Impact of Torque on Assessment of Syndesmotic Injuries Using Weightbearing Computed Tomography Scans

2019 ◽  
Vol 40 (6) ◽  
pp. 710-719 ◽  
Author(s):  
Nicola Krähenbühl ◽  
Travis L. Bailey ◽  
Maxwell W. Weinberg ◽  
Nathan P. Davidson ◽  
Beat Hintermann ◽  
...  

Background: The diagnosis of subtle injuries to the distal tibiofibular syndesmosis remains elusive. Conventional radiographs miss a large subset of injuries that present without frank diastasis. This study evaluated the impact of torque application on the assessment of syndesmotic injuries when using weightbearing computed tomography (CT) scans. Methods: Seven pairs of male cadavers (tibia plateau to toe-tip) were included. CT scans with axial load application (85 kg) and with (10 Nm) or without torque to the tibia (corresponding to external rotation of the foot and ankle) were taken during 4 test conditions. First, intact ankles (native) were scanned. Second, 1 specimen from each pair underwent anterior inferior tibiofibular ligament (AITFL) transection (condition 1A), while the contralateral underwent deltoid transection (condition 1B). Third, the lesions were reversed on the same specimens and the remaining intact deltoid or AITFL was transected (condition 2). Finally, the distal tibiofibular interosseous membrane (IOM) was transected in all ankles (condition 3). Measurements were performed to assess the integrity of the distal tibiofibular syndesmosis on digitally reconstructed radiographs (DRRs) and on axial CT scans. Results: Torque impacted DRR and axial CT scan measurements in almost all conditions. The ability to diagnose syndesmotic injuries using axial CT measurements improved when torque was applied. No significant syndesmotic morphological change was observed with or without torque for either isolated AITFL or deltoid ligament transection. Discussion: Torque application had a notable impact on two-dimensional (2-D) measurements used to diagnose syndesmotic injuries for both DRRs and axial CT scans. Because weightbearing conditions allow for standardized positioning of the foot while radiographs or CT scans are taken, the combination of axial load and torque application may be desirable. Clinical Relevance: Application of torque to the tibia impacts 2-D measurements and may be useful when diagnosing syndesmotic injuries by DRRs or axial CT images.

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0009
Author(s):  
Alexej Barg ◽  
Maxwell W. Weinberg ◽  
Nathan P. Davidson ◽  
Beat Hintermann ◽  
Charles L. Saltzman ◽  
...  

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


2007 ◽  
Vol 36 (2) ◽  
pp. 348-352 ◽  
Author(s):  
Atsushi Teramoto ◽  
Hideji Kura ◽  
Eiichi Uchiyama ◽  
Daisuke Suzuki ◽  
Toshihiko Yamashita

Background Rupture of the distal tibiofibular syndesmosis commonly occurs with extreme external rotation. Most studies of syndesmosis injuries have concentrated only on external rotation instability of the ankle joint and have not examined other defects. Hypothesis Syndesmosis injuries cause multidirectional ankle instability. Study Design Controlled laboratory study. Methods Ankle instability caused by distal tibiofibular syndesmosis injuries was examined using 7 normal fresh-frozen cadaveric legs. The anterior tibiofibular ligament, interosseous membrane, and posterior tibiofibular ligament, which compose the distal tibiofibular syndesmosis, were sequentially cut. Anterior, posterior, medial, and lateral traction forces, as well as internal and external rotation torque, were applied to the tibia; the diastasis between the tibia and fibula and the angular motion among the tibia, fibula, and talus were measured using a magnetic tracking system. Results A medial traction force with a cut anterior tibiofibular ligament significantly increased the diastasis from 1.1 to 2.0 mm ( P = .001) and talar tilt angles from 9.6° to 15.2° ( P < .001). External rotation torque significantly increased the diastasis from 0.5 to 1.8 mm ( P= .009) with a complete cut; external rotation torque also significantly increased rotational angles from 7.1° to 9.4° ( P = .05) with an anterior tibiofibular ligament cut. Conclusion Syndesmosis injuries caused ankle instability with medial traction force and external rotation torque to the tibia. Clinical Relevance Both physicians and athletes should be aware of inversion instability of the ankle joint caused by tibiofibular syndesmosis injuries.


