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Introduction/Purpose: Minimal invasive proximal metatarsal osteotomy (PMO) offers a successful approach for addressing metatarsus adductus while avoiding exposure of all metatarsals, thereby reducing the risk of complications such as wound infections and non-unions. An important hurdle is the absence of direct visualization for precise osteotomy placement. Staying within the tarsometatarsal (TMT) capsule enhances the chances of better union due to improved blood supply, although operating outside the capsule can aid in correcting more significant deformities. Despite having a macroscopic understanding of anatomical locations through specimens, there has been a lack of prior reports on their mapping in fluoroscopic images. Developing such maps could significantly improve the navigational skills of surgeons. This study aims to present heatmaps that illustrate the positions of distal attachments of TMT capsules. Methods: A total of nine specimens below the knee, devoid of any prior bone or joint abnormalities, were thawed a day prior to the experiments. After dissecting the dorsal skin, neurovascular structures, and tendons, only the bones and capsules remained. Flexible wires were placed alongside the distal edges of TMT capsules, encompassing the 1st, 2nd, 3rd, and 4th tarsometatarsal joints. This arrangement aimed to make the paths of these capsules visible when observed through X-ray imaging. The wires were then securely attached to the structures using a soft tissue adhesive. Fluoroscopy images were captured, including a calibration marker of a known diameter, in addition to taking macroscopic photographs. The specific coordinates of these structures were marked in a three-dimensional space within specialized 3D software. Subsequently, these coordinates were imported into a custom-designed Python script crafted for the purpose of generating heatmaps. Results: The heatmaps were successfully produced encompassing all TMT capsules spanning from the 1st to the 4th, and these were overlaid onto an anteroposterior fluoroscopy image of the foot (refer to Figure 1). This gradient of colors serves as a visual representation of differing magnitudes, with red denoting the most prevalent areas of the distal attachment of the TMT capsule, while blue corresponds to lower occurrences. Conclusion: These heatmaps not only showcase the predominantly observed sites of distal TMT attachments, depicted in red, but also signify diverse deviations, identifiable by the presence of less frequent zones indicated in blue. Consequently, surgeons are advised to consider these findings while planning their osteotomies based on their preferred positions. By furnishing surgeons with an extensive heatmap that outlines potential tarsometatarsal capsule insertions, this research not only furnishes them with a dependable guiding resource but also establishes a foundation for more assured and prosperous minimally invasive midfoot fusion procedures. Figure 1: The heatmap of 1st to 4th tarsometatarsal capsules on AP fluoroscopy.

Category: Ankle; Trauma Introduction/Purpose: The use of artificial intelligence (AI) is particularly salient to visually oriented medical professions, especially orthopedics. The most prominent use of AI in orthopedics comes in the form of medical imaging examinations. AI has a huge potential to help doctors make diagnoses by acting as a second pair of eyes. Some results suggested a very high level of agreement between AI models’ and the clinician’s assessments of radiographs. Furthermore, it was also suggested that the sensitivity and specificity of emergency medicine physicians for detecting some pathologies are significantly improved when aided by an AI tool. In view of these observations, our study aimed to create an AI-based ankle fracture detection tool that can be used on smart devices for X-ray interpretation. Methods: We examined 2,193 patients’ charts from 2 academic and 1 community hospital in Boston. We retrieved the anteroposterior (AP), oblique, and lateral ankle X-rays of each patient. Patients with ankle fractures and adults older than 18 years met our inclusion criteria. We excluded patients younger than 18 years old and those with any artifact, such as a cast, screws, or other artifacts in their X-rays. The study comprised 352 healthy controls and a total of 579 ankle fracture patients. Other than the digital images obtained from Electronic patient records (EPR), we used two different smart devices, a cellphone, and a tablet, to capture images from the monitor screen. Using Machine Learning models, we developed a fracture detection model using all three types of imaging and named it the “combination model”. We subsequently tested the combination model on digital X-rays, smart devices, and on both datasets together (Table 1). Results: We extracted the X-rays of a total of 931 patients in this study. Following the development and testing of our AI models, we noticed that all performed well with AUCs and accuracies above 0.85 and 0.86, respectively (Table1). The best performance was found when the combination model was tested on images taken from the camera of our smart devices, with an AUC of 0.88, a sensitivity of 0.86, and an accuracy of 0.89. This performance was closely followed by that of our model tested on a mix of both smart devices and original digital images with an AUC of 0.88, a sensitivity of 0.86, and an accuracy of 0.88. Conclusion: Our AI-based tool showed promising performance in the detection of ankle fractures using smart devices and images obtained from the monitor screen. We were able to reach an accuracy of diagnosis on smart device-captured images that were comparable with the original digital X-rays. The outcome of this study can be used to help providers who lack sufficient experience in detecting fractures. It can also be used for educational purposes for trainees in this field.

