Association of Extraosseous Arterial Diameter With Talar Dome Osteochondral Lesions.

BACKGROUND: Etiology of osteochondral lesions of the talus (OLT) is multifactorial and may develop from trauma, genetics, or hypovascularity. The talar dome is supplied by the posterior tibial artery (PTA) and, to a lesser degree, the sinus tarsi artery (STA). The role of talar dome hypovascularity on OLT remains poorly studied. We aimed to determine any relationship between the diameter of PTA (dPTA) and STA (dSTA) and the incidence and characteristics of talus OLT. METHODS: This retrospective study included 77 patients with OLT and 77 subjects as a matched control group (age range: 30-40 years). Using magnetic resonance imaging, the dPTA was measured 1 cm above the tibial plafond, at the plafond, and at the level of medial malleolar tip. Likewise, dSTA was measured at the level of the talar neck. The area, volume, depth, localization, and surgical intervention for OLT were recorded as well. RESULTS: The study group had significantly smaller dPTA at all 3 levels (1.05 ± 0.22 mm, 0.99 ± 0.18 mm, 0.98 ± 0.31 mm, proximal to distal, respectively) compared with controls (1.25 ± 0.23 mm, 1.20 ± 0.22 mm, 1.14 ± 0.18 mm, respectively) (P < .001). The dSTA was also significantly smaller in the study group compared with the control group (0.5 ± 0.11 mm vs 0.57 ± 0.08 mm, respectively; P = .001). The mean dPTA (of all 3 levels) cutoff value for predicting the occurrence of OLT was 1.1 mm with 74% sensitivity and 75% specificity. A significant inverse correlation was observed between OLT area and arterial diameters (P < .001). CONCLUSION: Smaller luminal dPTA and dSTA appear to be associated with higher incidence of OLT, with defect size inversely correlated to arterial diameter.

Open ankle fractures in the elderly: predisposing factors and the associated mortality.

The purpose of this study was to investigate the independent effect of open ankle fractures on postoperative mortality and to identify factors leading to open ankle fractures in the elderly population. This is a retrospective case-control study of 1,045 patients aged 65 years and older, with ankle fractures undergoing surgical fixation between 2010 and 2020 at three medical centers (Levels 1-2). A logistic regression analysis was used to identify risk factors for open fractures. Propensity score matching and survival analysis were used to measure the hazard of mortality attributable to open versus closed ankle fractures. There were 128 (12.2%) patients with open ankle fractures. Patients with open ankle fractures were more likely to be older, to be active smokers (OR = 1.7, p = 0.049), and tended to have a higher number of medical comorbidities including hypertension (OR = 2, p = 0.006) and chronic kidney disease (OR = 2.9, p = 0.005). Open ankle fractures were, independently of comorbid conditions and age, associated with higher risk of mortality (HR = 1.7, p = 0.03).

Gender Differences in Achilles Tendon Ruptures-A Retrospective Study and a Review of the Literature.

Achilles tendon ruptures are common injuries typically sustained during sport with higher incidence in men, though little is understood regarding sex-specific risk factors or outcomes following injury management. This cross-sectional clinical study and systematic review aimed to examine sex-specific Achilles tendon rupture incidence and outcomes following intervention. This study included patients who sustained a rupture between 2011-2021, were ≥18 years old, and who had a minimum follow-up of at least six months, and evaluated age, sex, sport involvement, mechanism of injury, and postoperative complications and revision. Separately, a systematic literature review in the PubMed, EMBASE, and Cochrane databases was performed. A total of 705 male and 158 female patients were included in this retrospective study. 71.1% of men and 52.5% of women sustained a sports-related rupture (p < .001), with sport involvement demonstrating a positive correlation with revision rate (coefficient = 0.09, p = .02). A total of 21 studies with 250,907 patients (87,514 male, 35,792 female) were included in the systematic review. All studies revealed an increased incidence of ATR in men. Functional outcomes were worse in women, and female sex was an independent risk factor for postoperative complications and need for revision surgery. This study demonstrated a higher incidence of sports-related ATR in men than women, likely related to their higher ball sport participation. Although the retrospective analysis did not find a significant difference in complication or revision rates, the systematic review demonstrates poorer functional outcomes, with increased likelihood for postoperative complication and revision surgery in women as compared to men.

