Acute syndesmotic instability in ankle fractures: A review

Standardized analysis of syndesmosis stability in ankle trauma with an innovative syndesmosis-test-tool: a biomechanical study

When treating ankle fractures, the question of syndesmosis complex involvement often arises. So far, there is no standardized method to reliably detect syndesmosis injuries in the surgical treatment of ankle fractures. For this reason, an intraoperative syndesmosis-test-tool (STT) was developed and compared to the recommended and established hook-test (HT). Tests were performed on cadaveric lower legs (n = 20) and the diastasis was visualized by 3D camera. Tests were performed at 50, 80, and 100 N in native conditions and four instability levels. Instability was induced from anterior to posterior and the reverse on the opposite side. The impact on diastasis regarding the direction, the force level, the instability level, and the device used was checked using a general linear model for repeated measurement. The direction of the induced instability showed no influence on the diastasis during the stability tests. The diastasis measured with the STT increased from 0.5 to 3.0 mm depending on the instability, while the range was lower with the HT (1.1 to 2.3 mm). The results showed that the differentiation between the instability levels was statistically significantly better for the developed STT. The last level of maximum instability was significantly better differentiable with the STT compared to the HT. An average visualizable diastasis of more than 2 mm could only be achieved at maximum instability. In conclusion, the newly developed STT was superior to the commonly used HT to detect instability.

Normal Values for Distal Tibiofibular Syndesmotic Space With and Without Subject-Driven External Rotation Stress

BACKGROUND

The diagnosis and treatment of distal tibiofibular syndesmosis (DTFS) injury can be challenging, especially in cases of subtle instability that may be masked on 2-dimensional conventional radiographs. Weightbearing computed tomography (WBCT) has recently emerged as a useful diagnostic tool allowing direct assessment of distal tibiofibular area widening. The purpose of the current study was to examine and report normal threshold values for DTFS area measurements in a cohort of healthy volunteers, assessing the ankles in natural weightbearing position and under subject-driven external rotation stress.

METHODS

In this prospective study, we enrolled 25 healthy volunteers without a history of DTFS injury or high ankle sprain, previous foot and ankle surgery, or current ankle pain. Subjects with any prior ankle injuries were excluded. Study participants underwent bilateral standing nonstress and external rotation stress WBCT scans. The DTFS area (mm2) was semiautomatically quantified on axial-plane WBCT images 1 cm proximal to the apex of the talar dome using validated software. Syndesmosis area values were compared between "unstressed" and "stressed" ankles, as well as left and right ankles. Statistical analysis was performed using independent t tests/Wilcoxon analysis with statistical significance defined as P <.05.

RESULTS

The study cohort consisted of 50 ankles in 25 patients (12 males, 48%) with a mean age of 28.7 ± 9.3 years. In the unstressed ankle, the mean pooled DTFS area was determined to be 103.8 + 20.8 mm2. The mean syndesmosis area of unstressed left ankles (104.2 + 19.5 mm2) was similar to unstressed right ankles (109.2 + 17.2 mm2) in the cohort (P = .117). With external rotation stress, the DTFS area of left ankles (mean difference -0.304 mm2, CI -12.1 to 11.5; P = .082), right ankles (mean difference -5.5 mm2, CI 16.7-5.7; P = .132), and all ankles (mean difference -2.9 mm2, CI -10.8 to 5.1; P = .324) remained similar.

CONCLUSION

This study presents normal values and range for DTFS area calculation. In uninjured ankles with expected intact ligaments, subject-driven external rotation stress did not result in significant widening of the DTFS space as imaged on with WBCT.

LEVEL OF EVIDENCE

Level II, cross-sectional study.

Equivalent Fracture Patterns Demonstrate Poorer Postoperative Functional Outcomes Among Pronation-External Rotation IV Ankle Fractures

BACKGROUND

Pronation-external rotation IV (PER IV) ankle fractures are relatively uncommon among rotational ankle fractures, but they are the most severe type. Although recent studies have shown satisfactory functional recovery in PER IV after surgical treatment, the different outcomes between fracture patterns and equivalent fracture patterns have not yet been evaluated. This study aims to compare short-term outcomes in PER IV ankle injuries between fracture patterns and equivalent fracture patterns.

METHODS

This retrospective study was conducted at Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou, China, from July 2023 to October 2023. A total of 41 PER IV injuries from 2018 to 2022 were included and followed for at least one year. The American Orthopaedic Foot and Ankle Society (AOFAS) Ankle‑Hindfoot Scale, Ankle Range of Motions (ROM), and Visual Analogue Scale (VAS) for pain scores were the main outcome measures. The rate of postoperative complications was the secondary outcome measure. Patient demographics were compared in PER IV fractures and PER IV ankle equivalent fractures.

RESULTS

The mean follow-up time was 18.2 ± 4.2 (range, 12-24) months. Postoperative X-ray and CT scans showed a satisfactory reduction of the ankle joint and syndesmosis. No reduction loss of distal tibiofibular syndesmosis or ankle joints was found at the 12-month follow-up. The average AOFAS scores after one year in both groups were satisfactory (fracture group vs. fracture equivalent group, 96.72 ± 4.21 vs. 92.63 ± 5.36; P < 0.05). The average VAS scores after one year in both groups were satisfactory (fracture group vs. fracture equivalent group, 1.45 ± 2.01 vs. 1.38 ± 1.96; P > 0.05). The average ROM scores after one year in both groups were satisfactory (dorsiflexion, fracture group vs. fracture equivalent group, 15.21 ± 5.62 vs. 13.46 ± 4.35; P > 0.05; plantar flexion, fracture group vs. fracture equivalent group, 38.62 ± 9.68 vs. 42.32 ± 5.28; P > 0.05).

