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Category: Ankle; Ankle Arthritis Introduction/Purpose: Prior studies on the INBONE II and Salto Talaris total ankle arthroplasty (TAA) systems have reported favorable outcomes for both implants. However, it is unclear whether there were significant differences in survivorship between and if this led to subsequent differences in clinical or radiographic outcomes the two. To date, no similar comparisons have been done in the literature, although it is important to understand the clinically relevant distinctions between these more recent third generation TAA systems. This retrospective study aimed to compare the midterm differences between INBONE II and Salto Talaris TAA. Methods: Between 2007 and 2015, 44 INBONE II consecutive cases and 85 Salto Talaris consecutive cases had minimum 5-year clinical and radiographic follow-up. The endpoints for survivorship were revision, defined as removal or replacement of any implant component, and reoperation, defined as a non-revision surgery. Preoperative and midterm postoperative Foot and Ankle Outcome Score (FAOS), which has been validated for ankle osteoarthritis, and radiographic measures including tibiotalar alignment (TTA) and medial distal tibial angle (MDTA) were compared. Talar inclination angle (TIA) was compared to examine subsidence and cysts were examined for osteolysis. Average midterm follow-up for these patients was 6.4 +- 1.1 (range, 5-9) years for the INBONE II group, and 7 +- 1.9 (range, 5-12.7) years for the Salto Talaris group. Results: Survivorship to revision was 97.6% (95% CI, 93.1%-100%) for the INBONE II group and 97% (95% CI, 93%-100%) for the Salto Talaris group (P = .93). Survivorship to reoperation was significantly different; 95.5% for the INBONE II and 76.4% for Salto Talaris (P = .021) (Figure 1). All FAOS improved postoperatively (P < .001), although the INBONE II had superior postoperative scores in pain (P = .01), symptoms (P = .004), and sports activity (P = .02). There were no differences between groups in postoperative radiographic alignment, despite the INBONE group having greater preoperative deformity. There was one instance of subsidence in each group and similar rates of cyst occurrence across the INBONE II (18.2%) and Salto Talaris (21.2%) groups. Conclusion: Although both implants had similar longevity and postoperative alignment, the INBONE II resulted in greater clinical improvement and fewer reoperations than the Salto Talaris at midterm follow-up. The majority of reoperations in the Salto Talaris group were due to gutter impingement. The contrasting reoperation rates between groups may be explained by differences in implant design and technique, such as rotational malpositioning of the talus and the lateral sulcus design of the Salto Talaris. Additionally, the INBONE II TAA system was able to correct deformity and improve clinical outcomes even though this cohort exhibited greater preoperative deformity.

Category: Ankle; Ankle Arthritis; Hindfoot; Midfoot/Forefoot; Other Introduction/Purpose: Subtalar fusion is a powerful option for correcting hindfoot deformity in progressive collapsing foot deformity (PCFD). Despite successful correction through subtalar fusion, the development of valgus tibiotalar tilt at the ankle joint has been documented as a significant complication. This can be detrimental since abnormal forces on the ankle joint can induce cartilage wear and subsequent ankle arthritis over time. However, the incidence of valgus tilt of the ankle following subtalar fusion for PCFD reconstruction has not been extensively studied, and little is known about its etiological factors. The purpose of this study was to define the incidence of valgus tibiotalar tilt after subtalar fusion for PCFD reconstruction, and to determine if any demographic and radiographic parameters predict which patients develop this complication. Methods: This study reviewed 59 patients (median age: 59 years) who underwent PCFD reconstruction with subtalar fusion and had pre-and postoperative weightbearing anteroposterior radiographs of the ankle in the registry. Patients with a tibiotalar tilt prior to surgery were excluded. On standard weightbearing radiographs, the talonavicular coverage angle, talo-1st metatarsal angle, calcaneal pitch, and hindfoot moment arm (HMA), and medial distal tibial angle were measured. Weightbearing computed tomography (WBCT) was used to determine the presence of preoperative sinus tarsi or calcaneofibular bony impingement. A radiologist evaluated the superficial and deep deltoid ligaments using magnetic resonance imaging (MRI). Postoperative valgus tibiotalar tilt was defined as tilt >2 degrees. Univariate regression analysis was used to identify the factors associated with development of postoperative valgus tibiotalar tilt. These factors included age, gender, BMI, as well as concomitant procedures, radiographic parameters, lateral bony impingement on WBCT, and deltoid ligament status on MRI. Results: A total of 17 patients (28.8%) developed postoperative valgus tibiotalar tilt at a mean of 7.7 (range, 2-31) months. Eight (47.1%) of the 17 patients developed valgus tibiotalar tilt (mean talar tilt of 5.3 degrees, range: 4-8) on postoperative weightbearing within 3 months. In bivariate analysis, male gender and preoperative HMA were significantly associated with development of valgus tibiotalar tilt (Table 1). Univariate logistic regression demonstrated that preoperative HMA was associated with postoperative valgus tibiotalar tilt (odds ratio 1.06, P = .026), with a 6% increase in risk per millimeter of increased HMA. Deltoid ligament status on MRI and concomitant procedures on other joints including fusion did not correlate with postoperative valgus tibiotalar tilt. Conclusion: The incidence of valgus tibiotalar tilt after subtalar fusion in PCFD reconstruction was 28.8% in this study. Preoperative valgus hindfoot alignment rather than the condition of the deltoid ligament was a significant predictor of postoperative valgus tibiotalar tilt. Our findings indicate that surgeons should be cognizant of patients with a greater degree of hindfoot valgus and of their propensity to develop a valgus ankle deformity. Additionally, our relatively high incidence of valgus tibiotalar tilt suggests that weightbearing ankle radiographs should be included in the initial and subsequent follow-up of PCFD patients with hindfoot valgus treated with subtalar fusions.

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: Lateral bony impingement, one of the main causes of lateral foot pain in progressive collapsing foot deformity (PCFD), reflects disease severity and may affect surgical planning. Weightbearing computed tomography (WBCT) is known to provide better sensitivity in detecting impingement over simple radiographs, however, many Orthopaedic centers have not yet acquired WBCT imaging. This study aimed to (1) investigate the correlation of common radiographic parameters measured on standard weightbearing radiographs with talocalcaneal and calcaneofibular distance assessed with WBCT and (2) establish cut-off values for radiographic measurements on standard radiographs to detect lateral bony impingement as identified on WBCT. Methods: Ninety-one adult patients (mean age and standard deviation, 54.1 +- 17.2 years) treated for PCFD with standard preoperative radiographs and WBCT within 6 months of each other were retrospectively identified. Patients with previous ipsilateral foot and ankle surgery or asymmetric ankle arthritis (talar tilt > 2 degrees) were excluded. The talocalcaneal distance at the sinus tarsi and subfibular calcaneofibular distance were measured in multiplanar reconstructed WBCT images. Bony impingement was defined as direct contact between the structures. The relationships between WBCT measurements and four common parameters (Talonavicular coverage angle [TNC], Talo-1st metatarsal angle, Calcaneal pitch, and hindfoot moment arm [HMA]) in standard radiographs were assessed with Pearson correlations. Receiver operating characteristic (ROC) curve analysis was performed to determine the ability of radiographic parameter thresholds to predict sinus tarsi or calcaneofibular bony impingement, and the area under curve (AUC), sensitivity, specificity, negative and positive predictive value were calculated. Results: Talocalcaneal distance narrowing at the sinus tarsi on WBCT was strongly correlated with TNC (r = 0.64, p < 0.001), and the calcaneofibular distance narrowing on WBCT correlated with the HMA moderately yet best among the parameters (r=0.55, p

Category: Hindfoot; Midfoot/Forefoot; Other Introduction/Purpose: Peritalar subluxation (PTS) is a crucial feature of Progressive Collapsing Foot Deformity (PCFD). Surrounding structures assume distinct behaviors, contributing to different disease deformities (classes). One of its most traditional aspects is the midfoot abduction (class B), usually noted by a lateral deviation of distal structures at the talonavicular joint. This finding commonly leads surgeons to perform a lateral column lengthening osteotomy for abduction correction, a complex surgery with potential complications. The first ray's ability to reestablish the tripod and restore the hindfoot by derotating structures under the talus was previously theorized. This study aimed to test the capability of the Lapidus and the Cotton procedures in conjunction with a calcaneus displacement osteotomy (MDCO) to improve midfoot abduction in the setting of a collapsed foot. Methods: In this IRB-approved, prospective cohort study, we analyzed patients undergoing medial column instability surgery and evaluated preoperatively with a weight-bearing CT (WBCT). We included individuals receiving a Lapidus bone block procedure or a Cotton for PCFD or Hallux Valgus (HV). Patients having a lateral column lengthening procedure of any type were excluded. Talonavicular coverage angle (TNCA) was measured as a marker of midfoot abduction. Medial arch collapse and forefoot varus were evaluated by the sagittal talus-first metatarsal angle (TFMA), and the forefoot arch angle (FFA) was measured. Associated procedures and the correction amount (displacement or wedge size) were recorded. Normality was estimated by the Shapiro- Wilk test and comparison among timelines by the one-way ANOVA. A multivariate regression analysis was executed to evaluate which of the measurements influenced abduction improvement. Statistical significance was considered for p-values of less than 0.05. Results: A total of 20 patients (age: 43.85 [19-72], BMI 30.98 [SD: 5.95]) were included, 11 PCFD (55%) and 9 HV (45%) with a mean follow-up of 7.5 months (3-12). Bone block Lapidus was performed in most subjects (90%), and the median wedge used was 9mm (5-12mm). MDCO occurred in 55% of patients. All measured variables had improvement with surgery (TNCA: 23.74 to 10.66, p

Category: Ankle Arthritis; Ankle Introduction/Purpose: A relatively frequent need for secondary surgery is an important consideration when treating end-stage ankle arthritis with total ankle arthroplasty (TAA). Despite a significant reported rate of non-revision reoperation after TAA, it is uncertain if these subsequent procedures have an impact on the longer term outcomes. It is imperative to know whether patients undergoing reoperation after TAA would have comparable functional ability compared to those with uncomplicated TAA in order to optimize patient outcomes when faced with complications after TAA. This study aimed to compare minimum five-year functional outcomes of patients who had undergone reoperation after TAA to those who did not require reoperation. Methods: Seventy-six ankles (74 patients) who underwent TAA with the Salto Talaris fixed bearing system between 2007 to 2014 were allocated into two groups based on presence (n=16) or absence of reoperation (n=60). Reoperations included all secondary procedures after index TAA, excluding revision surgeries requiring removal or exchange of the original prosthesis. The foot and ankle outcome score (FAOS) at preoperative and minimum five-year follow-up was compared between the groups. Additionally, improvements in FAOS subscales were compared. Preoperative deformity, postoperative implant alignment, number of periprosthetic cysts, and subsidence between groups were compared using standard weightbearing radiographs. A subgroup analysis was performed to compare clinical and radiographic outcomes of gutter impingement patients to those of uncomplicated group. Results: The most common cause of reoperation was gutter impingement (n=11), followed by stress fracture of the medial malleolus (n=2), tarsal tunnel syndrome (n=1), periprosthetic cyst (n=1), and infection (n=1). In comparison to the non- reoperation group, all FAOS subscales except for the Sports and Recreational Activities subscale were significantly lower in the reoperation group at final follow-up. The reoperation group exhibited significantly less improvement in the Pain, Symptoms, and Quality of Life subscales at final follow-up (p

Category: Midfoot/Forefoot Introduction/Purpose: Cheilectomy with and without Moberg osteotomy is used to improve function and remove pain in early- moderate stage hallux rigidus. The rise of patient-reported outcome measurements allows greater precision in comparing treatments as value-driven paradigms become increasingly important in clinical decision-making. This study provides the first comparison of patient-reported outcomes between isolated cheilectomy (C) and cheilectomy with Moberg (CM) osteotomy for hallux rigidus. We compared one and two-year PROM scores between patients who underwent C and CM for hallux rigidus using PROMIS, a validated patient-reported outcomes measurement system, and compared rates of complications and subsequent operations between the two groups. We hypothesized that patients who underwent CM would experience better clinical outcomes and fewer returns to the operating room than patients undergoing cheilectomy alone. Methods: A single-center, retrospective registry search identified all patients with preoperative PROMIS scores who underwent cheilectomy, with and without concomitant proximal phalangeal dorsiflexion osteotomy, for hallux rigidus between January 2016 and December 2020. An a priori power analysis determined that 24 patients per cohort were needed to detect a previously published minimum clinically important difference of 5.8 points on the PROMIS Physical Function scale with alpha = .05 and 80% power. However, all C patients were included. Because there were far fewer isolated cheilectomies (62), all C patients were compared with a commensurate number of consecutive CM cases (67) using preoperative, one-year, and two-year PROMIS scores for Physical Function, Pain Interference, Pain Intensity, Global Physical Health, Global Mental Health, and Depression, as well as complication and revision data from chart review. Age, sex, BMI, preoperative radiographic hallux rigidus grade, and preoperative range of motion were compared between the two cohorts. Results: PROMIS outcome data is given in Table 1. Both groups demonstrated statistically significant improvements in PROMIS Physical Function, Pain Interference, Pain Intensity, and Global Physical Health (P