Category: Ankle; Trauma Introduction/Purpose: The term ‘quadrimalleolar fracture’ (QMF) describes a trimalleolar (TM) ankle fracture with an associated Chaput or Wagstaffe fracture. Optimal fixation of these injuries not only allows for bone-to-bone healing but also facilitates syndesmotic reduction. However, this is a relatively new concept, and the literature on QMFs is limited to a few case series. Hence, we conducted this study to determine the epidemiology, patterns, and clinicoradiologic correlations of QMFs. The primary objective of this study was to describe the prevalence and patterns of QMFs. The secondary objective was to determine if certain clinical or radiological parameters were associated with different types and patterns of QMFs. Methods: A retrospective analysis of ankle fractures presenting to three tertiary referral hospitals was undertaken. Adult patients (≥18 years) presenting with an acute, traumatic TM ankle fracture over 3 years (July 2018 to July 2021) were included. Isolated medial and lateral malleolar fractures, bimalleolar ankle fractures, pediatric patients, pilon fractures, pathological fractures, and those with delayed presentation or (≥3 weeks of injury) were excluded. Clinical demographic variables were obtained from the patients’ medical records. AP, lateral, and mortise ankle radiographs, and CT scans, (axial, coronal, and sagittal sections along with 3D volume reconstructed models) whenever available, were evaluated in detail. Demographics and radiological parameters were compared between TM and QMF, as well as between different types of QMFs. Odds ratios with 95% confidence intervals were determined to test the strength of association. Results: A total of 876 adult patients with ankle fractures were included after the screening, of which 323 had a TM ankle fracture for which a CT scan had been performed. A total of 159 AITFL avulsions were identified, yielding a prevalence of 18.2% amongst all ankle fractures and 26.1% in ankle fractures where a CT scan had been performed. TMFs had the significantly highest proportion of CT-confirmed AITFL avulsions (44.4%) in comparison to unimalleolar (4.4%) and bimalleolar fractures (6.4%) (P < 0.0001). Age and osteoporosis were significant associations of QMFs. Avulsion of the medial malleolus, Weber B fibular fracture, and supination external rotation mechanism were significantly associated with Wagstaffe fractures. Size of the Chaput fracture was inversely related to that of the posterior malleolar fracture. Conclusion: Quadrimalleolar ankle fractures account for a significant proportion of ankle fractures. The strengths of this study include a large sample size, which was derived from three different hospitals, consecutive inclusion (or exclusion) of cases, strict adherence to the STROBE guidelines, and the fact that only CT-confirmed cases were used to determine clinic-radiological associations. Wagstaffe and Chaput fractures have distinct clinical and radiological correlations. However, further research is needed to determine the optimal fixation protocols for these injuries.

Category: Trauma; Ankle Introduction/Purpose: Ankle fractures represent an increasingly common injury world-wide and the decision for operative fixation often hinges on the definition of acceptable stability. Mortise malalignment has generally been considered as the main predictive factor leading to poorer outcomes and the development of post-traumatic osteoarthritis. Following pioneering work by Ramsey & Hamilton, 1-2 mm of lateral talar displacement has commonly been regarded as a cutoff value for surgical decision making. However, isolated lateral talar translation (as studied in previous works) does not fully replicate the multidirectional joint subluxation seen in ankle fractures. Furthermore, previous studies have been limited by low fidelity methodologic techniques. Therefore, the aim of this study was to analyze the influence of multiplanar talar displacement on tibiotalar contact mechanics utilizing finite element analysis (FEA). Methods: 19 patients having undergone advanced computed tomography (CT) scanning of the ankle were included. A female patient (age 18 years, weight 60 kg) without preexisting articular ankle pathology underwent a weightbearing CT-arthrogram of the left ankle. Additionally, 18 ankles derived from the contralateral healthy side in patients who underwent bilateral weightbearing CT scans (WBCT ) for evaluation of a contralateral ankle fracture were included (mean age = 38.70 years, mean weight = 80.00 kg, left/right: 9/9). Segmentation of the WBCT images into 3D models of bone and cartilage was performed semi-automatically, while on the non-arthrography WBCT images, personalized cartilage layers were modeled based on a previously validated methodology. 3D multiplanar talar displacement was simulated to investigate their respective influence on the tibiotalar contact mechanics. Tibial peak contact stress, talar peak contact stress and contact area were extracted from the FEA models for each condition. Results: The talar peak contact stress (in MPa), tibial peak contact stress (in MPa) and contact area (in mm²) for each condition are presented in Table 1. Overall, both the mean and peak contact stress for the talus and tibia incrementally increased when the talus was displaced, for all directions. Correspondingly, the contact area incrementally decreased. Contact stress maps of the talus and tibia were computed for each of the conditions, demonstrating unique patterns of pressure derangement. 1 mm of lateral translation resulted in 11% increase in peak contact pressure and a 12% decrease in contact area. External rotation exhibited the greatest influence on contact stress, reaching a peak talar stress of 510% above baseline after 20 degrees of external talar rotation. Conclusion: In this study, we were able to build on the paradigm of prior uniplanar cadaveric studies and provide a multiplanar mortise malalignment model. The use of advanced computational technologies allowed for more precise quantitative evaluation of articular contact mechanics. With lateral talar translation, our model demonstrated less dramatic increases in tibiotalar contact area compared to previous studies, whereas external rotation had the largest effect regarding pathologic joint loading. Clinically, this study provides a novel understanding of the mechanical sequelae of 3D talar displacement and the importance for adequate mortise alignment.

Category: Midfoot/Forefoot; Midfoot/Forefoot Introduction/Purpose: Lisfranc injury consists of a spectrum of injuries affecting the tarsometatarsal joint. Various fixation methods are used to treat Lisfranc injuries and each show different outcomes. Metal implants have been used for open reduction and internal fixation (ORIF) of Lisfranc injuries routinely. However, other than the complications in these patients, such as non- anatomical reduction, implant loosening, breakage, and arthrosis, most of these patients will undergo a second surgery for implant removal. Using bio-degradable and bio-integrative materials in these implants reduces the need for these re-operations; however, whether other complications reported for metal implants occur by using bio-integrative materials has yet to be proven. The aim of our study is to assess patient-reported outcome measures (PROMs) and complications in patients received bio-integrative screws for Lisfranc fixation. Methods: The inclusion criteria were 1) ≥ 18 years old, and 2) had ORIF for Lisfranc injury using bio-integrative (OSSIOfiber ™) screws. The patients’ charts were reviewed, and the variables were gathered, including the type of injury, pain score, and PROMs. The questionnaires used to evaluate PROMs were Patient-Reported Outcome Measurement Information System (PROMIS) surveys for physical function, pain interference, pain intensity, and depression. We also reported the average scores for these PROMs among a randomly sampled population of patients who had ORIF with metal screws for Lisfranc injuries for comparison (n=12). Results: We recruited 12 patients for this study. The minimum follow-up time of the patients in this study was three months. Out of 12 patients, 1 patient showed non-union. The mean (SD) PROMIS scores for physical function, pain interference, pain intensity, and depression were 43.9 (14.9), 56.1 (13.9), 45.9 (10.1), and 43.5 (4.9) in patients who received bio-integrative screws, respectively. In the sampled population treated with metal screws, these PROMs were 42.1 (9.5), 55 (10.1), 46.4 (8.1), and 44.4 (6.4) for physical function, pain interference, pain intensity, and depression, respectively. No significant difference was observed between the two groups regarding physical function (P=0.72), pain interference (P0.82), pain intensity (P=0.88), and depression (P=0.69). Conclusion: The current report showed promising patient-reported outcomes after Lisfranc ORIF with bio-integrative screws. However, longer term follow-ups, as well as comparison with a larger population for both types of instruments, bio-integrative and metal, will shed light on the pros and cons of both materials. Moreover, cost-effective studies are highly suggested to assess the usefulness of these implants against their costs for the healthcare system and the patients.

