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Whether or not populations diverge with respect to the genetic contribution to risk of specific complex diseases is relevant to understanding the evolution of susceptibility and origins of health disparities. Here, we describe a large-scale whole-genome sequencing study of inflammatory bowel disease encompassing 1,774 affected individuals and 1,644 healthy control Americans with African ancestry (African Americans). Although no new loci for inflammatory bowel disease are discovered at genome-wide significance levels, we identify numerous instances of differential effect sizes in combination with divergent allele frequencies. For example, the major effect at PTGER4 fine maps to a single credible interval of 22 SNPs corresponding to one of four independent associations at the locus in European ancestry individuals but with an elevated odds ratio for Crohn disease in African Americans. A rare variant aggregate analysis implicates Ca2+-binding neuro-immunomodulator CALB2 in ulcerative colitis. Highly significant overall overlap of common variant risk for inflammatory bowel disease susceptibility between individuals with African and European ancestries was observed, with 41 of 241 previously known lead variants replicated and overall correlations in effect sizes of 0.68 for combined inflammatory bowel disease. Nevertheless, subtle differences influence the performance of polygenic risk scores, and we show that ancestry-appropriate weights significantly improve polygenic prediction in the highest percentiles of risk. The median amount of variance explained per locus remains the same in African and European cohorts, providing evidence for compensation of effect sizes as allele frequencies diverge, as expected under a highly polygenic model of disease.

BACKGROUND & AIMS: The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohns disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities. METHODS: We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P

Background & aimsInflammatory bowel disease (IBD) has familial aggregation in African Americans (AAs), but little is known about the molecular genetic susceptibility. Mapping studies using the Immunochip genotyping array expand the number of susceptibility loci for IBD in Caucasians to 163, but the contribution of the 163 loci and European admixture to IBD risk in AAs is unclear. We performed a genetic mapping study using the Immunochip to determine whether IBD susceptibility loci in Caucasians also affect risk in AAs and identify new associated loci.MethodsWe recruited AAs with IBD and without IBD (controls) from 34 IBD centers in the United States; additional controls were collected from 4 other Immunochip studies. Association and admixture loci were mapped for 1088 patients with Crohn's disease, 361 with ulcerative colitis, 62 with IBD type unknown, and 1797 controls; 130,241 autosomal single-nucleotide polymorphisms (SNPs) were analyzed.ResultsThe strongest associations were observed between ulcerative colitis and HLA rs9271366 (P = 7.5 × 10(-6)), Crohn's disease and 5p13.1 rs4286721 (P = 3.5 × 10(-6)), and IBD and KAT2A rs730086 (P = 2.3 × 10(-6)). Additional suggestive associations (P < 4.2 × 10(-5)) were observed between Crohn's disease and IBD and African-specific SNPs in STAT5A and STAT3; between IBD and SNPs in IL23R, IL12B, and C2orf43; and between ulcerative colitis and SNPs near HDAC11 and near LINC00994. The latter 3 loci have not been previously associated with IBD, but require replication. Established Caucasian associations were replicated in AAs (P < 3.1 × 10(-4)) at NOD2, IL23R, 5p15.3, and IKZF3. Significant admixture (P < 3.9 × 10(-4)) was observed for 17q12-17q21.31 (IZKF3 through STAT3), 10q11.23-10q21.2, 15q22.2-15q23, and 16p12.2-16p12.1. Network analyses showed significant enrichment (false discovery rate