Factors Associated With Symptom Recurrence After Surgical Treatment of Interdigital Neuroma: A Retrospective Chart Review of 127 Patients.

INTRODUCTION: Interdigital neuroma (IN) is a benign enlargement of tissue surrounding the common plantar digital nerve. Although the standard surgical treatment of IN remains debated, recent attention has been given to less-invasive surgical decompression by intermetatarsal ligament (IML) release with neurolysis. This study aimed to compare the outcomes of IML release with neurolysis with standard interdigital neurectomy. METHODS: A retrospective chart review was conducted on 350 consecutive patients who underwent surgical treatment of IN. Patients who satisfied our inclusion and exclusion criteria were categorized into two groups based on the surgical treatment received: IML release with neurolysis or interdigital neurectomy. Outcomes assessed included recurrence of symptoms, rate of revision surgery, and postoperative wound infection. RESULTS: Of the total sample, 40 patients (31.5%) reported recurrence of symptoms within a 12-month follow-up period. Patients who underwent IML release with neurolysis had a markedly higher recurrence rate (47.50%) than those who underwent interdigital neurectomy (24.14%). The rate of postoperative wound infection was similar between the two groups. Binary logistic regression revealed that only the surgical technique was associated with the recurrence of symptoms. Despite the higher rate of symptom recurrence in the IML release with neurolysis patient group, the rate of revision surgery in those with symptom recurrence was similar between both groups. DISCUSSION: IML release with neurolysis seems to have a higher risk of symptom recurrence than interdigital neurectomy. No patient-specific factors were identified as being associated with symptom recurrence. However, patients who did experience symptom recurrence in either surgical group had similar rates of revision surgery, which may be due to mild recurrent symptom severity in the IML release group that does not warrant revision surgery in these patients. Future studies should consider objective symptom recurrence severity and patient satisfaction. LEVEL OF EVIDENCE: Level III.

Critical Portions of a Foot or Ankle Surgical Procedure From Patient and Surgeon Perspectives.

BACKGROUND: Over the past decade, overlapping procedures in orthopaedic surgery have come under increased public scrutiny. Central to this discussion is what should constitute a "critical portion" of any surgical procedure-a definition which may differ between patients and surgeons. This study therefore aimed to assess which components of three common foot and ankle procedures are considered "critical" from both the patient and surgeon perspectives. METHODS: For this survey-based study, questionnaires were administered to patients who presented to an orthopaedic foot and ankle clinic and separately administered to foot and ankle surgeons through e-mail. The questionnaires broached all steps involved in three common foot and ankle procedures: open reduction and internal fixation of ankle fracture, Achilles tendon repair, and ankle arthroscopy. Respondents were asked to characterize each step as "always critical," "often critical," sometimes critical," rarely critical," or "never critical." A combined "always critical" and "often critical" response rate of greater than 50% was used to define a step as genuinely critical. Patient and surgeon responses were thereafter compared using Mann-Whitney U and Kruskal-Wallis tests ( P -value <0.05 was considered significant). RESULTS: Notably, both patients and surgeons considered informed consent, preoperative marking of the surgical site, preoperative time-out, surgical soft-tissue dissection, and certain procedure-specific steps (critical portions) of these procedures. By contrast, only patients considered skin incision and wound closure to be critical steps. CONCLUSION: Patients and surgeons were largely in agreement as to what should comprise the critical portions of several common foot and ankle procedures. Certain discrepancies did exist, however, such as skin incision and closure, and both groups were also in general agreement regarding what was not considered a critical component of these operations. Such findings highlight a potential opportunity for improved preoperative patient education and patient-physician communication. LEVEL OF EVIDENCE: Level IV: Evidence from well-designed case-control or cohort studies.

The Influence of Patient Characteristics and Social Determinants of Health on Postoperative Complications Following Achilles Tendon Rupture.