CONCLUSION

For patients with PER-IV ankle injuries, the fracture mode had a better prognosis than the fracture equivalent mode.

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

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

LEVEL OF EVIDENCE

II.

Comparison of Two Different Methods to Evaluate Ankle Syndesmosis on Lateral Ankle Radiographs

Background Ankle sprains and fractures rank among the most commonly occurring musculoskeletal injuries and hold significant relevance in current medical practice. Accurate information regarding these injuries is crucial for their effective treatment. This study aimed to explore the viability of utilizing ankle lateral radiographs to evaluate syndesmosis in both emergency settings and operating theatres. Methods This randomized retrospective clinical study involved the analysis of 150 ankle lateral radiographs (54 males and 96 females) from patients who presented at our emergency department with suspected ankle injuries. Two authors jointly examined these radiographs and reached a consensus. The anterior tibiofibular (ATF) ratio and anterior-posterior tibiofibular (APTF) ratio were computed. Patients requiring syndesmotic fixation were classified as having experienced a genuine syndesmotic injury. Participants were randomly divided into two equal groups: Group I (normal group) without fractures and Group II (abnormal group) with fractures. Comprehensive patient data, including medical history and clinical examinations, were recorded. Results Gender distribution within the studied population consisted of 54.67% males (n=41) and 45.33% females (n=34) in the abnormal group, while the normal group comprised 37.33% males (n=28) and 62.67% females (n=47). Both APTFR and ATFR methods were found to be inconclusive and unreliable for syndesmosis assessment in ankles. The sensitivity of APTFR stood at 21.33%, with a specificity of 86.67%, a positive predictive value (PPV) of 61.5%, and a negative predictive value (NPV) of 52.4%. Meanwhile, the sensitivity of ATFR was 32%, with a specificity of 80%, a PPV of 61.5%, and an NPV of 54.1%. Conclusions Both techniques demonstrated low sensitivity when ankle fractures were present, indicating their unsuitability for routine clinical diagnosis of syndesmotic disruption via lateral ankle radiographs.

Early versus late weight-bearing in operatively treated ankle fractures with syndesmotic injury: A systematic review

BACKGROUND

Over the past 30 years, several studies have compared early weight-bearing versus late weight-bearing following open reduction and internal fixation of ankle fractures; however, no review strictly including patients with ankle fractures and complete syndesmotic disruption has been performed.

OBJECTIVE

The objective of this systematic review was to compare early versus late weight-bearing following surgery for ankle fracture with syndesmotic injury regarding clinical and patient-reported outcomes.

METHODS

A comprehensive search strategy was applied to the Cochrane Library, MEDLINE, Embase, CINAHL and PubMed databases from their inception to the 17th of January 2022. The articles were screened independently by two blinded reviewers. Data were extracted by one author, then cross-checked and approved by the other.

RESULTS

No comparative studies were found; therefore, studies describing either early or late weight-bearing were included. It was thus not possible to perform a meta-analysis. 11 studies and 751 patients were included. An early partial weight-bearing protocol was used in three studies (253 patients) and late in eight studies (498 patients). Functional outcomes suggested that there were no clear differences between early partial weight-bearing and late weight-bearing. The reoperation rate was 9-31% in the early group and 0-11% in the late. Similar results were seen for loss of syndesmotic reduction, malreduction, infection, and fixation failure.

CONCLUSION

Pros and cons were reported for early partial weight-bearing and late weight-bearing, but the evidence was very limited as our results were based on noncomparative studies. In the future, high-quality comparative studies focusing on functional outcomes within 6 months postoperatively are needed.

LEVEL OF CLINICAL EVIDENCE

1.

Implementing automated 3D measurements to quantify reference values and side-to-side differences in the ankle syndesmosis

Detection of syndesmotic ankle instability remains challenging in clinical practice due to the limitations of two-dimensional (2D) measurements. The transition to automated three-dimensional (3D) measurement techniques is on the verge of a breakthrough but normative and side-to-side comparative data are missing. Therefore, our study aim was two-fold: (1) to establish 3D anatomical reference values of the ankle syndesmosis based on automated measurements and (2) to determine to what extent the ankle syndesmosis is symmetric across all 3D measurements. Patients without syndesmotic pathology with a non-weight-bearing CT scan (NWBCT; N = 38; Age = 51.6 ± 17.43 years) and weight-bearing CT scan (WBCT; N = 43; Age = 48.9 ± 14.3 years) were retrospectively included. After training and validation of a neural network to automate the segmentation of 3D ankle models, an iterative closest point registration was performed to superimpose the left on the right ankle. Subsequently, 3D measurements were manually and automatically computed using a custom-made algorithm and side-to-side comparison of these landmarks allowed one to investigate symmetry. Intra-observer analysis showed excellent agreements for all manual measurements (ICC range 0.85-0.99) and good (i.e. < 2.7° for the angles and < 0.5 mm for the distances) accuracy was found between the automated and manual measurements. A mean Dice coefficient of 0.99 was found for the automated segmentation framework. The established mean, standard deviation and range were provided for each 3D measurement. From these data, reference values were derived to differ physiological from pathological syndesmotic alignment. Furthermore, side-to-side symmetry was revealed when comparing left to right measurements (P > 0.05). In clinical practice, our novel algorithm could surmount the current limitations of manual 2D measurements and distinguish patients with a syndesmotic ankle lesion from normal variance.

Predictors of Hardware Removal in Orthopaedic Trauma Patients Undergoing Syndesmotic Ankle Fixation With Screws

Background

Indications for removal of syndesmotic screws are not fully elucidated. This study aimed to determine factors related to elective syndesmotic screw removal.

