Mortise Radiographs Research Articles

Radiographic evaluation of the normal ankle joint in children and adolescent.

The purpose of this study was to determine the reliability of numerous radiographic measurements of the skeletally immature ankle joint, timing of ossification of medial malleolus and appearance of tibial incisura and differences in the values of radiographic measurements based on age and sex. This study included 590 subjects (0-15 years), who underwent ankle AP, lateral and mortise radiographs. Presence of the medial malleolus and incisura fibularis were recorded. Tibiofibular overlap, tibiofibular clear space, medial clear space, talar tilt, talocrural angle, relative fibular width and fibular position were measured. All radiographic measurements showed good to excellent intraobserver and interobserver reliability (ICCs, 0.603 to 0.949). The timing of ossification of medial malleolus and appearance of tibial incisura between boys and girls were not different. Tibiofibular clear space on mortise views, and medial clear space on AP and mortise view significantly decreased by age. Tibiofibular overlap on AP and mortise views, relative fibular width on AP view significantly increased by age. Talocrural angle, tibiofibular overlap on AP view, tibiofibular clear space on AP and mortise views, medial clear space on AP and mortise views and fibular position were significantly larger in boys than in girls. The difference in tibiofibular overlap, tibiofibular clear space and medial clear space on AP view of both sides was <50% in 97.1%, 93.1%, and 97.2% of patients, respectively. The difference in tibiofibular overlap, tibiofibular clear space and medial clear space on mortise view of both sides was <50% in 98.0%, 96.5%, and 100% of patients, respectively. For skeletally immature patients, the criteria for absolute radiographic values used in adults to assess distal tibiofibular syndesmosis or deltoid ligament injury cannot be applied, but comparison of both sides of ankle joint could help physicians to predict the need for additional evaluations.

Utility of Third-Week Postoperative Radiographs in the Management of Ankle Fractures.

To evaluate the costs and efficacy of radiographs taken in the third week after fixation of bimalleolar and trimalleolar fractures. A retrospective evaluation was made of patients who underwent surgical fixation because of bimalleolar and trimalleolar fractures between January 1, 2008, and October 1, 2013. Patient demographics (age, gender, body mass index), fracture type, follow-up periods, and fixation methods were recorded, and the radiographs taken on postoperative day 1, at 3 weeks, 6 weeks, and the final follow-up were examined by 2 orthopedists. Measurements were taken of the medial clear space (MCS ≤ 4 mm), the tibiofibular clear space (TFCS < 5 mm), and the talocrural angle (TCA = 83° ± 4°) on the mortise radiograph and of the overlap between the tibial tubercle and fibula (TFO > 10 mm) on the anteroposterior radiograph; residual step (mm) was measured on the lateral radiograph. A total of 263 patients were examined, and of these, 112 were included for evaluation. In the measurements of postoperative day 1, third week, and sixth week and the final radiographs, no statistically significant difference was determined in the MCS, TFCS, TCA, TFO, and residual step values. Because the cost of a series of 3-way ankle radiographs in Turkey is US$3.81 per patient, the cost of the control series for the 112 patients in this study was US$ 427.3. In patients treated surgically for bimalleolar and trimalleolar fractures, the radiographs taken in the third week rarely resulted in a change of patient management. Therefore, it simply constitutes an additional cost for the patient or the hospital. Level III: Retrospective Cohort study.

Syndesmotic screw fixation in tibiofibular diastasis

In chronic instability of syndesmosis, osteoarthritis and poor functional outcome were seen more prevalently. To avoid diastasis of ankle joint, the affected distal tibiofibular syndesmosis should be restored. We evaluated the clinical and radiological results of operative treatment of ankle fractures in patients who required syndesmotic stabilization. Twenty-one patients operated for ankle fracture were evaluated. Patients were followed up for 12 to 81 months, with a mean value of 49 months. Anteroposterior (AP), lateral, and mortise radiographs were taken at the follow-up period, and AP tibiofibular distance, lateral fibular distance, and medial mortise distance were measured on the preoperative, postoperative, and last follow-up radiographs. At the last follow-up, patients were evaluated clinically with Hannover scoring system. The decrease in AP tibiofibular distance was statistically significant postoperatively in Weber Type B and C fractures. The mean preoperative AP tibiofibular distance which was 7.1 mm decreased to 3.6 mm after operation. There was no statistically significant relation between the amount of decrease and fracture type, either Weber B or C. At the same time, the AP tibiofibular distance did not change at the last follow-up. At the last follow-up clinical evaluation, patient scores were ranging from 74 to 94, with a mean value of 86, which was designated as a fair result. In ankle fractures, if diastasis of distal tibiofibular joint is present, syndesmosis should be fixed for both Weber Type B and C fractures. The most important predictor of good clinical outcome is accurate reduction of the syndesmosis.