Category: Bunion Introduction/Purpose: The modified Lapidus procedure offers effective correction of the triplanar deformity of hallux valgus; however, complications such as nonunion and recurrence range up to 15% when using a crossing lag screw fixation technique. An alternative form of fixation using a dorsomedial plate and first metatarsal-intermediate cuneiform (1MT-IC) screw has been proposed. This construct may reduce complication rates, facilitate earlier weightbearing and maintain 3-dimensional correction, especially rotation of the first ray. We investigated single-surgeon Lapidus patient cohorts utilizing cross screws (CS) versus plate and 1MT-IC screw (PS) fixation to compare patient reported outcomes, radiologic parameters on pre- and postoperative weightbearing CT (WBCT) and complications. We hypothesized that patients undergoing PS fixation would experience improved correction of first ray pronation. Methods: This single-center, IRB-approved retrospective study identified all patients who underwent first tarsometatarsal joint arthrodesis for hallux valgus by a single surgeon and divided them by CS or PS fixation. Patients were minimum 18 years old with at least 12 months of follow-up. Revision forefoot surgeries, concomitant flatfoot reconstruction or ankle replacement, and patients with history of rheumatoid arthritis or gout were excluded. PROMIS scores in six key domains were compared between groups both preoperatively and at one year postoperatively. Radiographic assessment of hallux valgus angle (HVA) and intermetatarsal angle (IMA) were performed on pre- and postoperative XR. Pronation of the first ray was measured on WBCT using the validated triplanar angle of pronation. Clinical notes were reviewed for complications and reoperations. The PS group began weightbearing at an average 3.6 weeks versus 6 weeks the PS group. Results: We compared 44 patients who underwent Lapidus with PS and 43 with CS fixation. The age, BMI and gender distribution in the two groups were similar. Both groups had significant improvement in HVA and IMA following Lapidus, (p

Category: Hindfoot; Ankle; Midfoot/Forefoot Introduction/Purpose: Optimization of articular joint coverage has been shown to decrease the progression of arthritic degeneration and to improve outcomes in patients with hip and shoulder pathologies. Progressive Collapsing Foot Deformity (PCFD), previously known as Adult-Acquired Flatfoot Deformity, has been demonstrated to advance with peritalar subluxation (PTS), progressively decreased articular coverage of the subtalar joint articular facets (anterior, middle, and posterior), as well as the development of sinus tarsi and subfibular impingements. Outcome assessment in PCFD has focused on improving conventional radiographic measurements such as the talus-first metatarsal angle and the hindfoot moment arm. This study aimed to evaluate improvements of PTS, subtalar joint articular coverage, and extra-articular impingement following PCFD joint-sparing surgical treatment, as well as the influence of these improvements in patient-reported outcomes. Methods: IRB-approved prospective comparative study. Adult PCFD patients that failed conservative treatment for three-months and underwent hindfoot joint-sparing surgical procedures by a single-surgeon were enrolled. Realignment soft-tissue and bony procedures performed were recorded. All patients underwent Weight Bearing CT (WBCT) preoperatively, and at the 3- and 12- months follow-up. Two observers performed traditional WBCT PCFD measurements. The foot bones were segmented, and distance measurements were performed along the entire 3D superior surface of the calcaneus, including the subtalar joint (SJ) articular facets (anterior, middle, and posterior), sinus tarsi and subfibular area. Color-coded coverage maps (CM) were calculated to grade the amount of articular joint coverage and extra-articular impingement. Patient Reported Outcomes (PROs) were recorded at all follow-up time-points. Pre- and postoperative measurements were compared by paired T-Tests/Wilcoxon and a Multivariate regression analysis was utilized to assess the influence of improvements of articular coverage and impingement in PROs. Results: Twenty patients were included (15F/5M), mean age, BMI, and follow-up of respectively 48.1 (22 to 72) years, 33.88 (23.8 to 46.8) kg/m2, and 13.2 (4 to 27) months. Significant improvements in all traditional PCFD WBCT measurements were noted postoperatively. Articular coverage (CM) of the SJ middle and anterior facets improved postoperatively by respectively 13.5% (p=0.02) and 78% (p=0.001). Similarly, improvement in sinus tarsi impingement, with a 69% decrease in sinus tarsi coverage was observed (p

Category: Ankle Arthritis; Ankle Introduction/Purpose: In the last decade, there has been a rapid increase in the number of total ankle arthroplasties (TAA) performed annually. In addition, multiple novel TAA implants have been introduced onto the market. The Exactech Vantage TAA is a fixed-bearing implant that has been in use since 2016. The tibial component is low-profile with vertically oriented pegs and a cage, while the talus is curved with an anterior flange to prevent subsidence. This study sought to describe the early experience with the Vantage TAA, including reoperation, revision, and radiographic outcomes. Methods: This is a single-center retrospective review of patients who underwent primary TAA using the Vantage Total Ankle (Exactech, Gainesville, FL). Concomitant procedures at the time of index surgery were recorded. Five surgeons contributed patients. Demographics, clinical and operative data, postoperative complications, reoperations, and revisions were collected. Revisions and reoperations were classified by standardized criteria. Radiographs were reviewed by a fellowship-trained foot and ankle surgeon to assess for alignment and peri-implant complications. There were 190 patients included in the study who were all minimum 2 years post-TAR, with mean clinical follow-up of 1.8 years (range: 1-48 months), and mean age 63.3 +- 9.4 years. Ankle arthritis etiologies were 45% post-traumatic (fracture history), 33% instability, 12% primary osteoarthritis, 5% flatfoot, 2% inflammatory arthritis, and 4% other. Thirteen patients (7%) had hindfoot fusion performed previously or at the time of index surgery. Concomitant procedures are shown in Table. Results: Overall implant survivorship was 95.3%. There were 5 intraoperative complications: 4 anterolateral tibial fractures and 1 medial malleolar fracture, all treated with internal fixation at the time of surgery with no further complications. Nine patients (4.8%) underwent revision: 7/9 for tibial loosening, 1 for talar loosening, and 1 for periprosthetic joint infection. Eleven patients (5.8%) underwent reoperation: open gutter debridement (5); irrigation and debridement for superficial infection (4); and bone grafting for cysts (2). Radiographically, preoperative coronal alignment was mean 10.1°, with 87 (49%) ankles with >10° deformity. Three patients had tibial component subsidence that was stable, 3 had stable radiolucency around the tibial component, and 1 had valgus failure through the ankle joint. Nineteen had asymptomatic peri-implant cysts; 16/19 were at the tibia. Conclusion: Short-term results of the Vantage TAA implant demonstrate survivorship of 95.3% at 2 years, which is comparable to similar studies of low-profile, non-stemmed implants. Asymptomatic radiographic complications were primarily cystic changes at the tibial component. Revisions occurred primarily due to loosening of the tibial component. Additional follow-up and multi- institutional support are warranted to further quantify survivorship and risk factors.

Category: Hindfoot; Midfoot/Forefoot; Other Introduction/Purpose: Lateral column lengthening (LCL) is an established procedure for progressive collapsing foot deformity (PCFD) patients. While functional improvements are often reported after LCL, increased post-surgical lateral foot pain, attributed to decreased subtalar joint motion, remains a concern. The optimal wedge size is determined intraoperatively by measuring passive eversion of the hindfoot to ensure adequate eversion motion and radiographic correction. However, it is unknown whether a subjective assessment of passive eversion is associated with objective postoperative measurements of foot stiffness, such as plantar pressure. Our goal was to quantify the relationship between eversion during a passive assessment and plantar pressures during simulations of level walking. We hypothesized that a strong relationship exists between the location of plantar pressure and the eversion measured with passive manipulation. Methods: A deformity was created in ten mid-tibia cadaveric specimens (four female, age range: 35-72) by transecting the spring ligament and medial talonavicular joint capsule followed by cyclic loading. A six degrees-of-freedom robotic gait simulator was used to simulate the stance phase of level walking. Joint kinematics and plantar pressure data were collected during each simulation. A passive assessment of hindfoot eversion was then conducted manually by a fellowship-trained orthopaedic surgeon and recorded by the motion capture system. Five conditions were tested: intact, PCFD, and three LCL wedge conditions (4, 6, 8mm). Outcome measures for each condition included the lateral-to-medial forefoot plantar pressure ratio during walking simulations and the peak subtalar eversion measured during the assessment. A linear mixed effects model was used to determine the association between the plantar pressure and LCL wedge thickness. Pearson correlation coefficients were calculated to determine the relationship between subtalar eversion and plantar pressure. Results: There was a significant relationship between the size of LCL wedge and the forefoot lateral-to-medial average pressure ratio (p

Category: Ankle Arthritis; Ankle Introduction/Purpose: Total ankle replacements (TAR) have rapidly advanced in terms of volume, technique, design, and indications. However, they are still at risk for failure and need for revision, even early in the postoperative period. Although recently there has been extensive research on TAR, many studies are limited in their power and sample size to assess risk factors for failure/revision. Using a large multi-surgeon retrospective database, we sought to describe the incidence and etiology of mechanical failure across modern implants. We also aimed to identify risk factors for early mechanical failure. We hypothesized that greater body mass index (BMI) and ipsilateral hindfoot fusion would be predictors of mechanical failure, and that implants with greater extent of tibial fixation (stems and keels) would be protective against mechanical failure. Methods: This is a single-center retrospective review of TAR patients in a prospective database. Adults undergoing primary TAR using any implant (Cadence, Inbone, Infinity, Invision, Salto, STAR, Vantage, Zimmer) who were minimum 2 years post-surgery were included. Exclusion criteria included revision TAR or patients undergoing ankle fusion takedown and conversion to TAR. Five surgeons contributed patients. Demographics, etiology of arthritis, operative data, and postoperative complications, reoperations, and revisions were collected. Revisions and reoperations were classified by standard criteria. Cause of revision was recorded. There were 560 TARs eligible for 2-year follow-up (mean 3.9 +- 1.1 years postoperative), with mean follow-up of 2.2 +- 1.4 years (range 1-71 months). The cohort had mean age 63.8 +- 9.1 years, BMI 29.4 +- 5.2 kg/m2, and 57% were male. Kaplan- Meier survival plots were created. Risk factors for revision due to mechanical failure were analyzed using multivariable logistic regression with partial Wald chi square statistics. Results: Most implants were low-profile (n=444, 79.3%), with 28 implants having tibial keels (5%) and 88 with tibial/talar stems (15.7%). There were 25 (4.5%) revisions of tibial and/or talar components at mean 1.6 years after index surgery (Figure). Preoperative coronal deformity did not impact revision rates (p=0.433). Patients who underwent revision for mechanical failure had significantly higher rates of concomitant hindfoot fusion (20% vs. 8.4%, p=0.047) and greater BMI (31.4 kg/m2 vs. 29.3 kg/m2, p=0.04). In multivariable logistic regression, hindfoot fusion was just short of statistical significance (odds ratio [OR] 2.96, p=0.056), and BMI was not significant (OR 1.05, p=0.417). Stemmed or keeled implants did not significantly decrease revision rates compared to low-profile implants, although the revision rate of stemmed implants was substantially low (1/88, 1.1%). Conclusion: Among 560 modern TAR implants, short-term survivorship was 95% at 2-year follow-up, which is consistent with existing studies. Patients who underwent revision for early mechanical failure had significantly higher BMI and rates of hindfoot arthrodesis. However, these variables fell short of statistical significance in multivariable regression, suggesting that there are either additional factors contributing to revision, or a larger cohort is needed. In addition, these results are likely biased by surgeons' tendencies to use stemmed implants in patients with hindfoot fusions. Further research is warranted to determine if stemmed implants provide a protective effect in these high-risk patients.