Methods

Patients who underwent fixation of ankle syndesmotic injuries were included. Screw removal was offered after a minimum of 12 weeks after surgery for pain, stiffness or patient desire to remove painful or broken hardware. Patient demographics, surgical data, distance of the syndesmotic screw from the joint, location of the screw at the physeal scar, and number of syndesmotic screws placed were collected for all patients. Bivariate and multivariate analyses were performed to determine the relationship between patient characteristics and screw removal and independent predictors of hardware removal.

Results

Of 160 patients, 60 patients (38%) with an average age of 36.1 (range: 18-84) years underwent elective syndesmotic screw removal at a mean of 7 (range, 3-47) months after initial fixation. The most common reason for screw removal (50/60 patients) was ankle stiffness and pain (83%). Patients who underwent screw removal were more likely to be younger (36.1 years ± 13.0 vs 46.6 years ± 18.2, P < .001) and have a lower ASA score (2 ± 0.8 vs 2.1 ± 0.7, P = .003) by bivariate analysis. Of patients who underwent screw removal, 21.7% (13/60) had a broken screw at the time of removal. Whether the screw was placed at the physeal scar was not significantly associated with patient decision for hardware removal (P = .80).

Conclusion

Younger and healthier patients were more likely to undergo elective removal of syndesmotic hardware. Screw distance from joint and screw placement at the physeal scar were not significantly associated with hardware removal.

Level of Evidence

Level III, retrospective cohort study.

Instability of the distal tibiofibular syndesmosis

The distal tibiofibular syndesmosis (DTFS) is more frequently injured than previously thought. Early diagnosis and appropriate treatment is essential to avoid long term complications like chronic instability, early osteoarthritis and residual pain. Management of these injuries require a complete understanding of the anatomy of DTFS, and the role played by the ligaments stabilizing the DTFS and ankle. High index of suspicion, appreciating the areas of focal tenderness and utilizing the provocative maneuvers help in early diagnosis. In pure ligamentous injuries radiographs with stress of weight bearing help to detect subtle instability. If these images are inconclusive, then further imaging with MRI, CT scan, stress examination under anesthesia, and arthroscopic examination facilitate diagnosis. An injury to syndesmosis frequently accompanies rotational fractures and all ankle fractures need to be stressed intra-operatively under fluoroscopy after fixation of the osseous components to detect syndesmotic instability. Non-operative treatment is appropriate for stable injuries. Unstable injuries should be treated operatively. Anatomic reduction of the syndesmosis is critical, and currently both trans-syndesmotic screws and suture button fixation are commonly used for syndesmotic stabilization. Chronic syndesmotic instability (CSI) requires debridement of syndesmosis, restoration of ankle mortise with or without syndesmotic stabilization. Arthrodesis of ankle is used a last resort in the presence of significant ankle arthritis. This article reviews anatomy and biomechanics of the syndesmosis, the mechanism of pure ligamentous injury and injury associated with ankle fractures, clinical, radiological and arthroscopic diagnosis and surgical treatment.

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

BACKGROUND

The fixation method of syndesmotic injuries in ankle fractures remains controversial. The goal of the study was to compare radiographic and clinical outcomes between anterior inferior tibiofibular ligament (AITFL) anatomical repair with syndesmosis screw fixation in syndesmotic injuries.

METHODS

We analyzed 62 patients who were treated with AITFL anatomical repair or syndesmosis screw fixation for syndesmotic injuries in an advanced teaching hospital between March 2016 and March 2019. Fixation was performed with AITFL anatomical repair in 30 patients (AAR group) and syndesmosis screw in 32 patients (SS group). Radiographic evaluations were the differences in mean anterior and posterior (A difference and P difference) tibiofibular distance between injured and uninjured ankle computed tomography (CT) scan at 6 months postoperatively. Clinical evaluation of patients was done using the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle Hindfoot Score, the Olerud-Molander Ankle (OMA) score and visual analogue scale (VAS) score at 1, 3, 6 months and 1, 2 years postoperatively.

RESULTS

The A difference and P difference on CT was no differences (1.6 ± 0.8 mm, 1.3 ± 0.7 mm vs. 1.5 ± 0.7 mm, 1.2 ± 0.7 mm) between the two groups (All of P > 0.05). The AAR group had higher mean AOFAS score (65.6 ± 5.9, 82.3 ± 4.2, 87.6 ± 5.6 vs. 61.8 ± 5.2, 79.1 ± 4.0, 83.8 ± 4.9; P = 0.008, 0.003, 0.007) and higher mean OMA score (45.7 ± 8.7, 79.2 ± 6.5, 84.1 ± 5.3 vs. 40.4 ± 7.3, 74.8 ± 6.3, 80.3 ± 5.8; P = 0.012, 0.009, 0.010)) at 1, 3 and 6 months postoperatively. The AAR group had lower mean VAS scores (2.6 ± 1.2, 1.7 ± 0.7 vs. 3.4 ± 1.2, 2.2 ± 1.1; P = 0.018, 0.038) at 1 and 3 months postoperatively.

CONCLUSIONS

The results of this study suggest that the AITFL anatomical repair technique could effectively improve ankle function during daily activity. Therefore, AITFL anatomical repair technique is expected to become a better fixation method for syndesmotic injuries.

