Total Ankle Arthroplasty Patients Research Articles

Gait asymmetry persists following unilateral and bilateral total ankle arthroplasty.

Total ankle arthroplasty (TAA) improves gait symmetry in patients with unilateral end-stage ankle arthritis but has not been studied in patients undergoing bilateral TAA (B-TAA), and few studies compare TAA patients to control subjects. The purpose of this study was to compare gait symmetry in U-TAA and B-TAA patients and healthy controls. Using prospective databases, 19 unilateral and 19 bilateral ankle arthritis patients undergoing TAA were matched to 19 control subjects by age, sex, and BMI. The Normalized Symmetry Index (NSI) was determined for joint mechanics and ground reaction forces (GRF) during walking trials at a single visit for controls and preoperatively and 1 to 2 years postoperatively for TAA patients. Data was analyzed using linear mixed-effects models to determine differences among time points and cohorts at a significance of α = 0.05. Following surgery, B-TAA and U-TAA experienced improved peak plantarflexion moment symmetry (p = 0.017) but remained less symmetric than controls. B-TAA patients had more symmetry than U-TAA patients during peak weight acceptance GRF (p = 0.002), while U-TAA patients had greater peak dorsiflexion symmetry than B-TAA patients. TAA patients demonstrated more asymmetry compared to control subjects for all outcome measures. There was no significant impact of TAA on gait symmetry for GRF or peak ankle angles, and neither U-TAA nor B-TAA was consistently associated with higher gait symmetry. These results indicate that TAA improves symmetry during peak plantarflexion moment, and that significant gait asymmetry persists for B-TAA and U-TAA patients compared to healthy participants.

COMPARISON OF PROMIS SCORES AFTER TOTAL HIP AND TOTAL ANKLE ARTHROPLASTY: A PROPENSITY SCORE-MATCHED STUDY

This study evaluates patient reported outcome measurement information system (PROMIS) scores after total hip arthroplasty (THA) and total ankle arthroplasty (TAA) in matched cohorts, while simultaneously evaluating implant survivorship and 90-day hospital utilization. It is hypothesized that while both procedures would yield similar PROMIS score improvements, THA would demonstrate superior mid-term implant survivorship.Primary THA and TAA patients from 2015–2022 with minimum one-year follow-up were retrospectively reviewed. After applying exclusion criteria, 2,092 THAs and 478 TAAs were included for analysis. Demographics, pre- and post-operative patient reported outcome measures (PROMs), revision surgeries, ED visits, and re-admissions were collected. THA and TAA patients were then propensity score matched at 2:1 ratio for age, sex, race, BMI, ASA, and comorbidities, resulting in a final cohort of 844 THAs and 455 TAAs for comparison.There were similar pre-operative PROMIS Pain Interference (PI) scores between THA and TAA, with both showing improvement at six weeks. However, THA patients exhibited lower PI scores at one year (53.0 versus 54.0; p=0.009). Pre-operative PROMIS Physical Function (PF) was worse in THA patients but showed greater improvement compared to TAA patients at both six weeks (p<0.001) and one year (p<0.001). Pre-operative PROMIS depression scores were similar and improved similarly in both groups. Joint-specific PROMs (HOOS for THA and FAAM for TAA) improved in both cohorts. THA demonstrated superior survivorship free of all-cause revision at five years compared to TAA (95% versus 77%; p<0.0001).Patients undergoing THA or TAA experienced significant improvements in their general and joint-specific PROMs post-operatively. However, patients undergoing THA demonstrated higher PROMIS PI and PF scores at one-year when compared to TAA, as well as improved survivorship. Generic PRO instruments enable comparison of medical treatments in different anatomic sites to the patients overall health.

Comparison of postoperative gait parameters after total ankle arthroplasty and ankle fusion: A systematic review.

Ankle pathology, such as severe arthritis, often necessitates surgical intervention to restore mobility and alleviate pain. Two commonly performed procedures for end-stage ankle disease are ankle fusion (AF) and total ankle arthroplasty (TAA). This review aims to compare the impact of AF and TAA on postoperative gait parameters. An extensive search in PubMed, Scopus, and Web of Science electronic databases was conducted with the use of the keywords ("ankle arthrodesis" OR "ankle fusion") AND ("ankle replacement" OR "ankle arthroplasty") AND "gait." Clinical studies in terms of postoperative gait parameters were included in this review. At least one of the following gait parameters, included in gait analysis, should be researched: spatiotemporal variables and joint kinematics and kinetics. An initial search revealed 221 studies. After the removal of duplicates and screening of titles,10 studies (7 prospective and 3 retrospective case series) were included for qualitative analysis. In the majority of studies, there is no significant difference in spatiotemporal parameters, such as walking speed, cadence, stance duration, step length, and stride length among AF and TAA patients. Postoperative sagittal ankle ROM, mainly maximum ankle dorsiflexion angle is significantly higher in TAA patients, while results concerning hip and knee ROM are variable. The comparison of AF and TAA in terms of postoperative gait parameters has shown variable results. In the majority of studies, there is no significant difference in spatiotemporal and kinetic parameters among AF and TAA patients. Further high-quality prospective studies are needed to fully elucidate the comparison of postoperative gait parameters.