Background: The modified Lapidus procedure (first metatarso-cuneiform fusion) is a powerful technique for correcting triplanar deformity in hallux valgus. Although traditionally fixed with cross-screws (CS), growing awareness of intercuneiform stability and pronation deformity has led to fixation using a plate and first metatarsal–second cuneiform (1MT-2C) screw fixation (PS). We investigated Lapidus patient cohorts using CS vs PS fixation to understand patient-reported outcomes, angular and rotational correction, and complication rates. Methods: We retrospectively reviewed cases of modified Lapidus for hallux valgus by a single surgeon. Patients were divided into CS or PS groups according to fixation. All patients had preoperative Patient Reported Outcome Measurement Information System (PROMIS) scores and minimum 12 months of follow-up. PROMIS scores in 6 key domains were compared within and between groups. Radiographic assessment of hallux valgus angle and intermetatarsal angle were performed on pre- and postoperative XR. Pronation of the first ray was measured on pre- and postoperative weightbearing computed tomography. Results: We compared 42 patients with PS fixation to 43 with CS fixation. Both groups had significant improvement in hallux valgus angle and intermetatarsal angle ( P < .001), with no difference between groups. PS patients experienced a greater correction of first metatarsal pronation, an average reduction of 11 degrees, compared to 8 degrees in the CS group ( P < .039). Both cohorts experienced improvement in PROMIS physical function, pain interference, pain intensity, and global physical function. There were no differences in PROMIS score improvements between the cohorts. The CS group started weightbearing at 6 weeks vs 3.6 weeks for the PS group. Complication and revision rates were similar. Conclusion: A plate and 1MT-2C screw fixation provides safe, robust fixation of Lapidus procedure and prevents instability through the intercuneiform joint. We observed similar improvement in PROMIS compared with patients treated with cross-screws. Complications did not increase despite the PS group weightbearing much earlier. PS patients achieved greater first ray rotational correction. Level of Evidence: Level III, retrospective cohort study.

Category: Hindfoot; Midfoot/Forefoot; Sports Introduction/Purpose: Progressive collapsing foot deformity (PCFD) is a condition encompassing multiple interrelated, progressive bony and soft tissue deformities, often requiring surgical correction. Patients are often debilitated, with postoperative goals commonly cited as walking and low-impact activities without pain. However, some patients engage in sports and more rigorous activities. Surgeons may struggle to set expectations after surgery since few studies investigate returns to activity following flatfoot reconstruction and every patient is different. Existing studies are limited by small sample sizes, lack of data of activity-specific data, and cohorts confined to one or two of the many possible concomitant procedures in flatfoot reconstruction. This study aims to provide the first generalizable assessment of returns to sports and physical activity following reconstruction surgery in patients with flexible PCFD. Methods: Patients who underwent reconstructive surgery from February 2016-May 2019 for flexible-stage PCFD were identified by registry review and contacted with IRB approval. 70/119 patients (72/121 feet, 60%) were reached at mean 3.1 (range, 2.0 to 5.4) years post-operatively with mean age 43.5 (range, 18 to 59) years at surgery. Concomitant procedures were noted. Physical activity was evaluated with a previously published questionnaire that assessed participation in 15 sports and activities, allowed patients to list additional activities, and classified activities as high or low-impact. Patients specified postoperative number of sessions per week, session duration, return times to participation and maximal activity, relative pre/postoperative difficulty, and satisfaction with outcome regarding sports. Clinical outcomes were evaluated with Patient-Reported Outcomes Measurement Information System (PROMIS) scores. Multivariable regressions assessed associations between PROMIS domain changes and survey responses and linear models measured association of sports participation with the most performed procedures, controlling for concomitant procedures. Results: Patients experienced significant improvements in all PROMIS domains except Depression and surpassed previously reported minimal clinically important differences for PCFD in Physical Function and Pain Interference scores. Patients reported participation in 21 specific sports and activities (Table 1). Compared to preoperatively, patients rated 16.7% (45/270) of activities as more difficult postoperatively, 33.3% (90/270) as equally difficult, and 50% (135/270) as less difficult. Median return times were 6-9 months for participation in activities and 13-18 months to reach maximum preoperative participation. Patients spent a median 7.6 (range, 0-29.8) hours/week engaged in physical activity. 3% of patients (2/72) were sedentary, 31% (22/72) were moderately active, 28% (20/72), were highly active and 36% (26/72) were extremely active. Improvements in Physical Function ( P =.021), Pain Interference ( P =.001), and Global Physical Health ( P =.001) were associated with increased outcome satisfaction regarding physical activities. No associations were found between procedures performed and any PROMIS domains or return parameters. Conclusion: This is the largest and most comprehensive analysis of patient participation in sports and physical activities following flatfoot reconstruction. Results suggest that flatfoot reconstruction surgery generally results in good returns to physical activity in terms of return time, pre-postoperative difficulty changes, and satisfaction. Some patients reported increased difficulty or inability to return to their preoperative maximum level of participation, indicating that flatfoot reconstructions can lead to some athletic limitations. However, ninety percent of patients reported satisfaction with their surgical outcomes with respect to returns to physical activity, indicating that, for most patients, flatfoot reconstruction provides meaningful relief from debilitation.

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: Peritalar subluxation (PTS) of the hindfoot is a critical finding in Progressive Collapsing Foot Deformity (PCFD). Subluxation of the middle facet and sinus tarsi recently been shown to represent essential markers of pronounced and potentially progressive deformity. Weightbearing CT (WBCT) imaging and three-dimensional (3D) distancing coverage maps (CM) allow a complete and accurate assessment of PTS markers across the entire peritalar surface. This prospective comparative study aimed to assess the effectiveness of joint-sparing realignment surgical treatment for flexible PCFD in reducing PTS and to correlate the improvement with patient-reported outcomes (PROs). We hypothesized that would significantly improve PTS markers, mainly decreasing sinus tarsi coverage/impingement and middle facet subluxation, and that this improvement would correlate with increased PROs. Methods: In this IRB-approved prospective and comparative study, we enrolled patients with flexible PCFD, no prior surgeries, and failed conservative treatment. Included females/3 males, mean age 57.2, range 37-74) underwent joint-sparing surgical realignment procedure by a single surgeon. Standing weightbearing CT (WBCT) was complete 3-months postoperatively. Following automatic bone segmentation, 3D distance maps (DMs) of the entire peritalar surface were generated, and coverage of the subtalar joint (anterior, middle, and posterior) and sinus tarsi were assessed as markers of PTS. Joint coverage was defined as the percentage of articular space where DMs were

Category: Hindfoot; Ankle; Ankle Arthritis; Midfoot/Forefoot Introduction/Purpose: Markers used for diagnosis and severity grading are well studied in patients with Progressive Collapsing Foot Deformity (PCFD). Medial facet subluxation (MFS) in weight-bearing computerized tomography (WBCT) has been established as an early indicator of peritalar subluxation (PTS). When the disease affects the ankle leading to a valgus talar tilt (class E), structures distal to this topography may behave differently, trying to compensate for proximal deformity. The aim of this study is to assess predictors of deformity in PCFD patients with and without valgus of the ankle. Our hypothesis is that MFS cannot be used in Class E patients as an accurate marker for the evaluation and staging of PCFD. Methods: In this IRB-approved retrospective case-control study, we analyzed WBCT imaging of 21 consecutive patients with PCFD with valgus of the ankle and 64 controls (flexible PCFD without ankle involvement). MFS (defined by the percentage of uncoverage), middle facet incongruence angle, middle cuneiform-to-floor distance, forefoot arch angle, talonavicular uncoverage angle, hindfoot moment arm (HMA), Foot and Ankle Offset (FAO), and talar tilt angle (TTA) were obtained and compared between groups using one-way ANOVA. A multivariate regression analysis was performed to evaluate which of the measurements influenced the alignment. A partition prediction model was constructed to assess how the variables contributed to the deformity. P values

Background: Many foot pathologies have been associated with foot type. However, the association of first ray hypermobility remains enigmatic. The purpose of this study was to investigate first ray hypermobility among participants with planus and rectus foot types and its influence on static measures of foot structure. Methods: Twenty asymptomatic participants with planus (n = 23 feet) and rectus (n = 17 feet) foot types were enrolled. Several parameters of static foot structure (arch height index, arch height flexibility, first metatarsophalangeal joint flexibility, and first ray mobility) were measured. Participants were further stratified into groups with nonhypermobile (n = 26 feet) and hypermobile (n = 14 feet) first rays. First ray mobility ≥ 8 mm was used to define “first ray hypermobility”. Generalized estimating equations, best-fit regression lines, and stepwise linear regression were used to identify significant differences and predictors between the study variables Results: Overall, 86% of subjects categorized with first ray hypermobility exhibited a planus foot type. Arch height flexibility, weightbearing first ray mobility, and first metatarsophalangeal joint flexibility showed no significant between-group differences. However, weightbearing ray mobility and first metatarsophalangeal joint laxity were associated with partial weightbearing first ray mobility, accounting for 38% of the model variance. Conclusion: The planus foot type was found to be associated with first ray hypermobility. Furthermore, weightbearing first ray mobility and first metatarsophalangeal joint laxity were predictive of partial weightbearing first ray mobility, demonstrating an interaction between the translation and rotational mechanics of the first ray. Clinical Relevance: Association of first ray hypermobility with foot type and first metatarsophalangeal joint flexibility may help understand the sequela to symptomatic pathologies of the foot.

Category: Ankle; Ankle Arthritis; Basic Sciences/Biologics Introduction/Purpose: Clinical and functional improvement after total ankle arthroplasty (TAA) in end-stage ankle arthritis has been well documented. However, despite the implantation of TAA devices designed to restore normal walking kinematics, patients with end-stage arthritis develop compensatory walking patterns which do not return to normal, postoperatively. This discrepancy between the normative and adaptive gait patterns could influence implant loading and intended function; however, the independent influence of implant constraints and adaptive gait on joint function is unknown. Therefore, this study aimed to isolate the individual and combined effects of TAA implantation and gait adaption from ankle arthritis on foot and ankle kinematics during simulated level walking. We hypothesized that foot and ankle kinematics would primarily be altered through adaptations in gait resulting from ankle arthritis. Methods: Twelve mid-tibia cadaveric specimens were utilized. A validated six-degree of freedom robotic gait simulator was used to simulate the stance phase [3]. The specimen was first placed on the simulator in the intact condition, simulated with both healthy and adaptive gait inputs collected from healthy and post-surgical TAA subjects (average follow-up: 46 months), respectively. The TAA (Salto Talaris; Integra LifeSciences) was then implanted, and adaptive and healthy gait trials were conducted in the implanted condition. Four conditions were collected on each specimen: intact with a healthy walking trajectory (intact- healthy), intact with an adaptive walking trajectory (intact-adaptive), implanted with TAA with a healthy walking trajectory (TAA- healthy), and implanted with TAA with an adaptive gait trajectory (TAA-adaptive). Ankle, subtalar, and talonavicular joint kinematics in each condition were compared to intact-healthy to isolate the effects of implantation and adaptive gait on kinematics. Bias-corrected 95% confidence intervals were calculated for the difference between conditions. Results: Significant differences were observed in the ankle, subtalar, and talonavicular joints across all comparisons. In the comparison between the intact-healthy and intact-adaptive conditions, to isolate the effect of adaptive gait (Figure 1A), ankle dorsiflexion and subtalar eversion increased late in stance, while talonavicular abduction increased in early and late stance. In the comparison between intact-healthy and TAA-healthy conditions, to isolate the effect of implant constraints (Figure 1B), ankle plantarflexion, subtalar eversion, and talonavicular abduction significantly increased in mid-stance after implantation. In the comparison between the intact healthy and the TAA-adaptive conditions, to evaluate the combined effect of adaptive gait and implantation (Figure 1C), ankle plantarflexion was increased during early stance and decreased in late stance, subtalar eversion increased during mid-to-late stance, and talonavicular abduction increased throughout most of the stance phase. Conclusion: The results from this study indicate that both gait adaption and implant constraint contributed to changes in ankle and adjacent joint kinematics. The two factors appear to influence different aspects of the stance phase, where gait adaption appeared to influence early, and late stance and implantation influenced kinematics in mid-stance. The synergistic influence of both factors seemed to exaggerate deviations away from normal kinematics in the subtalar and talonavicular joints while negating deviations from normal in the ankle joint. This suggests that ankle implants designed to restore normative walking patterns may not account for the loading environment seen in patients.

