls. Fully automated volume measurements of the syndesmosis at 1cm, 3cm, and 5cm from the tibiotalar joint were performed as well as of the medial and lateral tibiotalar gutters based on models created in Disior Bonelogic. Distance Maps (DMs) were obtained for the tibiofibular incisura, tibiotalar joint, and gutters. Coverage maps (CMs) were created using the measured 3DDMs to identify joint interaction, subluxation, and impingement. Data were checked for normality using the Shapiro- Wilk W test. Two-tailed independent samples student t-tests or Wilcoxon Tests were used to assess differences between groups.Results:There were significant decreases in coverage of all 3 anterior regions of the tibiotalar joint in PCFD patients when compared to controls along with corresponding significant increases in coverage of all 3 posterior regions (Figure). There were no significant differences in mean or minimum distances in any region of the tibiotalar joint surface. Significant increases in average and minimum DMs of the anterior medial (36%, p<0.01, 19%, p<0.03) gutter were observed with significant decreases in coverage of both anterior medial and anterior lateral regions. Significant decreases in the average and minimum distances of the tibiofibular joint were found anteriorly in PCFD patients compared to controls (-26%, p<0.006). There were no significant differences in overall syndesmotic distance or volume at any level.Conclusion:The results of our study were able to identify that, compared to controls, patients with early stage PCFD demonstrated significant tibiotalar and tibiofibular joint changes ahead of developing the tibiotalar narrowing associated with arthritis and syndesmotic widening associated with instability. Decreases in anterior coverage with increases posteriorly support early plantarflexion of the talus in PCFD. When combined with plantarflexion of the talus and unchanged syndesmotic volume, decreases in anterior tibiofibular distances support the absence of syndesmotic joint instability in early PCFD. Novel tools may assist with clinical decision-making regarding restoration of normal tibiotalar and tibiofibular alignment during PCFD correction.

Investigating the Radiological Outcomes of Syndesmosis Injuries in Ankle Fracture Patients After Suture Button Fixation

Concomitant syndesmotic injury occurs in 10% of ankle fractures. Anatomic reduction and maintenance of this reduction is critical in ensuring ankle stability and preventing long-term complications. This is a retrospective cohort study aimed at evaluating the mid-term radiological outcomes of syndesmotic injuries in ankle fracture patients after surgical fixation with suture button device. The study group included 33 patients. Plain radiographs including anteroposterior, lateral and mortise views of the affected ankle were performed preoperatively, postoperatively and at 3-month follow-up. Anteroposterior views were used to measure the amount of tibiofibular overlap and tibiofibular clear space. Paired Student's t test and linear model regression were performed. Between the immediate postoperative and 3-month follow-up period, there was a mean decrease in tibiofibular overlap of 0.841 (±2.07) mm (p = .0259). There was a mean increase in tibiofibular clear space of 0.621 (±1.46) mm (p = .0201). In addition, we found significant correlation between fracture type and change in tibiofibular clear space (p = .047). Our study showed that there is statistically significant widening of the syndesmosis after suture button fixation at 3-month follow-up as evidenced by reduced tibiofibular overlap and increase in tibiofibular clear space. However, they remain within the maximum threshold for acceptable syndesmotic widening of 1.5 mm. Further correlation between radiological outcomes and patient function is needed to determine clinical significance of these changes.

Distal Tibiofibular Syndesmotic Widening in Progressive Collapsing Foot Deformity.

