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Category: Ankle Arthritis Introduction/Purpose: End-stage ankle osteoarthritis (OA) is a debilitating condition that adversely affects quality of life and causes considerable functional impairment. Total ankle arthroplasty (TAA) is growing in popularity as a motion-preserving option for ankle OA. A previously published meta-analysis evaluated the mid-term outcomes of TAA with a minimum average follow-up of 5 years, demonstrating excellent survivorship. To our knowledge, there is no such manuscript that evaluates the outcomes of TAA at the long-term, with a minimum follow-up of ten years or greater. Due to a lack of long-term follow-up of TAA implants in the current literature, the aim of this review was to aggregate findings from the most up-to-date analyses of the long-term outcomes of TAA via meta-analysis. Methods: We conducted a systematic review and meta-analysis according to the PRISMA guidelines. Electronic databases were searched from the date of inception to September 12, 2022. These databases included Medline, Embase, and Scopus. We included all studies that 1) involved patients that underwent uncemented TAA, and 2) all patients who had an average follow-up period of at least ten years. We excluded abstracts, as well as manuscripts written in languages other than English. We collected American Orthopaedic Foot and Ankle Score (AOFAS) and Visual Analog Scale (VAS) scores from the included studies for pooled meta- analysis. Due to the varying definition of survivability between studies, this metric was not assessed in our final evaluation. Results: Our data included a total of 2,562 patients and 2,895 ankles with an average follow-up of 10 years. Of the 25 studies included in the systematic review, 7 provided pre- and post-operative AOFAS means and 5 provided pre- and post-operative VAS means with associated measures of variability and were included in our meta-analysis. The weighted mean difference between pre- and post-operative AOFAS scores was -41.98 (95% CI: -48.28 to -35.69) (Fig. 1A), indicating that patients improved by almost 42 points between pre-and post-surgery. The weighted mean difference between pre-and postoperative VAS scores was 4.52 (95% CI: 2.26-6.43) (Fig. 1B), indicating patients improved by about 4.5 points on average between pre-and post-surgery. Survivability was not assessed due to the heterogeneity in survivability definition between studies. Conclusion: Outcomes following TAA are favorable and indicate patient-reported outcomes improve over long-term follow-up. Future, prospective, randomized research should be conducted to better assess TAA, and authors should work towards standardization of survivorship and complication reporting methodologies to allow for pooled metanalysis of these important outcome metrics.

Category: Ankle Arthritis; Ankle Introduction/Purpose: Although many patients with postraumatic ankle arthritis are of a younger age, studies evaluating the impact of age on outcomes of primary total ankle arthroplasty (TAA) reveal heterogenous results. The purpose of this study is to determine the effect of age on complication rates and patient reported outcomes after TAA. Methods: This was a retrospective study of 1,185 primary TAA divided into 3 age cohorts (Age < 55, n=219; Age55-70, n=688; Age>70, n=278). Patient demographics, intraoperative variables, postoperative complications, and patient reported outcome measures were compared among groups using univariable analyses. Multivariable Cox regression was performed to assess risk for implant failure by age group. Mean follow-up was 5.7 years. Results: Compared to Age55-70 and Age>70 groups, Age < 55 patients had the lowest mean ASA score (2.2 vs 2.4 vs 2.5; p< 0.001) and highest rates of all complications (33.8% vs 23.1% vs 19.8%; p=0.001), implant failure (9.1% vs 6.0% vs 3.2%; p=0.022), and component removal (5.0% vs 2.8% vs 1.1%; p=0.030). Univariable and multivariable cox regression analysis revealed decreased risk for implant failure for Age>70 compared to Age < 55 patients (HR: 0.43 [95%CI: 0.19-0.94], p=0.034; and HR: 0.42 [95%CI: 0.18-0.95], p=0.038, respectively). Across the AOFAS Hindfoot and all FAOS subscales, Age < 55 group reported the lowest (worst) mean pre and postoperative scores (p < 0.001). The age < 55 group had the highest mean VAS score at final follow-up (22 vs 14 vs 14; p< 0.001). Conclusion: Studies involving large sample sizes with mid-to long-term follow up are critical to reveal age-related impacts on outcomes after TAA. Younger patients had higher rates of complications and implant failure and fared worse on patient reported outcome measures in the largest single-institution series to date evaluating the effect of age on outcomes in TAA.

Category: Ankle Arthritis; Other Introduction/Purpose: Utilization rates of total ankle arthroplasty (TAA) have greatly increased in recent years. For patients with rheumatoid arthritis (RA) undergoing TAA, conflicting data have been reported regarding risk of complications and patient reported outcome (PRO) improvement when compared to patients with osteoarthritis. The purpose of this study is to compare complication rates and PROs of patients with RA to patients with osteoarthritis and posttraumatic arthritis. Methods: This was a retrospective study of 1,071 primary TAA performed at a single institution between 2001 and 2020. Minimum follow-up was two years. Patients were stratified by indication for TAA (osteoarthritis, n=372; posttraumatic arthritis, n=642; RA, n=57). Patient demographics, intraoperative variables, postoperative complications, and PRO measures were compared between groups using univariable statistics. Multivariable Cox regression was performed to assess risk for implant failure. Mean follow-up was 5.6 years (SD: 3.1). Results: Compared to the osteoarthritis and posttraumatic arthritis groups, the RA cohort had the lowest mean age (p < 0.001), lowest percentage of males (p < 0.001), and highest ASA score (p < 0.001). Univariate analysis showed no statistically significant difference for infection rates among groups (p=1.0). The RA cohort had the highest rate of heterotopic ossification postoperatively (2/57, 3.5%, p< 0.001). Multivariable regression analysis showed no increased risk of implant failure for the RA cohort (p=0.23). For the SMFA, SF-36, AOFAS-hindfoot, FAOS-symptoms, and FAOS-ADL the RA group reported the worst scores at final follow-up (p < 0.001). However, the RA cohort demonstrated the largest improvements from preoperative to postoperative scores on the FADI, SF-36, and the symptoms and ADL subscales of the FAOS (p=0.04, 0.01, 0.03, 0.03). Conclusion: In the largest single institution study to date, patients with RA had the worst PRO scores compared to the osteoarthritis and posttraumatic arthritis groups. However, they experienced significantly higher improvements in functional outcomes from their preoperative baseline. Large patient samples with mid- to long-term follow up such as a presented in this series are imperative to fully understand the risk-benefit of TAA in various patient cohorts.

Category: Ankle; Sports Introduction/Purpose: Social media platforms, like TikTok, have become popular options for the distribution of healthcare information. Due to the lack of scientific oversight, the quality of healthcare-related videos has become a focus of the current literature. However, orthopaedic surgery has lagged behind other fields in acknowledging the widespread utilization of TikTok videos for medical information consumption. This study aims to assess the quality and educational benefits of ankle sprain-related TikTok videos. Methods: TikTok was queried using the hashtag “#anklesprainexercises". 100 videos were included after applying the exclusion criteria. The number of views, likes, shares, comments, and favorites was recorded. The content was graded using DISCERN (a well-validated informational analysis tool) and ASEES (a self-designed tool for exercise evaluation). Results: The total number of views of the 100 videos included was 6,483,412, with a median of 5,377.5 (IQR = 1,074- 20,275). The videos collectively received 385,847 likes, 3,642 comments, 55,574 favorites, and 14,918 shares with a median of 267.5 (IQR=41.5-1,678.0), 4.0 (IQR= 0.0-23.0), 42.0 (IQR= 4.8-264.5), and 13.0 (IQR= 1.8-67.8), respectively. General users uploaded more videos (68%) in comparison to healthcare professionals (32%). The dissemination statistics between the general users and healthcare professionals were statistically insignificant. There were significant differences in DISCERN 1, DISCERN 3, TOTAL DISCERN, and ASEES between the two groups. General users had a higher percentage of videos graded as “very poor” (61.8%) in comparison to healthcare professionals (34.4%). Neither general users nor healthcare professionals had videos graded “good” or “excellent”. Conclusion: Although TikTok is a powerful tool for information distribution, the educational value of the videos related to ankle sprain injury exercises was poor. With only 2% of videos receiving a grade of ‘fair,’ and no videos reaching a score of ‘good’ or ‘excellent’, healthcare professionals should be aware of the low-quality content easily accessible on TikTok.

Category: Hindfoot; Sports Introduction/Purpose: Insertional and non-insertional Achilles tendinopathy (AT) are prevalent diseases in the active, working-age population. Ultrasound (US) and magnetic resonance imaging (MRI) are frequently utilized in the assessment and grading of AT. Use of these imaging modalities are limited by operator interpretation/variability and costs, respectively. Also, these assessments are performed in the non-weight bearing positioning of the lower extremity, thus poorly evaluating the functional position of the loaded tendon. Validation of weight-bearing computed tomography (WBCT) for Achilles tendon imaging could provide a novel and functional means of quantifying tendon pathology. The study’s purposes were to: 1) Correlate Achilles tendon tissue structural findings when assessed by WBCT and US imaging, and 2) Compare WBCT Achilles tendon tissue changes between AT patients and controls. Methods: This was a prospective-comparative IRB-approved cohort study including 10 adults with AT (Age = 54.7 ± 10.3 years, BMI = 40.65 ± 10.07 kg/m 2 , 8F/2M), 10 age-matched controls (Age = 54.6 ± 11.33 years, BMI = 37.9 ± 9.55 kg/m 2 , 8F/2M), and 4 younger controls (Age = 32.25 ± 8.3 years, BMI = 24.32 ± 5.14 kg/m 2 , 2F/2M). WBCT scans (Curvebeam HiRise/PedCAT) and US imaging (Butterfly iQ+) of the Achilles tendon were collected. Tendons were manually segmented in WBCT images (3D Slicer software) and tendon thickness was measured at the maximum anterior-posterior (AP) diameter of the tendon (insertion and midportion regions). Radiodensity was quantified by the average Hounsfield Units (HU) of each tendon region and normalized to the radiodensity of each participant’s talus (segmented using Disior Bonelogic). US measures of the tendon thickness were similarly completed by independent observers who were blinded to the WBCT measurement. Intraclass correlation coefficient (ICC) assessed correlation between WBCT and US findings. Paired T-tests compared WBCT HU between patients and controls. P-values < 0.05 were considered significant. Results: There was excellent correlation (ICC= 0.83-0.94, Table 1) between WBCT and US imaging regarding tendon thickness, with WBCT overestimating thickness by only 0.27-0.55mm (4-9% of total tendon thickness). These findings could be explained by decreased US tendon thickness measurements secondary to the tendon’s compression by the US probe. WBCT imaging demonstrated a higher radiodensity (HU) within the Achilles tendon (for both insertion and midportion regions) in AT patients when compared to controls (Table 2), with p-values of 0.009 and 0.001 for insertional and midportion regions, respectively. Findings are consistent with tendinopathic differentiation of the Achilles tendon substance in the AT patients. Color-coded maps demonstrating HU distributions across the Achilles tendon were created to facilitate interpretation of tissue characteristics (Fig. 1). Conclusion: In this prospective, comparative, and controlled study, we observed a high correlation between US and WBCT imaging in the assessment of Achilles tendon thickness in AT patients and controls. We also found that WBCT HU distribution in the Achilles tendon was significantly increased in the AT patients when compared to controls. Findings are likely explained by tendinopathic tissue changes in the diseased tendons, potentially related to the well-known chondroid metaplasia observed in Achilles tendinopathy pathological process. WBCT imaging and color-coded maps can represent a promising tool in the assessment of AT patients.