Category: Ankle; Hindfoot; Other Introduction/Purpose: There is limited documentation of the results of the treatment of advanced progressive collapsing deformity with talar tilt. No article to our knowledge with pre-and post-operative ankle x-rays has more than eight patients and average follow up more than three years. Methods: This article presents the results of twenty consecutive patients with medium to long term follow up. All patients had deltoid reconstruction with tendon graft from the talus to the tibia and foot reconstruction to achieve a heel centered under the lower leg, a stable midfoot and a mild to moderately plantarflexed first metatarsal. Patients were followed an average 10.8 years (SD = 4.6, Range 4.6-17) and had standing pre-and post-operative radiographs along with FAOS and PROMIS scores. Radiographs were assessed for talar tilt preoperatively, early postoperatively and at final follow up. Data was analyzed with paired t-tests, Mann Whitney U test, fisher's exact test and univariable linear regression. All p-values are two-sided and statistical significance was evaluated at the 0.05 alpha level. Results: Two patients failed the procedure; one had an ankle fusion and the second infection eventually required a BKA. The remaining 18 patients were satisfied with their procedure, maintained significant improvement in outcome scores and talar tilt and required no other procedure on their ankle. The mean talar tilt preoperatively was 10.9 degrees (SD = 3.9) and at final follow up 4.2 degrees (SD = 2.8) (P

Category: Basic Sciences/Biologics; Hindfoot; Midfoot/Forefoot Introduction/Purpose: Over the past three decades, the historical notion that adult acquired flatfoot was attributed to posterior tibial tendon dysfunction (PTTD) has been questioned. Advances in the understanding of arch stabilizers and biomechanics of the midfoot joints have led to the new concept of progressively collapsing foot deformity (PCFD). Most recently, the consensus group proposed a new classification system and recommended renaming PTTD to PCFD. The proposed PCFD classification system incorporates the latest understanding of the condition and provides a concise, standardized description of the deformity. To date, there has been no study reporting the frequency of each subclass of PCFD with various combination of deformity components and evaluating intra- and interrater reliability. Methods: This was a single-center, retrospective study conducted from prospectively collected registry data. 84 patients (92 feet) were assessed between 2014 and 2020. Classification of each patient was made utilizing clinical and radiographic findings by three independent observers. Clinical aspects of the deformity included hindfoot valgus, forefoot/midfoot abduction, forefoot varus deformity, hypermobile medial column, sinus tarsi impingement, peritalar subluxation and valgus tilting of the ankle joint. Radiographic evaluation was focused on Hindfoot valgus (A), increased talar head undercoverage, significant sinus tarsi impingement (B), increased lateral talus-first metatarsal angle, plantar gapping at first TMT/NC joints (C), significant subtalar joint subluxation/subfibular impingement with obliterated joint space (D), and ankle joint valgus tilting with or without arthritic changes (E). Intra- and interrater reliabilities were analyzed with Cohen's Kappa and Fleiss' kappa respectively. Results: Mean age was 54.4, 38% male and 62% female. Mean BMI was 33.6 kg/m 2 . 1ABC (21 feet, 22.8%) was most common subclass followed by 1AC (12 feet, 13%) and 1ABCD (8 feet, 8.7%). Cumulative percent of frequency of 1ABC, 1AC, and 1ABCD was 44.5%. Only a small percentage of patients had an isolated deformity. 58.7% were flexible, 5.5% were rigid, and 35.8% were combined deformities with flexible and rigid components. A was most frequent component (93.5%) followed by C in 88% and B in 71.7%. D was in 29.4% and E was the least frequently observed component in 23.9%. Moderate inter-rater reliability (Fleiss Kappa=0.561, p

Category: Ankle Arthritis Introduction/Purpose: One of the proposed benefits of total ankle replacement, when compared to ankle fusion is the preservation of range of motion (ROM) of the ankle. Preservation of ankle motion may improve quality of life as evidenced by patient-reported outcome measures (PROMs). However, despite improving dorsiflexion intraoperatively during TAR, studies have not demonstrated large improvements in dorsiflexion (DF) at final followup after TAR. The objective of this study was to radiographically evaluate and quantify preoperative, intraoperative ankle dorsiflexion and plantarflexion (PF), compare it to post- operative ankle ROM, and determine the effect of Achilles lengthening (TAL) on preserving dorsiflexion motion that is gained during surgery. Methods: This prospective study compared 111 patients with an average age of 62.3 years who underwent primary total ankle replacement with one of four different implants between March and December 2019. A total of 71 patients (64%) had an associated TAL based on the surgeon's decision. Intraoperative fluoroscopy was utilized by the primary surgeon to document the maximal dorsiflexion and plantar flexion at the end of the case. This was completed after the TAL on a perfect lateral. Standardized weight bearing at maximum ROM positions lateral radiographs were obtained twelve months postoperatively. The change in range of motion was analyzed using a paired t-test with a significance level of 0.05. Results: The cohort's preoperative range was 22.0° (8.1°DF, 14°PF) and was increased to 38.5° intraoperatively (12.7°DF, 25.8°PF) as described in Table 1. Postoperative ROM is 24.9° (11.7°DF, 13.2°PF) which means that 65% of the intraoperative ROM is preserved. Preoperative and intraoperative range of motion was not different between the group that had a TAL compared to no TAL. At the year postoperatively, the dorsiflexion was similar between both groups. The group who did not have a TAL went from 12.8 intraoperatively to 12.2° postoperatively whereas the group who had a TAL went from 12.2° to 11.3° which was statistically equivalent. Conclusion: This study is the first to assess how much ankle range of motion is retained after TAR. Overall, we observed that 65% of dorsiflexion was retained after TAR. TAL as a concomitant procedure did not effect the proportion of dorsiflexion motion that was retained. Additional studies are needed to determine how to best optimize and increase ROM after TAR.

Category: Basic Sciences/Biologics; Hindfoot Introduction/Purpose: Progressive collapsing foot deformity (PCFD) is a 3-dimensional pathology associated with insufficiency of the posterior tibial tendon (PTT), ligamentous failure, joint malalignment, and aberrant plantar force distribution. Existing knowledge of PCFD consists of static measurements, which provide information about the structure of the foot but none about its function. Cadaveric gait models provide an opportunity to measure motion both at the joints primarily affected in PCFD and the adjacent joints that are at risk for progressive subluxation and arthritis. This study sought to develop a flatfoot model for a robotic gait simulator and quantify gait kinematics and plantar pressure between normal and flatfoot conditions, which we hypothesized would be altered after the creation of a flatfoot deformity model. Methods: Cadaveric specimens were loaded on a 6-degree of freedom robotic gait simulator and the extrinsic tendons were attached to linear motors. Ground reaction forces and muscle forces were optimized utilizing an established iterative process. An 8-camera motion capture system was utilized to calculate joint kinematics using reflective markers attached by k-wires into bone. A plantar pressure mat attached to the force platform was used to calculate the center of pressure excursion index (CPEI) for each condition. The flatfoot model was created via sectioning of the spring ligament and medial talonavicular joint capsule followed by cyclic axial compression until 5-15° of talonavicular abduction was achieved in a static, loaded pose. Testing of the flatfoot state was then performed with inactivation of the PTT. Bias-corrected bootstrapped 95% confidence intervals were constructed from the repeated measures difference between flatfoot and normal conditions. Paired t-tests were used to compare the CPEI between conditions. Results: Twelve mid-tibia cadaveric specimens (mean age 73 years, 8 female) with no prior foot/ankle surgery were used. There were significant differences in kinematics between normal and PCFD conditions at the ankle, subtalar, and talonavicular joints (Figure). There was significantly increased ankle plantar flexion in flatfoot in the first 80% of stance phase. There was significantly greater subtalar eversion in flatfoot compared to normal from 10-90% of stance phase. Talonavicular abduction and eversion were also significantly greater in flatfoot from 10-100% of stance. The CPEI was significantly decreased in the flatfoot condition (Figure), indicating a medialization in center of pressure (p

Category: Basic Sciences/Biologics; Hindfoot Introduction/Purpose: Progressive collapsing foot deformity (PCFD) is a complex 3-dimensional pathology with a wide variety of surgical treatments. Regardless of technique, operative management of PCFD aims to restore normal foot architecture with attention to avoid the consequences of under- or over-correction. However, current methods of evaluating PCFD correction rely on static measurements, which do not assess dynamic function of the foot. Recent advances in robotic technology allow for the dynamic assessment of surgical correction of PCFD. This study sought to assess the effects of 2 osteotomies for PCFD, the medializing calcaneal osteotomy (MCO) and lateral column lengthening (LCL), on kinematics and plantar pressure during simulated gait. We hypothesized that the combination of LCL and MCO would restore joint kinematics and plantar pressure values to normal levels. Methods: Twelve cadaveric mid-tibia specimens (mean age 73 years, 8 female) were loaded on a 6-degree of freedom robotic gait simulator. Ground reaction forces and muscle forces were optimized utilizing an established iterative process. An 8-camera motion capture system was utilized to calculate joint kinematics using reflective markers attached by k-wires into bone. Plantar pressures were recorded using a pedography mat attached to the force platform. Testing was performed first in the native intact state, and again after creation of the flatfoot model. After flatfoot testing, surgical reconstruction and testing were performed in stages with MCO, and LCL with sequential 6mm and 8mm grafts. Bias-corrected bootstrapped 95% confidence intervals were calculated from the repeated measures difference between normal, flatfoot, post-MCO, post-MCO and post-reconstructive conditions. Center of plantar pressure excursion index (CPEI) was calculated and compared between conditions using a repeated measures ANOVA with Tukey post hoc analysis. Results: Overall, surgical correction restored kinematics to normal levels (Figure). MCO alone resulted in statistically significant improvement in subtalar eversion in the first 20% of stance, and post-MCO subtalar kinematics were statistically similar to normal. LCL (either 6mm and 8mm) alone did not significantly correct talonavicular abduction after PCFD. However, in conjunction with MCO, LCL was able to significantly correct talonavicular kinematics throughout the majority of stance phase, with kinematics statistically similar to normal levels. Each surgical step (LCL 6mm, LCL 8mm, MCO) resulted in sequential lateralization of the center of plantar pressure. At the culmination of surgical reconstruction (MCO + LCL), plantar pressure was significantly corrected compared to PCFD (P

Category: Ankle; Hindfoot; Other Introduction/Purpose: Peritalar subluxation (PTS) of the hindfoot is a critical finding in Progressive Collapsing Foot Deformity (PCFD). Subluxation of the middle facet and sinus tarsi impingement have recently been shown to represent essential markers of pronounced and potentially progressive deformity. Weightbearing CT (WBCT) imaging and three-dimensional (3D) distance (DM) and coverage maps (CM) allow a complete and accurate assessment of PTS markers across the entire peritalar surface. This prospective comparative study aimed to assess the effectiveness of joint-sparing realignment surgical treatment for flexible PCFD in reducing PTS and to correlate the improvement with patient-reported outcomes (PROs). We hypothesized that surgical treatment would significantly improve PTS markers, mainly decreasing sinus tarsi coverage/impingement and middle facet subluxation, and that this improvement would correlate with increased PROs. Methods: In this IRB-approved prospective and comparative study, we enrolled patients with flexible PCFD, no prior surgeries, and failed conservative treatment. Included patients (n=10, 7 females/3 males, mean age 57.2, range 37-74) underwent joint-sparing surgical realignment procedure by a single surgeon. Standing weightbearing CT (WBCT) was completed preoperatively and 3- months postoperatively. Following automatic bone segmentation, 3D distance maps (DMs) of the entire peritalar surface were generated, and coverage of the subtalar joint articular facets (anterior, middle, and posterior) and sinus tarsi were assessed as markers of PTS. Joint coverage was defined as the percentage of articular space where DMs were

Category: Ankle; Ankle Arthritis Introduction/Purpose: The treatment of ankle arthritis has changed significantly with the recent advances in total ankle arthroplasty (TAR). Many different designs of TAR have been used around the world as the biomechanical technology advances and our understanding increases. Most implant system are anterior-based and have a flat cut on the tibial prosthesis. Only one implant, the Trabecular Metal (Zimmer-Biomet, Warsaw, IN), utilizes a lateral approach with a fibular osteotomy to gain access to the tibiotalar joint and a sagittally curved tibial component. Recent publications have described a higher reoperation rate with this implant system. This study aimed to report the 5-year clinical and radiographic outcome as well as the survivorship of the implant. Methods: Over a three-year period, two fellowship-trained foot and ankle surgeons used this implant system for patients indicated for TAR. A total of 38 patients were reviewed with an average age of 63.4+-8.6 years-old, BMI of 28.9+-4.6 and the majority (78%) had post-traumatic arthritis. Reoperations and revisions were collected prospectively as part of the local database. Patients participated in surveys preoperatively and at every annual follow-up which included the Foot and Ankle Outcome Score (FAOS). Patients were also evaluated with weightbearing radiographs preoperatively, at the 3 months postoperative and at the 5 year-mark. Those were analyzed by looking at the implant position with validated angles and comparing those over time. Further statistical analysis used paired t-test and Mann-Whitney U test. Results: The survivorship for our cohort was 92% at the 5-year mark. Three patients had the implant extracted at 12 and 15 months postoperative. Two of those patients had revisions to stemmed TARs and one had a below-knee amputation. Reoperations otherwise included 4 fibular hardware removal and 5 medial gutter debridement. As seen in Table 1, the FAOS improved significantly for all domains at 5-year compared to preoperative status. The Pain and Symptoms domains improved above than the MCID. The implant positioning both tibial coronal and sagittal as well as talar sagittal did not significantly change between 3 months and 5 years postoperative. Conclusion: This study describes the use of a laterally based Trabecular Metal TAR with great survivorship (92%) and clinically significant improvement in patient-reported outcomes. The rate of reoperation is higher due to prominent lateral hardware or poorly visualized medial gutters and revisions had to be performed through an anterior approach. Few other studies report 5-year outcomes from this prosthesis. There is a growing need to present more data from different centers to guide its ongoing clinical use.