Total Ankle Arthroplasty Polyethylene Wear Varies with Implant Type and Mode of Failure

Introduction/Purpose: Polyethylene wear is a concern for failure of any joint replacement, including total ankle arthroplasty (TAA). Heterogeneity in bearing surface design among current TAA systems show no clear solution to the competing objectives of function (constraint and kinematics) and wear (contact stresses). Literature has begun to investigate polyethylene wear and damage; however, a comprehensive understanding of polyethylene wear patterns in vivo and location remains unknown. This study aims to quantify the type and severity of differing damage modes on the polyethylene insert from retrieved TAA prostheses following reoperation or revision. We hypothesized that polyethylene wear amount will be greater in TAAs that underwent revisions rather than reoperation, and that wear would vary between implants based on extent of constraint. Methods: This is a retrospective study of TAA patients (2007-2021) who underwent revision (removal of polyethylene and tibial and/or talar components) or reoperation (removal of polyethylene only) following primary TAA with a symmetric bicondylar (SB) implant with more constraint or an asymmetric bicondylar (AB) implant with less constraint. Demographics and surgical data were recorded. Retrieved polyethylene inserts were examined microscopically to characterize wear patterns according to a standardized protocol. Polyethylenes were divided into four regions on both the articular and backside surfaces: 1) lateral anterior, 2) lateral posterior, 3) medial anterior, and 4) medial posterior. Each region was graded by two independent raters on a scale of 0-3 based on severity for each of the following damage modes: 1) burnishing, 2) pitting, 3) scratching, 4) third body debris, 5) abrasion, 6) surface deformation, and 7) delamination. We assessed associations between polyethylene wear pattern and severity with implant type, revision, and reoperation. Results: 55 TAAs underwent revision (n=28) or reoperation (n=27). 30 (55%) ankles had primary TAA with AB implants (Salto Talaris) and 25 (45%) with SB implants (Inbone/Infinity) (Table 1). SB cohort had a shorter mean in-body duration (time from polyethylene implant to polyethylene explant) versus AB cohort (P=0.011). SB cohort had significantly greater overall polyethylene damage severity (P=0.007) and greater damage severity in all articular regions versus AB (P≤0.035 for all). Burnishing was significantly greater in SB versus AB (P < 0.001). TAAs that underwent revision had significantly greater overall damage severity versus reoperation (P=0.005), with significantly greater damage severity on articular medial posterior (P=0.003), lateral anterior (P=0.001), and lateral posterior (P=0.004) regions. Scratching (P=0.005), pitting (P < 0.001), and third body debris (P=0.036) were significantly greater in revision TAAs. Conclusion: While damage modes between SB and AB total ankle implants were similar, ankles with primary SB implants exhibited greater overall polyethylene damage severity in comparison to AB implants, despite being in-body for a shorter duration. In accordance with existing literature for total knee arthroplasty, this may suggest increased polyethylene damage severity with increased constraint. Irrespective of time in-body, failure for revision was associated with greater polyethylene damage than reoperation. This study provides the foundation for additional analyses to investigate radiographic alignment, mode of failure, and, ultimately, the association between polyethylene wear, peri-implant cysts and lucency, and TAA failure. Table 1 Patient demographics, revision, reoperation, and polyethylene in-body duration for the two patient cohorts: Patients with primary TAA with a symmetric bicondylar (SB) implant with more constraint and patients with primary TAA with an asymmetric bicondylar (AB) implant with less constraint. Values are expressed as means ± standard deviation for continuous variables, and frequencies with percentages for categorical variables. P-values reflect chi-square analyses and t tests between the two cohorts for categorical variables and continuous variables, respectively. SB cohort had significantly lower percentage of females, higher body weight, and shorter in-body duration. There was no significant difference in reoperations and revisions between the two groups.

The Effect of Operative Time on Short-Term Total Ankle Arthroplasty Outcomes

Introduction/Purpose: There is a paucity of literature investigating the association of operative time and postoperative outcomes following total ankle arthroplasty (TAA). Thus, this study seeks to evaluate the relationship between total operative time and postoperative outcomes following TAA. Methods: The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database was queried from 2007-2020 to identify 2133 TAA patients. Demographics, medical comorbidities, concomitant procedures, hospital length of stay (LOS), and 30-day complication, readmission, and reoperation rates were compared between groups. Patients were excluded based on an operative time greater than 290 minutes to limit the influence of extreme outliers. The cohort was predominantly male (53.8%) and mean patient age was 64.10 (range 19-87) years with a mean BMI of 31.00 (range 17.14-57.78) m/kg2. The mean operative time of the cohort was 149.56 (standard deviation [SD]=49.60) minutes. Results: Demographic characteristics associated with increased operative time were decreased age (p 1 SD above the mean), independently predicted were readmission (OR=2.817; 95%CI=1.334-5.951; p=0.007), urinary tract infection (OR=6.410; 95%CI=1.384-29.6866; p=0.018), wound dehiscence (OR=5.127; 95%CI=1.282-20.508; p=0.021), and bleeding requiring transfusion (OR=18.364; 95%CI=1.846-182.682; p=0.013). Conclusion: The study found longer operative time during TAA is associated with a statistically significant increase in wound dehiscence, urinary tract infection, readmission, reoperation, and increased length of stay. Therefore, surgeons should prioritize measures to reduce operative time when appropriate while optimizing implant placement, deformity correction, and implant stability in TAA.

Effects of Travel Distance on Complications and Outcomes in Total Ankle Arthroplasty.

