Malreduction of syndesmosis injury associated with malleolar ankle fracture can be avoided using Weber's three indexes in the mortise view

Measuring External Rotation of the Fibula and Fibular Length in Bilateral Computed Tomography Scans: How Reliable Is This Method?

OBJECTIVES

During ankle fracture surgery, goals include accurate reduction and fixation of the fibula regarding rotation and fibular length. Bilateral postoperative computed tomography (CT) can be performed to assess fibular rotation using the talar dome angle, and fibular length. The aim of this study was to compare side-to-side differences of the fibular rotation and fibular length using bilateral CT scans of uninjured ankles.

METHODS

DESIGN

Retrospective.

SETTING

Single center, Level I Academic Trauma Center.

PATIENT SELECTION CRITERIA

Patients with bilateral CT scans of uninjured ankles.

OUTCOME MEASURES AND COMPARISONS

External rotation using the Nault talar dome method and fibular length using the coronal method of Prior et al. The average, difference, and ratio (injured side/healthy side) and interobserver variability were calculated.

RESULTS

There were 83 patients included (166 ankles, mean age 47 years, 77.1% male). A random set of 66 ankles (33 CT scans) were used to measure interobserver variability. The mean degrees of external rotation ranged from 6.6 to 7.7, mean difference ranged from 1.4 to 3.4 degrees, mean ratio ranged from 1.1 to 1.5, and interobserver variability ranged from 0.27 to 0.65. For fibular length, the mean ranged from 24.6 to 25.8 mm, mean difference in fibular length ranged from 0.5 to 2.1 mm, mean ratio ranged from 1.0 to 1.1 mm, and interobserver variability ranged from 0.45 to 0.73.

CONCLUSIONS

Using bilateral ankle CT scans, mean differences in fibular rotation using the Nault talar dome method were 1.4-3.4 degrees. The distal fibular length had a mean difference between both sides of 0.5-2.1 mm. Although the intraclass correlation's were low, the interleg differences between patients were small, making them useful for clinical practice.

LEVEL OF EVIDENCE

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Center-Center Surgical Technique With Dynamic Syndesmosis Fixation: A Cadaveric Pilot Study

The objective of this cadaveric biomechanical study was to evaluate if the center-center surgical technique is a reliable and repeatable method of achieving proper syndesmotic reduction when using dynamic syndesmotic fixation. Nine fresh frozen above-knee cadaveric lower extremities were used. Computerized tomography (CT) scans were first obtained for each intact specimen as the baseline for comparison. A simulated complete syndesmotic disruption was created by transection of all deltoid and syndesmotic ligaments. Instability of the ankle was confirmed with stress imaging using fluoroscopy. Each unstable specimen was repaired using the center-center surgical technique with dynamic syndesmosis fixation. A series of measurements from the axial CT images of intact and repaired specimens were used to determine the anatomic distal tibiofibular relationships for comparison of changes from intact to postfixation. All radiographic measurements were performed by 4 independent foot and ankle surgeons. The level of inter-rater reliability for all the measurements was found to be "moderate" to "excellent" agreement (ICC value: 0.865-0.983, 95% confidence interval: 0.634-0.996). There was no statistical difference found between rotational alignment of native and postfixation (a/b: p = .843; b-a: p = .125; θ: p = .062). There was a statistical difference detected for lateral alignment at the center of fibularis incisura between native and postfixation (average: -0.6 ± 0.8 mm, range: -2.3 to 1.2 mm, p < .001). There was no statistical difference found for the anteroposterior translation alignment between native and postfixation (d/e: p = .251; f: p = .377). This study demonstrated the use of the center-center surgical technique as a viable and repeatable method for achieving anatomical reduction of the tibiofibular syndesmosis when used with dynamic fixation modalities.

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.

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

BACKGROUND

Acute isolated syndesmotic injuries (AISIs) have a high potential to be misdiagnosed or underdiagnosed at initial presentation to the hospital. Although magnetic resonance imaging (MRI) is the gold standard in noninvasive diagnostics, it is not always available immediately and is much more expensive than other imaging modalities. This study identifies improvements in conventional radiography and computed tomography (CT) to diagnose AISI and aims to reduce the number of MRI scans needed to verify the diagnosis.

METHODS

A retrospective case match control study was conducted by searching our trauma database between 2008 and 2022. A study group of patients with AISI (n = 64) and a control group of patients without AISI (n = 76) were formed to generate an equal number of images from both groups (62 radiographs and 22 CT scans). A total of 16 parameters that quantify the distal tibiofibular relation in injured and uninjured ankles were analyzed. For statistical analysis, a two-sided t-test was applied to calculate significant differences (p < 0.05). In a further step, a receiver operating characteristic curve (ROC) was used to determine cut-off values for the most significant parameters.