Radiographic Assessment of Fibular Length Variance: The Case for “Fibula Minus”

Given the high prevalence of ankle fractures and morbidity of malalignment after fixation, an appropriate anatomic relationship between the distal fibula and adjacent tibia and talus is important. The tip of the lateral malleolus of the fibula has often been described to be at the level of the lateral talar process. However, no studies to date have examined the relationship of the distal fibular tip to the lateral process of the talus. We assessed 66 weightbearing mortise radiographs for variability of the distal fibular tip in relation to the lateral process of the talus. The subjects were all skeletally mature, with a mean age of 45.3 ± 14.6 years. We used a paired t test with a null hypothesis that the true mean difference in the distance from the distal fibula to the lateral process was equal to 0. The mean distance of the distal tip of the fibula was 0.257 ± 0.127 cm proximal to the tip of the lateral process of the talus. The 95% confidence interval was 0.226 to 0.288. Of the 66 subjects, 65 had the distal tip of the fibula proximal to the lateral process of the talus, corresponding to a negative fibular variance. In the remaining subject, the distal tip of the fibula was at the same level of the tip as the lateral process of the talus. The distal tip of the fibula is most commonly not at the level of the talus lateral process, as often described in published reports. Instead, it has a variance analogous to the relationship between the lengths of the ulna compared with the radius. The distal tip of the fibula in our study was more often proximal to the tip of the lateral process of the talus and can be described as a negative fibular variance, or “fibula minus.”

Radiographic markers for measuring tibial rotation based on CT-reconstructed radiographs: an accuracy and feasibility study.

Malreduction in the axial plane (malrotation) following tibial fracture surgery is often undiagnosed. A few clinical and radiographic methods have been proposed for measuring tibial rotation intraoperatively, yet have failed to match the accuracy of computed tomography (CT). The aim of this study was to develop radiographic tools for future intraoperative assessment of the tibial shaft rotation profile. The setting was a laboratory computerized analysis. Twenty lower limb CT scans were used to construct a three-dimensional (3D) model using AMIRA© software. A virtual 3D cylinder was implanted in the posterior condylar line and in the transmalleolar axis. The 3D models were used to simulate four standard knee and ankle plain radiographs. On each radiograph, four landmarks were depicted by two observers and their relation with the cylinder was measured and analyzed for accuracy and reproducibility. A cadaveric lower leg was implanted with two Kirschner wires. A CT scan was performed in addition to 2D fluoroscopy. The simulated radiographs and the fluoroscopy were compared for accuracy. Measurement of the landmarks showed reliability in most of the knee anteroposterior and ankle mortise radiographs (coefficients of variation <0.01 and =0.01) respectively. Cadaveric measurement of the landmarks using real fluoroscopy and simulated radiographs were similar. To date, no reliable and common methods have been reported for the evaluation of tibial axial rotation. We propose a model in which simple radiographic landmarks can be used to calculate a 3D coordinate system that accurately assesses the axial rotation angle of the tibial shaft.

A Cross-sectional Analysis of Radiographic Ankle Osteoarthritis Frequency and Associated Factors: The Johnston County Osteoarthritis Project.

Because there are no epidemiologic data regarding the frequency of ankle osteoarthritis (OA) in a general population, we sought to analyze this disabling condition in a large, well-characterized, community-based cohort of older individuals. Cross-sectional data, including ankle radiographs, were from the most recent data collection (2013-2015) of the Johnston County OA Project. Radiographic ankle OA (rAOA) was defined as a Kellgren-Lawrence arthritis grading scale of ≥ 2 on weight-bearing lateral and mortise radiographs. The presence of pain, aching, or stiffness in the ankles as well as history of ankle injury (limiting ability to walk for at least 2 days) were assessed. Chi-square statistics (categorical variables) and Student t tests (continuous variables) were used to compare all participant characteristics by rAOA status. Joint-based logistic regression models with generalized estimating equations were used to examine associations of rAOA and covariates of interest [age, body mass index (BMI), sex, race, ankle symptoms, and injury history]. Of 864 participants with available data, 68% were women, 34% were African American, with a mean age of 72 years and BMI of 31 kg/m2. Nearly 7% of this sample had rAOA. Increasing age, high BMI, history of ankle injury, and presence of ankle symptoms were all independently associated with greater odds of having rAOA; no significant differences were seen by sex or race. The frequency of rAOA was higher than estimates generally quoted in the literature. While injury was an important contributor, other factors such as age, BMI, and symptoms were also significantly associated with rAOA.