Category: Midfoot/Forefoot Introduction/Purpose: Pes Planus (flatfoot) and Pes Cavus (high arch) are common foot deformities requiring clinical assessment and radiographic imaging for diagnosis and subsequent management. While effective, traditional diagnostic methods pose limitations such as cost, radiation exposure, and accessibility, particularly in underserved areas. With the advent of artificial intelligence and its integration into mobile cameras, we aim to develop a tool that detects and classifies such deformities using photos taken with smartphone cameras. Methods: An algorithm that integrated a deep learning, convolutional neural network (CNN) into a smartphone camera was utilized to detect Pes planus and Pes cavus deformities. The study was conducted at a tertiary hospital with participants recruited from two orthopaedic foot and ankle clinics. The CNN model was trained and tested using photographs of the medial aspect of participants' feet. Participants included subjects with standard foot alignment, pes planus, or pes cavus determined by an expert clinician using the Foot Posture Index (FPI). The model's performance was compared to clinical assessment and radiographic measurements, including the lateral tarsal-first metatarsal angle (LTMA) and calcaneal inclination angle (CIA). Results: The CNN model demonstrated high accuracy in diagnosing Pes planus and Pes cavus, with an optimized area under the curve of 0.897 for Pes Planus and 0.898 for Pes cavus. It showed a specificity and sensitivity of 84% and 87% for Pes Planus detection, respectively; for Pes cavus, 97% and 70%, respectively. The model's prediction correlated moderately and significantly with radiographic LTMA measurements (r=-0.65, P< 0.001), indicating the model's excellent reliability in assessing food arch deformity. Conclusion: Our smartphone-based CNN model is highly accurate as a decision-support tool, and it is reliable and accessible for predicting Pes planus and Pes cavus deformities. This tool may be very useful in underserved healthcare settings and for patients with limited access to expert clinical assessment. Future efforts should enhance this technology for pediatric use and improve severity differentiation, paving the way for more personalized and inclusive healthcare solutions. [ABSTRACT FROM AUTHOR]

Category: Bunion; Other Introduction/Purpose: Hallux valgus (HV) is a prevalent forefoot deformity that leads to pain, stiffness, and difficulties with footwear. Conventional diagnosis of HV relies on clinical and radiographic examination, which can be cumbersome and expose patients to ionizing radiation. The emergence of 3D scanning technologies, such as structured light, integrated into smartphones, presents a novel approach to early detection and diagnosis of HV, potentially allowing for earlier intervention and subsequent reduction in the progression of the deformity. Methods: This prospective non-randomized clinical trial recruited patients from the foot and ankle clinic, identifying cases and controls based on the presence or lack of clinically diagnosed HV. Patients older than 18 years of age and able to consent were included. The 3D scanning of the foot utilized structured light technology integrated into smartphones, with an algorithm developing a surrogate angle for HV detection. This angle was correlated with conventional radiographic measurements, including hallux valgus angle (HVA) and intermetatarsal angle (IMA) from weightbearing radiographs. A cluster analysis assessed the algorithm's capacity to identify deformity severity according to radiographic severity grading. The algorithm's accuracy and performance were assessed using the area under the receiver operating characteristic curve, precision-recall Curves, and the leave-one-out cross-validation method. Results: 120 patients were enrolled in this trial. Out of 240 feet examined, HV was present in 29.1% of cases. The algorithm's surrogate angle showed a robust correlation with the clinical hallux valgus angle (HVA), with a correlation coefficient of 0.91 and a specificity of 0.882. Notably, the surrogate angle's correlation with the intermetatarsal angle (IMA) was also significant, albeit lower (r = 0.65). The area under the ROC curve (AUC) was 0.947, and the precision-recall AUC scores for positive and negative classes were 0.89 and 0.92, respectively. These metrics confirmed the algorithm's potential as a reliable diagnostic tool for detecting HV and determining its severity through non-invasive, commonly available smartphone technology. Conclusion: This study validates the accuracy of a smartphone-based 3D scanning algorithm in detecting and grading HV deformity, providing a low-cost, accessible decision-support tool for physicians and patients. This approach could improve early detection, reduce the need for clinical visits, and potentially expand to remote monitoring of HV and other pathologies, aligning with the growing trend of telemedicine and personalized healthcare. [ABSTRACT FROM AUTHOR]