Category: Sports; Ankle Introduction/Purpose: Acute Achilles tendon ruptures (ATRs) can be treated surgically through either open repair or minimally invasive surgical techniques (MIS). While the relative complication rates between these techniques, including wound dehiscence, re-rupture, and sural nerve injury, have been debated, many studies demonstrate no significant difference between these two approaches. In this study, we conducted a Kaplan-Meier survival analysis to compare the incidence and timing of complications between open and MIS repair of acute ATRs and examine factors that may influence these rates. Methods: A retrospective study was conducted to evaluate the outcomes of patients (≥18 years) who underwent surgical intervention for acute ATR within a four-week period following injury, with a minimum follow-up of three months. Data on demographic variables, type of surgical procedure (MIS or open approach), and the occurrence and timing of postoperative complications were collected. Postoperative complications were classified as venous thromboembolism (VTE), re-rupture, surgical site infecti+D2on (SSI), wound dehiscence, and sural nerve injury.The Kaplan-Meier method was employed to compare the complication rates between the MIS and open repair groups. The log-rank test was used to test the equality of survivor functions. The Cox proportional hazards model was employed to determine predictors of complications. Results: In total, 417 patients were included in the final analysis. The MIS group had a higher proportion of patients with tobacco use. Fifty-two complications in 50 patients were recorded (Table 1). We found no significant difference in the complication rates between the MIS and open repair groups. However, Cox proportional hazards modeling revealed that body mass index (BMI) was a significant predictor of re-ruptures (HR 1.2, 95% CI = 1.05–1.4) and that surgical delay was found to be a significant predictor of wound dehiscence (HR 1.2, 95% CI =1.01–1.3) and sural nerve injury (HR 1.2, 95% CI =1.1–1.3). A surgical delay of more than 2 weeks was noted to have a positive likelihood ratio of 2.3 for wound dehiscence and 3.1 for sural nerve injury. Conclusion: The results of this study indicate that MIS and open repair techniques for acute ATRs demonstrate comparable complication rates. However, patients with elevated BMI exhibit an increased risk of re-rupture. Those with surgical delay beyond two weeks have an elevated likelihood of wound dehiscence and sural nerve injury, presumptively due to associated scaring and the requisite tissue manipulation. Surgeons and patients may consider these variables when formulating a surgical treatment plan.

Category: Ankle; Trauma Introduction/Purpose: The Medial Clear Space (MCS) is an anatomic space between the lateral cortex of the medial malleolus and the medial cortex of the talus. Measurement of the MCS is helpful in differentiating which ankle fractures are amenable to non- operative treatment, and which may require fixation. The MCS is often evaluated on radiographic views of the ankle, and several different methods of measuring the MCS have been described in the literature. There is little information on intra-observer reliability of MCS measurement, nor validation of the various medial clear space measurement techniques. As such, the aim of this study was to better understand intra-observer reliability of MCS via several of the most popularly described techniques. Methods: Patients with matched ankle X-rays and CT scans - either weight bearing or non-weight bearing imaging pairs - were identified via electronic medical record database review of a Level-1, academic medical system after IRB approval. Measurement of the MCS on CT scan was used as the gold standard against which radiographic measurements were compared given its superior osseous definition. Four independent reviewers measured the medial clear space on 20 weight bearing, and 20 non-weight bearing x-rays via the five most commonly described methods: 5mm inferior to the talar dome (MCS #1), half way down the medial articular surface of the talus (MCS #2), obliquely at the supero-medial corner of the talus (MCS #3), and at the level of the talar dome (MCS #4). Intraclass Correlation Coefficients (ICC) were then calculated for each of the four MCS measurements methods after compilation of all independent reviewer data. Results: The ICC varied between each of the four MCS measurement techniques. For measurements 5mm below the talar dome (MCS #1) the ICC was 0.041. Measured halfway down the medial talar articular surface, the ICC was 0.466. The superior oblique MCS measurement ICC was 0.725, and the MCS measured at the level of the talar dome had an ICC of 0.419. MCS measurement 5mm below the talar dome had poor intra-observer reliability, while measurement halfway down the medial articular surface and at the level of the talar dome had fair intra-observer correlation. Overall, measurement of the MCS at the superomedial talar dome had good intra-observer reliability, ranking as the most favorable measurement method. Conclusion: The commonality of ankle fractures demands accurate radiographic interpretation for the determination of need for surgical intervention. The medial clear space measurement is the most common metric used to determine the need for surgery. There is no consensus regarding the optimal method, nor reliability of the various MCS measurement techniques. The results of this study suggest that measurement of the medial clear space at the superomedial corner of the talar dome has the highest intra- observer reliability.