Category: Basic Sciences/Biologics; Ankle Arthritis Introduction/Purpose: The first stage of fracture healing consists of hematoma formation with recruitment of proinflammatory cytokines and matrix metalloproteinases. Unfortunately, when there is an intra-articular fracture, these inflammatory mediators are not retained at the fracture site, but instead, bathe the healthy cartilage of the entire joint via the synovial fluid fracture hematoma (SFFH). These inflammatory cytokines and matrix metalloproteinases are known factors in the progression of osteoarthritis and rheumatoid arthritis. Despite the known inflammatory contents of the SFFH, little research has been done on the effects of the SFFH on healthy cartilage with regard to cell death and alteration in gene expression that could lead to post- traumatic osteoarthritis (PTOA). Methods: SFFH was collected from 12 patients with intraarticular ankle fracture at the time of surgery. Separately, human chondrocytes were three-dimensionally cultured to create scaffold -free cartilage tissue analogues (CTAs) to simulate articular cartilage. Experimental CTAs (n=12) were exposed to 100% SFFH for 3 days, washed, and transferred to complete media for 3 days. Control CTAs (n=12) were simultaneously cultured in complete medium. Subsequently, CTAs were harvested and underwent biochemical, histological, and gene expression analysis. Results: Exposure of CTAs to ankle SFFH 3 days significantly decreased chondrocyte viability by 34% (p = .027). Gene expression of both COL2A1 and SOX9 were significantly decreased after exposure to SFFH (p= .012 and p=.0013 respectively). COL1A1 expression trended upward in the SFFH exposure group while there was no difference in RUNX2 and MMP13 gene expression. Quantitative analysis of Picrosirius red staining demonstrated increased collagen I deposition with poor ultrastructural organization in SFFH exposed CTAs. Conclusion: Exposure of an organoid model of healthy cartilage tissue to SFFH after intraarticular ankle fracture resulted in decreased chondrocyte viability, decreased expression of genes regulating normal chondrocyte phenotype, and altered matrix ultrastructure indicating differentiation toward an osteoarthritis phenotype.

Category: Ankle Arthritis Introduction/Purpose: The Vantage total ankle arthroplasty (TAA) features a design based on careful study of arthritic ankles and current ankle biomechanics, with theoretical advantages of a vertically-oriented tibial fixation and a fully congruent talar dome bone-implant interface. In this design-team, single-institution investigation, we report early-to-intermediate term clinical and radiographic outcomes, implant survivorship, and complications of the Vantage TAA. Methods: We retrospectively reviewed prospectively collected data for 278 consecutive patients undergoing Vantage fixed-bearing TAA. Ankles with coronal plane deformity > 25 degrees and suspected poor bone quality were prospectively excluded. Prospectively collected data includes: PROMIS, SF-36, SMFA, VAS and AOFAS hindfoot-ankle scores. Using previously published and commonly accepted evaluation methods, independent radiographic analysis, performed by a non-design surgeon investigator, included pre-operative, 1-year, and most recent follow-up assessments of 2-plane alignment, component position, and the bone- implant interface. A non-design surgeon investigator with dedicated training in statistics performed the statistical analysis using descriptive statistics to report PROM and radiographic measures and Kaplan-Meier survivorship analysis. Results: Mean patient age was 64.8yrs (range:33-86), 44.2% were female, and mean follow-up was 3.1yrs (2.0-5.5). Mean preoperative and postoperative PROMs were as following: PROMIS-Depression 50.3+/-4.2 and 45.6+/-9.8, PROMIS-Physical Function 39.0+/-3.4 and 45.0+/-7.8, SF-36 total score 55.8+/-15.3 and 73.2+/-20.0, SMFA-Function 29.0+/-13.5 and 15.9+/-5.4, VAS 15.8+/-24.8 and 3.1+/-10.1, and AOFAS hindfoot-ankle 46.3+/-16.5 and 81.1+/-16.3 (Table 1). Radiographic lucency at the bone- implant interface was noted in 33 (18.5%) TAAs at final follow-up; 20 (11.2%) were progressive. Lucency was almost exclusive to the tibial component. Implant survivorship was 99.6% [98.9-100.0] at 1-year and 93.3% [88.7-98.2] at the 5-year mark (Table 2, Figure 1). We identified suboptimal bone preparation, initial component alignment and/or component position in all 11 implant failures (Table 3). Conclusion: At early-to-intermediate followup, we observed favorable clinical outcomes, radiographic results and implant survivorship for the fixed-bearing Vantage TAA, especially with optimal bone preparation and component position. Tibial component lucency remains a concern and warrants further investigation. Suboptimal bone preparation, initial component alignment and/or component position was observed in all implant failures.

Category: Ankle; Other Introduction/Purpose: Social media platforms, like TikTok, have become popular options for the consumption and distribution of healthcare information. Due to the lack of scientific oversight, the consistency of healthcare-related videos has become a focus of the current literature. However, orthopaedic surgery has lagged behind other specialties in acknowledging the widespread utilization of TikTok videos for medical information. This study aims to assess the quality and educational benefits of Achilles tendinopathy-related TikTok videos. Methods: TikTok was queried using the hashtags "#achillestendonexercises”, “achillestendonitisexercises", "achillestendinosisexercises" and "achillestendinopathyexercises". 100 videos (25 for each term) were included after applying the exclusion criteria. The number of views, likes, shares, comments, and favorites was recorded. The content was graded using DISCERN (a well-validated informational analysis tool) and ATEES (a self-designed tool for exercise evaluation). Results: The total number of views of the 100 videos was 1,647,148, with a median of 7,562.5 (IQR = 2,281- 19,575). The videos collectively received 73,765 likes, 1,125 comments, 14,491 favorites and 6,897 shares with a median of 283 (IQR= 73. 8-957.8), 7 (IQR= 1.8-16.0), 61.5 (IQR= 8.8-184.3), and 18.5 (IQR= 2.0-49.8), respectively. General users uploaded slightly less (48%) when compared to healthcare professionals (52%). Healthcare professionals had more videos graded as “very poor” (43.4%) in comparison to the general users (36.2%). General users had more videos graded as “poor” (63.8%) in comparison to healthcare professionals (54.7%). However, there were no significant differences between the groups on either of the video grading scales. Conclusion: Although TikTok is a powerful tool for information distribution, the educational value of the videos related to Achilles tendinopathy exercises was poor. With only 1% of videos receiving a grade of ‘fair,’ and no videos reaching a score of ‘good’ or ‘excellent’, healthcare professionals should be aware of the high viewership of low-quality content easily accessible on TikTok.

Category: Ankle Arthritis Introduction/Purpose: Talar collapse can occur from a variety of etiologies and may pose a unique challenge to the foot and ankle surgeon due to the complexity of the deformity and associated adjacent joint degenerative change. Total talus replacement (TTR) has emerged as an attractive option to help patients return to activities sooner than with arthrodesis and improve pain and joint mechanics postoperatively. However, there is limited long-term data on the most recent generation of implants. In this multi- institution case series, we present the severe complications that can occur after TTR, including instability, infection, and adjacent joint osteoarthritis. Methods: We present three cases from Duke University Hospital in Durham, North Carolina, and the Hospital for Special Surgery In New York City, New York. All three patients were treated with a total talus replacement (TTR) during their clinical course and experienced subsequent complications. Clinical data and radiographs were collected from chart review under an IRB-exempt protocol. Results: Case 1 demonstrates the risk of ligamentous insufficiency leading to dislocation following placement of a TTR. This case highlights the posterior instability due to soft tissue mobilization and division. Case 2 highlights the risk for adjacent joint degeneration with TTR. Case 3 presents an instance of non-union following a total ankle and total talus replacement (TATTR) with subtalar arthrodesis. To our knowledge, this represents the first case of nonunion following TTR in the literature. Finally, we discuss our institution’s experience with infection following TTR and possible contributing factors to this specific procedural risk. Conclusion: TTR shows promise in the properly selected patient with end-stage talar collapse. However, heterogeneous surgical techniques, implant composition, indications, and patient demographic variables complicate the interpretation of the literature. Moreover, few studies report mid-to long-term outcomes after this procedure and the occurrence of adjacent joint OA is likely underreported in the literature. Thus, until further, high-quality studies with long-term follow-up validate the positive early outcomes of TTR, we urge extreme caution in patient selection, choice of implants, and surgical techniques.

Category: Ankle Arthritis Introduction/Purpose: Obesity is a well-established risk factor for complications after total hip and knee arthroplasty. The incidence of total ankle arthroplasty (TAA) continues to grow, but few studies have evaluated TAA outcomes in patients with obesity. The present study sought to measure the impact of obesity on TAA outcomes using a national database. Methods: The 2012-2020 National Surgical Quality Improvement Program (NSQIP) database was queried for primary TAA (CPT:27002). 1,610 patients were identified and stratified by preoperative body mass index (BMI): non-obese (18 5-29.9kg/m 2 , n=760), obesity class I (30.0-34.9kg/m 2 , n=455), and class II and III (>35.0kg/m 2 , n=395). Preoperative and perioperative patient data, operative time, hospital length of stay (LOS), and 30-day complications were compared using univariable statistics. Multivariable analyses controlling for patient characteristics were employed to measure the effect of obesity on operative time and LOS. Results: Compared to the non-obese group, obesity class II and III patients were younger (61.9 versus 65.6 years;p < 0.001), more female (57.2% versus 42.0%;p < 0.001), higher ASA class (p < 0.001) and had more comorbidities such as hypertension, diabetes, and dyspnea (p < 0.001). Mean preoperative albumin was lower (p=0.013) and white blood count was higher (p < 0.001) in the obesity class II and III group. Home discharge rate was lowest in class II and III patients (88.6%;p=0.017). Multivariable regression revealed longer hospital LOS for obesity class II and III (μ=0.21; p=0.005) relative to the non-obese group. Obesity group was not associated with operative time or 30-day readmissions and reoperations. Conclusion: Obesity class II and III patients undergoing TAA had more comorbidities and longer hospital LOS compared to lower BMI patients. Despite the well-established association between obesity and postoperative complications after hip and knee arthroplasty, the present NSQIP analysis of 1,610 TAA patients did not find a greater burden of acute complications among patients with obesity.

Category: Ankle Arthritis Introduction/Purpose: Total joint arthroplasty is increasingly being performed in younger individuals across the United States. While age-specific outcomes have been evaluated in total hip and knee replacements, the data are not as clear for total ankle arthroplasty (TAA). The purpose of this study was to analyze TAA outcomes and complications by age to improve shared decision-making when considering ankle replacements. Methods: A total of 1,619 primary and revision TAAs from 2012-2020 were collected and included from the National Surgical Quality Improvement Program. Patients were stratified by age into groups less than 55, between 55-70, and greater than 70 years of age. Demographics, medical comorbidities, ASA class, operative time, 30-day complications, and comorbid conditions were compared by univariable analysis. Multivariable analysis was used to analyze readmission rates, reoperation rates, operative time, and hospital length of stay. Results: By univariable analysis, patients greater than 70 have significantly more comorbidities when compared to patients younger than 55. Younger patients have a significantly longer hospital stay, with an average of 1.64 days for those younger than 55 compared to patients 55-70 (1.50 days) and patients older than 70 (1.38 days, p< 0.001). Younger patients also have a significantly longer operative time and a higher risk of still being in the hospital after 30 days (p < 0.001, p=0.034). By multivariable analysis, patients 55-70 have a statistically lower risk of readmission compared to the other two cohorts (p = 0.043). Conclusion: As the incidence of total ankle arthroplasty increases across all ages, it is important to understand specific risks for each age group. Patients younger than 55 experience higher operative times and longer lengths of stay. Patients between 55-70 have a significantly lower risk of reoperation but longer hospital stays. Patients older than 70 tend to have lower reoperation rates, lower readmission rates, and shorter operative times.