Category: Hindfoot; Trauma Introduction/Purpose: Fractures of the calcaneus are the most frequent form of fractures among the tarsal bones. The treatment plan depends on various fracture characteristics, particularly the extension of the fracture line into the subtalar joint surfaces. While X-rays are the primary diagnostic tool, Computed Tomography (CT) scans are often necessary as they provide a more detailed description of these fractures, especially if the articular surfaces are involved. Although informative, CT scans expose patients to higher doses of ionizing radiation, and they might not be readily available in certain settings. This study aims to develop a deep learning model that will first detect calcaneal fractures and then classify the type of fracture based on its extension into the subtalar joint surfaces. Methods: A retrospective case-control study was conducted. Patients aged >18 years who sustained a calcaneal fracture were included in the case group, along with the same number of healthy adults for the control group. Various X-ray views of the foot including anterior, posterior, lateral, along with the axial and lateral calcaneal views were obtained. Two experienced orthopaedic researchers screened the dataset and confirmed the type of fracture. Two models were developed using an Inception V3 architecture and a split ratio of 60:20:20 for training, validation, and testing purposes. The first model was designed for fracture detection, and the second one was designed for detecting intra-articular fracture extension, if present. Conventional model metrics including sensitivity, specificity, Youden index, area under the receiver operating characteristic curve (AUC), and F1 score were reported for each model. A p-value below 0.05 was statistically significant. Baseline values are presented in median and interquartile ranges (IQR). Results: A total of 1102 individuals (n=551 for each group) with a female-to-male ratio of 1.6:1 were included. Baseline comparisons showed a significant difference in the age of the groups [cases: 55 (IQR 42, 67) years; controls: 62 (IQR 51, 72 years), p-value < 0.001]. The first model for fracture detection demonstrated a high performance with an AUC of 0.99 and a Youden index of 0.96. The intra-articular fracture detection model showed a slightly lower performance with an AUC of 0.97 and a Youden index of 0.88 (Table 1, Figure 1). Conclusion: Our study showed promising results with the utility of deep learning methods for detecting calcaneal fractures and classifying intra- vs extra-articular fractures. This algorithm may help facilitate the diagnosis and treatment of patients with suspected calcaneal fractures, serving as a decision-support tool in settings where CT scanning is not available. [ABSTRACT FROM AUTHOR]

Category: Midfoot/Forefoot; Trauma Introduction/Purpose: Lisfranc injuries have a reported incidence of 1 in 55,000 people. However, given the subtle displacement present in some of these injuries, up to one third are missed on initial diagnosis. Weightbearing imaging is the gold standard for evaluation and diagnosis of the Lisfranc complex, and diastasis between the medial cuneiform and second metatarsal (C1-M2) is the most commonly discussed parameter. However, no explicit consensus on precisely where within the Lisfranc complex to measure the diastasis has been established. Therefore, the aim of this study was to determine what specific diastasis measurement is most sensitive in diagnosing Lisfranc instability using weightbearing radiographs and computed tomography (WBCT). Methods: A total of 159 adult patients with bilateral foot WBCTs were included: 44 with confirmed Lisfranc instability and 115 controls. A subset had unilateral weightbearing X-rays (38 and 83 patients, respectively). Lisfranc instability was confirmed intraoperatively or by physical exam. Exclusion criteria were: prior midfoot surgery, Charcot arthropathy, severe midfoot arthropathy, cuneiform fractures, and significantly displaced 1st-3rd metatarsal base fractures. In the axial plane, C1-M2 diastasis was measured on weightbearing radiograph and WBCT. In the coronal plane, diastasis was measured at different levels between C1-M2 (dorsal, interosseus, plantar, planter apex) and C1-M3 (plantar apex) on WBCT. For WBCT measurements, percent difference between feet was calculated. Case and control measurements were compared with Mann-Whitney U tests (p < 0.05). Diagnostic cutoffs were determined using receiver operator curves (ROC) and minimum distance to the corner. Sensitivity, specificity, negative and positive predictive values, and area under the curve were calculated for each cutoff value. Results: A significant portion of the subjects were female (Lisfranc instability: 60% and controls: 61%). Average age was 39±17 years and 44±17 years for the Lisfranc instability and control groups, respectively. Mann-Whitney U testing revealed a significant difference between groups for all measurements except plantar C1-M2 (p=0.13), C1-M2 plantar apex (p=0.69) and C1-M3 plantar apex (p=0.07). Figure 1 summarizes the diagnostic cutoff values and the associated efficacy measures. Axial WBCT diastasis was the most effective diagnostic measure, followed by dorsal coronal WBCT diastasis. Using a percent difference cutoff of 34%, axial WBCT diastasis (AUC=0.90) demonstrated outstanding diagnostic capability. Dorsal coronal WBCT diastasis with a percent difference cutoff of 46% (AUC=0.80) demonstrated excellent capability. The remaining measurements provided less reliable diagnostic capability, including diastasis on radiograph (AUC=0.77). Conclusion: Axial WBCT diastasis and dorsal coronal WBCT diastasis both effectively diagnose Lisfranc instability on WBCT, with axial WBCT diastasis demonstrating outstanding diagnostic capability. The traditional method of C1-M2 diastasis on weightbearing radiograph is not as effective as either of these WBCT measurements and only provides adequate diagnostic capability. Our results emphasize the value of diastasis measurements using bilateral WBCT imaging to diagnose Lisfranc instability. These results also suggest that diastasis measurements should be performed in the axial plane and on the dorsal aspect of the Lisfranc complex. [ABSTRACT FROM AUTHOR]

