Tibial Axis-to-Talus Distance: A Clinically Reliable Measurement for Sagittal Translation of the Talus in Total Ankle Arthroplasty.

Background: Sagittal talar translation is an important factor influencing the sagittal alignment of total ankle arthroplasty (TAA). Thus, accurate measurement of sagittal talar translation is crucial. This study proposes a simple method (tibiotalar distance [TTD]) that can quantify talar translation without being affected by the ankle and subtalar joint condition or the talar component position in patients with TAA. Methods: We enrolled 280 eligible patients (296 ankles) who underwent primary TAA between 2005 and 2019 and retrospectively reviewed them for sagittal talar translation. The TTD was measured for each patient on weight-bearing lateral ankle radiographs by 3 raters. In addition, we analyzed interrater and intrarater reliability for the TTD method. Results: We found that the TTD method could quantify the talar translation and was not affected by the preoperative condition of the ankle joint surface, subtalar joint pathologies, or the postoperative talar component position. The TTD method showed an excellent intraclass correlation coefficient (> 0.9) in all interrater and intrarater reliability analyses. In the analysis of 157 healthy, unoperated contralateral ankles, we identified that TTD showed a Gaussian distribution (p = 0.284) and a mean of 38.91 mm (normal range, 29.63-48.20 mm). Conclusions: The TTD method is a simple and reliable method that could be applied to patients with TAA to assess the sagittal talar translation regardless of the pre-and postoperative joint condition and implantation status.

Bone grafting for periprosthetic bone cysts following total ankle arthroplasty.

Aims: The purpose of this study was to assess the success rate and functional outcomes of bone grafting for periprosthetic bone cysts following total ankle arthroplasty (TAA). Additionally, we evaluated the rate of graft incorporation and identified associated predisposing factors using CT scan. Methods: We reviewed a total of 37 ankles (34 patients) that had undergone bone grafting for periprosthetic bone cysts. A CT scan was performed one year after bone grafting to check the status of graft incorporation. For accurate analysis of cyst volumes and their postoperative changes, 3D-reconstructed CT scan processed with 3D software was used. For functional outcomes, variables such as the Ankle Osteoarthritis Scale score and the visual analogue scale for pain were measured. Results: Out of 37 ankles, graft incorporation was successful in 30 cases. Among the remaining seven cases, four (10.8%) exhibited cyst re-progression, so secondary bone grafting was needed. After secondary bone grafting, no further progression has been noted, resulting in an overall 91.9% success rate (34 of 37) at a mean follow-up period of 47.5 months (24 to 120). The remaining three cases (8.1%) showed implant loosening, so tibiotalocalcaneal arthrodesis was performed. Functional outcomes were also improved after bone grafting in all variables at the latest follow-up (p < 0.05). The mean incorporation rate of the grafts according to the location of the cysts was 84.8% (55.2% to 96.1%) at the medial malleolus, 65.1% (27.6% to 97.1%) at the tibia, and 81.2% (42.8% to 98.7%) at the talus. Smoking was identified as a significant predisposing factor adversely affecting graft incorporation (p = 0.001). Conclusion: Bone grafting for periprosthetic bone cysts following primary TAA is a reliable procedure with a satisfactory success rate and functional outcomes. Regular follow-up, including CT scan, is important for the detection of cyst re-progression to prevent implant loosening after bone grafting.

Effect of diabetes mellitus on the outcomes of total ankle arthroplasty: is controlled diabetes mellitus a risk factor?