Lateral overload in progressive collapsing foot deformity (PCFD) takes place as hindfoot valgus, peritalar subluxation, and valgus instability of the ankle increase. Fibular strain due to chronic lateral impingement may lead to distraction forces over the distal tibiofibular syndesmosis (DTFS). This study aimed to assess and correlate the severity of the foot and ankle offset (FAO) as a marker of progressive PCFD with the amount of DTFS widening and to compare it to controls. In this case-control study, 62 symptomatic patients with PCFD and 29 controls who underwent standing weightbearing computed tomography (WBCT) examination were included. Two fellowship-trained blinded orthopedic foot and ankle surgeons performed FAO (%) and DTFS area measurements (mm2). DTFS was assessed semiautomatically on axial-plane WBCT images, 1 cm proximal to the apex of the tibial plafond. Values were compared between patients with PCFD and controls, and Spearman correlation between FAO and DTFS area measurements was assessed. P values of less than .05 were considered significant. Patients with PCFD demonstrated significantly increased FAO and DTFS measurements in comparison to controls. A mean difference of 6.9% (P < .001) in FAO and 10.4 mm2 (P = .026) in DTFS was observed. A significant but weak correlation was identified between the variables, with a Þ of 0.22 (P = .03). A partition predictive model demonstrated that DTFS area measurements were highest when FAO values were between 7% and 9.3%, with mean (SD) values of 92.7 (22.4) mm2. To our knowledge, this was the first study to assess syndesmotic widening in patients with PCFD. We found patients with PCFD to demonstrate increased DTFS area measurements compared to controls, with a mean difference of approximately 10 mm2. A significantly weak positive correlation was found between FAO and DTFS area measurements, with the highest syndesmotic widening occurring when FAO values were between 7% and 9.3%. Our study findings suggest that chronic lateral impingement in patients with PCFD can result in a negative biomechanical impact on syndesmotic alignment, with increased DTFS stress and subsequent widening. Level III, retrospective comparative study.

Does Hindfoot Valgus Deformity Affect the Distal Tibiofibular Syndesmotic Space?

Category:Hindfoot; Ankle; Ankle Arthritis; SportsIntroduction/Purpose:Severe hindfoot valgus deformity has been reported as one of the main causes of sinus tarsi and subfibular impingement in patients with adult acquired foot deformity (AAFD). Chronic Impingement and overload of the talus and/or calcaneus on the articular surface of the distal fibula can potentially lead to distraction stresses on the distal tibiofibular syndesmosis (DTFS). However, to the authors knowledge, no direct assessment of DTFS widening in patients with AAFD has been reported in the literature. The purpose of this study was to evaluate the correlation between hindfoot alignment and DTFS widening using weightbearing computed tomography (WBCT) images, and to compare the results between AAFD patients and controls.Methods:In this case-control study, we included 97 patients who underwent WBCT examination, 63 AAFD patients and 34 controls, with no history of major ankle trauma or surgeries of the foot and ankle. Hindfoot alignment was assessed using Foot and Ankle Offset (FAO) and the widening of the DTFS was evaluated by measuring the syndesmotic area (mm2) on axial plane WBCT images, at a level 1cm proximal to the apex of the tibial plafond. Controls were defined as patients with no clinical AAFD and normal FAO values (from -0.6 to 5.2). FAO and DTFS area measurements were compared by paired T-tests and ANOVA. Correlation between variables was assessed by bivariate linear regression. A partition predictive model was used to define threshold values of FAO that would influence DTFS area measurements. P-values of less than 0.05 were considered significant.Results:AAFD patients demonstrated significantly increased mean values for DTFS area (90.0mm2; 95%CI, 84.3 to 95.7) when compared to controls (79.9 mm2; 95%CI 73.8 to 85.9), p=0.03. However, no significant direct linear correlation was found between FAO and DTFS area measurements (p=0.07) in the bivariate analysis. The partition predictive model demonstrated that two threshold values of FAO would significantly influence DTFS area (R2=0.14): when FAO was <7 the average DTFS area was 80.8mm2 (SD 17.8), when FAO was >7, the mean DTFS area was 92.7mm2 (SD 22.4). Interestingly, when assessing patients with more severe valgus (FAO>7), the DTFS area measurements were even higher when FAO values were in between 7 and 9.3 (average, 104.6mm2, SD 22.5), but decreased when FAO>9.3 (average, 88 mm2; SD 22.3).Conclusion:This is the first study to compare distal tibiofibular syndesmotic widening in patients with AAFD and controls. We found that AAFD patients had significant syndesmotic widening when compared to controls, with a difference of about 10 mm2 in the measured area. More than that, we found that AAFD patients with FAO in between 7 and 9.3 would demonstrate the largest amount of syndesmotic widening. However, no direct linear correlation was found between FAO and syndesmotic area measurements. Our findings suggest that increased hindfoot valgus deformity may have negative biomechanical impact on syndesmotic alignment, with increased stresses and resultant widening.