Anatomical Augmentation Using Suture Tape for Acute Syndesmotic Injury in Maisonneuve Fracture: A Case Report

Ankle syndesmosis is crucial to the integrity of the ankle joint and weight-bearing; an injury to this structure can lead to significant disability. The treatment methods for distal syndesmosis injuries are controversial. The representative treatment methods include transsyndesmotic screw fixation and suture-button fixation, and good results with suture tape augmentation have recently been reported. However, an augmentation using suture tape is only possible when the posterior inferior tibiofibular ligament (PITFL) is intact. This study describes the case of an unstable syndesmosis injury, accompanied by anterior inferior tibiofibular ligament (AITFL) and PITFL injuries, which were treated successfully using suture tape. A 39-year-old male patient sustained right ankle damage while skateboarding. His leg and ankle radiographs revealed a widening of the medial clear space, a posterior malleolus fracture, a reduced “syndesmosis overlap” compared with the contralateral side, and a proximal fibula fracture. The magnetic resonance imaging revealed ruptured deltoid ligaments, accompanied by AITFL, PITFL, and interosseous ligament injuries. A diagnosis of a Maisonneuve fracture with an unstable syndesmotic injury was made. The patient underwent an open syndesmotic joint reduction, along with an AITFL and PITFL augmentation. This anatomical reduction was confirmed using intraoperative arthroscopy and postoperative computed tomography (CT). An axial CT that was performed at the 6-month follow-up exam revealed a similar alignment of the syndesmosis between the injured and uninjured sides. There were no surgical complications and the patient did not complain of discomfort in his daily life. At the 12-month follow-up exam, a good clinical outcome was confirmed. As a treatment for unstable syndesmosis injury, ligament augmentation using suture tape shows satisfactory clinical outcomes and can be considered as a useful and reliable method for anatomical restoration and rapid rehabilitation.

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

OBJECTIVE

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.

METHODS

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 2-3 cm; inferior-syndesmotic group: screw level <2 cm; and supra-syndesmotic group: screw level >3 cm. 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.

RESULTS

The median follow-up duration was 15 months (range, 10-22 months). 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.

CONCLUSION

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 2-3 cm above the ankle.

Can Weightbearing Cone-beam CT Reliably Differentiate Between Stable and Unstable Syndesmotic Ankle Injuries? A Systematic Review and Meta-analysis

BACKGROUND

Ankle injuries are common presentations to the emergency department and may lead to syndesmotic instability. These have a high socioeconomic burden due to prolonged rehabilitation, chronic pain, and posttraumatic arthritis. Early diagnosis is essential to minimize these complications, and the assessment of instability in the clinical setting is often limited by pain and clinician experience. Cross-sectional imaging of the distal syndesmosis accurately evaluates the syndesmosis through abnormal bony relationships, which in the presence of instability, worsens during physiological loading. Cone-beam CT (CBCT) has gained popularity in the diagnosis of these injuries because it enables syndesmotic assessment under weightbearing conditions, it mitigates the high radiation dose, and it is time-efficient.

QUESTIONS/PURPOSES

The purposes of this systematic review were: (1) to establish normal values for weightbearing CBCT of the syndesmosis in uninjured ankles and ascertain interobserver reliability and (2) to identify the impact of weightbearing on the syndesmosis in patients with occult ankle injuries and assess the effect of patient demographics on these metrics.

METHODS

This systematic review was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered in PROSPERO (ID CRD42021248623). MEDLINE, PubMed, Embase, and Emcare databases were searched for studies assessing for syndesmotic instability, of which 307 studies were screened and 11 studies with 559 ankles in 408 uninjured patients and 151 patients with syndesmotic instability were included. All patients 18 years of age or older presenting with unilateral ankle injuries who underwent weightbearing CBCT for the diagnosis of an occult fracture or syndesmotic instability compared with the uninjured contralateral side were included. A control group of uninjured ankles was identified during weightbearing CBCT performed for other indications such as forefoot or midfoot injuries. Methodological assessment of the studies was performed using the Risk of Bias In Non-randomized Studies (ROBINS-1) tool and most included studies had a low risk of bias. Thus, a random-effects restricted maximum likelihood ratio model was used.

RESULTS

In the uninjured ankle, the mean area of the tibiofibular syndesmosis was 112.5 ± 7.1 mm 2 , which increased to 157.5 ± 9.6 mm 2 after injury when compared with uninjured ankles with a standardized mean difference of 29.5 (95% confidence interval 19.5 to 39.5; p < 0.01), and an excellent interobserver agreement (κ = 1.0 [95% CI 0.9 to 1.0]). However, syndesmosis volume decreased with age (β = -0.76; p = 0.04), and therefore, has a negative association with increasing age.

CONCLUSION

Our study has shown that the syndesmotic area is the most reliable parameter in the assessment of syndesmotic injuries because it increases in the presence of instability during weightbearing status. It is a composite measurement that could potentially allow clinicians to use weightbearing CBCT as an adjunct when there is a clinical suspicion of syndesmotic instability. Thus, weightbearing CBCT has the potential of being diagnostic of syndesmotic instability and should be evaluated against current radiological modalities to evaluate its accuracy.

LEVEL OF EVIDENCE

Level IV, prognostic study.

A Tension-Band Wiring Technique for Direct Fixation of a Chaput Tubercle Fracture: Technical Note

Few reports have described direct fixation of the Chaput tubercle; screw fixation is usually employed. Herein, we introduce a novel technique for Chaput tubercle fixation using tension-band wiring. This technique is applicable to fractured tubercles of various sizes and has the advantage that the fragment breakage that may occur during screw fixation is impossible. In addition, our technique increases fixation strength.

Prospective Results of the Modified Glide Path Technique for Improved Syndesmotic Reduction During Ankle Fracture Fixation

BACKGROUND

Malreduction after syndesmotic stabilization occurs in as many as 52% of cases and has been shown to detrimentally affect clinical outcomes. We propose that the modified Glide Path technique reduces the occurrence of syndesmotic malreduction.