BACKGROUND: It is still uncertain whether diabetes mellitus (DM) is a risk factor for poor outcomes and increased complications after total ankle arthroplasty (TAA). The objective of this study was to compare clinical outcomes and complication rates of TAA in patients with and without DM. METHODS: This study enrolled patients with symptomatic end-stage ankle osteoarthritis with a minimum follow-up period of 24 months after TAA. A total of 252 patients (266 ankles) were classified into two groups according to the presence of DM: (1) DM group (59 patients, 67 ankles) and (2) non-DM group (193 patients, 199 ankles). We defined controlled diabetes as (1) HbA1c level < 7.0%, or (2) fasting glucose level < 130 mg/dL with HbA1c level ≥ 7.0% for hospitalization period. Clinical outcomes data (Ankle Osteoarthritis Scale, American Orthopedic Foot and Ankle Society ankle-hindfoot score, Short Form-36 Physical Component Summary score, and visual analog scale for pain) were compared preoperatively and at the final follow-up between the two groups. Complications following TAA were also compared between the two groups. RESULTS: All clinical variables had improved in both groups by the final follow-up (mean follow-up = 77.8 months). There was no significant difference in any clinical variable between the two groups at the final follow-up (P > 0.05). Of the 266 ankles, 73 ankles (19 in the DM group, 54 in the non-DM group) developed periprosthetic osteolysis. Although the DM group showed a higher prevalence of aseptic loosening or subsidence, the difference between the two groups was not statistically significant (P = 0.236). CONCLUSIONS: In the intermediate-term follow-up, TAA in patients with controlled DM showed clinical outcomes and complication rates comparable to patients without DM. Our results suggest that TAA can be done safely in diabetic patients if the DM is controlled in the perioperative period. LEVEL OF EVIDENCE: Therapeutic Level III.

Derivation of riding risk precursors using 100 delivery motor scooter naturalistic riding study.

The rapid growth of the delivery service market in Korea due to the impact of COVID-19 has resulted in an increase in crashes associated with delivery motor scooters. In particular, required minimum delivery time, which is an important factor for food delivery service, can lead to hazardous riding situations leading to traffic crashes. Although the food delivery service industry is continuously increasing, effective measures to improve the traffic safety of delivery motor scooters are insufficient. This study derived precursors in order to detect risky riding events using real-world naturalistic riding study data. It is essential to understand the riding characteristics of food delivery motor scooters to conduct the riding safety monitoring in more scientific and automated manners. Various candidate precursors were derived from riding characteristics data collected from GPS sensors and inertial measurement unit sensors. A decision tree model was then adopted to classify unsafe and normal riding events in order to determine the priority of precursors. A classification accuracy of 95.7% was obtained using three salient riding risk precursors including the norm of the angular velocity, which represents composite vector quantity of 3-axis measurements, acceleration, and X-axis angular velocity. The results of this study are expected to be used as a fundamental data to prepare for riding safety management systems that contribute to enhancing the safety of food delivery motor scooters.

Two-dimensional Convolutional Neural Network Using Quantitative US for Noninvasive Assessment of Hepatic Steatosis in NAFLD.

Background Quantitative US (QUS) using radiofrequency data analysis has been recently introduced for noninvasive evaluation of hepatic steatosis. Deep learning algorithms may improve the diagnostic performance of QUS for hepatic steatosis. Purpose To evaluate a two-dimensional (2D) convolutional neural network (CNN) algorithm using QUS parametric maps and B-mode images for diagnosis of hepatic steatosis, with the MRI-derived proton density fat fraction (PDFF) as the reference standard, in patients with nonalcoholic fatty liver disease (NAFLD). Materials and Methods: Consecutive adult participants with suspected NAFLD were prospectively enrolled at a single academic medical center from July 2020 to June 2021. Using radiofrequency data analysis, two QUS parameters (tissue attenuation imaging [TAI] and tissue scatter-distribution imaging [TSI]) were measured. On B-mode images, hepatic steatosis was graded using visual scoring (none, mild, moderate, or severe). Using B-mode images and two QUS parametric maps (TAI and TSI) as input data, the algorithm estimated the US fat fraction (USFF) as a percentage. The correlation between the USFF and MRI PDFF was evaluated using the Pearson correlation coefficient. The diagnostic performance of the USFF for hepatic steatosis (MRI PDFF ≥5%) was evaluated using receiver operating characteristic curve analysis and compared with that of TAI, TSI, and visual scoring. Results Overall, 173 participants (mean age, 51 years ± 14 [SD]; 96 men) were included, with 126 (73%) having hepatic steatosis (MRI PDFF ≥5%). USFF correlated strongly with MRI PDFF (Pearson r = 0.86, 95% CI: 0.82, 0.90; P < .001). For diagnosing hepatic steatosis (MRI PDFF ≥5%), the USFF yielded an area under the receiver operating characteristic curve of 0.97 (95% CI: 0.93, 0.99), higher than those of TAI, TSI, and visual scoring (P = .015, .006, and < .001, respectively), with a sensitivity of 90% (95% CI: 84, 95 [114 of 126]) and a specificity of 91% (95% CI: 80, 98 [43 of 47]) at a cutoff value of 5.7%. Conclusion A deep learning algorithm using quantitative US parametric maps and B-mode images accurately estimated the hepatic fat fraction and diagnosed hepatic steatosis in participants with nonalcoholic fatty liver disease. ClinicalTrials.gov registration nos. NCT04462562, NCT04180631 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Sidhu and Fang in this issue.