RESULTS

The most significant measurement (p < 0.001) on axial CT scans was the syndesmotic area (SA). The ROC curve revealed an area under the curve (AUC) of 0.94 (95% CI 0.86-1.0) and a cut-off value of 71.68 mm2 that shows a sensitivity and specificity of 95.5% and 81.8%, respectively.

CONCLUSION

This study suggests that radiographic imaging could represent an equally accurate alternative to MRI. These methods might generate the correct diagnosis faster due to their availability and inexpensiveness. By applying our new cut-off values in a clinical setting, the number of underdiagnosed and untreated unstable syndesmotic injuries could be reduced.

LEVEL OF EVIDENCE

III, retrospective comparative study.

Arthroscopic handlebar technique for the treatment of posterior malleolar fractures

Treating posterior malleolar fractures of the ankle remains a challenge. The arthroscopic handlebar technique is our novel surgical method used for reduction and fixation of posterior malleolar fractures and involves the restoration of posterior malleolar fractures under anterior arthroscopic guidance and the use of Kirschner wires that penetrates the fractured posterior malleolus. Arthroscopy enables visualization of the intra-articular fracture of the posterior malleolus, and a handlebar reduction bar is used to control the fractured posterior malleolus. The arthroscopic handlebar technique is a promising procedure for reduction and internal fixation of the posterior malleolar fractures.

The use of intraoperative comparative fluoroscopy allows for assessing sagittal reduction and predicting syndesmosis reduction in ankle fractures

Intraoperative fluoroscopic parameters have shown to be poor predictors for ankle syndesmosis reduction, with up to 52% of syndesmotic malreduction (SMR) reported in the literature. Anteroposterior Tibio-Fibular index (APTF) was previously described to evaluate sagittal tibiofibular alignment in lateral ankle radiographs with a high correlation between both ankles in uninjured subjects. Reproducible intraoperative measurements for sagittal syndesmotic reduction are lacking. We propose the use of the "cAPTF," calculated as the absolute difference between the APTF of the non-injured and the operated ankle, to evaluate sagittal syndesmotic reduction.

OBJECTIVE

Determine the predictive capability of cAPTF for SMR.

METHOD

Prospective observational study.

INCLUSION CRITERIA

patients with unstable ankle fractures requiring syndesmotic fixation, with a healthy contralateral ankle. Intraoperatively APTF was measured in both ankles after syndesmotic fixation. Postoperatively cAPTF was calculated. Only direct syndesmosis visualization through the lateral approach and AP and mortise views were used by surgeons to assess syndesmotic reduction. Quality of syndesmotic reduction was evaluated with bilateral postoperative CT. To estimate cAPTF discriminatory power for SMR, a receiver operative characteristic (ROC) curve was obtained and the area under the ROC curve was calculated. Youden index was used to determine the ideal cAPTF cut-off value for predicting SMR. For this determined cut-off value, sensitivity, specificity, and likelihood ratio were calculated.

RESULTS

Fifty-two patients were included. Sixteen (30%) had SMR. Patients with SMR had a statistically significant higher cAPTF value than the well reduced (median 0.26 vs 0.09; P < 0.01). The cAPTF cut-off value to predict SMR was 0.161. A cAPTF greater than 0.161 had 100% sensitivity and 97,2% specificity for SMR. The area under the ROC curve was 0.99.

CONCLUSION

Intraoperative cAPTF has excellent discriminatory power for predicting syndesmotic malreduction. We propose the routine use of intraoperative bilateral comparative fluoroscopy to assess sagittal syndesmotic reduction.

A Quantitative Method for Intraoperative Evaluation of Distal Fibular Malrotation

Background

Due to the low sensitivity of commonly used radiographic parameters for the evaluation of rotational malreduction of the distal fibula under intraoperative fluoroscopy, a quantitative method is needed to make up for this defect.

Methods

A total of 96 sets of computed tomography images of normal ankles were imported into MIMICS to reconstruct 3D models. The fibula models were rotated along the longitudinal axis from 30 degrees of external rotation to 30 degrees of internal rotation. Virtual X-ray function in MIMICS was used to obtain radiographic images in mortise view. A line was drawn through the tip of the medial malleolus and parallel to the distal tibial plafond, the distances from the medial edge of the fibula to the lateral malleolar fossa cortex and from the medial edge of the fibula to the lateral edge of the fibula were measured on this line, and the ratio of them was calculated and marked as ratio α.

