Intraoperative syndesmotic reduction: three-dimensional versus standard fluoroscopic imaging

Evaluating the Efficacy of Tension Band Wiring Fixation for Chaput Tubercle Fractures

BACKGROUND

Chaput tubercle fractures, located at the attachment site of the anterior inferior tibiofibular ligament (AITFL) on the distal tibia, have the potential to destabilize the syndesmosis joint. This study aims to assess the effectiveness of tension band wiring (TBW) as a surgical intervention for managing Chaput fractures and the consequent syndesmosis instability.

METHODS

A retrospective review of patient charts was undertaken for those who had undergone ankle fracture surgery from April 2019 through May 2022. The surgical procedure involved direct fixation of the Chaput fractures using the TBW method. Radiological assessments were performed using postoperative simple radiographs and computed tomography (CT) scans, while clinical outcomes were evaluated using the Olerud-Molander Ankle Score (OMAS) and the visual analog scale (VAS).

RESULTS

The study included 21 patients. The average OMAS improved significantly, rising from 5.95 preoperatively to 83.57 postoperatively. Similarly, the average VAS score dropped from 7.95 before the surgery to 0.19 thereafter. Minor wound complications were reported by three patients, and one case of superficial infection was resolved with antibiotic therapy.

CONCLUSIONS

Our findings suggest that the TBW technique is an effective surgical approach for treating Chaput fractures and associated syndesmosis instability. It provides reliable fixation strength and leads to improved long-term functional outcomes. Further research is needed to compare the TBW technique with alternative methods and optimize the treatment strategies for these complex ankle fractures.

Preoperative CT parameters to predict tibiofibular syndesmosis injury associated with ankle fracture: a propensity score-matched analysis

BACKGROUND

Untreated ankle fractures with concomitant tibiofibular syndesmosis injury often lead to postoperative pain and early traumatic arthritis. CT has advantages in the preoperative diagnosis of combined ankle injuries. However, a few studies have investigated the best preoperative CT parameters to predict tibiofibular syndesmosis injuries associated with ankle fractures. This study aimed to identify and evaluate the optimal preoperative CT parameters for predicting tibiofibular syndesmosis injuries associated with ankle fractures.

METHODS

We retrospectively analyzed 129 patients who underwent preoperative CT of an ankle fracture treated between January 2016 and April 2022 at a tertiary A hospital. All patients underwent open reduction and internal fixation and intraoperative stability testing. Based on the Cotton test, the patients were divided into the stable group (n = 83, 64.3%) and unstable group (n = 46, 35.7%). After 1:1 propensity score matching, the general conditions, anterior tibiofibular distance (TFD), posterior TFD, maximum TFD, tibiofibular syndesmosis area, sagittal fracture angle, Angle-A, and Angle-B were compared between the stable and unstable groups.

RESULTS

The propensity score-matched cohort comprised 82 patients. There were no significant differences between the stable and unstable groups in sex, age, affected side, operation interval, injury mechanism, Lauge-Hansen classification, sagittal fracture angle, and Angle-A (all P > 0.05). Compared with the stable group, the unstable group had a significantly greater aTFD, pTFD, maxTFD, and area (all P < 0.05). PTFD, maxTFD, and area were positively correlated with joint instability. Angle-B was smaller in the unstable group (57.13°) than the stable group (65.56°). ROC analysis showed that Area (AUC 0.711) and maxTFD (AUC 0.707) had the highest diagnostic efficacy.

CONCLUSION

MaxTFD and Area were the best predictive parameters; a larger Area was associated with a higher likelihood of instability of the tibiofibular syndesmosis after ankle fracture fixation.

What is the best treatment for syndesmosis fixation? Suture-button or syndesmotic screw ? Bilateral CT-based early postoperative analysis

BACKGROUND

The aim of this study was to compare the effectiveness of syndesmotic screw (SS) and suture button (SB) on the reduction and fixation of syndesmosis via early postoperative bilateral computed tomography (CT).

METHODS

This single-center retrospective study included 76 patients aged ≥ 18 years with a unilateral syndesmosis injury. SS was applied to 40 patients and SB to 36 patients. The differences between the sides stabilized using SB or SS and the intact sides were analyzed using the parameters of tibio-fibular clear space (∆CS) and anterior or posterior sagittal translation (∆ST) depending on the orientation of the fibula. The cases in which the fibula was translocated to the posterior of the tibia after the change of ∆ST and ∆CS> 2 mm were evaluated as malreduction. Axial CT images taken from the level of syndesmosis fixation were divided into 4 zones according to the orientation angle of the implant sent from the fibula to the tibia.

RESULTS

No significant difference was found in the analyses performed between total patient group with malreduction and fixation groups in terms of ∆CS and ∆ST values (p = 0.708, p = 0.289). It was observed that the fixation material was in zone 3 in 54 patients and in zone 2 in 22 patients. No significant difference was found in the analyses performed between the SS and SB groups according to the implant zone (p = 0.191). In the SS group sent from Zone 2, the malreduction rate according to the ∆ST value of syndesmosis was found to be significantly higher than in the SB group (p = 0.008, p = 0.003).

CONCLUSION

When the implant is applied with the correct technique, there is no difference between SS and SB in terms of early postoperative reduction. When the SS is advanced at an inappropriate angle, it negatively affects the reduction of the fibula, while SB can better tolerate angle errors up to certain degrees due to its flexible structure. Therefore, it can be presumed that the suture button system is a more convenient method in the reduction and fixation of syndesmosis than the syndesmotic screw.

LEVEL OF EVIDENCE

Level IV.

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

BACKGROUND

The quality of reduction of the distal tibiofibular joint (DTFJ) has a major impact on the outcome. Novel suture-button systems as well as intraoperative 3D imaging can be applied to increase the quality of DTFJ reduction intraoperatively. The individual effect of either remains unknown. The aim of this study was to investigate the value of intraoperative 3D imaging on the quality of reduction of the DTFJ when using a suture-button system.

METHODS

Retrospective, radiographic study including adult patients who underwent surgical stabilization of the syndesmosis with a suture-button system for acute, unilateral, unstable syndesmotic injuries with postoperative bilateral CT imaging. The use of an intraoperative 3D scan was the individual surgeon's choice. Assessed was whether the intraoperative 3D imaging had an influence on the postoperative quality of DTFJ reduction and revision rates. These findings were put in perspective to the correction potential of the suture-button system.

RESULTS

A total of 147 patients were included; 76 of these received an intraoperative 3D imaging. Neither the rate of formal malreduction (17% vs 17%) nor the postoperative revision rate (4% vs 3%) differed significantly between patients with or without intraoperative 3D imaging. Intraoperative 3D imaging revealed a false-negative rate of 14%. The intrinsic correction potential of the suture-button system reduced the number of formally malreduced DTFJs in both groups by 51%.

CONCLUSION

The additional value of intraoperative 3D imaging to assess the quality of DTFJ reduction in our series did not improve syndesmotic reduction when using a flexible suture-button system.

LEVEL OF EVIDENCE

Level III, retrospective comparative cohort study.

Intraoperative revision rates due to three-dimensional imaging in orthopedic trauma surgery: results of a case series of 4721 patients

PURPOSE

Intraoperative 3D imaging has become a valued tool in assessing the quality of reduction and implant placement in orthopedic trauma surgery. In our institution, 3D imaging is used routinely since 2001. To evaluate the intraoperative findings and consequences of this technique, intraoperative revision rates in cases with 3D imaging were analyzed.

METHODS

All operative procedures carried out with intraoperative 3D imaging between August 2001 and December 2016 were included. The scans were assessed intraoperatively and documented thereafter. In case of malreduction or misplaced implants, an immediate revision was performed. The number of scans per case as well as the findings and consequences drawn regarding the anatomical region were analyzed.

RESULTS

4721 cases with 7201 3D scans were included in this study. The most common anatomical regions were the ankle (22.3%), the calcaneus (14.8%) and the tibial head (9.5%). In 19.1% of all cases, an intraoperative revision was performed. The highest revision rates were found with 36.0% in calcaneal fractures, 24.8% in fractures of the tibial plateau, 22.3% in injuries of the ankle. In 52.0% of revisions, the reduction was improved regarding intra-articular steps or joint congruency. In 30.5% an implant was corrected.

CONCLUSION

Intraoperative revision due to results of 3D imaging was performed in almost one-fifth of cases. This illustrates the improved possibilities to detect malreduction and implant misplacements intraoperatively and thus the abilities to improve surgical outcome.

LEVEL OF EVIDENCE

III.

Fluoroscopic imaging: New advances

Today's orthopedic surgery could not be imagined without intraoperative x-ray-based imaging. This enables surgeons to assess operative interim steps as well as the result before wound closure and finishing the procedure. Although there have been mobile C-arms used for decades, there are recent advances that do not only affect the quality of the imaging itself but also the way, the information is processed and presented. These very exciting developments will change the integration of imaging into the surgical workflows, giving options of augmented reality, reduction of radiation dose, automatized acquisition and analysis of images and low-level guidance in procedures. This paper gives a review of current innovations and possible future trends in fluoroscopic 2D and 3D imaging.

Kirschner Wire as a Reference Marker for the Positioning of a Syndesmotic Screw: A Radiological Study and Clinical Evaluation

OBJECTIVE

No consensus has been reached regarding optimal implantation for a syndesmotic screw. Thus, we aimed to explore the feasibility of a reliable and static fibular incisura plane reference for ideal syndesmotic screw placement.