Periprosthetic Osteolysis as a Risk Factor for Revision After Total Ankle Arthroplasty: A Single-Center Experience of 250 Consecutive Cases.

BACKGROUND: Periprosthetic osteolysis after total ankle arthroplasty (TAA) is a challenging problem. This study aimed to evaluate the prevalence of and predisposing factors for osteolysis and its effects on clinical outcomes. METHODS: We enrolled 236 patients (250 ankles) who underwent primary TAA using a mobile-bearing HINTEGRA prosthesis, with a mean follow-up of 83.5 months (range, 36 to 182 months), and subsequently divided them into 2 groups: the osteolysis group (79 ankles) and non-osteolysis group (171 ankles). Clinical and radiographic outcomes were compared between the 2 groups, and a bivariable logistic regression analysis was performed to identify predisposing factors for the development of osteolysis. RESULTS: In the osteolysis group (31.6% of the 250 ankles), the mean time of detection was 28.8 months postoperatively. Forty of these ankles were closely monitored without surgical treatment. Another 29 ankles underwent bone grafting and exchange of the polyethylene inlay, and the remaining 10 ankles underwent revision TAA or arthrodesis. All clinical outcome variables were significantly lower in patients with osteolysis, compared with those without osteolysis, at the final follow-up (p < 0.05). In the investigation of predisposing factors, only rheumatoid arthritis was identified as having a significant association with an increased prevalence of osteolysis (p = 0.030). CONCLUSIONS: This study demonstrated that the prevalence of periprosthetic osteolysis after TAA was considerable and that the development of osteolysis negatively affected the clinical outcome. Therefore, the prevention and appropriate treatment of osteolysis are crucial for the satisfactory long-term survival of TAA. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Older Korean men with inadequate vitamin D status have lower odds of radiologic osteoarthritis.

Most studies on osteoarthritis (OA) and vitamin D status were performed in Whites with relatively adequate vitamin D status. Associations may differ by baseline 25-hydroxyvitamin D (25(OH)D) and race. We assessed the odds of OA and joint pain according to vitamin D status in Korean adults ≥ 50 years of age in the nationally representative Korea National Health and Nutrition Examination Survey (n = 8575). Agreement between radiologic OA (ROA) and self-reported OA were also assessed. Multivariate logistic regression was performed and participants were stratified by sex. Adults with serum 25(OH)D < 12 ng/mL and 12 to < 20 ng/mL had 26% and 18% lower odds of knee ROA, respectively, compared to those with 25(OH)D ≥ 20 ng/mL. Similar results were observed in men, but not women. No associations were found between 25(OH)D and knee ROA severity, lumbar spine ROA, symptomatic OA, or knee pain. Sensitivity of self-reported OA was low (27%), indicating a weak possibility of reverse causation. Prospective studies are required to identify the possible causality of vitamin D on OA in Korean men.

Human Epidural AD-MSC Exosomes Improve Function Recovery after Spinal Cord Injury in Rats.

Spinal cord injury (SCI) interferes with the normal function of the autonomic nervous system by blocking circuits between the sensory and motor nerves. Although many studies focus on functional recovery after neurological injury, effective neuroregeneration is still being explored. Recently, extracellular vesicles such as exosomes have emerged as cell-free therapeutic agents owing to their ability of cell-to-cell communication. In particular, exosomes released from mesenchymal stem cells (MSCs) have the potential for tissue regeneration and exhibit therapeutic effectiveness in neurological disorders. In this study, we isolated exosomes from human epidural adipose tissue-derived MSCs (hEpi AD-MSCs) using the tangential flow filtration method. The isolated exosomes were analyzed for size, concentration, shape, and major surface markers using nanoparticle tracking analysis, transmission electron microscopy, and flow cytometry. To evaluate their effect on SCI recovery, hEpi AD-MSC exosomes were injected intravenously in SCI-induced rats. hEpi AD-MSC exosomes improved the locomotor function of SCI-induced rats. The results of histopathological and cytokine assays showed that hEpi AD-MSC exosomes regulated inflammatory response. Genetic profiling of the rat spinal cord tissues revealed changes in the expression of inflammation-related genes after exosome administration. Collectively, hEpi AD-MSC exosomes are effective in restoring spinal functions by reducing the inflammatory response.