2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0001
Author(s):  
Alexej Barg ◽  
Maxwell W. Weinberg ◽  
Nathan P. Davidson ◽  
Beat Hintermann ◽  
Charles L. Saltzman ◽  
...  

Category: Ankle, Trauma, Imaging Introduction/Purpose: Injury to the distal tibio-fibular syndesmosis is common and appears in up to 20% of patients with an ankle sprain or ankle fracture. While pronounced injuries can be reliably diagnosed using conventional radiographs, assessment of subtle syndesmotic injuries is challenging. With the introduction of weightbearing CT (WBCT) scans, detailed assessment of foot and ankle disorders under load bearing conditions became possible. The purpose of this cadaver study was to assess the influence of weight on assessment of incomplete and more complete syndesmotic injuries using two-dimensional (2D) measurements on axial CT images. We hypothesized that weight would significantly impact assessment of both incomplete and more complete injuries to the distal tibio-fibular syndesmosis. Methods: Fourteen paired male cadavers (tibial plateau to toe-tip) were included. A radiolucent frame held specimens in a plantigrade position while both non-weightbearing and weightbearing CT scans were taken. Four conditions were tested: First, intact ankles (Native) were scanned. Second, one specimen from each pair underwent anterior inferior tibio-fibular ligament (AITFL) transection (Condition 1A), while the contralateral underwent deltoid transection (Condition 1B). Third, the remaining intact deltoid or AITFL was transected (Condition 2). Finally, the distal tibio-fibular interosseous membrane (IOM) was transected in all ankles (Condition 3). For each condition, non-weightbearing, half-bodyweight (42.5 kg), and full-bodyweight (85 kg) CT scans were taken. Six measurements were performed to assess the integrity of the distal tibio-fibular syndesmosis on axial CT scans 1 cm above the ankle joint (Figure 1A/ B) and two measurements at the level of the talar surface (Figure 1C). Inter- and intra- observer agreement were additionally calculated. Results: Inter- and intra-observer agreement differed between measurements. Excellent agreement was evident for the tibio- fibular clear space (TFCS) and tibio-fibular overlap (TFO) with an intra-observer agreement of 0.79 and 0.94, respectively. Poor agreement was evident for Angle 1 (inter-observer, 0.39). Agreement of the other measurements (inter- and intra-observer) was either rated as fair or good and ranged from 0.44 to 0.71. Weightbearing had no significant influence on measurements. Only more complete injuries (Condition 3) differed from native ankles when using either the anterior tibio-fibular distance (ATFD) or TFO. For these two measurements, no significant differences were observed within each condition between non-, half-, and full- weightbearing. Also, no significant differences were evident between single AITFL and deltoid ligament transection for the ATFD and TFO. Conclusion: Load application does not impact the ability of WBCT scans to diagnose incomplete and also more complete syndesmotic injuries in a cadaver model. The utility of current 2D measurements on axial WBCT scans for diagnosing incomplete syndesmotic injuries is questionable. Nevertheless, the ability to reliably position the foot during imaging is an advantage of WBCT technology over other imaging options. Further investigations using more precise measurement options (e.g. 3-dimensional [3D] measurements) are necessary to better understand the potential role of weight bearing to diagnose syndesmotic injuries with CT scan imaging technology.


2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0009
Author(s):  
Alexej Barg ◽  
Maxwell W. Weinberg ◽  
Nathan P. Davidson ◽  
Arne Burssens ◽  
Beat Hintermann ◽  
...  