Results

The mean ratio α for normal ankles was 0.49 ± 0.06, while the 95% confidence interval was 0.48–0.50. The ratio α decreased when the fibula was externally rotated and increased when the fibula was internally rotated. The effects of different genders or different types on each group of data were compared, and the p values were all greater than 0.05.

Conclusions

This is a new method to quantitatively evaluate rotational malreduction of the distal fibula during operation. The ratio α can correspond to the rotation angle of the fibula. The larger the ratio α, the more the internal rotation of the fibula. Contrarily, the smaller the ratio α, the more the external rotation of the fibula. Making the ratio α close to 0.5 may be an intuitive approach that can be used intraoperatively.

Fibular fixation improves ankle functional outcomes and alignment in the intramedullary nailing of distal third tibiofibular diaphyseal fractures

PURPOSE

The study aims to determine the effect of fibular fixation on alignment and fracture healing of tibia, and ankle functional outcomes in the treatment of distal third tibiofibular diaphyseal fractures.

METHODS

Consecutive 111 patients (33 females and 78 males) with distal third tibiofibular diaphyseal fracture who met the inclusion criteria were included in the study. Patients were divided into two groups as those who underwent fibular fixation with tibia intramedullary nailing (study group) and those who did not (control group). Groups were compared in terms of demographic features, trauma and fracture characteristics, functional and radiological outcomes.

RESULTS

No significant difference was observed between the groups in terms of demographic features, trauma characteristics, complications, and follow-up time (p > 0.05). Surgery time was significantly lower in the control group (p = 0.001). Ankle joint range of motion, AOFAS score, OMAS score, and full weight-bearing time were significantly better in the fibular fixation group (p = 0.023, p = 0.001, p = 0.001 and p = 0.039, respectively). Significantly better coronal alignment and sagittal alignment were found in the fibular fixation group (p = 0.001 and p = 0.001, respectively). Patients who underwent fibular fixation had significantly better radiological outcomes in terms of fibular rotation angle and ankle arthrosis (p = 0.000 and p = 0.022, respectively).

CONCLUSION

Fibular fixation not only contributes to fracture union, early full weight-bearing, and alignment but also improves ankle functional outcomes in the distal third tibiofibular fractures treated with intramedullary nailing for tibia.

LEVEL OF EVIDENCE

Level III, retrospective study.

The effect of the ankle syndesmosis reduction quality on the short-term functional outcome following ankle fractures

INTRODUCTION

A few radiographic techniques have been proposed to evaluate ankle syndesmosis reduction. The purpose of this study was to analyze post-operatively with CT-scanning the quality of ankle syndesmotic reduction. Moreover, to assess the impact of quality of syndesmotic reduction to functional outcome.

MATERIALS AND METHODS

A prospective cohort study focused on patients older than 17 years with lateral and medial malleolar fracture with verified syndesmotic disruption.

EXCLUSION CRITERIA

open fracture, concomitant injury, surgery delayed for more than 24 hours, additional posterior malleolar fracture, ASA score of ≥ 3, complication requiring revision surgery, articular step or gap of ≥ 2mm on the postoperative CT scans.

RESULTS

Out of 41 patients, 34 participants completed the follow-up. There was a male predominance (20 patients - 58.82%) and the mean age was 48.46±16.1 years (range (20-72 years). 22 patients (64.71%) have sustained type B fracture, while in 12 patients (35.29%) the fracture was of a type C. The reduction was classified as anatomical in 26 patients (76.50%), while in 8 patients (23.50%) the reduction of the syndesmosis was non-anatomical. In those 26 patients in whom the reduction was anatomical, 17 (65.39%) were males and there were 18 (66.67%) type B fractures. In the patients with non-anatomical reduction, 3 patients (37.5%) were of a male gender and there was the equal number of type B and C fractures. The statistical analysis showed significantly favorable scores for both AOFAS score and VAS scale for the patients with anatomical reduction.

CONCLUSION

Functional analysis showed a strong association with the CT observed reduction quality and both the AOFAS score and VAS scale. Further studies are desirable to provide further evidence in relation to the findings of this study.