Category: Ankle; Other Introduction/Purpose: The Invision talar component was launched in 2018 as a revision total ankle arthroplasty (TAA) specific option geared towards avoiding further subsidence when poor talar bone stock is present. Due to the recency of the market- availability of the Invision, studies evaluating the efficacy of the implant, even in the short-term, are lacking. Thus, the purpose of this study was to present the early-term outcomes of a series of patients undergoing revision TAA with the use of the Invision talar component. Methods: This was a single-center, retrospective review of 28 patients undergoing revision TAA with the Invision talar component and Inbone II tibial component (Wright Medical; Memphis, Tennessee) performed between 2007 and 2022. Mean follow-up was 1.3 ± 0.93 years. Data on patient preoperative characteristics, postoperative complications, and survivorship were collected. The primary outcome measures were time to major complication, reoperation, and infection. Results: The most common concurrent procedures performed with revision TAA with the Invision talar component were gastrocnemius recession (n=14, 50%), subtalar arthrodesis (n=3, 10.7%) and cotton osteotomy (n = 1, 3.6%). The mean preoperative coronal deformity off the tibia was 4.07 ± 3.06 degrees for varus and 3.67 ± 4.36 degrees for valgus deformities, respectively, and postoperatively, was 1.67 ± 2.16 degrees for varus and 2.00 ± 3.48 degrees for valgus. The mean preoperative coronal plane deformity off the talus was 4.83 ± 6.68 degrees for varus and 4.22 ± 4.21 degrees for valgus, respectively, and postoperatively, was 1.23 ± 2.45 degrees for varus and 2.32 ± 3.93 degrees for valgus. The survivorship from any complication, major complication, reoperation, and infection is shown in Table 2. Conclusion: In a series of 28 patients undergoing revision TAA with the Invision talar component and Inbone II tibial component, we demonstrate a survivorship of 92.7% at 1-year follow up. The Invision appears to have a reasonable safety profile in this non- designer series. The implant compares favorably with others utilized in the revision TAA setting at the early-term, but further studies evaluating mid-and long-term outcomes are required to fully assess the efficacy of the Invision.

Category: Ankle Arthritis Introduction/Purpose: As total ankle arthroplasty (TAA) rises in popularity nationwide, the incidence of major complications and need for revision TAA will continue to increase. A better understanding of the ability to durably correct deformity and improve patient reported outcomes (PROs) in the TAA revision setting is paramount for surgeons facing the impending wave of failed TAA. Thus, the purpose of this study was to present the largest single-center case series of revision TAA to date and to evaluate improvement in PROs and maintenance of correction of coronal plane deformity in patients undergoing this procedure. Methods: This was a single-center, retrospective review of 87 revision TAAs performed between 2007 and 2022. Reoperations for cyst formations only or without metallic component exchange were excluded. The two most common implants used for revision TAA were Inbone II (n=65) and Inbone I (n=14). Mean follow-up was 2.8 ± 2.9 years. Data on patient preoperative characteristics, concurrent procedures, and postoperative complications were collected. The primary outcome measures were time to major complication, reoperation, and infection. Secondary outcomes included PROs and correction of coronal plane deformity measured from both the tibial plafond and talar articulating surface from pre- to post-operatively. Cox regression analyses were performed to compute survivorship. Results: The most common concurrent procedures performed concomitantly with revision TAA were gastrocnemius recession (n=31, 35.6%), subtalar arthrodesis (n=18, 20.7%), and talonavicular arthrodesis (n=5, 5.7%). Mean preoperative coronal plane deformity measured off both the tibial plafond and talar articular surface improved after revision TAA. 1- and 5-year survivorship from major complication, reoperation, and infection is shown in Table 2. Fourteen patients underwent subsequent revision, including TAA (n= 6, 6.9%), arthrodesis (n= 4, 4.6%), below-the-knee amputation (n= 2, 2.3%), or implantation of an antibiotic spacer (n= 2, 2.3%). At one-year postoperatively, mean VAS pain score, SF36, and AOFAS Hindfoot score was 18.2 ± 16.0, 73.0 ± 13.3, and 68.8 ±:9.3, respectively, representing an improvement in PROs after revision TAA. Conclusion: In the largest single-center series of patients undergoing single or double component exchange revision TAA, we demonstrate durable improvements in coronal plane deformity measured off both the tibial plafond and talar articular surface. We also noted 63.0% survivorship with regards to reoperation and improvements in average PROs across the cohort. Overall, revision TAA is a successful procedure, but is associated with higher failure rates at 5 years than primary TAA.

Category: Ankle Arthritis Introduction/Purpose: There is limited data evaluating the effect of obesity on outcomes following total ankle arthroplasty (TAA), especially in adequate sample sizes to detect impacts on patient reported outcomes (PROs). The purpose of this study was to assess the effect of obesity on complication rates and PROs. Methods: This was a single-institution, retrospective study of 1,093 primary TAA performed between 2001 and 2020. Minimum follow-up was 2 years. Patients were stratified by body mass index (BMI) into Control (BMI=18.5-29.9; n=615), Obesity Class I (BMI=30.0-34.9; n=285), and Obesity Class II (BMI>35.0; n=193) groups. Patient information, intraoperative variables, postoperative complications, PRO measures were compared between groups using univariable statistics. Multivariable Cox regression was performed to assess risk for implant failure. Mean follow-up was 5.6 years (sd:3.1). Results: Compared to Control and Class I, Class II patients had the lowest mean age (p=0.001), highest mean ASA score (p < 0.001), and greatest proportion of female sex (p < 0.001) and Black/African American race (p=0.005). There were no statistically significant differences in postoperative complications (infection, implant failure, or impingement) across the BMI classes (p>0.05). Preoperatively, Class II had lower (worse) mean scores for FAOS Pain and ADL subscales than Controls (posthoc pairwise p< 0.001 for both). At final follow-up, both Class II and Class I had lower (worse) mean SMFA (posthoc pairwise p< 0.001 and p=0.030, respectively) and SF36 scores (posthoc pairwise p< 0.001 and p=0.005, respectively) than Controls. Conclusion: At midterm follow-up, obesity was not associated with increased rates of complications after TAA. Patients with obesity reported worse musculoskeletal function and overall quality of life after TAA but there was no differential improvement in PROs across BMI classes. To our knowledge, this is the largest single institution study to date examining the effect of obesity on outcomes after primary TAA.

Category: Ankle, Basic Sciences/Biologics Introduction/Purpose: Subchondroplasty® (SCP®) (Zimmer Holdings, Inc, Warsaw, IN) is a relatively new procedure that was developed in 2007 for the treatment of bone-marrow lesions (BMLs). It involves the injection of flowable nanocrystalline calcium phosphate (CaP) synthetic bone substitute into the BML using fluoroscopic-guidance, in order to promote healing and reinforce the effected region. Although a newer technique, SCP has been shown promising results in the knee through several different small case-series. The foot and ankle literature is sparser, with only a few documented case-reports or case-series. As a result, we wanted to report our small case-series of patients who underwent talar SCP and went on to develop avascular necrosis (AVN). Methods: A retrospective review was conducted of patients who underwent SCP for a talar BML at our facility or were referred to our facility after undergoing SCP at an outside institution. Patients who developed iatrogenic talar AVN postoperatively were included in the study. Patient characteristics, comorbidities, imaging, and need for further surgery was analyzed. Results: Four patients were identified who had previously undergone talar SCP and went on to develop iatrogenic talar AVN. Two patients had their original SCP performed at our facility, whereas the other two patients were referred from outside institutions. All four patients were symptomatic from their AVN. Two patients have undergone revision surgical intervention, while the other two patients are pending surgical intervention. Conclusion: This case-series is the first study, to our knowledge, to report iatrogenic talar AVN after undergoing SCP for talar BMLs. Although early studies in the Foot and Ankle literature are promising for use of this technology, these studies have been small and surgeons should be aware of this potential complication.

Category: Trauma Introduction/Purpose: The current gold-standard for unstable distal fibula fractures is plate and screw fixation; however, intramedullary distal fibular fixation is becoming more commonplace. Although surgeons may consider this technique only for patients requiring extra soft tissue protection, recent studies are showing that it is a safe and effective technique for maintaining adequate reduction and promoting proper fracture healing in a wide-variety of ankle fractures. As newer techniques and equipment are developed, it is important to continue with analyzation of patient outcomes. Our study evaluates a intramedullary device that contains a unique proximal locking mechanism that deploys fins against the inner cortex to help maintain fracture length and control rotation. To our knowledge, no other study in the literature has evaluated this technique for distal fibula fractures. Methods: A retrospective case-series was conducted on all patients >18-years old with unstable ankle fractures treated with the same intramedullary distal fibular fixation, that contained the unique proximal locking system. Surgeries were performed at a single institution by a single surgeon between September 2015 and June 2018. Patient imaging was carefully assessed for quality of reduction using previously established guidelines classifying reductions as “good”, ”fair”, or “poor”. Patient charts were also assessed for comorbidities, initial fracture classification, postoperative complications, and need for additional surgery. Results: Forty-one patients were included in the study. Twenty-five patients were female and 16 patients were male. Average age was 52. Average follow-up was 10.0 months. Eleven fractures were bimalleolar (27%), eight were isolated distal fibula fractures (20%), eight were bimalleolar-equivalent fractures (20%), nine were trimalleolar fractures (22%), and five were pilon fractures (12%). Seventy-one percent were Weber B and 29% were Weber C. Based on the classification system, 37 fracture reductions (90%) were classified as ”good”, four were “fair” (10%), and no reductions were ”poor”. There were no instances of hardware failure, loss of reduction, or nonunion. One patient had a superficial wound infection, one patient had a deep wound infection, five patients require painful hardware removal, and one patient had a delayed union. Conclusion: This large case-series is the first study, to our knowledge, in the Foot and Ankle literature to evaluate this specific intramedullary distal fibular fixation system that contains a unique-proximal fixation mechanism within the canal itself. This technique was used for a variety of unstable ankle fractures and was shown to be both safe and effective, and will help guide future prospective studies comparing outcomes with the gold-standard plate and screw fixation.