BACKGROUND: The influence of social determinants of health (SDH) on postoperative complications has been investigated in several studies, although correlation with Achilles tendon rupture (ATR) repair remains uninvestigated. SDH encompasses several factors, including insurance status and area-based measurements, including the Area Deprivation Index (ADI) and Social Vulnerability Index (SVI), which ranks neighborhoods by social disadvantage. This study investigated the correlation between patient demographics, SDH, and complications following ATR repair. METHODS: A retrospective cohort study was conducted on 521 patients who presented with acute ATR and met the inclusion criteria, including age ≥18 years, a minimum of 30-day follow-up, and repair within 28 days of rupture. We reviewed patient demographics, time to surgery (TTS), and postoperative complications, including venous thromboembolism (VTE), rerupture, surgical site infection (SSI), wound dehiscence, and sural nerve injury. SDH variables included race, smoking status, insurance status, level of education, ADI, and SVI. Univariate regression tested the correlation between complications and SDH indicators. Significant variables (P < .05) were included in a multivariate regression. RESULTS: Sixty-eight complications occurred in 59 patients (11.3%). Multivariate regression showed that a higher ADI, that is, socially deprived individuals, was associated with lower rates of VTE (OR = 0.41, P = .04). Higher body mass index (BMI) was associated with rerupture (OR = 8.73, P < .01). Male patients had lower rates of wound dehiscence (OR = 0.31, P = .03) and VTE (OR = 0.32, P = .02) compared with women. Longer TTS correlated with sural nerve injuries (OR = 2.23, P < .01) and shorter TTS with reruptures (OR = 0.02, P = .02). CONCLUSION: Some measures of SDH were associated with postoperative complications. Gender also may have an effect, with male sex associated with lower rates of wound dehiscence and VTE. BMI was associated with higher rates of reruptures and overall general complications.

Automation improves the efficiency of weightbearing CT scan 3D volumetric assessments of the syndesmosis.

BACKGROUND: Weight-bearing CT (WBCT) 3D volumetric measurement has shown promising accuracy for the diagnosis of syndesmotic instability. However, these measurements are rather complex and time-consuming, rendering them a clinically unfavorable option. We hypothesized that automatized measurements would be more accurate and time-efficient than manual ones. METHODS: Thirty cases of intraoperatively confirmed syndesmotic instability along with thirty individuals with no injuries to the ankle joint were recruited as cases and controls, retrospectively. Two observers conducted the manual volumetric measurements two times, at a one-week interval. An automated algorithm for 3D WBCT measurements was developed to conduct the measurements on the axial images. The time spent on each method was recorded. Mann-Whitney U test was used to compare the values between human raters and computers. Inter- and intra-class reliability were calculated. RESULTS: The intra-class correlation coefficient was found to be "excellent" for the automated measurements (0.97) and "good" for the observers (0.75). Similarly, the Cronbach's alpha was shown to be higher for the computer (0.88) than the observers (0.60 and 0.62). The mean time spent on the measurements was different between human raters and the computer-assisted method (p < 0.001). CONCLUSION: Automated volumetric assessment of syndesmosis seems to be a faster and more reliable option than the manual one. We suggest future larger-scale prospective studies conducted under actual clinical circumstances for more definitive conclusions. LEVEL OF EVIDENCE: Retrospective case-control study - Level 3.

Using machine learning in the prediction of symptomatic venous thromboembolism following ankle fracture.