Category: Hindfoot; Sports Introduction/Purpose: Posterior heel pain at the Achilles tendon insertion is a prevalent and debilitating condition that is not yet fully understood. It results from a combination of bony and soft tissue abnormalities, including insertional Achilles tendinopathy, retrocalcaneal bursitis, and posterosuperior bony prominence. While the most commonly used surgical technique for treatment is debridement and reattachment of the tendon, dorsal closing wedge calcaneal osteotomy (DCWCO) has recently gained popularity. In this meta-analysis, we aimed to analyze the published literature related to both surgical techniques and compare their outcomes. Our hypothesis was that DCWCO can provide similar clinical outcomes with a lower complication rate. Methods: We conducted a literature search in Medline, Embase, and Scopus databases. Clinical studies reporting at least one of the clinical outcomes among AOFAS score and complications, with an open technique and sufficient data to extract and pool, were included. The extraction was made by two users using the Covidence platform. Studies with less than 10 patients or less than 12 months follow-up were excluded. Initial search yielded 329 papers, and after excluding duplicates and irrelevant studies, 43 papers were left. After a full-text review of these 43 papers, we found 15 papers eligible for meta-analysis. We used the Modified Coleman Methodology to assess the quality of papers. Results: Out of the 15 articles, seven included reattachment patients, while eight included DCWCO patients. 171 feet underwent reattachment, while 239 feet underwent DCWCO. The average follow-up of patients was significantly higher in the DCWCO group (42.2 months) than reattachment group (23.2 months). The average AOFAS score improvement was similar between the groups. The total complication numbers were 30 (16.6%) in the reattachment group and 28 (9.2%) in the DCWCO group, but the difference did not reach significance since the confidence intervals were overlapping. However, wound complications were significantly more common in Reattachment group (10.1%) compared to DCWCO (2.5%). The number of revision surgeries and neurological complications (sural neuritis, hypersensitivity, etc.) were similar between the groups. The average AOFAS score improvement was similar between the groups. Conclusion: Both techniques yielded comparable clinical outcomes. The overall complication rate was similar, but DCWCO exhibited a lower wound complication rate than reattachment. Therefore, the study results imply that DCWCO can provide similar clinical outcomes with fewer wound complications. However, further well-designed studies are necessary to reach a definitive conclusion on this matter and compare both techniques in the same study setting.

Category: Hindfoot; Sports Introduction/Purpose: The use of a dorsal closing wedge calcaneal osteotomy (DCWCO) in the treatment of insertional Achilles tendinopathy (IAT) has recently gained popularity. The anatomical changes imposed by the osteotomy are believed to improve both the biological and mechanical processes involved in IAT. However, the impact of shortening the Achilles leverage arm after DCWCO and the full impact of DCWCO on foot anatomy and function is not well understood. This study aimed to examine the effects of DCWCO on the 3D alignment and biomechanics of the foot and ankle in IAT patients through simulated models of DCWCO. The hypothesis was that DCWCO would significantly impact foot alignment and decrease gastrocsoleus lever arm. Methods: Six weightbearing ankle CTs of patients with IAT were identified from the clinical database. Bone segmentation was performed and DCWCOs were conducted in standardized planes with six variations, resulting in a total of 36 foot models. Two plantar osteotomy starting points were defined as 1-cm anterior (posterior osteotomy) and 2-cm anterior (anterior osteotomy) to the most plantar point of calcaneus. The osteotomies were extended to dorsal surface at 1-cm anterior to posterosuperior calcaneus with 6, 10, or 14-mm wedges anteriorly. After the osteotomies, the posterior part of the calcaneus was rotated around the plantar starting point until proper bone contact was achieved. Achilles reconstruction was also performed using pre-defined Achilles insertion points. All models were then transferred to a MATLAB-based algorithm for automated measurements. These measurements included talocalcaneal, calcaneal pitch, Böhler, and Achilles tendon sagittal angles, Achilles moment arm, Achilles- posterosuperior calcaneus distance, and difference in soleus-Achilles length. Results: Anteriorly placed osteotomy caused more significant decrease in the Böhler angle (p < 0.001). Evaluation of the posteriorly placed osteotomy separately showed no significant decrease in the Böhler angle for patients with more than 30- degrees of preoperative Böhler angle (p=0.26). However, patients with a preoperative Böhler angle less than 30-degrees showed a significant decrease, approaching values close to 5-degrees (p=0.004). Gastrocsoleus moment arm decrease was found to be 2-3% by using force/moment equation. The change in the distance between Achilles tendon and the posterosuperior calcaneus was similar between anterior and posterior osteotomies, with less than 3-mm in a 6-mm wedge and more than 5-mm in a 10-mm wedge osteotomy. The calculations showed that ankle dorsiflexion can increase by one degree for each mm of resection. Conclusion: An anteriorly placed starting point for a DCWCO can negatively affect foot alignment and offer limited benefits for Achilles decompression. If the preoperative Böhler angle is less than 30, a DCWCO can significantly decrease the Böhler angle, potentially putting the subtalar joint at risk for arthritis by increasing the load as reported by some finite element studies. The maximum decrease in gastrocsoleus power is less than 3%, which may be clinically insignificant. A posterior starting point with 10- mm wedge can be adequate to move Haglund around 5-mm anteriorly and can move Achilles insertion 10-mm superiorly to decrease tension.

Category: Trauma; Ankle Introduction/Purpose: There is a paucity of literature regarding the effect of socioeconomic disparity on patient access to health care following surgery for acute musculoskeletal injuries. We hypothesized that lower socioeconomic status (SES) is independently associated with increased utilization of the emergency department (ED) for care, and less reliable outpatient follow up after ankle fracture surgery. Methods: A retrospective analysis was performed of 1,571 patients who underwent ankle fracture surgery between 2010 and 2020 at three large academic medical centers and one community hospital. Using 2010 United States Census data linked to place of residence, a summary measure of SES was created for each zip code. SES was divided into three percentile groups: 0-25%, 26-75% and 76-100%, wherein the 0- 25% group represented the lowest SES score. Independent patient and injury factors associated with ED visits and outpatient in-office follow up within 90 days of ankle fracture surgery were examined using multivariable Poisson regression models. Results: Patients in the lowest quintile of SES had a higher incidence of ED visits within 90 days after surgery (adjusted incidence ratio [aIR], 1.54, p< 0.001). Patients in the highest quintile of SES had a higher frequency of outpatient follow up within 90 days after surgery (aIR, 1.23, p< 0.001) compared to those in the middle SES quintile. Independent factors associated with increased ED visits following ankle fracture surgery were lower SES, lateral malleolus fracture, heightened comorbidities, increased BMI, Spanish-speaking patients, and patients with drug and/or alcohol dependence. Conclusion: Patients of lower socioeconomic status, those with substance use disorders, and those who must overcome language barriers to seek care demonstrate higher emergency resource utilization and are less likely to follow up in clinic after ankle fracture surgery. A better understanding of patient and injury factors associated with such increased ED visits may provide guidance as to which patient subpopulations may require more attention after ankle fracture surgery.