A Radiological Study for Assessing Syndesmosis Malreduction: Its Validity and Limitation

This study assessed the diagnostic utility of different X-ray radiological methods on syndesmosis malreduction. Thirteen fresh ankle specimens were used to make a syndesmotic separation model. The specimen was fixed in the anatomic position and in malreduction positions, including internal rotation 10° (IR10°), IR20°, external rotation 10° (ER10°), and ER20°. The tibiofibular clear space (TCS), tibiofibular overlap (TFO) on the anteroposterior view, and anteroposterior ratio (A/P ratio) on the lateral view were measured. When the syndesmosis was fixed in IR20°, the sensitivity of the TCS, TFO, and A/P ratio for malreduction diagnosis was 92.3% (12/13), 69.2% (9/13), and 100%, respectively. When the syndesmosis was fixed in IR10° malreduction, the sensitivity of the TCS, TFO, and A/P ratio for malreduction diagnosis was 38.4% (5/13), 38.4% (5/13), and 84.6% (11/13); in ER10°, 30.7% (4/13), 76.9% (10/13), and 69.2% (9/13); and in ER20°, 92.3% (12/13), 100% and 92.3% (12/13). In the anatomic reduction, the false-positive rate of the TCF, TFO, and A/P ratio was 7.6% (1/13), 7.6% (1/13), and 0%, respectively. The TFO and A/P ratio exhibited differences between all malreduction groups and the anatomic group. However, the TCS measurements had no statistical difference between the anatomic position and IR10° malreduction (p = .109). On the AP view, the TCS and TFO measurements are not sensitive enough to detect the syndesmosis malreduction. The A/P ratio on the lateral view exhibits better diagnostic utility for syndesmosis malreduction.

Implications of the Overlapping Degree Between Proximal Fibula and Tibia for Placing the Optimal Syndesmotic Screw: A Virtual Cadaveric Study

BACKGROUND

To determine the optimal direction of the syndesmotic screw and to introduce a consistent landmark for practical application by analyzing three-dimensional (3D) modeling and virtual implantation.

METHODS

A total of 105 cadaveric lower legs (50 males and 55 females; average height, 160.6 ± 7.1 cm) were used to reconstruct a 3D model by using the Mimics® software and the joint morphology was evaluated. Syndesmotic cylinders (Ø3.5 mm/Length 100 mm) were transversely placed in the proximal end of the incisura fibularis for simulating screw fixation. The tibial proximal cylinder, which was tangent to the posterior tibial condyles, was traced and the angle between the two cylinders was measured as the tibial torsion angle (TTA). After rotating the syndesmotic cylinder parallel to the ground, the overlapping degree between the proximal fibula and tibia was assessed as a radiologic indicator.

RESULTS

Concerning tibial torsion, the TTA was an average of 36.7° (range, 17.2°-54.4°; SD, 8.78) When the syndesmotic cylinder was rotated to be parallel to the ground, the proximal fibula had nonlinear or linear overlap with the lateral border of the tibia, regardless of the joint morphology. In this non-overlapping view, three Weber's indices for normal fibular length could be better visualized than the mortise view.

CONCLUSION

The syndesmotic cylinder in the proximal end of the incisura fibularis could be consistently placed parallel to the ground by internally rotating the tibia until there was a nonlinear or linear overlap between the proximal fibula and the tibia, regardless of the joint morphology.

Strategies to Avoid Syndesmosis Malreduction in Ankle Fractures

Nearly half of surgically treated ankle fractures may have associated syndesmotic disruption, and the quality of reduction has been shown to affect functional outcomes. Malreduction ranges from 15% to 50% in the literature, and achieving anatomic reduction remains a significant challenge, even for experienced surgeons. Keys to success include having a stepwise plan and an understanding of reliable fluoroscopic parameters to help achieve reduction in both the coronal and sagittal planes. This article summarizes the literature on syndesmotic reduction and provides the authors' preferred technique using fluoroscopy.

[Research progress in diagnosis and treatment of distal tibiofibular syndesmosis injury]

Objective

To review the research progress in the diagnosis and treatment of distal tibiofibular syndesmosis injury.

Methods

The recent literature about distal tibiofibular syndesmosis injury was reviewed and analyzed.

Results

Distal tibiofibular syndesmosis injury is commonly seen in ankle joint injury, the anatomical complexities make diagnosis and treatment difficult. Preoperative physical examination, radiologic evaluation, and intraoperative stress-testing are important for the diagnosis. Aggressive treatment is also recommended for these injuries to prevent long-term chronic instability. Internal fixation is the main treatment, including metal screw, degradable screw, elastic fixation, and hybrid techniques. Metal screw fixation is still the current mainstream, but elastic fixation represented by Suture-button is more in line with the physiological characteristics of ankle joint, and the rate of secondary operation is low while the clinical outcome is satisfactory. The application prospect of elastic fixation is worthy of expectation.

Conclusion

It's crucial for patient with ankle fracture to repair the distal tibiofibular syndesmosis injury. How to diagnose the injury more accurately and simply, how to increase the success rate of reduction, and how to reduce the complications of surgery are still worthy for further exploration.