Category: Ankle; Trauma Introduction/Purpose: Osteochondral lesions of the talus (OLT) impact both sedentary individuals and athletes, affecting both daily function as well as athletic performance. Purported causations include trauma, genetics, and hypovascularity. Although it is known that the talar dome's vascularity is mainly supplied the posterior tibialis artery (PTA) and to a lesser degree the sinus tarsi artery (STA), the pathophysiological impact of talar dome hypovascularity on OLT remains poorly studied. Our first hypothesis was that the patients with OLT have a lower diameter of PTA (dPTA) and STA (dSTA), and the second hypothesis was that among the group of the patients with OLT, the patients that require surgery have a lower d PTA and dSTA. Methods: This was a retrospective study that included 77 patients with OLT, and for the control group 77 patients with peroneal tendinitis. To mitigate the effect of comorbidities the patients between 30 to 40 years of age were included and the ones with a history of smoking, diabetes, rheumatologic, and peripheral artery diseases were excluded. The dPTA measurements were done in three different levels for all groups: at the level of 1 cm above plafond, at the level of plafond and at the level of medial malleolar tip (MMT). dSTA was measured at the level of talar neck. Area, volume, depth, and localization of OLT were recorded, as well. Results: The study group had significantly lower dPTA at three levels (1.05±0.22mm, 0.99±0.18mm, 0.98±0.31mm, proximal to distal) compared to the control group (1.25±0.23mm, 1.20±0.22mm, 1.14±0.18mm, proximal to distal) (P< 0.001). The dSTA was also lower in study group as compared to control group (0.5±0.11mm vs. 0.57±0.08mm, respectively P=0.001). ROC Curve analysis revealed the cutoff values for OLT occurrence after ankle injury as; 1.115 mm for the level of 1 cm above plafond, 1.075 mm for the level of plafond,1.055 mm for the level of MMT, 1.085 mm for mean dTPA and 0.5665mm for dSTA (Table-1). A significant negative correlation was observed between OLT size area (mean: 42.24±24.76 mm2) and arterial diameters (P< 0.01, P< 0.01, and P=0.014 for three different levels of dPTA and P< 0.001 for dSTA). Conclusion: Smaller dPTA and dSTA appear to be associated with the occurrence of OLT, with the defect size inversely correlated to arterial diameters. The determined cutoff values for dPTA may help clinicians identify high risk patients to develop OLT after an acute ankle injury. Further elucidation of these vascular abnormalities, particularly dPTA, could hold significant prognostic potential and be used to predict disease progression as well as the likelihood of surgical success in OLT treatment. [ABSTRACT FROM AUTHOR]

Category: Ankle; Sports Introduction/Purpose: Osteochondral lesions of the talus (OLT) commonly arise after chronic ankle sprains and fractures. Conservative treatment is the first step, yet surgical intervention is often warranted in patients with persistent symptoms. The effect of social determinants of health (SDOH) on treatment outcomes of this patient population has rarely been investigated to date. Methods: Patients with OLT who were 18 years of age and older and underwent operative treatment, with at least one patient-reported outcome and SDOH data available, were included. Patient-Reported Outcome Measures (PROMs) and Visual Analog Scale (VAS) pain scores were collected, and their trends were analyzed based on the patients' SDOH, including Area DeprivationIndex(ADI)andSocialVulnerabilityIndex(SVI). Pre-operativePROMsorVAS pain scores had to have been collected within 90 days of surgery, immediate post-operative PROMs or VAS scores were recorded within 90 days of surgery were and post-operative PROMs or VAS scores within 180 days (± 30 days). Exclusion criteria were presence of concomitant pathologies such as fractures, bone lesions, cysts, foot and ankle deformities, presence of hardware, and lack of follow-up visits and lack of any patient reported outcomes in their profile. A P-value < 0.5 was considered statistically significant. Results: 109 of 551 confirmed patients with OLT met the inclusion criteria. Significant correlations were found between SDOH and PROMs, elucidating disparities in pain scores, physical function, and depression. A multitude of SVI components, but most profoundly overall SVI, and ADI rank, were found to be significantly correlated to VAS pain scores (Table 1.). Furthermore, insurance status showed a significant impact on pain intensity and depression measures. Nuanced influences of race, insurance status, and social vulnerability were observed. Conclusion: This study shows that SDOH have a significant effect on postoperative PROMs and VAS scores. Based on our results, these most prominently include overall SVI, insurance status, ethnicity, and race. Systemic interventions guided by neighborhood-level measures of disadvantage are key in advancing health equity. [ABSTRACT FROM AUTHOR]