Background and Aims: Endoscopic assessment is a co-primary end point in inflammatory bowel disease registration trials, yet it is subject to inter- and intraobserver variability. We present an original machine learning approach to Endoscopic Mayo Score (eMS) prediction in ulcerative colitis and report the model’s performance in differentiating key levels of endoscopic disease activity on full-length procedure videos. Methods: Seven hundred ninety-three full-length videos with centrally-read eMS were obtained from 249 patients with ulcerative colitis, who participated in a phase II trial evaluating mirikizumab (NCT02589665). A video annotation approach was established to extract mucosal features and associated eMS classification labels from each video to be used as inputs for model training. The primary objective of the model was a categorical prediction of inactive vs active endoscopic disease evaluated against 2 independent test sets: a full set with a baseline single human expert read and a consensus subset in which 2 human reads agreed. Results: On the full test set of 147 videos, the model predicted inactive vs active endoscopic disease via the eMS with an area under the curve of 89%, accuracy of 84%, positive predictive value of 80%, and negative predictive value of 85%. In the consensus test set of 94 videos, the model predicted inactive vs active endoscopic disease with an area under the curve of 92%, accuracy of 89%, positive predictive value of 87%, and negative predictive value of 90%. Conclusion: We have demonstrated that this machine learning model supervised by mucosal features and eMS video annotations accurately differentiates key levels of endoscopic disease activity.

Category: Hindfoot, Trauma Introduction/Purpose: The axial alignment of the calcaneus has paramount importance in the management of these fractures. The Harris view has long stood as the recommended radiograph to assess axial alignment. However, given the obliquity at which the radiograph is obtained, it doesn´t represent a true axial view and is subject to inaccuracies secondary to rotational malpositioning of the foot and mismeasurement of angulation. Multiple reports have described the axial alignment as a surgical outcome, but usually this assessment of the residual deformity have no described method. The objectives of this study are to evaluate the capacity of Harris view to assess axial alignment in a cadaveric model and to describe the use of a true AP view of the calcaneus that we have named Captain´s view. Methods: Five below knee amputated fresh-frozen cadaveric specimens were used in the study. For each specimen, the soft tissues over the lateral side were removed to access to the lateral wall. A small wedge of the cuboid was removed to visualize the center of the calcaneocuboid articular surface. LCA-guide and a cannulated drill were used to create a tunnel in the axis of the calcaneus. An oblique osteotomy was performed in order to simulate a non-comminuted fracture. Varus deformity was created by inserting solid radiolucent wedges into the osteotomy to create models of 10, 20, and 30 degrees of varus angulation. Harris and Captain views were obtained for each specimen with 0 (control), 10, 20, and 30 degrees of varus malalignment. Measurements of the deformity were made digitally on each fluoroscopic image. Results: The average degrees of varus in Harris views were 10,9 (5,5-16); 11,5 (8,2-13,6); and 18,3 (13,3-23,6) for 10,20 and 30 degrees of deformity respectively. The average degrees of varus in Captain´s view were 13,0 (7,3-20,9); 18,4 (11,7-23,5); and 28,2 (24,4-31,1) for 10,20 and 30 degrees of deformity respectively. The average degrees of error for varus deformity in Harris views were 4,1 (41%); 8,4 (42%) and 11,6 (39%) for 10,20 and 30 degrees of deformity respectively. The average degrees of error for varus deformity in Captain´s views were 4,8 (48%); 3,6 (18%) and 2,8 (8%) for 10,20 and 30 degrees of deformity respectively. Conclusion: The results of this study show a high rate of mismeasurement for both radiographic views. Despite the average angles have a clear correlation with the severity of varus, the wide range of error observed between specimens make this assessment unreliable and inaccurate. We observed an improvement of accuracy of captain´s view for more severe deformities, but not with Harris views which maintain a 40% mismeasurement in all the settings. Therefore, intraoperative Harris views should not be used in isolation to evaluate axial alignment and Captain´s view provides an additional perspective that can be useful to rule out severe deformities.

Category: Other Introduction/Purpose: Orthopedic surgery lies at the forefront of the initiative to deliver value-based care. As a result, cost utility analyses have gained increased importance in the orthopedic literature. While other authors have previously reviewed the quality of US-based cost-utility analyses in orthopedic trauma, spine, sports, and arthroplasty, a similar analysis specific to foot and ankle surgery has not been performed. As such, the practicing foot and ankle surgeon does not yet have a comprehensive analysis of the available cost-utility analyses or the quality of the available evidence. The purpose of this study was to perform a systematic review of cost-utility analyses in foot and ankle surgery. Methods: A systematic review of foot and ankle studies was conducted to identify cost-utility based analyses published between 2000 and 2017. Of 687 studies screened by abstract, eight cost-utility foot and ankle studies were identified that met inclusion criteria and were scored by the Quality of Health Economic Studies instrument for overall quality. Results: Of the eight studies that met inclusion criteria, four were published in the U.S. Regarding topic, three examined end-stage arthritis, two examined diabetic foot ulcers, two examined ankle fractures and one examined ankle sprains. Cost-effective interventions identified by these studies included total ankle arthroplasty over ankle fusion or nonoperative treatment, adjunctive hyperbaric oxygen therapy for diabetic foot ulcers, suture button fixation over syndesmotic screws for unstable supination-external rotation type IV ankle fractures, and below knee cast and fracture boot immobilization over tubular bandages for acute severe ankle sprains respectively. The mean Quality of Health Economic Studies scores for these studies was 81.9 with interquartile range, 25th percentile score of 74.8 to 75th percentile score of 86. Conclusion: Despite the increasing focus on value-based care delivery, there are few foot and ankle cost-utility analyses in the current literature. Nonetheless, the quality of existing analyses is high as rated by the Quality of Health Economic Studies and certain interventions have been identified as cost-effective as highlighted above. The findings of this review can be used to help design future analyses in order to best demonstrate the cost-effectiveness of foot and ankle interventions.