METHODS

A retrospective review of computed tomography (CT) scans of 42 uninjured adult ankles with foot fractures were analyzed to measure the tibiofibular vertical distance (TFVD) at 2.5 cm proximal to the plafond from August 2016 to June 2017 in our hospital. The patients (20 females, 22 males) were divided into four groups according to their TFVD: 0-1, 1-2, 2-3, and 3-4 mm, and patients in each group were counted. We retrospectively assessed 41 patients (15 females, 26 males) who underwent syndesmotic screw fixation for ankle fractures from December 2015 to June 2020. We performed t-testing of two independent samples to determine the differences in the angle between the anatomic axis of the syndesmosis and screw axis (AAS) and ankle function using the American Orthopaedic Foot and Ankle Society (AOFAS) score at 3 and 6 months postoperatively between the conventional (20 patients) and K-wire marker (21 patients) groups. The correlation between the AAS and AOFAS score was analyzed.

RESULTS

The TFVD measured 2.23 ± 1.01 mm at 2.5 cm proximal to the plafond, and occurred at 25% of the distance from 2 to 3 mm in 47.6% of the patients. This new technique decreased AAS deformation by 62%, from 13.01° ± 2.84° to 4.89° ± 2.43°, in the conventional group (p < 0.001). At 3 months postoperatively, the AOFAS scores of ankle function were similar in both groups, but it was significantly better in the new group than that of conventional group at the 6-month follow-up (p = 0.024). There was a moderate negative correlation between AAS and AOFAS score at 6 months postoperatively (R = -0.684). No obvious complications affecting ankle function were observed in either group postoperatively.

CONCLUSIONS

Surgeons can accurately place a screw trajectory using the fibular incisura plane as a reliable intraoperative reference. A 1.6-mm K-wire placed in the syndesmosis at 2.5 cm proximal to the tibial plafond could act as a static marker of the syndesmotic plane.

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.

Intraoperative Assessment of Reduction of the Ankle Syndesmosis

PURPOSE OF REVIEW

Postoperative malreduction of the ankle syndesmosis is common, poorly defined, and its assessment is controversial. In the absence of a gold standard method to evaluate the ankle syndesmosis, a variety of techniques have been described. As the knowledgebase expands, data illustrating caveats for such techniques has become available. The purpose of this review is to highlight literature-sourced technical pearls and their related caveats for the intraoperative assessment of the ankle syndesmosis.

RECENT FINDINGS

Although numerical criteria are commonly used to assess syndesmotic reduction, anatomical variation in the healthy population frequently exceeds proposed cutoffs. Patient-specific uninjured anatomy can be defined by comparing to the uninjured contralateral ankle; however, side-to-side variation is present for many anatomical relationships. Advanced imaging (e.g., lateral radiographs, 3-dimensional radiography) can influence intraoperative surgeon decision-making and improve syndesmosis reduction, but minute improvements in syndesmosis reduction may not outweigh increased operating time and costs. Intraoperative imaging is an adjunct, not a replacement for direct visualization or palpation when reducing the syndesmosis. Arthroscopy may benefit younger patients with high physical demands by improving identification of intra-articular pathology absent on MRI. Although anatomical reduction is important to restore pre-injury biomechanics, it is unclear whether differences in reduction quality influence patient-reported outcomes. In the absence of a gold standard, awareness of the options for intraoperative assessment of the syndesmosis and their respective accuracy and limitations reported herein could enhance surgeons' ability to intraoperatively reduce the syndesmosis with the tools currently available.

Analysis of the uninjured tibiofibular syndesmosis using conventional CT-imaging and axial force in different foot positions

BACKGROUND

Syndesmosis measurments and indices have been controversial and showed interindividual variability. The purpose of this study was to analyze, by conventional axial computed tomography images and a simulated load device, the uninjured tibiofibular syndesmosis under axial force and forced foot positions.

METHODS

A total of 15 healthy patients (30 ankles) were studied using adjustable simulated load device (ASLD). This device allowed to perform bilateral ankle CT scans in two forced foot and ankle positions (30° of plantar flexion, 15° of inversion, 20° of internal rotation and 15° of dorsal flexion, 15° of eversion, 30° of external rotation). Axial load was applied simultaneously in a controlled manner (70% body weight). Measurements on the axial image of computed tomography were: syndesmotic area (SA), fibular rotation (FR), position of the fibula in the sagittal plane (FPS), depth of the incisura (ID) and direct anterior difference (ADD), direct middle difference (MDD) and direct posterior difference (PDD).

RESULTS

In patients without injury to the tibiofibular syndesmosis, the application of axial load and forced foot and ankle positions showed statistically significant differences on the distal tibiofibular measurements between the stressed and the relaxed position, it also showed interindividual variability : SA (median = 4.12 [IQR = 2.42, 6.63]) (p < 0.001), ADD (0.67 [0.14, 0.67]) (p < 0.001), MDD(0.45, [0.05, 0.9]) (p < 0.001), PDD (0.73 [-0.05, 0.73]) (p < 0.002). However, it did not detect statistically significant differences when the tibiofibular differences between the stressed and the relaxed position in one ankle were compared with the contralateral side: SA (-0.14, SD = 4.33 [95% CI = -2.53, 2.26]), ADD (-0.42, 1.08 [-1.02, 0.18]), MDD (0.29, 0.54 [-0.01, 0.59]), PDD (-0.1, 1.42 [-0.89, 0.68]). Interobserver reliability showed an Intraclass correlation coefficient of 0.990 [95% CI = 0.972, 0.997].

CONCLUSIONS

Wide interindividual variability was observed in all syndesmotic measurements, but no statistically significant differences were found when comparing one ankle to the contralateral side. Measuring syndesmosis alignment parameters, may only be of value, if those are compared to the contralateral ankle.

Effect of weightbearing and foot positioning on 3D distal tibiofibular joint parameters

The aim of this study was to investigate the effect of different loading scenarios and foot positions on the configuration of the distal tibiofibular joint (DTFJ). Fourteen paired human cadaveric lower legs were mounted in a loading frame. Computed tomography scans were obtained in unloaded state (75 N) and single-leg loaded stand (700 N) of each specimen in five foot positions: neutral, 15° external rotation, 15° internal rotation, 20° dorsiflexion, and 20° plantarflexion. An automated three-dimensional measurement protocol was used to assess clear space (diastasis), translational angle (rotation), and vertical offset (fibular shortening) in each foot position and loading condition. Foot positioning had a significant effect on DTFJ configuration. Largest effects were related to clear space increase by 0.46 mm (SD 0.21 mm) in loaded dorsal flexion and translation angle of 2.36° (SD 1.03°) in loaded external rotation, both versus loaded neutral position. Loading had no effect on clear space and vertical offset in any position. Translation angle was significantly influenced under loading by - 0.81° (SD 0.69°) in internal rotation only. Foot positioning noticeably influences the measurements when evaluating DTFJ configuration. Loading seems to have no relevant effect on native ankles in neutral position.

Utility of WBCT to Diagnose Syndesmotic Instability in Patients With Weber B Lateral Malleolar Fractures

BACKGROUND

Diagnosing syndesmotic instability accompanying Weber B ankle fractures can be challenging. This study aimed to evaluate the ability of weight-bearing computed tomography (WBCT) to diagnose syndesmotic instability using one-dimensional, two-dimensional, and three-dimensional measurements among patients with unilateral Weber B lateral malleolar fractures with symmetric medial clear space (MCS) on initial radiographs and yet demonstrated operatively confirmed syndesmotic instability.

METHODS

The treatment group included 23 patients with unilateral surgically confirmed syndesmotic instability accompanying Weber B ankle fractures who underwent preoperative bilateral foot and ankle WBCT. The control group included 18 unilateral Weber B ankle fracture patients without syndesmotic instability who underwent bilateral WBCT. Measurements on WBCT images included the following: (1) syndesmotic area, (2) anterior, middle, and posterior distal tibiofibular distance, (3) fibular rotation, (4) distance from fibular tip to plafond, (5) fibular fracture displacement, and (6) MCS distance. In addition, the following volumetric measurements were calculated: (1) syndesmotic joint volume from the tibial plafond extending to 3 and 5 cm proximally, (2) MCS volume, and (3) lateral clear space volume. Area under the receiver operating characteristic curve analysis and Delong test were used, and optimal cutoff values to distinguish between stable and unstable syndesmosis were determined using Youden J statistic.

RESULTS

Among patients with unilateral syndesmotic instability and Weber B ankle fractures, all WBCT measurements were significantly greater than uninjured side, except MCS distance, syndesmotic area, and anterior and posterior tibiofibular distances (P values <0.001 to 0.004). Moreover, syndesmosis volume spanning from the tibial plafond to 5 cm proximally had the largest area under the curve of 0.96 (sensitivity = 90%; specificity = 95%), followed by syndesmosis volume up to 3 cm proximally (area under the curve = 0.91; sensitivity = 90%; specificity = 90%). Except for MCS volume and distal fibular tip to tibial plafond distance, the control group showed no side-to-side difference in any parameter.

CONCLUSION

Syndesmotic joint volume measurements seem to be best suited to diagnose syndesmotic instability among patients with Weber B ankle fractures, compared with other two-dimensional and three-dimensional WBCT measurements.

LEVEL OF EVIDENCE

Level III, comparative diagnostic study.