Category: Hindfoot, Trauma Introduction/Purpose: Accurate assessment of subtalar joint stability is difficult. Weightbearing CT (WBCT) scans have increased in popularity among foot and ankle surgeons as it offers an accurate representation of hindfoot joint alignment under weightbearing conditions. However, the clinical utility of this imaging modality to diagnose subtalar joint instability has yet to be investigated. The purpose of this study was to assess the impact of load and torque application on the assessment of subtalar joint instability when using WBCT scans. We hypothesized that load and torque application would improve the ability to identify subtalar joint instability. Methods: Fourteen paired male cadavers (tibial plateau to toe-tip) were included. A radiolucent frame held specimens in a plantigrade position while non-weightbearing and weightbearing CT scans (with and without torque application) were taken. First, intact ankles (Native) were scanned. Second, one specimen from each pair underwent interosseous talo-calcaneal ligament (ITCL) transection (Condition 1A), while the contralateral underwent calcaneo-fibular ligament (CFL) transection (Condition 1B). Third, the lesions were reversed on the same specimens and the remaining intact ITCL or CFL was transected (Condition 2). Finally, the deltoid ligament was transected in all ankles (Condition 3). Two radiographic measurements were performed on the level of the ankle joint (talar tilt [TT], anterior talar translation [ATT]), while the subtalar tilt (STT) was measured at the anterior, middle, and posterior plane of the subtalar joint. Inter- and intra-observer agreement calculations were additionally performed. Results: Weight did not impact most measurements, while the majority of measurements differed significantly within each condition after torque application. Measurements performed at the level of the subtalar joint were more reliable and better predictors for subtalar joint instability compared to measurements performed at the level of the ankle joint. Discrete ITFL, combined ITFL/ CFL, and combined ITFL/ CFL/ deltoid ligament injuries had significantly different STT values than native ankles (Figure 1). Conclusion: Measurements to assess the stability of the subtalar joint should primarily be performed at the level of the subtalar joint rather than at the level of the ankle joint when using WBCT scans. Torque application is crucial for identifying subtalar joint instability, while the application of load should be avoided. Future clinical studies will therefore face substantial technical challenges should they attempt to determine the clinical utility of WBCT scans for assessment of subtalar joint instability.


2006 ◽  
Vol 13 (6) ◽  
pp. 311-316 ◽  
Author(s):  
Mark O Turner ◽  
John R Mayo ◽  
Nestor L Müller ◽  
Michael Schulzer ◽  
J Mark FitzGerald

BACKGROUND: Computed tomography (CT) scans are used extensively to investigate chest disease because of their cross-sectional perspective and superior contrast resolution compared with chest radiographs. These advantages lead to a more accurate imaging assessment of thoracic disease. The actual use and evaluation of the clinical impact of thoracic CT has not been assessed since scanners became widely available.OBJECTIVE: To identify patterns of utilization, waiting times and the impact of CT scan results on clinical diagnoses.DESIGN: A before and after survey of physicians who had ordered thoracic CT scans.SETTING: Vancouver General Hospital – a tertiary care teaching centre in Vancouver, British Columbia.SUBJECTS: Physicians who had ordered CT scans.INTERVENTION: Physicians completed a standard questionnaire before and after the CT scan result was available.MEASUREMENTS: Changes in the clinical diagnosis, estimates of the probabilities for the diagnosis both before and after the CT scan, and waiting times.RESULTS: Four hundred fifty-four thoracic CT cases had completed questionnaires, of whom 80% were outpatients. A change in diagnosis was made in 48% of cases (25% with a normal CT scan and 23% with CT scan findings that indicated a different diagnosis). The largest change in probability scores for the clinical diagnosis before and after the CT scan was 43.9% for normal scans, while it was 36.3% for a different diagnosis and 26.3% for the same diagnosis. High-priority scans were associated with decreased waiting time (−7.89 days for each unit increase in priority).CONCLUSIONS: The CT scan results were associated with a change in diagnosis in 48% of cases. Normal scans constituted 25% of the total and had the greatest impact scores. Waiting times were highly correlated with increased urgency of the presenting problem.


2021 ◽  
pp. 219256822110468
Author(s):  
Zachariah W. Pinter ◽  
Ryder Reed ◽  
Sarah E. Townsley ◽  
Anthony L Mikula ◽  
Lauren Dittman ◽  
...  