Category: Trauma Introduction/Purpose: Surgical fixation of Jones fractures is often recommended to facilitate recovery and achieve union. Iatrogenic fracture displacement during intramedullary screw fixation is a commonly encountered technical issue. This may be related to fracture location in relation to the surrounding ligamentous attachments, namely the robust intermetatarsal ligaments found at the proximal articulation of the 4th and 5th metatarsals. This study examines the relationship between fracture line and its location in regards to the surrounding ligamentous structures and its effect on Jones fracture displacement, reduction and fixation in a cadaveric model. Methods: Eighteen fresh-frozen cadaveric feet were dissected with preservation of all ligamentous attachments. Given the similar anatomic distal extent of the dorsal and plantar intermetatarsal ligaments on the 5th metatarsal, measurements were obtained detailing the anatomic position of the dorsal intermetatarsal ligament (DIL) only. The specimens were divided into two groups with modelled fractures created at the 4th & 5th metatarsal articulation proximal to the distal extent of the DIL (Group 1) or just distal to the DIL (Group 2). Fractures were fixed in standard fashion with serial fluoroscopic images obtained to study fracture gapping and rotation. Results: There was approximately 5 mm of fracture gapping created iatrogenically during tapping with no statistically significant differences between Group 1 and Group 2 (4.53 mm versus 5.25 mm, p=0.5430). The distal aspect of the DIL was anatomically located 2.77 mm (Range 1.58 mm – 4.46 mm) distal to the 4th & 5th metatarsal articulation. Conclusion: Considerable iatrogenic fracture gapping occurs during intramedullary screw fixation of Jones fractures in a cadaveric model regardless of fracture location in relation to the intermetatarsal ligamentous attachments. Intraoperative displacement may be related to iatrogenic distraction caused by canal tapping when utilizing a common surgical method. Specific techniques may be required to maintain anatomic alignment during tapping and screw fixation to prevent iatrogenic displacement.

Category: Trauma Introduction/Purpose: A shortened fibula may be caused by several conditions like tumors, premature closure of the growth plate and most frequently, malunion. Biomechanically a shortened fibula causes a lateral shift of the talus, widening of the ankle mortise, decreased tibiotalar contact area and eventually could lead to osteoarthritis. Even in a posttraumatic scenario, with moderate or severe osteoarthritis, fibular lengthening has shown to be beneficial in terms of pain reduction and improved function.Several osteotomies have been described with their advantages and disadvantages in terms of technical difficulty, need for bone graft and the ability to correct length and rotation.We present an easy and reproducible surgical technique on a case, that allow restoring length and rotation independently and it does not require complex distractor devices. Methods: Case report: A 34 year old female patient who presented 8 months status post initial open reduction internal fixation (ORIF). She developed a fibular nonunion, broken distal fixation with a shortened fibula and non-anatomic mortise and presented for revision surgery.Surgical technique: The fibula is exposed in standard fashion. A fully-threaded cortical screw is placed across the tibia, distal to the fibula fracture and parallel to the plafond. Next, a second screw is placed into the fibula bicortically from anterior to posterior and approximately 12 mm distal to the tibial screw. A toothed laminar spreader is then placed in-between the screws and distracted resulting in a lengthening of the fibula. A 2 mm Kirschner wire is placed to hold reduction once fibular length is restored and ORIF continues in standard fashion. Results: The technique we present has several advantages. The technique is straightforward, easy to reproduce, and cost effective. Since the anchoring points used for distraction are not both in the fibula, rotation is not implicitly locked in as in the case when both anchoring points are in the fibula, allowing for independent and progressive adjustment of both length and rotation. There is also less risk of proximal migration of the fibular head as no force is applied directly to the proximal fibula. There is also less risk of proximal migration of the fibular head as no force is applied directly to the proximal fibula. Conclusion: Fibular lengthening can achieve improved function, pain relief and decrease the risk of osteoarthritis in selected patients. Several techniques with different degrees of difficulty have been described to treat this condition, but most are not versatile enough in correcting the length and rotation independently. The technique that we present has the advantage of correcting the length and rotation as needed, without requiring complex devices.

Category: Other Introduction/Purpose: The peer-review process is a rigorous process under which manuscripts are assessed for their overall scientific quality and is generally accepted as the highest standard of scientific scrutiny with regard to medical publishing. A common criticism regards the often disparate nature of reviewer recommendations when a decision is rendered which belies the supposed uniformity of the review process. The purpose of this investigation was to: (1) examine the historic level of agreement amongst reviewers for Foot & Ankle International (FAI) and (2) to assess variables which may influence agreement in order to improve the peer-review process. Methods: Approval to conduct this study was obtained from the Editorial Board of FAI. All manuscripts submitted to FAI during 2015 which underwent peer-review were included in the analysis. For each reviewed manuscript, demographic data was collected regarding specific reviewer and manuscript characteristics in a de-identified manner. Univariate analysis was performed. Results: 442 manuscripts underwent peer-review by 198 reviewers during the study period. During this time period, other papers were reviewed by the Editor-in-Chief and rejected prior to being sent out for review. Of the 884 reviews performed, 339 (38%) recommended rejection, 353 (40%) recommended revision and resubmission and191(22%) recommended accept. Only 199 manuscripts (45%) had a decision rendered in which both reviewers agreed on the initial recommendation.The most common initial decision was rejection (52.7%) followed by revise and resubmit (42.8%). Only 20 manuscripts (4.5%) received an outright acceptance upon initial review. Comparing the agreeing versus disagreeing reviewers, there was no difference in demographic data such as reviewer age or experience. When examining key words (designated by reviewers as a particular area of interest within foot and ankle), there was no association between shared interests and level of reviewer agreement. Overall, for all reviewers, mean acceptance rate was19% (+/- 16%), mean reject rate 37% (+/- 20%) and mean revise 44% (+/- 19%). Conclusion: Regarding initial decision for publication in FAI, there was only 45% agreement amongst reviewers for manuscripts which underwent peer-review in 2015. However, no reviewer-specific variables examined in this investigation were found to correlate with agreement. Despite reviewers having similar interests in various aspects of foot and ankle surgery, this did not lead to an increased likelihood of agreement. Agreement and more uniform assessment of manuscripts by reviewers may be increased by specific education.