Does Proximal Placement of the Syndesmotic Reduction Clamp Affect the Optimal Position for the Medial Tine? A Cadaveric Pilot Study

Sagittal plane syndesmotic malreduction is associated with off-axis, eccentric reduction clamping and preferential placement of the medial tine anteriorly has been proposed to minimize the malreduction risk. Although clamp placement 1cm proximal to the plafond is recommend, no previous study has assessed whether differences in the anatomic position of the fibula within the incisura (eccentric 1cm superior and concentric 2 cm superior to the tibial plafond) affect the optimal position for the clamps medial tine during reduction of the syndesmosis. The purpose of the present cadaveric pilot study was to evaluate and compare the sagittal syndesmotic malreduction rate with various clamping vectors, 1cm and 2cm from the tibial plafond, respectively. Six through the knee cadaveric specimens were obtained. Kirschner wires and a surgical maker were used to denote placement of the reduction clamp laterally on the peroneal ridge of the fibula, and medially within the anterior, middle, and posterior thirds (Zones A, B, C) of tibia's width; 1 cm and 2 cm from the plafond. CT scans were obtained as controls, followed by destabilization of the syndesmosis. Reductions were then performed sequentially at each level (1 cm, 2 cm) and zone (A, B, C); and CT scans repeated for assessment. In most specimens (n = 5), an eccentric (1 cm) to concentric (2 cm) positional transition was observed within incisura fibularis. The transition altered the resulting fibular displacements in some specimens (2A anterior, vs 2B posterior), resulting in a higher malreduction rate with anterior (zone 2A, 33%) vs central (Zone 2B, 17%) positioning of medial tine. Although no definitive conclusions can be reached from the present pilot study, future studies with a greater number of specimens and clamping vectors are warranted to determine whether positional transitions of the fibula within the incisura fibularis affect the optimal position for the clamps medial tine.

Intraoperative chertsey test, is it a reliable alternative to computed tomography scan for diagnosing syndesmotic injuries of the ankle?

Background:

The present study aims to evaluate the diagnostic exactitude of the intraoperative Chertsey test in tibiofibular syndesmotic injuries in patients with malleolar fractures, in comparison with a computed tomography (CT) scan.

Materials and Methods:

In this study, patients with malleolar fractures operated between 2018 and 2020 were examined. Thirty-nine patients were enrolled in the study. A three-dimensional preoperative CT scan was obtained. The opposite unfractured ankle was also scanned and considered as the control group. The Chertsey test was performed during the operation to assess the syndesmosis injury. Then, patients were partitioned into two distinct groups, considering the condition of their ankle, namely the Chertsey positive (unstable syndesmosis) group and the Chertsey negative (stable syndesmosis) group.

Results:

The outcomes of the present survey illustrated that the Chertsey test was positive in 16 patients (41.03%) and negative in 23 patients (59.07%). The median of all CT scan parameters (anterior tibiofibular distances (TFD), middle TFD, posterior TFD, and maximal TFD and volume) before surgery in the group of patients with a positive Chertsey test was significantly higher, measured against the unfractured control group (P < 0.001 for all parameters). Furthermore, a comparison of CT scan parameters and syndesmosis space volume before surgery between the two groups of patients with positive and negative Chertsey test results showed that the measurement of parameters in Chertsey-positive patients was significantly higher than the Chertsey-negative patients (P < 0.001).

Conclusion:

Chertsey test could be used to diagnose syndesmosis injuries in patients with malleolar fractures due to its high importance in the outcome of patients.

Suture button versus syndesmotic screw in ankle fractures - evaluation with 3D imaging-based measurements

BACKGROUND

Inadequate reduction of syndesmotic injuries can result in disabling clinical outcomes. The aim of the study was to compare syndesmosis congruity after fixation by syndesmotic screws (SYS) or a suture button system (SBS) using three-dimensional (3D) computed imaging techniques.

METHODS

In a retrospective single-center study, patients with unilateral stabilization of an ankle fracture with a syndesmotic injury and post-operative bilateral CT scans were analyzed using a recently established 3D method. The side-to-side differences were compared for tibio-fibular clear space (∆CS), translation angle (∆α), and vertical offset (∆z) among patients stabilized with syndesmotic screws or suture button system. Syndesmotic malreduction was defined for ∆CS > 2 mm and for |∆α| > 5°. ∆CS and ∆α were correlated with two-dimensional (2D) measurements.

RESULTS

Eighteen patients stabilized with a syndesmosis screw and 29 stabilized with a suture button system were analyzed. After stabilization, both groups revealed mild diastasis (SYS: mean ∆CS 0.3 mm, SD 1.1 mm vs SBS: mean ∆CS 0.2 mm, SD 1.2 mm, p = 0.710). In addition, both stabilization methods showed slight dorsalization of the fibula (SYS: mean ∆α 0.5°, SD 4.6° vs SBS: mean ∆α 2.1°, SD 3.7°, p = 0.192). Also, restoration of the fibula-to-tibia length ratio also did not differ between the two groups (SYS: mean Δz of 0.5 mm, SD 2.4 mm vs SBS: mean Δz of 0 mm, SD 1.2 mm; p = 0.477). Malreduction according to high ∆α was most common (26% of cases), with equal distribution between the groups (p = 0.234). ∆CS and ∆α showed good correlation with 2D measurements (ρ = 0.567; ρ = 0.671).

CONCLUSION

This in vivo analysis of post-operative 3D models showed no differences in immediate post-operative alignment after syndesmotic screws or suture button system. Special attention should be paid to syndesmotic malreduction in the sagittal orientation of the fibula in relation to the tibia in radiological control of the syndesmotic congruity as well as intra-operatively.

Four-Dimensional CT Analysis of Normal Syndesmotic Motion

BACKGROUND

The syndesmosis ligament complex stabilizes the distal tibiofibular joint while allowing for small amounts of physiologic motion. When injured, malreduction of the syndesmosis is the most important factor that contributes to inferior functional outcomes. Syndesmotic reduction is a dynamic measure, which is not adequately captured by conventional computed tomography (CT). Four-dimensional CT (4DCT) can image joints as they move through range of motion (ROM). The aim of this study was to employ 4DCT to determine in vivo syndesmotic motion with ankle ROM in uninjured ankles.

METHODS

Uninjured ankles were analyzed in patients who had contralateral syndesmotic injuries, as well as a cohort of healthy volunteers with bilateral uninjured ankles. Bilateral ankle 4DCT scans were performed as participants moved their ankles between maximal dorsiflexion and plantarflexion. Multiple measures of syndesmotic width, as well as sagittal translation and fibular rotation, were automatically extracted from 4DCT using a custom program to determine the change in syndesmotic position with ankle ROM.

RESULTS

Fifty-eight ankles were analyzed. Measures of syndesmotic width decreased by 0.7 to 1.1 mm as the ankle moved from dorsiflexion to plantarflexion (P < .001 for each measure). The fibula externally rotated by 1.2 degrees with ankle ROM (P < .001), but there was no significant motion in the sagittal plane (P = .43). No participants with bilateral uninjured ankles had a side-to-side difference in syndesmotic width of 2 mm or greater.

CONCLUSION

4DCT allows accurate, in vivo syndesmotic measurements, which change with ankle ROM, confirming prior work that was limited to biomechanical studies. Side-to-side syndesmotic measurements are consistent within subjects, validating the method of templating syndesmotic reduction off the contralateral ankle, in a consistent ankle position, to achieve anatomic reduction of syndesmotic injury.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Predisposing factors for chronic syndesmotic instability following syndesmotic fixation in ankle fracture: Minimum 5-year follow-up outcomes

BACKGROUND

This study aimed to identify risk factors for chronic syndesmotic instability following syndesmotic fixation.

METHODS

We performed a retrospective review of consecutive patients who had sustained ankle fractures requiring syndesmotic fixation. Patients available for a minimum 5 years of follow-up were classified into 2 groups according to the presence of syndesmotic instability. Statistical binary logistic regression analyses were performed to investigate the significance of various risk factors. Functional outcomes were assessed using the FAOS.

RESULTS

In total, 166 patients who met the study inclusion criteria underwent analysis. The overall postoperative instability rate was 20.5%, which was significantly affected due to BMI (p = 0.018; OR 6.72), and concomitant posterior malleolar fracture (p = 0.032, OR 2.77). The mean scores in the syndesmotic instability (SI) group were significantly lower than those in the no syndesmotic instability (NSI) group (p = 0.021).

CONCLUSIONS

Obesity and concomitant posterior malleolar fracture were significant risk factors for postoperative syndesmotic instability.

Suture button versus syndesmosis screw fixation in pronation-external rotation ankle fractures: A minimum 6-year follow-up of a randomised controlled trial

OBJECTIVE

Randomised controlled trials (RCT) with short-term follow-ups have shown that, in treatment of syndesmosis injuries, a suture button device (SB) resulted in better radiographic and functional outcome compared to syndesmosis screw fixation (SS). However, only one RCT has reported long-term results; thus, the syndesmosis malreduction rates for both implants might increase during longer follow-up. The primary objective of this RCT was to evaluate the maintenance of syndesmosis reduction with the SS compared to the SB fixation in patients during a minimum follow-up of 6-years. The secondary objectives were to assess the post-traumatic osteoarthritis (OA) grade and the functional outcome.