Category: Trauma; Ankle Introduction/Purpose: Syndesmosis fixation, a common procedure, is vital for restoring ankle biomechanics, but malreduction occurs in up to 52% of cases, necessitating precise anatomic reduction. While AO guidelines recommend a 20-30 degree trajectory in the coronal plane, the proposed ideal syndesmotic alignment is the line connecting fibula and tibia centroids. Intraoperatively determining the ideal fixation angle is challenging due to non-patient-specific and surgeon-dependent angular direction decisions. This study explores the angle bisector method's potential in establishing a patient- and level-specific syndesmotic fixation angle in cadavers, aiming for reproducibility independent of the surgeon. Additionally, the research assesses the safety of this method concerning major neurovascular structures for potential surgical application. By addressing these aspects, the study contributes to enhancing the precision and reliability of syndesmotic fixation procedures. Methods: Fixations on cadaveric leg specimens were conducted utilizing the angle bisector method at two levels (2 cm and 3.5 cm proximal) parallel to the tibial plafond. Two surgeons employed an open lateral approach for the procedure. The angle bisector method involved using a drill (2.8 mm) and screw (3.5 mm) directed along the bisector of the angle formed between two percutaneously placed K-wires (1.8 mm) at the fixation level, tangent to the anterior and posterior aspects of the fibula and tibia (Figure 1a). Subsequently, CT images of the cadavers were obtained (Figure 1b). The angle between the true centroidal axis (determined by software) and the axis of the screw placed with the angle bisector method was measured. Furthermore, distances between entry points of the centroidal axis and the screw were measured. Distances in millimeters between the positioned K-wires and major neurovascular structures were measured on cadaver dissections. (Sponsored by AOFAS-grant) Results: The mean angle between the centroidal axis and the trajectory of the screw was 2.7 degrees (±2.2, range 0-9.2 degrees) at the 2 cm level and 1.8 degrees (±2.1, 0-7.8 degrees) at the 3.5 cm level. At the 2 cm level, the average distance between the fibular entry points of the centroidal axis and the screw was 1.7 mm (±1.2, range 0-3.2 mm), while at the 3.5 cm level, it was 1.2 mm (±1.3, range 0-2.5 mm). The results exhibited low inter-surgeon variability (ICC > 0.80). The distance between the placed K-wires and major neurovascular structures consistently exceeded 5 mm, ensuring the safety of the technique, as none of these structures incurred damage. Conclusion: Our findings demonstrate that the angle bisector method offers a precise trajectory for syndesmotic fixation, proving its safety and efficacy in surgical applications. It can provide a more precise and patient-specific anatomical trajectory for syndesmotic implant compared to the conventional freehand technique, without increasing fluoroscopy exposure. [ABSTRACT FROM AUTHOR]