Radiographic Evaluation of the Normal Ankle Joint in Children and Adolescent

Category: Ankle Introduction/Purpose: Although comparison to radiographic standards for ankle joint is critical for evaluation of syndemosis injuries, such standards are not well defined for children and adolescents. The purpose of this study was to determine the reliability of numerous radiographic measurements of the skeletally immature ankle joint, timing of ossification of medial malleolus and appearance of tibial incisura and differences in the values of radiographic measurements based on age and sex. Methods: This study included 590 subjects (0 to 15 years), who underwent ankle AP, lateral and mortise radiographs. Presence of the medial malleolus and incisura fibularis were recorded (Fig 1). Tibiofibular overlap, tibiofibular clear space, medial clear space, talar tilt, talocrural angle, relative fibular width and fibular position were measured (Fig 2). A inter- and intrareliability test was conducted before the main measurements using intraclass correlation coefficients (ICC). To determine the timing of the ossification center of medial malleolus and appearance of tibial incisura, multinomial logistic regression was used. The generalized linear model was used to estimate the radiographic measurements by age and sex. The 100-quantiles were calculated to determine the normal value of the tibiofibular clear space, tibiofibular overlap and medial clear space. Results: All radiographic measurements showed good to excellent intraobserver(ICC, 0.603–0.934) and interobserver reliability(ICC, 0.704–0.972). The timing of ossification of medial malleolus and appearance of tibial incisura between boys and girls were not different. Tibiofibular clear space on mortise view, and medial clear space on AP and mortise view significantly decreased by age. Tibiofibular overlap on AP and mortise views, relative fibular width on AP view significantly increased by age. Talocrural angle, tibiofibular overlap on AP view, tibiofibular clear space on AP and mortise views, medial clear space on AP and mortise views and fibular position were significantly larger in boys than in girls. The difference in tibiofibular overlap, tibiofibular clear space and medial clear space on mortise view of both sides was &lt; 50% in 98.1%, 99.3%, and 100% of patients, respectively. Conclusion: Tibiofibular clear space, tibiofibular overlap and medial clear space can be parameter to assess distal tibiofibular syndesmosis or deltoid ligament injury in skeletally immature patients. For these patients, the criteria of absolute radiographic values used in adults cannot be applied, but comparison of both sides could help physicians to predict the need for additional evaluations.

Radiographic Identification of the Deltoid Ligament Complex of the Medial Ankle

Background: An injury to the deltoid ligament complex of the ankle can require surgical intervention in cases of chronic instability. There is an absence of data describing medial ankle ligament anatomy on standard radiographic views. Purpose: To quantitatively describe the anatomic origins and insertions of the individual ligamentous bands of the superficial and deep deltoid on standard lateral and mortise radiographic views with reference to osseous landmarks and anatomic axes. Study Design: Descriptive laboratory study. Methods: Twelve nonpaired, fresh-frozen cadaveric foot and ankle specimens were utilized. Specimens were dissected free of all overlying soft tissue to identify individual ligamentous bands of the superficial and deep deltoid ligaments and to isolate their distinct origins and insertions. Footprint centers were identified on standard lateral and mortise radiographs by 2-mm stainless steel spheres embedded at the level of the cortical bone. Distances to osseous landmarks were measured independently by 2 blinded reviewers to calculate mean distances and evaluate reliability and repeatability measures using intraclass correlation coefficients. Results: Varying subsets of the 4 superficial deltoid bands including the tibionavicular (12/12), tibiospring (12/12), tibiocalcaneal (9/12), and superficial posterior tibiotalar (9/12) ligaments were found across specimens. On the lateral view, the tibionavicular ligament was the most anterior and attached 7.6 ± 1.9 mm superior and anterior to the inferior tip of the medial malleolus. The tibiospring ligament attached 12.1 ± 2.2 mm superior and anterior to the inferior tip of the medial malleolus and attached to the spring ligament, which coursed from its origin 12.3 ± 1.6 mm anterior and slightly inferior to the posterior point of the sustentaculum tali to its insertion on the navicular tuberosity. The tibiocalcaneal ligament and superficial posterior tibiotalar ligament were found posteriorly in the majority of specimens. Two constituents of the deep deltoid, including the deep anterior tibiotalar (11/12) and deep posterior tibiotalar (12/12) ligaments, were found in the majority of specimens. The deep posterior was larger and coursed from the tibia, 8.1 ± 2.2 mm posterior and superior to the inferior tip of the medial malleolus, to its attachment on the talus, 15.5 ± 2.4 mm superior and anterior to the posterior inferior point of the talus on the lateral view. Conclusion: Quantitative radiographic relationships describing the anatomic origins and insertions of the individual superficial and deep deltoid constituents were defined with excellent reliability and reproducibility. Clinical Relevance: Radiographic parameters will augment current anatomic data by assisting with preoperative planning, intraoperative guidance, and postoperative assessment. These radiographic guidelines will facilitate the development of novel anatomic reconstructions and allow surgeons to plan the locations of reconstruction tunnels.

Outcomes and Return to Activity After Operative Repair of Chronic Latent Syndesmotic Instability.