Category: Arthroscopy Introduction/Purpose: Ankle impingement and ankle osteochondral defects are common problems seen by foot and ankle specialist that often go on to require surgical managment. After conservative treatment fails, ankle impingement is often managed by arthroscopic debridement, whereas ankle OCDs are often treated with ankle arthroscopy and microfracture as a first line treatment. However, surgeons have various treatment protocols post-operatively after these procedures, with some surgeons allowing immediate weight bearing, were as other surgeons restrict patients weight bearing. There is similar heterogeneity in the manner of immobilization post-operatively. The purpose of this study is to retrospectively review the outcomes of patients undergoing ankle arthroscopy and micro fracture, to determine if immediate weight bearing or removable immobilization had any impact on outcomes. Methods: We retrospectively reviewed 79 patients at our institution who underwent ankle arthroscopy with microfracture for talar osteochondral defects over 3 years. This included surgeries performed by one of 7 fellowship trained foot and ankle surgeons at our institution. Each surgeon had different protocols for post-operative weight bearing and immobilization, allowing for a comparison of various post-operative protocols. Patient outcomes were reviewed pre-operatively and post-operatively including age, sex, comorbidities, etiology of talar pathology, post-operative weight bearing status, time to first weight bearing, as well as method and length of immobilization, VAS scores, range of motion, and complications. Clinical outcomes such as time to return to work and return to sport were also evaluated. Results: The average patient age was 38. 42 patients (53%) had an additional procedure performed at the time of ankle arthroscopy and microfracture. There was no significant difference in the average pre-op and post-op VAS or range of motion between the immediate weight bearing group and the delayed weight bearing group. There was interestingly a trend towards lower VAS scores in the immediate weight bearing group (1.4 vs 2.6). Conclusion: Following ankle arthroscopy and microfracture, we found no difference in VAS, range of motion, or complications when allowing immediate, full weight bearing as well as using removable immobilization as compared to a variety of other protocols at early follow up. In fact, there was a trend towards lower VAS scores in the immediate full weight bearing group. Though this study has early follow up, it does suggest at least the equivalency of allowing immediate weight bearing and removable immobilization following ankle arthroscopy and talar microfracture.

Category: Ankle Arthritis Introduction/Purpose: Total ankle arthroplasty (TAA) for ankle arthritis leads to a more normal gait pattern compared to ankle arthrodesis, prompting many to hypothesize that TAA slows development of adjacent joint arthrosis. However, following TAA, patients may also develop hindfoot pain, deformity and dysfunction, ultimately requiring arthrodesis procedures. Many patients with AA also have subtalar and/or talonavicular arthrosis. In these cases, simultaneous TAA and hindfoot arthrodesis may be performed. Previous studies have found that TAA in conjunction with hindfoot arthrodesis procedures led to inferior outcomes compared to isolated TAA. The purpose of this analysis was to compare the functional outcomes of simultaneous vs. subsequent hindfoot arthrodesis procedures and to describe the change, if any, in outcome scores following a subsequent hindfoot arthrodesis procedure. Methods: After receiving Institutional Review Board approval, the TAA database at our institution was reviewed for all TAA performed between 1998 and 2015. All patients who received a TAA and either a simultaneous or subsequent hindfoot arthrodesis with at least two years of clinical follow up were included in the analysis. All surgeries were performed by one of three fellowship-trained orthopaedic foot and ankle surgeons with extensive experience in TAA and associated hindfoot arthrodesis procedures. Outcome measures included preoperative and 2-year postoperative visual analog scale (VAS) scores, Short Musculoskeletal Function Assessment (SMFA), Short Form (SF)-36 and American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot scores. Results: 64 patients met the inclusion criteria. 39 patients underwent TAA with simultaneous hindfoot arthrodesis (Sim) and 25 underwent a subsequent arthrodesis procedure (Sub) an average 22.2 months following TAA. 20 patients underwent double arthrodesis (11 Sub) and 44 patients underwent subtalar fusion (14 Sub). There were no differences in preoperative questionnaire scores between the two groups. Both the Sim and Sub groups experienced significant improvement in their postoperative VAS, SMFA, SF-36 and AOFAS scores. Postoperative VAS and SMFA bother scores were significantly lower for the Sim group (p

Category: Trauma Introduction/Purpose: Lateral malleolus (LM) fixation is necessary for unstable ankle fractures. Traditional fixation relies on the use of plates through a lateral incision, wound healing can be an issue for such incisions. A novel intramedullary (IM) fixation device has been developed that can be placed through a minimal incision. The purpose of this study was to demonstrate the clinical efficacy of this device. Methods: A retrospective analysis was performed on patients who received IM fixation for isolated fibula, bimalleolar (BM), and trimalleolar (TM) fractures. Pertinent demographic information, operative factors, complications, and clinical outcomes were recorded. Results: Sixteen patients were included in the study with an average age of 59 (Range of 35 to 86). Six patients presented with isolated LM fractures, four patients had a BM fracture with a syndesmotic injury, two patients sustained a LM fracture with an associated syndesmotic injury, two patients had a BM fracture, and two patients had a TM fracture with a syndesmotic injury. There was a 100% healing rate of the lateral malleolus without any cases of malunion or shortening. There were no cases of sural nerve or peroneal tendon injuries, nor any wound complications found. Conclusion: These findings demonstrate the safe and efficacious use of a novel intramedullary fixation device for fibula fractures with a lower wound complication and infection rates compared to published outcomes found with lateral fibular plating. The features of this device allow for reliable fixation of the fibula, maintaining length and minimizing wound issues.

Category: Ankle Arthritis Introduction/Purpose: Metal component failure in total ankle arthroplasty(TAA) is difficult to treat. Traditionally, to an arthrodesis has been advocated. Revision TAA surgery has become more and more common with availability of revision implants and refinement of bone conserving primary implants. It this study, patient reported results and clinical outcomes are analyzed for patients undergoing revision total ankle arthroplasty. Methods: We retrospectively reviewed prospectively collected data on 45 patients (cases) with a mean age of 63.7 +/-10.2 years who developed loosening or collapse of either major metal component in the primary total ankle arthroplasty. Cases of isolated polyethylene exchange, infection, or extra-articular realignment procedures were excluded. Prospectively collected patient reported outcomes measures including the American Orthopaedic Foot and Ankle Society(AOFAS) hindfoot score, Visual Analog Scale (VAS), Short Form 36 (SF-36), Short Musculoskeletal Function Assessment (SMFA), and the Foot and Ankle Outcomes Score (FAOS) questionnaires were collected. Clinical data was collected through thorough review of the electronic medical record to identify clinical failure defined as explant and second revision or conversion to arthrodesis or amputation. Results: The causes of failure of primary TAA in this study were aseptic loosening of both components (40%), talar component subsidence/loosening (37.7%), tibial loosening (8.8%), coronal talar subluxation (8.8%) and talar malrotation (2.2%). Twenty-four patients (53.3%) underwent revision of all components, nineteen (42.2%) just the talar and polyethylene components, and two (4.4%) the tibial and polyethylene components. The average time to revision was 5.56 years +/- 5.71 with a follow-up of 3.02 years +/- 1.25 after revision. Ten (22.2%) revision arthroplasties required further surgery; five required conversion to arthrodesis and five required second revision TAA. VAS scores, SF36 scores, SMFA scores, AOFAS Hindfoot scores, and FAOS all improved after revision surgery but took 2 years to reach scores comparable to 1 year after primary TAA. Conclusion: Clinical and patient reported results of revision ankle arthroplasty after metal component failure were comparable to those after primary ankle arthroplasty. In our series, 22.2% of revision TAAs required a second revision TAA or arthrodesis surgery. Various prosthesis performed similarly when used in revision scenarios. Patients recovered faster from primary ankle arthroplasty when compared to revision ankle arthroplasty but all scores were comparable by the two-year follow-up visit after revision arthroplasty surgery.

Category: Other Introduction/Purpose: One of the most common complications in orthopaedic surgery of the foot and ankle is nonunion or delayed union and bone or implant fractures. Although foot and ankle surgery has improved dramatically over the past decades primarily due to the development of better techniques, little progress has been made in the development of new materials for implants. Titanium, the most commonly used alloy for foot and ankle implants, has limited strength and is notch-sensitive so repetitive stress leads to fatigue failure of implants and limits design options. Better materials with optimized biomechanical properties could result in the development of superior foot and ankle implants and surgical techniques. The mechanical properties of Molybdenum-Rhenium (MoRe®), a promising new alloy for foot and ankle implants were tested. Methods: Standard test methods (ASTM 1717) were performed to evaluate the mechanical properties of Molybdenum Rhenium (MoRe®) alloy compared to Titanium (Ti-6Al-4 V, ASTM F136-13 annealed bar, Ti-ELI). Results: MoRe® is composed purely (99.99%) of molybdenum and rhenium and does not contain Nickel. Molybdenum is found in food and is a cofactor to the enzymes xanthine oxidase and sulfite oxidase, which are essential to bone and connective tissue metabolism. Rhenium is an inert metal with no biological affect. Mechanical testing showed MoRe to be superior to Titanium: Yield Strength: MoRe® 280ksi, Titanium 115ksi, Ultimate Tensile Strength: MoRe® 300ksi, Titanium 125 ksi. Elongation and Reduction in Area: MoRe® 13%, 50%, respectively; Titanium 10%, 25%. Recoil: MoRe®

Category: Ankle Arthritis Introduction/Purpose: Among patients with end-stage ankle arthritis, total ankle arthroplasty (TAA) utilization has significantly increased in recent years, while ankle arthrodesis utilization has declined. Significant coronal plane deformity is frequently encountered in this patient population, and was previously considered a contraindication to TAA. However, the advent of newer fixed-bearing prostheses, coupled with improved surgical techniques and a better understanding of ligamentous balancing, have allowed surgeons to extend their indications for TAA with respect to deformity correction. Several authors have demonstrated good outcomes from TAA in patients with significant varus deformities, but not specifically in patients with valgus deformities. We aimed to determine the clinical, radiographic, and patient-reported outcomes of patients with moderate to severe valgus deformity who underwent TAA for end-stage ankle arthritis. Methods: Eighty patients with valgus deformities =10 degrees who underwent TAA were retrospectively reviewed. All surgeries were performed by one of three fellowship-trained orthopaedic foot and ankle surgeons with extensive experience in TAA. One of three prostheses were used: INBONE (Wright Medical Technology, Arlington, TN), Salto-Talaris (Integra, Plainsboro, NJ), or the Scandinavian Total Ankle Replacement (STAR; Stryker, Kalamazoo, MI). We assessed the coronal tibiotalar angle on standardized weightbearing radiographs preoperatively, at one year, and at final follow-up. The visual analog scale (VAS) for pain, Short Form (SF)-36 scale, American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot-ankle scale, and Short Musculoskeletal Function Assessment (SMFA) scores were assessed preoperatively and at final follow-up. Subgroup analyses were performed to determine differences in outcome scores, deformity correction, and maintenance of alignment between patients with moderate (=10 degrees, 20 degrees) preoperative deformity. Complication, reoperation, and revision rates were collected from chart review. Results: Mean preoperative valgus deformity was 15.5 ± 5.0 degrees, and was corrected to a mean 1.2 ± 2.6 degrees of valgus postoperatively (Figure; P

Category: Basic Sciences/Biologics Introduction/Purpose: Large osteochondral lesion of the talus (OLT) can be difficult to treat. Although many treatment options exist, fresh osteochondral allograft transplantation has demonstrated promise as the primary treatment for OLTs with substantial cartilage and bone involvement as well as a secondary treatment option after failure of other cartilage repair techniques. Fresh osteochondral allografts are size-matched from organ donors and, in theory, have healthy articular cartilage and bone. However, the quality of allograft cartilage and bone has never been examined with respect to the OLT cartilage and bone being replaced. The purpose of this study was to perform a matched comparison of the cartilage and bone from patients OLTs to the fresh osteochondral allograft replacement. Methods: Discarded intact osteochondral specimens were collected from 8 patients undergoing surgery for an OLT. The specimens included the excised OLT and a portion of the fresh allograft replacement that the same patient received at the time of surgery. Histologic analysis was performed. The safranin-o histology was then scored using the International Cartilage Repair Society (ICRS) histopathology grading and staging system. In this system the grade determines cartilage and bone destruction on a scale of 0 to 6.5, the stage determines the percentage of involvement in the specimen on a scale of 0 to 4, and the total score is the grade multiplied by the stage. The surface roughness was also compared between the OLT and allograft cartilage using ImageJ software (NIH). Paired t-tests were performed on the ICRS grade, stage, and total score, and surface roughness comparing the OLTs and allografts. Significance was set at p