PATIENTS AND METHODS

At Oulu University Hospital, between January 2010 and December 2011, we enrolled 43 patients with Lauge-Hansen pronation-external rotation type 4/Weber C, ankle fractures with unstable syndesmosis. Patients were randomised to treatment with either a single 3.5-mm tricortical SS (22 patients) or an SB (21 patients). The mean follow-up was 7.1 years (range, 6.2-7.9). Syndesmosis reduction and OA grade was assessed with standing cone-beam computed tomography (CBCT) of both ankles. Malreduction was defined as >2 mm side-to-side difference in the mean width of the syndesmosis. OA was graded according to the Morrey & Wiedeman classification. The Olerud-Molander Ankle Outcome Score (OMAS) and a quality of life questionnaire (RAND 36-Item Health Survey) were used to evaluate functional outcome.

RESULTS

Two syndesmoses in the SS group and one in the SB group were malreduced (P = 0.58). Moderate OA after a mean of 7 years post-injury was common. In the SS and SB groups, 9 of 16 and 11 of 13 patients, respectively, had one or more grades serious OA in the injured ankle than in the uninjured ankle (P = 0.11). The mean OMAS was 88 in the SS group and 78 in the SB group (difference between means 7.1, 95% CI: -7.0-21.1, P = 0.32). The RAND-36 results did not differ between groups.

CONCLUSION

The SS and SB maintained syndesmosis reduction equally well during follow-up. Our study findings also suggest that both methods result in moderate OA rates and the functional outcome is comparable between these two syndesmosis fixation methods.

The Syndesmosis, Part II: Surgical Treatment Strategies

Syndesmotic injuries in the setting of ankle fracture are critically important to diagnosis and treat to restore an anatomic tibiotalar relationship. Physical examination and clinical suspicion remain critically important for diagnosis. Ultrasound examination and weight-bearing computed tomography scans are evolving to help diagnosis more subtle injuries. Although flexible syndesmotic fixation may decrease malreduction rates, the benefits over rigid fixation is the subject of ongoing study. Anatomic reduction remains critical regardless of fixation choice. Routine removal of rigid syndesmotic hardware does not seem to offer substantial clinical improvement in pain or range of motion; however, broken hardware may cause irritation.

Changes in the Syndesmotic Reduction After Syndesmotic Suture-Button Fixation for Ankle Malleolar Fractures: 1-Year Longitudinal Evaluations Using Computed Tomography

BACKGROUND

Evaluation over time is important in assessing the reduction of the syndesmosis after suture-button fixation for ankle malleolar fractures. The purposes of this study were to evaluate time-dependent change in the syndesmotic reduction immediately after suture-button fixation for ankle malleolus fractures and 1 year after surgery using computed tomography, and to investigate the reliability of the measurement values to evaluate the reduction of syndesmosis.

METHODS

We assessed 28 patients who underwent suture-button fixation for ankle fractures. Syndesmotic reduction was assessed within 2 weeks of the fracture surgery and 1 year after surgery using axial computer tomographic images. Side-to-side differences in the anterior, central, and posterior tibiofibular distances, anteroposterior fibular translation, fibular rotation, and syndesmosis area were measured.

RESULTS

The mean anterior tibiofibular distance and anteroposterior fibular translation were 1.8 mm and 1.5 mm, respectively, after syndesmotic fixation. They decreased to 1.2 mm and 0.6 mm, respectively, at 1 year after surgery (P = .03 and P = .01, respectively). The other measurement values did not change over time. The minimum detectable change in the distance of measurements was 1 mm or less.

CONCLUSION

The anterior tibiofibular distance and anteroposterior fibular translation had decreased 1 year after fixation in ankle malleolar fractures with syndesmotic suture button. Even if the fibula is posteriorly malreduced by the time computed tomography is performed immediately after surgery, the fibula may return to a good position 1 year after surgery.

LEVEL OF EVIDENCE

Level IV, case series.

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.

Does the use of intraoperative CT scan improve outcomes in Orthopaedic surgery? A systematic review and meta-analysis of 871 cases

BACKGROUND

Intraoperative imaging is frequently made use of in Orthopaedic surgery. Historically, conventional 2-dimensional fluoroscopy has been extensively used for this purpose. However, 2D imaging falls short when it is required to visualise complex anatomical regions such as pelvis, spine, foot and ankle etc. Intraoperative 3D imaging was introduced to counter these limitations, and is increasingly being employed in various sub-specialities of Orthopaedic Surgery.

OBJECTIVES

This review aims to outline the clinical and radiological outcomes of surgeries done under the guidance of intraoperative 3D imaging and compare them to those done under conventional 2D fluoroscopy.

METHODS

Three electronic databases (PubMed, Embase and Scopus) were searched for relevant studies that directly compared intraoperative 3D imaging with conventional fluoroscopy. Case series on intraoperative 3D imaging were also included for qualitative synthesis. The outcomes evaluated included accuracy of implant placement, mean surgical duration and rate of revision surgery due to faulty implants.

RESULTS

A total of 31 studies from sub-specialities of spine surgery, pelvi-acetabular surgery, foot and ankle surgery and trauma surgery, having data on a total of 658 patients were analysed. The study groups which had access to intraoperative 3D imaging was found to have significantly increased accuracy of implant positioning (Odds Ratio 0.35 [0.20, 0.62], p = 0.0002) without statistically significant difference in mean surgical time (p = 0.57). Analysis of the studies that included clinical follow up showed that the use of intraoperative 3D imaging led to a significant decrease in the need for revision surgeries due to faulty implant placement.

CONCLUSION

There is sufficient evidence that the application of intraoperative 3D imaging leads to precise implant positioning and improves the radiological outcome. Further research in the form of prospective studies with long term follow up is required to determine whether this superior radiological outcome translates to better clinical results in the long run.

Percutaneous reduction, cannulated screw fixation and calcium sulfate cement grafting assisted by 3D printing technology in the treatment of calcaneal fractures

BACKGROUND

Percutaneous reduction, cannulated screw fixation and calcium sulfate cement grafting (PR + CSC) for treatment of displaced and intra-articular calcaneal fractures (DIACFs) is a difficult technique, because the minimally invasive treatment has limited exposure and cannot be used to reduce articular surface under direct vision. The goal of this study was to apply 3D printing technology to preoperative planning and surgery of DIACFs, and to evaluate its effectiveness, feasibility and safety in fracture repair.

METHODS

We enrolled 81 patients with DIACFs in the study from August 2015 to August 2017. Patients with DIACFs in our hospital were randomly divided into the 3D printing group (40 cases) and the conventional group (41 cases). The operation duration, blood loss volume and the number of fluoroscopy were compared. Radiological results were evaluated using radiographs and functional results were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score. The complications were also assessed. In addition, we made a questionnaire to verify the usefulness of the 3D printed model for both doctors and patients.

RESULTS

The operation duration, blood loss volume and the number of fluoroscopy in 3D printing group were significantly less than that in the conventional group. Besides, 3D printing group achieved significantly better radiological results than conventional group both postoperatively and at the final follow-up except the calcaneal width at the final follow-up. The AOFAS score in the 3D printing group was significantly higher than that in the conventional group. In addition, the questionnaire from doctors and patients exhibited high scores of overall satisfaction of the 3D printed models. As for complications, there was no significant difference among the two groups.

CONCLUSION

This study suggested the clinical feasibility of PR + CSC assisted by 3D printing technology in the treatment of DIACFs.

LEVEL OF EVIDENCE

II.

The utilization of intraoperative contralateral ankle images for syndesmotic reduction

PURPOSE

To evaluate the variability in ankle syndesmotic morphology on contralateral ankle fluoroscopic images and the reductions obtained utilizing these images.

METHODS

A retrospective cohort study was performed at a level one trauma center including 46 adult patients undergoing operative fixation of malleolar ankle fractures that also had anteroposterior (AP) and lateral fluoroscopic images of the uninjured contralateral ankle intraoperatively. Contralateral and post-fixation fluoroscopic images were used to measure the tibiofibular clear space (TFCS) as a proportion of the superior clear space (SCS) on mortise images and the posterior tibiofibular distance (PTFD) as a proportion of the lateral superior clear space (LSCS) on lateral images. Differences between contralateral and post-fixation ankle measurements were compared between those patients with syndesmotic injuries and those without (control group).

RESULTS

The mean TFCS/SCS and PTFD/LSCS ratios measured on contralateral ankle images were 1.2 (95% confidence interval (CI) 1.1 to 1.3; range 0.7 to 1.8) and 1.8 (95% CI 1.5 to 2; range 0.5 to 3.4). The mean difference between the contralateral and post-fixation TFCS/SCS and PTFD/LSCS in patients with and without syndesmotic fixation was 0.07 vs. 0.13 (F-ratio 0.3, p = 0.5) and -0.2 vs 0.5 (F ratio 5.2,  p= 0.02).

CONCLUSIONS

Contralateral syndesmotic measurements varied widely and the utilization of these images allowed for syndesmotic reductions with similar measurements. Intraoperative contralateral ankle images should be considered to assess syndesmotic reduction.