Background: There is no current consensus on whether to use an open or minimally invasive (MIS) approach for Achilles tendon repair after acute rupture. We hypothesized that patients in both open and MIS groups would have improved patient-reported outcome scores using the PROMIS system postoperatively, but that there would be minimal differences in these scores and complication rates between operative techniques. Methods: A total of 185 patients who underwent surgery for an acute, unilateral Achilles tendon rupture between January 2016 and June 2019, with minimum 1-year follow-up were included in the cohort studied. The minimally invasive group was defined by use of a commercially available minimally invasive device through a smaller surgical incision (n=118). The open repair group did not use the device, and suture repair was performed through larger surgical incisions (n=67). Postoperative protocols were similar between groups. Preoperative and postoperative PROMIS scores were collected prospectively through our institution’s registry. Demographics and complications were recorded. Results: PROMIS scores overall improved in both study groups after operative repair. No significant differences in postoperative PROMIS scores were observed between the open and MIS repair groups. There were also no significant differences in complication rates between groups. Overall, 19.5% of patients in the MIS group had at least 1 postoperative complication (8.5% deep vein thrombosis [DVT], 3.3% rerupture, 1.7% sural nerve injury, 2.5% infection), compared to 16.4% in the open group (9.0% DVT, 1.5% rerupture, 1.5% sural nerve injury, 0% infection). Conclusion: Patients undergoing either minimally invasive or open Achilles tendon repair after acute rupture have similar PROMIS outcomes and complication types and incidences. Level of Evidence: Level III, retrospective cohort study.

Background: Despite good evidence that supports significant improvements in pain and physical function following a total ankle replacement (TAR) for end-stage ankle arthritis, there is a subset of patients who do not significantly benefit from surgery. The purpose of this study was to perform a preliminary analysis to determine if preoperative Patient-Reported Outcome Measurement Information System (PROMIS) scores could be used to predict which patients were at risk of not meaningfully improving following a TAR. Methods: Prospectively collected preoperative and ≥2-year postoperative PROMIS physical function, pain interference, pain intensity, and depression scores for 111 feet in 105 patients were included in the study. Significant postoperative improvement was defined using minimal clinically important differences (MCIDs). Logistic regression models and area under the curve (AUC) analyses were used to determine whether preoperative PROMIS scores were predictive of postoperative outcomes. Results: Receiver operating characteristic curves found statistically significant AUCs for the PROMIS physical function (AUC = 0.728, P = .004), pain intensity (AUC = 0.720, P = .018), and depression (AUC = 0.761, P < .001) domains. The preoperative PROMIS pain interference domain did not achieve a statistically significant AUC. Conclusion: Preoperative PROMIS physical function and pain intensity t scores may be used to predict postoperative improvement in patients following a fixed-bearing TAR; however, preoperative PROMIS pain interference scores were not good predictors. The results of this study may be used to guide research regarding patient-reported outcomes following TAR. Level of Evidence: Level III, retrospective comparative series.

Category: Ankle Arthritis; Ankle Introduction/Purpose: The use of total ankle arthroplasty (TAA) in the treatment of ankle arthritis has grown substantially as advancements are made in design and surgical technique. Among the criteria guiding the choice between arthroplasty versus arthrodesis, the long-term survival and postoperative outcomes are of crucial importance. First FDA approved in 2005, the INBONE I prosthesis was subsequently replaced by the INBONE II in 2010. While outcomes of the INBONE I have been published, there is limited long-term survivorship data for the INBONE II. The purpose of this study is to determine the minimum 5-year survivorship of the INBONE II prosthesis and causes of failure. In addition, we evaluate long-term radiographic and patient- reported outcomes. Methods: We retrospectively identified 46 prospectively followed patients from 2010 to 2015 who underwent TAA with the INBONE II prosthesis at our institution. Of these, 44 cases (41 patients) had minimum follow-up of 5 years (mean, 6; range, 5 to 9). Mean age was 65.6 years (range, 42 to 81) and mean BMI was 27.6 (range 20.1 to 33). Survivorship was determined by incidence of revision, defined as removal/exchange of a metal component. Chart review was performed to record incidences of revision and reoperation. Preoperative, immediate and minimum 5-year x-rays were reviewed; coronal tibiotalar alignment (TTA) was measured on standing AP radiographs to assess alignment of the prosthesis. A TTA of +-5° from 90° indicated neutral alignment, while 95° was considered varus and valgus alignment, respectively. Radiographic subsidence as well as presence and location of periprosthetic cysts were documented. Pre- and minimum 5-year FAOS domains were compared. Results: Survivorship was 97.7% with one revision of the talar component due to aseptic loosening and subsidence. The rate of other reoperations was 4.5% (2); one patient underwent medializing calcaneal osteotomy for valgus heel alignment, another patient underwent ostectomy and debridement for ankle impingement. Average preoperative TTA was 88.5 degrees with 15 neutral (average TTA of 89.7°), 14 varus (74°) and 12 valgus (104°) ankles. Average postoperative TTA was 88.6° with 35 neutral (89.3°), 6 varus (84.7°), and no valgus ankles. Radiographic subsidence was observed in one patient who underwent revision, and periprosthetic cysts were observed in 7 patients. There was significant improvement in all FAOS domains at final follow-up. Conclusion: This is the largest study to date dedicated to evaluating survivorship of the INBONE II prosthesis. Our data suggests a high survival rate and low reoperation rate with long-term follow-up of the INBONE II implant. We observed significant improvement in radiographic alignment as well as patient-reported clinical outcomes at minimum 5-year follow-up.

Category: Ankle; Ankle Arthritis; Trauma Introduction/Purpose: Although total ankle replacement (TAR) for the treatment of end-stage ankle arthritis has been shown to have excellent radiographic and clinical outcomes, there is a risk for complications such as periprosthetic fractures. While periprosthetic fractures of the tibia are well described in the literature, little is known about such fractures involving the talus. The purpose of this case series is to describe the radiographic findings and surgical management of talar fractures sustained after placement of total ankle prostheses. Methods: We retrospectively reviewed 489 patients who underwent total ankle replacement from June 2015 to March 2019, and identified five cases (2 males, 3 females, average age 45.7 years) in which patients sustained a periprosthetic fracture of the talus. All patients presented symptomatically with ankle pain during postoperative follow-up, and fractures of the talus were confirmed on computed tomography (CT) imaging. One patient had psoriatic arthritis and four patients had primary osteoarthritis of the ankle. CTs were reviewed to confirm location and pattern of the fracture, as well as related pathology such as osteolysis and subsidence. Hospital charts and operative reports were reviewed to record patient demographics and postoperative management including reoperations. Results: Overall the incidence of talar fractures was 1% (5/489) and all occurred in implants with a talar stem (4 INBONE II, 1 Salto Talaris). All fractures extended from the stem of the talar component into the subtalar joint, with one case of a non- displaced fracture. Osteolysis surrounding the talar stem was observed in all cases, with subsidence of the talar component observed in four out of five patients on CT. All five patients presented symptomatically and underwent reoperation (1 revision of talar component with ORIF, 3 subtalar fusions, 1 tibiotalar fusion). Conclusion: The findings in this case series suggest that periprosthetic fractures of the talus following total ankle replacement is a possible complication of stemmed implants and is associated with poor clinical outcomes requiring reoperation. Therefore, a periprosthetic fracture of the talus should be considered in a patient with unexplained pain and evidence of radiographic osteolysis around the stemmed component.

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: Surgical correction of the collapsing flatfoot deformity has been well studied in the literature, with the average patient being a female in her 50s. While reconstruction of the flexible, symptomatic flatfoot in children and adolescents has been described, assessment of outcomes across age groups is limited. Therefore, the purpose of our study is to compare the clinical and radiographic outcomes in younger patients 30 years or less undergoing flatfoot reconstruction with that of older patients. In addition, the procedures performed for reconstruction and the incidence of subsequent reoperations were compared between the two groups. Methods: Ninety-four feet (51 left, 43 right) in 87 patients who underwent reconstruction for flexible collapsing flatfoot deformity were divided into 2 groups based on age: 30 years (n=72). Exclusion criteria included tarsal coalition or neuromuscular disease. Average age and BMI was 20.8 years (range, 13 to 30) and 26.8 (range, 18 to 38) in the younger cohort, and 57.5 years (range, 35 to 81) and 29.8 (range, 18 to 46) in the older cohort. Preoperative and minimum 2-year postoperative PROMIS scores were compared. Average follow-up was 30.6 and 27 months in the younger and older cohorts, respectively. We assessed five radiographic parameters both preoperatively and postoperatively, including talonavicular (TN) coverage angle, lateral talo-first metatarsal angle (Meary’s), lateral talocalcaneal angle, calcaneal pitch, and hindfoot moment arm (HMA). Operative reports and hospital records were reviewed to compare procedures performed for reconstruction as well as subsequent reoperations. Results: Younger patients demonstrated significant preoperative to postoperative improvements in Physical Function (p=0.01), Pain Interference (p

Category: Ankle Arthritis; Ankle Introduction/Purpose: Total ankle arthroplasty (TAA) has garnered significant interest and increased use over the past decade, with advancements made in both design and surgical technique. The main advantage of TAA for the surgical treatment of ankle arthritis is to preserve range of motion compared to ankle arthrodesis. Among the criteria guiding the choice between arthroplasty and arthrodesis, the long-term survival and postoperative outcomes are of crucial importance. The Salto Talaris is a fixed-bearing implant first approved in the US in 2006, and long-term survivorship data is limited. The purpose of this study is to determine minimum 5-year survivorship of the Salto Talaris prosthesis and causes of failure. In addition, we evaluate long-term radiographic and patient-reported outcomes. Methods: We retrospectively identified 86 prospectively followed patients from 2007 to 2014 who underwent TAA with the Salto Talaris prosthesis at our institution. Of these, 81 patients (84 feet) had a minimum follow-up of 5 years (mean, 7.1; range, 5 to 12). Mean age was 63.5 years (range, 42 to 82) and mean BMI was 28.1 (range, 17.9 to 41.2). Survivorship was determined by incidence of revision, defined as removal/exchange of a metal component. Chart review was performed to record incidences of revision and reoperation. Preoperative, immediate and minimum 5-year postoperative x-rays were reviewed; coronal tibiotalar alignment (TTA) was measured on standing AP radiographs to assess alignment of the prosthesis. A TTA of +-5° from 90° indicated neutral alignment, while 95° was considered varus and valgus alignment, respectively. Radiographic subsidence as well as presence and location of periprosthetic cysts were documented. Pre- and minimum 5-year FAOS domains were compared. Results: Survivorship was 97.6% with two revisions. One patient underwent tibial and talar component revision for varus malalignment of the ankle, another underwent talar component revision for aseptic loosening and subsidence. The rate of other reoperations was 19.5% (18) with the main reoperation being exostectomy with debridement for ankle impingement (12). Average preoperative TTA was 88.8° with 48 neutral (average TTA of 90.1°), 18 varus (82.3°) and 8 valgus (99.6°) ankles. Average postoperative TTA was 89.0° with 69 neutral (89.7°), 6 varus (83°), and 1 valgus ankle (99.3°). Radiographic subsidence was observed in one patient who underwent revision, and periprosthetic cysts were observed in 18 patients. There was significant improvement in all FAOS domains at final follow-up. Conclusion: This is the largest study to date dedicated to evaluating survivorship of the Salto Talaris prosthesis. Our data reflects a high survival rate and moderate reoperation rate with long-term follow-up of the Salto Talaris implant. We observed significant improvement in radiographic alignment as well as patient-reported clinical outcomes at minimum 5-year follow-up.