[Clinical analysis of full-repair strategy under small incision for closed Lauge-Hansen pronation-external rotation type ankle fracture]

OBJECTIVE

To investigate the safety, feasibility, and efficacy of full repair strategy under small incision in the treatment of closed Lauge-Hansen pronation-external rotation type Ⅳ ankle fracture.

METHODS

The clinical data of 57 patients with closed Lauge-Hansen pronation-external rotation type Ⅳ ankle fracture treated by full repair strategy (fracture, ligament, and cartilage repair) under small incision between January 2012 and January 2017 were retrospectively analyzed. There were 31 males and 26 females, with an average age of 41.1 years (range, 21-65 years). The causes of injury included traffic accident injury in 33 cases and falling injury in 24 cases. All of them were closed fractures, including 20 cases of medial malleolus fracture, 37 cases of complete medial malleolus but deep and shallow rupture of deltoid ligament. The average time from injury to admission was 9.6 hours (range, 3-34 hours). The quality of reduction of distal tibial articular surface (based on Ketz-Sanders standard), the reduction of tibiofibular syndesmosis (the anterior and posterior distances of distal tibiofibular syndesmosis and the lateral ankle twist angle measured by CT scan at 10 mm above the ankle joint line), and the fracture healing were evaluated. The medial clear space (MCS), tibiofibular clear space (TFCS), and distal fibular tip to lateral process of talus (DFTL) were measured on the X-ray films of ankle points. Before and after operation, the pain and functional improvement of ankle joint were evaluated by visual analogue scale (VAS) score and American Orthopedic Foot and Ankle Association (AOFAS) score, and the activities of ankle dorsiflexion and plantar flexion were measured.

RESULTS

Three cases with osteochondral lesions of the talus were found during operation and all were treated with microfracture techniques. Tournament paralysis occurred in 2 cases after anesthesia. The surgical incisions healed by first intention in all patients. All the 57 patients were followed up 24-84 months, with an average of 38.6 months. All patients achieved bone healing without bone nonunion and malunion at 12 months after operation. The reduction quality of distal tibial articular surface was excellent in 56 cases and good in 1 case at 3 months after operation, the excellent and good rate was 100%. There was no significant difference in the MCS, TFCS, DFTL, anterior distance of distal tibiofibular syndesmosis, posterior distance of distal tibiofibular syndesmosis, and lateral ankle twist angle between the affected and healthy sides at 12 months after operation ( P>0.05). At last follow-up, the VAS score, AOFAS score, ankle dorsiflexion and plantar flexion activities of the affected side were significantly improved when compared with preoperative ones ( P<0.05). Compared with the healthy side, there was no significant difference in ankle dorsiflexion and plantar flexion activities ( P>0.05).

CONCLUSION

Full-repair strategy under small incisions for the treatment of Lauge-Hansen pronation-external rotation type Ⅳ ankle fracture is effective and safe. It can not only reduce wound complications, but also improve the quality of joint reduction of the ankle joint and distal tibiofibular syndesmosis. Full repair of ligaments and cartilage can improve the internal fixation strength and joint stability of the ankle joint.

Revision of Syndesmosis Screw Fixation

Background: Many syndesmosis screw fixations do not achieve success at the first attempt. Currently, there are no data available to evaluate revision of syndesmosis screw failure. Methods: A total of 160 consecutive patients who underwent syndesmosis screw fixation from 2014 to 2016 were reviewed. The current study focuses on 13 of 160 patients who underwent revision surgery and analyzes reasons, methods, and outcomes of syndesmotic screw revisions. Results: Thirteen out of 160 patients had revision surgeries. Incidence of recurrent diastasis was 92.3%. Seven out of 19 screws had broken. Two patients had screw loosening, 9 patients underwent early weightbearing, 1 patient developed osteomyelitis, 1 patient developed osteoarthritis, and 1 patient had fibular nonunion. Eleven patients underwent removal, 3 patients underwent clamp reduction, and 4 patients underwent fibular osteotomy. Six patients experienced good reduction with 0/10 pain, 3 patients experienced good reduction with some pain, 1 patient experienced poor reduction; 1 patient developed osteomyelitis and subsequent 7/10 pain; 1 patient underwent fusion with 5/10 pain, and 1 patient experienced medial malleolar mal-union with 3/10 pain. Conclusion: It was found that the main reason for syndesmosis revision was reoccurring diastasis. Most patients ultimately experienced good reduction and were able to ambulate, despite some residual pain. Levels of Evidence: Level IV: Case series.