Owing to the last decade's increase in the number of total ankle arthroplasty (TAA) procedures performed annually, there is a concern that the disproportionate distribution of orthopaedic surgeons who regularly perform TAA may impact complications and/or patient satisfaction. This study examines patient-reported outcomes and complications in TAA patients who had to travel for surgery compared to those treated locally. This is a single-center retrospective review of 160 patients undergoing primary TAA between January 2016 and December 2018, with mean age 65 (range: 59-71) years, mean body mass index (BMI) 28.7 kg/m2, 69 (43.1%) females, and mean 1.5 (SD = 0.51) years follow-up. Patients were grouped by distance traveled (<50 miles [n = 89] versus >50 miles traveled [n = 71]). There were no significant differences in rate or type of postoperative complications between the <50 mile group (16.9%) and the >50 mile group (22.5%) (P = .277). Similarly, there were no significant difference in postoperative PROMIS scores between the groups (P = .858). Given uneven distribution of high-volume surgeons performing TAA, this is important for patients who are deciding where to have their TAA surgery and for surgeons on how to counsel patients regarding risks when traveling longer distances for TAA care.Levels of Evidence: Level III: Retrospective Cohort Study.

Midterm Survivorship and Complications of the Cadence Total Ankle Arthroplasty

Category: Ankle Arthritis; Ankle Introduction/Purpose: The Cadence total ankle arthroplasty (TAA) system first entered clinical use in 2016. Short-term outcomes with a minimum of two-year follow-up time have demonstrated survivorship between 93.7% and 100% with improvements in patient-reported outcomes measures, coronal alignment, and range of motion1–4. The purpose of this study is to report the midterm survivorship and complications of Cadence TAA patients with a minimum of 4.5-year radiographic follow-up. Methods: A retrospective chart review was conducted to identify a total of 22 TAA patients with the Cadence implant and a minimum follow-up time of 4.5-years. Patient age, sex, body mass index, diabetes mellitus status, rheumatoid arthritis status, smoking status, laterality, and diagnosis for TAA were collected from patient chart reviews. Preoperative FAAM-ADL subscore, FAAM-Sport subscore, and VAS pain scores and the postoperative scores at the last follow-up visit was also collected. 13 out of 22 patients had preoperative FAAM-VAS scores available while 10 out of 22 patients had postoperative FAAM-VAS scores available. Postoperative complications in the form of wound-related issues and those requiring reoperation or revision were noted, with revision defined as removal or exchange of metal component. 5-view radiographs obtained preoperatively and at the last follow-up visit were used to measure coronal alignment, range of motion, evidence of subsidence or loosening, and osteolysis as previously described1. Results: 3 out of 22 patients required a revision surgery, 1 for loosening of tibial component and 2 for infection. 4 out of 22 patients underwent a reoperation, 2 for gutter debridement due to impingement or heterotopic ossification, 1 for periprosthetic medial malleolar fracture, and 1 for removal of painful medial malleolar screws. The average FAAM-ADL, FAAM-Sport, and VAS pain scores improved from 50.6, 26.5, and 59.9 to 69.5, 35.5, and 23.6, respectively. The coronal alignment angle decreased from 5.96 degrees from neutral to 2.31 degrees. The average dorsiflexion and plantarflexion angles were 14.74 and 17.18 degrees, respectively, for an average range of motion of 31.9 degrees. 3 out of 22 patients had evidence of osteolysis while no patients had evidence of loosening or subsidence. Conclusion: The midterm survivorship of Cadence TAA system in 22 patients was 86.4%. Excluding the two cases of infection which are typically not attributed to implant performance, the survivorship was 95.4%. The reasons for reoperation included impingement, heterotopic ossification, periprosthetic fracture, and removal of painful hardware. The average FAAM-ADL, FAAM- Sport, VAS pain scores and coronal alignment improved. Analysis of longer follow-up time in greater patient cohorts is necessary for clearer understanding of this fixed-bearing implant’s performance.

Effects of Ankle Arthrodesis vs Total Ankle Arthroplasty on Patient’s Shoe-Wear: What Fits Better?

Category: Ankle Arthritis; Ankle Introduction/Purpose: Currently there are two major surgical options for the treatment of end-stage ankle arthritis (ESAA), namely total ankle arthroplasty (TAA) and ankle arthrodesis (AA). Many patients inquire about what shoes they can expect to wear after surgery. Shoes should fit to the patient’s feet, help shielding pathological joints, be comfortable, but also fashionable, as they are part of personal style and fashion. The impact ESAA surgery has on choice of shoes and consecutively on quality of life, has not been studied. Potentially maintenance of ankle range of motion and improved gait mechanics with TAA could also improve the ability to comfortably wear different styles of shoes. The purpose of this study is to evaluate the effects of either AA and TAA on shoe-wear. Methods: This study is a retrospective analysis of a cohort of ESAA patients surgically treated with AA or TAA from the COFAS (Canadian Orthopaedic Foot and Ankle Society) database. Patient’s shoe wear comfort was obtained from the Musculoskeletal Outcomes Data Evaluation and Management Scale questionnaire, completed pre-operatively and post-operatively two and five years following surgery. The relationship between ankle-related quality of life and shoe-wear comfort, adjusting for patient factors was evaluated. A linear regression model adjusted for age, gender, BMI, smoking status, presence of inflammatory arthritis and baseline score was calculated. Additionally, differences within each pre-operative COFAS grades were analyzed. Results: 104 patients after AA and 106 following TAR have been included. The mean pre-operative baseline score did not differ between the cohorts (39.36 for AA and 38.94 for TAA, respectively; p= 0.74). Comparing AA patients with TAA patient scores over a 5-year period, there was no difference in shoe-wear comfort after 2 years, but after 5 years scores significantly improved for TAA patients (p= 0.02). Subgroup analysis showed that COFAS 4 patients improved the most with significant changes already after 2 years (mean difference 5.4, p=0.05), which further improved after 5 years of follow-up (mean difference 10.7, p=0.001). Conclusion: This study is the first study to elucidate patient experience after ankle arthrodesis and total ankle arthroplasty with regards to their shoe-wear. Patients undergoing TAR have better shoe-wear scores by five years post-operatively than those undergoing AA. Especially patients with a COFAS 4 grade, which represents a patient population with adjacent joint arthritis, show significant improvement already 2 years after surgery. This data is useful when counselling patients preoperatively, and further provides support for TAA over AA after appropriate patient selection.