Category: Ankle Introduction/Purpose: Total ankle replacements (TAR) are an increasingly popular option for the management of tibiotalar arthritis. Periprosthetic fracture is an uncommon but challenging complication of patients undergoing arthroplasty. Evidence on the management of and outcomes from periprosthetic fractures about a TAR are limited. The purpose of this study was to evaluate patients with postoperative periprosthetic fractures about a TAR and determine clinical outcomes of these patients following operative fixation. Additionally, we propose an algorithm for the management of these patients. Methods: We retrospectively analyzed 400 patients who underwent TAR from 2007 through 2017. Charts were reviewed and patients with postoperative fractures were selected for inclusion. Patients with a fracture >4 weeks from index surgery were considered candidates for inclusion. Patients with intraoperative fractures were excluded. Univariate analyses were used to identify differences in outcomes. Results: 32 patients were identified with a postoperative periprosthetic fracture about a TAR. Average age was 65.3 years. Average time to fracture was 39.5 months while average follow up from fracture was 26 months. Fractures were primarily located about the medial malleolus (60.6%). 76.8% of fractures were deemed to be stable (Table 1); 75% of these fractures were managed with ORIF or IMN, while 21% of these fractures were treated with immobilization. 80% of patients with stable fractures treated with immobilization ultimately required surgical intervention. 24.2% of fractures were deemed to be unstable. Fractures about the talus were always unstable and always required revision TAR surgery (100%, p= 0.0002). Conclusion: This retrospective review demonstrates that the majority of periprosthetic fractures about a TAR involve the medial malleolus. Additionally, the majority of stable fractures about a TAR required operative fixation. Despite attempts at nonoperative management, management with immobilization is fraught with a high rate of subsequent surgical intervention. Fractures about the talus should be treated with revision TAR surgery or arthrodesis. Based on these findings, we propose an algorithm for the management of patients with a periprosthetic fracture about a TAR.

Category: Ankle Arthritis Introduction/Purpose: Outcomes of total ankle replacement for the treatment of end-stage ankle arthritis continue to improve. Debate continues whether a mobile-bearing total ankle replacement (MB-TAR) or a fixed-bearing total ankle replacement (FB-TAR) is superior, with successful outcomes reported longterm for MB-TAR and at intermediate-to-longterm follow-up for newer generation FB-TAR. Although comparisons between the two total ankle designs have been reported, to our knowledge, no investigation has compared the two designs with a high level of evidence. This prospective, randomized controlled trial conducted at a single institution compares patient satisfaction, functional outcomes and radiographic results of the mobile-bearing STAR and the fixed-bearing Salto-Talaris in the treatment of end-stage ankle arthritis. Methods: This investigation was approved by our institution’s IRB committee. Between November 2011 and November 2014, adult patients with end-stage ankle osteoarthritis failing nonoperative treatment were introduced to the study. With informed consent, 100 patients (31 male and 69 female, average age 65, range 35 to 85) were enrolled; demographic comparison between the two cohorts was similar. Exclusion criteria included inflammatory arthropathy, neuropathy, weight exceeding 250 pounds, radiographic coronal plane deformity greater than 15 degrees or extensive talar dome wear pattern (“flat top talus”). Prospective patient-reported outcomes, physical exam and standardized weightbearing ankle radiographs were obtained preoperatively, at 6 and 12 months postoperatively, and then at yearly intervals. Data collection included visual analog pain score (VAS), short form 36 (SF-36), foot and ankle disability index (FADI), short musculoskeletal functional assessment (SMFA) and AOFAS ankle-hindfoot score. Surgeries were performed by non-design team orthopaedic foot and ankle specialists with total ankle replacement expertise. Statistically analysis was performed by a qualified statistician. Results: At average follow-up of 4.5 years (range 2-6 years) complete clinical data and radiographs were available for 84 patients; 7 had incomplete data, one had died, 4 were withdrawn after enrolling but prior to surgery and 4 were lost to follow-up. In all outcome measures, the entire cohort demonstrated statistically significant improvements from preoperative evaluation to most recent follow-up. There was no statistically significant difference in improvement in clinical outcomes between the two groups. Radiographically, tibial lucency/cyst formation was 26.8% and 20.9% for MB-TAR and FB-TAR, respectively. Tibial settling/subsidence occurred in 7.3% of MB-TAR. Talar lucency/cyst formation occurred in 24.3% and 2.0% of MB-TAR and FB-TAR, respectively. Talar subsidence was observed in 21.9% and 2.0% of MB-TAR and FB-TAR, respectively. Re-operations were performed in 8 MB-TAR and 3 FB-TAR, with the majority of procedures being to relieve impingement or treat cysts and not to revise or remove metal implants. Conclusion: For the first time, with a high level of evidence, our study confirms that patient reported and clinical outcomes are favorable for both designs and that there is no significant difference in clinical improvement between the two implants. The incidence of lucency/cyst formation was similar for MB-TAR and FB-TAR for the tibial component, but the MB-TAR had greater talar lucency/cyst formation and tibial and talar subsidence. As has been suggested in previous studies, clinical outcomes do not correlate with radiographic findings. Re-operations were more common for MB-TAR and in the majority of cases were to relieve impingement or treat cysts rather than revise or remove metal implants.

Category: Ankle Arthritis Introduction/Purpose: The Comprehensive Care for Joint Replacement model (CJR) provides bundled payments for in-hospital and 90-day post-discharge care of patients undergoing total ankle arthroplasty (TAA). Defining patient factors associated with increased costs during TAA could help refine patient selection strategies and identify modifiable preoperative patient factors that can be addressed prior to the patient entering the bundle. Methods: This study is part of an IRB-approved single-center observational study of patients undergoing TAA from 1/1/2012 to 12/15/2016. Patients were included if they met CJR criteria for inclusion into the bundled payment model and had Medicare as the insurance payer. Costs related to readmissions, diagnosis, and procedures that had been excluded by CJR were also excluded from this financial analysis. All inpatient and outpatient payments beginning at the index procedure through 90 days postoperatively were identified. Patient medical profile including Charlson-Deyo and Elixhauser comorbidity scores, preoperative comorbidities, and perioperative factors were then completed based on institutional data and chart review. Additionally, post-discharge disposition, readmissions, emergency department (ED) utilization, and outpatient plastic surgery consultation were recorded within the 90-day bundled payment period. Results: Out of 199 patients with Medicare payments in the study timeframe, 137 had consented to the study and were analyzed. Baseline and operative characteristics are given in Table 1. Increased length of stay (LOS) at the initial procedure, increased Charlson-Deyo comorbidity score, cerebrovascular disease, and peripheral vascular disease were significantly associated with higher payments. Discharge to skilled nursing facility (skilled nursing facility), admissions, ED visits, and wound complications were significant drivers of payment. Conclusion: Increased Charlson-Deyo score and vascular disease along with increased LOS were associated with increased payments from Medicare. Discharge to SNF, readmission, ED visits, and wound complications considerably increased payments. This study identifies the relationship between patient profile and increased financial burden, highlighting the potential utility of pre-operative mitigation of modifiable risk factors and stratification of payments based on patient profile. Lastly, reducing rates of SNF placement, readmission, ED visitation, and wound complications are targets for decreasing costs for patients undergoing TAA.

Category: Ankle Introduction/Purpose: Acute hematogenous periprosthetic joint infection(PJI) is defined in the literature as infection diagnosed and treated within two to four weeks from the onset of symptoms. In total hip and knee arthroplasty, irrigation, debridement(I&D) and polyethylene exchange with component retention is the treatment of choice. There is minimal literature evaluating this treatment method for PJI in total ankle arthroplasty (TAA), however, with four patients being the largest sample size. The purpose of this study was to evaluate both the clinical and patient reported outcomes and survivorship of treating PJI in TAA with I&D and polyethylene exchange in patients with acute hematogenous PJIs. Methods: A single center, retrospective chart review of prospectively collected data in patients with TAA PJI who subsequently underwent I&D and polyethylene exchange with retention of metal components was conducted. The primary outcome was failure rate of I&D and polyethylene exchange where failure was defined as subsequent removal of all components and two-stage revision or arthrodesis. Patient reported outcomes collected before primary arthroplasty, after primary arthroplasty and after polyethylene exchange were also analyzed. Results: We identified 11 patients with acute hematogenous PJI who underwent I&D/ polyethylene exchange with retention of metal components. The average time from onset of symptoms to I&D/ polyethylene exchange was 11.55 days +/-5.57. The mean follow-up after this surgery was 2.8 years +/-1.45. The long-term failure rate was 50%. The most common bacteria isolated in patients who failed was Methicillin Resistant Staphylococcus Aureus (MRSA). The most common bacteria isolated in patients who retained their implants was Methicillin Sensitive Staphylococcus Aureus(MSSA). Visual Analog Scale (VAS), Short Musculoskeletal Function Assessment (SMFA), Short Form-36 (SF36), and American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scale showed significant improvement when compared to preoperative scores in patients who retained their implants both after primary and after I&D and polyethylene exchange. Conclusion: I&D and polyethylene exchange with retention of metal components has comparable long-term survivorship to those reported in the Knee and Hip Arthroplasty literature. Patient reported outcomes after I&D and polyethylene exchange were comparable to those collected after primary arthroplasty in patients who ultimately retained their implants. Two variables which were independent predictors of failure of this surgery include duration of symptoms prior to I&D as well as organism isolated on culture. With a failure rate of 50%, the authors recommend thorough evaluation on a case by case basis prior to indicating a patient for single stage I&D with polyethylene exchange.