[Application of anatomical approach osteoligaments repair technique in treatment of pronation ankle fractures]

Objective

To investigate the safety and effectiveness of anatomical approach osteoligaments repair technique in treatment of pronation ankle fractures.

Methods

The clinical data of 53 patients with pronation ankle fractures between April 2015 and October 2016, who were treated with anatomical approach osteoligaments repair technique applied for fracture reduction and internal fixation, were analysed retrospectively. There were 35 males and 18 females with an average age of 33.1 years (range, 18-60 years). The cause of injury included traffic accidents in 27 cases, tumbling in 5 cases, fall from height in 4 cases, twisted injury in 6 cases, sports injuries in 4 cases, and bruises in 7 cases. According to Lauge-Hansen classification, there were 44 cases of pronation external rotation stage Ⅳ and 9 cases of pronation abduction stage Ⅲ. The interval between injury and operation was 4-10 days (mean, 7 days). Postoperative pain and function of ankles were assessed by American Orthopedic Foot and Ankle Score (AOFAS) and visual analogue pain scale (VAS) score. The medial clear space (MCS), tibiofibular clear space (TFCS), distal fibular tip to lateral process of talus (DFTL), the anterior and posterior tibiofibular syndesmosis distance, and the lateral malleolus twist angle were measured by X-ray films and CT of bilateral ankle joints.

Results

The tourniquet application time was 55-90 minutes (mean, 72.5 minutes); the frequency of fluoroscopy was 5-13 times (mean, 8.9 times). All incisions healed by first intention and no infection, deep vein thrombosis occurred after operation. All patients were followed up 28-48 months (mean, 36 months). There was no significant difference in postoperative MCS, TFCS, DFTL, the anterior and posterior tibiofibular syndesmosis distance, and the lateral malleolus twist angle between bilateral ankle joints ( P>0.05). At last follow-up, no ankle instability occurred and the degenerative changes of ankle joints (Kellgren-Lawrence grading Ⅱ) occurred in 5 cases. The average AOFAS score of the ankle joint was 90.84 (range, 85-95); mean VAS score was 1.23 (range, 0-5). The average dorsiflexion and plantar flexion of ankle joints was 20.24° (range, 15-25°) and 42.56° (range, 30-50°), respectively.

Conclusion

Anatomical approach osteoligaments repair technique in treatment of pronation ankle fractures can expose the talocrural joint and lower tibiofibular syndesmosis clearly, repair the osteoligaments injury directly, and assist the syndesmosis and talocrural joint reduction, and decline the incidence of ankle degeneration.

Functional Outcome of Pronation-External Rotation-Weber C Ankle Fractures with Supracollicular Medial Malleolar Fracture Treated with or without Syndesmotic Screws: A Retrospective Comparative Cohort Study

Background:

In treatment of ankle fracture, intraoperative stress tests are used to assess the syndesmotic injury and instability. However, the optimized timing of the strees test should be applied whether in pre- or post-bony fixation during operation is seldom be reported in previous studies. The different strategies on stress test timing would exhibit opposite results within a type of pronation-external rotation (PER) fractures with supracollicular medial malleolar (SMM) fractures. This study was designed to assess the 3-year functional outcomes of the special PER fractures with or without a syndesmotic transfixation based on the results of two different intraoperative stress test strategies.

Methods:

This retrospective cohort study included 61 PER injury-Weber C ankle fractures combined with SMM fractures who were treated in Beijing Jishuitan Hospital between 2013 and 2014 and followed up for 3 years. Stress test was performed twice intraoperatively. A positive intraoperative stress test before bony fixation and a negative intraoperative stress test after bony fixation were found in these included patients. Twenty-nine patients (Group 1) were treated without a supplemental syndesmotic screw fixation, according to the negative intraoperative stress test after bony fixation, while 32 patients (Group 2) were treated with an additional syndesmotic screw fixation based on the positive intraoperative stress test before bony fixation. The American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale and Visual Analog Scale (VAS) for pain scores were the main measurements of outcome. The statistical index of demographic data, fracture morphologic data, time interval of follow-up, AOFAS and VAS were recorded and assessed by SPSS 21.0 software through Fisher exact tests and one-way analysis of variance. The associations between the main outcomes and influential factors were evaluated by linear regression models.

Results:

We observed no difference in the distribution of age, sex, presence of associated posterior malleolus (PM), fracture dislocation, and fixation of associated PM between two treatment groups. With the numbers available, no statistically significant association could be detected with regard to the AOFAS (Group 1 vs. Group 2, 96.72 ± 6.20 vs. 94.63 ± 8.26, F = 1.24, P = 0.27) and VAS (Group 1 vs. Group 2, 1.47 ± 2.14 vs. 0.72 ± 1.49, F = 2.44, P = 0.12) in association with two strategies.