Increased Hospital Length of Stay for Obesity Class II and III Patients After Primary Total Ankle Arthroplasty: A NSQIP Analysis

Category: Ankle Arthritis Introduction/Purpose: Obesity is a well-established risk factor for complications after total hip and knee arthroplasty. The incidence of total ankle arthroplasty (TAA) continues to grow, but few studies have evaluated TAA outcomes in patients with obesity. The present study sought to measure the impact of obesity on TAA outcomes using a national database. Methods: The 2012-2020 National Surgical Quality Improvement Program (NSQIP) database was queried for primary TAA (CPT:27002). 1,610 patients were identified and stratified by preoperative body mass index (BMI): non-obese (18 5-29.9kg/m2, n=760), obesity class I (30.0-34.9kg/m2, n=455), and class II and III (&gt;35.0kg/m2, n=395). Preoperative and perioperative patient data, operative time, hospital length of stay (LOS), and 30-day complications were compared using univariable statistics. Multivariable analyses controlling for patient characteristics were employed to measure the effect of obesity on operative time and LOS. Results: Compared to the non-obese group, obesity class II and III patients were younger (61.9 versus 65.6 years;p &lt; 0.001), more female (57.2% versus 42.0%;p &lt; 0.001), higher ASA class (p &lt; 0.001) and had more comorbidities such as hypertension, diabetes, and dyspnea (p &lt; 0.001). Mean preoperative albumin was lower (p=0.013) and white blood count was higher (p &lt; 0.001) in the obesity class II and III group. Home discharge rate was lowest in class II and III patients (88.6%;p=0.017). Multivariable regression revealed longer hospital LOS for obesity class II and III (μ=0.21; p=0.005) relative to the non-obese group. Obesity group was not associated with operative time or 30-day readmissions and reoperations. Conclusion: Obesity class II and III patients undergoing TAA had more comorbidities and longer hospital LOS compared to lower BMI patients. Despite the well-established association between obesity and postoperative complications after hip and knee arthroplasty, the present NSQIP analysis of 1,610 TAA patients did not find a greater burden of acute complications among patients with obesity.

Long-Term Outcomes of Infinity Total Ankle Arthroplasty Compared to Ankle Arthrodesis

Category: Ankle Arthritis; Ankle Introduction/Purpose: End-stage ankle arthritis causes severe pain and disability. The most common treatment has been ankle arthrodesis (AA) with proven long-term results. However, total ankle arthroplasty (TAA) has become a viable option to preserve ankle joint motion, relieve pain and shield adjacent joints. And with the evolution of TAA prostheses over the past 2 decades, the use of TAA has been steadily increasing. Nevertheless, long term outcome data on the latest generation of TAA prostheses is scarce. The primary purpose of this study is to evaluate long-term PROMs after Infinity™ TAA and to compare the outcome to a patient cohort of ankle arthrodesis (AA) performed during the same time period. Methods: Patients with end-stage ankle arthritis who received surgical treatment with a primary Infinity TAA or AA performed between 2013-2015 were included in this study. All surgeries were performed by four fellowship trained foot and ankle surgeons. Patient reported outcomes (PROMs) comprising the AOS and SF-36 PCS score were prospectively collected for patients who were willing to enroll into the Canadian Orthopaedic Foot and Ankle Society (COFAS) database. PROM data was compared between the TAA and AA patient cohorts. Implant survivorship as well as revision and reoperation rates were also analyzed. Results: 33 patients/ankles underwent primary Infinity™ TAA and 59 patients/ankles underwent AA. Of these, 25 TAA and 46 AA were enrolled in the prospective database, 20 and 46 had PROMs available for follow-up, respectively. Mean TAA PROM follow- up was 6.8 years (3-9) and for AA 6.4 years (2-9). Mean TAA age at surgery was 67 years (54-85) and 58 years for AA (27-84). TAA total AOS score pre-operatively was 52.9, which improved significantly to 23.9. SF-36 PCS scores improved from 33.1 to 43.3. Pre- and post-operative PROMs were similar to the AA cohort. At clinical follow up of 8-10 years, TAA implant survival was 97% with one metal component exchange. Two TAA patients had two reoperations each. In the AA cohort, the reoperation rate was 10.8%. Conclusion: This is the first report on patient reported outcomes and implant survival at 8 or more years after primary Infinity™ TAA. PROMs remain significantly improved at long term follow-up and are comparable to a cohort of long-term AA patients. Revision rates were low with a single component revision in 33 patients resulting in an implant survivorship of 97%. Long-term outcome of the Infinity™ total ankle arthroplasty is promising.