Quantitative Evaluation of Hepatic Steatosis Using Advanced Imaging Techniques: Focusing on New Quantitative Ultrasound Techniques.

Nonalcoholic fatty liver disease, characterized by excessive accumulation of fat in the liver, is the most common chronic liver disease worldwide. The current standard for the detection of hepatic steatosis is liver biopsy; however, it is limited by invasiveness and sampling errors. Accordingly, MR spectroscopy and proton density fat fraction obtained with MRI have been accepted as non-invasive modalities for quantifying hepatic steatosis. Recently, various quantitative ultrasonography techniques have been developed and validated for the quantification of hepatic steatosis. These techniques measure various acoustic parameters, including attenuation coefficient, backscatter coefficient and speckle statistics, speed of sound, and shear wave elastography metrics. In this article, we introduce several representative quantitative ultrasonography techniques and their diagnostic value for the detection of hepatic steatosis.

Effects and Safety of Intra-Articular Sodium Hyaluronate Injection for the Treatment of Ankle Osteoarthritis: A Prospective Clinical Trial.

Various nonoperative treatments have been implemented to reduce pain and improve the quality of life in patients with ankle osteoarthritis. Among these treatments, intra-articular hyaluronate injection has proven efficacy and safety in patients with knee osteoarthritis. The purpose of this study was to evaluate the efficacy and complications of hyaluronate injection using various clinical scoring systems. This study included 37 patients with unilateral ankle osteoarthritis (grade 2 or 3 according to the Takakura classification) who did not respond to previous pharmacological treatment. 3 weekly hyaluronate injections (2 mL Hyruan Plus®) were administered. The efficacy of intra-articular hyaluronate injection was evaluated on the basis of patient-reported foot and ankle clinical assessment at a mean follow-up of 13.8 ± 8.3 (range 6-33) months. Ankle Osteoarthritis Scale scores for pain and disability, American Orthopedic Foot and Ankle Society ankle-hindfoot scores, and visual analog scale for pain significantly improved at the final follow-up compared to that before intra-articular hyaluronate injection (p ≤ .05). When patients were dichotomized according to age, sex, body mass index, symptom duration, and Takakura classification, all these factors were not related to clinical outcomes. This study suggests that 3 weekly intra-articular hyaluronate injections can be performed safely to reduce pain and improve function without serious complications in patients with early or intermediate-grade ankle osteoarthritis when patients inadequately respond to medication. Larger controlled studies are needed to clarify the effects of hyaluronate injection and identify patients who can benefit most from hyaluronate injection.

Comparison of 2-octyl cyanoacrylate skin adhesive and interrupted polypropylene sutures for wound closure in total ankle arthroplasty.

BACKGROUND: Adhesive skin materials have increasingly been used in orthopedic surgery. We aimed to compare the efficacy and safety of skin adhesive (2-octyl cyanoacrylate and polymer mesh, Dermabond Prineo) and interrupted polypropylene sutures for wound closure in patients undergoing total ankle arthroplasty (TAA). METHODS: We prospectively enrolled 107 consecutive patients (108 ankles) undergoing TAA and divided them into two groups: skin adhesive group (36 ankles) and suture group (72 ankles). The primary outcome assessment included wound complications and patient satisfaction for wound cosmesis. The secondary outcome assessment included duration of surgery, length of hospital stay, and the Ankle Osteoarthritis Scale (AOS) pain and disability score. RESULTS: There was one case of allergic contact dermatitis, three cases of wound dehiscence, and one case of superficial surgical site infection in the skin adhesive group. Among them, one case each with allergic contact dermatitis and wound dehiscence finally progressed to deep surgical site infection. Three cases of wound dehiscence were also reported in the suture group; however, there was no case of surgical site infection. Patient satisfaction for wound cosmesis was significantly higher in the skin adhesive group than in the suture group (p = 0.001). There was no statistically significant difference between the groups in terms of secondary outcomes (p > 0.05). CONCLUSIONS: Although the use of Dermabond Prineo showed better patient satisfaction for wound cosmesis, it showed significantly high wound complication rates and no other clinical benefits compared to interrupted polypropylene suture in TAA. Our results suggest that awareness of the possibility of wound complications is necessary when Dermabond Prineo is used in TAA.