BACKGROUND: Venous thromboembolism (VTE) is a major cause of morbidity and mortality in the trauma setting, and both prediction and prevention of VTE have long been a concern for healthcare providers in orthopedic surgery. The purpose of this study was to evaluate the use of novel statistical analysis and machine-learning in predicting the risk of VTE and the usefulness of prophylaxis following ankle fractures. METHODS: The medical profiles of 16,421 patients with ankle fractures were screened retrospectively for symptomatic VTE. In total, 238 patients sustaining either surgical or nonsurgical treatment for ankle fracture with subsequently confirmed VTE within 180 days following the injury were placed in the case group. Alternatively, 937 patients who sustained ankle fractures managed similarly but had no documented evidence of VTE were randomly chosen as the control group. Individuals from both the case and control populations were also divided into those who had received VTE prophylaxis and those who had not. Over 110 variables were included. Conventional statistics and machine learning methods were used for data analysis. RESULTS: Patients who had a motor vehicle accident, surgical treatment, increased hospital stay, and were on warfarin were shown to have a higher incidence of VTE, whereas patients who were on statins had a lower incidence of VTE. The highest Area Under the Receiver Operating Characteristic Curves (AUROC) showing the performance of our machine learning approach was 0.88 with 0.94 sensitivity and 0.36 specificity. The most balanced performance was seen in a model that was trained using selected variables with 0.86 AUROC, 0.75 sensitivity, and 0.85 specificity. CONCLUSION: By using machine learning, this study successfully pinpointed several predictive factors linked to the occurrence or absence of VTE in patients who experienced an ankle fracture. Training these algorithms using larger, more granular, and multicentric data will further increase their validity and reliability and should be considered the standard for the development of such algorithms. LEVEL OF EVIDENCE: Case-Control study - 3.

Talonavicular Osteochondral Lesions: Surgical Technique and Clinical Outcomes from the Boston and Amsterdam Perspectives.

PURPOSE: The primary purpose of the present study was to assess the patient-reported outcomes, complications, and reoperation rate of patient who underwent surgical treatment for symptomatic osteochondral lesions of the talonavicular joint (TNJ). METHODS: Patients undergoing surgical treatment for symptomatic osteochondral lesions of the TNJ with a minimum of 12-month follow-up were included. Outcomes included clinical patient-reported outcome measures (PROMs), return to sports and work outcomes, and postoperative complications or reoperations. Medical records were screened by 2 independent reviewers. Patients were contacted by phone and underwent an in-depth interview. Additionally, operative techniques for both arthroscopic and open surgical approaches for treating TNJ osteochondral lesions were described. DESIGN: Retrospective Case Series (Level IV) and Surgical Technique. RESULTS: A total of 7 patients were included with a final follow-up time of 25.4 (SD: 15.2) months follow-up. PROMs were considered satisfactory for 5 out of 7 patients, 6 out of 7 patients returned to any level of sports at a mean of 3.7 (SD: 4.2) months, and 5 out of 6 patients returned to preinjury level of sports at a mean of 14 (SD: 7.5) months. All patients returned to work at an average of 5.4 (SD: 3.6) weeks. No complications or reoperations after index surgery were reported. CONCLUSION: Surgical treatment of TNJ osteochondral lesions is a feasible procedure that may offer successful clinical, sport, and work outcomes in the majority of patients. Both open and arthroscopic surgical treatments are available and can be considered in a patient-specific treatment plan.

Comparison between achilles tendon reinsertion and dorsal closing wedge calcaneal osteotomy for the treatment of insertional achilles tendinopathy: A meta-analysis.

BACKGROUND: The debridement and Achilles tendon reinsertion (DATR) have been the most common surgical approach for the treatment of Insertional Achilles Tendinopathy (IAT), while dorsal closing wedge calcaneal osteotomy (DCWCO) has recently gained popularity as an alternative surgical option. This study aimed to systematically review the published literature on both surgical techniques and compare their clinical outcomes and complication rates. METHODS: A systematic review was performed according to the PRISMA guidelines using Medline, Embase, and Scopus databases. The inclusion criteria encompassed clinical studies reporting functional outcomes and complications, with a minimum of 10 patients and at least 12 months of follow-up. RESULTS: Seven studies (n = 169) were included for the analysis of DATR, and eight studies (n = 227) were included for the analysis of open DCWCO. Both groups showed a similar improvement in AOFAS score. The overall complication rates were 16.6% in the DATR group and 9.2% in the DCWCO group, but the difference was not statistically significant. However, there was a significantly higher incidence of wound complications in the DATR group (10.1%, 95% C.I.: 4.7-15.6) compared to the DCWCO group (2.5%, 95% C.I.: 0.6-4.4) as the confidence intervals did not overlap. CONCLUSIONS: Clinical outcomes and overall complication rates of both techniques were comparable, although DCWCO had a lower incidence of wound complications. Further research should be focused on prospective studies comparing the two techniques to corroborate the current findings. LEVEL OF EVIDENCE: Level IV; meta-analysis.