Trends in Geographic Utilization of Total Ankle Arthroplasty and Ankle Arthrodesis

Category: Ankle Arthritis Introduction/Purpose: Total ankle arthroplasty (TAA) and ankle arthrodesis (AA) are common surgical treatment options for end-stage ankle arthritis. Previous studies of trends in TAA utilization have shown a rapid increase in use from 2000-2010, likely due to improvements in implants and surgical techniques. The purpose of this study is to assess relative rates of TAA and AA utilization, investigate these trends in across populations and hospital settings, and project these trends in 2030. Methods: The National Inpatient Sample database was queried from 2016-2019 using International Classification of Diseases codes for TAA and AA to identify 8,787 patients (TAA=4,664, AA=4,123). Patient information collected included age, sex, race, primary payer status, year of surgery, length of hospital stay, and median household income quartile. The latter was determined by the NIS database using patient zip code, with the first quartile being the poorest and fourth quartile the richest. Hospital information included bed size, census region, teaching status, and ownership. Results: The ratio of TAA to AA increased from 0.90 in 2016 to 1.33 in 2019. Compared to AA patients, TAA patients were more significantly likely to be male (p=.004), white (p &lt;.001), older (p &lt;.001), and have higher income (p &lt;.001). TAA was more likely to be performed over AA at hospitals which were either smaller (p &lt;.001), urban non-teaching (p &lt;.001), in the western U.S. (p &lt;.001) or with a private, for-profit ownership structure (p=.002). The overall highest volume of both TAAs and AAs were performed in large (TAA=45.6%, AA=55.6%), southern (TAA=31.5%, AA=34.9%), urban-teaching (TAA=75.9%, AA=78.9%) hospitals with private, non-profit ownership (TAA=75.8%, AA=75.0%). TAA utilization is estimated to increase by 79.5% and AA to decline by 63.8%. (Table 1) Conclusion: TAA has continued to grow in utilization from 2016-2019 and is projected to continue this growth to 2030, while AA is expected to decrease in use. Furthermore, patients more likely to receive a TAA than AA are disproportionally white, male, and have a higher income and hospitals more likely to preform TAA are small, urban, for-profit hospitals in the western United States.

Are Body Mass Index (BMI) Cutoffs Creating Racial, Ethnic, Gender, or Age Disparities in Patient Eligibility for Total Ankle Arthroplasty?

Category: Ankle; Other Introduction/Purpose: The rising prevalence of obesity may drastically affect arthroplasty eligibility as Body Mass Index (BMI) remains a commonly used screening criterion. As obesity disproportionately affects Black adults and women, using such a criterion without scientific merit may lead to inequitable access to care. Particularly in total ankle arthroplasty – where weight has been previously attributed to aseptic implant failure – close examination of screening criteria is imperative. The purpose of this study was to evaluate for disparities in patient eligibility for total ankle arthroplasty (TAA) based on race, ethnicity, gender, and age by applying commonly used BMI cutoffs to the American College of Surgeons National Surgical Quality Improvement Program (ACS- NSQIP) database. Methods: Patients in the ACS-NSQIP database who underwent TAA from 2011- 2020 were retrospectively reviewed. BMI cutoffs of &lt; 35, &lt; 40, &lt; 45, and &lt; 50 were applied to the cohort to model the rate of surgical eligibility for TAA. Patients were deemed eligible for surgery if their BMI was less than each modeled BMI cutoff and ineligible if their BMI was equal to or greater than the cutoff. The relative eligibility rate, which was defined as the rate of eligibility minus the rate of ineligibility, was examined for each BMI cutoff. The cohorts were then stratified by race, ethnicity, gender, and age. Independent T-tests, Chi-squared tests, and Fisher’s exact tests were performed to compare differences at an α = 0.05. Results: 65.1% of all TAA patients were included after applying the exclusion criteria. Black patients had disproportionately lower rates of eligibility at the most stringent BMI cutoff of &lt; 35kg/m² (p=0.004). Hispanic patients had generally lower rates of eligibility across all BMI cutoffs. In contrast, Asian American and Pacific Islander patients had higher rates of eligibility at the BMI cutoffs of &lt; 35kg/m² (p=0.033) and &lt; 40kg/m² (p=0.039), and White non-Hispanic patients had higher rates of eligibility across all BMI cutoffs. Females had lower eligibility rates across all BMI cutoffs. Ineligible patients were also younger compared to eligible patients across all BMI cutoffs. Conclusion: Stringent BMI cutoffs may disproportionately disqualify Black, female, and younger patients from receiving total ankle arthroplasty. The data suggests that current eligibility criteria may exacerbate disparity in access to TAA for historically vulnerable populations. While eligibility criteria exist to protect patients from interventions that put them at unacceptable risk, these criteria are not uniformly distributed across populations. Given these data and the rising obesity epidemic, additional highly powered studies are needed to determine the safety of TAA in patients with BMI 35-40 to ensure at-risk populations are not disproportionately excluded from mobility-improving surgery.

The Effect of ASA Score on Total Ankle Arthroplasty

Category: Ankle; Other Introduction/Purpose: The American Society of Anesthesiologist (ASA) physical status classification system serves as a useful measure of patient comorbidities. Multiple studies have found an increased risk of readmission in patients undergoing total knee or hip arthroplasty with elevated ASA scores. There is a paucity of literature investigating the association of ASA score and postoperative outcomes following total ankle arthroplasty (TAA). Thus, this study seeks to evaluate the relationship between ASA score and postoperative outcomes following TAA. Methods: The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database was queried from 2007-2020 to identify 2210 TAA patients. Patients were stratified based on preoperative ASA score, 1-normal healthy patient (n=101), 2-mild systemic disease (n=1228), 3-severe systemic disease (n=855), 4-severe, life-threatening systemic disease (n=26). Demographics, medical comorbidities, concomitant procedures, hospital length of stay (LOS), and 30-day complication, readmission, and reoperation rates were compared between groups. The cohort was predominantly male (54.0%) and mean patient age was 63.99 (range 19-87) years with a mean BMI of 31.01 (range 17.14-57.78) m/kg2. Results: Patients with an ASA score ≥3 were significantly older (≤2 =62.78, ≥3 =65.81%; p&lt;.001), with higher BMI (≤2 =29.72, ≥3=32.97; p&lt;.001). 2210 patients were discharged following TAA, with 37 readmitted within 30 days following surgery. There was no statistically significant difference in readmission or reoperation rate based on ASA score. (Table 1) The average LOS following TAA was 1.81 (range 0-28) days, and increased ASA score was statistically significantly associated with longer length of stay (≤2=1.69 days, ≥3 =1.98 days; p&lt;.001). Patients with ASA score ≥3 were discharged home at a significantly lower rate than those with lower ASA scores (≤2 =95.3%, ≥3 =87.4%; p&lt;.001). There was no statistically significant difference in postoperative complication rates within 30 days of surgery. Conclusion: Higher ASA score was statically significantly associated with increased length of stay and non-home discharge disposition. These findings are valuable for physicians and patients to consider prior to TAA given the increased utilization of resources and cost associated with higher ASA scores.