Deep learning-based automated quantification of the hepatorenal index for evaluation of fatty liver by ultrasonography.

PURPOSE: The aim of this study was to develop and validate a fully-automatic quantification of the hepatorenal index (HRI) calculated by a deep convolutional neural network (DCNN) comparable to the interpretations of radiologists experienced in ultrasound (US) imaging. METHODS: In this retrospective analysis, DCNN-based organ segmentation with Gaussian mixture modeling for automated quantification of the HRI was developed using abdominal US images from a previous study. For validation, 294 patients who underwent abdominal US examination before living-donor liver transplantation were selected. Interobserver agreement for the measured brightness of the liver and kidney and the calculated HRI were analyzed between two board-certified radiologists and DCNN using intraclass correlation coefficients (ICCs). RESULTS: Most patients had normal (n=95) or mild (n=198) fatty liver. The ICCs of hepatic and renal brightness measurements and the calculated HRI between the two radiologists were 0.892 (95% confidence interval [CI], 0.866 to 0.913), 0.898 (95% CI, 0.873 to 0.918), and 0.681 (95% CI, 0.615 to 0.738) for the first session and 0.920 (95% CI, 0.901 to 0.936), 0.874 (95% CI, 0.844 to 0.898), and 0.579 (95% CI, 0.497 to 0.650) for the second session, respectively; the results ranged from moderate to excellent agreement. Using the same task, the ICCs of the hepatic and renal measurements and the calculated HRI between the average values of the two radiologists and DCNN were 0.919 (95% CI, 0.899 to 0.935), 0.916 (95% CI, 0.895 to 0.932), and 0.734 (95% CI, 0.676 to 0.782), respectively, showing high to excellent agreement. CONCLUSION: Automated quantification of HRI using DCNN can yield HRI measurements similar to those obtained by experienced radiologists in patients with normal or mild fatty liver.

Gate-controlled amplifiable ultraviolet AlGaN/GaN high-electron-mobility phototransistor.

Gate-controlled amplifiable ultraviolet phototransistors have been demonstrated using AlGaN/GaN high-electron-mobility transistors (HEMTs) with very thin AlGaN barriers. In the AlGaN/GaN HEMTs, the dark current between the source and drain increases with increasing thickness of the AlGaN barrier from 10 to 30 nm owing to the increase in piezoelectric polarization-induced two-dimensional electron gas (2-DEG). However, the photocurrent of the AlGaN/GaN HEMT decreases with increasing thickness of the AlGaN barrier under ultraviolet exposure conditions. It can be observed that a thicker AlGaN barrier exhibits a much higher 2-DEG than the photogenerated carriers at the interface between AlGaN and GaN. In addition, regardless of the AlGaN barrier thickness, the source-drain dark current increases as the gate bias increases from - 1.0 to + 1.0 V. However, the photocurrent of the phototransistor with the 30 nm thick AlGaN barrier was not affected by the gate bias, whereas that of the phototransistor with 10 nm thick AlGaN barrier was amplified from reduction of the gate bias. From these results, we suggest that by controlling the gate bias, a thin AlGaN barrier can amplify/attenuate the photocurrent of the AlGaN/GaN HEMT-based phototransistor.

Comparison of Preoperative Bone Density in Patients With and Without Periprosthetic Osteolysis Following Total Ankle Arthroplasty.