Comparison of Different Magnitudes of Applied Syndesmotic Clamp Force: A Cadaveric Study

Overcompression of the ankle syndesmosis was once thought to be improbable. Recent studies using computerized tomography (CT) however, have demonstarted otherwise; raising pertinent questions regarding the factors associated with and consequences of syndesmotic overcompression. The purpose of the present study was to directly compare different magnitudes of applied clamp force on the coronal reduction of ankle syndesmosis. Eight through-the-knee cadaveric specimens were obtained. Fiducial cannulated screws were placed in the tibia and fibula to standardize placement of the reduction clamp's tines. CT scans were obtained as baseline controls, followed by destabilization of the syndesmosis. Reductions were then performed using a clamp equipped with an inline load cell, and objective forces (60, 80, 100, 120, 140, and 160 N) applied sequentially to each of the specimens. The syndesmosis was fixed with a single quadricortical screw, and CT were scans repeated. Applied clamp forces of 60 and 80 N resulted in lateral fibular displacement and undercompression (42.9% and 57.1%, respectively), whereas forces of 140 and 160 N resulted in medial fibular displacement (p = .011 and p = .001) and overcompression (100%). The smallest mediolateral displacements were observed with 100 and 120 N, respectively. Malreduction assessment with CT was superior to traditional radiographs [r(54) = 0.22; 95% confidence interval -0.04 to 0.45; p = .101]. In our cadaveric model, an applied clamp force of 100 N most effectively mitigated iatrogenic coronal syndesmotic malreduction from under- or overcompression. Although additional research is warranted, based on the data, inherent variabilities in the applied clamp force by surgeons appear to contribute to the unacceptably high coronal syndesmotic malreduction rate.

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

BACKGROUND

The superiority of screw or suture button fixation for syndesmotic instability remains debatable. Our aim is to compare radiographic outcomes of screw and suture button fixation of syndesmotic instability using weight bearing CT scan (WBCT).

METHODS

Twenty patients with fixation of unilateral syndesmotic instability were recruited and divided among two groups (screw = 10, suture button = 10). All patients had WBCT of both ankles ≥12 months postoperatively.

RESULTS

In suture button group, injured side measurements were significantly different from normal side for syndesmotic area (P = 0.003), fibular rotation (P = 0.004), anterior difference (P = 0.025) and direct anterior difference (P = 0.035). In screw group, syndesmotic area was the only significantly different measurement (P = 0.006).

CONCLUSION

While both screw and suture button didn't completely restore the syndesmotic area as compared to the contralateral uninjured ankle, external malrotation of the fibula was uniquely associated with suture button fixation.

LEVEL OF EVIDENCE

III Retrospective Cohort Study.

A standardized approach for exact CT-based three-dimensional position analysis in the distal tibiofibular joint

Background

Assessment of tibiofibular reduction presents an intra- and postoperative challenge. Numerous two-dimensional measurement methods have been described, most of them highly dependent on leg orientation and rater. Aim of the present work was to develop a standardized and orientation-independent 3D based method for the assessment of syndesmotic joint position.

Methods

In a retrospective single center study, 3D models of bilateral ankle joints, either after unilateral syndesmosis stabilization (operative group) or with no injury (native group) were superimposed (best fit matching) and aligned uniformly. Based on center of gravity calculations three orientation- and rater-independent parameters were determined: tibiofibular clears space (CS), vertical offset between both fibulae, and translation angle of the fibulae about tibia axis.

Results

Bilateral CT datasets of 57 native and 47 postoperative patients were analyzed. In the native group mean CS was 2.7 (SD, 0.8; range, 0.7–4.9) mm, mean CS side difference was 0.62 (SD, 0.45) mm and mean translation angle was 1.6 (SD, 1.4) degrees regarding absolute values. The operative group was found to show a significantly higher CS side difference of 0.88 (SD, 0.75) mm compared to native group (P = .046). Compared to the healthy contralateral side, operated fibulae showed mean proximal displacement of 0.56 (SD, 1.67) mm (P = .025), dorsal displacement of 1.5 (SD 4.1) degrees (P = .017).

Conclusion

By using 3D best fit matching, orientation- and rater-dependent errors can be minimized. Large interindividual and small intraindividual differences of uninjured couples support previous recommendations for bilateral imaging.

Trial registration: AZ 131/18-ek; AZ 361/19-ek

Level of evidence

Level III.

Outcomes of Posterior Arthroscopic Reduction and Internal Fixation (PARIF) for the Posterior Malleolar Fragment in Trimalleolar Ankle Fractures

BACKGROUND

Posterior malleolar fractures within a trimalleolar ankle fracture pattern are challenging to manage. Posterior ankle arthroscopy provides a means to assess the intra-articular and syndesmotic reductions, while removing loose bodies. The purpose of this study was to determine the radiographic and patient reported outcomes of posterior arthroscopic reduction and internal fixation (PARIF) in trimalleolar ankle fractures.

METHODS

From November 2015 to March 2019, we prospectively enrolled consecutive trimalleolar ankle fractures that underwent PARIF by a single surgeon. Preoperative and postoperative computed tomography (CT) scans were interpreted by 2 blinded musculoskeletal radiologists for articular reduction, syndesmosis congruity, and presence of ossific loose bodies. Patient outcomes were assessed using the Foot and Ankle Disability Index (FADI), American Orthopaedic Foot & Ankle Society (AOFAS) ankle score, Olerud-Molander Ankle Score (OMAS), and visual analog scale (VAS). A total of 28 trimalleolar ankle fractures were treated with PARIF. Mean patient age was 36 years (range, 19-69).

RESULTS

Preoperative CT identified 18 intra-articular loose bodies (range, 0-4) in 36% of ankles and 75% (n = 21) syndesmosis incongruity. Postoperative CT scans demonstrated anatomic intra-articular reduction in all fractures, 41.7% (5/12) syndesmosis incongruity without fixation, and 0% (0/9) with suture-button fixation. At mean 2-year follow-up, the results were good to excellent with mean VAS score 1 (range, 0-4), AOFAS score 84 (range, 63-100), FADI 85 (range, 59-100), and OMAS 76 (range, 40-100).

CONCLUSION

The PARIF technique for displaced posterior malleolar fractures was effective in achieving anatomic intra-articular reduction, syndesmosis congruity, and intra-articular loose body removal, while safely preserving the soft tissues.

LEVEL OF EVIDENCE

Level IV, prospective case series.

Assessment of malreduction standards for the syndesmosis in bilateral CT scans of uninjured ankles

AIMS

Malreduction of the syndesmosis has been reported in up to 52% of patients after fixation of ankle fractures. Multiple radiological parameters are used to define malreduction; there has been limited investigation of the accuracy of these measurements in differentiating malreduction from inherent anatomical asymmetry. The purpose of this study was to identify the prevalence of positive malreduction standards within the syndesmosis of native, uninjured ankles.

METHODS

Three observers reviewed 213 bilateral lower limb CT scans of uninjured ankles. Multiple measurements were recorded on the axial CT 1 cm above the plafond: anterior syndesmotic distance; posterior syndesmotic distance; central syndesmotic distance; fibular rotation; and sagittal fibular translation. Previously studied malreduction standards were evaluated on bilateral CT, including differences in: anterior, central and posterior syndesmotic distance; mean syndesmotic distance; fibular rotation; sagittal translational distance; and syndesmotic area. Unilateral CT was used to compare the anterior to posterior syndesmotic distances.

RESULTS

A difference of anterior to posterior syndesmotic distance > 2 mm was observed in 89% of ankles (n = 190) on unilateral CT assessment. Using bilateral CT, we found that 35% (n = 75) of normal ankles would be considered malreduced by current malreduction parameters. In 50 patients (23%), only one parameter was anomalous, 18 patients (8%) had two positive parameters and seven patients (3%) had three. Difference in fibular rotation had the lowest false positive rate of all parameters at 6%, whereas posterior syndesmotic distance difference had the highest at 15%.

CONCLUSION

In this study, 35% of native, uninjured syndesmoses (n = 75) would be classified as malreduced by current diagnostic standards on bilateral CT and 89% had an asymmetric incisura on unilateral CT (n = 190). Current radiological parameters are insufficient to differentiate mild inherent anatomical asymmetry from malreduction of the syndesmosis. Cite this article: Bone Joint J 2021;103-B(1):178-183.

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.

Is the Fibular Station on Lateral Ankle Radiographs Symmetric? A Retrospective Observational Radiographic Study

BACKGROUND

Precise reduction of a syndesmosis after disruption is critical to improve patient physical function. Intraoperative lateral radiographs of the unaffected ankle are often used in clinical practice as a template for anatomic syndesmotic reduction because sagittal plane malreduction is common. However, there is little data to suggest fibular station, or the position of the fibula in the AP plane on the lateral radiograph, is symmetric side-to-side in patients.

QUESTIONS/PURPOSES

(1) Is the position of the fibula in the AP plane (fibular station) on lateral ankle radiographs symmetric in an individual? (2) Do the measurements used to judge the position of the fibula on lateral radiographs have good inter- and intraobserver reliability?

METHODS

Over the period from August 2016 to October 2018, we identified 478 patients who presented to an orthopaedic clinic with forefoot and midfoot complaints. Skeletally mature patients with acceptable bilateral lateral ankle radiographs, which are common radiographs obtained for new patients to clinic for any complaint, were included. Based on that, 52% (247 of 478 patients) were included with most (22%, 107 patients) excluded for poor lateral radiographs. The most common diagnosis in the patient cohort was midfoot OA (14%, 35 patients). The median (range) age of the included patients was 54 years (15 to 88), and 65% (159 of 247) of the patients were female. Fibular station, defined as the position of the fibula in the AP plane, and fibular length were measured using a digital ruler and goniometer on lateral radiographs. A paired t-test was used to determine if no difference in fibular station existed between the left and right ankles. With 247 paired-samples, with 80% power and an alpha level of 0.05, we could detect a difference between sides of 0.008 for the posterior ratio, 0.010 for the anterior ratio, and 0.012 for fibular length. Two readers, one fellowship-trained orthopaedic traumatologist and one PGY-4, measured 40 patients to determine the inter- and intraobserver reliability by intraclass correlation coefficient (ICC).