Midterm Outcomes of the Salto Talaris Total Ankle Arthroplasty

Category: Ankle Arthritis; Ankle Introduction/Purpose: Total ankle arthroplasty (TAA) has become an accepted alternative to ankle arthrodesis for end-stage ankle arthritis and has seen significantly increased utilization in the past decade1. The Salto Talaris total ankle prosthesis has shown excellent short-term and mid-term survivorship results since its FDA approval in the U.S. in 20062,3. At a minimum of five-year follow-up, the currently reported midterm survivorship has ranged from 93.3% to 100% with equally satisfactory clinical outcomes as evidenced in short-term outcome studies4–8. The purpose of this study is to report the outcomes of one of the largest cohort of patients who underwent a Salto Talaris total ankle arthroplasty with a minimum of five-year follow-up. Methods: 103 Salto Talaris TAA patients with 5-view weight-bearing series of radiographs and minimum follow-up time of 5 years since index surgery were included. Age at time of surgery, gender, body mass index, diagnosis, diabetes status, and tobacco use were collected through chart review. Radiographic imaging was assessed at the most recent follow-up for evidence of radiolucency and osteolysis as previously described9. Range of motion was assessed on plantarflexion and dorsiflexion views on sagittal radiographs as previously described10. The Foot and Ankle Ability Measure (FAAM) and Visual Analog Scale for pain (VAS) scores were obtained at the most recent follow up visit and compared with preoperative scores. Baseline characteristics were compared between groups using Wilcoxon rank-sum test for continuous data or Fisher exact test for discrete data. Survivorship probability was calculated using a Kaplan-Meier analysis for revisions and reoperations. Revisions were defined as exchange or removal of metal component. Results: The survivorship for revision surgery was 93.2% (95% CI [89.8,98.8]). 5 out of the 7 patients requiring revision surgery experienced talar subsidence, 1 patient experienced an infection, and 1 patient experienced lateral impingement. The survivorship for reoperation was 90.2% (95% CI [83.4-95.4]). 5 out of the 10 patients requiring reoperation experienced pain from impingement, 2 experienced periprosthetic fractures, 1 experienced infection, and 2 experienced osteolytic cysts. At last follow- up, the FAAM-ADL, FAAM-Sport, and VAS pain scores were improved from preoperatively. The average range of motion at last follow-up was 31.6 degrees. On the AP view, radiolucency and osteolysis were most frequently detected in zones 3 and 4, while on the lateral view they were most frequently seen in zones 2 and 6. Conclusion: Patients undergoing Salto Talaris prosthesis showed improvements in patient-reported outcomes with satisfactory survival rates.

Revision of total ankle arthroplasty: Survival and medium-term functional results

BackgroundThe objective of this study was to analyze the results and survivorship of total ankle arthroplasty (TAA) revision surgery with standard (Salto Talaris®) or revision (Salto Talaris XT®) implants. MethodsBetween January 2005 and December 2017, all patients undergoing TAA revision at our hospital were included. Indications for revision, type of surgery performed, improvement in function assessed with the AOFAS score, occurrence of complications and implant survival at last follow-up were analyzed. ResultsIn the end, 25 TAA patients who had undergone revision (11 unipolar, 14 bipolar) were included. The mean follow-up time was 5.1 ± 1.9 years. At the last follow-up, function was improved compared to the preoperative AOFAS score (51.3 ± 17.5 vs. 83.5 ± 10.1; p < .001), but not plantar flexion (17.5 ± 5.7 vs. 15.4 ± 7.1; p = 0.28) or dorsal flexion (7 ± 5.6 vs. 8.3 ± 4.9; p = 0.3). Complications occurred in six patients (24 %) that led to reoperation: three infections, one lateral impingement, one implant malposition, and one hindfoot alignment disorder. At the last follow-up, implant survival was 96 %, but the probability of survival without reoperation was 78.7 ± 8.5 % at 4 years. ConclusionTAA revision by arthroplasty is feasible, produces good functional results in the medium term, but has a high risk of complications. The challenge of revision TAA is managing the loss of bone stock and anchoring the new implants.

Preoperative Hypoalbuminemia Not Associated With Total Ankle Arthroplasty Outcomes.