Category: Ankle Introduction/Purpose: Biologic fixation of total joint replacements by bone ingrowth requires minimal bone-implant micromotion [1]. Computational finite element (FE) models used to evaluate the interaction between implant and bone typically only consider simplified loading conditions based on the peak compressive force which occurs near toe-off [2,3]. However, a previous study focused on cementless knee replacements demonstrated that peak micromotion during activity cycles occurred with sub-maximal forces and moments [4]. Our objective was to calculate multi-axial loading at the ankle joint throughout level walking and evaluate tibial fixation of ankle replacements under these loading conditions. We hypothesized that peak micromotion would occur with sub-maximal loads and moments instead of at the instant of peak compressive load. Methods: Our validated six-degree-of-freedom robotic simulator utilizes in vivo data from human subjects to replicate the individual bone kinematics in cadaveric specimen throughout activity [5]. We rigidly fixed retro-reflective markers using bone pins to the tibia, talus, and calcaneus bones of three cadaveric specimens to record individual bone kinematics using motion capture cameras. We recorded the ground reaction and muscle-tendon forces during the simulated stance phase of level walking. Musculoskeletal models were then developed in OpenSim using the specimen-specific morphology and implant position from CT- scans and from the simulator outputs to determine the loading profile at the ankle joint during stance. The calculated loads were then applied to specimen-specific finite element models to evaluate the bone-implant interaction. Peak micromotion at each time point of loading was measured and compared to the loading profile to determine if it corresponded with the peak compressive load. Results: For all specimens, the peak compressive load at the ankle joint was accompanied by multi-axial moments and relatively small shear forces (Figure 1). The peak compressive load for each specimens was between 750 N and 850 N and occurred during 75-80% of gait. The largest moment experienced by all specimens was an internal moment late in stance. The peak micromotion for each specimen did not correspond to the instance of peak compressive load, as indicated in Figure 1. Instead, peak micromotion occurred at 54%, 88%, and 96% of gait. For each specimen, these instances corresponded to the combination of a sub-maximal compressive load with high eversion and internal moments. Conclusion: We have developed a workflow to calculate ankle joint loads corresponding to cadaveric simulations that reproduce a daily activity based on in vivo data. The specimen-specific, multi-axial loading profile at the ankle for our initial results suggests that peak micromotion at the bone-implant interface of the tibial implant does not coincide with the peak compressive force. The instant of peak compressive load may not capture the worst-case scenario for the interaction between the implant and the bone. Instead, the multi-axial forces and moments at the ankle joint throughout activity should be considered when evaluating implant fixation.

Category: Bunion; Other Introduction/Purpose: Cone Beam Weight Bearing CT (WBCT) is gaining traction, particularly in the foot and ankle, due to the ability to perform natural stance weight bearing 3D scans. However, the resulting wealth of 3D data renders daily clinical use time consuming. Therefore, reliable automatic measurements are indispensable in order to make best use of the technology. The aim of this study was to evaluate a beta-version WBCT artificial intelligence (AI) automatic measurement system for the M1-M2 intermetatarsal angle (IMA), which is applicable in the absence of metallic hardware in the foot and ankle. We hypothesized that automatic measurements would correlate well with human measurements, and that software reproducibility would be better and close to perfect compared to manual measurements. Methods: In this retrospective case-control study, 90 feet were included from patients who underwent WBCT scans during routine follow up: 44 feet (90.9% female, mean age 54 years) with symptomatic hallux valgus (HV), 46 controls (76.1% female, mean age 49 years). Patients were excluded if they had history of surgery or trauma involving the first or second metatarsals, hallux rigidus, or presence of metal in their foot/ankle. IMA was measured manually on Digitally Reconstructed Radiographs (DRR IMA) and automatically with AI software producing auto 2D (ground plane projection) and 3D (multiplanar) measurements. Each IMA DRR was measured by two independent raters twice to calculate intraclass correlation coefficients (ICCs). To assess intra- software reliability, AI software measurements were made twice on each dataset. Manual and automatic measurements were compared between HV and control groups. Failures of the AI software to produce a measurement were recorded. Results: Mean values for controls were 8.6° +-1.8° (range, 5°-14°) for the manually measured DRR IMA, 9.3° +-2.8° (range, 3°- 17°) for auto 2D, and 9.2° +-2.6° (range, 3°-16°) for auto 3D IMA measurements. Compared to controls, HV patients demonstrated significantly increased IMA (p

Category: Hindfoot; Ankle; Other Introduction/Purpose: Semi-automatic three-dimensional (3D) biometric weightbearing CT (WBCT) tools have been shown to accurately demonstrate the relationship between the center of the ankle joint and the tripod of the foot. The measurement of the Foot and Ankle Offset (FAO) represents an optimized biomechanical assessment of foot alignment. The objective of this study was to evaluate the correlation between FAO and traditional adult acquired flatfoot deformity (AAFD) markers, measured in different planes. We hypothesized that the FAO would significantly correlate with other radiographic markers of pronounced AAFD. Methods: In this retrospective comparative study, we included 113 patients with stage II AAFD, 43 men and 70 women, mean age of 53.5 (range, 20 to 86) years. Three-dimensional coordinates (X, Y and Z planes) of the foot tripod (most plantar voxel of the first and fifth metatarsal heads, and calcaneal tuberosity) and the center of the ankle joint (most proximal and central voxel of the talar dome) were harvested by two blinded and independent fellowship-trained orthopedic foot and ankle surgeons. The FAO was automatically calculated using the 3D coordinates by dedicated software. Multiple WBCT parameters related to the severity of the deformity in the coronal, sagittal, and transverse plane were manually measured. Results: We found overall good to excellent intra (range, 0.84-0.99) and interobserver reliability (range, 0.71-0.96) for manual AAFD measurements. FAO semi-automatic measurements demonstrated excellent intra (0.99) and interobserver reliabilities (0.98). Hindfoot moment arm (p

Category: Ankle Arthritis Introduction/Purpose: One of the proposed benefits of total ankle replacement (TAR), when compared to ankle fusion is the restoration of the functional range of motion (ROM) of the ankle. Preservation of ankle motion may improve quality of life as evidenced by patient-reported outcome measures (PROMs). However, some studies have shown a lack of improvement of ankle range of motion after the postoperative recovery period, despite satisfactory motion being observed intra-operatively. The objective of this study was to radiographically compare intraoperative and pre-operative ankle range of motion. Methods: This single-center retrospective study compared 56 patients with an average age of 62.27 years who underwent primary TAR with one of four different implants between March and December 2019. 48% of patients had post-traumatic arthritis secondary to an ankle fracture, 50% had post-traumatic arthritis secondary to instability. Seventy-two percent of patients had an associated Achilles lengthening, 16% had an associated lateral ligament reconstruction procedure. Standardized weight-bearing maximum dorsiflexion and plantarflexion sagittal radiographs were obtained pre-operatively. In order to record intraoperative fluoroscopic imaging, the primary surgeon passively placed the ankle into maximum dorsiflexion and plantarflexion. Intraoperatively, the neutral lateral position of the ankle was determined after the replacement when the talus was in perfect lateral view. All angular measurements were made using the PACS system (Picture Archiving and Communication System). The change in range of motion was analyzed using a paired t-test with a significance level of 0.05. Results: The intraoperative range of motion increased significantly for all measures when compared to the pre-operative range of motion. The average pre-operative global arc of motion significantly increased from 20.21 degrees to 38.49 degrees intra- operatively (p=2.45x10-18, t(55)=2.00). The average pre-operative plantar flexion significantly increased from 12.80 degrees to 25.50 degrees intra-operatively (p=2.56x10-15, t(55)=2.00). The average pre-operative dorsiflexion significantly increased from 7.28 degrees to 13.35 degrees intra-operatively (p=4.68x10-6 t(55)=2.00). Patients who had an Achilles lengthening had an average increase in the global arc of motion of 18.78 degrees; patients who did not have an Achilles lengthening had an average increase of 17.02 degrees (p=0.562, t(31)=2.04). Overall, 93% of patients increased their range of motion after their total ankle replacement. Conclusion: This study demonstrates notable improvement in ankle range of motion intraoperatively following total ankle replacement, especially in plantarflexion. Total Ankle Replacement provides an improvement in the functional range of motion of the ankle intraoperatively, suggesting that the loss of motion observed in previous studies may occur during the postoperative period. The present study may help inform and adjust the postoperative rehabilitation protocol after total ankle replacement in order to avoid losing the amplitude of motion gained during the operation.

Category: Midfoot/Forefoot; Other Introduction/Purpose: Severe adult-acquired flatfoot deformity (AAFD) is often associated with painful medial column collapse at the naviculocuneiform (NC) joint. The purpose of this study was to examine the role of first tarsometatarsal (1st TMT) fusion combined with subtalar fusion in correcting deformity at this joint. Methods: We retrospectively analyzed 40 patients (41 feet) who underwent 1st TMT and subtalar (ST) fusion as part of a flatfoot reconstructive procedure. We assessed six radiographic parameters both preoperatively and at a minimum of 6 months postoperatively, including talonavicular (TN) coverage angle, lateral talo-first metatarsal angle, lateral talocalcaneal angle, calcaneal pitch, hindfoot moment arm, and a newly defined navicular-cuneiform incongruency angle (NCIA). Patient-Reported Outcomes Measurement Information System (PROMIS) clinical outcomes were assessed preoperatively and at a minimum 1 year follow-up. Results: The NCIA demonstrated excellent interobserver reliability, with no significant change between pre- and postoperative measurements. All other radiographic parameters, except calcaneal pitch, demonstrated statistically significant improvement postoperatively (p

Category: Ankle; Ankle Arthritis Introduction/Purpose: Surgeons who perform a higher volume of total ankle arthroplasty (TAA) are known to have decreased complication rates; evidence shows that low volume centers performing TAA have decreased survivorship when compared with high volume centers. Understanding differences in outcomes for patients traveling different distances for their TAA is important for future patients deciding where to travel for their surgery. No study has previously examined differences in outcomes of patients traveling different distances to a high volume center for their TAA. This study compares preoperative and postoperative PROMIS scores for patients undergoing total ankle arthroplasty who traveled less than and more than 50 miles for their TAA. We hypothesized that there would be no difference in outcome scores based on distance traveled or estimated drive time. Methods: This study is a single center retrospective review of 162 patients undergoing primary total ankle arthroplasty between January 2016 and December 2018. We collected the primary address as listed in the patient’s medical record and used the directions feature on Google Maps to estimate driving mileage and estimated driving time from the patient’s address to the hospital. To analyze the distance patients traveled, patients were divided into two groups: 50 miles traveled (n=71). To analyze the estimated drive time, patients were divided into two groups: 90 minutes (n=85). We collected preoperative and most recent postoperative PROMIS scores for all patients. Differences in most recent post-operative PROMIS scores between distance groups and travel time groups were assessed using multivariable linear regression models, adjusting for the pre-operative score and follow-up time. Results: We found no significant difference in post-operative PROMIS scores between the two groups when analyzed for distance traveled or for estimated travel time after adjustment for pre-operative PROMIS score and follow-up time (Table 1). The average follow-up for all 162 patients was 1.49 years. Power analysis showed that with a sample size of 110 (55 in each group), we had 81% power to detect an effect size of 4. Patients saw an increase in their Physical Function scores and a decrease in their Pain Interference and Pain Intensity scores with postoperative scores better than population means (Table 1). Overall complication rate for the 50 miles group had an overall complication rate of 24.0%, 9.9% required surgery. Conclusion: Patients traveling further distances to a high volume orthopedic specialty hospital for their total ankle arthroplasty do not have different clinical outcomes than patients traveling shorter distances. This is particularly important for patients deciding where to have their total ankle arthroplasty surgery. Patients who travel further have the opportunity to be treated at a local academic center; however our results show that outcomes do not change when traveling further for total ankle arthroplasty.

Category: Other Introduction/Purpose: Cases of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus (COVID-19) first emerged in Wuhan, China, in December 2019. Since then, the virus has spread globally at a rapid pace. The first case in New York City was reported on March 1, 2020, and the World Health Organization (WHO) declared a pandemic on March 11, 2020. New York City rapidly became the epicenter of the pandemic, with hospitals across the city making a number of changes to accommodate the influx of COVID-19 patients. Here, we describe our experience in adapting to the COVID-19 pandemic as a department consisting of 10 foot and ankle fellowship-trained surgeons with up to 28 years of individual experience in an academic orthopedic hospital. Methods: Information was obtained from direct interviews with surgeons in the Foot and Ankle Service and from our institution’s intranet. Additional information was obtained by viewing twice-weekly livestreams from March 27th, 2020 to May 1st, 2020 held by the Surgeon-In-Chief, which detailed hospital-wide policies and initiatives being implemented in the wake of the COVID-19 pandemic. Results: On March 17, 2020, all elective surgeries were suspended at our institution, and a list of essential procedures was established. In-person clinical visits were limited to new patients being evaluated for essential procedures and first postoperative visits for returning patients, with all patients receiving pre-visit and on-site screening for COVID-19. All other new patient and follow-up appointments were conducted via telehealth visits. Much of our main hospital was repurposed to accept transfers of both COVID-negative and COVID-positive patients. A postanesthesia care unit and a floor of 9 operating rooms were repurposed as negative-pressure rooms for the care of critical COVID-positive patients on ventilators. An Orthopedic Triage Center (OTC) was established to relieve the patient load in the emergency departments of other hospitals in the city. Conclusion: By changing the way we delivered foot and ankle care and repurposing the roles of our employees and our institution, we have adapted strategies to continue delivering care to our patients. As we transition toward a ‘new normal,’ our goals are to gradually progress toward normal operations while keeping our patients and employees safe. With these gradual steps, we hope to emerge from this pandemic stronger and ready to adapt to the ever-changing needs of our community.