Category: Ankle Arthritis Introduction/Purpose: Tibiotalocalcaneal (TTC) fusion is a salvage operation for patients with significant arthritis and deformity of ankle and subtalar joints. Despite overall clinic success, fusion across both joints continues to be a major challenge with nonunion rates reported up to 48% [Franceschi]. Aside from certain patient comorbidities, nonunion may result when compression across the joint is lost in the setting of bone resorption. The use of a pseudoelastic intramedullary nail has been shown to maintain compression across fusion site in response to bone resorption. The purpose of this study was to evaluate the fusion rate in a high-risk population at a tertiary care center using a psuedoelastic intramedullary nail with an internal nitinol element. Methods: After obtaining IRB approval, a retrospective review of consecutive patients that underwent procedures with TTC fusion with novel intramedullary nail system with super elastic internal nickel titanium (NiTiNOL, DynaNail, Medshape Inc, Atlanta, GA) was performed at a single academic institution. From 2014 to 2016, 58 patients were identified, 55 of which had minimum one year follow up or clinical and radiographic fusion (20 months average, range 6-41 months). The primary outcome was radiographic fusion analysis which was reviewed by three authors. Fusion was determined by consensus with criteria of 3 of 4 cortices with osseous bridging in asymptomatic patients[1, 2] or CT fusion based on Glazebrook et. al. criteria for hindfoot fusion[3, 4]. Average age of this cohort was 59 (SD= 16.3) years with BMI average 33.1 (SD= 8.87). Exclusion criteria include: follow-up less than 12 months in non-fused patients, and incomplete clinical or radiologic data. Results: The fusion rate in this high-risk population was 80.0% with the use of the NiTiNOL tibiotalocalcaneal nailing system. Univariate analysis demonstrated no significant difference (p>0.05) in fusion rates with patient comorbidities that portend to non-union: current or former history of tobacco use, diabetes mellitus, rheumatoid arthritis, nor patients with chronic kidney disease. The average BMI in the fusion group was 31.97 compared to 27.4 in the non-union group (p=0.016). There were 5 deep infections requiring reoperation with a single patient requiring a below the knee amputation. Seven patients required a second operation for removal of prominent interlocking screws. Conclusion: This preliminary data demonstrates fusion rates with this novel intramedullary device are consistent with historical data. These findings are encouraging in that this nailing system shows equal rates of fusion in patients with high risk comorbidities for non-union compared to historical controls demonstrating increased non-union rates in diabetics, patients with chronic renal failure and those with a history of smoking. This Tibiotalocalcaneal nailing system is safe and offers theoretical sustained compression with up to 6 mm of resorption or settling.

Category: Bunion Introduction/Purpose: Hallux valgus (HV) is one of the most common deformities of the foot resulting in pain and lifestyle modification of the patient. Recurrence rates of 10-47% have been documented in single individual osteotomy series. Unfortunately, surgical correction and recurrence are often defined as changes related to normal radiographs and not actually as the magnitude of correction lost with follow-up. Currently there have not been studies evaluating the percentage of recurrence of intermetatarsal angle (IMA) and hallux valgus angle (HVA). As there is substantial difference in starting IMA and HVA, as well as amount of surgical correction, our goal was to evaluate the percentage loss of correction over time comparing preoperative, initial postoperative and minimum of 2-year follow up radiographs among three different surgical correction techniques. Methods: This is a retrospective chart review study that examines the weight-bearing radiographic measurements of patients undergoing hallux valgus corrective surgery at a single institution over 5 years. Fifty-three patients were divided into first tarsometatarsal arthrodesis (i.e. Lapidus), mid-diaphyseal osteotomies (i.e. scarf), and distal metatarsal osteotomies (i.e. chevron). The preoperative, initial postoperative, and final follow up weight-bearing radiographs were measured for intermetatarsal angle (IMA) and hallux valgus angle (HVA). Primary outcome was percentage of recurrence of IMA and HVA, with the difference in angles between preoperative and initial postoperative weight-bearing films being considered 100% correction. The percentage of recurrence between initial postoperative and most recent follow up was then calculated (Figure 1A). A one-way analysis of variance (ANOVA) test and post-hoc Tukey-Kramer tests were used to compare preoperative IMA and HVA and percentage recurrence of IMA and HVA at most recent follow up. Results: There was no significant difference between Lapidus (14.3deg) and mid-diaphyseal osteotomies (12.7deg) in preoperative IMA (p-value=0.26). There was a significant difference between Lapidus (-0.3deg) and mid-diaphyseal (2.8deg) osteotomies for degree of hallux valgus recurrence as measured by IMA between initial postoperative films and final 2-year follow up (p-value=0.009). Lapidus procedure showed a greater magnitude decrease in IMA degrees from preoperation to final follow up compared to distal osteotomy (p-value=0.037) and trended toward significance compared to mid-diaphyseal (p-value=0.056). Mid-diaphyseal osteotomies (30%) showed a statistically significant higher percentage of IMA recurrence compared to Lapidus (-11%) (p-value=0.0014) (Figure 1B). When comparing percentage recurrence of HVA, distal osteotomies had a significantly smaller rate of recurrence when compared to the diaphyseal osteotomies (p-value=0.030). Conclusion: Though Lapidus and mid-diaphyseal osteotomies were performed for patients with a similar preoperative IMA, mid-diaphyseal osteotomies had a significantly higher percentage of recurrence at 2-year follow up compared to Lapidus procedures. Moreover, Lapidus procedures trended toward greater overall of IMA correction compared to mid-diaphyseal osteotomies. When either a Lapidus or mid-diaphyseal osteotomy is indicated, a Lapidus procedure may result in decreased rate of radiographic recurrence of hallux valgus at 2 years.

Category: Ankle Arthritis Introduction/Purpose: End-Stage arthritis is one of the leading causes of chronic disability in the United States. Improvement in Health-Related Quality of Life(HRQOL) after total ankle arthroplasty(TAA) has been demonstrated in the literature. This improvement has not been compared to that of other common Orthopaedic and non-Orthopaedic procedures including Anterior Cervical Discectomy and Fusion(ACDF), Total Knee Arthroplasty(TKA), Coronary Artery Bypass Grafting(CABG), and Orthotopic Liver Transplant(OLT). Although TAA is noted to be effective in eliminating symptoms in end-stage arthritis, it is difficult to gauge the impact of TAA relative to other meaningful procedures that have been shown to have great impact on HRQOL improvement. The purpose of this study was to compare changes in HRQOL between TAA and other common procedures with large impacts on this outcomes measure. Methods: Five hundred consecutive patients with minimum of two-years follow-up after TAA were prospectively evaluated with the Short Form-36(SF-36) outcome instrument preoperatively, at six months, one year and two years post-operatively. An exhaustive literature review was conducted identifying studies with comparatively sample sizes comparing preoperative and postoperative SF-36 scores after ACDF, TKA, CABG, and OLT. The SF-36 Physical and Mental component scores were included in each cohort and compared for magnitude of improvement and significant differences between them. Results: Patients in all cohorts had preoperative SF-36 mental and physical function scores significantly lower than the general population scores. The preoperative physical function scores were lowest in the TKA group (average 31.1 +/-9.7) followed by TAA group (average 40.6 +/-16.3), ACDF group (average 41.5 +/-21.6), OLT group (average 51.9 +/-23.6) and CABG groups (57.8 +/-21.3), respectively. Improvement after surgery was greatest in the ACDF group (Mental +31.5, Physical +22.9), followed by the TAA group (Mental +13.9, Physical +26.8), TKA group (Mental +14.3, Physical +22.4), CABG group (Mental +7.6, Physical +15.4) and OLT group (Mental -4.47, Physical +9.8), respectively. The greatest improvement in physical function score occurred in the TAA group (see attached table). Conclusion: The mental and physical disability associated with end-stage ankle arthritis is as severe as that associated with many other Orthopaedic and non-Orthopaedic conditions. The improvement in HRQOL after TAA is greater than that obtained after TKA, CABG, and OLT but not as great as the improvement seen after ACDF; however, the improvement in physical function score was greatest in the TAA cohort. The HRQOL benefits of TAA are comparable to the benefits achieved after several other relatively common and successful surgical procedures.

Category: Other Introduction/Purpose: The most common complications in orthopaedic surgery of the foot and ankle documented in the literature are postoperative infections with a frequency between 1 and 8%. The development of an implant-associated infection can be a potentially devastating complication following foot and ankle surgery. This leads to a high number of revision surgeries after initial fracture stabilization and potential loss of function of the joint and quality of life in the long-term follow-up. Titanium, the most commonly used alloy for foot and ankle implants, has limited strength and is notch-sensitive so repetitive stress leads to fatigue failure of implants and limits design options. Better materials with both optimized mechanical and biological properties could result in the development of superior foot and ankle implants. Methods: Several studies were performed to evaluate the biological properties of MoRe®: A study was conducted to characterize the hydrophilic properties by contact angle comparisons of the MoRe alloy compared to Titanium. A cell growth study was conducted to look at the influence of MoRe alloy on osteoblast growth and differentiation as compared to Titanium. A bone implantation study was conducted based on ISO 10993: Biological Evaluation of Medical Devices, Part 6: Tests for Local Effects after Implantation to evaluate the local tissue and bone response of MoRe® alloy test coupon compared to Titanium controls, when implanted in the mid-shaft femoral bone of rabbits for 4, 13 and 26 weeks. Biofilm formation study was conducted to quantify attachment and biofilm development of S. aureus bacteria upon MoRe® alloy in comparison to CoCr alloy in a well-controlled, reproducible, ex vivo laboratory experiment. Results: MoRe®, composed purely (99.99%) of molybdenum and rhenium, is a cofactor to the enzymes xanthine and sulfite oxidase, which are essential to bone metabolism. Rhenium is an inert metal with no biological affect. MoRe® has superior hydrophilicity (CA 37°±3°) compared to Titanium (CA 58°±3°), a key factor in cell adhesion, migration and replication. Pre-osteoblast cell seeding was found to be equivalent between MoRe° and Titanium alloy (10,000 cells/cm2). The bone implantation study demonstrated continued bone maturation over time for both MoRe® and Titanium implant sites with similar osteoconduction and bone remodeling histology of the cortical and medullary bone at 4, 13 and 26 weeks. The biofilm study found that S. aureus better colonized cobalt chrome alloy in comparison to MoRe® (p = 0.009). Conclusion: The MoRe® alloy, with its advantageous biological properties and hydrophilicity, offers great promise for the design of a new generation of bio-friendly foot and ankle implants with superior cell growth, osseointegration and biofilm resistance resulting in better outcomes for patients.

Category: Midfoot/Forefoot Introduction/Purpose: Hallux rigidus (HR) is a degenerative disease of the first metatarsalphalangeal (MTP) joint, and the most common type of foot arthritis. It affects 2.5% of population aged over 50 years. During the gait cycle, the MTP joint normally carries a force of about 119% body weight. We hypothesize that the altered gait mechanics in patients with end stage ankle arthritis would increase the stress on the MTP joint resulting in hallux rigidus. The purpose of the study was to evaluate the prevalence of radiographic hallux rigidus in a population with ankle arthritis, its association with factors such as gender, age, and severity of the disease compared to the normal population. Methods: Patients from a prospectively-collected total ankle database were screened for the inclusion in the present study. All patients with ankle arthritis who underwent a primary total ankle arthroplasty (TAA) between November 2006 and November 2017 with anteroposterior and lateral views on foot x-rays within 3 months pre or postoperative were included. Foot x-rays were reviewed to assess the prevalence of radiographic hallux rigidus and to grade the severity of diagnosis according to Couglin and Shurnas Radiographic Classification. The association among the grades of severity, demographics, and bilateral involvement were evaluated. Results: A group of 870 patients out of 1044 patients who underwent TAA were included in the study. The mean age was 63 years (standard deviation 10.3). The prevalence of HR in the total group was 72.9% with a slightly higher proportion in males compared to females (51.7% versus 48.3%). The distribution among the grades of severity was grade 1, 58%; grade 2, 24%; and grade 3, 18%. Although, we did not find an association between prevalence and gender (P=0.2) or severity (P=0.37); HR grade 2 and grade 3 were higher in females. Bilateral involvement was found in 16.4% of patients with HR. Conclusion: The prevalence of radiographic hallux rigidus in a population with altered gait mechanics was significantly higher compared to that reported in the literature in the normal population. However, no association among demographic factors such as age or gender was found. Women tended to present a more severe diagnosis compared to men but the difference was no statistically significant.