BACKGROUND: Modern total ankle arthroplasty (TAA) prostheses are uncemented press-fit designs whose stability is dependent on bone ingrowth. Preoperative insufficient bone density reduces initial local stability at the bone-implant interface, and we hypothesized that this may play a role in periprosthetic osteolysis. We aimed to investigate the preoperative bone density of the distal tibia and talus and compare these in patients with and without osteolysis. METHODS: We enrolled 209 patients (218 ankles) who underwent primary TAA using the HINTEGRA prosthesis. The overall mean follow-up duration was 66 (range, 24-161) months. The patients were allocated into 2 groups according to the presence of periprosthetic osteolysis: the osteolysis group (64 patients, 65 ankles) and nonosteolysis group (145 patients, 153 ankles). Between the 2 groups, we investigated and compared the radiographic outcomes, including the Hounsfield unit (HU) value around the ankle joint and the coronal plane alignment. RESULTS: HU values of the tibia and talus measured at 5 mm from the reference points were higher than those at 10 mm in each group. However, comparing the osteolysis and nonosteolysis groups, we found no significant intergroup difference in HU value at every measured level in the tibia and talus (P > .05). Concerning the coronal plane alignment, there were no significant between-group differences in the tibiotalar and talar tilt angles (P > .05). CONCLUSION: Patients with osteolysis showed similar preoperative bone density of the distal tibia and talus compared with patients without osteolysis. Our results suggest that low bone density around the ankle joint may not be associated with increased development of osteolysis. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Deep-Learning-Based Prediction of High-Risk Taxi Drivers Using Wellness Data.

BACKGROUND: Factors related to the wellness of taxi drivers are important for identifying high-risk drivers based on human factors. The purpose of this study is to predict high-risk taxi drivers based on a deep learning method by identifying the wellness of a driver, which reflects the personal characteristics of the driver. METHODS: In-depth interviews with taxi drivers are conducted to collect wellness data. The priorities of factors affecting the severity of accidents are derived through a random forest model. In addition, based on the derived priority of variables, various combinations of inputs are set as scenarios and optimal artificial neural network models are derived for each scenario. Finally, the model with the best performance for predicting high-risk taxi drivers is selected based on three criteria. RESULTS: A model with variables up to the 16th priority as inputs is selected as the best model; this has a classification accuracy of 86% and an F1-score of 0.77. CONCLUSIONS: The wellness-based model for predicting high-risk taxi drivers presented in this study can be used for developing a taxi driver management system. In addition, it is expected to be useful when establishing customized traffic safety improvement measures for commercial vehicle drivers.

Signal amplification by reversible exchange for COVID-19 antiviral drug candidates.

Several drug candidates have been proposed and tested as the latest clinical treatment for coronavirus pneumonia (COVID-19). Chloroquine, hydroxychloroquine, ritonavir/lopinavir, and favipiravir are under trials for the treatment of this disease. The hyperpolarization technique has the ability to further provide a better understanding of the roles of these drugs at the molecular scale and in different applications in the field of nuclear magnetic resonance/magnetic resonance imaging. This technique may provide new opportunities in diagnosis and research of COVID-19. Signal amplification by reversible exchange-based hyperpolarization studies on large-sized drug candidates were carried out. We observed hyperpolarized proton signals from whole structures, due to the unprecedented long-distance polarization transfer by para-hydrogen. We also found that the optimal magnetic field for the maximum polarization transfer yield was dependent on the molecular structure. We can expect further research on the hyperpolarization of other important large molecules, isotope labeling, as well as polarization transfer on nuclei with a long spin relaxation time. A clinical perspective of these features on drug molecules can broaden the application of hyperpolarization techniques for therapeutic studies.

Fusion of the SLAM with Wi-Fi-Based Positioning Methods for Mobile Robot-Based Learning Data Collection, Localization, and Tracking in Indoor Spaces.

The ability to estimate the current locations of mobile robots that move in a limited workspace and perform tasks is fundamental in robotic services. However, even if the robot is given a map of the workspace, it is not easy to quickly and accurately determine its own location by relying only on dead reckoning. In this paper, a new signal fluctuation matrix and a tracking algorithm that combines the extended Viterbi algorithm and odometer information are proposed to improve the accuracy of robot location tracking. In addition, to collect high-quality learning data, we introduce a fusion method called simultaneous localization and mapping and Wi-Fi fingerprinting techniques. The results of the experiments conducted in an office environment confirm that the proposed methods provide accurate and efficient tracking results. We hope that the proposed methods will also be applied to different fields, such as the Internet of Things, to support real-life activities.

Unrecognized tibial nerve injury in total-ankle arthroplasty: Two case reports.