This study aims to investigate the effect of hypoalbuminemia on the rates of 30-day complication, readmission, and reoperation following total ankle arthroplasty (TAA). The American College of Surgeons National Surgical Quality Improvement Program database was queried from 2007 to 2019 to identify 710 TAA patients. Patients were then stratified into normal (n = 673) or low (n = 37) albumin groups. Demographics, medical comorbidities, concomitant procedures, hospital length of stay, and 30-day complication, readmission, and reoperation rates were compared between groups. Preoperative serum albumin level was also used as a continuous variable when analyzing postoperative outcomes. The overall cohort was predominantly male (51.5%), and the mean age was 65.02 (range, 45-87) years. We found there to be no statistically significant difference in demographics between cohorts. However, hypoalbuminemia patients were significantly more likely to use long-term steroids for a chronic condition (normal = 6.1%, low = 18.9%; P = .009). Additionally, there was no difference in 30-day complication (normal = 3.0%, low = 0.0%; P = .618), readmission (normal = 2.4%, low = 0.0%; P = .632), and reoperation (normal = 1.0%, low = 0.0%; P = 1.000) rates between groups. The results of this study show that malnourished patients are not at an increased risk of 30-day complication, readmission, or reoperation following TAA despite having a worse preoperative comorbidity profile. Level III, Retrospective cohort study.

Correlating the Patient Reported Outcomes Measurement Information System (PROMIS) to the Foot and Ankle Outcome Score and Patient Functional Testing in Total Ankle Arthroplasty Patients

Category: Ankle Arthritis; Other Introduction/ Purpose: The orthopaedic field, including foot and ankle surgery, continues to rely on patient reported outcome measures (PROMs) as the cornerstone of research studies. Various questionnaires exist, each with their advantages and disadvantages. The Patient-Reported Outcomes Measurement Information System (PROMIS) has become increasingly popular due to its reliability, validity, and efficiency. This system has been tested against the Foot and Ankle Outcome Score (FAOS) for foot and ankle conditions, however little is known about its validity for patients with ankle arthritis undergoing total ankle arthroplasty (TAA). Additionally, its relationship to functional tests is unknown, which could reveal whether it could be used in lieu of these resource-intensive assessments. Therefore, we aimed to validate PROMIS against the FAOS and functional tests in TAA patients. Methods: This prospective cohort study included 102 patients (mean age: 63.5 years) who were diagnosed with ankle arthritis and underwent subsequent TAA. Preoperative PROMIS scores, FAOS, and functional tests including the 4 square test (4SST), timed up and go (TUG), and sit-to-stand (STS) were gathered and analyzed preoperatively. PROMIS physical function and pain interference domains were tested for reliability using Rasch partial credit models. Convergent validity between PROMIS physical function and pain interference, and FAOS function, daily living was evaluated using Spearman’s correlation coefficient. In addition, the relationship between the functional tests and all 6 PROMIS domains were evaluated using Spearman’s correlation coefficient. Results: Infit and outfit mean squares (MSQs) for PROMIS physical function ranged from 0.61 – 0.78, indicating a good fit in the Rasch model. Similarly, infit and outfit MSQs for PROMIS pain interference ranged from 0.77 – 0.8, also indicating a good fit. Separation reliability was 0.89 for physical function and 0.85 for pain interference, indicating good reliability to actual patient function and pain levels. PROMIS physical function demonstrated a moderate positive correlation with FAOS function, daily living (r=0.52) while pain interference demonstrated a moderate negative correlation (r=-0.52). PROMIS physical function demonstrated statistically significant weak negative correlations for all 3 functional tests (r=-0.19 for 4SST, r=-0.27 for TUG, r=-0.2 for STS) [Figure 1]. Conclusion: Our study revealed good reliability of PROMIS physical function and pain interference domains, with a moderate correlation to FAOS function, daily living. Additionally, we found weak correlations between PROMIS physical function and functional tests and no significant correlations between pain interference and functional tests. This indicates acceptable convergent validity to the FAOS but not to functional tests. Therefore, while PROMIS provides reliable and valid measures, it does not replace the need for functional tests, which should be pursued in conjunction to deliver a complete assessment of TAA patients.

Emergency Department Visits Within 90 Days of Total Ankle Arthroplasty

Category: Arthroscopy; Ankle Introduction/Purpose: Emergency department (ED) visits following total ankle arthroplasty (TAA) may impact patient satisfaction and healthcare cost. Elucidating the timing of and risk factors for ED visits in this patient population might help facilitate targeted risk reduction strategies. Methods: This retrospective cohort study utilized data from the 2010 to 2019 M91Ortho PearlDiver administrative dataset to identify patients who underwent TAA with at least 90 days of follow-up. Patient factors were extracted including: age, sex, Elixhauser Comorbidity Index (ECI), region of the country in which their procedure was performed (midwest, northeast, south, west), and insurance plan (commercial, Medicaid, Medicare). The incidence, timing, frequency, and primary diagnoses for 90-day postoperative ED visits were identified and interpreted in the context of one-year postoperative ED visit baseline data. Univariate and multivariate logistic regression analyses were used to determine risk factors for such ED visits. Results: Of 7,600 TAA patients identified, 743 (9.8%) visited the ED within 90 days of their procedure. Of those who visited the ED, one ED visit was reported for 571 patients, two for 117 patients, three for 26 patients, and four or more visits for 29 patients. 37.2% of all ED visits occurred within two weeks following surgery; weekly visits returned to within 0.5% of the population baseline by three weeks after surgery. 90-day readmissions were identified for 289 patients (3.80%) of the cohort. Multivariate analysis revealed several predictors of ED utilization following TAA: younger age (odds ratio (OR) 1.40 per decade decrease), female sex (OR 1.18), higher ECI (OR 1.36 per 2-point increase), and Medicaid coverage (OR 2.74; 1.92-3.90 relative to Medicare) (p &lt; 0.05 each). Regarding reasons for ED visits, surgical site issues were identified for 74.4%, with the most common reason being surgical site pain (60.4%). Conclusion: Of 7,600 TAA patients, 9.8% returned to the ED within 90 days of surgery, with predisposing demographic actors identified. The highest incidence for these ED visits was in the first two postoperative weeks, with surgical site pain being the most common reason. By identifying the timing, predisposing factors, and reasons for ED visits following TAA, targeted care pathways should be able to be adjusted to minimize their occurrence, improve patient experience, and minimize health care utilization/costs.