This study is a retrospective review of prospectively gathered data determining the postoperative outcomes of patients who underwent operative treatment to address chronic syndesmotic instability. The cohort is composed of 19 individuals who elected to undergo operative treatment of chronic syndesmotic instability. The operative repair consisted of arthroscopic debridement in all cases with reduction and suture button fixation of those patients who had greater than 4 mm of syndesmotic diastasis on arthroscopic evaluation. All patients had a minimum of 24 months follow-up. This study retrospectively examined the prospectively gathered preoperative and postoperative outcome scores to include a Visual Analog Scale (VAS) pain score and an American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score. In addition, patients were questioned on their ability to return to their preinjury level of activity and their ability to continue running sports. Fourteen patients returned their postoperative surveys. Mean AOFAS scores improved significantly from 48 to 82.7 (P = .014). Mean VAS scores improved from 6.1 to 1.0 (P = .002). Overall, 86% (12/14) of patients were able to return to running and 79% (11/14) of patients were able to return to their preinjury level of sport. Preoperative and postoperative weight-bearing ankle radiographs were reviewed to evaluate the tibiofibular clear space and overlap. The clear space measured on anteroposterior (AP) radiographs decreased from 5.4 mm to 4.6 mm (P = .005), the clear space evaluated on the mortise radiograph decreased from 4.5 mm to 3.6 mm (P = .006), and the overlap measured on the AP radiograph increased from 5.7 mm to 6.9 mm (P = .019). All radiographs were measured by a board-certified musculoskeletal radiologist. This study presents a treatment method that can be instituted at the time of diagnosis for syndesmotic injuries with greater than 4 mm of diastasis that were treated with debridement and stabilization. The results of this treatment technique are promising, with significant improvements in subjective outcome scores and a high rate of return to running sports. Level IV, retrospective case series.

Radiographic identification of the primary structures of the ankle syndesmosis.

The purpose of this study was to quantitatively describe the locations of the syndesmotic ligaments and the tibiofibular articulating cartilage surfaces on standard radiographic views using reproducible radiographic landmarks and reference axes. Twelve non-paired ankles were dissected to identify the anterior-inferior tibiofibular ligament (AITFL), posterior-inferior tibiofibular ligament (PITFL), interosseous tibiofibular ligament (ITFL), and the cartilage surfaces of the syndesmosis. Structures were marked with 2-mm radiopaque spheres prior to obtaining lateral and mortise radiographs. Measurements were performed by two independent raters to assess intra- and interobserver reliability via intraclass correlation coefficients (ICCs). Measurements demonstrated excellent agreement between observers and across trials (all ICCs≥0.960). On the lateral view, the AITFL tibial origin was 9.6±1.5mm superior and posterior to the anterior tibial plafond. Its fibular insertion was 4.4±1.7mm superior and posterior to the anterior fibular tubercle. The centre of the tibial cartilage facet of the tibiofibular contact zone was 8.4±2.1mm posterior and superior to the anterior plafond. The proximal and distal aspects of the ITFL tibial attachment were 45.9±7.9 and 12.4±3.4mm proximal to the central plafond, respectively. The superficial and deep PITFL coursed anterior and distally from the posterior tibia to fibula. On the mortise view, the AITFL tibial attachment centre was 5.6±2.4mm lateral and superior to the lateral extent of the plafond (4.3mm lateral, 3.3mm superior), and its fibular insertion was 21.2±2.1mm superior and medial to the inferior tip of the lateral malleolus. Quantitative radiographic guidelines describing the locations of the primary syndesmotic structures demonstrated excellent reliability and reproducibility. Defined guidelines provide additional clinically relevant information regarding the radiographic anatomy of the syndesmosis and may assist with preoperative planning, augment intraoperative navigation, and provide additional means for objective postoperative assessment.