Mismanaged Ankle Fractures, is it too Late to Save the Joint?

Category:Trauma; AnkleIntroduction/Purpose:Mimanaged ankle fractures with a short fibula, talat shift, syndesmotic widening, malunion or nonunion following inappropriate conservative treatment or inadequate operative treatment are very challenging, especially in young patients. Whether or not to revise the fracture fixation after a period of time with weight bearing with a malaligned joint is a difficult question regarding the value of the operation after that time to prevent arthritis.The aim of the study was to evaluate the effect of operative intervention in these cases in improving symptoms and preventing arthritisMethods:The study was a prospective study. Inclusion criteria were mismanaged ankle fractures with a reasonable range of motion. Exclusion criteria were infection, severe arthritis, complete loss of motion, ischemia and diabetes. Standing radiographs for both limbs and CT scans were obtained for all patients to analyze the problem. Operative treatment was planned accordingly, and regular follow up was performed clinically and radiologically.Results:29 patients were included. The average duration from the primary injury or primary fixation was 6 months (range 1.5 to 28 months). The lateral malleolus with or without the syndesmosis were affected in 25 out of 29 cases, the posterior malleolus was affected in 2 cases, the medical malleolus in 6 cases and the deltoid ligament in 12 cases. The minimum follow up duration was 9 months with a range from 9 months to 6 years. Three patients required an ankle fusion later. Ten patients report excellent results, 10 patients report good results, 4 patients report fair results and five patients report bad results, three of them underwent ankle arthrodesis.AOFAS score improved significantly from a mean of 28 points preoperative to a mean 85 points postoperative.Conclusion:Perfect primary treatment for ankle fractures is the best method for a good prognosis, but it is not late to reconstruct the joint if there is a reasonable range of motion.This can give good results and delay fusion, and it can make arthroplasty a valid option by restoring ankle anatomy and stability.

Syndesmotic Behavior after Sequential Sectioning: Simulation of Ligamentous Ankle Injuries in Vitro

Category:Ankle, Trauma, Distal Tibiofibular JointIntroduction/Purpose:Ankle fractures are often associated with ligamentous injuries of the distal tibiofibular syndesmosis and the deltoid ligament. These injuries may predispose to instability, early joint degeneration and long-term ankle dysfunction. In the classic article of Boden it was made clear that injuries of the syndesmotic ligaments were of no importance in absence of a deltoid ligament rupture. Even in the presence of a deltoid ligament rupture, the interosseous membrane withstood lateralization of the talus in fixated fibula fractures up to 4.5 mm above the ankle joint. However, detection of ligamentous injuries and the need for treatment remain subject of ongoing debate. Syndesmotic injuries are often treated operatively by temporary fixation performed with positioning screws. But do isolated syndesmotic injuries need to be treated operatively at all?Methods:Ten fresh-frozen, exarticulated through the knee, human cadaveric lower limbs were tested under axial compressive loads of 50 and 700 N, simulating non-weightbearing and weightbearing conditions. All specimens were tested with different foot positions (plantigrade, dorsiflexion, inversion, eversion, and 10 Nm external rotational torque) during sequential sectioning of the syndesmotic ligaments and the deltoid ligament. We triangulated Boden’s classic findings with an active motion capture system (0.1 mm accuracy) to track the translations and rotations of the fibula relative to the tibia.Results:Isolated sectioning of the AITFL resulted in an increase of external fibula rotation up to 8.9 degrees (doubling the physiological 4.0 degrees) with an external rotation stress of 10 Nm in non-weightbearing conditions. However, weightbearing appeared somewhat protective, reducing the external rotation to 7.9 degrees. Sectioning of all syndesmotic ligaments with an intact deltoid ligament resulted in a syndesmotic widening of 0.9 mm in weightbearing conditions with a plantigrade foot. Dorsiflexion of the foot resulted in a significant increase of syndesmotic widening for all conditions of the syndesmotic ligaments. Sectioning of the deltoid ligament resulted in a significant increase of all fibula translations in all foot positions during weightbearing conditions.Conclusion:The results of our study have implications for common ligamentous ankle injuries and their treatment. In isolated syndesmotic injuries with a plantigrade foot, weightbearing seemed protective and limiting syndesmotic widening probably due to the saddle shape of the tibiotalar surface. Conservative treatment in a cast seems justifiable. External rotation stress causes the “open-book-phenomenon” in isolated AITFL injuries, especially in non-weightbearing conditions. Protection with cast or surgery is necessary. The deltoid ligament prevents lateralization of the talus but allows increased syndesmotic widening and external rotation of the fibula in dorsiflexion and external rotation stress due to the shape of the talus.