Study Design Retrospective cohort study Objective Substantial variability in both the measurement and classification of subsidence limits the strength of conclusions that can be drawn from previous studies. The purpose of this study was to precisely characterize patterns of cervical cage subsidence utilizing computed tomography (CT) scans, determine risk factors for cervical cage subsidence, and investigate the impact of subsidence on pseudarthrosis rates. Methods We performed a retrospective review of patients who underwent one- to three-levels of anterior cervical discectomy and fusion (ACDF) utilizing titanium interbodies with anterior plating between the years 2018 and 2020. Subsidence measurements were performed by two independent reviewers on CT scans obtained 6 months postoperatively. Subsidence was then classified as mild if subsidence into the inferior and superior endplate were both ≤2 mm, moderate if the worst subsidence into the inferior or superior endplate was between 2 to 4 mm, or severe if the worst subsidence into the inferior or superior endplate was ≥4 mm. Results A total of 51 patients (100 levels) were included in this study. A total of 48 levels demonstrated mild subsidence (≤2 mm), 38 demonstrated moderate subsidence (2-4 mm), and 14 demonstrated severe subsidence (≥4 mm). Risk factors for severe subsidence included male gender, multilevel constructs, greater mean vertebral height loss, increased cage height, lower Taillard index, and lower screw tip to vertebral body height ratio. Severe subsidence was not associated with an increased rate of pseudarthrosis. Conclusion Following ACDF with titanium cervical cages, subsidence is an anticipated postoperative occurrence and is not associated with an increased risk of pseudarthrosis.


Author(s):  
Feng Wei ◽  
John W. Powell ◽  
Roger C. Haut

Numerous studies on the mechanisms of ankle injury deal with injuries to the syndesmosis and anterior ligamentous structures, but previous sectioning and clinical studies also describe the important role of the posterior talofibular ligament (PTaFL) in the ankle’s resistance to external rotation of the foot. Foot constraint may influence subtalar motion and the movement of the bones in the foot, thereby influencing the mode of injury during external rotation [1]. Stiehl et al. [2] constrain the foot with fiberglass cast tape, externally rotate the foot 90°, and produce injury to the deltoid ligament and anterior tibiofibular ligament (ATiFL) with bone fracture. In contrast, Stormont et al. [3] fix the foot in a potting alloy and conclude the primary ligamentous restraints to external rotation are the PTaFL and calcaneofibular ligament (CaFL).


2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0035
Author(s):  
Huang Qiang ◽  
Xu Xiangyang

Category: Arthroscopy, Trauma Introduction/Purpose: To investigate clinical significance of ankle arthroscopy in the diagnosis of type B ankle fracture associated with the distal tibiofibular syndesmosis injury. Methods: From February 2014 to December 2016, the authors diagnosed and treated 35 cases of type B ankle fractures. including 23 males and 12 females; with an average age of (43.05±12.480) years. Each patient underwent preoperative assessment: according to the patient’s clinical manifestations and imaging examination, and before the operation and after internal fixation of ankle fracture, the Cotton test and the external rotation test were done in the C arm X-ray, the initial diagnosis whether there is the distal tibiofibular syndesmosis injury. When the Cotton test and the external rotation test was used, Ankle arthroscopy was used to observe and evaluate whether there is the distal tibiofibular syndesmosis injury. For patients with the distal tibiofibular syndesmosis injury, In addition to the internal fixation of the ankle fracture, the TightRope was used to repair the injury. And observation of repair effect by ankle arthroscopy. Results: After internal fixation of ankle fracture, the Cotton test and the external rotation test was performed under the C arm X-ray, there were no the distal tibiofibular syndesmosis injury in 22 patients. Preoperative CT showed 6 cases of combined the distal tibiofibular syndesmosis injury, Preoperative MRI showed 13 cases of combined the distal tibiofibular syndesmosis injury. Ankle arthroscopy confirmed 11 cases of combined the distal tibiofibular syndesmosis injury. The sensitivity of ankle arthroscopy and MRI diagnosis combined with the distal tibiofibular syndesmosis injury was higher than that of CT sensitivity(P<0.05). The sensitivity of ankle arthroscopy for the diagnosis of the distal tibiofibular syndesmosis injury was weaker than that of MRI in the diagnosis of the distal tibiofibular syndesmosis injury (P<0.05). MRI diagnosis of the distal tibiofibular syndesmosis injury can be false positive. Conclusion: Ankle arthroscopy can directly observe the medial triangle ligament of the ankle, the distal tibiofibular syndesmosis injury, which provides the basis for correct diagnosis and treatment of Type B ankle fracture with the distal tibiofibular syndesmosis injury. And it can evaluate the stability of ankle after repairing the distal tibiofibular syndesmosis injury.


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