Category: Ankle; Trauma Introduction/Purpose: There has been limited investigation into physician reimbursement trends in foot and ankle procedures. The objective of the present study is to query a large, national insurance claims database to assess how utilization and reimbursement has evolved for ankle arthrodesis (AA) and total ankle arthroplasty (TAR) procedures from 2010 to 2021. Methods: A large national insurance claims database was queried for ankle arthrodesis and total ankle arthroplasty from 2010 to 2021 using Current Procedural Terminology (CPT) codes. Utilization rates, hospital reimbursement rates by payor (commercial, Medicare, Medicaid, Government, cash, other) and demographic data including gender, age, region, payor type, and service location were extracted. Subsequently, physician Medicare reimbursement rates were obtained from 2010 to 2021 using the Physician Fee Look-up Tool from the Centers for Medicare and Medicaid Services. Dollar values were then adjusted using the Consumer Price Index and are reported in 2023 US dollars. Trend analysis of utilization and reimbursement rates was then performed, with a p value of < 0.05 as significant. Results: A total of 16833 TAR patients and 33109 AA patients were identified by the query. Both procedures demonstrated a significantly positive linear trend in volume over the included time period, with increase from 2010 to 2021 of 30.28% (2453 to 3196 patients; p< 0.001) for AA cases and 140.64% for TAR (994 to 2392 patients; p< 0.001). Without consideration of inflation, Medicare physician reimbursement values were stable, demonstrating a non-significant increase for both AA (+2.67%) and TAR (+3.40%) over the included time period. On the other hand, after accounting for inflation, values declined across both AA and TA, with decrease from 2010 to 2021 of 16.78% ($1194.24 to $993.81; p< 0.001) for TAR procedures and 17.37% ($1368.26 to $1130.62) for AA procedures (Figure 1). Conclusion: Despite the growing number of Medicare beneficiaries and utilization of TAR and AA, the present data has demonstrated a decrease in Medicare reimbursement. Knowledge of such trends is important for the orthopedic field in order to advocate for sustainable reimbursement that supports the consistent delivery of high-quality patient care. [ABSTRACT FROM AUTHOR]

Category: Trauma; Sports Introduction/Purpose: Prior studies have shown the potential of a rigid fixation, such as a trans-syndesmotic screw, to produce tibiofibular malreduction. Flexible implants, although capable of allowing forgiveness in these situations, may not provide sufficient initial stability for all injury patterns. The purpose of this study is to assess the malreduction forgiveness of a two-phase syndesmotic device that is designed to transition from a rigid screw construct to a flexible suture-type device upon weightbearing. Methods: Below-knee cadaveric specimens were mounted in a radiolucent frame with a static axial load of 356N under four conditions: native ankle (control), syndesmotic instability (injured), malreduced with two-phase syndesmotic device engaged (malreduced), and post-disengagement of the two-phase device (disengaged). A lateral approach was used to destabilize the joint. The malreduction targets for each group were 5mm anterior displacement, 5mm posterior displacement, 15° of rotation, and over-compressed (140N) states. Fixation was performed with a single implant 20mm proximal to the joint. Weightbearing Computed Tomography (WBCT) scans were obtained for each condition. The device was manually disengaged to allow for semi-constrained motion of the syndesmosis, reproducing the release that would occur when a patient initiates weightbearing. Anatomic axes of the tibia and fibula were extracted from WBCT scans to calculate tibiofibular joint position with an established orthogonal joint coordinate system representation. Results were normalized to the control states and compared. Results: A total of 42 limbs were included (anterior=10, posterior=11, rotation=12, over-compression=9). Anterior and posterior malreduction specimens demonstrated 2.50mm (SD: ±1.37mm) and 5.04mm (SD: ±2.23mm) of average malreduction in the malreduced state. The disengaged device condition resulted in an average recovery of 1.79mm (95%CI: 0.72mm, 2.85mm; p=0.0034; 72% recovery) and 1.69mm (95%CI: 0.09mm, 3.28mm; p=0.0006; 33% recovery) toward the control position of the joint, for anterior and posterior malreduction, respectively. Rotational malreduction specimens demonstrated 2.44° (SD: ±2.09°) of average absolute rotational malreduction, with 1.98° (95%CI: -0.13°, 4.09°; p=0.0707; 81% recovery) of recovery. Over-compression specimens demonstrated an average medial translation of 0.89mm (SD: ±1.10mm), and the disengaged device condition had 0.74mm (95%CI: 0.05mm, 1.51mm; p=0.0128; 82% recovery) of joint pose recovery. Conclusion: In this cadaveric study, malreduction forgiveness using a two-phase syndesmotic implant that transitions from a rigid screw to a flexible device was tested. Using the computational methods described, overall syndesmotic malreduction and specific corrective changes in fibular malpositioning following disengagement from a rigid construct were noted. The results support the implant concept on malreduction recovery in multiple planes, potentially impacting the clinical management of syndesmotic injuries. Application of this implant and our study methodology to a clinical cohort of patients with syndesmotic instability is paramount to confirm our findings. [ABSTRACT FROM AUTHOR]