The Impact of Torque on Assessment of Syndesmotic Injuries Using Weightbearing CT Scans: A Cadaver Study

Category:Ankle, Basic Sciences/Biologics, TraumaIntroduction/Purpose:Injury to the distal tibio-fibular syndesmosis can occur as an isolated ligamentous injury or can be associated with bony ankle trauma. The missed diagnosis of such injuries is believed to lead to chronic pain and early degeneration. Weightbearing CT (WBCT) has increased in popularity among foot and ankle surgeons as it offers an accurate representation of joint alignment under weightbearing conditions. However, the use of this imaging modality to diagnose syndesmotic injuries has not been investigated. The purpose of this study was to assess the influence of torque on the assessment of syndesmotic injuries using axial CT images under weightbearing conditions. We hypothesized that torque application would improve the ability to detect syndesmotic injuries.Methods:Seven pairs of male cadavers (tibia plateau to toe-tip) were included. CT scans with axial load application (85 kilograms, kg) and with (10 newton meters, Nm) or without torque to the tibia (corresponding to external rotation of the foot and ankle) were taken during four test conditions. First, intact ankles (Native) were scanned. Second, one specimen from each pair underwent anterior inferior tibio-fibular ligament (AITFL) transection (Condition 1A) while the contralateral underwent deltoid transection (Condition 1B). Third, the lesions were reversed on the same specimens and the remaining intact deltoid or AITFL was transected (Condition 2). Finally, the distal tibiofibular interosseous membrane (IOM) was transected in all ankles (Condition 3). Eight different measurements were performed to assess the integrity of the distal tibio-fibular syndesmosis on axial CT scans.Results:Torque impacted axial CT scan measurements in almost all conditions (Table I). The ability to diagnose syndesmotic injuries using axial CT measurements improved when torque was applied. No significant syndesmotic morphological change was observed with or without torque for either isolated AITFL or deltoid ligament transection.Conclusion:Low magnitude torque rotational stress application had a notable impact on 2D measurements used to diagnose syndesmotic injuries with axial CT scans (cadaveric model). Two dimensional measurements are not effective to distinguish between single AITFL and single deltoid ligament injuries. Because weightbearing conditions allow for a standardized positioning of the foot while radiographs or CT scans are taken, a combination of axial load and torque application is desirable. Further studies including patients with syndesmotic injuries will be necessary to clarify the clinical potential of WBCT scans with torque applied to identify syndesmotic widening.

Syndesmotic Ankle Injuries: A Comparison Of Etiology, Mechanism Of Injury, And Return-to-Play Time In NFL And NHL Athletes