Category: Trauma Introduction/Purpose: Surgical fixation of ankle fractures with syndesmotic instability using quadricortical fixation through the fibula and tibia is commonly performed to maintain mortise congruency. Quadricortical fixation can be achieved by screws or suture buttons however both involve unprotected drilling and placement of hardware through the medial distal tibia which places anatomic structures at iatrogenic risk. These structures may include the anterior tibialis tendon, the saphenous neurovascular bundle (SNVB) and posteriorly, the posterior tibialis tendon (PTT). This study aims to radiographically map the anatomic course of these structures at risk on a lateral radiograph as would be used intraoperatively during syndesmotic fixation. Methods: Eighteen fresh-frozen cadaveric feet were dissected with preservation of all soft tissue and neurovascular structures over the medial distal tibia. While preserving fascial and tendinous sheath attachments, the SNVB and the PTT were identified and marked with metal wiring. Standardized and calibrated lateral radiographs were obtained to determine the anatomic course of these structures. Lateral radiographs of the distal tibia and fibula were analyzed by a grid system comprised of 1 cm row-increments moving cranially from the ankle joint up to 5 cm and by 3 evenly distributed parallel columnar zones from anterior to posterior (see Figure). The anterior boundary of the columnar zone was placed at the anterior tibial shaft and the posterior boundary was placed at the posterior malleolus of the tibia. The position of respective metal wires placed within the SNVB and the anterior portion of the PTT were charted according to this grid system and results compiled. Results: The SNVB was located in zone 1 or 2 (or anterior to zone 1) in 97.3% of specimens (107/110). The SNVB traversed from proximal-posterior to distal-anterior. For the 16 specimens that crossed a columnar zone, the most common crossover was from zone 2 to zone 1 at 3-4 cm above the ankle joint which occurred in 43.8% (7 of 16) specimens. The PPT was found in zone 3 in all specimens (n=18) with only one specimen demonstrating crossover of a columnar zone into zone 2 at its most distal extent (0-1 cm). The PTT was noted to pass behind (radiographically overlap) with the tibia in 83.3% (15 of 18) of specimens between 1 and 3 cm above the ankle joint. Conclusion: Inappropriate placement of quadricortical syndesmotic fixation may place structures on the medial ankle at risk given blind drilling and hardware placement. The SNVB is at considerable risk along the anterior course of the distal tibial while the PTT is only at risk in zone 3 at the distal extent of the tibia when a true lateral radiograph is obtained. This grid system allows a simple intra-operative check to guide safer placement of quadricortical syndesmotic fixation.

Category: Ankle, Basic Sciences/Biologics, Trauma Introduction/Purpose: The extensile lateral approach (EL) has been associated with increased wound complications such as apical necrosis which may be due partially from violation of the lateral calcaneal artery (LCA). Traditionally, the vertical limb has been placed half-way between the fibula and Achilles tendon, which may be suboptimal given the proximity to the LCA. We hypothesized that placing the vertical limb further posterior (ie, modified EL [MEL]) would increase the distance from the LCA. The purposes of this study were to quantify the location of the LCA in relation to the vertical limb of the traditional EL approach and to determine if utilizing the MEL approach endangered the LCA to a lesser extent. Methods: 20 cadavers were used. For the EL approach, the fibula and Achilles tendon were palpated and a line parallel to the plantar foot was drawn between the two. A vertical line (VL), representing the vertical limb of the approach, was drawn at the midway point as a perpendicular extending proximally from the junction of the glabrous/non-glabrous skin (JGNG). For the MEL approach, the anterior border of the Achilles tendon was palpated and a similar vertical line (MVL) was drawn 0.75 cm anterior. Dissection was performed and if the LCA was identified crossing the line VL/MVL, the distance from the JGNG was documented. Results: For the EL approach, the LCA was identified in 17/20 (85%) cadavers at an average distance of 5.0 cm (range 3-7 cm, SD = 1.3 cm) from JGNG. For the ML approach, the LCA was identified in 4/20 (20%) cadavers at an average distance of 5.9 cm (range 3-6.5 cm, SD = 1.7 cm) from the JGNG (P < .001). Conclusion: The LCA was encountered 4 times more often during the EL approach as compared to the MEL approach.