METHODS

This study is a prospective series comparing 16 patients reduced with the modified Glide Path technique with a retrospectively reviewed series of 25 patients reduced with a traditional technique using fluoroscopy and a clamp. The modified Glide Path technique consists of manual reduction of the fibula and placement of a Kirschner wire through the fibula and tibia along the transmalleolar axis. The syndesmosis can then be reduced along the glide path created by the Kirschner wire to prevent posterior or anterior malreduction. Computed tomographic scans of the repaired and contralateral ankles were obtained postoperatively to assess reduction.

RESULTS

We found a statistically significant decrease of syndesmotic malreductions using the modified Glide Path technique when compared with technique that did not use a glide path. In our study, 2 of 16 patients (12.5%) had syndesmotic malreductions using the modified Glide Path technique, compared with 11 of 25 patients (44%) with syndesmotic malreductions in the historical cohort.

CONCLUSION

The modified Glide Path technique is a simple method for ankle syndesmotic reduction. The technique has lower rates of malreduction compared with historical methods and may be useful for most operative syndesmotic injuries.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Syndesmotic Screw Breakage May Be More Problematic Than Previously Reported: Increased Rates of Hardware Removal Secondary to Pain With Intraosseous Screw Breakage

BACKGROUND

The majority of retained syndesmotic screws will either loosen or break once the patient resumes weight-bearing. While evidence is limited, anecdotal experience suggests that intraosseous screw breakage may be problematic for some patients due to painful bony erosion. This study seeks to identify the incidence of intraosseous screw breakage, variables that may predict intraosseous screw breakage, and whether intraosseous screw breakage is associated with higher rates of implant removal secondary to pain.

METHODS

Five hundred thirty-one patients undergoing syndesmotic stabilization were screened, of which 43 patients (with 58 screws) experiencing postoperative screw breakage met inclusion criteria. Patient charts were retrospectively reviewed for demographic data, comorbidities, time to screw breakage, location of screw breakage, and implant removal. Several radiographic parameters were evaluated for their potential to influence the site of screw breakage.

RESULTS

Intraosseous screw breakage occurred in 32 patients (74.4%). Screw breakage occurred exclusively in the tibiofibular clear space in the remaining 11 instances (25.6%). Intraosseous screw breakage was significantly associated with eventual implant removal after breakage (P = .034). Screws placed further from the tibiotalar joint were at less risk for intraosseous breakage (odds ratio 0.818, P = .002). Screws placed at a threshold height of 20 mm or greater were more likely to break in the clear space (odds ratio 12.1, P = .002).

CONCLUSION

Syndesmotic screw breakage may be more problematic than previously described. Intraosseous breakage was associated with higher rates of implant removal secondary to pain in this study. Placement of screws 20 mm or higher from the tibiotalar joint may decrease risk of intraosseous breakage.Levels of Evidence: Level III: Retrospective study.

Volume measurements on weightbearing computed tomography can detect subtle syndesmotic instability

While weightbearing computed tomography (WBCT) allows three-dimensional (3D) visualization of the distal syndesmosis, image interpretation has largely relied on one-dimensional (1D) distance and, more recently, two-dimensional (2D) area measurements. This study aimed to (1) determine the sensitivity and specificity of 2D area and 3D volume WBCT measurements towards detecting subtle syndesmotic instability, (2) evaluate whether the patterns of changes in the 3D shape of the syndesmosis can be attributed to the type of ligament injury. A total of 24 patients with unilateral subtle syndesmotic instability and 24 individuals with uninjured ankles (controls) with bilateral ankle WBCT were assessed retrospectively. First, 2D areas at 0, 1, 3, 5, and 10 cm, and 3D volumes at 1, 3, 5, and 10 cm above the tibial plafond were measured bilaterally. Secondly, the 3D model of the distal tibiofibular space was created based on WBCT in a subset of 8 out of 24 patients in whom the type of ligament injury was recognized via magnetic resonance imaging. The 3D model of the injured side was superimposed on the uninjured contralateral side to visualize the pattern of changes in different planes. Volume measurement up to 5 cm above the tibial plafond showed the lowest p-value (<0.001 vs. other methods), higher sensitivity (95.8%, 95% confidence interval [CI]: 87.8-100), and specificity (83.3%, 95% CI: 68.4-98.2) for detection of syndesmotic instability. No specific pattern of changes in the 3D shape could be attributed to a type of ligament rupture. We suggest 3D volume measurements, best measured up to 5 cm proximal to the plafond, as a promising means of diagnosing syndesmotic instability, particularly for subtle cases that are hard to detect. Clinical significance: The ability to compare the ankle joints bilaterally in a 3D manner under physiologic weight provided by weightbearing CT has led to a more accurate diagnostic method. Using volumetric measurement up to 5 cm above the tibial plafond showed higher sensitivity and specificity for recognizing an unstable syndesmosis, especially in subtle cases. However, our preliminary investigations showed that the pattern of 3D alterations in the distal tibiofibular joint space based on WBCT images does not indicate the type of syndesmotic ligamentous injury. Our results can also help image viewing programs to improve their measurement tools to facilitate 3D measurement for the syndesmosis as well as other conditions that may benefit from 3D evaluation of the clinical images.

Syndesmosis screw breakage: An analysis of multiple breakage locations

INTRODUCTION/PURPOSE

Concerns have been raised about screw breakage within the tibia or fibula, referred to as intraosseous breakage. The purpose of this investigation is to analyze the technical aspects of syndesmotic screw placement in multiple anatomic breakage locations.