The use of deep learning enables high diagnostic accuracy in detecting syndesmotic instability on weight-bearing CT scanning.

PURPOSE: Delayed diagnosis of syndesmosis instability can lead to significant morbidity and accelerated arthritic change in the ankle joint. Weight-bearing computed tomography (WBCT) has shown promising potential for early and reliable detection of isolated syndesmotic instability using 3D volumetric measurements. While these measurements have been reported to be highly accurate, they are also experience-dependent, time-consuming, and need a particular 3D measurement software tool that leads the clinicians to still show more interest in the conventional diagnostic methods for syndesmotic instability. The purpose of this study was to increase accuracy, accelerate analysis time, and reduce interobserver bias by automating 3D volume assessment of syndesmosis anatomy using WBCT scans. METHODS: A retrospective study was conducted using previously collected WBCT scans of patients with unilateral syndesmotic instability. One-hundred and forty-four bilateral ankle WBCT scans were evaluated (48 unstable, 96 control). We developed three deep learning models for analyzing WBCT scans to recognize syndesmosis instability. These three models included two state-of-the-art models (Model 1-3D Convolutional Neural Network [CNN], and Model 2-CNN with long short-term memory [LSTM]), and a new model (Model 3-differential CNN LSTM) that we introduced in this study. RESULTS: Model 1 failed to analyze the WBCT scans (F1 score = 0). Model 2 only misclassified two cases (F1 score = 0.80). Model 3 outperformed Model 2 and achieved a nearly perfect performance, misclassifying only one case (F1 score = 0.91) in the control group as unstable while being faster than Model 2. CONCLUSIONS: In this study, a deep learning model for 3D WBCT syndesmosis assessment was developed that achieved very high accuracy and accelerated analytics. This deep learning model shows promise for use by clinicians to improve diagnostic accuracy, reduce measurement bias, and save both time and expenditure for the healthcare system. LEVEL OF EVIDENCE: II.

Correlation Between Statin Use and Symptomatic Venous Thromboembolism Incidence in Patients With Ankle Fracture: A Machine Learning Approach.

BACKGROUND: Identifying factors that correlate with the incidence of venous thromboembolism (VTE) has the potential to improve VTE prevention and positively influence decision-making regarding prophylaxis. In this study, we aimed to investigate the correlation between statin consumption and the incidence of VTE in patients who sustained an ankle fracture. METHODS: In this retrospective, case-controlled study, cases were those who developed VTE and controls were those who had no VTE, and the ratio was 1:4. Patients' demographics, history of hyperlipidemia, and reported statins use were obtained. A random forest classifier (RFC) model was used to predict whether statin consumers were at risk of VTE after ankle fracture regardless of VTE prophylaxis administration based on statin consumption, body mass index (BMI), age, and biological sex. RESULTS: Of the 1175 patients with ankle fractures, 238 had confirmed VTE (case group), and 937 had no symptomatic VTE (control group; ratio 1:4). Fifty (21%) cases and 407 (43%) controls were on a statin. Statin users had a significantly lower incidence of VTE after ankle fracture, odds ratio (OR) = 0.35, 95% CI: 0.25, 0.49, P < .001. Our model showed an area under the receiving operator curve (AUROC) of 78%, a sensitivity of 73%, and a specificity of 83% in predicting the risk of VTE. The importance of the predictors of VTE, other than the use of statins (model importance = 0.1), were age (model importance of 0.72), BMI (model importance of 0.24), and biological sex (model importance of 0.02). CONCLUSION: Statins were significantly associated with a lower rate of VTE in our population of patients who sustained an ankle fracture. LEVELS OF EVIDENCE: 3.

Republication of "Stress Fractures of the Foot and Ankle in Athletes".