RATIONALE: Tibial nerve injury is a sustainable but rare complication during total-ankle arthroplasty (TAA). We outlined 2 previously unreported cases of tibial nerve injury in TAA, including the prognoses and possible causes. PATIENT CONCERNS: First, a 63-year-old woman complained of a 5-month history of persistent tingling sensation and numbness on the medial and plantar aspects of her foot after TAA. Second, a 50-year-old woman complained of a 6-month history of tingling sensation and numbness on the plantar surface of her forefoot after TAA. DIAGNOSIS: Explorations were performed on suspicion of tarsal tunnel syndrome; however, both patients exhibited complete laceration of tibial nerve with neuroma formation. INTERVENTIONS: In both patients, we excised the neuroma and performed end-to-end nerve repair. OUTCOMES: The sensory disturbance of the sole considerably improved at long-term follow-up over 8 years after the neurorrhaphy procedures. LESSONS: Tibial nerve injury is rare following TAA, and is sometimes unrecognized or misdiagnosed. If tibial nerve injury is suspected, prompt surgical exploration should be performed; great precaution must also be taken to prevent injury of the tibial nerve during TAA.

Does gender influence the outcomes of total ankle arthroplasty in patients with ankle osteoarthritis?

BACKGROUND: Total ankle arthroplasty has progressed as a treatment option for patients with ankle osteoarthritis. However, no studies have been conducted to evaluate the effect of gender on the outcome. The purpose of the present study was to evaluate outcomes, survivorship, and complications rates of total ankle arthroplasty, according to gender differences. METHODS: This study included 187 patients (195 ankles) that underwent mobile-bearing HINTEGRA prosthesis at a mean follow-up of 7.5 years (range, 4 to 14). The two groups consisted of a men's group (106 patients, 109 ankles) and a women's group (81 patients, 86 ankles). Average age was 64.4 years (range, 45 to 83). RESULTS: Clinical scores on the Ankle Osteoarthritis Scale for pain and disability, and American Orthopaedic Foot and Ankle Society ankle-hindfoot score improved and the difference was not statistically significant between the two groups at the final follow-up. There were no significant differences in complication rates and implant survivorship between the two groups. The overall survival rate was 96.4% in men and 93.4% in women at a mean follow-up of 7.5 years (p = 0.621). CONCLUSIONS: Clinical outcomes, complication rates, and survivorship of total ankle arthroplasty were comparable between men and women. These results suggest that gender did not seem to affect outcomes of total ankle arthroplasty in patients with ankle osteoarthritis. LEVEL OF EVIDENCE: Therapeutic level III.

Deep learning with ultrasonography: automated classification of liver fibrosis using a deep convolutional neural network.

OBJECTIVES: The aim of this study was to develop a deep convolutional neural network (DCNN) for the prediction of the METAVIR score using B-mode ultrasonography images. METHODS: Datasets from two tertiary academic referral centers were used. A total of 13,608 ultrasonography images from 3446 patients who underwent surgical resection, biopsy, or transient elastography were used for training a DCNN for the prediction of the METAVIR score. Pathological specimens or estimated METAVIR scores derived from transient elastography were used as a reference standard. A four-class model (F0 vs. F1 vs. F23 vs. F4) was developed. Diagnostic performance of the algorithm was validated on a separate internal test set of 266 patients with 300 images and external test set of 572 patients with 1232 images. Performance in classification of cirrhosis was compared between the DCNN and five radiologists. RESULTS: The accuracy of the four-class model was 83.5% and 76.4% on the internal and external test set, respectively. The area under the receiver operating characteristic curve (AUC) for classification of cirrhosis (F4) was 0.901 (95% confidence interval [CI], 0.865-0.937) on the internal test set and 0.857 (95% CI, 0.825-0.889) on the external test set, respectively. The AUC of the DCNN for classification of cirrhosis (0.857) was significantly higher than that of all five radiologists (AUC range, 0.656-0.816; p value < 0.05) using the external test set. CONCLUSIONS: The DCNN showed high accuracy for determining METAVIR score using ultrasonography images and achieved better performance than that of radiologists in the diagnosis of cirrhosis. KEY POINTS: • DCNN accurately classified the ultrasonography images according to the METAVIR score. • The AUROC of this algorithm for cirrhosis assessment was significantly higher than that of radiologists. • DCNN using US images may offer an alternative tool for monitoring liver fibrosis.