RESULTS

The posterior fibular station (mean right 0.147 [σ = 0.056], left 0.145 [σ = 0.054], difference = 0.03 [95% CI 0 to 0.06]; p = 0.59), anterior fibular station (right 0.294 [σ = 0.062], left 0.299 [σ = 0.061], difference = 0.04 [95% CI 0 to 0.08]; p = 0.20), and fibular length (right 0.521 [σ = 0.080], left 0.522 [σ = 0.078], difference = 0.05 [95% CI 0.01 to 0.09]; p = 0.87) ratios did not differ with the numbers available between ankles. Inter- and intraobserver reliability were excellent for the posterior ratio (ICC = 0.928 and ICC = 0.985, respectively) and the anterior ratio (ICC = 0.922 and ICC = 0.929, respectively) and moderate-to-good for the fibular length ratio (ICC = 0.732 and ICC = 0.887, respectively).

CONCLUSION

The use of lateral radiographs of the contralateral uninjured ankle appears to be a valid template for determining the position of the fibula in the sagittal plane. However, further prospective studies are required to determine the efficacy of this method in reducing the syndesmosis over other methods that exists.

LEVEL OF EVIDENCE

Level III, diagnostic study.

The Valid Diagnostic Parameters in Bilateral CT Scan to Predict Unstable Syndesmotic Injury with Ankle Fracture

The purpose of this study is to evaluate the reasonable parameters to predict unstable syndesmotic injuries in ankle fractures. Seventy consecutive patients who underwent preoperative bilateral computed tomography (CT) scans were enrolled. Group A consisted of 20 patients intraoperatively diagnosed with syndesmotic injuries according to an intraoperative stress test and group B consisted of 50 patients who had nosyndesmotic injuries. The tibiofibular overlap (TFO) and tibiofibular clear space (TFCS) were measured using preoperative ankle radiographs. Measuring the anterior fibular distance (AFD), posterior fibular distance (PFD), anterior translation distance (AT), fibular diastasis (FD), anterior-posterior translation (APT), fibular length (FL), and surface area of syndesmosis (SAS) 1.0 and 1.5 which 1.0 cm and 1.5 cm above the tibial plafond was done via preoperative CT scan. The ratio of measurements (Injured/Intact) of the TFO, PFD, APD, and SAS 1.0 showed statistically significant differences. The researchers identified the SAS 1.0 as the most reasonable parameter to predict transfixation using receiver-operating characteristic (ROC) curve analysis. The SAS 1.0 is most valid parameter to predict syndesmotic injuries in this study and these results show that performing a bilateral CT scan on an ankle fracture may provide substantial information in measuring valid parameters.

Patterns and Implications of Early Syndesmotic Screw Failure in Rotational Ankle Fractures

BACKGROUND

The purpose of this study was to identify characteristic patterns of syndesmotic screw (SS) failure, and any effects on clinical outcome.

METHODS

A retrospective study was performed using a consecutive series of patients treated with open reduction and internal fixation with trans-syndesmotic screws for unstable ankle fractures with syndesmotic injury between 2015 and 2017. Patient demographics, fracture characteristics and classification, rates and patterns of trans-syndesmotic screw breakage, and backout were analyzed. Functional outcome was assessed using passive range of motion (ROM) and Maryland Foot Score (MFS).

RESULTS

A total of 113 patients (67%) had intact screws and 56 patients (33%) demonstrated either screw breakage or backout. Patients with SS failure were younger (P = .002) and predominantly male (P = .045). Fracture classification and energy level of injury were not associated with screw failure. Nine screws (11%) demonstrated backout (2 also broke) and 56 other screws broke. There was no association between the number of screws or cortices of purchase and screw failure. There was a trend toward a higher proportion of screw removal (20%) in this failed SS group compared with the intact SS group (12%) (P = .25), but with similar ankle ROM and MFS (P > .07).

CONCLUSION

Syndesmotic screw breakage was common in younger, male patients. Despite similarities in ankle range of motion and clinical outcome scores to patients with intact screws, there was a trend towards more frequent screw removal. This information can be used to counsel patients pre- and postoperatively regarding the potential for screw failure and subsequent implant removal.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Normal Kinematics of the Syndesmosis and Ankle Mortise During Dynamic Movements

Background:

Documenting the healthy articulation of the syndesmosis and talocrural joints, and measurement of 3D medial and lateral clear spaces may improve diagnostic and treatment guidelines for patients suffering from severe syndesmotic injury or chronic instability. This study aimed to define the range of motion (ROM) and displacement of the fibula and talus during static and dynamic activities, and measure the 3D movement in the tibiofibular (syndesmosis) and medial clear space.

Methods:

Six healthy volunteers performed dynamic weightbearing motions on a single-leg: heel-rise, squat, torso twist, and box jump. Participants posed in a nonweightbearing neutral stance as well as weightbearing neutral standing, plantarflexion, and dorsiflexion. High-speed stereoradiography measured 3D rotation and translation of the fibula and talus throughout each task. Medial clear space and tibiofibular gap distances were measured under each condition.

Results:

Total ROM for the fibula was greatest in internal-external rotation (9.3 ± 3.5 degrees), and anteroposterior (3.3 ± 2.2 mm) and superior-inferior (2.5 ± 0.9 mm) translation, rather than lateral widening (1.7 ± 1.0 mm). The total rotational ROM of the talus was greatest in dorsiflexion-plantarflexion (34.7 ± 12.9 degrees) and internal-external rotation (15.0 ± 3.4 degrees). Single-leg squatting increased the lateral clear space (P = .045) and widened the medial tibiofibular joint, whereas single-leg heel-rises decreased the lateral clear space (P = .001) and widened the tibiotalar space. Gap spaces in the tibiofibular and medial clear spaces did not exceed 2.3 ± 0.9 mm and 2.7 ± 1.2 mm, respectively.

Conclusion:

These data support a potential shift in the clinical understanding of fibula displacements during dynamic activities and how implant device constructs might be developed to restore physiologic mechanics.

Clinical Relevance:

Syndesmosis stabilization and rehabilitation should consider restoration of normal physiologic rotation and translation of the fibula and ankle mortise rather than focusing solely on the restriction of lateral translation.

An Assessment of Normal Tibiofibular Anatomy on Lateral Fluoroscopy

BACKGROUND

Intraoperative identification of syndesmotic malreduction during ankle fracture fixation can be challenging. Prior studies describe the normal tibiofibular relationship on anteroposterior and mortise views to aid assessment, but the normal anatomic variation on the lateral view has not been well defined. The aim of this study was to describe the normal anatomy of the lateral radiographic view of the ankle, focusing on the relative position of the fibula and tibial plafond.

METHODS

We retrospectively identified consecutive adults undergoing ankle fracture open reduction internal fixation in 2011-2018. Two independent observers assessed the tibiofibular relationship on perfect lateral images of the uninjured side. Measurements were made in pixels, converted into millimeters using published parameters, and averaged for analysis. Reliability was calculated using Pearson correlation coefficients.

RESULTS

Of 751 cases of adult ankle fracture fixation identified, 50 patients had perfect lateral images of the contralateral side. In 11 patients (22%), the posterior border of the fibula intersected precisely at the posterior edge of the tibial plafond. Ten patients (20%) had anterior intersections, whereas 29 (58%) had posterior intersections. The intersection was within ±2 mm of the plafond edge in 27 patients (54%). Intrarater reliability was 0.86 and 0.93. Interrater reliability was 0.88.

CONCLUSION

In most ankles, the posterior border of the fibula intersects the posterior extent of the tibial plafond within 2 mm. If more than 2 mm away, one should query malreduction, especially if anterior. This method of intraoperative assessment may decrease the occurrence of syndesmotic malreduction.

LEVEL OF EVIDENCE

Level III, comparative series.

Use of Anatomical Landmarks in Ankle Arthroscopy to Determine Accuracy of Syndesmotic Reduction: A Cadaveric Study

Background. The aim of this study was to determine the accuracy of ankle arthroscopy as a means for diagnosing syndesmotic reduction or malreduction and to determine anatomical landmarks for diagnosis. Methods. Six matched-pair cadavers (n = 12) with through-knee amputations were studied. Component parts of the syndesmosis and distal 10 cm of the interosseous membrane (IOM) were sectioned in each. The 12 specimens were divided into 2 groups: 6 specimens in the in-situ group fixed with suture button technique and 6 specimens in the malreduced group rigidly held with a 3.5-mm screw. Specimens were randomized to undergo diagnostic arthroscopy by 3 fellowship-trained foot and ankle orthopaedic surgeons in a blinded fashion. Surgeons were asked to determine if the syndesmosis was reduced or malreduced and provide arthroscopic measurements of their findings. Results. Of 36 arthroscopic evaluations, 34 (94%) were correctly diagnosed. Arthroscopic measurement of 3.5 mm diastasis or greater at the anterior aspect of the distal tibiofibular syndesmosis correlated with a posteriorly malreduced fibula. Arthroscopic evaluation of the Anterior inferior tibiofibular ligament (AITFL), IOM, Posterior inferior tibiofibular ligament (PITFL), lateral fibular gutter, and the tibia/fibula relationship were found to be reliable landmarks in determining syndesmotic reduction. An intraclass correlation coefficient (ICC) for interrater reliability of 1.00 was determined for each of these landmarks between 2 surgeons (P < .001). The ICCs between 2 surgeons' measurements and the computed tomography measurements were found to be 0.896 (P value < .001). Conclusions. Ankle arthroscopy is a reliable method to assess syndesmotic relationship when reduced in situ or posteriorly malreduced 10 mm. Levels of Evidence: Level V: Cadaveric.