Category: Ankle, Trauma Introduction/Purpose: The association between tibial shaft fractures and concomitant posterior malleolus fractures has been well-studied; however less is known about tibial shaft fractures and concomitant medial malleolus fractures. Treatment of tibial shaft fractures with a plate or intramedullary nail in the setting of concomitant medial malleolus fracture may pose obstacles to standard medial malleolus fractures fixation due to hardware that impedes optimal screw placement. The purpose of this study is to report the presentation and management strategies used to treat medial malleolus fractures in the setting of concomitant tibial shaft fractures. Methods: From 2011 to 2015, seven (1.4%) patients were identified with concomitant tibial shaft fractures and isolated medial malleolus fractures. Data was collected through review of patient charts, radiographs, and operative reports including the following variables: demographics, injury patterns, fixation techniques, and outcomes. Five male patients and two female patients with a mean age of 39.1 years (range, 13.9-67.9 years) were included. Three patients reported tobacco use. Mechanisms of injury included motor vehicle accident (n=4), fall from standing (n=2), and pedestrian versus vehicle (n=1). Average medial malleolus fracture fragment length was 19.1 mm (range, 14.3-29.4 mm). Tibial shaft fractures were open in four cases, and included five transverse patterns, one spiral pattern, and one segmental fracture. All patients were treated surgically for tibial shaft and medial malleolus fractures simultaneously. All medial malleolus reductions were anatomic. The average time to union for medial malleolus fractures was 3.12 months (range 1.53 to 5.93 months). Results: Fixation techniques included screw (n=5) or buttress plate (n=2) fixation for the medial malleolus, and intramedullary nailing (6) or blade plate fixation (n=1, prior TKA) for the tibial shaft. Of the five medial malleolus fractures treated with screw fixation, screws were positioned anteriorly (n=2) or medially (n=2) to tibial shaft fixation implant in four cases; in one case the distal extent of the tibial nail was proximal to the medial malleolar screws. One buttress plate was placed with screws distal to the tibial nail, another was placed angling one proximal screw anterior and one posterior to the tibial nail. Two patients reported complications following surgery: one with chronic pain and one with wound dehiscence and delayed union at the open tibial shaft fracture site. Conclusion: Seven patients were treated operatively for concomitant tibial shaft and medial malleolus fractures, requiring careful attention to placement of medial malleolar screws or buttress plate due to the presence of implant used to treat the tibial shaft fracture. Medial malleolar screws can safely be redirected anteriorly or medially to accommodate the tibial shaft fracture implant, with acceptable fracture union outcomes in this small case series. Further biomechanical and long-term data may help to validate these adjustments to standard techniques.

Category: Ankle, Ankle Arthritis, Hindfoot Introduction/Purpose: A variety of operative approaches and fixation techniques have been described for tibiotalocalcaneal (TTC) arthrodesis. As a durable, load-sharing device with favorable biomechanical properties, the intramedullary (IM) nail is commonly used. Lateral, fixed-angle plating continues to be popular as well, due to ease of use and lack of significant clinical inferiority. A lateral approach with distal fibula resection allows for direct access to the tibiotalar and subtalar joints, but the posterior, Achilles tendon-splitting (PAS) approach offers a robust soft tissue envelope. The purpose of this study was to compare the results of TTC arthrodesis with either PAS approach and IM nailing or lateral, trans-fibular (LTF) approach with lateral, fixed- angle plating. Methods: Following institutional review board approval, all patients who underwent simultaneous tibiotalar and subtalar arthrodesis were identified with minimum one year clinical and radiographic follow up. A retrospective review of all clinic notes, operative details, and radiographs was performed by a fellowship-trained orthopaedic foot and ankle surgeon not associated with the procedures. Patients were excluded if they underwent TTC arthrodesis through an approach other than PAS or LTF, and received fixation without an IM nail or lateral, fixed-angle plate. Primary outcomes examined were union rate and complications. Statistical analysis was performed with student’s t-test for continuous data and Chi-square test for categorical variables. P-values less than 0.05 were considered significant. Results: 38 patients underwent TTC arthrodesis with a PAS approach and IM nailing, and 28 with a LTF approach and lateral plating. The overall union rate for the PAS/IM nail group was 76.3% (29 of 38), and 64.3% (18 of 28) for LTF/lateral plating group (p=0.41). 15.8% (6 of 38) in the PAS/IM nail group underwent revision arthrodesis versus 7.1% (2 of 28) in the LTF/lateral plating group (p=0.45). Nonunion at the subtalar joint occurred in 25.0% (7 of 28) in the LTF/lateral plating group and 5.3% (2 of 38) in the PAS/IM nail group (p=0.03), but there was not a significant difference in tibiotalar union. Patients were allowed to bear weight 3 weeks earlier in the PAS/IM nail group (11.2 vs 14.4 weeks, p=0.01). Conclusion: Despite similar overall union rates, nonunion of the subtalar joint was significantly increased in the LTF/lateral plating group. This could be due to disruption of blood supply during exposure, insufficient stability, or inadequate compression of the arthrodesis site. However, revision arthrodesis rates were similar between groups because some nonunions were not symptomatic enough to warrant correction. Patients were allowed to fully weight bear significantly earlier in the PAS/IM nail group. PAS approach and IM nailing for TTC arthrodesis may allow for quicker recovery and increased likelihood of radiographic union at the subtalar joint.

Category: Ankle,Ankle Arthritis,Basic Sciences/Biologics,Trauma Introduction/Purpose: Intra-articular ankle fracture (IAF) is known to cause post-traumatic osteoarthritis (PTOA) of the ankle. While the exact etiology remains elusive, the sequelae of intra-articular inflammation has been suggested and our previous work demonstrated a highly pro-inflammatory environment at the time of IAF fixation. ORIF of an IAF can occur 10-14days, or later, after fracture, subjecting the cartilage to this pro-inflammatory environment during this time. Therefore, there is ample time to intervene with an anti-inflammatory agent, yet the exact synovial fluid (SF) composition is unknown. This study examined the effect of time and fracture severity on the SF microenvironment during the acute phase following IAF. Knowledge of the intra- articular metabolic derangement after IAF will help to understand the pathology of PTOA and to develop therapeutic interventions. Methods: Ankle SF was collected from 54 patients with an IAF at the time of surgery for initial external fixation or definitive ORIF and analyzed for concentrations of 10 cytokines, 5 matrix metalloprotienases, 2 products of cartilage catabolism, and combined products of heme metabolism. All analytes were correlated with time from fracture and further analyzed for an effect of 3 clinically relevant time subgroups that correspond to potential clinical intervention time points for ankle fracture management: 0-2 days (initial ER presentation), 3-9 days (clinic presentation), and =10 days (definitive fixation). The effect of fracture severity was determined by grouping SF according to the number of radiographic intra-articular fracture lines. Results: Correlation analysis revealed a significant relationship with time from fracture for 15 of 18 analytes (Figure 1). Temporal grouping of SF revealed an initial (0-2 days) spike of pro-inflammatory (IL-12p70, IL-1?, IL-6) and anti-inflammatory (IL-10 and IL-4) cytokines, MMP-9, and sGAG, followed immediately (3-9 days) by exposure of the joint space to heme breakdown products and an accompanying surge in mediators and products of cartilage catabolism (MMP-1, MMP-2, MMP-3, MMP-10 and CTX-II). After 10 days there was a decrease in pro- and anti-inflammatory cytokines, but a persistence of mediators of cartilage matrix catabolism. While fracture severity had a significant effect on SF levels of MMP-2, MMP-9, and CTXII, there was no clear relationship between the number of fracture lines and SF levels of analytes. Conclusion: This study provides novel insights into temporal inflammatory fluctuations following acute IAF of the ankle and supports consideration of an early evacuation of the jointspace to reduce the intra-articular inflammatory burden and exposure of the cartilage and synovium to these detrimental factors. Moreover, this study identifies the temporal composition of SF products that are known to cause osteoarthritis. Therefore, this information can be used to develop novel therapeutics that can tailored to the time of presentation after intra-articular ankle fracture.

Category: Sports, Trauma Introduction/Purpose: Percutaneous intramedullary screw fixation of Zone II fifth metatarsal fractures has become commonplace. The potential for injury to the important surrounding anatomy has not been well documented, though some authors have reported unexplained postoperative pain and paresthesia over the lateral aspect of the foot despite hardware removal. The purpose of this study was to determine the contact and injury rate of surrounding anatomic structures with either the use of the traditional intramedullary screw (IMS) inserted “high and inside” or a novel intramedullary nail (IMN) inserted “low and outside” through a relative “safe-zone.” Methods: Zone II fifth metatarsal fractures were created in ten cadaver matched-pairs using a 1 mm thick saw through a small incision. Fractures were randomized to receive either an IMS or an IMN. The surgical technique was performed in accordance with the manufacturer’s instructions. For the IMS group, the guide pin was inserted percutaneously according to the “high and inside” starting point on the base of the fifth metatarsal using fluoroscopy; followed by insertion of the 3.5 mm drill, tissue protector, tap, and screw. For the IMN group, the guide pin was inserted percutaneously “low and outside,” positioned slightly medial and dorsal to the tip of the tuberosity of the fifth metatarsal; followed by the 5.2 mm reamer, tissue protector, and IMN. Dissection was performed to identify damage or contact to the peroneus brevis tendon (PB), peroneus longus tendon (PL), sural nerve (SN), lateral insertion of the plantar fascia (PF) and cuboid-fifth metatarsal jointspace. Results: There were significantly more episodes of PB injury, PL contact, SN contact, and presence in the cuboid-fifth metatarsal jointspace for the IMS group. There were significantly more episodes of contact of the PF with the IMN group but no episodes of damage. The results are summarized in Table 1. Images of contact and damage are shown in Figure 1. Fluoroscopic images of the IMN inserted through the “low and outside” position are shown in Figure 2. Conclusion: We have demonstrated significant contact and injury to surrounding structures with the placement of a “high and inside” IMS for the fixation of Zone II fifth metatarsal fractures. We believe there is a relative safe zone at the “low and outside” position that affords less potential damage to the important surrounding structures. Consideration should be given to the development of implants inserted through the relative safe zone.