Radiographic Identification of the Syndesmotic Structures of the Ankle

Objectives:Syndesmotic ligament sprains may result in significant time lost from sport and can lead to chronic pain and instability. While syndesmotic anatomy has been well-defined, quantitative radiographic guidelines for identifying the anatomic ligament attachment sites and tibiofibular cartilage surfaces have not been adequately defined. The purpose was to define quantitative radiographic guidelines for identifying the origins and insertions of the syndesmotic ligaments and tibiofibular articulating cartilage surfaces with respect to radiographic landmarks and standard reference lines.Methods:Twelve non-paired fresh-frozen ankles were dissected to identify the attachments of the anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), interosseous tibiofibular ligament (ITFL), and the cartilage surfaces of the tibiofibular articulation. The center of each structure was marked with a 2 mm radiopaque sphere at the level of the cortex. Standard lateral and mortise radiographs were obtained using a fluoroscopy c-arm and calibrated using a 25.4 mm diameter radiopaque sphere positioned in the field of view. Using a picture archiving and communications system, measurements were performed twice by two independent raters to calculate intra- and inter-rater reliability via intraclass correlation coefficients (ICCs).Results:Measurements demonstrated excellent agreement between raters and across trials (All inter- and intra-rater ICCs ≥ 0.960) for all structures and radiographic views. On the lateral view, the AITFL tibial origin was 9.6 ± 1.5 mm superior and posterior to the anterior tibial plafond (Table 1). Its fibular insertion was 4.4 ± 1.7 mm superior and posterior to the anterior fibular tubercle. The superficial PITFL originated 7.4 ± 1.6 mm superior to the posterior plafond and inserted 22.0 ± 2.3 mm superior and posterior to the lateral malleolus. The corresponding measurements for the deep PITFL were 3.2 ± 1.5 mm superior and 15.4 ± 3.4 mm superior and posterior, respectively. The proximal and distal edges of the ITFL tibial origin were 45.9 ± 7.9 mm and 12.4 ± 3.4 mm proximal to the central aspect of the plafond respectively. The center of the tibiofibular contact area was 8.4 ± 2.1 mm posterior and superior to the anterior plafond. On the mortise view, the AITFL tibial attachment was 5.6 ± 2.4 mm medial and superior to the lateral extent of the plafond and its fibular insertion was 21.2 ± 2.2 mm superior and medial to the lateral malleolus. The corresponding superficial PITFL measurements were 2.7 ± 1.7 mm and 21.5 ± 3.2 mm respectively. The ITFL distal tibial margin was 11.1 ± 3.5 mm proximal to the tibial plafond.Conclusion:Radiographic measurements demonstrated excellent agreement among reviewers and across trials suggesting clinical reproducibility and surgical utility of the defined parameters. Regardless of the type of surgical treatment, these parameters will assist with preoperative planning, augment intraoperative navigation, and provide additional means for objective post-operative assessment of hardware and tunnel placement. Furthermore, radiographic landmarks may be of particular use in revision or arthroscopic assisted cases where surgical landmarks may be obscured or not readily visible.

Radiographic Identification of the Primary Lateral Ankle Structures

Background: Lateral ankle ligament injuries rank among the most frequently observed athletic injuries, requiring repair or reconstruction when indicated. However, there is a lack of quantitative data detailing the ligament attachment sites on standard radiographic views. Purpose: To quantitatively describe the anatomic attachment sites of the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and posterior talofibular ligament (PTFL) on standard radiographic views with respect to reproducible osseous landmarks to assist with intraoperative and postoperative assessment of lateral ankle ligament repairs and reconstructions. Study Design: Descriptive laboratory study. Methods: Twelve nonpaired, fresh-frozen cadaveric foot and ankle specimens were dissected to identify the origins and insertions of the 3 primary lateral ankle ligaments. Ligament footprint centers were marked with 2-mm stainless steel spheres shallowly embedded at the level of the cortical bone prior to obtaining standard lateral and mortise radiographs. Measurements were performed twice by 2 blinded raters independently to calculate mean distances and assess reliability via intraclass correlation coefficients (ICCs). Results: Radiographic measurements demonstrated excellent reproducibility between raters (all interobserver ICCs > 0.97) and across trials (all intraobserver ICCs >0.99). On the lateral view, the ATFL fibular attachment (mean ± SD) was 8.4 ± 1.8 mm proximal and anterior to the inferior tip of the lateral malleolus and attached on the talus 13.8 ± 2.0 mm proximal and anterior to the apex of the lateral talar process. The CFL originated 5.0 ± 1.4 mm superior and anterior to the inferior tip of the lateral malleolus and inserted on the calcaneus 18.5 ± 4.6 mm posterior and superior to the posterior point of the peroneal tubercle. On the mortise view, the ATFL origin was 4.9 ± 1.4 mm proximal to the inferior tip of the lateral malleolus and inserted on the talus 9.0 ± 2.1 mm medial and superior of the apex of the lateral talar process and 18.9 ± 3.1 mm inferior and slightly lateral to the superior lateral corner of the talar dome. The fibular CFL origin was 2.9 ± 1.6 mm proximal and slightly medial to the inferior tip of the lateral malleolus and inserted on the calcaneus 18.0 ± 5.1 mm distal to the apex of the lateral talar process. Conclusion: Radiographic parameters quantitatively describing the anatomic origins and insertions of the lateral ankle ligaments were defined with excellent reproducibility and agreement between reviewers. Clinical Relevance: Quantitative radiographic anatomy data will assist in preoperative planning, improve intraoperative localization, and provide objective measures for postoperative assessment of anatomic repairs and reconstructions.