Stress fractures of the foot and ankle are common injuries in athletes. Management differs considerably based on fracture location and predisposing factors. Repetitive loading of the foot and ankle in athletes should result in physiologic bone remodeling in accordance with Wolff's law. However, when there is not sufficient time for complete healing to occur before additional loads are incurred, this process can instead lead to stress fracture. Assessment of the athlete's training regimen and overall bone health is paramount to both the discovery and treatment of these injuries, although diagnosis is often delayed in the setting of normal-appearing initial radiographs. While most stress fractures of the foot or ankle can usually be treated nonoperatively with a period of activity modification, fractures in certain locations are considered "high risk" due to poor intrinsic healing and may warrant more proactive operative management.

Evaluating and Comparing the Correlation and Performance of PROMIS and FAAM ADL in a Foot and Ankle Patient Population.

BACKGROUND: There is a paucity of literature assessing 2 of the commonly used static Patient-Reported Outcomes Measurement Information System (PROMIS) forms (PROMIS Global-10 and PROMIS Physical Function Short Form 10a [PF SF 10a]) and the Foot and Ankle Ability Measure Activities of Daily Living (FAAM ADL). METHODS: The PROMIS Global-10, PROMIS PF SF 10a, and FAAM ADL were compared among new foot and ankle patients. Spearman rho (ρ) correlations were calculated, and ceiling and floor effects were determined. RESULTS: The FAAM ADL demonstrated strong correlations with PROMIS PF SF 10a, P = .88, 95% confidence interval (CI): 0.86-0.90, P < .001, and PROMIS Global-10 Physical Health (P = .75, 95% CI: 0.71-0.78, p < .001). The FAAM ADL and PROMIS Global-10 Mental Health demonstrated a moderate correlation (P = .41, 95% CI: 0.34-0.47, P < .001). No PROM demonstrated an appreciable floor effect. The PROMIS Global-10 Physical Health demonstrated the lowest ceiling effect (n=11 [1.6%]). CONCLUSION: Because the PROMIS Global-10 captures physical health adequately, provides mental health insight, and performs as well (if not better), we recommend the PROMIS Global-10 among the PROMs studied.Level of Evidence: Level III.

Implementing automated 3D measurements to quantify reference values and side-to-side differences in the ankle syndesmosis.

Detection of syndesmotic ankle instability remains challenging in clinical practice due to the limitations of two-dimensional (2D) measurements. The transition to automated three-dimensional (3D) measurement techniques is on the verge of a breakthrough but normative and side-to-side comparative data are missing. Therefore, our study aim was two-fold: (1) to establish 3D anatomical reference values of the ankle syndesmosis based on automated measurements and (2) to determine to what extent the ankle syndesmosis is symmetric across all 3D measurements. Patients without syndesmotic pathology with a non-weight-bearing CT scan (NWBCT; N = 38; Age = 51.6 ± 17.43 years) and weight-bearing CT scan (WBCT; N = 43; Age = 48.9 ± 14.3 years) were retrospectively included. After training and validation of a neural network to automate the segmentation of 3D ankle models, an iterative closest point registration was performed to superimpose the left on the right ankle. Subsequently, 3D measurements were manually and automatically computed using a custom-made algorithm and side-to-side comparison of these landmarks allowed one to investigate symmetry. Intra-observer analysis showed excellent agreements for all manual measurements (ICC range 0.85-0.99) and good (i.e. < 2.7° for the angles and < 0.5 mm for the distances) accuracy was found between the automated and manual measurements. A mean Dice coefficient of 0.99 was found for the automated segmentation framework. The established mean, standard deviation and range were provided for each 3D measurement. From these data, reference values were derived to differ physiological from pathological syndesmotic alignment. Furthermore, side-to-side symmetry was revealed when comparing left to right measurements (P > 0.05). In clinical practice, our novel algorithm could surmount the current limitations of manual 2D measurements and distinguish patients with a syndesmotic ankle lesion from normal variance.

Development and external validation of automated detection, classification, and localization of ankle fractures: inside the black box of a convolutional neural network (CNN).