Physical Therapy Utilization Within 90 Days of Total Ankle Arthroplasty

Category: Ankle; Arthroscopy; Other Introduction/Purpose: Physical therapy (PT) following total ankle arthroplasty (TAA) is often considered, but guidelines for its use are not standardized. While there may be patient factors that dictate recommendations, establishing a baseline of utilization practices may set the stage for establishing generalizable recommendations. Methods: This retrospective cohort study employed data from the 2010 to 2019 M91Ortho PearlDiver administrative dataset. Those undergoing TAA were identified based on coding, and patient factors were extracted, including: age, sex, Elixhauser Comorbidity Index (ECI), region of the country in which patients' surgery was performed (midwest, northeast, south, west), and insurance plan (commercial, Medicaid, Medicare). The incidence, timing, and frequency of PT utilization in the 90-days following TAA were identified as occurring at home or in an outpatient setting. Univariate and multivariate logistic regression analyses allowed the identification of predictive factors for PT utilization. Results: Of 6,563 TAA patients identified, 2788 (42.5%) utilized postoperative PT services. Most services were done as an outpatient (63.4%), compared to at home (6.1%). Weekly utilization of PT was greatest in the first week following surgery (17.7% of those who utilized PT) and thereafter followed a roughly bell-shaped curve of utilization with the greatest incidence at seven weeks following surgery (14.9% of those who utilized PT). Multivariate analysis identified multiple predictors of PT utilization following TAA, including: older age (odds ratio [OR] 1.23 per decade increase, p &lt; 0.0001), higher ECI (OR 1.03 per 2-point increase, p = 0.0383), having surgery performed in the midwest, northeast, or western US (relative to the South OR 1.43, p &lt; 0.0001; 1.20, p = 0.0109; and 1.32, p &lt; 0.0001, respectively), and having commercial or Medicaid insurance coverage (relative to Medicare OR 1.96, p &lt; 0.0001 and 1.62, p = 0.0006, respectively). Conclusion: Of 6,563 TAA patients, 42.5% utilized PT within 90 days of surgery. PT utilization was highest in the first- and seventh weeks following surgery, and demographic predictors of PT use were defined. Through identification of timing and predictors of PT utilization following TAA, algorithms for PT usage may be better defined and consistently employed.

After Total Ankle Arthroplasty, When Does Bone Perfusion and Metabolic Activity at the Bone-Implant Interface Normalize? A PET/CT Study

Category: Ankle Arthritis Introduction/Purpose: Radionuclide bone scintigraphy in combination with computed tomography (CT) has been used to evaluate painful total hip and knee arthroplasties, and has also been used in the evaluation of the painful total ankle arthroplasty (TAA). Increased tracer uptake around implants may indicate loosening, but uptake characteristics of bone-seeking radiopharmaceuticals in asymptomatic total ankle patients have not been clarified. While findings of increased metabolic activity may prompt surgical intervention, there has been no work performed to define when postoperatively periprosthetic activity normalizes, if at all. In this study, we plan to establish normative data on 18F sodium fluoride (18F-NaF) positron emission tomography/CT (PET/CT) uptake ratios around TAA implants at various time intervals after surgery in asymptomatic TAA patients. Methods: The majority of the arthroplasty literature has investigated use of SPECT/CT performed with 99mTc-labeled bisphosphonates. However, data suggest that 18F-NaF PET/CT may be superior for this indication, with more favorable pharmacokinetics and similar sensitivity to detect aseptic loosening. In the present study, asymptomatic patients who underwent TAA with a modern fixed-bearing TAA prosthesis (either the Wright Infinity Adaptis or Exactech Vantage prosthesis) for posttraumatic arthritis were eligible for inclusion. Patients with ipsilateral hindfoot fusion and with any periprosthetic lucencies or cysts were excluded. Patients were enrolled at one of four time intervals following TAA: 6, 12, 18, or 24 months. Standard uptake values were measured at the bone-implant interface for the tibial and talar components on static PET, in regions of interest defined on axial CT scan slices. Periprosthetic bone blood flow (K1) and bone turnover (flux) were assessed at each time interval in each periprosthetic region using dynamic PET. Results: Sixteen asymptomatic patients underwent PET/CT: 4 patients at 6 months postoperatively, 6 at 12 months, and 6 at 24 months. We are currently still in data collection and at this time only 2 patients at 18 months have completed the scan, therefore their data were excluded. The average age was 65 years (range, 55 to 80) and 6 patients were female (38%), with individual patient data shown in the Table. Talar K1 and flux both appeared to increase from 6 to 12 months, and decrease between 12 and 24 months, although there was no statistically significant difference between timepoints. Overall tibial K1 and flux appeared to decrease slightly from 6 to 12 months, and stayed relatively stable between 12 and 24 months, again with no significant difference between timepoints (Figure). Conclusion: There is currently no normative data to help guide interpretation of radionuclide bone scintigraphy for the painful TAA. The present study utilizing 18F-NaF PET/CT scans demonstrates that even in asymptomatic patients, periprosthetic bone blood flow and bone turnover remain elevated up to 24 months following modern fixed-bearing TAA. Not only do these values remain elevated at 24 months, but we found that there does not appear to be any significant decrease in either measurement over time from 6 to 24 months postoperatively. Our findings suggest that radionuclide bone scintigraphy should be cautiously interpreted when performed within 2 years of TAA.