Category: Sports Introduction/Purpose: While there is no current consensus on whether to use an open or minimally invasive (MIS) approach for Achilles tendon repair after acute rupture, there is a recent trend towards decreasing complication rates for both procedures as well as favorable clinical outcomes. While many studies have compared complication rates between these procedures, no study has examined differences in clinical outcomes using PROMIS scores with a large cohort of patients. PROMIS has been validated for use in assessing outcomes following Achilles repair and allows for evaluation of surgical outcomes compared to population means. We hypothesized that patients in both open and MIS groups would have improved PROMIS scores postoperatively, but that there would be minimal differences in PROMIS scores and complication rates between surgical techniques. Methods: 228 patients were identified who underwent surgery for acute unilateral Achilles tendon repair between January 2016 and December 2018. Nine surgeons were represented. The open repair group was defined by a larger incision (>4 cm) and no use of a commercially available minimally invasive device. The minimally invasive group was defined by a smaller incision (

Category: Other Introduction/Purpose: Aligning patient and surgeon expectations is important, as it allows for informed and shared decision- making and may improve postoperative satisfaction. Patient-provider communication factors have been found to affect differences between patient and surgeon expectations of total knee arthroplasty. Patients with limited health literacy have been found to ask fewer questions and spend less time with their surgeons, and to perceive themselves to have a more passive decision-making role in hand surgery clinic visits. Understanding how these factors affect differences in expectations of foot and ankle surgery is important in order to increase patient-surgeon agreement. This study aimed to assess associations between patient-reported physical and mental status, patient-surgeon communication factors, and musculoskeletal health literacy with differences between patient and surgeon expectations of foot and ankle surgery. Methods: Two hundred two patients scheduled to undergo foot or ankle surgery by one of seven fellowship-trained foot and ankle surgeons at an academic hospital were enrolled. Preoperatively, patients and surgeons completed the Hospital for Special Surgery Foot & Ankle Surgery Expectations Survey independently. Patients also completed Patient-Reported Outcomes Measurement Information System (PROMIS) scores in Physical Function, Pain Interference, Pain Intensity, Depression, and Global Health. Patient involvement in care, provider partnership building, and provider information giving were assessed with the modified Patients’ Perceived Involvement in Care Scale (PICS). Musculoskeletal health literacy was assessed with the Literacy in Musculoskeletal Problems (LiMP) questionnaire. A score >= 6 reflects adequate musculoskeletal literacy and a score < 6 reflects limited musculoskeletal literacy. Associations between scores and differences between patient and surgeon expectations were assessed with Pearson Correlation coefficients. Associations between musculoskeletal health literacy and differences were assessed with Student’s t-tests and Mann Whitney U tests. Results: Greater differences in patient and surgeon overall expectations scores were associated with worse PROMIS scores in Physical Function (p = 0.003), Pain Interference (p = 0.001), Pain Intensity (p = 0.009), Global Physical Health (p < 0.001), and Depression (p = 0.009). A greater difference in the number of expectations between patients and surgeons was associated with all of the above (p = 0.155). Conclusion: Worse baseline patient physical and mental status and higher patient perceptions of provider partnership building were associated with greater patient to surgeon differences in expectations of foot and ankle surgery. It may be beneficial for surgeons to set more realistic expectations with patients who have greater disability and in those whom they have stronger partnerships with in order to increase agreement in expectations. Further studies are warranted to understand how modifications in patient and surgeon interactions affect agreement in their expectations of foot and ankle surgery, and whether musculoskeletal literacy affects these interactions.

Category: Ankle; Arthroscopy; Basic Sciences/Biologics Introduction/Purpose: Historically, microfracture has been used to treat small talar osteochondral lesions (OLTs) with good results, while osteochondral autologous transplantation (OAT) has proven superior for the treatment of larger lesions. It is not clear which method is more effective for medium-sized lesions, around the critical size of 150 mm2 above which microfracture outcomes tend to be poor. While OAT carries the risk of co-morbidity at the knee and often requires a malleolar osteotomy, it is thought to result in superior repair tissue compared to microfracture by introducing native hyaline cartilage to the ankle. Microfracture, in contrast, results in the formation of structurally inferior fibrocartilage. The purpose of this study was to determine the relative benefits of OAT and microfracture in the treatment of medium-sized OLTs. Methods:: Patients treated for an OLT with OAT or microfracture by a single surgeon fellowship-trained in foot and ankle orthopedics between 2015 and 2018 were screened. Both OAT and microfracture techniques were augmented with a mixture of extracellular matrix and bone marrow aspirate concentrate (ECM-BMAC) for every case included in this study. Patients treated without ECM-BMAC were excluded. Only patients with a lesion size between 80 and 165 mm 2 were included. Minimum follow-up was 12 months. Clinical outcomes were collected in the form of FAOS or PROMIS scores, depending on departmental standards at the time of treatment. MRIs were collected for radiographic analysis of cartilage repair tissue. MRIs were scored using the MOCART system by a fellowship trained radiologist and were also evaluated for the presence of cysts and edema. Patient charts were reviewed to determine rates of revision surgery and therapeutic injection for pain. Results:: 52 patients were identified who fit inclusion criteria. 27 of these patients received microfracture and 25 received OAT. The average lesion size for all patients was 117.5 mm2. Patients treated with OAT had significantly higher average total MOCART scores (69 vs. 55, p = 0.04) and significantly lower rates of cyst (14% vs. 55%, p

Category: Ankle; Hindfoot; Other Introduction/Purpose: Adult acquired flatfoot deformity (AAFD) is a complex deformity. Previous work has demonstrated correlation between postoperative foot alignment and patient-reported outcomes. While this work has provided essential targets for surgeons performing flatfoot reconstruction, there is an absence of data that would enable surgeons to predict which patients are likely to have greater or less improvement after surgery based on their preoperative deformity. Conventional radiographs alone may not provide enough detail to isolate individual elements of the deformity. Weightbearing CT (WBCT) allows for far more precise analysis in this regard. We hypothesized that there would be a set of parameters defining preoperative alignment on WBCT that would predict which patients are at risk for a lower magnitude of postoperative improvement in patient-reported outcomes (PROs). Methods: In this retrospective IRB-approved study, patients that underwent surgical flatfoot reconstruction after having a preoperative standing WBCT were identified. Preoperative WBCT images were evaluated by two independent/blinded observers. Multiple parameters related to preoperative alignment and AAFD severity were measured in the sagittal, coronal and transverse planes. Parameters measured included talus-first metatarsal angle; distances between the floor and the navicular, medial cuneiform and cuboid; subtalar joint horizontal angle; superior talar - inferior talar angle; subtalar joint subluxation; talonavicular uncoverage angle; hindfoot moment arm (HMA); and foot and ankle offset (FAO). Prospectively collected data regarding preoperative and postoperative PROs was evaluated. Six PROs components were assessed: physical function; pain interference, pain intensity, global mental health, global physical health and depression. Multivariate regression analysis and a partition prediction model were used to assess the correlation between preoperative alignment and improvement in PROs. P-values of less than 0.05 were considered significant. Results: A total of 51 patients with a preoperative WBCT and postoperative PROs scores were identified and included. Demographic data is shown in Table 1. Multivariate regression analysis demonstrated that preoperative alignment significantly correlated with improvement in three out six components of PROs: pain interference, pain intensity and global mental health. The strongest predictor of improvement in PROMIS physical function t-score was medial cuneiform to floor distance, for pain interference t-score: cuboid to floor distance, for pain intensity: subtalar joint subluxation, for depression t-score: superior talar - inferior talar angle, and for global physical and mental health t-scores: sagittal talus-first metatarsal angle. Conclusion: Our analysis yielded readily identifiable cutoffs for WBCT measurements, where values above or below were correlated with significant differences in the magnitude of PRO score change. Interestingly, measures of sagittal plane collapse and hindfoot valgus were the most predictive of score changes. This data provides useful information for surgeons counseling patients prior to flatfoot reconstruction. Future work using this data to develop prediction models for postoperative outcomes would be valuable, as would studies using WBCT to evaluate the relationship between postoperative corrected alignment and PROs. Complete results are shown in the attached Table.

Category: Hindfoot; Ankle; Midfoot/Forefoot Introduction/Purpose: Multiple surgical techniques are used in the correction of Adult Acquired Flatfoot Deformity (AAFD). Assessment of the efficacy of a surgical treatment in the correction of the deformity is usually performed by clinical evaluation and conventional radiographic imaging. Weightbearing CT (WBCT) allows a more reliable and multiplanar evaluation of AAFD. The Foot and Ankle Offset (FAO) is a WBCT biometric semi-automatic measurement that gauges the relative positioning between the foot tripod and the center of the ankle joint. This study aimed to investigate the efficacy of surgical treatment in correcting AAFD, comparing preoperative and postoperative FAO measurements. We hypothesized that surgical treatment would provide significant correction of the deformity, centering the tripod of the foot underneath the ankle joint. Methods: In this prospective comparative study, 21 adult patients (22 feet) with flexible AAFD were included, mean age 55 (range, 23-81) years, 13 females and eight males. Patients underwent preoperative and postoperative standing WBCT examination. Three-dimensional coordinates (X, Y and Z planes) of the foot tripod (weightbearing point of the first and fifth metatarsals and calcaneal tuberosity) and center of the ankle (apex of the talar dome) were harvested by two independent and blinded observers. The FAO was automatically calculated from the harvested 3D coordinates by dedicated software. Data regarding the surgical technique used was recorded. Patient Reported Outcomes (PROs) were collected preoperatively and postoperatively at a mean follow-up of 22 (range, 8-36) months. Pre and postoperative FAO measurements were compared by paired T-tests. Multivariate analysis was used to assess the influence of surgical procedures in the amount of FAO correction. P-values of less than 0.05 were considered significant. Results: We found excellent intra (0.98) and interobserver reliability (0.96) for FAO measurements. The mean preoperative FAO was 10.4 (95% CI, 8.5 to 12.1). There was a significant correction of the deformity postoperatively (p

Category: Lesser Toes; Other Introduction/Purpose: Lesser toe metatarsal phalangeal (MTP) joint pathology presents a challenge for surgical treatment. Recently, synthetic cartilage implants have been shown to be safe and efficacious in treating hallux ridigus, offering pain relief while preserving motion at the MTP joint. At our institution, metatarsophalangeal joint arthroplasty using a polyvinyl alcohol (PVA) hydrogel implant has been utilized in the 2nd and 3rd MTP joints for advanced arthritis, failed management of Freiberg’s infraction, and osteochondral defects. We present a case series describing the clinical outcomes of 12 patients following PVA implantation of the 2nd or 3rd MTP. Methods: We retrospectively identified 12 consecutive patients (13 joints) who underwent PVA hydrogel implantation of the 2nd (n=12) or 3rd (n=1) metatarsal head between 2017 and 2019. PVA implant was indicated for advanced arthritis in 6 patients (7 joints), Freiberg’s infraction in 4 patients, and osteochondral defect in 2 patients. Average age was 51 years (range, 20-67), with 100% females. Patient-reported outcomes measurement information system (PROMIS) scores were collected preoperatively and at latest follow-up, with an average follow-up of 20.4 months (range, 8.3 to 29.2). Retrospective chart review was performed to evaluate postoperative complications, including need for revision, implant removal, and persistent pain. Results: Overall, patients demonstrated mean improvement in all PROMIS domains, with a significant improvement in Pain Intensity of 11.9 points (p=0.03) postoperatively. A total of 4 postoperative complications occurred in the 12 patients: one case of AVN at 2 years postoperatively, one revision with removal of the implant and bone grafting of the second metatarsal head at 1 year postoperatively, one periprosthetic fracture at 9 months postoperatively, and one recurrence of pain requiring ultrasound- guided injection at 7 months postoperatively. Three additional patients reported persistent pain postoperatively. Conclusion: This study represents the largest case series to date evaluating the use of PVA hydrogel implant in the surgical correction of lesser toe MTP joint pathology. While the PVA implant presents a viable option in the setting of advanced arthritis, Freiberg’s infraction, and certain osteochondral defects, it is not without complications. The specific indications for use of the PVA implant should be carefully considered before implantation.