Objectives:The purpose of our study is to examine the differences in mechanism of injury, severity, and diagnosis of syndesmotic injuries and determine if the variation among these factors is associated with return-to-play time among US professional football and hockey players. Notably prior literature indicates an unexplained disparity in time lost to injury for syndesmotic pathologies: Wright et al. (2004) reported a mean return-to-play time of 45 days for 14 examined NHL players, whereas Osbahr et al. (2013) reported a mean return-to-play time of 15 days for 36 examined NFL players. Specifically we posit that patterns of injury, verified by expert MRI evaluation, account for the greater time losses reported among NHL athletes, when compared to NFL athletes.Methods:We reviewed the injury databases of the Pittsburgh Penguins and Pittsburgh Steelers in order to identify athletes who incurred syndesmotic injuries (without co-existing pathology) within the last 10 years. To be eligible for the study, subjects must have received diagnostic MRI imaging within 7 days of injury and no prior history of ipsilateral syndesmotic injury. We then extracted the following data: return-to-practice time (days), age, height, weight, position within sport, date of injury, side of injury, proportion of season remaining, mechanism of injury, and MRI studies. The MRI studies evaluated injuries to the AITFL, PITFL, interosseous membrane, and interosseous ligament, as well as edema height and syndesmotic widening. We generated descriptive statistics of the outcome variables and predictors, including frequencies and proportions for categorical variables and measures of central tendency and dispersion for continuous variables. We assessed univariable measures of association of the predictors with each sport, using the appropriate non-parametric tests for small sample sizes (Mood’s median test and Fisher’s exact test for continuous and categorical predictors, respectively). We then tested differences in return-to-play by sport using survival analysis methods using Kaplan-Meier Estimators and later Cox Proportional Hazards (CPH) Regression Models, allowing us to model time-to-return as a function of multiple continuous and discrete predictors.Results:The initial investigation revealed nine professional hockey and thirty-three professional football players that suffered injuries over the course of the ten-year study horizon. The median return-to-play times were 34 days (mean=35.2, range=1-79) and 11 days (mean=14.8, range=1-68) for hockey and football athletes, respectively. Non-parametric univariable analysis indicated preferential involvement of the PITFL (p<.05) and minimal syndesmotic width widening (p<.05) among NHL athletes. Sport-specific survival curves indicated statistically significant differences in return-to-play time between the second and fourth weeks of recovery, further supported by the statistical significance of sport (p<.05) as a predictor of return-to-play time in the regression analyses.Conclusion:Our study, unique in its direct access to injury databases of two professional teams from different sports, confirms a known disparity in recovery times among professional athletes. Specifically the results suggest that the preferential involvement of the PITFL combined with a lesser degree of syndesmotic widening in NHL athletes may account for the greater time losses, when compared to NFL athletes.

Treatment for displaced Tillaux fractures in adolescent age group

BackgroundAround age 11–15 years, a forced external rotation of the foot in a supination or a medial rotation of the leg on the fixed foot usually is responsible for an avulsion injury to the anterolateral epiphysis, known as Tillaux fracture. Ligamentous injuries are rare in children because ligaments are stronger than is the growth plate that frequently is injured. ObjectiveThe aim of this study was to present the clinical outcome until the end of growth after surgical treatment for displaced adolescent Tillaux fractures. Patients and methods13 patients with Tillaux fractures in the adolescent age group. Patient`s age ranged (12–17 years) with an average 13.4 years. Of those 13 patients, there were 9 females and 4 males. ResultsFracture union was obtained in all cases (100%) and was assed radiologically when X-ray check-ups in all projections showed the significant presence of trabeculation crossing the fracture, without pain and functionally using the American Orthopedic Foot and Ankle Society (AOFAS) score of the ankle joint. Overall average score was 97 ranged 95–100. There was no recorded post-operative complication. ConclusionThe plain radiographs of patients with an avulsion injury of anterolateral tubercle (Tillaux fragment) should be carefully examined for evidence of syndesmotic widening. If there is any doubt, CT scans is helpful. If fracture displacement was greater than 2 mm, a surgical intervention is recommended to restore the normal anatomy of the ankle joint. Anatomically reduced Tillaux fractures at adolescent age group either by closed or opened means, followed by post-operative plaster cast immobilization will lead to excellent results.