Effectiveness of weight-bearing lateral radiographs in evaluation of ankle malunited fractures restoration

Objective To evaluate the significance of weight-bearing lateral radiographs in evaluation of malunited frac-tures of the ankle. Methods 17 patients with malunited fractures of the ankle were treated by different reconstructive operations be-tween March 2010 and October 2012, including 9 females and 8 males, aged from 17 to 64 years. According to the Takakura classifi- cation of ankle arthritis, there were 7 patients in grade 1, 4 in grade 2 and 6 in grade 3. Simple open reduction and internal fixation were performed in 5 patients, supramalleolar tibial osteotomy in 5, lengthening osteotomy of the fibula in 2, supramalleolar tibial and fibular osteotomy in 5. Tibiofibular clear space on the anteroposterior radiograph. Medial clear space, tibiofibular clear space and tib-iofibular overlap on ankle mortise radiographs were compared preoperatively and at last follow-up. Tibial lateral surface angle （TLS）, the offset of the center of talar rotation from the tibial axis, and the displacement of tibiotalar articular surface center on weight-bear-ing lateral X-ray were also compared preoperatively and at last follow-up. AOFAS score was used to evaluate the function of the ankle. Results The duration of follow-up was 9 to 32 months. Bone healing was observed in all patients, and the average healing time was 11 to 14 weeks. Ankle joint degeneration grade had no exacerbation. The medial clear space, tibiofibular clear space and tibiofibular overlap had no significant difference between the pre and postoperative. Statistically significant change was seen postoperatively in the values of TLS （76.9°±4.1° vs 80.9°±5.2°）. The offset of the center of rotation from the tibial axis and the displacement of tibiotalar articular surface center were changed from 10.8＋2.1 mm to 2.0_＋0.5 mm and 4.5±1.5 mm to 2.2±1.0 ram, respectively. The average AOFAS score was improved from 45.7±15.9 points preoperatively to 82.0±9.9 points postoperatively. Conclusion Weight-bearing lateral radiographs can be used to judge the ankle restoration. Even if the mortise radiograph had relative good realignment, it may ap-pear obvious deformity on lateral radiographs. Good reduction of lateral radiographs requires that the mid axis of the tibia should pass through the center of talar rotation and tibiotalar articular surface be parallel on the lateral radiograph. Key words: Ankle joint; Fractures, bone; Fracture healing; Radiography; Weight-bearing

Syndesmotic fixation in supination-external rotation ankle fractures: a prospective randomized study.

This study compared mid-term functional and radiologic results of syndesmotic transfixation with no fixation in supination external rotation (SER) ankle fractures with intraoperatively confirmed syndesmosis disruption. Our hypothesis was that early-stage good functional results would remain and unfixed syndesmosis disruption in SER IV ankle fractures would not lead to an increased incidence of osteoarthritis. A prospective study of 140 operatively treated patients with Lauge-Hansen SER IV (Weber B) ankle fractures was performed. After bony fixation, the 7.5-Nm standardized external rotation stress test for both ankles was performed under fluoroscopy. A positive stress examination was defined as a difference of more than 2 mm side-to-side in the tibiotalar or tibiofibular clear spaces on mortise radiographs. The patients were randomized to either syndesmotic screw fixation (13 patients) or no syndesmotic fixation (11 patients). After a minimum of 4 years of follow-up (mean, 58 months), ankle function and pain (Olerud-Molander, a 100-mm visual analogue scale [VAS] for ankle function and pain) and quality of life (RAND-36) of all 24 patients were assessed. Ankle joint congruity and osteoarthritis were assessed using mortise and lateral projection plain weight-bearing radiographs and magnetic resonance imaging (MRI; 3T) scans. Improvement in Olerud-Molander score, VAS, and RAND-36 showed no significant difference between groups during the follow-up. In the syndesmotic transfixation group, improvements in all functional parameters and pain measurements were not significant, whereas in the group without syndesmotic fixation, the Olerud-Molander score improved from 84 to 93 (P = .007) and the pain (VAS) score improved from 11 to 4 (P = .038) from 1 year to last follow-up. X-ray or MRI imaging showed no difference between groups at the last follow-up visit. With the numbers available, no significant difference in functional outcome or radiologic findings could be detected between syndesmosis transfixation and no-fixation patients with SER IV ankle fracture after a minimum of 4 years of follow-up. Level II, prospective comparative study.