Conclusions:

The present study indicates no difference to the use of the syndesmotic screw in terms of the functional outcome between syndesmosis transfixation and no-fixation patients among PER-Weber C ankle fracture patients with SMM fracture after 3-year follow-up. More attention should be paid to pre- and post-bony-fixation intraoperative stress tests and the morphology of medial malleoli fractures in ankle fractures.

Dynamic Fixation Versus Static Fixation for Distal Tibiofibular Syndesmosis Injuries: A Meta-Analysis

Background

Ankle sprains with distal tibiofibular syndesmosis injuries (DTSIs) require anatomic reduction and fixation to restore the normal biomechanics of the ankle joint. In the last decade, dynamic fixation (DF) for DTSIs using a suture-button device has gained popularity because of its advantages over static fixation (SF).

Material/Methods

The present meta-analysis was conducted to compare clinical outcomes between DF and SF of DTSIs. PubMed, Cochrane Central Register of Controlled Trials, and Embase were systematically searched. Three randomized controlled studies and 7 cohort studies, with a total of 420 patients, were involved in this study. DTSIs patients treated with DF were assigned to the experimental group, and patients treated with SF were assigned to the control group. Outcomes were evaluated and analyzed by using review-manager software. Mean difference (MD) or risk ratio (RR) with 95% confidence interval (95% CI) was analyzed and calculated by utilizing the random effects models.

Results

Analysis revealed no statistically significant differences between DF and SF in American Orthopedic Foot and Ankle Society Ankle-Hindfoot score (MD, 1.90; 95% CI, −0.23–4.03; p=0.08; I²=0%), Olerud-Molander score (MD, 1.92; 95% CI, −7.96–11.81; p=0.70; I²=55%), incidence of syndesmotic malreduction (RR, 0.19; 95% CI, 0.03–1.09; p=0.06; I²=0%), and overall postoperative complication rate (RR, 0.30; 95% CI, 0.09–0.99; p=0.05, I²=75%). The rate of second procedure was significantly lower compared with DF (RR, 0.17; 95% CI, 0.07–0.43; p=0.0002, I²=54%).

Conclusions

The dynamic fixation and static fixation methods are equal in clinical outcomes, with dynamic fixation needing fewer second interventions for DTSIs.

Assessing Quality of Syndesmotic Reduction in Surgically Treated Acute Syndesmotic Injuries: A Systematic Review

There is no universal method with cutoff values for the assessment of distal tibiofibular joint reduction in acute syndesmotic injuries. It is important to detect malreductions because they may lead to impaired functional outcome and may demand reoperations. The aim of this study was to systematically review the literature to evaluate the appropriateness of different image techniques in determining syndesmotic malalignment. A literature search was conducted in Medline, Embase, and the Cochrane Library to search for articles assessing syndesmotic reduction. Excluded were articles where no criteria and/or measurements for syndesmotic reduction were provided, only normative values were provided and reviews. In total, 2157 articles were found, of which 1421 studies were screened for title and abstract after exclusion of duplicates. One hundred ten studies were eligible for full-text analysis. Of these, 61 were excluded. Three studies where added after screening the included references. Fifty-two studies were included, of which 32 were original publications and 20 were publications referring to the original publications. From the original publications, 14 used plains radiographs, 19 computed tomographic (CT) scans, and 5 used 3-dimensional CT scans (some authors used >1 modality in their study). For each modality, a large number of parameters and different cutoff values were reported. CT scanning is superior to plain radiography in the assessment of the quality of joint reduction. Parameters used the most were fibular position in the incisura and fibular rotation. The criteria for adequate reduction should at least include the position of the fibula in the incisura and rotation of the fibula, while ensuring adequate fibular length, all equaling or at least approaching the values of the uninjured contralateral side.

Beyond the pillars of the ankle: A prospective randomized CT analysis of syndesmosis' injuries in Weber B and C type fractures

BACKGROUND

This study compared clinical and radiographic results of patients who underwent stabilization of syndesmosis with one tricortical syndesmotic screw divided into three different groups: Group A without preoperative fractured ankle computed tomography (CT) scan, Group B with preoperative fractured CT scan, and Group C with preoperative bilateral ankle CT analysis.

METHODS

Between June 2016 and May 2017, fifty-one patients with fracture type AO/OTA 44 B and C were analyzed. Of those, 14 (27.45%) were assigned to Group A, 19 (37.25%) to Group B, and 18 (35.30%) to Group C. Clinical outcomes with AOFAS score at 3, 6 and 12 months were recorded. Seven measurements on axial CT scan images were confronted between the injured and uninjured ankle to check the accuracy of reduction.