Category: Midfoot/Forefoot; Trauma Introduction/Purpose: The diagnosis of fractures can be challenging in specific medical settings due to limited expertise or time. While deep learning has shown promising results, its use is confined to the quality of images and the hassle of importing images to the models. This study aims to develop a model to detect fifth metatarsal fractures based on cell phone photos of radiographs directly taken from a regular screen. Methods: retrospective case-control study was conducted including patients aged > 18 years with fifth metatarsal fractures (n=1240) (Fx), and healthy controls (n=1224) (NoF). Three view radiographs (anterior, posterior, and lateral) were obtained from the Electronic Health Record (EHR) in PNG format. To generate a mixed-quality dataset, Android and iOS smartphones (SP) were used to create two separate datasets for each Fx and NoF group. Two separate deep learning models on each EHR, SP, and combined datasets were developed using Inception V3 architecture (Figure 1.). The models were also tested on a separate SP dataset (SP-test) that was not included in the development process. Area Under the Receiver Operating Characteristics Curve (AUC) along with other performance metrics were calculated and reported. Continuous data were presented as median (interquartile range), and a p-value of < 0.05 was considered to be significant. Results: Baseline analysis revealed differences between the groups with a median age of 56 years (36-68) for the Fx group, and 62 years (51-72) for the NoF group (p < 0.001). Similarly, the racial composition of the groups was also different (Fx: 84.8% white; NoF: 92.2% white; p < 0.001). Initially, the SP model showed the best performance (Youden Index (YI): 0.92, AUC: 0.99) followed by the EHR (YI: 0.74, AUC: 0.96), and combined (YI: 0.52, AUC: 0.97) models. When tested on the SP-test dataset the EHR model's performance dropped markedly showing a YI of 0.33, an AUC of 0.78, and a sensitivity of 0.49 (Table 1.). However, the SP and combined models continued to perform optimally (YI: 0.94, AUC: 0.99; YI: 0.78, AUC: 0.98, respectively). Conclusion: This study highlights the crucial role of image quality in developing deep learning models for detecting fifth metatarsal fractures. Our findings demonstrate a markedly reduced performance of the EHR model in identifying fractures within lower-quality images. This emphasizes the need for training algorithms on images of varying quality to create more generalizable models capable of operating effectively across diverse settings. [ABSTRACT FROM AUTHOR]

Category: Midfoot/Forefoot Introduction/Purpose: The popularity of minimally invasive (MIS) techniques in foot and ankle surgery continues to grow exponentially. However, it comes with certain limitations that present notable challenges. One significant hurdle is the absence of direct visualization of neurovascular structures and tendons. This study aims to present fluoroscopic heatmaps that illustrate the trajectories of major structures encountered during MIS midfoot procedures. Methods: Sequential dissection was performed on nine below-knee specimens identifying the following anatomy structures: anterior tibialis tendon (ATT), extensor hallucis tendon (EHL), extensor digitorum longus tendon (EDL), superficial peroneal nerve (SPN) and dorsal neurovascular bundle (DNVB). Subsequently, flexible wires were positioned and securely placed adjacent to the medial and/or lateral borders of these structures to visualize their trajectories on X-ray imaging. Anteroposterior (AP) and oblique fluoroscopy images of the foot, featuring a calibration marker of a known diameter, were taken, alongside macroscopic photos. All fluoroscopy images were adjusted to a uniform scale and standardized to a single foot fluoroscopy. The coordinates of the structures were marked on these standardized foot AP and oblique fluoroscopy views. These coordinates were then inputted into a custom-made Python script to generate heatmaps. Results: Successfully generated heatmaps encompassed the DNVB, ATT, EDL, EHL, and SPN, on AP and oblique fluoroscopy images of the foot. The color gradient used visually represents varying magnitudes, with red indicating the most frequent locations of the structures and blue signifying lower occurrences. These heatmaps also illustrate the highest-risk areas for iatrogenic injury to the structures during MIS procedures. Conclusion: This study can empower surgical navigation and improve safety in MIS midfoot procedures by providing surgeons with a fluoroscopic heatmap detailing the trajectories of major anatomical structures. [ABSTRACT FROM AUTHOR]