MATERIALS

A retrospective analysis of over 1056 patients who underwent syndesmosis fixation was completed. Demographics, screw length, width, number, height above the tibial plafond, angle, breakage location, and breakage location on the screw were collected and analyzed.

RESULTS

Intraosseous (IO) screw breakage (91 screws, 68 patients) was more common than clear space (CS) breakage (28 screws, 18 patients) (P = < 0.001). Within the IO group, screw breakage within the tibia (60 screws, 52 patients) was more common compared to fibula breakage (29 screws, 24 patients) (P = < 0.001).Increased BMI and the use of multiple screws were associated with IO breakage (P = .007) and CS breakage (P = .012), respectively. Increased screw angle and age were associated with fibular IO breakage (P = .021, P = .036) when compared to other IO breakage locations. Screw angle and placement showed no significant differences between compared groups (P = .629, P = .570).

CONCLUSION

Syndesmosis screw breakage, overall, occurred more commonly in an IO location. When compared to IO breakage, the use of multiple syndesmosis screws is most associated with CS breakage. Increased BMI is associated with increased IO breakage when compared to CS breakage. Patients with IO screw breakage within the fibula had increased age and placed at a higher angle when compared to other IO breakage locations. No other factors related to screw placement, including the height of placement, were found to be significantly associated with location of screw breakage.

Acute syndesmotic injuries in ankle fractures: From diagnosis to treatment and current concepts

A stable and precise articulation of the distal tibiofibular syndesmosis maintains the tibiofibular relationship, and it is essential for normal motion of the ankle joint. The disruption of this joint is frequently accompanied by rotational ankle fracture, such as pronation-external rotation, and rarely occurs without ankle fracture. The diagnosis is not simple, and ideal management of the various presentations of syndesmotic injury remains controversial to this day. Anatomical restoration and stabilization of the disrupted tibiofibular syndesmosis is essential to improve functional outcomes. In such an injury, including inadequately treated, misdiagnosed and correctly diagnosed cases, a chronic pattern characterized by persistent ankle pain, function disability and early osteoarthritis can result. This paper reviews anatomical and biomechanical characteristics of this syndesmosis, the mechanism of its acute injury associated to fractures, radiological and arthroscopic diagnosis and surgical treatment.

A systematic review of the "Logsplitter" injury: how much do we know?

BACKGROUND

As an emerging proposed type of ankle joint injury, the concept of logsplitter injury is a unified overview of the high-energy ankle fracture and dislocation accompanied by distal tibiofibular syndesmosis separation and displacement. Since the concept of logsplitter injury is still relatively novel, there is no uniform standard for its clinical classification, diagnosis and treatment currently. Thus, we reviewed previous literatures here to provide certain references for its better clinical diagnosis and treatment in future.

METHODS

The available literatures from January 1985 to June 2020 in five medical databases were searched and analyzed. The original articles that evaluated the outcomes of patients treated surgically for the logsplitter injury were included. The detailed data were then extracted from each research, including the researchers, type of study, level of evidence, type of center research, groups, number of patients, gender, age, causes of injury, time from injury to surgery, operative time, intraoperative blood loss, length of follow-up, postoperative complications and clinical outcomes. The overall search procedures were performed by the two independent reviewers.

RESULTS

Seven pieces of researches (199 patients) were eligible for inclusion. All researches were either retrospective or prospective study, and all but one was single center study. Falling from height ranked first in the causes of injury (52.8%), and followed by the traffic accidents (29.6%). Clinical outcomes were all measured using the American Orthopaedic Foot and Ankle Society (AOFAS) score, and the mean AOFAS score at the final follow-up was 77.9 points.

CONCLUSIONS

None of the definitive consensuses exists on how logsplitter injury should be diagnosed and surgically managed. In light of the novel concept, short presentation time and numerous postoperative complications, the logsplitter injury has not been well understood by most surgeons currently, and its overall situation still needs to be supported by a larger sample size of multicenter research in the future.

Traumatic injuries of the distal tibiofibular syndesmosis

The distal tibiofibular syndesmosis (DTFS) is frequently injured during ankle trauma. The sequelae can be significant, including chronic instability, early osteoarthritis and residual pain. The aim of this study is to summarize the current state knowledge about these injuries by answering four questions. They frequently occur in the context of an ankle sprain (20-40% of cases) or during various types of ankle fractures (20-100% of cases). They cannot be ruled out based solely on fracture type and must be investigated when a fibular or posterior malleolar fracture is present. Clinical examination and imaging are essential but do not provide a definitive diagnosis. Ultrasonography, CT scan and MRI have high sensitivity, but their static nature does not allow a treatment strategy to be defined. Dynamic radiographs must be taken, either with load or during a procedure. If instability is detected, stabilization is the general rule. In fracture cases, reduction is achieved by restoring the length and rotation of the distal fibular fragment, preferably during an open procedure. In sprain cases, reduction is not a problem unless there is ligament interposition. Tibiofibular fixation is done 1.5 to 3cm from the talocrural joint, while ensuring the reduction is perfect. The main complication-non-healing of the syndesmosis-is attributed to poor initial reduction. This or functional discomfort during weight bearing will require removal of the fixation hardware. In most cases, this allows functional recovery and correction of the inadequate reduction. Persistence of instability will require ligament reconstruction or fusion of the syndesmosis. Chronic instability can lead to ankle osteoarthritis. LEVEL OF EVIDENCE: V, expert opinion.

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

BACKGROUND

Numerous 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.

METHODS

Over 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.

RESULTS

In 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.

CONCLUSION

Syndesmosis 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.