Category: Ankle, Ankle Arthritis Introduction/Purpose: Concerns for limited coronal plane stability prompted the manufacturer and designers of the INBONE total ankle arthroplasty system to replace the original saddle-shaped talar component (INBONE I) with a sulcus-shaped talar component (INBONE II). Prior to the availability of the INBONE II talar component, numerous INBONE I total ankle replacements were performed. To our knowledge mid-term outcomes of INBONE I total ankle arthroplasty have not been reported. This study compares the mid-term outcomes of patients with and without preoperative coronal plane deformity who underwent total ankle replacement with the INBONE I prosthesis. In our opinion, the longer-term outcomes of the INBONE I prosthesis are important for patient and surgeon education. Methods: A consecutive series of patients, from May, 2007 to September, 2011, at a single institution who underwent total ankle arthroplasty with the INBONE I Total Ankle Arthroplasty (Wright Medical) were prospectively enrolled. Pain and patient- reported function were assessed preoperatively and at yearly follow-ups with use of a visual analog scale (VAS) for pain, the American Orthopaedic Foot & Ankle Society (AOFAS) ankle- hindfoot score, the Short Musculoskeletal Function Assessment (SMFA), and the Short Form-36 (SF-36) Health Survey. We analyzed the data for complications, reoperations, and failures (defined as undergoing revision for exchange or removal of the metallic components for any reason). Patients were grouped according to coronal plane tibiotalar alignment (preoperative coronal plane malalignment of >10 degrees and 10 degrees (47.7%) and 10 degrees had fewer reoperations (19 vs. 30) and fewer revisions (5 vs. 9) when compared to patients with

Category: Ankle,Ankle Arthritis Introduction/Purpose: The Comprehensive Care for Joint Replacement model (CJR) provides bundled payments for in-hospital and 90-day post-discharge care of patients undergoing lower extremity joint replacement including hip, knee, and ankle arthroplasty (THA, TKA, and TAA). Pre-operative risk factors influencing in-hospital and post-discharge costs are, thus, of keen interest. While THA and TKA have been reported to have a 5.3% 90-day readmission rate associated with race, gender, increased BMI, >2 medical comorbidities, increased length of stay, and discharge to inpatient rehab, little is known about factors that influence readmission rates after TAA. The purpose of this study is to identify risk factors associated with 90-day readmission after TAA. Methods: 1,048 patients undergoing TAA (ICD-9 81.56 or ICD-10 0SRF/G) at a single academic institution were prospectively enrolled into an ongoing, IRB-approved longitudinal TAR outcome study between 2007 and 2016. Records were retrospectively reviewed to determine patient, operative, and post-operative characteristics including age, gender, race, risk factors of the Charlson-Deyo comorbidity and Elixhauser indices, post-discharge disposition, BMI, length of stay, and ASA score. Pre-operative Elixhauser and Charlson-Deyo comorbidities were recorded using standardized ICD-9 and ICD-10 codes. Univariate tests of significance (t-tests for continuous inputs and chi-square tests for categorical inputs) were performed to determine the potential relationship between patient characteristics and 90-day readmission using JMP Pro version 13.0.0. The tables display pre-operative cohort-level and outcome-specific patient characteristics as well as the results of significance testing for comorbidities with >1% prevalence. Results: Thirty of 1048 (2.9%) patients were readmitted after TAA during the 90 day post-discharge window. Twenty-two (73%) of the patients were readmitted for surgical wound complication. The majority of the remaining 8 admissions were for medical illnesses not clearly related to the index procedure. Prevalent comorbidities included hypertension, cardiac arrhythmias, depression, obesity, rheumatoid arthritis, diabetes, hypothyroidism, and chronic obstructive pulmonary disease. However, there were no significant differences in patient characteristics between those who were readmitted and those who were not readmitted although patients that were readmitted tended to be slightly older, were less likely to be discharged to SNF or in-hospital rehabilitation, and had higher ASA score and Charlson-Deyo comorbidity index. No individual patient comorbidities were statistically associated with 90-day readmission. Conclusion: The 90-day readmission rate of 2.9% after TAA at our institution is lower than reported rates for THA and TKA nationally (5.3%). Although our patient population had a similar prevalence of risk factors when compared to THA/TKA patients, none of these factors were significantly associated with 90-day readmission. These data suggest that grouping TAA with THA and TKA for CJR may not be advisable. In an emerging era of bundled payments, further work is needed to delineate factors strongly associated with costly readmissions specific to surgical treatment and individualized based on pre-operative patient profile.

Category: Ankle,Ankle Arthritis,Basic Sciences/Biologics,Trauma Introduction/Purpose: Large lower extremity bony defects, complex foot and ankle deformities, and high-risk arthrodesis situations can be difficult to treat. These challenging pathologies, often require a critical-sizes and/or shaped structural bone void filler which may not be available with allograft bone. The advancement of 3D printing technology has allowed for the use of custom designed implants for foot and ankle surgery. This study reports on the radiographic and functional outcomes of a case series of patients treated with patient-specific 3D printed titanium implants. Methods: Seven consecutive patients who were treated with custom designed 3D printed implant cages for severe bone loss, deformity correction, and arthrodesis procedures were included in this study. A minimum of 1-year follow-up was required. No patients were lost to follow-up. Patients completed preoperative and most recent follow-up VAS for pain, FAAM, and SF-36 outcomes questionnaires. All patients had post-operative radiographs and CT scans to assess bony incorporation. Results: The mean age of these patients was 54.6 (35-73 years of age). The mean follow-up of these seven patients was 17.1 months (range 12 to 31). Radiographic fusion with cage ingrowth and integration occurred in all seven patients verified by CT scan. There was statistically significant improvement in all functional outcome score measures (VAS for pain, FAAM, and SF-36). All patients returned were satisfied with surgery. There were no failures. Case examples are demonstrated in Figure 1. Conclusion: This cohort of patients demonstrated the successful use of custom 3D printed implants to treat complex large bony defects, deformities and arthrodesis procedures of the lower extremity. These implants offer the surgeon a patient specific approach to treat both pain and deformity that is not necessarily available with allograft bone.

Category: Ankle, Ankle Arthritis Introduction/Purpose: The onus has been placed on surgeons to prove the value of procedures to patients, payers, policymakers and other key stakeholders. Demonstration of patient reported outcome measures (PROMs) constitutes an integral component of success within the context of value-based healthcare. The proposed benefit of total ankle replacement (TAR) over ankle fusion is preserved ankle motion, thus we hypothesized that an increase in range of motion (ROM) is positively correlated with validated PROMs in individuals receiving TAR. Methods: Patients undergoing TAR at a single academic medical center between 2007-2013 were evaluated in this study. In addition to a minimum of two-year follow-up, complete preoperative and postoperative outcome measures for the Foot and Ankle Disability Index (FADI), Short Musculoskeletal Function Assessment (SMFA) Bother and Function Indices, Visual Analog Scale (VAS) and 36-Item Short Form Health Survey (SF-36) were requisite for inclusion. Standardized weightbearing maximum dorsiflexion and plantarflexion sagittal radiographs were obtained and previously described ankle and foot measurements were performed to determine ankle ROM. Results: Eighty-eight patients met inclusion criteria (33 INBONE, 18 Salto-Talaris, 37 STAR). Mean time to final ROM radiographs was 43.8 months (range: 24-89 months). All aforementioned PROMs improved between preoperative evaluation and most recent follow-up (p

Category: Ankle Arthritis Introduction/Purpose: The Salto Talaris total ankle replacement is a modern fixed-bearing implant used to treat symptomatic ankle arthritis with the goals of providing pain relief, restoring mechanical alignment, and allowing motion of the ankle joint. This prosthesis has been used in the United States increasingly over the last 10 years, primarily for older patients with end-stage ankle arthritis but indications are expanding to younger and more active patients. The goal of this study is to report the midterm clinical results of one of the largest cohort of patients in the United States who underwent ankle replacement with this prosthesis. Methods: This is a review of patients with a minimum of 5-year up to 10-year follow-up who were prospectively registered within our institutional database prior to proceeding with total ankle arthroplasty using the Salto Talaris prosthesis. Follow-up examinations were scheduled annually after the one-year postoperative mark to evaluate patients both clinically and radiographically. At each annual assessment, patients rated their current level of pain using the visual analog score (VAS) and reported their functional level using the American Orthopaedic Foot and Ankle (AOFAS) ankle-hindfoot scores, the Short Musculoskeletal Function Assessment (SMFA), and the Short Form-36 (SF-36) Health survey. These scores were analyzed to assess differences between their levels preoperatively, one year postoperatively and at their most recent follow-up. Preoperative and postoperative radiographs were reviewed for component loosening. Criteria for failure was defined as undergoing revision requiring exchange or removal of the metallic components for any reason. Results: We identified 106 patients who had a Salto Talaris total ankle replacement between March 2007 and February 2012. Of these, 72 patients (mean age, 61.9 years) met the requirement for a minimum follow-up of 5 years (range 60 to 115 months, mean 81.1 months). Average outcome in the VAS was 7.1 at one year post-op and 11.7 at last follow-up (preop: 70.0). Significant improvements were seen in the SMFA, AOFAS ankle-hindfoot score, and the SF-36 from preoperatively to their final follow-up. Survivorship was 97.2% with two patients undergoing revision arthroplasty for aseptic loosening and a third patient scheduled for revision for a chronic wound infection. 14 patients (19%) with midterm follow-up required a total of 17 additional surgical procedures on the ipsilateral ankle or hindfoot. Conclusion: Patients who underwent total ankle arthroplasty with the Salto Talaris prosthesis have continued to show significant improvements in pain and functional outcomes at mid-term follow-up. This has shown to be an effective treatment option with durable results for patients with end-stage ankle arthritis.

Category: Ankle, Arthroscopy, Basic Sciences/Biologics, Sports Introduction/Purpose: Symptomatic osteochondral lesions of the talus (OLTs) are difficult to treat. As such, a broad array of cartilage treatment options exist. Despite the various techniques, many patients require multiple procedures due to persistent pain, failure of cartilage adherence, or persistent mechanical symptoms. The cartilage replacement technique, particulated juvenile cartilage allograft transplantation (PJCAT), is a novel treatment option supported by the benefits of ease of application, no need for perpendicular access to the OLT, and the delivery of viable hyaline cartilage. However, there is minimal clinical data to support this treatment option. The purpose of this study was to determine the efficacy of PJCAT. Methods: After obtaining IRB approval, we conducted a retrospective review of patients that underwent PJCAT for the treatment of OLTs at a single academic institution. From 2012 to 2015, 18 patients were identified. However, one patient died of an unrelated cause and two patients were lost to follow-up leaving 15 patients (7 males and 8 females) whom had a minimum of 12 months of follow up (mean 34.6, range, 12-51 months). The mean age of this cohort was 32.7 years (15-48) at time of surgery with BMI average 29.9 (18.8-40.2). The primary outcome was failure of the procedure defined as: recurrent or worsening symptoms with corresponding imaging demonstrating delamination, and/or the need for a secondary cartilage restoration procedure. Variables studied included: size of lesion denoted by MRI, intraoperative size, etiology (traumatic versus atraumatic), location of lesion, sex, age, and history of prior surgery. Results: Failure of primary procedure as defined by continued pain with corresponding imaging and/or necessity of secondary cartilage procedure after use of PJCAT was 40% (6/15). Preoperative MRI size (188.7 +/- 81.7mm2 vs. 113.5 +/- 50.5mm2, p

Category: Ankle, Trauma Introduction/Purpose: Open approaches are often used for the operative treatment of medial malleolar (MM) fractures. Compared to percutaneous approaches, open approaches may entail an increased risk of operative morbidity, postoperative pain, wound complications, and reoperation for hardware removal. However, inherent to minimally invasive or percutaneous techniques is incomplete fracture visualizationwhich may hinder acceptable reduction. In this study, we aimed to compare patients treated with closed reduction and percutaneous fixation (CRPF) to those patients treated with traditional open reduction and internal fixation (ORIF). We hypothesized that the two groups would be similar with regard to patient factors, injury variables, and outcomes. Methods: The study group consisted of 184 consecutive patients who met inclusion criteria and were treated with operative fixation of a MM fracture from 2011-2015 at a single institution. Forty underwent CRPF and 144 underwent ORIF. Patient demographics, injury characteristics, treatment methods, and outcome variables were recorded through review of patient charts, radiographs, and operative reports. Results: Patient variables were similar between groups except for years of age, which was greater on average in the CRPF group (55 vs. 48, p = 0.03). The CRPF treatment group had a higher rate of initial open injury (22% vs. 7%, p