Category: Other Introduction/Purpose: Orthopedic surgery is witnessing a substantial increase in fellowship training, with a notable shift from almost 50% practicing as "generalists" to less than 15% over the least 35 years. The Orthopaedic Fellowship Match has expanded to include various subspecialties, contributing to a favorable job market for fellowship-trained surgeons. However, the surplus of fellowship positions compared to graduating residents raises considerations regarding individualized selection processes and addressing disparities in the orthopedic field. Methods: A scoping review of the literature on orthopedic surgery fellowship choices utilized a literature search following PRISMA-ScR guidelines, which were subsequently analyzed using Covidence systematic review software; inclusion criteria encompassed primary, survey-based studies from 2010-2023, involving orthopedic surgery residents, fellows, attending physicians, and plastic surgery residents pursuing hand surgery fellowships, who completed their residency training in the United States. Data extraction involved compiling an evidence table encompassing respondent training levels, target demographics, survey types, factors considered, survey distribution details, response rates, results, and study limitations. Results: Intellectual curiosity dominated all other reasons for choosing fellowship among orthopedic residents across various studies, even when considering gender discrepancies and differing response measurement forms. The choice of surgical procedures also significantly influences the fellowship preferences of medical residents; factors such as the complexity and case variety, exposure to bread-and-butter cases, and surgical experience consistently emerge as crucial considerations in determining fellowship preferences, reflecting a common trend among applicants. Mentorship plays a pivotal role in residents' choice of subspecialty, particularly for female residents facing challenges finding mentors of the same gender. Other less prevalent contributing factors influencing a resident's decision in pursuing a specific fellowship include family commitments, financial debt, lifestyle preferences, previous research, and timing of their decision. Conclusion: The surge in orthopedic surgery fellowship training is marked by a substantial increase in graduates opting for subspecialization, driven by factors like intellectual interest, the nature of procedures in a specific fellowship, and mentor influence or experience. Our study emphasizes these factors as pivotal in residents' choices. However, the need for extensive prospective studies arises to conclusively ascertain if these influences remain consistent across all residents and if additional unexplored factors might play a more significant role in determining specific fellowship paths. [ABSTRACT FROM AUTHOR]

Category: Hindfoot; Ankle Introduction/Purpose: Tibiotalocalcaneal (TTC) arthrodesis is a complex procedure for severe ankle and hindfoot pathologies like end-stage osteoarthritis or avascular necrosis of the talus. Proper calcaneal fixation with the talus and tibia is crucial for postoperative stability and neurovascular protection in intramedullary nailing. A cadaveric study by Hyer et al. showed that a wire placed anterograde through the tibial shaft may miss the calcaneus medially. Methodologic limitations included a limited number of cadavers, non-loaded specimens, and a lack of critical examination of hindfoot alignment. This study aims to determine the feasibility of using weightbearing computed tomography (WBCT) and 3D segmentation software to ascertain an optimal entry point for a straight intramedullary nail in TTC arthrodesis in weightbearing patients. Methods: A total of 100 normal ankles (48 left, 52 right) from 52 patients (Age: 39.9 ± 16.7 years; Gender: 68% F; BMI: 28.1 ± 5.8 kg/m^2) with WBCT scans were obtained and subsequently segmented for inclusion in the study. A novel mathematical algorithm was developed to determine the 3D intersection of the distal tibial central axis extension at the inferior calcaneus. The algorithm approximates the central axis by mapping the center point of the tibial medulla at each CT slice, from the shaft to the tibiotalar joint using 3D surface contours in the axial plane. Then, the central axis is extended through the talus and calcaneus to approximate its exit point on the inferior surface of the calcaneus for each individual ankle (Figure 1a). A 2D linear transformation (affine transformation) was applied to obtain a heat map of all intersection points on the inferior surface of the calcaneus. Results: The mean (SD) polar angle of the central axis with respect to the ground was 84.9 ± 2.3 degrees. The root mean (SD) square error of the affine transformation was 1.62 ± 1.02 mm, demonstrating the validity of mapping. The exit points of the central axis across all patients fall predominantly along the sustentaculum tali (Figure 1b). Conclusion: A straight nail passing through the sustentaculum tali places surrounding neurovascular structures at risk and can also compromise the biomechanical stability of the implant. Our novel 3D algorithm shows that intraoperative adjustment of the starting point lateral to the central tibial axis is required to obtain optimal alignment of the hindfoot nail. Additionally, the novel algorithm can also be used preoperatively to estimate the required calcaneal medialization and ensure precise implant positioning. Proper nail alignment may potentially improve the success of TTC arthrodesis and decrease the risk of postoperative complications, including implant failure. [ABSTRACT FROM AUTHOR]