PURPOSE: Convolutional neural networks (CNNs) are increasingly being developed for automated fracture detection in orthopaedic trauma surgery. Studies to date, however, are limited to providing classification based on the entire image-and only produce heatmaps for approximate fracture localization instead of delineating exact fracture morphology. Therefore, we aimed to answer (1) what is the performance of a CNN that detects, classifies, localizes, and segments an ankle fracture, and (2) would this be externally valid? METHODS: The training set included 326 isolated fibula fractures and 423 non-fracture radiographs. The Detectron2 implementation of the Mask R-CNN was trained with labelled and annotated radiographs. The internal validation (or 'test set') and external validation sets consisted of 300 and 334 radiographs, respectively. Consensus agreement between three experienced fellowship-trained trauma surgeons was defined as the ground truth label. Diagnostic accuracy and area under the receiver operator characteristic curve (AUC) were used to assess classification performance. The Intersection over Union (IoU) was used to quantify accuracy of the segmentation predictions by the CNN, where a value of 0.5 is generally considered an adequate segmentation. RESULTS: The final CNN was able to classify fibula fractures according to four classes (Danis-Weber A, B, C and No Fracture) with AUC values ranging from 0.93 to 0.99. Diagnostic accuracy was 89% on the test set with average sensitivity of 89% and specificity of 96%. External validity was 89-90% accurate on a set of radiographs from a different hospital. Accuracies/AUCs observed were 100/0.99 for the 'No Fracture' class, 92/0.99 for 'Weber B', 88/0.93 for 'Weber C', and 76/0.97 for 'Weber A'. For the fracture bounding box prediction by the CNN, a mean IoU of 0.65 (SD ± 0.16) was observed. The fracture segmentation predictions by the CNN resulted in a mean IoU of 0.47 (SD ± 0.17). CONCLUSIONS: This study presents a look into the 'black box' of CNNs and represents the first automated delineation (segmentation) of fracture lines on (ankle) radiographs. The AUC values presented in this paper indicate good discriminatory capability of the CNN and substantiate further study of CNNs in detecting and classifying ankle fractures. LEVEL OF EVIDENCE: II, Diagnostic imaging study.

Short-Term Risk Factors for Subtalar Arthrodesis After Primary Tibiotalar Arthrodesis.

While adjacent joint arthritis is a recognized long-term downside of primary tibiotalar arthrodesis (TTA), few studies have identified risk factors for early subtalar arthrodesis (STA) after TTA. This study aims to identify the risk factors for STA within the first few years following TTA. All patients older than 18 years undergoing TTA between 2008 and 2016 were identified retrospectively. Demographic data and comorbidities were collected alongside prior operative procedures, postoperative complications, and subsequent STA. Pre-and postoperative Kellgren-Lawrence osteoarthritis grade of the subtalar joint and postoperative radiographic alignment were obtained. A total of 240 patients who underwent primary TTA were included in this study with median follow up of 13.8 months. Twenty patients (8.3%) underwent STA after TTA due to symptomatic nonunion of TTA in 13 (65%), progression of symptomatic subtalar osteoarthritis (OA) in 4 (20%), and symptomatic nonunion of primary TTA combined progressively symptomatic subtalar OA in 2 (10%). Preoperative radiographic subtalar OA severity and postoperative radiographic alignment were not correlated with subsequent STA. Diabetes mellitus, Charcot arthropathy, neuropathy, alcohol use, substance use disorder, and psychiatric disease were significantly associated with having a subsequent STA. The most common postoperative contributing factor for subsequent STA following primary TTA was the salvage of symptomatic ankle nonunion rather than subtalar joint disease. Patients considering an ankle fusion should be counseled of the risk of subsequent STA, especially if they have risk factors that include diabetes, Charcot arthropathy, neuropathy, alcohol use, substance use disorder, or psychiatric disease.

Arthroscopic assessment of syndesmotic instability: Are we pulling correctly in the coronal plane?