Comparison of Radiographic Stress Tests for Syndesmotic Instability of Supination–External Rotation Ankle Fractures

According to the classification of Lauge-Hansen, supination-external rotation IV (OTA 44-B) injuries should not have syndesmotic instability; yet, several studies have suggested disruption is present in up to 40% of these injuries based on stress tests. In this study, we examine various stress radiographic parameters in a cadaver model of supination-external rotation IV equivalent injury. We hypothesize that external rotation stress testing and widening of the medial clear space do not always represent syndesmotic instability. Rather, the better predictor of syndesmotic instability will be an increased tibia-fibula clear space with the lateral stress test. Eleven fresh frozen human lower limbs were each secured into a custom frame. External rotation stress test was performed by applying an external moment of 7.5 Nm, and lateral stress test was performed by applying 100 N lateral pull at the distal fibula. True mortise radiographs were taken of intact ankles and while performing external rotation and lateral stress tests at each stage of sequentially sectioning the ankle ligaments. The deltoid ligament was sectioned first, then anterior-inferior tibiofibular ligament, posterior-inferior tibiofibular ligament, and interosseous membrane. Tibiofibular clear space and medial clear space were measured on each radiograph. External rotation stress test produced significant medial clear space widening when the deltoid ligaments were sectioned (P < 0.05). Lateral stress test produced no significant widening of the tibiofibular clear space until interosseous membranes were sectioned (P < 0.05). Lateral stress test with widening of the tibiofibular clear space is the preferred indicator of syndesmotic instability. The external rotation stress is a poor indicator of syndesmotic injury in the setting of deltoid ligament injury.

Relationship Among Radiographic Ankle Medial Clear Space, Sex, and Height

The ankle medial clear space (MCS) is frequently measured to evaluate ankle stability after an injury. However, controversy exists regarding a threshold size that distinguishes a normal MCS from an abnormal MCS. A retrospective radiographic review of mortise ankle radiographs in the uninjured ankle was performed, with the goal of defining the relationship among patient height, sex, and radiographic ankle MCS. Forty-nine patients with normal mortise radiographs and with information on patient height available in the electronic medical chart were identified for inclusion. For men, mean±standard deviation (in millimeters) was 3.3±0.8 for MCS perpendicular (MCSp), 3.8±0.7 for MCS oblique (MCSo), and 3.8±0.5 for superior clear space (SCS). For women, mean±standard deviation was 2.3±0.6 for MCSp, 2.9±0.5 for MCSo, and 3±0.4 for SCS. Univariate analysis showed that all 3 variables (MCSp, MCSo, and SCS) were statistically different when men were compared with women (P<.0001). Bivariate regression models showed statistically significant (P<.001) positive relationships between each of the measures of clear space and height. In multivariate analysis, female sex alone was associated with a decrease in clear space. When evaluating isolated lateral malleolus fractures, clinicians should consider the patient's height and sex when measuring MCS and SCS to determine deltoid ligament competence. These data suggest that men and people of tall stature are at risk for a false-positive diagnosis of deltoid ligament rupture when previously published threshold MCS and SCS values, such as 4 mm or 5 mm, are used for diagnosis and operative indication.

Varus External Rotation Stress Test for Radiographic Detection of Deep Deltoid Ligament Disruption With and Without Syndesmotic Disruption

External rotation stress is used intraoperatively for diagnosing medial ankle and syndesmotic instability in rotational ankle fractures after reduction and fixation of the fibula. However, external rotation includes hindfoot, midfoot, and ankle motion. The purpose of this study was to determine the effect of hindfoot positioning when using the external rotation stress test. Isolated deep deltoid ligament (DDL) instability and combined DDL and syndesmotic instability were modeled. An intact fibula was used as a surrogate for an anatomically fixed fibula fracture. Six cadaver specimens with full-length tib-fib articulations were used. Specimens were fixed into a Taylor Spatial Frame (Smith&Nephew, Memphis, TN) with 4 to 5 points of fixation in the tibia and the foot. Specimens were mounted in ankle and foot neutral position. Metal markers were placed at the medial gutter and syndesmosis. Anteroposterior (AP) and mortise radiographs were obtained in 3 positions: neutral hindfoot, valgus external rotation stress, and varus external rotation stress. For both valgus and varus external rotation stress, the frame was loosened and stressed to a hard end point and then locked. Three modes were studied: intact ligaments, DDL transected, and DDL+ syndesmosis transected. Digital radiographs were used to measure the displacement of the markers. The varus external rotation stress test demonstrated significant widening of the medial gutter in specimens with isolated DDL instability, in both AP (P = .01) and mortise (P = .02) views. Both maneuvers demonstrated significant medial gutter widening with combined DDL and syndesmosis disruption (P ≤ .01), although the varus external rotation stress test produced nearly twice as much displacement (10.7 vs 5.4 mm). Syndesmotic widening was not significant with either maneuver. Varus external rotation stress was more effective than valgus external rotation stress in demonstrating displacement of markers at the medial gutter and on AP and mortise radiographs for both DDL and DDL with syndesmotic instability. These findings may lead to improved clinical detection of rotational ankle instability from combined DDL and syndesmotic disruption, which may affect decision making for using syndesmotic fixation when using intraoperative stress fluoroscopy images. Occult DDL instability may be underdiagnosed, and this may affect future directions of the treatment of rotational ankle fractures and severe sprains.