Radiological outcome from Tight-RopeTM fixation for acute syndesmotic injury

Category: Trauma Introduction/Purpose: The reduction and maintenance of tibiofibular joint is essential in the treatment of syndesmotic ankle injury. Tight-RopeTM (Arthrex, Naples, FL, USA) has been used recently but suspected in terms of tightening and sustaining power in spite of biomechanical results. We aimed to assess fixation-tightness and delayed syndesmotic widening after rehabilitation in syndesmotic injuries treated with Tight-RopeTM comparing with conventional screws. Methods: 62 consecutive patients with acute syndesmotic injury were retrospectively reviewed. They were divided into 28 cases of Tight-RopeTM(TR) group and 34 cases of conventional screw fixation(Screw) group. We divided them into subgroups along the fixation methods such as 2 screws, 1 screw, TR only, and TR combined with screw. We analyzed syndesmotic widening by percentage. We measured tibiofibular clear space(TFCS) and tibiofibular overlap(TFOL). Tibiofibular clear space ratio and tibiofibular overlap ratio is measured as a ratio of tibiofibular clear space and tibiofibular overlap to the width of talar dome at preoperative, immediate postoperative, 3 months, and last (one year) visit time points and measured as a percentage of each measured value on the injured side to that on the contralateral side at the respective time points. The independent t-test and paired t-test were used for statistical analysis. Results: Mean TFCS ratio at each time point was 145.7±43.8%, 80.6±29.3%, 95.2±32.5%, and 96.3±31.1% in TR group and 126.2±42.6%, 73.9±22.6%, 104.8±59.2%, 106.4±35.0% in screw group. There were no statistical differences between groups in all 4 time points, no meaningful difference between subgroups. TFCS widening at 3 months in TR was less than screw group but no statistical significance. The TFCS was significantly tightened postoperatively then widened at 3 months and no meaningful change until last visit on both group. Mean TFOL ratio at each point was 51.84±43.6%, 119.2±36.7%, 110.7±44.5%, 96.8±27.7% in TR and 65.7±34.5%, 110.8±36.6%, 114.2±45.6%, 102.4±37.8% in screw group. There was no statistical difference between groups and subgroups. The overlap was increased postoperatively and no change between every sequential time points until last visit. Conclusion: The Tight-RopeTM fixation has a similar tightening and sustaining power compared to conventional screws and it was determined that the sustaining capacity did not decreased with time. Tight-RopeTM fixation can be effective treatment because it enables effective fixation, early weight-bearing and rehabilitation after surgery, and maintaining device for longer time in severe injury.

Repair of Bimalleolar Ankle Fracture

The incidence of ankle fractures is rapidly increasing in geriatric populations. Of the 4 fracture patterns described by the Lauge-Hansen classification system, supination-external rotation (SER) accounts for most ankle fractures. This video demonstrates surgical repair of a SER type 4 ankle fracture in a geriatric patient. SER type 4 ankle fractures are considered unstable and are generally treated with surgical fixation. After placement of plate and screws, intraoperative stress tests can be used to assess for syndesmotic widening. If necessary, the syndesmosis can be reduced open, with screw fixation placed parallel to the joint. Patients are kept non-weight-bearing for 6 weeks after surgery. This video, shot on an iPhone 6S, shows the case of a 66-year-old female status after a fall with twisting mechanism resulting in an unstable SER type 4 fracture requiring operative repair. Intraoperative stress test revealed medial clear space widening requiring syndesmotic reduction. SER type 4 ankle fractures are a common injury that must be properly managed to return patients to baseline functional status. The surgical technique described in this video provides for good stabilization and allows for early range of motion with advancement to weight-bearing as tolerated at 6 weeks postoperatively.

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.

Ankle Joint Contact Loads and Displacement With Progressive Syndesmotic Injury.

Ligamentous injuries to the distal tibiofibular syndesmosis are predictive of long-term ankle dysfunction. Mild and moderate syndesmotic injuries are difficult to stratify, and the impact of syndesmosis injury on the magnitude and distribution of forces within the ankle joint during athletic activities is unknown. Eight below-knee cadaveric specimens were tested in the intact state and after sequential sectioning of the following ligaments: anterior-inferior tibiofibular, anterior deltoid (1 cm), interosseous/transverse (IOL/TL), posterior-inferior tibiofibular, and whole deltoid. In each condition, specimens were loaded in axial compression to 700 N and then externally rotated to 20 N·m torque. During axial loading and external rotation, both the fibula and the talus rotated significantly after each ligament sectioning as compared to the intact condition. After IOL/TL release, a significant increase in posterior translation of the fibula was observed, although no syndesmotic widening was observed. Mean tibiotalar contact pressure increased significantly after IOL/TL release, and the center of pressure shifted posterolaterally, relative to more stable conditions, after IOL/TL release. There were significant increases in mean contact pressure and peak pressure along with a reduction in contact area with axial loading and external rotation as compared to axial loading alone for all 5 conditions. Significant increases in tibiotalar contact pressures occur when external rotation stresses are added to axial loading. Moderate and severe injuries are associated with a significant increase in mean contact pressure combined with a shift in the center of pressure and rotation of the fibula and talus. Considerable changes in ankle joint kinematics and contact mechanics may explain why moderate syndesmosis injuries take longer to heal and are more likely to develop long-term dysfunction and, potentially, ankle arthritis.