Category: Midfoot/Forefoot; Other Introduction/Purpose: In 2016, the US Food and Drug Administration (FDA) approved the use of a polvinvyl alcohol (PVA) hydrogel implant (Cartiva, Elmsford, NY) for surgical treatment of hallux rigidus, or degenerative arthritis of the first metatarsophalangeal (1st MTP) joint. While studies have demonstrated the safety and usability of PVA implant, clinical outcomes following hemiarthroplasty with the PVA have not yet been compared to that of traditional joint-preserving procedures such as cheilectomy with Moberg osteotomy in the treatment of hallux rigidus. The purpose of this study is to compare patient-reported outcomes and postoperative complications between PVA hemiarthroplasty and cheilectomy with Moberg osteotomy, with the hypothesis that the addition of PVA would result in superior clinical outcomes. Methods: Patients were retrospectively identified who underwent hallux rigidus correction by one of seven Foot and Ankle fellowship-trained orthopaedic surgeons between March 2016 and November 2018. Out of 162 patients, a total of 133 patients constituted our study cohort after excluding patients with insufficient follow-up. Of the 133, 60 patients (mean age 57.2 years) were treated with combination PVA, cheilectomy, and Moberg osteotomy (PCM) and 73 patients (mean age 54.1) were treated with cheilectomy and Moberg (CM) alone. Both preoperative as well as minimum 1-year postoperative patient-reported outcome scores (PROMIS) were compared between the two cohorts. Chart review was performed to compare rates of revision and complications. Results: Average time to follow-up was 14.5 months for PCM and 15.6 for CM groups. Both PCM and CM cohorts demonstrated significant improvement in PROMIS scores, with the CM group demonstrating significantly greater increase in Physical Function (7.14 +- 8.48 vs 3.58 +- 6.24, p=0.01). While preoperative scores were comparable, postoperatively the CM group had a significantly higher average Physical Function (51.8 +- 8.7 vs 48.8 +- 8.0, p=0.04) and lower Pain Intensity (39.9 +- 8.3 vs 43.4 +- 8.7, p=0.02). There were 2 cases of revision with re-implantation and 1 case of conversion to arthrodesis in the PCM group. There was 1 case of conversion to PVA in the CM group. Three patients who underwent PCM had a documented postoperative infection requiring antibiotics. Conclusion: Our data suggests that the addition of polyvinyl alcohol implant in the treatment of hallux rigidus results in significant improvement in patient-reported outcomes. However, patient-reported physical function may not be up to par at minimum 1-year follow-up compared to cheilectomy and Moberg osteotomy alone. In addition, while incidence was low in our cohort, revision of the implant as well as conversion to arthrodesis remain possible complications of PVA. Therefore, we believe that proper patient selection is recommended when considering surgical treatment options for hallux rigidus.

Background: Operative correction of flatfoot deformity has been well studied in the older population. There is a subset of younger patients without congenital foot deformity that also develop a collapsing flatfoot. However, assessment of outcomes across age groups is limited, especially in the young demographic. The purpose of our study was to compare operative outcomes of flatfoot reconstruction between these 2 age groups. Methods: Seventy-six feet (41 left, 35 right) in 71 patients who underwent flexible flatfoot reconstruction were divided into 2 groups based on age: ≤30 years (n = 22) and >30 years (n = 54). Exclusion criteria included congenital causes of flatfoot (tarsal coalition, vertical talus, overcorrected clubfoot). Average age was 20.8 years (range, 14-30) and 55.4 years (range, 35-74) in the younger and older cohorts, respectively. Preoperative and minimum 2-year postoperative Patient-Reported Outcomes Measurement Information Systems (PROMIS) scores were compared. Five radiographic parameters were assessed pre- and postoperatively: talonavicular coverage angle, lateral talo–first metatarsal angle, lateral talocalcaneal angle, calcaneal pitch, and hindfoot moment arm. Procedures performed and incidence of minor (removal of symptomatic hardware) and major (revision) reoperations were compared. Results: Younger patients were less likely to undergo flexor digitorum longus transfer, first tarsometatarsal fusion, spring ligament repair, and posterior tibial tendon repair (all P < .05). Both younger and older cohorts demonstrated significant improvement in multiple PROMIS domains at an average follow-up of 30.6 (range, 24-44) and 26.8 (range, 24-45) months, respectively ( P = .07). Younger patients demonstrated significantly higher pre- and postoperative Physical Function (mean difference postoperatively, 4.6; 95% confidence interval, 1.5-7.8; P = .03). There were no differences in radiographic parameters postoperatively. There were 8 (36.4%) reoperations (all minor) in the younger group, and 21 (38.9%) reoperations (6 major, 15 minor) in the older group ( P = .84). Conclusion: Our data suggest that age may play a role in clinical outcomes, procedures indicated, and subsequent corrective reoperations. Younger patients maintained greater physical function with comparable radiographic correction, with less frequent indication for tendon transfers, arthrodesis, and additional corrective surgeries. Level of Evidence: Level III, retrospective comparative study.

Background: The posteromedial ankle structures are at risk during total ankle replacement (TAR). The purpose of our study was to investigate the distance of these structures from the posterior cortex of the tibia and talus in order to determine their anatomy at different levels of bone resection during a TAR and whether plantarflexion of the ankle reliably moved these structures posteriorly. Methods: Ten feet in 10 patients with end-stage tibiotalar arthritis indicated for a TAR were included. Preoperative magnetic resonance images were obtained with the foot in a neutral position as well as in maximum plantarflexion to measure the distance of posteromedial ankle structures to the closest part of the posterior cortex of the tibia or talus. Wilcoxon signed-rank rests were used to investigate differences in these distances. Results: The mean distance from the posterior tibial cortex to the tibial nerve at 14 and 7 mm above the tibial plafond was 8.7 mm (range 5.0-11.8 mm) and 6.7 mm (range 2.7-10.6 mm), respectively, which represented a statistically significant movement anteriorly ( P = .021). The posterior tibial artery was, on average, 8.0 mm (range 3.6-13.9 mm) and 7.2 mm (range 3.1-9.4 mm) from the posterior tibial cortex at 14 and 7 mm above the tibial plafond, respectively. Distal to the tibial plafond, the posterior tibial artery and flexor digitorum longus tendons moved posteriorly by less than 1 mm in plantarflexion (all P < .05); otherwise, plantarflexion of the ankle did not affect the position of the tibial nerve, posterior tibial tendon, or flexor hallucis longus. Conclusion: In patients with end-stage ankle arthritis, the tibial nerve and posterior tibial artery lie, on average, between 6.5 and 10 mm from the posterior tibial and talar cortices. Plantarflexion of the ankle did not reliably move the posteromedial ankle structures posteriorly. Level of Evidence: Level IV, case series, therapeutic

Background: Restoring the joint line is an important principle in total knee arthroplasty. However, the effect of joint line level on patient outcomes after total ankle arthroplasty (TAA) remains unclear, as there is no established method for measuring ankle joint level in TAA. The objective of this study was to develop a reliable radiographic ankle joint line measurement method and to compare ankle joint line level measured pre-TAA, post-TAA, and in nonarthritic ankles. Methods: A total of 112 radiographic sets were analyzed. Each set included weightbearing anteroposterior radiographs of the operative ankle taken preoperatively, 1-year postoperatively, and of the contralateral ankle. Measurements of vertical intermalleolar distance (VIMD) and vertical joint line distance (VJLD) at pre-TAA, post-TAA, and of the contralateral ankle were recorded by 2 authors on 2 separate occasions. The ratio of VJLD to VIMD was defined as the joint line height ratio (JLHR). Reliability of measurements and correlation between VIMD and VJLD were assessed. Pre-TAA, nonarthritic contralateral ankle, and post-TAA JLHR were compared and considered significantly different if P 0.9). There were strong positive correlations of VIMD and VJLD, r = 0.809 (pre-TAA)/0.756 (post-TAA), P < .001. Mean (SD) pre-TAA, nonarthritic contralateral ankle, and post-TAA JLHRs were 1.54 (0.31), 1.39 (0.26), and 1.62 (0.49), respectively. Pre- and post-TAA JLHRs were significantly higher compared to the nonarthritic contralateral ankle ( P < .05). JHLR was not significantly different between pre- and post-TAA ( P = .15). Conclusion: The JLHR was reliable and could be a clinically applicable method for assessing ankle joint line level in patients undergoing TAA. End-stage ankle arthritis demonstrated elevated joint line level compared with nonarthritic ankles, and the joint line level post-TAA remained elevated compared with nonarthritic ankles. Further studies are needed to understand the effect of joint line elevation on clinical outcomes after TAA. Level of Evidence: Level III, retrospective comparative study.

Category: Ankle, Ankle Arthritis Introduction/Purpose: Treatment options for ankle arthritis in younger patients are currently limited. Since the longevity of modern total ankle replacements is not sufficient for this patient population, ankle arthrodesis is typically utilized when joint preserving treatment is not a viable option. A new procedure using a pyrocarbon ankle spacer has been developed as a potential alternative, allowing for talar articular resurfacing for pain relief with minimal bone resection. The objective of this study was to assess whether this pyrocarbon ankle spacer could provide normal ankle kinematics as the native ankle joint using cadaveric gait simulation. Methods: Five mid-tibia cadaveric specimens without deformity and no history of lower limb injury or surgery were utilized. The stance phase of gait was simulated for each specimen using a six degree-of-freedom robotic device. A force plate was moved relative to stationary specimen through an inverse tibial kinematic path calculated from in vivo data while extrinsic tendons were actuated using physiologic loads (Figure 1A). Magnitudes of load were scaled to that of 25% bodyweight. Ankle kinematics were measured from reflective markers attached to the tibia and talus via surgical pins. The pyrocarbon ankle spacer (Exactech, Gainesville, FL, USA) was implanted in a nest formed 3-4 mm in depth on the talar articular surface using a custom burring technique (Figure 1B). Ankle spacer kinematics were compared to 95% confidence intervals of native, intact ankle joint kinematics to assess agreement. Results: Outcomes revealed no significant difference in ankle joint kinematics between the native, intact condition and post- pyrocarbon spacer implantation (Figure 1C). This result was consistent for the sagittal, coronal and axial planes of motion. Conclusion: The results of this study demonstrate that a pyrocarbon spacer permits normal ankle kinematics. Further, the device was observed to be stable in the joint throughout simulations. While the testing was performed at 25% bodyweight for analyses on all specimens, load magnitudes were also increased up to 75% on a subset of specimens and the structural integrity of the device remained pristine. With these findings, we concluded that the pyrocarbon spacer device offers promising potential as a treatment option for ankle arthritis.

Category: Ankle, Hindfoot, Flatfoot Introduction/Purpose: Adult acquired flatfoot deformity (AAFD) is a complex deformity characterized by hindfoot valgus, medial longitudinal arch collapse, midfoot abduction, and forefoot supination. In its most advanced stages (stage IV), the deltoid ligament is compromised, which leads to valgus talar tilt at the tibiotalar joint. This talar tilt puts patients at high risk of developing ankle arthritis necessitating ankle arthrodesis or arthroplasty. Tendon graft reconstruction of the deltoid ligament has previously demonstrated good clinical and radiographic outcomes at short to intermediate-term follow-up but controversy over efficacy of the procedure remains. The goal of the current study was to present the intermediate to long-term clinical and radiographic outcomes of the largest series to date of patients undergoing this procedure. Methods: Data from a prospectively collected Foot and Ankle Registry was reviewed. All consecutive patients undergoing deltoid ligament reconstruction with tendon allograft or autograft as part of their flatfoot surgery by the senior author prior to 1/1/2015 were eligible for inclusion. Patients with radiographic follow-up of

Category: Hindfoot, Midfoot/Forefoot Introduction/Purpose: During reconstruction of the stage II adult acquired flatfoot deformity (AAFD), residual supination of the midfoot is often addressed with an opening wedge medial cuneiform (Cotton) osteotomy after adequate correction of the hindfoot valgus deformity. The purpose of this study was to determine if there was a correlation between postoperative alignment of the medial cuneiform using the previously described cuneiform articular angle (CAA) on lateral radiographs and postoperative patient-reported outcomes using the Foot and Ankle Outcome Score (FAOS). Methods: Sixty-three feet in 61 patients with stage II AAFD who underwent a Cotton osteotomy as part of a flatfoot reconstruction were included the study. The CAA, medial arch sag angle (MASA), and lateral talo-first metatarsal (Meary’s) angles were measured on postoperative weightbearing lateral radiographs at a minimum of 40 weeks postoperatively. Pearson’s correlation analysis was used to determine if there was an association between postoperative radiographic angles and FAOS at a minimum of 24 months postoperatively. Patients were also divided into mild plantarflexion (CAA> or =-2 degrees) and moderate plantarflexion (CAA .40). Conclusion: Our study suggests that the surgeon should avoid excessive plantarflexion of the medial cuneiform and use the Cotton osteotomy judiciously as part of a flatfoot reconstruction for stage II AAFD.