Variability in Radiographic Medial Clear Space Measurement of the Normal Weight-Bearing Ankle

Medial clear space (MCS) width on mortise radiographs of the ankle is commonly used by clinicians for determining the competence of the deltoid ligament in the Weber B supination-external rotation ankle fracture. Significant variability exists in the current literature regarding methods of obtaining this measure and definition of a normal measure in comparison with a pathologic state. Seventy-three paired bilateral ankle mortise radiographs that were without ankle pathology were retrospectively reviewed. MCS width at two separate locations (oblique and perpendicular) and superior clear space (SCS) were measured on digital radiographs. A Student's t test was used to compare mean values. Mean values (± SD) were 3.2 (± 0.7)~mm for MCS oblique, 2.6 (± 0.7)~mm for MCS perpendicular, and 3.3 (± 0.6)~mm for SCS. A significant difference (p < .001) existed for all three measures between males and females. MCS oblique was statistically different than MCS perpendicular (p < .001) for all patients and for males and females independently. The mean difference between paired bilateral radiographs was 0.3 (± 0.2)~mm for MCS oblique, 0.6 (± 0.6)~mm for MCS perpendicular, and 0.2 (± 0.2)~mm for SCS. MCS width has variability based on the location chosen for measurement and gender. Contralateral radiographic comparison of MCS should be routinely used to identify pathologic widening versus normal anatomic variation. Use of single threshold values for MCS width as an operative indicator may produce a false-positive diagnosis of deltoid incompetence in Weber B supination-external rotation ankle fractures and possibly lead to unnecessary surgery.

Radiographic Evaluation of the Normal Distal Tibiofibular Syndesmosis

Diagnosis of syndesmotic injuries is primarily based upon the assessment of ankle radiographs. The purpose of our study was to redefine the radiographic relationships of the ankle syndesmosis based on a large series of normal ankle radiographs in living subjects. The study involved 392 patients (218 females, 174 males) with ankle radiographs without known clinical or radiographic evidence of abnormality. Eighty-three of the 392 patients had also had normal contralateral radiographs. Tibiofibular overlap and tibiofibular clear space were measured on anteroposterior (AP) and mortise radiographs. The radiographic measurements were used to calculate means, standard deviations, and intra- and interobserver reliabilities, and compare genders and side-to-side radiographs. The mean overlap was 8.3 mm on the AP and 3.5 mm on the mortise while the mean clear space was 4.6 mm on the AP and 4.3 mm on the mortise view. The least amount of overlap on the AP view was 1.8 mm. On the mortise view, there was a subset of patients that had a complete lack of overlap (less than 0 mm) with the greatest gap noted to be 1.9 mm. The greatest clear space on AP was 8 mm and on the mortise was 7.6 mm. Mortise clear space was the most accurate measure when obtaining contralateral radiographs, with a mean side-to-side difference of 0.7 ± 0.7 mm. Lack of overlap on the mortise view can represent a normal variant, which has not been definitively reported in prior investigations. Our data form the basis for revised radiographic criteria to evaluate the distal tibiofibular syndesmosis which may influence clinical management of these patients.

Axial Load Weightbearing Radiography in Determining Lateral Malleolus Fracture Stability: A Cadaveric Study

Ankle fractures are the most common fracture treated by orthopaedic surgeons in the United States. Isolated lateral malleolus fractures are treated nonoperatively, while associated deltoid disruption injuries are unstable and usually treated by fixation of the fracture. Various stress radiographs and MRI have been used to determine deltoid competency and the subsequent need for operative stabilization of lateral malleolus fractures. To date, no standardization of stress radiography has been performed. The aim of this study was to evaluate the ability of weightbearing ankle X-rays to determine stability and their reliability. This study sought to utilize simulated weightbearing radiography as a potential method to determine the need for lateral malleolus fixation. Twelve cadaveric ankle specimens were tested by obtaining ankle mortise radiographs for interpretation of medial clear space. Each ankle was tested with 0, 25, 36, and 50 kg of axially applied weight. The groups of measurements obtained were: intact ankles (Group A), ankles with an isolated oblique fibular osteotomy (Group B), and osteotomized ankles after complete deltoid ligament transaction (Group C). Three authors measured the medial clear space for every ankle using PACSR software. Instability of the ankle mortise was defined as medial clear space widening of greater than 2 mm from the intact ankle. An isolated lateral malleolus fracture (Group B) and a lateral malleolus fracture with an incompetent deltoid ligament (Group C) showed no statistical medial clear space widening with simulated axial weightbearing radiography when compared to intact ankles (Group A). ANOVA's between Group A and B had p < 0.001, and between Group A and C of p < 0.001. Our model did not find instability with an osteotomized fibula and a disrupted deltoid. This study suggests a weightbearing radiograph of an isolated lateral malleolus fracture cannot determine deltoid ligament integrity and thus need for fibular operative fixation.