Validation of a new method for evaluation of syndesmotic injuries of the ankle

PURPOSE

To define a new parameter in CT that could make imaging of the contralateral ankle dispensable evaluating the position of the fibula after syndesmotic injury.

METHODS

Thirty bilateral CTs of 30 patients were included. Five parameters were defined in axial CT for the injured (_inju) and uninjured (_unin) ankle. Reproducibility was examined for inter-observer and intra-observer reliability. Comparisons for all parameters were performed between the CT scans of both ankles.

RESULTS

All measurements had a high agreement for the inter-observer and intra-observer correlation coefficients. A large interindividual variance could be found between all parameters. If the difference of the anterior tibiofibular distance antTFD_unin and antTFD_inju was less than 2 mm, there was a strong significant pairwise correlation between all parameters between both sides.

CONCLUSION

Bilateral CT is still to be recommended, as it is the only way to exactly assess anterior posterior reduction of the fibula.

Factors associated with adverse events after distal tibiofibular syndesmosis fixation

PURPOSE AND HYPOTHESIS

Factors associated with adverse outcomes following surgery for syndesmotic instability with associated closed fibula fracture are incompletely understood. The purpose of this study was to determine the pathoetiology and incidence of adverse events after stabilization of syndesmotic instability. In addition, we aimed to identify any patient or surgeon related factors that might be associated with unanticipated outcomes.

METHODS

Between January 2000 and May 2015, a total of 849 adult patients who were surgically treated with either screw or suture button fixation for syndesmotic instability with associated fibula fracture without open wound were identified and retrospectively evaluated. Multivariable logistic regression analyses were used to determine factors associated with any postoperative complication or unplanned reoperation.

RESULTS

Within one year after surgery, 10.7% (91 patients) suffered an infectious complication and 22.0% (187 patients) underwent unplanned reoperation. Factors associated with infectious complications were increased duration of hospital admission (OR: 1.08, p = .014), use of an external fixator device before ORIF (OR: 5.19 p < .001), peripheral vascular disease (OR: 4.33, p = .008), and osteoporosis (OR: 2.71, p = .022). For unplanned hardware removal specifically, patients' BMI below 30 was an associated risk factor. (OR: 1.50, p = .010).

CONCLUSION

Certain patient groups have an increased risk of adverse events following the use of current surgical fixation methods for stabilizing the syndesmosis. Patients undergoing surgery for syndesmotic instability with associated fibula fracture without open wound should be counseled that up to 1 in 10 suffer an infectious complication and that 1 in 5 require unplanned hardware removal.

Sagittal ankle position does not affect axial CT measurements of the syndesmosis in a cadaveric model

BACKGROUND

The purpose of this study was to evaluate the effect of ankle plantarflexion and the axial location of measurement on quantitative syndesmosis assessment.

METHODS

Twelve fresh-frozen cadaveric specimens were secured in three positions of ankle plantarflexion (0°, 15°, and 30°) using an ankle-spanning external fixator and underwent CT scans at each position. Syndesmotic measurements were obtained on axial images using three previously described methods (six measurements) at the level of the tibial plafond and 1 cm proximal to the plafond. Method 1 evaluated the distance between the most anterior and posterior aspects of the fibula and tibia. Method 2 measured medial-lateral diastasis of the anterior and posterior aspects of the fibula, and fibular anterior-posterior translation. Method 3 evaluated axial rotation of the fibula. All measurements were performed by two independent observers. Inter-rater reliability of each measurement was evaluated using intra-class coefficients. Repeated measures analysis of variance (RM-ANOVA) was performed to evaluate within-specimen differences in measurements obtained at varying ankle positions.

RESULTS

The anterior incisura component of method 1 demonstrated poor-to-moderate inter-rater reliability across all ankle positions and at both measurement locations. Inter-rater reliability was highest for method 2, especially when measured 1 cm proximal to the plafond. Method 3 demonstrated moderate reliability 1 cm proximal to the plafond. After correcting for multiple comparisons, RM-ANOVA and pairwise analysis revealed that none of the measurements changed significantly with varying ankle position.

CONCLUSION

The inter-rater reliability of the most common method of syndesmotic evaluation (method 1) was found to be lower than in previous studies. The most reliable syndesmotic evaluation can be made by measuring diastasis and anteroposterior translation 1 cm proximal to the plafond (method 2). Ankle position from 0° to 30° of plantarflexion did not change the measurements obtained.

LEVEL OF EVIDENCE

IV.

How Does Perioperative Ketorolac Affect Opioid Consumption and Pain Management After Ankle Fracture Surgery?

BACKGROUND

The investigation of nonnarcotic drug regimens for postoperative pain management is important in addressing the opioid epidemic. NSAIDs can be a powerful adjunct in managing postoperative pain, but the possibility of delayed bone healing is a major concern for orthopaedic surgeons. Our recent retrospective study on ketorolac administration demonstrated that the NSAID is not associated with an increased risk of delayed union or nonunion after ankle fracture surgery.

QUESTIONS/PURPOSES

To determine whether postoperative ketorolac (1) reduces opioid consumption, (2) improves VAS pain control, and (3) affects fracture healing after open reduction and internal fixation of ankle fractures.

METHODS

Between August 2016 and December 2017, 128 patients undergoing open reduction and internal fixation of an acute ankle fracture were randomized before surgery via simple randomization to treatment with or without ketorolac. No patients changed treatment regimen groups or opted out of randomization. All other aspects of perioperative care were treated identically. A once-daily survey was distributed via email on postoperative Days 1 to 7. Unblinded participants were asked to report their daily opioid consumption, pain level, and sleep interference using the VAS, and pain frequency using a five-point Likert scale, and side effects with the VAS. For VAS pain, > 20 mm/100 mm on the VAS scale was required to be considered "improved." In all, 83% (106 of 128) patients completed all seven postoperative surveys with 14 in the control group and eight in the ketorolac group lost to follow-up. Fifty-six patients were administered ketorolac with opioid medication (treatment group) and 50 were administered opioids alone (control group). Participants were comprised of 42% men (44), and 58% women (62); mean age was 48 years. The treating surgeon assessed clinical healing based on the patient's ability to ambulate comfortably at 12 weeks postoperatively. Radiographic healing was assessed by two fellowship-trained orthopaedic foot and ankle surgeons blinded to the patient's name and time since surgery. The surgeons evaluated randomized standard ankle series (anteroposterior, mortise, and lateral) radiographs for resolution of each fracture line to determine fracture union, with delayed union being defined as fracture lines present on radiographs taken at 12-week postoperative visits. Intention-to-treat analysis was performed.

RESULTS

Patients in the treatment group consumed a mean of 14 opioid pills, which was less than the mean of 19.3 opioids pills consumed by patients in the control group (p = 0.037). Patients with ketorolac had lower median VAS scores for pain (p < 0.035) postoperatively on postoperative Days 1 and 2 than did control patients. By contrast, patient-reported pain scores and scores for sleep did not convincingly show a benefit to the use of ketorolac. For patients whose ankle fractures healed at 12 weeks, there was no difference between the groups in terms of clinical healing (p = 0.575) and radiographic healing (p = 0.961).

CONCLUSIONS

In this randomized study, adding ketorolac to the postoperative drug regimen decreased the use of opioid medication after open reduction and internal fixation of ankle fractures in the early postoperative period, and there were mixed, small effects on pain reduction. This NSAID is a valuable tool in helping patients manage postoperative pain with less use of narcotic analgesia. However, our study was underpowered to determine the true safety of this drug in terms of fracture healing and side effects and these questions warrant higher-powered randomized study investigation.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Reliability of distal tibio-fibular syndesmotic instability measurements using weightbearing and non-weightbearing cone-beam CT

BACKGROUND

To investigate the reliability and reproducibility of syndesmosis measurements on weightbearing (WB) cone-beam computed tomography (CBCT) images and compare them with measurements obtained using non-weightbearing (NWB) images.

METHODS

In this IRB-approved, retrospective study of 5 men and 9 women with prior ankle injuries, simultaneous WB and NWB CBCT scans were taken. A set of 21 syndesmosis measurements using WB and NWB images were performed by 3 independent observers. Pearson/Spearman correlation and intra-class correlation (ICC) were used to assess intra- and inter-observer reliability, respectively.

RESULTS

We observed substantial to perfect intra-observer reliability (ICC=0.72-0.99) in 20 measurements. Moderate to perfect agreement (ICC=0.45-0.97) between observers was noted in 19 measurements.

CONCLUSION

Measurements evaluating the distance between tibia and fibula in the axial plane 10mm above the plafond had high intra- and inter-observer reliability. Mean posterior tibio-fibular distance, diastasis, and angular measurement were significantly different between WB and NWB images.