RESULTS

At three months of follow up the median AOFAS score was 70.86 ± 2.98 with no significative difference between groups (p = 0.105). At 12 months of follow up the median AOFAS score was higher in group C (93.44 ± 3.01) compared to Group B and Group C. The seven variables measured at the CT scan after syndesmotic reduction were statistically different between groups. We found a better restoration of the tibiofibular distances and the correct ankle anatomy in Group C respect to Group A and Group B.

CONCLUSIONS

Use of the pre-operative CT scan of the injured and uninjured ankle give to the surgeons the more and accurate information for the reduction and help him intraoperative in the correct maneuvers. The accuracy of the syndesmosis reduction determines better clinical outcomes.

Radiological indicator of reduction adequacy during ankle syndesmosis surgery: A computational cadaveric study

PURPOSE

We introduced the intraoperative radiological indicator to assess the reduction adequacy without additional procedure or instrument, and propose the optimal syndesmotic screw trajectory.

METHODS

Thirty adult cadavers (15 males and 15 females) without ankle problems were enrolled and subjected to continuous 0.75 mm-slice computed tomography (CT) scans. CT images were imported into Mimics^® software to reconstruct three-dimensional (3D) model of ankle. Using free 360° rotations with magnification, the 3D mutual relationships of ankle syndesmosis were assessed, and the fibular congruency of incisura was evaluated to determine the optimal screw trajectory. By reformatting the CT scanning plane along the screw direction, the coronal relation of ankle syndesmosis was evaluated to verify the distance between the adjacent bones.

RESULTS

The fibula was placed in the concentric position of fibular incisura in the 20 models (concentric group) and 40 models, in an eccentric position (eccentric group). Despite this variant, all fibulas were changed into the concentric position in the proximal part of syndesmotic footprint, which might be the ideal height for syndesmotic screw in our study. The fibular bisecting screw trajectory associated with the ideal height of screw was parallel to the ground if the tibial tubercle was directed to the superior and nearly vertical to the ground floor (TT view). Through the reformatted scanning plane parallel to the screw, the lateral border of talus was always placed more medial than the lateral border of distal tibia in the coronal image. All models had a perfectly equidistant and parallel joint space except the medial aspect.

CONCLUSION

The lateral border of talus in the TT view was intraoperatively used as the radiological indicator for ankle syndesmosis widening because it was always placed more medial than the lateral border of distal tibia. The optimal syndesmotic screw trajectory was placed around the proximal syndesmotic footprint and parallel to the ground via the TT view.

Stability in ankle fractures: Diagnosis and treatment

Medial column (deltoid ligament) integrity is of key importance when considering the stability of isolated lateral malleolus ankle fractures.Weight-bearing radiographs are the best method of evaluating stability of isolated distal fibula fractures.Computed tomography (CT) scanning is mandatory for the assessment of complex ankle fractures, especially those involving the posterior malleolus.Most isolated trans-syndesmotic fibular fractures (Weber-B, SER, AO 44-B) are stable and can safely be treated non-operatively.Posterior malleolus fractures, regardless of size, should be considered for surgical fixation to restore stability, reduce the need for syndesmosis fixation, and improve contact pressure distribution. Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170057.

Correlation of Incisura Anatomy With Syndesmotic Malreduction

BACKGROUND

The anatomy of the syndesmosis is variable, yet little is known on the correlation between differences in anatomy and syndesmosis reduction results. The aim of this study was to analyze the correlation between syndesmotic anatomy and the modes of syndesmotic malreduction.

METHODS

Bilateral postreduction ankle computed tomography (CT) scans of 72 patients treated for fractures with syndesmotic disruption were analyzed. Incisura depth, fibular engagement into the incisura, and incisura rotation were correlated with degree of syndesmotic malreduction in coronal and sagittal planes as well as rotational malreduction.

RESULTS

Clinically relevant malreduction in the coronal plane, sagittal plane, and rotation affected 8.3%, 27.8%, and 19.4% of syndesmoses, respectively. The syndesmoses with a deep incisura and the fibula not engaged into the tibial incisura were at risk of overcompression, anteverted incisuras at risk of anterior fibular translation, and retroverted incisuras at risk of posterior fibular translation.

CONCLUSIONS

Certain morphologic configurations of the tibial incisura increased the risk of specific syndesmotic malreduction patterns.

LEVEL OF EVIDENCE

Level III, comparative study.