Functional outcome 3-6 years after operative treatment of closed Weber B ankle fractures with or without syndesmotic fixation

BACKGROUND

To compare the long-term functional outcomes of patients surgically treated for Weber B ankle fractures with or without syndesmotic fixation.

METHODS

In total, 959 adult patients with previous treatment with open reduction and internal fixation (ORIF) for closed ankle fractures were eligible for inclusion in a cross-sectional postal survey 3-6 years after surgery; 645 had Weber B fractures. The survey assessed functional outcomes with three validated ankle questionnaires.

RESULTS

In total 365 (57%) patients responded at a median of 4.2 years after the trauma. After adjusting for age, sex, education, smoking status, body mass index, diabetes, physical status before surgery, fracture classification, and duration of surgery, patients with a syndesmotic fixation had no different OMAS score (p = 0.98), LEFS score (p = 0.61), and SEFAS score (p = 0.98) than those without a syndesmotic fixation. Trimalleolar fracture was associated with worse functional outcomes than unimalleolar on two of the scales, the OMAS (p = 0.028) and LEFS (p = 0.046).

CONCLUSIONS

In multivariable analysis, patients with a syndesmotic fixation had no worse long-term functional outcomes than those without syndesmotic fixation.

Fibular-Lengthening Osteotomy in Patient with Progressive Valgus Deformity After an Ankle Fracture

Patient: Male, 23-year-old

Final Diagnosis: Malunion fracture of the fibula

Symptoms: Pain and limited movement in the right ankle

Medication:—

Clinical Procedure: Fibular-lengthening osteotomy

Specialty: Orthopedics and Traumatology

Treatment of a high-energy transsyndesmotic ankle fracture: A case report of "logsplitter injury"

INTRODUCTION

The "logsplitter injury" is a special type of ankle fractures that results from high energy violence with combined rotational forces and axial loads. So far, the diagnose and treatment of "logsplitter injury" remain largely unsettled and related literature is rare.

PATIENT CONCERNS

An 18-year-old male fell from a fence and got his left ankle injured with severe malformation and swollen condition. No open wound was observed.

DIAGNOSIS

Logsplitter injury, ankle fracture (AO/OTA classification 44C1.1, Lauge-Hansen classification: pronation-external rotation).

INTERVENTIONS AND OUTCOMES

The patient was initially treated by internal fixation of fibular, repair of deltoid ligaments, and 1 syndesmotic screw fixation. When the X-ray applied after surgery, another 2 syndesmotic screws were performed to enhance stability. The syndesmotic screws were removed at 12-week and 16-week respectively. The patient was allowed for full weight-bearing immediately. However, the syndesmotic space was slightly increased compared to the contralateral side in CT views at 1-year follow-up, the function outcome was satisfied.

CONCLUSION

The logsplitter injury is a high-energy ankle fracture that requires both axial and rotational load. It is categorized as 44B or 44C by the AO/OTA classification. In the classification scheme of Lauge-Hansen, our case is in line with the pronation-external rotation classification. Anatomic reduction and fixation of ankle syndesmotic injuries are required to restore the biomechanics of the ankle joint so that long-term complications can be prevented. How to fixation the syndesmosis, whether to reconstruct the deltoid ligament remains in debate in the treatment of logsplitter injury, whether and when to remove the syndesmotic screws were still debated. Correct surgical intervention is successful in the treatment of "logsplitter injury", however, the optimal fixation of syndesmosis and repair of deltoid ligaments need further investigate.

Reduction and fixation of anterior inferior tibiofibular ligament avulsion fracture without syndesmotic screw fixation in rotational ankle fracture

Objective

We aimed to present the radiographic and functional outcomes of anatomical reduction and fixation of anterior inferior tibiofibular ligament (AITFL) avulsion fracture without syndesmotic screw fixation in rotational ankle fracture.

Methods

We retrospectively reviewed 66 consecutive patients with displaced malleolar fracture combined with AITFL avulsion fracture. We performed reduction and fixation for the AITFL avulsion fracture when syndesmotic instability was present after malleolar fracture fixation. A syndesmotic screw was inserted only when residual syndesmotic instability was present even after AITFL avulsion fracture fixation. The radiographic parameters were compared with those of the contralateral uninjured ankles. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores were assessed 1 year postoperatively.

Results

Fifty-four patients showed syndesmotic instability after malleolar fracture fixation and underwent reduction and fixation for AITFL avulsion fracture. Among them, 45 (83.3%) patients achieved syndesmotic stability, while 9 (16.7%) patients with residual syndesmotic instability needed additional syndesmotic screw fixation. The postoperative radiographic parameters were not significantly different from those of the uninjured ankles. The mean AOFAS score was 94.

Conclusion

Reduction and fixation of AITFL avulsion fracture obviated the need for syndesmotic screw fixation in more than 80% of patients with AITFL avulsion fracture and syndesmotic instability.

Alterations in tibiotalar joint reaction force following syndesmotic injury are restored with static syndesmotic fixation

INTRODUCTION

Syndesmotic injury alters joint mechanics, which may fail to be restored unless an anatomic reduction is obtained.

METHODS

A minimally invasive method of measuring joint forces was utilized that does not require significant dissection or intraarticular placement of sensory instruments. Steinmann pins were placed in the tibia and talus of eight fresh-frozen human cadaveric lower extremities and a baseline joint reaction force was determined. A syndesmotic injury was created and reduction (anatomic and anterior malreduction) performed with one or two quadricortical screws and joint reaction forces were measured after the injury and subsequent repairs.