Category: Trauma Introduction/Purpose: The determination of stability and ultimate need for operative stabilization of Weber B fibula fractures largely depends on the presence of a competent deltoid ligament. While various radiographic parameters and the application of manual or gravity stress have been proposed to elucidate instability, the prognostic capability of these modalities remains unclear. Given that a recent study found no difference between operative and nonoperative treatment for stress-positive Weber B ankle fractures, the value of stress views is questionable; what may be ultimately more important is the determination of anatomic positioning of the mortise. We propose a novel view, the Gravity Reduction View (GRV), which helps elucidate non-anatomic positioning and reducibility of the mortise. We also propose a treatment algorithm based on the use of the GRV. Methods: To obtain the GRV, the patient is positioned in lateral decubitus with the injured fibula directed upward and elevated with a leg holder. The x-ray cassette is placed posterior to the heel, with the beam angled at 15˚ of internal rotation to obtain a mortise view. Our treatment algorithm is based upon the measurement of the medial clear space (MCS) on the GRV versus the static mortise view. If the MCS on GRV remains wide or decreases, surgery is recommended as the GRV confirms a non- anatomic mortise. If the MCS remains within normal limits on the static and GRV views, a trial of nonoperative treatment with immobilization and repeat radiographs in 1-2 weeks is undertaken. If the MCS is normal on repeat weightbearing x-rays, the patient is treated conservatively; if increased, surgery is recommended. To further assess mortise stability, the MCS is compared to the superior clear space (SCS). Results: 23 patients with Weber B distal fibula fractures were managed according to this treatment algorithm. The mean age was 49.1 years old (range: 18-74). Of these patients, 15 underwent operative treatment and 10 patients were initially treated nonoperatively, although 2 patients demonstrated late displacement and were treated surgically. Using this algorithm, all patients had a final MCS that was less than the SCS (final mean MCS for patients treated operatively or nonoperatively 2.85 mm vs. mean SCS of 3.34), indicating effectiveness of the treatment algorithm. Conclusion: The Gravity Reduction View is a novel radiographic view in which deltoid competency, reducibility and initial anatomic positioning of the mortise are assessed by comparing a static mortise view with the appearance of the mortise on the reduction view (GRV). We have developed a treatment algorithm based on the GRV and have found it to be predictive of mortise alignment and useful in guiding treatment.

Category: Ankle Introduction/Purpose: Intra-articular calcaneus fractures typically result in a classic deformity which includes heel shortening, heel widening, varus malalignment and loss of height from depression of the posterior facet. When requiring operative management, correction of these various deformities is important and has been correlated with outcomes. However, little has been written regarding superior displacement of the calcaneal tuber. This previously undescribed deformity warrants consideration when treating calcaneus fractures as various studies have demonstrated functional weakness resulting from a shortened triceps surae mechanism. This investigation sought to determine the amount of tuber elevation seen in intra-articular calcaneus fractures as compared to normal uninjured calcanei. Furthermore, we propose two new measurements, the talo-tuber angle and talo-tuber distance, which aid in quantifying displacement and may aid in the surgical management of calcaneus fractures. Methods: Lateral radiographs of normal uninjured calcanei in 220 consecutive patients who met our criteria were examined. Radiographs demonstrating significant obliquity, previous bony injury or subtalar arthrosis were excluded. Two novel measurements were utilized to establish normative data for calcaneal tuber positioning. Two lines are drawn from the superior most portion of the talar head, one tangential to the talar dome and the other to the superior most portion of the calcaneal tuberosity. The angle subtended by these lines is termed the talo-tuber angle and the distance between these two lines at the level of superior most portion of calcaneal tuberosity measured as a perpendicular is termed the talo-tuber distance. Lateral radiographs of 50 consecutive calcaneus fractures treated operatively were examined and the same measurements were obtained before and after surgery to determine the amount of superior tuber elevation seen in patients sustaining intra-articular calcaneus fractures. Results: Normative data demonstrated a mean of 38.6 degrees (range: 26.2 to 58.44, SD=4.28) when utilizing the talo-tuber angle and 54.46 millimeters (range: 36.15 to 72.57, SD=7.30) when utilizing the talo-tuber distance (Figure 1) in normal uninjured calcanei. Patients sustaining intra-articular calcaneus fractures demonstrated a mean of 29.54 degrees (range: 20 to 46.4, SD=5.86) for the talo-tuber angle and 39.01 millimeters (range: 24.02 to 62.9, SD=9.41) for talo-tuber distance (Figure 2). These values changed to a mean of 37 degrees (range: 26.4 to 50, SD=5.18) for the talo-tuber angle and 51.76 millimeters (range: 33.18 to 75.65, SD=8.62) for talo-tuber distance after surgery (Figure 3). There was a statistically significant difference (P value < .00001) for both talo-tuber angle and distance between normal calcanei and fractured ones. There was no significant differences between normal calcanei and those treated surgically in these two measurements. Conclusion: Superior displacement of the calcaneal tuber is an additional deformity seen in intra-articular calcaneus fractures that has been poorly described in the literature. Given that functional weakness can occur with a shortened triceps surae mechanism, increased awareness and correction at the time of surgery is warranted. We propose two novel measurements with associated normative data that may aid surgeons in quantifying this deformity and assessing anatomic reduction.

Category: Trauma Introduction/Purpose: Determining the stability of ankle fractures, particularly for apparent isolated Weber B fibula fractures, can be difficult. While the ultimate goal remains achieving an anatomic mortise, different techniques to predict ankle stability such as stress and weightbearing radiographs have been utilized with variable results. History of injury and the ability to walk after sustaining ankle trauma may be predictive of stability. Therefore, this study seeks to determine whether a patient’s ability to fully weight bear immediately after injury is an effective indicator for ankle stability following ankle fracture. Methods: A prospective review was conducted of patients sustaining isolated, unilateral ankle fractures presenting to two level I trauma centers. Aside from demographic data and fracture characteristics, a patient’s ability or inability to fully weightbear immediately after injury was elicited by interview at their initial assessment. This information was correlated with their ankle radiographs, which were deemed stable or unstable fractures based on commonly used indices to assess ankle stability. Results: 102 consecutive patients sustaining ankle fractures were included. Mean age was 45. When analyzing the entire cohort, patients who were able to ambulate immediately after injury were 10 times more likely to have a stable ankle fracture than those who could not bear weight (odds ratio (OR) 9.9 (P < 0.001). The positive predictive value (PPV) for being able to fully weightbear as it relates to a stable ankle fracture was 77%. Additionally, inability to weightbear was 89% specific for an unstable fracture. When separately analyzing patients with apparent isolated fibula fractures (n=56), the PPV was 75%, specificity was 83%, while the OR was 5.8 (p=0.003) for those who could fully bear weight having a stable ankle fracture. Conclusion: This study demonstrates that patient’s self-reported ability to fully weightbear immediately after injury is a specific and convenient prognostic indicator for ankle stability across a range of ankle fracture subtypes. Future studies can analyze whether initial weightbearing accurately predicts ultimate management and good outcome.

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