BACKGROUND: While the lateral hook test (LHT) has been widely used to arthroscopically evaluate syndesmotic instability in the coronal plane, it is unclear whether the angulation of the applied force has any impact on the degree of instability. We aimed to determine if changing the direction of the force applied while performing the LHT impacts the amount of coronal diastasis observed in subtle syndesmotic injuries. METHODS: In 10 cadaveric specimens, arthroscopic evaluation of the syndesmotic joint was performed by measuring anterior and posterior-third coronal plane diastasis in the intact state, and repeated after sequential transection of the 1) anterior inferior tibiofibular ligament (AITFL), 2) interosseous ligament (IOL), and 3) posterior inferior tibiofibular ligament (PITFL). In all scenarios, LHT was performed under 100 N of laterally directed force. Additionally, LHT was also performed under: 1) anterior inclination of 15 degrees and 2) posterior inclination of 15 degrees in intact and AITFL+IOL deficient state. RESULTS: Compared to the intact state, the syndesmosis became unstable after AITFL +IOL transection under laterally directed force with no angulation (p = 0.029 and 0.025 for anterior and posterior-third diastasis, respectively), which worsened with subsequent PITFL transection (p = <0.001). Moreover, there was no statistical difference in anterior and posterior-third coronal diastasis in both intact and AITFL+IOL deficient states under neutral, anterior, and posteriorly directed force (p-values ranging from 0.816 to 0.993 and 0.396-0.80, respectively). However, in AITFL+IOL transected state, posteriorly directed forces resulted in greater diastasis than neutral or anteriorly directed forces. CONCLUSIONS: Angulation of the applied force ranging from 15 degrees anteriorly to 15 degrees posteriorly during intraoperative LHT has no effect on coronal plane measurements in patients with subtle syndesmotic instability. On the other hand, posteriorly directed forces result in more sizable diastasis, potentially increasing their sensitivity. CLINICAL RELEVANCE: When arthroscopically evaluating subtle syndesmotic instability, clinicians should assess coronal diastasis with the hook angled 15 degrees posteriorly.

Dynamic Ultrasound Can Accurately Quantify Severity of Medial Knee Injury: A Cadaveric Study.

Purpose: To quantify the severity of medial knee injuries based on medial compartment gapping as measured by stress ultrasonography. Methods: In 8 cadaveric knees, the distance between the medial tibial and femoral condyles was measured using ultrasonography. These measurements were obtained in the intact state and repeated after open sequential transection of the superficial medial collateral ligament (sMCL), deep medial collateral ligament (dMCL), posterior oblique ligament (POL), and arthroscopic transection of the anterior cruciate ligament (ACL). Knees were evaluated at 0° and 20° of knee flexion using the Telos device under 0 N and 100 N of valgus force. Receiver operating characteristic curve analysis and the DeLong test were used to determine whether measurements could distinguish between successive severity of MCL injury after identifying the optimal cutoff value for each injury state. Results: Of the 8 cadaveric knees included in this study, 3 were male and 5 were female. The mean age was 58 ± 11 years (range 48-82 years). When measured using ultrasonography at 20° knee flexion with valgus load, the medial tibiofemoral distance significantly increased with increasing severity of medial knee injury (P values ranging from .049 to <.001). The optimal cutoff values for distinguishing between an intact knee and sMCL injury were 8.3 mm (area under the curve [AUC] = 0.98), between sMCL and dMCL injury 9.9 mm (AUC = 0.89), dMCL and POL 16.7 mm (AUC = 0.88), and POL and ACL 18.6 mm (AUC = 0.84). When we compared combined intact and sMCL-transected stages with dMCL-transected stage, the optimal cut-off point to differentiate stable from unstable injuries was equal to 13.8 mm of medial tibiofemoral distance (AUC = 0.97; sensitivity = 100%; specificity = 94.1%). Conclusions: Dynamic ultrasonographic assessment can accurately quantify the severity of medial knee ligament injury based on medial compartment gapping. In our study, we found medial tibiofemoral distance >13.8 mm at 20° knee flexion under valgus force indicates the presence of dMCL injury with a diagnostic accuracy of 0.97. Clinical Relevance: Dynamic ultrasonography can quantify severity of medial knee injury without radiation and at point of care in multiple clinical settings.