Range of Normal and Abnormal Syndesmotic Measurements Using Weightbearing CT

BACKGROUND

Early recognition of syndesmotic instability is critical for optimizing clinical outcome. Injuries causing a more subtle instability, however, can be difficult to diagnose. The purpose of this study was to evaluate both distal tibiofibular articulations using weightbearing computed tomography (CT) in patients with known syndesmotic instability, thereafter comparing findings between the injured and uninjured sides. We also aimed to define the range of normal measurement variation among patients without syndesmotic injury.

METHODS

Patients with unilateral syndesmotic instability requiring operative fixation (n = 12) underwent preoperative bilateral ankle weightbearing CT. A separate cohort of patients without ankle injury who also underwent bilateral ankle weightbearing CT were included as comparative controls (n = 24). For each weightbearing CT, a series of 7 axial plane tibiofibular joint measurements, including 1 angular measurement, were utilized to evaluate parameters of the syndesmotic anatomy at a level 1 cm above the tibial plafond. Values were recorded by 2 independent observers to assess for interobserver reliability.

RESULTS

Among those with unilateral syndesmotic instability, values differed between the injured and uninjured sides in 4 of the 7 measurements performed including the syndesmotic area: direct anterior, middle, and posterior differences, and sagittal translation (P < .001, < .001, < .001, and < .001, respectively). In the control population without ankle injury, no differences were identified between any of the bilateral measurements (P value range, .172-.961).

CONCLUSION

This study highlights the ability of weightbearing CT to effectively differentiate syndesmotic diastasis among patients with surgically confirmed syndesmotic instability from those without syndesmotic instability. It underscores the substantial utility and importance of using the contralateral, uninjured side as a valid internal control whenever the need for confirming potential syndesmotic instability arises. Prospective studies are necessary to fully understand the accuracy of weightbearing CT in diagnosing occult syndesmotic instability among patients for whom the diagnosis remains in question.

LEVEL OF EVIDENCE

Level III, comparative diagnostic study.

[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.

Diagnostic capability of dynamic ultrasound evaluation of supination-external rotation ankle injuries: a cadaveric study

BACKGROUND

Ankle syndesmosis injuries are common and range in severity from subclinical to grossly unstable. Definitive diagnosis of these injuries can be made with plain film radiographs, but are often missed when severity or image quality is low. Computed tomography (CT) and magnetic resonance imaging (MRI) can provide definitive diagnosis, but are costly and introduce the patient to radiation when CT is used. Ultrasonography may circumvent many of these disadvantages by being inexpensive, efficient, and able to detect injuries without radiation exposure. The purpose of this study was to evaluate the ability of ultrasonography to detect early stage supination-external rotation (SER) ankle syndesmosis injuries with a dynamic external rotational stress test.

METHODS

Nine, all male, fresh frozen specimens were secured to an ankle rig and stress tested to 10 Nm of external rotational torque with ultrasonography at the tibiofibular clear space. The ankles were subjected to syndesmosis ligament sectioning and repeat stress measurements of the tibiofibular clear space at peak torque. Stress tests and measurements were repeated three times and averaged and analyzed using a repeated one-way analysis of variance (ANOVA). There were six ankle injury states examined including: Intact State, 75% of AITFL Cut, 100% of AITFL Cut, Fibula FX - Cut 8 cm proximal, 75% PITFL Cut, and 100% PITFL Cut.

RESULTS

Dynamic external rotation stress evaluation using ultrasonography was able to detect a significant difference between the uninjured ankle with a tibiofibular clear space of 4.5 mm and the stage 1 complete injured ankle with a clear space of 6.0 mm (P < .02). Additionally, this method was able to detect significant differences between the uninjured ankle and the stage 2-4 injury states.

CONCLUSION

Dynamic external rotational stress evaluation using ultrasonography was able to detect stage 1 Lauge-Hansen SER injuries with statistical significance and corroborates criteria for diagnosing a syndesmosis injury at ≥6.0 mm of tibiofibular clear space widening.

Advances in the Surgical Management of Ankle Fractures

Ankle fractures are one of the most common injuries treated by orthopedic surgeons worldwide. However, operative indications, techniques, and reported outcomes following operative fixation vary widely in the literature. This evidence-based review focuses on recent advances in the operative management of ankle fractures including arthroscopic-assisted surgery, deltoid ligament complex repair, expanded indications for posterior malleolus fixation, fibula intramedullary nailing, and dynamic syndesmosis repair.

LEVEL OF EVIDENCE

Level V, expert opinion.

Evaluation of Syndesmosis Reduction on CT Scan

BACKGROUND

Computed tomography (CT) imaging has traditionally been considered the gold standard for evaluation of syndesmostic reduction, but there is no uniformly accepted method to assess reduction. The aim of this study was to evaluate the intra- and interobserver reliability of published measurement techniques for evaluation of syndesmotic reduction on weightbearing CT scan (WBCT) in hopes of determining which method is best.

METHODS

Medical records were reviewed to identify patients who underwent operative stabilization of unilateral syndesmotic injuries. Exclusion criteria included patients younger than 18 years, ipsilateral fractures extending to the tibial plafond, any contralateral ankle fracture or syndesmotic injury, and body mass index greater than 40 kg/m². Twenty eligible patients underwent WBCT evaluation of both ankles at an average of 3 years after syndesmotic fixation. The anatomic accuracy of syndesmotic reduction was evaluated by 2 observers using axial CT images at a level 1 cm proximal to the tibial plafond using 9 previously published radiological measurement techniques. Inter- and intraobserver reliability were assessed for each evaluation method.

RESULTS

The syndesmotic area calculation showed the highest interobserver reliability (0.96), the highest intraobserver reliability for observer 2 (0.97), and the second highest intraobserver reliability for observer 1 (0.92). Fibular rotation had the second highest interobserver reliability in our results (0.84), with intraobserver reliability of 0.91 and 0.8 for first and second observers, respectively. The intraobserver reliability of the side-by-side method was 0.49 and 0.24 for the first and second observers, respectively, and the interobserver reliability was 0.26.

CONCLUSION

Qualitatively assessing syndesmotic reduction via side-by-side comparison with the uninjured ankle had the least intra- and interobserver reliability and should not be relied on to determine syndesmotic reduction quality. In contradistinction, syndesmotic area calculation demonstrated the highest reliability when evaluating syndesmotic reduction, followed by fibular rotation. Given that syndesmotic area measurement techniques are not readily available on standard image viewers, technologically updating image viewers to allow such calculation would make this approach more accessible in clinical practice.

LEVEL OF EVIDENCE

Level IV, case series.

Defining the three most responsive and specific CT measurements of ankle syndesmotic malreduction

PURPOSE

The purpose of this study was to compare the reliability and accuracy of existing computed tomography (CT) methods for measuring the distal tibiofibular syndesmosis in uninjured, paired cadaveric specimens and in simulated malreduction models. It was hypothesized that a repeatable set of measurements exists to accurately and quantitatively describe the typical forms of syndesmotic malreduction using contralateral ankle comparison.

METHODS

Twelve cadaveric lower-leg specimen pairs were imaged with CT to generate models for this study. Thirty-five measurements were performed on each native model. Next, four distinct fibular malreductions were produced via digital simulation and all measurements were repeated for each state: (1) 2-mm lateral translation; (2) 2-mm posterior translation; (3) 7-degree external rotation; (4) the previous three states combined. The modified standardized response mean (mSRM) was calculated for each measurement. To assess rater reliability and side-to-side agreements of the native state measurements, intraclass correlation coefficients (ICC) and Pearson correlation coefficients (PCC) were calculated, respectively.

RESULTS

The most responsive measurements for detecting isolated malreduction were the Leporjärvi clear space for lateral translation, the Nault anterior tibiofibular distance for posterior translation, and the Nault talar dome angle for external rotation of the fibula. These measurements demonstrated fair to excellent inter-rater ICCs (0.64-0.76) and variable side-to-side PCCs (0.14-0.47).

CONCLUSIONS

The most reliable method to assess the syndesmosis on CT was to compare side-to-side differences using three distinct measurements, one for each type of fibular malreduction, allowing assessment of the magnitude and directionality of syndesmosis malreduction. Reliable evaluation is essential for assessing subtle syndesmosis injuries, malreduction and surgical planning.

Ankle Fractures: An Expert Survey of Orthopaedic Trauma Association Members and Evidence-Based Treatment Recommendations

OBJECTIVES

To describe current practice patterns of orthopaedic trauma experts regarding the management of ankle fractures, to review the current literature, and to provide recommendations for care based on a standardized grading system.

DESIGN

Web-based survey.

PARTICIPANTS

Orthopaedic Trauma Association (OTA) members.

METHODS

A 27-item web-based questionnaire was advertised to members of the OTA. Using a cross-sectional survey study design, we evaluated the preferences in diagnosis and treatment of ankle fractures.

RESULTS

One hundred sixty-six of 1967 OTA members (8.4%) completed the survey (16% of active members). There is considerable variability in the preferred method of diagnosis and treatment of ankle fractures among the members surveyed. Most responses are in keeping with best evidence available.

CONCLUSIONS

Current controversy remains in the management of ankle fractures. This is reflected in the treatment preferences of the OTA members who responded to this survey.

LEVEL OF EVIDENCE

Therapeutic Level V. See Instructions for authors for a complete description of levels of evidence.