High-Energy Transsyndesmotic Ankle Fracture Dislocation—The “Logsplitter” Injury

To describe and investigate the injury pattern and outcomes of high-energy transsyndesmotic ankle fracture dislocations, or "Logsplitter" injuries, in which the talus is axially wedged into the tibiofibular joint. Prospective Cohort Study. Level 1 trauma center. Prospective evaluation of 23 high-energy transsyndesmotic ankle fracture dislocations (OTA 44-B). Operative fixation. Radiographs, clinical examination, American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale, Short Musculoskeletal Function Assessment. Fracture characteristics included 52% open fractures (all medial) and syndesmotic widening of 30.7 ± 11.9 mm. The tibial plafond was involved in 11 (48%) of 23 injuries, with 5 (22%) Chaput, 5 (22%) posterior malleolar fragments, and 6 (26%) with articular impaction. A fibula fracture occurred in all but 1 patient, on average 64.2 ± 40.0 mm above the distal tip. All patients had fixation of their fibular and medial malleolar fractures, 21 of 23 patients had syndesmotic screws, and 8 of 23 had tibial plafond fixation. Anatomic alignment (within <= 2 mm) was obtained in 21 (87%) of 23 injuries. Mean follow-up was 20.6 ± 6.2 months. Sixteen (70%) of 23 patients had radiographic evidence of posttraumatic ankle arthritis. Dorsiflexion and plantarflexion at final follow-up were 6.9 ± 9.6 and 35.6 ± 12.1 degrees, respectively. Complications included a 17% infection and 17% nonunion rate. Average American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale score was 67.0 ± 26.8, whereas Short Musculoskeletal Function Assessment Dysfunction index was 32.9 ± 28.6 and Bother index 34.5 ± 29.5. Transsyndesmotic ankle fracture dislocations, or "Logsplitter" injuries, represent an exceptional pattern of high-energy fractures with significant syndesmotic disruption, potential soft tissue compromise, and possible associated plafond injuries. Careful attention to radiographic findings can identify unique fracture characteristics relative to operative decision-making. Outcomes are comparable to those of high-energy pilon fractures, thereby providing the treating surgeon with prognostic information.

Stabilization of the Syndesmosis in the Maisonneuve Fracture—A Biomechanical Study Comparing 2-Hole Locking Plate and Quadricortical Screw Fixation

The aim of this study is to determine whether a 2-hole locking plate has biomechanical advantages over conventional screw stabilization of the syndesmosis in this injury pattern. Six pairs of fresh-frozen human cadaver lower legs were prepared to simulate an unstable Maisonneuve fracture. Each limb was compared with its pair; the syndesmosis in one being stabilized with two 4.5-mm quadricortical cortical screws, the other a 2-hole locking plate with 3.2-mm locking screws. The limbs were then mounted on a servohydraulic testing rig and axially loaded to a peak load of 800N for 12000 cycles. Fibula shortening and diastasis were measured. Each limb was then externally rotated until failure occurred. Failure was defined as fracture of bone or metalwork, syndesmotic widening, or axial migration >2 mm. Both constructs effectively stabilized the syndesmosis during the cyclical loading within 0.1 mm of movement. However, the locking plate group demonstrated greater resistance to torque compared with quadricortical screw fixation (40.6 Nm vs. 21.2 Nm, respectively, P value < 0.03). A 2-hole locking plate (with 3.2-mm screws) provides significantly greater stability of the syndesmosis to torque when compared with 4.5-mm quadricortical fixation.