FINDINGS

Baseline mean tibiotalar joint reaction force was 31.4 (SD 7.3 N) and syndesmotic injury resulted in a 35% decrease (mean 20.3, SD 8.4 N, p < 0.01). Fixation of the injury using one or two syndesmotic screws resulted in significant increase compared to the injury state (mean 28.7, SD3.9 N, and mean 28.3, SD 6.4 N, p < 0.05), however there was no significant difference between the two methods of fixation. Malreduction of the fibula also increased joint reaction force compared to the injury state (mean 31.5, SD 5.2 N, p < 0.01), however a significant difference was not detected between malreduction and anatomic reduction.

INTERPRETATION

The present study demonstrates that syndesmotic injury decreases joint reaction force within the tibiotalar joint, suggesting ankle joint instability. Tibiotalar force was restored with anatomic reduction with either a 1 or 2 quadricortical syndesmotic screws. Furthermore, anterior malreduction restored joint reaction force to levels similar to those observed at baseline and with anatomic reduction.

LEVEL OF EVIDENCE

Level V: biomechanical/cadaver study.

Arthroscopically Assisted Reduction of Sagittal-Plane Disruption of Distal Tibiofibular Syndesmosis

Injuries to the distal tibiofibular syndesmosis can occur in conjunction with ankle fractures. Sagittal instability of the syndesmosis is more critical than coronal instability and must be taken into account when considering reduction and fixation of the syndesmosis. The purpose of this Technical Note is to report the technique of arthroscopically assisted reduction of sagittal-plane disruption of the distal tibiofibular syndesmosis. This ensures a comprehensive assessment of the pattern of syndesmotic disruption, which can aid anatomic reduction of the syndesmosis.

[Effectiveness comparison of open reduction and internal fixation for open and closed ankle Logsplitter fractures]

Objective

To investigate the effectiveness of open reduction and internal fixation on high-energy ankle Logsplitter injuries (a kind of transsyndesmotic ankle fracture dislocation), and compare the prognosis between open and closed Logsplitter fracture.

Methods

The clinical data of 36 Logsplitter fractures treated with open reduction and internal fixation between April 2011 and May 2016 were retrospectively analyzed. Among them, 15 cases were open fracture and dislocation (open group) and 21 cases were closed fracture and dislocation (closed group). There was no significant difference between the two groups in gender, age, combined injury, injury to hospital admission time, and other general data ( P>0.05), with comparability. The wound healing, ankle mobility recovery, complications, and fracture healing were observed after operation. The ankle function was evaluated by the American Orthopaedic Foot and Ankle Society (AOFAS) score.

Results

Both groups were followed up 12-29 months (mean, 19 months). There was no significant difference in the follow-up time between the open group and the closed group ( t=1.169, P=0.251). In the open group, there were 3 cases of postoperative infection, 3 cases of nonunion, and 5 cases of post-traumatic osteoarthritis; the above complications occurred in 1 case in the closed group; there was no significant difference in complications between the two groups ( P=0.41) except post-traumatic osteoarthritis ( P=0.02). At last follow-up, there was no significant difference in AOFAS score between the two groups ( t=1.981, P=0.056). According to AOFAS score criterion, the results were good in 10 cases and general in 5 cases in the open group, and good in 13 cases and general in 8 cases in the closed group, showing no significant difference ( P=0.45). There was no significant difference in the fracture healing time and ankle flexion, dorsal extension, varus, and valgus motion between the two groups ( P>0.05).

Conclusion

Open reduction and internal fixation for open or closed Logsplitter fractures can achieve satisfactory results, improve fracture healing rate, effectively reduce the incidence of complications, and improve ankle function.

Repair of syndesmosis injury in ankle fractures: Current state of the art

Conventional treatment of syndesmosis injuries in rotationally unstable ankle fractures is associated with an unacceptably high rate of malreduction, and this has led to a paradigm shift in the approach to a newer concept of anatomical repair.

In the anatomical approach, the principle is to ‘directly fix what is broken and repair what is torn’. The approach is effective in reducing the rate of syndesmosis malreduction, increasing the biomechanical strength of syndesmosis fixation and avoiding the need for trans-syndesmotic fixation and its secondary removal.

The objective of this review article is to compare the conventional treatment of these injuries (accepted usage, general consent, traditional, generally accepted) with a newer anatomical approach to be considered as a shift in thinking.

Cite this article: EFORT Open Rev 2018;3:24-29. DOI: 10.1302/2058-5241.3.170017

A new approach to local DCO in ankle fracture dislocations: external fixation with diaphyseal unicortical screws applied by local anaesthesia

PURPOSE

Ankle fracture dislocations represent a great threat for soft tissue viability and articular instability. The use of a temporary ankle bridging ExFix plays a fundamental role in the local damage control orthopaedics while waiting for definitive synthesis.

METHODS

For this prospective research, we have developed a full application protocol of innovative diaphyseal monocortical screws fixator (Unyco-Orthofix^TM) exclusively under local anaesthesia. Rigid selection criteria allowed us to collect nine patients during a period of almost 2 years. VAS score was analysed for the feasibility of the procedure, and a thorough radiologic evaluation was performed.

RESULTS

Results pointed out that the calcaneus pin insertion (VAS: 3.44) followed by the local anaesthetics injection (VAS: 3.22) was the most painful, without precluding to continue the procedure; fracture temporary stability was achieved in all the cases.

CONCLUSIONS

The procedure of monocortical diaphyseal application in bridging external fixation is comparable to the conventional transcalcaneal traction maintaining the advantage in terms of speediness, independence from anaesthetists and feasibility within few minutes from hospital admittance even in patients under anticoagulants therapy, but increasing the stability of the reduction and improving the quality of nursing (so-called portable traction).